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[DCCP]: Move the ack vector code to net/dccp/ackvec.[ch]

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Isolating it, that will be used when we introduce a CCID2 (TCP-Like)
implementation.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Arnaldo Carvalho de Melo
2005-09-18 00:17:51 -07:00
committed by David S. Miller
parent 21f130a237
commit ae31c3399d
10 changed files with 612 additions and 631 deletions
Download Patch File Download Diff File Expand all files Collapse all files

440
net/dccp/options.c
View File

@@ -18,15 +18,10 @@
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include "ackvec.h"
#include "ccid.h"
#include "dccp.h"
static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts *ap,
struct sock *sk,
const u64 ackno,
const unsigned char len,
const unsigned char *vector);
/* stores the default values for new connection. may be changed with sysctl */
static const struct dccp_options dccpo_default_values = {
.dccpo_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW,
@@ -113,25 +108,13 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
opt_recv->dccpor_ndp);
break;
case DCCPO_ACK_VECTOR_0:
if (len > DCCP_MAX_ACK_VECTOR_LEN)
goto out_invalid_option;
case DCCPO_ACK_VECTOR_1:
if (pkt_type == DCCP_PKT_DATA)
continue;
opt_recv->dccpor_ack_vector_len = len;
opt_recv->dccpor_ack_vector_idx = value - options;
dccp_pr_debug("%sACK vector 0, len=%d, ack_ackno=%llu\n",
debug_prefix, len,
(unsigned long long)
DCCP_SKB_CB(skb)->dccpd_ack_seq);
dccp_ackvector_print(DCCP_SKB_CB(skb)->dccpd_ack_seq,
value, len);
dccp_ackpkts_check_rcv_ackvector(dp->dccps_hc_rx_ackpkts,
sk,
DCCP_SKB_CB(skb)->dccpd_ack_seq,
len, value);
if (dp->dccps_options.dccpo_send_ack_vector &&
dccp_ackvec_parse(sk, skb, opt, value, len))
goto out_invalid_option;
break;
case DCCPO_TIMESTAMP:
if (len != 4)
@@ -352,86 +335,6 @@ void dccp_insert_option_elapsed_time(struct sock *sk,
EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
static void dccp_insert_option_ack_vector(struct sock *sk, struct sk_buff *skb)
{
struct dccp_sock *dp = dccp_sk(sk);
#ifdef CONFIG_IP_DCCP_DEBUG
const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
"CLIENT TX opt: " : "server TX opt: ";
#endif
struct dccp_ackpkts *ap = dp->dccps_hc_rx_ackpkts;
int len = ap->dccpap_buf_vector_len + 2;
struct timeval now;
u32 elapsed_time;
unsigned char *to, *from;
dccp_timestamp(sk, &now);
elapsed_time = timeval_delta(&now, &ap->dccpap_time) / 10;
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) {
LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to "
"insert ACK Vector!\n");
return;
}
/*
* 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 (ap->dccpap_ack_seqno != DCCP_MAX_SEQNO + 1)
return;
DCCP_SKB_CB(skb)->dccpd_opt_len += len;
to = skb_push(skb, len);
*to++ = DCCPO_ACK_VECTOR_0;
*to++ = len;
len = ap->dccpap_buf_vector_len;
from = ap->dccpap_buf + ap->dccpap_buf_head;
/* Check if buf_head wraps */
if (ap->dccpap_buf_head + len > ap->dccpap_buf_len) {
const unsigned int tailsize = (ap->dccpap_buf_len -
ap->dccpap_buf_head);
memcpy(to, from, tailsize);
to += tailsize;
len -= tailsize;
from = ap->dccpap_buf;
}
memcpy(to, from, len);
/*
* From draft-ietf-dccp-spec-11.txt:
*
* 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.
*
* This implemention uses just one ack record for now.
*/
ap->dccpap_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
ap->dccpap_ack_ptr = ap->dccpap_buf_head;
ap->dccpap_ack_ackno = ap->dccpap_buf_ackno;
ap->dccpap_ack_nonce = ap->dccpap_buf_nonce;
ap->dccpap_ack_vector_len = ap->dccpap_buf_vector_len;
dccp_pr_debug("%sACK Vector 0, len=%d, ack_seqno=%llu, "
"ack_ackno=%llu\n",
debug_prefix, ap->dccpap_ack_vector_len,
(unsigned long long) ap->dccpap_ack_seqno,
(unsigned long long) ap->dccpap_ack_ackno);
}
void dccp_timestamp(const struct sock *sk, struct timeval *tv)
{
const struct dccp_sock *dp = dccp_sk(sk);
@@ -528,9 +431,8 @@ void dccp_insert_options(struct sock *sk, struct sk_buff *skb)
if (!dccp_packet_without_ack(skb)) {
if (dp->dccps_options.dccpo_send_ack_vector &&
(dp->dccps_hc_rx_ackpkts->dccpap_buf_ackno !=
DCCP_MAX_SEQNO + 1))
dccp_insert_option_ack_vector(sk, skb);
dccp_ackvec_pending(dp->dccps_hc_rx_ackvec))
dccp_insert_option_ackvec(sk, skb);
if (dp->dccps_timestamp_echo != 0)
dccp_insert_option_timestamp_echo(sk, skb);
}
@@ -557,331 +459,3 @@ void dccp_insert_options(struct sock *sk, struct sk_buff *skb)
}
}
}
struct dccp_ackpkts *dccp_ackpkts_alloc(const unsigned int len,
const unsigned int __nocast priority)
{
struct dccp_ackpkts *ap = kmalloc(sizeof(*ap) + len, priority);
if (ap != NULL) {
#ifdef CONFIG_IP_DCCP_DEBUG
memset(ap->dccpap_buf, 0xFF, len);
#endif
ap->dccpap_buf_len = len;
ap->dccpap_buf_head =
ap->dccpap_buf_tail =
ap->dccpap_buf_len - 1;
ap->dccpap_buf_ackno =
ap->dccpap_ack_ackno =
ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1;
ap->dccpap_buf_nonce = ap->dccpap_buf_nonce = 0;
ap->dccpap_ack_ptr = 0;
ap->dccpap_time.tv_sec = 0;
ap->dccpap_time.tv_usec = 0;
ap->dccpap_buf_vector_len = ap->dccpap_ack_vector_len = 0;
}
return ap;
}
void dccp_ackpkts_free(struct dccp_ackpkts *ap)
{
if (ap != NULL) {
#ifdef CONFIG_IP_DCCP_DEBUG
memset(ap, 0xFF, sizeof(*ap) + ap->dccpap_buf_len);
#endif
kfree(ap);
}
}
static inline u8 dccp_ackpkts_state(const struct dccp_ackpkts *ap,
const unsigned int index)
{
return ap->dccpap_buf[index] & DCCP_ACKPKTS_STATE_MASK;
}
static inline u8 dccp_ackpkts_len(const struct dccp_ackpkts *ap,
const unsigned int index)
{
return ap->dccpap_buf[index] & DCCP_ACKPKTS_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;
* this simplifies table updates if one of the missing packets arrives.
*/
static inline int dccp_ackpkts_set_buf_head_state(struct dccp_ackpkts *ap,
const unsigned int packets,
const unsigned char state)
{
unsigned int gap;
signed long new_head;
if (ap->dccpap_buf_vector_len + packets > ap->dccpap_buf_len)
return -ENOBUFS;
gap = packets - 1;
new_head = ap->dccpap_buf_head - packets;
if (new_head < 0) {
if (gap > 0) {
memset(ap->dccpap_buf, DCCP_ACKPKTS_STATE_NOT_RECEIVED,
gap + new_head + 1);
gap = -new_head;
}
new_head += ap->dccpap_buf_len;
}
ap->dccpap_buf_head = new_head;
if (gap > 0)
memset(ap->dccpap_buf + ap->dccpap_buf_head + 1,
DCCP_ACKPKTS_STATE_NOT_RECEIVED, gap);
ap->dccpap_buf[ap->dccpap_buf_head] = state;
ap->dccpap_buf_vector_len += packets;
return 0;
}
/*
* Implements the draft-ietf-dccp-spec-11.txt Appendix A
*/
int dccp_ackpkts_add(struct dccp_ackpkts *ap, const struct sock *sk,
u64 ackno, u8 state)
{
/*
* 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 dccpap_buf.
*
* We may well decide to do buffer compression, etc, but for now lets
* just drop.
*
* From Appendix A:
*
* 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 (ap->dccpap_buf_vector_len == 0) {
ap->dccpap_buf[ap->dccpap_buf_head] = state;
ap->dccpap_buf_vector_len = 1;
} else if (after48(ackno, ap->dccpap_buf_ackno)) {
const u64 delta = dccp_delta_seqno(ap->dccpap_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_ackpkts_state(ap, ap->dccpap_buf_head) == state &&
(dccp_ackpkts_len(ap, ap->dccpap_buf_head) <
DCCP_ACKPKTS_LEN_MASK))
ap->dccpap_buf[ap->dccpap_buf_head]++;
else if (dccp_ackpkts_set_buf_head_state(ap, delta, state))
return -ENOBUFS;
} else {
/*
* A.1.2. Old Packets
*
* When a packet with Sequence Number S arrives, and
* S <= buf_ackno, 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, ap->dccpap_buf_ackno);
unsigned int index = ap->dccpap_buf_head;
while (1) {
const u8 len = dccp_ackpkts_len(ap, index);
const u8 state = dccp_ackpkts_state(ap, index);
/*
* valid packets not yet in dccpap_buf have a reserved
* entry, with a len equal to 0.
*/
if (state == DCCP_ACKPKTS_STATE_NOT_RECEIVED &&
len == 0 && delta == 0) { /* Found our
reserved seat! */
dccp_pr_debug("Found %llu reserved seat!\n",
(unsigned long long) ackno);
ap->dccpap_buf[index] = state;
goto out;
}
/* len == 0 means one packet */
if (delta < len + 1)
goto out_duplicate;
delta -= len + 1;
if (++index == ap->dccpap_buf_len)
index = 0;
}
}
ap->dccpap_buf_ackno = ackno;
dccp_timestamp(sk, &ap->dccpap_time);
out:
dccp_pr_debug("");
dccp_ackpkts_print(ap);
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;
}
#ifdef CONFIG_IP_DCCP_DEBUG
void dccp_ackvector_print(const u64 ackno, const unsigned char *vector,
int len)
{
if (!dccp_debug)
return;
printk("ACK vector len=%d, ackno=%llu |", len,
(unsigned long long) ackno);
while (len--) {
const u8 state = (*vector & DCCP_ACKPKTS_STATE_MASK) >> 6;
const u8 rl = (*vector & DCCP_ACKPKTS_LEN_MASK);
printk("%d,%d|", state, rl);
++vector;
}
printk("\n");
}
void dccp_ackpkts_print(const struct dccp_ackpkts *ap)
{
dccp_ackvector_print(ap->dccpap_buf_ackno,
ap->dccpap_buf + ap->dccpap_buf_head,
ap->dccpap_buf_vector_len);
}
#endif
static void dccp_ackpkts_trow_away_ack_record(struct dccp_ackpkts *ap)
{
/*
* As we're keeping track of the ack vector size
* (dccpap_buf_vector_len) and the sent ack vector size
* (dccpap_ack_vector_len) we don't need dccpap_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
ap->dccpap_buf_tail = ap->dccpap_ack_ptr + 1;
if (ap->dccpap_buf_tail >= ap->dccpap_buf_len)
ap->dccpap_buf_tail -= ap->dccpap_buf_len;
#endif
ap->dccpap_buf_vector_len -= ap->dccpap_ack_vector_len;
}
void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap, struct sock *sk,
u64 ackno)
{
/* Check if we actually sent an ACK vector */
if (ap->dccpap_ack_seqno == DCCP_MAX_SEQNO + 1)
return;
if (ackno == ap->dccpap_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: ";
#endif
dccp_pr_debug("%sACK packet 0, len=%d, ack_seqno=%llu, "
"ack_ackno=%llu, ACKED!\n",
debug_prefix, 1,
(unsigned long long) ap->dccpap_ack_seqno,
(unsigned long long) ap->dccpap_ack_ackno);
dccp_ackpkts_trow_away_ack_record(ap);
ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1;
}
}
static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts *ap,
struct sock *sk, u64 ackno,
const unsigned char len,
const unsigned char *vector)
{
unsigned char i;
/* Check if we actually sent an ACK vector */
if (ap->dccpap_ack_seqno == DCCP_MAX_SEQNO + 1)
return;
/*
* We're in the receiver half connection, so if the received an ACK
* vector ackno (e.g. 50) before dccpap_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, ap->dccpap_ack_seqno); */
if (before48(ackno, ap->dccpap_ack_seqno)) {
/* dccp_pr_debug_cat("yes\n"); */
return;
}
/* dccp_pr_debug_cat("no\n"); */
i = len;
while (i--) {
const u8 rl = (*vector & DCCP_ACKPKTS_LEN_MASK);
u64 ackno_end_rl;
dccp_set_seqno(&ackno_end_rl, ackno - rl);
/*
* dccp_pr_debug("is %llu <= %llu <= %llu? ", ackno_end_rl,
* ap->dccpap_ack_seqno, ackno);
*/
if (between48(ap->dccpap_ack_seqno, ackno_end_rl, ackno)) {
const u8 state = (*vector &
DCCP_ACKPKTS_STATE_MASK) >> 6;
/* dccp_pr_debug_cat("yes\n"); */
if (state != DCCP_ACKPKTS_STATE_NOT_RECEIVED) {
#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: ";
#endif
dccp_pr_debug("%sACK vector 0, len=%d, "
"ack_seqno=%llu, ack_ackno=%llu, "
"ACKED!\n",
debug_prefix, len,
(unsigned long long)
ap->dccpap_ack_seqno,
(unsigned long long)
ap->dccpap_ack_ackno);
dccp_ackpkts_trow_away_ack_record(ap);
}
/*
* If dccpap_ack_seqno was not received, no problem
* we'll send another ACK vector.
*/
ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1;
break;
}
/* dccp_pr_debug_cat("no\n"); */
dccp_set_seqno(&ackno, ackno_end_rl - 1);
++vector;
}
}