4 files changed, 147 insertions, 1 deletions
diff --git a/test/core/channel/channel_args_test.c b/test/core/channel/channel_args_test.c
index 8ef1bff22e..d3eb969f09 100644
--- a/test/core/channel/channel_args_test.c
+++ b/test/core/channel/channel_args_test.c
@@ -134,12 +134,26 @@ static void test_compression_algorithm_states(void) {
   grpc_channel_args_destroy(ch_args);
 }
 
+static void test_set_socket_mutator(void) {
+  grpc_channel_args *ch_args;
+  grpc_socket_mutator mutator;
+  grpc_socket_mutator_init(&mutator, NULL);
+
+  ch_args = grpc_channel_args_set_socket_mutator(NULL, &mutator);
+  GPR_ASSERT(ch_args->num_args == 1);
+  GPR_ASSERT(strcmp(ch_args->args[0].key, GRPC_ARG_SOCKET_MUTATOR) == 0);
+  GPR_ASSERT(ch_args->args[0].type == GRPC_ARG_POINTER);
+
+  grpc_channel_args_destroy(ch_args);
+}
+
 int main(int argc, char **argv) {
   grpc_test_init(argc, argv);
   grpc_init();
   test_create();
   test_set_compression_algorithm();
   test_compression_algorithm_states();
+  test_set_socket_mutator();
   grpc_shutdown();
   return 0;
 }
diff --git a/test/core/iomgr/socket_utils_test.c b/test/core/iomgr/socket_utils_test.c
index 67bc914c15..7eee2d1d10 100644
--- a/test/core/iomgr/socket_utils_test.c
+++ b/test/core/iomgr/socket_utils_test.c
@@ -39,13 +39,57 @@
 #include "src/core/lib/iomgr/socket_utils_posix.h"
 
 #include <errno.h>
+#include <netinet/ip.h>
 #include <string.h>
 
+#include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/useful.h>
+#include "src/core/lib/iomgr/socket_mutator.h"
 #include "test/core/util/test_config.h"
 
+struct test_socket_mutator {
+  grpc_socket_mutator base;
+  int option_value;
+};
+
+static bool mutate_fd(int fd, grpc_socket_mutator *mutator) {
+  int newval;
+  socklen_t intlen = sizeof(newval);
+  struct test_socket_mutator *m = (struct test_socket_mutator *)mutator;
+
+  if (0 != setsockopt(fd, IPPROTO_IP, IP_TOS, &m->option_value,
+                      sizeof(m->option_value))) {
+    return false;
+  }
+  if (0 != getsockopt(fd, IPPROTO_IP, IP_TOS, &newval, &intlen)) {
+    return false;
+  }
+  if (newval != m->option_value) {
+    return false;
+  }
+  return true;
+}
+
+static void destroy_test_mutator(grpc_socket_mutator *mutator) {
+  struct test_socket_mutator *m = (struct test_socket_mutator *)mutator;
+  gpr_free(m);
+}
+
+static int compare_test_mutator(grpc_socket_mutator *a,
+                                grpc_socket_mutator *b) {
+  struct test_socket_mutator *ma = (struct test_socket_mutator *)a;
+  struct test_socket_mutator *mb = (struct test_socket_mutator *)b;
+  return GPR_ICMP(ma->option_value, mb->option_value);
+}
+
+static const grpc_socket_mutator_vtable mutator_vtable = {
+    mutate_fd, compare_test_mutator, destroy_test_mutator};
+
 int main(int argc, char **argv) {
   int sock;
+  grpc_error *err;
   grpc_test_init(argc, argv);
 
   sock = socket(PF_INET, SOCK_STREAM, 0);
@@ -68,6 +112,29 @@ int main(int argc, char **argv) {
   GPR_ASSERT(GRPC_LOG_IF_ERROR("set_socket_low_latency",
                                grpc_set_socket_low_latency(sock, 0)));
 
+  struct test_socket_mutator mutator;
+  grpc_socket_mutator_init(&mutator.base, &mutator_vtable);
+
+  mutator.option_value = IPTOS_LOWDELAY;
+  GPR_ASSERT(GRPC_LOG_IF_ERROR(
+      "set_socket_with_mutator",
+      grpc_set_socket_with_mutator(sock, (grpc_socket_mutator *)&mutator)));
+
+  mutator.option_value = IPTOS_THROUGHPUT;
+  GPR_ASSERT(GRPC_LOG_IF_ERROR(
+      "set_socket_with_mutator",
+      grpc_set_socket_with_mutator(sock, (grpc_socket_mutator *)&mutator)));
+
+  mutator.option_value = IPTOS_RELIABILITY;
+  GPR_ASSERT(GRPC_LOG_IF_ERROR(
+      "set_socket_with_mutator",
+      grpc_set_socket_with_mutator(sock, (grpc_socket_mutator *)&mutator)));
+
+  mutator.option_value = -1;
+  err = grpc_set_socket_with_mutator(sock, (grpc_socket_mutator *)&mutator);
+  GPR_ASSERT(err != GRPC_ERROR_NONE);
+  GRPC_ERROR_UNREF(err);
+
   close(sock);
 
   return 0;
diff --git a/test/core/profiling/mark_timings.stp b/test/core/profiling/mark_timings.stp
index 0c0a417faf..e96edbc149 100644
--- a/test/core/profiling/mark_timings.stp
+++ b/test/core/profiling/mark_timings.stp
@@ -2,7 +2,7 @@
  * probe definition.
  *
  * For a statically build binary, that'd be the name of the binary itself.
- * For dinamically built ones, point to the location of the libgprc.so being
+ * For dynamically built ones, point to the location of the libgrpc.so being
  * used. */
 
 global starts, times, times_per_tag
diff --git a/test/cpp/common/channel_arguments_test.cc b/test/cpp/common/channel_arguments_test.cc
index 342f6a5339..60d3215265 100644
--- a/test/cpp/common/channel_arguments_test.cc
+++ b/test/cpp/common/channel_arguments_test.cc
@@ -35,11 +35,56 @@
 
 #include <grpc++/grpc++.h>
 #include <grpc/grpc.h>
+#include <grpc/support/useful.h>
 #include <gtest/gtest.h>
+#include "src/core/lib/iomgr/socket_mutator.h"
 
 namespace grpc {
 namespace testing {
 
+namespace {
+
+// A simple grpc_socket_mutator to be used to test SetSocketMutator
+class TestSocketMutator : public grpc_socket_mutator {
+ public:
+  TestSocketMutator();
+
+  bool MutateFd(int fd) {
+    // Do nothing on the fd
+    return true;
+  }
+};
+
+//
+// C API for TestSocketMutator
+//
+
+bool test_mutator_mutate_fd(int fd, grpc_socket_mutator* mutator) {
+  TestSocketMutator* tsm = (TestSocketMutator*)mutator;
+  return tsm->MutateFd(fd);
+}
+
+int test_mutator_compare(grpc_socket_mutator* a, grpc_socket_mutator* b) {
+  return GPR_ICMP(a, b);
+}
+
+void test_mutator_destroy(grpc_socket_mutator* mutator) {
+  TestSocketMutator* tsm = (TestSocketMutator*)mutator;
+  delete tsm;
+}
+
+grpc_socket_mutator_vtable test_mutator_vtable = {
+    test_mutator_mutate_fd, test_mutator_compare, test_mutator_destroy};
+
+//
+// TestSocketMutator implementation
+//
+
+TestSocketMutator::TestSocketMutator() {
+  grpc_socket_mutator_init(this, &test_mutator_vtable);
+}
+}
+
 class ChannelArgumentsTest : public ::testing::Test {
  protected:
   ChannelArgumentsTest()
@@ -166,6 +211,26 @@ TEST_F(ChannelArgumentsTest, SetPointer) {
   EXPECT_TRUE(HasArg(arg0));
 }
 
+TEST_F(ChannelArgumentsTest, SetSocketMutator) {
+  VerifyDefaultChannelArgs();
+  grpc_arg arg0, arg1;
+  TestSocketMutator* mutator0 = new TestSocketMutator();
+  TestSocketMutator* mutator1 = new TestSocketMutator();
+  arg0 = grpc_socket_mutator_to_arg(mutator0);
+  arg1 = grpc_socket_mutator_to_arg(mutator1);
+
+  channel_args_.SetSocketMutator(mutator0);
+  EXPECT_TRUE(HasArg(arg0));
+
+  channel_args_.SetSocketMutator(mutator1);
+  EXPECT_TRUE(HasArg(arg1));
+  // arg0 is replaced by arg1
+  EXPECT_FALSE(HasArg(arg0));
+
+  // arg0 is destroyed by grpc_socket_mutator_to_arg(mutator1)
+  arg1.value.pointer.vtable->destroy(arg1.value.pointer.p);
+}
+
 TEST_F(ChannelArgumentsTest, SetUserAgentPrefix) {
   VerifyDefaultChannelArgs();
   grpc::string prefix("prefix");