1 /* $OpenBSD: syslog_r.c,v 1.20 2024/04/03 04:36:53 deraadt Exp $ */
2 /*
3 * Copyright (c) 1983, 1988, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <sys/types.h>
32 #include <sys/uio.h>
33 #include <netdb.h>
34
35 #include <errno.h>
36 #include <fcntl.h>
37 #include <paths.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <syslog.h>
42 #include <time.h>
43 #include <unistd.h>
44 #include <limits.h>
45 #include <stdarg.h>
46
47 /* Reentrant version of syslog, i.e. syslog_r() */
48 void
syslog_r(int pri,struct syslog_data * data,const char * fmt,...)49 syslog_r(int pri, struct syslog_data *data, const char *fmt, ...)
50 {
51 va_list ap;
52
53 va_start(ap, fmt);
54 vsyslog_r(pri, data, fmt, ap);
55 va_end(ap);
56 }
57 DEF_WEAK(syslog_r);
58
59 void
vsyslog_r(int pri,struct syslog_data * data,const char * fmt,va_list ap)60 vsyslog_r(int pri, struct syslog_data *data, const char *fmt, va_list ap)
61 {
62 __vsyslog_r(pri, data, 1, fmt, ap);
63 }
64 DEF_WEAK(vsyslog_r);
65
66 /*
67 * This is used by both syslog_r and syslog.
68 */
69 void
__vsyslog_r(int pri,struct syslog_data * data,int reentrant,const char * fmt,va_list ap)70 __vsyslog_r(int pri, struct syslog_data *data,
71 int reentrant, const char *fmt, va_list ap)
72 {
73 int cnt;
74 char ch, *p, *t;
75 int saved_errno = errno; /* use original errno */
76 #define TBUF_SIZE (LOG_MAXLINE+1)
77 #define FMT_SIZE (1024+1)
78 char *stdp = NULL, tbuf[TBUF_SIZE], fmt_cpy[FMT_SIZE];
79 int tbuf_left, fmt_left, prlen;
80
81 #define INTERNALLOG LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID
82 /* Check for invalid bits. */
83 if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
84 syslog_r(INTERNALLOG, data,
85 "syslog%s: unknown facility/priority: %x",
86 reentrant ? "_r" : "", pri);
87 pri &= LOG_PRIMASK|LOG_FACMASK;
88 }
89
90 /* Check priority against setlogmask values. */
91 if (!(LOG_MASK(LOG_PRI(pri)) & data->log_mask))
92 goto done;
93
94 /* Set default facility if none specified. */
95 if ((pri & LOG_FACMASK) == 0)
96 pri |= data->log_fac;
97
98 p = tbuf;
99 tbuf_left = TBUF_SIZE;
100
101 #define DEC() \
102 do { \
103 if (prlen < 0) \
104 prlen = 0; \
105 if (prlen >= tbuf_left) \
106 prlen = tbuf_left - 1; \
107 p += prlen; \
108 tbuf_left -= prlen; \
109 } while (0)
110
111 prlen = snprintf(p, tbuf_left, "<%d>", pri);
112 DEC();
113
114 if (data->log_stat & LOG_PERROR)
115 stdp = p;
116 if (data->log_tag == NULL)
117 data->log_tag = __progname;
118 if (data->log_tag != NULL) {
119 prlen = snprintf(p, tbuf_left, "%.*s", NAME_MAX, data->log_tag);
120 DEC();
121 }
122 if (data->log_stat & LOG_PID) {
123 prlen = snprintf(p, tbuf_left, "[%ld]", (long)getpid());
124 DEC();
125 }
126 if (data->log_tag != NULL) {
127 if (tbuf_left > 1) {
128 *p++ = ':';
129 tbuf_left--;
130 }
131 if (tbuf_left > 1) {
132 *p++ = ' ';
133 tbuf_left--;
134 }
135 }
136
137 for (t = fmt_cpy, fmt_left = FMT_SIZE;
138 (ch = *fmt) != '\0' && fmt_left > 1;
139 ++fmt) {
140 if (ch == '%' && fmt[1] == 'm') {
141 char ebuf[NL_TEXTMAX];
142
143 ++fmt;
144 (void)strerror_r(saved_errno, ebuf, sizeof(ebuf));
145 prlen = snprintf(t, fmt_left, "%s", ebuf);
146 if (prlen < 0)
147 prlen = 0;
148 if (prlen >= fmt_left)
149 prlen = fmt_left - 1;
150 t += prlen;
151 fmt_left -= prlen;
152 } else if (ch == '%' && fmt[1] == '%' && fmt_left > 2) {
153 ++fmt;
154 *t++ = '%';
155 *t++ = '%';
156 fmt_left -= 2;
157 } else {
158 *t++ = ch;
159 fmt_left--;
160 }
161 }
162 *t = '\0';
163
164 prlen = vsnprintf(p, tbuf_left, fmt_cpy, ap);
165 DEC();
166 cnt = p - tbuf;
167 while (cnt > 0 && p[-1] == '\n') {
168 *(--p) = '\0';
169 --cnt;
170 }
171
172 /* Output to stderr if requested. */
173 if (data->log_stat & LOG_PERROR) {
174 struct iovec iov[2];
175
176 iov[0].iov_base = stdp;
177 iov[0].iov_len = cnt > stdp - tbuf ? cnt - (stdp - tbuf) : 0;
178 iov[1].iov_base = "\n";
179 iov[1].iov_len = 1;
180 (void)writev(STDERR_FILENO, iov, 2);
181 }
182
183 /*
184 * If the sendsyslog() fails, it means that syslogd
185 * is not running or the kernel ran out of buffers.
186 */
187 sendsyslog(tbuf, cnt, data->log_stat & LOG_CONS);
188 done:
189 errno = saved_errno;
190 }
191
192 void
openlog_r(const char * ident,int logstat,int logfac,struct syslog_data * data)193 openlog_r(const char *ident, int logstat, int logfac, struct syslog_data *data)
194 {
195 if (ident != NULL)
196 data->log_tag = ident;
197 data->log_stat = logstat;
198 if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
199 data->log_fac = logfac;
200 }
201 DEF_WEAK(openlog_r);
202
203 void
closelog_r(struct syslog_data * data)204 closelog_r(struct syslog_data *data)
205 {
206 data->log_tag = NULL;
207 }
208 DEF_WEAK(closelog_r);
209