1 /***
2 This file is part of avahi.
3
4 avahi is free software; you can redistribute it and/or modify it
5 under the terms of the GNU Lesser General Public License as
6 published by the Free Software Foundation; either version 2.1 of the
7 License, or (at your option) any later version.
8
9 avahi is distributed in the hope that it will be useful, but WITHOUT
10 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
12 Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with avahi; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
17 USA.
18 ***/
19
20 #ifdef HAVE_CONFIG_H
21 #include <config.h>
22 #endif
23
24 #include <pthread.h>
25 #include <unistd.h>
26 #include <limits.h>
27 #include <stdio.h>
28 #include <string.h>
29 #include <stdlib.h>
30 #include <assert.h>
31 #include <stdarg.h>
32 #include <syslog.h>
33
34 #include "warn.h"
35
36 #ifndef COMPAT_LAYER
37 #define COMPAT_LAYER "Apple Bonjour"
38 #endif
39
40 #ifndef CGI_SUBSYSTEM
41 #define CGI_SUBSYSTEM "libdns_sd"
42 #endif
43
44 static pthread_mutex_t linkage_mutex = PTHREAD_MUTEX_INITIALIZER;
45 static int linkage_warning = 0;
46
avahi_exe_name(void)47 const char *avahi_exe_name(void) {
48 #ifdef HAVE_GETPROGNAME
49 return getprogname();
50 #elif defined(__linux__)
51 static char exe_name[1024] = "";
52 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
53
54 /* Yes, I know, this is not portable. But who cares? It's for
55 * cosmetics only, anyway. */
56
57 pthread_mutex_lock(&mutex);
58
59 if (exe_name[0] == 0) {
60 int k;
61
62 if ((k = readlink("/proc/self/exe", exe_name, sizeof(exe_name)-1)) < 0)
63 snprintf(exe_name, sizeof(exe_name), "(unknown)");
64 else {
65 char *slash;
66
67 assert((size_t) k <= sizeof(exe_name)-1);
68 exe_name[k] = 0;
69
70 if ((slash = strrchr(exe_name, '/')))
71 memmove(exe_name, slash+1, strlen(slash)+1);
72 }
73 }
74
75 pthread_mutex_unlock(&mutex);
76
77 return exe_name;
78 #else
79 #ifdef __GNUC__
80 #warning "avahi_exe_name() needs to be implemented for your operating system"
81 #endif
82 return "(unknown)";
83 #endif
84 }
85
avahi_warn(const char * fmt,...)86 void avahi_warn(const char *fmt, ...) {
87 char msg[512] = "*** WARNING *** ";
88 va_list ap;
89 size_t n;
90
91 assert(fmt);
92
93 va_start(ap, fmt);
94 n = strlen(msg);
95 vsnprintf(msg + n, sizeof(msg) - n, fmt, ap);
96 va_end(ap);
97
98 fprintf(stderr, "%s\n", msg);
99
100 openlog(avahi_exe_name(), LOG_PID, LOG_USER);
101 syslog(LOG_WARNING, "%s", msg);
102 closelog();
103 }
104
avahi_warn_linkage(void)105 void avahi_warn_linkage(void) {
106 int w;
107
108 pthread_mutex_lock(&linkage_mutex);
109 w = linkage_warning;
110 linkage_warning = 1;
111 pthread_mutex_unlock(&linkage_mutex);
112
113 if (!w && !getenv("AVAHI_COMPAT_NOWARN")) {
114 avahi_warn("The program '%s' uses the "COMPAT_LAYER" compatibility layer of Avahi.", avahi_exe_name());
115 avahi_warn("Please fix your application to use the native API of Avahi!");
116 avahi_warn("For more information see <http://0pointer.de/avahi-compat?s="CGI_SUBSYSTEM"&e=%s>", avahi_exe_name());
117 }
118 }
119
avahi_warn_unsupported(const char * function)120 void avahi_warn_unsupported(const char *function) {
121 avahi_warn("The program '%s' called '%s()' which is not supported (or only supported partially) in the "COMPAT_LAYER" compatibility layer of Avahi.", avahi_exe_name(), function);
122 avahi_warn("Please fix your application to use the native API of Avahi!");
123 avahi_warn("For more information see <http://0pointer.de/avahi-compat?s="CGI_SUBSYSTEM"&e=%s&f=%s>", avahi_exe_name(), function);
124 }
125