[PATCH 35/37] 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 changes are introduced: * 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. Until the handshake completes with activating negotiated values, the local/remote Sequence-Window values are undefined and thus can not reliably be estimated. This issue is addressed in a separate patch. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> --- Documentation/networking/dccp.txt | 3 ++- include/linux/dccp.h | 24 ++++-------------------- net/dccp/dccp.h | 16 +++++++--------- net/dccp/feat.c | 13 +++++++++++-- net/dccp/minisocks.c | 11 ----------- net/dccp/proto.c | 2 -- 6 files changed, 24 insertions(+), 45 deletions(-) --- a/Documentation/networking/dccp.txt +++ b/Documentation/networking/dccp.txt @@ -141,7 +141,8 @@ rx_ccid = 2 Default CCID for the receiver-sender half-connection; see tx_ccid. seq_window = 100 - The initial sequence window (sec. 7.5.2). + The initial sequence window (sec. 7.5.2) of the sender. This influences + the local ackno validity and the remote seqno validity windows (7.5.1). tx_qlen = 5 The size of the transmit buffer in packets. A value of 0 corresponds --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -364,19 +364,6 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb) #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 * @dreq_iss: initial sequence number sent on the Response (RFC 4340, 7.1) @@ -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) { --- a/net/dccp/dccp.h +++ b/net/dccp/dccp.h @@ -409,23 +409,21 @@ static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack, static inline void dccp_update_gsr(struct sock *sk, u64 seq) { struct dccp_sock *dp = dccp_sk(sk); - const struct dccp_minisock *dmsk = dccp_msk(sk); dp->dccps_gsr = seq; - dccp_set_seqno(&dp->dccps_swl, - dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4)); - dccp_set_seqno(&dp->dccps_swh, - dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4); + /* Sequence validity window depends on remote Sequence Window (7.5.1) */ + dp->dccps_swl = SUB48(ADD48(dp->dccps_gsr, 1), dp->dccps_r_seq_win / 4); + dp->dccps_swh = ADD48(dp->dccps_gsr, (3 * dp->dccps_r_seq_win) / 4); } static inline void dccp_update_gss(struct sock *sk, u64 seq) { struct dccp_sock *dp = dccp_sk(sk); - dp->dccps_awh = dp->dccps_gss = seq; - dccp_set_seqno(&dp->dccps_awl, - (dp->dccps_gss - - dccp_msk(sk)->dccpms_sequence_window + 1)); + dp->dccps_gss = seq; + /* Ack validity window depends on local Sequence Window value (7.5.1) */ + dp->dccps_awl = SUB48(ADD48(dp->dccps_gss, 1), dp->dccps_l_seq_win); + dp->dccps_awh = dp->dccps_gss; } static inline int dccp_ack_pending(const struct sock *sk) --- a/net/dccp/feat.c +++ b/net/dccp/feat.c @@ -52,8 +52,17 @@ static int dccp_hdlr_ccid(struct sock *sk, u64 ccid, bool rx) static int dccp_hdlr_seq_win(struct sock *sk, u64 seq_win, bool rx) { - if (!rx) - dccp_msk(sk)->dccpms_sequence_window = seq_win; + struct dccp_sock *dp = dccp_sk(sk); + + if (rx) { + dp->dccps_r_seq_win = seq_win; + /* propagate changes to update SWL/SWH */ + dccp_update_gsr(sk, dp->dccps_gsr); + } else { + dp->dccps_l_seq_win = seq_win; + /* propagate changes to update AWL */ + dccp_update_gss(sk, dp->dccps_gss); + } return 0; } --- a/net/dccp/minisocks.c +++ b/net/dccp/minisocks.c @@ -42,11 +42,6 @@ struct inet_timewait_death_row dccp_death_row = { EXPORT_SYMBOL_GPL(dccp_death_row); -void dccp_minisock_init(struct dccp_minisock *dmsk) -{ - dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window; -} - void dccp_time_wait(struct sock *sk, int state, int timeo) { struct inet_timewait_sock *tw = NULL; @@ -110,7 +105,6 @@ struct sock *dccp_create_openreq_child(struct sock *sk, struct dccp_request_sock *dreq = dccp_rsk(req); struct inet_connection_sock *newicsk = inet_csk(newsk); struct dccp_sock *newdp = dccp_sk(newsk); - struct dccp_minisock *newdmsk = dccp_msk(newsk); newdp->dccps_role = DCCP_ROLE_SERVER; newdp->dccps_hc_rx_ackvec = NULL; @@ -128,10 +122,6 @@ struct sock *dccp_create_openreq_child(struct sock *sk, * Initialize S.GAR := S.ISS * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies */ - - /* See dccp_v4_conn_request */ - newdmsk->dccpms_sequence_window = req->rcv_wnd; - newdp->dccps_gar = newdp->dccps_iss = dreq->dreq_iss; dccp_update_gss(newsk, dreq->dreq_iss); @@ -289,7 +279,6 @@ int dccp_reqsk_init(struct request_sock *req, inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport; inet_rsk(req)->acked = 0; - req->rcv_wnd = sysctl_dccp_feat_sequence_window; dreq->dreq_timestamp_echo = 0; /* inherit feature negotiation options from listening socket */ --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -180,8 +180,6 @@ int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized) struct dccp_sock *dp = dccp_sk(sk); struct inet_connection_sock *icsk = inet_csk(sk); - dccp_minisock_init(&dp->dccps_minisock); - icsk->icsk_rto = DCCP_TIMEOUT_INIT; icsk->icsk_syn_retries = sysctl_dccp_request_retries; sk->sk_state = DCCP_CLOSED; -- 1.6.0.rc2 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html


linux-kernel:
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git:

linux-netdev:
Gerrit Renker	[PATCH 27/37] dccp: Integration of dynamic feature activation - part 2 (server side)
David Miller	[GIT]: Networking
Jarek Poplawski	[PATCH] pkt_sched: Destroy gen estimators under rtnl_lock().
Joakim Tjernlund	ucc_geth: nf_conntrack: table full, dropping packet.
openbsd-misc: