* net/dccp/options.c
*
* An implementation of the DCCP protocol
- * Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
- * Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
+ * Copyright (c) 2005 Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
+ * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
+ * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
#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,
- .dccpo_ccid = DCCPF_INITIAL_CCID,
+ .dccpo_rx_ccid = DCCPF_INITIAL_CCID,
+ .dccpo_tx_ccid = DCCPF_INITIAL_CCID,
.dccpo_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR,
.dccpo_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT,
};
int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
{
struct dccp_sock *dp = dccp_sk(sk);
-#ifdef DCCP_DEBUG
- const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? "CLIENT rx opt: " :
- "server rx opt: ";
+#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);
+ 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;
+ u32 elapsed_time;
memset(opt_recv, 0, sizeof(*opt_recv));
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);
+ 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;
-
+ 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)
opt_recv->dccpor_timestamp = ntohl(*(u32 *)value);
dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
- dp->dccps_timestamp_time = jiffies;
+ dccp_timestamp(sk, &dp->dccps_timestamp_time);
dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
debug_prefix, opt_recv->dccpor_timestamp,
DCCP_SKB_CB(skb)->dccpd_ack_seq);
break;
case DCCPO_TIMESTAMP_ECHO:
- if (len < 4 || len > 8)
+ if (len != 4 && len != 6 && 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,
+ dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, ",
+ 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);
+ DCCP_SKB_CB(skb)->dccpd_ack_seq);
- 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);
+
+ if (len == 4)
+ break;
+
+ if (len == 6)
+ elapsed_time = ntohs(*(u16 *)(value + 4));
+ else
+ elapsed_time = ntohl(*(u32 *)(value + 4));
+
+ /* Give precedence to the biggest ELAPSED_TIME */
+ if (elapsed_time > opt_recv->dccpor_elapsed_time)
+ opt_recv->dccpor_elapsed_time = elapsed_time;
break;
case DCCPO_ELAPSED_TIME:
- if (len > 4)
+ if (len != 2 && len != 4)
goto out_invalid_option;
if (pkt_type == DCCP_PKT_DATA)
continue;
- opt_recv->dccpor_elapsed_time = dccp_decode_value_var(value, len);
+
+ if (len == 2)
+ elapsed_time = ntohs(*(u16 *)value);
+ else
+ elapsed_time = ntohl(*(u32 *)value);
+
+ if (elapsed_time > opt_recv->dccpor_elapsed_time)
+ opt_recv->dccpor_elapsed_time = elapsed_time;
+
dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix,
- opt_recv->dccpor_elapsed_time);
+ 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.
+ * 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)
+ 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)
+ 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",
+ pr_info("DCCP(%p): option %d(len=%d) not "
+ "implemented, ignoring\n",
sk, opt, len);
break;
}
unsigned char *to;
if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) {
- LIMIT_NETDEBUG(pr_info("DCCP: packet too small to insert %d option!\n", option));
+ LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
+ "%d option!\n", option);
return;
}
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;
+ return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
}
void dccp_insert_option_elapsed_time(struct sock *sk,
struct sk_buff *skb,
u32 elapsed_time)
{
-#ifdef DCCP_DEBUG
+#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: ";
+ 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)
+ if (elapsed_time_len == 0)
return;
if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
- LIMIT_NETDEBUG(pr_info("DCCP: packet too small to insert elapsed time!\n"));
+ LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to "
+ "insert elapsed time!\n");
return;
}
*to++ = DCCPO_ELAPSED_TIME;
*to++ = len;
- dccp_encode_value_var(elapsed_time, to, elapsed_time_len);
+ if (elapsed_time_len == 2) {
+ const u16 var16 = htons((u16)elapsed_time);
+ memcpy(to, &var16, 2);
+ } else {
+ const u32 var32 = htonl(elapsed_time);
+ memcpy(to, &var32, 4);
+ }
dccp_pr_debug("%sELAPSED_TIME=%u, len=%d, seqno=%llu\n",
debug_prefix, elapsed_time,
(unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
}
-EXPORT_SYMBOL(dccp_insert_option_elapsed_time);
+EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
-static void dccp_insert_option_ack_vector(struct sock *sk, struct sk_buff *skb)
+void dccp_timestamp(const struct sock *sk, struct timeval *tv)
{
- struct dccp_sock *dp = dccp_sk(sk);
-#ifdef 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(pr_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;
+ const struct dccp_sock *dp = dccp_sk(sk);
- len = ap->dccpap_buf_vector_len;
- from = ap->dccpap_buf + ap->dccpap_buf_head;
+ do_gettimeofday(tv);
+ tv->tv_sec -= dp->dccps_epoch.tv_sec;
+ tv->tv_usec -= dp->dccps_epoch.tv_usec;
- /* 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;
+ while (tv->tv_usec < 0) {
+ tv->tv_sec--;
+ tv->tv_usec += USEC_PER_SEC;
}
-
- 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)
+EXPORT_SYMBOL_GPL(dccp_timestamp);
+
+void dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
{
- const u32 now = htonl(tcp_time_stamp);
+ struct timeval tv;
+ u32 now;
+
+ dccp_timestamp(sk, &tv);
+ now = timeval_usecs(&tv) / 10;
+ /* yes this will overflow but that is the point as we want a
+ * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
+
+ now = htonl(now);
dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
}
-static void dccp_insert_option_timestamp_echo(struct sock *sk, struct sk_buff *skb)
+EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
+
+static void dccp_insert_option_timestamp_echo(struct sock *sk,
+ struct sk_buff *skb)
{
struct dccp_sock *dp = dccp_sk(sk);
-#ifdef DCCP_DEBUG
- const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? "CLIENT TX opt: " :
- "server TX opt: ";
+#ifdef CONFIG_IP_DCCP_DEBUG
+ const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
+ "CLIENT TX opt: " : "server TX opt: ";
#endif
+ struct timeval now;
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;
+ u32 elapsed_time;
+ int len, elapsed_time_len;
unsigned char *to;
+ dccp_timestamp(sk, &now);
+ elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
+ elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
+ len = 6 + elapsed_time_len;
+
if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
- LIMIT_NETDEBUG(pr_info("DCCP: packet too small to insert timestamp echo!\n"));
+ LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
+ "timestamp echo!\n");
return;
}
tstamp_echo = htonl(dp->dccps_timestamp_echo);
memcpy(to, &tstamp_echo, 4);
to += 4;
- dccp_encode_value_var(elapsed_time, to, elapsed_time_len);
+
+ if (elapsed_time_len == 2) {
+ const u16 var16 = htons((u16)elapsed_time);
+ memcpy(to, &var16, 2);
+ } else if (elapsed_time_len == 4) {
+ const u32 var32 = htonl(elapsed_time);
+ memcpy(to, &var32, 4);
+ }
dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, seqno=%llu\n",
debug_prefix, dp->dccps_timestamp_echo,
(unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
dp->dccps_timestamp_echo = 0;
- dp->dccps_timestamp_time = 0;
+ dp->dccps_timestamp_time.tv_sec = 0;
+ dp->dccps_timestamp_time.tv_usec = 0;
}
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_insert_option_timestamp(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);
}
- ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb);
- ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb);
+ if (dp->dccps_hc_rx_insert_options) {
+ ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb);
+ dp->dccps_hc_rx_insert_options = 0;
+ }
+ if (dp->dccps_hc_tx_insert_options) {
+ ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb);
+ dp->dccps_hc_tx_insert_options = 0;
+ }
/* XXX: insert other options when appropriate */
}
}
}
-
-struct dccp_ackpkts *dccp_ackpkts_alloc(unsigned int len, int priority)
-{
- struct dccp_ackpkts *ap = kmalloc(sizeof(*ap) + len, priority);
-
- if (ap != NULL) {
-#ifdef 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 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 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 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 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;
- }
-}
projects / linux-2.6-omap-h63xx.git / blobdiff