diff options
| -rw-r--r-- | net/dccp/ackvec.c | 240 | ||||
| -rw-r--r-- | net/dccp/ackvec.h | 31 |
2 files changed, 173 insertions, 98 deletions
diff --git a/net/dccp/ackvec.c b/net/dccp/ackvec.c index 6440825..b4ff14f 100644 --- a/net/dccp/ackvec.c +++ b/net/dccp/ackvec.c @@ -22,6 +22,47 @@ #include <net/sock.h> static kmem_cache_t *dccp_ackvec_slab; +static kmem_cache_t *dccp_ackvec_record_slab; + +static struct dccp_ackvec_record *dccp_ackvec_record_new(void) +{ + struct dccp_ackvec_record *avr = + kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC); + + if (avr != NULL) + INIT_LIST_HEAD(&avr->dccpavr_node); + + return avr; +} + +static void dccp_ackvec_record_delete(struct dccp_ackvec_record *avr) +{ + if (unlikely(avr == NULL)) + return; + /* Check if deleting a linked record */ + WARN_ON(!list_empty(&avr->dccpavr_node)); + kmem_cache_free(dccp_ackvec_record_slab, avr); +} + +static void dccp_ackvec_insert_avr(struct dccp_ackvec *av, + struct dccp_ackvec_record *avr) +{ + /* + * AVRs are sorted by seqno. Since we are sending them in order, we + * just add the AVR at the head of the list. + * -sorbo. + */ + if (!list_empty(&av->dccpav_records)) { + const struct dccp_ackvec_record *head = + list_entry(av->dccpav_records.next, + struct dccp_ackvec_record, + dccpavr_node); + BUG_ON(before48(avr->dccpavr_ack_seqno, + head->dccpavr_ack_seqno)); + } + + list_add(&avr->dccpavr_node, &av->dccpav_records); +} int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) { @@ -35,6 +76,14 @@ int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) struct timeval now; u32 elapsed_time; unsigned char *to, *from; + struct dccp_ackvec_record *avr; + + if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) + return -1; + + avr = dccp_ackvec_record_new(); + if (avr == NULL) + return -1; dccp_timestamp(sk, &now); elapsed_time = timeval_delta(&now, &av->dccpav_time) / 10; @@ -42,19 +91,6 @@ int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) if (elapsed_time != 0) dccp_insert_option_elapsed_time(sk, skb, elapsed_time); - if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) - return -1; - - /* - * XXX: now we have just one ack vector sent record, so - * we have to wait for it to be cleared. - * - * Of course this is not acceptable, but this is just for - * basic testing now. - */ - if (av->dccpav_ack_seqno != DCCP_MAX_SEQNO + 1) - return -1; - DCCP_SKB_CB(skb)->dccpd_opt_len += len; to = skb_push(skb, len); @@ -65,8 +101,8 @@ int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) from = av->dccpav_buf + av->dccpav_buf_head; /* Check if buf_head wraps */ - if ((int)av->dccpav_buf_head + len > av->dccpav_vec_len) { - const u32 tailsize = av->dccpav_vec_len - av->dccpav_buf_head; + if ((int)av->dccpav_buf_head + len > DCCP_MAX_ACKVEC_LEN) { + const u32 tailsize = DCCP_MAX_ACKVEC_LEN - av->dccpav_buf_head; memcpy(to, from, tailsize); to += tailsize; @@ -83,21 +119,21 @@ int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) * 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. - * - * This implemention uses just one ack record for now. */ - av->dccpav_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq; - av->dccpav_ack_ptr = av->dccpav_buf_head; - av->dccpav_ack_ackno = av->dccpav_buf_ackno; - av->dccpav_ack_nonce = av->dccpav_buf_nonce; - av->dccpav_sent_len = av->dccpav_vec_len; + avr->dccpavr_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq; + avr->dccpavr_ack_ptr = av->dccpav_buf_head; + avr->dccpavr_ack_ackno = av->dccpav_buf_ackno; + avr->dccpavr_ack_nonce = av->dccpav_buf_nonce; + avr->dccpavr_sent_len = av->dccpav_vec_len; + + dccp_ackvec_insert_avr(av, avr); dccp_pr_debug("%sACK Vector 0, len=%d, ack_seqno=%llu, " "ack_ackno=%llu\n", - debug_prefix, av->dccpav_sent_len, - (unsigned long long)av->dccpav_ack_seqno, - (unsigned long long)av->dccpav_ack_ackno); - return -1; + debug_prefix, avr->dccpavr_sent_len, + (unsigned long long)avr->dccpavr_ack_seqno, + (unsigned long long)avr->dccpavr_ack_ackno); + return 0; } struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority) @@ -107,13 +143,13 @@ struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority) if (av != NULL) { av->dccpav_buf_head = av->dccpav_buf_tail = DCCP_MAX_ACKVEC_LEN - 1; - av->dccpav_buf_ackno = - av->dccpav_ack_ackno = av->dccpav_ack_seqno = ~0LLU; + av->dccpav_buf_ackno = DCCP_MAX_SEQNO + 1; av->dccpav_buf_nonce = av->dccpav_buf_nonce = 0; av->dccpav_ack_ptr = 0; av->dccpav_time.tv_sec = 0; av->dccpav_time.tv_usec = 0; av->dccpav_sent_len = av->dccpav_vec_len = 0; + INIT_LIST_HEAD(&av->dccpav_records); } return av; @@ -121,6 +157,9 @@ struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority) void dccp_ackvec_free(struct dccp_ackvec *av) { + if (unlikely(av == NULL)) + return; + WARN_ON(!list_empty(&av->dccpav_records)); kmem_cache_free(dccp_ackvec_slab, av); } @@ -299,44 +338,50 @@ void dccp_ackvec_print(const struct dccp_ackvec *av) } #endif -static void dccp_ackvec_throw_away_ack_record(struct dccp_ackvec *av) +static void dccp_ackvec_throw_record(struct dccp_ackvec *av, + struct dccp_ackvec_record *avr) { - /* - * As we're keeping track of the ack vector size (dccpav_vec_len) and - * the sent ack vector size (dccpav_sent_len) we don't need - * dccpav_buf_tail at all, but keep this code here as in the future - * we'll implement a vector of ack records, as suggested in - * draft-ietf-dccp-spec-11.txt Appendix A. -acme - */ -#if 0 - u32 new_buf_tail = av->dccpav_ack_ptr + 1; - if (new_buf_tail >= av->dccpav_vec_len) - new_buf_tail -= av->dccpav_vec_len; - av->dccpav_buf_tail = new_buf_tail; -#endif - av->dccpav_vec_len -= av->dccpav_sent_len; + struct dccp_ackvec_record *next; + + av->dccpav_buf_tail = avr->dccpavr_ack_ptr - 1; + if (av->dccpav_buf_tail == 0) + av->dccpav_buf_tail = DCCP_MAX_ACKVEC_LEN - 1; + + av->dccpav_vec_len -= avr->dccpavr_sent_len; + + /* free records */ + list_for_each_entry_safe_from(avr, next, &av->dccpav_records, + dccpavr_node) { + list_del_init(&avr->dccpavr_node); + dccp_ackvec_record_delete(avr); + } } void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk, const u64 ackno) { - /* Check if we actually sent an ACK vector */ - if (av->dccpav_ack_seqno == DCCP_MAX_SEQNO + 1) - return; + struct dccp_ackvec_record *avr; - if (ackno == av->dccpav_ack_seqno) { + /* + * 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->dccpav_records, dccpavr_node) { + if (ackno == avr->dccpavr_ack_seqno) { #ifdef CONFIG_IP_DCCP_DEBUG - struct dccp_sock *dp = dccp_sk(sk); - const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? - "CLIENT rx ack: " : "server rx ack: "; + struct dccp_sock *dp = dccp_sk(sk); + const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? + "CLIENT rx ack: " : "server rx ack: "; #endif - dccp_pr_debug("%sACK packet 0, len=%d, ack_seqno=%llu, " - "ack_ackno=%llu, ACKED!\n", - debug_prefix, 1, - (unsigned long long)av->dccpav_ack_seqno, - (unsigned long long)av->dccpav_ack_ackno); - dccp_ackvec_throw_away_ack_record(av); - av->dccpav_ack_seqno = DCCP_MAX_SEQNO + 1; + dccp_pr_debug("%sACK packet 0, len=%d, ack_seqno=%llu, " + "ack_ackno=%llu, ACKED!\n", + debug_prefix, 1, + (unsigned long long)avr->dccpavr_ack_seqno, + (unsigned long long)avr->dccpavr_ack_ackno); + dccp_ackvec_throw_record(av, avr); + break; + } } } @@ -346,28 +391,20 @@ static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av, const unsigned char *vector) { unsigned char i; + struct dccp_ackvec_record *avr; /* Check if we actually sent an ACK vector */ - if (av->dccpav_ack_seqno == DCCP_MAX_SEQNO + 1) + if (list_empty(&av->dccpav_records)) return; - /* - * We're in the receiver half connection, so if the received an ACK - * vector ackno (e.g. 50) before dccpav_ack_seqno (e.g. 52), we're - * not interested. - * - * Extra explanation with example: - * - * if we received an ACK vector with ackno 50, it can only be acking - * 50, 49, 48, etc, not 52 (the seqno for the ACK vector we sent). - */ - /* dccp_pr_debug("is %llu < %llu? ", ackno, av->dccpav_ack_seqno); */ - if (before48(ackno, av->dccpav_ack_seqno)) { - /* dccp_pr_debug_cat("yes\n"); */ - return; - } - /* dccp_pr_debug_cat("no\n"); */ i = len; + /* + * XXX + * I think it might be more efficient to work backwards. See comment on + * rcv_ackno. -sorbo. + */ + avr = list_entry(av->dccpav_records.next, struct dccp_ackvec_record, + dccpavr_node); while (i--) { const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK; u64 ackno_end_rl; @@ -375,14 +412,20 @@ static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av, dccp_set_seqno(&ackno_end_rl, ackno - rl); /* - * dccp_pr_debug("is %llu <= %llu <= %llu? ", ackno_end_rl, - * av->dccpav_ack_seqno, ackno); + * If our AVR sequence number is greater than the ack, go + * forward in the AVR list until it is not so. */ - if (between48(av->dccpav_ack_seqno, ackno_end_rl, ackno)) { + list_for_each_entry_from(avr, &av->dccpav_records, + dccpavr_node) { + if (!after48(avr->dccpavr_ack_seqno, ackno)) + goto found; + } + /* End of the dccpav_records list, not found, exit */ + break; +found: + if (between48(avr->dccpavr_ack_seqno, ackno_end_rl, ackno)) { const u8 state = (*vector & DCCP_ACKVEC_STATE_MASK) >> 6; - /* dccp_pr_debug_cat("yes\n"); */ - if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED) { #ifdef CONFIG_IP_DCCP_DEBUG struct dccp_sock *dp = dccp_sk(sk); @@ -395,19 +438,16 @@ static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av, "ACKED!\n", debug_prefix, len, (unsigned long long) - av->dccpav_ack_seqno, + avr->dccpavr_ack_seqno, (unsigned long long) - av->dccpav_ack_ackno); - dccp_ackvec_throw_away_ack_record(av); + avr->dccpavr_ack_ackno); + dccp_ackvec_throw_record(av, avr); } /* - * If dccpav_ack_seqno was not received, no problem - * we'll send another ACK vector. + * If it wasn't received, continue scanning... we might + * find another one. */ - av->dccpav_ack_seqno = DCCP_MAX_SEQNO + 1; - break; } - /* dccp_pr_debug_cat("no\n"); */ dccp_set_seqno(&ackno, ackno_end_rl - 1); ++vector; @@ -428,19 +468,31 @@ int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, } static char dccp_ackvec_slab_msg[] __initdata = - KERN_CRIT "DCCP: Unable to create ack vectors slab cache\n"; + KERN_CRIT "DCCP: Unable to create ack vectors slab caches\n"; int __init dccp_ackvec_init(void) { dccp_ackvec_slab = kmem_cache_create("dccp_ackvec", sizeof(struct dccp_ackvec), 0, SLAB_HWCACHE_ALIGN, NULL, NULL); - if (dccp_ackvec_slab == NULL) { - printk(dccp_ackvec_slab_msg); - return -ENOBUFS; - } + 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, NULL); + if (dccp_ackvec_record_slab == NULL) + goto out_destroy_slab; return 0; + +out_destroy_slab: + kmem_cache_destroy(dccp_ackvec_slab); + dccp_ackvec_slab = NULL; +out_err: + printk(dccp_ackvec_slab_msg); + return -ENOBUFS; } void dccp_ackvec_exit(void) @@ -449,4 +501,8 @@ void dccp_ackvec_exit(void) kmem_cache_destroy(dccp_ackvec_slab); dccp_ackvec_slab = NULL; } + if (dccp_ackvec_record_slab != NULL) { + kmem_cache_destroy(dccp_ackvec_record_slab); + dccp_ackvec_record_slab = NULL; + } } diff --git a/net/dccp/ackvec.h b/net/dccp/ackvec.h index 470bae8..ec7a89b 100644 --- a/net/dccp/ackvec.h +++ b/net/dccp/ackvec.h @@ -13,6 +13,7 @@ #include <linux/config.h> #include <linux/compiler.h> +#include <linux/list.h> #include <linux/time.h> #include <linux/types.h> @@ -42,11 +43,8 @@ * Ack Vectors it has recently sent. For each packet sent carrying an * Ack Vector, it remembers four variables: * - * @dccpav_ack_seqno - the Sequence Number used for the packet - * (HC-Receiver seqno) * @dccpav_ack_ptr - the value of buf_head at the time of acknowledgement. - * @dccpav_ack_ackno - the Acknowledgement Number used for the packet - * (HC-Sender seqno) + * @dccpav_records - list of dccp_ackvec_record * @dccpav_ack_nonce - the one-bit sum of the ECN Nonces for all State 0. * * @dccpav_time - the time in usecs @@ -54,8 +52,7 @@ */ struct dccp_ackvec { u64 dccpav_buf_ackno; - u64 dccpav_ack_seqno; - u64 dccpav_ack_ackno; + struct list_head dccpav_records; struct timeval dccpav_time; u8 dccpav_buf_head; u8 dccpav_buf_tail; @@ -67,6 +64,28 @@ struct dccp_ackvec { u8 dccpav_buf[DCCP_MAX_ACKVEC_LEN]; }; +/** struct dccp_ackvec_record - ack vector record + * + * ACK vector record as defined in Appendix A of spec. + * + * The list is sorted by dccpavr_ack_seqno + * + * @dccpavr_node - node in dccpav_records + * @dccpavr_ack_seqno - sequence number of the packet this record was sent on + * @dccpavr_ack_ackno - sequence number being acknowledged + * @dccpavr_ack_ptr - pointer into dccpav_buf where this record starts + * @dccpavr_ack_nonce - dccpav_ack_nonce at the time this record was sent + * @dccpavr_sent_len - lenght of the record in dccpav_buf + */ +struct dccp_ackvec_record { + struct list_head dccpavr_node; + u64 dccpavr_ack_seqno; + u64 dccpavr_ack_ackno; + u8 dccpavr_ack_ptr; + u8 dccpavr_ack_nonce; + u8 dccpavr_sent_len; +}; + struct sock; struct sk_buff; |
