nghttpx: Refactor backend proxy configuration

src/shrpx.cc

@@ -972,8 +972,6 @@ void fill_default_config() {
   mod_config()->pid = getpid();
   mod_config()->backend_ipv4 = false;
   mod_config()->backend_ipv6 = false;
-  mod_config()->downstream_http_proxy_userinfo = nullptr;
-  mod_config()->downstream_http_proxy_host = nullptr;
   mod_config()->downstream_http_proxy_port = 0;
   mod_config()->read_rate = 0;
   mod_config()->read_burst = 0;
@@ -2572,13 +2570,12 @@ int main(int argc, char **argv) {
     }
   }
 
-  if (get_config()->downstream_http_proxy_host) {
+  auto &proxy = mod_config()->downstream_http_proxy;
+  if (!proxy.host.empty()) {
     if (LOG_ENABLED(INFO)) {
       LOG(INFO) << "Resolving backend http proxy address";
     }
-    if (resolve_hostname(&mod_config()->downstream_http_proxy_addr,
-                         get_config()->downstream_http_proxy_host.get(),
-                         get_config()->downstream_http_proxy_port,
+    if (resolve_hostname(&proxy.addr, proxy.host.c_str(), proxy.port,
                          AF_UNSPEC) == -1) {
       exit(EXIT_FAILURE);
     }

src/shrpx_config.cc

@@ -1705,6 +1705,10 @@ int parse_config(const char *opt, const char *optarg,
 
     return 0;
   case SHRPX_OPTID_BACKEND_HTTP_PROXY_URI: {
+    auto &proxy = mod_config()->downstream_http_proxy;
+    // Reset here so that multiple option occurrence does not merge
+    // the results.
+    proxy = {};
     // parse URI and get hostname, port and optionally userinfo.
     http_parser_url u{};
     int rv = http_parser_parse_url(optarg, strlen(optarg), 0, &u);
@@ -1715,19 +1719,17 @@ int parse_config(const char *opt, const char *optarg,
         // Surprisingly, u.field_set & UF_USERINFO is nonzero even if
         // userinfo component is empty string.
         if (!val.empty()) {
-          val = util::percent_decode(std::begin(val), std::end(val));
-          mod_config()->downstream_http_proxy_userinfo = strcopy(val);
+          proxy.userinfo = util::percent_decode(std::begin(val), std::end(val));
         }
       }
       if (u.field_set & UF_HOST) {
-        http2::copy_url_component(val, &u, UF_HOST, optarg);
-        mod_config()->downstream_http_proxy_host = strcopy(val);
+        http2::copy_url_component(proxy.host, &u, UF_HOST, optarg);
       } else {
         LOG(ERROR) << opt << ": no hostname specified";
         return -1;
       }
       if (u.field_set & UF_PORT) {
-        mod_config()->downstream_http_proxy_port = u.port;
+        proxy.port = u.port;
       } else {
         LOG(ERROR) << opt << ": no port specified";
         return -1;

src/shrpx_config.h

@@ -283,6 +283,15 @@ struct TicketKeys {
   std::vector<TicketKey> keys;
 };
 
+struct HttpProxy {
+  Address addr;
+  // host in http proxy URI
+  std::string host;
+  // userinfo in http proxy URI, not percent-encoded form
+  std::string userinfo;
+  uint16_t port;
+};
+
 struct Config {
   // The list of (private key file, certificate file) pair
   std::vector<std::pair<std::string, std::string>> subcerts;
@@ -298,11 +307,10 @@ struct Config {
   std::vector<std::string> npn_list;
   // list of supported SSL/TLS protocol strings.
   std::vector<std::string> tls_proto_list;
-  // binary form of http proxy host and port
-  Address downstream_http_proxy_addr;
   Address session_cache_memcached_addr;
   Address tls_ticket_key_memcached_addr;
   Router router;
+  HttpProxy downstream_http_proxy;
   // obfuscated value used in "by" parameter of Forwarded header
   // field.
   std::string forwarded_by_obfuscated;
@@ -335,10 +343,6 @@ struct Config {
   std::unique_ptr<char[]> conf_path;
   std::unique_ptr<char[]> ciphers;
   std::unique_ptr<char[]> cacert;
-  // userinfo in http proxy URI, not percent-encoded form
-  std::unique_ptr<char[]> downstream_http_proxy_userinfo;
-  // host in http proxy URI
-  std::unique_ptr<char[]> downstream_http_proxy_host;
   std::unique_ptr<char[]> http2_upstream_dump_request_header_file;
   std::unique_ptr<char[]> http2_upstream_dump_response_header_file;
   // Path to file containing CA certificate solely used for client

src/shrpx_http2_session.cc

@@ -271,27 +271,24 @@ int Http2Session::initiate_connection() {
 
   auto &downstream_addr = addrs[addr_idx_];
 
-  if (get_config()->downstream_http_proxy_host && state_ == DISCONNECTED) {
+  const auto &proxy = get_config()->downstream_http_proxy;
+  if (!proxy.host.empty() && state_ == DISCONNECTED) {
     if (LOG_ENABLED(INFO)) {
-      SSLOG(INFO, this) << "Connecting to the proxy "
-                        << get_config()->downstream_http_proxy_host.get() << ":"
-                        << get_config()->downstream_http_proxy_port;
+      SSLOG(INFO, this) << "Connecting to the proxy " << proxy.host << ":"
+                        << proxy.port;
     }
 
-    conn_.fd = util::create_nonblock_socket(
-        get_config()->downstream_http_proxy_addr.su.storage.ss_family);
+    conn_.fd = util::create_nonblock_socket(proxy.addr.su.storage.ss_family);
 
     if (conn_.fd == -1) {
       connect_blocker_->on_failure();
       return -1;
     }
 
-    rv = connect(conn_.fd, &get_config()->downstream_http_proxy_addr.su.sa,
-                 get_config()->downstream_http_proxy_addr.len);
+    rv = connect(conn_.fd, &proxy.addr.su.sa, proxy.addr.len);
     if (rv != 0 && errno != EINPROGRESS) {
-      SSLOG(ERROR, this) << "Failed to connect to the proxy "
-                         << get_config()->downstream_http_proxy_host.get()
-                         << ":" << get_config()->downstream_http_proxy_port;
+      SSLOG(ERROR, this) << "Failed to connect to the proxy " << proxy.host
+                         << ":" << proxy.port;
       connect_blocker_->on_failure();
       return -1;
     }
@@ -523,12 +520,10 @@ int Http2Session::downstream_connect_proxy() {
   req += " HTTP/1.1\r\nHost: ";
   req.append(downstream_addr.host.c_str(), downstream_addr.host.size());
   req += "\r\n";
-  if (get_config()->downstream_http_proxy_userinfo) {
+  const auto &proxy = get_config()->downstream_http_proxy;
+  if (!proxy.userinfo.empty()) {
     req += "Proxy-Authorization: Basic ";
-    size_t len = strlen(get_config()->downstream_http_proxy_userinfo.get());
-    req += base64::encode(get_config()->downstream_http_proxy_userinfo.get(),
-                          get_config()->downstream_http_proxy_userinfo.get() +
-                              len);
+    req += base64::encode(std::begin(proxy.userinfo), std::end(proxy.userinfo));
     req += "\r\n";
   }
   req += "\r\n";