增加设置upstream, downstream的TTL或MaxHop功能，便于在捕获的报文中区分上、下行连接。

platform/include/internal/proxy.h

@@ -32,6 +32,7 @@ enum TFE_STAT_FIELD
 
 struct tfe_proxy_tcp_options
 {
+	/* TCP OPTIONS */
 	int sz_rcv_buffer;
 	int sz_snd_buffer;
 	int so_keepalive;
@@ -39,6 +40,10 @@ struct tfe_proxy_tcp_options
 	int tcp_keepintvl;
 	int tcp_keepcnt;
 	int tcp_user_timeout;
+
+	/* TRACE FOR DEBUG */
+	int tcp_ttl_upstream;
+	int tcp_ttl_downstream;
 };
 
 struct tfe_proxy_accept_para

platform/src/proxy.cpp

@@ -236,8 +236,10 @@ int tfe_proxy_config(struct tfe_proxy * proxy, const char * profile)
 {
 	/* Worker threads */
 	MESA_load_profile_uint_def(profile, "main", "nr_worker_threads", &proxy->nr_work_threads, 1);
+
 	/* Debug */
 	MESA_load_profile_uint_def(profile, "debug", "passthrough_all_tcp", &proxy->tcp_all_passthrough, 0);
+
 	/* TCP options, -1 means unset, we shall not call setsockopt */
 	MESA_load_profile_int_def(profile, "tcp", "sz_rcv_buffer", &proxy->tcp_options.sz_rcv_buffer, -1);
 	MESA_load_profile_int_def(profile, "tcp", "sz_snd_buffer", &proxy->tcp_options.sz_snd_buffer, -1);
@@ -246,7 +248,9 @@ int tfe_proxy_config(struct tfe_proxy * proxy, const char * profile)
 	MESA_load_profile_int_def(profile, "tcp", "tcp_keepintvl", &proxy->tcp_options.tcp_keepintvl, -1);
 	MESA_load_profile_int_def(profile, "tcp", "tcp_keepcnt", &proxy->tcp_options.tcp_keepcnt, -1);
 	MESA_load_profile_int_def(profile, "tcp", "tcp_user_timeout", &proxy->tcp_options.tcp_user_timeout, -1);
-
+	MESA_load_profile_int_def(profile, "tcp", "tcp_ttl_upstream", &proxy->tcp_options.tcp_ttl_upstream, -1);
+	MESA_load_profile_int_def(profile, "tcp", "tcp_ttl_downstream", &proxy->tcp_options.tcp_ttl_downstream, -1);
+	
 	return 0;
 }
 

platform/src/tcp_stream.cpp

@@ -950,7 +950,44 @@ __errout:
 	return NULL;
 }
 
-void __stream_fd_option_setup(struct tfe_stream_private * _stream, evutil_socket_t fd)
+int __fd_ttl_option_setup(struct tfe_stream_private * _stream, evutil_socket_t fd, int ttl)
+{
+	struct sockaddr_storage sk_storage;
+	socklen_t sk_storage_len = sizeof(sk_storage);
+
+	if (getsockname(fd, (struct sockaddr *)&sk_storage, &sk_storage_len) < 0)
+	{
+		TFE_STREAM_LOG_ERROR(_stream, "getsockname(fd = %d) failed: %s", fd, strerror(errno));
+		return -1;
+	}
+
+	/* For IPv4, set TTL */
+	unsigned int __ttl = (unsigned int)ttl;
+	const char  * __str_family = NULL;
+	int ret = 0;
+
+	if (sk_storage.ss_family == AF_INET)
+	{
+		ret = setsockopt(fd, IPPROTO_IP, IP_TTL, &__ttl, sizeof(__ttl));
+		__str_family = "AF_INET";
+	}
+	else if (sk_storage.ss_family == AF_INET6)
+	{
+		ret = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &__ttl, sizeof(__ttl));
+		__str_family = "AF_INET6";
+	}
+	else { assert(0); }
+
+	if(ret < 0)
+	{
+		TFE_STREAM_LOG_ERROR(_stream, "setsockopt(ttl = %u, fd = %d, family = %s) failed: %s",
+			__ttl, fd, __str_family, strerror(errno)); return -2;
+	}
+
+	return 0;
+}
+
+void __stream_fd_option_setup(struct tfe_stream_private * _stream, evutil_socket_t fd, tfe_conn_dir dir)
 {
 	struct tfe_stream * stream = &_stream->head;
 	struct tfe_proxy_tcp_options * tcp_options = &_stream->proxy_ref->tcp_options;
@@ -1025,6 +1062,12 @@ void __stream_fd_option_setup(struct tfe_stream_private * _stream, evutil_socket
 		}
 	}
 
+	int __ttl = (dir == CONN_DIR_UPSTREAM) ? tcp_options->tcp_ttl_upstream : tcp_options->tcp_ttl_downstream;
+	if(__ttl > 0 && __fd_ttl_option_setup(_stream, fd, __ttl) < 0)
+	{
+		TFE_STREAM_LOG_ERROR(stream, "Failed at setup FD's ttl option, ttl = %d, fd = %d", __ttl, fd);
+	}
+
 	return;
 }
 
@@ -1038,8 +1081,8 @@ int tfe_stream_init_by_fds(struct tfe_stream * stream, evutil_socket_t fd_downst
 	_stream->log_fd_downstream = fd_downstream;
 	_stream->log_fd_upstream = fd_upstream;
 
-	__stream_fd_option_setup(_stream, fd_downstream);
+	__stream_fd_option_setup(_stream, fd_downstream, CONN_DIR_DOWNSTREAM);
-	__stream_fd_option_setup(_stream, fd_upstream);
+	__stream_fd_option_setup(_stream, fd_upstream, CONN_DIR_UPSTREAM);
 
 	_stream->head.addr = tfe_stream_addr_create_by_fd(fd_downstream, CONN_DIR_DOWNSTREAM);
 	if (unlikely(_stream->head.addr == NULL))