fix(router): forward the matched path when nginx normalizes the request uri

apisix/init.lua

@@ -591,6 +591,17 @@ local function build_match_uri_keep_encoded_slash(path, current_uri)
 end
 
 
+-- whether the decoded path has a "." or ".." segment
+local function has_dot_segment(path)
+    if not core.string.find(path, ".") and not core.string.find(path, "%") then
+        return false
+    end
+    local decoded = percent_decode(path, false) .. "/"
+    return core.string.find(decoded, "/./") ~= nil
+           or core.string.find(decoded, "/../") ~= nil
+end
+
+
 local function common_phase(phase_name)
     local api_ctx = ngx.ctx.api_ctx
     if not api_ctx then
@@ -887,6 +898,20 @@ function _M.http_access_phase()
         end
     end
 
+    -- Nginx resolved dot segments in $uri, so forward the path the route was
+    -- matched on.
+    if not (local_conf.apisix and local_conf.apisix.normalize_uri_like_servlet) then
+        local path = api_ctx.var.request_uri
+        local args_pos = core.string.find(path, "?")
+        if args_pos then
+            path = str_sub(path, 1, args_pos - 1)
+        end
+        if path ~= uri and has_dot_segment(path) then
+            api_ctx.var.upstream_uri = core.utils.uri_safe_encode(uri)
+                                       .. api_ctx.var.is_args .. (api_ctx.var.args or "")
+        end
+    end
+
     -- To prevent being hacked by untrusted request_uri, here we
     -- record the normalized but not rewritten uri as request_uri,
     -- the original request_uri can be accessed via var.real_request_uri

docs/en/latest/router-radixtree.md

@@ -240,6 +240,20 @@ when either actually rewrites the URI (a stripped trailing slash, a servlet-styl
 matching without keeping `%2F`. The fallback is safe; the encoded-slash match
 simply does not apply to such requests.
 
+#### 6. Path forwarded to the upstream
+
+Routes are matched on the normalized `$uri`: Nginx percent-decodes the path,
+resolves dot segments (including encoded ones such as `..%2F` and `%2e%2e`) and
+merges consecutive slashes. When the decoded request path has no `.` or `..`
+segment, APISIX forwards the original request line to the upstream, consecutive
+slashes included. When it has one, APISIX forwards the matched path re-encoded,
+followed by the original query string. For example, a request to
+`/admin/..%2Fapi/x` matches a route for `/api/*` and the upstream receives
+`/api/x`.
+
+Plugins that set the upstream URI, such as `proxy-rewrite`, still take
+precedence.
+
 ### How to filter route by Nginx built-in variable?
 
 Nginx provides a variety of built-in variables that can be used to filter routes based on certain criteria. Here is an example of how to filter routes by Nginx built-in variables:

docs/zh/latest/router-radixtree.md

@@ -231,6 +231,12 @@ apisix:
 
 该选项会让位于 `delete_uri_tail_slash` 和 `normalize_uri_like_servlet`：等价性检查是与这两个选项处理之后的 URI 比较的，因此当其中任一确实改写了 URI（去掉末尾斜杠、剥离 servlet 风格的 `;` 参数）时，检查将不再成立，请求会回退到普通匹配而不保留 `%2F`。这种回退是安全的，只是保留编码斜杠的匹配对这类请求不再生效。
 
+#### 6. 转发给上游的路径
+
+路由基于归一化后的 `$uri` 进行匹配：Nginx 会对路径进行百分号解码、解析点段（包括 `..%2F`、`%2e%2e` 等编码形式）并合并连续斜杠。当解码后的请求路径不含 `.` 或 `..` 段时，APISIX 将原始请求行（包括连续斜杠）转发给上游。当路径包含这类段时，APISIX 会转发重新编码后的匹配路径，并附带原始查询字符串。例如，请求 `/admin/..%2Fapi/x` 会匹配 `/api/*` 路由，上游收到的是 `/api/x`。
+
+设置上游 URI 的插件（如 `proxy-rewrite`）仍然优先生效。
+
 ### 如何通过 Nginx 内置变量过滤路由
 
 具体参数及使用方式请查看 [radixtree#new](https://github.com/api7/lua-resty-radixtree#new) 文档，下面是一个简单的示例：

t/router/radixtree-uri-normalized-upstream.t

@@ -0,0 +1,185 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+use t::APISIX 'no_plan';
+
+repeat_each(1);
+log_level('info');
+worker_connections(256);
+no_root_location();
+no_shuffle();
+
+add_block_preprocessor(sub {
+    my ($block) = @_;
+
+    if (!$block->upstream_server_config) {
+        $block->set_value("upstream_server_config", <<'_EOC_');
+        location /admin/ {
+            content_by_lua_block {
+                ngx.say("request-uri=", ngx.var.request_uri)
+            }
+        }
+
+        location /api/ {
+            content_by_lua_block {
+                ngx.say("request-uri=", ngx.var.request_uri)
+            }
+        }
+
+        location = /fixed {
+            content_by_lua_block {
+                ngx.say("request-uri=", ngx.var.request_uri)
+            }
+        }
+_EOC_
+    }
+
+    if (!$block->request) {
+        $block->set_value("request", "GET /t");
+    }
+});
+
+run_tests();
+
+__DATA__
+
+=== TEST 1: set routes with and without auth on the same upstream
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            local routes = {
+                {
+                    id = "admin",
+                    uri = "/admin/*",
+                    plugins = {
+                        ["key-auth"] = {},
+                    },
+                },
+                {
+                    id = "api",
+                    uri = "/api/*",
+                },
+                {
+                    id = "rewrite",
+                    uri = "/rewrite/*",
+                    plugins = {
+                        ["proxy-rewrite"] = {
+                            uri = "/fixed",
+                        },
+                    },
+                },
+            }
+
+            for _, route in ipairs(routes) do
+                route.upstream = {
+                    nodes = { ["127.0.0.1:1980"] = 1 },
+                    type = "roundrobin",
+                }
+
+                local code, body = t("/apisix/admin/routes/" .. route.id,
+                    ngx.HTTP_PUT, route)
+                if code >= 300 then
+                    ngx.status = code
+                    ngx.say(body)
+                    return
+                end
+            end
+
+            ngx.say("passed")
+        }
+    }
+--- response_body
+passed
+
+
+
+=== TEST 2: route with key-auth requires an API key
+--- request
+GET /admin/x
+--- error_code: 401
+--- response_body
+{"message":"Missing API key in request"}
+
+
+
+=== TEST 3: encoded slash dot segment forwards the matched path
+--- request
+GET /admin/..%2Fapi/x
+--- response_body
+request-uri=/api/x
+
+
+
+=== TEST 4: encoded dot segment forwards the matched path with args
+--- request
+GET /admin/%2e%2e/api/x?a=1&b=%2F
+--- response_body
+request-uri=/api/x?a=1&b=%2F
+
+
+
+=== TEST 5: plain dot segment forwards the matched path
+--- request
+GET /admin/../api/x
+--- response_body
+request-uri=/api/x
+
+
+
+=== TEST 6: merged slashes alone are forwarded unchanged
+--- request
+GET /api/https://example.com//x
+--- response_body
+request-uri=/api/https://example.com//x
+
+
+
+=== TEST 7: encoded path without normalization is forwarded unchanged
+--- request
+GET /api/a%2Fb%20c?x=1
+--- response_body
+request-uri=/api/a%2Fb%20c?x=1
+
+
+
+=== TEST 8: proxy-rewrite uri still takes precedence
+--- request
+GET /rewrite/a/..%2Fb
+--- response_body
+request-uri=/fixed
+
+
+
+=== TEST 9: remove the routes
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            for _, id in ipairs({"admin", "api", "rewrite"}) do
+                local code, body = t("/apisix/admin/routes/" .. id, ngx.HTTP_DELETE)
+                if code >= 300 then
+                    ngx.status = code
+                    ngx.say(body)
+                    return
+                end
+            end
+
+            ngx.say("passed")
+        }
+    }
+--- response_body
+passed