1 files changed, 61 insertions, 5 deletions

diff --git a/src/usr.bin/nc/socks.c b/src/usr.bin/nc/socks.c
index 1b06e0e12d..79b97bbffa 100644
--- a/src/usr.bin/nc/socks.c
+++ b/src/usr.bin/nc/socks.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: socks.c,v 1.21 2015/03/26 21:19:51 tobias Exp $       */
+/*      $OpenBSD: socks.c,v 1.22 2015/12/10 16:49:28 mmcc Exp $ */
 
 /*
  * Copyright (c) 1999 Niklas Hallqvist.  All rights reserved.
@@ -122,6 +122,58 @@ getproxypass(const char *proxyuser, const char *proxyhost)
         return (pw);
 }
 
+/*
+ * Error strings adapted from the generally accepted SOCKSv4 spec:
+ *
+ * http://ftp.icm.edu.pl/packages/socks/socks4/SOCKS4.protocol
+ */
+static const char *
+socks4_strerror(int e)
+{
+        switch (e) {
+        case 90:
+                return "Succeeded";
+        case 91:
+                return "Request rejected or failed";
+        case 92:
+                return "SOCKS server cannot connect to identd on the client";
+        case 93:
+                return "Client program and identd report different user-ids";
+        default:
+                return "Unknown error";
+        }
+}
+
+/*
+ * Error strings taken almost directly from RFC 1928.
+ */
+static const char *
+socks5_strerror(int e)
+{
+        switch (e) {
+        case 0:
+                return "Succeeded";
+        case 1:
+                return "General SOCKS server failure";
+        case 2:
+                return "Connection not allowed by ruleset";
+        case 3:
+                return "Network unreachable";
+        case 4:
+                return "Host unreachable";
+        case 5:
+                return "Connection refused";
+        case 6:
+                return "TTL expired";
+        case 7:
+                return "Command not supported";
+        case 8:
+                return "Address type not supported";
+        default:
+                return "Unknown error";
+        }
+}
+
 int
 socks_connect(const char *host, const char *port,
     struct addrinfo hints __attribute__ ((__unused__)),
@@ -225,8 +277,10 @@ socks_connect(const char *host, const char *port,
                 cnt = atomicio(read, proxyfd, buf, 4);
                 if (cnt != 4)
                         err(1, "read failed (%zu/4)", cnt);
-                if (buf[1] != 0)
-                        errx(1, "connection failed, SOCKS error %d", buf[1]);
+                if (buf[1] != 0) {
+                        errx(1, "connection failed, SOCKS error: %s",
+                            socks5_strerror(buf[1]));
+                }
                 switch (buf[3]) {
                 case SOCKS_IPV4:
                         cnt = atomicio(read, proxyfd, buf + 4, 6);
@@ -261,8 +315,10 @@ socks_connect(const char *host, const char *port,
                 cnt = atomicio(read, proxyfd, buf, 8);
                 if (cnt != 8)
                         err(1, "read failed (%zu/8)", cnt);
-                if (buf[1] != 90)
-                        errx(1, "connection failed, SOCKS error %d", buf[1]);
+                if (buf[1] != 90) {
+                        errx(1, "connection failed, SOCKS error: %s",
+                            socks4_strerror(buf[1]));
+                }
         } else if (socksv == -1) {
                 /* HTTP proxy CONNECT */