banan-os/tools/update-image-perms.c

61 lines
1.3 KiB
C

#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
int main(int argc, char** argv)
{
if (argc != 3)
{
fprintf(stderr, "usage: %s MOUNT_POINT PERMS_FILE\n", argv[0]);
return 1;
}
int mount_fd = open(argv[1], O_RDONLY | O_DIRECTORY);
if (mount_fd == -1)
{
fprintf(stderr, "could not open %s: %s\n", argv[1], strerror(errno));
return 1;
}
FILE* perm_fp = fopen(argv[2], "r");
if (perm_fp == NULL)
{
fprintf(stderr, "could not open %s: %s\n", argv[2], strerror(errno));
return 1;
}
char buffer[1024];
while (fgets(buffer, sizeof(buffer), perm_fp))
{
char path[PATH_MAX];
uid_t uid;
gid_t gid;
mode_t mode;
if (sscanf(buffer, "%[^|\n]|%d|%d|%o\n", path, &uid, &gid, &mode) != 4)
continue;
struct stat st;
if (fstatat(mount_fd, path, &st, AT_SYMLINK_NOFOLLOW) != 0)
continue;
if (st.st_uid != uid || st.st_gid != gid)
if (fchownat(mount_fd, path, uid, gid, AT_SYMLINK_NOFOLLOW) != 0)
fprintf(stderr, "fchownat: %s: %s\n", path, strerror(errno));
const mode_t mode_mask = S_ISUID | S_ISGID | S_ISVTX | 0777;
if (mode != (st.st_mode & mode_mask))
if (fchmodat(mount_fd, path, mode, AT_SYMLINK_NOFOLLOW) != 0)
fprintf(stderr, "fchmodat: %s: %s\n", path, strerror(errno));
}
fclose(perm_fp);
close(mount_fd);
return 0;
}