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kernel-ark/net/dccp/options.c
Arnaldo Carvalho de Melo a1d3a35518 [DCCP]: Fix sparse warnings 
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:59:59 -07:00

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/*
* net/dccp/options.c
*
* An implementation of the DCCP protocol
* Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
* Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/config.h>
#include <linux/dccp.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/skbuff.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,
.dccpo_ccid = DCCPF_INITIAL_CCID,
.dccpo_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR,
.dccpo_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT,
};
void dccp_options_init(struct dccp_options *dccpo)
{
memcpy(dccpo, &dccpo_default_values, sizeof(*dccpo));
}
static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
{
u32 value = 0;
if (len > 3)
value += *bf++ << 24;
if (len > 2)
value += *bf++ << 16;
if (len > 1)
value += *bf++ << 8;
if (len > 0)
value += *bf;
return value;
}
int dccp_parse_options(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 rx opt: " : "server rx opt: ";
#endif
const struct dccp_hdr *dh = dccp_hdr(skb);
const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
unsigned char *opt_ptr = options;
const unsigned char *opt_end = (unsigned char *)dh +
(dh->dccph_doff * 4);
struct dccp_options_received *opt_recv = &dp->dccps_options_received;
unsigned char opt, len;
unsigned char *value;
memset(opt_recv, 0, sizeof(*opt_recv));
while (opt_ptr != opt_end) {
opt = *opt_ptr++;
len = 0;
value = NULL;
/* Check if this isn't a single byte option */
if (opt > DCCPO_MAX_RESERVED) {
if (opt_ptr == opt_end)
goto out_invalid_option;
len = *opt_ptr++;
if (len < 3)
goto out_invalid_option;
/*
* Remove the type and len fields, leaving
* just the value size
*/
len -= 2;
value = opt_ptr;
opt_ptr += len;
if (opt_ptr > opt_end)
goto out_invalid_option;
}
switch (opt) {
case DCCPO_PADDING:
break;
case DCCPO_NDP_COUNT:
if (len > 3)
goto out_invalid_option;
opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
dccp_pr_debug("%sNDP count=%d\n", debug_prefix,
opt_recv->dccpor_ndp);
break;
case DCCPO_ACK_VECTOR_0:
if (len > DCCP_MAX_ACK_VECTOR_LEN)
goto out_invalid_option;
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);
break;
case DCCPO_TIMESTAMP:
if (len != 4)
goto out_invalid_option;
opt_recv->dccpor_timestamp = ntohl(*(u32 *)value);
dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
dp->dccps_timestamp_time = jiffies;
dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
debug_prefix, opt_recv->dccpor_timestamp,
(unsigned long long)
DCCP_SKB_CB(skb)->dccpd_ack_seq);
break;
case DCCPO_TIMESTAMP_ECHO:
if (len < 4 || len > 8)
goto out_invalid_option;
opt_recv->dccpor_timestamp_echo = ntohl(*(u32 *)value);
dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, "
"diff=%u\n",
debug_prefix,
opt_recv->dccpor_timestamp_echo,
len + 2,
(unsigned long long)
DCCP_SKB_CB(skb)->dccpd_ack_seq,
(tcp_time_stamp -
opt_recv->dccpor_timestamp_echo));
opt_recv->dccpor_elapsed_time =
dccp_decode_value_var(value + 4,
len - 4);
dccp_pr_debug("%sTIMESTAMP_ECHO ELAPSED_TIME=%d\n",
debug_prefix,
opt_recv->dccpor_elapsed_time);
break;
case DCCPO_ELAPSED_TIME:
if (len > 4)
goto out_invalid_option;
if (pkt_type == DCCP_PKT_DATA)
continue;
opt_recv->dccpor_elapsed_time =
dccp_decode_value_var(value, len);
dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix,
opt_recv->dccpor_elapsed_time);
break;
/*
* From draft-ietf-dccp-spec-11.txt:
*
* Option numbers 128 through 191 are for
* options sent from the HC-Sender to the
* HC-Receiver; option numbers 192 through 255
* are for options sent from the HC-Receiver to
* the HC-Sender.
*/
case 128 ... 191: {
const u16 idx = value - options;
if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
opt, len, idx,
value) != 0)
goto out_invalid_option;
}
break;
case 192 ... 255: {
const u16 idx = value - options;
if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
opt, len, idx,
value) != 0)
goto out_invalid_option;
}
break;
default:
pr_info("DCCP(%p): option %d(len=%d) not "
"implemented, ignoring\n",
sk, opt, len);
break;
}
}
return 0;
out_invalid_option:
DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
pr_info("DCCP(%p): invalid option %d, len=%d\n", sk, opt, len);
return -1;
}
static void dccp_encode_value_var(const u32 value, unsigned char *to,
const unsigned int len)
{
if (len > 3)
*to++ = (value & 0xFF000000) >> 24;
if (len > 2)
*to++ = (value & 0xFF0000) >> 16;
if (len > 1)
*to++ = (value & 0xFF00) >> 8;
if (len > 0)
*to++ = (value & 0xFF);
}
static inline int dccp_ndp_len(const int ndp)
{
return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
}
void dccp_insert_option(struct sock *sk, struct sk_buff *skb,
const unsigned char option,
const void *value, const unsigned char len)
{
unsigned char *to;
if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) {
LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
"%d option!\n", option);
return;
}
DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
to = skb_push(skb, len + 2);
*to++ = option;
*to++ = len + 2;
memcpy(to, value, len);
}
EXPORT_SYMBOL_GPL(dccp_insert_option);
static void dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
{
struct dccp_sock *dp = dccp_sk(sk);
int ndp = dp->dccps_ndp_count;
if (dccp_non_data_packet(skb))
++dp->dccps_ndp_count;
else
dp->dccps_ndp_count = 0;
if (ndp > 0) {
unsigned char *ptr;
const int ndp_len = dccp_ndp_len(ndp);
const int len = ndp_len + 2;
if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
return;
DCCP_SKB_CB(skb)->dccpd_opt_len += len;
ptr = skb_push(skb, len);
*ptr++ = DCCPO_NDP_COUNT;
*ptr++ = len;
dccp_encode_value_var(ndp, ptr, ndp_len);
}
}
static inline int dccp_elapsed_time_len(const u32 elapsed_time)
{
return elapsed_time == 0 ? 0 :
elapsed_time <= 0xFF ? 1 :
elapsed_time <= 0xFFFF ? 2 :
elapsed_time <= 0xFFFFFF ? 3 : 4;
}
void dccp_insert_option_elapsed_time(struct sock *sk,
struct sk_buff *skb,
u32 elapsed_time)
{
#ifdef CONFIG_IP_DCCP_DEBUG
struct dccp_sock *dp = dccp_sk(sk);
const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
"CLIENT TX opt: " : "server TX opt: ";
#endif
const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
const int len = 2 + elapsed_time_len;
unsigned char *to;
/* If elapsed_time == 0... */
if (elapsed_time_len == 2)
return;
if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to "
"insert elapsed time!\n");
return;
}
DCCP_SKB_CB(skb)->dccpd_opt_len += len;
to = skb_push(skb, len);
*to++ = DCCPO_ELAPSED_TIME;
*to++ = len;
dccp_encode_value_var(elapsed_time, to, elapsed_time_len);
dccp_pr_debug("%sELAPSED_TIME=%u, len=%d, seqno=%llu\n",
debug_prefix, elapsed_time,
len,
(unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
}
EXPORT_SYMBOL(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;
const u32 elapsed_time = jiffies_to_usecs(jiffies - ap->dccpap_time) / 10;
unsigned char *to, *from;
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);
}
static inline void dccp_insert_option_timestamp(struct sock *sk,
struct sk_buff *skb)
{
const u32 now = htonl(tcp_time_stamp);
dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
}
static void dccp_insert_option_timestamp_echo(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
u32 tstamp_echo;
const u32 elapsed_time = jiffies_to_usecs(jiffies -
dp->dccps_timestamp_time) / 10;
const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
const int len = 6 + elapsed_time_len;
unsigned char *to;
if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
"timestamp echo!\n");
return;
}
DCCP_SKB_CB(skb)->dccpd_opt_len += len;
to = skb_push(skb, len);
*to++ = DCCPO_TIMESTAMP_ECHO;
*to++ = len;
tstamp_echo = htonl(dp->dccps_timestamp_echo);
memcpy(to, &tstamp_echo, 4);
to += 4;
dccp_encode_value_var(elapsed_time, to, elapsed_time_len);
dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, seqno=%llu\n",
debug_prefix, dp->dccps_timestamp_echo,
len,
(unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
dp->dccps_timestamp_echo = 0;
dp->dccps_timestamp_time = 0;
}
void dccp_insert_options(struct sock *sk, struct sk_buff *skb)
{
struct dccp_sock *dp = dccp_sk(sk);
DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
if (dp->dccps_options.dccpo_send_ndp_count)
dccp_insert_option_ndp(sk, 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_insert_option_timestamp(sk, skb);
if (dp->dccps_timestamp_echo != 0)
dccp_insert_option_timestamp_echo(sk, skb);
}
ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb);
ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb);
/* XXX: insert other options when appropriate */
if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
/* The length of all options has to be a multiple of 4 */
int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
if (padding != 0) {
padding = 4 - padding;
memset(skb_push(skb, padding), 0, padding);
DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
}
}
}
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 = 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, 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;
ap->dccpap_time = jiffies;
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;
}
}
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