mirror of
https://git.rtems.org/rtems-libbsd/
synced 2025-10-14 13:15:21 +08:00
SYSLOG(3): Replace implementation
Avoid potential buffer overflows on the stack. Expand the %m in the format string.
This commit is contained in:
Sebastian Huber
@@ -1,194 +1,193 @@
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/*
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* RTEMS version of syslog and associated routines
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/**
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* @file
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*
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* @ingroup rtems_bsd_rtems
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*
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* @brief TODO.
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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/*
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* Copyright (c) 2014 embedded brains GmbH. All rights reserved.
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*
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* embedded brains GmbH
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* Dornierstr. 4
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* 82178 Puchheim
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* Germany
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* <rtems@embedded-brains.de>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <machine/rtems-bsd-user-space.h>
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#include <machine/rtems-bsd-program.h>
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#include <rtems.h>
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#include <stdio.h>
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#include <stdarg.h>
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#include <errno.h>
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#include <syslog.h>
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#include <rtems/bsd/sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <errno.h>
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#include <stdio.h>
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#include <string.h>
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#include <unistd.h>
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typedef struct {
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int mask;
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} rtems_bsd_syslog_context;
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#include <machine/rtems-bsd-printf-to-iprintf.h>
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/* FIXME: This should be thread specific */
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static rtems_bsd_syslog_context rtems_bsd_syslog_instance = {
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.mask = LOG_UPTO(LOG_DEBUG)
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};
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static int LogStatus = LOG_CONS;
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static const char *LogTag = "syslog";
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static int LogFacility = LOG_USER;
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static int LogMask = 0xff;
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static const char * const rtems_bsd_syslog_priorities[] = {
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[LOG_EMERG] = "emerg",
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[LOG_ALERT] = "alert",
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[LOG_CRIT] = "crit",
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[LOG_ERR] = "err",
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[LOG_WARNING] = "warning",
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[LOG_NOTICE] = "notice",
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[LOG_INFO] = "info",
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[LOG_DEBUG] = "debug"
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};
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static int LogFd = -1;
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static rtems_id LogSemaphore;
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extern struct in_addr rtems_bsdnet_log_host_address;
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static rtems_bsd_syslog_context *
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rtems_bsd_syslog_get_context(void)
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{
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return &rtems_bsd_syslog_instance;
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}
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#define SYSLOG_PORT 514
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static void
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rtems_bsd_syslog_format_buffer_overflow(void)
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{
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fputs("err: syslog: format buffer overflow\n", stderr);
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}
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void
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syslog (int pri, const char *fmt, ...)
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syslog(int priority, const char *format, ...)
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{
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va_list ap;
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va_start (ap, fmt);
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vsyslog (pri, fmt, ap);
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va_end (ap);
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}
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/*
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* FIXME: Should cbuf be static? It could be if we put the mutex
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* around the entire body of this routine. Then we wouldn't
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* have to worry about blowing stacks with a local variable
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* that large. Could make cbuf bigger, too.
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*/
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void
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vsyslog (int pri, const char *fmt, va_list ap)
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{
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int cnt;
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char *cp;
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char *msgp, cbuf[200];
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int sent;
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if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
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syslog (LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID,
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"syslog: unknown facility/priority: %#x", pri);
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pri &= LOG_PRIMASK|LOG_FACMASK;
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}
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if (!(LOG_MASK(LOG_PRI(pri)) & LogMask))
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return;
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if ((pri & LOG_FACMASK) == 0)
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pri |= LogFacility;
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cnt = sprintf (cbuf, "<%d>", pri);
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cp = msgp = cbuf + cnt;
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if (LogTag) {
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const char *lp = LogTag;
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while ((*cp = *lp++) != '\0')
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cp++;
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}
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if (LogStatus & LOG_PID) {
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rtems_id tid;
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rtems_task_ident (RTEMS_SELF, 0, &tid);
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cnt = sprintf (cp, "[%#lx]", (unsigned long)tid);
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cp += cnt;
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}
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if (LogTag) {
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*cp++ = ':';
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*cp++ = ' ';
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}
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cnt = vsprintf (cp, fmt, ap);
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cnt += cp - cbuf;
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if (cbuf[cnt-1] == '\n')
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cbuf[--cnt] = '\0';
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if (LogStatus & LOG_PERROR)
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printf ("%s\n", cbuf);
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/*
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* Grab the mutex
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*/
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sent = 0;
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if ((rtems_bsdnet_log_host_address.s_addr != INADDR_ANY)
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&& (LogFd >= 0)
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&& (rtems_semaphore_obtain (LogSemaphore, RTEMS_WAIT, RTEMS_NO_TIMEOUT) == RTEMS_SUCCESSFUL)) {
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/*
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* Set the destination address/port
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*/
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struct sockaddr_in farAddress;
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farAddress.sin_family = AF_INET;
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farAddress.sin_port = htons (SYSLOG_PORT);
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farAddress.sin_addr = rtems_bsdnet_log_host_address;
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memset (farAddress.sin_zero, '\0', sizeof farAddress.sin_zero);
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/*
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* Send the message
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*/
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if (sendto (LogFd, cbuf, cnt, 0, (struct sockaddr *)&farAddress, sizeof farAddress) >= 0)
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sent = 1;
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rtems_semaphore_release (LogSemaphore);
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}
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if (!sent && (LogStatus & LOG_CONS) && !(LogStatus & LOG_PERROR))
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printf ("%s\n", msgp);
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va_start(ap, format);
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vsyslog(priority, format, ap);
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va_end(ap);
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}
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void
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openlog (const char *ident, int logstat, int logfac)
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vsyslog(int priority, const char *format, va_list ap)
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{
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rtems_status_code sc;
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struct sockaddr_in myAddress;
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rtems_bsd_syslog_context *ctx = rtems_bsd_syslog_get_context();
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int pri = LOG_PRI(priority);
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char fmt[128];
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char buf[128];
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const char *src;
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char *dst;
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size_t rem;
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char *m;
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int n;
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size_t len;
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if (ident != NULL)
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LogTag = ident;
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LogStatus = logstat;
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if (logfac != 0 && (logfac & ~LOG_FACMASK) == 0)
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LogFacility = logfac;
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/*
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* Create the socket
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*/
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if ((LogFd = socket (AF_INET, SOCK_DGRAM, 0)) < 0) {
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printf ("Can't create syslog socket: %d\n", errno);
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if ((LOG_MASK(pri) & ctx->mask) == 0) {
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return;
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}
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/*
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* Bind socket to name
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*/
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myAddress.sin_family = AF_INET;
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myAddress.sin_addr.s_addr = INADDR_ANY;
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myAddress.sin_port = 0;
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memset (myAddress.sin_zero, '\0', sizeof myAddress.sin_zero);
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if (bind (LogFd, (struct sockaddr *)&myAddress, sizeof (myAddress)) < 0) {
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close (LogFd);
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LogFd = -1;
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printf ("Can't bind syslog socket: %d\n", errno);
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/* Expand the %m in the format string and add a newline character */
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src = format;
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dst = &fmt[0];
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rem = sizeof(fmt) - 2;
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while ((m = strstr(src, "%m")) != NULL) {
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size_t c = m - src;
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if (c > rem) {
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rtems_bsd_syslog_format_buffer_overflow();
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return;
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}
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memcpy(dst, src, c);
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dst += c;
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src += c + 2;
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rem -= c;
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n = sniprintf(dst, rem, "%s", strerror(errno));
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if (n > rem || n < 0) {
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rtems_bsd_syslog_format_buffer_overflow();
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return;
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}
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dst += (size_t) n;
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rem -= (size_t) n;
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}
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len = strlen(src);
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if (len > rem) {
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rtems_bsd_syslog_format_buffer_overflow();
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return;
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}
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/*
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* Create the mutex
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*/
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sc = rtems_semaphore_create (rtems_build_name('s', 'L', 'o', 'g'),
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1,
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RTEMS_PRIORITY |
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RTEMS_BINARY_SEMAPHORE |
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RTEMS_INHERIT_PRIORITY |
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RTEMS_NO_PRIORITY_CEILING |
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RTEMS_LOCAL,
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0,
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&LogSemaphore);
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if (sc != RTEMS_SUCCESSFUL) {
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printf ("Can't create syslog semaphore: %d\n", sc);
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close (LogFd);
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LogFd = -1;
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memcpy(dst, src, len);
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dst += len;
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dst[0] = '\n';
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dst[1] = '\0';
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/* Print into buffer */
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dst = &buf[0];
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rem = sizeof(buf) - 1;
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n = sniprintf(dst, rem, "%s: ", rtems_bsd_syslog_priorities[pri]);
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if (n <= rem) {
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dst += (size_t) n;
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rem -= (size_t) n;
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}
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n = sniprintf(dst, rem, "%s: ", rtems_bsd_program_get_name());
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if (n <= rem) {
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dst += (size_t) n;
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rem -= (size_t) n;
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}
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vsniprintf(dst, rem, &fmt[0], ap);
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/* Write in one rush */
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fputs(&buf[0], stderr);
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}
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void
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openlog(const char *ident, int option, int facility)
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{
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/* TODO */
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}
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void
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closelog(void)
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{
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if (LogFd >= 0) {
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close (LogFd);
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LogFd = -1;
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rtems_semaphore_delete (LogSemaphore);
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}
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/* TODO */
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}
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int
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setlogmask (int pmask)
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setlogmask(int mask)
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{
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int omask;
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rtems_bsd_syslog_context *ctx = rtems_bsd_syslog_get_context();
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int cur = ctx->mask;
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omask = LogMask;
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if (pmask != 0)
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LogMask = pmask;
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return (omask);
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ctx->mask = mask & LOG_UPTO(LOG_DEBUG);
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return cur;
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}
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@@ -50,6 +50,7 @@
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <syslog.h>
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#define RTEMS_BSD_PROGRAM_NO_EXIT_WRAP
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#define RTEMS_BSD_PROGRAM_NO_PRINTF_WRAP
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@@ -1691,6 +1692,28 @@ test_err(void)
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assert(exit_code == 15);
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}
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static void
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test_syslog(void)
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{
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puts("test syslog");
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errno = 0;
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syslog(LOG_ERR, "%m");
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syslog(LOG_ERR, "b%m");
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syslog(LOG_ERR, "%me");
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errno = ENXIO;
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syslog(LOG_ERR, "<%m><%m><%m>");
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syslog(LOG_INFO, "%m%m%m%m%m%m%m%m%m%m%m%m%m%m");
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syslog(LOG_EMERG, "emerg");
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syslog(LOG_ALERT, "alert");
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syslog(LOG_CRIT, "crit");
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syslog(LOG_ERR, "err");
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syslog(LOG_WARNING, "warning");
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syslog(LOG_NOTICE, "notice");
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syslog(LOG_INFO, "info");
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syslog(LOG_DEBUG, "debug");
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}
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static void
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test_main(void)
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{
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@@ -1720,6 +1743,7 @@ test_main(void)
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test_bsd_program();
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test_warn();
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test_err();
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test_syslog();
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exit(0);
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}
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