Eliminate redundant places where server name was stored.

include/grpc/impl/codegen/grpc_types.h

@@ -215,8 +215,6 @@ typedef struct {
 #define GRPC_ARG_LB_POLICY_NAME "grpc.lb_policy_name"
 /** Server URI. Not intended for external use. */
 #define GRPC_ARG_SERVER_URI "grpc.server_uri"
-/** Server name. Not intended for external use. */
-#define GRPC_ARG_SERVER_NAME "grpc.server_name"
 /** Resolved addresses in a form used by the LB policy.
     Not intended for external use. */
 #define GRPC_ARG_LB_ADDRESSES "grpc.lb_addresses"

src/core/ext/client_channel/http_connect_handshaker.c

@@ -40,6 +40,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/ext/client_channel/resolver_registry.h"
 #include "src/core/ext/client_channel/uri_parser.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/http/format_request.h"
@@ -51,7 +52,6 @@ typedef struct http_connect_handshaker {
   grpc_handshaker base;
 
   char* proxy_server;
-  char* server_name;
 
   gpr_refcount refcount;
   gpr_mu mu;
@@ -86,7 +86,6 @@ static void http_connect_handshaker_unref(grpc_exec_ctx* exec_ctx,
       gpr_free(handshaker->read_buffer_to_destroy);
     }
     gpr_free(handshaker->proxy_server);
-    gpr_free(handshaker->server_name);
     grpc_slice_buffer_destroy(&handshaker->write_buffer);
     grpc_http_parser_destroy(&handshaker->http_parser);
     grpc_http_response_destroy(&handshaker->http_response);
@@ -265,18 +264,27 @@ static void http_connect_handshaker_do_handshake(
     grpc_tcp_server_acceptor* acceptor, grpc_closure* on_handshake_done,
     grpc_handshaker_args* args) {
   http_connect_handshaker* handshaker = (http_connect_handshaker*)handshaker_in;
-  gpr_mu_lock(&handshaker->mu);
+  // Get server name from channel args.
+  const grpc_arg* arg = grpc_channel_args_find(args->args, GRPC_ARG_SERVER_URI);
+  GPR_ASSERT(arg != NULL);
+  GPR_ASSERT(arg->type == GRPC_ARG_STRING);
+  char *canonical_uri =
+      grpc_resolver_factory_add_default_prefix_if_needed(arg->value.string);
+  grpc_uri* uri = grpc_uri_parse(canonical_uri, 1);
+  char* server_name = uri->path;
+  if (server_name[0] == '/') ++server_name;
   // Save state in the handshaker object.
+  gpr_mu_lock(&handshaker->mu);
   handshaker->args = args;
   handshaker->on_handshake_done = on_handshake_done;
   // Send HTTP CONNECT request.
-  gpr_log(GPR_INFO, "Connecting to server %s via HTTP proxy %s",
-          handshaker->server_name, handshaker->proxy_server);
+  gpr_log(GPR_INFO, "Connecting to server %s via HTTP proxy %s", server_name,
+          handshaker->proxy_server);
   grpc_httpcli_request request;
   memset(&request, 0, sizeof(request));
-  request.host = handshaker->proxy_server;
+  request.host = server_name;
   request.http.method = "CONNECT";
-  request.http.path = handshaker->server_name;
+  request.http.path = server_name;
   request.handshaker = &grpc_httpcli_plaintext;
   grpc_slice request_slice = grpc_httpcli_format_connect_request(&request);
   grpc_slice_buffer_add(&handshaker->write_buffer, request_slice);
@@ -285,23 +293,23 @@ static void http_connect_handshaker_do_handshake(
   grpc_endpoint_write(exec_ctx, args->endpoint, &handshaker->write_buffer,
                       &handshaker->request_done_closure);
   gpr_mu_unlock(&handshaker->mu);
+  // Clean up.
+  gpr_free(canonical_uri);
+  grpc_uri_destroy(uri);
 }
 
 static const grpc_handshaker_vtable http_connect_handshaker_vtable = {
     http_connect_handshaker_destroy, http_connect_handshaker_shutdown,
     http_connect_handshaker_do_handshake};
 
-grpc_handshaker* grpc_http_connect_handshaker_create(const char* proxy_server,
-                                                     const char* server_name) {
+grpc_handshaker* grpc_http_connect_handshaker_create(const char* proxy_server) {
   GPR_ASSERT(proxy_server != NULL);
-  GPR_ASSERT(server_name != NULL);
   http_connect_handshaker* handshaker = gpr_malloc(sizeof(*handshaker));
   memset(handshaker, 0, sizeof(*handshaker));
   grpc_handshaker_init(&http_connect_handshaker_vtable, &handshaker->base);
   gpr_mu_init(&handshaker->mu);
   gpr_ref_init(&handshaker->refcount, 1);
   handshaker->proxy_server = gpr_strdup(proxy_server);
-  handshaker->server_name = gpr_strdup(server_name);
   grpc_slice_buffer_init(&handshaker->write_buffer);
   grpc_closure_init(&handshaker->request_done_closure, on_write_done,
                     handshaker);

src/core/ext/client_channel/http_connect_handshaker.h

@@ -36,9 +36,8 @@
 
 #include "src/core/lib/channel/handshaker.h"
 
-/// Does NOT take ownership of \a proxy_server or \a server_name.
-grpc_handshaker* grpc_http_connect_handshaker_create(const char* proxy_server,
-                                                     const char* server_name);
+/// Does NOT take ownership of \a proxy_server.
+grpc_handshaker* grpc_http_connect_handshaker_create(const char* proxy_server);
 
 /// Returns the name of the proxy to use, or NULL if no proxy is configured.
 /// Caller takes ownership of result.

src/core/ext/client_channel/resolver_registry.c

@@ -109,8 +109,8 @@ static grpc_resolver_factory *lookup_factory_by_uri(grpc_uri *uri) {
 }
 
 static grpc_resolver_factory *resolve_factory(const char *target,
-                                              grpc_uri **uri) {
-  char *tmp;
+                                              grpc_uri **uri,
+                                              char **canonical_target) {
   grpc_resolver_factory *factory = NULL;
 
   GPR_ASSERT(uri != NULL);
@@ -118,15 +118,15 @@ static grpc_resolver_factory *resolve_factory(const char *target,
   factory = lookup_factory_by_uri(*uri);
   if (factory == NULL) {
     grpc_uri_destroy(*uri);
-    gpr_asprintf(&tmp, "%s%s", g_default_resolver_prefix, target);
-    *uri = grpc_uri_parse(tmp, 1);
+    gpr_asprintf(canonical_target, "%s%s", g_default_resolver_prefix, target);
+    *uri = grpc_uri_parse(*canonical_target, 1);
     factory = lookup_factory_by_uri(*uri);
     if (factory == NULL) {
       grpc_uri_destroy(grpc_uri_parse(target, 0));
-      grpc_uri_destroy(grpc_uri_parse(tmp, 0));
-      gpr_log(GPR_ERROR, "don't know how to resolve '%s' or '%s'", target, tmp);
+      grpc_uri_destroy(grpc_uri_parse(*canonical_target, 0));
+      gpr_log(GPR_ERROR, "don't know how to resolve '%s' or '%s'", target,
+              *canonical_target);
     }
-    gpr_free(tmp);
   }
   return factory;
 }
@@ -134,7 +134,9 @@ static grpc_resolver_factory *resolve_factory(const char *target,
 grpc_resolver *grpc_resolver_create(const char *target,
                                     const grpc_channel_args *args) {
   grpc_uri *uri = NULL;
-  grpc_resolver_factory *factory = resolve_factory(target, &uri);
+  char *canonical_target = NULL;
+  grpc_resolver_factory *factory =
+      resolve_factory(target, &uri, &canonical_target);
   grpc_resolver *resolver;
   grpc_resolver_args resolver_args;
   memset(&resolver_args, 0, sizeof(resolver_args));
@@ -142,13 +144,25 @@ grpc_resolver *grpc_resolver_create(const char *target,
   resolver_args.args = args;
   resolver = grpc_resolver_factory_create_resolver(factory, &resolver_args);
   grpc_uri_destroy(uri);
+  gpr_free(canonical_target);
   return resolver;
 }
 
 char *grpc_get_default_authority(const char *target) {
   grpc_uri *uri = NULL;
-  grpc_resolver_factory *factory = resolve_factory(target, &uri);
+  char *canonical_target = NULL;
+  grpc_resolver_factory *factory =
+      resolve_factory(target, &uri, &canonical_target);
   char *authority = grpc_resolver_factory_get_default_authority(factory, uri);
   grpc_uri_destroy(uri);
+  gpr_free(canonical_target);
   return authority;
 }
+
+char *grpc_resolver_factory_add_default_prefix_if_needed(const char *target) {
+  grpc_uri *uri = NULL;
+  char *canonical_target = NULL;
+  resolve_factory(target, &uri, &canonical_target);
+  grpc_uri_destroy(uri);
+  return canonical_target == NULL ? gpr_strdup(target) : canonical_target;
+}

src/core/ext/client_channel/resolver_registry.h

@@ -71,4 +71,8 @@ grpc_resolver_factory *grpc_resolver_factory_lookup(const char *name);
     representing the default authority to pass from a client. */
 char *grpc_get_default_authority(const char *target);
 
+/** Returns a newly allocated string containing \a target, adding the
+    default prefix if needed. */
+char *grpc_resolver_factory_add_default_prefix_if_needed(const char *target);
+
 #endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_RESOLVER_REGISTRY_H */

src/core/ext/client_channel/subchannel.h

@@ -164,8 +164,6 @@ struct grpc_subchannel_args {
   size_t filter_count;
   /** Channel arguments to be supplied to the newly created channel */
   const grpc_channel_args *args;
-  /** Server name */
-  const char *server_name;
   /** Address to connect to */
   grpc_resolved_address *addr;
 };

src/core/ext/client_channel/subchannel_index.c

@@ -86,7 +86,6 @@ static grpc_subchannel_key *create_key(
   } else {
     k->args.filters = NULL;
   }
-  k->args.server_name = gpr_strdup(args->server_name);
   k->args.addr = gpr_malloc(sizeof(grpc_resolved_address));
   k->args.addr->len = args->addr->len;
   if (k->args.addr->len > 0) {
@@ -113,8 +112,6 @@ static int subchannel_key_compare(grpc_subchannel_key *a,
   if (c != 0) return c;
   c = GPR_ICMP(a->args.filter_count, b->args.filter_count);
   if (c != 0) return c;
-  c = strcmp(a->args.server_name, b->args.server_name);
-  if (c != 0) return c;
   if (a->args.addr->len) {
     c = memcmp(a->args.addr->addr, b->args.addr->addr, a->args.addr->len);
     if (c != 0) return c;
@@ -132,7 +129,6 @@ 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((void *)k->args.server_name);
   gpr_free(k->args.addr);
   gpr_free(k);
 }

src/core/ext/lb_policy/grpclb/grpclb.c

@@ -743,12 +743,6 @@ static void glb_rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
 static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
                                   grpc_lb_policy_factory *factory,
                                   grpc_lb_policy_args *args) {
-  /* Get server name. */
-  const grpc_arg *arg =
-      grpc_channel_args_find(args->args, GRPC_ARG_SERVER_NAME);
-  const char *server_name =
-      arg != NULL && arg->type == GRPC_ARG_STRING ? arg->value.string : NULL;
-
   /* Count the number of gRPC-LB addresses. There must be at least one.
    * TODO(roth): For now, we ignore non-balancer addresses, but in the
    * future, we may change the behavior such that we fall back to using
@@ -756,7 +750,8 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
    * time, this should be changed to allow a list with no balancer addresses,
    * since the resolver might fail to return a balancer address even when
    * this is the right LB policy to use. */
-  arg = grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
+  const grpc_arg *arg =
+      grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
   GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER);
   grpc_lb_addresses *addresses = arg->value.pointer.p;
   size_t num_grpclb_addrs = 0;
@@ -768,13 +763,19 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
   glb_lb_policy *glb_policy = gpr_malloc(sizeof(*glb_policy));
   memset(glb_policy, 0, sizeof(*glb_policy));
 
+  /* Get server name. */
+  arg = grpc_channel_args_find(args->args, GRPC_ARG_SERVER_URI);
+  GPR_ASSERT(arg != NULL);
+  GPR_ASSERT(arg->type == GRPC_ARG_STRING);
+  grpc_uri *uri = grpc_uri_parse(arg->value.string, 1);
+  glb_policy->server_name = gpr_strdup(uri->path);
+  grpc_uri_destroy(uri);
+
   /* All input addresses in addresses come from a resolver that claims
    * they are LB services. It's the resolver's responsibility to make sure
-   * this
-   * policy is only instantiated and used in that case.
+   * this policy is only instantiated and used in that case.
    *
    * Create a client channel over them to communicate with a LB service */
-  glb_policy->server_name = gpr_strdup(server_name);
   glb_policy->cc_factory = args->client_channel_factory;
   glb_policy->args = grpc_channel_args_copy(args->args);
   GPR_ASSERT(glb_policy->cc_factory != NULL);
@@ -824,9 +825,8 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
    * channel.  (The client channel factory will re-add this arg with
    * the right value.)
    */
-  static const char *keys_to_remove[] = {GRPC_ARG_LB_POLICY_NAME,
-                                         GRPC_ARG_LB_ADDRESSES,
-                                         GRPC_ARG_SERVER_URI};
+  static const char *keys_to_remove[] = {
+      GRPC_ARG_LB_POLICY_NAME, GRPC_ARG_LB_ADDRESSES, GRPC_ARG_SERVER_URI};
   grpc_channel_args *new_args = grpc_channel_args_copy_and_remove(
       args->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove));
   glb_policy->lb_channel = grpc_client_channel_factory_create_channel(

src/core/ext/lb_policy/pick_first/pick_first.c

@@ -438,15 +438,10 @@ static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
                                          grpc_lb_policy_args *args) {
   GPR_ASSERT(args->client_channel_factory != NULL);
 
-  /* Get server name. */
-  const grpc_arg *arg =
-      grpc_channel_args_find(args->args, GRPC_ARG_SERVER_NAME);
-  const char *server_name =
-      arg != NULL && arg->type == GRPC_ARG_STRING ? arg->value.string : NULL;
-
   /* Find the number of backend addresses. We ignore balancer
    * addresses, since we don't know how to handle them. */
-  arg = grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
+  const grpc_arg *arg =
+      grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
   GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER);
   grpc_lb_addresses *addresses = arg->value.pointer.p;
   size_t num_addrs = 0;
@@ -472,9 +467,6 @@ static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
     }
 
     memset(&sc_args, 0, sizeof(grpc_subchannel_args));
-    /* server_name will be copied as part of the subchannel creation. This makes
-     * the copying of server_name (a borrowed pointer) OK. */
-    sc_args.server_name = server_name;
     sc_args.addr = &addresses->addresses[i].address;
     sc_args.args = args->args;
 

src/core/ext/lb_policy/round_robin/round_robin.c

@@ -703,15 +703,10 @@ static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
                                           grpc_lb_policy_args *args) {
   GPR_ASSERT(args->client_channel_factory != NULL);
 
-  /* Get server name. */
-  const grpc_arg *arg =
-      grpc_channel_args_find(args->args, GRPC_ARG_SERVER_NAME);
-  const char *server_name =
-      arg != NULL && arg->type == GRPC_ARG_STRING ? arg->value.string : NULL;
-
   /* Find the number of backend addresses. We ignore balancer
    * addresses, since we don't know how to handle them. */
-  arg = grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
+  const grpc_arg *arg =
+      grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
   GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER);
   grpc_lb_addresses *addresses = arg->value.pointer.p;
   size_t num_addrs = 0;
@@ -734,9 +729,6 @@ static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
     if (addresses->addresses[i].is_balancer) continue;
 
     memset(&sc_args, 0, sizeof(grpc_subchannel_args));
-    /* server_name will be copied as part of the subchannel creation. This makes
-     * the copying of server_name (a borrowed pointer) OK. */
-    sc_args.server_name = server_name;
     sc_args.addr = &addresses->addresses[i].address;
     sc_args.args = args->args;
 

src/core/ext/resolver/dns/native/dns_resolver.c

@@ -264,12 +264,7 @@ static grpc_resolver *dns_create(grpc_resolver_args *args,
   grpc_resolver_init(&r->base, &dns_resolver_vtable);
   r->name_to_resolve = proxy_name == NULL ? gpr_strdup(path) : proxy_name;
   r->default_port = gpr_strdup(default_port);
-  grpc_arg server_name_arg;
-  server_name_arg.type = GRPC_ARG_STRING;
-  server_name_arg.key = GRPC_ARG_SERVER_NAME;
-  server_name_arg.value.string = (char *)path;
-  r->channel_args =
-      grpc_channel_args_copy_and_add(args->args, &server_name_arg, 1);
+  r->channel_args = grpc_channel_args_copy(args->args);
   gpr_backoff_init(&r->backoff_state, GRPC_DNS_INITIAL_CONNECT_BACKOFF_SECONDS,
                    GRPC_DNS_RECONNECT_BACKOFF_MULTIPLIER,
                    GRPC_DNS_RECONNECT_JITTER,

src/core/ext/resolver/sockaddr/sockaddr_resolver.c

@@ -198,12 +198,7 @@ static grpc_resolver *sockaddr_create(grpc_resolver_args *args,
   sockaddr_resolver *r = gpr_malloc(sizeof(sockaddr_resolver));
   memset(r, 0, sizeof(*r));
   r->addresses = addresses;
-  grpc_arg server_name_arg;
-  server_name_arg.type = GRPC_ARG_STRING;
-  server_name_arg.key = GRPC_ARG_SERVER_NAME;
-  server_name_arg.value.string = args->uri->path;
-  r->channel_args =
-      grpc_channel_args_copy_and_add(args->args, &server_name_arg, 1);
+  r->channel_args = grpc_channel_args_copy(args->args);
   gpr_mu_init(&r->mu);
   grpc_resolver_init(&r->base, &sockaddr_resolver_vtable);
   return &r->base;

src/core/ext/transport/chttp2/client/chttp2_connector.c

@@ -58,7 +58,6 @@ typedef struct {
   bool shutdown;
   bool connecting;
 
-  char *server_name;
   grpc_chttp2_add_handshakers_func add_handshakers;
   void *add_handshakers_user_data;
 
@@ -89,7 +88,6 @@ static void chttp2_connector_unref(grpc_exec_ctx *exec_ctx,
     // If handshaking is not yet in progress, destroy the endpoint.
     // Otherwise, the handshaker will do this for us.
     if (c->endpoint != NULL) grpc_endpoint_destroy(exec_ctx, c->endpoint);
-    gpr_free(c->server_name);
     gpr_free(c);
   }
 }
@@ -155,9 +153,8 @@ static void start_handshake_locked(grpc_exec_ctx *exec_ctx,
   c->handshake_mgr = grpc_handshake_manager_create();
   char *proxy_name = grpc_get_http_proxy_server();
   if (proxy_name != NULL) {
-    grpc_handshake_manager_add(
-        c->handshake_mgr,
-        grpc_http_connect_handshaker_create(proxy_name, c->server_name));
+    grpc_handshake_manager_add(c->handshake_mgr,
+                               grpc_http_connect_handshaker_create(proxy_name));
     gpr_free(proxy_name);
   }
   if (c->add_handshakers != NULL) {
@@ -254,15 +251,13 @@ static const grpc_connector_vtable chttp2_connector_vtable = {
     chttp2_connector_connect};
 
 grpc_connector *grpc_chttp2_connector_create(
-    grpc_exec_ctx *exec_ctx, const char *server_name,
-    grpc_chttp2_add_handshakers_func add_handshakers,
+    grpc_exec_ctx *exec_ctx, grpc_chttp2_add_handshakers_func add_handshakers,
     void *add_handshakers_user_data) {
   chttp2_connector *c = gpr_malloc(sizeof(*c));
   memset(c, 0, sizeof(*c));
   c->base.vtable = &chttp2_connector_vtable;
   gpr_mu_init(&c->mu);
   gpr_ref_init(&c->refs, 1);
-  c->server_name = gpr_strdup(server_name);
   c->add_handshakers = add_handshakers;
   c->add_handshakers_user_data = add_handshakers_user_data;
   return &c->base;

src/core/ext/transport/chttp2/client/chttp2_connector.h

@@ -45,8 +45,7 @@ typedef void (*grpc_chttp2_add_handshakers_func)(
 /// If \a add_handshakers is non-NULL, it will be called with
 /// \a add_handshakers_user_data to add handshakers.
 grpc_connector* grpc_chttp2_connector_create(
-    grpc_exec_ctx* exec_ctx, const char* server_name,
-    grpc_chttp2_add_handshakers_func add_handshakers,
+    grpc_exec_ctx* exec_ctx, grpc_chttp2_add_handshakers_func add_handshakers,
     void* add_handshakers_user_data);
 
 #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_CLIENT_CHTTP2_CONNECTOR_H */

src/core/ext/transport/chttp2/client/insecure/channel_create.c

@@ -54,8 +54,7 @@ static grpc_subchannel *client_channel_factory_create_subchannel(
     grpc_exec_ctx *exec_ctx, grpc_client_channel_factory *cc_factory,
     const grpc_subchannel_args *args) {
   grpc_connector *connector = grpc_chttp2_connector_create(
-      exec_ctx, args->server_name, NULL /* add_handshakers */,
-      NULL /* user_data */);
+      exec_ctx, NULL /* add_handshakers */, NULL /* user_data */);
   grpc_subchannel *s = grpc_subchannel_create(exec_ctx, connector, args);
   grpc_connector_unref(exec_ctx, connector);
   return s;

src/core/ext/transport/chttp2/client/secure/secure_channel_create.c

@@ -79,7 +79,7 @@ static grpc_subchannel *client_channel_factory_create_subchannel(
     const grpc_subchannel_args *args) {
   client_channel_factory *f = (client_channel_factory *)cc_factory;
   grpc_connector *connector = grpc_chttp2_connector_create(
-      exec_ctx, args->server_name, add_handshakers, f->security_connector);
+      exec_ctx, add_handshakers, f->security_connector);
   grpc_subchannel *s = grpc_subchannel_create(exec_ctx, connector, args);
   grpc_connector_unref(exec_ctx, connector);
   return s;

test/core/end2end/fake_resolver.c

@@ -181,12 +181,7 @@ static grpc_resolver* fake_resolver_create(grpc_resolver_factory* factory,
   // Instantiate resolver.
   fake_resolver* r = gpr_malloc(sizeof(fake_resolver));
   memset(r, 0, sizeof(*r));
-  grpc_arg server_name_arg;
-  server_name_arg.type = GRPC_ARG_STRING;
-  server_name_arg.key = GRPC_ARG_SERVER_NAME;
-  server_name_arg.value.string = args->uri->path;
-  r->channel_args =
-      grpc_channel_args_copy_and_add(args->args, &server_name_arg, 1);
+  r->channel_args = grpc_channel_args_copy(args->args);
   r->addresses = addresses;
   gpr_mu_init(&r->mu);
   grpc_resolver_init(&r->base, &fake_resolver_vtable);