Changeset 12f041d for lib/proxy.c

Timestamp:

2015-10-21T13:14:17Z (9 years ago)

Author:

dequis <dx@…>

Branches:

master

Children:

b0da3b8

Parents:

3314ced

Message:

socks4a proxy support (like socks4 with remote DNS)

Fixes trac ticket 995 ​https://bugs.bitlbee.org/bitlbee/ticket/995

This is slightly pointless for the suggested use case (tor), since with
socks5 we already send a hostname instead of an IP address.

Either way, it was easy to implement, so I hope it helps.

File:

• lib/proxy.c (modified) (4 diffs)

lib/proxy.c

@@ -294 +294 @@
         socklen_t len;
         int error = ETIMEDOUT;
+        gboolean is_socks4a = (proxytype == PROXY_SOCKS4A);
 
         if (phb->inpa > 0) {
@@ -304 +305 @@
         sock_make_blocking(source);
 
-        /* XXX does socks4 not support host name lookups by the proxy? */
-        if (!(hp = gethostbyname(phb->host))) {
+        if (!is_socks4a && !(hp = gethostbyname(phb->host))) {
                 return phb_close(phb);
         }
@@ -313 +313 @@
         packet[2] = phb->port >> 8;
         packet[3] = phb->port & 0xff;
-        packet[4] = (unsigned char) (hp->h_addr_list[0])[0];
-        packet[5] = (unsigned char) (hp->h_addr_list[0])[1];
-        packet[6] = (unsigned char) (hp->h_addr_list[0])[2];
-        packet[7] = (unsigned char) (hp->h_addr_list[0])[3];
+        if (is_socks4a) {
+                packet[4] = 0;
+                packet[5] = 0;
+                packet[6] = 0;
+                packet[7] = 1;
+        } else {
+                packet[4] = (unsigned char) (hp->h_addr_list[0])[0];
+                packet[5] = (unsigned char) (hp->h_addr_list[0])[1];
+                packet[6] = (unsigned char) (hp->h_addr_list[0])[2];
+                packet[7] = (unsigned char) (hp->h_addr_list[0])[3];
+        }
         packet[8] = 0;
         if (write(source, packet, 9) != 9) {
                 return phb_close(phb);
+        }
+
+        if (is_socks4a) {
+                size_t host_len = strlen(phb->host) + 1; /* include the \0 */
+
+                if (write(source, phb->host, host_len) != host_len) {
+                        return phb_close(phb);
+                }
         }
 
@@ -506 +521 @@
         } else if (proxytype == PROXY_HTTP) {
                 return proxy_connect_http(host, port, phb);
-        } else if (proxytype == PROXY_SOCKS4) {
+        } else if (proxytype == PROXY_SOCKS4 || proxytype == PROXY_SOCKS4A) {
                 return proxy_connect_socks4(host, port, phb);
         } else if (proxytype == PROXY_SOCKS5) {