aboutsummaryrefslogtreecommitdiff
path: root/lib/tar
diff options
context:
space:
mode:
Diffstat (limited to 'lib/tar')
-rw-r--r--lib/tar/read_header.c145
-rw-r--r--lib/tar/write_header.c4
2 files changed, 123 insertions, 26 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;
diff --git a/lib/tar/write_header.c b/lib/tar/write_header.c
index 80db327..d9db24a 100644
--- a/lib/tar/write_header.c
+++ b/lib/tar/write_header.c
@@ -33,14 +33,14 @@ static int name_to_tar_header(tar_header_t *hdr, const char *path)
return -1;
len = ptr - path;
- if (len >= sizeof(hdr->prefix))
+ if (len >= sizeof(hdr->tail.posix.prefix))
continue;
if (strlen(ptr + 1) >= sizeof(hdr->name))
continue;
break;
}
- memcpy(hdr->prefix, path, ptr - path);
+ memcpy(hdr->tail.posix.prefix, path, ptr - path);
memcpy(hdr->name, ptr + 1, strlen(ptr + 1));
return 0;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 04:23:06 +0000