diff options
Diffstat (limited to 'util/libreboot-utils')
| -rw-r--r-- | util/libreboot-utils/.gitignore | 7 | ||||
| -rw-r--r-- | util/libreboot-utils/AUTHORS | 2 | ||||
| -rw-r--r-- | util/libreboot-utils/COPYING | 21 | ||||
| -rw-r--r-- | util/libreboot-utils/Makefile | 161 | ||||
| -rw-r--r-- | util/libreboot-utils/include/common.h | 622 | ||||
| -rw-r--r-- | util/libreboot-utils/lib/checksum.c | 108 | ||||
| -rw-r--r-- | util/libreboot-utils/lib/command.c | 564 | ||||
| -rw-r--r-- | util/libreboot-utils/lib/file.c | 1065 | ||||
| -rw-r--r-- | util/libreboot-utils/lib/io.c | 591 | ||||
| -rw-r--r-- | util/libreboot-utils/lib/mkhtemp.c | 1091 | ||||
| -rw-r--r-- | util/libreboot-utils/lib/num.c | 119 | ||||
| -rw-r--r-- | util/libreboot-utils/lib/rand.c | 219 | ||||
| -rw-r--r-- | util/libreboot-utils/lib/state.c | 233 | ||||
| -rw-r--r-- | util/libreboot-utils/lib/string.c | 284 | ||||
| -rw-r--r-- | util/libreboot-utils/lib/usage.c | 30 | ||||
| -rw-r--r-- | util/libreboot-utils/lib/word.c | 68 | ||||
| -rw-r--r-- | util/libreboot-utils/lottery.c | 51 | ||||
| -rw-r--r-- | util/libreboot-utils/mkhtemp.c | 211 | ||||
| -rw-r--r-- | util/libreboot-utils/nvmutil.c | 138 |
19 files changed, 5585 insertions, 0 deletions
diff --git a/util/libreboot-utils/.gitignore b/util/libreboot-utils/.gitignore new file mode 100644 index 00000000..fbfbd130 --- /dev/null +++ b/util/libreboot-utils/.gitignore @@ -0,0 +1,7 @@ +/nvm +/nvmutil +/mkhtemp +/lottery +*.bin +*.o +*.d diff --git a/util/libreboot-utils/AUTHORS b/util/libreboot-utils/AUTHORS new file mode 100644 index 00000000..f38ea210 --- /dev/null +++ b/util/libreboot-utils/AUTHORS @@ -0,0 +1,2 @@ +Leah Rowe +Riku Viitanen diff --git a/util/libreboot-utils/COPYING b/util/libreboot-utils/COPYING new file mode 100644 index 00000000..47c35a86 --- /dev/null +++ b/util/libreboot-utils/COPYING @@ -0,0 +1,21 @@ +Copyright (C) 2022-2026 Leah Rowe <leah@libreboot.org> +Copyright (c) 2023 Riku Viitanen <riku.viitanen@protonmail.com> + +Permission is hereby granted, free of charge, to any person obtaining a +copy of this software and associated documentation files (the +"Software"), to deal in the Software without restriction, including +without limitation the rights to use, copy, modify, merge, publish, +distribute, sublicense, and/or sell copies of the Software, and to +permit persons to whom the Software is furnished to do so, subject to +the following conditions: + +The above copyright notice and this permission notice shall be included +in all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS +OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. +IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY +CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, +TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE +SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. diff --git a/util/libreboot-utils/Makefile b/util/libreboot-utils/Makefile new file mode 100644 index 00000000..a48b8ef9 --- /dev/null +++ b/util/libreboot-utils/Makefile @@ -0,0 +1,161 @@ +# SPDX-License-Identifier: MIT +# Copyright (c) 2022,2026 Leah Rowe <leah@libreboot.org> +# Copyright (c) 2023 Riku Viitanen <riku.viitanen@protonmail.com> + +# Makefile for nvmutil, which is an application +# that modifies Intel GbE NVM configurations. + +CC = cc +HELLCC = clang + +CFLAGS = +LDFLAGS = +DESTDIR = +PREFIX = /usr/local +INSTALL = install + +.SUFFIXES: .c .o + +LDIR = + +PORTABLE = $(LDIR) $(CFLAGS) +WARN = $(PORTABLE) -Wall -Wextra +STRICT = $(WARN) -std=c90 -pedantic -Werror +HELLFLAGS = $(STRICT) -Weverything + +PROG = nvmutil +PROGMKH = mkhtemp +PROGLOT = lottery + +OBJS_NVMUTIL = \ + obj/nvmutil.o \ + obj/lib/state.o \ + obj/lib/file.o \ + obj/lib/string.o \ + obj/lib/usage.o \ + obj/lib/command.o \ + obj/lib/num.o \ + obj/lib/io.o \ + obj/lib/checksum.o \ + obj/lib/word.o \ + obj/lib/mkhtemp.o \ + obj/lib/rand.o + +OBJS_MKHTEMP = \ + obj/mkhtemp.o \ + obj/lib/file.o \ + obj/lib/string.o \ + obj/lib/num.o \ + obj/lib/mkhtemp.o \ + obj/lib/rand.o + +OBJS_LOTTERY = \ + obj/lottery.o \ + obj/lib/file.o \ + obj/lib/string.o \ + obj/lib/num.o \ + obj/lib/mkhtemp.o \ + obj/lib/rand.o + +# default mode +CFLAGS_MODE = $(PORTABLE) +CC_MODE = $(CC) + +all: $(PROG) $(PROGMKH) $(PROGLOT) + +$(PROG): $(OBJS_NVMUTIL) + $(CC_MODE) $(OBJS_NVMUTIL) -o $(PROG) $(LDFLAGS) + +$(PROGMKH): $(OBJS_MKHTEMP) + $(CC_MODE) $(OBJS_MKHTEMP) -o $(PROGMKH) $(LDFLAGS) + +$(PROGLOT): $(OBJS_LOTTERY) + $(CC_MODE) $(OBJS_LOTTERY) -o $(PROGLOT) $(LDFLAGS) + +# ensure obj directory exists +$(OBJS_NVMUTIL): obj +$(OBJS_MKHTEMP): obj +$(OBJS_LOTTERY): obj + +obj: + mkdir obj || true + mkdir obj/lib || true + +# main program object + +obj/nvmutil.o: nvmutil.c + $(CC_MODE) $(CFLAGS_MODE) -c nvmutil.c -o obj/nvmutil.o + +obj/mkhtemp.o: mkhtemp.c + $(CC_MODE) $(CFLAGS_MODE) -c mkhtemp.c -o obj/mkhtemp.o + +obj/lottery.o: lottery.c + $(CC_MODE) $(CFLAGS_MODE) -c lottery.c -o obj/lottery.o + +# library/helper objects + +obj/lib/state.o: lib/state.c + $(CC_MODE) $(CFLAGS_MODE) -c lib/state.c -o obj/lib/state.o + +obj/lib/file.o: lib/file.c + $(CC_MODE) $(CFLAGS_MODE) -c lib/file.c -o obj/lib/file.o + +obj/lib/string.o: lib/string.c + $(CC_MODE) $(CFLAGS_MODE) -c lib/string.c -o obj/lib/string.o + +obj/lib/usage.o: lib/usage.c + $(CC_MODE) $(CFLAGS_MODE) -c lib/usage.c -o obj/lib/usage.o + +obj/lib/command.o: lib/command.c + $(CC_MODE) $(CFLAGS_MODE) -c lib/command.c -o obj/lib/command.o + +obj/lib/num.o: lib/num.c + $(CC_MODE) $(CFLAGS_MODE) -c lib/num.c -o obj/lib/num.o + +obj/lib/io.o: lib/io.c + $(CC_MODE) $(CFLAGS_MODE) -c lib/io.c -o obj/lib/io.o + +obj/lib/checksum.o: lib/checksum.c + $(CC_MODE) $(CFLAGS_MODE) -c lib/checksum.c -o obj/lib/checksum.o + +obj/lib/word.o: lib/word.c + $(CC_MODE) $(CFLAGS_MODE) -c lib/word.c -o obj/lib/word.o + +obj/lib/mkhtemp.o: lib/mkhtemp.c + $(CC_MODE) $(CFLAGS_MODE) -c lib/mkhtemp.c -o obj/lib/mkhtemp.o + +obj/lib/rand.o: lib/rand.c + $(CC_MODE) $(CFLAGS_MODE) -c lib/rand.c -o obj/lib/rand.o + +# install + +install: $(PROG) $(PROGMKH) $(PROGLOT) + $(INSTALL) -d $(DESTDIR)$(PREFIX)/bin + $(INSTALL) $(PROG) $(DESTDIR)$(PREFIX)/bin/$(PROG) + chmod 755 $(DESTDIR)$(PREFIX)/bin/$(PROG) + $(INSTALL) $(PROGMKH) $(DESTDIR)$(PREFIX)/bin/$(PROGMKH) + chmod 755 $(DESTDIR)$(PREFIX)/bin/$(PROGMKH) + $(INSTALL) $(PROGLOT) $(DESTDIR)$(PREFIX)/bin/$(PROGLOT) + chmod 755 $(DESTDIR)$(PREFIX)/bin/$(PROGLOT) + +uninstall: + rm -f $(DESTDIR)$(PREFIX)/bin/$(PROG) + rm -f $(DESTDIR)$(PREFIX)/bin/$(PROGMKH) + rm -f $(DESTDIR)$(PREFIX)/bin/$(PROGLOT) + +clean: + rm -f $(PROG) $(PROGMKH) $(OBJS_NVMUTIL) $(OBJS_MKHTEMP) \ + $(OBJS_LOTTERY) + +distclean: clean + +# mode targets (portable replacement for ifeq) + +warn: + $(MAKE) CFLAGS_MODE="$(WARN)" + +strict: + $(MAKE) CFLAGS_MODE="$(STRICT)" + +hell: + $(MAKE) CFLAGS_MODE="$(HELLFLAGS)" CC_MODE="$(HELLCC)" diff --git a/util/libreboot-utils/include/common.h b/util/libreboot-utils/include/common.h new file mode 100644 index 00000000..4668cffa --- /dev/null +++ b/util/libreboot-utils/include/common.h @@ -0,0 +1,622 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2022-2026 Leah Rowe <leah@libreboot.org> + + TODO: this file should be split, into headers for each + C source file specifically. it was originally just + for nvmutil, until i added mkhtemp to the mix + */ + + +#ifndef COMMON_H +#define COMMON_H + +#include <sys/types.h> +#include <sys/stat.h> +#include <limits.h> +#include <errno.h> + +/* for linux getrandom + */ +#if defined(__linux__) +#include <sys/random.h> +#include <sys/syscall.h> +#endif + +#define items(x) (sizeof((x)) / sizeof((x)[0])) + +/* system prototypes + */ + +int fchmod(int fd, mode_t mode); + +#define MKHTEMP_RETRY_MAX 512 +#define MKHTEMP_SPIN_THRESHOLD 32 + +#define MKHTEMP_FILE 0 +#define MKHTEMP_DIR 1 + + +/* if 1: on operations that + * check ownership, always + * permit root to access even + * if not the file/dir owner + */ +#ifndef ALLOW_ROOT_OVERRIDE +#define ALLOW_ROOT_OVERRIDE 0 +#endif + +/* + */ + +#ifndef SSIZE_MAX +#define SSIZE_MAX ((ssize_t)(~((ssize_t)1 << (sizeof(ssize_t)*CHAR_BIT-1)))) +#endif + + +/* build config + */ + +#ifndef NVMUTIL_H +#define NVMUTIL_H + +#define MAX_CMD_LEN 50 + +#ifndef PATH_LEN +#define PATH_LEN 4096 +#endif + +#define OFF_ERR 0 +#ifndef OFF_RESET +#define OFF_RESET 1 +#endif + +#ifndef S_ISVTX +#define S_ISVTX 01000 +#endif + +#if defined(S_IFMT) && ((S_ISVTX & S_IFMT) != 0) +#error "Unexpected bit layout" +#endif + +#ifndef MAX_ZERO_RW_RETRY +#define MAX_ZERO_RW_RETRY 5 +#endif + +#ifndef REAL_POS_IO +#define REAL_POS_IO 0 +#endif + +#ifndef LOOP_EAGAIN +#define LOOP_EAGAIN 1 +#endif +#ifndef LOOP_EINTR +#define LOOP_EINTR 1 +#endif + +#ifndef _FILE_OFFSET_BITS +#define _FILE_OFFSET_BITS 64 +#endif + +#ifndef EXIT_FAILURE +#define EXIT_FAILURE 1 +#endif + +#ifndef EXIT_SUCCESS +#define EXIT_SUCCESS 0 +#endif + +#ifndef O_NOCTTY +#define O_NOCTTY 0 +#endif + +#ifndef O_ACCMODE +#define O_ACCMODE (O_RDONLY | O_WRONLY | O_RDWR) +#endif + +#ifndef O_BINARY +#define O_BINARY 0 +#endif + +#ifndef O_EXCL +#define O_EXCL 0 +#endif + +#ifndef O_CREAT +#define O_CREAT 0 +#endif + +#ifndef O_NONBLOCK +#define O_NONBLOCK 0 +#endif + +#ifndef O_CLOEXEC +#define O_CLOEXEC 0 +#endif + +#ifndef O_NOFOLLOW +#define O_NOFOLLOW 0 +#endif + +#ifndef FD_CLOEXEC +#define FD_CLOEXEC 0 +#endif + +/* Sizes in bytes: + */ + +#define SIZE_1KB 1024 +#define SIZE_4KB (4 * SIZE_1KB) +#define SIZE_8KB (8 * SIZE_1KB) +#define SIZE_16KB (16 * SIZE_1KB) +#define SIZE_128KB (128 * SIZE_1KB) + +#define GBE_BUF_SIZE (SIZE_128KB) + +/* First 128 bytes of gbe.bin is NVM. + * Then extended area. All of NVM must + * add up to BABA, truncated (LE) + * + * First 4KB of each half of the file + * contains NVM+extended. + */ + +#define GBE_WORK_SIZE (SIZE_8KB) +#define GBE_PART_SIZE (GBE_WORK_SIZE >> 1) +#define NVM_CHECKSUM 0xBABA +#define NVM_SIZE 128 +#define NVM_WORDS (NVM_SIZE >> 1) +#define NVM_CHECKSUM_WORD (NVM_WORDS - 1) + +/* argc minimum (dispatch) + */ + +#define ARGC_3 3 +#define ARGC_4 4 + +#define NO_LOOP_EAGAIN 0 +#define NO_LOOP_EINTR 0 + +/* For checking if an fd is a normal file. + * Portable for old Unix e.g. v7 (S_IFREG), + * 4.2BSD (S_IFMT), POSIX (S_ISREG). + * + * IFREG: assumed 0100000 (classic bitmask) + */ + +#ifndef S_ISREG +#if defined(S_IFMT) && defined(S_IFREG) +#define S_ISREG(m) (((m) & S_IFMT) == S_IFREG) +#elif defined(S_IFREG) +#define S_ISREG(m) (((m) & S_IFREG) != 0) +#else +#error "can't determine types with stat()" +#endif +#endif + +#define IO_READ 0 +#define IO_WRITE 1 +#define IO_PREAD 2 +#define IO_PWRITE 3 + +/* for nvmutil commands + */ + +#define CMD_DUMP 0 +#define CMD_SETMAC 1 +#define CMD_SWAP 2 +#define CMD_COPY 3 +#define CMD_CAT 4 +#define CMD_CAT16 5 +#define CMD_CAT128 6 + +#define ARG_NOPART 0 +#define ARG_PART 1 + +#define SKIP_CHECKSUM_READ 0 +#define CHECKSUM_READ 1 + +#define SKIP_CHECKSUM_WRITE 0 +#define CHECKSUM_WRITE 1 + +/* command table + */ + +struct commands { + size_t chk; + char *str; + void (*run)(void); + int argc; + unsigned char arg_part; + unsigned char chksum_read; + unsigned char chksum_write; + size_t rw_size; /* within the 4KB GbE part */ + int flags; /* e.g. O_RDWR or O_RDONLY */ +}; + +/* mac address + */ + +struct macaddr { + char *str; /* set to rmac, or argv string */ + char rmac[18]; /* xx:xx:xx:xx:xx:xx */ + unsigned short mac_buf[3]; +}; + +/* gbe.bin and tmpfile + */ + +struct xfile { + int gbe_fd; + struct stat gbe_st; + + int tmp_fd; + struct stat tmp_st; + + char *tname; /* path of tmp file */ + char *fname; /* path of gbe file */ + + unsigned char *buf; /* work memory for files */ + + int io_err_gbe; /* intermediary write (verification) */ + int io_err_gbe_bin; /* final write (real file) */ + int rw_check_err_read[2]; + int rw_check_partial_read[2]; + int rw_check_bad_part[2]; + + int post_rw_checksum[2]; + + off_t gbe_file_size; + off_t gbe_tmp_size; + + size_t part; + unsigned char part_modified[2]; + unsigned char part_valid[2]; + + unsigned char real_buf[GBE_BUF_SIZE]; + unsigned char bufcmp[GBE_BUF_SIZE]; /* compare gbe/tmp/reads */ + + unsigned char pad[GBE_WORK_SIZE]; /* the file that wouldn't die */ + + /* we later rename in-place, using old fd. renameat() */ + int dirfd; + char *base; + char *tmpbase; +}; + +/* Command table, MAC address, files + * + * BE CAREFUL when editing this + * to ensure that you also update + * the tables in xstatus() + */ + +struct xstate { + struct commands cmd[7]; + struct macaddr mac; + struct xfile f; + + char *argv0; + + size_t i; /* index to cmd[] for current command */ + int no_cmd; + + /* Cat commands set this. + the cat cmd helpers check it */ + int cat; +}; + +struct filesystem { + int rootfd; +}; + +struct xstate *xstart(int argc, char *argv[]); +struct xstate *xstatus(void); + +/* Sanitize command tables. + */ + +void sanitize_command_list(void); +void sanitize_command_index(size_t c); + +/* Argument handling (user input) + */ + +void set_cmd(int argc, char *argv[]); +void set_cmd_args(int argc, char *argv[]); +size_t conv_argv_part_num(const char *part_str); + +/* Prep files for reading + */ + +void open_gbe_file(void); +int fd_verify_regular(int fd, + const struct stat *expected, + struct stat *out); +int fd_verify_identity(int fd, + const struct stat *expected, + struct stat *out); +int fd_verify_dir_identity(int fd, + const struct stat *expected); +int is_owner(struct stat *st); +int lock_file(int fd, int flags); +int same_file(int fd, struct stat *st_old, int check_size); +void xopen(int *fd, const char *path, int flags, struct stat *st); + +/* Read GbE file and verify checksums + */ + +void copy_gbe(void); +void read_file(void); +void read_checksums(void); +int good_checksum(size_t partnum); + +/* validate commands + */ + +void check_command_num(size_t c); +unsigned char valid_command(size_t c); + +/* Helper functions for command: setmac + */ + +void cmd_helper_setmac(void); +void parse_mac_string(void); +void set_mac_byte(size_t mac_byte_pos); +void set_mac_nib(size_t mac_str_pos, + size_t mac_byte_pos, size_t mac_nib_pos); +void write_mac_part(size_t partnum); + +/* string functions + */ + +int slen(const char *scmp, size_t maxlen, + size_t *rval); +int scmp(const char *a, const char *b, + size_t maxlen, int *rval); +int sdup(const char *s, + size_t n, char **dest); +int scat(const char *s1, const char *s2, + size_t n, char **dest); +int dcat(const char *s, size_t n, + size_t off, char **dest1, + char **dest2); +/* numerical functions + */ + +unsigned short hextonum(char ch_s); +void *mkrbuf(size_t n); +void rset(void *buf, size_t n); +void *mkrbuf(size_t n); +char *mkrstr(size_t n); +int win_lottery(void); + +/* Helper functions for command: dump + */ + +void cmd_helper_dump(void); +void print_mac_from_nvm(size_t partnum); +void hexdump(size_t partnum); + +/* Helper functions for command: swap + */ + +void cmd_helper_swap(void); + +/* Helper functions for command: copy + */ + +void cmd_helper_copy(void); + +/* Helper functions for commands: + * cat, cat16 and cat128 + */ + +void cmd_helper_cat(void); +void cmd_helper_cat16(void); +void cmd_helper_cat128(void); +void cat(size_t nff); +void cat_buf(unsigned char *b); + +/* Command verification/control + */ + +void check_cmd(void (*fn)(void), const char *name); +void cmd_helper_err(void); + +/* Write GbE files to disk + */ + +void write_gbe_file(void); +void set_checksum(size_t part); +unsigned short calculated_checksum(size_t p); + +/* NVM read/write + */ + +unsigned short nvm_word(size_t pos16, size_t part); +void set_nvm_word(size_t pos16, + size_t part, unsigned short val16); +void set_part_modified(size_t p); +void check_nvm_bound(size_t pos16, size_t part); +void check_bin(size_t a, const char *a_name); + +/* GbE file read/write + */ + +void rw_gbe_file_part(size_t p, int rw_type, + const char *rw_type_str); +void write_to_gbe_bin(void); +int gbe_mv(void); +void check_written_part(size_t p); +void report_io_err_rw(void); +unsigned char *gbe_mem_offset(size_t part, const char *f_op); +off_t gbe_file_offset(size_t part, const char *f_op); +off_t gbe_x_offset(size_t part, const char *f_op, + const char *d_type, off_t nsize, off_t ncmp); +ssize_t rw_gbe_file_exact(int fd, unsigned char *mem, size_t nrw, + off_t off, int rw_type); + +/* Generic read/write + */ + +int fsync_dir(const char *path); +ssize_t rw_file_exact(int fd, unsigned char *mem, size_t len, + off_t off, int rw_type, int loop_eagain, int loop_eintr, + size_t max_retries, int off_reset); +ssize_t prw(int fd, void *mem, size_t nrw, + off_t off, int rw_type, int loop_eagain, int loop_eintr, + int off_reset); +int io_args(int fd, void *mem, size_t nrw, + off_t off, int rw_type); +int check_file(int fd, struct stat *st); +ssize_t rw_over_nrw(ssize_t r, size_t nrw); +#if !defined(REAL_POS_IO) || \ + REAL_POS_IO < 1 +off_t lseek_on_eintr(int fd, off_t off, + int whence, int loop_eagain, int loop_eintr); +#endif +int try_err(int loop_err, int errval); + +/* Error handling and cleanup + */ + +void usage(void); +void err_no_cleanup(int stfu, int nvm_errval, const char *msg, ...); +void b0rk(int nvm_errval, const char *msg, ...); +int exit_cleanup(void); +const char *getnvmprogname(void); + +void err_mkhtemp(int stfu, int errval, const char *msg, ...); + +/* libc hardening + */ + +int new_tmpfile(int *fd, char **path, char *tmpdir, + const char *template); +int new_tmpdir(int *fd, char **path, char *tmpdir, + const char *template); +int new_tmp_common(int *fd, char **path, int type, + char *tmpdir, const char *template); +int mkhtemp_try_create(int dirfd, + struct stat *st_dir_initial, + char *fname_copy, + char *p, + size_t xc, + int *fd, + struct stat *st, + int type); +int +mkhtemp_tmpfile_linux(int dirfd, + struct stat *st_dir_initial, + char *fname_copy, + char *p, + size_t xc, + int *fd, + struct stat *st); +int mkhtemp(int *fd, struct stat *st, + char *template, int dirfd, const char *fname, + struct stat *st_dir_initial, int type); +int mkhtemp_fill_random(char *p, size_t xc); +int world_writeable_and_sticky(const char *s, + int sticky_allowed, int always_sticky); +int same_dir(const char *a, const char *b); +int tmpdir_policy(const char *path, + int *allow_noworld_unsticky); +char *env_tmpdir(int always_sticky, char **tmpdir, + char *override_tmpdir); +int secure_file(int *fd, + struct stat *st, + struct stat *expected, + int bad_flags, + int check_seek, + int do_lock, + mode_t mode); +int close_on_eintr(int fd); +int fsync_on_eintr(int fd); +int fs_rename_at(int olddirfd, const char *old, + int newdirfd, const char *new); +int fs_open(const char *path, int flags); +void close_no_err(int *fd); +void free_if_null(char **buf); +int close_warn(int *fd, char *s); +struct filesystem *rootfs(void); +int fs_resolve_at(int dirfd, const char *path, int flags); +int fs_next_component(const char **p, + char *name, size_t namesz); +int fs_open_component(int dirfd, const char *name, + int flags, int is_last); +int fs_dirname_basename(const char *path, + char **dir, char **base, int allow_relative); +int openat2p(int dirfd, const char *path, + int flags, mode_t mode); +int mkdirat_on_eintr(int dirfd, + const char *pathname, mode_t mode); +int if_err(int condition, int errval); +int if_err_sys(int condition); +char *lbgetprogname(char *argv0); + +/* asserts */ + +/* type asserts */ +typedef char static_assert_char_is_8_bits[(CHAR_BIT == 8) ? 1 : -1]; +typedef char static_assert_char_is_1[(sizeof(char) == 1) ? 1 : -1]; +typedef char static_assert_unsigned_char_is_1[ + (sizeof(unsigned char) == 1) ? 1 : -1]; +typedef char static_assert_unsigned_short_is_2[ + (sizeof(unsigned short) >= 2) ? 1 : -1]; +typedef char static_assert_short_is_2[(sizeof(short) >= 2) ? 1 : -1]; +typedef char static_assert_unsigned_int_is_4[ + (sizeof(unsigned int) >= 4) ? 1 : -1]; +typedef char static_assert_unsigned_ssize_t_is_4[ + (sizeof(size_t) >= 4) ? 1 : -1]; +typedef char static_assert_ssize_t_ussize_t[ + (sizeof(size_t) == sizeof(ssize_t)) ? 1 : -1]; +typedef char static_assert_int_ge_32[(sizeof(int) >= 4) ? 1 : -1]; +typedef char static_assert_twos_complement[ + ((-1 & 3) == 3) ? 1 : -1 +]; +typedef char assert_unsigned_ssize_t_ptr[ + (sizeof(size_t) >= sizeof(void *)) ? 1 : -1 +]; + +/* + * We set _FILE_OFFSET_BITS 64, but we only handle + * but we only need smaller files, so require 4-bytes. + * Some operating systems ignore the define, hence assert: + */ +typedef char static_assert_off_t_is_32[(sizeof(off_t) >= 4) ? 1 : -1]; + +/* + * asserts (variables/defines sanity check) + */ +typedef char assert_argc3[(ARGC_3==3)?1:-1]; +typedef char assert_argc4[(ARGC_4==4)?1:-1]; +typedef char assert_read[(IO_READ==0)?1:-1]; +typedef char assert_write[(IO_WRITE==1)?1:-1]; +typedef char assert_pread[(IO_PREAD==2)?1:-1]; +typedef char assert_pwrite[(IO_PWRITE==3)?1:-1]; +typedef char assert_pathlen[(PATH_LEN>=256)?1:-1]; +/* commands */ +typedef char assert_cmd_dump[(CMD_DUMP==0)?1:-1]; +typedef char assert_cmd_setmac[(CMD_SETMAC==1)?1:-1]; +typedef char assert_cmd_swap[(CMD_SWAP==2)?1:-1]; +typedef char assert_cmd_copy[(CMD_COPY==3)?1:-1]; +typedef char assert_cmd_cat[(CMD_CAT==4)?1:-1]; +typedef char assert_cmd_cat16[(CMD_CAT16==5)?1:-1]; +typedef char assert_cmd_cat128[(CMD_CAT128==6)?1:-1]; +/* bool */ +typedef char bool_arg_nopart[(ARG_NOPART==0)?1:-1]; +typedef char bool_arg_part[(ARG_PART==1)?1:-1]; +typedef char bool_skip_checksum_read[(SKIP_CHECKSUM_READ==0)?1:-1]; +typedef char bool_checksum_read[(CHECKSUM_READ==1)?1:-1]; +typedef char bool_skip_checksum_write[(SKIP_CHECKSUM_WRITE==0)?1:-1]; +typedef char bool_checksum_write[(CHECKSUM_WRITE==1)?1:-1]; +typedef char bool_loop_eintr[(LOOP_EINTR==1||LOOP_EINTR==0)?1:-1]; +typedef char bool_loop_eagain[(LOOP_EAGAIN==1||LOOP_EAGAIN==0)?1:-1]; +typedef char bool_no_loop_eintr[(NO_LOOP_EINTR==0)?1:-1]; +typedef char bool_no_loop_eagain[(NO_LOOP_EAGAIN==0)?1:-1]; +typedef char bool_off_err[(OFF_ERR==0)?1:-1]; +typedef char bool_off_reset[(OFF_RESET==0||OFF_RESET==1)?1:-1]; + +#endif +#endif diff --git a/util/libreboot-utils/lib/checksum.c b/util/libreboot-utils/lib/checksum.c new file mode 100644 index 00000000..9a041989 --- /dev/null +++ b/util/libreboot-utils/lib/checksum.c @@ -0,0 +1,108 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2022-2026 Leah Rowe <leah@libreboot.org> + * + * Functions related to GbE NVM checksums. + */ + +#include <sys/types.h> +#include <sys/stat.h> + +#include <errno.h> +#include <limits.h> +#include <stddef.h> +#include <stdlib.h> + +#include "../include/common.h" + +void +read_checksums(void) +{ + struct xstate *x = xstatus(); + struct commands *cmd = &x->cmd[x->i]; + struct xfile *f = &x->f; + + size_t _p; + size_t _skip_part; + + unsigned char _num_invalid; + unsigned char _max_invalid; + + f->part_valid[0] = 0; + f->part_valid[1] = 0; + + if (!cmd->chksum_read) + return; + + _num_invalid = 0; + _max_invalid = 2; + + if (cmd->arg_part) + _max_invalid = 1; + + /* Skip verification on this part, + * but only when arg_part is set. + */ + _skip_part = f->part ^ 1; + + for (_p = 0; _p < 2; _p++) { + + /* Only verify a part if it was *read* + */ + if (cmd->arg_part && (_p == _skip_part)) + continue; + + f->part_valid[_p] = good_checksum(_p); + if (!f->part_valid[_p]) + ++_num_invalid; + } + + if (_num_invalid >= _max_invalid) { + + if (_max_invalid == 1) + b0rk(ECANCELED, "%s: part %lu has a bad checksum", + f->fname, (size_t)f->part); + + b0rk(ECANCELED, "%s: No valid checksum found in file", + f->fname); + } +} + +int +good_checksum(size_t partnum) +{ + unsigned short expected_checksum; + unsigned short actual_checksum; + + expected_checksum = + calculated_checksum(partnum); + + actual_checksum = + nvm_word(NVM_CHECKSUM_WORD, partnum); + + if (expected_checksum == actual_checksum) { + return 1; + } else { + return 0; + } +} + +void +set_checksum(size_t p) +{ + check_bin(p, "part number"); + set_nvm_word(NVM_CHECKSUM_WORD, p, calculated_checksum(p)); +} + +unsigned short +calculated_checksum(size_t p) +{ + size_t c; + unsigned int val16; + + val16 = 0; + + for (c = 0; c < NVM_CHECKSUM_WORD; c++) + val16 += (unsigned int)nvm_word(c, p); + + return (unsigned short)((NVM_CHECKSUM - val16) & 0xffff); +} diff --git a/util/libreboot-utils/lib/command.c b/util/libreboot-utils/lib/command.c new file mode 100644 index 00000000..c7048a23 --- /dev/null +++ b/util/libreboot-utils/lib/command.c @@ -0,0 +1,564 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2022-2026 Leah Rowe <leah@libreboot.org> + */ + +#include <sys/types.h> +#include <sys/stat.h> + +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <stdio.h> +#include <stddef.h> +#include <string.h> +#include <unistd.h> + +#include "../include/common.h" + +/* Guard against regressions by maintainers (command table) + */ + +void +sanitize_command_list(void) +{ + struct xstate *x = xstatus(); + + size_t c; + size_t num_commands; + + num_commands = items(x->cmd); + + for (c = 0; c < num_commands; c++) + sanitize_command_index(c); +} + +void +sanitize_command_index(size_t c) +{ + struct xstate *x = xstatus(); + struct commands *cmd = &x->cmd[c]; + + int _flag; + size_t gbe_rw_size; + + size_t rval; + + check_command_num(c); + + if (cmd->argc < 3) + b0rk(EINVAL, "cmd index %lu: argc below 3, %d", + (size_t)c, cmd->argc); + + if (cmd->str == NULL) + b0rk(EINVAL, "cmd index %lu: NULL str", + (size_t)c); + + if (*cmd->str == '\0') + b0rk(EINVAL, "cmd index %lu: empty str", + (size_t)c); + + if (slen(cmd->str, MAX_CMD_LEN +1, &rval) < 0) + b0rk(errno, "Could not get command length"); + + if (rval > MAX_CMD_LEN) { + b0rk(EINVAL, "cmd index %lu: str too long: %s", + (size_t)c, cmd->str); + } + + if (cmd->run == NULL) + b0rk(EINVAL, "cmd index %lu: cmd ptr null", + (size_t)c); + + check_bin(cmd->arg_part, "cmd.arg_part"); + check_bin(cmd->chksum_read, "cmd.chksum_read"); + check_bin(cmd->chksum_write, "cmd.chksum_write"); + + gbe_rw_size = cmd->rw_size; + + switch (gbe_rw_size) { + case GBE_PART_SIZE: + case NVM_SIZE: + break; + default: + b0rk(EINVAL, "Unsupported rw_size: %lu", + (size_t)gbe_rw_size); + } + + if (gbe_rw_size > GBE_PART_SIZE) + b0rk(EINVAL, "rw_size larger than GbE part: %lu", + (size_t)gbe_rw_size); + + _flag = (cmd->flags & O_ACCMODE); + + if (_flag != O_RDONLY && + _flag != O_RDWR) + b0rk(EINVAL, "invalid cmd.flags setting"); +} + +void +set_cmd(int argc, char *argv[]) +{ + struct xstate *x = xstatus(); + const char *cmd; + + int rval; + + size_t c; + + for (c = 0; c < items(x->cmd); c++) { + + cmd = x->cmd[c].str; + + if (scmp(argv[2], cmd, MAX_CMD_LEN, &rval) < 0) + err_no_cleanup(0, EINVAL, + "could not compare command strings"); + if (rval != 0) + continue; /* not the right command */ + + /* valid command found */ + if (argc >= x->cmd[c].argc) { + x->no_cmd = 0; + x->i = c; /* set command */ + + return; + } + + err_no_cleanup(0, EINVAL, + "Too few args on command '%s'", cmd); + } + + + x->no_cmd = 1; +} + +void +set_cmd_args(int argc, char *argv[]) +{ + struct xstate *x = xstatus(); + size_t i = x->i; + struct commands *cmd = &x->cmd[i]; + struct xfile *f = &x->f; + + if (!valid_command(i) || argc < 3) + usage(); + + if (x->no_cmd) + usage(); + + /* Maintainer bug + */ + if (cmd->arg_part && argc < 4) + b0rk(EINVAL, + "arg_part set for command that needs argc4"); + + if (cmd->arg_part && i == CMD_SETMAC) + b0rk(EINVAL, + "arg_part set on CMD_SETMAC"); + + if (i == CMD_SETMAC) { + + if (argc >= 4) + x->mac.str = argv[3]; + else + x->mac.str = x->mac.rmac; + + } else if (cmd->arg_part) { + + f->part = conv_argv_part_num(argv[3]); + } +} + +size_t +conv_argv_part_num(const char *part_str) +{ + unsigned char ch; + + if (part_str[0] == '\0' || part_str[1] != '\0') + b0rk(EINVAL, "Partnum string '%s' wrong length", part_str); + + /* char signedness is implementation-defined + */ + ch = (unsigned char)part_str[0]; + if (ch < '0' || ch > '1') + b0rk(EINVAL, "Bad part number (%c)", ch); + + return (size_t)(ch - '0'); +} + +void +check_command_num(size_t c) +{ + if (!valid_command(c)) + b0rk(EINVAL, "Invalid run_cmd arg: %lu", + (size_t)c); +} + +unsigned char +valid_command(size_t c) +{ + struct xstate *x = xstatus(); + struct commands *cmd; + + if (c >= items(x->cmd)) + return 0; + + cmd = &x->cmd[c]; + + if (c != cmd->chk) + b0rk(EINVAL, + "Invalid cmd chk value (%lu) vs arg: %lu", + cmd->chk, c); + + return 1; +} + +void +cmd_helper_setmac(void) +{ + struct xstate *x = xstatus(); + struct macaddr *mac = &x->mac; + + size_t partnum; + + check_cmd(cmd_helper_setmac, "setmac"); + + printf("MAC address to be written: %s\n", mac->str); + parse_mac_string(); + + for (partnum = 0; partnum < 2; partnum++) + write_mac_part(partnum); +} + +void +parse_mac_string(void) +{ + struct xstate *x = xstatus(); + struct macaddr *mac = &x->mac; + + size_t mac_byte; + + size_t rval; + + if (slen(x->mac.str, 18, &rval) < 0) + b0rk(EINVAL, "Could not determine MAC length"); + + if (rval != 17) + b0rk(EINVAL, "MAC address is the wrong length"); + + memset(mac->mac_buf, 0, sizeof(mac->mac_buf)); + + for (mac_byte = 0; mac_byte < 6; mac_byte++) + set_mac_byte(mac_byte); + + if ((mac->mac_buf[0] | mac->mac_buf[1] | mac->mac_buf[2]) == 0) + b0rk(EINVAL, "Must not specify all-zeroes MAC address"); + + if (mac->mac_buf[0] & 1) + b0rk(EINVAL, "Must not specify multicast MAC address"); +} + +void +set_mac_byte(size_t mac_byte_pos) +{ + struct xstate *x = xstatus(); + struct macaddr *mac = &x->mac; + + char separator; + + size_t mac_str_pos; + size_t mac_nib_pos; + + mac_str_pos = mac_byte_pos * 3; + + if (mac_str_pos < 15) { + if ((separator = mac->str[mac_str_pos + 2]) != ':') + b0rk(EINVAL, "Invalid MAC address separator '%c'", + separator); + } + + for (mac_nib_pos = 0; mac_nib_pos < 2; mac_nib_pos++) + set_mac_nib(mac_str_pos, mac_byte_pos, mac_nib_pos); +} + +void +set_mac_nib(size_t mac_str_pos, + size_t mac_byte_pos, size_t mac_nib_pos) +{ + struct xstate *x = xstatus(); + struct macaddr *mac = &x->mac; + + char mac_ch; + unsigned short hex_num; + + mac_ch = mac->str[mac_str_pos + mac_nib_pos]; + + if ((hex_num = hextonum(mac_ch)) > 15) { + if (hex_num >= 17) + b0rk(EIO, "Randomisation failure"); + else + b0rk(EINVAL, "Invalid character '%c'", + mac->str[mac_str_pos + mac_nib_pos]); + } + + /* If random, ensure that local/unicast bits are set. + */ + if ((mac_byte_pos == 0) && (mac_nib_pos == 1) && + ((mac_ch | 0x20) == 'x' || + (mac_ch == '?'))) + hex_num = (hex_num & 0xE) | 2; /* local, unicast */ + + /* MAC words stored big endian in-file, little-endian + * logically, so we reverse the order. + */ + mac->mac_buf[mac_byte_pos >> 1] |= hex_num << + (((mac_byte_pos & 1) << 3) /* left or right byte? */ + | ((mac_nib_pos ^ 1) << 2)); /* left or right nib? */ +} + +void +write_mac_part(size_t partnum) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + struct macaddr *mac = &x->mac; + + size_t w; + + check_bin(partnum, "part number"); + if (!f->part_valid[partnum]) + return; + + for (w = 0; w < 3; w++) + set_nvm_word(w, partnum, mac->mac_buf[w]); + + printf("Wrote MAC address to part %lu: ", + (size_t)partnum); + print_mac_from_nvm(partnum); +} + +void +cmd_helper_dump(void) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + size_t p; + + check_cmd(cmd_helper_dump, "dump"); + + f->part_valid[0] = good_checksum(0); + f->part_valid[1] = good_checksum(1); + + for (p = 0; p < 2; p++) { + + if (!f->part_valid[p]) { + + fprintf(stderr, + "BAD checksum %04x in part %lu (expected %04x)\n", + nvm_word(NVM_CHECKSUM_WORD, p), + (size_t)p, + calculated_checksum(p)); + } + + printf("MAC (part %lu): ", + (size_t)p); + + print_mac_from_nvm(p); + + hexdump(p); + } +} + +void +print_mac_from_nvm(size_t partnum) +{ + size_t c; + unsigned short val16; + + for (c = 0; c < 3; c++) { + + val16 = nvm_word(c, partnum); + + printf("%02x:%02x", + (unsigned int)(val16 & 0xff), + (unsigned int)(val16 >> 8)); + + if (c == 2) + printf("\n"); + else + printf(":"); + } +} + +void +hexdump(size_t partnum) +{ + size_t c; + size_t row; + unsigned short val16; + + for (row = 0; row < 8; row++) { + + printf("%08lx ", + (size_t)((size_t)row << 4)); + + for (c = 0; c < 8; c++) { + + val16 = nvm_word((row << 3) + c, partnum); + + if (c == 4) + printf(" "); + + printf(" %02x %02x", + (unsigned int)(val16 & 0xff), + (unsigned int)(val16 >> 8)); + + } + + printf("\n"); + } +} + +void +cmd_helper_swap(void) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + check_cmd(cmd_helper_swap, "swap"); + + memcpy( + f->buf + (size_t)GBE_WORK_SIZE, + f->buf, + GBE_PART_SIZE); + + memcpy( + f->buf, + f->buf + (size_t)GBE_PART_SIZE, + GBE_PART_SIZE); + + memcpy( + f->buf + (size_t)GBE_PART_SIZE, + f->buf + (size_t)GBE_WORK_SIZE, + GBE_PART_SIZE); + + set_part_modified(0); + set_part_modified(1); +} + +void +cmd_helper_copy(void) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + check_cmd(cmd_helper_copy, "copy"); + + memcpy( + f->buf + (size_t)((f->part ^ 1) * GBE_PART_SIZE), + f->buf + (size_t)(f->part * GBE_PART_SIZE), + GBE_PART_SIZE); + + set_part_modified(f->part ^ 1); +} + +void +cmd_helper_cat(void) +{ + struct xstate *x = xstatus(); + + check_cmd(cmd_helper_cat, "cat"); + + x->cat = 0; + cat(0); +} + +void +cmd_helper_cat16(void) +{ + struct xstate *x = xstatus(); + + check_cmd(cmd_helper_cat16, "cat16"); + + x->cat = 1; + cat(1); +} + +void +cmd_helper_cat128(void) +{ + struct xstate *x = xstatus(); + + check_cmd(cmd_helper_cat128, "cat128"); + + x->cat = 15; + cat(15); +} + +void +cat(size_t nff) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + size_t p; + size_t ff; + + p = 0; + ff = 0; + + if ((size_t)x->cat != nff) { + + b0rk(ECANCELED, "erroneous call to cat"); + } + + fflush(NULL); + + memset(f->pad, 0xff, GBE_PART_SIZE); + + for (p = 0; p < 2; p++) { + + cat_buf(f->bufcmp + + (size_t)(p * (f->gbe_file_size >> 1))); + + for (ff = 0; ff < nff; ff++) { + + cat_buf(f->pad); + } + } +} + +void +cat_buf(unsigned char *b) +{ + if (b == NULL) + b0rk(errno, "null pointer in cat command"); + + if (rw_file_exact(STDOUT_FILENO, b, + GBE_PART_SIZE, 0, IO_WRITE, LOOP_EAGAIN, LOOP_EINTR, + MAX_ZERO_RW_RETRY, OFF_ERR) < 0) + b0rk(errno, "stdout: cat"); +} +void +check_cmd(void (*fn)(void), + const char *name) +{ + struct xstate *x = xstatus(); + size_t i = x->i; + + if (x->cmd[i].run != fn) + b0rk(ECANCELED, "Running %s, but cmd %s is set", + name, x->cmd[i].str); + + /* prevent second command + */ + for (i = 0; i < items(x->cmd); i++) + x->cmd[i].run = cmd_helper_err; +} + +void +cmd_helper_err(void) +{ + b0rk(ECANCELED, + "Erroneously running command twice"); +} diff --git a/util/libreboot-utils/lib/file.c b/util/libreboot-utils/lib/file.c new file mode 100644 index 00000000..552618d6 --- /dev/null +++ b/util/libreboot-utils/lib/file.c @@ -0,0 +1,1065 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2026 Leah Rowe <leah@libreboot.org> + * + * Pathless i/o, and some stuff you + * probably never saw in userspace. + * + * Be nice to the demon. + */ + +#include <sys/types.h> +#include <sys/stat.h> + +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +/* for openat2: */ +#ifdef __linux__ +#include <linux/openat2.h> +#include <sys/syscall.h> +#endif + +#include "../include/common.h" + +/* check that a file changed + */ + +int +same_file(int fd, struct stat *st_old, + int check_size) +{ + struct stat st; + int saved_errno = errno; + + /* TODO: null/-1 checks + * like this can be + * generalised + */ + if (st_old == NULL) { + errno = EFAULT; + goto err_same_file; + } + if (fd < 0) { + errno = EBADF; + goto err_same_file; + } + + if (fstat(fd, &st) == -1) + goto err_same_file; + + if (fd_verify_regular(fd, st_old, &st) < 0) + goto err_same_file; + + if (check_size && + st.st_size != st_old->st_size) + goto err_same_file; + + errno = saved_errno; + return 0; + +err_same_file: + + if (errno == saved_errno) + errno = ESTALE; + + return -1; +} + +/* open() but with abort traps + */ +/* TODO: also support other things here than files. + and then use, throughout the program. + in particular, use of openat might help + (split the path) + (see: link attack mitigations throughout nvmutil) + + make it return, and handle the return value/errno + + (this could return e.g. EINTR) + + TODO: this function is not used by mkhtemp, nor will + it probably be, it's currently used by nvmutil, + for opening intel gbe nvm config files. i can + probably remove it though and unify witth some + of the verification code now used for mkhtemp + +TODO: and don't abort. return -1. and handle in the caller. + +minor obstacle: the mkhtemp code always requires absolute +paths, whereas the gbe editor takes relative paths. + */ +void +xopen(int *fd_ptr, const char *path, int flags, struct stat *st) +{ + if ((*fd_ptr = open(path, flags)) < 0) + err_no_cleanup(0, errno, "%s", path); + + if (fstat(*fd_ptr, st) < 0) + err_no_cleanup(0, errno, "%s: stat", path); + + if (!S_ISREG(st->st_mode)) + err_no_cleanup(0, errno, "%s: not a regular file", path); + + if (lseek_on_eintr(*fd_ptr, 0, SEEK_CUR, 1, 1) == (off_t)-1) + err_no_cleanup(0, errno, "%s: file not seekable", path); +} + +/* fsync() the directory of a file, + * useful for atomic writes + */ + +int +fsync_dir(const char *path) +{ + int saved_errno = errno; + + size_t pathlen = 0; + size_t maxlen = 0; + + char *dirbuf = NULL; + int dirfd = -1; + + char *slash = NULL; + struct stat st = {0}; + + int close_errno; + +#if defined(PATH_LEN) && \ + (PATH_LEN) >= 256 + maxlen = PATH_LEN; +#else + maxlen = 4096; +#endif + + if (if_err(path == NULL, EFAULT) || + if_err_sys(slen(path, maxlen, &pathlen) < 0) || + if_err(pathlen >= maxlen || pathlen < 0, EMSGSIZE) || + if_err(pathlen == 0, EINVAL) + || + if_err_sys((dirbuf = malloc(pathlen + 1)) == NULL)) + goto err_fsync_dir; + + memcpy(dirbuf, path, pathlen + 1); + slash = strrchr(dirbuf, '/'); + + if (slash != NULL) { + *slash = '\0'; + if (*dirbuf == '\0') { + dirbuf[0] = '/'; + dirbuf[1] = '\0'; + } + } else { + dirbuf[0] = '.'; + dirbuf[1] = '\0'; + } + + dirfd = fs_open(dirbuf, + O_RDONLY | O_CLOEXEC | O_NOCTTY +#ifdef O_DIRECTORY + | O_DIRECTORY +#endif +#ifdef O_NOFOLLOW + | O_NOFOLLOW +#endif +); + + if (if_err_sys(dirfd < 0) || + if_err_sys(fstat(dirfd, &st) < 0) || + if_err(!S_ISDIR(st.st_mode), ENOTDIR) + || + if_err_sys(fsync_on_eintr(dirfd) == -1)) + goto err_fsync_dir; + + if (close_on_eintr(dirfd) == -1) { + + dirfd = -1; + goto err_fsync_dir; + } + + free_if_null(&dirbuf); + + errno = saved_errno; + return 0; + +err_fsync_dir: + + if (errno == saved_errno) + errno = EIO; + + free_if_null(&dirbuf); + close_no_err(&dirfd); + + return -1; +} + +/* + * Safe I/O functions wrapping around + * read(), write() and providing a portable + * analog of both pread() and pwrite(). + * These functions are designed for maximum + * robustness, checking NULL inputs, overflowed + * outputs, and all kinds of errors that the + * standard libc functions don't. + * + * Looping on EINTR and EAGAIN is supported. + * EINTR/EAGAIN looping is done indefinitely. + */ + +/* rw_file_exact() - Read perfectly or die + * + * Read/write, and absolutely insist on an + * absolute read; e.g. if 100 bytes are + * requested, this MUST return 100. + * + * This function will never return zero. + * It will only return below (error), + * or above (success). On error, -1 is + * returned and errno is set accordingly. + * + * Zero-byte returns are not allowed. + * It will re-spin a finite number of + * times upon zero-return, to recover, + * otherwise it will return an error. + */ + +ssize_t +rw_file_exact(int fd, unsigned char *mem, size_t nrw, + off_t off, int rw_type, int loop_eagain, + int loop_eintr, size_t max_retries, + int off_reset) +{ + ssize_t rval; + ssize_t rc; + + size_t nrw_cur; + + off_t off_cur; + void *mem_cur; + + size_t retries_on_zero; + + int saved_errno = errno; + + rval = 0; + + rc = 0; + retries_on_zero = 0; + + if (io_args(fd, mem, nrw, off, rw_type) == -1) + goto err_rw_file_exact; + + while (1) { + + /* Prevent theoretical overflow */ + if (rval >= 0 && (size_t)rval > (nrw - rc)) { + errno = EOVERFLOW; + goto err_rw_file_exact; + } + + rc += rval; + if ((size_t)rc >= nrw) + break; + + mem_cur = (void *)(mem + (size_t)rc); + nrw_cur = (size_t)(nrw - (size_t)rc); + + if (off < 0) { + errno = EOVERFLOW; + goto err_rw_file_exact; + } + + off_cur = off + (off_t)rc; + + rval = prw(fd, mem_cur, nrw_cur, off_cur, + rw_type, loop_eagain, loop_eintr, + off_reset); + + if (rval < 0) + goto err_rw_file_exact; + + if (rval == 0) { + if (retries_on_zero++ < max_retries) + continue; + + errno = EIO; + goto err_rw_file_exact; + } + + retries_on_zero = 0; + } + + if ((size_t)rc != nrw) { + + errno = EIO; + goto err_rw_file_exact; + } + + rval = rw_over_nrw(rc, nrw); + if (rval < 0) + goto err_rw_file_exact; + + errno = saved_errno; + + return rval; + +err_rw_file_exact: + + if (errno == saved_errno) + errno = EIO; + + return -1; +} + +/* prw() - portable read-write with more + * safety checks than barebones libc + * + * portable pwrite/pread on request, or real + * pwrite/pread libc functions can be used. + * the portable (non-libc) pread/pwrite is not + * thread-safe, because it does not prevent or + * mitigate race conditions on file descriptors + * + * If you need real pwrite/pread, just compile + * with flag: REAL_POS_IO=1 + * + * A fallback is provided for regular read/write. + * rw_type can be IO_READ (read), IO_WRITE (write), + * IO_PREAD (pread) or IO_PWRITE + * + * loop_eagain does a retry loop on EAGAIN if set + * loop_eintr does a retry loop on EINTR if set + * + * race conditions on non-libc pread/pwrite: + * if a file offset changes, abort, to mitage. + * + * off_reset 1: reset the file offset *once* if + * a change was detected, assuming + * nothing else is touching it now + * off_reset 0: never reset if changed + */ + +ssize_t +prw(int fd, void *mem, size_t nrw, + off_t off, int rw_type, + int loop_eagain, int loop_eintr, + int off_reset) +{ + ssize_t rval; + ssize_t r; + int positional_rw; + struct stat st; +#if !defined(REAL_POS_IO) || \ + REAL_POS_IO < 1 + off_t verified; + off_t off_orig; + off_t off_last; +#endif + int saved_errno = errno; + + if (io_args(fd, mem, nrw, off, rw_type) + == -1) + goto err_prw; + + r = -1; + + /* do not use loop_eagain on + * normal files + */ + + if (!loop_eagain) { + /* check whether the file + * changed + */ + + if (check_file(fd, &st) == -1) + goto err_prw; + } + + if (rw_type >= IO_PREAD) + positional_rw = 1; /* pread/pwrite */ + else + positional_rw = 0; /* read/write */ + +try_rw_again: + + if (!positional_rw) { +#if defined(REAL_POS_IO) && \ + REAL_POS_IO > 0 +real_pread_pwrite: +#endif + if (rw_type == IO_WRITE) + r = write(fd, mem, nrw); + else if (rw_type == IO_READ) + r = read(fd, mem, nrw); +#if defined(REAL_POS_IO) && \ + REAL_POS_IO > 0 + else if (rw_type == IO_PWRITE) + r = pwrite(fd, mem, nrw, off); + else if (rw_type == IO_PREAD) + r = pread(fd, mem, nrw, off); +#endif + + if (r == -1 && (errno == try_err(loop_eintr, EINTR) + || errno == try_err(loop_eagain, EAGAIN))) + goto try_rw_again; + + rval = rw_over_nrw(r, nrw); + if (rval < 0) + goto err_prw; + + errno = saved_errno; + + return rval; + } + +#if defined(REAL_POS_IO) && \ + REAL_POS_IO > 0 + goto real_pread_pwrite; +#else + if ((off_orig = lseek_on_eintr(fd, (off_t)0, SEEK_CUR, + loop_eagain, loop_eintr)) == (off_t)-1) { + r = -1; + } else if (lseek_on_eintr(fd, off, SEEK_SET, + loop_eagain, loop_eintr) == (off_t)-1) { + r = -1; + } else { + verified = lseek_on_eintr(fd, (off_t)0, SEEK_CUR, + loop_eagain, loop_eintr); + + /* abort if the offset changed, + * indicating race condition. if + * off_reset enabled, reset *ONCE* + */ + + if (off_reset && off != verified) + lseek_on_eintr(fd, off, SEEK_SET, + loop_eagain, loop_eintr); + + do { + /* check offset again, repeatedly. + * even if off_reset is set, this + * aborts if offsets change again + */ + + verified = lseek_on_eintr(fd, (off_t)0, SEEK_CUR, + loop_eagain, loop_eintr); + + if (off != verified) { + + errno = EBUSY; + goto err_prw; + } + + if (rw_type == IO_PREAD) + r = read(fd, mem, nrw); + else if (rw_type == IO_PWRITE) + r = write(fd, mem, nrw); + + if (rw_over_nrw(r, nrw) == -1) + break; + + } while (r == -1 && + (errno == try_err(loop_eintr, EINTR) || + errno == try_err(loop_eagain, EAGAIN))); + } + + saved_errno = errno; + + off_last = lseek_on_eintr(fd, off_orig, SEEK_SET, + loop_eagain, loop_eintr); + + if (off_last != off_orig) { + errno = saved_errno; + goto err_prw; + } + + errno = saved_errno; + + rval = rw_over_nrw(r, nrw); + if (rval < 0) + goto err_prw; + + errno = saved_errno; + + return rval; + +#endif + +err_prw: + + if (errno == saved_errno) + errno = EIO; + + return -1; +} + +int +io_args(int fd, void *mem, size_t nrw, + off_t off, int rw_type) +{ + int saved_errno = errno; + + if (if_err(mem == NULL, EFAULT) || + if_err(fd < 0, EBADF) || + if_err(off < 0, ERANGE) || + if_err(!nrw, EPERM) || /* TODO: toggle zero-byte check */ + if_err(nrw > (size_t)SSIZE_MAX, ERANGE) || + if_err(((size_t)off + nrw) < (size_t)off, ERANGE) || + if_err(rw_type > IO_PWRITE, EINVAL)) + goto err_io_args; + + errno = saved_errno; + return 0; + +err_io_args: + if (errno == saved_errno) + errno = EINVAL; + + return -1; +} + +int +check_file(int fd, struct stat *st) +{ + int saved_errno = errno; + + if (if_err(fd < 0, EBADF) || + if_err(st == NULL, EFAULT) || + if_err(fstat(fd, st) == -1, 0) || + if_err(!S_ISREG(st->st_mode), EBADF)) + goto err_is_file; + + errno = saved_errno; + return 0; + +err_is_file: + if (errno == saved_errno) + errno = EINVAL; + + return -1; +} + +/* POSIX can say whatever it wants. + * specification != implementation + */ + +ssize_t +rw_over_nrw(ssize_t r, size_t nrw) +{ + int saved_errno = errno; + + if (if_err(!nrw, 0) || + if_err(r == -1, 0) || + if_err((size_t)r > SSIZE_MAX, ERANGE) || + if_err((size_t)r > nrw, ERANGE)) + goto err_rw_over_nrw; + + errno = saved_errno; + return r; + +err_rw_over_nrw: + if (errno == saved_errno) + errno = EIO; + + return -1; +} + +#if !defined(REAL_POS_IO) || \ + REAL_POS_IO < 1 +off_t +lseek_on_eintr(int fd, off_t off, int whence, + int loop_eagain, int loop_eintr) +{ + off_t old; + + old = -1; + + do { + old = lseek(fd, off, whence); + } while (old == (off_t)-1 && ( + errno == try_err(loop_eintr, EINTR) || + errno == try_err(loop_eintr, ETXTBSY) || + errno == try_err(loop_eagain, EAGAIN) || + errno == try_err(loop_eagain, EWOULDBLOCK))); + + return old; +} +#endif + +/* two functions that reduce sloccount by + * two hundred lines... no, now three. */ +int +if_err(int condition, int errval) +{ + if (!condition) + return 0; + + if (errval) + errno = errval; + + return 1; +} +/* technically pointless, but stylistically + * pleasing alongside if_err chains. + * use this one for syscalls that are + * expected to set errno + * also use it for non-system calls + * that act like them, e.g. prw() or + * rw_write_exact() */ +int +if_err_sys(int condition) +{ + if (!condition) + return 0; + return 1; +} +/* errno can never be -1, so you can + * use this to conditionally set an integer + * for comparison. see example in lseek_on_eintr + */ +int +try_err(int loop_err, int errval) +{ + if (loop_err) + return errval; + return -1; +} + +void +free_if_null(char **buf) +{ + if (buf == NULL || *buf == NULL) + return; + + free(*buf); + *buf = NULL; +} + +/* also returns error code */ +int +close_warn(int *fd, char *s) +{ + int saved_errno = errno; + + if (fd == NULL) { + if (s != NULL) + fprintf(stderr, "FAIL: %s: bad fd ptr\n", s); + return -1; + } + + if (*fd < 0 && s != NULL) { + fprintf(stderr, "WARN: %s: already closed\n", s); + } else if (close(*fd) < 0) { + if (s != NULL) + fprintf(stderr, "FAIL: %s: close\n", s); + return -1; + } + + *fd = -1; + errno = saved_errno; + + return 0; +} + +/* TODO: remove this. giant liability. + make close calls always err instead, + when they fail. otherwise we hide bugs! + */ +void +close_no_err(int *fd) +{ + int saved_errno = errno; + + if (fd == NULL || *fd < 0) + return; + + (void) close_on_eintr(*fd); + *fd = -1; + + errno = saved_errno; +} + +/* TODO: make fd a pointer insttead + and automatically reset -1 here */ +/* BUT DO NOT reset -1 on error */ +int +close_on_eintr(int fd) +{ + int r; + int saved_errno = errno; + + do { + r = close(fd); + } while (r == -1 && ( + errno == EINTR || errno == EAGAIN || + errno == EWOULDBLOCK || errno == ETXTBSY)); + + if (r >= 0) + errno = saved_errno; + + return r; +} + +int +fsync_on_eintr(int fd) +{ + int r; + int saved_errno = errno; + + do { + r = fsync(fd); + } while (r == -1 && (errno == EINTR || errno == EAGAIN || + errno == ETXTBSY || errno == EWOULDBLOCK)); + + if (r >= 0) + errno = saved_errno; + + return r; +} + +int +fs_rename_at(int olddirfd, const char *old, + int newdirfd, const char *new) +{ + if (if_err(new == NULL || old == NULL, EFAULT) || + if_err(olddirfd < 0 || newdirfd < 0, EBADF)) + return -1; + + return renameat(olddirfd, old, newdirfd, new); +} + +/* secure open, based on + * relative path to root + * + * always a fixed fd for / + * see: rootfs() + */ +int +fs_open(const char *path, int flags) +{ + struct filesystem *fs; + + if (if_err(path == NULL, EFAULT) || + if_err(path[0] != '/', EINVAL) || + if_err_sys((fs = rootfs()) == NULL)) + return -1; + + return fs_resolve_at(fs->rootfd, path + 1, flags); +} + +/* singleton function + * that returns a fixed + * descriptor of / + * + * used throughout, for + * repeated integrity checks + */ +struct filesystem * +rootfs(void) +{ + static struct filesystem global_fs; + static int fs_initialised = 0; + + if (!fs_initialised) { + + global_fs.rootfd = + open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC); + + if (global_fs.rootfd < 0) + return NULL; + + fs_initialised = 1; + } + + return &global_fs; +} + +/* filesystem sandboxing. + * (in userspace) + */ +int +fs_resolve_at(int dirfd, const char *path, int flags) +{ + int nextfd = -1; + int curfd; + const char *p; +#if defined(PATH_LEN) && \ + ((PATH_LEN) >= 256) + char name[PATH_LEN]; +#else + char name[4096]; +#endif + int saved_errno = errno; + int r; + int is_last; + + if (dirfd < 0 || path == NULL || *path == '\0') { + errno = EINVAL; + return -1; + } + + p = path; + curfd = dirfd; /* start here */ + + for (;;) { + r = fs_next_component(&p, name, sizeof(name)); + if (r < 0) + goto err; + if (r == 0) + break; + + is_last = (*p == '\0'); + + nextfd = fs_open_component(curfd, name, flags, is_last); + if (nextfd < 0) + goto err; + + /* close previous fd IF it is not the original input */ + if (curfd != dirfd) { + (void) close_on_eintr(curfd); + } + + curfd = nextfd; + nextfd = -1; + } + + errno = saved_errno; + return curfd; + +err: + saved_errno = errno; + + if (nextfd >= 0) + (void) close_on_eintr(nextfd); + + /* close curfd only if it's not the original */ + if (curfd != dirfd && curfd >= 0) + (void) close_on_eintr(curfd); + + errno = saved_errno; + return -1; +} + +int +fs_next_component(const char **p, + char *name, size_t namesz) +{ + const char *s = *p; + size_t len = 0; +#if defined(PATH_LEN) && \ +(PATH_LEN) >= 256 + size_t maxlen = PATH_LEN; +#else + size_t maxlen = 4096; +#endif + + while (*s == '/') + s++; + + if (*s == '\0') { + *p = s; + return 0; + } + + while (s[len] != '/' && s[len] != '\0') + len++; + + if (len == 0 || len >= namesz || + len >= maxlen) { + errno = ENAMETOOLONG; + return -1; + } + + memcpy(name, s, len); + name[len] = '\0'; + + /* reject . and .. */ + if ((name[0] == '.' && name[1] == '\0') || + (name[0] == '.' && name[1] == '.' && name[2] == '\0')) { + errno = EPERM; + return -1; + } + + *p = s + len; + return 1; +} + +int +fs_open_component(int dirfd, const char *name, + int flags, int is_last) +{ + int fd; + struct stat st; + + fd = openat2p(dirfd, name, + (is_last ? flags : (O_RDONLY | O_DIRECTORY)) | + O_NOFOLLOW | O_CLOEXEC, (flags & O_CREAT) ? 0600 : 0); + + /* the patient always lies + */ + if (!is_last) { + + if (if_err(fd < 0, EBADF) || + if_err_sys(fstat(fd, &st) < 0)) + return -1; + + if (!S_ISDIR(st.st_mode)) { + + (void) close_on_eintr(fd); + errno = ENOTDIR; + return -1; + } + } + + return fd; +} + +int +fs_dirname_basename(const char *path, + char **dir, char **base, + int allow_relative) +{ + char *buf; + char *slash; + size_t len; + int rval; +#if defined(PATH_LEN) && \ +(PATH_LEN) >= 256 + size_t maxlen = PATH_LEN; +#else + size_t maxlen = 4096; +#endif + + if (path == NULL || dir == NULL || base == NULL || + if_err_sys(slen(path, maxlen, &len) < 0) || + if_err_sys((buf = malloc(len + 1)) == NULL)) + return -1; + + memcpy(buf, path, len + 1); + + /* strip trailing slashes */ + while (len > 1 && buf[len - 1] == '/') + buf[--len] = '\0'; + + slash = strrchr(buf, '/'); + + if (slash) { + + *slash = '\0'; + *dir = buf; + *base = slash + 1; + + if (**dir == '\0') { + (*dir)[0] = '/'; + (*dir)[1] = '\0'; + } + } else if (allow_relative) { + + *dir = strdup("."); + *base = buf; + } else { + errno = EINVAL; + free_if_null(&buf); + return -1; + } + + return 0; +} + +/* portable wrapper for use of openat2 on linux, + * with fallback for others e.g. openbsd + * + * BONUS: arg checks + * TODO: consider EINTR/EAGAIN retry loop + */ +int +openat2p(int dirfd, const char *path, + int flags, mode_t mode) +{ +#ifdef __linux__ + struct open_how how = { + .flags = flags, + .mode = mode, + .resolve = + RESOLVE_BENEATH | + RESOLVE_NO_SYMLINKS | + RESOLVE_NO_MAGICLINKS + }; + int saved_errno = errno; + int rval; +#endif + + if (if_err(dirfd < 0, EBADF) || + if_err(path == NULL, EFAULT)) + return -1; + +retry: + errno = 0; + +#ifdef __linux__ + /* more secure than regular openat, + * but linux-only at the time of writing + */ + rval = syscall(SYS_openat2, dirfd, path, &how, sizeof(how)); +#else + /* less secure, but e.g. openbsd + * doesn't have openat2 yet + */ + rval = openat(dirfd, path, flags, mode); +#endif + if (rval == -1 && ( + errno == EINTR || + errno == EAGAIN || + errno == EWOULDBLOCK || + errno == ETXTBSY)) + goto retry; + + if (rval >= 0) + errno = saved_errno; + + return rval; +} + +int +mkdirat_on_eintr( /* <-- say that 10 times to please the demon */ + int dirfd, + const char *path, mode_t mode) +{ + int saved_errno = errno; + int rval; + + if (if_err(dirfd < 0, EBADF) || + if_err(path == NULL, EFAULT)) + return -1; + +retry: + errno = 0; + rval = mkdirat(dirfd, path, mode); + + if (rval == -1 && ( + errno == EINTR || + errno == EAGAIN || + errno == EWOULDBLOCK || + errno == ETXTBSY)) + goto retry; + + if (rval >= 0) + errno = saved_errno; + + return rval; +} + + + + + + + + + + + diff --git a/util/libreboot-utils/lib/io.c b/util/libreboot-utils/lib/io.c new file mode 100644 index 00000000..d05adbcc --- /dev/null +++ b/util/libreboot-utils/lib/io.c @@ -0,0 +1,591 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2026 Leah Rowe <leah@libreboot.org> + * + * I/O functions specific to nvmutil. + */ + +#include <sys/types.h> +#include <sys/stat.h> + +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include "../include/common.h" + +void +open_gbe_file(void) +{ + struct xstate *x = xstatus(); + struct commands *cmd = &x->cmd[x->i]; + struct xfile *f = &x->f; + + int _flags; + + xopen(&f->gbe_fd, f->fname, + cmd->flags | O_BINARY | + O_NOFOLLOW | O_CLOEXEC | O_NOCTTY, &f->gbe_st); + + if (f->gbe_st.st_nlink > 1) + b0rk(EINVAL, + "%s: warning: file has multiple (%lu) hard links\n", + f->fname, (size_t)f->gbe_st.st_nlink); + + if (f->gbe_st.st_nlink == 0) + b0rk(EIO, "%s: file unlinked while open", f->fname); + + _flags = fcntl(f->gbe_fd, F_GETFL); + if (_flags == -1) + b0rk(errno, "%s: fcntl(F_GETFL)", f->fname); + + /* O_APPEND allows POSIX write() to ignore + * the current write offset and write at EOF, + * which would break positional read/write + */ + + if (_flags & O_APPEND) + b0rk(EIO, "%s: O_APPEND flag", f->fname); + + f->gbe_file_size = f->gbe_st.st_size; + + switch (f->gbe_file_size) { + case SIZE_8KB: + case SIZE_16KB: + case SIZE_128KB: + break; + default: + b0rk(EINVAL, "File size must be 8KB, 16KB or 128KB"); + } + + if (lock_file(f->gbe_fd, cmd->flags) == -1) + b0rk(errno, "%s: can't lock", f->fname); +} + +void +copy_gbe(void) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + read_file(); + + if (f->gbe_file_size == SIZE_8KB) + return; + + memcpy(f->buf + (size_t)GBE_PART_SIZE, + f->buf + (size_t)(f->gbe_file_size >> 1), + (size_t)GBE_PART_SIZE); +} + +void +read_file(void) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + struct stat _st; + ssize_t _r; + + /* read main file + */ + _r = rw_file_exact(f->gbe_fd, f->buf, f->gbe_file_size, + 0, IO_PREAD, NO_LOOP_EAGAIN, LOOP_EINTR, + MAX_ZERO_RW_RETRY, OFF_ERR); + + if (_r < 0) + b0rk(errno, "%s: read failed", f->fname); + + /* copy to tmpfile + */ + _r = rw_file_exact(f->tmp_fd, f->buf, f->gbe_file_size, + 0, IO_PWRITE, NO_LOOP_EAGAIN, LOOP_EINTR, + MAX_ZERO_RW_RETRY, OFF_ERR); + + if (_r < 0) + b0rk(errno, "%s: %s: copy failed", + f->fname, f->tname); + + /* file size comparison + */ + if (fstat(f->tmp_fd, &_st) == -1) + b0rk(errno, "%s: stat", f->tname); + + f->gbe_tmp_size = _st.st_size; + + if (f->gbe_tmp_size != f->gbe_file_size) + b0rk(EIO, "%s: %s: not the same size", + f->fname, f->tname); + + /* needs sync, for verification + */ + if (fsync_on_eintr(f->tmp_fd) == -1) + b0rk(errno, "%s: fsync (tmpfile copy)", f->tname); + + _r = rw_file_exact(f->tmp_fd, f->bufcmp, f->gbe_file_size, + 0, IO_PREAD, NO_LOOP_EAGAIN, LOOP_EINTR, + MAX_ZERO_RW_RETRY, OFF_ERR); + + if (_r < 0) + b0rk(errno, "%s: read failed (cmp)", f->tname); + + if (memcmp(f->buf, f->bufcmp, f->gbe_file_size) != 0) + b0rk(errno, "%s: %s: read contents differ (pre-test)", + f->fname, f->tname); +} + +void +write_gbe_file(void) +{ + struct xstate *x = xstatus(); + struct commands *cmd = &x->cmd[x->i]; + struct xfile *f = &x->f; + + size_t p; + unsigned char update_checksum; + + if ((cmd->flags & O_ACCMODE) == O_RDONLY) + return; + + if (same_file(f->tmp_fd, &f->tmp_st, 0) < 0) + b0rk(errno, "%s: file inode/device changed", f->tname); + + if (same_file(f->gbe_fd, &f->gbe_st, 1) < 0) + b0rk(errno, "%s: file has changed", f->fname); + + update_checksum = cmd->chksum_write; + + for (p = 0; p < 2; p++) { + if (!f->part_modified[p]) + continue; + + if (update_checksum) + set_checksum(p); + + rw_gbe_file_part(p, IO_PWRITE, "pwrite"); + } +} + +void +rw_gbe_file_part(size_t p, int rw_type, + const char *rw_type_str) +{ + struct xstate *x = xstatus(); + struct commands *cmd = &x->cmd[x->i]; + struct xfile *f = &x->f; + + ssize_t rval; + + off_t file_offset; + + size_t gbe_rw_size; + unsigned char *mem_offset; + + gbe_rw_size = cmd->rw_size; + + if (rw_type < IO_PREAD || rw_type > IO_PWRITE) + b0rk(errno, "%s: %s: part %lu: invalid rw_type, %d", + f->fname, rw_type_str, (size_t)p, rw_type); + + mem_offset = gbe_mem_offset(p, rw_type_str); + file_offset = (off_t)gbe_file_offset(p, rw_type_str); + + rval = rw_gbe_file_exact(f->tmp_fd, mem_offset, + gbe_rw_size, file_offset, rw_type); + + if (rval == -1) + b0rk(errno, "%s: %s: part %lu", + f->fname, rw_type_str, (size_t)p); + + if ((size_t)rval != gbe_rw_size) + b0rk(EIO, "%s: partial %s: part %lu", + f->fname, rw_type_str, (size_t)p); +} + +void +write_to_gbe_bin(void) +{ + struct xstate *x = xstatus(); + struct commands *cmd = &x->cmd[x->i]; + struct xfile *f = &x->f; + + int saved_errno; + int mv; + + if ((cmd->flags & O_ACCMODE) != O_RDWR) + return; + + write_gbe_file(); + + /* We may otherwise read from + * cache, so we must sync. + */ + + if (fsync_on_eintr(f->tmp_fd) == -1) + b0rk(errno, "%s: fsync (pre-verification)", + f->tname); + + check_written_part(0); + check_written_part(1); + + report_io_err_rw(); + + if (f->io_err_gbe) + b0rk(EIO, "%s: bad write", f->fname); + + saved_errno = errno; + + f->io_err_gbe_bin |= -close_warn(&f->tmp_fd, f->tname); + f->io_err_gbe_bin |= -close_warn(&f->gbe_fd, f->fname); + + errno = saved_errno; + + /* tmpfile written, now we + * rename it back to the main file + * (we do atomic writes) + */ + + f->tmp_fd = -1; + f->gbe_fd = -1; + + if (!f->io_err_gbe_bin) { + + mv = gbe_mv(); + + if (mv < 0) { + + f->io_err_gbe_bin = 1; + + fprintf(stderr, "%s: %s\n", + f->fname, strerror(errno)); + } else { + + /* removed by rename + */ + free_if_null(&f->tname); + } + } + + if (!f->io_err_gbe_bin) + return; + + fprintf(stderr, "FAIL (rename): %s: skipping fsync\n", + f->fname); + if (errno) + fprintf(stderr, + "errno %d: %s\n", errno, strerror(errno)); +} + +void +check_written_part(size_t p) +{ + struct xstate *x = xstatus(); + struct commands *cmd = &x->cmd[x->i]; + struct xfile *f = &x->f; + + ssize_t rval; + + size_t gbe_rw_size; + + off_t file_offset; + unsigned char *mem_offset; + + unsigned char *buf_restore; + + if (!f->part_modified[p]) + return; + + gbe_rw_size = cmd->rw_size; + + mem_offset = gbe_mem_offset(p, "pwrite"); + file_offset = (off_t)gbe_file_offset(p, "pwrite"); + + memset(f->pad, 0xff, sizeof(f->pad)); + + if (same_file(f->tmp_fd, &f->tmp_st, 0) < 0) + b0rk(errno, "%s: file inode/device changed", f->tname); + + if (same_file(f->gbe_fd, &f->gbe_st, 1) < 0) + b0rk(errno, "%s: file changed during write", f->fname); + + rval = rw_gbe_file_exact(f->tmp_fd, f->pad, + gbe_rw_size, file_offset, IO_PREAD); + + if (rval == -1) + f->rw_check_err_read[p] = f->io_err_gbe = 1; + else if ((size_t)rval != gbe_rw_size) + f->rw_check_partial_read[p] = f->io_err_gbe = 1; + else if (memcmp(mem_offset, f->pad, gbe_rw_size) != 0) + f->rw_check_bad_part[p] = f->io_err_gbe = 1; + + if (f->rw_check_err_read[p] || + f->rw_check_partial_read[p]) + return; + + /* We only load one part on-file, into memory but + * always at offset zero, for post-write checks. + * That's why we hardcode good_checksum(0) + */ + + buf_restore = f->buf; + + /* good_checksum works on f->buf + * so let's change f->buf for now + */ + + f->buf = f->pad; + + if (good_checksum(0)) + f->post_rw_checksum[p] = 1; + + f->buf = buf_restore; +} + +void +report_io_err_rw(void) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + size_t p; + + if (!f->io_err_gbe) + return; + + for (p = 0; p < 2; p++) { + if (!f->part_modified[p]) + continue; + + if (f->rw_check_err_read[p]) + fprintf(stderr, + "%s: pread: p%lu (post-verification)\n", + f->fname, (size_t)p); + if (f->rw_check_partial_read[p]) + fprintf(stderr, + "%s: partial pread: p%lu (post-verification)\n", + f->fname, (size_t)p); + if (f->rw_check_bad_part[p]) + fprintf(stderr, + "%s: pwrite: corrupt write on p%lu\n", + f->fname, (size_t)p); + + if (f->rw_check_err_read[p] || + f->rw_check_partial_read[p]) { + fprintf(stderr, + "%s: p%lu: skipped checksum verification " + "(because read failed)\n", + f->fname, (size_t)p); + + continue; + } + + fprintf(stderr, "%s: ", f->fname); + + if (f->post_rw_checksum[p]) + fprintf(stderr, "GOOD"); + else + fprintf(stderr, "BAD"); + + fprintf(stderr, " checksum in p%lu on-disk.\n", + (size_t)p); + + if (f->post_rw_checksum[p]) { + fprintf(stderr, + " This does NOT mean it's safe. it may be\n" + " salvageable if you use the cat feature.\n"); + } + } +} + +int +gbe_mv(void) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + int rval; + + int saved_errno; + int tmp_gbe_bin_exists; + + char *dest_tmp; + int dest_fd = -1; + + char *dir = NULL; + char *base = NULL; + char *dest_name = NULL; + + int dirfd = -1; + + struct stat st_dir; + + /* will be set 0 if it doesn't + */ + tmp_gbe_bin_exists = 1; + + dest_tmp = NULL; + dest_fd = -1; + + saved_errno = errno; + + rval = fs_rename_at(f->dirfd, f->tmpbase, + f->dirfd, f->base); + + if (rval > -1) + tmp_gbe_bin_exists = 0; + +ret_gbe_mv: + + /* TODO: this whole section is bloat. + it can be generalised + */ + + if (f->gbe_fd > -1) { + if (close_on_eintr(f->gbe_fd) < 0) { + f->gbe_fd = -1; + rval = -1; + } + f->gbe_fd = -1; + + if (fsync_dir(f->fname) < 0) { + f->io_err_gbe_bin = 1; + rval = -1; + } + } + + if (f->tmp_fd > -1) { + if (close_on_eintr(f->tmp_fd) < 0) { + f->tmp_fd = -1; + rval = -1; + } + f->tmp_fd = -1; + } + + /* before this function is called, + * tmp_fd may have been moved + */ + if (tmp_gbe_bin_exists) { + if (unlink(f->tname) < 0) + rval = -1; + else + tmp_gbe_bin_exists = 0; + } + + if (rval < 0) { + /* if nothing set errno, + * we assume EIO, or we + * use what was set + */ + if (errno == saved_errno) + errno = EIO; + } else { + errno = saved_errno; + } + + return rval; +} + +/* This one is similar to gbe_file_offset, + * but used to check Gbe bounds in memory, + * and it is *also* used during file I/O. + */ +unsigned char * +gbe_mem_offset(size_t p, const char *f_op) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + off_t gbe_off; + + gbe_off = gbe_x_offset(p, f_op, "mem", + GBE_PART_SIZE, GBE_WORK_SIZE); + + return (unsigned char *) + (f->buf + (size_t)gbe_off); +} + +/* I/O operations filtered here. These operations must + * only write from the 0th position or the half position + * within the GbE file, and write 4KB of data. + */ +off_t +gbe_file_offset(size_t p, const char *f_op) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + off_t gbe_file_half_size; + + gbe_file_half_size = f->gbe_file_size >> 1; + + return gbe_x_offset(p, f_op, "file", + gbe_file_half_size, f->gbe_file_size); +} + +off_t +gbe_x_offset(size_t p, const char *f_op, const char *d_type, + off_t nsize, off_t ncmp) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + off_t off; + + check_bin(p, "part number"); + + off = ((off_t)p) * (off_t)nsize; + + if (off > ncmp - GBE_PART_SIZE) + b0rk(ECANCELED, "%s: GbE %s %s out of bounds", + f->fname, d_type, f_op); + + if (off != 0 && off != ncmp >> 1) + b0rk(ECANCELED, "%s: GbE %s %s at bad offset", + f->fname, d_type, f_op); + + return off; +} + +ssize_t +rw_gbe_file_exact(int fd, unsigned char *mem, size_t nrw, + off_t off, int rw_type) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + ssize_t r; + + if (io_args(fd, mem, nrw, off, rw_type) == -1) + return -1; + + if (mem != (void *)f->pad) { + if (mem < f->buf) + goto err_rw_gbe_file_exact; + + if ((size_t)(mem - f->buf) >= GBE_WORK_SIZE) + goto err_rw_gbe_file_exact; + } + + if (off < 0 || off >= f->gbe_file_size) + goto err_rw_gbe_file_exact; + + if (nrw > (size_t)(f->gbe_file_size - off)) + goto err_rw_gbe_file_exact; + + if (nrw > (size_t)GBE_PART_SIZE) + goto err_rw_gbe_file_exact; + + r = rw_file_exact(fd, mem, nrw, off, rw_type, + NO_LOOP_EAGAIN, LOOP_EINTR, MAX_ZERO_RW_RETRY, + OFF_ERR); + + return rw_over_nrw(r, nrw); + +err_rw_gbe_file_exact: + errno = EIO; + return -1; +} diff --git a/util/libreboot-utils/lib/mkhtemp.c b/util/libreboot-utils/lib/mkhtemp.c new file mode 100644 index 00000000..a669e208 --- /dev/null +++ b/util/libreboot-utils/lib/mkhtemp.c @@ -0,0 +1,1091 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2026 Leah Rowe <leah@libreboot.org> + * + * Hardened mktemp (be nice to the demon). + */ + +#if defined(__linux__) && !defined(_GNU_SOURCE) +/* for openat2 syscall on linux */ +#define _GNU_SOURCE 1 +#endif + +#include <sys/types.h> +#include <sys/stat.h> + +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +/* for openat2 / fast path: */ +#ifdef __linux__ +#include <linux/openat2.h> +#include <sys/syscall.h> +#ifndef O_TMPFILE +#define O_TMPFILE 020000000 +#endif +#ifndef AT_EMPTY_PATH +#define AT_EMPTY_PATH 0x1000 +#endif +#endif + +#include "../include/common.h" + +/* note: tmpdir is an override of TMPDIR or /tmp or /var/tmp */ +int +new_tmpfile(int *fd, char **path, char *tmpdir, + const char *template) +{ + return new_tmp_common(fd, path, MKHTEMP_FILE, + tmpdir, template); +} + +/* note: tmpdir is an override of TMPDIR or /tmp or /var/tmp */ +int +new_tmpdir(int *fd, char **path, char *tmpdir, + const char *template) +{ + return new_tmp_common(fd, path, MKHTEMP_DIR, + tmpdir, template); +} + +/* note: tmpdir is an override of TMPDIR or /tmp or /var/tmp */ +/* WARNING: + * on error, *path (at **path) may be + NULL, or if the error pertains to + an actual TMPDIR, set. if set, it + will be using *static* memory and + must not be freed. on success, + a pointer to heap memory is set + instead. + * see: + * env_tmpdir() + * this is for error reports if e.g. + * TMPDIR isn't found (but is set) + * if TMPDIR isn't set, it will + * default to /tmp or /var/tmp + */ +int +new_tmp_common(int *fd, char **path, int type, + char *tmpdir, const char *template) +{ +#if defined(PATH_LEN) && \ + (PATH_LEN) >= 256 + size_t maxlen = PATH_LEN; +#else + size_t maxlen = 4096; +#endif + struct stat st; + + const char *templatestr; + size_t templatestr_len; + + size_t dirlen; + size_t destlen; + char *dest = NULL; /* final path (will be written into "path") */ + int saved_errno = errno; + int dirfd = -1; + const char *fname = NULL; + + struct stat st_dir_initial; + + char *fail_dir = NULL; + + if (path == NULL || fd == NULL) { + errno = EFAULT; + goto err; + } + + /* don't mess with someone elses file */ + if (*fd >= 0) { + errno = EEXIST; + goto err; + } + + /* regarding **path: + * the pointer (to the pointer) + * must nott be null, but we don't + * care about the pointer it points + * to. you should expect it to be + * replaced upon successful return + * + * (on error, it will not be touched) + */ + + *fd = -1; + + if (tmpdir == NULL) { /* no user override */ +#if defined(PERMIT_NON_STICKY_ALWAYS) && \ + ((PERMIT_NON_STICKY_ALWAYS) > 0) + tmpdir = env_tmpdir(PERMIT_NON_STICKY_ALWAYS, &fail_dir, NULL); +#else + tmpdir = env_tmpdir(0, &fail_dir, NULL); +#endif + } else { + +#if defined(PERMIT_NON_STICKY_ALWAYS) && \ + ((PERMIT_NON_STICKY_ALWAYS) > 0) + tmpdir = env_tmpdir(PERMIT_NON_STICKY_ALWAYS, &fail_dir, + tmpdir); +#else + tmpdir = env_tmpdir(0, &fail_dir, tmpdir); +#endif + } + if (tmpdir == NULL) + goto err; + + if (slen(tmpdir, maxlen, &dirlen) < 0) + goto err; + if (*tmpdir == '\0') + goto err; + if (*tmpdir != '/') + goto err; + + if (template != NULL) + templatestr = template; + else + templatestr = "tmp.XXXXXXXXXX"; + + if (slen(templatestr, maxlen, &templatestr_len) < 0) + goto err; + + /* sizeof adds an extra byte, useful + * because we also want '.' or '/' + */ + destlen = dirlen + 1 + templatestr_len; + if (destlen > maxlen - 1) { + errno = EOVERFLOW; + goto err; + } + + dest = malloc(destlen + 1); + if (dest == NULL) { + errno = ENOMEM; + goto err; + } + + memcpy(dest, tmpdir, dirlen); + *(dest + dirlen) = '/'; + memcpy(dest + dirlen + 1, templatestr, templatestr_len); + *(dest + destlen) = '\0'; + + fname = dest + dirlen + 1; + + dirfd = fs_open(tmpdir, + O_RDONLY | O_DIRECTORY); + if (dirfd < 0) + goto err; + + if (fstat(dirfd, &st_dir_initial) < 0) + goto err; + + *fd = mkhtemp(fd, &st, dest, dirfd, + fname, &st_dir_initial, type); + if (*fd < 0) + goto err; + + close_no_err(&dirfd); + + errno = saved_errno; + *path = dest; + + return 0; + +err: + + if (errno != saved_errno) + saved_errno = errno; + else + saved_errno = errno = EIO; + + free_if_null(&dest); + + close_no_err(&dirfd); + close_no_err(fd); + + /* where a TMPDIR isn't found, and we err, + * we pass this back through for the + * error message + */ + if (fail_dir != NULL) + *path = fail_dir; + + errno = saved_errno; + return -1; +} + + +/* hardened TMPDIR parsing + */ + +char * +env_tmpdir(int bypass_all_sticky_checks, char **tmpdir, + char *override_tmpdir) +{ + char *t; + int allow_noworld_unsticky; + int saved_errno = errno; + + char tmp[] = "/tmp"; + char vartmp[] = "/var/tmp"; + + /* tmpdir is a user override, if set */ + if (override_tmpdir == NULL) + t = getenv("TMPDIR"); + else + t = override_tmpdir; + + if (t != NULL && *t != '\0') { + + if (tmpdir_policy(t, + &allow_noworld_unsticky) < 0) { + if (tmpdir != NULL) + *tmpdir = t; + return NULL; /* errno already set */ + } + + if (!world_writeable_and_sticky(t, + allow_noworld_unsticky, + bypass_all_sticky_checks)) { + if (tmpdir != NULL) + *tmpdir = t; + return NULL; + } + + errno = saved_errno; + return t; + } + + allow_noworld_unsticky = 0; + + if (world_writeable_and_sticky("/tmp", + allow_noworld_unsticky, + bypass_all_sticky_checks)) { + + if (tmpdir != NULL) + *tmpdir = tmp; + + errno = saved_errno; + return "/tmp"; + } + + if (world_writeable_and_sticky("/var/tmp", + allow_noworld_unsticky, + bypass_all_sticky_checks)) { + + if (tmpdir != NULL) + *tmpdir = vartmp; + + errno = saved_errno; + return "/var/tmp"; + } + + return NULL; +} + +int +tmpdir_policy(const char *path, + int *allow_noworld_unsticky) +{ + int saved_errno = errno; + int r; + + if (path == NULL || + allow_noworld_unsticky == NULL) { + + errno = EFAULT; + return -1; + } + + *allow_noworld_unsticky = 1; + + r = same_dir(path, "/tmp"); + if (r < 0) + goto err_tmpdir_policy; + if (r > 0) + *allow_noworld_unsticky = 0; + + r = same_dir(path, "/var/tmp"); + if (r < 0) + goto err_tmpdir_policy; + if (r > 0) + *allow_noworld_unsticky = 0; + + errno = saved_errno; + return 0; + +err_tmpdir_policy: + + if (errno == saved_errno) + errno = EIO; + + return -1; +} + +int +same_dir(const char *a, const char *b) +{ + int fd_a = -1; + int fd_b = -1; + + struct stat st_a; + struct stat st_b; + + int saved_errno = errno; + int rval_scmp; + +#if defined(PATH_LEN) && \ + (PATH_LEN) >= 256 + size_t maxlen = (PATH_LEN); +#else + size_t maxlen = 4096; +#endif + + /* optimisation: if both dirs + are the same, we don't need + to check anything. sehr schnell: + */ + if (scmp(a, b, maxlen, &rval_scmp) < 0) + goto err_same_dir; + /* bonus: scmp checks null for us */ + if (rval_scmp == 0) + goto success_same_dir; + + fd_a = fs_open(a, O_RDONLY | O_DIRECTORY); + if (fd_a < 0) + goto err_same_dir; + + fd_b = fs_open(b, O_RDONLY | O_DIRECTORY); + if (fd_b < 0) + goto err_same_dir; + + if (fstat(fd_a, &st_a) < 0) + goto err_same_dir; + + if (fstat(fd_b, &st_b) < 0) + goto err_same_dir; + + if (st_a.st_dev == st_b.st_dev && + st_a.st_ino == st_b.st_ino) { + + close_no_err(&fd_a); + close_no_err(&fd_b); + +success_same_dir: + + /* SUCCESS + */ + + errno = saved_errno; + return 1; + } + + close_no_err(&fd_a); + close_no_err(&fd_b); + + /* FAILURE (logical) + */ + + errno = saved_errno; + return 0; + +err_same_dir: + + /* FAILURE (probably syscall) + */ + + close_no_err(&fd_a); + close_no_err(&fd_b); + + if (errno == saved_errno) + errno = EIO; + + return -1; +} + +/* bypass_all_sticky_checks: if set, + disable stickiness checks (libc behaviour) + (if not set: leah behaviour) + + allow_noworld_unsticky: + allow non-sticky files if not world-writeable + (still block non-sticky in standard TMPDIR) +*/ +int +world_writeable_and_sticky( + const char *s, + int allow_noworld_unsticky, + int bypass_all_sticky_checks) +{ + struct stat st; + int dirfd = -1; + + int saved_errno = errno; + + if (s == NULL || *s == '\0') { + errno = EINVAL; + goto sticky_hell; + } + + /* mitigate symlink attacks* + */ + dirfd = fs_open(s, O_RDONLY | O_DIRECTORY); + if (dirfd < 0) + goto sticky_hell; + + if (fstat(dirfd, &st) < 0) + goto sticky_hell; + + if (!S_ISDIR(st.st_mode)) { + errno = ENOTDIR; + goto sticky_hell; + } + + /* must be fully executable + * by everyone, or openat2 + * becomes unreliable** + * + * TODO: loosen these, as a toggle. + * execution rights isn't + * really a requirement for + * TMPDIR, except maybe search, + * but this function will be + * generalised at some point + * for use in other tools + * besides just mkhtemp. + */ + /* + if (!(st.st_mode & S_IXUSR) || + !(st.st_mode & S_IXGRP) || + !(st.st_mode & S_IXOTH)) { + */ + /* just require it for *you*, for now */ + if (!(st.st_mode & S_IXUSR)) { + errno = EACCES; + goto sticky_hell; + } + + /* *normal-**ish mode (libc): + */ + + if (bypass_all_sticky_checks) + goto sticky_heaven; /* normal == no security */ + + /* unhinged leah mode: + */ + + if (st.st_mode & S_IWOTH) { /* world writeable */ + + /* if world-writeable, only + * allow sticky files + */ + if (st.st_mode & S_ISVTX) + goto sticky_heaven; /* sticky */ + + errno = EPERM; + goto sticky_hell; /* not sticky */ + } + + /* if anyone even looks at you funny, drop + * everything on the floor and refuse to function + */ + if (faccessat(dirfd, ".", X_OK, AT_EACCESS) < 0) + goto sticky_hell; + + /* non-world-writeable, so + * stickiness is do-not-care + */ + if (allow_noworld_unsticky) + goto sticky_heaven; /* sticky! */ + + goto sticky_hell; /* heaven visa denied */ + +sticky_heaven: +/* i like the one in hamburg better */ + + close_no_err(&dirfd); + errno = saved_errno; + + return 1; + +sticky_hell: + + if (errno == saved_errno) + errno = EPERM; + + saved_errno = errno; + + close_no_err(&dirfd); + + errno = saved_errno; + + return 0; +} + +/* mk(h)temp - hardened mktemp. + * like mkstemp, but (MUCH) harder. + * + * designed to resist TOCTOU attacks + * e.g. directory race / symlink attack + * + * extremely strict and even implements + * some limited userspace-level sandboxing, + * similar in spirit to openbsd unveil, + * though unveil is from kernel space. + * + * supports both files and directories. + * file: type = MKHTEMP_FILE (0) + * dir: type = MKHTEMP_DIR (1) + * + * DESIGN NOTES: + * + * caller is expected to handle + * cleanup e.g. free(), on *st, + * *template, *fname (all of the + * pointers). ditto fd cleanup. + * + * some limited cleanup is + * performed here, e.g. directory/file + * cleanup on error in mkhtemp_try_create + * + * we only check if these are not NULL, + * and the caller is expected to take + * care; without too many conditions, + * these functions are more flexible, + * but some precauttions are taken: + * + * when used via the function new_tmpfile + * or new_tmpdir, thtis is extremely strict, + * much stricter than previous mktemp + * variants. for example, it is much + * stricter about stickiness on world + * writeable directories, and it enforces + * file ownership under hardened mode + * (only lets you touch your own files/dirs) + */ +int +mkhtemp(int *fd, + struct stat *st, + char *template, + int dirfd, + const char *fname, + struct stat *st_dir_initial, + int type) +{ + size_t len = 0; + size_t xc = 0; + size_t fname_len = 0; + + char *fname_copy = NULL; + char *p; + + size_t retries; + + int close_errno; + int saved_errno = errno; + +#if defined(PATH_LEN) && \ + (PATH_LEN) >= 256 + size_t max_len = PATH_LEN; +#else + size_t max_len = 4096; +#endif + int r; + char *end; + + if (if_err(fd == NULL || template == NULL || fname == NULL || + st_dir_initial == NULL, EFAULT) || + if_err(*fd >= 0, EEXIST) || + if_err(dirfd < 0, EBADF) + || + if_err_sys(slen(template, max_len, &len) < 0) || + if_err(len >= max_len, EMSGSIZE) + || + if_err_sys(slen(fname, max_len, &fname_len) < 0) || + if_err(fname == NULL, EINVAL) || + if_err(strrchr(fname, '/') != NULL, EINVAL)) + return -1; + + for (end = template + len; /* count X */ + end > template && *--end == 'X'; xc++); + + if (if_err(xc < 3 || xc > len, EINVAL) || + if_err(fname_len > len, EOVERFLOW)) + return -1; + + if (if_err(memcmp(fname, template + len - fname_len, + fname_len) != 0, EINVAL)) + return -1; + + if((fname_copy = malloc(fname_len + 1)) == NULL) + goto err; + + /* fname_copy = templatestr region only; p points to trailing XXXXXX */ + memcpy(fname_copy, + template + len - fname_len, + fname_len + 1); + p = fname_copy + fname_len - xc; + + for (retries = 0; retries < MKHTEMP_RETRY_MAX; retries++) { + + r = mkhtemp_try_create(dirfd, + st_dir_initial, fname_copy, + p, xc, fd, st, type); + + if (r == 0) + continue; + if (r < 0) + goto err; + + /* success: copy final name back */ + memcpy(template + len - fname_len, + fname_copy, fname_len); + + errno = saved_errno; + goto success; + } + + errno = EEXIST; + +err: + close_no_err(fd); + +success: + free_if_null(&fname_copy); + + return (*fd >= 0) ? *fd : -1; +} + +int +mkhtemp_try_create(int dirfd, + struct stat *st_dir_initial, + char *fname_copy, + char *p, + size_t xc, + int *fd, + struct stat *st, + int type) +{ + struct stat st_open; + int saved_errno = errno; + int rval = -1; + + int file_created = 0; + int dir_created = 0; + + if (if_err(fd == NULL || st == NULL || p ==NULL || fname_copy ==NULL || + st_dir_initial == NULL, EFAULT) || + if_err(*fd >= 0, EEXIST)) + goto err; + + if (if_err_sys(mkhtemp_fill_random(p, xc) < 0) || + if_err_sys(fd_verify_dir_identity(dirfd, st_dir_initial) < 0)) + goto err; + + if (type == MKHTEMP_FILE) { +#ifdef __linux__ + /* try O_TMPFILE fast path */ + if (mkhtemp_tmpfile_linux(dirfd, + st_dir_initial, fname_copy, + p, xc, fd, st) == 0) { + + errno = saved_errno; + rval = 1; + goto out; + } +#endif + + *fd = openat2p(dirfd, fname_copy, + O_RDWR | O_CREAT | O_EXCL | + O_NOFOLLOW | O_CLOEXEC | O_NOCTTY, 0600); + + /* O_CREAT and O_EXCL guarantees creation upon success + */ + if (*fd >= 0) + file_created = 1; + + } else { /* dir: MKHTEMP_DIR */ + + if (mkdirat_on_eintr(dirfd, fname_copy, 0700) < 0) + goto err; + + /* ^ NOTE: opening the directory here + will never set errno=EEXIST, + since we're not creating it */ + + dir_created = 1; + + /* do it again (mitigate directory race) */ + if (fd_verify_dir_identity(dirfd, st_dir_initial) < 0) + goto err; + + if ((*fd = openat2p(dirfd, fname_copy, + O_RDONLY | O_DIRECTORY | O_CLOEXEC, 0)) < 0) + goto err; + + if (if_err_sys(fstat(*fd, &st_open) < 0) || + if_err(!S_ISDIR(st_open.st_mode), ENOTDIR)) + goto err; + + /* NOTE: pointless to check nlink here (only just opened) */ + if (fd_verify_dir_identity(dirfd, st_dir_initial) < 0) + goto err; + + } + + /* NOTE: openat2p and mkdirat_on_eintr + * already handled EINTR/EAGAIN looping + */ + + if (*fd < 0) { + if (errno == EEXIST) { + + rval = 0; + goto out; + } + goto err; + } + + if (fstat(*fd, &st_open) < 0) + goto err; + + if (type == MKHTEMP_FILE) { + + if (fd_verify_dir_identity(dirfd, st_dir_initial) < 0) + goto err; + + if (secure_file(fd, st, &st_open, + O_APPEND, 1, 1, 0600) < 0) /* WARNING: only once */ + goto err; + + } else { /* dir: MKHTEMP_DIR */ + + if (fd_verify_identity(*fd, &st_open, st_dir_initial) < 0) + goto err; + + if (if_err(!S_ISDIR(st_open.st_mode), ENOTDIR) || + if_err_sys(is_owner(&st_open) < 0) || + if_err(st_open.st_mode & (S_IWGRP | S_IWOTH), EPERM)) + goto err; + } + + errno = saved_errno; + rval = 1; + goto out; + +err: + close_no_err(fd); + + if (file_created) + (void) unlinkat(dirfd, fname_copy, 0); + if (dir_created) + (void) unlinkat(dirfd, fname_copy, AT_REMOVEDIR); + + rval = -1; +out: + return rval; +} + +/* linux has its own special hardening + available specifically for tmpfiles, + which eliminates many race conditions. + + we still use openat() on bsd, which is + still ok with our other mitigations + */ +#ifdef __linux__ +int +mkhtemp_tmpfile_linux(int dirfd, + struct stat *st_dir_initial, + char *fname_copy, + char *p, + size_t xc, + int *fd, + struct stat *st) +{ + int saved_errno = errno; + int tmpfd = -1; + size_t retries; + int linked = 0; + + if (fd == NULL || st == NULL || + fname_copy == NULL || p == NULL || + st_dir_initial == NULL) { + errno = EFAULT; + return -1; + } + + /* create unnamed tmpfile */ + tmpfd = openat(dirfd, ".", + O_TMPFILE | O_RDWR | O_CLOEXEC, 0600); + + if (tmpfd < 0) + return -1; + + if (fd_verify_dir_identity(dirfd, st_dir_initial) < 0) + goto err; + + for (retries = 0; retries < MKHTEMP_RETRY_MAX; retries++) { + + if (mkhtemp_fill_random(p, xc) < 0) + goto err; + + if (fd_verify_dir_identity(dirfd, + st_dir_initial) < 0) + goto err; + + if (linkat(tmpfd, "", + dirfd, fname_copy, + AT_EMPTY_PATH) == 0) { + + linked = 1; /* file created */ + + if (fd_verify_dir_identity(dirfd, st_dir_initial) < 0) + goto err; + + /* success */ + *fd = tmpfd; + + if (fstat(*fd, st) < 0) + goto err; + + if (secure_file(fd, st, st, + O_APPEND, 1, 1, 0600) < 0) + goto err; + + errno = saved_errno; + return 0; + } + + if (errno != EEXIST) + goto err; + + /* retry on collision */ + } + + errno = EEXIST; + +err: + if (linked) + (void) unlinkat(dirfd, fname_copy, 0); + + close_no_err(&tmpfd); + return -1; +} +#endif + +int +mkhtemp_fill_random(char *p, size_t xc) +{ + static const char ch[] = + "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; + + unsigned char scratch[64]; + + size_t off = 0; + size_t i; + + /* clamp rand to prevent modulo bias */ + size_t limit = 256 - (256 % (sizeof(ch) - 1)); + + if (if_err(p == NULL, EFAULT)) + return -1; + +retry_rand: + rset(scratch, sizeof(scratch)); + + for (i = 0; i < sizeof(scratch) && off < xc; i++) { + if (scratch[i] < limit) + p[off++] = ch[scratch[i] % (sizeof(ch) - 1)]; + } + + if (off < xc) + goto retry_rand; + + return 0; +} + +/* WARNING: **ONCE** per file. + * + * !!! DO NOT RUN TWICE PER FILE. BEWARE OF THE DEMON !!! + * watch out for spikes! + */ +/* TODO: bad_flags can be negative, and is + * ignored if it is. should we err instead? + */ +int secure_file(int *fd, + struct stat *st, + struct stat *expected, + int bad_flags, + int check_seek, + int do_lock, + mode_t mode) +{ + int flags; + struct stat st_now; + int saved_errno = errno; + + if (if_err(fd == NULL || st == NULL, EFAULT) || + if_err(*fd < 0, EBADF) || + if_err_sys((flags = fcntl(*fd, F_GETFL)) == -1) || + if_err(bad_flags > 0 && (flags & bad_flags), EPERM)) + goto err_demons; + + if (expected != NULL) { + if (fd_verify_regular(*fd, expected, st) < 0) + goto err_demons; + } else if (if_err_sys(fstat(*fd, &st_now) == -1) || + if_err(!S_ISREG(st_now.st_mode), EBADF)) { + goto err_demons; /***********/ + } else /* ( >:3 ) */ + *st = st_now; /* /| |\ */ /* don't let him out */ + /* / \ */ + if (check_seek) { /***********/ + if (lseek(*fd, 0, SEEK_CUR) == (off_t)-1) + goto err_demons; + } /* don't release the demon */ + + if (if_err(st->st_nlink != 1, ELOOP) || + if_err(st->st_uid != geteuid() && geteuid() != 0, EPERM) || + if_err_sys(is_owner(st) < 0) || + if_err(st->st_mode & (S_IWGRP | S_IWOTH), EPERM)) + goto err_demons; + + if (do_lock) { + if (lock_file(*fd, flags) == -1) + goto err_demons; + + if (expected != NULL) + if (fd_verify_identity(*fd, expected, &st_now) < 0) + goto err_demons; + } + + if (fchmod(*fd, mode) == -1) + goto err_demons; + + errno = saved_errno; + return 0; + +err_demons: + + if (errno == saved_errno) + errno = EIO; + + return -1; +} + +int +fd_verify_regular(int fd, + const struct stat *expected, + struct stat *out) +{if ( + if_err_sys(fd_verify_identity(fd, expected, out) < 0) || + if_err(!S_ISREG(out->st_mode), EBADF) + ) return -1; + else + return 0; /* regular file */ +} + +int +fd_verify_identity(int fd, + const struct stat *expected, + struct stat *out) +{ + struct stat st_now; + int saved_errno = errno; + +if( if_err(fd < 0 || expected == NULL, EFAULT) || + if_err_sys(fstat(fd, &st_now)) || + if_err(st_now.st_dev != expected->st_dev || + st_now.st_ino != expected->st_ino, ESTALE)) + return -1; + + if (out != NULL) + *out = st_now; + + errno = saved_errno; + return 0; +} + +int +fd_verify_dir_identity(int fd, + const struct stat *expected) +{ + struct stat st_now; + int saved_errno = errno; + + if (if_err(fd < 0 || expected == NULL, EFAULT) || + if_err_sys(fstat(fd, &st_now) < 0)) + return -1; + + if (st_now.st_dev != expected->st_dev || + st_now.st_ino != expected->st_ino) { + errno = ESTALE; + return -1; + } + + if (!S_ISDIR(st_now.st_mode)) { + errno = ENOTDIR; + return -1; + } + + errno = saved_errno; + return 0; +} + +int +is_owner(struct stat *st) +{ + if (st == NULL) { + + errno = EFAULT; + return -1; + } + +#if ALLOW_ROOT_OVERRIDE + if (st->st_uid != geteuid() && /* someone else's file */ + geteuid() != 0) { /* override for root */ +#else + if (st->st_uid != geteuid()) { /* someone else's file */ +#endif /* and no root override */ + errno = EPERM; + return -1; + } + + return 0; +} + +int +lock_file(int fd, int flags) +{ + struct flock fl; + int saved_errno = errno; + + if (if_err(fd < 0, EBADF) || + if_err(flags < 0, EINVAL)) + goto err_lock_file; + + memset(&fl, 0, sizeof(fl)); + + if ((flags & O_ACCMODE) == O_RDONLY) + fl.l_type = F_RDLCK; + else + fl.l_type = F_WRLCK; + + fl.l_whence = SEEK_SET; + + if (fcntl(fd, F_SETLK, &fl) == -1) + goto err_lock_file; + + saved_errno = errno; + return 0; + +err_lock_file: + + if (errno == saved_errno) + errno = EIO; + + return -1; +} diff --git a/util/libreboot-utils/lib/num.c b/util/libreboot-utils/lib/num.c new file mode 100644 index 00000000..92710c35 --- /dev/null +++ b/util/libreboot-utils/lib/num.c @@ -0,0 +1,119 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2026 Leah Rowe <leah@libreboot.org> + * + * Numerical functions. + * NOTE: randomness was moved to rand.c + */ + +/* +TODO: properly handle errno in this file + */ + +#ifdef __OpenBSD__ +#include <sys/param.h> +#endif +#include <sys/types.h> + +#include <errno.h> +#if !((defined(__OpenBSD__) && (OpenBSD) >= 201) || \ + defined(__FreeBSD__) || \ + defined(__NetBSD__) || defined(__APPLE__)) +#include <fcntl.h> /* if not arc4random: /dev/urandom */ +#endif +#include <limits.h> +#include <stddef.h> +#include <string.h> +#include <unistd.h> + +#include "../include/common.h" + +/* TODO: + * make this and errno handling more + * flexible + + in particular: + hextonum could be modified to + write into a buffer instead, + with the converted numbers, + of an arbitrary length + */ +unsigned short +hextonum(char ch_s) +{ + int saved_errno = errno; + + /* rlong() can return error, + but preserves errno if no + error. we need to detect + this because it handles + /dev/urandom sometimes + + therefore, if it's zero + at start, we know if there + was an err at the end, by + return value zero, if errno + was set; this is technically + valid, since zero is also + a valid random number! + + it's an edge case that i had + to fix. i'll rewrite the code + better later. for now, it + should be ok. + */ + errno = 0; + + unsigned char ch; + size_t rval; + + ch = (unsigned char)ch_s; + + if ((unsigned int)(ch - '0') <= 9) { + + rval = ch - '0'; + goto hextonum_success; + } + + ch |= 0x20; + + if ((unsigned int)(ch - 'a') <= 5) { + + rval = ch - 'a' + 10; + goto hextonum_success; + } + + if (ch == '?' || ch == 'x') { + + rset(&rval, sizeof(rval)); + if (errno > 0) + goto err_hextonum; + + goto hextonum_success; + } + + goto err_hextonum; + +hextonum_success: + + errno = saved_errno; + return (unsigned short)rval & 0xf; + +err_hextonum: + + if (errno == saved_errno) + errno = EINVAL; + else + return 17; /* 17 indicates getrandom/urandom fail */ + + return 16; /* invalid character */ + + /* caller just checks >15. */ +} + +void +check_bin(size_t a, const char *a_name) +{ + if (a > 1) + err_no_cleanup(0, EINVAL, "%s must be 0 or 1, but is %lu", + a_name, (size_t)a); +} diff --git a/util/libreboot-utils/lib/rand.c b/util/libreboot-utils/lib/rand.c new file mode 100644 index 00000000..29a756ed --- /dev/null +++ b/util/libreboot-utils/lib/rand.c @@ -0,0 +1,219 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2026 Leah Rowe <leah@libreboot.org> + * + * Random number generation + */ + +#ifndef RAND_H +#define RAND_H + +#ifdef __OpenBSD__ +#include <sys/param.h> +#endif +#include <sys/types.h> + +#ifndef USE_URANDOM +#define USE_URANDOM 0 +#endif + +#include <errno.h> +#if defined(USE_URANDOM) && \ + ((USE_URANDOM) > 0) +#include <fcntl.h> /* if not arc4random: /dev/urandom */ +#endif + +#include <fcntl.h> +#include <limits.h> +#include <stddef.h> +#include <string.h> +#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <stdint.h> +#include <stdio.h> + +#include "../include/common.h" + +/* Regarding Linux getrandom/urandom: + * + * For maximum security guarantee, we *only* + * use getrandom via syscall, or /dev/urandom; + * use of urandom is ill advised. This is why + * we use the syscall, in case the libc version + * of getrandom() might defer to /dev/urandom + * + * We *abort* on error, for both /dev/urandom + * and getrandom(), because the BSD arc4random + * never returns with error; therefore, for the + * most parity in terms of behaviour, we abort, + * because otherwise the function would have two + * return modes: always successful (BSD), or only + * sometimes (Linux). The BSD arc4random could + * theoretically abort; it is extremely unlikely + * there, and just so on Linux, hence this design. + * + * This is important, because cryptographic code + * for example must not rely on weak randomness. + * We must therefore treat broken randomness as + * though the world is broken, and burn accordingly. + * + * Similarly, any invalid input (NULL, zero bytes + * requested) are treated as fatal errors; again, + * cryptographic code must be reliable. If your + * code erroneously requested zero bytes, you might + * then end up with a non-randomised buffer, where + * you likely intended otherwise. + * + * In other words: call rset() correctly, or your + * program dies, and rset will behave correctly, + * or your program dies. + */ + +#define ELOTTERY ECANCELED + +int +win_lottery(void) +{ + int saved_errno = errno; + size_t size1; + char *s1 = NULL; + size_t size2; + char *s2 = NULL; + size_t pool = BUFSIZ; + int rval; + + rset(&size1, sizeof(size1)); + rset(&size2, sizeof(size2)); + + size1 %= pool, size2 %= pool; + s1 = mkrstr(size1), s2 = mkrstr(size2); + + if (scmp(s1, s2, BUFSIZ + 2, &rval) < 0) + goto err; + if (rval == 0) + goto win; + + free_if_null(&s1), free_if_null(&s2); + + fprintf(stderr, "Sorry, you lose! Try again.\n"); + return 0; +win: + free_if_null(&s1), free_if_null(&s2); + + printf("Congratulations! you won the errno lottery!\n"); + return 1; +err: + /* the lottery won you */ + free_if_null(&s1), free_if_null(&s2); + err_no_cleanup(0, EFAULT, "lottery won you"); + return 0; +} + +char * +mkrstr(size_t n) /* emulates spkmodem-decode */ +{ + char *s; + size_t i; + + if (n == 0) + err_no_cleanup(0, EPERM, "mkrbuf: zero-byte request"); + + if (n == SIZE_MAX) + err_no_cleanup(0, EOVERFLOW, "mkrbuf: overflow"); + + if (if_err((s = mkrbuf(n + 1)) == NULL, EFAULT)) + err_no_cleanup(0, EFAULT, "mkrstr: null"); + + for (i = 0; i < n; i++) + while(*(s + i) == '\0') + rset(s + i, 1); + + *(s + n) = '\0'; + + return s; +} + +void * +mkrbuf(size_t n) +{ + void *buf; + + if (n == 0) + err_no_cleanup(0, EPERM, "mkrbuf: zero-byte request"); + + if ((buf = malloc(n)) == NULL) + err_no_cleanup(0, ENOMEM, "mkrbuf: malloc"); + + rset(buf, n); + return buf; /* basically malloc() but with rand */ +} + +void +rset(void *buf, size_t n) +{ + int saved_errno = errno; + + if (if_err(buf == NULL, EFAULT)) + goto err; + + if (n == 0) + err_no_cleanup(0, EPERM, "rset: zero-byte request"); + +#if (defined(__OpenBSD__) || defined(__FreeBSD__) || \ + defined(__NetBSD__) || defined(__APPLE__) || \ + defined(__DragonFly__)) && !(defined(USE_URANDOM) && \ + ((USE_URANDOM) > 0)) + + arc4random_buf(buf, n); + goto out; +#else + size_t off = 0; + ssize_t rc = 0; + +#if defined(USE_URANDOM) && \ + ((USE_URANDOM) > 0) + int fd = -1; + + if ((fd = open("/dev/urandom", O_RDONLY)) < 0) + goto err; +retry_rand: + if ((rc = read(fd, (unsigned char *)buf + off, n - off)) < 0) { +#elif defined(__linux__) +retry_rand: + if ((rc = (ssize_t)syscall(SYS_getrandom, + (unsigned char *)buf + off, n - off, 0)) < 0) { +#else +#error Unsupported operating system (possibly unsecure randomisation) +#endif + if (errno == EINTR || + errno == EAGAIN) + goto retry_rand; + + goto err; /* possibly unsupported by kernel */ + } + + if (rc == 0) + goto err; /* prevent infinite loop on fatal err */ + + if ((off += (size_t)rc) < n) + goto retry_rand; + +#if defined(USE_URANDOM) && \ + ((USE_URANDOM) > 0) + close_no_err(&fd); +#endif + goto out; +#endif +out: + errno = saved_errno; + return; +err: +#if defined(USE_URANDOM) && \ + ((USE_URANDOM) > 0) + close_no_err(&fd); +#endif + err_no_cleanup(0, ECANCELED, + "Randomisation failure, possibly unsupported in your kernel"); + exit(EXIT_FAILURE); +} +#endif diff --git a/util/libreboot-utils/lib/state.c b/util/libreboot-utils/lib/state.c new file mode 100644 index 00000000..42d060b7 --- /dev/null +++ b/util/libreboot-utils/lib/state.c @@ -0,0 +1,233 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2022-2026 Leah Rowe <leah@libreboot.org> + * + * State machine (singleton) for nvmutil data. + */ + +#ifdef __OpenBSD__ +#include <sys/param.h> +#endif +#include <sys/types.h> +#include <sys/stat.h> + +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <stdarg.h> +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include "../include/common.h" + +struct xstate * +xstart(int argc, char *argv[]) +{ + static int first_run = 1; + static char *dir = NULL; + static char *base = NULL; + char *realdir = NULL; + char *tmpdir = NULL; + char *tmpbase_local = NULL; + + static struct xstate us = { + { + /* be careful when modifying xstate. you + * must set everything precisely */ + { + CMD_DUMP, "dump", cmd_helper_dump, ARGC_3, + ARG_NOPART, + SKIP_CHECKSUM_READ, SKIP_CHECKSUM_WRITE, + NVM_SIZE, O_RDONLY + }, { + CMD_SETMAC, "setmac", cmd_helper_setmac, ARGC_3, + ARG_NOPART, + CHECKSUM_READ, CHECKSUM_WRITE, + NVM_SIZE, O_RDWR + }, { + CMD_SWAP, "swap", cmd_helper_swap, ARGC_3, + ARG_NOPART, + CHECKSUM_READ, SKIP_CHECKSUM_WRITE, + GBE_PART_SIZE, O_RDWR + }, { + CMD_COPY, "copy", cmd_helper_copy, ARGC_4, + ARG_PART, + CHECKSUM_READ, SKIP_CHECKSUM_WRITE, + GBE_PART_SIZE, O_RDWR + }, { + CMD_CAT, "cat", cmd_helper_cat, ARGC_3, + ARG_NOPART, + CHECKSUM_READ, SKIP_CHECKSUM_WRITE, + GBE_PART_SIZE, O_RDONLY + }, { + CMD_CAT16, "cat16", cmd_helper_cat16, ARGC_3, + ARG_NOPART, + CHECKSUM_READ, SKIP_CHECKSUM_WRITE, + GBE_PART_SIZE, O_RDONLY + }, { + CMD_CAT128, "cat128", cmd_helper_cat128, ARGC_3, + ARG_NOPART, + CHECKSUM_READ, SKIP_CHECKSUM_WRITE, + GBE_PART_SIZE, O_RDONLY + } + }, + + /* ->mac */ + {NULL, "xx:xx:xx:xx:xx:xx", {0, 0, 0}}, /* .str, .rmac, .mac_buf */ + + /* .f */ + {0}, + + /* .argv0 (for our getprogname implementation) */ + NULL, + + /* ->i (index to cmd[]) */ + 0, + + /* .no_cmd (set 0 when a command is found) */ + 1, + + /* .cat (cat helpers set this) */ + -1 + + }; + + if (!first_run) + return &us; + + if (argc < 3) + err_no_cleanup(0, EINVAL, "xstart: Too few arguments"); + if (argv == NULL) + err_no_cleanup(0, EINVAL, "xstart: NULL argv"); + + first_run = 0; + + us.f.buf = us.f.real_buf; + + us.argv0 = argv[0]; + us.f.fname = argv[1]; + + us.f.tmp_fd = -1; + us.f.tname = NULL; + + if ((realdir = realpath(us.f.fname, NULL)) == NULL) + err_no_cleanup(0, errno, "xstart: can't get realpath of %s", + us.f.fname); + + if (fs_dirname_basename(realdir, &dir, &base, 0) < 0) + err_no_cleanup(0, errno, "xstart: don't know CWD of %s", + us.f.fname); + + if ((us.f.base = strdup(base)) == NULL) + err_no_cleanup(0, errno, "strdup base"); + + us.f.dirfd = fs_open(dir, + O_RDONLY | O_DIRECTORY); + if (us.f.dirfd < 0) + err_no_cleanup(0, errno, "%s: open dir", dir); + + if (new_tmpfile(&us.f.tmp_fd, &us.f.tname, dir, ".gbe.XXXXXXXXXX") < 0) + err_no_cleanup(0, errno, "%s", us.f.tname); + + if (fs_dirname_basename(us.f.tname, + &tmpdir, &tmpbase_local, 0) < 0) + err_no_cleanup(0, errno, "tmp basename"); + + us.f.tmpbase = strdup(tmpbase_local); + if (us.f.tmpbase == NULL) + err_no_cleanup(0, errno, "strdup tmpbase"); + + free_if_null(&tmpdir); + + if (us.f.tname == NULL) + err_no_cleanup(0, errno, "x->f.tname null"); + if (*us.f.tname == '\0') + err_no_cleanup(0, errno, "x->f.tname empty"); + + if (fstat(us.f.tmp_fd, &us.f.tmp_st) < 0) + err_no_cleanup(0, errno, "%s: stat", us.f.tname); + + memset(us.f.real_buf, 0, sizeof(us.f.real_buf)); + memset(us.f.bufcmp, 0, sizeof(us.f.bufcmp)); + + /* for good measure */ + memset(us.f.pad, 0, sizeof(us.f.pad)); + + return &us; +} + +struct xstate * +xstatus(void) +{ + struct xstate *x = xstart(0, NULL); + + if (x == NULL) + err_no_cleanup(0, EACCES, "NULL pointer to xstate"); + + return x; +} + +void +b0rk(int nvm_errval, const char *msg, ...) +{ + struct xstate *x = xstatus(); + + va_list args; + + if (errno == 0) + errno = nvm_errval; + if (!errno) + errno = ECANCELED; + + (void)exit_cleanup(); + + if (x != NULL) + fprintf(stderr, "%s: ", getnvmprogname()); + + va_start(args, msg); + vfprintf(stderr, msg, args); + va_end(args); + + fprintf(stderr, ": %s\n", strerror(errno)); + + exit(EXIT_FAILURE); +} + +int +exit_cleanup(void) +{ + struct xstate *x = xstatus(); + struct xfile *f; + + int close_err; + int saved_errno; + + close_err = 0; + saved_errno = errno; + + if (x != NULL) { + f = &x->f; + + close_no_err(&f->gbe_fd); + close_no_err(&f->tmp_fd); + close_no_err(&f->tmp_fd); + + if (f->tname != NULL) + if (unlink(f->tname) == -1) + close_err = 1; + + close_no_err(&f->dirfd); + free_if_null(&f->base); + free_if_null(&f->tmpbase); + } + + if (saved_errno) + errno = saved_errno; + + if (close_err) + return -1; + + return 0; +} diff --git a/util/libreboot-utils/lib/string.c b/util/libreboot-utils/lib/string.c new file mode 100644 index 00000000..0329c6c3 --- /dev/null +++ b/util/libreboot-utils/lib/string.c @@ -0,0 +1,284 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2026 Leah Rowe <leah@libreboot.org> + * + * String functions + */ + +#include <sys/types.h> +#include <sys/stat.h> + +#include <errno.h> +#include <stdarg.h> +#include <stddef.h> +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> +#include <limits.h> +#include <stdint.h> + +#include "../include/common.h" + +/* strict strcmp */ +int +scmp(const char *a, + const char *b, + size_t maxlen, + int *rval) +{ + size_t ch; + unsigned char ac; + unsigned char bc; + + if (a == NULL || + b == NULL || + rval == NULL) { + errno = EFAULT; + goto err; + } + + for (ch = 0; ch < maxlen; ch++) { + + ac = (unsigned char)a[ch]; + bc = (unsigned char)b[ch]; + + if (ac != bc) { + *rval = ac - bc; + return 0; + } + + if (ac == '\0') { + *rval = 0; + return 0; + } + } + +err: + errno = EFAULT; + if (rval != NULL) + *rval = -1; + return -1; +} + +/* strict strlen */ +int +slen(const char *s, + size_t maxlen, + size_t *rval) +{ + size_t ch; + + if (s == NULL || + rval == NULL) { + errno = EFAULT; + goto err; + } + + for (ch = 0; + ch < maxlen && s[ch] != '\0'; + ch++); + + if (ch == maxlen) { + /* unterminated */ + errno = EFAULT; + goto err; + } + + *rval = ch; + return 0; +err: + if (rval != NULL) + *rval = 0; + return -1; +} + +/* strict strdup */ +int +sdup(const char *s, + size_t n, char **dest) +{ + size_t size; + char *rval; + + if (dest == NULL || + slen(s, n, &size) < 0 || + if_err(size == SIZE_MAX, EOVERFLOW) || + (rval = malloc(size + 1)) == NULL) { + + if (dest != NULL) + *dest = NULL; + return -1; + } + + memcpy(rval, s, size); + *(rval + size) = '\0'; + + *dest = rval; + return 0; +} + +/* strict strcat */ +int +scat(const char *s1, const char *s2, + size_t n, char **dest) +{ + size_t size1; + size_t size2; + char *rval; + + if (dest == NULL || + slen(s1, n, &size1) < 0 || + slen(s2, n, &size2) < 0 || + if_err(size1 > SIZE_MAX - size2 - 1, EOVERFLOW) || + (rval = malloc(size1 + size2 + 1)) == NULL) { + + if (dest != NULL) + *dest = NULL; + return -1; + } + + memcpy(rval, s1, size1); + memcpy(rval + size1, s2, size2); + *(rval + size1 + size2) = '\0'; + + *dest = rval; + return 0; +} + +/* strict split/de-cat - off is where + 2nd buffer will start from */ +int +dcat(const char *s, size_t n, + size_t off, char **dest1, + char **dest2) +{ + size_t size; + char *rval1 = NULL; + char *rval2 = NULL; + + if (dest1 == NULL || dest2 == NULL || + slen(s, n, &size) < 0 || + if_err(size == SIZE_MAX, EOVERFLOW) || + if_err(off >= size, EOVERFLOW) || + (rval1 = malloc(off + 1)) == NULL || + (rval2 = malloc(size - off + 1)) == NULL) { + + goto err; + } + + memcpy(rval1, s, off); + *(rval1 + off) = '\0'; + + memcpy(rval2, s + off, size - off); + *(rval2 + size - off) = '\0'; + + *dest1 = rval1; + *dest2 = rval2; + + return 0; + +err: + if (rval1 != NULL) + free(rval1); + if (rval2 != NULL) + free(rval2); + + if (dest1 != NULL) + *dest1 = NULL; + if (dest2 != NULL) + *dest2 = NULL; + + return -1; +} + +/* the one for nvmutil state is in state.c */ +/* this one just exits */ +void +err_no_cleanup(int stfu, int nvm_errval, const char *msg, ...) +{ + va_list args; + int saved_errno = errno; + const char *p; + +#if defined(__OpenBSD__) && defined(OpenBSD) +#if (OpenBSD) >= 509 + if (pledge("stdio", NULL) == -1) + fprintf(stderr, "pledge failure during exit"); +#endif +#endif + if (!errno) + saved_errno = errno = ECANCELED; + + if ((p = getnvmprogname()) != NULL) + fprintf(stderr, "%s: ", p); + + va_start(args, msg); + vfprintf(stderr, msg, args); + va_end(args); + + if (p != NULL) + fprintf(stderr, ": %s\n", strerror(errno)); + else + fprintf(stderr, "%s\n", strerror(errno)); + + exit(EXIT_FAILURE); +} + +const char * +getnvmprogname(void) +{ + static char *rval = NULL; + static char *p; + static int setname = 0; + + if (!setname) { + if ((rval = lbgetprogname(NULL)) == NULL) + return NULL; + + p = strrchr(rval, '/'); + if (p) + rval = p + 1; + + setname = 1; + } + + return rval; +} + +/* singleton. if string not null, + sets the string. after set, + will not set anymore. either + way, returns the string + */ +char * +lbgetprogname(char *argv0) +{ + static int setname = 0; + static char *progname = NULL; + size_t len; + + if (!setname) { + if (if_err(argv0 == NULL || *argv0 == '\0', EFAULT) || + slen(argv0, 4096, &len) < 0 || + (progname = malloc(len + 1)) == NULL) + return NULL; + + memcpy(progname, argv0, len + 1); + setname = 1; + } + + return progname; +} + + + + + + + + + + + + + diff --git a/util/libreboot-utils/lib/usage.c b/util/libreboot-utils/lib/usage.c new file mode 100644 index 00000000..2b5a93ca --- /dev/null +++ b/util/libreboot-utils/lib/usage.c @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2023 Riku Viitanen <riku.viitanen@protonmail.com> + * Copyright (c) 2026 Leah Rowe <leah@libreboot.org> + */ + +#include <errno.h> +#include <stdio.h> + +#include "../include/common.h" + +void +usage(void) +{ + const char *util = getnvmprogname(); + + fprintf(stderr, + "Modify Intel GbE NVM images e.g. set MAC\n" + "USAGE:\n" + "\t%s FILE dump\n" + "\t%s FILE setmac [MAC]\n" + "\t%s FILE swap\n" + "\t%s FILE copy 0|1\n" + "\t%s FILE cat\n" + "\t%s FILE cat16\n" + "\t%s FILE cat128\n", + util, util, util, util, + util, util, util); + + b0rk(EINVAL, "Too few arguments"); +} diff --git a/util/libreboot-utils/lib/word.c b/util/libreboot-utils/lib/word.c new file mode 100644 index 00000000..6563e67a --- /dev/null +++ b/util/libreboot-utils/lib/word.c @@ -0,0 +1,68 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2022-2026 Leah Rowe <leah@libreboot.org> + * + * Manipulate Intel GbE NVM words, which are 16-bit little + * endian in the files (MAC address words are big endian). + */ + +#include <sys/types.h> + +#include <errno.h> +#include <stddef.h> + +#include "../include/common.h" + +unsigned short +nvm_word(size_t pos16, size_t p) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + size_t pos; + + check_nvm_bound(pos16, p); + pos = (pos16 << 1) + (p * GBE_PART_SIZE); + + return (unsigned short)f->buf[pos] | + ((unsigned short)f->buf[pos + 1] << 8); +} + +void +set_nvm_word(size_t pos16, size_t p, unsigned short val16) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + size_t pos; + + check_nvm_bound(pos16, p); + pos = (pos16 << 1) + (p * GBE_PART_SIZE); + + f->buf[pos] = (unsigned char)(val16 & 0xff); + f->buf[pos + 1] = (unsigned char)(val16 >> 8); + + set_part_modified(p); +} + +void +set_part_modified(size_t p) +{ + struct xstate *x = xstatus(); + struct xfile *f = &x->f; + + check_bin(p, "part number"); + f->part_modified[p] = 1; +} + +void +check_nvm_bound(size_t c, size_t p) +{ + /* Block out of bound NVM access + */ + + check_bin(p, "part number"); + + if (c >= NVM_WORDS) + b0rk(ECANCELED, "check_nvm_bound: out of bounds %lu", + (size_t)c); +} diff --git a/util/libreboot-utils/lottery.c b/util/libreboot-utils/lottery.c new file mode 100644 index 00000000..f673a109 --- /dev/null +++ b/util/libreboot-utils/lottery.c @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2026 Leah Rowe <leah@libreboot.org> + */ + +#ifdef __OpenBSD__ +#include <sys/param.h> /* pledge(2) */ +#endif + +#include <stdio.h> +#include "include/common.h" + +int +main(int argc, char *argv[]) +{ +#if defined(__OpenBSD__) && defined(OpenBSD) +#if (OpenBSD) >= 509 + if (pledge("stdio", NULL) == -1) + err_no_cleanup(0, errno, "openbsd won it"); +#endif +#endif + + if (win_lottery()) { + printf("You won!"); + return 0; + } + + return 1; +}/* + + + ( >:3 ) + /| |\ + / \ + + + + + + */ + + + + + + + + + + + + diff --git a/util/libreboot-utils/mkhtemp.c b/util/libreboot-utils/mkhtemp.c new file mode 100644 index 00000000..261227cb --- /dev/null +++ b/util/libreboot-utils/mkhtemp.c @@ -0,0 +1,211 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2026 Leah Rowe <leah@libreboot.org> + * + * WORK IN PROGRESS (proof of concept), or, v0.0000001 + * + * Mkhtemp - Hardened mktemp. Create files and directories + * randomly as determined by user's TMPDIR, or fallback. It + * attemps to provide mitigation against several TOCTOU-based + * attacks e.g. directory rename / symlink attacks, and it + * generally provides much higher strictness than previous + * implementations such as mktemp, mkstemp or even mkdtemp. + * + * It uses several modern features by default, e.g. openat2 + * and O_TMPFILE on Linux, with additional hardening; BSD + * projects only have openat so the code uses that there. + * + * Many programs rely on mktemp, and they use TMPDIR in a way + * that is quite insecure. Mkhtemp intends to change that, + * quite dramatically, with: userspace sandbox (and use OS + * level options e.g. OBSD pledge where available), constant + * identity/ownership checks on files, MUCH stricter ownership + * restrictions (e.g. enforce sticky bit policy on world- + * writeable tmpdirs), preventing operation on other people's + * files (only your own files) - even root is restricted, + * depending on how the code is compiled. Please read the code. + * + * This is the utility version, which makes use of the also- + * included library. No docs yet - source code are the docs, + * and the (ever evolving, and hardening) specification. + * + * This was written from scratch, for use in nvmutil, and + * it is designed to be portable (BSD, Linux). Patches + * very much welcome. + * + * WARNING: This is MUCH stricter than every other mktemp + * implementation, even more so than mkdtemp or + * the OpenBSD version of mkstemp. It *will* break, + * or more specifically, reveal the flaws in, almost + * every major critical infrastructure, because most + * people already use mktemp extremely insecurely. + * + * This tool is written by me, for me, and also Libreboot, but + * it will be summitted for review to various Linux distros + * and BSD projects once it has reached maturity. + */ + +#if defined(__linux__) && !defined(_GNU_SOURCE) +/* for openat2 on linux */ +#define _GNU_SOURCE 1 +#endif + +#ifdef __OpenBSD__ +#include <sys/param.h> /* pledge(2) */ +#endif + +#include <sys/types.h> +#include <sys/stat.h> + +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <stdarg.h> +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include "include/common.h" + +int +main(int argc, char *argv[]) +{ +#if defined (PATH_LEN) && \ + (PATH_LEN) >= 256 + size_t maxlen = PATH_LEN; +#else + size_t maxlen = 4096; +#endif + size_t len; + size_t tlen; + size_t xc = 0; + + char *tmpdir = NULL; + char *template = NULL; + char *p; + char *s = NULL; + char *rp; + char resolved[maxlen]; + char c; + + int fd = -1; + int type = MKHTEMP_FILE; + int stfu = 0; /* -q option */ + + if (lbgetprogname(argv[0]) == NULL) + err_no_cleanup(stfu, errno, "could not set progname"); + +/* https://man.openbsd.org/pledge.2 */ +#if defined(__OpenBSD__) && defined(OpenBSD) +#if (OpenBSD) >= 509 + if (pledge("stdio flock rpath wpath cpath", NULL) == -1) + goto err_usage; +#endif +#endif + + while ((c = + getopt(argc, argv, "qdp:")) != -1) { + + switch (c) { + case 'd': + type = MKHTEMP_DIR; + break; + + case 'p': + tmpdir = optarg; + break; + + case 'q': /* don't print errors */ + /* (exit status unchanged) */ + stfu = 1; + break; + + default: + goto err_usage; + } + } + + if (optind < argc) + template = argv[optind]; + if (optind + 1 < argc) + goto err_usage; + + /* custom template e.g. foo.XXXXXXXXXXXXXXXXXXXXX */ + if (template != NULL) { + if (slen(template, maxlen, &tlen) < 0) + err_no_cleanup(stfu, EINVAL, + "invalid template"); + + for (p = template + tlen; + p > template && *--p == 'X'; xc++); + + if (xc < 3) /* the gnu mktemp errs on less than 3 */ + err_no_cleanup(stfu, EINVAL, + "template must have 3 X or more on end (12+ advised"); + } + + /* user supplied -p PATH - WARNING: + * this permits symlinks, but only here, + * not in the library, so they are resolved + * here first, and *only here*. the mkhtemp + * library blocks them. be careful + * when using -p + */ + if (tmpdir != NULL) { + rp = realpath(tmpdir, resolved); + if (rp == NULL) + err_no_cleanup(stfu, errno, "%s", tmpdir); + + tmpdir = resolved; + } + + if (new_tmp_common(&fd, &s, type, + tmpdir, template) < 0) + err_no_cleanup(stfu, errno, "%s", s); + +#if defined(__OpenBSD__) && defined(OpenBSD) +#if (OpenBSD) >= 509 + if (pledge("stdio", NULL) == -1) + err_no_cleanup(stfu, errno, "pledge, exit"); +#endif +#endif + + if (s == NULL) + err_no_cleanup(stfu, EFAULT, "bad string initialisation"); + if (*s == '\0') + err_no_cleanup(stfu, EFAULT, "empty string initialisation"); + if (slen(s, maxlen, &len) < 0) + err_no_cleanup(stfu, EFAULT, "unterminated string initialisiert"); + + printf("%s\n", s); + + return EXIT_SUCCESS; + +err_usage: + err_no_cleanup(stfu, EINVAL, + "usage: %s [-d] [-p dir] [template]\n", getnvmprogname()); +}/* + + + ( >:3 ) + /| |\ + / \ + + + + + + */ + + + + + + + + + + + + diff --git a/util/libreboot-utils/nvmutil.c b/util/libreboot-utils/nvmutil.c new file mode 100644 index 00000000..313390c0 --- /dev/null +++ b/util/libreboot-utils/nvmutil.c @@ -0,0 +1,138 @@ +/* SPDX-License-Identifier: MIT + * Copyright (c) 2022-2026 Leah Rowe <leah@libreboot.org> + * + * This tool lets you modify Intel GbE NVM (Gigabit Ethernet + * Non-Volatile Memory) images, e.g. change the MAC address. + * These images configure your Intel Gigabit Ethernet adapter. + */ + +#ifdef __OpenBSD__ +/* for pledge/unveil test: + */ +#include <sys/param.h> +#endif + +#include <sys/types.h> +#include <sys/stat.h> + +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "include/common.h" + +int +main(int argc, char *argv[]) +{ + struct xstate *x; + + struct commands *cmd; + struct xfile *f; + + size_t c; + + if (lbgetprogname(argv[0]) == NULL) + err_no_cleanup(0, errno, "could not set progname"); + +/* https://man.openbsd.org/pledge.2 + https://man.openbsd.org/unveil.2 */ +#if defined(__OpenBSD__) && defined(OpenBSD) +#if (OpenBSD) >= 604 + if (pledge("stdio flock rpath wpath cpath unveil", NULL) == -1) + err_no_cleanup(0, errno, "pledge plus unveil, main"); +#if defined(USE_URANDOM) && \ + ((USE_URANDOM) > 0) + if (unveil("/dev/null", "r") == -1) + err_no_cleanup(0, errno, "unveil r: /dev/null"); +#else + if (unveil("/dev/urandom", "r") == -1) + err_no_cleanup(0, errno, "unveil r: /dev/urandom"); +#endif +#elif (OpenBSD) >= 509 + if (pledge("stdio flock rpath wpath cpath", NULL) == -1) + err_no_cleanup(0, errno, "pledge, main"); +#endif +#endif + +#ifndef S_ISREG + err_no_cleanup(0, ECANCELED, + "Can't determine file types (S_ISREG undefined)"); +#endif +#if ((CHAR_BIT) != 8) + err_no_cleanup(0, ECANCELED, "Unsupported char size"); +#endif + + x = xstart(argc, argv); + + if (x == NULL) + err_no_cleanup(0, ECANCELED, "NULL state on init"); + + /* parse user command */ +/* TODO: CHECK ACCESSES VIA xstatus() */ + set_cmd(argc, argv); + set_cmd_args(argc, argv); + + cmd = &x->cmd[x->i]; + f = &x->f; + +/* https://man.openbsd.org/pledge.2 + https://man.openbsd.org/unveil.2 */ +#if defined(__OpenBSD__) && defined(OpenBSD) +#if (OpenBSD) >= 604 + + if ((us.cmd[i].flags & O_ACCMODE) == O_RDONLY) { + if (unveil(us.f.fname, "r") == -1) + b0rk(errno, "%s: unveil r", us.f.fname); + } else { + if (unveil(us.f.fname, "rwc") == -1) + b0rk(errno, "%s: unveil rw", us.f.fname); + } + + if (unveil(us.f.tname, "rwc") == -1) + b0rk(errno, "unveil rwc: %s", us.f.tname); + + if (unveil(NULL, NULL) == -1) + b0rk(errno, "unveil block (rw)"); + + if (pledge("stdio flock rpath wpath cpath", NULL) == -1) + b0rk(errno, "pledge (kill unveil)"); + +#elif (OpenBSD) >= 509 + if (pledge("stdio flock rpath wpath cpath", NULL) == -1) + b0rk(errno, "pledge"); +#endif +#endif + + if (cmd->run == NULL) + b0rk(errno, "Command not set"); + + + sanitize_command_list(); + + open_gbe_file(); + + copy_gbe(); + read_checksums(); + + cmd->run(); + + for (c = 0; c < items(x->cmd); c++) + x->cmd[c].run = cmd_helper_err; + + if ((cmd->flags & O_ACCMODE) == O_RDWR) + write_to_gbe_bin(); + + if (exit_cleanup() == -1) + b0rk(EIO, "%s: close", f->fname); + + if (f->io_err_gbe_bin) + b0rk(EIO, "%s: error writing final file"); + + free_if_null(&f->tname); + + return EXIT_SUCCESS; +} |