X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fcore%2Fselinux-access.c;h=a8c9a4b888f6e8a268e089d053741f0cf133b3a2;hp=4b1dc74e93b8dc6bce77fcfd976b6ad28cf5eb33;hb=5bd4b173605142c7be493aa4d958ebaef21f421d;hpb=ffc227c9568eb0a12dc750761d1e5d68ea125aad diff --git a/src/core/selinux-access.c b/src/core/selinux-access.c index 4b1dc74e9..a8c9a4b88 100644 --- a/src/core/selinux-access.c +++ b/src/core/selinux-access.c @@ -6,16 +6,16 @@ Copyright 2012 Dan Walsh systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or + 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 - General Public License for more details. + Lesser General Public License for more details. - You should have received a copy of the GNU General Public License + You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see . ***/ @@ -24,111 +24,32 @@ #ifdef HAVE_SELINUX #include -#include #include -#include #include #include #ifdef HAVE_AUDIT #include #endif -#include +#include "sd-bus.h" +#include "bus-util.h" #include "util.h" #include "log.h" -#include "bus-errors.h" -#include "dbus-common.h" -#include "audit.h" #include "selinux-util.h" #include "audit-fd.h" +#include "strv.h" static bool initialized = false; -struct auditstruct { +struct audit_info { + sd_bus_creds *creds; const char *path; - char *cmdline; - uid_t loginuid; - uid_t uid; - gid_t gid; + const char *cmdline; }; -static int bus_get_selinux_security_context( - DBusConnection *connection, - const char *name, - char **scon, - DBusError *error) { - - _cleanup_dbus_message_unref_ DBusMessage *m = NULL, *reply = NULL; - - m = dbus_message_new_method_call( - DBUS_SERVICE_DBUS, - DBUS_PATH_DBUS, - DBUS_INTERFACE_DBUS, - "GetConnectionSELinuxSecurityContext"); - if (!m) { - dbus_set_error_const(error, DBUS_ERROR_NO_MEMORY, NULL); - return -ENOMEM; - } - - if (!dbus_message_append_args( - m, - DBUS_TYPE_STRING, &name, - DBUS_TYPE_INVALID)) { - dbus_set_error_const(error, DBUS_ERROR_NO_MEMORY, NULL); - return -ENOMEM; - } - - reply = dbus_connection_send_with_reply_and_block(connection, m, -1, error); - if (!reply) - return -EIO; - - if (dbus_set_error_from_message(error, reply)) - return -EIO; - - if (!dbus_message_get_args( - reply, error, - DBUS_TYPE_STRING, scon, - DBUS_TYPE_INVALID)) - return -EIO; - - return 0; -} - -static int bus_get_audit_data( - DBusConnection *connection, - const char *name, - struct auditstruct *audit, - DBusError *error) { - - pid_t pid; - int r; - - pid = bus_get_unix_process_id(connection, name, error); - if (pid <= 0) - return -EIO; - - r = audit_loginuid_from_pid(pid, &audit->loginuid); - if (r < 0) - return r; - - r = get_process_uid(pid, &audit->uid); - if (r < 0) - return r; - - r = get_process_gid(pid, &audit->gid); - if (r < 0) - return r; - - r = get_process_cmdline(pid, LINE_MAX, true, &audit->cmdline); - if (r < 0) - return r; - - return 0; -} - /* Any time an access gets denied this callback will be called - with the aduit data. We then need to just copy the audit data into the msgbuf. + with the audit data. We then need to just copy the audit data into the msgbuf. */ static int audit_callback( void *auditdata, @@ -136,21 +57,25 @@ static int audit_callback( char *msgbuf, size_t msgbufsize) { - struct auditstruct *audit = (struct auditstruct *) auditdata; + 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=%d uid=%d gid=%d%s%s%s%s%s%s", - audit->loginuid, - audit->uid, - audit->gid, - (audit->path ? " path=\"" : ""), - strempty(audit->path), - (audit->path ? "\"" : ""), - (audit->cmdline ? " cmdline=\"" : ""), - strempty(audit->cmdline), - (audit->cmdline ? "\"" : "")); - - msgbuf[msgbufsize-1] = 0; + "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; } @@ -161,23 +86,27 @@ static int audit_callback( user_avc's into the /var/log/audit/audit.log, otherwise they will be sent to syslog. */ -static int log_callback(int type, const char *fmt, ...) { +_printf_(2, 3) static int log_callback(int type, const char *fmt, ...) { va_list ap; - va_start(ap, fmt); - #ifdef HAVE_AUDIT if (get_audit_fd() >= 0) { - char buf[LINE_MAX]; + _cleanup_free_ char *buf = NULL; + int r; - vsnprintf(buf, sizeof(buf), fmt, ap); - audit_log_user_avc_message(get_audit_fd(), AUDIT_USER_AVC, buf, NULL, NULL, NULL, 0); + va_start(ap, fmt); + r = vasprintf(&buf, fmt, ap); va_end(ap); - return 0; + if (r >= 0) { + audit_log_user_avc_message(get_audit_fd(), AUDIT_USER_AVC, buf, NULL, NULL, NULL, 0); + return 0; + } } #endif - log_metav(LOG_USER | LOG_INFO, __FILE__, __LINE__, __FUNCTION__, fmt, ap); + + va_start(ap, fmt); + log_internalv(LOG_AUTH | LOG_INFO, 0, __FILE__, __LINE__, __FUNCTION__, fmt, ap); va_end(ap); return 0; @@ -189,129 +118,49 @@ static int log_callback(int type, const char *fmt, ...) { If you want to cleanup memory you should need to call selinux_access_finish. */ static int access_init(void) { - int r; + int r = 0; - if (avc_open(NULL, 0)) { - log_error("avc_open() failed: %m"); - return -errno; - } + if (avc_open(NULL, 0)) + return log_error_errno(errno, "avc_open() failed: %m"); selinux_set_callback(SELINUX_CB_AUDIT, (union selinux_callback) audit_callback); selinux_set_callback(SELINUX_CB_LOG, (union selinux_callback) log_callback); - if (security_getenforce() >= 0) - return 0; - - r = -errno; - avc_destroy(); + if (security_getenforce() < 0){ + r = -errno; + avc_destroy(); + } return r; } -static int selinux_access_init(DBusError *error) { +static int mac_selinux_access_init(sd_bus_error *error) { int r; if (initialized) return 0; - if (use_selinux()) { - r = access_init(); - if (r < 0) { - dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "Failed to initialize SELinux."); - return r; - } - } + if (!mac_selinux_use()) + return 0; + + r = access_init(); + if (r < 0) + return sd_bus_error_set(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to initialize SELinux."); initialized = true; return 0; } +#endif + +void mac_selinux_access_free(void) { -void selinux_access_free(void) { +#ifdef HAVE_SELINUX if (!initialized) return; avc_destroy(); initialized = false; -} - -static int get_audit_data( - DBusConnection *connection, - DBusMessage *message, - struct auditstruct *audit, - DBusError *error) { - - const char *sender; - int r, fd; - struct ucred ucred; - socklen_t len; - - sender = dbus_message_get_sender(message); - if (sender) - return bus_get_audit_data(connection, sender, audit, error); - - if (!dbus_connection_get_unix_fd(connection, &fd)) - return -EINVAL; - - r = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len); - if (r < 0) { - log_error("Failed to determine peer credentials: %m"); - return -errno; - } - - audit->uid = ucred.uid; - audit->gid = ucred.gid; - - r = audit_loginuid_from_pid(ucred.pid, &audit->loginuid); - if (r < 0) - return r; - - r = get_process_cmdline(ucred.pid, LINE_MAX, true, &audit->cmdline); - if (r < 0) - return r; - - return 0; -} - -/* - This function returns the security context of the remote end of the dbus - connections. Whether it is on the bus or a local connection. -*/ -static int get_calling_context( - DBusConnection *connection, - DBusMessage *message, - security_context_t *scon, - DBusError *error) { - - const char *sender; - int r; - int fd; - - /* - If sender exists then - if sender is NULL this indicates a local connection. Grab the fd - from dbus and do an getpeercon to peers process context - */ - sender = dbus_message_get_sender(message); - if (sender) { - r = bus_get_selinux_security_context(connection, sender, scon, error); - if (r >= 0) - return r; - - log_debug("bus_get_selinux_security_context failed %m"); - } - - if (!dbus_connection_get_unix_fd(connection, &fd)) { - log_error("bus_connection_get_unix_fd failed %m"); - return -EINVAL; - } - - r = getpeercon(fd, scon); - if (r < 0) { - log_error("getpeercon failed %m"); - return -errno; - } - - return 0; +#endif } /* @@ -320,103 +169,111 @@ static int get_calling_context( 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 selinux_access_check( - DBusConnection *connection, - DBusMessage *message, +int mac_selinux_generic_access_check( + sd_bus_message *message, const char *path, const char *permission, - DBusError *error) { + sd_bus_error *error) { - security_context_t scon = NULL, fcon = NULL; +#ifdef HAVE_SELINUX + _cleanup_bus_creds_unref_ 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; - const char *tclass = NULL; - struct auditstruct audit; - assert(connection); assert(message); assert(permission); assert(error); - if (!use_selinux()) + if (!mac_selinux_use()) return 0; - r = selinux_access_init(error); + r = mac_selinux_access_init(error); if (r < 0) return r; - log_debug("SELinux access check for path=%s permission=%s", strna(path), permission); - - audit.uid = audit.loginuid = (uid_t) -1; - audit.gid = (gid_t) -1; - audit.cmdline = NULL; - audit.path = path; + 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; - r = get_calling_context(connection, message, &scon, error); - if (r < 0) { - log_error("Failed to get caller's security context on: %m"); + r = sd_bus_creds_get_selinux_context(creds, &scon); + if (r < 0) goto finish; - } if (path) { - tclass = "service"; - /* get the file context of the unit file */ + /* Get the file context of the unit file */ + r = getfilecon(path, &fcon); if (r < 0) { - dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "Failed to get file context on %s.", path); - r = -errno; - log_error("Failed to get security context on %s: %m",path); + r = sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to get file context on %s.", path); goto finish; } + tclass = "service"; } else { - tclass = "system"; r = getcon(&fcon); if (r < 0) { - dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "Failed to get current context."); - r = -errno; - log_error("Failed to get current process context on: %m"); + r = sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to get current context."); goto finish; } + + tclass = "system"; } - (void) get_audit_data(connection, message, &audit, error); + sd_bus_creds_get_cmdline(creds, &cmdline); + cl = strv_join(cmdline, " "); - errno = 0; - r = selinux_check_access(scon, fcon, tclass, permission, &audit); - if (r < 0) { - dbus_set_error(error, DBUS_ERROR_ACCESS_DENIED, "SELinux policy denies access."); - r = -errno; - log_error("SELinux policy denies access."); - } + audit_info.creds = creds; + audit_info.path = path; + audit_info.cmdline = cl; + + r = selinux_check_access((security_context_t) 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, audit.cmdline, r); + 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: - free(audit.cmdline); - freecon(scon); freecon(fcon); - if (r && security_getenforce() != 1) { - dbus_error_init(error); + if (r < 0 && security_getenforce() != 1) { + sd_bus_error_free(error); r = 0; } return r; -} - #else - -int selinux_access_check( - DBusConnection *connection, - DBusMessage *message, - const char *path, - const char *permission, - DBusError *error) { - return 0; +#endif } -void selinux_access_free(void) { -} +int mac_selinux_unit_access_check_strv(char **units, + sd_bus_message *message, + Manager *m, + const char *permission, + sd_bus_error *error) { +#ifdef HAVE_SELINUX + char **i; + Unit *u; + int r; + STRV_FOREACH(i, units) { + u = manager_get_unit(m, *i); + if (u) { + r = mac_selinux_unit_access_check(u, message, permission, error); + if (r < 0) + return r; + } + } #endif + return 0; +}