1 files changed, 66 insertions, 49 deletions

diff --git a/src/device.c b/src/device.c
index 15f829b..1297a85 100644
--- a/src/device.c
+++ b/src/device.c
@@ -2,6 +2,7 @@
         usbmuxd - iPhone/iPod Touch USB multiplex server daemon
 
 Copyright (C) 2009      Hector Martin "marcan" <hector@marcansoft.com>
+Copyright (C) 2014  Mikkel Kamstrup Erlandsen <mikkel.kamstrup@xamarin.com>
 
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -126,6 +127,41 @@ static uint64_t mstime64(void)
         return tv.tv_sec * 1000 + tv.tv_usec / 1000;
 }
 
+static struct mux_device* get_mux_device_for_id(int device_id)
+{
+  struct mux_device *dev = NULL;
+        pthread_mutex_lock(&device_list_mutex);
+        FOREACH(struct mux_device *cdev, &device_list) {
+                if(cdev->id == device_id) {
+                        dev = cdev;
+                        break;
+                }
+        } ENDFOREACH
+        pthread_mutex_unlock(&device_list_mutex);
+
+        return dev;
+}
+
+static struct mux_connection* get_mux_connection(int device_id, struct mux_client *client)
+{
+        struct mux_connection *conn = NULL;
+        pthread_mutex_lock(&device_list_mutex);
+        FOREACH(struct mux_device *dev, &device_list) {
+                if(dev->id == device_id) {
+                        FOREACH(struct mux_connection *lconn, &dev->connections) {
+                                if(lconn->client == client) {
+                                        conn = lconn;
+                                        break;
+                                }
+                        } ENDFOREACH
+                        break;
+                }
+        } ENDFOREACH
+        pthread_mutex_unlock(&device_list_mutex);
+
+        return conn;
+}
+
 static int get_next_device_id(void)
 {
         while(1) {
@@ -274,15 +310,7 @@ static void connection_teardown(struct mux_connection *conn)
 
 int device_start_connect(int device_id, uint16_t dport, struct mux_client *client)
 {
-        struct mux_device *dev = NULL;
-        pthread_mutex_lock(&device_list_mutex);
-        FOREACH(struct mux_device *cdev, &device_list) {
-                if(cdev->id == device_id) {
-                        dev = cdev;
-                        break;
-                }
-        } ENDFOREACH
-        pthread_mutex_unlock(&device_list_mutex);
+        struct mux_device *dev = get_mux_device_for_id(device_id);
         if(!dev) {
                 usbmuxd_log(LL_WARNING, "Attempted to connect to nonexistent device %d", device_id);
                 return -RESULT_BADDEV;
@@ -369,6 +397,19 @@ static void update_connection(struct mux_connection *conn)
         client_set_events(conn->client, conn->events);
 }
 
+static int send_tcp_ack(struct mux_connection *conn)
+{
+        if(send_tcp(conn, TH_ACK, NULL, 0) < 0) {
+                usbmuxd_log(LL_ERROR, "Error sending TCP ACK (%d->%d)", conn->sport, conn->dport);
+                connection_teardown(conn);
+    return -1;
+        }
+
+  update_connection(conn);
+
+  return 0;
+}
+
 /**
  * Flush input and output buffers for a client connection.
  *
@@ -380,21 +421,7 @@ static void update_connection(struct mux_connection *conn)
  */
 void device_client_process(int device_id, struct mux_client *client, short events)
 {
-    // Find the connection for the given device_id
-        struct mux_connection *conn = NULL;
-        pthread_mutex_lock(&device_list_mutex);
-        FOREACH(struct mux_device *dev, &device_list) {
-                if(dev->id == device_id) {
-                        FOREACH(struct mux_connection *lconn, &dev->connections) {
-                                if(lconn->client == client) {
-                                        conn = lconn;
-                                        break;
-                                }
-                        } ENDFOREACH
-                        break;
-                }
-        } ENDFOREACH
-        pthread_mutex_unlock(&device_list_mutex);
+        struct mux_connection *conn = get_mux_connection(device_id, client);
 
         if(!conn) {
                 usbmuxd_log(LL_WARNING, "Could not find connection for device %d client %p", device_id, client);
@@ -405,8 +432,8 @@ void device_client_process(int device_id, struct mux_client *client, short event
         int res;
         int size;
         if(events & POLLOUT) {
-        // Client is ready to receive data, send what we have
-        // in the client's connection buffer
+                // Client is ready to receive data, send what we have
+                // in the client's connection buffer
                 size = client_write(conn->client, conn->ib_buf, conn->ib_size);
                 if(size <= 0) {
                         usbmuxd_log(LL_DEBUG, "error writing to client (%d)", size);
@@ -422,8 +449,8 @@ void device_client_process(int device_id, struct mux_client *client, short event
                 }
         }
         if(events & POLLIN) {
-        // There is inbound trafic on the client socket,
-        // convert it to tcp and send to the device
+                // There is inbound trafic on the client socket,
+                // convert it to tcp and send to the device
                 size = client_read(conn->client, conn->ob_buf, conn->sendable);
                 if(size <= 0) {
                         if (size < 0) {
@@ -475,23 +502,12 @@ static void connection_device_input(struct mux_connection *conn, unsigned char *
 
 void device_abort_connect(int device_id, struct mux_client *client)
 {
-        pthread_mutex_lock(&device_list_mutex);
-        FOREACH(struct mux_device *dev, &device_list) {
-                if(dev->id == device_id) {
-                        FOREACH(struct mux_connection *conn, &dev->connections) {
-                                if(conn->client == client) {
-                                        connection_teardown(conn);
-                                        pthread_mutex_unlock(&device_list_mutex);
-                                        return;
-                                }
-                        } ENDFOREACH
-                        pthread_mutex_unlock(&device_list_mutex);
-                        usbmuxd_log(LL_WARNING, "Attempted to abort for nonexistent connection for device %d", device_id);
-                        return;
-                }
-        } ENDFOREACH
-        pthread_mutex_unlock(&device_list_mutex);
-        usbmuxd_log(LL_WARNING, "Attempted to abort connection for nonexistent device %d", device_id);
+  struct mux_connection *conn = get_mux_connection(device_id, client);
+        if (conn) {
+                connection_teardown(conn);
+        } else {
+                usbmuxd_log(LL_WARNING, "Attempted to abort for nonexistent connection for device %d", device_id);
+        }
 }
 
 static void device_version_input(struct mux_device *dev, struct version_header *vh)
@@ -543,6 +559,7 @@ static void device_tcp_input(struct mux_device *dev, struct tcphdr *th, unsigned
                 return;
         }
 
+        // Find the connection on this device that has the right sport and dport
         FOREACH(struct mux_connection *lconn, &dev->connections) {
                 if(lconn->sport == sport && lconn->dport == dport) {
                         conn = lconn;
@@ -603,6 +620,9 @@ static void device_tcp_input(struct mux_device *dev, struct tcphdr *th, unsigned
                         connection_teardown(conn);
                 } else {
                         connection_device_input(conn, payload, payload_length);
+
+                        // Device likes it best when we are prompty ACKing data
+                        send_tcp_ack(conn);
                 }
         }
 }
@@ -866,10 +886,7 @@ void device_check_timeouts(void)
                                                 (conn->flags & CONN_ACK_PENDING) && 
                                                 (ct - conn->last_ack_time) > ACK_TIMEOUT) {
                                         usbmuxd_log(LL_DEBUG, "Sending ACK due to expired timeout (%" PRIu64 " -> %" PRIu64 ")", conn->last_ack_time, ct);
-                                        if(send_tcp(conn, TH_ACK, NULL, 0) < 0) {
-                                                usbmuxd_log(LL_ERROR, "Error sending TCP ACK to device %d (%d->%d)", dev->id, conn->sport, conn->dport);
-                                                connection_teardown(conn);
-                                        }
+                                        send_tcp_ack(conn);
                                 }
                         } ENDFOREACH
                 }