In order to not get problems with DNS cache pruning, we no longer store

any name resolved data in any curl handle struct. That way, we won't mind
if the cache entries are pruned for the next time we need them. We'll just
resolve them again instead.

This changes the Curl_resolv() proto. It modifies the SessionHandle struct
but perhaps most importantly, it'll make the internals somewhat dependent
on the DNS cache not being disabled as that will cripple operations somewhat.
Especially for persistant connections.

1 files changed, 19 insertions, 21 deletions

diff --git a/lib/url.c b/lib/url.c
index bd010e6df..553c67e74 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -1241,7 +1241,8 @@ ConnectionStore(struct SessionHandle *data,
   return i;
 }
 
-static CURLcode ConnectPlease(struct connectdata *conn)
+static CURLcode ConnectPlease(struct connectdata *conn,
+                              Curl_addrinfo *hostaddr)
 {
   CURLcode result;
   Curl_ipconnect *addr;
@@ -1250,7 +1251,7 @@ static CURLcode ConnectPlease(struct connectdata *conn)
    * Connect to server/proxy
    *************************************************************/
   result= Curl_connecthost(conn,
-                           conn->hostaddr,
+                           hostaddr,
                            conn->port,
                            &conn->firstsocket,
                            &addr);
@@ -1264,7 +1265,7 @@ static CURLcode ConnectPlease(struct connectdata *conn)
     memset((char *) &conn->serv_addr, '\0', sizeof(conn->serv_addr));
     memcpy((char *)&(conn->serv_addr.sin_addr),
            (struct in_addr *)addr, sizeof(struct in_addr));
-    conn->serv_addr.sin_family = conn->hostaddr->h_addrtype;
+    conn->serv_addr.sin_family = hostaddr->h_addrtype;
     conn->serv_addr.sin_port = htons(conn->port);
 #endif
   }
@@ -1272,7 +1273,8 @@ static CURLcode ConnectPlease(struct connectdata *conn)
   return result;
 }
 
-static void verboseconnect(struct connectdata *conn)
+static void verboseconnect(struct connectdata *conn,
+                           Curl_addrinfo *hostaddr)
 {
 #ifdef HAVE_INET_NTOA_R
   char ntoa_buf[64];
@@ -1281,6 +1283,7 @@ static void verboseconnect(struct connectdata *conn)
 
   /* Figure out the ip-number and display the first host name it shows: */
 #ifdef ENABLE_IPV6
+  (void)hostaddr; /* not used in the IPv6 enabled version */
   {
     char hbuf[NI_MAXHOST];
 #ifdef NI_WITHSCOPEID
@@ -1305,7 +1308,7 @@ static void verboseconnect(struct connectdata *conn)
   {
     struct in_addr in;
     (void) memcpy(&in.s_addr, &conn->serv_addr.sin_addr, sizeof (in.s_addr));
-    infof(data, "Connected to %s (%s) port %d\n", conn->hostaddr->h_name,
+    infof(data, "Connected to %s (%s) port %d\n", hostaddr->h_name,
 #if defined(HAVE_INET_NTOA_R)
           inet_ntoa_r(in, ntoa_buf, sizeof(ntoa_buf)),
 #else
@@ -1327,6 +1330,7 @@ static CURLcode CreateConnection(struct SessionHandle *data,
   struct connectdata *conn_temp;
   char endbracket;
   int urllen;
+  Curl_addrinfo *hostaddr;
 #ifdef HAVE_ALARM
   unsigned int prev_alarm;
 #endif
@@ -2178,27 +2182,21 @@ static CURLcode CreateConnection(struct SessionHandle *data,
     conn->port =  conn->remote_port; /* it is the same port */
 
     /* Resolve target host right on */
-    if(!conn->hostaddr) {
-      /* it might already be set if reusing a connection */
-      conn->hostaddr = Curl_resolv(data, conn->name, conn->port,
-                                   &conn->hostent_buf);
-    }
-    if(!conn->hostaddr) {
+    hostaddr = Curl_resolv(data, conn->name, conn->port);
+
+    if(!hostaddr) {
       failf(data, "Couldn't resolve host '%s'", conn->name);
       result =  CURLE_COULDNT_RESOLVE_HOST;
       /* don't return yet, we need to clean up the timeout first */
     }
   }
-  else if(!conn->hostaddr) {
-    /* This is a proxy that hasn't been resolved yet. It may be resolved
-       if we're reusing an existing connection. */
+  else {
+    /* This is a proxy that hasn't been resolved yet. */
 
     /* resolve proxy */
-    /* it might already be set if reusing a connection */
-    conn->hostaddr = Curl_resolv(data, conn->proxyhost, conn->port,
-                                 &conn->hostent_buf);
+    hostaddr = Curl_resolv(data, conn->proxyhost, conn->port);
 
-    if(!conn->hostaddr) {
+    if(!hostaddr) {
       failf(data, "Couldn't resolve proxy '%s'", conn->proxyhost);
       result = CURLE_COULDNT_RESOLVE_PROXY;
       /* don't return yet, we need to clean up the timeout first */
@@ -2282,14 +2280,14 @@ static CURLcode CreateConnection(struct SessionHandle *data,
   
   if(-1 == conn->firstsocket) {
     /* Connect only if not already connected! */
-    result = ConnectPlease(conn);
+    result = ConnectPlease(conn, hostaddr);
     Curl_pgrsTime(data, TIMER_CONNECT); /* connect done, good or bad */
 
     if(CURLE_OK != result)
       return result;
 
     if(data->set.verbose)
-      verboseconnect(conn);
+      verboseconnect(conn, hostaddr);
 
     if(conn->curl_connect) {
       /* is there a protocol-specific connect() procedure? */
@@ -2308,7 +2306,7 @@ static CURLcode CreateConnection(struct SessionHandle *data,
   else {
     Curl_pgrsTime(data, TIMER_CONNECT); /* we're connected already */
     if(data->set.verbose)
-      verboseconnect(conn);
+      verboseconnect(conn, hostaddr);
   }
 
   conn->now = Curl_tvnow(); /* time this *after* the connect is done, we