From 52394eecec4e6fa677a61af26f0bd35de665344e Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Sun, 14 Nov 2010 17:26:02 +0100 Subject: dccp ccid-2: Remove old infrastructure This removes * functions for which updates have been provided in the preceding patches and * the @av_vec_len field - it is no longer necessary since the buffer length is now always computed dynamically. Signed-off-by: Gerrit Renker --- net/dccp/ackvec.c | 251 ------------------------------------------------------ 1 file changed, 251 deletions(-) (limited to 'net/dccp/ackvec.c') diff --git a/net/dccp/ackvec.c b/net/dccp/ackvec.c index f7e647e608bb..66b8a51300c0 100644 --- a/net/dccp/ackvec.c +++ b/net/dccp/ackvec.c @@ -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 -#include #include -#include #include -#include - static struct kmem_cache *dccp_ackvec_slab; static struct kmem_cache *dccp_ackvec_record_slab; @@ -281,249 +273,6 @@ void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb) } } -/* - * 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. - */ -static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av, - const unsigned int packets, - const unsigned char state) -{ - long gap; - long new_head; - - if (av->av_vec_len + packets > DCCPAV_MAX_ACKVEC_LEN) - return -ENOBUFS; - - gap = packets - 1; - new_head = av->av_buf_head - packets; - - 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; - } - - av->av_buf_head = new_head; - - if (gap > 0) - memset(av->av_buf + av->av_buf_head + 1, - DCCPAV_NOT_RECEIVED, gap); - - av->av_buf[av->av_buf_head] = state; - av->av_vec_len += packets; - return 0; -} - -/* - * Implements the RFC 4340, Appendix A - */ -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 - * 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. - */ - - /* 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); - - /* - * 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(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); - - 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; - - delta -= len + 1; - if (++cur_head == buf_end) - cur_head = av->av_buf; - } - } - - 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; -} - -static void dccp_ackvec_throw_record(struct dccp_ackvec *av, - struct dccp_ackvec_record *avr) -{ - struct dccp_ackvec_record *next; - - /* 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; - - /* 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); - } -} - -void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk, - const u64 ackno) -{ - struct dccp_ackvec_record *avr; - - /* - * 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 */ - } -} - -static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av, - struct sock *sk, u64 *ackno, - const unsigned char len, - const unsigned char *vector) -{ - unsigned char i; - struct dccp_ackvec_record *avr; - - /* Check if we actually sent an ACK vector */ - if (list_empty(&av->av_records)) - return; - - i = len; - /* - * XXX - * I think it might be more efficient to work backwards. See comment on - * rcv_ackno. -sorbo. - */ - 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; - - dccp_set_seqno(&ackno_end_rl, *ackno - rl); - - /* - * If our AVR sequence number is greater than the ack, go - * forward in the AVR list until it is not so. - */ - 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; - } - /* - * If it wasn't received, continue scanning... we might - * find another one. - */ - } - - dccp_set_seqno(ackno, ackno_end_rl - 1); - ++vector; - } -} - -int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, - u64 *ackno, const u8 opt, const u8 *value, const u8 len) -{ - if (len > DCCP_SINGLE_OPT_MAXLEN) - return -1; - - /* 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); - return 0; -} - /** * dccp_ackvec_clear_state - Perform house-keeping / garbage-collection * This routine is called when the peer acknowledges the receipt of Ack Vectors -- cgit v1.2.3-59-g8ed1b