TCP_SKB_CB(skb)->end_seq = seq;
}
+static inline int tcp_urg_mode(const struct tcp_sock *tp)
+{
+ return tp->snd_una != tp->snd_up;
+}
+
#define OPTION_SACK_ADVERTISE (1 << 0)
#define OPTION_TS (1 << 1)
#define OPTION_MD5 (1 << 2)
__u32 tsval, tsecr; /* need to include OPTION_TS */
};
+/* Beware: Something in the Internet is very sensitive to the ordering of
+ * TCP options, we learned this through the hard way, so be careful here.
+ * Luckily we can at least blame others for their non-compliance but from
+ * inter-operatibility perspective it seems that we're somewhat stuck with
+ * the ordering which we have been using if we want to keep working with
+ * those broken things (not that it currently hurts anybody as there isn't
+ * particular reason why the ordering would need to be changed).
+ *
+ * At least SACK_PERM as the first option is known to lead to a disaster
+ * (but it may well be that other scenarios fail similarly).
+ */
static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp,
const struct tcp_out_options *opts,
__u8 **md5_hash) {
*md5_hash = NULL;
}
+ if (unlikely(opts->mss)) {
+ *ptr++ = htonl((TCPOPT_MSS << 24) |
+ (TCPOLEN_MSS << 16) |
+ opts->mss);
+ }
+
if (likely(OPTION_TS & opts->options)) {
if (unlikely(OPTION_SACK_ADVERTISE & opts->options)) {
*ptr++ = htonl((TCPOPT_SACK_PERM << 24) |
*ptr++ = htonl(opts->tsecr);
}
- if (unlikely(opts->mss)) {
- *ptr++ = htonl((TCPOPT_MSS << 24) |
- (TCPOLEN_MSS << 16) |
- opts->mss);
- }
-
if (unlikely(OPTION_SACK_ADVERTISE & opts->options &&
!(OPTION_TS & opts->options))) {
*ptr++ = htonl((TCPOPT_NOP << 24) |
if (tp->rx_opt.dsack) {
tp->rx_opt.dsack = 0;
- tp->rx_opt.eff_sacks--;
+ tp->rx_opt.eff_sacks = tp->rx_opt.num_sacks;
}
}
}
th->check = 0;
th->urg_ptr = 0;
- if (unlikely(tp->urg_mode &&
+ /* The urg_mode check is necessary during a below snd_una win probe */
+ if (unlikely(tcp_urg_mode(tp) &&
between(tp->snd_up, tcb->seq + 1, tcb->seq + 0xFFFF))) {
th->urg_ptr = htons(tp->snd_up - tcb->seq);
th->urg = 1;
/* Compute the current effective MSS, taking SACKs and IP options,
* and even PMTU discovery events into account.
*
- * LARGESEND note: !urg_mode is overkill, only frames up to snd_up
+ * LARGESEND note: !tcp_urg_mode is overkill, only frames up to snd_up
* cannot be large. However, taking into account rare use of URG, this
* is not a big flaw.
*/
mss_now = tp->mss_cache;
- if (large_allowed && sk_can_gso(sk) && !tp->urg_mode)
+ if (large_allowed && sk_can_gso(sk) && !tcp_urg_mode(tp))
doing_tso = 1;
if (dst) {
/* Don't use the nagle rule for urgent data (or for the final FIN).
* Nagle can be ignored during F-RTO too (see RFC4138).
*/
- if (tp->urg_mode || (tp->frto_counter == 2) ||
+ if (tcp_urg_mode(tp) || (tp->frto_counter == 2) ||
(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN))
return 1;
/* changed transmit queue under us so clear hints */
tcp_clear_retrans_hints_partial(tp);
+ if (next_skb == tp->retransmit_skb_hint)
+ tp->retransmit_skb_hint = skb;
sk_wmem_free_skb(sk, next_skb);
}
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
unsigned int mss = tcp_current_mss(sk, 0);
- int lost = 0;
+ u32 prior_lost = tp->lost_out;
tcp_for_write_queue(skb, sk) {
if (skb == tcp_send_head(sk))
TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
tp->retrans_out -= tcp_skb_pcount(skb);
}
- if (!(TCP_SKB_CB(skb)->sacked & TCPCB_LOST)) {
- TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
- tp->lost_out += tcp_skb_pcount(skb);
- lost = 1;
- }
+ tcp_skb_mark_lost_uncond_verify(tp, skb);
}
}
- tcp_clear_all_retrans_hints(tp);
+ tcp_clear_retrans_hints_partial(tp);
- if (!lost)
+ if (prior_lost == tp->lost_out)
return;
if (tcp_is_reno(tp))
/* Collapse two adjacent packets if worthwhile and we can. */
if (!(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN) &&
(skb->len < (cur_mss >> 1)) &&
- (tcp_write_queue_next(sk, skb) != tcp_send_head(sk)) &&
(!tcp_skb_is_last(sk, skb)) &&
+ (tcp_write_queue_next(sk, skb) != tcp_send_head(sk)) &&
(skb_shinfo(skb)->nr_frags == 0 &&
skb_shinfo(tcp_write_queue_next(sk, skb))->nr_frags == 0) &&
(tcp_skb_pcount(skb) == 1 &&
return err;
}
-/* This gets called after a retransmit timeout, and the initially
- * retransmitted data is acknowledged. It tries to continue
- * resending the rest of the retransmit queue, until either
- * we've sent it all or the congestion window limit is reached.
- * If doing SACK, the first ACK which comes back for a timeout
- * based retransmit packet might feed us FACK information again.
- * If so, we use it to avoid unnecessarily retransmissions.
- */
-void tcp_xmit_retransmit_queue(struct sock *sk)
+static int tcp_can_forward_retransmit(struct sock *sk)
{
const struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
- struct sk_buff *skb;
- int packet_cnt;
-
- if (tp->retransmit_skb_hint) {
- skb = tp->retransmit_skb_hint;
- packet_cnt = tp->retransmit_cnt_hint;
- } else {
- skb = tcp_write_queue_head(sk);
- packet_cnt = 0;
- }
-
- /* First pass: retransmit lost packets. */
- if (tp->lost_out) {
- tcp_for_write_queue_from(skb, sk) {
- __u8 sacked = TCP_SKB_CB(skb)->sacked;
-
- if (skb == tcp_send_head(sk))
- break;
- /* we could do better than to assign each time */
- tp->retransmit_skb_hint = skb;
- tp->retransmit_cnt_hint = packet_cnt;
-
- /* Assume this retransmit will generate
- * only one packet for congestion window
- * calculation purposes. This works because
- * tcp_retransmit_skb() will chop up the
- * packet to be MSS sized and all the
- * packet counting works out.
- */
- if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)
- return;
-
- if (sacked & TCPCB_LOST) {
- if (!(sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))) {
- int mib_idx;
-
- if (tcp_retransmit_skb(sk, skb)) {
- tp->retransmit_skb_hint = NULL;
- return;
- }
- if (icsk->icsk_ca_state != TCP_CA_Loss)
- mib_idx = LINUX_MIB_TCPFASTRETRANS;
- else
- mib_idx = LINUX_MIB_TCPSLOWSTARTRETRANS;
- NET_INC_STATS_BH(sock_net(sk), mib_idx);
-
- if (skb == tcp_write_queue_head(sk))
- inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
- inet_csk(sk)->icsk_rto,
- TCP_RTO_MAX);
- }
-
- packet_cnt += tcp_skb_pcount(skb);
- if (packet_cnt >= tp->lost_out)
- break;
- }
- }
- }
-
- /* OK, demanded retransmission is finished. */
/* Forward retransmissions are possible only during Recovery. */
if (icsk->icsk_ca_state != TCP_CA_Recovery)
- return;
+ return 0;
/* No forward retransmissions in Reno are possible. */
if (tcp_is_reno(tp))
- return;
+ return 0;
/* Yeah, we have to make difficult choice between forward transmission
* and retransmission... Both ways have their merits...
*/
if (tcp_may_send_now(sk))
- return;
+ return 0;
- /* If nothing is SACKed, highest_sack in the loop won't be valid */
- if (!tp->sacked_out)
- return;
+ return 1;
+}
- if (tp->forward_skb_hint)
- skb = tp->forward_skb_hint;
- else
+/* This gets called after a retransmit timeout, and the initially
+ * retransmitted data is acknowledged. It tries to continue
+ * resending the rest of the retransmit queue, until either
+ * we've sent it all or the congestion window limit is reached.
+ * If doing SACK, the first ACK which comes back for a timeout
+ * based retransmit packet might feed us FACK information again.
+ * If so, we use it to avoid unnecessarily retransmissions.
+ */
+void tcp_xmit_retransmit_queue(struct sock *sk)
+{
+ const struct inet_connection_sock *icsk = inet_csk(sk);
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct sk_buff *skb;
+ struct sk_buff *hole = NULL;
+ u32 last_lost;
+ int mib_idx;
+ int fwd_rexmitting = 0;
+
+ if (!tp->lost_out)
+ tp->retransmit_high = tp->snd_una;
+
+ if (tp->retransmit_skb_hint) {
+ skb = tp->retransmit_skb_hint;
+ last_lost = TCP_SKB_CB(skb)->end_seq;
+ if (after(last_lost, tp->retransmit_high))
+ last_lost = tp->retransmit_high;
+ } else {
skb = tcp_write_queue_head(sk);
+ last_lost = tp->snd_una;
+ }
+ /* First pass: retransmit lost packets. */
tcp_for_write_queue_from(skb, sk) {
- if (skb == tcp_send_head(sk))
- break;
- tp->forward_skb_hint = skb;
+ __u8 sacked = TCP_SKB_CB(skb)->sacked;
- if (!before(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))
+ if (skb == tcp_send_head(sk))
break;
+ /* we could do better than to assign each time */
+ if (hole == NULL)
+ tp->retransmit_skb_hint = skb;
+ /* Assume this retransmit will generate
+ * only one packet for congestion window
+ * calculation purposes. This works because
+ * tcp_retransmit_skb() will chop up the
+ * packet to be MSS sized and all the
+ * packet counting works out.
+ */
if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)
- break;
+ return;
+
+ if (fwd_rexmitting) {
+begin_fwd:
+ if (!before(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))
+ break;
+ mib_idx = LINUX_MIB_TCPFORWARDRETRANS;
- if (TCP_SKB_CB(skb)->sacked & TCPCB_TAGBITS)
+ } else if (!before(TCP_SKB_CB(skb)->seq, tp->retransmit_high)) {
+ tp->retransmit_high = last_lost;
+ if (!tcp_can_forward_retransmit(sk))
+ break;
+ /* Backtrack if necessary to non-L'ed skb */
+ if (hole != NULL) {
+ skb = hole;
+ hole = NULL;
+ }
+ fwd_rexmitting = 1;
+ goto begin_fwd;
+
+ } else if (!(sacked & TCPCB_LOST)) {
+ if (hole == NULL && !(sacked & TCPCB_SACKED_RETRANS))
+ hole = skb;
continue;
- /* Ok, retransmit it. */
- if (tcp_retransmit_skb(sk, skb)) {
- tp->forward_skb_hint = NULL;
- break;
+ } else {
+ last_lost = TCP_SKB_CB(skb)->end_seq;
+ if (icsk->icsk_ca_state != TCP_CA_Loss)
+ mib_idx = LINUX_MIB_TCPFASTRETRANS;
+ else
+ mib_idx = LINUX_MIB_TCPSLOWSTARTRETRANS;
}
+ if (sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))
+ continue;
+
+ if (tcp_retransmit_skb(sk, skb))
+ return;
+ NET_INC_STATS_BH(sock_net(sk), mib_idx);
+
if (skb == tcp_write_queue_head(sk))
inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
inet_csk(sk)->icsk_rto,
TCP_RTO_MAX);
-
- NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFORWARDRETRANS);
}
}
struct sk_buff *skb;
struct tcp_md5sig_key *md5;
__u8 *md5_hash_location;
+ int mss;
skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15, 1, GFP_ATOMIC);
if (skb == NULL)
skb->dst = dst_clone(dst);
+ mss = dst_metric(dst, RTAX_ADVMSS);
+ if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss)
+ mss = tp->rx_opt.user_mss;
+
if (req->rcv_wnd == 0) { /* ignored for retransmitted syns */
__u8 rcv_wscale;
/* Set this up on the first call only */
req->window_clamp = tp->window_clamp ? : dst_metric(dst, RTAX_WINDOW);
/* tcp_full_space because it is guaranteed to be the first packet */
tcp_select_initial_window(tcp_full_space(sk),
- dst_metric(dst, RTAX_ADVMSS) - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0),
+ mss - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0),
&req->rcv_wnd,
&req->window_clamp,
ireq->wscale_ok,
memset(&opts, 0, sizeof(opts));
TCP_SKB_CB(skb)->when = tcp_time_stamp;
- tcp_header_size = tcp_synack_options(sk, req,
- dst_metric(dst, RTAX_ADVMSS),
+ tcp_header_size = tcp_synack_options(sk, req, mss,
skb, &opts, &md5) +
sizeof(struct tcphdr);
th->syn = 1;
th->ack = 1;
TCP_ECN_make_synack(req, th);
- th->source = inet_sk(sk)->sport;
+ th->source = ireq->loc_port;
th->dest = ireq->rmt_port;
/* Setting of flags are superfluous here for callers (and ECE is
* not even correctly set)
if (!tp->window_clamp)
tp->window_clamp = dst_metric(dst, RTAX_WINDOW);
tp->advmss = dst_metric(dst, RTAX_ADVMSS);
+ if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < tp->advmss)
+ tp->advmss = tp->rx_opt.user_mss;
+
tcp_initialize_rcv_mss(sk);
tcp_select_initial_window(tcp_full_space(sk),
tcp_init_wl(tp, tp->write_seq, 0);
tp->snd_una = tp->write_seq;
tp->snd_sml = tp->write_seq;
+ tp->snd_up = tp->write_seq;
tp->rcv_nxt = 0;
tp->rcv_wup = 0;
tp->copied_seq = 0;
tcp_event_new_data_sent(sk, skb);
return err;
} else {
- if (tp->urg_mode &&
- between(tp->snd_up, tp->snd_una + 1, tp->snd_una + 0xFFFF))
+ if (between(tp->snd_up, tp->snd_una + 1, tp->snd_una + 0xFFFF))
tcp_xmit_probe_skb(sk, 1);
return tcp_xmit_probe_skb(sk, 0);
}
projects / linux-2.6-omap-h63xx.git / blobdiff