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Message-Id: <1198074355-18842-7-git-send-email-gerrit@erg.abdn.ac.uk>
Date: Wed, 19 Dec 2007 14:25:47 +0000
From: Gerrit Renker <gerrit@....abdn.ac.uk>
To: acme@...hat.com
Cc: dccp@...r.kernel.org, netdev@...r.kernel.org,
Gerrit Renker <gerrit@....abdn.ac.uk>
Subject: [PATCH 06/14] [ACKVEC]: Simplify adding Ack Vector records, split option-specific code
This patch
* simplifies the dccp_ackvec_insert_avr() routine: the BUG_ON was redundant,
since the list is automatically arranged in descending order of ack_no;
* separates Ack Vector housekeeping code from option-specific code;
* shifts option-specific code into options.c.
Signed-off-by: Gerrit Renker <gerrit@....abdn.ac.uk>
---
net/dccp/ackvec.c | 107 +++++++++-------------------------------------------
net/dccp/ackvec.h | 5 +-
net/dccp/options.c | 65 +++++++++++++++++++++++++++++++
3 files changed, 85 insertions(+), 92 deletions(-)
--- a/net/dccp/ackvec.h
+++ b/net/dccp/ackvec.h
@@ -108,7 +108,7 @@ 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 int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb);
+extern int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seq, u8 sum);
static inline int dccp_ackvec_pending(const struct dccp_ackvec *av)
{
@@ -151,8 +151,7 @@ static inline int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
return -1;
}
-static inline int dccp_insert_option_ackvec(const struct sock *sk,
- const struct sk_buff *skb)
+static inline int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seq, u8 nonce)
{
return -1;
}
--- a/net/dccp/ackvec.c
+++ b/net/dccp/ackvec.c
@@ -54,106 +54,35 @@ void dccp_ackvec_free(struct dccp_ackvec *av)
}
}
-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->av_records)) {
- const struct dccp_ackvec_record *head =
- list_entry(av->av_records.next,
- struct dccp_ackvec_record,
- avr_node);
- BUG_ON(before48(avr->avr_ack_seqno, head->avr_ack_seqno));
- }
-
- list_add(&avr->avr_node, &av->av_records);
-}
-
-int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
+/**
+ * dccp_ackvec_update_records - Record information about sent Ack Vectors
+ * @av: Ack Vector records to update
+ * @seqno: Sequence number of the packet carrying the Ack Vector just sent
+ * @nonce_sum: The sum of all buffer nonces contained in the Ack Vector
+ */
+int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seqno, u8 nonce_sum)
{
- struct dccp_sock *dp = dccp_sk(sk);
- struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
- /* Figure out how many options do we need to represent the ackvec */
- const u16 nr_opts = DIV_ROUND_UP(av->av_vec_len, DCCP_SINGLE_OPT_MAXLEN);
- 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;
- if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
- /*
- * FIXME: when running out of option space while piggybacking on
- * DataAck, return 0 here and schedule a separate Ack instead.
- */
- DCCP_WARN("Lacking space for %u bytes on %s packet\n", len,
- dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
- return -1;
- }
-
avr = kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC);
if (avr == NULL)
- return -1;
-
- DCCP_SKB_CB(skb)->dccpd_opt_len += len;
-
- to = skb_push(skb, len);
- len = av->av_vec_len;
- from = av->av_buf + av->av_buf_head;
- tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN;
-
- for (i = 0; i < nr_opts; ++i) {
- int copylen = len;
-
- if (len > DCCP_SINGLE_OPT_MAXLEN)
- copylen = DCCP_SINGLE_OPT_MAXLEN;
-
- /*
- * 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 */
- if (from + copylen > tail) {
- const u16 tailsize = tail - from;
-
- memcpy(to, from, tailsize);
- to += tailsize;
- len -= tailsize;
- copylen -= tailsize;
- from = av->av_buf;
- }
-
- memcpy(to, from, copylen);
- from += copylen;
- to += copylen;
- len -= copylen;
- }
+ return -ENOBUFS;
- /*
- * 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_seqno = seqno;
avr->avr_ack_ptr = av->av_buf_head;
avr->avr_ack_ackno = av->av_buf_ackno;
- avr->avr_ack_nonce = nonce;
+ avr->avr_ack_nonce = nonce_sum;
avr->avr_ack_runlen = dccp_ackvec_runlen(av->av_buf + av->av_buf_head);
+ /*
+ * Since GSS is incremented for each packet, the list is automatically
+ * arranged in descending order of @ack_seqno.
+ */
+ list_add(&avr->avr_node, &av->av_records);
- 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_ack_runlen,
+ dccp_pr_debug("Added Vector, ack_seqno=%llu, ack_ackno=%llu (rl=%u)\n",
(unsigned long long)avr->avr_ack_seqno,
- (unsigned long long)avr->avr_ack_ackno);
+ (unsigned long long)avr->avr_ack_ackno,
+ avr->avr_ack_runlen);
return 0;
}
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -433,6 +433,71 @@ static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
return 0;
}
+int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
+{
+ struct dccp_ackvec *av = dccp_sk(sk)->dccps_hc_rx_ackvec;
+ /* Figure out how many options do we need to represent the ackvec */
+ const u16 nr_opts = DIV_ROUND_UP(av->av_vec_len, DCCP_SINGLE_OPT_MAXLEN);
+ u16 len = av->av_vec_len + 2 * nr_opts;
+ u8 i, nonce = 0;
+ const unsigned char *tail, *from;
+ unsigned char *to;
+
+ if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
+ /*
+ * FIXME: when running out of option space while piggybacking on
+ * DataAck, return 0 here and schedule a separate Ack instead.
+ */
+ DCCP_WARN("Lacking space for %u bytes on %s packet\n", len,
+ dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
+ return -1;
+ }
+ DCCP_SKB_CB(skb)->dccpd_opt_len += len;
+
+ to = skb_push(skb, len);
+ len = av->av_vec_len;
+ from = av->av_buf + av->av_buf_head;
+ tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN;
+
+ for (i = 0; i < nr_opts; ++i) {
+ int copylen = len;
+
+ if (len > DCCP_SINGLE_OPT_MAXLEN)
+ copylen = DCCP_SINGLE_OPT_MAXLEN;
+
+ /*
+ * 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 */
+ if (from + copylen > tail) {
+ const u16 tailsize = tail - from;
+
+ memcpy(to, from, tailsize);
+ to += tailsize;
+ len -= tailsize;
+ copylen -= tailsize;
+ from = av->av_buf;
+ }
+
+ memcpy(to, from, copylen);
+ from += copylen;
+ to += copylen;
+ len -= copylen;
+ }
+ /*
+ * Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340.
+ */
+ if (dccp_ackvec_update_records(av, DCCP_SKB_CB(skb)->dccpd_seq, nonce))
+ return -ENOBUFS;
+ return 0;
+}
+
/**
* dccp_insert_option_mandatory - Mandatory option (5.8.2)
* Note that since we are using skb_push, this function needs to be called
--
1.5.3.GIT
--
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