MEDIUM: connection: Upstream SOCKS4 proxy support
Have "socks4" and "check-via-socks4" server keyword added.
Implement handshake with SOCKS4 proxy server for tcp stream connection.
See issue #82.
I have the "SOCKS: A protocol for TCP proxy across firewalls" doc found
at "https://www.openssh.com/txt/socks4.protocol". Please reference to it.
[wt: for now connecting to the SOCKS4 proxy over unix sockets is not
supported, and mixing IPv4/IPv6 is discouraged; indeed, the control
layer is unique for a connection and will be used both for connecting
and for target address manipulation. As such it may for example report
incorrect destination addresses in logs if the proxy is reached over
IPv6]
diff --git a/include/types/server.h b/include/types/server.h
index 0d53d26..219f5ab 100644
--- a/include/types/server.h
+++ b/include/types/server.h
@@ -141,6 +141,7 @@
#define SRV_F_AGENTADDR 0x0080 /* this server has a agent addr configured */
#define SRV_F_COOKIESET 0x0100 /* this server has a cookie configured, so don't generate dynamic cookies */
#define SRV_F_FASTOPEN 0x0200 /* Use TCP Fast Open to connect to server */
+#define SRV_F_SOCKS4_PROXY 0x0400 /* this server uses SOCKS4 proxy */
/* configured server options for send-proxy (server->pp_opts) */
#define SRV_PP_V1 0x0001 /* proxy protocol version 1 */
@@ -336,6 +337,8 @@
char reason[128];
} op_st_chg; /* operational status change's reason */
char adm_st_chg_cause[48]; /* administrative status change's cause */
+
+ struct sockaddr_storage socks4_addr; /* the address of the SOCKS4 Proxy, including the port */
};
/* Descriptor for a "server" keyword. The ->parse() function returns 0 in case of