sh/jshn.sh: add json_for_each_item()
[project/libubox.git] / ulog.c
1 /*
2  * ulog - simple logging functions
3  *
4  * Copyright (C) 2015 Jo-Philipp Wich <jow@openwrt.org>
5  *
6  * Permission to use, copy, modify, and/or distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18
19 #include "ulog.h"
20
21 #include <stdio.h>
22 #include <stdarg.h>
23 #include <stdlib.h>
24 #include <unistd.h>
25 #include <string.h>
26
27 static int _ulog_channels = -1;
28 static int _ulog_facility = -1;
29 static int _ulog_threshold = LOG_DEBUG;
30 static int _ulog_initialized = 0;
31 static const char *_ulog_ident = NULL;
32
33 static const char *ulog_default_ident(void)
34 {
35         FILE *self;
36         static char line[64];
37         char *p = NULL;
38         char *sbuf;
39
40         if ((self = fopen("/proc/self/status", "r")) != NULL) {
41                 while (fgets(line, sizeof(line), self)) {
42                         if (!strncmp(line, "Name:", 5)) {
43                                 strtok_r(line, "\t\n", &sbuf);
44                                 p = strtok_r(NULL, "\t\n", &sbuf);
45                                 break;
46                         }
47                 }
48                 fclose(self);
49         }
50
51         return p;
52 }
53
54 static void ulog_defaults(void)
55 {
56         char *env;
57
58         if (_ulog_initialized)
59                 return;
60
61         env = getenv("PREINIT");
62
63         if (_ulog_channels < 0) {
64                 if (env && !strcmp(env, "1"))
65                         _ulog_channels = ULOG_KMSG;
66                 else if (isatty(1))
67                         _ulog_channels = ULOG_STDIO;
68                 else
69                         _ulog_channels = ULOG_SYSLOG;
70         }
71
72         if (_ulog_facility < 0) {
73                 if (env && !strcmp(env, "1"))
74                         _ulog_facility = LOG_DAEMON;
75                 else if (isatty(1))
76                         _ulog_facility = LOG_USER;
77                 else
78                         _ulog_facility = LOG_DAEMON;
79         }
80
81         if (_ulog_ident == NULL && _ulog_channels != ULOG_STDIO)
82                 _ulog_ident = ulog_default_ident();
83
84         if (_ulog_channels & ULOG_SYSLOG)
85                 openlog(_ulog_ident, 0, _ulog_facility);
86
87         _ulog_initialized = 1;
88 }
89
90 static void ulog_kmsg(int priority, const char *fmt, va_list ap)
91 {
92         FILE *kmsg;
93
94         if ((kmsg = fopen("/dev/kmsg", "r+")) != NULL) {
95                 fprintf(kmsg, "<%u>", priority);
96
97                 if (_ulog_ident)
98                         fprintf(kmsg, "%s: ", _ulog_ident);
99
100                 vfprintf(kmsg, fmt, ap);
101                 fclose(kmsg);
102         }
103 }
104
105 static void ulog_stdio(int priority, const char *fmt, va_list ap)
106 {
107         FILE *out = stderr;
108
109         if (_ulog_ident)
110                 fprintf(out, "%s: ", _ulog_ident);
111
112         vfprintf(out, fmt, ap);
113 }
114
115 static void ulog_syslog(int priority, const char *fmt, va_list ap)
116 {
117         vsyslog(priority, fmt, ap);
118 }
119
120 void ulog_open(int channels, int facility, const char *ident)
121 {
122         ulog_close();
123
124         _ulog_channels = channels;
125         _ulog_facility = facility;
126         _ulog_ident = ident;
127 }
128
129 void ulog_close(void)
130 {
131         if (!_ulog_initialized)
132                 return;
133
134         if (_ulog_channels & ULOG_SYSLOG)
135                 closelog();
136
137         _ulog_initialized = 0;
138 }
139
140 void ulog_threshold(int threshold)
141 {
142         _ulog_threshold = threshold;
143 }
144
145 void ulog(int priority, const char *fmt, ...)
146 {
147         va_list ap;
148
149         if (priority > _ulog_threshold)
150                 return;
151
152         ulog_defaults();
153
154         if (_ulog_channels & ULOG_KMSG)
155         {
156                 va_start(ap, fmt);
157                 ulog_kmsg(priority, fmt, ap);
158                 va_end(ap);
159         }
160
161         if (_ulog_channels & ULOG_STDIO)
162         {
163                 va_start(ap, fmt);
164                 ulog_stdio(priority, fmt, ap);
165                 va_end(ap);
166         }
167
168         if (_ulog_channels & ULOG_SYSLOG)
169         {
170                 va_start(ap, fmt);
171                 ulog_syslog(priority, fmt, ap);
172                 va_end(ap);
173         }
174 }