Loading include/linux/dccp.h +2 −0 Original line number Diff line number Diff line Loading @@ -462,6 +462,7 @@ struct dccp_ackvec; * @dccps_hc_rx_insert_options - receiver wants to add options when acking * @dccps_hc_tx_insert_options - sender wants to add options when sending * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3) * @dccps_sync_scheduled - flag which signals "send out-of-band message soon" * @dccps_xmitlet - tasklet scheduled by the TX CCID to dequeue data packets * @dccps_xmit_timer - used by the TX CCID to delay sending (rate-based pacing) * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs) Loading Loading @@ -503,6 +504,7 @@ struct dccp_sock { __u8 dccps_hc_rx_insert_options:1; __u8 dccps_hc_tx_insert_options:1; __u8 dccps_server_timewait:1; __u8 dccps_sync_scheduled:1; struct tasklet_struct dccps_xmitlet; struct timer_list dccps_xmit_timer; }; Loading net/dccp/ackvec.c +216 −201 Original line number Diff line number Diff line Loading @@ -9,18 +9,10 @@ * under the terms of the GNU General Public License as published by the * Free Software Foundation; version 2 of the License; */ #include "ackvec.h" #include "dccp.h" #include <linux/init.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/skbuff.h> #include <linux/slab.h> #include <net/sock.h> static struct kmem_cache *dccp_ackvec_slab; static struct kmem_cache *dccp_ackvec_record_slab; Loading Loading @@ -92,6 +84,24 @@ int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seqno, u8 nonce_sum) return 0; } static struct dccp_ackvec_record *dccp_ackvec_lookup(struct list_head *av_list, const u64 ackno) { struct dccp_ackvec_record *avr; /* * Exploit that records are inserted in descending order of sequence * number, start with the oldest record first. If @ackno is `before' * the earliest ack_ackno, the packet is too old to be considered. */ list_for_each_entry_reverse(avr, av_list, avr_node) { if (avr->avr_ack_seqno == ackno) return avr; if (before48(ackno, avr->avr_ack_seqno)) break; } return NULL; } /* * Buffer index and length computation using modulo-buffersize arithmetic. * Note that, as pointers move from right to left, head is `before' tail. Loading @@ -113,248 +123,253 @@ u16 dccp_ackvec_buflen(const struct dccp_ackvec *av) 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. /** * dccp_ackvec_update_old - Update previous state as per RFC 4340, 11.4.1 * @av: non-empty buffer to update * @distance: negative or zero distance of @seqno from buf_ackno downward * @seqno: the (old) sequence number whose record is to be updated * @state: state in which packet carrying @seqno was received */ static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av, const unsigned int packets, const unsigned char state) static void dccp_ackvec_update_old(struct dccp_ackvec *av, s64 distance, u64 seqno, enum dccp_ackvec_states state) { long gap; long new_head; u16 ptr = av->av_buf_head; if (av->av_vec_len + packets > DCCPAV_MAX_ACKVEC_LEN) return -ENOBUFS; BUG_ON(distance > 0); if (unlikely(dccp_ackvec_is_empty(av))) return; gap = packets - 1; new_head = av->av_buf_head - packets; do { u8 runlen = dccp_ackvec_runlen(av->av_buf + ptr); if (new_head < 0) { if (gap > 0) { memset(av->av_buf, DCCPAV_NOT_RECEIVED, gap + new_head + 1); gap = -new_head; } new_head += DCCPAV_MAX_ACKVEC_LEN; if (distance + runlen >= 0) { /* * Only update the state if packet has not been received * yet. This is OK as per the second table in RFC 4340, * 11.4.1; i.e. here we are using the following table: * RECEIVED * 0 1 3 * S +---+---+---+ * T 0 | 0 | 0 | 0 | * O +---+---+---+ * R 1 | 1 | 1 | 1 | * E +---+---+---+ * D 3 | 0 | 1 | 3 | * +---+---+---+ * The "Not Received" state was set by reserve_seats(). */ if (av->av_buf[ptr] == DCCPAV_NOT_RECEIVED) av->av_buf[ptr] = state; else dccp_pr_debug("Not changing %llu state to %u\n", (unsigned long long)seqno, state); break; } av->av_buf_head = new_head; distance += runlen + 1; ptr = __ackvec_idx_add(ptr, 1); if (gap > 0) memset(av->av_buf + av->av_buf_head + 1, DCCPAV_NOT_RECEIVED, gap); } while (ptr != av->av_buf_tail); } av->av_buf[av->av_buf_head] = state; av->av_vec_len += packets; return 0; /* Mark @num entries after buf_head as "Not yet received". */ static void dccp_ackvec_reserve_seats(struct dccp_ackvec *av, u16 num) { u16 start = __ackvec_idx_add(av->av_buf_head, 1), len = DCCPAV_MAX_ACKVEC_LEN - start; /* check for buffer wrap-around */ if (num > len) { memset(av->av_buf + start, DCCPAV_NOT_RECEIVED, len); start = 0; num -= len; } if (num) memset(av->av_buf + start, DCCPAV_NOT_RECEIVED, num); } /* * Implements the RFC 4340, Appendix A /** * dccp_ackvec_add_new - Record one or more new entries in Ack Vector buffer * @av: container of buffer to update (can be empty or non-empty) * @num_packets: number of packets to register (must be >= 1) * @seqno: sequence number of the first packet in @num_packets * @state: state in which packet carrying @seqno was received */ int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, const u64 ackno, const u8 state) static void dccp_ackvec_add_new(struct dccp_ackvec *av, u32 num_packets, u64 seqno, enum dccp_ackvec_states state) { u8 *cur_head = av->av_buf + av->av_buf_head, *buf_end = av->av_buf + DCCPAV_MAX_ACKVEC_LEN; /* * Check at the right places if the buffer is full, if it is, tell the * caller to start dropping packets till the HC-Sender acks our ACK * vectors, when we will free up space in av_buf. * * We may well decide to do buffer compression, etc, but for now lets * just drop. * * From Appendix A.1.1 (`New Packets'): * * Of course, the circular buffer may overflow, either when the * HC-Sender is sending data at a very high rate, when the * HC-Receiver's acknowledgements are not reaching the HC-Sender, * or when the HC-Sender is forgetting to acknowledge those acks * (so the HC-Receiver is unable to clean up old state). In this * case, the HC-Receiver should either compress the buffer (by * increasing run lengths when possible), transfer its state to * a larger buffer, or, as a last resort, drop all received * packets, without processing them whatsoever, until its buffer * shrinks again. */ u32 num_cells = num_packets; /* See if this is the first ackno being inserted */ if (av->av_vec_len == 0) { *cur_head = state; av->av_vec_len = 1; } else if (after48(ackno, av->av_buf_ackno)) { const u64 delta = dccp_delta_seqno(av->av_buf_ackno, ackno); if (num_packets > DCCPAV_BURST_THRESH) { u32 lost_packets = num_packets - 1; DCCP_WARN("Warning: large burst loss (%u)\n", lost_packets); /* * Look if the state of this packet is the same as the * previous ackno and if so if we can bump the head len. * We received 1 packet and have a loss of size "num_packets-1" * which we squeeze into num_cells-1 rather than reserving an * entire byte for each lost packet. * The reason is that the vector grows in O(burst_length); when * it grows too large there will no room left for the payload. * This is a trade-off: if a few packets out of the burst show * up later, their state will not be changed; it is simply too * costly to reshuffle/reallocate/copy the buffer each time. * Should such problems persist, we will need to switch to a * different underlying data structure. */ if (delta == 1 && dccp_ackvec_state(cur_head) == state && dccp_ackvec_runlen(cur_head) < DCCPAV_MAX_RUNLEN) *cur_head += 1; else if (dccp_ackvec_set_buf_head_state(av, delta, state)) return -ENOBUFS; } else { /* * A.1.2. Old Packets * * When a packet with Sequence Number S <= buf_ackno * arrives, the HC-Receiver will scan the table for * the byte corresponding to S. (Indexing structures * could reduce the complexity of this scan.) */ u64 delta = dccp_delta_seqno(ackno, av->av_buf_ackno); for (num_packets = num_cells = 1; lost_packets; ++num_cells) { u8 len = min(lost_packets, (u32)DCCPAV_MAX_RUNLEN); while (1) { const u8 len = dccp_ackvec_runlen(cur_head); /* * valid packets not yet in av_buf have a reserved * entry, with a len equal to 0. */ if (*cur_head == DCCPAV_NOT_RECEIVED && delta == 0) { dccp_pr_debug("Found %llu reserved seat!\n", (unsigned long long)ackno); *cur_head = state; goto out; } /* len == 0 means one packet */ if (delta < len + 1) goto out_duplicate; av->av_buf_head = __ackvec_idx_sub(av->av_buf_head, 1); av->av_buf[av->av_buf_head] = DCCPAV_NOT_RECEIVED | len; delta -= len + 1; if (++cur_head == buf_end) cur_head = av->av_buf; lost_packets -= len; } } av->av_buf_ackno = ackno; out: return 0; out_duplicate: /* Duplicate packet */ dccp_pr_debug("Received a dup or already considered lost " "packet: %llu\n", (unsigned long long)ackno); return -EILSEQ; if (num_cells + dccp_ackvec_buflen(av) >= DCCPAV_MAX_ACKVEC_LEN) { DCCP_CRIT("Ack Vector buffer overflow: dropping old entries\n"); av->av_overflow = true; } static void dccp_ackvec_throw_record(struct dccp_ackvec *av, struct dccp_ackvec_record *avr) { struct dccp_ackvec_record *next; av->av_buf_head = __ackvec_idx_sub(av->av_buf_head, num_packets); if (av->av_overflow) av->av_buf_tail = av->av_buf_head; /* sort out vector length */ if (av->av_buf_head <= avr->avr_ack_ptr) av->av_vec_len = avr->avr_ack_ptr - av->av_buf_head; else av->av_vec_len = DCCPAV_MAX_ACKVEC_LEN - 1 - av->av_buf_head + avr->avr_ack_ptr; av->av_buf[av->av_buf_head] = state; av->av_buf_ackno = seqno; /* free records */ list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) { list_del(&avr->avr_node); kmem_cache_free(dccp_ackvec_record_slab, avr); } if (num_packets > 1) dccp_ackvec_reserve_seats(av, num_packets - 1); } void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk, const u64 ackno) /** * dccp_ackvec_input - Register incoming packet in the buffer */ void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb) { struct dccp_ackvec_record *avr; u64 seqno = DCCP_SKB_CB(skb)->dccpd_seq; enum dccp_ackvec_states state = DCCPAV_RECEIVED; /* * If we traverse backwards, it should be faster when we have large * windows. We will be receiving ACKs for stuff we sent a while back * -sorbo. */ list_for_each_entry_reverse(avr, &av->av_records, avr_node) { if (ackno == avr->avr_ack_seqno) { dccp_pr_debug("%s ACK packet 0, len=%d, ack_seqno=%llu, " "ack_ackno=%llu, ACKED!\n", dccp_role(sk), avr->avr_ack_runlen, (unsigned long long)avr->avr_ack_seqno, (unsigned long long)avr->avr_ack_ackno); dccp_ackvec_throw_record(av, avr); break; } else if (avr->avr_ack_seqno > ackno) break; /* old news */ if (dccp_ackvec_is_empty(av)) { dccp_ackvec_add_new(av, 1, seqno, state); av->av_tail_ackno = seqno; } else { s64 num_packets = dccp_delta_seqno(av->av_buf_ackno, seqno); u8 *current_head = av->av_buf + av->av_buf_head; if (num_packets == 1 && dccp_ackvec_state(current_head) == state && dccp_ackvec_runlen(current_head) < DCCPAV_MAX_RUNLEN) { *current_head += 1; av->av_buf_ackno = seqno; } else if (num_packets > 0) { dccp_ackvec_add_new(av, num_packets, seqno, state); } else { dccp_ackvec_update_old(av, num_packets, seqno, state); } } } static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av, struct sock *sk, u64 *ackno, const unsigned char len, const unsigned char *vector) /** * dccp_ackvec_clear_state - Perform house-keeping / garbage-collection * This routine is called when the peer acknowledges the receipt of Ack Vectors * up to and including @ackno. While based on on section A.3 of RFC 4340, here * are additional precautions to prevent corrupted buffer state. In particular, * we use tail_ackno to identify outdated records; it always marks the earliest * packet of group (2) in 11.4.2. */ void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno) { unsigned char i; struct dccp_ackvec_record *avr; struct dccp_ackvec_record *avr, *next; u8 runlen_now, eff_runlen; s64 delta; /* Check if we actually sent an ACK vector */ if (list_empty(&av->av_records)) avr = dccp_ackvec_lookup(&av->av_records, ackno); if (avr == NULL) return; /* * Deal with outdated acknowledgments: this arises when e.g. there are * several old records and the acks from the peer come in slowly. In * that case we may still have records that pre-date tail_ackno. */ delta = dccp_delta_seqno(av->av_tail_ackno, avr->avr_ack_ackno); if (delta < 0) goto free_records; /* * Deal with overlapping Ack Vectors: don't subtract more than the * number of packets between tail_ackno and ack_ackno. */ eff_runlen = delta < avr->avr_ack_runlen ? delta : avr->avr_ack_runlen; i = len; runlen_now = dccp_ackvec_runlen(av->av_buf + avr->avr_ack_ptr); /* * XXX * I think it might be more efficient to work backwards. See comment on * rcv_ackno. -sorbo. * The run length of Ack Vector cells does not decrease over time. If * the run length is the same as at the time the Ack Vector was sent, we * free the ack_ptr cell. That cell can however not be freed if the run * length has increased: in this case we need to move the tail pointer * backwards (towards higher indices), to its next-oldest neighbour. */ avr = list_entry(av->av_records.next, struct dccp_ackvec_record, avr_node); while (i--) { const u8 rl = dccp_ackvec_runlen(vector); u64 ackno_end_rl; if (runlen_now > eff_runlen) { dccp_set_seqno(&ackno_end_rl, *ackno - rl); av->av_buf[avr->avr_ack_ptr] -= eff_runlen + 1; av->av_buf_tail = __ackvec_idx_add(avr->avr_ack_ptr, 1); /* This move may not have cleared the overflow flag. */ if (av->av_overflow) av->av_overflow = (av->av_buf_head == av->av_buf_tail); } else { av->av_buf_tail = avr->avr_ack_ptr; /* * If our AVR sequence number is greater than the ack, go * forward in the AVR list until it is not so. * We have made sure that avr points to a valid cell within the * buffer. This cell is either older than head, or equals head * (empty buffer): in both cases we no longer have any overflow. */ list_for_each_entry_from(avr, &av->av_records, avr_node) { if (!after48(avr->avr_ack_seqno, *ackno)) goto found; } /* End of the av_records list, not found, exit */ break; found: if (between48(avr->avr_ack_seqno, ackno_end_rl, *ackno)) { if (dccp_ackvec_state(vector) != DCCPAV_NOT_RECEIVED) { dccp_pr_debug("%s ACK vector 0, len=%d, " "ack_seqno=%llu, ack_ackno=%llu, " "ACKED!\n", dccp_role(sk), len, (unsigned long long) avr->avr_ack_seqno, (unsigned long long) avr->avr_ack_ackno); dccp_ackvec_throw_record(av, avr); break; av->av_overflow = 0; } /* * If it wasn't received, continue scanning... we might * find another one. * The peer has acknowledged up to and including ack_ackno. Hence the * first packet in group (2) of 11.4.2 is the successor of ack_ackno. */ } av->av_tail_ackno = ADD48(avr->avr_ack_ackno, 1); dccp_set_seqno(ackno, ackno_end_rl - 1); ++vector; free_records: list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) { list_del(&avr->avr_node); kmem_cache_free(dccp_ackvec_record_slab, avr); } } int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, u64 *ackno, const u8 opt, const u8 *value, const u8 len) /* * Routines to keep track of Ack Vectors received in an skb */ int dccp_ackvec_parsed_add(struct list_head *head, u8 *vec, u8 len, u8 nonce) { if (len > DCCP_SINGLE_OPT_MAXLEN) return -1; struct dccp_ackvec_parsed *new = kmalloc(sizeof(*new), GFP_ATOMIC); /* dccp_ackvector_print(DCCP_SKB_CB(skb)->dccpd_ack_seq, value, len); */ dccp_ackvec_check_rcv_ackvector(dccp_sk(sk)->dccps_hc_rx_ackvec, sk, ackno, len, value); if (new == NULL) return -ENOBUFS; new->vec = vec; new->len = len; new->nonce = nonce; list_add_tail(&new->node, head); return 0; } EXPORT_SYMBOL_GPL(dccp_ackvec_parsed_add); void dccp_ackvec_parsed_cleanup(struct list_head *parsed_chunks) { struct dccp_ackvec_parsed *cur, *next; list_for_each_entry_safe(cur, next, parsed_chunks, node) kfree(cur); INIT_LIST_HEAD(parsed_chunks); } EXPORT_SYMBOL_GPL(dccp_ackvec_parsed_cleanup); int __init dccp_ackvec_init(void) { Loading net/dccp/ackvec.h +24 −14 Original line number Diff line number Diff line Loading @@ -29,6 +29,9 @@ /* Estimated minimum average Ack Vector length - used for updating MPS */ #define DCCPAV_MIN_OPTLEN 16 /* Threshold for coping with large bursts of losses */ #define DCCPAV_BURST_THRESH (DCCPAV_MAX_ACKVEC_LEN / 8) enum dccp_ackvec_states { DCCPAV_RECEIVED = 0x00, DCCPAV_ECN_MARKED = 0x40, Loading Loading @@ -61,7 +64,6 @@ static inline u8 dccp_ackvec_state(const u8 *cell) * %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 */ struct dccp_ackvec { u8 av_buf[DCCPAV_MAX_ACKVEC_LEN]; Loading @@ -72,7 +74,6 @@ struct dccp_ackvec { bool av_buf_nonce[DCCPAV_NUM_ACKVECS]; u8 av_overflow:1; struct list_head av_records; u16 av_vec_len; }; /** struct dccp_ackvec_record - Records information about sent Ack Vectors Loading @@ -98,29 +99,38 @@ struct dccp_ackvec_record { u8 avr_ack_nonce:1; }; struct sock; struct sk_buff; extern int dccp_ackvec_init(void); extern void dccp_ackvec_exit(void); extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority); extern void dccp_ackvec_free(struct dccp_ackvec *av); extern int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, const u64 ackno, const u8 state); extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk, const u64 ackno); extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, u64 *ackno, const u8 opt, const u8 *value, const u8 len); extern void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb); extern int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seq, u8 sum); extern void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno); extern u16 dccp_ackvec_buflen(const struct dccp_ackvec *av); static inline bool dccp_ackvec_is_empty(const struct dccp_ackvec *av) { return av->av_overflow == 0 && av->av_buf_head == av->av_buf_tail; } /** * struct dccp_ackvec_parsed - Record offsets of Ack Vectors in skb * @vec: start of vector (offset into skb) * @len: length of @vec * @nonce: whether @vec had an ECN nonce of 0 or 1 * @node: FIFO - arranged in descending order of ack_ackno * This structure is used by CCIDs to access Ack Vectors in a received skb. */ struct dccp_ackvec_parsed { u8 *vec, len, nonce:1; struct list_head node; }; extern int dccp_ackvec_parsed_add(struct list_head *head, u8 *vec, u8 len, u8 nonce); extern void dccp_ackvec_parsed_cleanup(struct list_head *parsed_chunks); #endif /* _ACKVEC_H */ net/dccp/ccids/ccid2.c +41 −93 Original line number Diff line number Diff line Loading @@ -246,68 +246,6 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, unsigned int len) #endif } /* XXX Lame code duplication! * returns -1 if none was found. * else returns the next offset to use in the function call. */ static int ccid2_ackvector(struct sock *sk, struct sk_buff *skb, int offset, unsigned char **vec, unsigned char *veclen) { const struct dccp_hdr *dh = dccp_hdr(skb); unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); unsigned char *opt_ptr; const unsigned char *opt_end = (unsigned char *)dh + (dh->dccph_doff * 4); unsigned char opt, len; unsigned char *value; BUG_ON(offset < 0); options += offset; opt_ptr = options; if (opt_ptr >= opt_end) return -1; while (opt_ptr != opt_end) { opt = *opt_ptr++; len = 0; value = NULL; /* Check if this isn't a single byte option */ if (opt > DCCPO_MAX_RESERVED) { if (opt_ptr == opt_end) goto out_invalid_option; len = *opt_ptr++; if (len < 3) goto out_invalid_option; /* * Remove the type and len fields, leaving * just the value size */ len -= 2; value = opt_ptr; opt_ptr += len; if (opt_ptr > opt_end) goto out_invalid_option; } switch (opt) { case DCCPO_ACK_VECTOR_0: case DCCPO_ACK_VECTOR_1: *vec = value; *veclen = len; return offset + (opt_ptr - options); } } return -1; out_invalid_option: DCCP_BUG("Invalid option - this should not happen (previous parsing)!"); return -1; } /** * ccid2_rtt_estimator - Sample RTT and compute RTO using RFC2988 algorithm * This code is almost identical with TCP's tcp_rtt_estimator(), since Loading Loading @@ -432,16 +370,28 @@ static void ccid2_congestion_event(struct sock *sk, struct ccid2_seq *seqp) ccid2_change_l_ack_ratio(sk, hc->tx_cwnd); } static int ccid2_hc_tx_parse_options(struct sock *sk, u8 packet_type, u8 option, u8 *optval, u8 optlen) { struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); switch (option) { case DCCPO_ACK_VECTOR_0: case DCCPO_ACK_VECTOR_1: return dccp_ackvec_parsed_add(&hc->tx_av_chunks, optval, optlen, option - DCCPO_ACK_VECTOR_0); } return 0; } static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) { struct dccp_sock *dp = dccp_sk(sk); struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); const bool sender_was_blocked = ccid2_cwnd_network_limited(hc); struct dccp_ackvec_parsed *avp; u64 ackno, seqno; struct ccid2_seq *seqp; unsigned char *vector; unsigned char veclen; int offset = 0; int done = 0; unsigned int maxincr = 0; Loading Loading @@ -475,17 +425,12 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) } /* check forward path congestion */ /* still didn't send out new data packets */ if (hc->tx_seqh == hc->tx_seqt) if (dccp_packet_without_ack(skb)) return; switch (DCCP_SKB_CB(skb)->dccpd_type) { case DCCP_PKT_ACK: case DCCP_PKT_DATAACK: break; default: return; } /* still didn't send out new data packets */ if (hc->tx_seqh == hc->tx_seqt) goto done; ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; if (after48(ackno, hc->tx_high_ack)) Loading @@ -509,15 +454,16 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) maxincr = DIV_ROUND_UP(dp->dccps_l_ack_ratio, 2); /* go through all ack vectors */ while ((offset = ccid2_ackvector(sk, skb, offset, &vector, &veclen)) != -1) { list_for_each_entry(avp, &hc->tx_av_chunks, node) { /* go through this ack vector */ while (veclen--) { u64 ackno_end_rl = SUB48(ackno, dccp_ackvec_runlen(vector)); for (; avp->len--; avp->vec++) { u64 ackno_end_rl = SUB48(ackno, dccp_ackvec_runlen(avp->vec)); ccid2_pr_debug("ackvec start:%llu end:%llu\n", ccid2_pr_debug("ackvec %llu |%u,%u|\n", (unsigned long long)ackno, (unsigned long long)ackno_end_rl); dccp_ackvec_state(avp->vec) >> 6, dccp_ackvec_runlen(avp->vec)); /* if the seqno we are analyzing is larger than the * current ackno, then move towards the tail of our * seqnos. Loading @@ -536,7 +482,7 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) * run length */ while (between48(seqp->ccid2s_seq,ackno_end_rl,ackno)) { const u8 state = dccp_ackvec_state(vector); const u8 state = dccp_ackvec_state(avp->vec); /* new packet received or marked */ if (state != DCCPAV_NOT_RECEIVED && Loading @@ -563,7 +509,6 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) break; ackno = SUB48(ackno_end_rl, 1); vector++; } if (done) break; Loading Loading @@ -631,10 +576,11 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) sk_stop_timer(sk, &hc->tx_rtotimer); else sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto); done: /* check if incoming Acks allow pending packets to be sent */ if (sender_was_blocked && !ccid2_cwnd_network_limited(hc)) tasklet_schedule(&dccp_sk(sk)->dccps_xmitlet); dccp_ackvec_parsed_cleanup(&hc->tx_av_chunks); } static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) Loading Loading @@ -663,6 +609,7 @@ static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) hc->tx_last_cong = ccid2_time_stamp; setup_timer(&hc->tx_rtotimer, ccid2_hc_tx_rto_expire, (unsigned long)sk); INIT_LIST_HEAD(&hc->tx_av_chunks); return 0; } Loading Loading @@ -703,6 +650,7 @@ struct ccid_operations ccid2_ops = { .ccid_hc_tx_exit = ccid2_hc_tx_exit, .ccid_hc_tx_send_packet = ccid2_hc_tx_send_packet, .ccid_hc_tx_packet_sent = ccid2_hc_tx_packet_sent, .ccid_hc_tx_parse_options = ccid2_hc_tx_parse_options, .ccid_hc_tx_packet_recv = ccid2_hc_tx_packet_recv, .ccid_hc_rx_obj_size = sizeof(struct ccid2_hc_rx_sock), .ccid_hc_rx_packet_recv = ccid2_hc_rx_packet_recv, Loading net/dccp/ccids/ccid2.h +2 −0 Original line number Diff line number Diff line Loading @@ -55,6 +55,7 @@ struct ccid2_seq { * @tx_rtt_seq: to decay RTTVAR at most once per flight * @tx_rpseq: last consecutive seqno * @tx_rpdupack: dupacks since rpseq * @tx_av_chunks: list of Ack Vectors received on current skb */ struct ccid2_hc_tx_sock { u32 tx_cwnd; Loading @@ -79,6 +80,7 @@ struct ccid2_hc_tx_sock { int tx_rpdupack; u32 tx_last_cong; u64 tx_high_ack; struct list_head tx_av_chunks; }; static inline bool ccid2_cwnd_network_limited(struct ccid2_hc_tx_sock *hc) Loading Loading
include/linux/dccp.h +2 −0 Original line number Diff line number Diff line Loading @@ -462,6 +462,7 @@ struct dccp_ackvec; * @dccps_hc_rx_insert_options - receiver wants to add options when acking * @dccps_hc_tx_insert_options - sender wants to add options when sending * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3) * @dccps_sync_scheduled - flag which signals "send out-of-band message soon" * @dccps_xmitlet - tasklet scheduled by the TX CCID to dequeue data packets * @dccps_xmit_timer - used by the TX CCID to delay sending (rate-based pacing) * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs) Loading Loading @@ -503,6 +504,7 @@ struct dccp_sock { __u8 dccps_hc_rx_insert_options:1; __u8 dccps_hc_tx_insert_options:1; __u8 dccps_server_timewait:1; __u8 dccps_sync_scheduled:1; struct tasklet_struct dccps_xmitlet; struct timer_list dccps_xmit_timer; }; Loading
net/dccp/ackvec.c +216 −201 Original line number Diff line number Diff line Loading @@ -9,18 +9,10 @@ * under the terms of the GNU General Public License as published by the * Free Software Foundation; version 2 of the License; */ #include "ackvec.h" #include "dccp.h" #include <linux/init.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/skbuff.h> #include <linux/slab.h> #include <net/sock.h> static struct kmem_cache *dccp_ackvec_slab; static struct kmem_cache *dccp_ackvec_record_slab; Loading Loading @@ -92,6 +84,24 @@ int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seqno, u8 nonce_sum) return 0; } static struct dccp_ackvec_record *dccp_ackvec_lookup(struct list_head *av_list, const u64 ackno) { struct dccp_ackvec_record *avr; /* * Exploit that records are inserted in descending order of sequence * number, start with the oldest record first. If @ackno is `before' * the earliest ack_ackno, the packet is too old to be considered. */ list_for_each_entry_reverse(avr, av_list, avr_node) { if (avr->avr_ack_seqno == ackno) return avr; if (before48(ackno, avr->avr_ack_seqno)) break; } return NULL; } /* * Buffer index and length computation using modulo-buffersize arithmetic. * Note that, as pointers move from right to left, head is `before' tail. Loading @@ -113,248 +123,253 @@ u16 dccp_ackvec_buflen(const struct dccp_ackvec *av) 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. /** * dccp_ackvec_update_old - Update previous state as per RFC 4340, 11.4.1 * @av: non-empty buffer to update * @distance: negative or zero distance of @seqno from buf_ackno downward * @seqno: the (old) sequence number whose record is to be updated * @state: state in which packet carrying @seqno was received */ static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av, const unsigned int packets, const unsigned char state) static void dccp_ackvec_update_old(struct dccp_ackvec *av, s64 distance, u64 seqno, enum dccp_ackvec_states state) { long gap; long new_head; u16 ptr = av->av_buf_head; if (av->av_vec_len + packets > DCCPAV_MAX_ACKVEC_LEN) return -ENOBUFS; BUG_ON(distance > 0); if (unlikely(dccp_ackvec_is_empty(av))) return; gap = packets - 1; new_head = av->av_buf_head - packets; do { u8 runlen = dccp_ackvec_runlen(av->av_buf + ptr); if (new_head < 0) { if (gap > 0) { memset(av->av_buf, DCCPAV_NOT_RECEIVED, gap + new_head + 1); gap = -new_head; } new_head += DCCPAV_MAX_ACKVEC_LEN; if (distance + runlen >= 0) { /* * Only update the state if packet has not been received * yet. This is OK as per the second table in RFC 4340, * 11.4.1; i.e. here we are using the following table: * RECEIVED * 0 1 3 * S +---+---+---+ * T 0 | 0 | 0 | 0 | * O +---+---+---+ * R 1 | 1 | 1 | 1 | * E +---+---+---+ * D 3 | 0 | 1 | 3 | * +---+---+---+ * The "Not Received" state was set by reserve_seats(). */ if (av->av_buf[ptr] == DCCPAV_NOT_RECEIVED) av->av_buf[ptr] = state; else dccp_pr_debug("Not changing %llu state to %u\n", (unsigned long long)seqno, state); break; } av->av_buf_head = new_head; distance += runlen + 1; ptr = __ackvec_idx_add(ptr, 1); if (gap > 0) memset(av->av_buf + av->av_buf_head + 1, DCCPAV_NOT_RECEIVED, gap); } while (ptr != av->av_buf_tail); } av->av_buf[av->av_buf_head] = state; av->av_vec_len += packets; return 0; /* Mark @num entries after buf_head as "Not yet received". */ static void dccp_ackvec_reserve_seats(struct dccp_ackvec *av, u16 num) { u16 start = __ackvec_idx_add(av->av_buf_head, 1), len = DCCPAV_MAX_ACKVEC_LEN - start; /* check for buffer wrap-around */ if (num > len) { memset(av->av_buf + start, DCCPAV_NOT_RECEIVED, len); start = 0; num -= len; } if (num) memset(av->av_buf + start, DCCPAV_NOT_RECEIVED, num); } /* * Implements the RFC 4340, Appendix A /** * dccp_ackvec_add_new - Record one or more new entries in Ack Vector buffer * @av: container of buffer to update (can be empty or non-empty) * @num_packets: number of packets to register (must be >= 1) * @seqno: sequence number of the first packet in @num_packets * @state: state in which packet carrying @seqno was received */ int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, const u64 ackno, const u8 state) static void dccp_ackvec_add_new(struct dccp_ackvec *av, u32 num_packets, u64 seqno, enum dccp_ackvec_states state) { u8 *cur_head = av->av_buf + av->av_buf_head, *buf_end = av->av_buf + DCCPAV_MAX_ACKVEC_LEN; /* * Check at the right places if the buffer is full, if it is, tell the * caller to start dropping packets till the HC-Sender acks our ACK * vectors, when we will free up space in av_buf. * * We may well decide to do buffer compression, etc, but for now lets * just drop. * * From Appendix A.1.1 (`New Packets'): * * Of course, the circular buffer may overflow, either when the * HC-Sender is sending data at a very high rate, when the * HC-Receiver's acknowledgements are not reaching the HC-Sender, * or when the HC-Sender is forgetting to acknowledge those acks * (so the HC-Receiver is unable to clean up old state). In this * case, the HC-Receiver should either compress the buffer (by * increasing run lengths when possible), transfer its state to * a larger buffer, or, as a last resort, drop all received * packets, without processing them whatsoever, until its buffer * shrinks again. */ u32 num_cells = num_packets; /* See if this is the first ackno being inserted */ if (av->av_vec_len == 0) { *cur_head = state; av->av_vec_len = 1; } else if (after48(ackno, av->av_buf_ackno)) { const u64 delta = dccp_delta_seqno(av->av_buf_ackno, ackno); if (num_packets > DCCPAV_BURST_THRESH) { u32 lost_packets = num_packets - 1; DCCP_WARN("Warning: large burst loss (%u)\n", lost_packets); /* * Look if the state of this packet is the same as the * previous ackno and if so if we can bump the head len. * We received 1 packet and have a loss of size "num_packets-1" * which we squeeze into num_cells-1 rather than reserving an * entire byte for each lost packet. * The reason is that the vector grows in O(burst_length); when * it grows too large there will no room left for the payload. * This is a trade-off: if a few packets out of the burst show * up later, their state will not be changed; it is simply too * costly to reshuffle/reallocate/copy the buffer each time. * Should such problems persist, we will need to switch to a * different underlying data structure. */ if (delta == 1 && dccp_ackvec_state(cur_head) == state && dccp_ackvec_runlen(cur_head) < DCCPAV_MAX_RUNLEN) *cur_head += 1; else if (dccp_ackvec_set_buf_head_state(av, delta, state)) return -ENOBUFS; } else { /* * A.1.2. Old Packets * * When a packet with Sequence Number S <= buf_ackno * arrives, the HC-Receiver will scan the table for * the byte corresponding to S. (Indexing structures * could reduce the complexity of this scan.) */ u64 delta = dccp_delta_seqno(ackno, av->av_buf_ackno); for (num_packets = num_cells = 1; lost_packets; ++num_cells) { u8 len = min(lost_packets, (u32)DCCPAV_MAX_RUNLEN); while (1) { const u8 len = dccp_ackvec_runlen(cur_head); /* * valid packets not yet in av_buf have a reserved * entry, with a len equal to 0. */ if (*cur_head == DCCPAV_NOT_RECEIVED && delta == 0) { dccp_pr_debug("Found %llu reserved seat!\n", (unsigned long long)ackno); *cur_head = state; goto out; } /* len == 0 means one packet */ if (delta < len + 1) goto out_duplicate; av->av_buf_head = __ackvec_idx_sub(av->av_buf_head, 1); av->av_buf[av->av_buf_head] = DCCPAV_NOT_RECEIVED | len; delta -= len + 1; if (++cur_head == buf_end) cur_head = av->av_buf; lost_packets -= len; } } av->av_buf_ackno = ackno; out: return 0; out_duplicate: /* Duplicate packet */ dccp_pr_debug("Received a dup or already considered lost " "packet: %llu\n", (unsigned long long)ackno); return -EILSEQ; if (num_cells + dccp_ackvec_buflen(av) >= DCCPAV_MAX_ACKVEC_LEN) { DCCP_CRIT("Ack Vector buffer overflow: dropping old entries\n"); av->av_overflow = true; } static void dccp_ackvec_throw_record(struct dccp_ackvec *av, struct dccp_ackvec_record *avr) { struct dccp_ackvec_record *next; av->av_buf_head = __ackvec_idx_sub(av->av_buf_head, num_packets); if (av->av_overflow) av->av_buf_tail = av->av_buf_head; /* sort out vector length */ if (av->av_buf_head <= avr->avr_ack_ptr) av->av_vec_len = avr->avr_ack_ptr - av->av_buf_head; else av->av_vec_len = DCCPAV_MAX_ACKVEC_LEN - 1 - av->av_buf_head + avr->avr_ack_ptr; av->av_buf[av->av_buf_head] = state; av->av_buf_ackno = seqno; /* free records */ list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) { list_del(&avr->avr_node); kmem_cache_free(dccp_ackvec_record_slab, avr); } if (num_packets > 1) dccp_ackvec_reserve_seats(av, num_packets - 1); } void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk, const u64 ackno) /** * dccp_ackvec_input - Register incoming packet in the buffer */ void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb) { struct dccp_ackvec_record *avr; u64 seqno = DCCP_SKB_CB(skb)->dccpd_seq; enum dccp_ackvec_states state = DCCPAV_RECEIVED; /* * If we traverse backwards, it should be faster when we have large * windows. We will be receiving ACKs for stuff we sent a while back * -sorbo. */ list_for_each_entry_reverse(avr, &av->av_records, avr_node) { if (ackno == avr->avr_ack_seqno) { dccp_pr_debug("%s ACK packet 0, len=%d, ack_seqno=%llu, " "ack_ackno=%llu, ACKED!\n", dccp_role(sk), avr->avr_ack_runlen, (unsigned long long)avr->avr_ack_seqno, (unsigned long long)avr->avr_ack_ackno); dccp_ackvec_throw_record(av, avr); break; } else if (avr->avr_ack_seqno > ackno) break; /* old news */ if (dccp_ackvec_is_empty(av)) { dccp_ackvec_add_new(av, 1, seqno, state); av->av_tail_ackno = seqno; } else { s64 num_packets = dccp_delta_seqno(av->av_buf_ackno, seqno); u8 *current_head = av->av_buf + av->av_buf_head; if (num_packets == 1 && dccp_ackvec_state(current_head) == state && dccp_ackvec_runlen(current_head) < DCCPAV_MAX_RUNLEN) { *current_head += 1; av->av_buf_ackno = seqno; } else if (num_packets > 0) { dccp_ackvec_add_new(av, num_packets, seqno, state); } else { dccp_ackvec_update_old(av, num_packets, seqno, state); } } } static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av, struct sock *sk, u64 *ackno, const unsigned char len, const unsigned char *vector) /** * dccp_ackvec_clear_state - Perform house-keeping / garbage-collection * This routine is called when the peer acknowledges the receipt of Ack Vectors * up to and including @ackno. While based on on section A.3 of RFC 4340, here * are additional precautions to prevent corrupted buffer state. In particular, * we use tail_ackno to identify outdated records; it always marks the earliest * packet of group (2) in 11.4.2. */ void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno) { unsigned char i; struct dccp_ackvec_record *avr; struct dccp_ackvec_record *avr, *next; u8 runlen_now, eff_runlen; s64 delta; /* Check if we actually sent an ACK vector */ if (list_empty(&av->av_records)) avr = dccp_ackvec_lookup(&av->av_records, ackno); if (avr == NULL) return; /* * Deal with outdated acknowledgments: this arises when e.g. there are * several old records and the acks from the peer come in slowly. In * that case we may still have records that pre-date tail_ackno. */ delta = dccp_delta_seqno(av->av_tail_ackno, avr->avr_ack_ackno); if (delta < 0) goto free_records; /* * Deal with overlapping Ack Vectors: don't subtract more than the * number of packets between tail_ackno and ack_ackno. */ eff_runlen = delta < avr->avr_ack_runlen ? delta : avr->avr_ack_runlen; i = len; runlen_now = dccp_ackvec_runlen(av->av_buf + avr->avr_ack_ptr); /* * XXX * I think it might be more efficient to work backwards. See comment on * rcv_ackno. -sorbo. * The run length of Ack Vector cells does not decrease over time. If * the run length is the same as at the time the Ack Vector was sent, we * free the ack_ptr cell. That cell can however not be freed if the run * length has increased: in this case we need to move the tail pointer * backwards (towards higher indices), to its next-oldest neighbour. */ avr = list_entry(av->av_records.next, struct dccp_ackvec_record, avr_node); while (i--) { const u8 rl = dccp_ackvec_runlen(vector); u64 ackno_end_rl; if (runlen_now > eff_runlen) { dccp_set_seqno(&ackno_end_rl, *ackno - rl); av->av_buf[avr->avr_ack_ptr] -= eff_runlen + 1; av->av_buf_tail = __ackvec_idx_add(avr->avr_ack_ptr, 1); /* This move may not have cleared the overflow flag. */ if (av->av_overflow) av->av_overflow = (av->av_buf_head == av->av_buf_tail); } else { av->av_buf_tail = avr->avr_ack_ptr; /* * If our AVR sequence number is greater than the ack, go * forward in the AVR list until it is not so. * We have made sure that avr points to a valid cell within the * buffer. This cell is either older than head, or equals head * (empty buffer): in both cases we no longer have any overflow. */ list_for_each_entry_from(avr, &av->av_records, avr_node) { if (!after48(avr->avr_ack_seqno, *ackno)) goto found; } /* End of the av_records list, not found, exit */ break; found: if (between48(avr->avr_ack_seqno, ackno_end_rl, *ackno)) { if (dccp_ackvec_state(vector) != DCCPAV_NOT_RECEIVED) { dccp_pr_debug("%s ACK vector 0, len=%d, " "ack_seqno=%llu, ack_ackno=%llu, " "ACKED!\n", dccp_role(sk), len, (unsigned long long) avr->avr_ack_seqno, (unsigned long long) avr->avr_ack_ackno); dccp_ackvec_throw_record(av, avr); break; av->av_overflow = 0; } /* * If it wasn't received, continue scanning... we might * find another one. * The peer has acknowledged up to and including ack_ackno. Hence the * first packet in group (2) of 11.4.2 is the successor of ack_ackno. */ } av->av_tail_ackno = ADD48(avr->avr_ack_ackno, 1); dccp_set_seqno(ackno, ackno_end_rl - 1); ++vector; free_records: list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) { list_del(&avr->avr_node); kmem_cache_free(dccp_ackvec_record_slab, avr); } } int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, u64 *ackno, const u8 opt, const u8 *value, const u8 len) /* * Routines to keep track of Ack Vectors received in an skb */ int dccp_ackvec_parsed_add(struct list_head *head, u8 *vec, u8 len, u8 nonce) { if (len > DCCP_SINGLE_OPT_MAXLEN) return -1; struct dccp_ackvec_parsed *new = kmalloc(sizeof(*new), GFP_ATOMIC); /* dccp_ackvector_print(DCCP_SKB_CB(skb)->dccpd_ack_seq, value, len); */ dccp_ackvec_check_rcv_ackvector(dccp_sk(sk)->dccps_hc_rx_ackvec, sk, ackno, len, value); if (new == NULL) return -ENOBUFS; new->vec = vec; new->len = len; new->nonce = nonce; list_add_tail(&new->node, head); return 0; } EXPORT_SYMBOL_GPL(dccp_ackvec_parsed_add); void dccp_ackvec_parsed_cleanup(struct list_head *parsed_chunks) { struct dccp_ackvec_parsed *cur, *next; list_for_each_entry_safe(cur, next, parsed_chunks, node) kfree(cur); INIT_LIST_HEAD(parsed_chunks); } EXPORT_SYMBOL_GPL(dccp_ackvec_parsed_cleanup); int __init dccp_ackvec_init(void) { Loading
net/dccp/ackvec.h +24 −14 Original line number Diff line number Diff line Loading @@ -29,6 +29,9 @@ /* Estimated minimum average Ack Vector length - used for updating MPS */ #define DCCPAV_MIN_OPTLEN 16 /* Threshold for coping with large bursts of losses */ #define DCCPAV_BURST_THRESH (DCCPAV_MAX_ACKVEC_LEN / 8) enum dccp_ackvec_states { DCCPAV_RECEIVED = 0x00, DCCPAV_ECN_MARKED = 0x40, Loading Loading @@ -61,7 +64,6 @@ static inline u8 dccp_ackvec_state(const u8 *cell) * %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 */ struct dccp_ackvec { u8 av_buf[DCCPAV_MAX_ACKVEC_LEN]; Loading @@ -72,7 +74,6 @@ struct dccp_ackvec { bool av_buf_nonce[DCCPAV_NUM_ACKVECS]; u8 av_overflow:1; struct list_head av_records; u16 av_vec_len; }; /** struct dccp_ackvec_record - Records information about sent Ack Vectors Loading @@ -98,29 +99,38 @@ struct dccp_ackvec_record { u8 avr_ack_nonce:1; }; struct sock; struct sk_buff; extern int dccp_ackvec_init(void); extern void dccp_ackvec_exit(void); extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority); extern void dccp_ackvec_free(struct dccp_ackvec *av); extern int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, const u64 ackno, const u8 state); extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk, const u64 ackno); extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, u64 *ackno, const u8 opt, const u8 *value, const u8 len); extern void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb); extern int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seq, u8 sum); extern void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno); extern u16 dccp_ackvec_buflen(const struct dccp_ackvec *av); static inline bool dccp_ackvec_is_empty(const struct dccp_ackvec *av) { return av->av_overflow == 0 && av->av_buf_head == av->av_buf_tail; } /** * struct dccp_ackvec_parsed - Record offsets of Ack Vectors in skb * @vec: start of vector (offset into skb) * @len: length of @vec * @nonce: whether @vec had an ECN nonce of 0 or 1 * @node: FIFO - arranged in descending order of ack_ackno * This structure is used by CCIDs to access Ack Vectors in a received skb. */ struct dccp_ackvec_parsed { u8 *vec, len, nonce:1; struct list_head node; }; extern int dccp_ackvec_parsed_add(struct list_head *head, u8 *vec, u8 len, u8 nonce); extern void dccp_ackvec_parsed_cleanup(struct list_head *parsed_chunks); #endif /* _ACKVEC_H */
net/dccp/ccids/ccid2.c +41 −93 Original line number Diff line number Diff line Loading @@ -246,68 +246,6 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, unsigned int len) #endif } /* XXX Lame code duplication! * returns -1 if none was found. * else returns the next offset to use in the function call. */ static int ccid2_ackvector(struct sock *sk, struct sk_buff *skb, int offset, unsigned char **vec, unsigned char *veclen) { const struct dccp_hdr *dh = dccp_hdr(skb); unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); unsigned char *opt_ptr; const unsigned char *opt_end = (unsigned char *)dh + (dh->dccph_doff * 4); unsigned char opt, len; unsigned char *value; BUG_ON(offset < 0); options += offset; opt_ptr = options; if (opt_ptr >= opt_end) return -1; while (opt_ptr != opt_end) { opt = *opt_ptr++; len = 0; value = NULL; /* Check if this isn't a single byte option */ if (opt > DCCPO_MAX_RESERVED) { if (opt_ptr == opt_end) goto out_invalid_option; len = *opt_ptr++; if (len < 3) goto out_invalid_option; /* * Remove the type and len fields, leaving * just the value size */ len -= 2; value = opt_ptr; opt_ptr += len; if (opt_ptr > opt_end) goto out_invalid_option; } switch (opt) { case DCCPO_ACK_VECTOR_0: case DCCPO_ACK_VECTOR_1: *vec = value; *veclen = len; return offset + (opt_ptr - options); } } return -1; out_invalid_option: DCCP_BUG("Invalid option - this should not happen (previous parsing)!"); return -1; } /** * ccid2_rtt_estimator - Sample RTT and compute RTO using RFC2988 algorithm * This code is almost identical with TCP's tcp_rtt_estimator(), since Loading Loading @@ -432,16 +370,28 @@ static void ccid2_congestion_event(struct sock *sk, struct ccid2_seq *seqp) ccid2_change_l_ack_ratio(sk, hc->tx_cwnd); } static int ccid2_hc_tx_parse_options(struct sock *sk, u8 packet_type, u8 option, u8 *optval, u8 optlen) { struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); switch (option) { case DCCPO_ACK_VECTOR_0: case DCCPO_ACK_VECTOR_1: return dccp_ackvec_parsed_add(&hc->tx_av_chunks, optval, optlen, option - DCCPO_ACK_VECTOR_0); } return 0; } static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) { struct dccp_sock *dp = dccp_sk(sk); struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); const bool sender_was_blocked = ccid2_cwnd_network_limited(hc); struct dccp_ackvec_parsed *avp; u64 ackno, seqno; struct ccid2_seq *seqp; unsigned char *vector; unsigned char veclen; int offset = 0; int done = 0; unsigned int maxincr = 0; Loading Loading @@ -475,17 +425,12 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) } /* check forward path congestion */ /* still didn't send out new data packets */ if (hc->tx_seqh == hc->tx_seqt) if (dccp_packet_without_ack(skb)) return; switch (DCCP_SKB_CB(skb)->dccpd_type) { case DCCP_PKT_ACK: case DCCP_PKT_DATAACK: break; default: return; } /* still didn't send out new data packets */ if (hc->tx_seqh == hc->tx_seqt) goto done; ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; if (after48(ackno, hc->tx_high_ack)) Loading @@ -509,15 +454,16 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) maxincr = DIV_ROUND_UP(dp->dccps_l_ack_ratio, 2); /* go through all ack vectors */ while ((offset = ccid2_ackvector(sk, skb, offset, &vector, &veclen)) != -1) { list_for_each_entry(avp, &hc->tx_av_chunks, node) { /* go through this ack vector */ while (veclen--) { u64 ackno_end_rl = SUB48(ackno, dccp_ackvec_runlen(vector)); for (; avp->len--; avp->vec++) { u64 ackno_end_rl = SUB48(ackno, dccp_ackvec_runlen(avp->vec)); ccid2_pr_debug("ackvec start:%llu end:%llu\n", ccid2_pr_debug("ackvec %llu |%u,%u|\n", (unsigned long long)ackno, (unsigned long long)ackno_end_rl); dccp_ackvec_state(avp->vec) >> 6, dccp_ackvec_runlen(avp->vec)); /* if the seqno we are analyzing is larger than the * current ackno, then move towards the tail of our * seqnos. Loading @@ -536,7 +482,7 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) * run length */ while (between48(seqp->ccid2s_seq,ackno_end_rl,ackno)) { const u8 state = dccp_ackvec_state(vector); const u8 state = dccp_ackvec_state(avp->vec); /* new packet received or marked */ if (state != DCCPAV_NOT_RECEIVED && Loading @@ -563,7 +509,6 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) break; ackno = SUB48(ackno_end_rl, 1); vector++; } if (done) break; Loading Loading @@ -631,10 +576,11 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) sk_stop_timer(sk, &hc->tx_rtotimer); else sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto); done: /* check if incoming Acks allow pending packets to be sent */ if (sender_was_blocked && !ccid2_cwnd_network_limited(hc)) tasklet_schedule(&dccp_sk(sk)->dccps_xmitlet); dccp_ackvec_parsed_cleanup(&hc->tx_av_chunks); } static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) Loading Loading @@ -663,6 +609,7 @@ static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) hc->tx_last_cong = ccid2_time_stamp; setup_timer(&hc->tx_rtotimer, ccid2_hc_tx_rto_expire, (unsigned long)sk); INIT_LIST_HEAD(&hc->tx_av_chunks); return 0; } Loading Loading @@ -703,6 +650,7 @@ struct ccid_operations ccid2_ops = { .ccid_hc_tx_exit = ccid2_hc_tx_exit, .ccid_hc_tx_send_packet = ccid2_hc_tx_send_packet, .ccid_hc_tx_packet_sent = ccid2_hc_tx_packet_sent, .ccid_hc_tx_parse_options = ccid2_hc_tx_parse_options, .ccid_hc_tx_packet_recv = ccid2_hc_tx_packet_recv, .ccid_hc_rx_obj_size = sizeof(struct ccid2_hc_rx_sock), .ccid_hc_rx_packet_recv = ccid2_hc_rx_packet_recv, Loading
net/dccp/ccids/ccid2.h +2 −0 Original line number Diff line number Diff line Loading @@ -55,6 +55,7 @@ struct ccid2_seq { * @tx_rtt_seq: to decay RTTVAR at most once per flight * @tx_rpseq: last consecutive seqno * @tx_rpdupack: dupacks since rpseq * @tx_av_chunks: list of Ack Vectors received on current skb */ struct ccid2_hc_tx_sock { u32 tx_cwnd; Loading @@ -79,6 +80,7 @@ struct ccid2_hc_tx_sock { int tx_rpdupack; u32 tx_last_cong; u64 tx_high_ack; struct list_head tx_av_chunks; }; static inline bool ccid2_cwnd_network_limited(struct ccid2_hc_tx_sock *hc) Loading
