diff options
author | Luke Shumaker <lukeshu@sbcglobal.net> | 2016-07-30 11:51:52 -0400 |
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committer | Luke Shumaker <lukeshu@sbcglobal.net> | 2016-07-30 11:51:52 -0400 |
commit | 2bd52fb107528d459dabd5929794987c01a7270e (patch) | |
tree | e01842ceb4617c06dee673c2a09dd4707ae33ab8 /src/libcore/selinux-access.c | |
parent | 1ed649627c5dbf9254f325c8254bfa69c31466c9 (diff) |
stuff
Diffstat (limited to 'src/libcore/selinux-access.c')
-rw-r--r-- | src/libcore/selinux-access.c | 283 |
1 files changed, 0 insertions, 283 deletions
diff --git a/src/libcore/selinux-access.c b/src/libcore/selinux-access.c deleted file mode 100644 index a259e128c1..0000000000 --- a/src/libcore/selinux-access.c +++ /dev/null @@ -1,283 +0,0 @@ -/*** - This file is part of systemd. - - Copyright 2012 Dan Walsh - - 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 "selinux-access.h" - -#ifdef HAVE_SELINUX - -#include <errno.h> -#include <selinux/avc.h> -#include <selinux/selinux.h> -#include <stdio.h> -#ifdef HAVE_AUDIT -#include <libaudit.h> -#endif - -#include <systemd/sd-bus.h> - -#include "basic/alloc-util.h" -#include "audit-fd.h" -#include "shared/bus-util.h" -#include "basic/log.h" -#include "basic/path-util.h" -#include "basic/selinux-util.h" -#include "basic/stdio-util.h" -#include "basic/strv.h" -#include "basic/util.h" - -static bool initialized = false; - -struct audit_info { - sd_bus_creds *creds; - const char *path; - const char *cmdline; -}; - -/* - Any time an access gets denied this callback will be called - with the audit data. We then need to just copy the audit data into the msgbuf. -*/ -static int audit_callback( - void *auditdata, - security_class_t cls, - char *msgbuf, - size_t msgbufsize) { - - const struct audit_info *audit = auditdata; - uid_t uid = 0, login_uid = 0; - gid_t gid = 0; - char login_uid_buf[DECIMAL_STR_MAX(uid_t) + 1] = "n/a"; - char uid_buf[DECIMAL_STR_MAX(uid_t) + 1] = "n/a"; - char gid_buf[DECIMAL_STR_MAX(gid_t) + 1] = "n/a"; - - if (sd_bus_creds_get_audit_login_uid(audit->creds, &login_uid) >= 0) - xsprintf(login_uid_buf, UID_FMT, login_uid); - if (sd_bus_creds_get_euid(audit->creds, &uid) >= 0) - xsprintf(uid_buf, UID_FMT, uid); - if (sd_bus_creds_get_egid(audit->creds, &gid) >= 0) - xsprintf(gid_buf, GID_FMT, gid); - - snprintf(msgbuf, msgbufsize, - "auid=%s uid=%s gid=%s%s%s%s%s%s%s", - login_uid_buf, uid_buf, gid_buf, - audit->path ? " path=\"" : "", strempty(audit->path), audit->path ? "\"" : "", - audit->cmdline ? " cmdline=\"" : "", strempty(audit->cmdline), audit->cmdline ? "\"" : ""); - - return 0; -} - -static int callback_type_to_priority(int type) { - switch(type) { - - case SELINUX_ERROR: - return LOG_ERR; - - case SELINUX_WARNING: - return LOG_WARNING; - - case SELINUX_INFO: - return LOG_INFO; - - case SELINUX_AVC: - default: - return LOG_NOTICE; - } -} - -/* - libselinux uses this callback when access gets denied or other - events happen. If audit is turned on, messages will be reported - using audit netlink, otherwise they will be logged using the usual - channels. - - Code copied from dbus and modified. -*/ -_printf_(2, 3) static int log_callback(int type, const char *fmt, ...) { - va_list ap; - const char *fmt2; - -#ifdef HAVE_AUDIT - int fd; - - fd = get_audit_fd(); - - if (fd >= 0) { - _cleanup_free_ char *buf = NULL; - int r; - - va_start(ap, fmt); - r = vasprintf(&buf, fmt, ap); - va_end(ap); - - if (r >= 0) { - audit_log_user_avc_message(fd, AUDIT_USER_AVC, buf, NULL, NULL, NULL, 0); - return 0; - } - } -#endif - - fmt2 = strjoina("selinux: ", fmt); - - va_start(ap, fmt); - log_internalv(LOG_AUTH | callback_type_to_priority(type), 0, __FILE__, __LINE__, __FUNCTION__, fmt2, ap); - va_end(ap); - - return 0; -} - -static int access_init(sd_bus_error *error) { - - if (!mac_selinux_use()) - return 0; - - if (initialized) - return 1; - - if (avc_open(NULL, 0) != 0) { - int enforce, saved_errno = errno; - - enforce = security_getenforce(); - log_full_errno(enforce != 0 ? LOG_ERR : LOG_WARNING, saved_errno, "Failed to open the SELinux AVC: %m"); - - /* If enforcement isn't on, then let's suppress this - * error, and just don't do any AVC checks. The - * warning we printed is hence all the admin will - * see. */ - if (enforce == 0) - return 0; - - /* Return an access denied error, if we couldn't load - * the AVC but enforcing mode was on, or we couldn't - * determine whether it is one. */ - return sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to open the SELinux AVC: %s", strerror(saved_errno)); - } - - selinux_set_callback(SELINUX_CB_AUDIT, (union selinux_callback) audit_callback); - selinux_set_callback(SELINUX_CB_LOG, (union selinux_callback) log_callback); - - initialized = true; - return 1; -} - -/* - This function communicates with the kernel to check whether or not it should - allow the access. - If the machine is in permissive mode it will return ok. Audit messages will - still be generated if the access would be denied in enforcing mode. -*/ -int mac_selinux_generic_access_check( - sd_bus_message *message, - const char *path, - const char *permission, - sd_bus_error *error) { - - _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL; - const char *tclass = NULL, *scon = NULL; - struct audit_info audit_info = {}; - _cleanup_free_ char *cl = NULL; - security_context_t fcon = NULL; - char **cmdline = NULL; - int r = 0; - - assert(message); - assert(permission); - assert(error); - - r = access_init(error); - if (r <= 0) - return r; - - r = sd_bus_query_sender_creds( - message, - SD_BUS_CREDS_PID|SD_BUS_CREDS_EUID|SD_BUS_CREDS_EGID| - SD_BUS_CREDS_CMDLINE|SD_BUS_CREDS_AUDIT_LOGIN_UID| - SD_BUS_CREDS_SELINUX_CONTEXT| - SD_BUS_CREDS_AUGMENT /* get more bits from /proc */, - &creds); - if (r < 0) - goto finish; - - /* The SELinux context is something we really should have - * gotten directly from the message or sender, and not be an - * augmented field. If it was augmented we cannot use it for - * authorization, since this is racy and vulnerable. Let's add - * an extra check, just in case, even though this really - * shouldn't be possible. */ - assert_return((sd_bus_creds_get_augmented_mask(creds) & SD_BUS_CREDS_SELINUX_CONTEXT) == 0, -EPERM); - - r = sd_bus_creds_get_selinux_context(creds, &scon); - if (r < 0) - goto finish; - - if (path) { - /* Get the file context of the unit file */ - - r = getfilecon_raw(path, &fcon); - if (r < 0) { - r = sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to get file context on %s.", path); - goto finish; - } - - tclass = "service"; - } else { - r = getcon_raw(&fcon); - if (r < 0) { - r = sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to get current context."); - goto finish; - } - - tclass = "system"; - } - - sd_bus_creds_get_cmdline(creds, &cmdline); - cl = strv_join(cmdline, " "); - - audit_info.creds = creds; - audit_info.path = path; - audit_info.cmdline = cl; - - r = selinux_check_access(scon, fcon, tclass, permission, &audit_info); - if (r < 0) - r = sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "SELinux policy denies access."); - - log_debug("SELinux access check scon=%s tcon=%s tclass=%s perm=%s path=%s cmdline=%s: %i", scon, fcon, tclass, permission, path, cl, r); - -finish: - freecon(fcon); - - if (r < 0 && security_getenforce() != 1) { - sd_bus_error_free(error); - r = 0; - } - - return r; -} - -#else - -int mac_selinux_generic_access_check( - sd_bus_message *message, - const char *path, - const char *permission, - sd_bus_error *error) { - - return 0; -} - -#endif |