Attachment 167706 Details for Bug 37087 – Bug 37087: Add TCP keepalive support to SIP server

[patch] Bug 37087: Add TCP keepalive support to SIP server

Bug-37087-Add-TCP-keepalive-support-to-SIP-server.patch (text/plain), 7.49 KB, created by David Cook on 2024-06-14 04:41:21 UTC

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Creator: David Cook

Created: 2024-06-14 04:41:21 UTC

Size: 7.49 KB

patch

obsolete

>From 1a9e1d6e64bf03e0b11de335b7b06a73c4c0e8c3 Mon Sep 17 00:00:00 2001
>From: David Cook <dcook@prosentient.com.au>
>Date: Fri, 14 Jun 2024 04:34:47 +0000
>Subject: [PATCH] Bug 37087: Add TCP keepalive support to SIP server
>
>This change adds the ability to enable and configure TCP keepalive
>support for the SIP server using SIPconfig.xml.
>
>For the sake of backwards compatibility, it defaults to disabled
>and additional parameters default match typical kernel defaults.
>
>Technical detail can be found in the perldoc for C4/SIP/SIPserver.pm
>
>Test plan:
>0. Apply the patch
>1. koha-sip --restart kohadev
>2. apt-get update && apt-get install tcpdump
>3. In one window, run "tcpdump -A -n -v -i any 'port 6001'"
>4. In another window, run the following:
>echo -e "9300CNterm1|COterm1|CPCPL|\r" | nc 127.0.0.1 6001 -v
>5. Note in tcpdump output that after the initial flood of packets,
>nothing more is received
>
>6. vi /etc/koha/sites/kohadev/SIPconfig.xml
>7. In the "server-params" element, add attributes like the following:
>custom_tcp_keepalive='1'
>custom_tcp_keepalive_time='10'
>custom_tcp_keepalive_intvl='5'
>8. koha-sip --restart kohadev
>9. In one window, run "tcpdump -A -n -v -i any 'port 6001'"
>10. In another window, run the following:
>echo -e "9300CNterm1|COterm1|CPCPL|\r" | nc 127.0.0.1 6001 -v
>11. Note in tcpdump output that after the initial flood of packets,
>ACK packets are sent out every 10+ seconds for the idle connection
>---
> C4/SIP/SIPServer.pm            | 122 ++++++++++++++++++++++++++++++++-
> debian/templates/SIPconfig.xml |   3 +
> etc/SIPconfig.xml              |   3 +
> 3 files changed, 127 insertions(+), 1 deletion(-)
>
>diff --git a/C4/SIP/SIPServer.pm b/C4/SIP/SIPServer.pm
>index d26f5e25e6b..ac4cef69cb5 100644
>--- a/C4/SIP/SIPServer.pm
>+++ b/C4/SIP/SIPServer.pm
>@@ -8,7 +8,7 @@ use FindBin qw($Bin);
> use lib "$Bin";
> use Net::Server::PreFork;
> use IO::Socket::INET;
>-use Socket qw(:DEFAULT :crlf);
>+use Socket qw(:DEFAULT :crlf TCP_KEEPIDLE TCP_KEEPINTVL IPPROTO_TCP);
> use Scalar::Util qw(blessed);
> require UNIVERSAL::require;
> 
>@@ -90,6 +90,126 @@ push @parms, 'group=' . $>;
> # This is the main event.
> __PACKAGE__ ->run(@parms);
> 
>+#
>+# Server
>+#
>+
>+=head3 options
>+
>+As per Net::Server documentation, override "options" to provide your own
>+custom options to the Net::Server* object. This allows us to use the Net::Server
>+infrastructure for configuration rather than hacking our own configuration into the
>+object.
>+
>+=cut
>+
>+sub options {
>+    my $self     = shift;
>+    my $prop     = $self->{'server'};
>+    my $template = shift;
>+
>+    # setup options in the parent classes
>+    $self->SUPER::options($template);
>+
>+    $prop->{'custom_tcp_keepalive'} ||= undef;
>+    $template->{'custom_tcp_keepalive'} = \$prop->{'custom_tcp_keepalive'};
>+
>+    $prop->{'custom_tcp_keepalive_time'} ||= undef;
>+    $template->{'custom_tcp_keepalive_time'} = \$prop->{'custom_tcp_keepalive_time'};
>+
>+    $prop->{'custom_tcp_keepalive_intvl'} ||= undef;
>+    $template->{'custom_tcp_keepalive_intvl'} = \$prop->{'custom_tcp_keepalive_intvl'};
>+}
>+
>+=head3 post_configure_hook
>+
>+As per Net::Server documentation, this method validates our custom configuration.
>+
>+=cut
>+
>+sub post_configure_hook {
>+    my $self = shift;
>+    my $prop = $self->{'server'};
>+    if ( defined $prop->{'custom_tcp_keepalive'} && $prop->{'custom_tcp_keepalive'} ) {
>+
>+        #NOTE: Any true value defined is forced to 1 just for the sake of predictability
>+        $prop->{'custom_tcp_keepalive'} = 1;
>+    }
>+
>+    foreach my $key ( 'custom_tcp_keepalive_time', 'custom_tcp_keepalive_intvl' ) {
>+        my $value = $prop->{$key};
>+
>+        #NOTE: A regex is used here to detect a positive integer, as int() returns integers but does not validate them
>+        #NOTE: We do not allow zero as it can lead to problematic behaviour
>+        if ( $value && $value =~ /^\d+$/ ) {
>+
>+            #NOTE: Strictly, you must convert into an integer as a string will cause setsockopt to fail
>+            $prop->{$key} = int($value);
>+        }
>+    }
>+}
>+
>+=head3 post_accept_hook 
>+
>+This hook occurs after the client connection socket is created, which gives
>+us an opportunity to enable support for TCP keepalives using the SO_KEEPALIVE
>+socket option.
>+
>+By default, the kernel-level defaults (in seconds) are used. You can view these in the output of "sysctl -a":
>+net.ipv4.tcp_keepalive_intvl = 75
>+net.ipv4.tcp_keepalive_time = 7200
>+
>+Alternatively, you can use "custom_tcp_keepalive_time" and "custom_tcp_keepalive_intvl" to define
>+your own custom values for the socket. Note that these parameters are defined at the top server-level
>+and not on the listener-level.
>+
>+If you lower "custom_tcp_keepalive_time" below 75, you will also need to set "custom_tcp_keepalive_intvl".
>+The "tcp_keepalive_time" is the initial time used for the keepalive timer, and the "tcp_keepalive_intvl"
>+is the time used for subsequent keepalive timers. However, timers only send keepalive ACKs if the idle time
>+elapsed is greater than "tcp_keepalive_time". 
>+
>+Thus, if "tcp_keepalive_time = 10" and "tcp_keepalive_intvl = 5", a keepalive ACK will be sent every 10 seconds
>+of idle time. If "tcp_keepalive_intvl = 10" and "tcp_keepalive_time = 5", a keepalive ACK will be sent after 5
>+seconds of idle time, and the next keepalive ACK will be sent after 10 seconds of idle time. Generally speaking,
>+it's best to set "tcp_keepalive_time" to be higher than "tcp_keepalive_intvl". 
>+
>+Reminder: once these settings are set on the socket, they are handled by the operating system kernel, and not
>+by the SIP server application. If you are having trouble with your settings, monitor your TCP traffic using
>+a tool such as "tcpdump" to review and refine how they work. 
>+
>+=cut
>+
>+sub post_accept_hook {
>+    my $self   = shift;
>+    my $prop   = $self->{'server'};
>+    my $client = shift || $prop->{'client'};
>+
>+    my $tcp_keepalive       = $prop->{custom_tcp_keepalive};
>+    my $tcp_keepalive_time  = $prop->{custom_tcp_keepalive_time};
>+    my $tcp_keepalive_intvl = $prop->{custom_tcp_keepalive_intvl};
>+
>+    if ($tcp_keepalive) {
>+
>+        #NOTE: set the SO_KEEPALIVE option to enable TCP keepalives
>+        setsockopt( $client, SOL_SOCKET, SO_KEEPALIVE, 1 )
>+            or die "Unable to set SO_KEEPALIVE: $!";
>+
>+        if ($tcp_keepalive_time) {
>+
>+            #NOTE: override "net.ipv4.tcp_keepalive_time" kernel parameter for this socket
>+            setsockopt( $client, IPPROTO_TCP, TCP_KEEPIDLE, $tcp_keepalive_time )
>+                or die "Unable to set TCP_KEEPIDLE: $!";
>+        }
>+
>+        if ($tcp_keepalive_intvl) {
>+
>+            #NOTE: override "net.ipv4.tcp_keepalive_intvl" kernel parameter for this socket
>+            setsockopt( $client, IPPROTO_TCP, TCP_KEEPINTVL, $tcp_keepalive_intvl )
>+                or die "Unable to set TCP_KEEPINTVL: $!";
>+        }
>+    }
>+}
>+
> #
> # Child
> #
>diff --git a/debian/templates/SIPconfig.xml b/debian/templates/SIPconfig.xml
>index e79a2950b6c..f0a408c67b7 100644
>--- a/debian/templates/SIPconfig.xml
>+++ b/debian/templates/SIPconfig.xml
>@@ -10,6 +10,9 @@
>   <server-params
>     min_servers='1'
>     min_spare_servers='0'
>+    custom_tcp_keepalive='0'
>+    custom_tcp_keepalive_time='7200'
>+    custom_tcp_keepalive_intvl='75'
>   />
> 
>   <listeners>
>diff --git a/etc/SIPconfig.xml b/etc/SIPconfig.xml
>index 1816b91a234..a1432b13f34 100644
>--- a/etc/SIPconfig.xml
>+++ b/etc/SIPconfig.xml
>@@ -19,6 +19,9 @@
>     user='koha'
>     group='koha'
>     pid_file='/var/run/sipserver.pid'
>+    custom_tcp_keepalive='0'
>+    custom_tcp_keepalive_time='7200'
>+    custom_tcp_keepalive_intvl='75'
>   />
> 
>   <listeners>
>-- 
>2.34.1

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Attachments on bug 37087: 167706 | 167713 | 169642