diff options
| -rw-r--r-- | net/dccp/ackvec.c | 31 | ||||
| -rw-r--r-- | net/dccp/ackvec.h | 17 | ||||
| -rw-r--r-- | net/dccp/dccp.h | 14 | ||||
| -rw-r--r-- | net/dccp/options.c | 10 |
4 files changed, 56 insertions, 16 deletions
diff --git a/net/dccp/ackvec.c b/net/dccp/ackvec.c index de84dd34c93f..1184d5e5dc96 100644 --- a/net/dccp/ackvec.c +++ b/net/dccp/ackvec.c @@ -29,7 +29,7 @@ struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority) struct dccp_ackvec *av = kmem_cache_zalloc(dccp_ackvec_slab, priority); if (av != NULL) { - av->av_buf_head = DCCPAV_MAX_ACKVEC_LEN - 1; + av->av_buf_head = av->av_buf_tail = DCCPAV_MAX_ACKVEC_LEN - 1; INIT_LIST_HEAD(&av->av_records); } return av; @@ -72,6 +72,14 @@ int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seqno, u8 nonce_sum) avr->avr_ack_nonce = nonce_sum; avr->avr_ack_runlen = dccp_ackvec_runlen(av->av_buf + av->av_buf_head); /* + * When the buffer overflows, we keep no more than one record. This is + * the simplest way of disambiguating sender-Acks dating from before the + * overflow from sender-Acks which refer to after the overflow; a simple + * solution is preferable here since we are handling an exception. + */ + if (av->av_overflow) + dccp_ackvec_purge_records(av); + /* * Since GSS is incremented for each packet, the list is automatically * arranged in descending order of @ack_seqno. */ @@ -85,6 +93,27 @@ int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seqno, u8 nonce_sum) } /* + * Buffer index and length computation using modulo-buffersize arithmetic. + * Note that, as pointers move from right to left, head is `before' tail. + */ +static inline u16 __ackvec_idx_add(const u16 a, const u16 b) +{ + return (a + b) % DCCPAV_MAX_ACKVEC_LEN; +} + +static inline u16 __ackvec_idx_sub(const u16 a, const u16 b) +{ + return __ackvec_idx_add(a, DCCPAV_MAX_ACKVEC_LEN - b); +} + +u16 dccp_ackvec_buflen(const struct dccp_ackvec *av) +{ + if (unlikely(av->av_overflow)) + return DCCPAV_MAX_ACKVEC_LEN; + return __ackvec_idx_sub(av->av_buf_tail, av->av_buf_head); +} + +/* * If several packets are missing, the HC-Receiver may prefer to enter multiple * bytes with run length 0, rather than a single byte with a larger run length; * this simplifies table updates if one of the missing packets arrives. diff --git a/net/dccp/ackvec.h b/net/dccp/ackvec.h index b34e5ed4c342..92f65b0fef5b 100644 --- a/net/dccp/ackvec.h +++ b/net/dccp/ackvec.h @@ -21,6 +21,7 @@ * the maximum size of a single Ack Vector. Setting %DCCPAV_NUM_ACKVECS to 1 * will be sufficient for most cases of low Ack Ratios, using a value of 2 gives * more headroom if Ack Ratio is higher or when the sender acknowledges slowly. + * The maximum value is bounded by the u16 types for indices and functions. */ #define DCCPAV_NUM_ACKVECS 2 #define DCCPAV_MAX_ACKVEC_LEN (DCCP_SINGLE_OPT_MAXLEN * DCCPAV_NUM_ACKVECS) @@ -55,8 +56,10 @@ static inline u8 dccp_ackvec_state(const u8 *cell) * @av_buf_head: head index; begin of live portion in @av_buf * @av_buf_tail: tail index; first index _after_ the live portion in @av_buf * @av_buf_ackno: highest seqno of acknowledgeable packet recorded in @av_buf + * @av_tail_ackno: lowest seqno of acknowledgeable packet recorded in @av_buf * @av_buf_nonce: ECN nonce sums, each covering subsequent segments of up to * %DCCP_SINGLE_OPT_MAXLEN cells in the live portion of @av_buf + * @av_overflow: if 1 then buf_head == buf_tail indicates buffer wraparound * @av_records: list of %dccp_ackvec_record (Ack Vectors sent previously) * @av_veclen: length of the live portion of @av_buf */ @@ -65,7 +68,9 @@ struct dccp_ackvec { u16 av_buf_head; u16 av_buf_tail; u64 av_buf_ackno:48; + u64 av_tail_ackno:48; bool av_buf_nonce[DCCPAV_NUM_ACKVECS]; + u8 av_overflow:1; struct list_head av_records; u16 av_vec_len; }; @@ -113,10 +118,11 @@ extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, const u8 *value, const u8 len); extern int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seq, u8 sum); +extern u16 dccp_ackvec_buflen(const struct dccp_ackvec *av); -static inline int dccp_ackvec_pending(const struct dccp_ackvec *av) +static inline bool dccp_ackvec_is_empty(const struct dccp_ackvec *av) { - return av->av_vec_len; + return av->av_overflow == 0 && av->av_buf_head == av->av_buf_tail; } #else /* CONFIG_IP_DCCP_ACKVEC */ static inline int dccp_ackvec_init(void) @@ -160,9 +166,14 @@ static inline int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seq, u8 return -1; } -static inline int dccp_ackvec_pending(const struct dccp_ackvec *av) +static inline u16 dccp_ackvec_buflen(const struct dccp_ackvec *av) { return 0; } + +static inline bool dccp_ackvec_is_empty(const struct dccp_ackvec *av) +{ + return true; +} #endif /* CONFIG_IP_DCCP_ACKVEC */ #endif /* _ACKVEC_H */ diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h index e4d6e76ced41..1e65378eea3f 100644 --- a/net/dccp/dccp.h +++ b/net/dccp/dccp.h @@ -448,15 +448,15 @@ static inline void dccp_update_gss(struct sock *sk, u64 seq) dp->dccps_awh = dp->dccps_gss; } +static inline int dccp_ackvec_pending(const struct sock *sk) +{ + return dccp_sk(sk)->dccps_hc_rx_ackvec != NULL && + !dccp_ackvec_is_empty(dccp_sk(sk)->dccps_hc_rx_ackvec); +} + static inline int dccp_ack_pending(const struct sock *sk) { - const struct dccp_sock *dp = dccp_sk(sk); - return -#ifdef CONFIG_IP_DCCP_ACKVEC - (dp->dccps_hc_rx_ackvec != NULL && - dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) || -#endif - inet_csk_ack_scheduled(sk); + return dccp_ackvec_pending(sk) || inet_csk_ack_scheduled(sk); } extern int dccp_feat_signal_nn_change(struct sock *sk, u8 feat, u64 nn_val); diff --git a/net/dccp/options.c b/net/dccp/options.c index 392d7db31342..3163ae980f16 100644 --- a/net/dccp/options.c +++ b/net/dccp/options.c @@ -432,9 +432,10 @@ static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) { struct dccp_sock *dp = dccp_sk(sk); struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec; + const u16 buflen = dccp_ackvec_buflen(av); /* Figure out how many options do we need to represent the ackvec */ - const u8 nr_opts = DIV_ROUND_UP(av->av_vec_len, DCCP_SINGLE_OPT_MAXLEN); - u16 len = av->av_vec_len + 2 * nr_opts; + const u8 nr_opts = DIV_ROUND_UP(buflen, DCCP_SINGLE_OPT_MAXLEN); + u16 len = buflen + 2 * nr_opts; u8 i, nonce = 0; const unsigned char *tail, *from; unsigned char *to; @@ -445,7 +446,7 @@ static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) DCCP_SKB_CB(skb)->dccpd_opt_len += len; to = skb_push(skb, len); - len = av->av_vec_len; + len = buflen; from = av->av_buf + av->av_buf_head; tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN; @@ -583,8 +584,7 @@ int dccp_insert_options(struct sock *sk, struct sk_buff *skb) if (dccp_insert_option_timestamp(sk, skb)) return -1; - } else if (dp->dccps_hc_rx_ackvec != NULL && - dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) && + } else if (dccp_ackvec_pending(sk) && dccp_insert_option_ackvec(sk, skb)) { return -1; } |