From 252586941934d23073a8d167ec240b221062505f Mon Sep 17 00:00:00 2001
From: David 'Digit' Turner <digit@android.com>
Date: Thu, 21 Mar 2013 21:07:42 +0100
Subject: adb: implement "adb reverse <local> <remote>"

This implements the logical opposite of 'adb forward', i.e.
the ability to reverse network connections from the device
to the host.

This feature is very useful for testing various programs
running on an Android device without root or poking at the
host's routing table.

Options and parameters are exactly the same as those for
'adb forward', except that the direction is reversed.

Examples:

  adb reverse tcp:5000 tcp:6000
    connections to localhost:5000 on the device will be
    forwarded to localhost:6000 on the host.

  adb reverse --no-rebind tcp:5000 tcp:6000
    same as above, but fails if the socket is already
    bound through a previous 'adb reverse tcp:5000 ...'
    command.

  adb reverse --list
    list all active reversed connections for the target
    device. Note: there is no command to list all
    reversed connections for all devices at once.

  adb reverse --remove tcp:5000
    remove any reversed connection on the device from
    localhost:5000

  adb reverse --remove-all
    remove all reversed connections form the current
    device.

Reversed connections are tied to a transport, in other
words, they disappear as soon as a device is disconnected.

Simple testing protocol:

  adb forward tcp:5000 tcp:6000
  adb reverse tcp:6000 tcp:7000
  nc -l localhost 7000

in another terminal:
  echo "Hello" | nc localhost 5000

Will print "Hello" on the first terminal.

Change-Id: I761af790cdb06829b68430afa4145a919fa0e6d5
---
 adb/commandline.c | 38 +++++++++++++++++++++++++++++---------
 1 file changed, 29 insertions(+), 9 deletions(-)

(limited to 'adb/commandline.c')

diff --git a/adb/commandline.c b/adb/commandline.c
index 241cefc5b..3970ab155 100644
--- a/adb/commandline.c
+++ b/adb/commandline.c
@@ -136,6 +136,19 @@ void help()
         "                                 if <local> is already forwarded\n"
         "  adb forward --remove <local> - remove a specific forward socket connection\n"
         "  adb forward --remove-all     - remove all forward socket connections\n"
+        "  adb reverse --list           - list all reverse socket connections from device\n"
+        "  adb reverse <remote> <local> - reverse socket connections\n"
+        "                                 reverse specs are one of:\n"
+        "                                   tcp:<port>\n"
+        "                                   localabstract:<unix domain socket name>\n"
+        "                                   localreserved:<unix domain socket name>\n"
+        "                                   localfilesystem:<unix domain socket name>\n"
+        "  adb reverse --norebind <remote> <local>\n"
+        "                               - same as 'adb reverse <remote> <local>' but fails\n"
+        "                                 if <remote> is already reversed.\n"
+        "  adb reverse --remove <remote>\n"
+        "                               - remove a specific reversed socket connection\n"
+        "  adb reverse --remove-all     - remove all reversed socket connections from device\n"
         "  adb jdwp                     - list PIDs of processes hosting a JDWP transport\n"
         "  adb install [-l] [-r] [-s] [--algo <algorithm name> --key <hex-encoded key> --iv <hex-encoded iv>] <file>\n"
         "                               - push this package file to the device and install it\n"
@@ -1299,8 +1312,11 @@ top:
         return 0;
     }
 
-    if(!strcmp(argv[0], "forward")) {
+    if(!strcmp(argv[0], "forward") ||
+       !strcmp(argv[0], "reverse"))
+    {
         char host_prefix[64];
+        char reverse = (char) !strcmp(argv[0], "reverse");
         char remove = 0;
         char remove_all = 0;
         char list = 0;
@@ -1329,15 +1345,19 @@ top:
         }
 
         // Determine the <host-prefix> for this command.
-        if (serial) {
-            snprintf(host_prefix, sizeof host_prefix, "host-serial:%s",
-                    serial);
-        } else if (ttype == kTransportUsb) {
-            snprintf(host_prefix, sizeof host_prefix, "host-usb");
-        } else if (ttype == kTransportLocal) {
-            snprintf(host_prefix, sizeof host_prefix, "host-local");
+        if (reverse) {
+            snprintf(host_prefix, sizeof host_prefix, "reverse");
         } else {
-            snprintf(host_prefix, sizeof host_prefix, "host");
+            if (serial) {
+                snprintf(host_prefix, sizeof host_prefix, "host-serial:%s",
+                        serial);
+            } else if (ttype == kTransportUsb) {
+                snprintf(host_prefix, sizeof host_prefix, "host-usb");
+            } else if (ttype == kTransportLocal) {
+                snprintf(host_prefix, sizeof host_prefix, "host-local");
+            } else {
+                snprintf(host_prefix, sizeof host_prefix, "host");
+            }
         }
 
         // Implement forward --list
-- 
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