dccp ccid-2: Separate internals of Ack Vectors from option-parsing code
This patch * separates Ack Vector housekeeping code from option-insertion code; * shifts option-specific code from ackvec.c into options.c; * introduces a dedicated routine to take care of the Ack Vector records; * simplifies the dccp_ackvec_insert_avr() routine: the BUG_ON was redundant, since the list is automatically arranged in descending order of ack_seqno. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
This commit is contained in:
Gerrit Renker
parent
f17a37c9b8
commit
7d87093660
3 changed files with 79 additions and 83 deletions
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@ -52,99 +52,35 @@ void dccp_ackvec_free(struct dccp_ackvec *av)
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}
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}
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static void dccp_ackvec_insert_avr(struct dccp_ackvec *av,
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struct dccp_ackvec_record *avr)
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/**
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* dccp_ackvec_update_records - Record information about sent Ack Vectors
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* @av: Ack Vector records to update
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* @seqno: Sequence number of the packet carrying the Ack Vector just sent
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* @nonce_sum: The sum of all buffer nonces contained in the Ack Vector
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*/
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int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seqno, u8 nonce_sum)
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{
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/*
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* AVRs are sorted by seqno. Since we are sending them in order, we
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* just add the AVR at the head of the list.
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* -sorbo.
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*/
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if (!list_empty(&av->av_records)) {
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const struct dccp_ackvec_record *head =
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list_entry(av->av_records.next,
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struct dccp_ackvec_record,
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avr_node);
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BUG_ON(before48(avr->avr_ack_seqno, head->avr_ack_seqno));
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}
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list_add(&avr->avr_node, &av->av_records);
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}
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int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
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{
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struct dccp_sock *dp = dccp_sk(sk);
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struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
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/* Figure out how many options do we need to represent the ackvec */
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const u8 nr_opts = DIV_ROUND_UP(av->av_vec_len, DCCP_SINGLE_OPT_MAXLEN);
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u16 len = av->av_vec_len + 2 * nr_opts;
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u8 i, nonce = 0;
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const unsigned char *tail, *from;
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unsigned char *to;
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struct dccp_ackvec_record *avr;
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if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
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return -1;
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avr = kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC);
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if (avr == NULL)
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return -1;
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return -ENOBUFS;
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DCCP_SKB_CB(skb)->dccpd_opt_len += len;
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to = skb_push(skb, len);
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len = av->av_vec_len;
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from = av->av_buf + av->av_buf_head;
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tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN;
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for (i = 0; i < nr_opts; ++i) {
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int copylen = len;
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if (len > DCCP_SINGLE_OPT_MAXLEN)
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copylen = DCCP_SINGLE_OPT_MAXLEN;
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/*
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* RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via
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* its type; ack_nonce is the sum of all individual buf_nonce's.
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*/
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nonce ^= av->av_buf_nonce[i];
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*to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i];
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*to++ = copylen + 2;
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/* Check if buf_head wraps */
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if (from + copylen > tail) {
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const u16 tailsize = tail - from;
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memcpy(to, from, tailsize);
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to += tailsize;
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len -= tailsize;
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copylen -= tailsize;
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from = av->av_buf;
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}
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memcpy(to, from, copylen);
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from += copylen;
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to += copylen;
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len -= copylen;
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}
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/*
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* Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340.
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*/
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avr->avr_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
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avr->avr_ack_seqno = seqno;
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avr->avr_ack_ptr = av->av_buf_head;
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avr->avr_ack_ackno = av->av_buf_ackno;
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avr->avr_ack_nonce = nonce;
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avr->avr_ack_nonce = nonce_sum;
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avr->avr_ack_runlen = dccp_ackvec_runlen(av->av_buf + av->av_buf_head);
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/*
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* Since GSS is incremented for each packet, the list is automatically
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* arranged in descending order of @ack_seqno.
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*/
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list_add(&avr->avr_node, &av->av_records);
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dccp_ackvec_insert_avr(av, avr);
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dccp_pr_debug("%s ACK Vector 0, len=%d, ack_seqno=%llu, "
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"ack_ackno=%llu\n",
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dccp_role(sk), avr->avr_ack_runlen,
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dccp_pr_debug("Added Vector, ack_seqno=%llu, ack_ackno=%llu (rl=%u)\n",
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(unsigned long long)avr->avr_ack_seqno,
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(unsigned long long)avr->avr_ack_ackno);
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(unsigned long long)avr->avr_ack_ackno,
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avr->avr_ack_runlen);
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return 0;
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}
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@ -111,7 +111,7 @@ extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
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u64 *ackno, const u8 opt,
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const u8 *value, const u8 len);
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extern int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb);
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extern int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seq, u8 sum);
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static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
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{
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@ -425,6 +425,66 @@ static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
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return 0;
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}
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static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
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{
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struct dccp_sock *dp = dccp_sk(sk);
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struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
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/* Figure out how many options do we need to represent the ackvec */
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const u8 nr_opts = DIV_ROUND_UP(av->av_vec_len, DCCP_SINGLE_OPT_MAXLEN);
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u16 len = av->av_vec_len + 2 * nr_opts;
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u8 i, nonce = 0;
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const unsigned char *tail, *from;
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unsigned char *to;
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if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
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return -1;
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DCCP_SKB_CB(skb)->dccpd_opt_len += len;
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to = skb_push(skb, len);
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len = av->av_vec_len;
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from = av->av_buf + av->av_buf_head;
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tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN;
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for (i = 0; i < nr_opts; ++i) {
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int copylen = len;
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if (len > DCCP_SINGLE_OPT_MAXLEN)
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copylen = DCCP_SINGLE_OPT_MAXLEN;
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/*
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* RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via
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* its type; ack_nonce is the sum of all individual buf_nonce's.
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*/
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nonce ^= av->av_buf_nonce[i];
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*to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i];
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*to++ = copylen + 2;
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/* Check if buf_head wraps */
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if (from + copylen > tail) {
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const u16 tailsize = tail - from;
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memcpy(to, from, tailsize);
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to += tailsize;
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len -= tailsize;
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copylen -= tailsize;
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from = av->av_buf;
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}
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memcpy(to, from, copylen);
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from += copylen;
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to += copylen;
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len -= copylen;
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}
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/*
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* Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340.
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*/
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if (dccp_ackvec_update_records(av, DCCP_SKB_CB(skb)->dccpd_seq, nonce))
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return -ENOBUFS;
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return 0;
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}
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/**
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* dccp_insert_option_mandatory - Mandatory option (5.8.2)
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* Note that since we are using skb_push, this function needs to be called
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