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-rw-r--r--src/core/smack-setup.c396
1 files changed, 396 insertions, 0 deletions
diff --git a/src/core/smack-setup.c b/src/core/smack-setup.c
new file mode 100644
index 0000000..1fe592a
--- /dev/null
+++ b/src/core/smack-setup.c
@@ -0,0 +1,396 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/***
+ Copyright © 2013 Intel Corporation
+ Authors:
+ Nathaniel Chen <nathaniel.chen@intel.com>
+***/
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.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"
+
+#if ENABLE_SMACK
+
+static int fdopen_unlocked_at(int dfd, const char *dir, const char *name, int *status, FILE **ret_file) {
+ int fd, r;
+ FILE *f;
+
+ fd = openat(dfd, name, O_RDONLY|O_CLOEXEC);
+ if (fd < 0) {
+ if (*status == 0)
+ *status = -errno;
+
+ return log_warning_errno(errno, "Failed to open \"%s/%s\": %m", dir, name);
+ }
+
+ r = fdopen_unlocked(fd, "r", &f);
+ if (r < 0) {
+ if (*status == 0)
+ *status = r;
+
+ safe_close(fd);
+ return log_error_errno(r, "Failed to open \"%s/%s\": %m", dir, name);
+ }
+
+ *ret_file = f;
+ return 0;
+}
+
+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;
+ int dfd = -1, 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) {
+ _cleanup_fclose_ FILE *policy = NULL;
+
+ dirent_ensure_type(dir, entry);
+ if (!dirent_is_file(entry))
+ continue;
+
+ if (fdopen_unlocked_at(dfd, srcdir, entry->d_name, &r, &policy) < 0)
+ continue;
+
+ /* load2 write rules in the kernel require a line buffered stream */
+ for (;;) {
+ _cleanup_free_ char *buf = NULL, *sbj = NULL, *obj = NULL, *acc1 = NULL, *acc2 = NULL;
+ int q;
+
+ q = read_line(policy, NAME_MAX, &buf);
+ if (q < 0)
+ return log_error_errno(q, "Failed to read line from '%s': %m", entry->d_name);
+ if (q == 0)
+ break;
+
+ if (isempty(buf) || strchr(COMMENTS, buf[0]))
+ 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': %m",
+ 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;
+ int dfd = -1, 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) {
+ _cleanup_fclose_ FILE *policy = NULL;
+
+ dirent_ensure_type(dir, entry);
+ if (!dirent_is_file(entry))
+ continue;
+
+ if (fdopen_unlocked_at(dfd, srcdir, entry->d_name, &r, &policy) < 0)
+ continue;
+
+ /* cipso2 write rules in the kernel require a line buffered stream */
+ for (;;) {
+ _cleanup_free_ char *buf = NULL;
+ int q;
+
+ q = read_line(policy, NAME_MAX, &buf);
+ if (q < 0)
+ return log_error_errno(q, "Failed to read line from '%s': %m", entry->d_name);
+ if (q == 0)
+ break;
+
+ if (isempty(buf) || strchr(COMMENTS, buf[0]))
+ 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': %m",
+ buf, entry->d_name);
+ break;
+ }
+ }
+ }
+
+ return r;
+}
+
+static int write_netlabel_rules(const char *srcdir) {
+ _cleanup_fclose_ FILE *dst = NULL;
+ _cleanup_closedir_ DIR *dir = NULL;
+ struct dirent *entry;
+ int dfd = -1, r = 0;
+
+ dst = fopen("/sys/fs/smackfs/netlabel", "we");
+ if (!dst) {
+ if (errno != ENOENT)
+ log_warning_errno(errno, "Failed to open /sys/fs/smackfs/netlabel: %m");
+ return -errno; /* negative error */
+ }
+
+ /* write rules to dst 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) {
+ _cleanup_fclose_ FILE *policy = NULL;
+
+ if (fdopen_unlocked_at(dfd, srcdir, entry->d_name, &r, &policy) < 0)
+ continue;
+
+ /* load2 write rules in the kernel require a line buffered stream */
+ for (;;) {
+ _cleanup_free_ char *buf = NULL;
+ int q;
+
+ q = read_line(policy, NAME_MAX, &buf);
+ if (q < 0)
+ return log_error_errno(q, "Failed to read line from %s: %m", entry->d_name);
+ if (q == 0)
+ break;
+
+ if (!fputs(buf, dst)) {
+ if (r == 0)
+ r = -EINVAL;
+ log_error_errno(errno, "Failed to write line to /sys/fs/smackfs/netlabel: %m");
+ break;
+ }
+ q = fflush_and_check(dst);
+ if (q < 0) {
+ if (r == 0)
+ r = q;
+ log_error_errno(q, "Failed to flush writes to /sys/fs/smackfs/netlabel: %m");
+ break;
+ }
+ }
+ }
+
+ return r;
+}
+
+static int write_onlycap_list(void) {
+ _cleanup_close_ int onlycap_fd = -1;
+ _cleanup_free_ char *list = NULL;
+ _cleanup_fclose_ FILE *f = NULL;
+ size_t len = 0, allocated = 0;
+ int r;
+
+ f = fopen("/etc/smack/onlycap", "re");
+ if (!f) {
+ if (errno != ENOENT)
+ log_warning_errno(errno, "Failed to read '/etc/smack/onlycap': %m");
+
+ return errno == ENOENT ? ENOENT : -errno;
+ }
+
+ for (;;) {
+ _cleanup_free_ char *buf = NULL;
+ size_t l;
+
+ r = read_line(f, LONG_LINE_MAX, &buf);
+ if (r < 0)
+ return log_error_errno(r, "Failed to read line from /etc/smack/onlycap: %m");
+ if (r == 0)
+ break;
+
+ if (isempty(buf) || strchr(COMMENTS, *buf))
+ continue;
+
+ l = strlen(buf);
+ if (!GREEDY_REALLOC(list, allocated, len + l + 1))
+ return log_oom();
+
+ stpcpy(list + len, buf)[0] = ' ';
+ len += l + 1;
+ }
+
+ if (len == 0)
+ return 0;
+
+ list[len - 1] = 0;
+
+ onlycap_fd = open("/sys/fs/smackfs/onlycap", O_WRONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
+ if (onlycap_fd < 0) {
+ if (errno != ENOENT)
+ log_warning_errno(errno, "Failed to open '/sys/fs/smackfs/onlycap': %m");
+ return -errno; /* negative error */
+ }
+
+ r = write(onlycap_fd, list, len);
+ if (r < 0)
+ return log_error_errno(errno, "Failed to write onlycap list(%s) to '/sys/fs/smackfs/onlycap': %m", list);
+
+ return 0;
+}
+
+#endif
+
+int mac_smack_setup(bool *loaded_policy) {
+
+#if ENABLE_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, WRITE_STRING_FILE_DISABLE_BUFFER);
+ if (r < 0)
+ log_warning_errno(r, "Failed to set SMACK label \"" SMACK_RUN_LABEL "\" on self: %m");
+ r = write_string_file("/sys/fs/smackfs/ambient", SMACK_RUN_LABEL, WRITE_STRING_FILE_DISABLE_BUFFER);
+ if (r < 0)
+ log_warning_errno(r, "Failed to set SMACK ambient label \"" SMACK_RUN_LABEL "\": %m");
+ r = write_string_file("/sys/fs/smackfs/netlabel",
+ "0.0.0.0/0 " SMACK_RUN_LABEL, WRITE_STRING_FILE_DISABLE_BUFFER);
+ if (r < 0)
+ log_warning_errno(r, "Failed to set SMACK netlabel rule \"0.0.0.0/0 " SMACK_RUN_LABEL "\": %m");
+ r = write_string_file("/sys/fs/smackfs/netlabel", "127.0.0.1 -CIPSO", WRITE_STRING_FILE_DISABLE_BUFFER);
+ if (r < 0)
+ log_warning_errno(r, "Failed to set SMACK netlabel rule \"127.0.0.1 -CIPSO\": %m");
+#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");
+ break;
+ case 0:
+ log_info("Successfully loaded Smack/CIPSO policies.");
+ break;
+ default:
+ log_warning_errno(r, "Failed to load Smack/CIPSO access rules, ignoring: %m");
+ break;
+ }
+
+ r = write_netlabel_rules("/etc/smack/netlabel.d/");
+ switch(r) {
+ case -ENOENT:
+ log_debug("Smack/CIPSO is not enabled in the kernel.");
+ return 0;
+ case ENOENT:
+ log_debug("Smack network host rules directory '/etc/smack/netlabel.d/' not found");
+ break;
+ case 0:
+ log_info("Successfully loaded Smack network host rules.");
+ break;
+ default:
+ log_warning_errno(r, "Failed to load Smack network host rules: %m, ignoring.");
+ break;
+ }
+
+ r = write_onlycap_list();
+ switch(r) {
+ case -ENOENT:
+ log_debug("Smack is not enabled in the kernel.");
+ break;
+ case ENOENT:
+ log_debug("Smack onlycap list file '/etc/smack/onlycap' not found");
+ break;
+ case 0:
+ log_info("Successfully wrote Smack onlycap list.");
+ break;
+ default:
+ log_emergency_errno(r, "Failed to write Smack onlycap list: %m");
+ return r;
+ }
+
+ *loaded_policy = true;
+
+#endif
+
+ return 0;
+}
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