CURLOPT_RESOLVE: always purge old entry first

If there's an existing entry using the selected name.

Closes #2622

4 files changed, 228 insertions, 3 deletions

diff --git a/tests/unit/Makefile.inc b/tests/unit/Makefile.inc
index f77da7588..a2618813f 100644
--- a/tests/unit/Makefile.inc
+++ b/tests/unit/Makefile.inc
@@ -10,7 +10,7 @@ UNITPROGS = unit1300 unit1301 unit1302 unit1303 unit1304 unit1305 unit1307	\
  unit1330 unit1394 unit1395 unit1396 unit1397 unit1398	\
  unit1399	\
  unit1600 unit1601 unit1602 unit1603 unit1604 unit1605 unit1606 unit1607 \
- unit1608
+ unit1608 unit1609
 
 unit1300_SOURCES = unit1300.c $(UNITFILES)
 unit1300_CPPFLAGS = $(AM_CPPFLAGS)
@@ -92,3 +92,6 @@ unit1607_CPPFLAGS = $(AM_CPPFLAGS)
 
 unit1608_SOURCES = unit1608.c $(UNITFILES)
 unit1608_CPPFLAGS = $(AM_CPPFLAGS)
+
+unit1609_SOURCES = unit1609.c $(UNITFILES)
+unit1609_CPPFLAGS = $(AM_CPPFLAGS)
diff --git a/tests/unit/README b/tests/unit/README
index 301cd17d5..b8a513b3b 100644
--- a/tests/unit/README
+++ b/tests/unit/README
@@ -17,8 +17,8 @@ Run Unit Tests
 
 Unit tests are run as part of the regular test suite. If you have built
 everything to run unit tests, to can do 'make test' at the root level. Or you
-can 'cd tests' and then invoke individual unit tests with ./runtests.pl NNNN
-where NNNN is the specific test number.
+can 'cd tests' and 'make' and then invoke individual unit tests with
+./runtests.pl NNNN where NNNN is the specific test number.
 
 Debug Unit Tests
 ================
diff --git a/tests/unit/unit1607.c b/tests/unit/unit1607.c
index 697b8b5c4..64b6371ee 100644
--- a/tests/unit/unit1607.c
+++ b/tests/unit/unit1607.c
@@ -199,6 +199,14 @@ UNITTEST_START
         break;
       }
 
+      if(dns->timestamp != 0) {
+        fprintf(stderr, "%s:%d tests[%d] failed. the timestamp is not zero. "
+                "for tests[%d].address[%d\n",
+                __FILE__, __LINE__, i, i, j);
+        problem = true;
+        break;
+      }
+
       addr = addr->ai_next;
     }
 
diff --git a/tests/unit/unit1609.c b/tests/unit/unit1609.c
new file mode 100644
index 000000000..2b99bee9b
--- /dev/null
+++ b/tests/unit/unit1609.c
@@ -0,0 +1,214 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2018, 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 https://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.
+ *
+ ***************************************************************************/
+#include "curlcheck.h"
+
+#include "urldata.h"
+#include "connect.h"
+#include "share.h"
+
+#include "memdebug.h" /* LAST include file */
+
+static struct Curl_easy *easy;
+static struct curl_hash *hostcache;
+
+static void unit_stop(void)
+{
+  curl_easy_cleanup(easy);
+  curl_global_cleanup();
+}
+
+static CURLcode unit_setup(void)
+{
+  int res = CURLE_OK;
+
+  global_init(CURL_GLOBAL_ALL);
+
+  easy = curl_easy_init();
+  if(!easy) {
+    curl_global_cleanup();
+    return CURLE_OUT_OF_MEMORY;
+  }
+
+  hostcache = Curl_global_host_cache_init();
+  if(!hostcache) {
+    unit_stop();
+    return CURLE_OUT_OF_MEMORY;
+  }
+
+  return res;
+}
+
+struct testcase {
+  /* host:port:address[,address]... */
+  const char *optval;
+
+  /* lowercase host and port to retrieve the addresses from hostcache */
+  const char *host;
+  int port;
+
+  /* 0 to 9 addresses expected from hostcache */
+  const char *address[10];
+};
+
+
+/* CURLOPT_RESOLVE address parsing test - to test the following defect fix:
+
+ 1) if there is already existing host:port pair in the DNS cache and
+ we call CURLOPT_RESOLVE, it should also replace addresses.
+ for example, if there is "test.com:80" with address "1.1.1.1"
+ and we called CURLOPT_RESOLVE with address "2.2.2.2", then DNS entry needs to
+ reflect that.
+
+ 2) when cached address is already there and close to expire, then by the
+ time request is made, it can get expired.  This happens because, when
+ we set address using CURLOPT_RESOLVE,
+ it usually marks as permanent (by setting timestamp to zero). However,
+ if address already exists
+in the cache, then it does not mark it, but just leaves it as it is.
+ So we fixing this by timestamp to zero if address already exists too.
+
+Test:
+
+ - insert new entry
+ - verify that timestamp is not zero
+ - call set options with CURLOPT_RESOLVE
+ - then, call Curl_loadhostpairs
+
+ expected result: cached address has zero timestamp.
+
+ - call set options with CURLOPT_RESOLVE with same host:port pair,
+   different address.
+ - then, call Curl_loadhostpairs
+
+ expected result: cached address has zero timestamp and new address
+*/
+
+static const struct testcase tests[] = {
+  /* spaces aren't allowed, for now */
+  { "test.com:80:127.0.0.1",
+    "test.com", 80, { "127.0.0.1", }
+  },
+  { "test.com:80:127.0.0.2",
+    "test.com", 80, { "127.0.0.2", }
+  },
+};
+
+UNITTEST_START
+  int i;
+  int testnum = sizeof(tests) / sizeof(struct testcase);
+
+/* important: we setup cache outside of the loop
+  and also clean cache after the loop. In contrast,for example,
+  test 1607 sets up and cleans cache on each iteration. */
+  Curl_hostcache_clean(easy, hostcache);
+  easy->dns.hostcache = hostcache;
+  easy->dns.hostcachetype = HCACHE_GLOBAL;
+
+  for(i = 0; i < testnum; ++i, curl_easy_reset(easy)) {
+    int j;
+    int addressnum = sizeof (tests[i].address) / sizeof (*tests[i].address);
+    struct Curl_addrinfo *addr;
+    struct Curl_dns_entry *dns;
+    struct curl_slist *list;
+    void *entry_id;
+    bool problem = false;
+
+    list = curl_slist_append(NULL, tests[i].optval);
+    if(!list)
+        goto unit_test_abort;
+
+    curl_easy_setopt(easy, CURLOPT_RESOLVE, list);
+
+    Curl_loadhostpairs(easy);
+
+    entry_id = (void *)aprintf("%s:%d", tests[i].host, tests[i].port);
+    if(!entry_id) {
+      curl_slist_free_all(list);
+      goto unit_test_abort;
+    }
+    dns = Curl_hash_pick(easy->dns.hostcache, entry_id, strlen(entry_id) + 1);
+    free(entry_id);
+    entry_id = NULL;
+
+    addr = dns ? dns->addr : NULL;
+
+    for(j = 0; j < addressnum; ++j) {
+      long port = 0;
+      char ipaddress[MAX_IPADR_LEN] = {0};
+
+      if(!addr && !tests[i].address[j])
+        break;
+
+      if(addr && !Curl_getaddressinfo(addr->ai_addr,
+                                      ipaddress, &port)) {
+        fprintf(stderr, "%s:%d tests[%d] failed. getaddressinfo failed.\n",
+                __FILE__, __LINE__, i);
+        problem = true;
+        break;
+      }
+
+      if(addr && !tests[i].address[j]) {
+        fprintf(stderr, "%s:%d tests[%d] failed. the retrieved addr "
+                "is %s but tests[%d].address[%d] is NULL.\n",
+                __FILE__, __LINE__, i, ipaddress, i, j);
+        problem = true;
+        break;
+      }
+
+      if(!addr && tests[i].address[j]) {
+        fprintf(stderr, "%s:%d tests[%d] failed. the retrieved addr "
+                "is NULL but tests[%d].address[%d] is %s.\n",
+                __FILE__, __LINE__, i, i, j, tests[i].address[j]);
+        problem = true;
+        break;
+      }
+
+      if(!curl_strequal(ipaddress, tests[i].address[j])) {
+        fprintf(stderr, "%s:%d tests[%d] failed. the retrieved addr "
+                "%s is not equal to tests[%d].address[%d] %s.\n",
+                __FILE__, __LINE__, i, ipaddress, i, j, tests[i].address[j]);
+        problem = true;
+        break;
+      }
+
+      if(port != tests[i].port) {
+        fprintf(stderr, "%s:%d tests[%d] failed. the retrieved port "
+                "for tests[%d].address[%d] is %ld but tests[%d].port is %d.\n",
+                __FILE__, __LINE__, i, i, j, port, i, tests[i].port);
+        problem = true;
+        break;
+      }
+
+      addr = addr->ai_next;
+    }
+
+    curl_slist_free_all(list);
+
+    if(problem) {
+      unitfail++;
+      continue;
+    }
+  }
+
+  Curl_hostcache_clean(easy, easy->dns.hostcache);
+
+UNITTEST_STOP