Add locking in security handshaker.

3 files changed, 152 insertions, 133 deletions

diff --git a/src/core/lib/security/transport/security_connector.c b/src/core/lib/security/transport/security_connector.c
index ac68ab3125..cb2e8a2d9a 100644
--- a/src/core/lib/security/transport/security_connector.c
+++ b/src/core/lib/security/transport/security_connector.c
@@ -130,13 +130,15 @@ void grpc_server_security_connector_create_handshakers(
 void grpc_security_connector_check_peer(grpc_exec_ctx *exec_ctx,
                                         grpc_security_connector *sc,
                                         tsi_peer peer,
-                                        grpc_security_peer_check_cb cb,
-                                        void *user_data) {
+                                        grpc_auth_context **auth_context,
+                                        grpc_closure *on_peer_checked) {
   if (sc == NULL) {
-    cb(exec_ctx, user_data, GRPC_SECURITY_ERROR, NULL);
+    grpc_exec_ctx_sched(
+        exec_ctx, on_peer_checked,
+        GRPC_ERROR_CREATE("cannot check peer -- no security connector"), NULL);
     tsi_peer_destruct(&peer);
   } else {
-    sc->vtable->check_peer(exec_ctx, sc, peer, cb, user_data);
+    sc->vtable->check_peer(exec_ctx, sc, peer, auth_context, on_peer_checked);
   }
 }
 
@@ -242,37 +244,37 @@ static void fake_server_destroy(grpc_security_connector *sc) {
 
 static void fake_check_peer(grpc_exec_ctx *exec_ctx,
                             grpc_security_connector *sc, tsi_peer peer,
-                            grpc_security_peer_check_cb cb, void *user_data) {
+                            grpc_auth_context **auth_context,
+                            grpc_closure *on_peer_checked) {
   const char *prop_name;
-  grpc_security_status status = GRPC_SECURITY_OK;
-  grpc_auth_context *auth_context = NULL;
+  grpc_error *error = GRPC_ERROR_NONE;
+  *auth_context = NULL;
   if (peer.property_count != 1) {
-    gpr_log(GPR_ERROR, "Fake peers should only have 1 property.");
-    status = GRPC_SECURITY_ERROR;
+    error = GRPC_ERROR_CREATE("Fake peers should only have 1 property.");
     goto end;
   }
   prop_name = peer.properties[0].name;
   if (prop_name == NULL ||
       strcmp(prop_name, TSI_CERTIFICATE_TYPE_PEER_PROPERTY)) {
-    gpr_log(GPR_ERROR, "Unexpected property in fake peer: %s.",
-            prop_name == NULL ? "<EMPTY>" : prop_name);
-    status = GRPC_SECURITY_ERROR;
+    char *msg;
+    gpr_asprintf(&msg, "Unexpected property in fake peer: %s.",
+                 prop_name == NULL ? "<EMPTY>" : prop_name);
+    error = GRPC_ERROR_CREATE(msg);
+    gpr_free(msg);
     goto end;
   }
   if (strncmp(peer.properties[0].value.data, TSI_FAKE_CERTIFICATE_TYPE,
               peer.properties[0].value.length)) {
-    gpr_log(GPR_ERROR, "Invalid value for cert type property.");
-    status = GRPC_SECURITY_ERROR;
+    error = GRPC_ERROR_CREATE("Invalid value for cert type property.");
     goto end;
   }
-  auth_context = grpc_auth_context_create(NULL);
+  *auth_context = grpc_auth_context_create(NULL);
   grpc_auth_context_add_cstring_property(
-      auth_context, GRPC_TRANSPORT_SECURITY_TYPE_PROPERTY_NAME,
+      *auth_context, GRPC_TRANSPORT_SECURITY_TYPE_PROPERTY_NAME,
       GRPC_FAKE_TRANSPORT_SECURITY_TYPE);
 
 end:
-  cb(exec_ctx, user_data, status, auth_context);
-  grpc_auth_context_unref(auth_context);
+  grpc_exec_ctx_sched(exec_ctx, on_peer_checked, error, NULL);
   tsi_peer_destruct(&peer);
 }
 
@@ -466,57 +468,53 @@ grpc_auth_context *tsi_ssl_peer_to_auth_context(const tsi_peer *peer) {
   return ctx;
 }
 
-static grpc_security_status ssl_check_peer(grpc_security_connector *sc,
-                                           const char *peer_name,
-                                           const tsi_peer *peer,
-                                           grpc_auth_context **auth_context) {
+static grpc_error *ssl_check_peer(grpc_security_connector *sc,
+                                  const char *peer_name, const tsi_peer *peer,
+                                  grpc_auth_context **auth_context) {
   /* Check the ALPN. */
   const tsi_peer_property *p =
       tsi_peer_get_property_by_name(peer, TSI_SSL_ALPN_SELECTED_PROTOCOL);
   if (p == NULL) {
-    gpr_log(GPR_ERROR, "Missing selected ALPN property.");
-    return GRPC_SECURITY_ERROR;
+    return GRPC_ERROR_CREATE("Cannot check peer: "
+                             "missing selected ALPN property.");
   }
   if (!grpc_chttp2_is_alpn_version_supported(p->value.data, p->value.length)) {
-    gpr_log(GPR_ERROR, "Invalid ALPN value.");
-    return GRPC_SECURITY_ERROR;
+    return GRPC_ERROR_CREATE("Cannot check peer: invalid ALPN value.");
   }
 
   /* Check the peer name if specified. */
   if (peer_name != NULL && !ssl_host_matches_name(peer, peer_name)) {
-    gpr_log(GPR_ERROR, "Peer name %s is not in peer certificate", peer_name);
-    return GRPC_SECURITY_ERROR;
+    char *msg;
+    gpr_asprintf(&msg, "Peer name %s is not in peer certificate", peer_name);
+    grpc_error *error = GRPC_ERROR_CREATE(msg);
+    gpr_free(msg);
+    return error;
   }
   *auth_context = tsi_ssl_peer_to_auth_context(peer);
-  return GRPC_SECURITY_OK;
+  return GRPC_ERROR_NONE;
 }
 
 static void ssl_channel_check_peer(grpc_exec_ctx *exec_ctx,
                                    grpc_security_connector *sc, tsi_peer peer,
-                                   grpc_security_peer_check_cb cb,
-                                   void *user_data) {
+                                   grpc_auth_context **auth_context,
+                                   grpc_closure *on_peer_checked) {
   grpc_ssl_channel_security_connector *c =
       (grpc_ssl_channel_security_connector *)sc;
-  grpc_security_status status;
-  grpc_auth_context *auth_context = NULL;
-  status = ssl_check_peer(sc, c->overridden_target_name != NULL
-                                  ? c->overridden_target_name
-                                  : c->target_name,
-                          &peer, &auth_context);
-  cb(exec_ctx, user_data, status, auth_context);
-  grpc_auth_context_unref(auth_context);
+  grpc_error *error = ssl_check_peer(sc, c->overridden_target_name != NULL
+                                             ? c->overridden_target_name
+                                             : c->target_name,
+                                     &peer, auth_context);
+  grpc_exec_ctx_sched(exec_ctx, on_peer_checked, error, NULL);
   tsi_peer_destruct(&peer);
 }
 
 static void ssl_server_check_peer(grpc_exec_ctx *exec_ctx,
                                   grpc_security_connector *sc, tsi_peer peer,
-                                  grpc_security_peer_check_cb cb,
-                                  void *user_data) {
-  grpc_auth_context *auth_context = NULL;
-  grpc_security_status status = ssl_check_peer(sc, NULL, &peer, &auth_context);
+                                  grpc_auth_context **auth_context,
+                                  grpc_closure *on_peer_checked) {
+  grpc_error *error = ssl_check_peer(sc, NULL, &peer, auth_context);
   tsi_peer_destruct(&peer);
-  cb(exec_ctx, user_data, status, auth_context);
-  grpc_auth_context_unref(auth_context);
+  grpc_exec_ctx_sched(exec_ctx, on_peer_checked, error, NULL);
 }
 
 static void add_shallow_auth_property_to_peer(tsi_peer *peer,
diff --git a/src/core/lib/security/transport/security_connector.h b/src/core/lib/security/transport/security_connector.h
index 2dffb5c24a..0e4e0aa720 100644
--- a/src/core/lib/security/transport/security_connector.h
+++ b/src/core/lib/security/transport/security_connector.h
@@ -59,21 +59,11 @@ typedef struct grpc_security_connector grpc_security_connector;
 
 #define GRPC_SECURITY_CONNECTOR_ARG "grpc.security_connector"
 
-typedef void (*grpc_security_peer_check_cb)(grpc_exec_ctx *exec_ctx,
-                                            void *user_data,
-                                            grpc_security_status status,
-                                            grpc_auth_context *auth_context);
-
-/* Ownership of the secure_endpoint is transfered. */
-typedef void (*grpc_security_handshake_done_cb)(
-    grpc_exec_ctx *exec_ctx, void *user_data, grpc_security_status status,
-    grpc_endpoint *secure_endpoint, grpc_auth_context *auth_context);
-
 typedef struct {
   void (*destroy)(grpc_security_connector *sc);
   void (*check_peer)(grpc_exec_ctx *exec_ctx, grpc_security_connector *sc,
-                     tsi_peer peer, grpc_security_peer_check_cb cb,
-                     void *user_data);
+                     tsi_peer peer, grpc_auth_context **auth_context,
+                     grpc_closure *on_peer_checked);
 } grpc_security_connector_vtable;
 
 typedef struct grpc_security_connector_handshake_list {
@@ -108,12 +98,12 @@ void grpc_security_connector_unref(grpc_security_connector *policy);
 #endif
 
 /* Check the peer. Callee takes ownership of the peer object.
-   The callback will include the resulting auth_context. */
+   Sets *auth_context and invokes on_peer_checked when done. */
 void grpc_security_connector_check_peer(grpc_exec_ctx *exec_ctx,
                                         grpc_security_connector *sc,
                                         tsi_peer peer,
-                                        grpc_security_peer_check_cb cb,
-                                        void *user_data);
+                                        grpc_auth_context **auth_context,
+                                        grpc_closure *on_peer_checked);
 
 /* Util to encapsulate the connector in a channel arg. */
 grpc_arg grpc_security_connector_to_arg(grpc_security_connector *sc);
diff --git a/src/core/lib/security/transport/security_handshaker.c b/src/core/lib/security/transport/security_handshaker.c
index 4b04f58bfd..1f9a4dae4a 100644
--- a/src/core/lib/security/transport/security_handshaker.c
+++ b/src/core/lib/security/transport/security_handshaker.c
@@ -56,7 +56,8 @@ typedef struct {
   grpc_closure* on_handshake_done;
   grpc_security_connector *connector;
   tsi_handshaker *handshaker;
-// FIXME: add locking
+  gpr_mu mu;
+  gpr_refcount refs;
   unsigned char *handshake_buffer;
   size_t handshake_buffer_size;
 // FIXME: use args->endpoint instead
@@ -66,8 +67,8 @@ typedef struct {
   grpc_slice_buffer outgoing;
   grpc_closure on_handshake_data_sent_to_peer;
   grpc_closure on_handshake_data_received_from_peer;
+  grpc_closure on_peer_checked;
   grpc_auth_context *auth_context;
-  gpr_refcount refs;
 } security_handshaker;
 
 static void on_handshake_data_received_from_peer(grpc_exec_ctx *exec_ctx,
@@ -80,6 +81,7 @@ static void on_handshake_data_sent_to_peer(grpc_exec_ctx *exec_ctx, void *setup,
 static void unref_handshake(security_handshaker *h) {
   if (gpr_unref(&h->refs)) {
     if (h->handshaker != NULL) tsi_handshaker_destroy(h->handshaker);
+    gpr_mu_destroy(&h->mu);
     if (h->handshake_buffer != NULL) gpr_free(h->handshake_buffer);
     grpc_slice_buffer_destroy(&h->left_overs);
     grpc_slice_buffer_destroy(&h->outgoing);
@@ -89,9 +91,9 @@ static void unref_handshake(security_handshaker *h) {
   }
 }
 
-static void security_handshake_done(grpc_exec_ctx *exec_ctx,
-                                    security_handshaker *h,
-                                    grpc_error *error) {
+static void security_handshake_done_locked(grpc_exec_ctx *exec_ctx,
+                                           security_handshaker *h,
+                                           grpc_error *error) {
   if (error == GRPC_ERROR_NONE) {
     h->args->endpoint = h->secure_endpoint;
     grpc_arg auth_context_arg = grpc_auth_context_to_arg(h->auth_context);
@@ -116,60 +118,55 @@ static void security_handshake_done(grpc_exec_ctx *exec_ctx,
   grpc_slice_buffer_reset_and_unref(h->args->read_buffer);
   h->args = NULL;
   grpc_exec_ctx_sched(exec_ctx, h->on_handshake_done, error, NULL);
-  unref_handshake(h);
 }
 
-static void on_peer_checked(grpc_exec_ctx *exec_ctx, void *user_data,
-                            grpc_security_status status,
-                            grpc_auth_context *auth_context) {
-  security_handshaker *h = user_data;
-  tsi_frame_protector *protector;
-  tsi_result result;
-  if (status != GRPC_SECURITY_OK) {
-    security_handshake_done(
-        exec_ctx, h,
-        grpc_error_set_int(GRPC_ERROR_CREATE("Error checking peer."),
-                           GRPC_ERROR_INT_SECURITY_STATUS, status));
-    return;
+static void on_peer_checked(grpc_exec_ctx *exec_ctx, void *arg,
+                            grpc_error *error) {
+  security_handshaker *h = arg;
+  gpr_mu_lock(&h->mu);
+  if (error != GRPC_ERROR_NONE) {
+    // Take a new ref to pass to security_handshake_done_locked().
+    GRPC_ERROR_REF(error);
+    goto done;
   }
-  h->auth_context = GRPC_AUTH_CONTEXT_REF(auth_context, "handshake");
-  result =
+  // Get frame protector.
+  tsi_frame_protector *protector;
+  tsi_result result =
       tsi_handshaker_create_frame_protector(h->handshaker, NULL, &protector);
   if (result != TSI_OK) {
-    security_handshake_done(
-        exec_ctx, h,
-        grpc_set_tsi_error_result(
-            GRPC_ERROR_CREATE("Frame protector creation failed"), result));
-    return;
+    error = grpc_set_tsi_error_result(
+        GRPC_ERROR_CREATE("Frame protector creation failed"), result);
+    goto done;
   }
   h->secure_endpoint =
       grpc_secure_endpoint_create(protector, h->wrapped_endpoint,
                                   h->left_overs.slices, h->left_overs.count);
   h->left_overs.count = 0;
   h->left_overs.length = 0;
-  security_handshake_done(exec_ctx, h, GRPC_ERROR_NONE);
+done:
+  security_handshake_done_locked(exec_ctx, h, error);
+  gpr_mu_unlock(&h->mu);
+  unref_handshake(h);
 }
 
-static void check_peer(grpc_exec_ctx *exec_ctx, security_handshaker *h) {
+static grpc_error* check_peer_locked(grpc_exec_ctx *exec_ctx,
+                                     security_handshaker *h) {
   tsi_peer peer;
   tsi_result result = tsi_handshaker_extract_peer(h->handshaker, &peer);
-
   if (result != TSI_OK) {
-    security_handshake_done(
-        exec_ctx, h, grpc_set_tsi_error_result(
-                         GRPC_ERROR_CREATE("Peer extraction failed"), result));
-    return;
+    return grpc_set_tsi_error_result(
+        GRPC_ERROR_CREATE("Peer extraction failed"), result);
   }
   grpc_security_connector_check_peer(exec_ctx, h->connector, peer,
-                                     on_peer_checked, h);
+                                     &h->auth_context, &h->on_peer_checked);
+  return GRPC_ERROR_NONE;
 }
 
-static void send_handshake_bytes_to_peer(grpc_exec_ctx *exec_ctx,
-                                         security_handshaker *h) {
-  size_t offset = 0;
+static grpc_error* send_handshake_bytes_to_peer_locked(grpc_exec_ctx *exec_ctx,
+                                                       security_handshaker *h) {
+  // Get data to send.
   tsi_result result = TSI_OK;
-  grpc_slice to_send;
-
+  size_t offset = 0;
   do {
     size_t to_send_size = h->handshake_buffer_size - offset;
     result = tsi_handshaker_get_bytes_to_send_to_peer(
@@ -181,39 +178,37 @@ static void send_handshake_bytes_to_peer(grpc_exec_ctx *exec_ctx,
           gpr_realloc(h->handshake_buffer, h->handshake_buffer_size);
     }
   } while (result == TSI_INCOMPLETE_DATA);
-
   if (result != TSI_OK) {
-    security_handshake_done(exec_ctx, h,
-                            grpc_set_tsi_error_result(
-                                GRPC_ERROR_CREATE("Handshake failed"), result));
-    return;
+    return grpc_set_tsi_error_result(GRPC_ERROR_CREATE("Handshake failed"),
+                                     result);
   }
-
-  to_send =
+  // Send data.
+  grpc_slice to_send =
       grpc_slice_from_copied_buffer((const char *)h->handshake_buffer, offset);
   grpc_slice_buffer_reset_and_unref(&h->outgoing);
   grpc_slice_buffer_add(&h->outgoing, to_send);
   grpc_endpoint_write(exec_ctx, h->wrapped_endpoint, &h->outgoing,
                       &h->on_handshake_data_sent_to_peer);
+  return GRPC_ERROR_NONE;
 }
 
 static void on_handshake_data_received_from_peer(grpc_exec_ctx *exec_ctx,
                                                  void *handshake,
                                                  grpc_error *error) {
   security_handshaker *h = handshake;
-  size_t consumed_slice_size = 0;
-  tsi_result result = TSI_OK;
-  size_t i;
-  size_t num_left_overs;
-  int has_left_overs_in_current_slice = 0;
-
+  gpr_mu_lock(&h->mu);
   if (error != GRPC_ERROR_NONE) {
-    security_handshake_done(
+    security_handshake_done_locked(
         exec_ctx, h,
         GRPC_ERROR_CREATE_REFERENCING("Handshake read failed", &error, 1));
+    gpr_mu_unlock(&h->mu);
+    unref_handshake(h);
     return;
   }
-
+  // Process received data.
+  tsi_result result = TSI_OK;
+  size_t consumed_slice_size = 0;
+  size_t i;
   for (i = 0; i < h->args->read_buffer->count; i++) {
     consumed_slice_size = GRPC_SLICE_LENGTH(h->args->read_buffer->slices[i]);
     result = tsi_handshaker_process_bytes_from_peer(
@@ -221,31 +216,37 @@ static void on_handshake_data_received_from_peer(grpc_exec_ctx *exec_ctx,
         &consumed_slice_size);
     if (!tsi_handshaker_is_in_progress(h->handshaker)) break;
   }
-
   if (tsi_handshaker_is_in_progress(h->handshaker)) {
     /* We may need more data. */
     if (result == TSI_INCOMPLETE_DATA) {
       grpc_endpoint_read(exec_ctx, h->wrapped_endpoint, h->args->read_buffer,
                          &h->on_handshake_data_received_from_peer);
-      return;
+      goto done;
     } else {
-      send_handshake_bytes_to_peer(exec_ctx, h);
-      return;
+      error = send_handshake_bytes_to_peer_locked(exec_ctx, h);
+      if (error != GRPC_ERROR_NONE) {
+        security_handshake_done_locked(exec_ctx, h, error);
+        gpr_mu_unlock(&h->mu);
+        unref_handshake(h);
+        return;
+      }
+      goto done;
     }
   }
-
   if (result != TSI_OK) {
-    security_handshake_done(exec_ctx, h,
-                            grpc_set_tsi_error_result(
-                                GRPC_ERROR_CREATE("Handshake failed"), result));
+    security_handshake_done_locked(
+        exec_ctx, h,
+        grpc_set_tsi_error_result(GRPC_ERROR_CREATE("Handshake failed"),
+                                  result));
+    gpr_mu_unlock(&h->mu);
+    unref_handshake(h);
     return;
   }
-
   /* Handshake is done and successful this point. */
-  has_left_overs_in_current_slice =
+  bool has_left_overs_in_current_slice =
       (consumed_slice_size <
        GRPC_SLICE_LENGTH(h->args->read_buffer->slices[i]));
-  num_left_overs =
+  size_t num_left_overs =
       (has_left_overs_in_current_slice ? 1 : 0)
       + h->args->read_buffer->count - i - 1;
   if (num_left_overs > 0) {
@@ -262,31 +263,49 @@ static void on_handshake_data_received_from_peer(grpc_exec_ctx *exec_ctx,
         &h->left_overs, &h->args->read_buffer->slices[i + 1],
         num_left_overs - (size_t)has_left_overs_in_current_slice);
   }
-
-  check_peer(exec_ctx, h);
+  // Check peer.
+  error = check_peer_locked(exec_ctx, h);
+  if (error != GRPC_ERROR_NONE) {
+    security_handshake_done_locked(exec_ctx, h, error);
+    gpr_mu_unlock(&h->mu);
+    unref_handshake(h);
+    return;
+  }
+done:
+  gpr_mu_unlock(&h->mu);
 }
 
 /* If handshake is NULL, the handshake is done. */
 static void on_handshake_data_sent_to_peer(grpc_exec_ctx *exec_ctx,
                                            void *handshake, grpc_error *error) {
   security_handshaker *h = handshake;
-
   /* Make sure that write is OK. */
   if (error != GRPC_ERROR_NONE) {
-    if (handshake != NULL)
-      security_handshake_done(
+    if (handshake != NULL) {
+      gpr_mu_lock(&h->mu);
+      security_handshake_done_locked(
           exec_ctx, h,
           GRPC_ERROR_CREATE_REFERENCING("Handshake write failed", &error, 1));
+      gpr_mu_unlock(&h->mu);
+      unref_handshake(h);
+    }
     return;
   }
-
   /* We may be done. */
+  gpr_mu_lock(&h->mu);
   if (tsi_handshaker_is_in_progress(h->handshaker)) {
     grpc_endpoint_read(exec_ctx, h->wrapped_endpoint, h->args->read_buffer,
                        &h->on_handshake_data_received_from_peer);
   } else {
-    check_peer(exec_ctx, h);
+    error = check_peer_locked(exec_ctx, h);
+    if (error != GRPC_ERROR_NONE) {
+      security_handshake_done_locked(exec_ctx, h, error);
+      gpr_mu_unlock(&h->mu);
+      unref_handshake(h);
+      return;
+    }
   }
+  gpr_mu_unlock(&h->mu);
 }
 
 //
@@ -302,9 +321,11 @@ static void security_handshaker_destroy(grpc_exec_ctx* exec_ctx,
 static void security_handshaker_shutdown(grpc_exec_ctx* exec_ctx,
                                              grpc_handshaker* handshaker) {
   security_handshaker *h = (security_handshaker*)handshaker;
+  gpr_mu_lock(&h->mu);
   if (h->args != NULL) {
     grpc_endpoint_shutdown(exec_ctx, h->wrapped_endpoint);
   }
+  gpr_mu_unlock(&h->mu);
 }
 
 static void security_handshaker_do_handshake(
@@ -312,11 +333,19 @@ static void security_handshaker_do_handshake(
     grpc_tcp_server_acceptor* acceptor, grpc_closure* on_handshake_done,
     grpc_handshaker_args* args) {
   security_handshaker* h = (security_handshaker*)handshaker;
+  gpr_mu_lock(&h->mu);
   h->args = args;
   h->on_handshake_done = on_handshake_done;
   h->wrapped_endpoint = args->endpoint;  // FIXME: remove?
   gpr_ref(&h->refs);
-  send_handshake_bytes_to_peer(exec_ctx, h);
+  grpc_error* error = send_handshake_bytes_to_peer_locked(exec_ctx, h);
+  if (error != GRPC_ERROR_NONE) {
+    security_handshake_done_locked(exec_ctx, h, error);
+    gpr_mu_unlock(&h->mu);
+    unref_handshake(h);
+    return;
+  }
+  gpr_mu_unlock(&h->mu);
 }
 
 static const grpc_handshaker_vtable security_handshaker_vtable = {
@@ -331,13 +360,15 @@ static grpc_handshaker* security_handshaker_create(
   grpc_handshaker_init(&security_handshaker_vtable, &h->base);
   h->handshaker = handshaker;
   h->connector = GRPC_SECURITY_CONNECTOR_REF(connector, "handshake");
+  gpr_mu_init(&h->mu);
+  gpr_ref_init(&h->refs, 1);
   h->handshake_buffer_size = GRPC_INITIAL_HANDSHAKE_BUFFER_SIZE;
   h->handshake_buffer = gpr_malloc(h->handshake_buffer_size);
-  gpr_ref_init(&h->refs, 1);
   grpc_closure_init(&h->on_handshake_data_sent_to_peer,
                     on_handshake_data_sent_to_peer, h);
   grpc_closure_init(&h->on_handshake_data_received_from_peer,
                     on_handshake_data_received_from_peer, h);
+  grpc_closure_init(&h->on_peer_checked, on_peer_checked, h);
   grpc_slice_buffer_init(&h->left_overs);
   grpc_slice_buffer_init(&h->outgoing);
   return &h->base;