Fix TCP retransmission

diff --git a/grub-core/net/tcp.c b/grub-core/net/tcp.c
index f6d864523ee0bc77bdbaafaf95821ee76e4d8362..578a254f4eba46e7371720b30cc3184442ff945b 100644 (file)
--- a/grub-core/net/tcp.c
+++ b/grub-core/net/tcp.c
@@ -708,12 +708,14 @@ grub_net_recv_tcp_packet (struct grub_net_buff *nb,
        for (unack = sock->unack_first; unack; unack = next)
          {
            grub_uint32_t seqnr;
+           struct tcphdr *unack_tcph;
            next = unack->next;
            seqnr = grub_be_to_cpu32 (((struct tcphdr *) unack->nb->data)
                                      ->seqnr);
-           seqnr += (nb->tail - nb->data
-                     - (grub_be_to_cpu16 (tcph->flags) >> 12) * 4);
-           if (grub_be_to_cpu16 (tcph->flags) & TCP_FIN)
+           unack_tcph = (struct tcphdr *) unack->nb->data;
+           seqnr += (unack->nb->tail - unack->nb->data
+                     - (grub_be_to_cpu16 (unack_tcph->flags) >> 12) * 4);
+           if (grub_be_to_cpu16 (unack_tcph->flags) & TCP_FIN)
              seqnr++;
 
            if (seqnr > acked)