support plugin

Signed-off-by: Jianhui Zhao <zhaojh329@gmail.com>

README.md

@@ -29,6 +29,7 @@ A Lightweight and fully asynchronous HTTP server library based on [libev] and [h
 * Lightweight and fully asynchronous
 * Use [libev] as its event backend
 * Support HTTPS - OpenSSL, mbedtls and CyaSSl(wolfssl)
+* Support plugin
 * Flexible - you can easily extend your application to have HTTP/HTTPS services
 * Code structure is concise and understandable, also suitable for learning
 

README_ZH.md

@@ -29,6 +29,7 @@
 * 轻量、全异步
 * 使用[libev]作为其事件后端
 * 支持HTTPS - OpenSSL, mbedtls 和 CyaSSl(wolfssl)
+* 支持插件
 * 可伸缩 - 你可以非常方便的扩展你的应用程序，使之具备HTTP/HTTPS服务
 * 代码结构简洁通俗易懂，亦适合学习
 

example/example.c

@@ -102,6 +102,8 @@ int main(int argc, char **argv)
 
     srv->on_request = on_request;
 
+    srv->load_plugin(srv, "/usr/local/lib/uhttpd/test.so");
+
     uh_log_info("Listen on: *:%d\n", port);
 
     ev_signal_init(&signal_watcher, signal_cb, SIGINT);

src/CMakeLists.txt

@@ -97,6 +97,8 @@ target_link_libraries(uhttpd_s ${EXTRA_LIBS})
 # configure a header file to pass some of the CMake settings to the source code
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/config.h.in ${CMAKE_CURRENT_BINARY_DIR}/config.h)
 
+add_subdirectory(plugins)
+
 install(
     FILES
         uhttpd.h

src/connection.c

@@ -252,16 +252,32 @@ static int on_body_cb(struct http_parser *parser, const char *at, size_t length)
     return 0;
 }
 
+static bool run_plugins(struct uh_connection *conn)
+{
+    struct uh_plugin *p = conn->srv->plugins;
+
+    while (p) {
+        if (!strcmp(conn->get_url(conn), p->path)) {
+            p->handler(conn);
+            return true;
+        }
+        p = p->next;
+    }
+    return false;
+}
+
 static int on_message_complete_cb(struct http_parser *parser)
 {
     struct uh_connection *conn = (struct uh_connection *)parser->data;
     struct uh_request *req = &conn->req;
     int i;
 
+    if (!run_plugins(conn)) {
         if (conn->srv->on_request)
             conn->srv->on_request(conn);
         else
             conn_error(conn, 404, NULL);
+    }
 
     buffer_pull(&conn->rb, NULL, buffer_length(&conn->rb));
 

src/plugins/CMakeLists.txt

@@ -0,0 +1,14 @@
+option(BUILD_TEST_PLUGIN "Build test plugin" ON)
+
+set(PLUGINS "")
+
+if(BUILD_TEST_PLUGIN)
+	set(PLUGINS ${PLUGINS} test_plugin)
+	add_library(test_plugin MODULE  test.c)
+	set_target_properties(test_plugin PROPERTIES OUTPUT_NAME test PREFIX "")
+endif()
+
+install(
+    TARGETS ${PLUGINS}
+    LIBRARY DESTINATION lib/uhttpd
+)

src/plugins/test.c

@@ -0,0 +1,37 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 Jianhui Zhao <zhaojh329@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "uhttpd.h"
+
+static void test_handler(struct uh_connection *conn)
+{
+    conn->send_head(conn, 200, -1, NULL);
+    conn->chunk_printf(conn, "Url: %s\n", conn->get_url(conn));
+    conn->chunk_end(conn);
+}
+
+struct uh_plugin uh_plugin = {
+    .path = "/test",
+    .handler = test_handler
+};

src/uhttpd.c

@@ -26,7 +26,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <errno.h>
-#include <stdio.h>
+#include <dlfcn.h>
 #include <arpa/inet.h>
 #include <sys/socket.h>
 
@@ -111,6 +111,40 @@ static int uh_server_ssl_init(struct uh_server *srv, const char *cert, const cha
 }
 #endif
 
+static int uh_load_plugin(struct uh_server *srv, const char *path)
+{
+    struct uh_plugin *p;
+    void *dlh;
+
+    dlh = dlopen(path, RTLD_LAZY | RTLD_LOCAL);
+    if (!dlh) {
+        uh_log_err("dlopen fail: %s\n", dlerror());
+        return -1;
+    }
+
+    p = dlsym(dlh, "uh_plugin");
+    if (!p) {
+        uh_log_err("not found symbol 'uh_plugin'\n");
+        return -1;
+    }
+
+    if (!p->path || !p->path[0] || !p->handler) {
+        uh_log_err("invalid plugin\n");
+        return -1;
+    }
+
+    if (!srv->plugins) {
+        srv->plugins = p;
+        return 0;
+    }
+
+    p->next = srv->plugins;
+    srv->plugins->prev = p;
+    srv->plugins = p;
+
+    return 0;
+}
+
 int uh_server_init(struct uh_server *srv, struct ev_loop *loop, const char *host, int port)
 {
     struct sockaddr_in addr = {
@@ -150,6 +184,8 @@ int uh_server_init(struct uh_server *srv, struct ev_loop *loop, const char *host
     srv->ssl_init = uh_server_ssl_init;
 #endif
 
+    srv->load_plugin = uh_load_plugin;
+
     ev_io_init(&srv->ior, uh_accept_cb, sock, EV_READ);
     ev_io_start(srv->loop, &srv->ior);
 

src/uhttpd.h

@@ -31,6 +31,13 @@
 #include "config.h"
 #include "log.h"
 
+struct uh_plugin {
+    const char *path;
+    void (*handler)(struct uh_connection *conn);
+    struct uh_plugin *prev;
+    struct uh_plugin *next;
+};
+
 struct uh_server {
     int sock;
     struct ev_loop *loop;
@@ -42,6 +49,8 @@ struct uh_server {
     void *ssl_ctx;
     int (*ssl_init)(struct uh_server *srv, const char *cert, const char *key);
 #endif
+    struct uh_plugin *plugins;
+    int (*load_plugin)(struct uh_server *srv, const char *path);
 };
 
 /*