Use default port 443 in HTTP CONNECT request (#26331)

* Use default port 443 in HTTP CONNECT request

* s/data/c_str

* Fix use-after-free

* Reviewer comments

src/core/ext/filters/client_channel/http_proxy.cc

@@ -36,6 +36,7 @@
 #include "src/core/lib/gpr/env.h"
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/gprpp/host_port.h"
+#include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/slice/b64.h"
 #include "src/core/lib/uri/uri_parser.h"
 
@@ -107,6 +108,17 @@ done:
   return proxy_name;
 }
 
+// Adds the default port if target does not contain a port.
+std::string MaybeAddDefaultPort(absl::string_view target) {
+  absl::string_view host;
+  absl::string_view port;
+  SplitHostPort(target, &host, &port);
+  if (port.empty()) {
+    return JoinHostPort(host, kDefaultSecurePortInt);
+  }
+  return std::string(target);
+}
+
 class HttpProxyMapper : public ProxyMapperInterface {
  public:
   bool MapName(const char* server_uri, const grpc_channel_args* args,
@@ -118,6 +130,7 @@ class HttpProxyMapper : public ProxyMapperInterface {
     *name_to_resolve = GetHttpProxyServer(args, &user_cred);
     if (*name_to_resolve == nullptr) return false;
     char* no_proxy_str = nullptr;
+    std::string server_target;
     absl::StatusOr<URI> uri = URI::Parse(server_uri);
     if (!uri.ok() || uri->path().empty()) {
       gpr_log(GPR_ERROR,
@@ -173,10 +186,12 @@ class HttpProxyMapper : public ProxyMapperInterface {
         if (!use_proxy) goto no_use_proxy;
       }
     }
+    server_target =
+        MaybeAddDefaultPort(absl::StripPrefix(uri->path(), "/")).c_str();
     grpc_arg args_to_add[2];
     args_to_add[0] = grpc_channel_arg_string_create(
         const_cast<char*>(GRPC_ARG_HTTP_CONNECT_SERVER),
-        const_cast<char*>(absl::StripPrefix(uri->path(), "/").data()));
+        const_cast<char*>(server_target.c_str()));
     if (user_cred != nullptr) {
       /* Use base64 encoding for user credentials as stated in RFC 7617 */
       char* encoded_user_cred =

src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc

@@ -60,8 +60,6 @@ namespace grpc_core {
 
 namespace {
 
-const char kDefaultPort[] = "https";
-
 class AresDnsResolver : public Resolver {
  public:
   explicit AresDnsResolver(ResolverArgs args);
@@ -431,7 +429,7 @@ void AresDnsResolver::StartResolvingLocked() {
   resolving_ = true;
   service_config_json_ = nullptr;
   pending_request_ = grpc_dns_lookup_ares_locked(
-      dns_server_.c_str(), name_to_resolve_.c_str(), kDefaultPort,
+      dns_server_.c_str(), name_to_resolve_.c_str(), kDefaultSecurePort,
       interested_parties_, &on_resolved_, &addresses_,
       enable_srv_queries_ ? &balancer_addresses_ : nullptr,
       request_service_config_ ? &service_config_json_ : nullptr,

src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc

@@ -48,8 +48,6 @@ namespace grpc_core {
 
 namespace {
 
-const char kDefaultPort[] = "https";
-
 class NativeDnsResolver : public Resolver {
  public:
   explicit NativeDnsResolver(ResolverArgs args);
@@ -276,7 +274,7 @@ void NativeDnsResolver::StartResolvingLocked() {
   addresses_ = nullptr;
   GRPC_CLOSURE_INIT(&on_resolved_, NativeDnsResolver::OnResolved, this,
                     grpc_schedule_on_exec_ctx);
-  grpc_resolve_address(name_to_resolve_.c_str(), kDefaultPort,
+  grpc_resolve_address(name_to_resolve_.c_str(), kDefaultSecurePort,
                        interested_parties_, &on_resolved_, &addresses_);
   last_resolution_timestamp_ = grpc_core::ExecCtx::Get()->Now();
 }

src/core/lib/iomgr/resolve_address.cc

@@ -21,6 +21,10 @@
 #include <grpc/support/alloc.h>
 #include "src/core/lib/iomgr/resolve_address.h"
 
+namespace grpc_core {
+const char* kDefaultSecurePort = "https";
+}  // namespace grpc_core
+
 grpc_address_resolver_vtable* grpc_resolve_address_impl;
 
 void grpc_set_resolver_impl(grpc_address_resolver_vtable* vtable) {

src/core/lib/iomgr/resolve_address.h

@@ -49,6 +49,12 @@ struct grpc_resolved_addresses {
   size_t naddrs;
   grpc_resolved_address* addrs;
 };
+
+namespace grpc_core {
+extern const char* kDefaultSecurePort;
+constexpr int kDefaultSecurePortInt = 443;
+}  // namespace grpc_core
+
 typedef struct grpc_address_resolver_vtable {
   void (*resolve_address)(const char* addr, const char* default_port,
                           grpc_pollset_set* interested_parties,