Attachment 148911 Details for Bug 194751 – proposed patch

[patch] proposed patch

syslog.c.patch (text/plain), 1.75 KB, created by pjcreath+freebsd on 2014-11-02 02:01:56 UTC

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Creator: pjcreath+freebsd

Created: 2014-11-02 02:01:56 UTC

Size: 1.75 KB

patch

obsolete

>--- syslog.c.HEAD	2014-11-01 15:47:23.000000000 -0400
>+++ syslog.c	2014-11-01 21:03:57.000000000 -0400
>@@ -262,24 +262,36 @@
> 
> 	/*
>-	 * If the send() failed, there are two likely scenarios: 
>+	 * If the send() fails, there are two likely scenarios: 
> 	 *  1) syslogd was restarted
> 	 *  2) /var/run/log is out of socket buffer space, which
> 	 *     in most cases means local DoS.
>-	 * We attempt to reconnect to /var/run/log[priv] 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 the error does not indicate a full buffer, we address
>+	 * case #1 by attempting to reconnect to /var/run/log[priv]
>+	 * and resending the message once.
> 	 *
>-	 * If we are working with a priveleged socket, then take
>-	 * only one attempt, because we don't want to freeze a
>+	 * If we are working with a privileged socket, the retry
>+	 * attempts end there, because we don't want to freeze a
> 	 * critical application like su(1) or sshd(8).
> 	 *
>+	 * Otherwise, we address case #2 by repeatedly retrying the
>+	 * send() to give syslogd a chance to empty its socket buffer.
>+	 *
> 	 */
> 
> 	if (send(LogFile, tbuf, cnt, 0) < 0) {
> 		if (errno != ENOBUFS) {
>+			/* scenario 1: syslogd was restarted */
>+			/* reconnect and resend once */
> 			disconnectlog();
> 			connectlog();
>+			if (send(LogFile, tbuf, cnt, 0) >= 0) {
>+				THREAD_UNLOCK();
>+				return;
>+			}
>+			/* if the resend failed, fall through to possible scenario 2 */
> 		}
>-		do {
>+		while (errno == ENOBUFS) {
>+			/* scenario 2: out of socket buffer space */
>+			/* possible DoS, fail fast on a privileged socket */
> 			if (status == CONNPRIV)
> 				break;
>@@ -289,5 +301,5 @@
> 				return;
> 			}
>-		} while (errno == ENOBUFS);
>+		};
> 	} else {
> 		THREAD_UNLOCK();

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Attachments on bug 194751: 148911 | 148912