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() */ 48void 49syslog_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} 57DEF_WEAK(syslog_r); 58 59void 60vsyslog_r(int pri, struct syslog_data *data, const char *fmt, va_list ap) 61{ 62 __vsyslog_r(pri, data, 1, fmt, ap); 63} 64DEF_WEAK(vsyslog_r); 65 66/* 67 * This is used by both syslog_r and syslog. 68 */ 69void 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); 188done: 189 errno = saved_errno; 190} 191 192void 193openlog_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} 201DEF_WEAK(openlog_r); 202 203void 204closelog_r(struct syslog_data *data) 205{ 206 data->log_tag = NULL; 207} 208DEF_WEAK(closelog_r); 209