1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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__FBSDID("$FreeBSD$");
31
32#include <sys/dnv.h>
33#include <sys/nv.h>
34
35#include <assert.h>
36#include <errno.h>
37#include <stdarg.h>
38#include <stdio.h>
39#include <stdlib.h>
40#include <string.h>
41#include <syslog.h>
42
43#include <libcasper.h>
44#include <libcasper_service.h>
45
46#include "cap_syslog.h"
47
48#define	CAP_SYSLOG_LIMIT	2048
49
50void
51cap_syslog(cap_channel_t *chan, int pri, const char *fmt, ...)
52{
53	va_list ap;
54
55	va_start(ap, fmt);
56	cap_vsyslog(chan, pri, fmt, ap);
57	va_end(ap);
58}
59
60void
61cap_vsyslog(cap_channel_t *chan, int priority, const char *fmt, va_list ap)
62{
63	nvlist_t *nvl;
64	char message[CAP_SYSLOG_LIMIT];
65
66	(void)vsnprintf(message, sizeof(message), fmt, ap);
67
68	nvl = nvlist_create(0);
69	nvlist_add_string(nvl, "cmd", "vsyslog");
70	nvlist_add_number(nvl, "priority", priority);
71	nvlist_add_string(nvl, "message", message);
72	nvl = cap_xfer_nvlist(chan, nvl);
73	if (nvl == NULL) {
74		return;
75	}
76	nvlist_destroy(nvl);
77}
78
79void
80cap_openlog(cap_channel_t *chan, const char *ident, int logopt, int facility)
81{
82	nvlist_t *nvl;
83
84	nvl = nvlist_create(0);
85	nvlist_add_string(nvl, "cmd", "openlog");
86	if (ident != NULL) {
87		nvlist_add_string(nvl, "ident", ident);
88	}
89	nvlist_add_number(nvl, "logopt", logopt);
90	nvlist_add_number(nvl, "facility", facility);
91	if (logopt & LOG_PERROR) {
92		nvlist_add_descriptor(nvl, "stderr", STDERR_FILENO);
93	}
94	nvl = cap_xfer_nvlist(chan, nvl);
95	if (nvl == NULL) {
96		return;
97	}
98	nvlist_destroy(nvl);
99}
100
101void
102cap_closelog(cap_channel_t *chan)
103{
104	nvlist_t *nvl;
105
106	nvl = nvlist_create(0);
107	nvlist_add_string(nvl, "cmd", "closelog");
108	nvl = cap_xfer_nvlist(chan, nvl);
109	if (nvl == NULL) {
110		return;
111	}
112	nvlist_destroy(nvl);
113}
114
115int
116cap_setlogmask(cap_channel_t *chan, int maskpri)
117{
118	nvlist_t *nvl;
119	int omask;
120
121	nvl = nvlist_create(0);
122	nvlist_add_string(nvl, "cmd", "setlogmask");
123	nvlist_add_number(nvl, "maskpri", maskpri);
124	nvl = cap_xfer_nvlist(chan, nvl);
125	omask = nvlist_get_number(nvl, "omask");
126
127	nvlist_destroy(nvl);
128
129	return (omask);
130}
131
132/*
133 * Service functions.
134 */
135
136static char *LogTag;
137static int prev_stderr = -1;
138
139static void
140slog_vsyslog(const nvlist_t *limits __unused, const nvlist_t *nvlin,
141    nvlist_t *nvlout __unused)
142{
143
144	syslog(nvlist_get_number(nvlin, "priority"), "%s",
145	    nvlist_get_string(nvlin, "message"));
146}
147
148static void
149slog_openlog(const nvlist_t *limits __unused, const nvlist_t *nvlin,
150    nvlist_t *nvlout __unused)
151{
152	const char *ident;
153	uint64_t logopt;
154	int stderr_fd;
155
156	ident = dnvlist_get_string(nvlin, "ident", NULL);
157	if (ident != NULL) {
158		free(LogTag);
159		LogTag = strdup(ident);
160	}
161
162	logopt = nvlist_get_number(nvlin, "logopt");
163	if (logopt & LOG_PERROR) {
164		stderr_fd = dnvlist_get_descriptor(nvlin, "stderr", -1);
165		if (prev_stderr == -1)
166			prev_stderr = dup(STDERR_FILENO);
167		if (prev_stderr != -1)
168			(void)dup2(stderr_fd, STDERR_FILENO);
169	} else if (prev_stderr != -1) {
170		(void)dup2(prev_stderr, STDERR_FILENO);
171		close(prev_stderr);
172		prev_stderr = -1;
173	}
174	openlog(LogTag, logopt, nvlist_get_number(nvlin, "facility"));
175}
176
177static void
178slog_closelog(const nvlist_t *limits __unused, const nvlist_t *nvlin __unused,
179    nvlist_t *nvlout __unused)
180{
181
182	closelog();
183
184	free(LogTag);
185	LogTag = NULL;
186
187	if (prev_stderr != -1) {
188		(void)dup2(prev_stderr, STDERR_FILENO);
189		close(prev_stderr);
190		prev_stderr = -1;
191	}
192}
193
194static void
195slog_setlogmask(const nvlist_t *limits __unused, const nvlist_t *nvlin,
196    nvlist_t *nvlout)
197{
198	int omask;
199
200	omask = setlogmask(nvlist_get_number(nvlin, "maskpri"));
201	nvlist_add_number(nvlout, "omask", omask);
202}
203
204static int
205syslog_command(const char *cmd, const nvlist_t *limits, nvlist_t *nvlin,
206    nvlist_t *nvlout)
207{
208
209	if (strcmp(cmd, "vsyslog") == 0) {
210		slog_vsyslog(limits, nvlin, nvlout);
211	} else if (strcmp(cmd, "openlog") == 0) {
212		slog_openlog(limits, nvlin, nvlout);
213	} else if (strcmp(cmd, "closelog") == 0) {
214		slog_closelog(limits, nvlin, nvlout);
215	} else if (strcmp(cmd, "setlogmask") == 0) {
216		slog_setlogmask(limits, nvlin, nvlout);
217	} else {
218		return (EINVAL);
219	}
220
221	return (0);
222}
223
224CREATE_SERVICE("system.syslog", NULL, syslog_command, 0);
225