From 514c20aa99cd2f29c7e5da1e263ab7e81e3a9ff3 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Fri, 9 Dec 2016 20:46:40 +0000
Subject: [PATCH] timeout robustness: Introduce adns__timeout_{set,clear}

This abstracts away the open-coded handling of qu->timeout.
Rename the field to catch all call sites.

No functional change.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 src/event.c    | 9 +++++++--
 src/internal.h | 7 ++++++-
 src/query.c    | 2 +-
 src/transmit.c | 6 ++----
 4 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/event.c b/src/event.c
index 28cc60c..845bc69 100644
--- a/src/event.c
+++ b/src/event.c
@@ -149,6 +149,11 @@ void adns__tcp_tryconnect(adns_state ads, struct timeval now) {
 
 /* Timeout handling functions. */
 
+void adns__timeout_set(adns_query qu, struct timeval now, int ms) {
+  qu->timeout_expires= now;
+  timevaladd(&qu->timeout_expires,ms);
+}
+
 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
 			     struct timeval *tv_buf) {
   const struct timeval *now;
@@ -212,8 +217,8 @@ static void timeouts_queue(adns_state ads, int act,
   
   for (qu= queue->head; qu; qu= nqu) {
     nqu= qu->next;
-    if (!timercmp(&now,&qu->timeout,>)) {
-      inter_maxtoabs(tv_io,tvbuf,now,qu->timeout);
+    if (!timercmp(&now,&qu->timeout_expires,>)) {
+      inter_maxtoabs(tv_io,tvbuf,now,qu->timeout_expires);
     } else {
       if (!act) { inter_immed(tv_io,tvbuf); return; }
       LIST_UNLINK(*queue,qu);
diff --git a/src/internal.h b/src/internal.h
index 0fd64da..23c7aa6 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -298,7 +298,7 @@ struct adns__query {
   int id, flags, retries;
   int udpnextserver;
   unsigned long udpsent; /* bitmap indexed by server */
-  struct timeval timeout;
+  struct timeval timeout_expires;
   time_t expires; /* Earliest expiry time of any record we used. */
 
   qcontext ctx;
@@ -885,6 +885,11 @@ void adns__autosys(adns_state ads, struct timeval now);
  * lest we end up in recursive descent !
  */
 
+void adns__timeout_set(adns_query qu, struct timeval now, int ms);
+static inline void adns__timeout_clear(adns_query qu)
+  { timerclear(&qu->timeout_expires); }
+
+
 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
 			     struct timeval *tv_buf);
 /* Call with care - might reentrantly cause queries to be completed! */
diff --git a/src/query.c b/src/query.c
index 393478a..4eba888 100644
--- a/src/query.c
+++ b/src/query.c
@@ -72,7 +72,7 @@ static adns_query query_alloc(adns_state ads,
   qu->retries= 0;
   qu->udpnextserver= 0;
   qu->udpsent= 0;
-  timerclear(&qu->timeout);
+  adns__timeout_clear(qu);
   qu->expires= now.tv_sec + MAXTTLBELIEVE;
 
   memset(&qu->ctx,0,sizeof(qu->ctx));
diff --git a/src/transmit.c b/src/transmit.c
index 1674dbc..bf2f8c6 100644
--- a/src/transmit.c
+++ b/src/transmit.c
@@ -234,8 +234,7 @@ void adns__querysend_tcp(adns_query qu, struct timeval now) {
 
 static void query_usetcp(adns_query qu, struct timeval now) {
   qu->state= query_tcpw;
-  qu->timeout= now;
-  timevaladd(&qu->timeout,TCPWAITMS);
+  adns__timeout_set(qu,now,TCPWAITMS);
   LIST_LINK_TAIL(qu->ads->tcpw,qu);
   adns__querysend_tcp(qu,now);
   adns__tcp_tryconnect(qu->ads,now);
@@ -281,8 +280,7 @@ void adns__query_send(adns_query qu, struct timeval now) {
   if (r<0 && errno != EAGAIN)
     adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno));
   
-  qu->timeout= now;
-  timevaladd(&qu->timeout,UDPRETRYMS);
+  adns__timeout_set(qu, now, UDPRETRYMS);
   qu->udpsent |= (1<<serv);
   qu->udpnextserver= (serv+1)%ads->nservers;
   qu->retries++;
-- 
2.30.2