Change debugserver to open the socket it listens

to in INADDR_LOOPBACK mode by default ("localhost only")
instead of INADDR_ANY ("accept connections from any system").

Add a new command line argument to debugserver, --open-connection
or -H which will enable the previous behavior.  It would be used
if you were doing two-system debugging, with lldb running on one
system and debugserver running on the other.  But it is a less
common workflow and should not be the default.

<rdar://problem/12583284> 

llvm-svn: 177790

3 files changed, 22 insertions, 10 deletions

diff --git a/lldb/tools/debugserver/source/RNBSocket.cpp b/lldb/tools/debugserver/source/RNBSocket.cpp
index e6c669c0ab1..495c890ed27 100644
--- a/lldb/tools/debugserver/source/RNBSocket.cpp
+++ b/lldb/tools/debugserver/source/RNBSocket.cpp
@@ -31,7 +31,7 @@
    This function blocks while waiting for that connection.  */
 
 rnb_err_t
-RNBSocket::Listen (in_port_t port, PortBoundCallback callback, const void *callback_baton)
+RNBSocket::Listen (in_port_t port, PortBoundCallback callback, const void *callback_baton, bool localhost_only)
 {
     //DNBLogThreadedIf(LOG_RNB_COMM, "%8u RNBSocket::%s called", (uint32_t)m_timer.ElapsedMicroSeconds(true), __FUNCTION__);
     // Disconnect without saving errno
@@ -56,7 +56,14 @@ RNBSocket::Listen (in_port_t port, PortBoundCallback callback, const void *callb
     sa.sin_len = sizeof sa;
     sa.sin_family = AF_INET;
     sa.sin_port = htons (port);
-    sa.sin_addr.s_addr = htonl (INADDR_ANY);
+    if (localhost_only)
+    {
+        sa.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
+    }
+    else
+    {
+        sa.sin_addr.s_addr = htonl (INADDR_ANY);
+    }
 
     int error = ::bind (listen_fd, (struct sockaddr *) &sa, sizeof(sa));
     if (error == -1)
diff --git a/lldb/tools/debugserver/source/RNBSocket.h b/lldb/tools/debugserver/source/RNBSocket.h
index be2199d5316..2417d574f2c 100644
--- a/lldb/tools/debugserver/source/RNBSocket.h
+++ b/lldb/tools/debugserver/source/RNBSocket.h
@@ -43,7 +43,7 @@ public:
         Disconnect (false);
     }
 
-    rnb_err_t Listen (in_port_t port, PortBoundCallback callback, const void *callback_baton);
+    rnb_err_t Listen (in_port_t port, PortBoundCallback callback, const void *callback_baton, bool localhost_only);
     rnb_err_t Connect (const char *host, uint16_t port);
 
     rnb_err_t useFD(int fd);
diff --git a/lldb/tools/debugserver/source/debugserver.cpp b/lldb/tools/debugserver/source/debugserver.cpp
index 35918a3aee1..ecafaaf6796 100644
--- a/lldb/tools/debugserver/source/debugserver.cpp
+++ b/lldb/tools/debugserver/source/debugserver.cpp
@@ -684,13 +684,13 @@ PortWasBoundCallback (const void *baton, in_port_t port)
 }
 
 static int
-StartListening (RNBRemote *remote, int listen_port, const char *unix_socket_name)
+StartListening (RNBRemote *remote, int listen_port, const char *unix_socket_name, bool localhost_only)
 {
     if (!remote->Comm().IsConnected())
     {
         if (listen_port != 0)
             RNBLogSTDOUT ("Listening to port %i...\n", listen_port);
-        if (remote->Comm().Listen(listen_port, PortWasBoundCallback, unix_socket_name) != rnb_success)
+        if (remote->Comm().Listen(listen_port, PortWasBoundCallback, unix_socket_name, localhost_only) != rnb_success)
         {
             RNBLogSTDERR ("Failed to get connection from a remote gdb process.\n");
             return 0;
@@ -786,6 +786,7 @@ static struct option g_long_options[] =
     { "working-dir",        required_argument,  NULL,               'W' },  // The working directory that the inferior process should have (only if debugserver launches the process)
     { "platform",           required_argument,  NULL,               'p' },  // Put this executable into a remote platform mode
     { "unix-socket",        required_argument,  NULL,               'u' },  // If we need to handshake with our parent process, an option will be passed down that specifies a unix socket name to use
+    { "open-connection",    no_argument,        NULL,               'H' },  // If debugserver is listening to a TCP port, allow connections from any host (as opposed to just "localhost" connections)
     { NULL,                 0,                  NULL,               0   }
 };
 
@@ -841,6 +842,7 @@ main (int argc, char *argv[])
     useconds_t waitfor_interval = 1000;     // Time in usecs between process lists polls when waiting for a process by name, default 1 msec.
     useconds_t waitfor_duration = 0;        // Time in seconds to wait for a process by name, 0 means wait forever.
     bool no_stdio = false;
+    bool localhost_only = true;
 
 #if !defined (DNBLOG_ENABLED)
     compile_options += "(no-logging) ";
@@ -1080,7 +1082,10 @@ main (int argc, char *argv[])
             case 'u':
                 unix_socket_name.assign (optarg);
                 break;
-                
+
+            case 'H':
+                localhost_only = false;
+                break;
         }
     }
     
@@ -1286,7 +1291,7 @@ main (int argc, char *argv[])
 #endif
                 if (listen_port != INT32_MAX)
                 {
-                    if (!StartListening (remote, listen_port, unix_socket_name.c_str()))
+                    if (!StartListening (remote, listen_port, unix_socket_name.c_str(), localhost_only))
                         mode = eRNBRunLoopModeExit;
                 }
                 else if (str[0] == '/')
@@ -1399,7 +1404,7 @@ main (int argc, char *argv[])
                 {
                     if (listen_port != INT32_MAX)
                     {
-                        if (!StartListening (remote, listen_port, unix_socket_name.c_str()))
+                        if (!StartListening (remote, listen_port, unix_socket_name.c_str(), localhost_only))
                             mode = eRNBRunLoopModeExit;
                     }
                     else if (str[0] == '/')
@@ -1424,7 +1429,7 @@ main (int argc, char *argv[])
                     {
                         if (listen_port != INT32_MAX)
                         {
-                            if (!StartListening (remote, listen_port, unix_socket_name.c_str()))
+                            if (!StartListening (remote, listen_port, unix_socket_name.c_str(), localhost_only))
                                 mode = eRNBRunLoopModeExit;
                         }
                         else if (str[0] == '/')
@@ -1451,7 +1456,7 @@ main (int argc, char *argv[])
             case eRNBRunLoopModePlatformMode:
                 if (listen_port != INT32_MAX)
                 {
-                    if (!StartListening (remote, listen_port, unix_socket_name.c_str()))
+                    if (!StartListening (remote, listen_port, unix_socket_name.c_str(), localhost_only))
                         mode = eRNBRunLoopModeExit;
                 }
                 else if (str[0] == '/')