add android ipc function

src/android.c

@@ -0,0 +1,203 @@
+/*
+ * android.c - Setup IPC for shadowsocks-android
+ *
+ * Copyright (C) 2013 - 2015, Max Lv <max.c.lv@gmail.com>
+ *
+ * This file is part of the shadowsocks-libev.
+ *
+ * shadowsocks-libev is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * shadowsocks-libev is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with shadowsocks-libev; see the file COPYING. If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <locale.h>
+#include <signal.h>
+#include <string.h>
+#include <strings.h>
+#include <unistd.h>
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "netutils.h"
+#include "utils.h"
+#include "android.h"
+
+#ifndef EAGAIN
+#define EAGAIN EWOULDBLOCK
+#endif
+
+#ifndef EWOULDBLOCK
+#define EWOULDBLOCK EAGAIN
+#endif
+
+static void remote_recv_cb(EV_P_ ev_io *w, int revents);
+static void remote_send_cb(EV_P_ ev_io *w, int revents);
+
+static struct remote * new_remote(int fd, int timeout);
+
+static void free_remote(struct remote *remote);
+static void close_and_free_remote(EV_P_ struct remote *remote);
+
+int verbose = 0;
+
+static int setnonblocking(int fd)
+{
+    int flags;
+    if (-1 == (flags = fcntl(fd, F_GETFL, 0))) {
+        flags = 0;
+    }
+    return fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+}
+
+static void remote_timeout_cb(EV_P_ ev_timer *watcher, int revents)
+{
+    struct remote_ctx *remote_ctx = (struct remote_ctx *)(((void *)watcher) - sizeof(ev_io));
+    struct remote *remote = remote_ctx->remote;
+
+    if (verbose) {
+        LOGI("[android] IPC connection timeout");
+    }
+
+    remote->protect_cb(-1, remote->data);
+    close_and_free_remote(EV_A_ remote);
+}
+
+static void remote_recv_cb(EV_P_ ev_io *w, int revents)
+{
+    struct remote_ctx *remote_recv_ctx = (struct remote_ctx *)w;
+    struct remote *remote = remote_recv_ctx->remote;
+
+    int fd, ret = 0;
+
+    if (ancil_recv_fd(remote->fd, &fd)) {
+        ERROR("[android] ancil_recv_fd");
+        ret = -1;
+    }
+
+    if (fd != remote->protect_fd) {
+        ret = -1;
+    }
+
+    remote->protect_cb(ret, remote->data);
+    close_and_free_remote(remote);
+}
+
+static void remote_send_cb(EV_P_ ev_io *w, int revents)
+{
+    struct remote_ctx *remote_send_ctx = (struct remote_ctx *)w;
+    struct remote *remote = remote_send_ctx->remote;
+
+    int r = getpeername(remote->fd, (struct sockaddr *)&addr, &len);
+
+    if (r == 0) {
+        ev_io_stop(EV_A_ & remote_send_ctx->io);
+        ev_timer_stop(EV_A_ & remote_send_ctx->watcher);
+
+        if (ancil_send_fd(remote->fd, remote->protect_fd)) {
+            ERROR("[android] ancil_send_fd");
+            remote->protect_cb(-1, remote->data);
+            close_and_free_remote(EV_A_ remote);
+            return;
+        }
+
+        ev_io_start(EV_A_ & remote->recv_ctx->io);
+        ev_timer_start(EV_A_ & remote->recv_ctx->watcher);
+    } else {
+        ERROR("[android] getpeername");
+        remote->protect_cb(-1, remote->data);
+        close_and_free_remote(EV_A_ remote);
+        return;
+    }
+}
+
+
+static struct remote * new_remote(int fd, int timeout)
+{
+    struct remote *remote;
+    remote = malloc(sizeof(struct remote));
+    remote->recv_ctx = malloc(sizeof(struct remote_ctx));
+    remote->send_ctx = malloc(sizeof(struct remote_ctx));
+    remote->fd = fd;
+    ev_io_init(&remote->recv_ctx->io, remote_recv_cb, fd, EV_READ);
+    ev_io_init(&remote->send_ctx->io, remote_send_cb, fd, EV_WRITE);
+    ev_timer_init(&remote->send_ctx->watcher, remote_timeout_cb, timeout, 0);
+    ev_timer_init(&remote->recv_ctx->watcher, remote_timeout_cb, timeout, 0);
+    remote->recv_ctx->remote = remote;
+    remote->send_ctx->remote = remote;
+    return remote;
+}
+
+static void free_remote(struct remote *remote)
+{
+    if (remote != NULL) {
+        free(remote->recv_ctx);
+        free(remote->send_ctx);
+        free(remote);
+    }
+}
+
+static void close_and_free_remote(EV_P_ struct remote *remote)
+{
+    if (remote != NULL) {
+        ev_timer_stop(EV_A_ & remote->send_ctx->watcher);
+        ev_timer_stop(EV_A_ & remote->recv_ctx->watcher);
+        ev_io_stop(EV_A_ & remote->send_ctx->io);
+        ev_io_stop(EV_A_ & remote->recv_ctx->io);
+        close(remote->fd);
+        free_remote(remote);
+    }
+}
+
+int protect_socket(void (*protect_cb)(int ret, void *data), void *data, int fd) {
+    // Inilitialize ev loop
+    struct ev_loop *loop = EV_DEFAULT;
+
+    int remotefd;
+    struct sockaddr_un addr;
+
+    // Setup
+    setnonblocking(remotefd);
+
+    if ( (remotefd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
+        LOGE("[android] socket() failed: %s (socket fd = %d)\n", strerror(errno), remotefd);
+        return -1;
+    }
+
+    memset(&addr, 0, sizeof(addr));
+    addr.sun_family = AF_UNIX;
+    strncpy(addr.sun_path, "/data/data/com.github.shadowsocks/protect_path", sizeof(addr.sun_path)-1);
+
+    struct remote *remote = new_remote(remotefd, 100);
+
+    remote->protect_fd = fd;
+    remote->protect_cb = protect_cb;
+    remote->data = data;
+
+    if (connect(remotefd, (struct sockaddr*)&addr, sizeof(addr)) == -1) {
+        LOGE("[android] connect() failed: %s (fd = %d)\n", strerror(errno), remotefd);
+        close(remotefd);
+        return -1
+    }
+
+    // listen to remote connected event
+    ev_io_start(EV_A_ & remote->send_ctx->io);
+    ev_timer_start(EV_A_ & remote->send_ctx->watcher);
+
+    return 0;
+}
+

src/android.h

@@ -0,0 +1,45 @@
+/*
+ * android.h - Define Android IPC's buffers and callbacks
+ *
+ * Copyright (C) 2013 - 2015, Max Lv <max.c.lv@gmail.com>
+ *
+ * This file is part of the shadowsocks-libev.
+ *
+ * shadowsocks-libev is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * shadowsocks-libev is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with shadowsocks-libev; see the file COPYING. If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _ANDROID_H
+#define _ANDROID_H
+
+#include <ev.h>
+
+#include "common.h"
+
+struct remote_ctx {
+    ev_io io;
+    ev_timer watcher;
+    struct remote *remote;
+};
+
+struct remote {
+    int fd;
+    int protect_fd;
+    void *data;
+    void (*protect_cb)(int ret, void *data);
+    struct remote_ctx *recv_ctx;
+    struct remote_ctx *send_ctx;
+};
+
+#endif // _ANDROID_H

src/local.c

@@ -67,6 +67,10 @@
 #include "acl.h"
 #include "local.h"
 
+#ifdef ANDROID
+#include "android.h"
+#endif
+
 #ifndef EAGAIN
 #define EAGAIN EWOULDBLOCK
 #endif
@@ -98,6 +102,8 @@ static void remote_send_cb(EV_P_ ev_io *w, int revents);
 static void accept_cb(EV_P_ ev_io *w, int revents);
 static void signal_cb(EV_P_ ev_signal *w, int revents);
 
+static void protect_cb(int ret, void *data);
+
 static int create_and_bind(const char *addr, const char *port);
 static struct remote * create_remote(struct listen_ctx *listener, struct sockaddr *addr);
 static void free_remote(struct remote *remote);
@@ -195,6 +201,26 @@ static void free_connections(struct ev_loop *loop)
     }
 }
 
+#ifdef ANDROID
+static void protect_cb(int ret, void *data) {
+    struct remote_ctx *remote_ctx = (struct remote_ctx *)data;
+    struct remote *remote = remote_ctx->remote;
+    struct server *server = remote->server;
+
+    if (verbose) {
+        LOGI("[android] one connection protected");
+    }
+
+    if (ret == -1) {
+        close_and_free_remote(EV_DEFAULT, remote);
+        close_and_free_remote(EV_DEFAULT, server);
+        return;
+    }
+
+    server_recv_cb(EV_DEFAULT, server->recv_ctx, EV_CUSTOM);
+}
+#endif
+
 static void server_recv_cb(EV_P_ ev_io *w, int revents)
 {
     struct server_ctx *server_recv_ctx = (struct server_ctx *)w;
@@ -208,23 +234,27 @@ static void server_recv_cb(EV_P_ ev_io *w, int revents)
         buf = remote->buf;
     }
 
-    ssize_t r = recv(server->fd, buf, BUF_SIZE, 0);
+    ssize_t r;
 
-    if (r == 0) {
-        // connection closed
-        close_and_free_remote(EV_A_ remote);
-        close_and_free_server(EV_A_ server);
-        return;
-    } else if (r < 0) {
-        if (errno == EAGAIN || errno == EWOULDBLOCK) {
-            // no data
-            // continue to wait for recv
-            return;
-        } else {
-            ERROR("server_recv_cb_recv");
+    if (revents != EV_CUSTOM) {
+        r = recv(server->fd, buf, BUF_SIZE, 0);
+
+        if (r == 0) {
+            // connection closed
             close_and_free_remote(EV_A_ remote);
             close_and_free_server(EV_A_ server);
             return;
+        } else if (r < 0) {
+            if (errno == EAGAIN || errno == EWOULDBLOCK) {
+                // no data
+                // continue to wait for recv
+                return;
+            } else {
+                ERROR("server_recv_cb_recv");
+                close_and_free_remote(EV_A_ remote);
+                close_and_free_server(EV_A_ server);
+                return;
+            }
         }
     }
 
@@ -237,6 +267,14 @@ static void server_recv_cb(EV_P_ ev_io *w, int revents)
                 return;
             }
 
+#ifdef ANDROID
+            if (revents != EV_CUSTOM) {
+                ev_io_stop(EV_A_ & server_recv_ctx->io);
+                protect_socket(protect_cb, (void*)remote, remote->fd);
+                return;
+            }
+#endif
+
             // insert shadowsocks header
             if (!remote->direct) {
                 remote->buf = ss_encrypt(BUF_SIZE, remote->buf, &r,