Merge remote-tracking branch 'upstream/master' into http_connect

29 files changed, 614 insertions, 224 deletions

diff --git a/src/core/ext/census/trace_context.c b/src/core/ext/census/trace_context.c
new file mode 100644
index 0000000000..fbb20d3448
--- /dev/null
+++ b/src/core/ext/census/trace_context.c
@@ -0,0 +1,86 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/ext/census/trace_context.h"
+
+#include <grpc/census.h>
+#include <grpc/support/log.h>
+#include <stdbool.h>
+
+#include "third_party/nanopb/pb_decode.h"
+#include "third_party/nanopb/pb_encode.h"
+
+// This function assumes the TraceContext is valid.
+size_t encode_trace_context(google_trace_TraceContext *ctxt, uint8_t *buffer,
+                            const size_t buf_size) {
+  // Create a stream that will write to our buffer.
+  pb_ostream_t stream = pb_ostream_from_buffer(buffer, buf_size);
+
+  // encode message
+  bool status = pb_encode(&stream, google_trace_TraceContext_fields, ctxt);
+
+  if (!status) {
+    gpr_log(GPR_DEBUG, "TraceContext encoding failed: %s",
+            PB_GET_ERROR(&stream));
+    return 0;
+  }
+
+  return stream.bytes_written;
+}
+
+bool decode_trace_context(google_trace_TraceContext *ctxt, uint8_t *buffer,
+                          const size_t nbytes) {
+  // Create a stream that reads nbytes from the buffer.
+  pb_istream_t stream = pb_istream_from_buffer(buffer, nbytes);
+
+  // decode message
+  bool status = pb_decode(&stream, google_trace_TraceContext_fields, ctxt);
+
+  if (!status) {
+    gpr_log(GPR_DEBUG, "TraceContext decoding failed: %s",
+            PB_GET_ERROR(&stream));
+    return false;
+  }
+
+  // check fields
+  if (!ctxt->has_trace_id) {
+    gpr_log(GPR_DEBUG, "Invalid TraceContext: missing trace_id");
+    return false;
+  }
+  if (!ctxt->has_span_id) {
+    gpr_log(GPR_DEBUG, "Invalid TraceContext: missing span_id");
+    return false;
+  }
+
+  return true;
+}
diff --git a/src/core/ext/census/trace_context.h b/src/core/ext/census/trace_context.h
new file mode 100644
index 0000000000..ee71fef460
--- /dev/null
+++ b/src/core/ext/census/trace_context.h
@@ -0,0 +1,68 @@
+/*
+ *
+ * Copyright 2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+/* Functions for manipulating trace contexts as defined in
+   src/proto/census/trace.proto */
+#ifndef GRPC_CORE_EXT_CENSUS_TRACE_CONTEXT_H
+#define GRPC_CORE_EXT_CENSUS_TRACE_CONTEXT_H
+
+#include "src/core/ext/census/gen/trace_context.pb.h"
+
+/* Maximum number of bytes required to encode a TraceContext (31)
+1 byte for trace_id field
+1 byte for trace_id length
+1 byte for trace_id.hi field
+8 bytes for trace_id.hi (uint64_t)
+1 byte for trace_id.lo field
+8 bytes for trace_id.lo (uint64_t)
+1 byte for span_id field
+8 bytes for span_id (uint64_t)
+1 byte for is_sampled field
+1 byte for is_sampled (bool) */
+#define TRACE_MAX_CONTEXT_SIZE 31
+
+/* Encode a trace context (ctxt) into proto format to the buffer provided.  The
+size of buffer must be at least TRACE_MAX_CONTEXT_SIZE.  On success, returns the
+number of bytes successfully encoded into buffer.  On failure, returns 0. */
+size_t encode_trace_context(google_trace_TraceContext *ctxt, uint8_t *buffer,
+                            const size_t buf_size);
+
+/* Decode a proto-encoded TraceContext from the provided buffer into the
+TraceContext structure (ctxt).  The function expects to be supplied the number
+of bytes to be read from buffer (nbytes).  This function will also validate that
+the TraceContext has a span_id and a trace_id, and will return false if either
+of these do not exist. On success, returns true and false otherwise. */
+bool decode_trace_context(google_trace_TraceContext *ctxt, uint8_t *buffer,
+                          const size_t nbytes);
+
+#endif
diff --git a/src/core/ext/census/tracing.c b/src/core/ext/census/tracing.c
index 3b5d6dab2b..8f0e12296d 100644
--- a/src/core/ext/census/tracing.c
+++ b/src/core/ext/census/tracing.c
@@ -31,15 +31,19 @@
  *
  */
 
+//#include "src/core/ext/census/tracing.h"
+
 #include <grpc/census.h>
 
 /* TODO(aveitch): These are all placeholder implementations. */
 
-int census_trace_mask(const census_context *context) {
-  return CENSUS_TRACE_MASK_NONE;
-}
+// int census_trace_mask(const census_context *context) {
+//   return CENSUS_TRACE_MASK_NONE;
+// }
+
+// void census_set_trace_mask(int trace_mask) {}
 
-void census_set_trace_mask(int trace_mask) {}
+// void census_trace_print(census_context *context, uint32_t type,
+//                         const char *buffer, size_t n) {}
 
-void census_trace_print(census_context *context, uint32_t type,
-                        const char *buffer, size_t n) {}
+// void SetTracerParams(const Params& params);
diff --git a/src/core/ext/client_config/client_channel.c b/src/core/ext/client_config/client_channel.c
index 6b779efe57..b2b4fea83c 100644
--- a/src/core/ext/client_config/client_channel.c
+++ b/src/core/ext/client_config/client_channel.c
@@ -42,6 +42,7 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/useful.h>
 
+#include "src/core/ext/client_config/lb_policy_registry.h"
 #include "src/core/ext/client_config/subchannel.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/connected_channel.h"
@@ -63,6 +64,8 @@ typedef struct client_channel_channel_data {
   grpc_resolver *resolver;
   /** have we started resolving this channel */
   bool started_resolving;
+  /** client channel factory */
+  grpc_client_channel_factory *client_channel_factory;
 
   /** mutex protecting client configuration, including all
       variables below in this data structure */
@@ -173,20 +176,28 @@ static void on_resolver_result_changed(grpc_exec_ctx *exec_ctx, void *arg,
   grpc_error *state_error = GRPC_ERROR_CREATE("No load balancing policy");
 
   if (chand->resolver_result != NULL) {
-    lb_policy = grpc_resolver_result_get_lb_policy(chand->resolver_result);
+    grpc_lb_policy_args lb_policy_args;
+    lb_policy_args.server_name =
+        grpc_resolver_result_get_server_name(chand->resolver_result);
+    lb_policy_args.addresses =
+        grpc_resolver_result_get_addresses(chand->resolver_result);
+    lb_policy_args.additional_args =
+        grpc_resolver_result_get_lb_policy_args(chand->resolver_result);
+    lb_policy_args.client_channel_factory = chand->client_channel_factory;
+    lb_policy = grpc_lb_policy_create(
+        exec_ctx,
+        grpc_resolver_result_get_lb_policy_name(chand->resolver_result),
+        &lb_policy_args);
     if (lb_policy != NULL) {
-      GRPC_LB_POLICY_REF(lb_policy, "channel");
       GRPC_LB_POLICY_REF(lb_policy, "config_change");
       GRPC_ERROR_UNREF(state_error);
       state =
           grpc_lb_policy_check_connectivity(exec_ctx, lb_policy, &state_error);
     }
-
     grpc_resolver_result_unref(exec_ctx, chand->resolver_result);
+    chand->resolver_result = NULL;
   }
 
-  chand->resolver_result = NULL;
-
   if (lb_policy != NULL) {
     grpc_pollset_set_add_pollset_set(exec_ctx, lb_policy->interested_parties,
                                      chand->interested_parties);
@@ -346,6 +357,9 @@ static void cc_destroy_channel_elem(grpc_exec_ctx *exec_ctx,
     grpc_resolver_shutdown(exec_ctx, chand->resolver);
     GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel");
   }
+  if (chand->client_channel_factory != NULL) {
+    grpc_client_channel_factory_unref(exec_ctx, chand->client_channel_factory);
+  }
   if (chand->lb_policy != NULL) {
     grpc_pollset_set_del_pollset_set(exec_ctx,
                                      chand->lb_policy->interested_parties,
@@ -767,10 +781,12 @@ const grpc_channel_filter grpc_client_channel_filter = {
     "client-channel",
 };
 
-void grpc_client_channel_set_resolver(grpc_exec_ctx *exec_ctx,
-                                      grpc_channel_stack *channel_stack,
-                                      grpc_resolver *resolver) {
+void grpc_client_channel_finish_initialization(
+    grpc_exec_ctx *exec_ctx, grpc_channel_stack *channel_stack,
+    grpc_resolver *resolver,
+    grpc_client_channel_factory *client_channel_factory) {
   /* post construction initialization: set the transport setup pointer */
+  GPR_ASSERT(client_channel_factory != NULL);
   grpc_channel_element *elem = grpc_channel_stack_last_element(channel_stack);
   channel_data *chand = elem->channel_data;
   gpr_mu_lock(&chand->mu);
@@ -784,6 +800,8 @@ void grpc_client_channel_set_resolver(grpc_exec_ctx *exec_ctx,
     grpc_resolver_next(exec_ctx, resolver, &chand->resolver_result,
                        &chand->on_resolver_result_changed);
   }
+  chand->client_channel_factory = client_channel_factory;
+  grpc_client_channel_factory_ref(client_channel_factory);
   gpr_mu_unlock(&chand->mu);
 }
 
diff --git a/src/core/ext/client_config/client_channel.h b/src/core/ext/client_config/client_channel.h
index 1e47ad34ad..abb5ac4d87 100644
--- a/src/core/ext/client_config/client_channel.h
+++ b/src/core/ext/client_config/client_channel.h
@@ -34,6 +34,7 @@
 #ifndef GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CHANNEL_H
 #define GRPC_CORE_EXT_CLIENT_CONFIG_CLIENT_CHANNEL_H
 
+#include "src/core/ext/client_config/client_channel_factory.h"
 #include "src/core/ext/client_config/resolver.h"
 #include "src/core/lib/channel/channel_stack.h"
 
@@ -46,12 +47,12 @@
 
 extern const grpc_channel_filter grpc_client_channel_filter;
 
-/* post-construction initializer to let the client channel know which
-   transport setup it should cancel upon destruction, or initiate when it needs
-   a connection */
-void grpc_client_channel_set_resolver(grpc_exec_ctx *exec_ctx,
-                                      grpc_channel_stack *channel_stack,
-                                      grpc_resolver *resolver);
+/* Post-construction initializer to give the client channel its resolver
+   and factory. */
+void grpc_client_channel_finish_initialization(
+    grpc_exec_ctx *exec_ctx, grpc_channel_stack *channel_stack,
+    grpc_resolver *resolver,
+    grpc_client_channel_factory *client_channel_factory);
 
 grpc_connectivity_state grpc_client_channel_check_connectivity_state(
     grpc_exec_ctx *exec_ctx, grpc_channel_element *elem, int try_to_connect);
diff --git a/src/core/ext/client_config/lb_policy_factory.c b/src/core/ext/client_config/lb_policy_factory.c
index f86117aa38..c17af91a09 100644
--- a/src/core/ext/client_config/lb_policy_factory.c
+++ b/src/core/ext/client_config/lb_policy_factory.c
@@ -34,6 +34,7 @@
 #include <string.h>
 
 #include <grpc/support/alloc.h>
+#include <grpc/support/string_util.h>
 
 #include "src/core/ext/client_config/lb_policy_factory.h"
 
@@ -46,6 +47,25 @@ grpc_lb_addresses* grpc_lb_addresses_create(size_t num_addresses) {
   return addresses;
 }
 
+grpc_lb_addresses* grpc_lb_addresses_copy(grpc_lb_addresses* addresses,
+                                          void* (*user_data_copy)(void*)) {
+  grpc_lb_addresses* new_addresses =
+      grpc_lb_addresses_create(addresses->num_addresses);
+  memcpy(new_addresses->addresses, addresses->addresses,
+         sizeof(grpc_lb_address) * addresses->num_addresses);
+  for (size_t i = 0; i < addresses->num_addresses; ++i) {
+    if (new_addresses->addresses[i].balancer_name != NULL) {
+      new_addresses->addresses[i].balancer_name =
+          gpr_strdup(new_addresses->addresses[i].balancer_name);
+    }
+    if (user_data_copy != NULL) {
+      new_addresses->addresses[i].user_data =
+          user_data_copy(new_addresses->addresses[i].user_data);
+    }
+  }
+  return new_addresses;
+}
+
 void grpc_lb_addresses_set_address(grpc_lb_addresses* addresses, size_t index,
                                    void* address, size_t address_len,
                                    bool is_balancer, char* balancer_name,
diff --git a/src/core/ext/client_config/lb_policy_factory.h b/src/core/ext/client_config/lb_policy_factory.h
index 6247db2b61..ade55704f2 100644
--- a/src/core/ext/client_config/lb_policy_factory.h
+++ b/src/core/ext/client_config/lb_policy_factory.h
@@ -36,9 +36,9 @@
 
 #include "src/core/ext/client_config/client_channel_factory.h"
 #include "src/core/ext/client_config/lb_policy.h"
-#include "src/core/ext/client_config/resolver_result.h"
 
 #include "src/core/lib/iomgr/exec_ctx.h"
+#include "src/core/lib/iomgr/resolve_address.h"
 
 typedef struct grpc_lb_policy_factory grpc_lb_policy_factory;
 typedef struct grpc_lb_policy_factory_vtable grpc_lb_policy_factory_vtable;
@@ -68,6 +68,11 @@ typedef struct grpc_lb_addresses {
  * \a num_addresses addresses. */
 grpc_lb_addresses *grpc_lb_addresses_create(size_t num_addresses);
 
+/** Creates a copy of \a addresses.  If \a user_data_copy is not NULL,
+ * it will be invoked to copy the \a user_data field of each address. */
+grpc_lb_addresses *grpc_lb_addresses_copy(grpc_lb_addresses *addresses,
+                                          void *(*user_data_copy)(void *));
+
 /** Sets the value of the address at index \a index of \a addresses.
  * \a address is a socket address of length \a address_len.
  * Takes ownership of \a balancer_name. */
@@ -82,10 +87,14 @@ void grpc_lb_addresses_destroy(grpc_lb_addresses *addresses,
                                void (*user_data_destroy)(void *));
 
 /** Arguments passed to LB policies. */
+/* TODO(roth, ctiller): Consider replacing this struct with
+   grpc_channel_args.  See comment in resolver_result.h for details. */
 typedef struct grpc_lb_policy_args {
-  char *server_name;
+  const char *server_name;
   grpc_lb_addresses *addresses;
   grpc_client_channel_factory *client_channel_factory;
+  /* Can be used to pass implementation-specific parameters to the LB policy. */
+  grpc_channel_args *additional_args;
 } grpc_lb_policy_args;
 
 struct grpc_lb_policy_factory_vtable {
diff --git a/src/core/ext/client_config/resolver_factory.h b/src/core/ext/client_config/resolver_factory.h
index f69bf79564..9ec5b9a70e 100644
--- a/src/core/ext/client_config/resolver_factory.h
+++ b/src/core/ext/client_config/resolver_factory.h
@@ -47,10 +47,7 @@ struct grpc_resolver_factory {
   const grpc_resolver_factory_vtable *vtable;
 };
 
-typedef struct grpc_resolver_args {
-  grpc_uri *uri;
-  grpc_client_channel_factory *client_channel_factory;
-} grpc_resolver_args;
+typedef struct grpc_resolver_args { grpc_uri *uri; } grpc_resolver_args;
 
 struct grpc_resolver_factory_vtable {
   void (*ref)(grpc_resolver_factory *factory);
diff --git a/src/core/ext/client_config/resolver_registry.c b/src/core/ext/client_config/resolver_registry.c
index e7a4abd568..b5308a140c 100644
--- a/src/core/ext/client_config/resolver_registry.c
+++ b/src/core/ext/client_config/resolver_registry.c
@@ -128,15 +128,13 @@ static grpc_resolver_factory *resolve_factory(const char *target,
   return factory;
 }
 
-grpc_resolver *grpc_resolver_create(
-    const char *target, grpc_client_channel_factory *client_channel_factory) {
+grpc_resolver *grpc_resolver_create(const char *target) {
   grpc_uri *uri = NULL;
   grpc_resolver_factory *factory = resolve_factory(target, &uri);
   grpc_resolver *resolver;
   grpc_resolver_args args;
   memset(&args, 0, sizeof(args));
   args.uri = uri;
-  args.client_channel_factory = client_channel_factory;
   resolver = grpc_resolver_factory_create_resolver(factory, &args);
   grpc_uri_destroy(uri);
   return resolver;
diff --git a/src/core/ext/client_config/resolver_registry.h b/src/core/ext/client_config/resolver_registry.h
index 5ef1383cd3..92e248d548 100644
--- a/src/core/ext/client_config/resolver_registry.h
+++ b/src/core/ext/client_config/resolver_registry.h
@@ -55,8 +55,7 @@ void grpc_register_resolver_type(grpc_resolver_factory *factory);
     If a resolver factory was found, use it to instantiate a resolver and
     return it.
     If a resolver factory was not found, return NULL. */
-grpc_resolver *grpc_resolver_create(
-    const char *target, grpc_client_channel_factory *client_channel_factory);
+grpc_resolver *grpc_resolver_create(const char *target);
 
 /** Find a resolver factory given a name and return an (owned-by-the-caller)
  *  reference to it */
diff --git a/src/core/ext/client_config/resolver_result.c b/src/core/ext/client_config/resolver_result.c
index 242989a0da..63480d152b 100644
--- a/src/core/ext/client_config/resolver_result.c
+++ b/src/core/ext/client_config/resolver_result.c
@@ -34,40 +34,61 @@
 #include <string.h>
 
 #include <grpc/support/alloc.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/lib/channel/channel_args.h"
 
 struct grpc_resolver_result {
   gpr_refcount refs;
-  grpc_lb_policy* lb_policy;
+  char* server_name;
+  grpc_lb_addresses* addresses;
+  char* lb_policy_name;
+  grpc_channel_args* lb_policy_args;
 };
 
-grpc_resolver_result* grpc_resolver_result_create() {
-  grpc_resolver_result* c = gpr_malloc(sizeof(*c));
-  memset(c, 0, sizeof(*c));
-  gpr_ref_init(&c->refs, 1);
-  return c;
+grpc_resolver_result* grpc_resolver_result_create(
+    const char* server_name, grpc_lb_addresses* addresses,
+    const char* lb_policy_name, grpc_channel_args* lb_policy_args) {
+  grpc_resolver_result* result = gpr_malloc(sizeof(*result));
+  memset(result, 0, sizeof(*result));
+  gpr_ref_init(&result->refs, 1);
+  result->server_name = gpr_strdup(server_name);
+  result->addresses = addresses;
+  result->lb_policy_name = gpr_strdup(lb_policy_name);
+  result->lb_policy_args = lb_policy_args;
+  return result;
 }
 
-void grpc_resolver_result_ref(grpc_resolver_result* c) { gpr_ref(&c->refs); }
+void grpc_resolver_result_ref(grpc_resolver_result* result) {
+  gpr_ref(&result->refs);
+}
 
 void grpc_resolver_result_unref(grpc_exec_ctx* exec_ctx,
-                                grpc_resolver_result* c) {
-  if (gpr_unref(&c->refs)) {
-    if (c->lb_policy != NULL) {
-      GRPC_LB_POLICY_UNREF(exec_ctx, c->lb_policy, "resolver_result");
-    }
-    gpr_free(c);
+                                grpc_resolver_result* result) {
+  if (gpr_unref(&result->refs)) {
+    gpr_free(result->server_name);
+    grpc_lb_addresses_destroy(result->addresses, NULL /* user_data_destroy */);
+    gpr_free(result->lb_policy_name);
+    grpc_channel_args_destroy(result->lb_policy_args);
+    gpr_free(result);
   }
 }
 
-void grpc_resolver_result_set_lb_policy(grpc_resolver_result* c,
-                                        grpc_lb_policy* lb_policy) {
-  GPR_ASSERT(c->lb_policy == NULL);
-  if (lb_policy) {
-    GRPC_LB_POLICY_REF(lb_policy, "resolver_result");
-  }
-  c->lb_policy = lb_policy;
+const char* grpc_resolver_result_get_server_name(grpc_resolver_result* result) {
+  return result->server_name;
+}
+
+grpc_lb_addresses* grpc_resolver_result_get_addresses(
+    grpc_resolver_result* result) {
+  return result->addresses;
+}
+
+const char* grpc_resolver_result_get_lb_policy_name(
+    grpc_resolver_result* result) {
+  return result->lb_policy_name;
 }
 
-grpc_lb_policy* grpc_resolver_result_get_lb_policy(grpc_resolver_result* c) {
-  return c->lb_policy;
+grpc_channel_args* grpc_resolver_result_get_lb_policy_args(
+    grpc_resolver_result* result) {
+  return result->lb_policy_args;
 }
diff --git a/src/core/ext/client_config/resolver_result.h b/src/core/ext/client_config/resolver_result.h
index 5a69d81990..414c2e2482 100644
--- a/src/core/ext/client_config/resolver_result.h
+++ b/src/core/ext/client_config/resolver_result.h
@@ -32,22 +32,43 @@
 #ifndef GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_RESULT_H
 #define GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_RESULT_H
 
-#include <stdbool.h>
-
-#include "src/core/ext/client_config/lb_policy.h"
+#include "src/core/ext/client_config/lb_policy_factory.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 
+// TODO(roth, ctiller): In the long term, we are considering replacing
+// the resolver_result data structure with grpc_channel_args.  The idea is
+// that the resolver will return a set of channel args that contains the
+// information that is currently in the resolver_result struct.  For
+// example, there will be specific args indicating the set of addresses
+// and the name of the LB policy to instantiate.  Note that if we did
+// this, we would probably want to change the data structure of
+// grpc_channel_args such to a hash table or AVL or some other data
+// structure that does not require linear search to find keys.
+
 /// Results reported from a grpc_resolver.
 typedef struct grpc_resolver_result grpc_resolver_result;
 
-grpc_resolver_result* grpc_resolver_result_create();
+/// Takes ownership of \a addresses and \a lb_policy_args.
+grpc_resolver_result* grpc_resolver_result_create(
+    const char* server_name, grpc_lb_addresses* addresses,
+    const char* lb_policy_name, grpc_channel_args* lb_policy_args);
 void grpc_resolver_result_ref(grpc_resolver_result* result);
 void grpc_resolver_result_unref(grpc_exec_ctx* exec_ctx,
                                 grpc_resolver_result* result);
 
-void grpc_resolver_result_set_lb_policy(grpc_resolver_result* result,
-                                        grpc_lb_policy* lb_policy);
-grpc_lb_policy* grpc_resolver_result_get_lb_policy(
+/// Caller does NOT take ownership of result.
+const char* grpc_resolver_result_get_server_name(grpc_resolver_result* result);
+
+/// Caller does NOT take ownership of result.
+grpc_lb_addresses* grpc_resolver_result_get_addresses(
+    grpc_resolver_result* result);
+
+/// Caller does NOT take ownership of result.
+const char* grpc_resolver_result_get_lb_policy_name(
+    grpc_resolver_result* result);
+
+/// Caller does NOT take ownership of result.
+grpc_channel_args* grpc_resolver_result_get_lb_policy_args(
     grpc_resolver_result* result);
 
 #endif /* GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_RESULT_H */
diff --git a/src/core/ext/client_config/subchannel.c b/src/core/ext/client_config/subchannel.c
index 2c4364b259..1141844634 100644
--- a/src/core/ext/client_config/subchannel.c
+++ b/src/core/ext/client_config/subchannel.c
@@ -33,6 +33,7 @@
 
 #include "src/core/ext/client_config/subchannel.h"
 
+#include <limits.h>
 #include <string.h>
 
 #include <grpc/support/alloc.h>
@@ -347,21 +348,16 @@ grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
       }
       if (0 ==
           strcmp(c->args->args[i].key, GRPC_ARG_MAX_RECONNECT_BACKOFF_MS)) {
-        if (c->args->args[i].type == GRPC_ARG_INTEGER) {
-          if (c->args->args[i].value.integer >= 0) {
-            gpr_backoff_init(
-                &c->backoff_state, GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER,
-                GRPC_SUBCHANNEL_RECONNECT_JITTER,
-                GPR_MIN(c->args->args[i].value.integer,
-                        GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS * 1000),
-                c->args->args[i].value.integer);
-          } else {
-            gpr_log(GPR_ERROR, GRPC_ARG_MAX_RECONNECT_BACKOFF_MS
-                    " : must be non-negative");
-          }
-        } else {
-          gpr_log(GPR_ERROR,
-                  GRPC_ARG_MAX_RECONNECT_BACKOFF_MS " : must be an integer");
+        const grpc_integer_options options = {-1, 0, INT_MAX};
+        const int value =
+            grpc_channel_arg_get_integer(&c->args->args[i], options);
+        if (value >= 0) {
+          gpr_backoff_init(
+              &c->backoff_state, GRPC_SUBCHANNEL_RECONNECT_BACKOFF_MULTIPLIER,
+              GRPC_SUBCHANNEL_RECONNECT_JITTER,
+              GPR_MIN(value,
+                      GRPC_SUBCHANNEL_INITIAL_CONNECT_BACKOFF_SECONDS * 1000),
+              value);
         }
       }
     }
diff --git a/src/core/ext/client_config/subchannel.h b/src/core/ext/client_config/subchannel.h
index a24dbe80fb..218bb43e0a 100644
--- a/src/core/ext/client_config/subchannel.h
+++ b/src/core/ext/client_config/subchannel.h
@@ -163,7 +163,7 @@ struct grpc_subchannel_args {
   /** Channel arguments to be supplied to the newly created channel */
   const grpc_channel_args *args;
   /** Server name */
-  char *server_name;
+  const char *server_name;
   /** Address to connect to */
   struct sockaddr *addr;
   size_t addr_len;
diff --git a/src/core/ext/client_config/subchannel_index.c b/src/core/ext/client_config/subchannel_index.c
index 40ce91492d..673f85b8cb 100644
--- a/src/core/ext/client_config/subchannel_index.c
+++ b/src/core/ext/client_config/subchannel_index.c
@@ -132,7 +132,7 @@ void grpc_subchannel_key_destroy(grpc_exec_ctx *exec_ctx,
   grpc_connector_unref(exec_ctx, k->connector);
   gpr_free((grpc_channel_args *)k->args.filters);
   grpc_channel_args_destroy((grpc_channel_args *)k->args.args);
-  gpr_free(k->args.server_name);
+  gpr_free((void *)k->args.server_name);
   gpr_free(k->args.addr);
   gpr_free(k);
 }
diff --git a/src/core/ext/lb_policy/grpclb/grpclb.c b/src/core/ext/lb_policy/grpclb/grpclb.c
index a54cbb0b63..4ea164e639 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/lb_policy/grpclb/grpclb.c
@@ -283,7 +283,7 @@ typedef struct glb_lb_policy {
   /** mutex protecting remaining members */
   gpr_mu mu;
 
-  char *server_name;  // Does not own.
+  const char *server_name;  // Does not own.
   grpc_client_channel_factory *cc_factory;
 
   /** for communicating with the LB server */
diff --git a/src/core/ext/resolver/dns/native/dns_resolver.c b/src/core/ext/resolver/dns/native/dns_resolver.c
index cc028c3a55..e8ac1b12ae 100644
--- a/src/core/ext/resolver/dns/native/dns_resolver.c
+++ b/src/core/ext/resolver/dns/native/dns_resolver.c
@@ -61,8 +61,6 @@ typedef struct {
   char *name_to_resolve;
   /** default port to use */
   char *default_port;
-  /** subchannel factory */
-  grpc_client_channel_factory *client_channel_factory;
   /** load balancing policy name */
   char *lb_policy_name;
 
@@ -169,32 +167,21 @@ static void dns_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
                             grpc_error *error) {
   dns_resolver *r = arg;
   grpc_resolver_result *result = NULL;
-  grpc_lb_policy *lb_policy;
   gpr_mu_lock(&r->mu);
   GPR_ASSERT(r->resolving);
   r->resolving = false;
   if (r->addresses != NULL) {
-    grpc_lb_policy_args lb_policy_args;
-    memset(&lb_policy_args, 0, sizeof(lb_policy_args));
-    lb_policy_args.server_name = r->target_name;
-    lb_policy_args.addresses = grpc_lb_addresses_create(r->addresses->naddrs);
+    grpc_lb_addresses *addresses =
+        grpc_lb_addresses_create(r->addresses->naddrs);
     for (size_t i = 0; i < r->addresses->naddrs; ++i) {
       grpc_lb_addresses_set_address(
-          lb_policy_args.addresses, i, &r->addresses->addrs[i].addr,
+          addresses, i, &r->addresses->addrs[i].addr,
           r->addresses->addrs[i].len, false /* is_balancer */,
           NULL /* balancer_name */, NULL /* user_data */);
     }
     grpc_resolved_addresses_destroy(r->addresses);
-    lb_policy_args.client_channel_factory = r->client_channel_factory;
-    lb_policy =
-        grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
-    grpc_lb_addresses_destroy(lb_policy_args.addresses,
-                              NULL /* user_data_destroy */);
-    result = grpc_resolver_result_create();
-    if (lb_policy != NULL) {
-      grpc_resolver_result_set_lb_policy(result, lb_policy);
-      GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "construction");
-    }
+    result = grpc_resolver_result_create(r->target_name, addresses,
+                                         r->lb_policy_name, NULL);
   } else {
     gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
     gpr_timespec next_try = gpr_backoff_step(&r->backoff_state, now);
@@ -255,7 +242,6 @@ static void dns_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
   if (r->resolved_result) {
     grpc_resolver_result_unref(exec_ctx, r->resolved_result);
   }
-  grpc_client_channel_factory_unref(exec_ctx, r->client_channel_factory);
   gpr_free(r->target_name);
   gpr_free(r->name_to_resolve);
   gpr_free(r->default_port);
@@ -284,10 +270,8 @@ static grpc_resolver *dns_create(grpc_resolver_args *args,
   r->target_name = gpr_strdup(path);
   r->name_to_resolve = proxy_name == NULL ? gpr_strdup(path) : proxy_name;
   r->default_port = gpr_strdup(default_port);
-  r->client_channel_factory = args->client_channel_factory;
   gpr_backoff_init(&r->backoff_state, BACKOFF_MULTIPLIER, BACKOFF_JITTER,
                    BACKOFF_MIN_SECONDS * 1000, BACKOFF_MAX_SECONDS * 1000);
-  grpc_client_channel_factory_ref(r->client_channel_factory);
   r->lb_policy_name = gpr_strdup(lb_policy_name);
   return &r->base;
 }
diff --git a/src/core/ext/resolver/sockaddr/sockaddr_resolver.c b/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
index 34916e10be..74d2015e5c 100644
--- a/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
+++ b/src/core/ext/resolver/sockaddr/sockaddr_resolver.c
@@ -40,7 +40,6 @@
 #include <grpc/support/port_platform.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/ext/client_config/lb_policy_registry.h"
 #include "src/core/ext/client_config/parse_address.h"
 #include "src/core/ext/client_config/resolver_registry.h"
 #include "src/core/lib/iomgr/resolve_address.h"
@@ -52,8 +51,6 @@ typedef struct {
   grpc_resolver base;
   /** refcount */
   gpr_refcount refs;
-  /** subchannel factory */
-  grpc_client_channel_factory *client_channel_factory;
   /** load balancing policy name */
   char *lb_policy_name;
 
@@ -122,18 +119,10 @@ static void sockaddr_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver,
 static void sockaddr_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
                                               sockaddr_resolver *r) {
   if (r->next_completion != NULL && !r->published) {
-    grpc_resolver_result *result = grpc_resolver_result_create();
-    grpc_lb_policy_args lb_policy_args;
-    memset(&lb_policy_args, 0, sizeof(lb_policy_args));
-    lb_policy_args.server_name = "";
-    lb_policy_args.addresses = r->addresses;
-    lb_policy_args.client_channel_factory = r->client_channel_factory;
-    grpc_lb_policy *lb_policy =
-        grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
-    grpc_resolver_result_set_lb_policy(result, lb_policy);
-    GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "sockaddr");
     r->published = true;
-    *r->target_result = result;
+    *r->target_result = grpc_resolver_result_create(
+        "", grpc_lb_addresses_copy(r->addresses, NULL /* user_data_copy */),
+        r->lb_policy_name, NULL);
     grpc_exec_ctx_sched(exec_ctx, r->next_completion, GRPC_ERROR_NONE, NULL);
     r->next_completion = NULL;
   }
@@ -142,7 +131,6 @@ static void sockaddr_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx,
 static void sockaddr_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
   sockaddr_resolver *r = (sockaddr_resolver *)gr;
   gpr_mu_destroy(&r->mu);
-  grpc_client_channel_factory_unref(exec_ctx, r->client_channel_factory);
   grpc_lb_addresses_destroy(r->addresses, NULL /* user_data_destroy */);
   gpr_free(r->lb_policy_name);
   gpr_free(r);
@@ -244,8 +232,6 @@ static grpc_resolver *sockaddr_create(
   gpr_ref_init(&r->refs, 1);
   gpr_mu_init(&r->mu);
   grpc_resolver_init(&r->base, &sockaddr_resolver_vtable);
-  r->client_channel_factory = args->client_channel_factory;
-  grpc_client_channel_factory_ref(r->client_channel_factory);
 
   return &r->base;
 }
diff --git a/src/core/ext/transport/chttp2/client/insecure/channel_create.c b/src/core/ext/transport/chttp2/client/insecure/channel_create.c
index 14dc7f142f..c2b59569fd 100644
--- a/src/core/ext/transport/chttp2/client/insecure/channel_create.c
+++ b/src/core/ext/transport/chttp2/client/insecure/channel_create.c
@@ -161,7 +161,6 @@ typedef struct {
   grpc_client_channel_factory base;
   gpr_refcount refs;
   grpc_channel_args *merge_args;
-  grpc_channel *master;
 } client_channel_factory;
 
 static void client_channel_factory_ref(
@@ -174,10 +173,6 @@ static void client_channel_factory_unref(
     grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory) {
   client_channel_factory *f = (client_channel_factory *)cc_factory;
   if (gpr_unref(&f->refs)) {
-    if (f->master != NULL) {
-      GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, f->master,
-                                  "client_channel_factory");
-    }
     grpc_channel_args_destroy(f->merge_args);
     gpr_free(f);
   }
@@ -218,15 +213,15 @@ static grpc_channel *client_channel_factory_create_channel(
   grpc_channel *channel = grpc_channel_create(exec_ctx, target, final_args,
                                               GRPC_CLIENT_CHANNEL, NULL);
   grpc_channel_args_destroy(final_args);
-  grpc_resolver *resolver = grpc_resolver_create(target, &f->base);
+  grpc_resolver *resolver = grpc_resolver_create(target);
   if (!resolver) {
     GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, channel,
                                 "client_channel_factory_create_channel");
     return NULL;
   }
 
-  grpc_client_channel_set_resolver(
-      exec_ctx, grpc_channel_get_channel_stack(channel), resolver);
+  grpc_client_channel_finish_initialization(
+      exec_ctx, grpc_channel_get_channel_stack(channel), resolver, &f->base);
   GRPC_RESOLVER_UNREF(exec_ctx, resolver, "create_channel");
 
   return channel;
@@ -258,12 +253,8 @@ grpc_channel *grpc_insecure_channel_create(const char *target,
 
   grpc_channel *channel = client_channel_factory_create_channel(
       &exec_ctx, &f->base, target, GRPC_CLIENT_CHANNEL_TYPE_REGULAR, NULL);
-  if (channel != NULL) {
-    f->master = channel;
-    GRPC_CHANNEL_INTERNAL_REF(f->master, "grpc_insecure_channel_create");
-  }
-  grpc_client_channel_factory_unref(&exec_ctx, &f->base);
 
+  grpc_client_channel_factory_unref(&exec_ctx, &f->base);
   grpc_exec_ctx_finish(&exec_ctx);
 
   return channel != NULL ? channel : grpc_lame_client_channel_create(
diff --git a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
index a9616e92d0..31c54ff74c 100644
--- a/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
+++ b/src/core/ext/transport/chttp2/client/secure/secure_channel_create.c
@@ -221,7 +221,6 @@ typedef struct {
   gpr_refcount refs;
   grpc_channel_args *merge_args;
   grpc_channel_security_connector *security_connector;
-  grpc_channel *master;
 } client_channel_factory;
 
 static void client_channel_factory_ref(
@@ -236,10 +235,6 @@ static void client_channel_factory_unref(
   if (gpr_unref(&f->refs)) {
     GRPC_SECURITY_CONNECTOR_UNREF(&f->security_connector->base,
                                   "client_channel_factory");
-    if (f->master != NULL) {
-      GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, f->master,
-                                  "client_channel_factory");
-    }
     grpc_channel_args_destroy(f->merge_args);
     gpr_free(f);
   }
@@ -284,10 +279,10 @@ static grpc_channel *client_channel_factory_create_channel(
                                               GRPC_CLIENT_CHANNEL, NULL);
   grpc_channel_args_destroy(final_args);
 
-  grpc_resolver *resolver = grpc_resolver_create(target, &f->base);
+  grpc_resolver *resolver = grpc_resolver_create(target);
   if (resolver != NULL) {
-    grpc_client_channel_set_resolver(
-        exec_ctx, grpc_channel_get_channel_stack(channel), resolver);
+    grpc_client_channel_finish_initialization(
+        exec_ctx, grpc_channel_get_channel_stack(channel), resolver, &f->base);
     GRPC_RESOLVER_UNREF(exec_ctx, resolver, "create");
   } else {
     GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, channel,
@@ -364,10 +359,6 @@ grpc_channel *grpc_secure_channel_create(grpc_channel_credentials *creds,
 
   grpc_channel *channel = client_channel_factory_create_channel(
       &exec_ctx, &f->base, target, GRPC_CLIENT_CHANNEL_TYPE_REGULAR, NULL);
-  if (channel != NULL) {
-    f->master = channel;
-    GRPC_CHANNEL_INTERNAL_REF(f->master, "grpc_secure_channel_create");
-  }
 
   grpc_client_channel_factory_unref(&exec_ctx, &f->base);
   grpc_exec_ctx_finish(&exec_ctx);
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
index b6415e3f17..1dd7fef76f 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -33,6 +33,7 @@
 
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 
+#include <limits.h>
 #include <math.h>
 #include <stdio.h>
 #include <string.h>
@@ -46,6 +47,7 @@
 #include "src/core/ext/transport/chttp2/transport/http2_errors.h"
 #include "src/core/ext/transport/chttp2/transport/internal.h"
 #include "src/core/ext/transport/chttp2/transport/status_conversion.h"
+#include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/http/parser.h"
 #include "src/core/lib/iomgr/workqueue.h"
 #include "src/core/lib/profiling/timers.h"
@@ -333,76 +335,65 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
         if (is_client) {
           gpr_log(GPR_ERROR, "%s: is ignored on the client",
                   GRPC_ARG_MAX_CONCURRENT_STREAMS);
-        } else if (channel_args->args[i].type != GRPC_ARG_INTEGER) {
-          gpr_log(GPR_ERROR, "%s: must be an integer",
-                  GRPC_ARG_MAX_CONCURRENT_STREAMS);
         } else {
-          push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS,
-                       (uint32_t)channel_args->args[i].value.integer);
+          const grpc_integer_options options = {-1, 0, INT_MAX};
+          const int value =
+              grpc_channel_arg_get_integer(&channel_args->args[i], options);
+          if (value >= 0) {
+            push_setting(exec_ctx, t,
+                         GRPC_CHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS,
+                         (uint32_t)value);
+          }
         }
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_HTTP2_INITIAL_SEQUENCE_NUMBER)) {
-        if (channel_args->args[i].type != GRPC_ARG_INTEGER) {
-          gpr_log(GPR_ERROR, "%s: must be an integer",
-                  GRPC_ARG_HTTP2_INITIAL_SEQUENCE_NUMBER);
-        } else if ((t->global.next_stream_id & 1) !=
-                   (channel_args->args[i].value.integer & 1)) {
-          gpr_log(GPR_ERROR, "%s: low bit must be %d on %s",
-                  GRPC_ARG_HTTP2_INITIAL_SEQUENCE_NUMBER,
-                  t->global.next_stream_id & 1,
-                  is_client ? "client" : "server");
-        } else {
-          t->global.next_stream_id =
-              (uint32_t)channel_args->args[i].value.integer;
+        const grpc_integer_options options = {-1, 0, INT_MAX};
+        const int value =
+            grpc_channel_arg_get_integer(&channel_args->args[i], options);
+        if (value >= 0) {
+          if ((t->global.next_stream_id & 1) != (value & 1)) {
+            gpr_log(GPR_ERROR, "%s: low bit must be %d on %s",
+                    GRPC_ARG_HTTP2_INITIAL_SEQUENCE_NUMBER,
+                    t->global.next_stream_id & 1,
+                    is_client ? "client" : "server");
+          } else {
+            t->global.next_stream_id = (uint32_t)value;
+          }
         }
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_HTTP2_STREAM_LOOKAHEAD_BYTES)) {
-        if (channel_args->args[i].type != GRPC_ARG_INTEGER) {
-          gpr_log(GPR_ERROR, "%s: must be an integer",
-                  GRPC_ARG_HTTP2_STREAM_LOOKAHEAD_BYTES);
-        } else if (channel_args->args[i].value.integer <= 5) {
-          gpr_log(GPR_ERROR, "%s: must be at least 5",
-                  GRPC_ARG_HTTP2_STREAM_LOOKAHEAD_BYTES);
-        } else {
-          t->global.stream_lookahead =
-              (uint32_t)channel_args->args[i].value.integer;
+        const grpc_integer_options options = {-1, 5, INT_MAX};
+        const int value =
+            grpc_channel_arg_get_integer(&channel_args->args[i], options);
+        if (value >= 0) {
+          t->global.stream_lookahead = (uint32_t)value;
         }
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_HTTP2_HPACK_TABLE_SIZE_DECODER)) {
-        if (channel_args->args[i].type != GRPC_ARG_INTEGER) {
-          gpr_log(GPR_ERROR, "%s: must be an integer",
-                  GRPC_ARG_HTTP2_HPACK_TABLE_SIZE_DECODER);
-        } else if (channel_args->args[i].value.integer < 0) {
-          gpr_log(GPR_ERROR, "%s: must be non-negative",
-                  GRPC_ARG_HTTP2_HPACK_TABLE_SIZE_DECODER);
-        } else {
+        const grpc_integer_options options = {-1, 0, INT_MAX};
+        const int value =
+            grpc_channel_arg_get_integer(&channel_args->args[i], options);
+        if (value >= 0) {
           push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_HEADER_TABLE_SIZE,
-                       (uint32_t)channel_args->args[i].value.integer);
+                       (uint32_t)value);
         }
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_HTTP2_HPACK_TABLE_SIZE_ENCODER)) {
-        if (channel_args->args[i].type != GRPC_ARG_INTEGER) {
-          gpr_log(GPR_ERROR, "%s: must be an integer",
-                  GRPC_ARG_HTTP2_HPACK_TABLE_SIZE_ENCODER);
-        } else if (channel_args->args[i].value.integer < 0) {
-          gpr_log(GPR_ERROR, "%s: must be non-negative",
-                  GRPC_ARG_HTTP2_HPACK_TABLE_SIZE_ENCODER);
-        } else {
+        const grpc_integer_options options = {-1, 0, INT_MAX};
+        const int value =
+            grpc_channel_arg_get_integer(&channel_args->args[i], options);
+        if (value >= 0) {
           grpc_chttp2_hpack_compressor_set_max_usable_size(
-              &t->writing.hpack_compressor,
-              (uint32_t)channel_args->args[i].value.integer);
+              &t->writing.hpack_compressor, (uint32_t)value);
         }
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_MAX_METADATA_SIZE)) {
-        if (channel_args->args[i].type != GRPC_ARG_INTEGER) {
-          gpr_log(GPR_ERROR, "%s: must be an integer",
-                  GRPC_ARG_MAX_METADATA_SIZE);
-        } else if (channel_args->args[i].value.integer < 0) {
-          gpr_log(GPR_ERROR, "%s: must be non-negative",
-                  GRPC_ARG_MAX_METADATA_SIZE);
-        } else {
+        const grpc_integer_options options = {-1, 0, INT_MAX};
+        const int value =
+            grpc_channel_arg_get_integer(&channel_args->args[i], options);
+        if (value >= 0) {
           push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE,
-                       (uint32_t)channel_args->args[i].value.integer);
+                       (uint32_t)value);
         }
       } else if (0 == strcmp(channel_args->args[i].key,
                              GRPC_ARG_HTTP2_MAX_FRAME_SIZE)) {
diff --git a/src/core/lib/channel/channel_args.c b/src/core/lib/channel/channel_args.c
index 79ceeb66b3..3a56b1ff20 100644
--- a/src/core/lib/channel/channel_args.c
+++ b/src/core/lib/channel/channel_args.c
@@ -271,3 +271,21 @@ int grpc_channel_args_compare(const grpc_channel_args *a,
   }
   return 0;
 }
+
+int grpc_channel_arg_get_integer(grpc_arg *arg, grpc_integer_options options) {
+  if (arg->type != GRPC_ARG_INTEGER) {
+    gpr_log(GPR_ERROR, "%s ignored: it must be an integer", arg->key);
+    return options.default_value;
+  }
+  if (arg->value.integer < options.min_value) {
+    gpr_log(GPR_ERROR, "%s ignored: it must be >= %d", arg->key,
+            options.min_value);
+    return options.default_value;
+  }
+  if (arg->value.integer > options.max_value) {
+    gpr_log(GPR_ERROR, "%s ignored: it must be <= %d", arg->key,
+            options.max_value);
+    return options.default_value;
+  }
+  return arg->value.integer;
+}
diff --git a/src/core/lib/channel/channel_args.h b/src/core/lib/channel/channel_args.h
index aec61ee7c6..586a296d1f 100644
--- a/src/core/lib/channel/channel_args.h
+++ b/src/core/lib/channel/channel_args.h
@@ -89,4 +89,12 @@ uint32_t grpc_channel_args_compression_algorithm_get_states(
 int grpc_channel_args_compare(const grpc_channel_args *a,
                               const grpc_channel_args *b);
 
+typedef struct grpc_integer_options {
+  int default_value;  // Return this if value is outside of expected bounds.
+  int min_value;
+  int max_value;
+} grpc_integer_options;
+/** Returns the value of \a arg, subject to the contraints in \a options. */
+int grpc_channel_arg_get_integer(grpc_arg *arg, grpc_integer_options options);
+
 #endif /* GRPC_CORE_LIB_CHANNEL_CHANNEL_ARGS_H */
diff --git a/src/core/lib/channel/message_size_filter.c b/src/core/lib/channel/message_size_filter.c
new file mode 100644
index 0000000000..6613785dea
--- /dev/null
+++ b/src/core/lib/channel/message_size_filter.c
@@ -0,0 +1,165 @@
+//
+// Copyright 2016, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+
+#include "src/core/lib/channel/message_size_filter.h"
+
+#include <limits.h>
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/lib/channel/channel_args.h"
+
+// The protobuf library will (by default) start warning at 100 megs.
+#define DEFAULT_MAX_MESSAGE_LENGTH (4 * 1024 * 1024)
+
+typedef struct call_data {
+  // Receive closures are chained: we inject this closure as the
+  // recv_message_ready up-call on transport_stream_op, and remember to
+  // call our next_recv_message_ready member after handling it.
+  grpc_closure recv_message_ready;
+  // Used by recv_message_ready.
+  grpc_byte_stream** recv_message;
+  // Original recv_message_ready callback, invoked after our own.
+  grpc_closure* next_recv_message_ready;
+} call_data;
+
+typedef struct channel_data {
+  size_t max_send_size;
+  size_t max_recv_size;
+} channel_data;
+
+// Callback invoked when we receive a message.  Here we check the max
+// receive message size.
+static void recv_message_ready(grpc_exec_ctx* exec_ctx, void* user_data,
+                               grpc_error* error) {
+  grpc_call_element* elem = user_data;
+  call_data* calld = elem->call_data;
+  channel_data* chand = elem->channel_data;
+  if (*calld->recv_message != NULL &&
+      (*calld->recv_message)->length > chand->max_recv_size) {
+    char* message_string;
+    gpr_asprintf(
+        &message_string, "Received message larger than max (%u vs. %lu)",
+        (*calld->recv_message)->length, (unsigned long)chand->max_recv_size);
+    gpr_slice message = gpr_slice_from_copied_string(message_string);
+    gpr_free(message_string);
+    grpc_call_element_send_cancel_with_message(
+        exec_ctx, elem, GRPC_STATUS_INVALID_ARGUMENT, &message);
+  }
+  // Invoke the next callback.
+  grpc_exec_ctx_sched(exec_ctx, calld->next_recv_message_ready, error, NULL);
+}
+
+// Start transport op.
+static void start_transport_stream_op(grpc_exec_ctx* exec_ctx,
+                                      grpc_call_element* elem,
+                                      grpc_transport_stream_op* op) {
+  call_data* calld = elem->call_data;
+  channel_data* chand = elem->channel_data;
+  // Check max send message size.
+  if (op->send_message != NULL &&
+      op->send_message->length > chand->max_send_size) {
+    char* message_string;
+    gpr_asprintf(&message_string, "Sent message larger than max (%u vs. %lu)",
+                 op->send_message->length, (unsigned long)chand->max_send_size);
+    gpr_slice message = gpr_slice_from_copied_string(message_string);
+    gpr_free(message_string);
+    grpc_call_element_send_cancel_with_message(
+        exec_ctx, elem, GRPC_STATUS_INVALID_ARGUMENT, &message);
+  }
+  // Inject callback for receiving a message.
+  if (op->recv_message_ready != NULL) {
+    calld->next_recv_message_ready = op->recv_message_ready;
+    calld->recv_message = op->recv_message;
+    op->recv_message_ready = &calld->recv_message_ready;
+  }
+  // Chain to the next filter.
+  grpc_call_next_op(exec_ctx, elem, op);
+}
+
+// Constructor for call_data.
+static grpc_error* init_call_elem(grpc_exec_ctx* exec_ctx,
+                                  grpc_call_element* elem,
+                                  grpc_call_element_args* args) {
+  call_data* calld = elem->call_data;
+  calld->next_recv_message_ready = NULL;
+  grpc_closure_init(&calld->recv_message_ready, recv_message_ready, elem);
+  return GRPC_ERROR_NONE;
+}
+
+// Destructor for call_data.
+static void destroy_call_elem(grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
+                              const grpc_call_final_info* final_info,
+                              void* ignored) {}
+
+// Constructor for channel_data.
+static void init_channel_elem(grpc_exec_ctx* exec_ctx,
+                              grpc_channel_element* elem,
+                              grpc_channel_element_args* args) {
+  GPR_ASSERT(!args->is_last);
+  channel_data* chand = elem->channel_data;
+  memset(chand, 0, sizeof(*chand));
+  chand->max_send_size = DEFAULT_MAX_MESSAGE_LENGTH;
+  chand->max_recv_size = DEFAULT_MAX_MESSAGE_LENGTH;
+  const grpc_integer_options options = {DEFAULT_MAX_MESSAGE_LENGTH, 0, INT_MAX};
+  for (size_t i = 0; i < args->channel_args->num_args; ++i) {
+    if (strcmp(args->channel_args->args[i].key,
+               GRPC_ARG_MAX_SEND_MESSAGE_LENGTH) == 0) {
+      chand->max_send_size = (size_t)grpc_channel_arg_get_integer(
+          &args->channel_args->args[i], options);
+    }
+    if (strcmp(args->channel_args->args[i].key,
+               GRPC_ARG_MAX_RECEIVE_MESSAGE_LENGTH) == 0) {
+      chand->max_recv_size = (size_t)grpc_channel_arg_get_integer(
+          &args->channel_args->args[i], options);
+    }
+  }
+}
+
+// Destructor for channel_data.
+static void destroy_channel_elem(grpc_exec_ctx* exec_ctx,
+                                 grpc_channel_element* elem) {}
+
+const grpc_channel_filter grpc_message_size_filter = {
+    start_transport_stream_op,
+    grpc_channel_next_op,
+    sizeof(call_data),
+    init_call_elem,
+    grpc_call_stack_ignore_set_pollset_or_pollset_set,
+    destroy_call_elem,
+    sizeof(channel_data),
+    init_channel_elem,
+    destroy_channel_elem,
+    grpc_call_next_get_peer,
+    "message_size"};
diff --git a/src/core/lib/channel/message_size_filter.h b/src/core/lib/channel/message_size_filter.h
new file mode 100644
index 0000000000..a88ff7f81a
--- /dev/null
+++ b/src/core/lib/channel/message_size_filter.h
@@ -0,0 +1,39 @@
+//
+// Copyright 2016, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+
+#ifndef GRPC_CORE_LIB_CHANNEL_MESSAGE_SIZE_FILTER_H
+#define GRPC_CORE_LIB_CHANNEL_MESSAGE_SIZE_FILTER_H
+
+#include "src/core/lib/channel/channel_stack.h"
+
+extern const grpc_channel_filter grpc_message_size_filter;
+
+#endif /* GRPC_CORE_LIB_CHANNEL_MESSAGE_SIZE_FILTER_H */
diff --git a/src/core/lib/surface/call.c b/src/core/lib/surface/call.c
index 119f5e82ab..979e0aeaea 100644
--- a/src/core/lib/surface/call.c
+++ b/src/core/lib/surface/call.c
@@ -1163,17 +1163,6 @@ static void process_data_after_md(grpc_exec_ctx *exec_ctx, batch_control *bctl,
     if (gpr_unref(&bctl->steps_to_complete)) {
       post_batch_completion(exec_ctx, bctl);
     }
-  } else if (call->receiving_stream->length >
-             grpc_channel_get_max_message_length(call->channel)) {
-    cancel_with_status(exec_ctx, call, GRPC_STATUS_INTERNAL,
-                       "Max message size exceeded");
-    grpc_byte_stream_destroy(exec_ctx, call->receiving_stream);
-    call->receiving_stream = NULL;
-    *call->receiving_buffer = NULL;
-    call->receiving_message = 0;
-    if (gpr_unref(&bctl->steps_to_complete)) {
-      post_batch_completion(exec_ctx, bctl);
-    }
   } else {
     call->test_only_last_message_flags = call->receiving_stream->flags;
     if ((call->receiving_stream->flags & GRPC_WRITE_INTERNAL_COMPRESS) &&
diff --git a/src/core/lib/surface/channel.c b/src/core/lib/surface/channel.c
index 52e78567bd..6adb70a987 100644
--- a/src/core/lib/surface/channel.c
+++ b/src/core/lib/surface/channel.c
@@ -64,7 +64,6 @@ typedef struct registered_call {
 
 struct grpc_channel {
   int is_client;
-  uint32_t max_message_length;
   grpc_compression_options compression_options;
   grpc_mdelem *default_authority;
 
@@ -80,9 +79,6 @@ struct grpc_channel {
 #define CHANNEL_FROM_TOP_ELEM(top_elem) \
   CHANNEL_FROM_CHANNEL_STACK(grpc_channel_stack_from_top_element(top_elem))
 
-/* the protobuf library will (by default) start warning at 100megs */
-#define DEFAULT_MAX_MESSAGE_LENGTH (4 * 1024 * 1024)
-
 static void destroy_channel(grpc_exec_ctx *exec_ctx, void *arg,
                             grpc_error *error);
 
@@ -114,21 +110,10 @@ grpc_channel *grpc_channel_create(grpc_exec_ctx *exec_ctx, const char *target,
   gpr_mu_init(&channel->registered_call_mu);
   channel->registered_calls = NULL;
 
-  channel->max_message_length = DEFAULT_MAX_MESSAGE_LENGTH;
   grpc_compression_options_init(&channel->compression_options);
   if (args) {
     for (size_t i = 0; i < args->num_args; i++) {
-      if (0 == strcmp(args->args[i].key, GRPC_ARG_MAX_MESSAGE_LENGTH)) {
-        if (args->args[i].type != GRPC_ARG_INTEGER) {
-          gpr_log(GPR_ERROR, "%s ignored: it must be an integer",
-                  GRPC_ARG_MAX_MESSAGE_LENGTH);
-        } else if (args->args[i].value.integer < 0) {
-          gpr_log(GPR_ERROR, "%s ignored: it must be >= 0",
-                  GRPC_ARG_MAX_MESSAGE_LENGTH);
-        } else {
-          channel->max_message_length = (uint32_t)args->args[i].value.integer;
-        }
-      } else if (0 == strcmp(args->args[i].key, GRPC_ARG_DEFAULT_AUTHORITY)) {
+      if (0 == strcmp(args->args[i].key, GRPC_ARG_DEFAULT_AUTHORITY)) {
         if (args->args[i].type != GRPC_ARG_STRING) {
           gpr_log(GPR_ERROR, "%s ignored: it must be a string",
                   GRPC_ARG_DEFAULT_AUTHORITY);
@@ -370,7 +355,3 @@ grpc_mdelem *grpc_channel_get_reffed_status_elem(grpc_channel *channel, int i) {
   return grpc_mdelem_from_metadata_strings(GRPC_MDSTR_GRPC_STATUS,
                                            grpc_mdstr_from_string(tmp));
 }
-
-uint32_t grpc_channel_get_max_message_length(grpc_channel *channel) {
-  return channel->max_message_length;
-}
diff --git a/src/core/lib/surface/channel.h b/src/core/lib/surface/channel.h
index 4c62974346..23cc8656ca 100644
--- a/src/core/lib/surface/channel.h
+++ b/src/core/lib/surface/channel.h
@@ -64,7 +64,6 @@ grpc_channel_stack *grpc_channel_get_channel_stack(grpc_channel *channel);
     The returned elem is owned by the caller. */
 grpc_mdelem *grpc_channel_get_reffed_status_elem(grpc_channel *channel,
                                                  int status_code);
-uint32_t grpc_channel_get_max_message_length(grpc_channel *channel);
 
 #ifdef GRPC_STREAM_REFCOUNT_DEBUG
 void grpc_channel_internal_ref(grpc_channel *channel, const char *reason);
diff --git a/src/core/lib/surface/init.c b/src/core/lib/surface/init.c
index edda0c85fa..64bdfc3446 100644
--- a/src/core/lib/surface/init.c
+++ b/src/core/lib/surface/init.c
@@ -45,6 +45,7 @@
 #include "src/core/lib/channel/connected_channel.h"
 #include "src/core/lib/channel/http_client_filter.h"
 #include "src/core/lib/channel/http_server_filter.h"
+#include "src/core/lib/channel/message_size_filter.h"
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/http/parser.h"
 #include "src/core/lib/iomgr/combiner.h"
@@ -99,6 +100,15 @@ static bool maybe_add_http_filter(grpc_channel_stack_builder *builder,
 
 static void register_builtin_channel_init() {
   grpc_channel_init_register_stage(
+      GRPC_CLIENT_SUBCHANNEL, GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+      prepend_filter, (void *)&grpc_message_size_filter);
+  grpc_channel_init_register_stage(
+      GRPC_CLIENT_DIRECT_CHANNEL, GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
+      prepend_filter, (void *)&grpc_message_size_filter);
+  grpc_channel_init_register_stage(
+      GRPC_SERVER_CHANNEL, GRPC_CHANNEL_INIT_BUILTIN_PRIORITY, prepend_filter,
+      (void *)&grpc_message_size_filter);
+  grpc_channel_init_register_stage(
       GRPC_CLIENT_CHANNEL, GRPC_CHANNEL_INIT_BUILTIN_PRIORITY, prepend_filter,
       (void *)&grpc_compress_filter);
   grpc_channel_init_register_stage(