From bd0f15119a3563d16869262d4c38a419264799ec Mon Sep 17 00:00:00 2001 From: "Mark D. Roth" Date: Tue, 20 Feb 2018 10:28:22 -0800 Subject: Refactor code for generating balancer channel args. --- .../client_channel/lb_policy/grpclb/grpclb.cc | 115 ++++++++++-------- .../lb_policy/grpclb/grpclb_channel.cc | 52 +------- .../lb_policy/grpclb/grpclb_channel.h | 24 ++-- .../lb_policy/grpclb/grpclb_channel_secure.cc | 133 +++++++++++---------- 4 files changed, 144 insertions(+), 180 deletions(-) (limited to 'src/core/ext/filters/client_channel/lb_policy') diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc index 11163a56dc..e38211fbf4 100644 --- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc +++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc @@ -918,34 +918,8 @@ void GrpcLb::BalancerCallState::OnBalancerStatusReceivedLocked( // helper code for creating balancer channel // -// Helper function to construct a target info entry. -grpc_slice_hash_table_entry BalancerEntryCreate(const char* address, - const char* balancer_name) { - grpc_slice_hash_table_entry entry; - entry.key = grpc_slice_from_copied_string(address); - entry.value = gpr_strdup(balancer_name); - return entry; -} - -// Comparison function used for slice_hash_table vtable. -int BalancerNameCmp(void* a, void* b) { - const char* a_str = static_cast(a); - const char* b_str = static_cast(b); - return strcmp(a_str, b_str); -} - -/* Returns the channel args for the LB channel, used to create a bidirectional - * stream for the reception of load balancing updates. - * - * Inputs: - * - \a addresses: corresponding to the balancers. - * - \a response_generator: in order to propagate updates from the resolver - * above the grpclb policy. - * - \a args: other args inherited from the grpclb policy. */ -grpc_channel_args* BuildBalancerChannelArgs( - const grpc_lb_addresses* addresses, - FakeResolverResponseGenerator* response_generator, - const grpc_channel_args* args) { +grpc_lb_addresses* ExtractBalancerAddresses( + const grpc_lb_addresses* addresses) { size_t num_grpclb_addrs = 0; for (size_t i = 0; i < addresses->num_addresses; ++i) { if (addresses->addresses[i].is_balancer) ++num_grpclb_addrs; @@ -955,9 +929,6 @@ grpc_channel_args* BuildBalancerChannelArgs( GPR_ASSERT(num_grpclb_addrs > 0); grpc_lb_addresses* lb_addresses = grpc_lb_addresses_create(num_grpclb_addrs, nullptr); - grpc_slice_hash_table_entry* targets_info_entries = - (grpc_slice_hash_table_entry*)gpr_zalloc(sizeof(*targets_info_entries) * - num_grpclb_addrs); size_t lb_addresses_idx = 0; for (size_t i = 0; i < addresses->num_addresses; ++i) { if (!addresses->addresses[i].is_balancer) continue; @@ -965,32 +936,71 @@ grpc_channel_args* BuildBalancerChannelArgs( gpr_log(GPR_ERROR, "This LB policy doesn't support user data. It will be ignored"); } - char* addr_str; - GPR_ASSERT(grpc_sockaddr_to_string( - &addr_str, &addresses->addresses[i].address, true) > 0); - targets_info_entries[lb_addresses_idx] = - BalancerEntryCreate(addr_str, addresses->addresses[i].balancer_name); - gpr_free(addr_str); grpc_lb_addresses_set_address( lb_addresses, lb_addresses_idx++, addresses->addresses[i].address.addr, addresses->addresses[i].address.len, false /* is balancer */, addresses->addresses[i].balancer_name, nullptr /* user data */); } GPR_ASSERT(num_grpclb_addrs == lb_addresses_idx); - grpc_slice_hash_table* targets_info = grpc_slice_hash_table_create( - num_grpclb_addrs, targets_info_entries, gpr_free, BalancerNameCmp); - gpr_free(targets_info_entries); - grpc_channel_args* lb_channel_args = - grpc_lb_policy_grpclb_build_lb_channel_args(targets_info, - response_generator, args); - grpc_arg lb_channel_addresses_arg = - grpc_lb_addresses_create_channel_arg(lb_addresses); - grpc_channel_args* result = grpc_channel_args_copy_and_add( - lb_channel_args, &lb_channel_addresses_arg, 1); - grpc_slice_hash_table_unref(targets_info); - grpc_channel_args_destroy(lb_channel_args); + return lb_addresses; +} + +/* Returns the channel args for the LB channel, used to create a bidirectional + * stream for the reception of load balancing updates. + * + * Inputs: + * - \a addresses: corresponding to the balancers. + * - \a response_generator: in order to propagate updates from the resolver + * above the grpclb policy. + * - \a args: other args inherited from the grpclb policy. */ +grpc_channel_args* BuildBalancerChannelArgs( + const grpc_lb_addresses* addresses, + FakeResolverResponseGenerator* response_generator, + const grpc_channel_args* args) { + grpc_lb_addresses* lb_addresses = ExtractBalancerAddresses(addresses); + // Channel args to remove. + static const char* args_to_remove[] = { + // LB policy name, since we want to use the default (pick_first) in + // the LB channel. + GRPC_ARG_LB_POLICY_NAME, + // The channel arg for the server URI, since that will be different for + // the LB channel than for the parent channel. The client channel + // factory will re-add this arg with the right value. + GRPC_ARG_SERVER_URI, + // The resolved addresses, which will be generated by the name resolver + // used in the LB channel. Note that the LB channel will use the fake + // resolver, so this won't actually generate a query to DNS (or some + // other name service). However, the addresses returned by the fake + // resolver will have is_balancer=false, whereas our own addresses have + // is_balancer=true. We need the LB channel to return addresses with + // is_balancer=false so that it does not wind up recursively using the + // grpclb LB policy, as per the special case logic in client_channel.c. + GRPC_ARG_LB_ADDRESSES, + // The fake resolver response generator, because we are replacing it + // with the one from the grpclb policy, used to propagate updates to + // the LB channel. + GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR, + }; + // Channel args to add. + const grpc_arg args_to_add[] = { + // New LB addresses. + // Note that we pass these in both when creating the LB channel + // and via the fake resolver. The latter is what actually gets used. + grpc_lb_addresses_create_channel_arg(lb_addresses), + // The fake resolver response generator, which we use to inject + // address updates into the LB channel. + grpc_core::FakeResolverResponseGenerator::MakeChannelArg( + response_generator), + }; + // Construct channel args. + grpc_channel_args* new_args = grpc_channel_args_copy_and_add_and_remove( + args, args_to_remove, GPR_ARRAY_SIZE(args_to_remove), args_to_add, + GPR_ARRAY_SIZE(args_to_add)); + // Make any necessary modifications for security. + new_args = grpc_lb_policy_grpclb_modify_lb_channel_args(new_args); + // Clean up. grpc_lb_addresses_destroy(lb_addresses); - return result; + return new_args; } // @@ -1292,8 +1302,9 @@ void GrpcLb::ProcessChannelArgsLocked(const grpc_channel_args& args) { if (lb_channel_ == nullptr) { char* uri_str; gpr_asprintf(&uri_str, "fake:///%s", server_name_); - lb_channel_ = grpc_lb_policy_grpclb_create_lb_channel( - uri_str, client_channel_factory(), lb_channel_args); + lb_channel_ = grpc_client_channel_factory_create_channel( + client_channel_factory(), uri_str, + GRPC_CLIENT_CHANNEL_TYPE_LOAD_BALANCING, lb_channel_args); GPR_ASSERT(lb_channel_ != nullptr); gpr_free(uri_str); } diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.cc b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.cc index 013fb12aea..ebbe597d29 100644 --- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.cc +++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.cc @@ -16,57 +16,9 @@ * */ -#include -#include - -#include "src/core/ext/filters/client_channel/client_channel.h" #include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h" -#include "src/core/lib/channel/channel_args.h" -#include "src/core/lib/gpr/string.h" -#include "src/core/lib/iomgr/sockaddr_utils.h" -grpc_channel* grpc_lb_policy_grpclb_create_lb_channel( - const char* lb_service_target_addresses, - grpc_client_channel_factory* client_channel_factory, +grpc_channel_args* grpc_lb_policy_grpclb_modify_lb_channel_args( grpc_channel_args* args) { - grpc_channel* lb_channel = grpc_client_channel_factory_create_channel( - client_channel_factory, lb_service_target_addresses, - GRPC_CLIENT_CHANNEL_TYPE_LOAD_BALANCING, args); - return lb_channel; -} - -grpc_channel_args* grpc_lb_policy_grpclb_build_lb_channel_args( - grpc_slice_hash_table* targets_info, - grpc_core::FakeResolverResponseGenerator* response_generator, - const grpc_channel_args* args) { - const grpc_arg to_add[] = { - grpc_core::FakeResolverResponseGenerator::MakeChannelArg( - response_generator)}; - /* We remove: - * - * - The channel arg for the LB policy name, since we want to use the default - * (pick_first) in this case. - * - * - The channel arg for the resolved addresses, since that will be generated - * by the name resolver used in the LB channel. Note that the LB channel - * will use the fake resolver, so this won't actually generate a query - * to DNS (or some other name service). However, the addresses returned by - * the fake resolver will have is_balancer=false, whereas our own - * addresses have is_balancer=true. We need the LB channel to return - * addresses with is_balancer=false so that it does not wind up recursively - * using the grpclb LB policy, as per the special case logic in - * client_channel.c. - * - * - The channel arg for the server URI, since that will be different for the - * LB channel than for the parent channel (the client channel factory will - * re-add this arg with the right value). - * - * - The fake resolver generator, because we are replacing it with the one - * from the grpclb policy, used to propagate updates to the LB channel. */ - static const char* keys_to_remove[] = { - GRPC_ARG_LB_POLICY_NAME, GRPC_ARG_LB_ADDRESSES, GRPC_ARG_SERVER_URI, - GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR}; - return grpc_channel_args_copy_and_add_and_remove( - args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), to_add, - GPR_ARRAY_SIZE(to_add)); + return args; } diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h index 2e34e3cab5..6635010434 100644 --- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h +++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h @@ -20,25 +20,15 @@ #define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_CHANNEL_H #include "src/core/ext/filters/client_channel/lb_policy_factory.h" -#include "src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h" -#include "src/core/lib/slice/slice_hash_table.h" -/** Create the channel used for communicating with an LB service. - * Note that an LB *service* may be comprised of several LB *servers*. - * - * \a lb_service_target_addresses is the target URI containing the addresses - * from resolving the LB service's name (eg, ipv4:10.0.0.1:1234,10.2.3.4:9876). - * \a client_channel_factory will be used for the creation of the LB channel, - * alongside the channel args passed in \a args. */ -grpc_channel* grpc_lb_policy_grpclb_create_lb_channel( - const char* lb_service_target_addresses, - grpc_client_channel_factory* client_channel_factory, +/// Makes any necessary modifications to \a args for use in the grpclb +/// balancer channel. +/// +/// Takes ownership of \a args. +/// +/// Caller takes ownership of the returned args. +grpc_channel_args* grpc_lb_policy_grpclb_modify_lb_channel_args( grpc_channel_args* args); -grpc_channel_args* grpc_lb_policy_grpclb_build_lb_channel_args( - grpc_slice_hash_table* targets_info, - grpc_core::FakeResolverResponseGenerator* response_generator, - const grpc_channel_args* args); - #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_GRPCLB_GRPCLB_CHANNEL_H \ */ diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel_secure.cc b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel_secure.cc index 5e615addbf..254a5dfd16 100644 --- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel_secure.cc +++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel_secure.cc @@ -16,11 +16,14 @@ * */ +#include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h" + +#include + #include #include #include "src/core/ext/filters/client_channel/client_channel.h" -#include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_channel.h" #include "src/core/lib/channel/channel_args.h" #include "src/core/lib/gpr/string.h" #include "src/core/lib/iomgr/sockaddr_utils.h" @@ -28,73 +31,81 @@ #include "src/core/lib/security/transport/lb_targets_info.h" #include "src/core/lib/slice/slice_internal.h" -grpc_channel* grpc_lb_policy_grpclb_create_lb_channel( - const char* lb_service_target_addresses, - grpc_client_channel_factory* client_channel_factory, +static void destroy_balancer_name(void* balancer_name) { + gpr_free(balancer_name); +} + +static grpc_slice_hash_table_entry targets_info_entry_create( + const char* address, const char* balancer_name) { + grpc_slice_hash_table_entry entry; + entry.key = grpc_slice_from_copied_string(address); + entry.value = gpr_strdup(balancer_name); + return entry; +} + +static int balancer_name_cmp_fn(void* a, void* b) { + const char* a_str = static_cast(a); + const char* b_str = static_cast(b); + return strcmp(a_str, b_str); +} + +static grpc_slice_hash_table* build_targets_info_table( + grpc_lb_addresses* addresses) { + grpc_slice_hash_table_entry* targets_info_entries = + static_cast( + gpr_zalloc(sizeof(*targets_info_entries) * addresses->num_addresses)); + for (size_t i = 0; i < addresses->num_addresses; ++i) { + char* addr_str; + GPR_ASSERT(grpc_sockaddr_to_string( + &addr_str, &addresses->addresses[i].address, true) > 0); + targets_info_entries[i] = targets_info_entry_create( + addr_str, addresses->addresses[i].balancer_name); + gpr_free(addr_str); + } + grpc_slice_hash_table* targets_info = grpc_slice_hash_table_create( + addresses->num_addresses, targets_info_entries, destroy_balancer_name, + balancer_name_cmp_fn); + gpr_free(targets_info_entries); + return targets_info; +} + +grpc_channel_args* grpc_lb_policy_grpclb_modify_lb_channel_args( grpc_channel_args* args) { - grpc_channel_args* new_args = args; + const char* args_to_remove[1]; + size_t num_args_to_remove = 0; + grpc_arg args_to_add[2]; + size_t num_args_to_add = 0; + // Add arg for targets info table. + const grpc_arg* arg = grpc_channel_args_find(args, GRPC_ARG_LB_ADDRESSES); + GPR_ASSERT(arg != nullptr); + GPR_ASSERT(arg->type == GRPC_ARG_POINTER); + grpc_lb_addresses* addresses = + static_cast(arg->value.pointer.p); + grpc_slice_hash_table* targets_info = build_targets_info_table(addresses); + args_to_add[num_args_to_add++] = + grpc_lb_targets_info_create_channel_arg(targets_info); + // Substitute the channel credentials with a version without call + // credentials: the load balancer is not necessarily trusted to handle + // bearer token credentials. grpc_channel_credentials* channel_credentials = grpc_channel_credentials_find_in_args(args); + grpc_channel_credentials* creds_sans_call_creds = nullptr; if (channel_credentials != nullptr) { - /* Substitute the channel credentials with a version without call - * credentials: the load balancer is not necessarily trusted to handle - * bearer token credentials */ - static const char* keys_to_remove[] = {GRPC_ARG_CHANNEL_CREDENTIALS}; - grpc_channel_credentials* creds_sans_call_creds = + creds_sans_call_creds = grpc_channel_credentials_duplicate_without_call_credentials( channel_credentials); GPR_ASSERT(creds_sans_call_creds != nullptr); - grpc_arg args_to_add[] = { - grpc_channel_credentials_to_arg(creds_sans_call_creds)}; - /* Create the new set of channel args */ - new_args = grpc_channel_args_copy_and_add_and_remove( - args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), args_to_add, - GPR_ARRAY_SIZE(args_to_add)); - grpc_channel_credentials_unref(creds_sans_call_creds); + args_to_remove[num_args_to_remove++] = GRPC_ARG_CHANNEL_CREDENTIALS; + args_to_add[num_args_to_add++] = + grpc_channel_credentials_to_arg(creds_sans_call_creds); } - grpc_channel* lb_channel = grpc_client_channel_factory_create_channel( - client_channel_factory, lb_service_target_addresses, - GRPC_CLIENT_CHANNEL_TYPE_LOAD_BALANCING, new_args); - if (channel_credentials != nullptr) { - grpc_channel_args_destroy(new_args); + grpc_channel_args* result = grpc_channel_args_copy_and_add_and_remove( + args, args_to_remove, num_args_to_remove, args_to_add, num_args_to_add); + // Clean up. + grpc_channel_args_destroy(args); + grpc_slice_hash_table_unref(targets_info); + if (creds_sans_call_creds != nullptr) { + grpc_channel_credentials_unref(creds_sans_call_creds); } - return lb_channel; -} - -grpc_channel_args* grpc_lb_policy_grpclb_build_lb_channel_args( - grpc_slice_hash_table* targets_info, - grpc_core::FakeResolverResponseGenerator* response_generator, - const grpc_channel_args* args) { - const grpc_arg to_add[] = { - grpc_lb_targets_info_create_channel_arg(targets_info), - grpc_core::FakeResolverResponseGenerator::MakeChannelArg( - response_generator)}; - /* We remove: - * - * - The channel arg for the LB policy name, since we want to use the default - * (pick_first) in this case. - * - * - The channel arg for the resolved addresses, since that will be generated - * by the name resolver used in the LB channel. Note that the LB channel - * will use the fake resolver, so this won't actually generate a query - * to DNS (or some other name service). However, the addresses returned by - * the fake resolver will have is_balancer=false, whereas our own - * addresses have is_balancer=true. We need the LB channel to return - * addresses with is_balancer=false so that it does not wind up recursively - * using the grpclb LB policy, as per the special case logic in - * client_channel.c. - * - * - The channel arg for the server URI, since that will be different for the - * LB channel than for the parent channel (the client channel factory will - * re-add this arg with the right value). - * - * - The fake resolver generator, because we are replacing it with the one - * from the grpclb policy, used to propagate updates to the LB channel. */ - static const char* keys_to_remove[] = { - GRPC_ARG_LB_POLICY_NAME, GRPC_ARG_LB_ADDRESSES, GRPC_ARG_SERVER_URI, - GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR}; - /* Add the targets info table to be used for secure naming */ - return grpc_channel_args_copy_and_add_and_remove( - args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), to_add, - GPR_ARRAY_SIZE(to_add)); + return result; } -- cgit v1.2.3