1 /* 2 * 3 * Copyright 2017 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 #include <grpc/support/port_platform.h> 20 21 #include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h" 22 23 #include <string.h> 24 25 #include <grpc/support/alloc.h> 26 #include <grpc/support/string_util.h> 27 28 #include "src/core/ext/filters/client_channel/client_channel.h" 29 #include "src/core/lib/channel/channel_args.h" 30 #include "src/core/lib/gpr/string.h" 31 #include "src/core/lib/iomgr/sockaddr_utils.h" 32 #include "src/core/lib/security/credentials/credentials.h" 33 #include "src/core/lib/security/transport/target_authority_table.h" 34 #include "src/core/lib/slice/slice_internal.h" 35 36 namespace grpc_core { 37 namespace { 38 39 int BalancerNameCmp(const grpc_core::UniquePtr<char>& a, 40 const grpc_core::UniquePtr<char>& b) { 41 return strcmp(a.get(), b.get()); 42 } 43 44 RefCountedPtr<TargetAuthorityTable> CreateTargetAuthorityTable( 45 grpc_lb_addresses* addresses) { 46 TargetAuthorityTable::Entry* target_authority_entries = 47 static_cast<TargetAuthorityTable::Entry*>(gpr_zalloc( 48 sizeof(*target_authority_entries) * addresses->num_addresses)); 49 for (size_t i = 0; i < addresses->num_addresses; ++i) { 50 char* addr_str; 51 GPR_ASSERT(grpc_sockaddr_to_string( 52 &addr_str, &addresses->addresses[i].address, true) > 0); 53 target_authority_entries[i].key = grpc_slice_from_copied_string(addr_str); 54 target_authority_entries[i].value.reset( 55 gpr_strdup(addresses->addresses[i].balancer_name)); 56 gpr_free(addr_str); 57 } 58 RefCountedPtr<TargetAuthorityTable> target_authority_table = 59 TargetAuthorityTable::Create(addresses->num_addresses, 60 target_authority_entries, BalancerNameCmp); 61 gpr_free(target_authority_entries); 62 return target_authority_table; 63 } 64 65 } // namespace 66 } // namespace grpc_core 67 68 grpc_channel_args* grpc_lb_policy_grpclb_modify_lb_channel_args( 69 grpc_channel_args* args) { 70 const char* args_to_remove[1]; 71 size_t num_args_to_remove = 0; 72 grpc_arg args_to_add[2]; 73 size_t num_args_to_add = 0; 74 // Add arg for targets info table. 75 const grpc_arg* arg = grpc_channel_args_find(args, GRPC_ARG_LB_ADDRESSES); 76 GPR_ASSERT(arg != nullptr); 77 GPR_ASSERT(arg->type == GRPC_ARG_POINTER); 78 grpc_lb_addresses* addresses = 79 static_cast<grpc_lb_addresses*>(arg->value.pointer.p); 80 grpc_core::RefCountedPtr<grpc_core::TargetAuthorityTable> 81 target_authority_table = grpc_core::CreateTargetAuthorityTable(addresses); 82 args_to_add[num_args_to_add++] = 83 grpc_core::CreateTargetAuthorityTableChannelArg( 84 target_authority_table.get()); 85 // Substitute the channel credentials with a version without call 86 // credentials: the load balancer is not necessarily trusted to handle 87 // bearer token credentials. 88 grpc_channel_credentials* channel_credentials = 89 grpc_channel_credentials_find_in_args(args); 90 grpc_channel_credentials* creds_sans_call_creds = nullptr; 91 if (channel_credentials != nullptr) { 92 creds_sans_call_creds = 93 grpc_channel_credentials_duplicate_without_call_credentials( 94 channel_credentials); 95 GPR_ASSERT(creds_sans_call_creds != nullptr); 96 args_to_remove[num_args_to_remove++] = GRPC_ARG_CHANNEL_CREDENTIALS; 97 args_to_add[num_args_to_add++] = 98 grpc_channel_credentials_to_arg(creds_sans_call_creds); 99 } 100 grpc_channel_args* result = grpc_channel_args_copy_and_add_and_remove( 101 args, args_to_remove, num_args_to_remove, args_to_add, num_args_to_add); 102 // Clean up. 103 grpc_channel_args_destroy(args); 104 if (creds_sans_call_creds != nullptr) { 105 grpc_channel_credentials_unref(creds_sans_call_creds); 106 } 107 return result; 108 } 109
