Communicate secmod address to worker after successful authentication

This ensures all subsequent worker communications reach the original
secmod instance that authenticated the client, enabling correct session
accounting after IP address changes.

Closes: #674

Signed-off-by: Grigory Trenin <grigory.trenin@gmail.com>

NEWS

@@ -6,6 +6,7 @@
 - Fixed "unexpected URL" errors for Cisco AnyConnect clients
 - Fixed the 'ping-leases' option, which was broken since version 1.1.1
 - Fixed 'iroute' option processing to handle multiple routes (#625)
+- Fixed session accounting for roaming users (#674)
 - occtl: fix invalid JSON output in `occtl -j show iroutes` (#661)
 - occtl: fix regression with trailing commas in `occtl -j show sessions` (#669)
 - occtl: fix missing column headers in 'show ip bans' output (#677)

src/ipc.proto

@@ -83,6 +83,7 @@ message auth_cookie_reply_msg
 	optional string ipv6_local = 10;
 
 	required bytes sid = 11;
+	required bytes secmod_addr = 13;
 
 	/* additional config */
 	optional group_cfg_st config = 20;

src/main-auth.c

@@ -145,6 +145,13 @@ int send_cookie_auth_reply(main_server_st *s, struct proc_st *proc, AUTHREP r)
 		}
 
 		msg.config = proc->config;
+		msg.secmod_addr.data =
+			(uint8_t *)&s
+				->sec_mod_instances[proc->sec_mod_instance_index]
+				.secmod_addr;
+		msg.secmod_addr.len =
+			s->sec_mod_instances[proc->sec_mod_instance_index]
+				.secmod_addr_len;
 
 		ret = send_socket_msg_to_worker(
 			s, proc, AUTH_COOKIE_REP, proc->tun_lease.fd, &msg,

src/worker-auth.c

@@ -707,6 +707,17 @@ static int recv_cookie_auth_reply(worker_st *ws)
 			memcpy(ws->sid, msg->sid.data, sizeof(ws->sid));
 			ws->sid_set = 1;
 
+			if (msg->secmod_addr.len > sizeof(ws->secmod_addr)) {
+				oclog(ws, LOG_ERR,
+				      "msg->secmod_addr.len too large");
+				ret = ERR_AUTH_FAIL;
+				goto cleanup;
+			}
+
+			ws->secmod_addr_len = msg->secmod_addr.len;
+			memcpy(&ws->secmod_addr, msg->secmod_addr.data,
+			       msg->secmod_addr.len);
+
 			strlcpy(ws->vinfo.name, msg->vname,
 				sizeof(ws->vinfo.name));
 			strlcpy(ws->username, msg->user_name,