/* SPDX-License-Identifier: LGPL-2.1-or-later */ /*** Copyright © 2013 Intel Corporation Authors: Nathaniel Chen ***/ #include #include #include #include #include #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" #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 = -EBADF, change_fd = -EBADF; _cleanup_closedir_ DIR *dir = NULL; int dfd = -EBADF, 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; 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 = -EBADF; _cleanup_closedir_ DIR *dir = NULL; int dfd = -EBADF, 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; 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; int dfd = -EBADF, 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 = -EBADF; _cleanup_free_ char *list = NULL; _cleanup_fclose_ FILE *f = NULL; size_t len = 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, 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; } #if HAVE_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: return log_emergency_errno(r, "Failed to write Smack onlycap list: %m"); } *loaded_policy = true; #endif return 0; }