diff options
| -rw-r--r-- | net/dccp/ackvec.c | 178 | ||||
| -rw-r--r-- | net/dccp/ackvec.h | 103 | ||||
| -rw-r--r-- | net/dccp/ccids/ccid2.c | 13 | ||||
| -rw-r--r-- | net/dccp/input.c | 6 |
4 files changed, 127 insertions, 173 deletions
diff --git a/net/dccp/ackvec.c b/net/dccp/ackvec.c index 01e4d39..85ad70c 100644 --- a/net/dccp/ackvec.c +++ b/net/dccp/ackvec.c @@ -1,7 +1,8 @@ /* * net/dccp/ackvec.c * - * An implementation of the DCCP protocol + * An implementation of Ack Vectors for the DCCP protocol + * Copyright (c) 2007 University of Aberdeen, Scotland, UK * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net> * * This program is free software; you can redistribute it and/or modify it @@ -23,24 +24,32 @@ static struct kmem_cache *dccp_ackvec_slab; static struct kmem_cache *dccp_ackvec_record_slab; -static struct dccp_ackvec_record *dccp_ackvec_record_new(void) +struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority) { - struct dccp_ackvec_record *avr = - kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC); + struct dccp_ackvec *av = kmem_cache_zalloc(dccp_ackvec_slab, priority); + + if (av != NULL) { + av->av_buf_head = DCCPAV_MAX_ACKVEC_LEN - 1; + INIT_LIST_HEAD(&av->av_records); + } + return av; +} - if (avr != NULL) - INIT_LIST_HEAD(&avr->avr_node); +static void dccp_ackvec_purge_records(struct dccp_ackvec *av) +{ + struct dccp_ackvec_record *cur, *next; - return avr; + list_for_each_entry_safe(cur, next, &av->av_records, avr_node) + kmem_cache_free(dccp_ackvec_record_slab, cur); + INIT_LIST_HEAD(&av->av_records); } -static void dccp_ackvec_record_delete(struct dccp_ackvec_record *avr) +void dccp_ackvec_free(struct dccp_ackvec *av) { - if (unlikely(avr == NULL)) - return; - /* Check if deleting a linked record */ - WARN_ON(!list_empty(&avr->avr_node)); - kmem_cache_free(dccp_ackvec_record_slab, avr); + if (likely(av != NULL)) { + dccp_ackvec_purge_records(av); + kmem_cache_free(dccp_ackvec_slab, av); + } } static void dccp_ackvec_insert_avr(struct dccp_ackvec *av, @@ -68,24 +77,16 @@ int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec; /* 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, i; - u32 elapsed_time; + u16 len = av->av_vec_len + 2 * nr_opts; + u8 i, nonce = 0; const unsigned char *tail, *from; unsigned char *to; struct dccp_ackvec_record *avr; - suseconds_t delta; if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) return -1; - delta = ktime_us_delta(ktime_get_real(), av->av_time); - elapsed_time = delta / 10; - - if (elapsed_time != 0 && - dccp_insert_option_elapsed_time(sk, skb, elapsed_time)) - return -1; - - avr = dccp_ackvec_record_new(); + avr = kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC); if (avr == NULL) return -1; @@ -94,7 +95,7 @@ int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) to = skb_push(skb, len); len = av->av_vec_len; from = av->av_buf + av->av_buf_head; - tail = av->av_buf + DCCP_MAX_ACKVEC_LEN; + tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN; for (i = 0; i < nr_opts; ++i) { int copylen = len; @@ -102,7 +103,13 @@ int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) if (len > DCCP_SINGLE_OPT_MAXLEN) copylen = DCCP_SINGLE_OPT_MAXLEN; - *to++ = DCCPO_ACK_VECTOR_0; + /* + * RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via + * its type; ack_nonce is the sum of all individual buf_nonce's. + */ + nonce ^= av->av_buf_nonce[i]; + + *to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i]; *to++ = copylen + 2; /* Check if buf_head wraps */ @@ -123,75 +130,24 @@ int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) } /* - * From RFC 4340, A.2: - * - * For each acknowledgement it sends, the HC-Receiver will add an - * acknowledgement record. ack_seqno will equal the HC-Receiver - * sequence number it used for the ack packet; ack_ptr will equal - * buf_head; ack_ackno will equal buf_ackno; and ack_nonce will - * equal buf_nonce. + * Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340. */ - avr->avr_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq; - avr->avr_ack_ptr = av->av_buf_head; - avr->avr_ack_ackno = av->av_buf_ackno; - avr->avr_ack_nonce = av->av_buf_nonce; - avr->avr_sent_len = av->av_vec_len; + avr->avr_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq; + avr->avr_ack_ptr = av->av_buf_head; + avr->avr_ack_ackno = av->av_buf_ackno; + avr->avr_ack_nonce = nonce; + avr->avr_ack_runlen = dccp_ackvec_runlen(av->av_buf + av->av_buf_head); dccp_ackvec_insert_avr(av, avr); dccp_pr_debug("%s ACK Vector 0, len=%d, ack_seqno=%llu, " "ack_ackno=%llu\n", - dccp_role(sk), avr->avr_sent_len, + dccp_role(sk), avr->avr_ack_runlen, (unsigned long long)avr->avr_ack_seqno, (unsigned long long)avr->avr_ack_ackno); return 0; } -struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority) -{ - struct dccp_ackvec *av = kmem_cache_alloc(dccp_ackvec_slab, priority); - - if (av != NULL) { - av->av_buf_head = DCCP_MAX_ACKVEC_LEN - 1; - av->av_buf_ackno = UINT48_MAX + 1; - av->av_buf_nonce = 0; - av->av_time = ktime_set(0, 0); - av->av_vec_len = 0; - INIT_LIST_HEAD(&av->av_records); - } - - return av; -} - -void dccp_ackvec_free(struct dccp_ackvec *av) -{ - if (unlikely(av == NULL)) - return; - - if (!list_empty(&av->av_records)) { - struct dccp_ackvec_record *avr, *next; - - list_for_each_entry_safe(avr, next, &av->av_records, avr_node) { - list_del_init(&avr->avr_node); - dccp_ackvec_record_delete(avr); - } - } - - kmem_cache_free(dccp_ackvec_slab, av); -} - -static inline u8 dccp_ackvec_state(const struct dccp_ackvec *av, - const u32 index) -{ - return av->av_buf[index] & DCCP_ACKVEC_STATE_MASK; -} - -static inline u8 dccp_ackvec_len(const struct dccp_ackvec *av, - const u32 index) -{ - return av->av_buf[index] & DCCP_ACKVEC_LEN_MASK; -} - /* * 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; @@ -204,7 +160,7 @@ static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av, unsigned int gap; long new_head; - if (av->av_vec_len + packets > DCCP_MAX_ACKVEC_LEN) + if (av->av_vec_len + packets > DCCPAV_MAX_ACKVEC_LEN) return -ENOBUFS; gap = packets - 1; @@ -212,18 +168,18 @@ static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av, if (new_head < 0) { if (gap > 0) { - memset(av->av_buf, DCCP_ACKVEC_STATE_NOT_RECEIVED, + memset(av->av_buf, DCCPAV_NOT_RECEIVED, gap + new_head + 1); gap = -new_head; } - new_head += DCCP_MAX_ACKVEC_LEN; + new_head += DCCPAV_MAX_ACKVEC_LEN; } av->av_buf_head = new_head; if (gap > 0) memset(av->av_buf + av->av_buf_head + 1, - DCCP_ACKVEC_STATE_NOT_RECEIVED, gap); + DCCPAV_NOT_RECEIVED, gap); av->av_buf[av->av_buf_head] = state; av->av_vec_len += packets; @@ -236,6 +192,8 @@ static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av, int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, const u64 ackno, const u8 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 @@ -260,7 +218,7 @@ int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, /* See if this is the first ackno being inserted */ if (av->av_vec_len == 0) { - av->av_buf[av->av_buf_head] = state; + *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); @@ -269,10 +227,9 @@ int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, * Look if the state of this packet is the same as the * previous ackno and if so if we can bump the head len. */ - if (delta == 1 && - dccp_ackvec_state(av, av->av_buf_head) == state && - dccp_ackvec_len(av, av->av_buf_head) < DCCP_ACKVEC_LEN_MASK) - av->av_buf[av->av_buf_head]++; + 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 { @@ -285,21 +242,17 @@ int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, * could reduce the complexity of this scan.) */ u64 delta = dccp_delta_seqno(ackno, av->av_buf_ackno); - u32 index = av->av_buf_head; while (1) { - const u8 len = dccp_ackvec_len(av, index); - const u8 av_state = dccp_ackvec_state(av, index); + 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 (av_state == DCCP_ACKVEC_STATE_NOT_RECEIVED && - len == 0 && delta == 0) { /* Found our - reserved seat! */ + if (*cur_head == DCCPAV_NOT_RECEIVED && delta == 0) { dccp_pr_debug("Found %llu reserved seat!\n", (unsigned long long)ackno); - av->av_buf[index] = state; + *cur_head = state; goto out; } /* len == 0 means one packet */ @@ -307,13 +260,12 @@ int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, goto out_duplicate; delta -= len + 1; - if (++index == DCCP_MAX_ACKVEC_LEN) - index = 0; + if (++cur_head == buf_end) + cur_head = av->av_buf; } } av->av_buf_ackno = ackno; - av->av_time = ktime_get_real(); out: return 0; @@ -333,13 +285,13 @@ static void dccp_ackvec_throw_record(struct dccp_ackvec *av, 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 = DCCP_MAX_ACKVEC_LEN - 1 - + av->av_vec_len = DCCPAV_MAX_ACKVEC_LEN - 1 - av->av_buf_head + avr->avr_ack_ptr; /* free records */ list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) { - list_del_init(&avr->avr_node); - dccp_ackvec_record_delete(avr); + list_del(&avr->avr_node); + kmem_cache_free(dccp_ackvec_record_slab, avr); } } @@ -357,7 +309,7 @@ void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk, 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), 1, + 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); @@ -387,7 +339,7 @@ static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av, */ avr = list_entry(av->av_records.next, struct dccp_ackvec_record, avr_node); while (i--) { - const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK; + const u8 rl = dccp_ackvec_runlen(vector); u64 ackno_end_rl; dccp_set_seqno(&ackno_end_rl, *ackno - rl); @@ -404,8 +356,7 @@ static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av, break; found: if (between48(avr->avr_ack_seqno, ackno_end_rl, *ackno)) { - const u8 state = *vector & DCCP_ACKVEC_STATE_MASK; - if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED) { + 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", @@ -448,10 +399,9 @@ int __init dccp_ackvec_init(void) if (dccp_ackvec_slab == NULL) goto out_err; - dccp_ackvec_record_slab = - kmem_cache_create("dccp_ackvec_record", - sizeof(struct dccp_ackvec_record), - 0, SLAB_HWCACHE_ALIGN, NULL); + dccp_ackvec_record_slab = kmem_cache_create("dccp_ackvec_record", + sizeof(struct dccp_ackvec_record), + 0, SLAB_HWCACHE_ALIGN, NULL); if (dccp_ackvec_record_slab == NULL) goto out_destroy_slab; diff --git a/net/dccp/ackvec.h b/net/dccp/ackvec.h index 1c10814..df18f90 100644 --- a/net/dccp/ackvec.h +++ b/net/dccp/ackvec.h @@ -3,9 +3,9 @@ /* * net/dccp/ackvec.h * - * An implementation of the DCCP protocol + * An implementation of Ack Vectors for the DCCP protocol + * Copyright (c) 2007 University of Aberdeen, Scotland, UK * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@mandriva.com> - * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. @@ -13,75 +13,84 @@ #include <linux/dccp.h> #include <linux/compiler.h> -#include <linux/ktime.h> #include <linux/list.h> #include <linux/types.h> -/* We can spread an ack vector across multiple options */ -#define DCCP_MAX_ACKVEC_LEN (DCCP_SINGLE_OPT_MAXLEN * 2) +/* + * Ack Vector buffer space is static, in multiples of %DCCP_SINGLE_OPT_MAXLEN, + * 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. + */ +#define DCCPAV_NUM_ACKVECS 2 +#define DCCPAV_MAX_ACKVEC_LEN (DCCP_SINGLE_OPT_MAXLEN * DCCPAV_NUM_ACKVECS) /* Estimated minimum average Ack Vector length - used for updating MPS */ #define DCCPAV_MIN_OPTLEN 16 -#define DCCP_ACKVEC_STATE_RECEIVED 0 -#define DCCP_ACKVEC_STATE_ECN_MARKED (1 << 6) -#define DCCP_ACKVEC_STATE_NOT_RECEIVED (3 << 6) +enum dccp_ackvec_states { + DCCPAV_RECEIVED = 0x00, + DCCPAV_ECN_MARKED = 0x40, + DCCPAV_RESERVED = 0x80, + DCCPAV_NOT_RECEIVED = 0xC0 +}; +#define DCCPAV_MAX_RUNLEN 0x3F -#define DCCP_ACKVEC_STATE_MASK 0xC0 /* 11000000 */ -#define DCCP_ACKVEC_LEN_MASK 0x3F /* 00111111 */ +static inline u8 dccp_ackvec_runlen(const u8 *cell) +{ + return *cell & DCCPAV_MAX_RUNLEN; +} -/** struct dccp_ackvec - ack vector - * - * This data structure is the one defined in RFC 4340, Appendix A. - * - * @av_buf_head - circular buffer head - * @av_buf_tail - circular buffer tail - * @av_buf_ackno - ack # of the most recent packet acknowledgeable in the - * buffer (i.e. %av_buf_head) - * @av_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked - * by the buffer with State 0 - * - * Additionally, the HC-Receiver must keep some information about the - * Ack Vectors it has recently sent. For each packet sent carrying an - * Ack Vector, it remembers four variables: +static inline u8 dccp_ackvec_state(const u8 *cell) +{ + return *cell & ~DCCPAV_MAX_RUNLEN; +} + +/** struct dccp_ackvec - Ack Vector main data structure * - * @av_records - list of dccp_ackvec_record - * @av_ack_nonce - the one-bit sum of the ECN Nonces for all State 0. + * This implements a fixed-size circular buffer within an array and is largely + * based on Appendix A of RFC 4340. * - * @av_time - the time in usecs - * @av_buf - circular buffer of acknowledgeable packets + * @av_buf: circular buffer storage area + * @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_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_records: list of %dccp_ackvec_record (Ack Vectors sent previously) + * @av_veclen: length of the live portion of @av_buf */ struct dccp_ackvec { - u64 av_buf_ackno; - struct list_head av_records; - ktime_t av_time; + u8 av_buf[DCCPAV_MAX_ACKVEC_LEN]; u16 av_buf_head; + u16 av_buf_tail; + u64 av_buf_ackno:48; + bool av_buf_nonce[DCCPAV_NUM_ACKVECS]; + struct list_head av_records; u16 av_vec_len; - u8 av_buf_nonce; - u8 av_ack_nonce; - u8 av_buf[DCCP_MAX_ACKVEC_LEN]; }; -/** struct dccp_ackvec_record - ack vector record +/** struct dccp_ackvec_record - Records information about sent Ack Vectors * - * ACK vector record as defined in Appendix A of spec. + * These list entries define the additional information which the HC-Receiver + * keeps about recently-sent Ack Vectors; again refer to RFC 4340, Appendix A. * - * The list is sorted by avr_ack_seqno + * @avr_node: the list node in @av_records + * @avr_ack_seqno: sequence number of the packet the Ack Vector was sent on + * @avr_ack_ackno: the Ack number that this record/Ack Vector refers to + * @avr_ack_ptr: pointer into @av_buf where this record starts + * @avr_ack_runlen: run length of @avr_ack_ptr at the time of sending + * @avr_ack_nonce: the sum of @av_buf_nonce's at the time this record was sent * - * @avr_node - node in av_records - * @avr_ack_seqno - sequence number of the packet this record was sent on - * @avr_ack_ackno - sequence number being acknowledged - * @avr_ack_ptr - pointer into av_buf where this record starts - * @avr_ack_nonce - av_ack_nonce at the time this record was sent - * @avr_sent_len - lenght of the record in av_buf + * The list as a whole is sorted in descending order by @avr_ack_seqno. */ struct dccp_ackvec_record { struct list_head avr_node; - u64 avr_ack_seqno; - u64 avr_ack_ackno; + u64 avr_ack_seqno:48; + u64 avr_ack_ackno:48; u16 avr_ack_ptr; - u16 avr_sent_len; - u8 avr_ack_nonce; + u8 avr_ack_runlen; + u8 avr_ack_nonce:1; }; struct sock; diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c index f56ab68..813d5cd 100644 --- a/net/dccp/ccids/ccid2.c +++ b/net/dccp/ccids/ccid2.c @@ -580,8 +580,7 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) &vector, &veclen)) != -1) { /* go through this ack vector */ while (veclen--) { - const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK; - u64 ackno_end_rl = SUB48(ackno, rl); + u64 ackno_end_rl = SUB48(ackno, dccp_ackvec_runlen(vector)); ccid2_pr_debug("ackvec start:%llu end:%llu\n", (unsigned long long)ackno, @@ -604,17 +603,15 @@ 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 = *vector & - DCCP_ACKVEC_STATE_MASK; + const u8 state = dccp_ackvec_state(vector); /* new packet received or marked */ - if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED && + if (state != DCCPAV_NOT_RECEIVED && !seqp->ccid2s_acked) { - if (state == - DCCP_ACKVEC_STATE_ECN_MARKED) { + if (state == DCCPAV_ECN_MARKED) ccid2_congestion_event(sk, seqp); - } else + else ccid2_new_ack(sk, seqp, &maxincr); diff --git a/net/dccp/input.c b/net/dccp/input.c index e3f43d5..70ad0ba 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -377,8 +377,7 @@ int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, if (dp->dccps_hc_rx_ackvec != NULL && dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, - DCCP_SKB_CB(skb)->dccpd_seq, - DCCP_ACKVEC_STATE_RECEIVED)) + DCCP_SKB_CB(skb)->dccpd_seq, DCCPAV_RECEIVED)) goto discard; dccp_deliver_input_to_ccids(sk, skb); @@ -627,8 +626,7 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, if (dp->dccps_hc_rx_ackvec != NULL && dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, - DCCP_SKB_CB(skb)->dccpd_seq, - DCCP_ACKVEC_STATE_RECEIVED)) + DCCP_SKB_CB(skb)->dccpd_seq, DCCPAV_RECEIVED)) goto discard; dccp_deliver_input_to_ccids(sk, skb); |
