1 files changed, 67 insertions, 82 deletions

diff --git a/src/core/ext/lb_policy/grpclb/grpclb.c b/src/core/ext/lb_policy/grpclb/grpclb.c
index c6dfba0808..36db8ab00d 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/lb_policy/grpclb/grpclb.c
@@ -107,6 +107,7 @@
 #include <grpc/support/string_util.h>
 
 #include "src/core/ext/client_config/client_channel_factory.h"
+#include "src/core/ext/client_config/lb_policy_factory.h"
 #include "src/core/ext/client_config/lb_policy_registry.h"
 #include "src/core/ext/client_config/parse_address.h"
 #include "src/core/ext/lb_policy/grpclb/grpclb.h"
@@ -120,18 +121,6 @@
 
 int grpc_lb_glb_trace = 0;
 
-static void lb_addrs_destroy(grpc_lb_address *lb_addresses,
-                             size_t num_addresses) {
-  /* free "resolved" addresses memblock */
-  gpr_free(lb_addresses->resolved_address);
-  for (size_t i = 0; i < num_addresses; ++i) {
-    if (lb_addresses[i].user_data != NULL) {
-      GRPC_MDELEM_UNREF(lb_addresses[i].user_data);
-    }
-  }
-  gpr_free(lb_addresses);
-}
-
 /* add lb_token of selected subchannel (address) to the call's initial
  * metadata */
 static void initial_metadata_add_lb_token(
@@ -311,11 +300,8 @@ typedef struct glb_lb_policy {
    * response has arrived. */
   grpc_grpclb_serverlist *serverlist;
 
-  /** total number of valid addresses received in \a serverlist */
-  size_t num_ok_serverlist_addresses;
-
-  /** LB addresses from \a serverlist, \a num_ok_serverlist_addresses of them */
-  grpc_lb_address *lb_addresses;
+  /** addresses from \a serverlist */
+  grpc_lb_addresses *addresses;
 
   /** list of picks that are waiting on RR's policy connectivity */
   pending_pick *pending_picks;
@@ -368,26 +354,18 @@ static bool is_server_valid(const grpc_grpclb_server *server, size_t idx,
   return true;
 }
 
-/* populate \a addresses according to \a serverlist. Returns the number of
- * addresses successfully parsed and added to \a addresses */
-static size_t process_serverlist(const grpc_grpclb_serverlist *serverlist,
-                                 grpc_lb_address **lb_addresses) {
+/* Returns addresses extracted from \a serverlist. */
+static grpc_lb_addresses *process_serverlist(
+    const grpc_grpclb_serverlist *serverlist) {
   size_t num_valid = 0;
   /* first pass: count how many are valid in order to allocate the necessary
    * memory in a single block */
   for (size_t i = 0; i < serverlist->num_servers; ++i) {
     if (is_server_valid(serverlist->servers[i], i, true)) ++num_valid;
   }
-  if (num_valid == 0) {
-    return 0;
-  }
+  if (num_valid == 0) return NULL;
 
-  /* allocate the memory block for the "resolved" addresses. */
-  grpc_resolved_address *r_addrs_memblock =
-      gpr_malloc(sizeof(grpc_resolved_address) * num_valid);
-  memset(r_addrs_memblock, 0, sizeof(grpc_resolved_address) * num_valid);
-  grpc_lb_address *lb_addrs = gpr_malloc(sizeof(grpc_lb_address) * num_valid);
-  memset(lb_addrs, 0, sizeof(grpc_lb_address) * num_valid);
+  grpc_lb_addresses *lb_addresses = grpc_lb_addresses_create(num_valid);
 
   /* second pass: actually populate the addresses and LB tokens (aka user data
    * to the outside world) to be read by the RR policy during its creation.
@@ -399,56 +377,58 @@ static size_t process_serverlist(const grpc_grpclb_serverlist *serverlist,
     GPR_ASSERT(addr_idx < num_valid);
     const grpc_grpclb_server *server = serverlist->servers[sl_idx];
     if (!is_server_valid(serverlist->servers[sl_idx], sl_idx, false)) continue;
-    grpc_lb_address *const lb_addr = &lb_addrs[addr_idx];
 
     /* address processing */
     const uint16_t netorder_port = htons((uint16_t)server->port);
     /* the addresses are given in binary format (a in(6)_addr struct) in
      * server->ip_address.bytes. */
     const grpc_grpclb_ip_address *ip = &server->ip_address;
-
-    lb_addr->resolved_address = &r_addrs_memblock[addr_idx];
-    struct sockaddr_storage *sa =
-        (struct sockaddr_storage *)lb_addr->resolved_address->addr;
-    size_t *sa_len = &lb_addr->resolved_address->len;
-    *sa_len = 0;
+    grpc_resolved_address addr;
+    memset(&addr, 0, sizeof(addr));
     if (ip->size == 4) {
-      struct sockaddr_in *addr4 = (struct sockaddr_in *)sa;
-      *sa_len = sizeof(struct sockaddr_in);
-      memset(addr4, 0, *sa_len);
+      addr.len = sizeof(struct sockaddr_in);
+      struct sockaddr_in *addr4 = (struct sockaddr_in *)&addr.addr;
       addr4->sin_family = AF_INET;
       memcpy(&addr4->sin_addr, ip->bytes, ip->size);
       addr4->sin_port = netorder_port;
     } else if (ip->size == 16) {
-      struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)sa;
-      *sa_len = sizeof(struct sockaddr_in6);
-      memset(addr6, 0, *sa_len);
+      addr.len = sizeof(struct sockaddr_in6);
+      struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&addr.addr;
       addr6->sin6_family = AF_INET;
       memcpy(&addr6->sin6_addr, ip->bytes, ip->size);
       addr6->sin6_port = netorder_port;
     }
-    GPR_ASSERT(*sa_len > 0);
 
     /* lb token processing */
+    void *user_data;
     if (server->has_load_balance_token) {
       const size_t lb_token_size =
           GPR_ARRAY_SIZE(server->load_balance_token) - 1;
       grpc_mdstr *lb_token_mdstr = grpc_mdstr_from_buffer(
           (uint8_t *)server->load_balance_token, lb_token_size);
-      lb_addr->user_data = grpc_mdelem_from_metadata_strings(
+      user_data = grpc_mdelem_from_metadata_strings(
           GRPC_MDSTR_LOAD_REPORTING_INITIAL, lb_token_mdstr);
     } else {
       gpr_log(GPR_ERROR,
               "Missing LB token for backend address '%s'. The empty token will "
               "be used instead",
-              grpc_sockaddr_to_uri((struct sockaddr *)sa));
-      lb_addr->user_data = GRPC_MDELEM_LOAD_REPORTING_INITIAL_EMPTY;
+              grpc_sockaddr_to_uri((struct sockaddr *)&addr.addr));
+      user_data = GRPC_MDELEM_LOAD_REPORTING_INITIAL_EMPTY;
     }
+
+    grpc_lb_addresses_set_address(lb_addresses, addr_idx, &addr.addr, addr.len,
+                                  false /* is_balancer */,
+                                  NULL /* balancer_name */, user_data);
     ++addr_idx;
   }
   GPR_ASSERT(addr_idx == num_valid);
-  *lb_addresses = lb_addrs;
-  return num_valid;
+
+  return lb_addresses;
+}
+
+/* A plugin for grpc_lb_addresses_destroy that unrefs the LB token metadata. */
+static void lb_token_destroy(void *token) {
+  if (token != NULL) GRPC_MDELEM_UNREF(token);
 }
 
 static grpc_lb_policy *create_rr(grpc_exec_ctx *exec_ctx,
@@ -459,19 +439,15 @@ static grpc_lb_policy *create_rr(grpc_exec_ctx *exec_ctx,
   grpc_lb_policy_args args;
   memset(&args, 0, sizeof(args));
   args.client_channel_factory = glb_policy->cc_factory;
-  const size_t num_ok_addresses =
-      process_serverlist(serverlist, &args.addresses);
-  args.num_addresses = num_ok_addresses;
+  args.addresses = process_serverlist(serverlist);
 
   grpc_lb_policy *rr = grpc_lb_policy_create(exec_ctx, "round_robin", &args);
 
-  if (glb_policy->lb_addresses != NULL) {
+  if (glb_policy->addresses != NULL) {
     /* dispose of the previous version */
-    lb_addrs_destroy(glb_policy->lb_addresses,
-                     glb_policy->num_ok_serverlist_addresses);
+    grpc_lb_addresses_destroy(glb_policy->addresses, lb_token_destroy);
   }
-  glb_policy->num_ok_serverlist_addresses = num_ok_addresses;
-  glb_policy->lb_addresses = args.addresses;
+  glb_policy->addresses = args.addresses;
 
   return rr;
 }
@@ -565,6 +541,19 @@ 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) {
+  /* 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
+   * the non-balancer addresses if we cannot reach any balancers. At that
+   * 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. */
+  size_t num_grpclb_addrs = 0;
+  for (size_t i = 0; i < args->addresses->num_addresses; ++i) {
+    if (args->addresses->addresses[i].is_balancer) ++num_grpclb_addrs;
+  }
+  if (num_grpclb_addrs == 0) return NULL;
+
   glb_lb_policy *glb_policy = gpr_malloc(sizeof(*glb_policy));
   memset(glb_policy, 0, sizeof(*glb_policy));
 
@@ -576,36 +565,34 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
    * Create a client channel over them to communicate with a LB service */
   glb_policy->cc_factory = args->client_channel_factory;
   GPR_ASSERT(glb_policy->cc_factory != NULL);
-  if (args->num_addresses == 0) {
-    return NULL;
-  }
-
-  if (args->addresses[0].user_data != NULL) {
-    gpr_log(GPR_ERROR,
-            "This LB policy doesn't support user data. It will be ignored");
-  }
 
   /* construct a target from the addresses in args, given in the form
    * ipvX://ip1:port1,ip2:port2,...
    * TODO(dgq): support mixed ip version */
-  char **addr_strs = gpr_malloc(sizeof(char *) * args->num_addresses);
-  addr_strs[0] = grpc_sockaddr_to_uri(
-      (const struct sockaddr *)&args->addresses[0].resolved_address->addr);
-  for (size_t i = 1; i < args->num_addresses; i++) {
-    if (args->addresses[i].user_data != NULL) {
+  char **addr_strs = gpr_malloc(sizeof(char *) * num_grpclb_addrs);
+  size_t addr_index = 0;
+  for (size_t i = 0; i < args->addresses->num_addresses; i++) {
+    if (args->addresses->addresses[i].user_data != NULL) {
       gpr_log(GPR_ERROR,
               "This LB policy doesn't support user data. It will be ignored");
     }
-
-    GPR_ASSERT(
-        grpc_sockaddr_to_string(
-            &addr_strs[i],
-            (const struct sockaddr *)&args->addresses[i].resolved_address->addr,
-            true) == 0);
+    if (args->addresses->addresses[i].is_balancer) {
+      if (addr_index == 0) {
+        addr_strs[addr_index++] = grpc_sockaddr_to_uri(
+            (const struct sockaddr *)&args->addresses->addresses[i]
+                .address.addr);
+      } else {
+        GPR_ASSERT(grpc_sockaddr_to_string(
+                       &addr_strs[addr_index++],
+                       (const struct sockaddr *)&args->addresses->addresses[i]
+                           .address.addr,
+                       true) == 0);
+      }
+    }
   }
   size_t uri_path_len;
-  char *target_uri_str = gpr_strjoin_sep(
-      (const char **)addr_strs, args->num_addresses, ",", &uri_path_len);
+  char *target_uri_str = gpr_strjoin_sep((const char **)addr_strs,
+                                         num_grpclb_addrs, ",", &uri_path_len);
 
   /* will pick using pick_first */
   glb_policy->lb_channel = grpc_client_channel_factory_create_channel(
@@ -613,7 +600,7 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
       GRPC_CLIENT_CHANNEL_TYPE_LOAD_BALANCING, NULL);
 
   gpr_free(target_uri_str);
-  for (size_t i = 0; i < args->num_addresses; i++) {
+  for (size_t i = 0; i < num_grpclb_addrs; i++) {
     gpr_free(addr_strs[i]);
   }
   gpr_free(addr_strs);
@@ -649,9 +636,7 @@ static void glb_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
     grpc_grpclb_destroy_serverlist(glb_policy->serverlist);
   }
   gpr_mu_destroy(&glb_policy->mu);
-
-  lb_addrs_destroy(glb_policy->lb_addresses,
-                   glb_policy->num_ok_serverlist_addresses);
+  grpc_lb_addresses_destroy(glb_policy->addresses, lb_token_destroy);
   gpr_free(glb_policy);
 }