glibc/misc/syslog.c
Joseph Myers be7dc2b77e Fix syslog dprintf namespace (bug 18534).
syslog functions bring in references to dprintf, which wasn't added to
POSIX until the 2008 edition and so isn't in various standards
containing the syslog functions.  This patch fixes this by making
dprintf into a weak alias of __dprintf and using __dprintf as
appropriate.

Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).

	[BZ #18534]
	* stdio-common/dprintf.c (__dprintf): Use libc_hidden_def.
	(dprintf): Define as a weak alias of __dprintf, not a strong
	alias.
	* include/stdio.h (__dprintf): Declare.  Use libc_hidden_proto.
	* misc/syslog.c (__vsyslog_chk): Call __dprintf instead of
	dprintf.
	* conform/Makefile (test-xfail-XPG4/syslog.h/linknamespace):
	Remove variable.
	(test-xfail-UNIX98/syslog.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/syslog.h/linknamespace): Likewise.
2015-06-17 20:10:50 +00:00

465 lines
11 KiB
C

/*
* 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.
* 4. 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)syslog.c 8.4 (Berkeley) 3/18/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <netdb.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <stdlib.h>
#include <bits/libc-lock.h>
#include <signal.h>
#include <locale.h>
#include <stdarg.h>
#include <libio/iolibio.h>
#include <math_ldbl_opt.h>
#include <kernel-features.h>
#define ftell(s) _IO_ftell (s)
static int LogType = SOCK_DGRAM; /* type of socket connection */
static int LogFile = -1; /* fd for log */
static int connected; /* have done connect */
static int LogStat; /* status bits, set by openlog() */
static const char *LogTag; /* string to tag the entry with */
static int LogFacility = LOG_USER; /* default facility code */
static int LogMask = 0xff; /* mask of priorities to be logged */
extern char *__progname; /* Program name, from crt0. */
/* Define the lock. */
__libc_lock_define_initialized (static, syslog_lock)
static void openlog_internal(const char *, int, int) internal_function;
static void closelog_internal(void);
#ifndef NO_SIGPIPE
static void sigpipe_handler (int);
#endif
#ifndef send_flags
# define send_flags 0
#endif
struct cleanup_arg
{
void *buf;
struct sigaction *oldaction;
};
static void
cancel_handler (void *ptr)
{
#ifndef NO_SIGPIPE
/* Restore the old signal handler. */
struct cleanup_arg *clarg = (struct cleanup_arg *) ptr;
if (clarg != NULL && clarg->oldaction != NULL)
__sigaction (SIGPIPE, clarg->oldaction, NULL);
#endif
/* Free the lock. */
__libc_lock_unlock (syslog_lock);
}
/*
* syslog, vsyslog --
* print message on log file; output is intended for syslogd(8).
*/
void
__syslog(int pri, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
__vsyslog_chk(pri, -1, fmt, ap);
va_end(ap);
}
ldbl_hidden_def (__syslog, syslog)
ldbl_strong_alias (__syslog, syslog)
void
__syslog_chk(int pri, int flag, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
__vsyslog_chk(pri, flag, fmt, ap);
va_end(ap);
}
void
__vsyslog_chk(int pri, int flag, const char *fmt, va_list ap)
{
struct tm now_tm;
time_t now;
int fd;
FILE *f;
char *buf = 0;
size_t bufsize = 0;
size_t msgoff;
#ifndef NO_SIGPIPE
struct sigaction action, oldaction;
int sigpipe;
#endif
int saved_errno = errno;
char failbuf[3 * sizeof (pid_t) + sizeof "out of memory []"];
#define INTERNALLOG LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID
/* Check for invalid bits. */
if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
syslog(INTERNALLOG,
"syslog: unknown facility/priority: %x", pri);
pri &= LOG_PRIMASK|LOG_FACMASK;
}
/* Check priority against setlogmask values. */
if ((LOG_MASK (LOG_PRI (pri)) & LogMask) == 0)
return;
/* Set default facility if none specified. */
if ((pri & LOG_FACMASK) == 0)
pri |= LogFacility;
/* Build the message in a memory-buffer stream. */
f = __open_memstream (&buf, &bufsize);
if (f == NULL)
{
/* We cannot get a stream. There is not much we can do but
emitting an error messages. */
char numbuf[3 * sizeof (pid_t)];
char *nump;
char *endp = __stpcpy (failbuf, "out of memory [");
pid_t pid = __getpid ();
nump = numbuf + sizeof (numbuf);
/* The PID can never be zero. */
do
*--nump = '0' + pid % 10;
while ((pid /= 10) != 0);
endp = __mempcpy (endp, nump, (numbuf + sizeof (numbuf)) - nump);
*endp++ = ']';
*endp = '\0';
buf = failbuf;
bufsize = endp - failbuf;
msgoff = 0;
}
else
{
__fsetlocking (f, FSETLOCKING_BYCALLER);
fprintf (f, "<%d>", pri);
(void) time (&now);
f->_IO_write_ptr += __strftime_l (f->_IO_write_ptr,
f->_IO_write_end
- f->_IO_write_ptr,
"%h %e %T ",
__localtime_r (&now, &now_tm),
_nl_C_locobj_ptr);
msgoff = ftell (f);
if (LogTag == NULL)
LogTag = __progname;
if (LogTag != NULL)
__fputs_unlocked (LogTag, f);
if (LogStat & LOG_PID)
fprintf (f, "[%d]", (int) __getpid ());
if (LogTag != NULL)
{
putc_unlocked (':', f);
putc_unlocked (' ', f);
}
/* Restore errno for %m format. */
__set_errno (saved_errno);
/* We have the header. Print the user's format into the
buffer. */
if (flag == -1)
vfprintf (f, fmt, ap);
else
__vfprintf_chk (f, flag, fmt, ap);
/* Close the memory stream; this will finalize the data
into a malloc'd buffer in BUF. */
fclose (f);
}
/* Output to stderr if requested. */
if (LogStat & LOG_PERROR) {
struct iovec iov[2];
struct iovec *v = iov;
v->iov_base = buf + msgoff;
v->iov_len = bufsize - msgoff;
/* Append a newline if necessary. */
if (buf[bufsize - 1] != '\n')
{
++v;
v->iov_base = (char *) "\n";
v->iov_len = 1;
}
__libc_cleanup_push (free, buf == failbuf ? NULL : buf);
/* writev is a cancellation point. */
(void)__writev(STDERR_FILENO, iov, v - iov + 1);
__libc_cleanup_pop (0);
}
/* Prepare for multiple users. We have to take care: open and
write are cancellation points. */
struct cleanup_arg clarg;
clarg.buf = buf;
clarg.oldaction = NULL;
__libc_cleanup_push (cancel_handler, &clarg);
__libc_lock_lock (syslog_lock);
#ifndef NO_SIGPIPE
/* Prepare for a broken connection. */
memset (&action, 0, sizeof (action));
action.sa_handler = sigpipe_handler;
sigemptyset (&action.sa_mask);
sigpipe = __sigaction (SIGPIPE, &action, &oldaction);
if (sigpipe == 0)
clarg.oldaction = &oldaction;
#endif
/* Get connected, output the message to the local logger. */
if (!connected)
openlog_internal(LogTag, LogStat | LOG_NDELAY, 0);
/* If we have a SOCK_STREAM connection, also send ASCII NUL as
a record terminator. */
if (LogType == SOCK_STREAM)
++bufsize;
if (!connected || __send(LogFile, buf, bufsize, send_flags) < 0)
{
if (connected)
{
/* Try to reopen the syslog connection. Maybe it went
down. */
closelog_internal ();
openlog_internal(LogTag, LogStat | LOG_NDELAY, 0);
}
if (!connected || __send(LogFile, buf, bufsize, send_flags) < 0)
{
closelog_internal (); /* attempt re-open next time */
/*
* Output the message to the console; don't worry
* about blocking, if console blocks everything will.
* Make sure the error reported is the one from the
* syslogd failure.
*/
if (LogStat & LOG_CONS &&
(fd = __open(_PATH_CONSOLE, O_WRONLY|O_NOCTTY, 0)) >= 0)
{
__dprintf (fd, "%s\r\n", buf + msgoff);
(void)__close(fd);
}
}
}
#ifndef NO_SIGPIPE
if (sigpipe == 0)
__sigaction (SIGPIPE, &oldaction, (struct sigaction *) NULL);
#endif
/* End of critical section. */
__libc_cleanup_pop (0);
__libc_lock_unlock (syslog_lock);
if (buf != failbuf)
free (buf);
}
libc_hidden_def (__vsyslog_chk)
void
__vsyslog(int pri, const char *fmt, va_list ap)
{
__vsyslog_chk (pri, -1, fmt, ap);
}
ldbl_hidden_def (__vsyslog, vsyslog)
ldbl_weak_alias (__vsyslog, vsyslog)
static struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */
static void
internal_function
openlog_internal(const char *ident, int logstat, int logfac)
{
if (ident != NULL)
LogTag = ident;
LogStat = logstat;
if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
LogFacility = logfac;
int retry = 0;
while (retry < 2) {
if (LogFile == -1) {
SyslogAddr.sun_family = AF_UNIX;
(void)strncpy(SyslogAddr.sun_path, _PATH_LOG,
sizeof(SyslogAddr.sun_path));
if (LogStat & LOG_NDELAY) {
#ifdef SOCK_CLOEXEC
# ifndef __ASSUME_SOCK_CLOEXEC
if (__have_sock_cloexec >= 0) {
# endif
LogFile = __socket(AF_UNIX,
LogType
| SOCK_CLOEXEC, 0);
# ifndef __ASSUME_SOCK_CLOEXEC
if (__have_sock_cloexec == 0)
__have_sock_cloexec
= ((LogFile != -1
|| errno != EINVAL)
? 1 : -1);
}
# endif
#endif
#ifndef __ASSUME_SOCK_CLOEXEC
# ifdef SOCK_CLOEXEC
if (__have_sock_cloexec < 0)
# endif
LogFile = __socket(AF_UNIX, LogType, 0);
#endif
if (LogFile == -1)
return;
#ifndef __ASSUME_SOCK_CLOEXEC
# ifdef SOCK_CLOEXEC
if (__have_sock_cloexec < 0)
# endif
__fcntl(LogFile, F_SETFD, FD_CLOEXEC);
#endif
}
}
if (LogFile != -1 && !connected)
{
int old_errno = errno;
if (__connect(LogFile, &SyslogAddr, sizeof(SyslogAddr))
== -1)
{
int saved_errno = errno;
int fd = LogFile;
LogFile = -1;
(void)__close(fd);
__set_errno (old_errno);
if (saved_errno == EPROTOTYPE)
{
/* retry with the other type: */
LogType = (LogType == SOCK_DGRAM
? SOCK_STREAM : SOCK_DGRAM);
++retry;
continue;
}
} else
connected = 1;
}
break;
}
}
void
openlog (const char *ident, int logstat, int logfac)
{
/* Protect against multiple users and cancellation. */
__libc_cleanup_push (cancel_handler, NULL);
__libc_lock_lock (syslog_lock);
openlog_internal (ident, logstat, logfac);
__libc_cleanup_pop (1);
}
#ifndef NO_SIGPIPE
static void
sigpipe_handler (int signo)
{
closelog_internal ();
}
#endif
static void
closelog_internal (void)
{
if (!connected)
return;
__close (LogFile);
LogFile = -1;
connected = 0;
}
void
closelog (void)
{
/* Protect against multiple users and cancellation. */
__libc_cleanup_push (cancel_handler, NULL);
__libc_lock_lock (syslog_lock);
closelog_internal ();
LogTag = NULL;
LogType = SOCK_DGRAM; /* this is the default */
/* Free the lock. */
__libc_cleanup_pop (1);
}
/* setlogmask -- set the log mask level */
int
setlogmask(pmask)
int pmask;
{
int omask;
omask = LogMask;
if (pmask != 0)
LogMask = pmask;
return (omask);
}