dccp: Implement both feature-local and feature-remote Sequence Window feature

This adds full support for local/remote Sequence Window feature, from which the
  * sequence-number-validity (W) and
  * acknowledgment-number-validity (W') windows
derive as specified in RFC 4340, 7.5.3.

Specifically, the following is contained in this patch:
  * integrated new socket fields into dccp_sk;
  * updated the update_gsr/gss routines with regard to these fields;
  * updated handler code: the Sequence Window feature is located at the TX side,
    so the local feature is meant if the handler-rx flag is false;
  * the initialisation of `rcv_wnd' in reqsk is removed, since
    - rcv_wnd is not used by the code anywhere;
    - sequence number checks are not done in the LISTEN state (cf. 7.5.3);
    - dccp_check_req checks the Ack number validity more rigorously;
  * the `struct dccp_minisock' became empty and is now removed.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Gerrit Renker 2009-01-16 23:36:31 +00:00 committed by David S. Miller
parent f90f92eed7
commit 792b48780e
6 changed files with 24 additions and 45 deletions

View file

@ -363,19 +363,6 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
/* FIXME: for now we're default to 1 but it should really be 0 */
#define DCCPF_INITIAL_SEND_NDP_COUNT 1
/**
* struct dccp_minisock - Minimal DCCP connection representation
*
* Will be used to pass the state from dccp_request_sock to dccp_sock.
*
* @dccpms_sequence_window - Sequence Window Feature (section 7.5.2)
*/
struct dccp_minisock {
__u64 dccpms_sequence_window;
};
extern void dccp_minisock_init(struct dccp_minisock *dmsk);
/**
* struct dccp_request_sock - represent DCCP-specific connection request
* @dreq_inet_rsk: structure inherited from
@ -464,13 +451,14 @@ struct dccp_ackvec;
* @dccps_timestamp_time - time of receiving latest @dccps_timestamp_echo
* @dccps_l_ack_ratio - feature-local Ack Ratio
* @dccps_r_ack_ratio - feature-remote Ack Ratio
* @dccps_l_seq_win - local Sequence Window (influences ack number validity)
* @dccps_r_seq_win - remote Sequence Window (influences seq number validity)
* @dccps_pcslen - sender partial checksum coverage (via sockopt)
* @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
* @dccps_send_ndp_count - local Send NDP Count feature (7.7.2)
* @dccps_ndp_count - number of Non Data Packets since last data packet
* @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
* @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
* @dccps_minisock - associated minisock (accessed via dccp_msk)
* @dccps_featneg - tracks feature-negotiation state (mostly during handshake)
* @dccps_hc_rx_ackvec - rx half connection ack vector
* @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
@ -504,12 +492,13 @@ struct dccp_sock {
__u32 dccps_timestamp_time;
__u16 dccps_l_ack_ratio;
__u16 dccps_r_ack_ratio;
__u64 dccps_l_seq_win:48;
__u64 dccps_r_seq_win:48;
__u8 dccps_pcslen:4;
__u8 dccps_pcrlen:4;
__u8 dccps_send_ndp_count:1;
__u64 dccps_ndp_count:48;
unsigned long dccps_rate_last;
struct dccp_minisock dccps_minisock;
struct list_head dccps_featneg;
struct dccp_ackvec *dccps_hc_rx_ackvec;
struct ccid *dccps_hc_rx_ccid;
@ -527,11 +516,6 @@ static inline struct dccp_sock *dccp_sk(const struct sock *sk)
return (struct dccp_sock *)sk;
}
static inline struct dccp_minisock *dccp_msk(const struct sock *sk)
{
return (struct dccp_minisock *)&dccp_sk(sk)->dccps_minisock;
}
static inline const char *dccp_role(const struct sock *sk)
{
switch (dccp_sk(sk)->dccps_role) {