1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <stdarg.h>
29 #include <errno.h>
30 #include <stdio.h>
31 #include <syslog.h>
32 #include <libintl.h>
33 #include <string.h>
34 #include <limits.h>
35 
36 #include "dhcpmsg.h"
37 
38 static boolean_t	is_daemon  = B_FALSE;
39 static boolean_t	is_verbose = B_FALSE;
40 static char		program[PATH_MAX] = "<unknown>";
41 static int		debug_level;
42 
43 static const char	*err_to_string(int);
44 static int		err_to_syslog(int);
45 
46 /*
47  * dhcpmsg(): logs a message to the console or to syslog
48  *
49  *   input: int: the level to log the message at
50  *	    const char *: a printf-like format string
51  *	    ...: arguments to the format string
52  *  output: void
53  */
54 
55 void
dhcpmsg(int errlevel,const char * fmt,...)56 dhcpmsg(int errlevel, const char *fmt, ...)
57 {
58 	va_list		ap;
59 	char		buf[512];
60 	char		*errmsg;
61 
62 	if ((errlevel == MSG_DEBUG2 && (debug_level < 2)) ||
63 	    (errlevel == MSG_DEBUG && (debug_level < 1)) ||
64 	    (errlevel == MSG_VERBOSE && !is_verbose))
65 		return;
66 
67 	va_start(ap, fmt);
68 
69 	/*
70 	 * either log to stderr, or log to syslog.  print out unix
71 	 * error message if errlevel is MSG_ERR and errno is set
72 	 */
73 
74 	if (is_daemon) {
75 		(void) snprintf(buf, sizeof (buf), (errlevel == MSG_ERR &&
76 		    errno != 0) ? "%s: %%m\n" : "%s\n", gettext(fmt));
77 		(void) vsyslog(err_to_syslog(errlevel), buf, ap);
78 	} else {
79 		errmsg = strerror(errno);
80 		if (errmsg == NULL)
81 			errmsg = dgettext(TEXT_DOMAIN, "<unknown error>");
82 
83 		(void) snprintf(buf, sizeof (buf), (errlevel == MSG_ERR &&
84 		    errno != 0) ? "%s: %s: %s: %s\n" : "%s: %s: %s\n", program,
85 		    dgettext(TEXT_DOMAIN, err_to_string(errlevel)),
86 		    gettext(fmt), errmsg);
87 
88 		(void) vfprintf(stderr, buf, ap);
89 	}
90 
91 	va_end(ap);
92 }
93 
94 /*
95  * dhcpmsg_init(): opens and initializes the DHCP messaging facility
96  *
97  *   input: const char *: the name of the executable
98  *	    boolean_t: whether the executable is a daemon
99  *	    boolean_t: whether the executable is running "verbosely"
100  *	    int: the debugging level the executable is being run at
101  *  output: void
102  */
103 
104 void
dhcpmsg_init(const char * program_name,boolean_t daemon,boolean_t verbose,int level)105 dhcpmsg_init(const char *program_name, boolean_t daemon, boolean_t verbose,
106     int level)
107 {
108 	(void) strlcpy(program, program_name, sizeof (program));
109 
110 	debug_level = level;
111 	is_verbose = verbose;
112 
113 	if (daemon) {
114 		is_daemon = B_TRUE;
115 		(void) openlog(program, LOG_PID, LOG_DAEMON);
116 		if (is_verbose) {
117 			syslog(err_to_syslog(MSG_VERBOSE), "%s",
118 			    dgettext(TEXT_DOMAIN, "Daemon started"));
119 		}
120 	}
121 }
122 
123 /*
124  * dhcpmsg_fini(): closes the DHCP messaging facility.
125  *
126  *   input: void
127  *  output: void
128  */
129 
130 void
dhcpmsg_fini(void)131 dhcpmsg_fini(void)
132 {
133 	if (is_daemon) {
134 		if (is_verbose) {
135 			syslog(err_to_syslog(MSG_VERBOSE), "%s",
136 			    dgettext(TEXT_DOMAIN, "Daemon terminated"));
137 		}
138 		closelog();
139 	}
140 }
141 
142 /*
143  * err_to_syslog(): converts a dhcpmsg log level into a syslog log level
144  *
145  *   input: int: the dhcpmsg log level
146  *  output: int: the syslog log level
147  */
148 
149 static int
err_to_syslog(int errlevel)150 err_to_syslog(int errlevel)
151 {
152 	switch (errlevel) {
153 
154 	case MSG_DEBUG:
155 	case MSG_DEBUG2:
156 		return (LOG_DEBUG);
157 
158 	case MSG_ERROR:
159 	case MSG_ERR:
160 		return (LOG_ERR);
161 
162 	case MSG_WARNING:
163 		return (LOG_WARNING);
164 
165 	case MSG_NOTICE:
166 		return (LOG_NOTICE);
167 
168 	case MSG_CRIT:
169 		return (LOG_CRIT);
170 
171 	case MSG_VERBOSE:
172 	case MSG_INFO:
173 		return (LOG_INFO);
174 	}
175 
176 	return (LOG_INFO);
177 }
178 
179 /*
180  * err_to_string(): converts a log level into a string
181  *
182  *   input: int: the log level
183  *  output: const char *: the stringified log level
184  */
185 
186 static const char *
err_to_string(int errlevel)187 err_to_string(int errlevel)
188 {
189 	switch (errlevel) {
190 
191 	case MSG_DEBUG:
192 	case MSG_DEBUG2:
193 		return ("debug");
194 
195 	case MSG_ERR:
196 	case MSG_ERROR:
197 		return ("error");
198 
199 	case MSG_WARNING:
200 		return ("warning");
201 
202 	case MSG_NOTICE:
203 		return ("notice");
204 
205 	case MSG_CRIT:
206 		return ("CRITICAL");
207 
208 	case MSG_VERBOSE:
209 	case MSG_INFO:
210 		return ("info");
211 	}
212 
213 	return ("<unknown>");
214 }
215