Mobile sites: Use different default tuning parameters

Links involving mobile peers are best served by somewhat different
tuning parameters.  So make the defaults vary accordingly.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/README b/README
index 7e40edf..96114f0 100644 (file)
--- a/README
+++ b/README
@@ -281,16 +281,18 @@ site: dict argument
   transform (transform closure): how to mangle packets sent between sites
   dh (dh closure)
   hash (hash closure)
-  key-lifetime (integer): max lifetime of a session key, in ms [one hour]
+  key-lifetime (integer): max lifetime of a session key, in ms
+    [one hour; mobile: 2 days]
   setup-retries (integer): max number of times to transmit a key negotiation
-    packet [5]
+    packet [5; mobile: 30]
   setup-timeout (integer): time between retransmissions of key negotiation
-    packets, in ms [2000]
+    packets, in ms [2000; mobile: 1000]
   wait-time (integer): after failed key setup, wait this long (in ms) before
-    allowing another attempt [20000]
+    allowing another attempt [20000; mobile: 10000]
   renegotiate-time (integer): if we see traffic on the link after this time
     then renegotiate another session key immediately (in ms)
-    [half key-lifetime, or key-lifetime minus 5 mins, whichever is longer].
+    [half key-lifetime, or key-lifetime minus 5 mins (mobile: 12 hours),
+     whichever is longer].
   keepalive (bool): if True then attempt always to keep a valid session key.
     Not actually currently implemented. [false]
   log-events (string list): types of events to log for this site
@@ -327,7 +329,14 @@ site: dict argument
     for us have "mobile True" (and if we find a site configuration for
     ourselves in the config, we insist on this).  The effect is to
     check that there are no links both ends of which are allegedly
-    mobile (which is not supported, so those links are ignored). [false]
+    mobile (which is not supported, so those links are ignored) and
+    to change some of the tuning parameter defaults. [false]
+
+Links involving mobile peers have some different tuning parameter
+default values, which are generally more aggressive about retrying key
+setup but more relaxed about using old keys.  These are noted with
+"mobile:", above, and apply whether the mobile peer is local or
+remote.
 
 ** transform
 

diff --git a/site.c b/site.c
index 8be5523..ed9e803 100644 (file)
--- a/site.c
+++ b/site.c
@@ -32,6 +32,13 @@
 #define DEFAULT_SETUP_RETRIES 5
 #define DEFAULT_SETUP_RETRY_INTERVAL             (2*1000) /* [ms] */
 #define DEFAULT_WAIT_TIME                       (20*1000) /* [ms] */
+
+#define DEFAULT_MOBILE_KEY_LIFETIME      (2*24*3600*1000) /* [ms] */
+#define DEFAULT_MOBILE_KEY_RENEGOTIATE_GAP (12*3600*1000) /* [ms] */
+#define DEFAULT_MOBILE_SETUP_RETRIES 30
+#define DEFAULT_MOBILE_SETUP_RETRY_INTERVAL      (1*1000) /* [ms] */
+#define DEFAULT_MOBILE_WAIT_TIME                (10*1000) /* [ms] */
+
 #define DEFAULT_MOBILE_PEER_EXPIRY            (2*60)      /* [s] */
 #define DEFAULT_MOBILE_PEERS_MAX 3 /* send at most this many copies (default) */
 
@@ -1346,7 +1353,8 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
     st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
     st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
 
-#define DEFAULT(D) DEFAULT_##D
+#define DEFAULT(D) (st->peer_mobile || local_mobile    \
+                    ? DEFAULT_MOBILE_##D : DEFAULT_##D)
 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
 
     st->key_lifetime=         CFG_NUMBER("key-lifetime",  KEY_LIFETIME);