Merge pull request grpc#9318 from markdroth/subchannel_addr_channel_arg

Store subchannel address in a channel arg.

src/core/ext/client_channel/connector.h

@@ -48,9 +48,6 @@ struct grpc_connector {
 typedef struct {
   /** set of pollsets interested in this connection */
   grpc_pollset_set *interested_parties;
-  /** address to connect to */
-  const grpc_resolved_address *addr;
-  size_t addr_len;
   /** initial connect string to send */
   grpc_slice initial_connect_string;
   /** deadline for connection */

src/core/ext/client_channel/subchannel.c

@@ -38,12 +38,16 @@
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/avl.h>
+#include <grpc/support/string_util.h>
 
 #include "src/core/ext/client_channel/client_channel.h"
 #include "src/core/ext/client_channel/initial_connect_string.h"
+#include "src/core/ext/client_channel/parse_address.h"
 #include "src/core/ext/client_channel/subchannel_index.h"
+#include "src/core/ext/client_channel/uri_parser.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/connected_channel.h"
+#include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/iomgr/timer.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_internal.h"
@@ -95,8 +99,6 @@ struct grpc_subchannel {
   size_t num_filters;
   /** channel arguments */
   grpc_channel_args *args;
-  /** address to connect to */
-  grpc_resolved_address *addr;
 
   grpc_subchannel_key *key;
 
@@ -211,7 +213,6 @@ static void subchannel_destroy(grpc_exec_ctx *exec_ctx, void *arg,
   grpc_subchannel *c = arg;
   gpr_free((void *)c->filters);
   grpc_channel_args_destroy(exec_ctx, c->args);
-  gpr_free(c->addr);
   grpc_slice_unref_internal(exec_ctx, c->initial_connect_string);
   grpc_connectivity_state_destroy(exec_ctx, &c->state_tracker);
   grpc_connector_unref(exec_ctx, c->connector);
@@ -327,12 +328,17 @@ grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
   } else {
     c->filters = NULL;
   }
-  c->addr = gpr_malloc(sizeof(grpc_resolved_address));
-  if (args->addr->len)
-    memcpy(c->addr, args->addr, sizeof(grpc_resolved_address));
   c->pollset_set = grpc_pollset_set_create();
-  grpc_set_initial_connect_string(&c->addr, &c->initial_connect_string);
-  c->args = grpc_channel_args_copy(args->args);
+  grpc_resolved_address *addr = gpr_malloc(sizeof(*addr));
+  grpc_get_subchannel_address_arg(args->args, addr);
+  grpc_set_initial_connect_string(&addr, &c->initial_connect_string);
+  static const char *keys_to_remove[] = {GRPC_ARG_SUBCHANNEL_ADDRESS};
+  grpc_arg new_arg = grpc_create_subchannel_address_arg(addr);
+  gpr_free(addr);
+  c->args = grpc_channel_args_copy_and_add_and_remove(
+      args->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), &new_arg, 1);
+  gpr_free(new_arg.value.string);
+
   c->root_external_state_watcher.next = c->root_external_state_watcher.prev =
       &c->root_external_state_watcher;
   grpc_closure_init(&c->connected, subchannel_connected, c,
@@ -385,7 +391,6 @@ static void continue_connect_locked(grpc_exec_ctx *exec_ctx,
   grpc_connect_in_args args;
 
   args.interested_parties = c->pollset_set;
-  args.addr = c->addr;
   args.deadline = c->next_attempt;
   args.channel_args = c->args;
   args.initial_connect_string = c->initial_connect_string;
@@ -771,3 +776,37 @@ grpc_call_stack *grpc_subchannel_call_get_call_stack(
     grpc_subchannel_call *subchannel_call) {
   return SUBCHANNEL_CALL_TO_CALL_STACK(subchannel_call);
 }
+
+static void grpc_uri_to_sockaddr(char *uri_str, grpc_resolved_address *addr) {
+  grpc_uri *uri = grpc_uri_parse(uri_str, 0 /* suppress_errors */);
+  GPR_ASSERT(uri != NULL);
+  if (strcmp(uri->scheme, "ipv4") == 0) {
+    GPR_ASSERT(parse_ipv4(uri, addr));
+  } else if (strcmp(uri->scheme, "ipv6") == 0) {
+    GPR_ASSERT(parse_ipv6(uri, addr));
+  } else {
+    GPR_ASSERT(parse_unix(uri, addr));
+  }
+  grpc_uri_destroy(uri);
+}
+
+void grpc_get_subchannel_address_arg(const grpc_channel_args *args,
+                                     grpc_resolved_address *addr) {
+  const grpc_arg *addr_arg =
+      grpc_channel_args_find(args, GRPC_ARG_SUBCHANNEL_ADDRESS);
+  GPR_ASSERT(addr_arg != NULL);  // Should have been set by LB policy.
+  GPR_ASSERT(addr_arg->type == GRPC_ARG_STRING);
+  memset(addr, 0, sizeof(*addr));
+  if (*addr_arg->value.string != '\0') {
+    grpc_uri_to_sockaddr(addr_arg->value.string, addr);
+  }
+}
+
+grpc_arg grpc_create_subchannel_address_arg(const grpc_resolved_address *addr) {
+  grpc_arg new_arg;
+  new_arg.key = GRPC_ARG_SUBCHANNEL_ADDRESS;
+  new_arg.type = GRPC_ARG_STRING;
+  new_arg.value.string =
+      addr->len > 0 ? grpc_sockaddr_to_uri(addr) : gpr_strdup("");
+  return new_arg;
+}

src/core/ext/client_channel/subchannel.h

@@ -40,6 +40,9 @@
 #include "src/core/lib/transport/connectivity_state.h"
 #include "src/core/lib/transport/metadata.h"
 
+// Channel arg containing a grpc_resolved_address to connect to.
+#define GRPC_ARG_SUBCHANNEL_ADDRESS "grpc.subchannel_address"
+
 /** A (sub-)channel that knows how to connect to exactly one target
     address. Provides a target for load balancing. */
 typedef struct grpc_subchannel grpc_subchannel;
@@ -164,13 +167,19 @@ struct grpc_subchannel_args {
   size_t filter_count;
   /** Channel arguments to be supplied to the newly created channel */
   const grpc_channel_args *args;
-  /** Address to connect to */
-  grpc_resolved_address *addr;
 };
 
 /** create a subchannel given a connector */
 grpc_subchannel *grpc_subchannel_create(grpc_exec_ctx *exec_ctx,
                                         grpc_connector *connector,
                                         const grpc_subchannel_args *args);
 
+/// Sets \a addr from \a args.
+void grpc_get_subchannel_address_arg(const grpc_channel_args *args,
+                                     grpc_resolved_address *addr);
+
+/// Returns a new channel arg encoding the subchannel address as a string.
+/// Caller is responsible for freeing the string.
+grpc_arg grpc_create_subchannel_address_arg(const grpc_resolved_address *addr);
+
 #endif /* GRPC_CORE_EXT_CLIENT_CHANNEL_SUBCHANNEL_H */

src/core/ext/client_channel/subchannel_index.c

@@ -86,11 +86,6 @@ static grpc_subchannel_key *create_key(
   } else {
     k->args.filters = NULL;
   }
-  k->args.addr = gpr_malloc(sizeof(grpc_resolved_address));
-  k->args.addr->len = args->addr->len;
-  if (k->args.addr->len > 0) {
-    memcpy(k->args.addr, args->addr, sizeof(grpc_resolved_address));
-  }
   k->args.args = copy_channel_args(args->args);
   return k;
 }
@@ -108,14 +103,8 @@ static int subchannel_key_compare(grpc_subchannel_key *a,
                                   grpc_subchannel_key *b) {
   int c = GPR_ICMP(a->connector, b->connector);
   if (c != 0) return c;
-  c = GPR_ICMP(a->args.addr->len, b->args.addr->len);
-  if (c != 0) return c;
   c = GPR_ICMP(a->args.filter_count, b->args.filter_count);
   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;
-  }
   if (a->args.filter_count > 0) {
     c = memcmp(a->args.filters, b->args.filters,
                a->args.filter_count * sizeof(*a->args.filters));
@@ -129,7 +118,6 @@ 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(exec_ctx, (grpc_channel_args *)k->args.args);
-  gpr_free(k->args.addr);
   gpr_free(k);
 }
 

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

@@ -36,7 +36,9 @@
 #include <grpc/support/alloc.h>
 
 #include "src/core/ext/client_channel/lb_policy_registry.h"
+#include "src/core/ext/client_channel/subchannel.h"
 #include "src/core/lib/channel/channel_args.h"
+#include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
 typedef struct pending_pick {
@@ -466,11 +468,15 @@ static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
     }
 
     memset(&sc_args, 0, sizeof(grpc_subchannel_args));
-    sc_args.addr = &addresses->addresses[i].address;
-    sc_args.args = args->args;
-
+    grpc_arg addr_arg =
+        grpc_create_subchannel_address_arg(&addresses->addresses[i].address);
+    grpc_channel_args *new_args =
+        grpc_channel_args_copy_and_add(args->args, &addr_arg, 1);
+    gpr_free(addr_arg.value.string);
+    sc_args.args = new_args;
     grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel(
         exec_ctx, args->client_channel_factory, &sc_args);
+    grpc_channel_args_destroy(exec_ctx, new_args);
 
     if (subchannel != NULL) {
       p->subchannels[subchannel_idx++] = subchannel;

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

@@ -64,8 +64,10 @@
 #include <grpc/support/alloc.h>
 
 #include "src/core/ext/client_channel/lb_policy_registry.h"
+#include "src/core/ext/client_channel/subchannel.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/iomgr/sockaddr_utils.h"
 #include "src/core/lib/transport/connectivity_state.h"
 #include "src/core/lib/transport/static_metadata.h"
 
@@ -729,11 +731,15 @@ 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));
-    sc_args.addr = &addresses->addresses[i].address;
-    sc_args.args = args->args;
-
+    grpc_arg addr_arg =
+        grpc_create_subchannel_address_arg(&addresses->addresses[i].address);
+    grpc_channel_args *new_args =
+        grpc_channel_args_copy_and_add(args->args, &addr_arg, 1);
+    gpr_free(addr_arg.value.string);
+    sc_args.args = new_args;
     grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel(
         exec_ctx, args->client_channel_factory, &sc_args);
+    grpc_channel_args_destroy(exec_ctx, new_args);
 
     if (subchannel != NULL) {
       subchannel_data *sd = gpr_malloc(sizeof(*sd));

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

@@ -43,6 +43,7 @@
 
 #include "src/core/ext/client_channel/connector.h"
 #include "src/core/ext/client_channel/http_connect_handshaker.h"
+#include "src/core/ext/client_channel/subchannel.h"
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/handshaker.h"
@@ -220,6 +221,8 @@ static void chttp2_connector_connect(grpc_exec_ctx *exec_ctx,
                                      grpc_connect_out_args *result,
                                      grpc_closure *notify) {
   chttp2_connector *c = (chttp2_connector *)con;
+  grpc_resolved_address addr;
+  grpc_get_subchannel_address_arg(args->channel_args, &addr);
   gpr_mu_lock(&c->mu);
   GPR_ASSERT(c->notify == NULL);
   c->notify = notify;
@@ -231,8 +234,8 @@ static void chttp2_connector_connect(grpc_exec_ctx *exec_ctx,
   GPR_ASSERT(!c->connecting);
   c->connecting = true;
   grpc_tcp_client_connect(exec_ctx, &c->connected, &c->endpoint,
-                          args->interested_parties, args->channel_args,
-                          args->addr, args->deadline);
+                          args->interested_parties, args->channel_args, &addr,
+                          args->deadline);
   gpr_mu_unlock(&c->mu);
 }