make use of setproctitle() to change the process title of the daemon processes. This is especially useful to distuingish the main daemon and the chroot() helper process.

git-svn-id: file:///home/lennart/svn/public/avahi/trunk@908 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe

7 files changed, 184 insertions, 26 deletions

diff --git a/avahi-daemon/Makefile.am b/avahi-daemon/Makefile.am
index 0dadede..9819f56 100644
--- a/avahi-daemon/Makefile.am
+++ b/avahi-daemon/Makefile.am
@@ -50,7 +50,8 @@ avahi_daemon_SOURCES = \
 	main.c main.h \
 	simple-protocol.c simple-protocol.h \
 	static-services.c static-services.h \
-	ini-file-parser.c ini-file-parser.h
+	ini-file-parser.c ini-file-parser.h \
+	setproctitle.c setproctitle.h
 
 avahi_daemon_CFLAGS = $(AM_CFLAGS) $(LIBDAEMON_CFLAGS)
 avahi_daemon_LDADD = $(AM_LDADD) ../avahi-common/libavahi-common.la ../avahi-core/libavahi-core.la $(LIBDAEMON_LIBS) -lexpat
diff --git a/avahi-daemon/chroot.c b/avahi-daemon/chroot.c
index 5504cbd..3cace26 100644
--- a/avahi-daemon/chroot.c
+++ b/avahi-daemon/chroot.c
@@ -39,6 +39,7 @@
 
 #include "chroot.h"
 #include "caps.h"
+#include "setproctitle.h"
 
 enum {
     AVAHI_CHROOT_SUCCESS = 0,
@@ -286,7 +287,7 @@ fail:
     return ret;
 }
 
-int avahi_chroot_helper_start(void) {
+int avahi_chroot_helper_start(const char *argv0) {
     int sock[2];
     pid_t pid;
 
@@ -306,6 +307,8 @@ int avahi_chroot_helper_start(void) {
         
         /* Drop all remaining capabilities */
         avahi_caps_drop_all();
+
+        avahi_set_proc_title("%s: chroot helper process", argv0);
         
         close(sock[0]);
         helper_main(sock[1]);
diff --git a/avahi-daemon/chroot.h b/avahi-daemon/chroot.h
index 1255739..ea61c5a 100644
--- a/avahi-daemon/chroot.h
+++ b/avahi-daemon/chroot.h
@@ -24,7 +24,7 @@
 
 #include <stdio.h>
 
-int avahi_chroot_helper_start(void);
+int avahi_chroot_helper_start(const char *argv0);
 void avahi_chroot_helper_shutdown(void);
 int avahi_chroot_helper_get(const char *fname);
 
diff --git a/avahi-daemon/main.c b/avahi-daemon/main.c
index 7ebfcd7..7508cf3 100644
--- a/avahi-daemon/main.c
+++ b/avahi-daemon/main.c
@@ -61,6 +61,7 @@
 #include "caps.h"
 #endif
 
+#include "setproctitle.h"
 #include "main.h"
 #include "simple-protocol.h"
 #include "static-services.h"
@@ -72,6 +73,7 @@
 
 AvahiServer *avahi_server = NULL;
 AvahiSimplePoll *simple_poll_api = NULL;
+static char *argv0 = NULL;
 
 typedef enum {
     DAEMON_RUN,
@@ -97,6 +99,7 @@ typedef struct {
 #ifdef ENABLE_CHROOT
     int use_chroot;
 #endif
+    int modify_proc_title;
     
     int publish_resolv_conf;
     char ** publish_dns_servers;
@@ -259,6 +262,9 @@ static void server_callback(AvahiServer *s, AvahiServerState state, void *userda
     switch (state) {
         case AVAHI_SERVER_RUNNING:
             avahi_log_info("Server startup complete. Host name is %s. Local service cookie is %u.", avahi_server_get_host_name_fqdn(s), avahi_server_get_local_service_cookie(s));
+            
+            avahi_set_proc_title("%s: running [%s]", argv0, avahi_server_get_host_name_fqdn(s));
+            
             static_service_add_to_server();
             
             remove_dns_server_entry_groups();
@@ -283,6 +289,9 @@ static void server_callback(AvahiServer *s, AvahiServerState state, void *userda
             avahi_log_warn("Host name conflict, retrying with <%s>", n);
             avahi_server_set_host_name(s, n);
             avahi_free(n);
+
+            avahi_set_proc_title("%s: collision", argv0);
+            
             break;
         }
 
@@ -293,13 +302,16 @@ static void server_callback(AvahiServer *s, AvahiServerState state, void *userda
             break;
 
         case AVAHI_SERVER_REGISTERING:
+            avahi_set_proc_title("%s: registering [%s]", argv0, avahi_server_get_host_name_fqdn(s));
+
+
         case AVAHI_SERVER_INVALID:
             break;
             
     }
 }
 
-static void help(FILE *f, const char *argv0) {
+static void help(FILE *f) {
     fprintf(f,
             "%s [options]\n"
             "    -h --help          Show this help\n"
@@ -316,6 +328,7 @@ static void help(FILE *f, const char *argv0) {
 #ifdef ENABLE_CHROOT            
             "       --no-chroot     Don't chroot()\n"
 #endif            
+            "       --no-proc-title Don't modify process title\n"
             "       --debug         Increase verbosity\n",
             argv0);
 }
@@ -329,25 +342,27 @@ static int parse_command_line(DaemonConfig *c, int argc, char *argv[]) {
         OPTION_NO_DROP_ROOT,
 #ifdef ENABLE_CHROOT        
         OPTION_NO_CHROOT,
-#endif        
+#endif
+        OPTION_NO_PROC_TITLE,
         OPTION_DEBUG
     };
     
     static const struct option long_options[] = {
-        { "help",         no_argument,       NULL, 'h' },
-        { "daemonize",    no_argument,       NULL, 'D' },
-        { "kill",         no_argument,       NULL, 'k' },
-        { "version",      no_argument,       NULL, 'V' },
-        { "file",         required_argument, NULL, 'f' },
-        { "reload",       no_argument,       NULL, 'r' },
-        { "check",        no_argument,       NULL, 'c' },
-        { "syslog",       no_argument,       NULL, 's' },
-        { "no-rlimits",   no_argument,       NULL, OPTION_NO_RLIMITS },
-        { "no-drop-root", no_argument,       NULL, OPTION_NO_DROP_ROOT },
+        { "help",           no_argument,       NULL, 'h' },
+        { "daemonize",      no_argument,       NULL, 'D' },
+        { "kill",           no_argument,       NULL, 'k' },
+        { "version",        no_argument,       NULL, 'V' },
+        { "file",           required_argument, NULL, 'f' },
+        { "reload",         no_argument,       NULL, 'r' },
+        { "check",          no_argument,       NULL, 'c' },
+        { "syslog",         no_argument,       NULL, 's' },
+        { "no-rlimits",     no_argument,       NULL, OPTION_NO_RLIMITS },
+        { "no-drop-root",   no_argument,       NULL, OPTION_NO_DROP_ROOT },
 #ifdef ENABLE_CHROOT
-        { "no-chroot",    no_argument,       NULL, OPTION_NO_CHROOT },
-#endif        
-        { "debug",        no_argument,       NULL, OPTION_DEBUG },
+        { "no-chroot",      no_argument,       NULL, OPTION_NO_CHROOT },
+#endif
+        { "no-proc-title",  no_argument,       NULL, OPTION_NO_PROC_TITLE },
+        { "debug",          no_argument,       NULL, OPTION_DEBUG },
         { NULL, 0, NULL, 0 }
     };
 
@@ -392,7 +407,10 @@ static int parse_command_line(DaemonConfig *c, int argc, char *argv[]) {
             case OPTION_NO_CHROOT:
                 c->use_chroot = 0;
                 break;
-#endif                
+#endif
+            case OPTION_NO_PROC_TITLE:
+                c->modify_proc_title = 0;
+                break;
             case OPTION_DEBUG:
                 c->debug = 1;
                 break;
@@ -953,7 +971,6 @@ static void init_rand_seed(void) {
 
 int main(int argc, char *argv[]) {
     int r = 255;
-    const char *argv0;
     int wrote_pid_file = 0;
 
     avahi_set_log_function(log_function);
@@ -974,12 +991,12 @@ int main(int argc, char *argv[]) {
 #ifdef ENABLE_CHROOT
     config.use_chroot = 1;
 #endif
+    config.modify_proc_title = 1;
     
     config.publish_dns_servers = NULL;
     config.publish_resolv_conf = 0;
     config.use_syslog = 0;
     config.debug = 0;
-    
     config.rlimit_as_set = 0;
     config.rlimit_core_set = 0;
     config.rlimit_data_set = 0;
@@ -991,9 +1008,9 @@ int main(int argc, char *argv[]) {
 #endif
     
     if ((argv0 = strrchr(argv[0], '/')))
-        argv0++;
+        argv0 = avahi_strdup(argv0 + 1);
     else
-        argv0 = argv[0];
+        argv0 = avahi_strdup(argv[0]);
 
     daemon_pid_file_ident = (const char *) argv0;
     daemon_log_ident = (char*) argv0;
@@ -1002,12 +1019,15 @@ int main(int argc, char *argv[]) {
     if (parse_command_line(&config, argc, argv) < 0)
         goto finish;
 
+    if (config.modify_proc_title)
+        avahi_init_proc_title(argc, argv);
+
 #ifdef ENABLE_CHROOT
     config.use_chroot = config.use_chroot && config.drop_root;
 #endif
     
     if (config.command == DAEMON_HELP) {
-        help(stdout, argv0);
+        help(stdout);
         r = 0;
     } else if (config.command == DAEMON_VERSION) {
         printf("%s "PACKAGE_VERSION"\n", argv0);
@@ -1106,13 +1126,15 @@ int main(int argc, char *argv[]) {
 
 #ifdef ENABLE_CHROOT
         if (config.drop_root && config.use_chroot)
-            if (avahi_chroot_helper_start() < 0) {
+            if (avahi_chroot_helper_start(argv0) < 0) {
                 avahi_log_error("failed to start chroot() helper daemon.");
                 goto finish;
             }
 #endif
         avahi_log_info("%s "PACKAGE_VERSION" starting up.", argv0);
 
+        avahi_set_proc_title("%s: starting up", argv0);
+        
         if (run_server(&config) == 0)
             r = 0;
     }
@@ -1139,5 +1161,7 @@ finish:
     avahi_chroot_helper_shutdown();
 #endif
 
+    avahi_free(argv0);
+    
     return r;
 }
diff --git a/avahi-daemon/setproctitle.c b/avahi-daemon/setproctitle.c
new file mode 100644
index 0000000..819f7b0
--- /dev/null
+++ b/avahi-daemon/setproctitle.c
@@ -0,0 +1,102 @@
+/* $Id$ */
+
+/***
+  This file is part of avahi.
+ 
+  avahi 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.
+ 
+  avahi 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 avahi; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <unistd.h>
+
+#include <avahi-common/malloc.h>
+
+#include "setproctitle.h"
+
+#if !defined(HAVE_SETPROCTITLE) && defined(__linux__)
+static char** argv_buffer = NULL;
+static size_t argv_size = 0;
+
+#if !HAVE_DECL_ENVIRON
+extern char **environ;
+#endif
+
+#endif
+
+void avahi_init_proc_title(int argc, char **argv) {
+
+#if !defined(HAVE_SETPROCTITLE) && defined(__linux__)
+
+    unsigned i;
+    char **new_environ, *endptr;
+
+    /* This code is really really ugly. We make some memory layout
+     * assumptions and reuse the environment array as memory to store
+     * our process title in */
+
+    for (i = 0; environ[i]; i++);
+
+    endptr = i ? environ[i-1] + strlen(environ[i-1]) : argv[argc-1] + strlen(argv[argc-1]);
+
+    argv_buffer = argv;
+    argv_size = endptr - argv_buffer[0];
+
+    /* Make a copy of environ */
+    
+    new_environ = avahi_malloc(sizeof(char*) * (i + 1));
+    for (i = 0; environ[i]; i++)
+        new_environ[i] = avahi_strdup(environ[i]);
+    new_environ[i] = NULL;
+
+    environ = new_environ;
+
+#endif
+}	
+
+void avahi_set_proc_title(const char *fmt,...) {
+#ifdef HAVE_SETPROCTITLE
+    char t[256];
+
+    va_list ap;
+    va_start(ap);
+    vsnprintf(t, sizeof(t), fmt, ap);
+    va_end(ap);
+
+    setproctitle("-%s", t);
+#elif __linux__
+    size_t l;
+    va_list ap;
+    
+    if (!argv_buffer)
+        return;
+    
+    va_start(ap, fmt);
+    vsnprintf(argv_buffer[0], argv_size, fmt, ap);
+    va_end(ap);
+
+    l = strlen(argv_buffer[0]);
+    
+    memset(argv_buffer[0] + l, 0, argv_size - l);
+    argv_buffer[1] = NULL;
+#endif
+}
diff --git a/avahi-daemon/setproctitle.h b/avahi-daemon/setproctitle.h
new file mode 100644
index 0000000..6ac7612
--- /dev/null
+++ b/avahi-daemon/setproctitle.h
@@ -0,0 +1,28 @@
+#ifndef foosetproctitlehfoo
+#define foosetproctitlehfoo
+
+/* $Id$ */
+
+/***
+  This file is part of avahi.
+ 
+  avahi 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.
+ 
+  avahi 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 avahi; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+void avahi_init_proc_title(int argc, char **argv);
+void avahi_set_proc_title(const char *fmt, ...);
+
+#endif
diff --git a/configure.ac b/configure.ac
index 4e9a98a..a522b24 100644
--- a/configure.ac
+++ b/configure.ac
@@ -206,7 +206,7 @@ AC_FUNC_MEMCMP
 AC_FUNC_SELECT_ARGTYPES
 AC_FUNC_MALLOC
 AC_FUNC_REALLOC
-AC_CHECK_FUNCS([gethostname memchr memmove memset mkdir select socket strchr strcspn strdup strerror strrchr strspn strstr uname setresuid setreuid setresgid setregid strcasecmp gettimeofday putenv strncasecmp strlcpy gethostbyname seteuid setegid])
+AC_CHECK_FUNCS([gethostname memchr memmove memset mkdir select socket strchr strcspn strdup strerror strrchr strspn strstr uname setresuid setreuid setresgid setregid strcasecmp gettimeofday putenv strncasecmp strlcpy gethostbyname seteuid setegid setproctitle])
 
 AC_FUNC_CHOWN
 AC_FUNC_STAT