fixed memory leak: CURLOPT_RESOLVE with multi interface

DNS cache entries populated with CURLOPT_RESOLVE were not properly freed
again when done using the multi interface.

Test case 1502 added to verify.

Bug: http://curl.haxx.se/bug/view.cgi?id=3575448
Reported by: Alex Gruz

lib/hostip.c

@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -740,14 +740,18 @@ static int hostcache_inuse(void *data, void *hc)
   return 1; /* free all entries */
 }
 
-void Curl_hostcache_destroy(struct SessionHandle *data)
+void Curl_hostcache_clean(struct SessionHandle *data)
 {
   /* Entries added to the hostcache with the CURLOPT_RESOLVE function are
    * still present in the cache with the inuse counter set to 1. Detect them
    * and cleanup!
    */
   Curl_hash_clean_with_criterium(data->dns.hostcache, data, hostcache_inuse);
+}
 
+void Curl_hostcache_destroy(struct SessionHandle *data)
+{
+  Curl_hostcache_clean(data);
   Curl_hash_destroy(data->dns.hostcache);
   data->dns.hostcachetype = HCACHE_NONE;
   data->dns.hostcache = NULL;

lib/hostip.h

@@ -7,7 +7,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -200,11 +200,19 @@ extern sigjmp_buf curl_jmpenv;
  */
 CURLcode Curl_set_dns_servers(struct SessionHandle *data, char *servers);
 
+/*
+ * Clean off entries from the cache
+ */
+void Curl_hostcache_clean(struct SessionHandle *data);
+
 /*
  * Destroy the hostcache of this handle.
  */
 void Curl_hostcache_destroy(struct SessionHandle *data);
 
+/*
+ * Populate the cache with specified entries from CURLOPT_RESOLVE.
+ */
 CURLcode Curl_loadhostpairs(struct SessionHandle *data);
 
 #endif /* HEADER_CURL_HOSTIP_H */

lib/multi.c

@@ -1789,12 +1789,6 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi,
   } WHILE_FALSE; /* just to break out from! */
 
   if(CURLM_STATE_COMPLETED == easy->state) {
-    if(data->dns.hostcachetype == HCACHE_MULTI) {
-      /* clear out the usage of the shared DNS cache */
-      data->dns.hostcache = NULL;
-      data->dns.hostcachetype = HCACHE_NONE;
-    }
-
     /* now fill in the Curl_message with this info */
     msg = &easy->msg;
 
@@ -1911,9 +1905,6 @@ CURLMcode curl_multi_cleanup(CURLM *multi_handle)
       cl= n;
     }
 
-    Curl_hash_destroy(multi->hostcache);
-    multi->hostcache = NULL;
-
     Curl_hash_destroy(multi->sockhash);
     multi->sockhash = NULL;
 
@@ -1930,6 +1921,7 @@ CURLMcode curl_multi_cleanup(CURLM *multi_handle)
       nexteasy=easy->next;
       if(easy->easy_handle->dns.hostcachetype == HCACHE_MULTI) {
         /* clear out the usage of the shared DNS cache */
+        Curl_hostcache_clean(easy->easy_handle);
         easy->easy_handle->dns.hostcache = NULL;
         easy->easy_handle->dns.hostcachetype = HCACHE_NONE;
       }
@@ -1943,6 +1935,9 @@ CURLMcode curl_multi_cleanup(CURLM *multi_handle)
       easy = nexteasy;
     }
 
+    Curl_hash_destroy(multi->hostcache);
+    multi->hostcache = NULL;
+
     free(multi);
 
     return CURLM_OK;

tests/data/Makefile.am

@@ -93,7 +93,7 @@ test1379 test1380 test1381 test1382 test1383 test1384 test1385 test1386 \
 test1387 test1388 test1389 test1390 test1391 test1392 test1393 \
 test1400 test1401 test1402 test1403 test1404 test1405 test1406 test1407 \
 test1408 test1409 test1410 test1411 test1412 test1413 \
-test1500 test1501 \
+test1500 test1501 test1502 \
 test2000 test2001 test2002 test2003 test2004 test2005 test2006 test2007 \
 test2008 test2009 test2010 test2011 test2012 test2013 test2014 test2015 \
 test2016 test2017 test2018 test2019 test2020 test2021 test2022 \

tests/data/test1502

@@ -0,0 +1,58 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP GET
+multi
+CURLOPT_RESOLVE
+</keywords>
+</info>
+
+<reply>
+<data>
+HTTP/1.1 200 OK
+Date: Thu, 09 Nov 2010 14:49:00 GMT
+Server: test-server/fake
+Last-Modified: Tue, 13 Jun 2000 12:10:00 GMT
+ETag: "21025-dc7-39462498"
+Accept-Ranges: bytes
+Content-Length: 6
+Connection: close
+Content-Type: text/html
+Funny-head: yesyes
+
+-foo-
+</data>
+</reply>
+
+#
+# Client-side
+<client>
+<server>
+http
+</server>
+<tool>
+lib1502
+</tool>
+ <name>
+HTTP multi with CURLOPT_RESOLVE
+ </name>
+ <command>
+http://google.com:%HTTPPORT/1502 %HTTPPORT %HOSTIP
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<strip>
+^User-Agent:.*
+</strip>
+<protocol>
+GET /1502 HTTP/1.1
+Host: google.com:%HTTPPORT
+Accept: */*
+
+</protocol>
+</verify>
+</testcase>

tests/libtest/Makefile.inc

@@ -20,7 +20,7 @@ noinst_PROGRAMS = chkhostname \
   lib556 lib539 lib557 lib560 lib562 lib564 lib565 lib566 lib567 lib568	\
   lib569 lib570 lib571 lib572 lib573 lib582 lib583 lib585 lib586 lib587 \
   lib590 lib591 lib597 lib598 lib599 libauthretry libntlmconnect \
-  lib1500 lib1501
+  lib1500 lib1501 lib1502
 
 chkhostname_SOURCES = chkhostname.c $(top_srcdir)/lib/curl_gethostname.c
 chkhostname_LDADD = @CURL_NETWORK_LIBS@
@@ -191,6 +191,8 @@ lib1500_SOURCES = lib1500.c $(SUPPORTFILES) $(TESTUTIL)
 
 lib1501_SOURCES = lib1501.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
 
+lib1502_SOURCES = lib1502.c $(SUPPORTFILES)
+
 libauthretry_SOURCES = libauthretry.c $(SUPPORTFILES)
 
 libntlmconnect_SOURCES = libntlmconnect.c $(SUPPORTFILES) $(TESTUTIL)

tests/libtest/lib1502.c

@@ -0,0 +1,138 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+/*
+ * Test case converted from bug report #3575448, identifying a memory leak in
+ * the CURLOPT_RESOLVE handling with the multi interface.
+ */
+
+#include "test.h"
+
+#include <stdio.h>
+#include <string.h>
+
+/* somewhat unix-specific */
+#include <sys/time.h>
+#include <unistd.h>
+
+int test(char *URL)
+{
+  CURL *ehandle;
+  CURLM *multi_handle;
+  char redirect[160];
+  CURLcode result = CURLE_NOT_BUILT_IN;
+  int still_running; /* keep number of running handles */
+
+  CURLMsg *msg; /* for picking up messages with the transfer status */
+  int msgs_left; /* how many messages are left */
+
+  /* DNS cache injection */
+  struct curl_slist *dns_cache_list;
+
+  sprintf(redirect, "google.com:%s:%s", libtest_arg2, libtest_arg3);
+
+  fprintf(stderr, "Redirect: %s\n", redirect);
+
+  dns_cache_list = curl_slist_append(NULL, redirect);
+
+  /* Allocate one CURL handle per transfer */
+  ehandle = curl_easy_init();
+
+  /* set the options (I left out a few, you'll get the point anyway) */
+  curl_easy_setopt(ehandle, CURLOPT_URL, URL);
+  curl_easy_setopt(ehandle, CURLOPT_HEADER, 1L);
+
+  curl_easy_setopt(ehandle, CURLOPT_RESOLVE, dns_cache_list);
+
+  /* init a multi stack */
+  multi_handle = curl_multi_init();
+
+  /* add the individual transfers */
+  curl_multi_add_handle(multi_handle, ehandle);
+
+  /* we start some action by calling perform right away */
+  curl_multi_perform(multi_handle, &still_running);
+
+  do {
+    struct timeval timeout;
+    int rc; /* select() return code */
+
+    fd_set fdread;
+    fd_set fdwrite;
+    fd_set fdexcep;
+    int maxfd = -1;
+
+    long curl_timeo = -1;
+
+    FD_ZERO(&fdread);
+    FD_ZERO(&fdwrite);
+    FD_ZERO(&fdexcep);
+
+    /* set a suitable timeout to play around with */
+    timeout.tv_sec = 1;
+    timeout.tv_usec = 0;
+
+    curl_multi_timeout(multi_handle, &curl_timeo);
+    if(curl_timeo >= 0) {
+      timeout.tv_sec = curl_timeo / 1000;
+      if(timeout.tv_sec > 1)
+        timeout.tv_sec = 1;
+      else
+        timeout.tv_usec = (curl_timeo % 1000) * 1000;
+    }
+
+    /* get file descriptors from the transfers */
+    curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
+
+    /* In a real-world program you OF COURSE check the return code of the
+       function calls.  On success, the value of maxfd is guaranteed to be
+       greater or equal than -1.  We call select(maxfd + 1, ...), specially in
+       case of (maxfd == -1), we call select(0, ...), which is basically equal
+       to sleep. */
+
+    rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);
+
+    switch(rc) {
+    case -1:
+      /* select error */
+      break;
+    case 0: /* timeout */
+    default: /* action */
+      curl_multi_perform(multi_handle, &still_running);
+      break;
+    }
+  } while(still_running);
+
+  /* See how the transfers went */
+  while ((msg = curl_multi_info_read(multi_handle, &msgs_left))) {
+    if (msg->msg == CURLMSG_DONE)
+      result = msg->data.result;
+  }
+
+  curl_multi_cleanup(multi_handle);
+
+  /* Free the CURL handles */
+  curl_easy_cleanup(ehandle);
+
+  curl_slist_free_all(dns_cache_list);
+
+  return (int)result;
+}