nghttpx: Fix location rewrite, take 2

src/http2.cc

@@ -327,39 +327,24 @@ void dump_nv(FILE *out, const Headers &nva) {
 
 std::string rewrite_location_uri(const std::string &uri,
                                  const http_parser_url &u,
-                                 const std::string &request_host,
-                                 const std::string &upstream_scheme,
-                                 uint16_t upstream_port) {
-  // We just rewrite host and optionally port. We don't rewrite https
-  // link. Not sure it happens in practice.
-  if (u.field_set & (1 << UF_SCHEMA)) {
-    auto field = &u.field_data[UF_SCHEMA];
-    if (!util::streq("http", &uri[field->off], field->len)) {
-      return "";
-    }
-  }
+                                 const std::string &match_host,
+                                 const std::string &request_authority,
+                                 const std::string &upstream_scheme) {
+  // We just rewrite scheme and authority.
   if ((u.field_set & (1 << UF_HOST)) == 0) {
     return "";
   }
   auto field = &u.field_data[UF_HOST];
-  if (!util::startsWith(std::begin(request_host), std::end(request_host),
+  if (!util::startsWith(std::begin(match_host), std::end(match_host),
                         &uri[field->off], &uri[field->off] + field->len) ||
-      (request_host.size() != field->len && request_host[field->len] != ':')) {
+      (match_host.size() != field->len && match_host[field->len] != ':')) {
     return "";
   }
-  std::string res = upstream_scheme;
-  res += "://";
-  res.append(&uri[field->off], field->len);
-  if (upstream_scheme == "http") {
-    if (upstream_port != 80) {
-      res += ":";
-      res += util::utos(upstream_port);
-    }
-  } else if (upstream_scheme == "https") {
-    if (upstream_port != 443) {
-      res += ":";
-      res += util::utos(upstream_port);
-    }
+  std::string res;
+  if (!request_authority.empty()) {
+    res += upstream_scheme;
+    res += "://";
+    res += request_authority;
   }
   if (u.field_set & (1 << UF_PATH)) {
     field = &u.field_data[UF_PATH];

src/http2.h

@@ -163,19 +163,22 @@ void dump_nv(FILE *out, const Headers &nva);
 
 // Rewrites redirection URI which usually appears in location header
 // field. The |uri| is the URI in the location header field. The |u|
-// stores the result of parsed |uri|. The |request_host| is the host
-// or :authority header field value in the request. The
+// stores the result of parsed |uri|. The |request_authority| is the
+// host or :authority header field value in the request. The
 // |upstream_scheme| is either "https" or "http" in the upstream
-// interface.
+// interface.  Rewrite is done only if location header field value
+// contains |match_host| as host excluding port.  The |match_host| and
+// |request_authority| could be different.  If |request_authority| is
+// empty, strip authority.
 //
 // This function returns the new rewritten URI on success. If the
 // location URI is not subject to the rewrite, this function returns
 // emtpy string.
 std::string rewrite_location_uri(const std::string &uri,
                                  const http_parser_url &u,
-                                 const std::string &request_host,
-                                 const std::string &upstream_scheme,
-                                 uint16_t upstream_port);
+                                 const std::string &match_host,
+                                 const std::string &request_authority,
+                                 const std::string &upstream_scheme);
 
 // Checks the header name/value pair using nghttp2_check_header_name()
 // and nghttp2_check_header_value(). If both function returns nonzero,

src/http2_test.cc

@@ -187,40 +187,44 @@ void test_http2_lws(void) {
 }
 
 namespace {
-void check_rewrite_location_uri(const std::string &new_uri,
-                                const std::string &uri,
-                                const std::string &req_host,
-                                const std::string &upstream_scheme,
-                                uint16_t upstream_port) {
+void check_rewrite_location_uri(const std::string &want, const std::string &uri,
+                                const std::string &match_host,
+                                const std::string &req_authority,
+                                const std::string &upstream_scheme) {
   http_parser_url u;
   memset(&u, 0, sizeof(u));
   CU_ASSERT(0 == http_parser_parse_url(uri.c_str(), uri.size(), 0, &u));
-  CU_ASSERT(new_uri == http2::rewrite_location_uri(
-                           uri, u, req_host, upstream_scheme, upstream_port));
+  auto got = http2::rewrite_location_uri(uri, u, match_host, req_authority,
+                                         upstream_scheme);
+  CU_ASSERT(want == got);
 }
 } // namespace
 
 void test_http2_rewrite_location_uri(void) {
   check_rewrite_location_uri("https://localhost:3000/alpha?bravo#charlie",
                              "http://localhost:3001/alpha?bravo#charlie",
-                             "localhost:3001", "https", 3000);
+                             "localhost:3001", "localhost:3000", "https");
   check_rewrite_location_uri("https://localhost/", "http://localhost:3001/",
-                             "localhost:3001", "https", 443);
+                             "localhost", "localhost", "https");
   check_rewrite_location_uri("http://localhost/", "http://localhost:3001/",
-                             "localhost:3001", "http", 80);
+                             "localhost", "localhost", "http");
   check_rewrite_location_uri("http://localhost:443/", "http://localhost:3001/",
-                             "localhost:3001", "http", 443);
+                             "localhost", "localhost:443", "http");
   check_rewrite_location_uri("https://localhost:80/", "http://localhost:3001/",
-                             "localhost:3001", "https", 80);
-  check_rewrite_location_uri("", "http://localhost:3001/", "127.0.0.1", "https",
-                             3000);
+                             "localhost", "localhost:80", "https");
+  check_rewrite_location_uri("", "http://localhost:3001/", "127.0.0.1",
+                             "127.0.0.1", "https");
   check_rewrite_location_uri("https://localhost:3000/",
-                             "http://localhost:3001/", "localhost", "https",
-                             3000);
-  check_rewrite_location_uri("", "https://localhost:3001/", "localhost",
-                             "https", 3000);
+                             "http://localhost:3001/", "localhost",
+                             "localhost:3000", "https");
   check_rewrite_location_uri("https://localhost:3000/", "http://localhost/",
-                             "localhost", "https", 3000);
+                             "localhost", "localhost:3000", "https");
+
+  // match_host != req_authority
+  check_rewrite_location_uri("https://example.org", "http://127.0.0.1:8080",
+                             "127.0.0.1", "example.org", "https");
+  check_rewrite_location_uri("", "http://example.org", "127.0.0.1",
+                             "example.org", "https");
 }
 
 void test_http2_parse_http_status_code(void) {

src/shrpx-unittest.cc

@@ -55,7 +55,6 @@ int main(int argc, char *argv[]) {
   SSL_library_init();
 
   shrpx::create_config();
-  shrpx::mod_config()->no_host_rewrite = true;
 
   // initialize the CUnit test registry
   if (CUE_SUCCESS != CU_initialize_registry())

src/shrpx_downstream.cc

@@ -532,9 +532,8 @@ Downstream::get_response_header(int16_t token) const {
   return http2::get_header(response_hdidx_, token, response_headers_);
 }
 
-void
-Downstream::rewrite_location_response_header(const std::string &upstream_scheme,
-                                             uint16_t upstream_port) {
+void Downstream::rewrite_location_response_header(
+    const std::string &upstream_scheme) {
   auto hd =
       http2::get_header(response_hdidx_, http2::HD_LOCATION, response_headers_);
   if (!hd) {
@@ -550,24 +549,41 @@ Downstream::rewrite_location_response_header(const std::string &upstream_scheme,
   std::string new_uri;
   if (get_config()->no_host_rewrite) {
     if (!request_http2_authority_.empty()) {
-      new_uri =
-          http2::rewrite_location_uri((*hd).value, u, request_http2_authority_,
-                                      upstream_scheme, upstream_port);
+      new_uri = http2::rewrite_location_uri(
+          (*hd).value, u, request_http2_authority_, request_http2_authority_,
+          upstream_scheme);
     }
     if (new_uri.empty()) {
       auto host = get_request_header(http2::HD_HOST);
-      if (!host) {
+      if (host) {
+        new_uri = http2::rewrite_location_uri((*hd).value, u, (*host).value,
+                                              (*host).value, upstream_scheme);
+      } else if (!request_downstream_host_.empty()) {
+        new_uri = http2::rewrite_location_uri(
+            (*hd).value, u, request_downstream_host_, "", upstream_scheme);
+      } else {
         return;
       }
-      new_uri = http2::rewrite_location_uri((*hd).value, u, (*host).value,
-                                            upstream_scheme, upstream_port);
     }
   } else {
-    assert(dconn_);
-    auto request_host =
-        get_config()->downstream_addrs[dconn_->get_addr_idx()].host.get();
-    new_uri = http2::rewrite_location_uri((*hd).value, u, request_host,
-                                          upstream_scheme, upstream_port);
+    if (request_downstream_host_.empty()) {
+      return;
+    }
+    if (!request_http2_authority_.empty()) {
+      new_uri = http2::rewrite_location_uri(
+          (*hd).value, u, request_downstream_host_, request_http2_authority_,
+          upstream_scheme);
+    } else {
+      auto host = get_request_header(http2::HD_HOST);
+      if (host) {
+        new_uri = http2::rewrite_location_uri((*hd).value, u,
+                                              request_downstream_host_,
+                                              (*host).value, upstream_scheme);
+      } else {
+        new_uri = http2::rewrite_location_uri(
+            (*hd).value, u, request_downstream_host_, "", upstream_scheme);
+      }
+    }
   }
   if (!new_uri.empty()) {
     auto idx = response_hdidx_[http2::HD_LOCATION];
@@ -1044,4 +1060,8 @@ void Downstream::add_retry() { ++num_retry_; }
 
 bool Downstream::no_more_retry() const { return num_retry_ > 5; }
 
+void Downstream::set_request_downstream_host(std::string host) {
+  request_downstream_host_ = std::move(host);
+}
+
 } // namespace shrpx

src/shrpx_downstream.h

@@ -166,6 +166,7 @@ public:
   int64_t get_request_content_length() const;
   void set_request_content_length(int64_t len);
   bool request_pseudo_header_allowed(int16_t token) const;
+  void set_request_downstream_host(std::string host);
   bool expect_response_body() const;
   enum {
     INITIAL,
@@ -194,8 +195,7 @@ public:
   // This function must be called after response headers are indexed.
   const Headers::value_type *get_response_header(int16_t token) const;
   // Rewrites the location response header field.
-  void rewrite_location_response_header(const std::string &upstream_scheme,
-                                        uint16_t upstream_port);
+  void rewrite_location_response_header(const std::string &upstream_scheme);
   void add_response_header(std::string name, std::string value);
   void set_last_response_header_value(std::string value);
 
@@ -310,6 +310,10 @@ private:
   std::string request_path_;
   std::string request_http2_scheme_;
   std::string request_http2_authority_;
+  // host we requested to downstream.  This is used to rewrite
+  // location header field to decide the location should be rewritten
+  // or not.
+  std::string request_downstream_host_;
   std::string assembled_request_cookie_;
 
   DefaultMemchunks request_buf_;

src/shrpx_downstream_connection.h

@@ -58,8 +58,6 @@ public:
   virtual void on_upstream_change(Upstream *uptream) = 0;
   virtual int on_priority_change(int32_t pri) = 0;
 
-  virtual size_t get_addr_idx() const = 0;
-
   void set_client_handler(ClientHandler *client_handler);
   ClientHandler *get_client_handler();
   Downstream *get_downstream();

src/shrpx_downstream_test.cc

@@ -136,20 +136,22 @@ void test_downstream_assemble_request_cookie(void) {
 void test_downstream_rewrite_location_response_header(void) {
   {
     Downstream d(nullptr, 0, 0);
-    d.add_request_header("host", "localhost:3000");
+    d.set_request_downstream_host("localhost:3000");
+    d.add_request_header("host", "localhost");
     d.add_response_header("location", "http://localhost:3000/");
     d.index_request_headers();
     d.index_response_headers();
-    d.rewrite_location_response_header("https", 443);
+    d.rewrite_location_response_header("https");
     auto location = d.get_response_header(http2::HD_LOCATION);
     CU_ASSERT("https://localhost/" == (*location).value);
   }
   {
     Downstream d(nullptr, 0, 0);
+    d.set_request_downstream_host("localhost");
     d.set_request_http2_authority("localhost");
-    d.add_response_header("location", "http://localhost/");
+    d.add_response_header("location", "http://localhost:3000/");
     d.index_response_headers();
-    d.rewrite_location_response_header("https", 443);
+    d.rewrite_location_response_header("https");
     auto location = d.get_response_header(http2::HD_LOCATION);
     CU_ASSERT("https://localhost/" == (*location).value);
   }

src/shrpx_http2_downstream_connection.cc

@@ -260,6 +260,12 @@ int Http2DownstreamConnection::push_request_headers() {
     host = get_config()->downstream_addrs[0].hostport.get();
   }
 
+  if (authority) {
+    downstream_->set_request_downstream_host(authority);
+  } else {
+    downstream_->set_request_downstream_host(host);
+  }
+
   size_t nheader = downstream_->get_request_headers().size();
 
   Headers cookies;
@@ -578,6 +584,4 @@ int Http2DownstreamConnection::on_timeout() {
   return submit_rst_stream(downstream_, NGHTTP2_NO_ERROR);
 }
 
-size_t Http2DownstreamConnection::get_addr_idx() const { return 0; }
-
 } // namespace shrpx

src/shrpx_http2_downstream_connection.h

@@ -62,8 +62,6 @@ public:
   virtual void on_upstream_change(Upstream *upstream) {}
   virtual int on_priority_change(int32_t pri);
 
-  virtual size_t get_addr_idx() const;
-
   int send();
 
   void attach_stream_data(StreamData *sd);

src/shrpx_http2_upstream.cc

@@ -1232,7 +1232,7 @@ int Http2Upstream::on_downstream_header_complete(Downstream *downstream) {
   if (!get_config()->http2_proxy && !get_config()->client_proxy &&
       !get_config()->no_location_rewrite) {
     downstream->rewrite_location_response_header(
-        get_client_handler()->get_upstream_scheme(), get_config()->port);
+        downstream->get_request_http2_scheme());
   }
 
   size_t nheader = downstream->get_response_headers().size();

src/shrpx_http_downstream_connection.cc

@@ -235,6 +235,12 @@ int HttpDownstreamConnection::push_request_headers() {
     host = get_config()->downstream_addrs[addr_idx_].hostport.get();
   }
 
+  if (authority) {
+    downstream_->set_request_downstream_host(authority);
+  } else {
+    downstream_->set_request_downstream_host(host);
+  }
+
   downstream_->assemble_request_cookie();
 
   // Assume that method and request path do not contain \r\n.
@@ -767,6 +773,4 @@ void HttpDownstreamConnection::on_upstream_change(Upstream *upstream) {}
 
 void HttpDownstreamConnection::signal_write() { conn_.wlimit.startw(); }
 
-size_t HttpDownstreamConnection::get_addr_idx() const { return addr_idx_; }
-
 } // namespace shrpx

src/shrpx_http_downstream_connection.h

@@ -59,8 +59,6 @@ public:
   virtual void on_upstream_change(Upstream *upstream);
   virtual int on_priority_change(int32_t pri) { return 0; }
 
-  virtual size_t get_addr_idx() const;
-
   int on_connect();
   void signal_write();
 

src/shrpx_https_upstream.cc

@@ -649,7 +649,7 @@ int HttpsUpstream::on_downstream_header_complete(Downstream *downstream) {
   if (!get_config()->http2_proxy && !get_config()->client_proxy &&
       !get_config()->no_location_rewrite) {
     downstream->rewrite_location_response_header(
-        get_client_handler()->get_upstream_scheme(), get_config()->port);
+        get_client_handler()->get_upstream_scheme());
   }
 
   http2::build_http1_headers_from_headers(hdrs,

src/shrpx_spdy_upstream.cc

@@ -841,7 +841,7 @@ int SpdyUpstream::on_downstream_header_complete(Downstream *downstream) {
   if (!get_config()->http2_proxy && !get_config()->client_proxy &&
       !get_config()->no_location_rewrite) {
     downstream->rewrite_location_response_header(
-        get_client_handler()->get_upstream_scheme(), get_config()->port);
+        downstream->get_request_http2_scheme());
   }
   size_t nheader = downstream->get_response_headers().size();
   // 8 means server, :status, :version and possible via header field.