[src/trunk]: src/usr.sbin/syslogd syslogd: allow the receiving buffer size to...

[roy <roy%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/27f7db739c33
branches:  trunk
changeset: 445591:27f7db739c33
user:      roy <roy%NetBSD.org@localhost>
date:      Sun Nov 04 20:23:08 2018 +0000

description:
syslogd: allow the receiving buffer size to be set.

This allows the admin to try and avoid buffer overflow when a log of
logging appears in bursts.

diffstat:

 usr.sbin/syslogd/syslogd.8 |   9 +++++++--
 usr.sbin/syslogd/syslogd.c |  23 +++++++++++++++--------
 2 files changed, 22 insertions(+), 10 deletions(-)

diffs (111 lines):

diff -r 4a1e18dd8f47 -r 27f7db739c33 usr.sbin/syslogd/syslogd.8
--- a/usr.sbin/syslogd/syslogd.8        Sun Nov 04 20:02:07 2018 +0000
+++ b/usr.sbin/syslogd/syslogd.8        Sun Nov 04 20:23:08 2018 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: syslogd.8,v 1.55 2017/07/03 21:35:32 wiz Exp $
+.\"    $NetBSD: syslogd.8,v 1.56 2018/11/04 20:23:08 roy Exp $
 .\"
 .\" Copyright (c) 1983, 1986, 1991, 1993
 .\"    The Regents of the University of California.  All rights reserved.
@@ -29,7 +29,7 @@
 .\"
 .\"     from: @(#)syslogd.8    8.1 (Berkeley) 6/6/93
 .\"
-.Dd March 28, 2012
+.Dd November 4, 2018
 .Dt SYSLOGD 8
 .Os
 .Sh NAME
@@ -39,6 +39,7 @@
 .Nm
 .Op Fl dnrSsTUv
 .Op Fl b Ar bind_address
+.Op Fl B Ar buffer_length
 .Op Fl f Ar config_file
 .Op Fl g Ar group
 .Op Fl m Ar mark_interval
@@ -60,6 +61,10 @@
 Specify one specific IP address or hostname to bind to.
 If a hostname is specified, the IPv4 or IPv6 address
 which corresponds to it is used.
+.It Fl B Ar buffer_length
+Sets the receiving buffer length.
+The default is 16384 bytes.
+If syslogd reports buffer overflow, this needs increasing.
 .It Fl d
 Enable debugging to the standard output,
 and do not disassociate from the controlling terminal.
diff -r 4a1e18dd8f47 -r 27f7db739c33 usr.sbin/syslogd/syslogd.c
--- a/usr.sbin/syslogd/syslogd.c        Sun Nov 04 20:02:07 2018 +0000
+++ b/usr.sbin/syslogd/syslogd.c        Sun Nov 04 20:23:08 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: syslogd.c,v 1.125 2018/05/06 19:16:36 christos Exp $   */
+/*     $NetBSD: syslogd.c,v 1.126 2018/11/04 20:23:08 roy Exp $        */
 
 /*
  * Copyright (c) 1983, 1988, 1993, 1994
@@ -39,7 +39,7 @@
 #if 0
 static char sccsid[] = "@(#)syslogd.c  8.3 (Berkeley) 4/4/94";
 #else
-__RCSID("$NetBSD: syslogd.c,v 1.125 2018/05/06 19:16:36 christos Exp $");
+__RCSID("$NetBSD: syslogd.c,v 1.126 2018/11/04 20:23:08 roy Exp $");
 #endif
 #endif /* not lint */
 
@@ -114,6 +114,7 @@
 #define DQ_TIMO_INIT   2
 
 #define        RCVBUFLEN       16384
+int    buflen = RCVBUFLEN;
 /*
  * Intervals at which we flush out "message repeated" messages,
  * in seconds after previous message is logged.         After each flush,
@@ -315,11 +316,16 @@
        /* should we set LC_TIME="C" to ensure correct timestamps&parsing? */
        (void)setlocale(LC_ALL, "");
 
-       while ((ch = getopt(argc, argv, "b:dnsSf:m:o:p:P:ru:g:t:TUv")) != -1)
+       while ((ch = getopt(argc, argv, "b:B:dnsSf:m:o:p:P:ru:g:t:TUv")) != -1)
                switch(ch) {
                case 'b':
                        bindhostname = optarg;
                        break;
+               case 'B':
+                       buflen = atoi(optarg);
+                       if (buflen < RCVBUFLEN)
+                               buflen = RCVBUFLEN;
+                       break;
                case 'd':               /* debug */
                        Debug = D_DEFAULT;
                        /* is there a way to read the integer value
@@ -657,7 +663,8 @@
 {
 
        (void)fprintf(stderr,
-           "usage: %s [-dnrSsTUv] [-b bind_address] [-f config_file] [-g group]\n"
+           "usage: %s [-dnrSsTUv] [-b bind_address] [-B buffer_length]\n"
+           "\t[-f config_file] [-g group]\n"
            "\t[-m mark_interval] [-P file_list] [-p log_socket\n"
            "\t[-p log_socket2 ...]] [-t chroot_dir] [-u user]\n",
            getprogname());
@@ -667,15 +674,15 @@
 static void
 setsockbuf(int fd, const char *name)
 {
-       int buflen;
+       int curbuflen;
        socklen_t socklen = sizeof(buflen);
-       if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &buflen, &socklen) == -1) {
+
+       if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &curbuflen, &socklen) == -1) {
                logerror("getsockopt: SO_RCVBUF: `%s'", name);
                return;
        }
-       if (buflen >= RCVBUFLEN)
+       if (curbuflen >= buflen)
                return;
-       buflen = RCVBUFLEN;
        if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &buflen, socklen) == -1) {
                logerror("setsockopt: SO_RCVBUF: `%s'", name);
                return;