[src/trunk]: src/usr.sbin/btpand the default socket rcvbuf for L2CAP is only ...

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

details:   https://anonhg.NetBSD.org/src/rev/264fb8500aaa
branches:  trunk
changeset: 761835:264fb8500aaa
user:      plunky <plunky%NetBSD.org@localhost>
date:      Tue Feb 08 21:59:50 2011 +0000

description:
the default socket rcvbuf for L2CAP is only 4Kbytes which is only
2 and a bit ethernet packets. Check and increase SO_RCVBUF on startup
so that we have buffers for 10 complete packets, should solve a
reported problem with overruns at higher connection speeds (our L2CAP
does not have any flow control).

(the default can still be adjusted upwards using sysctl)

diffstat:

 usr.sbin/btpand/client.c |  19 ++++++++++++++++---
 usr.sbin/btpand/server.c |  20 +++++++++++++++++---
 2 files changed, 33 insertions(+), 6 deletions(-)

diffs (95 lines):

diff -r 0fa081824608 -r 264fb8500aaa usr.sbin/btpand/client.c
--- a/usr.sbin/btpand/client.c  Tue Feb 08 21:43:45 2011 +0000
+++ b/usr.sbin/btpand/client.c  Tue Feb 08 21:59:50 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: client.c,v 1.4 2009/05/12 21:50:38 plunky Exp $        */
+/*     $NetBSD: client.c,v 1.5 2011/02/08 21:59:50 plunky Exp $        */
 
 /*-
  * Copyright (c) 2008-2009 Iain Hibbert
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: client.c,v 1.4 2009/05/12 21:50:38 plunky Exp $");
+__RCSID("$NetBSD: client.c,v 1.5 2011/02/08 21:59:50 plunky Exp $");
 
 #include <bluetooth.h>
 #include <errno.h>
@@ -45,7 +45,7 @@
        struct sockaddr_bt sa;
        channel_t *chan;
        socklen_t len;
-       int fd;
+       int fd, bufsize;
        uint16_t mru, mtu;
 
        if (bdaddr_any(&remote_bdaddr))
@@ -102,6 +102,19 @@
                exit(EXIT_FAILURE);
        }
 
+       len = sizeof(bufsize);
+       if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &bufsize, &len) == -1) {
+               log_err("Could not read SO_RCVBUF");
+               exit(EXIT_FAILURE);
+       }
+       if (bufsize < 10 * mru) {
+               bufsize = 10 * mru;
+               if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &bufsize,
+                   sizeof(bufsize)) == -1)
+                       log_info("Could not increase SO_RCVBUF (from %d)",
+                           bufsize);
+       }
+
        len = sizeof(mtu);
        if (getsockopt(fd, BTPROTO_L2CAP, SO_L2CAP_OMTU, &mtu, &len) == -1) {
                log_err("Could not get L2CAP OMTU: %m");
diff -r 0fa081824608 -r 264fb8500aaa usr.sbin/btpand/server.c
--- a/usr.sbin/btpand/server.c  Tue Feb 08 21:43:45 2011 +0000
+++ b/usr.sbin/btpand/server.c  Tue Feb 08 21:59:50 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: server.c,v 1.6 2009/10/25 19:28:45 plunky Exp $        */
+/*     $NetBSD: server.c,v 1.7 2011/02/08 21:59:50 plunky Exp $        */
 
 /*-
  * Copyright (c) 2008-2009 Iain Hibbert
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: server.c,v 1.6 2009/10/25 19:28:45 plunky Exp $");
+__RCSID("$NetBSD: server.c,v 1.7 2011/02/08 21:59:50 plunky Exp $");
 
 #include <sys/ioctl.h>
 
@@ -134,7 +134,7 @@
        struct sockaddr_bt ra, la;
        channel_t *chan;
        socklen_t len;
-       int fd, n;
+       int fd, n, bufsize;
        uint16_t mru, mtu;
 
        assert(server_count < server_limit);
@@ -163,6 +163,20 @@
                return;
        }
 
+       len = sizeof(bufsize);
+       if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &bufsize, &len) == -1) {
+               log_err("Could not read SO_RCVBUF");
+               close(fd);
+               return;
+       }
+       if (bufsize < 10 * mru) {
+               bufsize = 10 * mru;
+               if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &bufsize,
+                   sizeof(bufsize)) == -1)
+                       log_info("Could not increase SO_RCVBUF (from %d)",
+                           bufsize);
+       }
+
        len = sizeof(mtu);
        if (getsockopt(fd, BTPROTO_L2CAP, SO_L2CAP_OMTU, &mtu, &len) == -1) {
                log_err("Could not get L2CAP OMTU: %m");