syslog_r() implementation. deraadt@ ok.

2 files changed, 275 insertions, 101 deletions

diff --git a/lib/libc/gen/syslog.3 b/lib/libc/gen/syslog.3
index 36f998b8ee2..3f09655a030 100644
--- a/lib/libc/gen/syslog.3
+++ b/lib/libc/gen/syslog.3
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: syslog.3,v 1.12 2001/07/27 16:41:20 marc Exp $
+.\"	$OpenBSD: syslog.3,v 1.13 2001/10/24 08:16:42 jjbg Exp $
 .\"
 .\" Copyright (c) 1985, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -36,10 +36,15 @@
 .Os
 .Sh NAME
 .Nm syslog ,
+.Nm syslog_r,
 .Nm vsyslog ,
+.Nm vsyslog_r,
 .Nm openlog ,
+.Nm openlog_r,
 .Nm closelog ,
-.Nm setlogmask
+.Nm closelog_r,
+.Nm setlogmask,
+.Nm setlogmask_r
 .Nd control system log
 .Sh SYNOPSIS
 .Fd #include <syslog.h>
@@ -47,13 +52,36 @@
 .Ft void
 .Fn syslog "int priority" "const char *message" "..."
 .Ft void
+.Fn syslog_r "int priority" "struct syslog_data *data" "const char *message" "..."
+.Ft void
 .Fn vsyslog "int priority" "const char *message" "va_list args"
 .Ft void
+.Fn vsyslog_r "int priority" "struct syslog_data *data" "const char *message" "va_list args"
+.Ft void
 .Fn openlog "const char *ident" "int logopt" "int facility"
 .Ft void
+.Fn openlog_r "const char *ident" "int logopt" "int facility" "struct syslog_data *data"
+.Ft void
 .Fn closelog void
+.Ft void
+.Fn closelog_r "struct syslog_data *data"
 .Ft int
 .Fn setlogmask "int maskpri"
+.Ft int
+.Fn setlogmask_r "int maskpri" "struct syslog_data *data"
+.Bd -literal
+
+struct syslog_data {
+        int     log_file;
+        int     connected;
+        int     opened;
+        int     log_stat;
+        const char      *log_tag;
+        int     log_fac;
+        int     log_mask;
+};
+
+#define SYSLOG_DATA_INIT {-1, 0, 0, 0, NULL, LOG_USER, 0xff}
 .Sh DESCRIPTION
 The
 .Fn syslog
@@ -76,6 +104,39 @@ see
 A trailing newline is added if none is present.
 .Pp
 The
+.Fn syslog_r 
+function is a reentrant version of the
+.Xr syslog 3
+function. It takes a pointer to a 
+.Fa syslog_data
+structure which is used to store
+information. This parameter must be initialized before
+.Fn syslog_r
+is called. The SYSLOG_DATA_INIT constant is used for this purpose. 
+The 
+.Fa syslog_data
+structure is composed of the following elements:
+.Bl -tag -width connected
+.It Dv log_file
+contains the file descriptor of the file where the message is logged.
+.It Dv connected
+indicates if connect has been done
+.It Dv opened
+indicates if 
+.Xr openlog_r 3 
+has been called.
+.It Dv log_stat
+status bits, set by
+.Xr openlog_r 3
+.It Dv log_tag
+string to tag the entry with
+.It Dv log_fac
+facility code
+.It Dv log_mask
+mask of priorities to be logged
+.El
+.Pp
+The
 .Fn vsyslog
 function is an alternate form in which the arguments have already been captured
 using the variable-length argument facilities of
@@ -116,6 +177,16 @@ normally of use only when debugging a program.
 .El
 .Pp
 The
+.Fn vsyslog_r
+is used the same way than 
+.Fn vsyslog
+except than it takes an additional pointer on a
+.Fa syslog_data
+structure. It is a reentrant version of the 
+.Fn vsyslog 
+function described above.
+.Pp 
+The
 .Fn openlog
 function provides for more specialized processing of the messages sent by
 .Fn syslog
@@ -210,8 +281,22 @@ through
 .El
 .Pp
 The
+.Fn openlog_r
+function is the reentrant version of the 
+.Fn openlog 
+function. It takes an additional pointer on a 
+.Fa syslog_data
+structure. This function must be used in conjunction with the other
+reentrant functions. 
+.Pp
+The
 .Fn closelog
-function can be used to close the log file.
+function can be used to close the log file. 
+.Fn closelog_r
+do the same thing but in a reentrant way and takes an additional
+pointer on a 
+.Fa syslog_data
+structure.
 .Pp
 The
 .Fn setlogmask
@@ -232,18 +317,32 @@ the mask for all priorities up to and including
 is given by the macro
 .Fn LOG_UPTO toppri ; .
 The default allows all priorities to be logged.
+.Pp
+The
+.Fn setlogmask_r
+function is the reentrant version of
+.Fn setlogmask .
+It takes an additional pointer on a
+.Fa syslog_data
+structure.
 .Sh RETURN VALUES
 The
 .Fn closelog ,
+.Fn closelog_r ,
 .Fn openlog ,
+.Fn openlog_r ,
 .Fn syslog ,
-and
+.Fn syslog_r ,
 .Fn vsyslog
+and
+.Fn vsyslog_r
 functions return no value.
 .Pp
-The routine
+The routines
 .Fn setlogmask
-always returns the previous log mask level.
+and
+.Fn setlogmask_r
+always return the previous log mask level.
 .Sh EXAMPLES
 .Bd -literal -offset indent -compact
 syslog(LOG_ALERT, "who: internal error 23");
@@ -263,6 +362,8 @@ syslog(LOG_INFO|LOG_LOCAL2, "foobar error: %m");
 These
 functions appeared in
 .Bx 4.2 .
+The reentrant functions appeared in
+.Ox 3.1 .
 .Sh CAVEATS
 It is important never to pass a string with user-supplied data as a
 format without using
diff --git a/lib/libc/gen/syslog.c b/lib/libc/gen/syslog.c
index fa6b9511921..beabbcce9ba 100644
--- a/lib/libc/gen/syslog.c
+++ b/lib/libc/gen/syslog.c
@@ -32,7 +32,7 @@
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static char rcsid[] = "$OpenBSD: syslog.c,v 1.11 2001/08/18 22:56:22 deraadt Exp $";
+static char rcsid[] = "$OpenBSD: syslog.c,v 1.12 2001/10/24 08:16:42 jjbg Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/types.h>
@@ -56,17 +56,15 @@ static char rcsid[] = "$OpenBSD: syslog.c,v 1.11 2001/08/18 22:56:22 deraadt Exp
 #include <varargs.h>
 #endif
 
-static int	LogFile = -1;		/* fd for log */
-static int	connected;		/* have done connect */
-static int	opened;			/* have done openlog() */
-static int	LogStat = 0;		/* status bits, set by openlog() */
-static const char *LogTag = NULL;	/* string to tag the entry with */
-static int	LogFacility = LOG_USER;	/* default facility code */
-static int	LogMask = 0xff;		/* mask of priorities to be logged */
+static struct syslog_data sdata = SYSLOG_DATA_INIT;
+
 extern char	*__progname;		/* Program name, from crt0. */
 
 static void	disconnectlog __P((void)); /* disconnect from syslogd */
 static void	connectlog __P((void));	/* (re)connect to syslogd */
+static void	disconnectlog_r __P((struct syslog_data *)); 
+static void	connectlog_r __P((struct syslog_data *)); 
+
 /*
  * syslog, vsyslog --
  *	print message on log file; output is intended for syslogd(8).
@@ -98,8 +96,76 @@ vsyslog(pri, fmt, ap)
 	register const char *fmt;
 	va_list ap;
 {
-	register int cnt;
-	register char ch, *p, *t;
+	vsyslog_r(pri, &sdata, fmt, ap);
+}
+
+static void
+disconnectlog()
+{
+	disconnectlog_r(&sdata);
+}
+
+static void
+connectlog()
+{
+	connectlog_r(&sdata);
+}
+
+void
+openlog(ident, logstat, logfac)
+	const char *ident;
+	int logstat, logfac;
+{
+	openlog_r(ident, logstat, logfac, &sdata);
+}
+
+void
+closelog()
+{
+	closelog_r(&sdata);
+}
+
+/* setlogmask -- set the log mask level */
+int
+setlogmask(pmask)
+	int pmask;
+{
+	return setlogmask_r(pmask, &sdata);
+}
+
+/* Reentrant version of syslog, i.e. syslog_r() */
+
+void
+#ifdef __STDC__
+syslog_r(int pri, struct syslog_data *data, const char *fmt, ...)
+#else
+syslog_r(pri, data, fmt, va_alist)
+	int pri;
+	struct syslog_data *data;
+	char *fmt;
+	va_dcl
+#endif
+{
+	va_list ap;
+
+#ifdef __STDC__
+	va_start(ap, fmt);
+#else
+	va_start(ap);
+#endif
+	vsyslog_r(pri, data, fmt, ap);
+	va_end(ap);
+}
+
+void
+vsyslog_r(pri, data, fmt, ap)
+	int pri;
+	struct syslog_data *data;
+	const char *fmt;
+	va_list ap;
+{
+	int cnt;
+	char ch, *p, *t;
 	time_t now;
 	int fd, saved_errno;
 #define	TBUF_LEN	2048
@@ -110,65 +176,64 @@ vsyslog(pri, fmt, ap)
 #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);
+		if (data == &sdata) {
+			syslog(INTERNALLOG,
+			    "syslog: unknown facility/priority: %x", pri);
+		} else {
+			syslog_r(INTERNALLOG, data,
+			    "syslog_r: unknown facility/priority: %x", pri);
+		}
 		pri &= LOG_PRIMASK|LOG_FACMASK;
 	}
 
 	/* Check priority against setlogmask values. */
-	if (!(LOG_MASK(LOG_PRI(pri)) & LogMask))
+	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 |= LogFacility;
+	/* If we have been called through syslog(), no need for reentrancy. */
+	if (data == &sdata)
+		(void)time(&now);
+
+        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();
 
-	/* Build the message. */
-	
-	/*
- 	 * Although it's tempting, we can't ignore the possibility of
-	 * overflowing the buffer when assembling the "fixed" portion
-	 * of the message.  Strftime's "%h" directive expands to the
-	 * locale's abbreviated month name, but if the user has the
-	 * ability to construct to his own locale files, it may be
-	 * arbitrarily long.
+	/* 
+	 * syslogd will expand time automagically for reentrant case, and
+	 * for normal case, just do like before
 	 */
-	(void)time(&now);
-
-	p = tbuf;  
-	tbuf_left = TBUF_LEN;
-	
-#define	DEC()	\
-	do {					\
-		if (prlen < 0)			\
-			prlen = 0;		\
-		else if (prlen >= tbuf_left)	\
-			prlen = tbuf_left - 1;	\
-		p += prlen;			\
-		tbuf_left -= prlen;		\
-	} while (0)
-
-	prlen = snprintf(p, tbuf_left, "<%d>", pri);
-	DEC();
-
-	prlen = strftime(p, tbuf_left, "%h %e %T ", localtime(&now));
-	DEC();
+	if (data == &sdata) {
+		prlen = strftime(p, tbuf_left, "%h %e %T ", localtime(&now));
+		DEC();
+	}
 
-	if (LogStat & LOG_PERROR)
+	if (data->log_stat & LOG_PERROR)
 		stdp = p;
-	if (LogTag == NULL)
-		LogTag = __progname;
-	if (LogTag != NULL) {
-		prlen = snprintf(p, tbuf_left, "%s", LogTag);
+	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 (LogStat & LOG_PID) {
+	if (data->log_stat & LOG_PID) {
 		prlen = snprintf(p, tbuf_left, "[%d]", getpid());
 		DEC();
 	}
-	if (LogTag != NULL) {
+	if (data->log_tag != NULL) {
 		if (tbuf_left > 1) {
 			*p++ = ':';
 			tbuf_left--;
@@ -179,15 +244,18 @@ vsyslog(pri, fmt, ap)
 		}
 	}
 
-	/* 
-	 * We wouldn't need this mess if printf handled %m, or if 
-	 * strerror() had been invented before syslog().
-	 */
+	/* strerror() is not reentrant */
+
 	for (t = fmt_cpy, fmt_left = FMT_LEN; (ch = *fmt); ++fmt) {
 		if (ch == '%' && fmt[1] == 'm') {
 			++fmt;
-			prlen = snprintf(t, fmt_left, "%s",
-			    strerror(saved_errno));
+			if (data == &sdata) {
+				prlen = snprintf(t, fmt_left, "%s",
+				    strerror(saved_errno)); 
+			} else {
+				prlen = snprintf(t, fmt_left, "Error %d",
+				    saved_errno); 
+			}
 			if (prlen >= fmt_left)
 				prlen = fmt_left - 1;
 			t += prlen;
@@ -206,7 +274,7 @@ vsyslog(pri, fmt, ap)
 	cnt = p - tbuf;
 
 	/* Output to stderr if requested. */
-	if (LogStat & LOG_PERROR) {
+	if (data->log_stat & LOG_PERROR) {
 		struct iovec iov[2];
 
 		iov[0].iov_base = stdp;
@@ -217,19 +285,19 @@ vsyslog(pri, fmt, ap)
 	}
 
 	/* Get connected, output the message to the local logger. */
-	if (!opened)
-		openlog(LogTag, LogStat, 0);
-	connectlog();
-	if (send(LogFile, tbuf, cnt, 0) >= 0)
+	if (!data->opened)
+		openlog_r(data->log_tag, data->log_stat, 0, data);
+	connectlog_r(data);
+	if (send(data->log_file, tbuf, cnt, 0) >= 0)
 		return;
 
 	/*
 	 * If the send() failed, the odds are syslogd was restarted.
 	 * Make one (only) attempt to reconnect to /dev/log.
 	 */
-	disconnectlog();
-	connectlog();
-	if (send(LogFile, tbuf, cnt, 0) >= 0)
+	disconnectlog_r(data);
+	connectlog_r(data);
+	if (send(data->log_file, tbuf, cnt, 0) >= 0)
 		return;
 
 	/*
@@ -237,7 +305,7 @@ vsyslog(pri, fmt, ap)
 	 * if console blocks everything will.  Make sure the error reported
 	 * is the one from the syslogd failure.
 	 */
-	if (LogStat & LOG_CONS &&
+	if (data->log_stat & LOG_CONS &&
 	    (fd = open(_PATH_CONSOLE, O_WRONLY, 0)) >= 0) {
 		struct iovec iov[2];
 		
@@ -252,79 +320,84 @@ vsyslog(pri, fmt, ap)
 }
 
 static void
-disconnectlog()
+disconnectlog_r(data)
+	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 (LogFile != -1) {
-		close(LogFile);
-		LogFile = -1;
+	if (data->log_file != -1) {
+		close(data->log_file);
+		data->log_file = -1;
 	}
-	connected = 0;		/* retry connect */
+	data->connected = 0;		/* retry connect */
 }
 
 static void
-connectlog()
+connectlog_r(data)
+	struct syslog_data *data;
 {
 	struct sockaddr_un SyslogAddr;	/* AF_UNIX address of local logger */
 
-	if (LogFile == -1) {
-		if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1)
+	if (data->log_file == -1) {
+		if ((data->log_file = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1)
 			return;
-		(void)fcntl(LogFile, F_SETFD, 1);
+		(void)fcntl(data->log_file, F_SETFD, 1);
 	}
-	if (LogFile != -1 && !connected) {
+	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(LogFile, (struct sockaddr *)&SyslogAddr,
+		if (connect(data->log_file, (struct sockaddr *)&SyslogAddr,
 		    sizeof(SyslogAddr)) == -1) {
-			(void)close(LogFile);
-			LogFile = -1;
+			(void)close(data->log_file);
+			data->log_file = -1;
 		} else
-			connected = 1;
+			data->connected = 1;
 	}
 }
 
 void
-openlog(ident, logstat, logfac)
+openlog_r(ident, logstat, logfac, data)
 	const char *ident;
 	int logstat, logfac;
+	struct syslog_data *data;
 {
 	if (ident != NULL)
-		LogTag = ident;
-	LogStat = logstat;
+		data->log_tag = ident;
+	data->log_stat = logstat;
 	if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
-		LogFacility = logfac;
+		data->log_fac = logfac;
 
-	if (LogStat & LOG_NDELAY)	/* open immediately */
-		connectlog();
+	if (data->log_stat & LOG_NDELAY)	/* open immediately */
+		connectlog_r(data);
 
-	opened = 1;	/* ident and facility has been set */
+	data->opened = 1;	/* ident and facility has been set */
 }
 
 void
-closelog()
+closelog_r(data)
+	struct syslog_data *data;
 {
-	(void)close(LogFile);
-	LogFile = -1;
-	connected = 0;
+	(void)close(data->log_file);
+	data->log_file = -1;
+	data->connected = 0;
 }
 
 /* setlogmask -- set the log mask level */
 int
-setlogmask(pmask)
+setlogmask_r(pmask, data)
 	int pmask;
+	struct syslog_data *data;
 {
 	int omask;
 
-	omask = LogMask;
+	omask = data->log_mask;
 	if (pmask != 0)
-		LogMask = pmask;
+		data->log_mask = pmask;
 	return (omask);
 }