protect udp relay socket

src/udprelay.c

@@ -86,6 +86,8 @@
 static void server_recv_cb(EV_P_ ev_io *w, int revents);
 static void remote_recv_cb(EV_P_ ev_io *w, int revents);
 static void remote_timeout_cb(EV_P_ ev_timer *watcher, int revents);
+static void protect_cb(int ret, void *data);
+
 static char *hash_key(const int af, const struct sockaddr_storage *addr);
 #ifdef UDPRELAY_REMOTE
 static void query_resolve_cb(struct sockaddr *addr, void *data);
@@ -98,6 +100,42 @@ extern int verbose;
 static int server_num = 0;
 static struct server_ctx *server_ctx_list[MAX_REMOTE_NUM] = { NULL };
 
+#ifdef ANDROID
+static struct protect_ctx *new_protect_ctx(char *buf, int buf_len,
+        struct sockaddr *addr, int addr_len) {
+    struct protect_ctx *protect_ctx = (struct protect_ctx *)malloc(sizeof(struct protect_ctx));
+    memset(protect_ctx, 0, sizeof(struct protect_ctx));
+
+    protect_ctx->buf = malloc(buf_len);
+    memcpy(protect_ctx->buf, buf, buf_len);
+    protect_ctx->buf_len = buf_len;
+
+    memcpy(&protect_ctx->addr, (const char*)addr, addr_len);
+    protect_ctx->addr_len = addr_len;
+
+    return protect_ctx;
+}
+
+static void free_protect_ctx(struct protect_ctx *protect_ctx) {
+    if (protect_ctx != NULL) {
+        free(protect_ctx->buf);
+        free(protect_ctx);
+    }
+}
+
+static void protect_cb(int ret, void *data) {
+    struct protect_ctx *protect_ctx = (struct protect_ctx*)data;
+    if (ret != -1) {
+        int s = sendto(protect_ctx->remote_ctx->fd, protect_ctx->buf,
+                protect_ctx->buf_len, 0, protect_ctx->addr, protect_ctx->addr_len);
+        if (s == -1) {
+            ERROR("[udp] sendto_remote");
+        }
+    }
+    free_protect_ctx(protect_ctx);
+}
+#endif
+
 #ifndef __MINGW32__
 static int setnonblocking(int fd)
 {
@@ -1058,11 +1096,17 @@ static void server_recv_cb(EV_P_ ev_io *w, int revents)
 
     buf = ss_encrypt_all(BUF_SIZE, buf, &buf_len, server_ctx->method);
 
+#ifdef ANDROID
+    struct protect_ctx *protect_ctx = new_protect_ctx(buf, buf_len, &remote_addr, remote_addr_len);
+    protect_ctx->remote_ctx = remote_ctx;
+    protect_socket(protect_cb, (void*)protect_ctx, remote_ctx->fd);
+#else
     int s = sendto(remote_ctx->fd, buf, buf_len, 0, remote_addr, remote_addr_len);
 
     if (s == -1) {
         ERROR("[udp] sendto_remote");
     }
+#endif
 
 #else
 

src/udprelay.h

@@ -82,4 +82,14 @@ struct remote_ctx {
     struct server_ctx *server_ctx;
 };
 
+#ifdef ANDROID
+struct protect_ctx {
+    int buf_len;
+    char *buf;
+    struct sockaddr_storage addr;
+    int addr_len;
+    struct remote_ctx *remote_ctx;
+}
+#endif
+
 #endif // _UDPRELAY_H