* server can transfer grpc error code and message

* client can receive grpc error code and message
* add percent encode/decode

example/grpc_c++/client.cpp

@@ -68,6 +68,8 @@ int main(int argc, char* argv[]) {
         // Because `done'(last parameter) is NULL, this function waits until
         // the response comes back or error occurs(including timedout).
         stub.SayHello(&cntl, &request, &response, NULL);
+        //cntl.http_request().uri() = FLAGS_server;
+        //channel.CallMethod(NULL, &cntl, &request, &response, NULL);
         if (!cntl.Failed()) {
             LOG(INFO) << "Received response from " << cntl.remote_side()
                 << " to " << cntl.local_side()
@@ -75,7 +77,10 @@ int main(int argc, char* argv[]) {
                 << cntl.response_attachment() << ")"
                 << " latency=" << cntl.latency_us() << "us";
         } else {
-            LOG(WARNING) << cntl.ErrorText();
+            LOG(WARNING) << cntl.ErrorCode() << ": " << cntl.ErrorText()
+                         << ", grpc-status=" << cntl.grpc_status()
+                         << ", grpc-message=" << cntl.grpc_message();
+
         }
         usleep(FLAGS_interval_ms * 1000L);
     }

example/grpc_c++/server.cpp

@@ -46,9 +46,10 @@ public:
         if (FLAGS_gzip) {
             cntl->set_response_compress_type(brpc::COMPRESS_TYPE_GZIP);
         }
-        std::string prefix("Hello ");
         LOG(INFO) << "req=" << req->name();
-        res->set_message(prefix + req->name());
+        res->set_message("Hello " + req->name());
+        // If an error happens, use controller::set_grpc_error_code to set errors
+        // e.g., cntl->set_grpc_error_code(brpc::GRPC_RESOURCEEXHAUSTED, "test grpc message");
     }
 };
 

src/brpc/controller.cpp

@@ -254,6 +254,8 @@ void Controller::InternalReset(bool in_constructor) {
     _response_stream = INVALID_STREAM_ID;
     _remote_stream_settings = NULL;
     _thrift_method_name = "";
+    _grpc_status = GRPC_OK;
+    _grpc_message = "";
 }
 
 Controller::Call::Call(Controller::Call* rhs)

src/brpc/controller.h

@@ -40,6 +40,7 @@
 #include "brpc/callback.h"
 #include "brpc/progressive_attachment.h"       // ProgressiveAttachment
 #include "brpc/progressive_reader.h"           // ProgressiveReader
+#include "brpc/grpc.h"
 
 // EAUTH is defined in MAC
 #ifndef EAUTH
@@ -476,6 +477,13 @@ public:
     // Get sock option. .e.g get vip info through ttm kernel module hook,
     int GetSockOption(int level, int optname, void* optval, socklen_t* optlen);
 
+    void set_grpc_error_code(GrpcStatus status, const std::string& msg) {
+        _grpc_status = status;
+        _grpc_message = msg;
+    }
+    GrpcStatus grpc_status() { return _grpc_status; }
+    std::string grpc_message() { return _grpc_message; }
+
 private:
     struct CompletionInfo {
         CallId id;           // call_id of the corresponding request
@@ -716,6 +724,10 @@ private:
 
     // Thrift method name, only used when thrift protocol enabled
     std::string _thrift_method_name;
+    uint32_t _thrift_seq_id;
+
+    GrpcStatus _grpc_status;
+    std::string _grpc_message;
 };
 
 // Advises the RPC system that the caller desires that the RPC call be

src/brpc/details/controller_private_accessor.h

@@ -134,6 +134,9 @@ public:
         _cntl->add_flag(Controller::FLAGS_REQUEST_WITH_AUTH);
     }
 
+    GrpcStatus grpc_status() { return _cntl->_grpc_status; }
+    std::string grpc_message() { return _cntl->_grpc_message; }
+
 private:
     Controller* _cntl;
 };

src/brpc/errno.proto

@@ -8,7 +8,8 @@ enum Errno {
     ENOSERVICE              = 1001;  // Service not found
     ENOMETHOD               = 1002;  // Method not found
     EREQUEST                = 1003;  // Bad Request
-    ERPCAUTH                = 1004;  // Unauthorized, can't be called EAUTH directly which is defined in MACOSX
+    ERPCAUTH                = 1004;  // Unauthorized, can't be called EAUTH
+                                     // directly which is defined in MACOSX
     ETOOMANYFAILS           = 1005;  // Too many sub calls failed
     EPCHANFINISH            = 1006;  // [Internal] ParallelChannel finished
     EBACKUPREQUEST          = 1007;  // Sending backup request
@@ -30,4 +31,5 @@ enum Errno {
     ELIMIT                  = 2004;  // Reached server's limit on resources
     ECLOSE                  = 2005;  // Close socket initiatively
     EITP                    = 2006;  // Failed Itp response
+    EGRPC                   = 2007;  // Failed Grpc response
 }

src/brpc/grpc.cpp

+// Copyright (c) 2018 Bilibili, Inc.
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// 
+//     http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Authors: Jiashun Zhu(zhujiashun@bilibili.com)
+
+
+#include <sstream>                  // std::stringstream
+#include <iomanip>                  // std::setw
+#include "brpc/grpc.h"
+#include "brpc/errno.pb.h"
+#include "brpc/http_status_code.h"
+#include "butil/logging.h"
+
+namespace brpc {
+
+// The mapping can be found in grpc-go internal/transport/http_util.go
+GrpcStatus HttpStatus2GrpcStatus(int http_status) {
+    switch(http_status) {
+        case HTTP_STATUS_BAD_REQUEST:
+            return GRPC_INTERNAL;
+        case HTTP_STATUS_UNAUTHORIZED:
+            return GRPC_UNAUTHENTICATED;
+        case HTTP_STATUS_FORBIDDEN:
+            return GRPC_PERMISSIONDENIED;
+        case HTTP_STATUS_NOT_FOUND:
+            return GRPC_UNIMPLEMENTED;
+        case HTTP_STATUS_BAD_GATEWAY:
+        case HTTP_STATUS_SERVICE_UNAVAILABLE:
+        case HTTP_STATUS_GATEWAY_TIMEOUT:
+            return GRPC_UNAVAILABLE;
+        default:
+            return GRPC_UNKNOWN;
+    }
+}
+
+GrpcStatus ErrorCode2GrpcStatus(int error_code) {
+    switch (error_code) {
+    case ENOSERVICE:
+    case ENOMETHOD:
+        return GRPC_UNIMPLEMENTED;
+    case ERPCAUTH:
+        return GRPC_UNAUTHENTICATED;
+    case EREQUEST:
+    case EINVAL:
+        return GRPC_INVALIDARGUMENT;
+    case ELIMIT:
+    case ELOGOFF:
+        return GRPC_UNAVAILABLE;
+    case EPERM:
+        return GRPC_PERMISSIONDENIED;
+    case ERPCTIMEDOUT:
+    case ETIMEDOUT:
+        return GRPC_INTERNAL;
+    default:
+        return GRPC_UNKNOWN;
+    }
+}
+
+void percent_encode(const std::string& str, std::string* str_out) {
+    std::ostringstream escaped;
+    escaped.fill('0');
+    escaped << std::hex;
+    for (std::string::const_iterator it = str.begin();
+         it != str.end(); ++it) {
+        const std::string::value_type& c = *it;
+        if (c >= ' ' && c <= '~' && c != '%') {
+            escaped << c;
+            continue;
+        }
+        escaped << '%' << std::setw(2) << int((unsigned char) c);
+    }
+    if (str_out) {
+        *str_out = escaped.str();
+    }
+}
+
+static int hex_to_int(char c) {
+    if (c >= 'a' && c <= 'f') {
+        return c - 'a' + 10;
+    } else if (c >= 'A' && c <= 'F') {
+        return c - 'A' + 10;
+    } else if (c >= '0' && c <= '9') {
+        return c - '0';
+    }
+    return 0;
+}
+
+void percent_decode(const std::string& str, std::string* str_out) {
+    std::ostringstream unescaped;
+    for (std::string::const_iterator it = str.begin();
+         it != str.end(); ++it) {
+        const std::string::value_type& c = *it;
+        if (c == '%' && it + 2 < str.end()) {
+            int i1 = hex_to_int(*++it);
+            int i2 = hex_to_int(*++it);
+            unescaped << (char)(i1 * 16 + i2);
+        } else {
+            unescaped << c;
+        } 
+    }
+    if (str_out) {
+        *str_out = unescaped.str();
+    }
+}
+
+} // namespace brpc

src/brpc/grpc.h

+// Copyright (c) 2018 Bilibili, Inc.
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// 
+//     http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Authors: Jiashun Zhu(zhujiashun@bilibili.com)
+
+#ifndef BRPC_GRPC_H
+#define BRPC_GRPC_H
+
+#include <map>
+
+namespace brpc {
+
+typedef std::map<std::string, std::string> TrailerMessage;
+
+enum GrpcStatus {
+    // OK is returned on success.
+    GRPC_OK = 0,
+
+    // CANCELED indicates the operation was canceled (typically by the caller).
+    GRPC_CANCELED,
+
+    // Unknown error. An example of where this error may be returned is
+    // if a Status value received from another address space belongs to
+    // an error-space that is not known in this address space. Also
+    // errors raised by APIs that do not return enough error information
+    // may be converted to this error.
+    GRPC_UNKNOWN,
+
+    // INVALIDARGUMENT Indicates client specified an invalid argument.
+    // Note that this differs from FAILEDPRECONDITION. It indicates arguments
+    // that are problematic regardless of the state of the system
+    // (e.g., a malformed file name).
+    GRPC_INVALIDARGUMENT,
+
+    // DEADLINEEXCEEDED Means operation expired before completion.
+    // For operations that change the state of the system, this error may be
+    // returned even if the operation has completed successfully. For
+    // example, a successful response from a server could have been delayed
+    // long enough for the deadline to expire.
+    GRPC_DEADLINEEXCEEDED,
+
+    // NOTFOUND Means some requested entity (e.g., file or directory) was
+    // not found.
+    GRPC_NOTFOUND,
+
+    // ALREADYEXISTS Means an attempt to create an entity failed because one
+    // already exists.
+    GRPC_ALREADYEXISTS,
+
+    // PERMISSIONDENIED Indicates the caller does not have permission to
+    // execute the specified operation. It must not be used for rejections
+    // caused by exhausting some resource (use ResourceExhausted
+    // instead for those errors). It must not be
+    // used if the caller cannot be identified (use UNAUTHENTICATED
+    // instead for those errors).
+    GRPC_PERMISSIONDENIED,
+
+    // RESOURCEEXHAUSTED Indicates some resource has been exhausted, perhaps
+    // a per-user quota, or perhaps the entire file system is out of space.
+    GRPC_RESOURCEEXHAUSTED,
+
+    // FAILEDPRECONDITION indicates operation was rejected because the
+    // system is not in a state required for the operation's execution.
+    // For example, directory to be deleted may be non-empty, an rmdir
+    // operation is applied to a non-directory, etc.
+    //
+    // A litmus test that may help a service implementor in deciding
+    // between FAILEDPRECONDITION, Aborted, and Unavailable:
+    //  (a) Use Unavailable if the client can retry just the failing call.
+    //  (b) Use Aborted if the client should retry at a higher-level
+    //      (e.g., restarting a read-modify-write sequence).
+    //  (c) Use FAILEDPRECONDITION if the client should not retry until
+    //      the system state has been explicitly fixed. E.g., if an "rmdir"
+    //      fails because the directory is non-empty, FAILEDPRECONDITION
+    //      should be returned since the client should not retry unless
+    //      they have first fixed up the directory by deleting files from it.
+    //  (d) Use FAILEDPRECONDITION if the client performs conditional
+    //      REST Get/Update/Delete on a resource and the resource on the
+    //      server does not match the condition. E.g., conflicting
+    //      read-modify-write on the same resource.
+    GRPC_FAILEDPRECONDITION,
+
+    // ABORTED indicates the operation was aborted, typically due to a
+    // concurrency issue like sequencer check failures, transaction aborts,
+    // etc.
+    //
+    // See litmus test above for deciding between FAILEDPRECONDITION,
+    // Aborted, and Unavailable.
+    GPRC_ABORTED,
+
+    // OUTOFRANGE means operation was attempted past the valid range.
+    // E.g., seeking or reading past end of file.
+    //
+    // Unlike INVALIDARGUMENT, this error indicates a problem that may
+    // be fixed if the system state changes. For example, a 32-bit file
+    // system will generate INVALIDARGUMENT if asked to read at an
+    // offset that is not in the range [0,2^32-1], but it will generate
+    // OUTOFRANGE if asked to read from an offset past the current
+    // file size.
+    //
+    // There is a fair bit of overlap between FAILEDPRECONDITION and
+    // OUTOFRANGE. We recommend using OUTOFRANGE (the more specific
+    // error) when it applies so that callers who are iterating through
+    // a space can easily look for an OUTOFRANGE error to detect when
+    // they are done.
+    GRPC_OUTOFRANGE,
+
+    // UNIMPLEMENTED indicates operation is not implemented or not
+    // supported/enabled in this service.
+    GRPC_UNIMPLEMENTED,
+
+    // INTERNAL errors. Means some invariants expected by underlying
+    // system has been broken. If you see one of these errors,
+    // something is very broken.
+    GRPC_INTERNAL,
+
+    // UNAVAILABLE indicates the service is currently unavailable.
+    // This is a most likely a transient condition and may be corrected
+    // by retrying with a backoff.
+    //
+    // See litmus test above for deciding between FAILEDPRECONDITION,
+    // ABORTED, and UNAVAILABLE.
+    GRPC_UNAVAILABLE,
+
+    // DATALOSS indicates unrecoverable data loss or corruption.
+    GRPC_DATALOSS,
+
+    // UNAUTHENTICATED indicates the request does not have valid
+    // authentication credentials for the operation.
+    GRPC_UNAUTHENTICATED,
+}; 
+
+GrpcStatus HttpStatus2GrpcStatus(int http_status);
+
+GrpcStatus ErrorCode2GrpcStatus(int error_code);
+
+void percent_encode(const std::string& str, std::string* str_out);
+
+void percent_decode(const std::string& str, std::string* str_out);
+
+
+} // namespace brpc
+
+#endif // BRPC_GRPC_H

src/brpc/policy/http2_rpc_protocol.cpp

@@ -1206,6 +1206,8 @@ int H2StreamContext::ConsumeHeaders(butil::IOBufBytesIterator& it) {
         if (rc == 0) {
             break;
         }
+        RPC_VLOG << "Header name: " << pair.name
+                 << ", header value: " << pair.value;
         const char* const name = pair.name.c_str();
         bool matched = false;
         if (name[0] == ':') { // reserved names
@@ -1627,7 +1629,15 @@ void H2UnsentRequest::Describe(butil::IOBuf* desc) const {
     }
 }
 
-H2UnsentResponse* H2UnsentResponse::New(Controller* c, int stream_id) {
+H2UnsentResponse::H2UnsentResponse(Controller* c, const TrailerMessage& trailers)
+    : _size(0)
+    , _stream_id(c->http_request().h2_stream_id())
+    , _http_response(c->release_http_response())
+    , _trailers(trailers) {
+    _data.swap(c->response_attachment());
+}
+
+H2UnsentResponse* H2UnsentResponse::New(Controller* c, const TrailerMessage& trailers) {
     const HttpHeader* const h = &c->http_response();
     const CommonStrings* const common = get_common_strings();
     const bool need_content_length =
@@ -1638,7 +1648,7 @@ H2UnsentResponse* H2UnsentResponse::New(Controller* c, int stream_id) {
         + (size_t)need_content_type;
     const size_t memsize = offsetof(H2UnsentResponse, _list) +
         sizeof(HPacker::Header) * maxsize;
-    H2UnsentResponse* msg = new (malloc(memsize)) H2UnsentResponse(c, stream_id);
+    H2UnsentResponse* msg = new (malloc(memsize)) H2UnsentResponse(c, trailers);
     // :status
     if (h->status_code() == 200) {
         msg->push(common->H2_STATUS, common->STATUS_200);
@@ -1710,14 +1720,12 @@ H2UnsentResponse::AppendAndDestroySelf(butil::IOBuf* out, Socket* socket) {
 
     butil::IOBufAppender trailer_appender;
     butil::IOBuf trailer_frag;
-    if (_grpc_protocol) {
-        // TODO(zhujiashun): how to decide status code and status message
-        HPacker::Header status("grpc-status", "0");
-        hpacker.Encode(&trailer_appender, status, options);
-        HPacker::Header message("grpc-message", "");
-        hpacker.Encode(&trailer_appender, message, options);
-        trailer_appender.move_to(trailer_frag);
+    for (TrailerMessage::iterator it = _trailers.begin();
+        it != _trailers.end(); ++it) {
+        HPacker::Header header(it->first, it->second);
+        hpacker.Encode(&trailer_appender, header, options);
     }
+    trailer_appender.move_to(trailer_frag);
 
     PackH2Message(out, frag, trailer_frag, _data, _stream_id, ctx);
     return butil::Status::OK();

src/brpc/policy/http2_rpc_protocol.h

@@ -194,7 +194,7 @@ private:
 
 class H2UnsentResponse : public SocketMessage {
 public:
-    static H2UnsentResponse* New(Controller* c, int stream_id);
+    static H2UnsentResponse* New(Controller* c, const TrailerMessage& trailers);
     void Destroy();
     void Describe(butil::IOBuf*) const;
     // @SocketMessage
@@ -208,14 +208,7 @@ private:
     void push(const std::string& name, const std::string& value)
     { new (&_list[_size++]) HPacker::Header(name, value); }
 
-    H2UnsentResponse(Controller* c, int stream_id)
-        : _size(0)
-        , _stream_id(stream_id)
-        , _http_response(c->release_http_response())
-        , _grpc_protocol(ParseContentType(c->http_request().content_type()) ==
-                HTTP_CONTENT_GRPC) {
-        _data.swap(c->response_attachment());
-    }
+    H2UnsentResponse(Controller* c, const TrailerMessage& trailers);
     ~H2UnsentResponse() {}
     H2UnsentResponse(const H2UnsentResponse&);
     void operator=(const H2UnsentResponse&);
@@ -225,7 +218,7 @@ private:
     uint32_t _stream_id;
     std::unique_ptr<HttpHeader> _http_response;
     butil::IOBuf _data;
-    bool _grpc_protocol;
+    TrailerMessage _trailers;
     HPacker::Header _list[0];
 };
 

src/brpc/policy/http_rpc_protocol.cpp

@@ -37,6 +37,7 @@
 #include "brpc/policy/gzip_compress.h"
 #include "brpc/policy/http2_rpc_protocol.h"
 #include "brpc/details/usercode_backup_pool.h"
+#include "brpc/grpc.h"
 
 extern "C" {
 void bthread_assign_data(void* data);
@@ -133,6 +134,8 @@ CommonStrings::CommonStrings()
     , TRAILERS("trailers")
     , GRPC_ENCODING("grpc-encoding")
     , GRPC_ACCEPT_ENCODING("grpc-accept-encoding")
+    , GRPC_STATUS("grpc-status")
+    , GRPC_MESSAGE("grpc-message")
 {}
 
 static CommonStrings* common = NULL;
@@ -268,12 +271,13 @@ void ProcessHttpResponse(InputMessageBase* msg) {
     CHECK(cntl->response_attachment().empty());
     const int saved_error = cntl->ErrorCode();
 
-    char compressed_grpc = false;
-    if (ParseContentType(res_header->content_type()) == HTTP_CONTENT_GRPC &&
-        !res_body.empty()) {
+    char grpc_compressed = false;
+    bool grpc_protocol =
+        ParseContentType(res_header->content_type()) == HTTP_CONTENT_GRPC;
+    if (grpc_protocol && !res_body.empty()) {
         /* 4 is the size of grpc Message-Length in Length-Prefixed-Message*/
         char buf[4];
-        res_body.cut1(&compressed_grpc);
+        res_body.cut1(&grpc_compressed);
         res_body.cutn(buf, 4);
         int message_length = ReadBigEndian4Bytes(buf);
         CHECK(message_length == res_body.length()) << message_length
@@ -295,6 +299,7 @@ void ProcessHttpResponse(InputMessageBase* msg) {
             }
         }
 
+
         if (imsg_guard->read_body_progressively()) {
             // Set RPA if needed
             accessor.set_readable_progressive_attachment(imsg_guard.get());
@@ -375,7 +380,7 @@ void ProcessHttpResponse(InputMessageBase* msg) {
         const std::string* grpc_encoding =
             res_header->GetHeader(common->GRPC_ENCODING);
         if ((encoding != NULL && *encoding == common->GZIP) ||
-            (compressed_grpc && grpc_encoding != NULL && *grpc_encoding ==
+            (grpc_compressed && grpc_encoding != NULL && *grpc_encoding ==
             common->GZIP)) {
             TRACEPRINTF("Decompressing response=%lu",
                         (unsigned long)res_body.size());
@@ -386,7 +391,6 @@ void ProcessHttpResponse(InputMessageBase* msg) {
             }
             res_body.swap(uncompressed);
         }
-        // message body is json
         if (content_type == HTTP_CONTENT_PROTO ||
             content_type == HTTP_CONTENT_GRPC) {
             if (!ParsePbFromIOBuf(cntl->response(), res_body)) {
@@ -394,6 +398,7 @@ void ProcessHttpResponse(InputMessageBase* msg) {
                 break;
             }
         } else {
+            // message body is json
             butil::IOBufAsZeroCopyInputStream wrapper(res_body);
             std::string err;
             json2pb::Json2PbOptions options;
@@ -404,6 +409,40 @@ void ProcessHttpResponse(InputMessageBase* msg) {
             }
         }
     } while (0);
+
+    do {
+        if (!grpc_protocol) {
+            break;
+        }
+        // begin to handle grpc case
+        const std::string* grpc_status = res_header->GetHeader(common->GRPC_STATUS);
+        const std::string* grpc_message = res_header->GetHeader(common->GRPC_MESSAGE);
+
+        if (grpc_status) {
+            GrpcStatus status = (GrpcStatus)strtol(grpc_status->data(), NULL, 10);
+            cntl->set_grpc_error_code(status, grpc_message? *grpc_message: "");
+            cntl->SetFailed(EGRPC, grpc_message? grpc_message->c_str(): "");
+            break;
+        }
+        // grpc-status is absent in http header, just convert error code
+        // to grpc status
+        if (!cntl->Failed()) {
+            break;
+        }
+        if (cntl->ErrorCode() == EHTTP) {
+            cntl->set_grpc_error_code(
+                    HttpStatus2GrpcStatus(res_header->status_code()),
+                    cntl->ErrorText());
+            // use empty string since gprc-status and grpc-message is absent
+            cntl->SetFailed(EGRPC, "");
+            break;
+        }
+        cntl->set_grpc_error_code(ErrorCode2GrpcStatus(cntl->ErrorCode()),
+                cntl->ErrorText());
+        // use empty string since gprc-status and grpc-message is absent
+        cntl->SetFailed(EGRPC, "");
+    } while (0);
+
     // Unlocks correlation_id inside. Revert controller's
     // error code if it version check of `cid' fails
     imsg_guard.reset();
@@ -748,7 +787,8 @@ HttpResponseSender::~HttpResponseSender() {
     bool grpc_compressed = false;
     bool grpc_protocol =
         ParseContentType(req_header->content_type()) == HTTP_CONTENT_GRPC;
-    if (cntl->Failed()) {
+
+    if (cntl->Failed() && !grpc_protocol) {
         // Set status-code with default value(converted from error code)
         // if user did not set it.
         if (res_header->status_code() == HTTP_STATUS_OK) {
@@ -802,35 +842,61 @@ HttpResponseSender::~HttpResponseSender() {
         }
     }
 
+    TrailerMessage trailers;
     if (grpc_protocol) {
+        // status code is always 200 according to grpc protocol
+        res_header->set_status_code(HTTP_STATUS_OK);
+        res_header->set_content_type(common->CONTENT_TYPE_GRPC);
+
+        GrpcStatus status = accessor.grpc_status();
+        std::string message = accessor.grpc_message();
+        if (status == GRPC_OK && cntl->Failed()) {
+            // In this case, request may not be handled by user-defined method or
+            // users use cntl.SetFailed to set grpc error instead of using
+            // cntl.set_grpc_error_code
+            status = ErrorCode2GrpcStatus(cntl->ErrorCode());
+            message = cntl->ErrorText();
+        }
+
+        std::string message_encoded;
+        percent_encode(message, &message_encoded);
+
+        trailers[common->GRPC_STATUS] = butil::string_printf("%d", status);
+        if (!message_encoded.empty()) {
+            trailers[common->GRPC_MESSAGE] = message_encoded;
+        }
+
         // always tell client gzip support
         // TODO(zhujiashun): add zlib and snappy?
         res_header->SetHeader(common->GRPC_ACCEPT_ENCODING,
             common->IDENTITY + "," + common->GZIP);
 
-        butil::IOBuf tmp_buf;
-        // Compressed-Flag as 0 / 1, encoded as 1 byte unsigned integer
-        if (grpc_compressed) {
-            tmp_buf.append("\1", 1);
+        if (status == GRPC_OK) {
+            butil::IOBuf tmp_buf;
+            // Compressed-Flag as 0 / 1, encoded as 1 byte unsigned integer
+            if (grpc_compressed) {
+                tmp_buf.append("\1", 1);
+            } else {
+                tmp_buf.append("\0", 1);
+            }
+            char size_buf[4];
+            WriteBigEndian4Bytes(size_buf, cntl->response_attachment().size());
+            tmp_buf.append(size_buf, 4);
+            tmp_buf.append(cntl->response_attachment());
+            cntl->response_attachment().swap(tmp_buf);
         } else {
-            tmp_buf.append("\0", 1);
+            cntl->response_attachment().clear();
         }
-        char size_buf[4];
-        WriteBigEndian4Bytes(size_buf, cntl->response_attachment().size());
-        tmp_buf.append(size_buf, 4);
-        tmp_buf.append(cntl->response_attachment());
-        cntl->response_attachment().swap(tmp_buf);
     }
 
-
     int rc = -1;
     // Have the risk of unlimited pending responses, in which case, tell
     // users to set max_concurrency.
     Socket::WriteOptions wopt;
     wopt.ignore_eovercrowded = true;
     if (req_header->is_http2()) {
-        SocketMessagePtr<H2UnsentResponse>
-            h2_response(H2UnsentResponse::New(cntl, _h2_stream_id));
+        SocketMessagePtr<H2UnsentResponse> h2_response(
+                H2UnsentResponse::New(cntl, trailers));
         if (h2_response == NULL) {
             LOG(ERROR) << "Fail to make http2 response";
             errno = EINVAL;
@@ -1195,11 +1261,12 @@ void ProcessHttpRequest(InputMessageBase *msg) {
     imsg_guard->header().Swap(req_header);
     butil::IOBuf& req_body = imsg_guard->body();
 
-    char compressed_grpc = false;
-    if (ParseContentType(req_header.content_type()) == HTTP_CONTENT_GRPC) {
+    char grpc_compressed = false;
+    if (ParseContentType(req_header.content_type()) == HTTP_CONTENT_GRPC &&
+        !req_body.empty()) {
         /* 4 is the size of grpc Message-Length in Length-Prefixed-Message*/
         char buf[4];
-        req_body.cut1(&compressed_grpc);
+        req_body.cut1(&grpc_compressed);
         req_body.cutn(buf, 4);
         int message_length = ReadBigEndian4Bytes(buf);
         CHECK(message_length == req_body.length());
@@ -1391,7 +1458,7 @@ void ProcessHttpRequest(InputMessageBase *msg) {
             const std::string* grpc_encoding =
                 req_header.GetHeader(common->GRPC_ENCODING);
             if ((encoding != NULL && *encoding == common->GZIP) ||
-                (compressed_grpc && grpc_encoding != NULL && *grpc_encoding ==
+                (grpc_compressed && grpc_encoding != NULL && *grpc_encoding ==
                  common->GZIP)) {
                 TRACEPRINTF("Decompressing request=%lu",
                             (unsigned long)req_body.size());

src/brpc/policy/http_rpc_protocol.h

@@ -69,6 +69,8 @@ struct CommonStrings {
     std::string TRAILERS;
     std::string GRPC_ENCODING;
     std::string GRPC_ACCEPT_ENCODING;
+    std::string GRPC_STATUS;
+    std::string GRPC_MESSAGE;
 
     CommonStrings();
 };

test/brpc_grpc_protocol_unittest.cpp

+// Copyright (c) 2018 Bilibili, Inc.
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// 
+//     http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Authors: Jiashun Zhu(zhujiashun@bilibili.com)
+
+#include <gtest/gtest.h>
+#include <gflags/gflags.h>
+#include "brpc/grpc.h"
+
+int main(int argc, char* argv[]) {
+    testing::InitGoogleTest(&argc, argv);
+    GFLAGS_NS::ParseCommandLineFlags(&argc, &argv, true);
+    if (GFLAGS_NS::SetCommandLineOption("crash_on_fatal_log", "true").empty()) {
+        std::cerr << "Fail to set -crash_on_fatal_log" << std::endl;
+        return -1;
+    }
+    return RUN_ALL_TESTS();
+}
+
+namespace {
+
+class GrpcTest : public ::testing::Test {
+protected:
+    GrpcTest() {}
+
+    virtual ~GrpcTest() {};
+    virtual void SetUp() {};
+    virtual void TearDown() {};
+};
+
+TEST_F(GrpcTest, percent_encode) {
+    std::string out;
+    std::string s1("abcdefg !@#$^&*()/");
+    brpc::percent_encode(s1, &out);
+    EXPECT_TRUE(out == s1) << s1 << " vs " << out;
+
+    char s2_buf[] = "\0\0%\33\35 brpc";
+    std::string s2(s2_buf, sizeof(s2_buf) - 1);
+    std::string s2_expected_out("%00%00%25%1b%1d brpc");
+    brpc::percent_encode(s2, &out);
+    EXPECT_TRUE(out == s2_expected_out) << s2_expected_out << " vs " << out;
+}
+
+TEST_F(GrpcTest, percent_decode) {
+    std::string out;
+    std::string s1("abcdefg !@#$^&*()/");
+    brpc::percent_decode(s1, &out);
+    EXPECT_TRUE(out == s1) << s1 << " vs " << out;
+
+    std::string s2("%00%00%1b%1d brpc");
+    char s2_expected_out_buf[] = "\0\0\33\35 brpc";
+    std::string s2_expected_out(s2_expected_out_buf, sizeof(s2_expected_out_buf) - 1);
+    brpc::percent_decode(s2, &out);
+    EXPECT_TRUE(out == s2_expected_out) << s2_expected_out << " vs " << out;
+}
+
+} // namespace