1 /* $OpenBSD: syslog_r.c,v 1.16 2016/10/19 16:09:24 millert 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 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 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 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; 76 #define TBUF_LEN (8192+1) 77 #define FMT_LEN 1024 78 char *conp = NULL, *stdp = NULL, tbuf[TBUF_LEN], fmt_cpy[FMT_LEN]; 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 return; 93 94 saved_errno = errno; 95 96 /* Set default facility if none specified. */ 97 if ((pri & LOG_FACMASK) == 0) 98 pri |= data->log_fac; 99 100 p = tbuf; 101 tbuf_left = TBUF_LEN; 102 103 #define DEC() \ 104 do { \ 105 if (prlen < 0) \ 106 prlen = 0; \ 107 if (prlen >= tbuf_left) \ 108 prlen = tbuf_left - 1; \ 109 p += prlen; \ 110 tbuf_left -= prlen; \ 111 } while (0) 112 113 prlen = snprintf(p, tbuf_left, "<%d>", pri); 114 DEC(); 115 if (data->log_stat & LOG_CONS) 116 conp = p; 117 118 if (data->log_stat & LOG_PERROR) 119 stdp = p; 120 if (data->log_tag == NULL) 121 data->log_tag = __progname; 122 if (data->log_tag != NULL) { 123 prlen = snprintf(p, tbuf_left, "%.*s", NAME_MAX, data->log_tag); 124 DEC(); 125 } 126 if (data->log_stat & LOG_PID) { 127 prlen = snprintf(p, tbuf_left, "[%ld]", (long)getpid()); 128 DEC(); 129 } 130 if (data->log_tag != NULL) { 131 if (tbuf_left > 1) { 132 *p++ = ':'; 133 tbuf_left--; 134 } 135 if (tbuf_left > 1) { 136 *p++ = ' '; 137 tbuf_left--; 138 } 139 } 140 141 for (t = fmt_cpy, fmt_left = FMT_LEN; (ch = *fmt); ++fmt) { 142 if (ch == '%' && fmt[1] == 'm') { 143 char ebuf[NL_TEXTMAX]; 144 145 ++fmt; 146 (void)strerror_r(saved_errno, ebuf, sizeof(ebuf)); 147 prlen = snprintf(t, fmt_left, "%s", ebuf); 148 if (prlen < 0) 149 prlen = 0; 150 if (prlen >= fmt_left) 151 prlen = fmt_left - 1; 152 t += prlen; 153 fmt_left -= prlen; 154 } else if (ch == '%' && fmt[1] == '%' && fmt_left > 2) { 155 *t++ = '%'; 156 *t++ = '%'; 157 fmt++; 158 fmt_left -= 2; 159 } else { 160 if (fmt_left > 1) { 161 *t++ = ch; 162 fmt_left--; 163 } 164 } 165 } 166 *t = '\0'; 167 168 prlen = vsnprintf(p, tbuf_left, fmt_cpy, ap); 169 DEC(); 170 cnt = p - tbuf; 171 while (cnt > 0 && p[-1] == '\n') { 172 *(--p) = '\0'; 173 --cnt; 174 } 175 176 /* Output to stderr if requested. */ 177 if (data->log_stat & LOG_PERROR) { 178 struct iovec iov[2]; 179 180 iov[0].iov_base = stdp; 181 iov[0].iov_len = cnt > stdp - tbuf ? cnt - (stdp - tbuf) : 0; 182 iov[1].iov_base = "\n"; 183 iov[1].iov_len = 1; 184 (void)writev(STDERR_FILENO, iov, 2); 185 } 186 187 /* 188 * If the sendsyslog() fails, it means that syslogd 189 * is not running or the kernel ran out of buffers. 190 */ 191 sendsyslog(tbuf, cnt, data->log_stat & LOG_CONS); 192 } 193 194 void 195 openlog_r(const char *ident, int logstat, int logfac, struct syslog_data *data) 196 { 197 if (ident != NULL) 198 data->log_tag = ident; 199 data->log_stat = logstat; 200 if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0) 201 data->log_fac = logfac; 202 } 203 DEF_WEAK(openlog_r); 204 205 void 206 closelog_r(struct syslog_data *data) 207 { 208 data->log_tag = NULL; 209 } 210 DEF_WEAK(closelog_r); 211