Proposed syslog patch [Re: [musl] Further bugs in syslog()]

[Rich Felker <dalias@aerifal.cx>]

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On Fri, Mar 22, 2013 at 11:45:39PM -0400, Rich Felker wrote:
> I'm going to review the proposed patches and probably put together a
> big syslog fix...

Comments on the attached?

Rich

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diff --git a/src/misc/syslog.c b/src/misc/syslog.c
index 8de34f8..81fb114 100644
--- a/src/misc/syslog.c
+++ b/src/misc/syslog.c
@@ -11,7 +11,7 @@
 #include "libc.h"
 
 static int lock[2];
-static const char *log_ident;
+static char *log_ident;
 static int log_opt;
 static int log_facility = LOG_USER;
 static int log_mask = 0xff;
@@ -43,15 +43,10 @@ void closelog(void)
 	pthread_setcancelstate(cs, 0);
 }
 
-static void __openlog(const char *ident, int opt, int facility)
+static void __openlog()
 {
-	log_ident = ident;
-	log_opt = opt;
-	log_facility = facility;
-
-	if (!(opt & LOG_NDELAY) || log_fd>=0) return;
-
 	log_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
+	connect(log_fd, (void *)&log_addr, sizeof log_addr);
 }
 
 void openlog(const char *ident, int opt, int facility)
@@ -59,7 +54,14 @@ void openlog(const char *ident, int opt, int facility)
 	int cs;
 	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
 	LOCK(lock);
-	__openlog(ident, opt, facility);
+
+	free(log_ident);
+	log_ident = strdup(ident);
+	log_opt = opt;
+	log_facility = facility;
+
+	if ((opt & LOG_NDELAY) && log_fd<0) __openlog();
+
 	UNLOCK(lock);
 	pthread_setcancelstate(cs, 0);
 }
@@ -74,11 +76,8 @@ static void _vsyslog(int priority, const char *message, va_list ap)
 	int l, l2;
 
 	if (log_fd < 0) {
-		__openlog(log_ident, log_opt | LOG_NDELAY, log_facility);
-		if (log_fd < 0) {
-			UNLOCK(lock);
-			return;
-		}
+		__openlog();
+		if (log_fd < 0) return;
 	}
 
 	now = time(NULL);
@@ -90,14 +89,14 @@ static void _vsyslog(int priority, const char *message, va_list ap)
 		priority, timebuf,
 		log_ident ? log_ident : "",
 		"["+!pid, pid, "]"+!pid);
+	if (l >= sizeof buf) return;
 	l2 = vsnprintf(buf+l, sizeof buf - l, message, ap);
 	if (l2 >= 0) {
-		l += l2;
+		if (l2 >= sizeof buf - l) l = sizeof buf - 1;
+		else l += l2;
 		if (buf[l-1] != '\n') buf[l++] = '\n';
-		sendto(log_fd, buf, l, 0, (void *)&log_addr, 11);
+		send(log_fd, buf, l, 0);
 	}
-
-	UNLOCK(lock);
 }
 
 void __vsyslog(int priority, const char *message, va_list ap)