1 /*
2  *
3  * Copyright 2016 gRPC authors.
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  *     http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  *
17  */
18 
19 #ifndef GRPC_CORE_EXT_FILTERS_LOAD_REPORTING_SERVER_LOAD_REPORTING_FILTER_H
20 #define GRPC_CORE_EXT_FILTERS_LOAD_REPORTING_SERVER_LOAD_REPORTING_FILTER_H
21 
22 #include <grpc/support/port_platform.h>
23 
24 #include "src/core/lib/channel/channel_stack.h"
25 #include "src/cpp/common/channel_filter.h"
26 
27 namespace grpc {
28 
29 class ServerLoadReportingChannelData : public ChannelData {
30  public:
31   grpc_error* Init(grpc_channel_element* elem,
32                    grpc_channel_element_args* args) override;
33 
34   // Getters.
peer_identity()35   const char* peer_identity() { return peer_identity_; }
peer_identity_len()36   size_t peer_identity_len() { return peer_identity_len_; }
37 
38  private:
39   // The peer's authenticated identity.
40   char* peer_identity_ = nullptr;
41   size_t peer_identity_len_ = 0;
42 };
43 
44 class ServerLoadReportingCallData : public CallData {
45  public:
46   grpc_error* Init(grpc_call_element* elem,
47                    const grpc_call_element_args* args) override;
48 
49   void Destroy(grpc_call_element* elem, const grpc_call_final_info* final_info,
50                grpc_closure* then_call_closure) override;
51 
52   void StartTransportStreamOpBatch(grpc_call_element* elem,
53                                    TransportStreamOpBatch* op) override;
54 
55  private:
56   // From the peer_string_ in calld, extracts the client IP string (owned by
57   // caller), e.g., "01020a0b". Upon failure, set the output pointer to null and
58   // size to zero.
59   void GetCensusSafeClientIpString(char** client_ip_string, size_t* size);
60 
61   // Concatenates the client IP address and the load reporting token, then
62   // stores the result into the call data.
63   void StoreClientIpAndLrToken(const char* lr_token, size_t lr_token_len);
64 
65   // This matches the classification of the status codes in
66   // googleapis/google/rpc/code.proto.
67   static const char* GetStatusTagForStatus(grpc_status_code status);
68 
69   // Records the call start.
70   static void RecvInitialMetadataReady(void* arg, grpc_error* err);
71 
72   // From the initial metadata, extracts the service_method_, target_host_, and
73   // client_ip_and_lr_token_.
74   static grpc_filtered_mdelem RecvInitialMetadataFilter(void* user_data,
75                                                         grpc_mdelem md);
76 
77   // Records the other call metrics.
78   static grpc_filtered_mdelem SendTrailingMetadataFilter(void* user_data,
79                                                          grpc_mdelem md);
80 
81   // The peer string (a member of the recv_initial_metadata op). Note that
82   // gpr_atm itself is a pointer type here, making "peer_string_" effectively a
83   // double pointer.
84   const gpr_atm* peer_string_;
85 
86   // The received initial metadata (a member of the recv_initial_metadata op).
87   // When it is ready, we will extract some data from it via
88   // recv_initial_metadata_ready_ closure, before the original
89   // recv_initial_metadata_ready closure.
90   grpc_metadata_batch* recv_initial_metadata_;
91 
92   // The original recv_initial_metadata closure, which is wrapped by our own
93   // closure (recv_initial_metadata_ready_) to capture the incoming initial
94   // metadata.
95   grpc_closure* original_recv_initial_metadata_ready_;
96 
97   // The closure that wraps the original closure. Scheduled when
98   // recv_initial_metadata_ is ready.
99   grpc_closure recv_initial_metadata_ready_;
100 
101   // Corresponds to the :path header.
102   grpc_slice service_method_;
103 
104   // The backend host that the client thinks it's talking to. This may be
105   // different from the actual backend in the case of, for example,
106   // load-balanced targets. We store a copy of the metadata slice in order to
107   // lowercase it. */
108   char* target_host_;
109   size_t target_host_len_;
110 
111   // The client IP address (including a length prefix) and the load reporting
112   // token.
113   char* client_ip_and_lr_token_;
114   size_t client_ip_and_lr_token_len_;
115 };
116 
117 }  // namespace grpc
118 
119 #endif /* GRPC_CORE_EXT_FILTERS_LOAD_REPORTING_SERVER_LOAD_REPORTING_FILTER_H \
120         */
121