diff options
author | Gerrit Renker <gerrit@erg.abdn.ac.uk> | 2007-12-13 14:31:26 (GMT) |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2008-01-28 22:57:50 (GMT) |
commit | 8109616e2ef978d142ea45850efd4f102b9bdce4 (patch) | |
tree | 338aa4e2bf9d9424090b0d698d20b3c465cf229c /net/dccp | |
parent | 8b819412481494fb6861c08d360b75fabcbbfbbf (diff) | |
download | linux-8109616e2ef978d142ea45850efd4f102b9bdce4.tar.xz |
[DCCP]: Add (missing) option parsing to request_sock processing
This adds option-parsing code to processing of Acks in the listening state
on request_socks on the server, serving two purposes
(i) resolves a FIXME (removed);
(ii) paves the way for feature-negotiation during connection-setup.
There is an intended subtlety here with regard to dccp_check_req:
Parsing options happens only after testing whether the received packet is
a retransmitted Request. Otherwise, if the Request contained (a possibly
large number of) feature-negotiation options, recomputing state would have to
happen each time a retransmitted Request arrives, which opens the door to an
easy DoS attack. Since in a genuine retransmission the options should not be
different from the original, reusing the already computed state seems better.
The other point is - if there are timestamp options on the Request, they will
not be answered; which means that in the presence of retransmission (likely
due to loss and/or other problems), the use of Request/Response RTT sampling
is suspended, so that startup problems here do not propagate.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dccp')
-rw-r--r-- | net/dccp/minisocks.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c index 831b76e..b1d5da6 100644 --- a/net/dccp/minisocks.c +++ b/net/dccp/minisocks.c @@ -200,10 +200,10 @@ struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb, struct request_sock **prev) { struct sock *child = NULL; + struct dccp_request_sock *dreq = dccp_rsk(req); /* Check for retransmitted REQUEST */ if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) { - struct dccp_request_sock *dreq = dccp_rsk(req); if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dreq->dreq_isr)) { dccp_pr_debug("Retransmitted REQUEST\n"); @@ -227,22 +227,22 @@ struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb, goto drop; /* Invalid ACK */ - if (DCCP_SKB_CB(skb)->dccpd_ack_seq != dccp_rsk(req)->dreq_iss) { + if (DCCP_SKB_CB(skb)->dccpd_ack_seq != dreq->dreq_iss) { dccp_pr_debug("Invalid ACK number: ack_seq=%llu, " "dreq_iss=%llu\n", (unsigned long long) DCCP_SKB_CB(skb)->dccpd_ack_seq, - (unsigned long long) - dccp_rsk(req)->dreq_iss); + (unsigned long long) dreq->dreq_iss); goto drop; } + if (dccp_parse_options(sk, dreq, skb)) + goto drop; + child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL); if (child == NULL) goto listen_overflow; - /* FIXME: deal with options */ - inet_csk_reqsk_queue_unlink(sk, req, prev); inet_csk_reqsk_queue_removed(sk, req); inet_csk_reqsk_queue_add(sk, req, child); |