| 1 | #include "lib.h" |
| 2 | |
| 3 | static int status = 0; |
| 4 | static unsigned flags = 0; |
| 5 | #define F_FIX 1u |
| 6 | |
| 7 | static void vgripe_syserr(int st, int err, const char *fmt, va_list ap) |
| 8 | { vmoan_syserr(err, fmt, ap); if (st > status) status = st; } |
| 9 | static void vgripe(int st, const char *fmt, va_list ap) |
| 10 | { vgripe_syserr(st, 0, fmt, ap); } |
| 11 | PRINTF_LIKE(3, 4) |
| 12 | static void gripe_syserr(int st, int err, const char *fmt, ...) |
| 13 | { |
| 14 | va_list ap; |
| 15 | va_start(ap, fmt); vgripe_syserr(st, err, fmt, ap); va_end(ap); |
| 16 | } |
| 17 | PRINTF_LIKE(2, 3) static void gripe(int st, const char *fmt, ...) |
| 18 | { va_list ap; va_start(ap, fmt); vgripe(st, fmt, ap); va_end(ap); } |
| 19 | |
| 20 | static int carefully_read(int fd, off_t off, |
| 21 | void *p, size_t sz, const char *file) |
| 22 | { |
| 23 | ssize_t n; |
| 24 | char *q = p; |
| 25 | |
| 26 | if (lseek(fd, off, SEEK_SET) < 0) |
| 27 | { gripe_syserr(2, errno, "failed to seek in `%s'", file); return (-1); } |
| 28 | |
| 29 | while (sz) { |
| 30 | n = read(fd, q, sz); |
| 31 | if (n < 0) |
| 32 | { gripe_syserr(2, errno, "failed to read `%s'", file); return (-1); } |
| 33 | else if (!n) |
| 34 | { gripe(2, "unexpected end-of-file reading `%s'", file); return (-1); } |
| 35 | q += n; sz -= n; |
| 36 | } |
| 37 | return (0); |
| 38 | } |
| 39 | |
| 40 | typedef uint_least32_t u32; |
| 41 | #define Pu32 PRIuLEAST32 |
| 42 | |
| 43 | static u32 load32(const unsigned char *p) |
| 44 | { |
| 45 | return (((u32)p[0] << 0) | ((u32)p[1] << 8) | |
| 46 | ((u32)p[2] << 16) | ((u32)p[3] << 24)); |
| 47 | } |
| 48 | |
| 49 | #define CAHF_GRIPE 1u |
| 50 | #define CAHF_FULL 1u |
| 51 | static int check_anchor_header(const unsigned char *b, secaddr addr, |
| 52 | unsigned f, const char *file) |
| 53 | { |
| 54 | unsigned i, t; |
| 55 | secaddr n; |
| 56 | |
| 57 | if (b[0] != 2) { |
| 58 | if (f&CAHF_GRIPE) |
| 59 | gripe(1, "anchor descriptor not found at `%s' sector %"PRIuSEC"", |
| 60 | file, addr); |
| 61 | return (-1); |
| 62 | } |
| 63 | |
| 64 | for (i = 0, t = 0; i < 16; i++) if (i != 4) t += b[i]; |
| 65 | t %= 256; |
| 66 | if (b[4] != t) { |
| 67 | if (f&CAHF_GRIPE) |
| 68 | gripe(1, "bad anchor descriptor header checksum (%u /= %u) " |
| 69 | "at `%s' sector %"PRIuSEC"", (unsigned)b[4], t, file, addr); |
| 70 | return (-1); |
| 71 | } |
| 72 | |
| 73 | if (f&CAHF_FULL) { |
| 74 | n = load32(b + 12); |
| 75 | if (n != addr) { |
| 76 | if (f&CAHF_GRIPE) |
| 77 | gripe(1, "bad sector number in anchor descriptor " |
| 78 | "(%"PRIuSEC" /= %"PRIuSEC") in `%s'", |
| 79 | n, addr, file); |
| 80 | return (-1); |
| 81 | } |
| 82 | } |
| 83 | |
| 84 | return (0); |
| 85 | } |
| 86 | |
| 87 | static int all_zero_p(const unsigned char *p, size_t sz) |
| 88 | { |
| 89 | while (sz) { |
| 90 | if (*p) return (0); |
| 91 | p++; sz--; |
| 92 | } |
| 93 | return (1); |
| 94 | } |
| 95 | |
| 96 | static void check_img(const char *file) |
| 97 | { |
| 98 | int fd = -1; |
| 99 | unsigned char b[SECTORSZ], bb[SECTORSZ]; |
| 100 | off_t volsz; |
| 101 | int blksz; |
| 102 | secaddr end; |
| 103 | unsigned i, j; |
| 104 | |
| 105 | fd = open(file, (flags&F_FIX) ? O_RDWR : O_RDONLY); |
| 106 | if (fd < 0) |
| 107 | { gripe_syserr(2, errno, "failed to open `%s'", file); goto end; } |
| 108 | blksz = SECTORSZ; volsz = device_size(fd, file, &blksz); |
| 109 | if (SECTORSZ != 2048) |
| 110 | { gripe(2, "device sector size %d /= 2048", blksz); goto end; } |
| 111 | if (volsz%SECTORSZ) { |
| 112 | gripe(2, "bad length for `%s' -- not whole number of sectors", file); |
| 113 | goto end; |
| 114 | } |
| 115 | end = volsz/SECTORSZ; |
| 116 | |
| 117 | if (carefully_read(fd, 256*SECTORSZ, b, SECTORSZ, file) || |
| 118 | check_anchor_header(b, 256, CAHF_GRIPE | CAHF_FULL, file)) |
| 119 | goto end; |
| 120 | |
| 121 | for (i = 1; i < 32768; i++) { |
| 122 | if (carefully_read(fd, (off_t)(end - i)*SECTORSZ, bb, SECTORSZ, file)) |
| 123 | goto end; |
| 124 | if (bb[0] || !all_zero_p(bb, SECTORSZ)) goto nonzero; |
| 125 | } |
| 126 | gripe(1, "too many trailing zero sectors: " |
| 127 | "couldn't find backup anchor descriptor in `%s'", file); |
| 128 | goto end; |
| 129 | nonzero: |
| 130 | j = i; |
| 131 | for (;;) { |
| 132 | if (bb[0] == 2 && !check_anchor_header(bb, end - j, 0, file)) |
| 133 | break; |
| 134 | j++; |
| 135 | if (j > i + 256) { |
| 136 | gripe(1, "failed to find backup anchor descriptor in `%s'", file); |
| 137 | goto end; |
| 138 | } |
| 139 | if (carefully_read(fd, (off_t)(end - j)*SECTORSZ, bb, SECTORSZ, file)) |
| 140 | goto end; |
| 141 | } |
| 142 | if (j > i) { |
| 143 | gripe(1, "found backup anchor descriptor at sector %"PRIuSEC" " |
| 144 | " = %"PRIuSEC" from end, = %"PRIuSEC" from trailing zeros", |
| 145 | end - j, j, j - i + 1); |
| 146 | i = j; |
| 147 | } |
| 148 | |
| 149 | if (check_anchor_header(bb, end - i, CAHF_GRIPE | CAHF_FULL, file)) |
| 150 | goto end; |
| 151 | |
| 152 | if (MEMCMP(b + 16, != , bb + 16, SECTORSZ - 16)) { |
| 153 | gripe(1, "backup anchor descriptor in sector %"PRIuSEC" " |
| 154 | "doesn't match primary in sector 256 of `%s'", |
| 155 | end - i, file); |
| 156 | goto end; |
| 157 | } |
| 158 | |
| 159 | if (i > 1) { |
| 160 | if (!(flags&F_FIX)) |
| 161 | gripe(1, "%u trailing zero sectors in `%s'", i - 1, file); |
| 162 | else { |
| 163 | if (ftruncate(fd, (off_t)(end - i + 1)*SECTORSZ)) |
| 164 | gripe_syserr(2, errno, |
| 165 | "failed to truncate `%s' to %"PRIuSEC" sectors", |
| 166 | file, end - i + 1); |
| 167 | else |
| 168 | moan("removed %u trailing zero sectors from `%s'", i - 1, file); |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | end: |
| 173 | if (fd != -1) close(fd); |
| 174 | } |
| 175 | |
| 176 | static void usage(FILE *fp) |
| 177 | { fprintf(fp, "usage: %s [-x] IMG ...\n", prog); } |
| 178 | |
| 179 | int main(int argc, char *argv[]) |
| 180 | { |
| 181 | int i, opt; |
| 182 | unsigned f = 0; |
| 183 | #define f_bogus 1u |
| 184 | |
| 185 | set_prog(argv[0]); |
| 186 | for (;;) { |
| 187 | opt = getopt(argc, argv, "hx"); if (opt < 0) break; |
| 188 | switch (opt) { |
| 189 | case 'h': usage(stdout); exit(0); |
| 190 | case 'x': flags |= F_FIX; break; |
| 191 | default: f |= f_bogus; break; |
| 192 | } |
| 193 | } |
| 194 | if (optind >= argc) f |= f_bogus; |
| 195 | if (f&f_bogus) { usage(stderr); exit(2); } |
| 196 | |
| 197 | for (i = optind; i < argc; i++) check_img(argv[i]); |
| 198 | return (status); |
| 199 | } |