summaryrefslogtreecommitdiff
path: root/util/nvmutil
diff options
context:
space:
mode:
Diffstat (limited to 'util/nvmutil')
-rw-r--r--util/nvmutil/.gitignore7
-rw-r--r--util/nvmutil/AUTHORS2
-rw-r--r--util/nvmutil/COPYING21
-rw-r--r--util/nvmutil/ChangeLog.md8
-rw-r--r--util/nvmutil/Makefile24
-rw-r--r--util/nvmutil/README.md4
-rw-r--r--util/nvmutil/nvmutil.c725
7 files changed, 791 insertions, 0 deletions
diff --git a/util/nvmutil/.gitignore b/util/nvmutil/.gitignore
new file mode 100644
index 00000000..fbfbd130
--- /dev/null
+++ b/util/nvmutil/.gitignore
@@ -0,0 +1,7 @@
+/nvm
+/nvmutil
+/mkhtemp
+/lottery
+*.bin
+*.o
+*.d
diff --git a/util/nvmutil/AUTHORS b/util/nvmutil/AUTHORS
new file mode 100644
index 00000000..f38ea210
--- /dev/null
+++ b/util/nvmutil/AUTHORS
@@ -0,0 +1,2 @@
+Leah Rowe
+Riku Viitanen
diff --git a/util/nvmutil/COPYING b/util/nvmutil/COPYING
new file mode 100644
index 00000000..a6ecf266
--- /dev/null
+++ b/util/nvmutil/COPYING
@@ -0,0 +1,21 @@
+Copyright (C) 2022-2025 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/nvmutil/ChangeLog.md b/util/nvmutil/ChangeLog.md
new file mode 100644
index 00000000..e1ed5754
--- /dev/null
+++ b/util/nvmutil/ChangeLog.md
@@ -0,0 +1,8 @@
+This change log has moved. Please refer here for historical pre-osboot-merge
+changes:
+
+<https://libreboot.org/docs/install/nvmutilimport.html>
+
+Osboot merged with Libreboot on November 17th, 2022. For nvmutil changes after
+this date, please check regular Libreboot release announcements which shall
+now specify any such changes.
diff --git a/util/nvmutil/Makefile b/util/nvmutil/Makefile
new file mode 100644
index 00000000..7c7411f9
--- /dev/null
+++ b/util/nvmutil/Makefile
@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: MIT
+# SPDX-FileCopyrightText: 2022,2025 Leah Rowe <leah@libreboot.org>
+# SPDX-FileCopyrightText: 2023 Riku Viitanen <riku.viitanen@protonmail.com>
+
+CC?=cc
+CFLAGS?=-Os -Wall -Wextra -Werror -pedantic
+DESTDIR?=
+PREFIX?=/usr/local
+INSTALL?=install
+
+nvmutil: nvmutil.c
+ $(CC) $(CFLAGS) nvmutil.c -o nvmutil
+
+install:
+ $(INSTALL) nvmutil $(DESTDIR)$(PREFIX)/bin/nvmutil
+
+uninstall:
+ rm -f $(DESTDIR)$(PREFIX)/bin/nvmutil
+
+distclean:
+ rm -f nvmutil
+
+clean:
+ rm -f nvmutil
diff --git a/util/nvmutil/README.md b/util/nvmutil/README.md
new file mode 100644
index 00000000..03a25bc4
--- /dev/null
+++ b/util/nvmutil/README.md
@@ -0,0 +1,4 @@
+
+This documentation has become part of lbwww. See:
+
+<https://libreboot.org/docs/install/nvmutil.html>
diff --git a/util/nvmutil/nvmutil.c b/util/nvmutil/nvmutil.c
new file mode 100644
index 00000000..1f211d6c
--- /dev/null
+++ b/util/nvmutil/nvmutil.c
@@ -0,0 +1,725 @@
+/* SPDX-License-Identifier: MIT */
+/* Copyright (c) 2022-2025 Leah Rowe <leah@libreboot.org> */
+/* Copyright (c) 2023 Riku Viitanen <riku.viitanen@protonmail.com> */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <err.h>
+#include <errno.h>
+#include <fcntl.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>
+
+void cmd_setchecksum(void), cmd_brick(void), swap(int partnum), writeGbe(void),
+ cmd_dump(void), cmd_setmac(void), readGbe(void),
+ macf(int partnum), hexdump(int partnum), openFiles(const char *path),
+ cmd_copy(void), parseMacString(const char *strMac, uint16_t *mac),
+ cmd_swap(void), xclose(int *fd);
+int goodChecksum(int partnum), open_on_eintr(const char *pathname, int flags),
+ fs_retry(int saved_errno, int rval),
+ rw_retry(int saved_errno, ssize_t rval), if_err(int condition, int errval),
+ if_err_sys(int condition);
+ssize_t rw_exact(int fd, unsigned char *mem, size_t nrw,
+ off_t off, int rw_type);
+ssize_t rw(int fd, void *mem, size_t nrw,
+ off_t off, int rw_type);
+int io_args(int fd, void *mem, size_t nrw,
+ off_t off, int rw_type);
+int with_fallback_errno(int fallback);
+ssize_t rw_over_nrw(ssize_t r, size_t nrw);
+uint8_t hextonum(char chs), rhex(void);
+
+#define COMMAND argv[2]
+#define MAC_ADDRESS argv[3]
+#define PARTN argv[3]
+#define NVM_CHECKSUM 0xBABA
+#define NVM_CHECKSUM_WORD 0x3F
+#define NVM_SIZE 128
+
+#define SIZE_4KB 0x1000
+#define SIZE_8KB 0x2000
+#define SIZE_16KB 0x4000
+#define SIZE_128KB 0x20000
+
+#define IO_READ 0
+#define IO_WRITE 1
+#define IO_PREAD 2
+#define IO_PWRITE 3
+
+uint16_t mac[3] = {0, 0, 0};
+ssize_t nf;
+size_t partsize, gbe[2];
+uint8_t nvmPartChanged[2] = {0, 0}, do_read[2] = {1, 1};
+int flags, rfd, fd, part;
+
+const char *strMac = NULL, *strRMac = "xx:xx:xx:xx:xx:xx", *filename = NULL;
+
+typedef struct op {
+ char *str;
+ void (*cmd)(void);
+ int args;
+} op_t;
+op_t op[] = {
+{ .str = "dump", .cmd = cmd_dump, .args = 3},
+{ .str = "setmac", .cmd = cmd_setmac, .args = 3},
+{ .str = "swap", .cmd = cmd_swap, .args = 3},
+{ .str = "copy", .cmd = cmd_copy, .args = 4},
+{ .str = "brick", .cmd = cmd_brick, .args = 4},
+{ .str = "setchecksum", .cmd = cmd_setchecksum, .args = 4},
+};
+void (*cmd)(void) = NULL;
+
+#define err_if(x) if (x) err(EXIT_FAILURE, "%s", filename)
+
+#define xopen(f,l,p) \
+ do { \
+ if ((f = open_on_eintr(l, p)) == -1) \
+ err(EXIT_FAILURE, "%s", l); \
+ if (fstat(f, &st) == -1) \
+ err(EXIT_FAILURE, "%s", l); \
+ } while(0)
+
+#define word(pos16, partnum) ((uint16_t *) gbe[partnum])[pos16]
+#define setWord(pos16, p, val16) if (word(pos16, p) != val16) \
+ nvmPartChanged[p] = 1 | (word(pos16, p) = val16)
+
+#define SUCCESS(x) ((x) >= 0)
+
+#define reset_caller_errno(return_value) \
+ do { \
+ if (SUCCESS(return_value) && (!errno)) \
+ errno = saved_errno; \
+ } while (0)
+
+int
+main(int argc, char *argv[])
+{
+#ifdef __OpenBSD__
+ err_if(pledge("stdio rpath wpath unveil", NULL) == -1);
+#endif
+
+ if (argc < 2) {
+#ifdef __OpenBSD__
+ err_if(pledge("stdio", NULL) == -1);
+#endif
+ fprintf(stderr, "Modify Intel GbE NVM images e.g. set MAC\n");
+ fprintf(stderr, "USAGE:\n");
+ fprintf(stderr, " %s FILE dump\n", argv[0]);
+ fprintf(stderr, " %s FILE\n # same as setmac without arg\n",
+ argv[0]);
+ fprintf(stderr, " %s FILE setmac [MAC]\n", argv[0]);
+ fprintf(stderr, " %s FILE swap\n", argv[0]);
+ fprintf(stderr, " %s FILE copy 0|1\n", argv[0]);
+ fprintf(stderr, " %s FILE brick 0|1\n", argv[0]);
+ fprintf(stderr, " %s FILE setchecksum 0|1\n", argv[0]);
+ errno = EINVAL;
+ err(EXIT_FAILURE, "Too few arguments");
+ }
+
+ filename = argv[1];
+
+ flags = O_RDWR;
+
+ if (argc > 2) {
+ if (strcmp(COMMAND, "dump") == 0) {
+ flags = O_RDONLY;
+#ifdef __OpenBSD__
+ err_if(pledge("stdio rpath unveil", NULL) == -1);
+#endif
+ }
+ }
+
+#ifdef __OpenBSD__
+ err_if(unveil("/dev/urandom", "r") == -1);
+
+ if (flags == O_RDONLY) {
+ err_if(unveil(filename, "r") == -1);
+ err_if(unveil(NULL, NULL) == -1);
+ err_if(pledge("stdio rpath", NULL) == -1);
+ } else {
+ err_if(unveil(filename, "rw") == -1);
+ err_if(unveil(NULL, NULL) == -1);
+ err_if(pledge("stdio rpath wpath", NULL) == -1);
+ }
+#endif
+
+ openFiles(filename);
+#ifdef __OpenBSD__
+ err_if(pledge("stdio", NULL) == -1);
+#endif
+
+ if (argc > 2) {
+ for (int i = 0; (i < 6) && (cmd == NULL); i++) {
+ if (strcmp(COMMAND, op[i].str) != 0)
+ continue;
+ if (argc >= op[i].args) {
+ cmd = op[i].cmd;
+ break;
+ }
+ errno = EINVAL;
+ err(EXIT_FAILURE, "Too few args on command '%s'",
+ op[i].str);
+ }
+ } else {
+ cmd = cmd_setmac;
+ }
+
+ if ((cmd == NULL) && (argc > 2)) { /* nvm gbe [MAC] */
+ strMac = COMMAND;
+ cmd = cmd_setmac;
+ } else if (cmd == cmd_setmac) { /* nvm gbe setmac [MAC] */
+ strMac = strRMac; /* random MAC */
+ if (argc > 3)
+ strMac = MAC_ADDRESS;
+ } else if ((cmd != NULL) && (argc > 3)) { /* user-supplied partnum */
+ err_if((errno = (!((part = PARTN[0] - '0') == 0 || part == 1))
+ || PARTN[1] ? EINVAL : 0)); /* only allow '0' or '1' */
+ }
+ if (cmd == NULL) {
+ errno = EINVAL;
+ err(EXIT_FAILURE, "Bad command");
+ }
+
+ readGbe();
+ (*cmd)();
+ writeGbe();
+
+ return EXIT_SUCCESS;
+}
+
+void
+openFiles(const char *path)
+{
+ struct stat st;
+
+ xopen(fd, path, flags);
+
+ switch(st.st_size) {
+ case SIZE_8KB:
+ case SIZE_16KB:
+ case SIZE_128KB:
+ partsize = st.st_size >> 1;
+ break;
+ default:
+ errno = ECANCELED;
+ err(EXIT_FAILURE, "Invalid file size (not 8/16/128KiB)");
+ break;
+ }
+
+ xopen(rfd, "/dev/urandom", O_RDONLY);
+}
+
+void
+readGbe(void)
+{
+ if ((cmd == cmd_swap) || (cmd == cmd_copy))
+ nf = SIZE_4KB;
+ else
+ nf = NVM_SIZE;
+
+ if ((cmd == cmd_copy) || (cmd == cmd_setchecksum) || (cmd == cmd_brick))
+ do_read[part ^ 1] = 0;
+
+ char *buf = malloc(nf << (do_read[0] & do_read[1]));
+ if (buf == NULL)
+ err(EXIT_FAILURE, "malloc");
+
+ gbe[0] = (size_t) buf;
+ gbe[1] = gbe[0] + (nf * (do_read[0] & do_read[1]));
+
+ ssize_t tnr = 0;
+
+ for (int p = 0; p < 2; p++) {
+ if (!do_read[p])
+ continue;
+
+ ssize_t nr = rw_exact(fd, (uint8_t *) gbe[p],
+ nf, p * partsize, IO_PREAD);
+ err_if(nr == -1);
+ if (nr != nf)
+ err(EXIT_FAILURE,
+ "%ld bytes read from '%s', expected %ld bytes\n",
+ nr, filename, nf);
+
+ tnr += nr;
+ swap(p); /* handle big-endian host CPU */
+ }
+
+ printf("%ld bytes read from file '%s'\n", tnr, filename);
+}
+
+void
+cmd_setmac(void)
+{
+ int mac_updated = 0;
+ parseMacString(strMac, mac);
+
+ printf("MAC address to be written: %s\n", strMac);
+
+ for (int partnum = 0; partnum < 2; partnum++) {
+ if (!goodChecksum(part = partnum))
+ continue;
+
+ for (int w = 0; w < 3; w++)
+ setWord(w, partnum, mac[w]);
+
+ printf("Wrote MAC address to part %d: ", partnum);
+ macf(partnum);
+
+ cmd_setchecksum();
+ mac_updated = 1;
+ }
+
+ if (mac_updated)
+ return;
+
+ errno = EINVAL;
+ err(EXIT_FAILURE, "Error updating MAC address");
+}
+
+void
+parseMacString(const char *strMac, uint16_t *mac)
+{
+ uint64_t total = 0;
+ if (strnlen(strMac, 20) != 17) {
+ errno = EINVAL;
+ err(EXIT_FAILURE, "Invalid MAC address string length");
+ }
+
+ for (uint8_t h, i = 0; i < 16; i += 3) {
+ if (i != 15)
+ if (strMac[i + 2] != ':') {
+ errno = EINVAL;
+ err(EXIT_FAILURE,
+ "Invalid MAC address separator '%c'",
+ strMac[i + 2]);
+ }
+
+ int byte = i / 3;
+
+ for (int nib = 0; nib < 2; nib++, total += h) {
+ if ((h = hextonum(strMac[i + nib])) > 15) {
+ errno = EINVAL;
+ err(EXIT_FAILURE, "Invalid character '%c'",
+ strMac[i + nib]);
+ }
+
+ /* If random, ensure that local/unicast bits are set */
+ if ((byte == 0) && (nib == 1))
+ if ((strMac[i + nib] == '?') ||
+ (strMac[i + nib] == 'x') ||
+ (strMac[i + nib] == 'X')) /* random */
+ h = (h & 0xE) | 2; /* local, unicast */
+
+ mac[byte >> 1] |= ((uint16_t ) h)
+ << ((8 * (byte % 2)) + (4 * (nib ^ 1)));
+ }
+ }
+
+ if (!((total == 0) || (mac[0] & 1)))
+ return;
+
+ errno = EINVAL;
+
+ if (total == 0)
+ err(EXIT_FAILURE, "Invalid MAC (all-zero MAC address)");
+ if (mac[0] & 1)
+ err(EXIT_FAILURE, "Invalid MAC (multicast bit set)");
+}
+
+uint8_t
+hextonum(char ch)
+{
+ if ((ch >= '0') && (ch <= '9'))
+ return ch - '0';
+ else if ((ch >= 'A') && (ch <= 'F'))
+ return ch - 'A' + 10;
+ else if ((ch >= 'a') && (ch <= 'f'))
+ return ch - 'a' + 10;
+ else if ((ch == '?') || (ch == 'x') || (ch == 'X'))
+ return rhex(); /* random hex value */
+ else
+ return 16; /* error: invalid character */
+}
+
+uint8_t
+rhex(void)
+{
+ static uint8_t n = 0, rnum[16];
+ if (!n)
+ err_if(rw_exact(rfd, (uint8_t *) &rnum,
+ (n = 15) + 1, 0, IO_READ) == -1);
+ return rnum[n--] & 0xf;
+}
+
+void
+cmd_dump(void)
+{
+ for (int partnum = 0, numInvalid = 0; partnum < 2; partnum++) {
+ if ((cmd != cmd_dump) && (flags != O_RDONLY) &&
+ (!nvmPartChanged[partnum]))
+ continue;
+
+ if (!goodChecksum(partnum))
+ ++numInvalid;
+
+ printf("MAC (part %d): ", partnum);
+ macf(partnum);
+ hexdump(partnum);
+ }
+}
+
+void
+macf(int partnum)
+{
+ for (int c = 0; c < 3; c++) {
+ uint16_t val16 = word(c, partnum);
+ printf("%02x:%02x", val16 & 0xff, val16 >> 8);
+ if (c == 2)
+ printf("\n");
+ else
+ printf(":");
+ }
+}
+
+void
+hexdump(int partnum)
+{
+ for (int row = 0; row < 8; row++) {
+ printf("%08x ", row << 4);
+ for (int c = 0; c < 8; c++) {
+ uint16_t val16 = word((row << 3) + c, partnum);
+ if (c == 4)
+ printf(" ");
+ printf(" %02x %02x", val16 & 0xff, val16 >> 8);
+ }
+ printf("\n");
+ }
+}
+
+void
+cmd_setchecksum(void)
+{
+ uint16_t val16 = 0;
+ for (int c = 0; c < NVM_CHECKSUM_WORD; c++)
+ val16 += word(c, part);
+
+ setWord(NVM_CHECKSUM_WORD, part, NVM_CHECKSUM - val16);
+}
+
+void
+cmd_brick(void)
+{
+ if (goodChecksum(part))
+ setWord(NVM_CHECKSUM_WORD, part,
+ ((word(NVM_CHECKSUM_WORD, part)) ^ 0xFF));
+}
+
+void
+cmd_copy(void)
+{
+ nvmPartChanged[part ^ 1] = goodChecksum(part);
+}
+
+void
+cmd_swap(void) {
+ err_if(!(goodChecksum(0) || goodChecksum(1)));
+ errno = 0;
+
+ gbe[0] ^= gbe[1];
+ gbe[1] ^= gbe[0];
+ gbe[0] ^= gbe[1];
+
+ nvmPartChanged[0] = nvmPartChanged[1] = 1;
+}
+
+int
+goodChecksum(int partnum)
+{
+ uint16_t total = 0;
+ for(int w = 0; w <= NVM_CHECKSUM_WORD; w++)
+ total += word(w, partnum);
+
+ if (total == NVM_CHECKSUM)
+ return 1;
+
+ fprintf(stderr, "WARNING: BAD checksum in part %d\n", partnum);
+ return 0;
+}
+
+void
+writeGbe(void)
+{
+ ssize_t tnw = 0;
+
+ for (int p = 0; p < 2; p++) {
+ if ((!nvmPartChanged[p]) || (flags == O_RDONLY))
+ continue;
+
+ swap(p); /* swap bytes on big-endian host CPUs */
+ ssize_t nw = rw_exact(fd, (uint8_t *) gbe[p], nf,
+ p * partsize, IO_PWRITE);
+ err_if(nw == -1);
+ if (nw != nf) {
+ errno = ECANCELED;
+ err(EXIT_SUCCESS,
+ "%ld bytes written to '%s', expected %ld bytes\n",
+ nw, filename, nf);
+ }
+
+ tnw += nf;
+ }
+
+ if ((flags != O_RDONLY) && (cmd != cmd_dump)) {
+ if (nvmPartChanged[0] || nvmPartChanged[1])
+ printf("The following nvm words were written:\n");
+ cmd_dump();
+ }
+
+ if ((!tnw) && (flags != O_RDONLY))
+ fprintf(stderr, "No changes needed on file '%s'\n", filename);
+ else if (tnw)
+ printf("%ld bytes written to file '%s'\n", tnw, filename);
+
+ xclose(&fd);
+}
+
+void
+xclose(int *fd)
+{
+ int saved_errno = errno;
+ int rval = 0;
+
+ if (fd == NULL)
+ err(EXIT_FAILURE, "xclose: null pointer");
+ if (*fd < 0)
+ return;
+
+ errno = 0;
+ if ((rval = close(*fd)) < 0) {
+ if (errno != EINTR)
+ err(EXIT_FAILURE, "xclose: could not close");
+
+ /* regard EINTR as a successful close */
+ rval = 0;
+ }
+
+ *fd = -1;
+
+ reset_caller_errno(rval);
+}
+
+void
+swap(int partnum)
+{
+ size_t w, x;
+ uint8_t *n = (uint8_t *) gbe[partnum];
+ int e = 1;
+
+ for (w = NVM_SIZE * ((uint8_t *) &e)[0], x = 1; w < NVM_SIZE;
+ w += 2, x += 2) {
+ n[w] ^= n[x];
+ n[x] ^= n[w];
+ n[w] ^= n[x];
+ }
+}
+
+int
+open_on_eintr(const char *pathname,
+ int flags)
+{
+ int saved_errno = errno;
+ int rval = 0;
+ errno = 0;
+
+ while (fs_retry(saved_errno,
+ rval = open(pathname, flags)));
+
+ reset_caller_errno(rval);
+ return rval;
+}
+
+
+ssize_t
+rw_exact(int fd, unsigned char *mem, size_t nrw,
+ off_t off, int rw_type)
+{
+ int saved_errno = errno;
+ ssize_t rval = 0;
+ ssize_t rc = 0;
+ size_t nrw_cur;
+ off_t off_cur;
+ void *mem_cur;
+ errno = 0;
+
+ if (io_args(fd, mem, nrw, off, rw_type) == -1)
+ goto err_rw_exact;
+
+ while (1) {
+
+ /* Prevent theoretical overflow */
+ if (if_err(rval >= 0 && (size_t)rval > (nrw - (size_t)rc),
+ EOVERFLOW))
+ goto err_rw_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 (if_err(off < 0, EOVERFLOW))
+ goto err_rw_exact;
+
+ off_cur = off + (off_t)rc;
+
+ if ((rval = rw(fd, mem_cur, nrw_cur, off_cur, rw_type)) <= 0)
+ goto err_rw_exact;
+ }
+
+ if (if_err((size_t)rc != nrw, EIO) ||
+ (rval = rw_over_nrw(rc, nrw)) < 0)
+ goto err_rw_exact;
+
+ reset_caller_errno(rval);
+ return rval;
+
+err_rw_exact:
+ return with_fallback_errno(EIO);
+}
+
+ssize_t
+rw(int fd, void *mem, size_t nrw,
+ off_t off, int rw_type)
+{
+ ssize_t rval = 0;
+ ssize_t r = -1;
+ int saved_errno = errno;
+ errno = 0;
+
+ if (io_args(fd, mem, nrw, off, rw_type) == -1 ||
+ if_err(mem == NULL, EFAULT) ||
+ if_err(fd < 0, EBADF) ||
+ if_err(off < 0, EFAULT) ||
+ if_err(nrw == 0, EINVAL))
+ return with_fallback_errno(EIO);
+
+ do {
+ switch (rw_type) {
+ case IO_READ:
+ r = read(fd, mem, nrw);
+ break;
+ case IO_WRITE:
+ r = write(fd, mem, nrw);
+ break;
+ case IO_PREAD:
+ r = pread(fd, mem, nrw, off);
+ break;
+ case IO_PWRITE:
+ r = pwrite(fd, mem, nrw, off);
+ break;
+ default:
+ errno = EINVAL;
+ break;
+ }
+
+ } while (rw_retry(saved_errno, r));
+
+ if ((rval = rw_over_nrw(r, nrw)) < 0)
+ return with_fallback_errno(EIO);
+
+ reset_caller_errno(rval);
+ return rval;
+}
+
+int
+io_args(int fd, void *mem, size_t nrw,
+ off_t off, int rw_type)
+{
+ int saved_errno = errno;
+ errno = 0;
+
+ 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;
+
+ reset_caller_errno(0);
+ return 0;
+
+err_io_args:
+ return with_fallback_errno(EINVAL);
+}
+
+ssize_t
+rw_over_nrw(ssize_t r, size_t nrw)
+{
+ if (if_err(!nrw, EIO) ||
+ (r == -1) ||
+ if_err((size_t)r > SSIZE_MAX, ERANGE) ||
+ if_err((size_t)r > nrw, ERANGE))
+ return with_fallback_errno(EIO);
+
+ return r;
+}
+
+int
+with_fallback_errno(int fallback)
+{
+ if (!errno)
+ errno = fallback;
+ return -1;
+}
+
+/* two functions that reduce sloccount by
+ * two hundred lines */
+int
+if_err(int condition, int errval)
+{
+ if (!condition)
+ return 0;
+ if (errval)
+ errno = errval;
+ return 1;
+}
+int
+if_err_sys(int condition)
+{
+ if (!condition)
+ return 0;
+ return 1;
+}
+
+#define fs_err_retry() \
+ do { \
+ if ((rval == -1) && \
+ (errno == EINTR)) \
+ return 1; \
+ if (rval >= 0 && !errno) \
+ errno = saved_errno; \
+ return 0; \
+ } while(0)
+
+int
+fs_retry(int saved_errno, int rval)
+{
+ fs_err_retry();
+}
+
+int
+rw_retry(int saved_errno, ssize_t rval)
+{
+ fs_err_retry();
+}