#include <errno.h>

#include <sys/stat.h>

#include <stdlib.h>

#include <string.h>

#include <assert.h>

#include <unistd.h>

#include "base-filesystem.h"

#include "log.h"

#include "macro.h"

#include "strv.h"

#include "util.h"

#include "label.h"

#include "mkdir.h"

typedef struct BaseFilesystem {

const char *dir;

mode_t mode;

const char *target;

const char *exists;

} BaseFilesystem;

static const BaseFilesystem table[] = {

{ "bin", 0, "usr/bin\0", NULL },

{ "lib", 0, "usr/lib\0", NULL },

{ "root", 0755, NULL, NULL },

{ "sbin", 0, "usr/sbin\0", NULL },

#if defined(__i386__) || defined(__x86_64__)

{ "lib64", 0, "usr/lib/x86_64-linux-gnu\0"

"usr/lib64\0", "ld-linux-x86-64.so.2" },

#endif

};

int base_filesystem_create(const char *root) {

_cleanup_close_ int fd = -1;

unsigned i;

int r;

fd = open(root, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW);

if (fd < 0) {

log_error("Failed to open root file system: %m");

return -errno;

}

for (i = 0; i < ELEMENTSOF(table); i ++) {

if (faccessat(fd, table[i].dir, F_OK, AT_SYMLINK_NOFOLLOW) >= 0)

continue;

if (table[i].target) {

const char *target = NULL, *s;

/* check if one of the targets exists */

NULSTR_FOREACH(s, table[i].target) {

if (faccessat(fd, s, F_OK, AT_SYMLINK_NOFOLLOW) < 0)

continue;

/* check if a specific file exists at the target path */

if (table[i].exists) {

_cleanup_free_ char *p = NULL;

p = strjoin(s, "/", table[i].exists, NULL);

if (!p)

return log_oom();

if (faccessat(fd, p, F_OK, AT_SYMLINK_NOFOLLOW) < 0)

continue;

}

target = s;

break;

}

if (!target)

continue;

r = symlinkat(target, fd, table[i].dir);

if (r < 0 && errno != EEXIST) {

log_error("Failed to create symlink at %s/%s: %m", root, table[i].dir);

return -errno;

}

continue;

}

RUN_WITH_UMASK(0000)

r = mkdirat(fd, table[i].dir, table[i].mode);

if (r < 0 && errno != EEXIST) {

log_error("Failed to create directory at %s/%s: %m", root, table[i].dir);

return -errno;

}

}

return 0;

}