journal-gatewayd: redirect microhttpd messages to journal

A prefix ("microhttpd: ") is added to the log lines to make it easy to
distinguish the source.

Makefile.am

@@ -2799,7 +2799,9 @@ rootlibexec_PROGRAMS += \
 	systemd-journal-gatewayd
 
 systemd_journal_gatewayd_SOURCES = \
-	src/journal/journal-gatewayd.c
+	src/journal/journal-gatewayd.c \
+	src/journal/microhttpd-util.h \
+	src/journal/microhttpd-util.c
 
 systemd_journal_gatewayd_LDADD = \
 	libsystemd-shared.la \

src/journal/journal-gatewayd.c

@@ -32,6 +32,7 @@
 #include "sd-journal.h"
 #include "sd-daemon.h"
 #include "logs-show.h"
+#include "microhttpd-util.h"
 #include "virt.h"
 #include "build.h"
 
@@ -962,11 +963,13 @@ int main(int argc, char *argv[]) {
                 struct MHD_OptionItem opts[] = {
                         { MHD_OPTION_NOTIFY_COMPLETED,
                           (intptr_t) request_meta_free, NULL },
+                        { MHD_OPTION_EXTERNAL_LOGGER,
+                          (intptr_t) microhttpd_logger, NULL },
                         { MHD_OPTION_END, 0, NULL },
                         { MHD_OPTION_END, 0, NULL },
                         { MHD_OPTION_END, 0, NULL },
                         { MHD_OPTION_END, 0, NULL }};
-                int opts_pos = 1;
+                int opts_pos = 2;
                 int flags = MHD_USE_THREAD_PER_CONNECTION|MHD_USE_POLL|MHD_USE_DEBUG;
 
                 if (n > 0)

src/journal/microhttpd-util.c

@@ -0,0 +1,37 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2012 Zbigniew Jędrzejewski-Szmek
+
+  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 <stddef.h>
+#include <stdio.h>
+
+#include "microhttpd-util.h"
+#include "log.h"
+#include "macro.h"
+#include "util.h"
+
+void microhttpd_logger(void *arg, const char *fmt, va_list ap) {
+        char _cleanup_free_ *f;
+        if (asprintf(&f, "microhttpd: %s", fmt) <= 0) {
+                log_oom();
+                return;
+        }
+        log_metav(LOG_INFO, NULL, 0, NULL, f, ap);
+}

src/journal/microhttpd-util.h

@@ -0,0 +1,26 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2012 Zbigniew Jędrzejewski-Szmek
+
+  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/>.
+***/
+
+#pragma once
+
+#include <stdarg.h>
+
+void microhttpd_logger(void *arg, const char *fmt, va_list ap);