Fix a double free error in vr_message_process_response

This patch fixes a double free error and introduces
user land unit test for the vrouter code. The cmocka
unit test framework is used for that purpose.

A first unit test is provided that check this fixes.

Change-Id: Ic8c84d076d078a87adaf6d4398373c368db0361c
Closes-bug: #1394147

SConscript

@@ -5,6 +5,7 @@
 import subprocess
 import sys
 import os
+import copy
 
 AddOption('--kernel-dir', dest = 'kernel-dir', action='store',
           help='Linux kernel source directory for vrouter.ko')
@@ -25,6 +26,16 @@ vr_root = './'
 makefile = vr_root + 'Makefile'
 dp_dir = Dir(vr_root).srcnode().abspath
 
+def MakeTestCmdFn(self, env, test_name, test_list, deps):
+    sources = copy.copy(deps)
+    sources.append(test_name + '.c')
+    tgt = env.UnitTest(target = test_name, source = sources)
+    env.Alias('vrouter:'+ test_name, tgt)
+    test_list.append(tgt)
+    return tgt
+
+VRouterEnv.AddMethod(MakeTestCmdFn, 'MakeTestCmd')
+
 def shellCommand(cmd):
     """ Return the output of a shell command
         This wrapper is required since check_output is not supported in
@@ -49,7 +60,7 @@ if sys.platform != 'darwin':
     env.Install(src_root, ['LICENSE', 'Makefile', 'GPL-2.0.txt'])
     env.Alias('install', src_root)
 
-    subdirs = ['linux', 'include', 'dp-core', 'host', 'sandesh', 'utils', 'uvrouter']
+    subdirs = ['linux', 'include', 'dp-core', 'host', 'sandesh', 'utils', 'uvrouter', 'test']
     for sdir in  subdirs:
         env.SConscript(sdir + '/SConscript',
                        exports='VRouterEnv',

dp-core/vr_message.c

@@ -81,7 +81,7 @@ vr_message_queue_response(char *buf, int len)
         return -ENOMEM;
 
     response->vr_message_buf = buf;
-    response->vr_message_len = len;;
+    response->vr_message_len = len;
     vr_queue_enqueue(&message_h.vm_response_queue,
             &response->vr_message_queue);
 
@@ -171,8 +171,6 @@ vr_message_process_response(int (*cb)(void *, unsigned int, void *),
     while ((response = vr_message_dequeue_response())) {
         proto->mproto_decode(response->vr_message_buf,
                 response->vr_message_len, cb, cb_arg);
-        if (response->vr_message_buf)
-            vr_mtrans_free(response->vr_message_buf);
         vr_message_free(response);
     }
 

host/vr_host_message.c

@@ -2,7 +2,7 @@
  * vr_host_message.c -- messaging infrastructure to interface with dp-core when
  *                      run as a library
  *
- * Copyright (c) 2013 Juniper Networks, Inc. All rights reserved. 
+ * Copyright (c) 2013 Juniper Networks, Inc. All rights reserved.
  */
 #include "vr_os.h"
 #include "vr_queue.h"
@@ -24,7 +24,7 @@ struct diet_message {
 };
 
 struct diet_object_md {
-    /* 
+    /*
      * when encoded, how much length will this object take. since encode
      * and decode does not do much to the object, encode/decode lengths
      * are the same
@@ -37,7 +37,7 @@ struct diet_object_md {
     int (*obj_response)(struct diet_message *, void *,
             int (*)(void *, unsigned int, void *), void *);
 };
-
+int diet_dropstats_object_copy(char *, unsigned int, void *);
 int diet_interface_object_copy(char *, unsigned int, void *);
 int diet_nexthop_object_copy(char *, unsigned int, void *);
 int diet_mpls_object_copy(char *, unsigned int, void *);
@@ -53,15 +53,15 @@ struct diet_object_md diet_md[] = {
     },
     [VR_INTERFACE_OBJECT_ID]    =   {
         .obj_len                =       sizeof(vr_interface_req) +
-                                        VR_ETHER_ALEN, 
+                                        VR_ETHER_ALEN,
 
         .obj_copy               =       diet_interface_object_copy,
         .obj_request            =       vr_interface_req_process,
         .obj_response           =       diet_object_response,
     },
     [VR_NEXTHOP_OBJECT_ID]    =   {
         .obj_len                =       sizeof(vr_nexthop_req) +
-                                        VR_ETHER_HLEN, 
+                                        VR_ETHER_HLEN,
 
         .obj_copy               =       diet_nexthop_object_copy,
         .obj_request            =       vr_nexthop_req_process,
@@ -84,8 +84,25 @@ struct diet_object_md diet_md[] = {
         .obj_copy               =       diet_response_object_copy,
         .obj_response           =       diet_object_response,
     },
+    [VR_DROP_STATS_OBJECT_ID]   =   {
+        .obj_len                =       sizeof(vr_drop_stats_req),
+        .obj_copy               =       diet_dropstats_object_copy,
+        .obj_response           =       diet_object_response,
+     }
 };
 
+int
+diet_dropstats_object_copy(char *dst, unsigned int buf_len, void *object)
+{
+    vr_drop_stats_req *src = (vr_drop_stats_req *)object;
+
+    if (buf_len < diet_md[VR_DROP_STATS_OBJECT_ID].obj_len)
+        return -ENOSPC;
+
+    memcpy(dst, src, sizeof(*src));
+    return sizeof(*src);
+}
+
 int
 diet_route_object_copy(char *dst, unsigned int buf_len, void *object)
 {
@@ -179,9 +196,9 @@ diet_object_response(struct diet_message *hdr, void *object,
             diet_md[hdr->m_oid].obj_len, object);
 
     if (ret > 0) {
-        if (cb(arg, hdr->m_oid, dst_buf))
-            vr_mtrans_free(dst_buf);
-    } 
+        cb(arg, hdr->m_oid, dst_buf);
+    }
+    vr_mtrans_free(dst_buf);
 
     return ret;
 }

test/SConscript

@@ -0,0 +1,25 @@
+#
+# Copyright (c) 2014 Juniper Networks, Inc. All rights reserved.
+#
+
+Import('VRouterEnv')
+env = VRouterEnv.Clone()
+
+vrouter_suite = []
+
+# Include paths
+
+# CFLAGS
+env.Append(CCFLAGS = '-g')
+
+env.Replace(LIBPATH = env['TOP_LIB'])
+env.Append(LIBPATH = ['../host', '../sandesh', '../dp-core'])
+env.Replace(LIBS = ['dp_core', 'vrouter', 'dp_sandesh_c', 'vrouter', 'dp_core', 'dp_sandesh_c', 'dp_core', 'sandesh-c', 'cmocka'])
+
+test_dep_srcs = ['common_test.c']
+
+dp_core_test = VRouterEnv.MakeTestCmd(env, 'dp_core_test', vrouter_suite, test_dep_srcs)
+
+test = env.TestSuite('vrouter-test', vrouter_suite)
+env.Alias('vrouter:test', test)
+Return('vrouter_suite')

test/common_test.c

@@ -0,0 +1,20 @@
+#include "vr_types.h"
+
+void
+get_random_bytes(void *buf, int nbytes)
+{
+}
+
+uint32_t
+jhash(void *key, uint32_t length, uint32_t interval)
+{
+    uint32_t ret;
+    int i;
+    unsigned char *data = (unsigned char *)key;
+
+    for (i = 0; i < length; i ++)
+        ret +=  data[i];
+
+    return ret;
+}
+

test/common_test.h

@@ -0,0 +1,9 @@
+#ifndef __COMMON_TEST_H__
+#define __COMMON_TEST_H__
+
+#include "vr_types.h"
+
+void get_random_bytes(void *buf, int nbytes);
+uint32_t jhash(void *key, uint32_t length, uint32_t interval);
+
+#endif /* __COMMON_TEST_H__ */

test/dp_core_test.c

@@ -0,0 +1,88 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <setjmp.h>
+#include <cmocka.h>
+
+#include "vr_types.h"
+#include "vr_os.h"
+#include "vr_packet.h"
+#include "vr_message.h"
+#include "vr_interface.h"
+
+#include "host/vr_host.h"
+#include "host/vr_host_packet.h"
+#include "host/vr_host_interface.h"
+
+extern int vrouter_host_init(unsigned int);
+extern unsigned int vr_num_cpus;
+
+unsigned int allocated = 0;
+
+void *alloc_for_test(unsigned int size) {
+    void *ptr;
+
+    ptr = malloc(size);
+    allocated++;
+
+    return ptr;
+}
+
+void free_for_test(void *ptr) {
+    free(ptr);
+    allocated--;
+}
+
+int fake_response_cb(void *ptr1, unsigned int i, void *ptr2) {
+    return 1;
+}
+
+void drop_stats_memory_test(void **state) {
+    vr_drop_stats_req req = {
+        .h_op = SANDESH_OP_GET,
+        .vds_rid = 0
+    };
+
+    /* process request */
+    vr_drop_stats_req_process(&req);
+
+    /* currently one response queued */
+    assert_int_equal(allocated, 2);
+
+    /* dequeue it, and check the alloctions */
+    vr_message_process_response(fake_response_cb, NULL);
+    assert_int_equal(allocated, 0);
+}
+
+static void setup(void **state) {
+    vrouter_host->hos_malloc = alloc_for_test;
+    vrouter_host->hos_zalloc = alloc_for_test;
+    vrouter_host->hos_free = free_for_test;
+}
+
+static void teardown(void **state) {
+    free(*state);
+}
+
+int main(void) {
+    int ret;
+
+    /* test suite */
+    const UnitTest tests[] = {
+        unit_test_setup_teardown(drop_stats_memory_test, setup, teardown),
+    };
+
+    vr_diet_message_proto_init();
+
+    /* init the vrouter */
+    ret = vrouter_host_init(VR_MPROTO_SANDESH);
+    if (ret)
+        return ret;
+
+
+    /* let's run the test suite */
+    ret = run_tests(tests);
+
+    return ret;
+}