From 805dd109a4aaf851d7293d25bad259493836ce5a Mon Sep 17 00:00:00 2001 From: David Gibson Date: Fri, 8 Sep 2023 11:49:48 +1000 Subject: tcp: Remove some redundant packet_get() operations Both tcp_data_from_tap() and tcp_tap_handler() call packet_get() to get the entire L4 packet length, then immediately call it again to check that the packet is long enough to include a TCP header. The features of packet_get() let us easily combine these together, we just need to adjust the length slightly, because we want the value to include the TCP header length. Signed-off-by: David Gibson Signed-off-by: Stefano Brivio --- tcp.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/tcp.c b/tcp.c index d8c2327..6a34f82 100644 --- a/tcp.c +++ b/tcp.c @@ -2320,16 +2320,12 @@ static void tcp_data_from_tap(struct ctx *c, struct tcp_tap_conn *conn, char *data; size_t off; - if (!packet_get(p, i, 0, 0, &len)) { - tcp_rst(c, conn); - return; - } - - th = packet_get(p, i, 0, sizeof(*th), NULL); + th = packet_get(p, i, 0, sizeof(*th), &len); if (!th) { tcp_rst(c, conn); return; } + len += sizeof(*th); off = th->doff * 4UL; if (off < sizeof(*th) || off > len) { @@ -2545,12 +2541,10 @@ int tcp_tap_handler(struct ctx *c, int af, const void *saddr, const void *daddr, int ack_due = 0; char *opts; - if (!packet_get(p, idx, 0, 0, &len)) - return 1; - - th = packet_get(p, idx, 0, sizeof(*th), NULL); + th = packet_get(p, idx, 0, sizeof(*th), &len); if (!th) return 1; + len += sizeof(*th); optlen = th->doff * 4UL - sizeof(*th); /* Static checkers might fail to see this: */ -- cgit v1.2.3