src/core/channel/http_server_filter.c - platform/external/grpc-grpc - Gitiles

 /*
  *
  * Copyright 2015, 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 <string.h>
 #include <grpc/grpc_http.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>

 typedef struct call_data {
   gpr_uint8 got_initial_metadata;
   gpr_uint8 seen_path;
   gpr_uint8 seen_post;
   gpr_uint8 sent_status;
   gpr_uint8 seen_scheme;
   gpr_uint8 seen_te_trailers;
   grpc_linked_mdelem status;

   grpc_stream_op_buffer *recv_ops;
   void (*on_done_recv)(void *user_data, int success);
   void *recv_user_data;
 } call_data;

 typedef struct channel_data {
   grpc_mdelem *te_trailers;
   grpc_mdelem *method_post;
   grpc_mdelem *http_scheme;
   grpc_mdelem *https_scheme;
   /* TODO(klempner): Remove this once we stop using it */
   grpc_mdelem *grpc_scheme;
   grpc_mdelem *content_type;
   grpc_mdelem *status_ok;
   grpc_mdelem *status_not_found;
   grpc_mdstr *path_key;
   grpc_mdstr *authority_key;
   grpc_mdstr *host_key;

   grpc_mdctx *mdctx;
 } channel_data;

 /* used to silence 'variable not used' warnings */
 static void ignore_unused(void *ignored) {}

 static grpc_mdelem *server_filter(void *user_data, grpc_mdelem *md) {
   grpc_call_element *elem = user_data;
   channel_data *channeld = elem->channel_data;
   call_data *calld = elem->call_data;

   /* Check if it is one of the headers we care about. */
   if (md == channeld->te_trailers || md == channeld->method_post ||
       md == channeld->http_scheme || md == channeld->https_scheme ||
       md == channeld->grpc_scheme || md == channeld->content_type) {
     /* swallow it */
     if (md == channeld->method_post) {
       calld->seen_post = 1;
     } else if (md->key == channeld->http_scheme->key) {
       calld->seen_scheme = 1;
     } else if (md == channeld->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 == channeld->content_type->key) {
     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",
               channeld->content_type->key);
     }
     return NULL;
   } else if (md->key == channeld->te_trailers->key ||
              md->key == channeld->method_post->key ||
              md->key == channeld->http_scheme->key ||
              md->key == channeld->content_type->key) {
     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(elem);
     return NULL;
   } else if (md->key == channeld->path_key) {
     if (calld->seen_path) {
       gpr_log(GPR_ERROR, "Received :path twice");
       return NULL;
     }
     calld->seen_path = 1;
     return md;
   } else if (md->key == channeld->host_key) {
     /* translate host to :authority since :authority may be
        omitted */
     grpc_mdelem *authority = grpc_mdelem_from_metadata_strings(
         channeld->mdctx, grpc_mdstr_ref(channeld->authority_key),
         grpc_mdstr_ref(md->value));
     grpc_mdelem_unref(md);
     return authority;
   } else {
     return md;
   }
 }

 static void hs_on_recv(void *user_data, int success) {
   grpc_call_element *elem = user_data;
   call_data *calld = elem->call_data;
   if (success) {
     size_t i;
     size_t nops = calld->recv_ops->nops;
     grpc_stream_op *ops = calld->recv_ops->ops;
     for (i = 0; i < nops; i++) {
       grpc_stream_op *op = &ops[i];
       if (op->type != GRPC_OP_METADATA) continue;
       calld->got_initial_metadata = 1;
       grpc_metadata_batch_filter(&op->data.metadata, server_filter, elem);
       /* 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) {
         /* do nothing */
       } else {
         if (!calld->seen_path) {
           gpr_log(GPR_ERROR, "Missing :path 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(elem);
       }
     }
   }
   calld->on_done_recv(calld->recv_user_data, success);
 }

 static void hs_mutate_op(grpc_call_element *elem, grpc_transport_op *op) {
   /* grab pointers to our data from the call element */
   call_data *calld = elem->call_data;
   channel_data *channeld = elem->channel_data;
   size_t i;

   if (op->send_ops && !calld->sent_status) {
     size_t nops = op->send_ops->nops;
     grpc_stream_op *ops = op->send_ops->ops;
     for (i = 0; i < nops; i++) {
       grpc_stream_op *op = &ops[i];
       if (op->type != GRPC_OP_METADATA) continue;
       calld->sent_status = 1;
       grpc_metadata_batch_add_head(&op->data.metadata, &calld->status,
                                    grpc_mdelem_ref(channeld->status_ok));
       break;
     }
   }

   if (op->recv_ops && !calld->got_initial_metadata) {
     /* substitute our callback for the higher callback */
     calld->recv_ops = op->recv_ops;
     calld->on_done_recv = op->on_done_recv;
     calld->recv_user_data = op->recv_user_data;
     op->on_done_recv = hs_on_recv;
     op->recv_user_data = elem;
   }
 }

 static void hs_start_transport_op(grpc_call_element *elem,
                                   grpc_transport_op *op) {
   GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
   hs_mutate_op(elem, op);
   grpc_call_next_op(elem, op);
 }

 /* Called on special channel events, such as disconnection or new incoming
    calls on the server */
 static void channel_op(grpc_channel_element *elem,
                        grpc_channel_element *from_elem, grpc_channel_op *op) {
   /* grab pointers to our data from the channel element */
   channel_data *channeld = elem->channel_data;

   ignore_unused(channeld);

   switch (op->type) {
     default:
       /* pass control up or down the stack depending on op->dir */
       grpc_channel_next_op(elem, op);
       break;
   }
 }

 /* Constructor for call_data */
 static void init_call_elem(grpc_call_element *elem,
                            const void *server_transport_data,
                            grpc_transport_op *initial_op) {
   /* grab pointers to our data from the call element */
   call_data *calld = elem->call_data;
   /* initialize members */
   memset(calld, 0, sizeof(*calld));
   if (initial_op) hs_mutate_op(elem, initial_op);
 }

 /* Destructor for call_data */
 static void destroy_call_elem(grpc_call_element *elem) {}

 /* Constructor for channel_data */
 static void init_channel_elem(grpc_channel_element *elem,
                               const grpc_channel_args *args, grpc_mdctx *mdctx,
                               int is_first, int is_last) {
   /* grab pointers to our data from the channel element */
   channel_data *channeld = elem->channel_data;

   /* The first and the last filters tend to be implemented differently to
      handle the case that there's no 'next' filter to call on the up or down
      path */
   GPR_ASSERT(!is_first);
   GPR_ASSERT(!is_last);

   /* initialize members */
   channeld->te_trailers = grpc_mdelem_from_strings(mdctx, "te", "trailers");
   channeld->status_ok = grpc_mdelem_from_strings(mdctx, ":status", "200");
   channeld->status_not_found =
       grpc_mdelem_from_strings(mdctx, ":status", "404");
   channeld->method_post = grpc_mdelem_from_strings(mdctx, ":method", "POST");
   channeld->http_scheme = grpc_mdelem_from_strings(mdctx, ":scheme", "http");
   channeld->https_scheme = grpc_mdelem_from_strings(mdctx, ":scheme", "https");
   channeld->grpc_scheme = grpc_mdelem_from_strings(mdctx, ":scheme", "grpc");
   channeld->path_key = grpc_mdstr_from_string(mdctx, ":path");
   channeld->authority_key = grpc_mdstr_from_string(mdctx, ":authority");
   channeld->host_key = grpc_mdstr_from_string(mdctx, "host");
   channeld->content_type =
       grpc_mdelem_from_strings(mdctx, "content-type", "application/grpc");

   channeld->mdctx = mdctx;
 }

 /* Destructor for channel data */
 static void destroy_channel_elem(grpc_channel_element *elem) {
   /* grab pointers to our data from the channel element */
   channel_data *channeld = elem->channel_data;

   grpc_mdelem_unref(channeld->te_trailers);
   grpc_mdelem_unref(channeld->status_ok);
   grpc_mdelem_unref(channeld->status_not_found);
   grpc_mdelem_unref(channeld->method_post);
   grpc_mdelem_unref(channeld->http_scheme);
   grpc_mdelem_unref(channeld->https_scheme);
   grpc_mdelem_unref(channeld->grpc_scheme);
   grpc_mdelem_unref(channeld->content_type);
   grpc_mdstr_unref(channeld->path_key);
   grpc_mdstr_unref(channeld->authority_key);
   grpc_mdstr_unref(channeld->host_key);
 }

 const grpc_channel_filter grpc_http_server_filter = {
     hs_start_transport_op, channel_op, sizeof(call_data), init_call_elem,
     destroy_call_elem, sizeof(channel_data), init_channel_elem,
     destroy_channel_elem, "http-server"};
	/*
	*
	* Copyright 2015, 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 <string.h>
	#include <grpc/grpc_http.h>
	#include <grpc/support/alloc.h>
	#include <grpc/support/log.h>

	typedef struct call_data {
	gpr_uint8 got_initial_metadata;
	gpr_uint8 seen_path;
	gpr_uint8 seen_post;
	gpr_uint8 sent_status;
	gpr_uint8 seen_scheme;
	gpr_uint8 seen_te_trailers;
	grpc_linked_mdelem status;

	grpc_stream_op_buffer *recv_ops;
	void (on_done_recv)(void user_data, int success);
	void *recv_user_data;
	} call_data;

	typedef struct channel_data {
	grpc_mdelem *te_trailers;
	grpc_mdelem *method_post;
	grpc_mdelem *http_scheme;
	grpc_mdelem *https_scheme;
	/* TODO(klempner): Remove this once we stop using it */
	grpc_mdelem *grpc_scheme;
	grpc_mdelem *content_type;
	grpc_mdelem *status_ok;
	grpc_mdelem *status_not_found;
	grpc_mdstr *path_key;
	grpc_mdstr *authority_key;
	grpc_mdstr *host_key;

	grpc_mdctx *mdctx;
	} channel_data;

	/* used to silence 'variable not used' warnings */
	static void ignore_unused(void *ignored) {}

	static grpc_mdelem server_filter(void user_data, grpc_mdelem *md) {
	grpc_call_element *elem = user_data;
	channel_data *channeld = elem->channel_data;
	call_data *calld = elem->call_data;

	/* Check if it is one of the headers we care about. */
	if (md == channeld->te_trailers \|\| md == channeld->method_post \|\|
	md == channeld->http_scheme \|\| md == channeld->https_scheme \|\|
	md == channeld->grpc_scheme \|\| md == channeld->content_type) {
	/* swallow it */
	if (md == channeld->method_post) {
	calld->seen_post = 1;
	} else if (md->key == channeld->http_scheme->key) {
	calld->seen_scheme = 1;
	} else if (md == channeld->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 == channeld->content_type->key) {
	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",
	channeld->content_type->key);
	}
	return NULL;
	} else if (md->key == channeld->te_trailers->key \|\|
	md->key == channeld->method_post->key \|\|
	md->key == channeld->http_scheme->key \|\|
	md->key == channeld->content_type->key) {
	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(elem);
	return NULL;
	} else if (md->key == channeld->path_key) {
	if (calld->seen_path) {
	gpr_log(GPR_ERROR, "Received :path twice");
	return NULL;
	}
	calld->seen_path = 1;
	return md;
	} else if (md->key == channeld->host_key) {
	/* translate host to :authority since :authority may be
	omitted */
	grpc_mdelem *authority = grpc_mdelem_from_metadata_strings(
	channeld->mdctx, grpc_mdstr_ref(channeld->authority_key),
	grpc_mdstr_ref(md->value));
	grpc_mdelem_unref(md);
	return authority;
	} else {
	return md;
	}
	}

	static void hs_on_recv(void *user_data, int success) {
	grpc_call_element *elem = user_data;
	call_data *calld = elem->call_data;
	if (success) {
	size_t i;
	size_t nops = calld->recv_ops->nops;
	grpc_stream_op *ops = calld->recv_ops->ops;
	for (i = 0; i < nops; i++) {
	grpc_stream_op *op = &ops[i];
	if (op->type != GRPC_OP_METADATA) continue;
	calld->got_initial_metadata = 1;
	grpc_metadata_batch_filter(&op->data.metadata, server_filter, elem);
	/* 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) {
	/* do nothing */
	} else {
	if (!calld->seen_path) {
	gpr_log(GPR_ERROR, "Missing :path 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(elem);
	}
	}
	}
	calld->on_done_recv(calld->recv_user_data, success);
	}

	static void hs_mutate_op(grpc_call_element elem, grpc_transport_op op) {
	/* grab pointers to our data from the call element */
	call_data *calld = elem->call_data;
	channel_data *channeld = elem->channel_data;
	size_t i;

	if (op->send_ops && !calld->sent_status) {
	size_t nops = op->send_ops->nops;
	grpc_stream_op *ops = op->send_ops->ops;
	for (i = 0; i < nops; i++) {
	grpc_stream_op *op = &ops[i];
	if (op->type != GRPC_OP_METADATA) continue;
	calld->sent_status = 1;
	grpc_metadata_batch_add_head(&op->data.metadata, &calld->status,
	grpc_mdelem_ref(channeld->status_ok));
	break;
	}
	}

	if (op->recv_ops && !calld->got_initial_metadata) {
	/* substitute our callback for the higher callback */
	calld->recv_ops = op->recv_ops;
	calld->on_done_recv = op->on_done_recv;
	calld->recv_user_data = op->recv_user_data;
	op->on_done_recv = hs_on_recv;
	op->recv_user_data = elem;
	}
	}

	static void hs_start_transport_op(grpc_call_element *elem,
	grpc_transport_op *op) {
	GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
	hs_mutate_op(elem, op);
	grpc_call_next_op(elem, op);
	}

	/* Called on special channel events, such as disconnection or new incoming
	calls on the server */
	static void channel_op(grpc_channel_element *elem,
	grpc_channel_element from_elem, grpc_channel_op op) {
	/* grab pointers to our data from the channel element */
	channel_data *channeld = elem->channel_data;

	ignore_unused(channeld);

	switch (op->type) {
	default:
	/* pass control up or down the stack depending on op->dir */
	grpc_channel_next_op(elem, op);
	break;
	}
	}

	/* Constructor for call_data */
	static void init_call_elem(grpc_call_element *elem,
	const void *server_transport_data,
	grpc_transport_op *initial_op) {
	/* grab pointers to our data from the call element */
	call_data *calld = elem->call_data;
	/* initialize members */
	memset(calld, 0, sizeof(*calld));
	if (initial_op) hs_mutate_op(elem, initial_op);
	}

	/* Destructor for call_data */
	static void destroy_call_elem(grpc_call_element *elem) {}

	/* Constructor for channel_data */
	static void init_channel_elem(grpc_channel_element *elem,
	const grpc_channel_args args, grpc_mdctx mdctx,
	int is_first, int is_last) {
	/* grab pointers to our data from the channel element */
	channel_data *channeld = elem->channel_data;

	/* The first and the last filters tend to be implemented differently to
	handle the case that there's no 'next' filter to call on the up or down
	path */
	GPR_ASSERT(!is_first);
	GPR_ASSERT(!is_last);

	/* initialize members */
	channeld->te_trailers = grpc_mdelem_from_strings(mdctx, "te", "trailers");
	channeld->status_ok = grpc_mdelem_from_strings(mdctx, ":status", "200");
	channeld->status_not_found =
	grpc_mdelem_from_strings(mdctx, ":status", "404");
	channeld->method_post = grpc_mdelem_from_strings(mdctx, ":method", "POST");
	channeld->http_scheme = grpc_mdelem_from_strings(mdctx, ":scheme", "http");
	channeld->https_scheme = grpc_mdelem_from_strings(mdctx, ":scheme", "https");
	channeld->grpc_scheme = grpc_mdelem_from_strings(mdctx, ":scheme", "grpc");
	channeld->path_key = grpc_mdstr_from_string(mdctx, ":path");
	channeld->authority_key = grpc_mdstr_from_string(mdctx, ":authority");
	channeld->host_key = grpc_mdstr_from_string(mdctx, "host");
	channeld->content_type =
	grpc_mdelem_from_strings(mdctx, "content-type", "application/grpc");

	channeld->mdctx = mdctx;
	}

	/* Destructor for channel data */
	static void destroy_channel_elem(grpc_channel_element *elem) {
	/* grab pointers to our data from the channel element */
	channel_data *channeld = elem->channel_data;

	grpc_mdelem_unref(channeld->te_trailers);
	grpc_mdelem_unref(channeld->status_ok);
	grpc_mdelem_unref(channeld->status_not_found);
	grpc_mdelem_unref(channeld->method_post);
	grpc_mdelem_unref(channeld->http_scheme);
	grpc_mdelem_unref(channeld->https_scheme);
	grpc_mdelem_unref(channeld->grpc_scheme);
	grpc_mdelem_unref(channeld->content_type);
	grpc_mdstr_unref(channeld->path_key);
	grpc_mdstr_unref(channeld->authority_key);
	grpc_mdstr_unref(channeld->host_key);
	}

	const grpc_channel_filter grpc_http_server_filter = {
	hs_start_transport_op, channel_op, sizeof(call_data), init_call_elem,
	destroy_call_elem, sizeof(channel_data), init_channel_elem,
	destroy_channel_elem, "http-server"};