From 3b38c1223851ac41288644e0b7618655f75fd89a Mon Sep 17 00:00:00 2001
From: defanor <defanor@uberspace.net>
Date: Mon, 2 Mar 2020 03:39:32 +0300
Subject: Improve reconnect timings

---
 src/rexmpp.c | 22 +++++++++++++++-------
 src/rexmpp.h |  1 +
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/rexmpp.c b/src/rexmpp.c
index 1ebe509..2ac87ce 100644
--- a/src/rexmpp.c
+++ b/src/rexmpp.c
@@ -16,6 +16,7 @@
 #include <libxml/tree.h>
 #include <libxml/xmlsave.h>
 #include <gnutls/gnutls.h>
+#include <gnutls/crypto.h>
 #include <gnutls/x509.h>
 #include <gsasl.h>
 
@@ -257,15 +258,22 @@ void rexmpp_done (rexmpp_t *s) {
 }
 
 void rexmpp_schedule_reconnect (rexmpp_t *s) {
-  gettimeofday(&(s->next_reconnect_time), NULL);
-  if (s->reconnect_number < 10) {
-    s->next_reconnect_time.tv_sec += (8 << s->reconnect_number);
-  } else {
-    s->next_reconnect_time.tv_sec += 3600;
+  if (s->reconnect_number == 0) {
+    gnutls_rnd(GNUTLS_RND_NONCE, &s->reconnect_seconds, sizeof(time_t));
+    if (s->reconnect_seconds < 0) {
+      s->reconnect_seconds = - s->reconnect_seconds;
+    }
+    s->reconnect_seconds %= 60;
   }
-  rexmpp_log(s, LOG_DEBUG, "Scheduled reconnect number %d, for %u.%u",
+  time_t seconds = s->reconnect_seconds << s->reconnect_number;
+  if (seconds > 3600) {
+    seconds = 3600;
+  }
+  gettimeofday(&(s->next_reconnect_time), NULL);
+  s->next_reconnect_time.tv_sec += seconds;
+  rexmpp_log(s, LOG_DEBUG, "Scheduled reconnect number %d, in %d seconds",
              s->reconnect_number,
-             s->next_reconnect_time.tv_sec, s->next_reconnect_time.tv_usec);
+             seconds);
   s->reconnect_number++;
 }
 
diff --git a/src/rexmpp.h b/src/rexmpp.h
index 08edf43..411be7d 100644
--- a/src/rexmpp.h
+++ b/src/rexmpp.h
@@ -206,6 +206,7 @@ struct rexmpp
   /* Connection and stream management. */
   unsigned int id_counter;
   unsigned int reconnect_number;
+  time_t reconnect_seconds;
   struct timeval next_reconnect_time;
   xmlNodePtr stanza_queue;
   uint32_t stanzas_out_count;
-- 
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