xref: /freebsd/lib/libcasper/services/cap_syslog/cap_syslog.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2017 Mariusz Zaborski <oshogbo@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 #include <sys/dnv.h>
31 #include <sys/nv.h>
32 
33 #include <assert.h>
34 #include <errno.h>
35 #include <stdarg.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <syslog.h>
40 
41 #include <libcasper.h>
42 #include <libcasper_service.h>
43 
44 #include "cap_syslog.h"
45 
46 #define	CAP_SYSLOG_LIMIT	2048
47 
48 void
49 cap_syslog(cap_channel_t *chan, int pri, const char *fmt, ...)
50 {
51 	va_list ap;
52 
53 	va_start(ap, fmt);
54 	cap_vsyslog(chan, pri, fmt, ap);
55 	va_end(ap);
56 }
57 
58 void
59 cap_vsyslog(cap_channel_t *chan, int priority, const char *fmt, va_list ap)
60 {
61 	nvlist_t *nvl;
62 	char message[CAP_SYSLOG_LIMIT];
63 
64 	(void)vsnprintf(message, sizeof(message), fmt, ap);
65 
66 	nvl = nvlist_create(0);
67 	nvlist_add_string(nvl, "cmd", "vsyslog");
68 	nvlist_add_number(nvl, "priority", priority);
69 	nvlist_add_string(nvl, "message", message);
70 	nvl = cap_xfer_nvlist(chan, nvl);
71 	if (nvl == NULL) {
72 		return;
73 	}
74 	nvlist_destroy(nvl);
75 }
76 
77 void
78 cap_openlog(cap_channel_t *chan, const char *ident, int logopt, int facility)
79 {
80 	nvlist_t *nvl;
81 
82 	nvl = nvlist_create(0);
83 	nvlist_add_string(nvl, "cmd", "openlog");
84 	if (ident != NULL) {
85 		nvlist_add_string(nvl, "ident", ident);
86 	}
87 	nvlist_add_number(nvl, "logopt", logopt);
88 	nvlist_add_number(nvl, "facility", facility);
89 	if (logopt & LOG_PERROR) {
90 		nvlist_add_descriptor(nvl, "stderr", STDERR_FILENO);
91 	}
92 	nvl = cap_xfer_nvlist(chan, nvl);
93 	if (nvl == NULL) {
94 		return;
95 	}
96 	nvlist_destroy(nvl);
97 }
98 
99 void
100 cap_closelog(cap_channel_t *chan)
101 {
102 	nvlist_t *nvl;
103 
104 	nvl = nvlist_create(0);
105 	nvlist_add_string(nvl, "cmd", "closelog");
106 	nvl = cap_xfer_nvlist(chan, nvl);
107 	if (nvl == NULL) {
108 		return;
109 	}
110 	nvlist_destroy(nvl);
111 }
112 
113 int
114 cap_setlogmask(cap_channel_t *chan, int maskpri)
115 {
116 	nvlist_t *nvl;
117 	int omask;
118 
119 	nvl = nvlist_create(0);
120 	nvlist_add_string(nvl, "cmd", "setlogmask");
121 	nvlist_add_number(nvl, "maskpri", maskpri);
122 	nvl = cap_xfer_nvlist(chan, nvl);
123 	omask = nvlist_get_number(nvl, "omask");
124 
125 	nvlist_destroy(nvl);
126 
127 	return (omask);
128 }
129 
130 /*
131  * Service functions.
132  */
133 
134 static char *LogTag;
135 static int prev_stderr = -1;
136 
137 static void
138 slog_vsyslog(const nvlist_t *limits __unused, const nvlist_t *nvlin,
139     nvlist_t *nvlout __unused)
140 {
141 
142 	syslog(nvlist_get_number(nvlin, "priority"), "%s",
143 	    nvlist_get_string(nvlin, "message"));
144 }
145 
146 static void
147 slog_openlog(const nvlist_t *limits __unused, const nvlist_t *nvlin,
148     nvlist_t *nvlout __unused)
149 {
150 	const char *ident;
151 	uint64_t logopt;
152 	int stderr_fd;
153 
154 	ident = dnvlist_get_string(nvlin, "ident", NULL);
155 	if (ident != NULL) {
156 		free(LogTag);
157 		LogTag = strdup(ident);
158 	}
159 
160 	logopt = nvlist_get_number(nvlin, "logopt");
161 	if (logopt & LOG_PERROR) {
162 		stderr_fd = dnvlist_get_descriptor(nvlin, "stderr", -1);
163 		if (prev_stderr == -1)
164 			prev_stderr = dup(STDERR_FILENO);
165 		if (prev_stderr != -1)
166 			(void)dup2(stderr_fd, STDERR_FILENO);
167 	} else if (prev_stderr != -1) {
168 		(void)dup2(prev_stderr, STDERR_FILENO);
169 		close(prev_stderr);
170 		prev_stderr = -1;
171 	}
172 	openlog(LogTag, logopt, nvlist_get_number(nvlin, "facility"));
173 }
174 
175 static void
176 slog_closelog(const nvlist_t *limits __unused, const nvlist_t *nvlin __unused,
177     nvlist_t *nvlout __unused)
178 {
179 
180 	closelog();
181 
182 	free(LogTag);
183 	LogTag = NULL;
184 
185 	if (prev_stderr != -1) {
186 		(void)dup2(prev_stderr, STDERR_FILENO);
187 		close(prev_stderr);
188 		prev_stderr = -1;
189 	}
190 }
191 
192 static void
193 slog_setlogmask(const nvlist_t *limits __unused, const nvlist_t *nvlin,
194     nvlist_t *nvlout)
195 {
196 	int omask;
197 
198 	omask = setlogmask(nvlist_get_number(nvlin, "maskpri"));
199 	nvlist_add_number(nvlout, "omask", omask);
200 }
201 
202 static int
203 syslog_command(const char *cmd, const nvlist_t *limits, nvlist_t *nvlin,
204     nvlist_t *nvlout)
205 {
206 
207 	if (strcmp(cmd, "vsyslog") == 0) {
208 		slog_vsyslog(limits, nvlin, nvlout);
209 	} else if (strcmp(cmd, "openlog") == 0) {
210 		slog_openlog(limits, nvlin, nvlout);
211 	} else if (strcmp(cmd, "closelog") == 0) {
212 		slog_closelog(limits, nvlin, nvlout);
213 	} else if (strcmp(cmd, "setlogmask") == 0) {
214 		slog_setlogmask(limits, nvlin, nvlout);
215 	} else {
216 		return (EINVAL);
217 	}
218 
219 	return (0);
220 }
221 
222 CREATE_SERVICE("system.syslog", NULL, syslog_command, 0);
223