Commit f2ef6541 authored by Shrek Wang's avatar Shrek Wang Committed by Benjamin Cabé
Browse files

net: tcp: Replace the FIN only case with FIN+ACK 

According to TCP Spec. RFC793, ACK flag should be always set
after sequences of both sides are sync-ed except for RST seg-
ment. It is not necessary to send FIN only packet in the
test case, using FIN | ACK instead.
Similarly, change the tcp_out(conn, FIN | ACK) in CLOSE_WAIT.

Signed-off-by: default avatarShrek Wang <inet_eman@outlook.com>
parent ee458692

subsys/net/ip/tcp.c

+1 −1
Changes for subsys/net/ip/tcp.c: 1 added line, 1 removed line.
Original line number Diff line number Diff line
@@ -3316,7 +3316,7 @@ next_state: 


		break;

	case TCP_CLOSE_WAIT:

		tcp_out(conn, FIN);

		tcp_out(conn, FIN | ACK);

		conn_seq(conn, + 1);

		next = TCP_LAST_ACK;

		tcp_setup_last_ack_timer(conn);

tests/net/tcp/src/main.c

+6 −17
Changes for tests/net/tcp/src/main.c: 6 added lines, 17 removed lines.
Original line number Diff line number Diff line
@@ -380,12 +380,6 @@ static struct net_pkt *prepare_fin_ack_packet(sa_family_t af, uint16_t src_port, 
				      NULL, 0U);

}



static struct net_pkt *prepare_fin_packet(sa_family_t af, uint16_t src_port,

					  uint16_t dst_port)

{

	return tester_prepare_tcp_pkt(af, src_port, dst_port, FIN, NULL, 0U);

}



static struct net_pkt *prepare_rst_packet(sa_family_t af, uint16_t src_port,

					  uint16_t dst_port)

{
@@ -1166,7 +1160,7 @@ send_next: 
		break;

	case T_FIN_2:

		t_state = T_FIN_ACK;

		reply = prepare_fin_packet(af, htons(MY_PORT), th->th_sport);

		reply = prepare_fin_ack_packet(af, htons(MY_PORT), th->th_sport);

		break;

	case T_FIN_ACK:

		test_verify_flags(th, ACK);
@@ -1459,7 +1453,7 @@ send_next: 
		break;

	case T_FIN_2:

		t_state = T_FIN_ACK;

		reply = prepare_fin_packet(af, htons(MY_PORT), th->th_sport);

		reply = prepare_fin_ack_packet(af, htons(MY_PORT), th->th_sport);

		break;

	case T_FIN_ACK:

		test_verify_flags(th, ACK);
@@ -1813,12 +1807,12 @@ static void handle_client_closing_failure_test(sa_family_t af, struct tcphdr *th 
	case T_FIN:

		test_verify_flags(th, FIN | ACK);

		t_state = T_FIN_1;

		reply = prepare_fin_packet(af, htons(MY_PORT), th->th_sport);

		reply = prepare_fin_ack_packet(af, htons(MY_PORT), th->th_sport);

		break;

	case T_FIN_1:

		test_verify_flags(th, FIN | ACK);

		t_state = T_CLOSING;

		reply = prepare_fin_packet(af, htons(MY_PORT), th->th_sport);

		reply = prepare_fin_ack_packet(af, htons(MY_PORT), th->th_sport);

		break;

	case T_CLOSING:

		test_verify_flags(th, FIN | ACK);
@@ -2418,7 +2412,6 @@ ZTEST(net_tcp, test_client_rst_on_unexpected_ack_on_syn) 
#define TEST_FIN_DATA "test_data"



static enum fin_data_variant {

	FIN_DATA_FIN,

	FIN_DATA_FIN_ACK,

	FIN_DATA_FIN_ACK_PSH,

} test_fin_data_variant;
@@ -2458,10 +2451,6 @@ static void handle_client_fin_ack_with_data_test(sa_family_t af, struct tcphdr * 
		return;

	case T_DATA:

		switch (test_fin_data_variant) {

		case FIN_DATA_FIN:

			flags = FIN;

			t_state = T_FIN;

			break;

		case FIN_DATA_FIN_ACK:

			flags = FIN | ACK;

			t_state = T_FIN_ACK;
@@ -2500,7 +2489,7 @@ static void handle_client_fin_ack_with_data_test(sa_family_t af, struct tcphdr * 
		break;



	case T_CLOSING:

		test_verify_flags(th, FIN);

		test_verify_flags(th, FIN | ACK);

		zassert_equal(get_rel_seq(th), 1, "Unexpected SEQ number in T_CLOSING, got %d",

			      get_rel_seq(th));
@@ -2568,7 +2557,7 @@ ZTEST(net_tcp, test_client_fin_ack_with_data) 


	k_work_init_delayable(&test_fin_data_work, test_fin_data_handler);



	for (enum fin_data_variant variant = FIN_DATA_FIN;

	for (enum fin_data_variant variant = FIN_DATA_FIN_ACK;

	     variant <= FIN_DATA_FIN_ACK_PSH; variant++) {

		test_fin_data_variant = variant;

		t_state = T_SYN;

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