Small utility collection for dealing with file archives that have dependencies
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pkg-utils/main/pkg_unpack.c

237 lines
4.5 KiB

/* SPDX-License-Identifier: ISC */
#include <sys/types.h>
#include <sys/stat.h>
#include <stdbool.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include "pkgio.h"
#include "util/util.h"
static int create_hierarchy(int dirfd, image_entry_t *list, int flags)
{
image_entry_t *ent;
for (ent = list; ent != NULL; ent = ent->next) {
if (S_ISDIR(ent->mode)) {
if (mkdirat(dirfd, ent->name, 0755)) {
if (errno == EEXIST)
continue;
fprintf(stderr, "mkdir %s: %s\n", ent->name,
strerror(errno));
return -1;
}
}
}
for (ent = list; ent != NULL; ent = ent->next) {
if (S_ISLNK(ent->mode)) {
if (flags & UNPACK_NO_SYMLINKS)
continue;
if (symlinkat(ent->data.symlink.target,
dirfd, ent->name)) {
fprintf(stderr, "symlink %s to %s: %s\n",
ent->name, ent->data.symlink.target,
strerror(errno));
return -1;
}
}
}
for (ent = list; ent != NULL; ent = ent->next) {
if (S_ISBLK(ent->mode) || S_ISCHR(ent->mode)) {
if (flags & UNPACK_NO_DEVICES)
continue;
if (mknodat(dirfd, ent->name, ent->mode,
ent->data.device.devno)) {
fprintf(stderr, "mknod %s: %s\n",
ent->name, strerror(errno));
return -1;
}
}
}
return 0;
}
static image_entry_t *get_file_entry(image_entry_t *list, uint32_t id)
{
while (list != NULL) {
if (S_ISREG(list->mode) && list->data.file.id == id)
return list;
list = list->next;
}
return NULL;
}
static int unpack_files(int dirfd, image_entry_t *list, pkg_reader_t *rd)
{
uint8_t buffer[2048];
image_entry_t *meta;
file_data_t frec;
ssize_t ret;
size_t diff;
uint64_t i;
int fd;
for (;;) {
ret = pkg_reader_read_payload(rd, &frec, sizeof(frec));
if (ret == 0)
break;
if (ret < 0)
return -1;
if ((size_t)ret < sizeof(frec))
goto fail_trunc;
frec.id = le32toh(frec.id);
meta = get_file_entry(list, frec.id);
if (meta == NULL) {
fprintf(stderr, "%s: missing meta information for "
"file %u\n", pkg_reader_get_filename(rd),
(unsigned int)frec.id);
return -1;
}
fd = openat(dirfd, meta->name, O_WRONLY | O_CREAT | O_EXCL,
0644);
if (fd < 0) {
perror(meta->name);
return -1;
}
for (i = 0; i < meta->data.file.size; i += ret) {
if ((meta->data.file.size - i) <
(uint64_t)sizeof(buffer)) {
diff = meta->data.file.size - i;
} else {
diff = sizeof(buffer);
}
ret = pkg_reader_read_payload(rd, buffer, diff);
if (ret < 0)
goto fail_fd;
if ((size_t)ret < diff)
goto fail_trunc;
ret = write_retry(fd, buffer, diff);
if (ret < 0) {
perror(meta->name);
goto fail_fd;
}
if ((size_t)ret < diff) {
fprintf(stderr, "%s: truncated write\n",
pkg_reader_get_filename(rd));
goto fail_fd;
}
}
close(fd);
}
return 0;
fail_fd:
close(fd);
return -1;
fail_trunc:
fprintf(stderr, "%s: truncated file data record\n",
pkg_reader_get_filename(rd));
return -1;
}
static int change_permissions(int dirfd, image_entry_t *list, int flags)
{
bool do_chmod, do_chown;
for (; list != NULL; list = list->next) {
do_chmod = (flags & UNPACK_NO_CHMOD) == 0;
do_chown = (flags & UNPACK_NO_CHOWN) == 0;
switch (list->mode & S_IFMT) {
case S_IFLNK:
if (flags & UNPACK_NO_SYMLINKS)
continue;
do_chmod = false;
break;
case S_IFBLK:
case S_IFCHR:
if (flags & UNPACK_NO_DEVICES)
continue;
do_chmod = false;
break;
default:
break;
}
if (do_chmod) {
if (fchmodat(dirfd, list->name,
list->mode & 07777, 0)) {
fprintf(stderr, "%s: chmod: %s\n", list->name,
strerror(errno));
return -1;
}
}
if (do_chown) {
if (fchownat(dirfd, list->name, list->uid, list->gid,
AT_SYMLINK_NOFOLLOW)) {
fprintf(stderr, "%s: chown: %s\n", list->name,
strerror(errno));
return -1;
}
}
}
return 0;
}
int pkg_unpack(int rootfd, int flags, pkg_reader_t *rd)
{
image_entry_t *list = NULL;
record_t *hdr;
int ret;
if (image_entry_list_from_package(rd, &list))
return -1;
if (pkg_reader_rewind(rd))
goto fail;
if (list == NULL)
return 0;
if (create_hierarchy(rootfd, list, flags))
goto fail;
for (;;) {
ret = pkg_reader_get_next_record(rd);
if (ret == 0)
break;
if (ret < 0)
goto fail;
hdr = pkg_reader_current_record_header(rd);
if (hdr->magic == PKG_MAGIC_DATA) {
if (unpack_files(rootfd, list, rd))
goto fail;
}
}
if (change_permissions(rootfd, list, flags))
goto fail;
image_entry_free_list(list);
return 0;
fail:
image_entry_free_list(list);
return -1;
}