#include <dirent.h>

#include <errno.h>

#include <fcntl.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "alloc-util.h"

#include "dirent-util.h"

#include "fd-util.h"

#include "fileio.h"

#include "log.h"

#include "macro.h"

#include "smack-setup.h"

#include "string-util.h"

#include "util.h"

#ifdef HAVE_SMACK

static int write_access2_rules(const char* srcdir) {

_cleanup_close_ int load2_fd = -1, change_fd = -1;

_cleanup_closedir_ DIR *dir = NULL;

struct dirent *entry;

char buf[NAME_MAX];

int dfd = -1;

int r = 0;

load2_fd = open("/sys/fs/smackfs/load2", O_RDWR|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);

if (load2_fd < 0) {

if (errno != ENOENT)

log_warning_errno(errno, "Failed to open '/sys/fs/smackfs/load2': %m");

return -errno; /* negative error */

}

change_fd = open("/sys/fs/smackfs/change-rule", O_RDWR|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);

if (change_fd < 0) {

if (errno != ENOENT)

log_warning_errno(errno, "Failed to open '/sys/fs/smackfs/change-rule': %m");

return -errno; /* negative error */

}

/* write rules to load2 or change-rule from every file in the directory */

dir = opendir(srcdir);

if (!dir) {

if (errno != ENOENT)

log_warning_errno(errno, "Failed to opendir '%s': %m", srcdir);

return errno; /* positive on purpose */

}

dfd = dirfd(dir);

assert(dfd >= 0);

FOREACH_DIRENT(entry, dir, return 0) {

int fd;

_cleanup_fclose_ FILE *policy = NULL;

if (!dirent_is_file(entry))

continue;

fd = openat(dfd, entry->d_name, O_RDONLY|O_CLOEXEC);

if (fd < 0) {

if (r == 0)

r = -errno;

log_warning_errno(errno, "Failed to open '%s': %m", entry->d_name);

continue;

}

policy = fdopen(fd, "re");

if (!policy) {

if (r == 0)

r = -errno;

safe_close(fd);

log_error_errno(errno, "Failed to open '%s': %m", entry->d_name);

continue;

}

/* load2 write rules in the kernel require a line buffered stream */

FOREACH_LINE(buf, policy,

log_error_errno(errno, "Failed to read line from '%s': %m",

entry->d_name)) {

_cleanup_free_ char *sbj = NULL, *obj = NULL, *acc1 = NULL, *acc2 = NULL;

if (isempty(truncate_nl(buf)))

continue;

/* if 3 args -> load rule : subject object access1 */

/* if 4 args -> change rule : subject object access1 access2 */

if (sscanf(buf, "%ms %ms %ms %ms", &sbj, &obj, &acc1, &acc2) < 3) {

log_error_errno(errno, "Failed to parse rule '%s' in '%s', ignoring.", buf, entry->d_name);

continue;

}

if (write(isempty(acc2) ? load2_fd : change_fd, buf, strlen(buf)) < 0) {

if (r == 0)

r = -errno;

log_error_errno(errno, "Failed to write '%s' to '%s' in '%s'",

buf, isempty(acc2) ? "/sys/fs/smackfs/load2" : "/sys/fs/smackfs/change-rule", entry->d_name);

}

}

}

return r;

}

static int write_cipso2_rules(const char* srcdir) {

_cleanup_close_ int cipso2_fd = -1;

_cleanup_closedir_ DIR *dir = NULL;

struct dirent *entry;

char buf[NAME_MAX];

int dfd = -1;

int r = 0;

cipso2_fd = open("/sys/fs/smackfs/cipso2", O_RDWR|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);

if (cipso2_fd < 0) {

if (errno != ENOENT)

log_warning_errno(errno, "Failed to open '/sys/fs/smackfs/cipso2': %m");

return -errno; /* negative error */

}

/* write rules to cipso2 from every file in the directory */

dir = opendir(srcdir);

if (!dir) {

if (errno != ENOENT)

log_warning_errno(errno, "Failed to opendir '%s': %m", srcdir);

return errno; /* positive on purpose */

}

dfd = dirfd(dir);

assert(dfd >= 0);

FOREACH_DIRENT(entry, dir, return 0) {

int fd;

_cleanup_fclose_ FILE *policy = NULL;

if (!dirent_is_file(entry))

continue;

fd = openat(dfd, entry->d_name, O_RDONLY|O_CLOEXEC);

if (fd < 0) {

if (r == 0)

r = -errno;

log_error_errno(errno, "Failed to open '%s': %m", entry->d_name);

continue;

}

policy = fdopen(fd, "re");

if (!policy) {

if (r == 0)

r = -errno;

safe_close(fd);

log_error_errno(errno, "Failed to open '%s': %m", entry->d_name);

continue;

}

/* cipso2 write rules in the kernel require a line buffered stream */

FOREACH_LINE(buf, policy,

log_error_errno(errno, "Failed to read line from '%s': %m",

entry->d_name)) {

if (isempty(truncate_nl(buf)))

continue;

if (write(cipso2_fd, buf, strlen(buf)) < 0) {

if (r == 0)

r = -errno;

log_error_errno(errno, "Failed to write '%s' to '/sys/fs/smackfs/cipso2' in '%s'",

buf, entry->d_name);

break;

}

}

}

return r;

}

#endif

int mac_smack_setup(bool *loaded_policy) {

#ifdef HAVE_SMACK

int r;

assert(loaded_policy);

r = write_access2_rules("/etc/smack/accesses.d/");

switch(r) {

case -ENOENT:

log_debug("Smack is not enabled in the kernel.");

return 0;

case ENOENT:

log_debug("Smack access rules directory '/etc/smack/accesses.d/' not found");

return 0;

case 0:

log_info("Successfully loaded Smack policies.");

break;

default:

log_warning_errno(r, "Failed to load Smack access rules, ignoring: %m");

return 0;

}

#ifdef SMACK_RUN_LABEL

r = write_string_file("/proc/self/attr/current", SMACK_RUN_LABEL, 0);

if (r)

log_warning_errno(r, "Failed to set SMACK label \"%s\" on self: %m", SMACK_RUN_LABEL);

#endif

r = write_cipso2_rules("/etc/smack/cipso.d/");

switch(r) {

case -ENOENT:

log_debug("Smack/CIPSO is not enabled in the kernel.");

return 0;

case ENOENT:

log_debug("Smack/CIPSO access rules directory '/etc/smack/cipso.d/' not found");

return 0;

case 0:

log_info("Successfully loaded Smack/CIPSO policies.");

break;

default:

log_warning_errno(r, "Failed to load Smack/CIPSO access rules, ignoring: %m");

return 0;

}

*loaded_policy = true;

#endif

return 0;

}