/* $OpenBSD: syslog_r.c,v 1.3 2011/05/30 18:48:33 martynas Exp $ */ /* * Copyright (c) 1983, 1988, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern char *__progname; /* Program name, from crt0. */ static void disconnectlog_r(struct syslog_data *); /* disconnect from syslogd */ static void connectlog_r(struct syslog_data *); /* (re)connect to syslogd */ void __vsyslog_r(int pri, struct syslog_data *, size_t (*)(char *, size_t), const char *, va_list); /* Reentrant version of syslog, i.e. syslog_r() */ /* PRINTFLIKE3 */ void syslog_r(int pri, struct syslog_data *data, const char *fmt, ...) { va_list ap; va_start(ap, fmt); vsyslog_r(pri, data, fmt, ap); va_end(ap); } void vsyslog_r(int pri, struct syslog_data *data, const char *fmt, va_list ap) { const char *ident; __vsyslog_r(pri, data, NULL, fmt, ap); /* close the socket without losing log_tag */ ident = data->log_tag; closelog_r(data); data->log_tag = ident; } /* * This is used by both syslog_r and syslog. The latter supplies * a non-NULL gettime callback for filling in the date, but we also * use the presence of that callback to decide whether it's safe * to call strerror and what the name of the caller is */ void __vsyslog_r(int pri, struct syslog_data *data, size_t (*gettime)(char *, size_t), const char *fmt, va_list ap) { int cnt; char ch, *p, *t; int fd, saved_errno, error; #define TBUF_LEN 2048 #define FMT_LEN 1024 char *stdp, tbuf[TBUF_LEN], fmt_cpy[FMT_LEN]; int tbuf_left, fmt_left, prlen; #define INTERNALLOG LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID /* Check for invalid bits. */ if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) { syslog_r(INTERNALLOG, data, "syslog%s: unknown facility/priority: %x", gettime != NULL ? "" : "_r", pri); pri &= LOG_PRIMASK|LOG_FACMASK; } /* Check priority against setlogmask values. */ if (!(LOG_MASK(LOG_PRI(pri)) & data->log_mask)) return; saved_errno = errno; /* Set default facility if none specified. */ if ((pri & LOG_FACMASK) == 0) pri |= data->log_fac; p = tbuf; tbuf_left = TBUF_LEN; #define DEC() \ do { \ if (prlen < 0) \ prlen = 0; \ if (prlen >= tbuf_left) \ prlen = tbuf_left - 1; \ p += prlen; \ tbuf_left -= prlen; \ } while (0) prlen = snprintf(p, tbuf_left, "<%d>", pri); DEC(); /* * syslogd will expand time automagically for reentrant case, and * for normal case, invoke the callback to do it just do like before */ if (gettime != NULL) { prlen = gettime(p, tbuf_left); DEC(); } if (data->log_stat & LOG_PERROR) stdp = p; if (data->log_tag == NULL) data->log_tag = __progname; if (data->log_tag != NULL) { prlen = snprintf(p, tbuf_left, "%s", data->log_tag); DEC(); } if (data->log_stat & LOG_PID) { prlen = snprintf(p, tbuf_left, "[%ld]", (long)getpid()); DEC(); } if (data->log_tag != NULL) { if (tbuf_left > 1) { *p++ = ':'; tbuf_left--; } if (tbuf_left > 1) { *p++ = ' '; tbuf_left--; } } /* strerror() is not reentrant */ for (t = fmt_cpy, fmt_left = FMT_LEN; (ch = *fmt); ++fmt) { if (ch == '%' && fmt[1] == 'm') { ++fmt; if (gettime != NULL) { prlen = snprintf(t, fmt_left, "%s", strerror(saved_errno)); } else { prlen = snprintf(t, fmt_left, "Error %d", saved_errno); } if (prlen < 0) prlen = 0; if (prlen >= fmt_left) prlen = fmt_left - 1; t += prlen; fmt_left -= prlen; } else if (ch == '%' && fmt[1] == '%' && fmt_left > 2) { *t++ = '%'; *t++ = '%'; fmt++; fmt_left -= 2; } else { if (fmt_left > 1) { *t++ = ch; fmt_left--; } } } *t = '\0'; prlen = vsnprintf(p, tbuf_left, fmt_cpy, ap); DEC(); cnt = p - tbuf; /* Output to stderr if requested. */ if (data->log_stat & LOG_PERROR) { struct iovec iov[2]; iov[0].iov_base = stdp; iov[0].iov_len = cnt - (stdp - tbuf); iov[1].iov_base = "\n"; iov[1].iov_len = 1; (void)writev(STDERR_FILENO, iov, 2); } /* Get connected, output the message to the local logger. */ if (!data->opened) openlog_r(data->log_tag, data->log_stat, 0, data); connectlog_r(data); /* * If the send() failed, there are two likely scenarios: * 1) syslogd was restarted * 2) /dev/log is out of socket buffer space * We attempt to reconnect to /dev/log to take care of * case #1 and keep send()ing data to cover case #2 * to give syslogd a chance to empty its socket buffer. */ if ((error = send(data->log_file, tbuf, cnt, 0)) < 0) { if (errno != ENOBUFS) { disconnectlog_r(data); connectlog_r(data); } do { struct timespec rqt = { 0, 1000 }; nanosleep(&rqt, NULL); if ((error = send(data->log_file, tbuf, cnt, 0)) >= 0) break; } while (errno == ENOBUFS); } /* * Output the message to the console; try not to block * as a blocking console should not stop other processes. * Make sure the error reported is the one from the syslogd failure. */ if (error == -1 && (data->log_stat & LOG_CONS) && (fd = open(_PATH_CONSOLE, O_WRONLY|O_NONBLOCK, 0)) >= 0) { struct iovec iov[2]; p = strchr(tbuf, '>') + 1; iov[0].iov_base = p; iov[0].iov_len = cnt - (p - tbuf); iov[1].iov_base = "\r\n"; iov[1].iov_len = 2; (void)writev(fd, iov, 2); (void)close(fd); } } static void disconnectlog_r(struct syslog_data *data) { /* * If the user closed the FD and opened another in the same slot, * that's their problem. They should close it before calling on * system services. */ if (data->log_file != -1) { close(data->log_file); data->log_file = -1; } data->connected = 0; /* retry connect */ } static void connectlog_r(struct syslog_data *data) { struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */ if (data->log_file == -1) { if ((data->log_file = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1) return; (void)fcntl(data->log_file, F_SETFD, 1); } if (data->log_file != -1 && !data->connected) { memset(&SyslogAddr, '\0', sizeof(SyslogAddr)); SyslogAddr.sun_len = sizeof(SyslogAddr); SyslogAddr.sun_family = AF_UNIX; strlcpy(SyslogAddr.sun_path, _PATH_LOG, sizeof(SyslogAddr.sun_path)); if (connect(data->log_file, (struct sockaddr *)&SyslogAddr, sizeof(SyslogAddr)) == -1) { (void)close(data->log_file); data->log_file = -1; } else data->connected = 1; } } void openlog_r(const char *ident, int logstat, int logfac, struct syslog_data *data) { if (ident != NULL) data->log_tag = ident; data->log_stat = logstat; if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0) data->log_fac = logfac; if (data->log_stat & LOG_NDELAY) /* open immediately */ connectlog_r(data); data->opened = 1; /* ident and facility has been set */ } void closelog_r(struct syslog_data *data) { (void)close(data->log_file); data->log_file = -1; data->connected = 0; data->log_tag = NULL; }