| /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
| |
| /*** |
| This file is part of systemd. |
| |
| Copyright 2010 Lennart Poettering |
| |
| systemd is free software; you can redistribute it and/or modify it |
| under the terms of the GNU Lesser General Public License as published by |
| the Free Software Foundation; either version 2.1 of the License, or |
| (at your option) any later version. |
| |
| systemd is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with systemd; If not, see <http://www.gnu.org/licenses/>. |
| ***/ |
| |
| #include <errno.h> |
| #include <sys/stat.h> |
| #include <unistd.h> |
| #include <malloc.h> |
| #include <sys/socket.h> |
| #include <sys/un.h> |
| |
| #include "label.h" |
| #include "util.h" |
| #include "path-util.h" |
| |
| #ifdef HAVE_SELINUX |
| #include <selinux/selinux.h> |
| #include <selinux/label.h> |
| |
| static struct selabel_handle *label_hnd = NULL; |
| |
| static int use_selinux_cached = -1; |
| |
| static inline bool use_selinux(void) { |
| |
| if (use_selinux_cached < 0) |
| use_selinux_cached = is_selinux_enabled() > 0; |
| |
| return use_selinux_cached; |
| } |
| |
| void label_retest_selinux(void) { |
| use_selinux_cached = -1; |
| } |
| |
| #endif |
| |
| int label_init(const char *prefixes[]) { |
| int r = 0; |
| |
| #ifdef HAVE_SELINUX |
| usec_t before_timestamp, after_timestamp; |
| struct mallinfo before_mallinfo, after_mallinfo; |
| |
| if (!use_selinux()) |
| return 0; |
| |
| if (label_hnd) |
| return 0; |
| |
| before_mallinfo = mallinfo(); |
| before_timestamp = now(CLOCK_MONOTONIC); |
| |
| if (prefixes) { |
| struct selinux_opt options[] = { |
| { .type = SELABEL_OPT_SUBSET, .values = prefixes }, |
| }; |
| |
| label_hnd = selabel_open(SELABEL_CTX_FILE, options, ELEMENTSOF(options)); |
| } else |
| label_hnd = selabel_open(SELABEL_CTX_FILE, NULL, 0); |
| |
| if (!label_hnd) { |
| log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG, |
| "Failed to initialize SELinux context: %m"); |
| r = security_getenforce() == 1 ? -errno : 0; |
| } else { |
| char timespan[FORMAT_TIMESPAN_MAX]; |
| int l; |
| |
| after_timestamp = now(CLOCK_MONOTONIC); |
| after_mallinfo = mallinfo(); |
| |
| l = after_mallinfo.uordblks > before_mallinfo.uordblks ? after_mallinfo.uordblks - before_mallinfo.uordblks : 0; |
| |
| log_debug("Successfully loaded SELinux database in %s, size on heap is %iK.", |
| format_timespan(timespan, sizeof(timespan), after_timestamp - before_timestamp), |
| (l+1023)/1024); |
| } |
| #endif |
| |
| return r; |
| } |
| |
| int label_fix(const char *path, bool ignore_enoent) { |
| int r = 0; |
| |
| #ifdef HAVE_SELINUX |
| struct stat st; |
| security_context_t fcon; |
| |
| if (!use_selinux() || !label_hnd) |
| return 0; |
| |
| r = lstat(path, &st); |
| if (r == 0) { |
| r = selabel_lookup_raw(label_hnd, &fcon, path, st.st_mode); |
| |
| /* If there's no label to set, then exit without warning */ |
| if (r < 0 && errno == ENOENT) |
| return 0; |
| |
| if (r == 0) { |
| r = lsetfilecon(path, fcon); |
| freecon(fcon); |
| |
| /* If the FS doesn't support labels, then exit without warning */ |
| if (r < 0 && errno == ENOTSUP) |
| return 0; |
| } |
| } |
| |
| if (r < 0) { |
| /* Ignore ENOENT in some cases */ |
| if (ignore_enoent && errno == ENOENT) |
| return 0; |
| |
| log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG, |
| "Unable to fix label of %s: %m", path); |
| r = security_getenforce() == 1 ? -errno : 0; |
| } |
| #endif |
| |
| return r; |
| } |
| |
| void label_finish(void) { |
| |
| #ifdef HAVE_SELINUX |
| if (use_selinux() && label_hnd) |
| selabel_close(label_hnd); |
| #endif |
| } |
| |
| int label_get_create_label_from_exe(const char *exe, char **label) { |
| |
| int r = 0; |
| |
| #ifdef HAVE_SELINUX |
| security_context_t mycon = NULL, fcon = NULL; |
| security_class_t sclass; |
| |
| if (!use_selinux()) { |
| *label = NULL; |
| return 0; |
| } |
| |
| r = getcon(&mycon); |
| if (r < 0) |
| goto fail; |
| |
| r = getfilecon(exe, &fcon); |
| if (r < 0) |
| goto fail; |
| |
| sclass = string_to_security_class("process"); |
| r = security_compute_create(mycon, fcon, sclass, (security_context_t *) label); |
| if (r == 0) |
| log_debug("SELinux Socket context for %s will be set to %s", exe, *label); |
| |
| fail: |
| if (r < 0 && security_getenforce() == 1) |
| r = -errno; |
| |
| freecon(mycon); |
| freecon(fcon); |
| #endif |
| |
| return r; |
| } |
| |
| int label_context_set(const char *path, mode_t mode) { |
| int r = 0; |
| |
| #ifdef HAVE_SELINUX |
| security_context_t filecon = NULL; |
| |
| if (!use_selinux() || !label_hnd) |
| return 0; |
| |
| r = selabel_lookup_raw(label_hnd, &filecon, path, mode); |
| if (r < 0) |
| r = -errno; |
| else if (r == 0) { |
| r = setfscreatecon(filecon); |
| if (r < 0) { |
| log_error("Failed to set SELinux file context on %s: %m", path); |
| r = -errno; |
| } |
| |
| freecon(filecon); |
| } |
| |
| if (r < 0 && security_getenforce() == 0) |
| r = 0; |
| #endif |
| |
| return r; |
| } |
| |
| int label_socket_set(const char *label) { |
| |
| #ifdef HAVE_SELINUX |
| if (!use_selinux()) |
| return 0; |
| |
| if (setsockcreatecon((security_context_t) label) < 0) { |
| log_full(security_getenforce() == 1 ? LOG_ERR : LOG_DEBUG, |
| "Failed to set SELinux context (%s) on socket: %m", label); |
| |
| if (security_getenforce() == 1) |
| return -errno; |
| } |
| #endif |
| |
| return 0; |
| } |
| |
| void label_context_clear(void) { |
| |
| #ifdef HAVE_SELINUX |
| if (!use_selinux()) |
| return; |
| |
| setfscreatecon(NULL); |
| #endif |
| } |
| |
| void label_socket_clear(void) { |
| |
| #ifdef HAVE_SELINUX |
| if (!use_selinux()) |
| return; |
| |
| setsockcreatecon(NULL); |
| #endif |
| } |
| |
| void label_free(const char *label) { |
| |
| #ifdef HAVE_SELINUX |
| if (!use_selinux()) |
| return; |
| |
| freecon((security_context_t) label); |
| #endif |
| } |
| |
| int label_mkdir(const char *path, mode_t mode) { |
| |
| /* Creates a directory and labels it according to the SELinux policy */ |
| |
| #ifdef HAVE_SELINUX |
| int r; |
| security_context_t fcon = NULL; |
| |
| if (!use_selinux() || !label_hnd) |
| goto skipped; |
| |
| if (path_is_absolute(path)) |
| r = selabel_lookup_raw(label_hnd, &fcon, path, S_IFDIR); |
| else { |
| char *newpath; |
| |
| newpath = path_make_absolute_cwd(path); |
| if (!newpath) |
| return -ENOMEM; |
| |
| r = selabel_lookup_raw(label_hnd, &fcon, newpath, S_IFDIR); |
| free(newpath); |
| } |
| |
| if (r == 0) |
| r = setfscreatecon(fcon); |
| |
| if (r < 0 && errno != ENOENT) { |
| log_error("Failed to set security context %s for %s: %m", fcon, path); |
| |
| if (security_getenforce() == 1) { |
| r = -errno; |
| goto finish; |
| } |
| } |
| |
| r = mkdir(path, mode); |
| if (r < 0) |
| r = -errno; |
| |
| finish: |
| setfscreatecon(NULL); |
| freecon(fcon); |
| |
| return r; |
| |
| skipped: |
| #endif |
| return mkdir(path, mode) < 0 ? -errno : 0; |
| } |
| |
| int label_bind(int fd, const struct sockaddr *addr, socklen_t addrlen) { |
| |
| /* Binds a socket and label its file system object according to the SELinux policy */ |
| |
| #ifdef HAVE_SELINUX |
| int r; |
| security_context_t fcon = NULL; |
| const struct sockaddr_un *un; |
| char *path = NULL; |
| |
| assert(fd >= 0); |
| assert(addr); |
| assert(addrlen >= sizeof(sa_family_t)); |
| |
| if (!use_selinux() || !label_hnd) |
| goto skipped; |
| |
| /* Filter out non-local sockets */ |
| if (addr->sa_family != AF_UNIX) |
| goto skipped; |
| |
| /* Filter out anonymous sockets */ |
| if (addrlen < sizeof(sa_family_t) + 1) |
| goto skipped; |
| |
| /* Filter out abstract namespace sockets */ |
| un = (const struct sockaddr_un*) addr; |
| if (un->sun_path[0] == 0) |
| goto skipped; |
| |
| path = strndup(un->sun_path, addrlen - offsetof(struct sockaddr_un, sun_path)); |
| if (!path) |
| return -ENOMEM; |
| |
| if (path_is_absolute(path)) |
| r = selabel_lookup_raw(label_hnd, &fcon, path, S_IFSOCK); |
| else { |
| char *newpath; |
| |
| newpath = path_make_absolute_cwd(path); |
| |
| if (!newpath) { |
| free(path); |
| return -ENOMEM; |
| } |
| |
| r = selabel_lookup_raw(label_hnd, &fcon, newpath, S_IFSOCK); |
| free(newpath); |
| } |
| |
| if (r == 0) |
| r = setfscreatecon(fcon); |
| |
| if (r < 0 && errno != ENOENT) { |
| log_error("Failed to set security context %s for %s: %m", fcon, path); |
| |
| if (security_getenforce() == 1) { |
| r = -errno; |
| goto finish; |
| } |
| } |
| |
| r = bind(fd, addr, addrlen); |
| if (r < 0) |
| r = -errno; |
| |
| finish: |
| setfscreatecon(NULL); |
| freecon(fcon); |
| free(path); |
| |
| return r; |
| |
| skipped: |
| #endif |
| return bind(fd, addr, addrlen) < 0 ? -errno : 0; |
| } |