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yaml
---
r: 111511
b: refs/heads/master
c: ff49e27
h: refs/heads/master
i:
  111509: 7e0c984
  111507: 55b7f41
  111503: 66cd132
v: v3
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Gerrit Renker committed Sep 4, 2008
1 parent 0cdf0ab commit 72fa76f
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Showing 5 changed files with 128 additions and 174 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: b8c6bcee1dbc1aadcd67af998e414e73fa166a7d
refs/heads/master: ff49e27089ec363b7fc3849504e0435d447ab18a
178 changes: 64 additions & 114 deletions trunk/net/dccp/ackvec.c
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Original file line number Diff line number Diff line change
@@ -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
Expand All @@ -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,
Expand Down Expand Up @@ -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;

Expand All @@ -94,15 +95,21 @@ 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;

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 */
Expand All @@ -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;
Expand All @@ -204,26 +160,26 @@ 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;
new_head = av->av_buf_head - packets;

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;
Expand All @@ -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
Expand All @@ -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);
Expand All @@ -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 {
Expand All @@ -285,35 +242,30 @@ 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 */
if (delta < len + 1)
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;

Expand All @@ -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);
}
}

Expand All @@ -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);
Expand Down Expand Up @@ -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);
Expand All @@ -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",
Expand Down Expand Up @@ -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;

Expand Down
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