/* Copyright (c) 2022, 2023 Leah Rowe <info@minifree.org> */ /* SPDX-License-Identifier: MIT */ #include "nvmutil.h" int main(int argc, char *argv[]) { xpledge("stdio rpath wpath unveil", NULL); xunveil("/dev/urandom", "r"); err_if((errno = argc < 3 ? EINVAL : errno)); if ((flags = (strcmp(COMMAND, "dump") == 0) ? O_RDONLY : flags) == O_RDONLY) { xunveil(FILENAME, "r"); xpledge("stdio rpath", NULL); } else { xunveil(FILENAME, "rw"); xpledge("stdio rpath wpath", NULL); } openFiles(FILENAME); xpledge("stdio", NULL); for (int i = 0; i < 6; i++) if (strcmp(COMMAND, op[i].str) == 0) if ((cmd = argc >= op[i].args ? op[i].cmd : NULL)) break; if (cmd == cmd_setmac) strMac = (argc > 3) ? MAC_ADDRESS : strRMac; else if ((cmd != NULL) && (argc > 3)) err_if((errno = (!((part = PARTNUM[0] - '0') == 0 || part == 1)) || PARTNUM[1] ? EINVAL : errno)); err_if((errno = (cmd == NULL) ? EINVAL : errno)); readGbeFile(FILENAME); (*cmd)(); if ((gbeFileModified) && (flags != O_RDONLY)) writeGbeFile(FILENAME); err_if((errno != 0) && (cmd != &cmd_dump)); return errno; } void openFiles(const char *path) { struct stat st; xopen(fd, path, flags); if ((st.st_size != SIZE_8KB)) err(errno = ECANCELED, "File `%s` not 8KiB", path); xopen(rfd, "/dev/urandom", O_RDONLY); errno = errno != ENOTDIR ? errno : 0; } void readGbeFile(const char *path) { nf = ((cmd == cmd_swap) || (cmd == cmd_copy)) ? SIZE_4KB : nf; skipread[part ^ 1] = (cmd == &cmd_copy) | (cmd == &cmd_setchecksum) | (cmd == &cmd_brick); gbe[1] = (gbe[0] = (size_t) buf) + SIZE_4KB; for (int p = 0; p < 2; p++) { if (skipread[p]) continue; xpread(fd, (uint8_t *) gbe[p], nf, p << 12, path); handle_endianness(p); } } void cmd_setmac(void) { if (invalidMacAddress(strMac, mac)) err(errno = ECANCELED, "Bad MAC address"); for (int partnum = 0; partnum < 2; partnum++) { if (!validChecksum(part = partnum)) continue; for (int w = 0; w < 3; w++) setWord(w, partnum, mac[w]); cmd_setchecksum(); } } int invalidMacAddress(const char *strMac, uint16_t *mac) { uint64_t total = 0; if (strnlen(strMac, 20) == 17) { for (uint8_t h, i = 0; i < 16; i += 3) { if (i != 15) if (strMac[i + 2] != ':') return 1; int byte = i / 3; for (int nib = 0; nib < 2; nib++, total += h) { if ((h = hextonum(strMac[i + nib])) > 15) return 1; if ((byte == 0) && (nib == 1)) if (strMac[i + nib] == '?') h = (h & 0xE) | 2; /* local, unicast */ mac[byte >> 1] |= ((uint16_t ) h) << ((8 * (byte % 2)) + (4 * (nib ^ 1))); } }} return ((total == 0) | (mac[0] & 1)); /* multicast/all-zero banned */ } 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; return (ch == '?') ? rhex() : 16; } uint8_t rhex(void) { static uint8_t n = 0, rnum[16]; if (!n) xpread(rfd, (uint8_t *) &rnum, (n = 15) + 1, 0, "/dev/urandom"); return rnum[n--] & 0xf; } void cmd_dump(void) { for (int partnum = 0, numInvalid = 0; partnum < 2; partnum++) { if (!validChecksum(partnum)) ++numInvalid; printf("MAC (part %d): ", partnum); showmac(partnum), hexdump(partnum); errno = ((numInvalid < 2) && (partnum)) ? 0 : errno; } } void showmac(int partnum) { for (int c = 0; c < 3; c++) { uint16_t val16 = word(c, partnum); printf("%02x:%02x", val16 & 0xff, val16 >> 8); printf(c == 2 ? "\n" : ":"); } } void hexdump(int partnum) { for (int row = 0; row < 8; row++) { printf("%07x", row << 4); for (int c = 0; c < 8; c++) { uint16_t val16 = word((row << 3) + c, partnum); printf(" %02x%02x", val16 >> 8, val16 & 0xff); } printf("\n"); } } void cmd_setchecksum(void) { uint16_t val16 = 0; for (int c = 0; c < 0x3F; c++) val16 += word(c, part); setWord(0x3F, part, 0xBABA - val16); } void cmd_brick(void) { if (validChecksum(part)) setWord(0x3F, part, (word(0x3F, part)) ^ 0xFF); } void cmd_swap(void) { if ((gbeFileModified = nvmPartModified[0] = nvmPartModified[1] = validChecksum(1) | validChecksum(0))) xorswap(gbe[0], gbe[1]); /* speedhack: swap ptr, not words */ } void cmd_copy(void) { if ((gbeFileModified = nvmPartModified[part ^ 1] = validChecksum(part))) gbe[part ^ 1] = gbe[part]; /* speedhack: copy ptr, not words */ } int validChecksum(int partnum) { uint16_t total = 0; for(int w = 0; w <= 0x3F; w++) total += word(w, partnum); if (total == 0xBABA) return 1; fprintf(stderr, "WARNING: BAD checksum in part %d\n", partnum); return (errno = ECANCELED) & 0; } void setWord(int pos16, int partnum, uint16_t val16) { if ((gbeFileModified = 1) && word(pos16, partnum) != val16) nvmPartModified[partnum] = 1 | (word(pos16, partnum) = val16); } void xorswap_buf(int partnum) { uint8_t *nbuf = (uint8_t *) gbe[partnum]; for (size_t w = 0; w < (nf >> 1); w++) xorswap(nbuf[w << 1], nbuf[(w << 1) + 1]); } void writeGbeFile(const char *filename) { errno = 0; for (int x = gbe[0] > gbe[1] ? 1 : 0, p = 0; p < 2; p++, x ^= 1) { if (!nvmPartModified[x]) continue; handle_endianness(x); xpwrite(fd, (uint8_t *) gbe[x], nf, x << 12, filename); } xclose(fd, filename); }