1 files changed, 135 insertions, 0 deletions

diff --git a/debian/patches/keepalive-extensions.patch b/debian/patches/keepalive-extensions.patch
new file mode 100644
index 000000000..734118a19
--- /dev/null
+++ b/debian/patches/keepalive-extensions.patch
@@ -0,0 +1,135 @@
+From 3558be2914c0127489faae40ce2eae66142c3287 Mon Sep 17 00:00:00 2001
+From: Richard Kettlewell <rjk@greenend.org.uk>
+Date: Sun, 9 Feb 2014 16:09:52 +0000
+Subject: Various keepalive extensions
+
+Add compatibility aliases for ProtocolKeepAlives and SetupTimeOut, supported
+in previous versions of Debian's OpenSSH package but since superseded by
+ServerAliveInterval.  (We're probably stuck with this bit for
+compatibility.)
+
+In batch mode, default ServerAliveInterval to five minutes.
+
+Adjust documentation to match and to give some more advice on use of
+keepalives.
+
+Author: Ian Jackson <ian@chiark.greenend.org.uk>
+Author: Matthew Vernon <matthew@debian.org>
+Author: Colin Watson <cjwatson@debian.org>
+Last-Update: 2020-02-21
+
+Patch-Name: keepalive-extensions.patch
+---
+ readconf.c    | 14 ++++++++++++--
+ ssh_config.5  | 21 +++++++++++++++++++--
+ sshd_config.5 |  3 +++
+ 3 files changed, 34 insertions(+), 4 deletions(-)
+
+diff --git a/readconf.c b/readconf.c
+index 0fc996871..2399208f8 100644
+--- a/readconf.c
++++ b/readconf.c
+@@ -176,6 +176,7 @@ typedef enum {
+        oFingerprintHash, oUpdateHostkeys, oHostbasedKeyTypes,
+        oPubkeyAcceptedKeyTypes, oCASignatureAlgorithms, oProxyJump,
+        oSecurityKeyProvider,
++       oProtocolKeepAlives, oSetupTimeOut,
+        oIgnore, oIgnoredUnknownOption, oDeprecated, oUnsupported
+ } OpCodes;
+ 
+@@ -326,6 +327,8 @@ static struct {
+        { "ignoreunknown", oIgnoreUnknown },
+        { "proxyjump", oProxyJump },
+        { "securitykeyprovider", oSecurityKeyProvider },
++       { "protocolkeepalives", oProtocolKeepAlives },
++       { "setuptimeout", oSetupTimeOut },
+ 
+        { NULL, oBadOption }
+ };
+@@ -1495,6 +1498,8 @@ parse_keytypes:
+                goto parse_flag;
+ 
+        case oServerAliveInterval:
++       case oProtocolKeepAlives: /* Debian-specific compatibility alias */
++       case oSetupTimeOut:       /* Debian-specific compatibility alias */
+                intptr = &options->server_alive_interval;
+                goto parse_time;
+ 
+@@ -2198,8 +2203,13 @@ fill_default_options(Options * options)
+                options->rekey_interval = 0;
+        if (options->verify_host_key_dns == -1)
+                options->verify_host_key_dns = 0;
+-       if (options->server_alive_interval == -1)
+-               options->server_alive_interval = 0;
++       if (options->server_alive_interval == -1) {
++               /* in batch mode, default is 5mins */
++               if (options->batch_mode == 1)
++                       options->server_alive_interval = 300;
++               else
++                       options->server_alive_interval = 0;
++       }
+        if (options->server_alive_count_max == -1)
+                options->server_alive_count_max = 3;
+        if (options->control_master == -1)
+diff --git a/ssh_config.5 b/ssh_config.5
+index 3f4906972..3079db19b 100644
+--- a/ssh_config.5
++++ b/ssh_config.5
+@@ -266,9 +266,13 @@ If set to
+ .Cm yes ,
+ user interaction such as password prompts and host key confirmation requests
+ will be disabled.
++In addition, the
++.Cm ServerAliveInterval
++option will be set to 300 seconds by default (Debian-specific).
+ This option is useful in scripts and other batch jobs where no user
+ is present to interact with
+-.Xr ssh 1 .
++.Xr ssh 1 ,
++and where it is desirable to detect a broken network swiftly.
+ The argument must be
+ .Cm yes
+ or
+@@ -1593,7 +1597,14 @@ from the server,
+ will send a message through the encrypted
+ channel to request a response from the server.
+ The default
+-is 0, indicating that these messages will not be sent to the server.
++is 0, indicating that these messages will not be sent to the server,
++or 300 if the
++.Cm BatchMode
++option is set (Debian-specific).
++.Cm ProtocolKeepAlives
++and
++.Cm SetupTimeOut
++are Debian-specific compatibility aliases for this option.
+ .It Cm SetEnv
+ Directly specify one or more environment variables and their contents to
+ be sent to the server.
+@@ -1673,6 +1684,12 @@ Specifies whether the system should send TCP keepalive messages to the
+ other side.
+ If they are sent, death of the connection or crash of one
+ of the machines will be properly noticed.
++This option only uses TCP keepalives (as opposed to using ssh level
++keepalives), so takes a long time to notice when the connection dies.
++As such, you probably want
++the
++.Cm ServerAliveInterval
++option as well.
+ However, this means that
+ connections will die if the route is down temporarily, and some people
+ find it annoying.
+diff --git a/sshd_config.5 b/sshd_config.5
+index f6b41a2f8..ebd09f891 100644
+--- a/sshd_config.5
++++ b/sshd_config.5
+@@ -1668,6 +1668,9 @@ This avoids infinitely hanging sessions.
+ .Pp
+ To disable TCP keepalive messages, the value should be set to
+ .Cm no .
++.Pp
++This option was formerly called
++.Cm KeepAlive .
+ .It Cm TrustedUserCAKeys
+ Specifies a file containing public keys of certificate authorities that are
+ trusted to sign user certificates for authentication, or