diff options
Diffstat (limited to 'include/net/tcp_ecn.h')
| -rw-r--r-- | include/net/tcp_ecn.h | 89 |
1 files changed, 88 insertions, 1 deletions
diff --git a/include/net/tcp_ecn.h b/include/net/tcp_ecn.h index 1a41a459aa07..08c7f4757e4e 100644 --- a/include/net/tcp_ecn.h +++ b/include/net/tcp_ecn.h @@ -24,6 +24,13 @@ enum tcp_ecn_mode { TCP_ECN_IN_ACCECN_OUT_NOECN = 5, }; +/* AccECN option sending when AccECN has been successfully negotiated */ +enum tcp_accecn_option { + TCP_ACCECN_OPTION_DISABLED = 0, + TCP_ACCECN_OPTION_MINIMUM = 1, + TCP_ACCECN_OPTION_FULL = 2, +}; + static inline void tcp_ecn_queue_cwr(struct tcp_sock *tp) { /* Do not set CWR if in AccECN mode! */ @@ -169,6 +176,79 @@ static inline void tcp_accecn_third_ack(struct sock *sk, } } +/* Maps IP ECN field ECT/CE code point to AccECN option field number, given + * we are sending fields with Accurate ECN Order 1: ECT(1), CE, ECT(0). + */ +static inline u8 tcp_ecnfield_to_accecn_optfield(u8 ecnfield) +{ + switch (ecnfield & INET_ECN_MASK) { + case INET_ECN_NOT_ECT: + return 0; /* AccECN does not send counts of NOT_ECT */ + case INET_ECN_ECT_1: + return 1; + case INET_ECN_CE: + return 2; + case INET_ECN_ECT_0: + return 3; + } + return 0; +} + +/* Maps IP ECN field ECT/CE code point to AccECN option field value offset. + * Some fields do not start from zero, to detect zeroing by middleboxes. + */ +static inline u32 tcp_accecn_field_init_offset(u8 ecnfield) +{ + switch (ecnfield & INET_ECN_MASK) { + case INET_ECN_NOT_ECT: + return 0; /* AccECN does not send counts of NOT_ECT */ + case INET_ECN_ECT_1: + return TCP_ACCECN_E1B_INIT_OFFSET; + case INET_ECN_CE: + return TCP_ACCECN_CEB_INIT_OFFSET; + case INET_ECN_ECT_0: + return TCP_ACCECN_E0B_INIT_OFFSET; + } + return 0; +} + +/* Maps AccECN option field #nr to IP ECN field ECT/CE bits */ +static inline unsigned int tcp_accecn_optfield_to_ecnfield(unsigned int option, + bool order) +{ + /* Based on Table 5 of the AccECN spec to map (option, order) to + * the corresponding ECN conuters (ECT-1, ECT-0, or CE). + */ + static const u8 optfield_lookup[2][3] = { + /* order = 0: 1st field ECT-0, 2nd field CE, 3rd field ECT-1 */ + { INET_ECN_ECT_0, INET_ECN_CE, INET_ECN_ECT_1 }, + /* order = 1: 1st field ECT-1, 2nd field CE, 3rd field ECT-0 */ + { INET_ECN_ECT_1, INET_ECN_CE, INET_ECN_ECT_0 } + }; + + return optfield_lookup[order][option % 3]; +} + +/* Handles AccECN option ECT and CE 24-bit byte counters update into + * the u32 value in tcp_sock. As we're processing TCP options, it is + * safe to access from - 1. + */ +static inline s32 tcp_update_ecn_bytes(u32 *cnt, const char *from, + u32 init_offset) +{ + u32 truncated = (get_unaligned_be32(from - 1) - init_offset) & + 0xFFFFFFU; + u32 delta = (truncated - *cnt) & 0xFFFFFFU; + + /* If delta has the highest bit set (24th bit) indicating + * negative, sign extend to correct an estimation using + * sign_extend32(delta, 24 - 1) + */ + delta = sign_extend32(delta, 23); + *cnt += delta; + return (s32)delta; +} + /* Updates Accurate ECN received counters from the received IP ECN field */ static inline void tcp_ecn_received_counters(struct sock *sk, const struct sk_buff *skb, u32 len) @@ -192,8 +272,12 @@ static inline void tcp_ecn_received_counters(struct sock *sk, tp->received_ce_pending = min(tp->received_ce_pending + pcount, 0xfU); - if (len > 0) + if (len > 0) { + u8 minlen = tcp_ecnfield_to_accecn_optfield(ecnfield); tp->received_ecn_bytes[ecnfield - 1] += len; + tp->accecn_minlen = max_t(u8, tp->accecn_minlen, + minlen); + } } } @@ -263,6 +347,9 @@ static inline void tcp_accecn_init_counters(struct tcp_sock *tp) tp->received_ce = 0; tp->received_ce_pending = 0; __tcp_accecn_init_bytes_counters(tp->received_ecn_bytes); + __tcp_accecn_init_bytes_counters(tp->delivered_ecn_bytes); + tp->accecn_minlen = 0; + tp->est_ecnfield = 0; } /* Used for make_synack to form the ACE flags */ |