diff options
Diffstat (limited to 'net/dccp/dccp.h')
| -rw-r--r-- | net/dccp/dccp.h | 46 |
1 files changed, 36 insertions, 10 deletions
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h index 3ccef1b70fe..3eb264b6082 100644 --- a/net/dccp/dccp.h +++ b/net/dccp/dccp.h @@ -153,18 +153,27 @@ static inline u64 max48(const u64 seq1, const u64 seq2) } /** - * dccp_loss_free - Evaluates condition for data loss from RFC 4340, 7.7.1 - * @s1: start sequence number - * @s2: end sequence number + * dccp_loss_count - Approximate the number of lost data packets in a burst loss + * @s1: last known sequence number before the loss ('hole') + * @s2: first sequence number seen after the 'hole' * @ndp: NDP count on packet with sequence number @s2 - * Returns true if the sequence range s1...s2 has no data loss. */ -static inline bool dccp_loss_free(const u64 s1, const u64 s2, const u64 ndp) +static inline u64 dccp_loss_count(const u64 s1, const u64 s2, const u64 ndp) { s64 delta = dccp_delta_seqno(s1, s2); WARN_ON(delta < 0); - return (u64)delta <= ndp + 1; + delta -= ndp + 1; + + return delta > 0 ? delta : 0; +} + +/** + * dccp_loss_free - Evaluate condition for data loss from RFC 4340, 7.7.1 + */ +static inline bool dccp_loss_free(const u64 s1, const u64 s2, const u64 ndp) +{ + return dccp_loss_count(s1, s2, ndp) == 0; } enum { @@ -246,7 +255,6 @@ static inline void dccp_clear_xmit_timers(struct sock *sk) extern unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu); extern const char *dccp_packet_name(const int type); -extern const char *dccp_state_name(const int state); extern void dccp_set_state(struct sock *sk, const int state); extern void dccp_done(struct sock *sk); @@ -415,6 +423,23 @@ static inline void dccp_update_gsr(struct sock *sk, u64 seq) dp->dccps_gsr = seq; /* 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); + /* + * Adjust SWL so that it is not below ISR. In contrast to RFC 4340, + * 7.5.1 we perform this check beyond the initial handshake: W/W' are + * always > 32, so for the first W/W' packets in the lifetime of a + * connection we always have to adjust SWL. + * A second reason why we are doing this is that the window depends on + * the feature-remote value of Sequence Window: nothing stops the peer + * from updating this value while we are busy adjusting SWL for the + * first W packets (we would have to count from scratch again then). + * Therefore it is safer to always make sure that the Sequence Window + * is not artificially extended by a peer who grows SWL downwards by + * continually updating the feature-remote Sequence-Window. + * If sequence numbers wrap it is bad luck. But that will take a while + * (48 bit), and this measure prevents Sequence-number attacks. + */ + if (before48(dp->dccps_swl, dp->dccps_isr)) + dp->dccps_swl = dp->dccps_isr; dp->dccps_swh = ADD48(dp->dccps_gsr, (3 * dp->dccps_r_seq_win) / 4); } @@ -425,14 +450,16 @@ static inline void dccp_update_gss(struct sock *sk, u64 seq) 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); + /* Adjust AWL so that it is not below ISS - see comment above for SWL */ + if (before48(dp->dccps_awl, dp->dccps_iss)) + dp->dccps_awl = dp->dccps_iss; dp->dccps_awh = dp->dccps_gss; } static inline int dccp_ack_pending(const struct sock *sk) { const struct dccp_sock *dp = dccp_sk(sk); - return dp->dccps_timestamp_echo != 0 || - (dp->dccps_hc_rx_ackvec != NULL && + return (dp->dccps_hc_rx_ackvec != NULL && dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) || inet_csk_ack_scheduled(sk); } @@ -449,7 +476,6 @@ extern int dccp_insert_options_rsk(struct dccp_request_sock*, struct sk_buff*); extern int dccp_insert_option_elapsed_time(struct sk_buff *skb, u32 elapsed); extern u32 dccp_timestamp(void); extern void dccp_timestamping_init(void); -extern int dccp_insert_option_timestamp(struct sk_buff *skb); extern int dccp_insert_option(struct sk_buff *skb, unsigned char option, const void *value, unsigned char len); |