diff options
Diffstat (limited to 'lib/tar/read_header.c')
| -rw-r--r-- | lib/tar/read_header.c | 145 |
1 files changed, 121 insertions, 24 deletions
diff --git a/lib/tar/read_header.c b/lib/tar/read_header.c index 01e4543..9ef20b6 100644 --- a/lib/tar/read_header.c +++ b/lib/tar/read_header.c @@ -46,36 +46,44 @@ static int read_octal(const char *str, int digits, uint64_t *out) static int read_binary(const char *str, int digits, uint64_t *out) { - uint64_t x, result = 0; + uint64_t x, ov, result; + bool first = true; - while (digits > 0 && isspace(*str)) { - ++str; + while (digits > 0) { + x = *((const unsigned char *)str++); --digits; - } - while (digits > 0) { - if (result > 0x00FFFFFFFFFFFFFFUL) { - fputs("numeric overflow parsing tar header\n", stderr); - return -1; + if (first) { + first = false; + if (x == 0xFF) { + result = 0xFFFFFFFFFFFFFFFFUL; + } else { + x &= 0x7F; + result = 0; + if (digits > 7 && x != 0) + goto fail_ov; + } } - x = *((const unsigned char *)str++); + ov = (result >> 56) & 0xFF; + + if (ov != 0 && ov != 0xFF) + goto fail_ov; + result = (result << 8) | x; - --digits; } *out = result; return 0; +fail_ov: + fputs("numeric overflow parsing tar header\n", stderr); + return -1; } static int read_number(const char *str, int digits, uint64_t *out) { - if (*((unsigned char *)str) & 0x80) { - if (read_binary(str, digits, out)) - return -1; - *out &= 0x7FFFFFFFFFFFFFFF; - return 0; - } + if (*((unsigned char *)str) & 0x80) + return read_binary(str, digits, out); return read_octal(str, digits, out); } @@ -260,13 +268,13 @@ static int decode_header(const tar_header_t *hdr, unsigned int set_by_pax, if (hdr->tail.posix.prefix[0] != '\0' && version == ETV_POSIX) { count = strlen(hdr->name) + 1; - count += strlen(hdr->prefix) + 1; + count += strlen(hdr->tail.posix.prefix) + 1; out->name = malloc(count); if (out->name != NULL) { sprintf(out->name, "%s/%s", - hdr->prefix, hdr->name); + hdr->tail.posix.prefix, hdr->name); } } else { out->name = strdup(hdr->name); @@ -313,14 +321,53 @@ static int decode_header(const tar_header_t *hdr, unsigned int set_by_pax, if (!(set_by_pax & PAX_MTIME)) { if (read_number(hdr->mtime, sizeof(hdr->mtime), &field)) return -1; - out->sb.st_mtime = field; + if (field & 0x8000000000000000UL) { + field = ~field + 1; + out->sb.st_mtime = -((int64_t)field); + } else { + out->sb.st_mtime = field; + } + } + + if (!(set_by_pax & PAX_ATIME)) { + field = out->sb.st_mtime; + + if (version == ETV_PRE_POSIX && + ((uint8_t)hdr->tail.gnu.atime[0] == 0x80 || + (uint8_t)hdr->tail.gnu.atime[0] == 0xFF || + isdigit(hdr->tail.gnu.atime[0]))) { + if (read_number(hdr->tail.gnu.atime, + sizeof(hdr->tail.gnu.atime), &field)) + return -1; + } + + if (field & 0x8000000000000000UL) { + field = ~field + 1; + out->sb.st_atime = -((int64_t)field); + } else { + out->sb.st_atime = field; + } } - if (!(set_by_pax & PAX_ATIME)) - out->sb.st_atime = out->sb.st_mtime; + if (!(set_by_pax & PAX_CTIME)) { + field = out->sb.st_mtime; + + if (version == ETV_PRE_POSIX && + ((uint8_t)hdr->tail.gnu.ctime[0] == 0x80 || + (uint8_t)hdr->tail.gnu.ctime[0] == 0xFF || + isdigit(hdr->tail.gnu.ctime[0]))) { + if (read_number(hdr->tail.gnu.ctime, + sizeof(hdr->tail.gnu.atime), &field)) + return -1; + } - if (!(set_by_pax & PAX_CTIME)) - out->sb.st_ctime = out->sb.st_mtime; + if (field & 0x8000000000000000UL) { + field = ~field + 1; + out->sb.st_ctime = -((int64_t)field); + } else { + out->sb.st_ctime = field; + } + } if (read_octal(hdr->mode, sizeof(hdr->mode), &field)) return -1; @@ -372,6 +419,37 @@ static int decode_header(const tar_header_t *hdr, unsigned int set_by_pax, return 0; } +static char *record_to_memory(int fd, uint64_t size) +{ + char *buffer = malloc(size + 1); + ssize_t ret; + + if (buffer == NULL) + goto fail_errno; + + ret = read_retry(fd, buffer, size); + if (ret == 0) + goto fail_eof; + if (ret < 0) + goto fail_errno; + if ((uint64_t)ret < size) + goto fail_eof; + + if (skip_padding(fd, size)) + goto fail; + + return buffer; +fail_errno: + perror("reading tar record"); + goto fail; +fail_eof: + fputs("reading tar record: unexpected end of file\n", stderr); + goto fail; +fail: + free(buffer); + return NULL; +} + int read_header(int fd, tar_header_decoded_t *out) { unsigned int set_by_pax = 0; @@ -408,7 +486,26 @@ int read_header(int fd, tar_header_decoded_t *out) if (!is_checksum_valid(&hdr)) goto fail_chksum; - if (hdr.typeflag == TAR_TYPE_PAX) { + switch (hdr.typeflag) { + case TAR_TYPE_GNU_SLINK: + if (read_number(hdr.size, sizeof(hdr.size), &pax_size)) + return -1; + free(out->link_target); + out->link_target = record_to_memory(fd, pax_size); + if (out->link_target == NULL) + goto fail; + set_by_pax |= PAX_SLINK_TARGET; + continue; + case TAR_TYPE_GNU_PATH: + if (read_number(hdr.size, sizeof(hdr.size), &pax_size)) + return -1; + free(out->name); + out->name = record_to_memory(fd, pax_size); + if (out->name == NULL) + goto fail; + set_by_pax |= PAX_NAME; + continue; + case TAR_TYPE_PAX: clear_header(out); if (read_number(hdr.size, sizeof(hdr.size), &pax_size)) return -1; |