Initial checkin of gRPC to third_party/

third_party/grpc/src/core/channel/http_server_filter.c

Index: third_party/grpc/src/core/channel/http_server_filter.c
diff --git a/third_party/grpc/src/core/channel/http_server_filter.c b/third_party/grpc/src/core/channel/http_server_filter.c
new file mode 100644
index 0000000000000000000000000000000000000000..370f8dbe423d3a6b4f09a18198369f0f4f930cbf
--- /dev/null
+++ b/third_party/grpc/src/core/channel/http_server_filter.c
@@ -0,0 +1,233 @@
+/*
+ *
+ * Copyright 2015-2016, 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/channel/http_server_filter.h"
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <string.h>
+#include "src/core/profiling/timers.h"
+#include "src/core/transport/static_metadata.h"
+
+typedef struct call_data {
+  uint8_t seen_path;
+  uint8_t seen_post;
+  uint8_t sent_status;
+  uint8_t seen_scheme;
+  uint8_t seen_te_trailers;
+  uint8_t seen_authority;
+  grpc_linked_mdelem status;
+  grpc_linked_mdelem content_type;
+
+  grpc_metadata_batch *recv_initial_metadata;
+  /** Closure to call when finished with the hs_on_recv hook */
+  grpc_closure *on_done_recv;
+  /** Receive closures are chained: we inject this closure as the on_done_recv
+      up-call on transport_op, and remember to call our on_done_recv member
+      after handling it. */
+  grpc_closure hs_on_recv;
+} call_data;
+
+typedef struct channel_data { uint8_t unused; } channel_data;
+
+typedef struct {
+  grpc_call_element *elem;
+  grpc_exec_ctx *exec_ctx;
+} server_filter_args;
+
+static grpc_mdelem *server_filter(void *user_data, grpc_mdelem *md) {
+  server_filter_args *a = user_data;
+  grpc_call_element *elem = a->elem;
+  call_data *calld = elem->call_data;
+
+  /* Check if it is one of the headers we care about. */
+  if (md == GRPC_MDELEM_TE_TRAILERS || md == GRPC_MDELEM_METHOD_POST ||
+      md == GRPC_MDELEM_SCHEME_HTTP || md == GRPC_MDELEM_SCHEME_HTTPS ||
+      md == GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC) {
+    /* swallow it */
+    if (md == GRPC_MDELEM_METHOD_POST) {
+      calld->seen_post = 1;
+    } else if (md->key == GRPC_MDSTR_SCHEME) {
+      calld->seen_scheme = 1;
+    } else if (md == GRPC_MDELEM_TE_TRAILERS) {
+      calld->seen_te_trailers = 1;
+    }
+    /* TODO(klempner): Track that we've seen all the headers we should
+       require */
+    return NULL;
+  } else if (md->key == GRPC_MDSTR_CONTENT_TYPE) {
+    if (strncmp(grpc_mdstr_as_c_string(md->value), "application/grpc+", 17) ==
+        0) {
+      /* Although the C implementation doesn't (currently) generate them,
+         any custom +-suffix is explicitly valid. */
+      /* TODO(klempner): We should consider preallocating common values such
+         as +proto or +json, or at least stashing them if we see them. */
+      /* TODO(klempner): Should we be surfacing this to application code? */
+    } else {
+      /* TODO(klempner): We're currently allowing this, but we shouldn't
+         see it without a proxy so log for now. */
+      gpr_log(GPR_INFO, "Unexpected content-type %s",
+              grpc_mdstr_as_c_string(md->value));
+    }
+    return NULL;
+  } else if (md->key == GRPC_MDSTR_TE || md->key == GRPC_MDSTR_METHOD ||
+             md->key == GRPC_MDSTR_SCHEME) {
+    gpr_log(GPR_ERROR, "Invalid %s: header: '%s'",
+            grpc_mdstr_as_c_string(md->key), grpc_mdstr_as_c_string(md->value));
+    /* swallow it and error everything out. */
+    /* TODO(klempner): We ought to generate more descriptive error messages
+       on the wire here. */
+    grpc_call_element_send_cancel(a->exec_ctx, elem);
+    return NULL;
+  } else if (md->key == GRPC_MDSTR_PATH) {
+    if (calld->seen_path) {
+      gpr_log(GPR_ERROR, "Received :path twice");
+      return NULL;
+    }
+    calld->seen_path = 1;
+    return md;
+  } else if (md->key == GRPC_MDSTR_AUTHORITY) {
+    calld->seen_authority = 1;
+    return md;
+  } else if (md->key == GRPC_MDSTR_HOST) {
+    /* translate host to :authority since :authority may be
+       omitted */
+    grpc_mdelem *authority = grpc_mdelem_from_metadata_strings(
+        GRPC_MDSTR_AUTHORITY, GRPC_MDSTR_REF(md->value));
+    calld->seen_authority = 1;
+    return authority;
+  } else {
+    return md;
+  }
+}
+
+static void hs_on_recv(grpc_exec_ctx *exec_ctx, void *user_data, bool success) {
+  grpc_call_element *elem = user_data;
+  call_data *calld = elem->call_data;
+  if (success) {
+    server_filter_args a;
+    a.elem = elem;
+    a.exec_ctx = exec_ctx;
+    grpc_metadata_batch_filter(calld->recv_initial_metadata, server_filter, &a);
+    /* Have we seen the required http2 transport headers?
+       (:method, :scheme, content-type, with :path and :authority covered
+       at the channel level right now) */
+    if (calld->seen_post && calld->seen_scheme && calld->seen_te_trailers &&
+        calld->seen_path && calld->seen_authority) {
+      /* do nothing */
+    } else {
+      if (!calld->seen_path) {
+        gpr_log(GPR_ERROR, "Missing :path header");
+      }
+      if (!calld->seen_authority) {
+        gpr_log(GPR_ERROR, "Missing :authority header");
+      }
+      if (!calld->seen_post) {
+        gpr_log(GPR_ERROR, "Missing :method header");
+      }
+      if (!calld->seen_scheme) {
+        gpr_log(GPR_ERROR, "Missing :scheme header");
+      }
+      if (!calld->seen_te_trailers) {
+        gpr_log(GPR_ERROR, "Missing te trailers header");
+      }
+      /* Error this call out */
+      success = 0;
+      grpc_call_element_send_cancel(exec_ctx, elem);
+    }
+  }
+  calld->on_done_recv->cb(exec_ctx, calld->on_done_recv->cb_arg, success);
+}
+
+static void hs_mutate_op(grpc_call_element *elem,
+                         grpc_transport_stream_op *op) {
+  /* grab pointers to our data from the call element */
+  call_data *calld = elem->call_data;
+
+  if (op->send_initial_metadata != NULL && !calld->sent_status) {
+    calld->sent_status = 1;
+    grpc_metadata_batch_add_head(op->send_initial_metadata, &calld->status,
+                                 GRPC_MDELEM_STATUS_200);
+    grpc_metadata_batch_add_tail(
+        op->send_initial_metadata, &calld->content_type,
+        GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC);
+  }
+
+  if (op->recv_initial_metadata) {
+    /* substitute our callback for the higher callback */
+    calld->recv_initial_metadata = op->recv_initial_metadata;
+    calld->on_done_recv = op->recv_initial_metadata_ready;
+    op->recv_initial_metadata_ready = &calld->hs_on_recv;
+  }
+}
+
+static void hs_start_transport_op(grpc_exec_ctx *exec_ctx,
+                                  grpc_call_element *elem,
+                                  grpc_transport_stream_op *op) {
+  GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
+  GPR_TIMER_BEGIN("hs_start_transport_op", 0);
+  hs_mutate_op(elem, op);
+  grpc_call_next_op(exec_ctx, elem, op);
+  GPR_TIMER_END("hs_start_transport_op", 0);
+}
+
+/* Constructor for call_data */
+static void init_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                           grpc_call_element_args *args) {
+  /* grab pointers to our data from the call element */
+  call_data *calld = elem->call_data;
+  /* initialize members */
+  memset(calld, 0, sizeof(*calld));
+  grpc_closure_init(&calld->hs_on_recv, hs_on_recv, elem);
+}
+
+/* Destructor for call_data */
+static void destroy_call_elem(grpc_exec_ctx *exec_ctx,
+                              grpc_call_element *elem) {}
+
+/* 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);
+}
+
+/* Destructor for channel data */
+static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
+                                 grpc_channel_element *elem) {}
+
+const grpc_channel_filter grpc_http_server_filter = {
+    hs_start_transport_op, grpc_channel_next_op, sizeof(call_data),
+    init_call_elem, grpc_call_stack_ignore_set_pollset, destroy_call_elem,
+    sizeof(channel_data), init_channel_elem, destroy_channel_elem,
+    grpc_call_next_get_peer, "http-server"};