Re: [PATCH v6 net-next 04/14] selftests/net: gro: add self-test for TCP CWR flag

On 11/14/25 8:13 AM, chia-yu.chang@nokia-bell-labs.com wrote:

+/* send extra flags of the (NUM_PACKETS / 2) and (NUM_PACKETS / 2 - 1)

• • pkts, not first and not last pkt
• */

+static void send_flags(int fd, struct sockaddr_ll *daddr, int psh, int syn,

•        int rst, int urg, int cwr)
  

+{

• static char flag_buf[2][MAX_HDR_LEN + PAYLOAD_LEN];
• static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
• int payload_len, pkt_size, i;
• struct tcphdr *tcph;
• int flag[2];
• payload_len = PAYLOAD_LEN * (psh || cwr);
• pkt_size = total_hdr_len + payload_len;
• flag[0] = NUM_PACKETS / 2;
• flag[1] = NUM_PACKETS / 2 - 1;
• // Create and configure packets with flags

Please use /* */ for comments.

Other than that:

Acked-by: Paolo Abeni pabeni@redhat.com

• for (i = 0; i < 2; i++) {

• if (flag[i] > 0) {
  

• 	create_packet(flag_buf[i], flag[i] * payload_len, 0,
  

• 		      payload_len, 0);
  

• 	tcph = (struct tcphdr *)(flag_buf[i] + tcp_offset);
  

• 	set_flags(tcph, payload_len, psh, syn, rst, urg, cwr);
  

• }
  

• }

for (i = 0; i < NUM_PACKETS + 1; i++) {

• if (i == flag) {
  

• 	write_packet(fd, flag_buf, pkt_size, daddr);
  

• if (i == flag[0]) {
  

• 	write_packet(fd, flag_buf[0], pkt_size, daddr);
  

• 	continue;
  

• } else if (i == flag[1] && cwr) {
  

• 	write_packet(fd, flag_buf[1], pkt_size, daddr);
  continue;
  

  } create_packet(buf, i * PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);

@@ -1020,16 +1045,19 @@ static void gro_sender(void) send_ack(txfd, &daddr); write_packet(txfd, fin_pkt, total_hdr_len, &daddr); } else if (strcmp(testname, "flags") == 0) {

• send_flags(txfd, &daddr, 1, 0, 0, 0);
  

• send_flags(txfd, &daddr, 1, 0, 0, 0, 0);
  

  write_packet(txfd, fin_pkt, total_hdr_len, &daddr);

• send_flags(txfd, &daddr, 0, 1, 0, 0);
  

• send_flags(txfd, &daddr, 0, 1, 0, 0, 0);
  

  write_packet(txfd, fin_pkt, total_hdr_len, &daddr);

• send_flags(txfd, &daddr, 0, 0, 1, 0);
  

• send_flags(txfd, &daddr, 0, 0, 1, 0, 0);
  

  write_packet(txfd, fin_pkt, total_hdr_len, &daddr);

• send_flags(txfd, &daddr, 0, 0, 0, 1);
  

• send_flags(txfd, &daddr, 0, 0, 0, 1, 0);
  

• write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
  

• send_flags(txfd, &daddr, 0, 0, 0, 0, 1);
  

  write_packet(txfd, fin_pkt, total_hdr_len, &daddr); } else if (strcmp(testname, "tcp") == 0) { send_changed_checksum(txfd, &daddr);

@@ -1163,6 +1191,12 @@ static void gro_receiver(void) printf("urg flag ends coalescing: "); check_recv_pkts(rxfd, correct_payload, 3);

• correct_payload[0] = PAYLOAD_LEN;
  

• correct_payload[1] = PAYLOAD_LEN * 2;
  

• correct_payload[2] = PAYLOAD_LEN * 2;
  

• printf("cwr flag ends coalescing: ");
  

• check_recv_pkts(rxfd, correct_payload, 3);
  

  } else if (strcmp(testname, "tcp") == 0) { correct_payload[0] = PAYLOAD_LEN; correct_payload[1] = PAYLOAD_LEN;