From a2fd7c09fac4190f90f12336622c7637dc41297c Mon Sep 17 00:00:00 2001
From: Belinsky-L-V <belinsky.leonid@gmail.com>
Date: Tue, 12 Nov 2019 21:58:36 +0300
Subject: [PATCH] make vsock config accept -1 for cid and port

linux/vm_sockets.h defines VMADDR_CID_ANY and VMADDR_PORT_ANY (both
equal to -1U) for vsock cid and port respectively. This change aims to
add the capability to parse negative cid and port numbers for vsock from
the config and pass them to the kernel.

Allows for valid configurations such as "port=vsock://-1:3389" to be
correctly processed, but will parse port and cid inputs like "---1" to
"-", which should currently get silently turned into 0 by atoi inside
g_sck_vsock_bind_address. Inputs that do not contain "-" get parsed as
by xrdp_listen_parse_integer.
---
 xrdp/xrdp_listen.c | 51 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 49 insertions(+), 2 deletions(-)

diff --git a/xrdp/xrdp_listen.c b/xrdp/xrdp_listen.c
index 63e2ca52..9632edd9 100644
--- a/xrdp/xrdp_listen.c
+++ b/xrdp/xrdp_listen.c
@@ -356,6 +356,53 @@ xrdp_listen_parse_integer(char *strout, int strout_max,
     return count;
 }
 
+/*****************************************************************************/
+static int
+xrdp_listen_parse_vsock(char *strout, int strout_max,
+                        const char *strin, int strin_max)
+{
+    int count;
+    int in;
+    int strin_index;
+    int strout_index;
+
+    strin_index = 0;
+    strout_index = 0;
+    in = 0;
+    count = 0;
+    while ((strin_index < strin_max) && (strout_index < strout_max))
+    {
+        if (in)
+        {
+            if ((strin[strin_index] >= '0') && (strin[strin_index] <= '9'))
+            {
+                strout[strout_index++] = strin[strin_index++];
+                count++;
+                continue;
+            }
+            else
+            {
+                break;
+            }
+        }
+        else
+        {
+            if (((strin[strin_index] >= '0') && (strin[strin_index] <= '9')) ||
+                 (strin[strin_index] == '-'))
+            {
+                in = 1;
+                strout[strout_index++] = strin[strin_index++];
+                count++;
+                continue;
+            }
+        }
+        strin_index++;
+        count++;
+    }
+    strout[strout_index] = 0;
+    return count;
+}
+
 /*****************************************************************************/
 static int
 xrdp_listen_parse_ipv4(char *strout, int strout_max,
@@ -559,10 +606,10 @@ xrdp_listen_pp(struct xrdp_listen *self, int *index,
         {
             str += 8;
             lindex += 8;
-            bytes = xrdp_listen_parse_integer(address, 128, str, str_end - str);
+            bytes = xrdp_listen_parse_vsock(address, 128, str, str_end - str);
             str += bytes;
             lindex += bytes;
-            bytes = xrdp_listen_parse_integer(port, 128, str, str_end - str);
+            bytes = xrdp_listen_parse_vsock(port, 128, str, str_end - str);
             str += bytes;
             lindex += bytes;
             *mode = TRANS_MODE_VSOCK;