journald: add support for wall forwarding

This will let journald forward logs as messages sent to all logged in
users (like wall).

Two options are added:
 * ForwardToWall (default yes)
 * MaxLevelWall (default emerg)
'ForwardToWall' is overridable by kernel command line option
'systemd.journald.forward_to_wall'.

This is used to emulate the traditional syslogd behaviour of sending
emergency messages to all logged in users.

9 files changed, 121 insertions, 0 deletions

diff --git a/src/journal/journald-gperf.gperf b/src/journal/journald-gperf.gperf
index 83bbbc8d2..74554c1c3 100644
--- a/src/journal/journald-gperf.gperf
+++ b/src/journal/journald-gperf.gperf
@@ -32,9 +32,11 @@ Journal.MaxFileSec,         config_parse_sec,        0, offsetof(Server, max_fil
 Journal.ForwardToSyslog,    config_parse_bool,       0, offsetof(Server, forward_to_syslog)
 Journal.ForwardToKMsg,      config_parse_bool,       0, offsetof(Server, forward_to_kmsg)
 Journal.ForwardToConsole,   config_parse_bool,       0, offsetof(Server, forward_to_console)
+Journal.ForwardToWall,      config_parse_bool,       0, offsetof(Server, forward_to_wall)
 Journal.TTYPath,            config_parse_path,       0, offsetof(Server, tty_path)
 Journal.MaxLevelStore,      config_parse_log_level,  0, offsetof(Server, max_level_store)
 Journal.MaxLevelSyslog,     config_parse_log_level,  0, offsetof(Server, max_level_syslog)
 Journal.MaxLevelKMsg,       config_parse_log_level,  0, offsetof(Server, max_level_kmsg)
 Journal.MaxLevelConsole,    config_parse_log_level,  0, offsetof(Server, max_level_console)
+Journal.MaxLevelWall,       config_parse_log_level,  0, offsetof(Server, max_level_wall)
 Journal.SplitMode,          config_parse_split_mode, 0, offsetof(Server, split_mode)
diff --git a/src/journal/journald-native.c b/src/journal/journald-native.c
index 359d962c7..0509c1eae 100644
--- a/src/journal/journald-native.c
+++ b/src/journal/journald-native.c
@@ -31,6 +31,7 @@
 #include "journald-kmsg.h"
 #include "journald-console.h"
 #include "journald-syslog.h"
+#include "journald-wall.h"
 
 /* Make sure not to make this smaller than the maximum coredump
  * size. See COREDUMP_MAX in coredump.c */
@@ -265,6 +266,9 @@ void server_process_native_message(
 
                 if (s->forward_to_console)
                         server_forward_console(s, priority, identifier, message, ucred);
+
+                if (s->forward_to_wall)
+                        server_forward_wall(s, priority, identifier, message, ucred);
         }
 
         server_dispatch_message(s, iovec, n, m, ucred, tv, label, label_len, NULL, priority, object_pid);
diff --git a/src/journal/journald-server.c b/src/journal/journald-server.c
index 868065075..f0117e742 100644
--- a/src/journal/journald-server.c
+++ b/src/journal/journald-server.c
@@ -1319,6 +1319,12 @@ static int server_parse_proc_cmdline(Server *s) {
                                 log_warning("Failed to parse forward to console switch %s. Ignoring.", word + 36);
                         else
                                 s->forward_to_console = r;
+                } else if (startswith(word, "systemd.journald.forward_to_wall=")) {
+                        r = parse_boolean(word + 33);
+                        if (r < 0)
+                                log_warning("Failed to parse forward to wall switch %s. Ignoring.", word + 33);
+                        else
+                                s->forward_to_wall = r;
                 } else if (startswith(word, "systemd.journald"))
                         log_warning("Invalid systemd.journald parameter. Ignoring.");
         }
@@ -1466,11 +1472,13 @@ int server_init(Server *s) {
         s->rate_limit_burst = DEFAULT_RATE_LIMIT_BURST;
 
         s->forward_to_syslog = true;
+        s->forward_to_wall = true;
 
         s->max_level_store = LOG_DEBUG;
         s->max_level_syslog = LOG_DEBUG;
         s->max_level_kmsg = LOG_NOTICE;
         s->max_level_console = LOG_INFO;
+        s->max_level_wall = LOG_EMERG;
 
         memset(&s->system_metrics, 0xFF, sizeof(s->system_metrics));
         memset(&s->runtime_metrics, 0xFF, sizeof(s->runtime_metrics));
diff --git a/src/journal/journald-server.h b/src/journal/journald-server.h
index 2a81061f2..e468b8293 100644
--- a/src/journal/journald-server.h
+++ b/src/journal/journald-server.h
@@ -97,6 +97,7 @@ typedef struct Server {
         bool forward_to_kmsg;
         bool forward_to_syslog;
         bool forward_to_console;
+        bool forward_to_wall;
 
         unsigned n_forward_syslog_missed;
         usec_t last_warn_forward_syslog_missed;
@@ -119,6 +120,7 @@ typedef struct Server {
         int max_level_syslog;
         int max_level_kmsg;
         int max_level_console;
+        int max_level_wall;
 
         Storage storage;
         SplitMode split_mode;
diff --git a/src/journal/journald-stream.c b/src/journal/journald-stream.c
index 36fc75526..c46ffe5d4 100644
--- a/src/journal/journald-stream.c
+++ b/src/journal/journald-stream.c
@@ -35,6 +35,7 @@
 #include "journald-syslog.h"
 #include "journald-kmsg.h"
 #include "journald-console.h"
+#include "journald-wall.h"
 
 #define STDOUT_STREAMS_MAX 4096
 
@@ -106,6 +107,9 @@ static int stdout_stream_log(StdoutStream *s, const char *p) {
         if (s->forward_to_console || s->server->forward_to_console)
                 server_forward_console(s->server, priority, s->identifier, p, &s->ucred);
 
+        if (s->server->forward_to_wall)
+                server_forward_wall(s->server, priority, s->identifier, p, &s->ucred);
+
         IOVEC_SET_STRING(iovec[n++], "_TRANSPORT=stdout");
 
         syslog_priority[strlen("PRIORITY=")] = '0' + LOG_PRI(priority);
diff --git a/src/journal/journald-syslog.c b/src/journal/journald-syslog.c
index 241f7edb6..cbb944f28 100644
--- a/src/journal/journald-syslog.c
+++ b/src/journal/journald-syslog.c
@@ -30,6 +30,7 @@
 #include "journald-syslog.h"
 #include "journald-kmsg.h"
 #include "journald-console.h"
+#include "journald-wall.h"
 
 /* Warn once every 30s if we missed syslog message */
 #define WARN_FORWARD_SYSLOG_MISSED_USEC (30 * USEC_PER_SEC)
@@ -380,6 +381,9 @@ void server_process_syslog_message(
         if (s->forward_to_console)
                 server_forward_console(s, priority, identifier, buf, ucred);
 
+        if (s->forward_to_wall)
+                server_forward_wall(s, priority, identifier, buf, ucred);
+
         IOVEC_SET_STRING(iovec[n++], "_TRANSPORT=syslog");
 
         if (asprintf(&syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK) >= 0)
diff --git a/src/journal/journald-wall.c b/src/journal/journald-wall.c
new file mode 100644
index 000000000..fcbd9183f
--- /dev/null
+++ b/src/journal/journald-wall.c
@@ -0,0 +1,69 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2014 Sebastian Thorarensen
+
+  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 "utmp-wtmp.h"
+#include "journald-server.h"
+#include "journald-wall.h"
+
+void server_forward_wall(
+                Server *s,
+                int priority,
+                const char *identifier,
+                const char *message,
+                struct ucred *ucred) {
+
+        _cleanup_free_ char *ident_buf = NULL, *l_buf = NULL;
+        const char *l;
+        int r;
+
+        assert(s);
+        assert(message);
+
+        if (LOG_PRI(priority) > s->max_level_wall)
+                return;
+
+        if (ucred) {
+                if (!identifier) {
+                        get_process_comm(ucred->pid, &ident_buf);
+                        identifier = ident_buf;
+                }
+
+                if (asprintf(&l_buf, "%s["PID_FMT"]: %s", strempty(identifier), ucred->pid, message) < 0) {
+                        log_oom();
+                        return;
+                }
+
+                l = l_buf;
+
+        } else if (identifier) {
+
+                l = l_buf = strjoin(identifier, ": ", message, NULL);
+                if (!l_buf) {
+                        log_oom();
+                        return;
+                }
+        } else
+                l = message;
+
+        r = utmp_wall(l, "systemd-journald", NULL);
+        if (r < 0)
+                log_debug("Failed to send wall message: %s", strerror(-r));
+}
diff --git a/src/journal/journald-wall.h b/src/journal/journald-wall.h
new file mode 100644
index 000000000..93c3cec1d
--- /dev/null
+++ b/src/journal/journald-wall.h
@@ -0,0 +1,26 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2014 Sebastian Thorarensen
+
+  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 "journald-server.h"
+
+void server_forward_wall(Server *s, int priority, const char *identifier, const char *message, struct ucred *ucred);
diff --git a/src/journal/journald.conf b/src/journal/journald.conf
index 54f6833a1..d106d00b5 100644
--- a/src/journal/journald.conf
+++ b/src/journal/journald.conf
@@ -26,8 +26,10 @@
 #ForwardToSyslog=yes
 #ForwardToKMsg=no
 #ForwardToConsole=no
+#ForwardToWall=yes
 #TTYPath=/dev/console
 #MaxLevelStore=debug
 #MaxLevelSyslog=debug
 #MaxLevelKMsg=notice
 #MaxLevelConsole=info
+#MaxLevelWall=emerg