#include <linux/compiler.h>
#include <linux/module.h>
-#include <linux/smp_lock.h>
/* People can turn this off for buggy TCP's found in printers etc. */
-int sysctl_tcp_retrans_collapse = 1;
+int sysctl_tcp_retrans_collapse __read_mostly = 1;
+
+/* People can turn this on to work with those rare, broken TCPs that
+ * interpret the window field as a signed quantity.
+ */
+int sysctl_tcp_workaround_signed_windows __read_mostly = 0;
/* This limits the percentage of the congestion window which we
* will allow a single TSO frame to consume. Building TSO frames
* which are too large can cause TCP streams to be bursty.
*/
-int sysctl_tcp_tso_win_divisor = 3;
+int sysctl_tcp_tso_win_divisor __read_mostly = 3;
+
+int sysctl_tcp_mtu_probing __read_mostly = 0;
+int sysctl_tcp_base_mss __read_mostly = 512;
-static inline void update_send_head(struct sock *sk, struct tcp_sock *tp,
- struct sk_buff *skb)
+/* By default, RFC2861 behavior. */
+int sysctl_tcp_slow_start_after_idle __read_mostly = 1;
+
+static void tcp_event_new_data_sent(struct sock *sk, struct sk_buff *skb)
{
- sk->sk_send_head = skb->next;
- if (sk->sk_send_head == (struct sk_buff *)&sk->sk_write_queue)
- sk->sk_send_head = NULL;
+ struct tcp_sock *tp = tcp_sk(sk);
+ unsigned int prior_packets = tp->packets_out;
+
+ tcp_advance_send_head(sk, skb);
tp->snd_nxt = TCP_SKB_CB(skb)->end_seq;
- tcp_packets_out_inc(sk, tp, skb);
+
+ /* Don't override Nagle indefinately with F-RTO */
+ if (tp->frto_counter == 2)
+ tp->frto_counter = 3;
+
+ tp->packets_out += tcp_skb_pcount(skb);
+ if (!prior_packets)
+ inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+ inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
}
/* SND.NXT, if window was not shrunk.
* Anything in between SND.UNA...SND.UNA+SND.WND also can be already
* invalid. OK, let's make this for now:
*/
-static inline __u32 tcp_acceptable_seq(struct sock *sk, struct tcp_sock *tp)
+static inline __u32 tcp_acceptable_seq(struct sock *sk)
{
- if (!before(tp->snd_una+tp->snd_wnd, tp->snd_nxt))
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ if (!before(tcp_wnd_end(tp), tp->snd_nxt))
return tp->snd_nxt;
else
- return tp->snd_una+tp->snd_wnd;
+ return tcp_wnd_end(tp);
}
/* Calculate mss to advertise in SYN segment.
tp->snd_cwnd_used = 0;
}
-static inline void tcp_event_data_sent(struct tcp_sock *tp,
- struct sk_buff *skb, struct sock *sk)
+static void tcp_event_data_sent(struct tcp_sock *tp,
+ struct sk_buff *skb, struct sock *sk)
{
struct inet_connection_sock *icsk = inet_csk(sk);
const u32 now = tcp_time_stamp;
- if (!tp->packets_out && (s32)(now - tp->lsndtime) > icsk->icsk_rto)
+ if (sysctl_tcp_slow_start_after_idle &&
+ (!tp->packets_out && (s32)(now - tp->lsndtime) > icsk->icsk_rto))
tcp_cwnd_restart(sk, __sk_dst_get(sk));
tp->lsndtime = now;
icsk->icsk_ack.pingpong = 1;
}
-static __inline__ void tcp_event_ack_sent(struct sock *sk, unsigned int pkts)
+static inline void tcp_event_ack_sent(struct sock *sk, unsigned int pkts)
{
tcp_dec_quickack_mode(sk, pkts);
inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
space = (space / mss) * mss;
/* NOTE: offering an initial window larger than 32767
- * will break some buggy TCP stacks. We try to be nice.
- * If we are not window scaling, then this truncates
- * our initial window offering to 32k. There should also
- * be a sysctl option to stop being nice.
+ * will break some buggy TCP stacks. If the admin tells us
+ * it is likely we could be speaking with such a buggy stack
+ * we will truncate our initial window offering to 32K-1
+ * unless the remote has sent us a window scaling option,
+ * which we interpret as a sign the remote TCP is not
+ * misinterpreting the window field as a signed quantity.
*/
- (*rcv_wnd) = min(space, MAX_TCP_WINDOW);
+ if (sysctl_tcp_workaround_signed_windows)
+ (*rcv_wnd) = min(space, MAX_TCP_WINDOW);
+ else
+ (*rcv_wnd) = space;
+
(*rcv_wscale) = 0;
if (wscale_ok) {
/* Set window scaling on max possible window
- * See RFC1323 for an explanation of the limit to 14
+ * See RFC1323 for an explanation of the limit to 14
*/
space = max_t(u32, sysctl_tcp_rmem[2], sysctl_rmem_max);
+ space = min_t(u32, space, *window_clamp);
while (space > 65535 && (*rcv_wscale) < 14) {
space >>= 1;
(*rcv_wscale)++;
* following RFC2414. Senders, not following this RFC,
* will be satisfied with 2.
*/
- if (mss > (1<<*rcv_wscale)) {
+ if (mss > (1 << *rcv_wscale)) {
int init_cwnd = 4;
- if (mss > 1460*3)
+ if (mss > 1460 * 3)
init_cwnd = 2;
else if (mss > 1460)
init_cwnd = 3;
- if (*rcv_wnd > init_cwnd*mss)
- *rcv_wnd = init_cwnd*mss;
+ if (*rcv_wnd > init_cwnd * mss)
+ *rcv_wnd = init_cwnd * mss;
}
/* Set the clamp no higher than max representable value */
* value can be stuffed directly into th->window for an outgoing
* frame.
*/
-static __inline__ u16 tcp_select_window(struct sock *sk)
+static u16 tcp_select_window(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
u32 cur_win = tcp_receive_window(tp);
u32 new_win = __tcp_select_window(sk);
/* Never shrink the offered window */
- if(new_win < cur_win) {
+ if (new_win < cur_win) {
/* Danger Will Robinson!
* Don't update rcv_wup/rcv_wnd here or else
* we will not be able to advertise a zero
/* Make sure we do not exceed the maximum possible
* scaled window.
*/
- if (!tp->rx_opt.rcv_wscale)
+ if (!tp->rx_opt.rcv_wscale && sysctl_tcp_workaround_signed_windows)
new_win = min(new_win, MAX_TCP_WINDOW);
else
new_win = min(new_win, (65535U << tp->rx_opt.rcv_wscale));
return new_win;
}
+static inline void TCP_ECN_send_synack(struct tcp_sock *tp, struct sk_buff *skb)
+{
+ TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_CWR;
+ if (!(tp->ecn_flags & TCP_ECN_OK))
+ TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_ECE;
+}
+
+static inline void TCP_ECN_send_syn(struct sock *sk, struct sk_buff *skb)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ tp->ecn_flags = 0;
+ if (sysctl_tcp_ecn) {
+ TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ECE | TCPCB_FLAG_CWR;
+ tp->ecn_flags = TCP_ECN_OK;
+ }
+}
+
+static __inline__ void
+TCP_ECN_make_synack(struct request_sock *req, struct tcphdr *th)
+{
+ if (inet_rsk(req)->ecn_ok)
+ th->ece = 1;
+}
+
+static inline void TCP_ECN_send(struct sock *sk, struct sk_buff *skb,
+ int tcp_header_len)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ if (tp->ecn_flags & TCP_ECN_OK) {
+ /* Not-retransmitted data segment: set ECT and inject CWR. */
+ if (skb->len != tcp_header_len &&
+ !before(TCP_SKB_CB(skb)->seq, tp->snd_nxt)) {
+ INET_ECN_xmit(sk);
+ if (tp->ecn_flags & TCP_ECN_QUEUE_CWR) {
+ tp->ecn_flags &= ~TCP_ECN_QUEUE_CWR;
+ tcp_hdr(skb)->cwr = 1;
+ skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
+ }
+ } else {
+ /* ACK or retransmitted segment: clear ECT|CE */
+ INET_ECN_dontxmit(sk);
+ }
+ if (tp->ecn_flags & TCP_ECN_DEMAND_CWR)
+ tcp_hdr(skb)->ece = 1;
+ }
+}
+
+/* Constructs common control bits of non-data skb. If SYN/FIN is present,
+ * auto increment end seqno.
+ */
+static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags)
+{
+ skb->csum = 0;
+
+ TCP_SKB_CB(skb)->flags = flags;
+ TCP_SKB_CB(skb)->sacked = 0;
+
+ skb_shinfo(skb)->gso_segs = 1;
+ skb_shinfo(skb)->gso_size = 0;
+ skb_shinfo(skb)->gso_type = 0;
+
+ TCP_SKB_CB(skb)->seq = seq;
+ if (flags & (TCPCB_FLAG_SYN | TCPCB_FLAG_FIN))
+ seq++;
+ TCP_SKB_CB(skb)->end_seq = seq;
+}
+
+static void tcp_build_and_update_options(__be32 *ptr, struct tcp_sock *tp,
+ __u32 tstamp, __u8 **md5_hash)
+{
+ if (tp->rx_opt.tstamp_ok) {
+ *ptr++ = htonl((TCPOPT_NOP << 24) |
+ (TCPOPT_NOP << 16) |
+ (TCPOPT_TIMESTAMP << 8) |
+ TCPOLEN_TIMESTAMP);
+ *ptr++ = htonl(tstamp);
+ *ptr++ = htonl(tp->rx_opt.ts_recent);
+ }
+ if (tp->rx_opt.eff_sacks) {
+ struct tcp_sack_block *sp = tp->rx_opt.dsack ? tp->duplicate_sack : tp->selective_acks;
+ int this_sack;
+
+ *ptr++ = htonl((TCPOPT_NOP << 24) |
+ (TCPOPT_NOP << 16) |
+ (TCPOPT_SACK << 8) |
+ (TCPOLEN_SACK_BASE + (tp->rx_opt.eff_sacks *
+ TCPOLEN_SACK_PERBLOCK)));
+
+ for (this_sack = 0; this_sack < tp->rx_opt.eff_sacks; this_sack++) {
+ *ptr++ = htonl(sp[this_sack].start_seq);
+ *ptr++ = htonl(sp[this_sack].end_seq);
+ }
+
+ if (tp->rx_opt.dsack) {
+ tp->rx_opt.dsack = 0;
+ tp->rx_opt.eff_sacks--;
+ }
+ }
+#ifdef CONFIG_TCP_MD5SIG
+ if (md5_hash) {
+ *ptr++ = htonl((TCPOPT_NOP << 24) |
+ (TCPOPT_NOP << 16) |
+ (TCPOPT_MD5SIG << 8) |
+ TCPOLEN_MD5SIG);
+ *md5_hash = (__u8 *)ptr;
+ }
+#endif
+}
+
+/* Construct a tcp options header for a SYN or SYN_ACK packet.
+ * If this is every changed make sure to change the definition of
+ * MAX_SYN_SIZE to match the new maximum number of options that you
+ * can generate.
+ *
+ * Note - that with the RFC2385 TCP option, we make room for the
+ * 16 byte MD5 hash. This will be filled in later, so the pointer for the
+ * location to be filled is passed back up.
+ */
+static void tcp_syn_build_options(__be32 *ptr, int mss, int ts, int sack,
+ int offer_wscale, int wscale, __u32 tstamp,
+ __u32 ts_recent, __u8 **md5_hash)
+{
+ /* We always get an MSS option.
+ * The option bytes which will be seen in normal data
+ * packets should timestamps be used, must be in the MSS
+ * advertised. But we subtract them from tp->mss_cache so
+ * that calculations in tcp_sendmsg are simpler etc.
+ * So account for this fact here if necessary. If we
+ * don't do this correctly, as a receiver we won't
+ * recognize data packets as being full sized when we
+ * should, and thus we won't abide by the delayed ACK
+ * rules correctly.
+ * SACKs don't matter, we never delay an ACK when we
+ * have any of those going out.
+ */
+ *ptr++ = htonl((TCPOPT_MSS << 24) | (TCPOLEN_MSS << 16) | mss);
+ if (ts) {
+ if (sack)
+ *ptr++ = htonl((TCPOPT_SACK_PERM << 24) |
+ (TCPOLEN_SACK_PERM << 16) |
+ (TCPOPT_TIMESTAMP << 8) |
+ TCPOLEN_TIMESTAMP);
+ else
+ *ptr++ = htonl((TCPOPT_NOP << 24) |
+ (TCPOPT_NOP << 16) |
+ (TCPOPT_TIMESTAMP << 8) |
+ TCPOLEN_TIMESTAMP);
+ *ptr++ = htonl(tstamp); /* TSVAL */
+ *ptr++ = htonl(ts_recent); /* TSECR */
+ } else if (sack)
+ *ptr++ = htonl((TCPOPT_NOP << 24) |
+ (TCPOPT_NOP << 16) |
+ (TCPOPT_SACK_PERM << 8) |
+ TCPOLEN_SACK_PERM);
+ if (offer_wscale)
+ *ptr++ = htonl((TCPOPT_NOP << 24) |
+ (TCPOPT_WINDOW << 16) |
+ (TCPOLEN_WINDOW << 8) |
+ (wscale));
+#ifdef CONFIG_TCP_MD5SIG
+ /*
+ * If MD5 is enabled, then we set the option, and include the size
+ * (always 18). The actual MD5 hash is added just before the
+ * packet is sent.
+ */
+ if (md5_hash) {
+ *ptr++ = htonl((TCPOPT_NOP << 24) |
+ (TCPOPT_NOP << 16) |
+ (TCPOPT_MD5SIG << 8) |
+ TCPOLEN_MD5SIG);
+ *md5_hash = (__u8 *)ptr;
+ }
+#endif
+}
/* This routine actually transmits TCP packets queued in by
* tcp_do_sendmsg(). This is used by both the initial
* We are working here with either a clone of the original
* SKB, or a fresh unique copy made by the retransmit engine.
*/
-static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb)
+static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
+ gfp_t gfp_mask)
{
- if (skb != NULL) {
- const struct inet_connection_sock *icsk = inet_csk(sk);
- struct inet_sock *inet = inet_sk(sk);
- struct tcp_sock *tp = tcp_sk(sk);
- struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
- int tcp_header_size = tp->tcp_header_len;
- struct tcphdr *th;
- int sysctl_flags;
- int err;
+ const struct inet_connection_sock *icsk = inet_csk(sk);
+ struct inet_sock *inet;
+ struct tcp_sock *tp;
+ struct tcp_skb_cb *tcb;
+ int tcp_header_size;
+#ifdef CONFIG_TCP_MD5SIG
+ struct tcp_md5sig_key *md5;
+ __u8 *md5_hash_location;
+#endif
+ struct tcphdr *th;
+ int sysctl_flags;
+ int err;
+
+ BUG_ON(!skb || !tcp_skb_pcount(skb));
+
+ /* If congestion control is doing timestamping, we must
+ * take such a timestamp before we potentially clone/copy.
+ */
+ if (icsk->icsk_ca_ops->flags & TCP_CONG_RTT_STAMP)
+ __net_timestamp(skb);
+
+ if (likely(clone_it)) {
+ if (unlikely(skb_cloned(skb)))
+ skb = pskb_copy(skb, gfp_mask);
+ else
+ skb = skb_clone(skb, gfp_mask);
+ if (unlikely(!skb))
+ return -ENOBUFS;
+ }
- BUG_ON(!tcp_skb_pcount(skb));
+ inet = inet_sk(sk);
+ tp = tcp_sk(sk);
+ tcb = TCP_SKB_CB(skb);
+ tcp_header_size = tp->tcp_header_len;
#define SYSCTL_FLAG_TSTAMPS 0x1
#define SYSCTL_FLAG_WSCALE 0x2
#define SYSCTL_FLAG_SACK 0x4
- /* If congestion control is doing timestamping */
- if (icsk->icsk_ca_ops->rtt_sample)
- __net_timestamp(skb);
-
- sysctl_flags = 0;
- if (tcb->flags & TCPCB_FLAG_SYN) {
- tcp_header_size = sizeof(struct tcphdr) + TCPOLEN_MSS;
- if(sysctl_tcp_timestamps) {
- tcp_header_size += TCPOLEN_TSTAMP_ALIGNED;
- sysctl_flags |= SYSCTL_FLAG_TSTAMPS;
- }
- if(sysctl_tcp_window_scaling) {
- tcp_header_size += TCPOLEN_WSCALE_ALIGNED;
- sysctl_flags |= SYSCTL_FLAG_WSCALE;
- }
- if(sysctl_tcp_sack) {
- sysctl_flags |= SYSCTL_FLAG_SACK;
- if(!(sysctl_flags & SYSCTL_FLAG_TSTAMPS))
- tcp_header_size += TCPOLEN_SACKPERM_ALIGNED;
- }
- } else if (tp->rx_opt.eff_sacks) {
- /* A SACK is 2 pad bytes, a 2 byte header, plus
- * 2 32-bit sequence numbers for each SACK block.
- */
- tcp_header_size += (TCPOLEN_SACK_BASE_ALIGNED +
- (tp->rx_opt.eff_sacks * TCPOLEN_SACK_PERBLOCK));
+ sysctl_flags = 0;
+ if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) {
+ tcp_header_size = sizeof(struct tcphdr) + TCPOLEN_MSS;
+ if (sysctl_tcp_timestamps) {
+ tcp_header_size += TCPOLEN_TSTAMP_ALIGNED;
+ sysctl_flags |= SYSCTL_FLAG_TSTAMPS;
}
-
- if (tcp_packets_in_flight(tp) == 0)
- tcp_ca_event(sk, CA_EVENT_TX_START);
-
- th = (struct tcphdr *) skb_push(skb, tcp_header_size);
- skb->h.th = th;
- skb_set_owner_w(skb, sk);
-
- /* Build TCP header and checksum it. */
- th->source = inet->sport;
- th->dest = inet->dport;
- th->seq = htonl(tcb->seq);
- th->ack_seq = htonl(tp->rcv_nxt);
- *(((__u16 *)th) + 6) = htons(((tcp_header_size >> 2) << 12) | tcb->flags);
- if (tcb->flags & TCPCB_FLAG_SYN) {
- /* RFC1323: The window in SYN & SYN/ACK segments
- * is never scaled.
- */
- th->window = htons(tp->rcv_wnd);
- } else {
- th->window = htons(tcp_select_window(sk));
+ if (sysctl_tcp_window_scaling) {
+ tcp_header_size += TCPOLEN_WSCALE_ALIGNED;
+ sysctl_flags |= SYSCTL_FLAG_WSCALE;
}
- th->check = 0;
- th->urg_ptr = 0;
-
- if (tp->urg_mode &&
- between(tp->snd_up, tcb->seq+1, tcb->seq+0xFFFF)) {
- th->urg_ptr = htons(tp->snd_up-tcb->seq);
- th->urg = 1;
+ if (sysctl_tcp_sack) {
+ sysctl_flags |= SYSCTL_FLAG_SACK;
+ if (!(sysctl_flags & SYSCTL_FLAG_TSTAMPS))
+ tcp_header_size += TCPOLEN_SACKPERM_ALIGNED;
}
+ } else if (unlikely(tp->rx_opt.eff_sacks)) {
+ /* A SACK is 2 pad bytes, a 2 byte header, plus
+ * 2 32-bit sequence numbers for each SACK block.
+ */
+ tcp_header_size += (TCPOLEN_SACK_BASE_ALIGNED +
+ (tp->rx_opt.eff_sacks *
+ TCPOLEN_SACK_PERBLOCK));
+ }
- if (tcb->flags & TCPCB_FLAG_SYN) {
- tcp_syn_build_options((__u32 *)(th + 1),
- tcp_advertise_mss(sk),
- (sysctl_flags & SYSCTL_FLAG_TSTAMPS),
- (sysctl_flags & SYSCTL_FLAG_SACK),
- (sysctl_flags & SYSCTL_FLAG_WSCALE),
- tp->rx_opt.rcv_wscale,
- tcb->when,
- tp->rx_opt.ts_recent);
- } else {
- tcp_build_and_update_options((__u32 *)(th + 1),
- tp, tcb->when);
+ if (tcp_packets_in_flight(tp) == 0)
+ tcp_ca_event(sk, CA_EVENT_TX_START);
- TCP_ECN_send(sk, tp, skb, tcp_header_size);
- }
- tp->af_specific->send_check(sk, th, skb->len, skb);
+#ifdef CONFIG_TCP_MD5SIG
+ /*
+ * Are we doing MD5 on this segment? If so - make
+ * room for it.
+ */
+ md5 = tp->af_specific->md5_lookup(sk, sk);
+ if (md5)
+ tcp_header_size += TCPOLEN_MD5SIG_ALIGNED;
+#endif
+
+ skb_push(skb, tcp_header_size);
+ skb_reset_transport_header(skb);
+ skb_set_owner_w(skb, sk);
+
+ /* Build TCP header and checksum it. */
+ th = tcp_hdr(skb);
+ th->source = inet->sport;
+ th->dest = inet->dport;
+ th->seq = htonl(tcb->seq);
+ th->ack_seq = htonl(tp->rcv_nxt);
+ *(((__be16 *)th) + 6) = htons(((tcp_header_size >> 2) << 12) |
+ tcb->flags);
+
+ if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) {
+ /* RFC1323: The window in SYN & SYN/ACK segments
+ * is never scaled.
+ */
+ th->window = htons(min(tp->rcv_wnd, 65535U));
+ } else {
+ th->window = htons(tcp_select_window(sk));
+ }
+ th->check = 0;
+ th->urg_ptr = 0;
+
+ if (unlikely(tp->urg_mode &&
+ between(tp->snd_up, tcb->seq + 1, tcb->seq + 0xFFFF))) {
+ th->urg_ptr = htons(tp->snd_up - tcb->seq);
+ th->urg = 1;
+ }
+
+ if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) {
+ tcp_syn_build_options((__be32 *)(th + 1),
+ tcp_advertise_mss(sk),
+ (sysctl_flags & SYSCTL_FLAG_TSTAMPS),
+ (sysctl_flags & SYSCTL_FLAG_SACK),
+ (sysctl_flags & SYSCTL_FLAG_WSCALE),
+ tp->rx_opt.rcv_wscale,
+ tcb->when,
+ tp->rx_opt.ts_recent,
+
+#ifdef CONFIG_TCP_MD5SIG
+ md5 ? &md5_hash_location :
+#endif
+ NULL);
+ } else {
+ tcp_build_and_update_options((__be32 *)(th + 1),
+ tp, tcb->when,
+#ifdef CONFIG_TCP_MD5SIG
+ md5 ? &md5_hash_location :
+#endif
+ NULL);
+ TCP_ECN_send(sk, skb, tcp_header_size);
+ }
+
+#ifdef CONFIG_TCP_MD5SIG
+ /* Calculate the MD5 hash, as we have all we need now */
+ if (md5) {
+ tp->af_specific->calc_md5_hash(md5_hash_location,
+ md5,
+ sk, NULL, NULL,
+ tcp_hdr(skb),
+ sk->sk_protocol,
+ skb->len);
+ }
+#endif
+
+ icsk->icsk_af_ops->send_check(sk, skb->len, skb);
- if (tcb->flags & TCPCB_FLAG_ACK)
- tcp_event_ack_sent(sk, tcp_skb_pcount(skb));
+ if (likely(tcb->flags & TCPCB_FLAG_ACK))
+ tcp_event_ack_sent(sk, tcp_skb_pcount(skb));
- if (skb->len != tcp_header_size)
- tcp_event_data_sent(tp, skb, sk);
+ if (skb->len != tcp_header_size)
+ tcp_event_data_sent(tp, skb, sk);
+ if (after(tcb->end_seq, tp->snd_nxt) || tcb->seq == tcb->end_seq)
TCP_INC_STATS(TCP_MIB_OUTSEGS);
- err = tp->af_specific->queue_xmit(skb, 0);
- if (err <= 0)
- return err;
+ err = icsk->icsk_af_ops->queue_xmit(skb, 0);
+ if (likely(err <= 0))
+ return err;
- tcp_enter_cwr(sk);
+ tcp_enter_cwr(sk, 1);
+
+ return net_xmit_eval(err);
- /* NET_XMIT_CN is special. It does not guarantee,
- * that this packet is lost. It tells that device
- * is about to start to drop packets or already
- * drops some packets of the same priority and
- * invokes us to send less aggressively.
- */
- return err == NET_XMIT_CN ? 0 : err;
- }
- return -ENOBUFS;
#undef SYSCTL_FLAG_TSTAMPS
#undef SYSCTL_FLAG_WSCALE
#undef SYSCTL_FLAG_SACK
}
-
-/* This routine just queue's the buffer
+/* This routine just queue's the buffer
*
* NOTE: probe0 timer is not checked, do not forget tcp_push_pending_frames,
* otherwise socket can stall.
/* Advance write_seq and place onto the write_queue. */
tp->write_seq = TCP_SKB_CB(skb)->end_seq;
skb_header_release(skb);
- __skb_queue_tail(&sk->sk_write_queue, skb);
- sk_charge_skb(sk, skb);
-
- /* Queue it, remembering where we must start sending. */
- if (sk->sk_send_head == NULL)
- sk->sk_send_head = skb;
+ tcp_add_write_queue_tail(sk, skb);
+ sk->sk_wmem_queued += skb->truesize;
+ sk_mem_charge(sk, skb->truesize);
}
-static void tcp_set_skb_tso_segs(struct sock *sk, struct sk_buff *skb, unsigned int mss_now)
+static void tcp_set_skb_tso_segs(struct sock *sk, struct sk_buff *skb,
+ unsigned int mss_now)
{
- if (skb->len <= mss_now ||
- !(sk->sk_route_caps & NETIF_F_TSO)) {
+ if (skb->len <= mss_now || !sk_can_gso(sk)) {
/* Avoid the costly divide in the normal
* non-TSO case.
*/
- skb_shinfo(skb)->tso_segs = 1;
- skb_shinfo(skb)->tso_size = 0;
+ skb_shinfo(skb)->gso_segs = 1;
+ skb_shinfo(skb)->gso_size = 0;
+ skb_shinfo(skb)->gso_type = 0;
} else {
- unsigned int factor;
-
- factor = skb->len + (mss_now - 1);
- factor /= mss_now;
- skb_shinfo(skb)->tso_segs = factor;
- skb_shinfo(skb)->tso_size = mss_now;
+ skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss_now);
+ skb_shinfo(skb)->gso_size = mss_now;
+ skb_shinfo(skb)->gso_type = sk->sk_gso_type;
}
}
+/* When a modification to fackets out becomes necessary, we need to check
+ * skb is counted to fackets_out or not.
+ */
+static void tcp_adjust_fackets_out(struct sock *sk, struct sk_buff *skb,
+ int decr)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ if (!tp->sacked_out || tcp_is_reno(tp))
+ return;
+
+ if (after(tcp_highest_sack_seq(tp), TCP_SKB_CB(skb)->seq))
+ tp->fackets_out -= decr;
+}
+
/* Function to create two new TCP segments. Shrinks the given segment
* to the specified size and appends a new segment with the rest of the
- * packet to the list. This won't be called frequently, I hope.
+ * packet to the list. This won't be called frequently, I hope.
* Remember, these are still headerless SKBs at this point.
*/
-int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss_now)
+int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len,
+ unsigned int mss_now)
{
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *buff;
int nsize, old_factor;
+ int nlen;
u16 flags;
BUG_ON(len > skb->len);
+
+ tcp_clear_retrans_hints_partial(tp);
nsize = skb_headlen(skb) - len;
if (nsize < 0)
nsize = 0;
buff = sk_stream_alloc_skb(sk, nsize, GFP_ATOMIC);
if (buff == NULL)
return -ENOMEM; /* We'll just try again later. */
- sk_charge_skb(sk, buff);
+
+ sk->sk_wmem_queued += buff->truesize;
+ sk_mem_charge(sk, buff->truesize);
+ nlen = skb->len - len - nsize;
+ buff->truesize += nlen;
+ skb->truesize -= nlen;
/* Correct the sequence numbers. */
TCP_SKB_CB(buff)->seq = TCP_SKB_CB(skb)->seq + len;
/* PSH and FIN should only be set in the second packet. */
flags = TCP_SKB_CB(skb)->flags;
- TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN|TCPCB_FLAG_PSH);
+ TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN | TCPCB_FLAG_PSH);
TCP_SKB_CB(buff)->flags = flags;
TCP_SKB_CB(buff)->sacked = TCP_SKB_CB(skb)->sacked;
- TCP_SKB_CB(skb)->sacked &= ~TCPCB_AT_TAIL;
- if (!skb_shinfo(skb)->nr_frags && skb->ip_summed != CHECKSUM_HW) {
+ if (!skb_shinfo(skb)->nr_frags && skb->ip_summed != CHECKSUM_PARTIAL) {
/* Copy and checksum data tail into the new buffer. */
- buff->csum = csum_partial_copy_nocheck(skb->data + len, skb_put(buff, nsize),
+ buff->csum = csum_partial_copy_nocheck(skb->data + len,
+ skb_put(buff, nsize),
nsize, 0);
skb_trim(skb, len);
skb->csum = csum_block_sub(skb->csum, buff->csum, len);
} else {
- skb->ip_summed = CHECKSUM_HW;
+ skb->ip_summed = CHECKSUM_PARTIAL;
skb_split(skb, buff, len);
}
if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)
tp->retrans_out -= diff;
- if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST) {
+ if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST)
tp->lost_out -= diff;
- tp->left_out -= diff;
- }
- if (diff > 0) {
- /* Adjust Reno SACK estimate. */
- if (!tp->rx_opt.sack_ok) {
- tp->sacked_out -= diff;
- if ((int)tp->sacked_out < 0)
- tp->sacked_out = 0;
- tcp_sync_left_out(tp);
- }
-
- tp->fackets_out -= diff;
- if ((int)tp->fackets_out < 0)
- tp->fackets_out = 0;
+ /* Adjust Reno SACK estimate. */
+ if (tcp_is_reno(tp) && diff > 0) {
+ tcp_dec_pcount_approx_int(&tp->sacked_out, diff);
+ tcp_verify_left_out(tp);
}
+ tcp_adjust_fackets_out(sk, skb, diff);
}
/* Link BUFF into the send queue. */
skb_header_release(buff);
- __skb_append(skb, buff, &sk->sk_write_queue);
+ tcp_insert_write_queue_after(skb, buff, sk);
return 0;
}
* eventually). The difference is that pulled data not copied, but
* immediately discarded.
*/
-static unsigned char *__pskb_trim_head(struct sk_buff *skb, int len)
+static void __pskb_trim_head(struct sk_buff *skb, int len)
{
int i, k, eat;
eat = len;
k = 0;
- for (i=0; i<skb_shinfo(skb)->nr_frags; i++) {
+ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
if (skb_shinfo(skb)->frags[i].size <= eat) {
put_page(skb_shinfo(skb)->frags[i].page);
eat -= skb_shinfo(skb)->frags[i].size;
}
skb_shinfo(skb)->nr_frags = k;
- skb->tail = skb->data;
+ skb_reset_tail_pointer(skb);
skb->data_len -= len;
skb->len = skb->data_len;
- return skb->tail;
}
int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
{
- if (skb_cloned(skb) &&
- pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+ if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
return -ENOMEM;
- if (len <= skb_headlen(skb)) {
+ /* If len == headlen, we avoid __skb_pull to preserve alignment. */
+ if (unlikely(len < skb_headlen(skb)))
__skb_pull(skb, len);
- } else {
- if (__pskb_trim_head(skb, len-skb_headlen(skb)) == NULL)
- return -ENOMEM;
- }
+ else
+ __pskb_trim_head(skb, len - skb_headlen(skb));
TCP_SKB_CB(skb)->seq += len;
- skb->ip_summed = CHECKSUM_HW;
+ skb->ip_summed = CHECKSUM_PARTIAL;
skb->truesize -= len;
sk->sk_wmem_queued -= len;
- sk->sk_forward_alloc += len;
+ sk_mem_uncharge(sk, len);
sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
/* Any change of skb->len requires recalculation of tso
return 0;
}
+/* Not accounting for SACKs here. */
+int tcp_mtu_to_mss(struct sock *sk, int pmtu)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct inet_connection_sock *icsk = inet_csk(sk);
+ int mss_now;
+
+ /* Calculate base mss without TCP options:
+ It is MMS_S - sizeof(tcphdr) of rfc1122
+ */
+ mss_now = pmtu - icsk->icsk_af_ops->net_header_len - sizeof(struct tcphdr);
+
+ /* Clamp it (mss_clamp does not include tcp options) */
+ if (mss_now > tp->rx_opt.mss_clamp)
+ mss_now = tp->rx_opt.mss_clamp;
+
+ /* Now subtract optional transport overhead */
+ mss_now -= icsk->icsk_ext_hdr_len;
+
+ /* Then reserve room for full set of TCP options and 8 bytes of data */
+ if (mss_now < 48)
+ mss_now = 48;
+
+ /* Now subtract TCP options size, not including SACKs */
+ mss_now -= tp->tcp_header_len - sizeof(struct tcphdr);
+
+ return mss_now;
+}
+
+/* Inverse of above */
+int tcp_mss_to_mtu(struct sock *sk, int mss)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct inet_connection_sock *icsk = inet_csk(sk);
+ int mtu;
+
+ mtu = mss +
+ tp->tcp_header_len +
+ icsk->icsk_ext_hdr_len +
+ icsk->icsk_af_ops->net_header_len;
+
+ return mtu;
+}
+
+void tcp_mtup_init(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct inet_connection_sock *icsk = inet_csk(sk);
+
+ icsk->icsk_mtup.enabled = sysctl_tcp_mtu_probing > 1;
+ icsk->icsk_mtup.search_high = tp->rx_opt.mss_clamp + sizeof(struct tcphdr) +
+ icsk->icsk_af_ops->net_header_len;
+ icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, sysctl_tcp_base_mss);
+ icsk->icsk_mtup.probe_size = 0;
+}
+
+/* Bound MSS / TSO packet size with the half of the window */
+static int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize)
+{
+ if (tp->max_window && pktsize > (tp->max_window >> 1))
+ return max(tp->max_window >> 1, 68U - tp->tcp_header_len);
+ else
+ return pktsize;
+}
+
/* This function synchronize snd mss to current pmtu/exthdr set.
tp->rx_opt.user_mss is mss set by user by TCP_MAXSEG. It does NOT counts
for TCP options, but includes only bare TCP header.
tp->rx_opt.mss_clamp is mss negotiated at connection setup.
- It is minumum of user_mss and mss received with SYN.
+ It is minimum of user_mss and mss received with SYN.
It also does not include TCP options.
- tp->pmtu_cookie is last pmtu, seen by this function.
+ inet_csk(sk)->icsk_pmtu_cookie is last pmtu, seen by this function.
tp->mss_cache is current effective sending mss, including
all tcp options except for SACKs. It is evaluated,
NOTE1. rfc1122 clearly states that advertised MSS
DOES NOT include either tcp or ip options.
- NOTE2. tp->pmtu_cookie and tp->mss_cache are READ ONLY outside
- this function. --ANK (980731)
+ NOTE2. inet_csk(sk)->icsk_pmtu_cookie and tp->mss_cache
+ are READ ONLY outside this function. --ANK (980731)
*/
-
unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu)
{
struct tcp_sock *tp = tcp_sk(sk);
+ struct inet_connection_sock *icsk = inet_csk(sk);
int mss_now;
- /* Calculate base mss without TCP options:
- It is MMS_S - sizeof(tcphdr) of rfc1122
- */
- mss_now = pmtu - tp->af_specific->net_header_len - sizeof(struct tcphdr);
-
- /* Clamp it (mss_clamp does not include tcp options) */
- if (mss_now > tp->rx_opt.mss_clamp)
- mss_now = tp->rx_opt.mss_clamp;
-
- /* Now subtract optional transport overhead */
- mss_now -= tp->ext_header_len;
-
- /* Then reserve room for full set of TCP options and 8 bytes of data */
- if (mss_now < 48)
- mss_now = 48;
-
- /* Now subtract TCP options size, not including SACKs */
- mss_now -= tp->tcp_header_len - sizeof(struct tcphdr);
+ if (icsk->icsk_mtup.search_high > pmtu)
+ icsk->icsk_mtup.search_high = pmtu;
- /* Bound mss with half of window */
- if (tp->max_window && mss_now > (tp->max_window>>1))
- mss_now = max((tp->max_window>>1), 68U - tp->tcp_header_len);
+ mss_now = tcp_mtu_to_mss(sk, pmtu);
+ mss_now = tcp_bound_to_half_wnd(tp, mss_now);
/* And store cached results */
- tp->pmtu_cookie = pmtu;
+ icsk->icsk_pmtu_cookie = pmtu;
+ if (icsk->icsk_mtup.enabled)
+ mss_now = min(mss_now, tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low));
tp->mss_cache = mss_now;
return mss_now;
mss_now = tp->mss_cache;
- if (large_allowed &&
- (sk->sk_route_caps & NETIF_F_TSO) &&
- !tp->urg_mode)
+ if (large_allowed && sk_can_gso(sk) && !tp->urg_mode)
doing_tso = 1;
if (dst) {
u32 mtu = dst_mtu(dst);
- if (mtu != tp->pmtu_cookie)
+ if (mtu != inet_csk(sk)->icsk_pmtu_cookie)
mss_now = tcp_sync_mss(sk, mtu);
}
mss_now -= (TCPOLEN_SACK_BASE_ALIGNED +
(tp->rx_opt.eff_sacks * TCPOLEN_SACK_PERBLOCK));
+#ifdef CONFIG_TCP_MD5SIG
+ if (tp->af_specific->md5_lookup(sk, sk))
+ mss_now -= TCPOLEN_MD5SIG_ALIGNED;
+#endif
+
xmit_size_goal = mss_now;
if (doing_tso) {
- xmit_size_goal = 65535 -
- tp->af_specific->net_header_len -
- tp->ext_header_len - tp->tcp_header_len;
-
- if (tp->max_window &&
- (xmit_size_goal > (tp->max_window >> 1)))
- xmit_size_goal = max((tp->max_window >> 1),
- 68U - tp->tcp_header_len);
+ xmit_size_goal = (65535 -
+ inet_csk(sk)->icsk_af_ops->net_header_len -
+ inet_csk(sk)->icsk_ext_hdr_len -
+ tp->tcp_header_len);
+ xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal);
xmit_size_goal -= (xmit_size_goal % mss_now);
}
tp->xmit_size_goal = xmit_size_goal;
}
/* Congestion window validation. (RFC2861) */
-
-static inline void tcp_cwnd_validate(struct sock *sk, struct tcp_sock *tp)
+static void tcp_cwnd_validate(struct sock *sk)
{
- __u32 packets_out = tp->packets_out;
+ struct tcp_sock *tp = tcp_sk(sk);
- if (packets_out >= tp->snd_cwnd) {
+ if (tp->packets_out >= tp->snd_cwnd) {
/* Network is feed fully. */
tp->snd_cwnd_used = 0;
tp->snd_cwnd_stamp = tcp_time_stamp;
if (tp->packets_out > tp->snd_cwnd_used)
tp->snd_cwnd_used = tp->packets_out;
- if ((s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= inet_csk(sk)->icsk_rto)
+ if (sysctl_tcp_slow_start_after_idle &&
+ (s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= inet_csk(sk)->icsk_rto)
tcp_cwnd_application_limited(sk);
}
}
-static unsigned int tcp_window_allows(struct tcp_sock *tp, struct sk_buff *skb, unsigned int mss_now, unsigned int cwnd)
+/* Returns the portion of skb which can be sent right away without
+ * introducing MSS oddities to segment boundaries. In rare cases where
+ * mss_now != mss_cache, we will request caller to create a small skb
+ * per input skb which could be mostly avoided here (if desired).
+ */
+static unsigned int tcp_mss_split_point(struct sock *sk, struct sk_buff *skb,
+ unsigned int mss_now, unsigned int cwnd)
{
- u32 window, cwnd_len;
+ struct tcp_sock *tp = tcp_sk(sk);
+ u32 needed, window, cwnd_len;
- window = (tp->snd_una + tp->snd_wnd - TCP_SKB_CB(skb)->seq);
+ window = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq;
cwnd_len = mss_now * cwnd;
- return min(window, cwnd_len);
+
+ if (likely(cwnd_len <= window && skb != tcp_write_queue_tail(sk)))
+ return cwnd_len;
+
+ if (skb == tcp_write_queue_tail(sk) && cwnd_len <= skb->len)
+ return cwnd_len;
+
+ needed = min(skb->len, window);
+ return needed - needed % mss_now;
}
/* Can at least one segment of SKB be sent right now, according to the
* congestion window rules? If so, return how many segments are allowed.
*/
-static inline unsigned int tcp_cwnd_test(struct tcp_sock *tp, struct sk_buff *skb)
+static inline unsigned int tcp_cwnd_test(struct tcp_sock *tp,
+ struct sk_buff *skb)
{
u32 in_flight, cwnd;
/* Don't be strict about the congestion window for the final FIN. */
- if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)
+ if ((TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) &&
+ tcp_skb_pcount(skb) == 1)
return 1;
in_flight = tcp_packets_in_flight(tp);
/* This must be invoked the first time we consider transmitting
* SKB onto the wire.
*/
-static inline int tcp_init_tso_segs(struct sock *sk, struct sk_buff *skb, unsigned int mss_now)
+static int tcp_init_tso_segs(struct sock *sk, struct sk_buff *skb,
+ unsigned int mss_now)
{
int tso_segs = tcp_skb_pcount(skb);
- if (!tso_segs ||
- (tso_segs > 1 &&
- skb_shinfo(skb)->tso_size != mss_now)) {
+ if (!tso_segs || (tso_segs > 1 && tcp_skb_mss(skb) != mss_now)) {
tcp_set_skb_tso_segs(sk, skb, mss_now);
tso_segs = tcp_skb_pcount(skb);
}
* 4. Or TCP_CORK is not set, and all sent packets are ACKed.
* With Minshall's modification: all sent small packets are ACKed.
*/
-
static inline int tcp_nagle_check(const struct tcp_sock *tp,
- const struct sk_buff *skb,
+ const struct sk_buff *skb,
unsigned mss_now, int nonagle)
{
return (skb->len < mss_now &&
- ((nonagle&TCP_NAGLE_CORK) ||
- (!nonagle &&
- tp->packets_out &&
- tcp_minshall_check(tp))));
+ ((nonagle & TCP_NAGLE_CORK) ||
+ (!nonagle && tp->packets_out && tcp_minshall_check(tp))));
}
/* Return non-zero if the Nagle test allows this packet to be
if (nonagle & TCP_NAGLE_PUSH)
return 1;
- /* Don't use the nagle rule for urgent data (or for the final FIN). */
- if (tp->urg_mode ||
+ /* 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) ||
(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN))
return 1;
}
/* Does at least the first segment of SKB fit into the send window? */
-static inline int tcp_snd_wnd_test(struct tcp_sock *tp, struct sk_buff *skb, unsigned int cur_mss)
+static inline int tcp_snd_wnd_test(struct tcp_sock *tp, struct sk_buff *skb,
+ unsigned int cur_mss)
{
u32 end_seq = TCP_SKB_CB(skb)->end_seq;
if (skb->len > cur_mss)
end_seq = TCP_SKB_CB(skb)->seq + cur_mss;
- return !after(end_seq, tp->snd_una + tp->snd_wnd);
+ return !after(end_seq, tcp_wnd_end(tp));
}
-/* This checks if the data bearing packet SKB (usually sk->sk_send_head)
+/* This checks if the data bearing packet SKB (usually tcp_send_head(sk))
* should be put on the wire right now. If so, it returns the number of
* packets allowed by the congestion window.
*/
return 0;
cwnd_quota = tcp_cwnd_test(tp, skb);
- if (cwnd_quota &&
- !tcp_snd_wnd_test(tp, skb, cur_mss))
+ if (cwnd_quota && !tcp_snd_wnd_test(tp, skb, cur_mss))
cwnd_quota = 0;
return cwnd_quota;
}
-static inline int tcp_skb_is_last(const struct sock *sk,
- const struct sk_buff *skb)
-{
- return skb->next == (struct sk_buff *)&sk->sk_write_queue;
-}
-
-int tcp_may_send_now(struct sock *sk, struct tcp_sock *tp)
+int tcp_may_send_now(struct sock *sk)
{
- struct sk_buff *skb = sk->sk_send_head;
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct sk_buff *skb = tcp_send_head(sk);
return (skb &&
tcp_snd_test(sk, skb, tcp_current_mss(sk, 1),
(tcp_skb_is_last(sk, skb) ?
- TCP_NAGLE_PUSH :
- tp->nonagle)));
+ tp->nonagle : TCP_NAGLE_PUSH)));
}
/* Trim TSO SKB to LEN bytes, put the remaining data into a new packet
* know that all the data is in scatter-gather pages, and that the
* packet has never been sent out before (and thus is not cloned).
*/
-static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len, unsigned int mss_now)
+static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
+ unsigned int mss_now)
{
struct sk_buff *buff;
int nlen = skb->len - len;
if (skb->len != skb->data_len)
return tcp_fragment(sk, skb, len, mss_now);
- buff = sk_stream_alloc_pskb(sk, 0, 0, GFP_ATOMIC);
+ buff = sk_stream_alloc_skb(sk, 0, GFP_ATOMIC);
if (unlikely(buff == NULL))
return -ENOMEM;
- buff->truesize = nlen;
+ sk->sk_wmem_queued += buff->truesize;
+ sk_mem_charge(sk, buff->truesize);
+ buff->truesize += nlen;
skb->truesize -= nlen;
/* Correct the sequence numbers. */
/* PSH and FIN should only be set in the second packet. */
flags = TCP_SKB_CB(skb)->flags;
- TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN|TCPCB_FLAG_PSH);
+ TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN | TCPCB_FLAG_PSH);
TCP_SKB_CB(buff)->flags = flags;
/* This packet was never sent out yet, so no SACK bits. */
TCP_SKB_CB(buff)->sacked = 0;
- buff->ip_summed = skb->ip_summed = CHECKSUM_HW;
+ buff->ip_summed = skb->ip_summed = CHECKSUM_PARTIAL;
skb_split(skb, buff, len);
/* Fix up tso_factor for both original and new SKB. */
/* Link BUFF into the send queue. */
skb_header_release(buff);
- __skb_append(skb, buff, &sk->sk_write_queue);
+ tcp_insert_write_queue_after(skb, buff, sk);
return 0;
}
*
* This algorithm is from John Heffner.
*/
-static int tcp_tso_should_defer(struct sock *sk, struct tcp_sock *tp, struct sk_buff *skb)
+static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
{
+ struct tcp_sock *tp = tcp_sk(sk);
const struct inet_connection_sock *icsk = inet_csk(sk);
u32 send_win, cong_win, limit, in_flight;
if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)
- return 0;
+ goto send_now;
if (icsk->icsk_ca_state != TCP_CA_Open)
- return 0;
+ goto send_now;
+
+ /* Defer for less than two clock ticks. */
+ if (tp->tso_deferred &&
+ ((jiffies << 1) >> 1) - (tp->tso_deferred >> 1) > 1)
+ goto send_now;
in_flight = tcp_packets_in_flight(tp);
- BUG_ON(tcp_skb_pcount(skb) <= 1 ||
- (tp->snd_cwnd <= in_flight));
+ BUG_ON(tcp_skb_pcount(skb) <= 1 || (tp->snd_cwnd <= in_flight));
- send_win = (tp->snd_una + tp->snd_wnd) - TCP_SKB_CB(skb)->seq;
+ send_win = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq;
/* From in_flight test above, we know that cwnd > in_flight. */
cong_win = (tp->snd_cwnd - in_flight) * tp->mss_cache;
limit = min(send_win, cong_win);
+ /* If a full-sized TSO skb can be sent, do it. */
+ if (limit >= 65536)
+ goto send_now;
+
if (sysctl_tcp_tso_win_divisor) {
u32 chunk = min(tp->snd_wnd, tp->snd_cwnd * tp->mss_cache);
*/
chunk /= sysctl_tcp_tso_win_divisor;
if (limit >= chunk)
- return 0;
+ goto send_now;
} else {
/* Different approach, try not to defer past a single
* ACK. Receiver should ACK every other full sized
* then send now.
*/
if (limit > tcp_max_burst(tp) * tp->mss_cache)
- return 0;
+ goto send_now;
}
/* Ok, it looks like it is advisable to defer. */
+ tp->tso_deferred = 1 | (jiffies << 1);
+
return 1;
+
+send_now:
+ tp->tso_deferred = 0;
+ return 0;
+}
+
+/* Create a new MTU probe if we are ready.
+ * Returns 0 if we should wait to probe (no cwnd available),
+ * 1 if a probe was sent,
+ * -1 otherwise
+ */
+static int tcp_mtu_probe(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct inet_connection_sock *icsk = inet_csk(sk);
+ struct sk_buff *skb, *nskb, *next;
+ int len;
+ int probe_size;
+ int size_needed;
+ int copy;
+ int mss_now;
+
+ /* Not currently probing/verifying,
+ * not in recovery,
+ * have enough cwnd, and
+ * not SACKing (the variable headers throw things off) */
+ if (!icsk->icsk_mtup.enabled ||
+ icsk->icsk_mtup.probe_size ||
+ inet_csk(sk)->icsk_ca_state != TCP_CA_Open ||
+ tp->snd_cwnd < 11 ||
+ tp->rx_opt.eff_sacks)
+ return -1;
+
+ /* Very simple search strategy: just double the MSS. */
+ mss_now = tcp_current_mss(sk, 0);
+ probe_size = 2 * tp->mss_cache;
+ size_needed = probe_size + (tp->reordering + 1) * tp->mss_cache;
+ if (probe_size > tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_high)) {
+ /* TODO: set timer for probe_converge_event */
+ return -1;
+ }
+
+ /* Have enough data in the send queue to probe? */
+ if (tp->write_seq - tp->snd_nxt < size_needed)
+ return -1;
+
+ if (tp->snd_wnd < size_needed)
+ return -1;
+ if (after(tp->snd_nxt + size_needed, tcp_wnd_end(tp)))
+ return 0;
+
+ /* Do we need to wait to drain cwnd? With none in flight, don't stall */
+ if (tcp_packets_in_flight(tp) + 2 > tp->snd_cwnd) {
+ if (!tcp_packets_in_flight(tp))
+ return -1;
+ else
+ return 0;
+ }
+
+ /* We're allowed to probe. Build it now. */
+ if ((nskb = sk_stream_alloc_skb(sk, probe_size, GFP_ATOMIC)) == NULL)
+ return -1;
+ sk->sk_wmem_queued += nskb->truesize;
+ sk_mem_charge(sk, nskb->truesize);
+
+ skb = tcp_send_head(sk);
+
+ TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(skb)->seq;
+ TCP_SKB_CB(nskb)->end_seq = TCP_SKB_CB(skb)->seq + probe_size;
+ TCP_SKB_CB(nskb)->flags = TCPCB_FLAG_ACK;
+ TCP_SKB_CB(nskb)->sacked = 0;
+ nskb->csum = 0;
+ nskb->ip_summed = skb->ip_summed;
+
+ tcp_insert_write_queue_before(nskb, skb, sk);
+
+ len = 0;
+ tcp_for_write_queue_from_safe(skb, next, sk) {
+ copy = min_t(int, skb->len, probe_size - len);
+ if (nskb->ip_summed)
+ skb_copy_bits(skb, 0, skb_put(nskb, copy), copy);
+ else
+ nskb->csum = skb_copy_and_csum_bits(skb, 0,
+ skb_put(nskb, copy),
+ copy, nskb->csum);
+
+ if (skb->len <= copy) {
+ /* We've eaten all the data from this skb.
+ * Throw it away. */
+ TCP_SKB_CB(nskb)->flags |= TCP_SKB_CB(skb)->flags;
+ tcp_unlink_write_queue(skb, sk);
+ sk_wmem_free_skb(sk, skb);
+ } else {
+ TCP_SKB_CB(nskb)->flags |= TCP_SKB_CB(skb)->flags &
+ ~(TCPCB_FLAG_FIN|TCPCB_FLAG_PSH);
+ if (!skb_shinfo(skb)->nr_frags) {
+ skb_pull(skb, copy);
+ if (skb->ip_summed != CHECKSUM_PARTIAL)
+ skb->csum = csum_partial(skb->data,
+ skb->len, 0);
+ } else {
+ __pskb_trim_head(skb, copy);
+ tcp_set_skb_tso_segs(sk, skb, mss_now);
+ }
+ TCP_SKB_CB(skb)->seq += copy;
+ }
+
+ len += copy;
+
+ if (len >= probe_size)
+ break;
+ }
+ tcp_init_tso_segs(sk, nskb, nskb->len);
+
+ /* We're ready to send. If this fails, the probe will
+ * be resegmented into mss-sized pieces by tcp_write_xmit(). */
+ TCP_SKB_CB(nskb)->when = tcp_time_stamp;
+ if (!tcp_transmit_skb(sk, nskb, 1, GFP_ATOMIC)) {
+ /* Decrement cwnd here because we are sending
+ * effectively two packets. */
+ tp->snd_cwnd--;
+ tcp_event_new_data_sent(sk, nskb);
+
+ icsk->icsk_mtup.probe_size = tcp_mss_to_mtu(sk, nskb->len);
+ tp->mtu_probe.probe_seq_start = TCP_SKB_CB(nskb)->seq;
+ tp->mtu_probe.probe_seq_end = TCP_SKB_CB(nskb)->end_seq;
+
+ return 1;
+ }
+
+ return -1;
}
/* This routine writes packets to the network. It advances the
struct sk_buff *skb;
unsigned int tso_segs, sent_pkts;
int cwnd_quota;
+ int result;
/* If we are closed, the bytes will have to remain here.
* In time closedown will finish, we empty the write queue and all
return 0;
sent_pkts = 0;
- while ((skb = sk->sk_send_head)) {
+
+ /* Do MTU probing. */
+ if ((result = tcp_mtu_probe(sk)) == 0) {
+ return 0;
+ } else if (result > 0) {
+ sent_pkts = 1;
+ }
+
+ while ((skb = tcp_send_head(sk))) {
unsigned int limit;
tso_segs = tcp_init_tso_segs(sk, skb, mss_now);
nonagle : TCP_NAGLE_PUSH))))
break;
} else {
- if (tcp_tso_should_defer(sk, tp, skb))
+ if (tcp_tso_should_defer(sk, skb))
break;
}
limit = mss_now;
- if (tso_segs > 1) {
- limit = tcp_window_allows(tp, skb,
- mss_now, cwnd_quota);
-
- if (skb->len < limit) {
- unsigned int trim = skb->len % mss_now;
-
- if (trim)
- limit = skb->len - trim;
- }
- }
+ if (tso_segs > 1)
+ limit = tcp_mss_split_point(sk, skb, mss_now,
+ cwnd_quota);
if (skb->len > limit &&
unlikely(tso_fragment(sk, skb, limit, mss_now)))
TCP_SKB_CB(skb)->when = tcp_time_stamp;
- if (unlikely(tcp_transmit_skb(sk, skb_clone(skb, GFP_ATOMIC))))
+ if (unlikely(tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC)))
break;
/* Advance the send_head. This one is sent out.
* This call will increment packets_out.
*/
- update_send_head(sk, tp, skb);
+ tcp_event_new_data_sent(sk, skb);
tcp_minshall_update(tp, mss_now, skb);
sent_pkts++;
}
if (likely(sent_pkts)) {
- tcp_cwnd_validate(sk, tp);
+ tcp_cwnd_validate(sk);
return 0;
}
- return !tp->packets_out && sk->sk_send_head;
+ return !tp->packets_out && tcp_send_head(sk);
}
/* Push out any pending frames which were held back due to
* TCP_CORK or attempt at coalescing tiny packets.
* The socket must be locked by the caller.
*/
-void __tcp_push_pending_frames(struct sock *sk, struct tcp_sock *tp,
- unsigned int cur_mss, int nonagle)
+void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss,
+ int nonagle)
{
- struct sk_buff *skb = sk->sk_send_head;
+ struct sk_buff *skb = tcp_send_head(sk);
if (skb) {
if (tcp_write_xmit(sk, cur_mss, nonagle))
- tcp_check_probe_timer(sk, tp);
+ tcp_check_probe_timer(sk);
}
}
*/
void tcp_push_one(struct sock *sk, unsigned int mss_now)
{
- struct tcp_sock *tp = tcp_sk(sk);
- struct sk_buff *skb = sk->sk_send_head;
+ struct sk_buff *skb = tcp_send_head(sk);
unsigned int tso_segs, cwnd_quota;
BUG_ON(!skb || skb->len < mss_now);
BUG_ON(!tso_segs);
limit = mss_now;
- if (tso_segs > 1) {
- limit = tcp_window_allows(tp, skb,
- mss_now, cwnd_quota);
-
- if (skb->len < limit) {
- unsigned int trim = skb->len % mss_now;
-
- if (trim)
- limit = skb->len - trim;
- }
- }
+ if (tso_segs > 1)
+ limit = tcp_mss_split_point(sk, skb, mss_now,
+ cwnd_quota);
if (skb->len > limit &&
unlikely(tso_fragment(sk, skb, limit, mss_now)))
/* Send it out now. */
TCP_SKB_CB(skb)->when = tcp_time_stamp;
- if (likely(!tcp_transmit_skb(sk, skb_clone(skb, sk->sk_allocation)))) {
- update_send_head(sk, tp, skb);
- tcp_cwnd_validate(sk, tp);
+ if (likely(!tcp_transmit_skb(sk, skb, 1, sk->sk_allocation))) {
+ tcp_event_new_data_sent(sk, skb);
+ tcp_cwnd_validate(sk);
return;
}
}
/* This function returns the amount that we can raise the
* usable window based on the following constraints
- *
+ *
* 1. The window can never be shrunk once it is offered (RFC 793)
* 2. We limit memory per socket
*
* side SWS prevention criteria. The problem is that under this rule
* a stream of single byte packets will cause the right side of the
* window to always advance by a single byte.
- *
+ *
* Of course, if the sender implements sender side SWS prevention
* then this will not be a problem.
- *
+ *
* BSD seems to make the following compromise:
- *
+ *
* If the free space is less than the 1/4 of the maximum
* space available and the free space is less than 1/2 mss,
* then set the window to 0.
{
struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
- /* MSS for the peer's data. Previous verions used mss_clamp
+ /* MSS for the peer's data. Previous versions used mss_clamp
* here. I don't know if the value based on our guesses
* of peer's MSS is better for the performance. It's more correct
* but may be worse for the performance because of rcv_mss
int window;
if (mss > full_space)
- mss = full_space;
+ mss = full_space;
- if (free_space < full_space/2) {
+ if (free_space < (full_space >> 1)) {
icsk->icsk_ack.quick = 0;
if (tcp_memory_pressure)
- tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U*tp->advmss);
+ tp->rcv_ssthresh = min(tp->rcv_ssthresh,
+ 4U * tp->advmss);
if (free_space < mss)
return 0;
* is too small.
*/
if (window <= free_space - mss || window > free_space)
- window = (free_space/mss)*mss;
+ window = (free_space / mss) * mss;
+ else if (mss == full_space &&
+ free_space > window + (full_space >> 1))
+ window = free_space;
}
return window;
}
/* Attempt to collapse two adjacent SKB's during retransmission. */
-static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int mss_now)
+static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb,
+ int mss_now)
{
struct tcp_sock *tp = tcp_sk(sk);
- struct sk_buff *next_skb = skb->next;
+ struct sk_buff *next_skb = tcp_write_queue_next(sk, skb);
+ int skb_size, next_skb_size;
+ u16 flags;
/* The first test we must make is that neither of these two
* SKB's are still referenced by someone else.
*/
- if (!skb_cloned(skb) && !skb_cloned(next_skb)) {
- int skb_size = skb->len, next_skb_size = next_skb->len;
- u16 flags = TCP_SKB_CB(skb)->flags;
+ if (skb_cloned(skb) || skb_cloned(next_skb))
+ return;
- /* Also punt if next skb has been SACK'd. */
- if(TCP_SKB_CB(next_skb)->sacked & TCPCB_SACKED_ACKED)
- return;
+ skb_size = skb->len;
+ next_skb_size = next_skb->len;
+ flags = TCP_SKB_CB(skb)->flags;
- /* Next skb is out of window. */
- if (after(TCP_SKB_CB(next_skb)->end_seq, tp->snd_una+tp->snd_wnd))
- return;
+ /* Also punt if next skb has been SACK'd. */
+ if (TCP_SKB_CB(next_skb)->sacked & TCPCB_SACKED_ACKED)
+ return;
- /* Punt if not enough space exists in the first SKB for
- * the data in the second, or the total combined payload
- * would exceed the MSS.
- */
- if ((next_skb_size > skb_tailroom(skb)) ||
- ((skb_size + next_skb_size) > mss_now))
- return;
+ /* Next skb is out of window. */
+ if (after(TCP_SKB_CB(next_skb)->end_seq, tcp_wnd_end(tp)))
+ return;
+
+ /* Punt if not enough space exists in the first SKB for
+ * the data in the second, or the total combined payload
+ * would exceed the MSS.
+ */
+ if ((next_skb_size > skb_tailroom(skb)) ||
+ ((skb_size + next_skb_size) > mss_now))
+ return;
- BUG_ON(tcp_skb_pcount(skb) != 1 ||
- tcp_skb_pcount(next_skb) != 1);
+ BUG_ON(tcp_skb_pcount(skb) != 1 || tcp_skb_pcount(next_skb) != 1);
- /* Ok. We will be able to collapse the packet. */
- __skb_unlink(next_skb, &sk->sk_write_queue);
+ tcp_highest_sack_combine(sk, next_skb, skb);
- memcpy(skb_put(skb, next_skb_size), next_skb->data, next_skb_size);
+ /* Ok. We will be able to collapse the packet. */
+ tcp_unlink_write_queue(next_skb, sk);
- if (next_skb->ip_summed == CHECKSUM_HW)
- skb->ip_summed = CHECKSUM_HW;
+ skb_copy_from_linear_data(next_skb, skb_put(skb, next_skb_size),
+ next_skb_size);
- if (skb->ip_summed != CHECKSUM_HW)
- skb->csum = csum_block_add(skb->csum, next_skb->csum, skb_size);
+ if (next_skb->ip_summed == CHECKSUM_PARTIAL)
+ skb->ip_summed = CHECKSUM_PARTIAL;
- /* Update sequence range on original skb. */
- TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(next_skb)->end_seq;
+ if (skb->ip_summed != CHECKSUM_PARTIAL)
+ skb->csum = csum_block_add(skb->csum, next_skb->csum, skb_size);
- /* Merge over control information. */
- flags |= TCP_SKB_CB(next_skb)->flags; /* This moves PSH/FIN etc. over */
- TCP_SKB_CB(skb)->flags = flags;
+ /* Update sequence range on original skb. */
+ TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(next_skb)->end_seq;
- /* All done, get rid of second SKB and account for it so
- * packet counting does not break.
- */
- TCP_SKB_CB(skb)->sacked |= TCP_SKB_CB(next_skb)->sacked&(TCPCB_EVER_RETRANS|TCPCB_AT_TAIL);
- if (TCP_SKB_CB(next_skb)->sacked&TCPCB_SACKED_RETRANS)
- tp->retrans_out -= tcp_skb_pcount(next_skb);
- if (TCP_SKB_CB(next_skb)->sacked&TCPCB_LOST) {
- tp->lost_out -= tcp_skb_pcount(next_skb);
- tp->left_out -= tcp_skb_pcount(next_skb);
- }
- /* Reno case is special. Sigh... */
- if (!tp->rx_opt.sack_ok && tp->sacked_out) {
- tcp_dec_pcount_approx(&tp->sacked_out, next_skb);
- tp->left_out -= tcp_skb_pcount(next_skb);
- }
+ /* Merge over control information. */
+ flags |= TCP_SKB_CB(next_skb)->flags; /* This moves PSH/FIN etc. over */
+ TCP_SKB_CB(skb)->flags = flags;
- /* Not quite right: it can be > snd.fack, but
- * it is better to underestimate fackets.
- */
- tcp_dec_pcount_approx(&tp->fackets_out, next_skb);
- tcp_packets_out_dec(tp, next_skb);
- sk_stream_free_skb(sk, next_skb);
- }
+ /* All done, get rid of second SKB and account for it so
+ * packet counting does not break.
+ */
+ TCP_SKB_CB(skb)->sacked |= TCP_SKB_CB(next_skb)->sacked & TCPCB_EVER_RETRANS;
+ if (TCP_SKB_CB(next_skb)->sacked & TCPCB_SACKED_RETRANS)
+ tp->retrans_out -= tcp_skb_pcount(next_skb);
+ if (TCP_SKB_CB(next_skb)->sacked & TCPCB_LOST)
+ tp->lost_out -= tcp_skb_pcount(next_skb);
+ /* Reno case is special. Sigh... */
+ if (tcp_is_reno(tp) && tp->sacked_out)
+ tcp_dec_pcount_approx(&tp->sacked_out, next_skb);
+
+ tcp_adjust_fackets_out(sk, next_skb, tcp_skb_pcount(next_skb));
+ tp->packets_out -= tcp_skb_pcount(next_skb);
+
+ /* changed transmit queue under us so clear hints */
+ tcp_clear_retrans_hints_partial(tp);
+
+ sk_wmem_free_skb(sk, next_skb);
}
/* Do a simple retransmit without using the backoff mechanisms in
- * tcp_timer. This is used for path mtu discovery.
+ * tcp_timer. This is used for path mtu discovery.
* The socket is already locked here.
- */
+ */
void tcp_simple_retransmit(struct sock *sk)
{
const struct inet_connection_sock *icsk = inet_csk(sk);
unsigned int mss = tcp_current_mss(sk, 0);
int lost = 0;
- sk_stream_for_retrans_queue(skb, sk) {
- if (skb->len > mss &&
- !(TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_ACKED)) {
- if (TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_RETRANS) {
+ tcp_for_write_queue(skb, sk) {
+ if (skb == tcp_send_head(sk))
+ break;
+ if (skb->len > mss &&
+ !(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) {
+ if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) {
TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
tp->retrans_out -= tcp_skb_pcount(skb);
}
- if (!(TCP_SKB_CB(skb)->sacked&TCPCB_LOST)) {
+ 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_clear_all_retrans_hints(tp);
+
if (!lost)
return;
- tcp_sync_left_out(tp);
+ tcp_verify_left_out(tp);
- /* Don't muck with the congestion window here.
+ /* Don't muck with the congestion window here.
* Reason is that we do not increase amount of _data_
* in network, but units changed and effective
* cwnd/ssthresh really reduced now.
int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
{
struct tcp_sock *tp = tcp_sk(sk);
- unsigned int cur_mss = tcp_current_mss(sk, 0);
+ struct inet_connection_sock *icsk = inet_csk(sk);
+ unsigned int cur_mss = tcp_current_mss(sk, 0);
int err;
+ /* Inconslusive MTU probe */
+ if (icsk->icsk_mtup.probe_size) {
+ icsk->icsk_mtup.probe_size = 0;
+ }
+
/* Do not sent more than we queued. 1/4 is reserved for possible
- * copying overhead: frgagmentation, tunneling, mangling etc.
+ * copying overhead: fragmentation, tunneling, mangling etc.
*/
if (atomic_read(&sk->sk_wmem_alloc) >
min(sk->sk_wmem_queued + (sk->sk_wmem_queued >> 2), sk->sk_sndbuf))
* case, when window is shrunk to zero. In this case
* our retransmit serves as a zero window probe.
*/
- if (!before(TCP_SKB_CB(skb)->seq, tp->snd_una+tp->snd_wnd)
+ if (!before(TCP_SKB_CB(skb)->seq, tcp_wnd_end(tp))
&& TCP_SKB_CB(skb)->seq != tp->snd_una)
return -EAGAIN;
}
/* Collapse two adjacent packets if worthwhile and we can. */
- if(!(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN) &&
- (skb->len < (cur_mss >> 1)) &&
- (skb->next != sk->sk_send_head) &&
- (skb->next != (struct sk_buff *)&sk->sk_write_queue) &&
- (skb_shinfo(skb)->nr_frags == 0 && skb_shinfo(skb->next)->nr_frags == 0) &&
- (tcp_skb_pcount(skb) == 1 && tcp_skb_pcount(skb->next) == 1) &&
- (sysctl_tcp_retrans_collapse != 0))
+ 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)) &&
+ (skb_shinfo(skb)->nr_frags == 0 &&
+ skb_shinfo(tcp_write_queue_next(sk, skb))->nr_frags == 0) &&
+ (tcp_skb_pcount(skb) == 1 &&
+ tcp_skb_pcount(tcp_write_queue_next(sk, skb)) == 1) &&
+ (sysctl_tcp_retrans_collapse != 0))
tcp_retrans_try_collapse(sk, skb, cur_mss);
- if(tp->af_specific->rebuild_header(sk))
+ if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk))
return -EHOSTUNREACH; /* Routing failure or similar. */
/* Some Solaris stacks overoptimize and ignore the FIN on a
* retransmit when old data is attached. So strip it off
* since it is cheap to do so and saves bytes on the network.
*/
- if(skb->len > 0 &&
- (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) &&
- tp->snd_una == (TCP_SKB_CB(skb)->end_seq - 1)) {
+ if (skb->len > 0 &&
+ (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) &&
+ tp->snd_una == (TCP_SKB_CB(skb)->end_seq - 1)) {
if (!pskb_trim(skb, 0)) {
- TCP_SKB_CB(skb)->seq = TCP_SKB_CB(skb)->end_seq - 1;
- skb_shinfo(skb)->tso_segs = 1;
- skb_shinfo(skb)->tso_size = 0;
+ /* Reuse, even though it does some unnecessary work */
+ tcp_init_nondata_skb(skb, TCP_SKB_CB(skb)->end_seq - 1,
+ TCP_SKB_CB(skb)->flags);
skb->ip_summed = CHECKSUM_NONE;
- skb->csum = 0;
}
}
*/
TCP_SKB_CB(skb)->when = tcp_time_stamp;
- err = tcp_transmit_skb(sk, (skb_cloned(skb) ?
- pskb_copy(skb, GFP_ATOMIC):
- skb_clone(skb, GFP_ATOMIC)));
+ err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
if (err == 0) {
/* Update global TCP statistics. */
tp->total_retrans++;
#if FASTRETRANS_DEBUG > 0
- if (TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_RETRANS) {
+ if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) {
if (net_ratelimit())
printk(KERN_DEBUG "retrans_out leaked.\n");
}
#endif
+ if (!tp->retrans_out)
+ tp->lost_retrans_low = tp->snd_nxt;
TCP_SKB_CB(skb)->sacked |= TCPCB_RETRANS;
tp->retrans_out += tcp_skb_pcount(skb);
const struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
- int packet_cnt = tp->lost_out;
+ 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 (packet_cnt) {
- sk_stream_for_retrans_queue(skb, sk) {
+ 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
if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)
return;
- if (sacked&TCPCB_LOST) {
- if (!(sacked&(TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))) {
- if (tcp_retransmit_skb(sk, skb))
+ if (sacked & TCPCB_LOST) {
+ if (!(sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))) {
+ if (tcp_retransmit_skb(sk, skb)) {
+ tp->retransmit_skb_hint = NULL;
return;
+ }
if (icsk->icsk_ca_state != TCP_CA_Loss)
NET_INC_STATS_BH(LINUX_MIB_TCPFASTRETRANS);
else
NET_INC_STATS_BH(LINUX_MIB_TCPSLOWSTARTRETRANS);
- if (skb ==
- skb_peek(&sk->sk_write_queue))
+ 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 <= 0)
+ packet_cnt += tcp_skb_pcount(skb);
+ if (packet_cnt >= tp->lost_out)
break;
}
}
return;
/* No forward retransmissions in Reno are possible. */
- if (!tp->rx_opt.sack_ok)
+ if (tcp_is_reno(tp))
return;
/* Yeah, we have to make difficult choice between forward transmission
* and retransmission... Both ways have their merits...
*
* For now we do not retransmit anything, while we have some new
- * segments to send.
+ * segments to send. In the other cases, follow rule 3 for
+ * NextSeg() specified in RFC3517.
*/
- if (tcp_may_send_now(sk, tp))
+ if (tcp_may_send_now(sk))
return;
- packet_cnt = 0;
+ /* If nothing is SACKed, highest_sack in the loop won't be valid */
+ if (!tp->sacked_out)
+ return;
- sk_stream_for_retrans_queue(skb, sk) {
- /* Similar to the retransmit loop above we
- * can pretend that the retransmitted SKB
- * we send out here will be composed of one
- * real MSS sized packet because tcp_retransmit_skb()
- * will fragment it if necessary.
- */
- if (++packet_cnt > tp->fackets_out)
+ if (tp->forward_skb_hint)
+ skb = tp->forward_skb_hint;
+ else
+ skb = tcp_write_queue_head(sk);
+
+ tcp_for_write_queue_from(skb, sk) {
+ if (skb == tcp_send_head(sk))
+ break;
+ tp->forward_skb_hint = skb;
+
+ if (!before(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))
break;
if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)
continue;
/* Ok, retransmit it. */
- if (tcp_retransmit_skb(sk, skb))
+ if (tcp_retransmit_skb(sk, skb)) {
+ tp->forward_skb_hint = NULL;
break;
+ }
- if (skb == skb_peek(&sk->sk_write_queue))
+ if (skb == tcp_write_queue_head(sk))
inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
inet_csk(sk)->icsk_rto,
TCP_RTO_MAX);
}
}
-
/* Send a fin. The caller locks the socket for us. This cannot be
* allowed to fail queueing a FIN frame under any circumstances.
*/
void tcp_send_fin(struct sock *sk)
{
- struct tcp_sock *tp = tcp_sk(sk);
- struct sk_buff *skb = skb_peek_tail(&sk->sk_write_queue);
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct sk_buff *skb = tcp_write_queue_tail(sk);
int mss_now;
-
+
/* Optimization, tack on the FIN if we have a queue of
* unsent frames. But be careful about outgoing SACKS
* and IP options.
*/
mss_now = tcp_current_mss(sk, 1);
- if (sk->sk_send_head != NULL) {
+ if (tcp_send_head(sk) != NULL) {
TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_FIN;
TCP_SKB_CB(skb)->end_seq++;
tp->write_seq++;
/* Reserve space for headers and prepare control bits. */
skb_reserve(skb, MAX_TCP_HEADER);
- skb->csum = 0;
- TCP_SKB_CB(skb)->flags = (TCPCB_FLAG_ACK | TCPCB_FLAG_FIN);
- TCP_SKB_CB(skb)->sacked = 0;
- skb_shinfo(skb)->tso_segs = 1;
- skb_shinfo(skb)->tso_size = 0;
-
/* FIN eats a sequence byte, write_seq advanced by tcp_queue_skb(). */
- TCP_SKB_CB(skb)->seq = tp->write_seq;
- TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq + 1;
+ tcp_init_nondata_skb(skb, tp->write_seq,
+ TCPCB_FLAG_ACK | TCPCB_FLAG_FIN);
tcp_queue_skb(sk, skb);
}
- __tcp_push_pending_frames(sk, tp, mss_now, TCP_NAGLE_OFF);
+ __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_OFF);
}
/* We get here when a process closes a file descriptor (either due to
* an explicit close() or as a byproduct of exit()'ing) and there
* was unread data in the receive queue. This behavior is recommended
- * by draft-ietf-tcpimpl-prob-03.txt section 3.10. -DaveM
+ * by RFC 2525, section 2.17. -DaveM
*/
void tcp_send_active_reset(struct sock *sk, gfp_t priority)
{
- struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
/* NOTE: No TCP options attached and we never retransmit this. */
/* Reserve space for headers and prepare control bits. */
skb_reserve(skb, MAX_TCP_HEADER);
- skb->csum = 0;
- TCP_SKB_CB(skb)->flags = (TCPCB_FLAG_ACK | TCPCB_FLAG_RST);
- TCP_SKB_CB(skb)->sacked = 0;
- skb_shinfo(skb)->tso_segs = 1;
- skb_shinfo(skb)->tso_size = 0;
-
+ tcp_init_nondata_skb(skb, tcp_acceptable_seq(sk),
+ TCPCB_FLAG_ACK | TCPCB_FLAG_RST);
/* Send it off. */
- TCP_SKB_CB(skb)->seq = tcp_acceptable_seq(sk, tp);
- TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq;
TCP_SKB_CB(skb)->when = tcp_time_stamp;
- if (tcp_transmit_skb(sk, skb))
+ if (tcp_transmit_skb(sk, skb, 0, priority))
NET_INC_STATS(LINUX_MIB_TCPABORTFAILED);
}
*/
int tcp_send_synack(struct sock *sk)
{
- struct sk_buff* skb;
+ struct sk_buff *skb;
- skb = skb_peek(&sk->sk_write_queue);
- if (skb == NULL || !(TCP_SKB_CB(skb)->flags&TCPCB_FLAG_SYN)) {
+ skb = tcp_write_queue_head(sk);
+ if (skb == NULL || !(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN)) {
printk(KERN_DEBUG "tcp_send_synack: wrong queue state\n");
return -EFAULT;
}
- if (!(TCP_SKB_CB(skb)->flags&TCPCB_FLAG_ACK)) {
+ if (!(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_ACK)) {
if (skb_cloned(skb)) {
struct sk_buff *nskb = skb_copy(skb, GFP_ATOMIC);
if (nskb == NULL)
return -ENOMEM;
- __skb_unlink(skb, &sk->sk_write_queue);
+ tcp_unlink_write_queue(skb, sk);
skb_header_release(nskb);
- __skb_queue_head(&sk->sk_write_queue, nskb);
- sk_stream_free_skb(sk, skb);
- sk_charge_skb(sk, nskb);
+ __tcp_add_write_queue_head(sk, nskb);
+ sk_wmem_free_skb(sk, skb);
+ sk->sk_wmem_queued += nskb->truesize;
+ sk_mem_charge(sk, nskb->truesize);
skb = nskb;
}
TCP_ECN_send_synack(tcp_sk(sk), skb);
}
TCP_SKB_CB(skb)->when = tcp_time_stamp;
- return tcp_transmit_skb(sk, skb_clone(skb, GFP_ATOMIC));
+ return tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
}
/*
* Prepare a SYN-ACK.
*/
-struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
- struct request_sock *req)
+struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
+ struct request_sock *req)
{
struct inet_request_sock *ireq = inet_rsk(req);
struct tcp_sock *tp = tcp_sk(sk);
struct tcphdr *th;
int tcp_header_size;
struct sk_buff *skb;
+#ifdef CONFIG_TCP_MD5SIG
+ struct tcp_md5sig_key *md5;
+ __u8 *md5_hash_location;
+#endif
skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15, 1, GFP_ATOMIC);
if (skb == NULL)
(ireq->wscale_ok ? TCPOLEN_WSCALE_ALIGNED : 0) +
/* SACK_PERM is in the place of NOP NOP of TS */
((ireq->sack_ok && !ireq->tstamp_ok) ? TCPOLEN_SACKPERM_ALIGNED : 0));
- skb->h.th = th = (struct tcphdr *) skb_push(skb, tcp_header_size);
+#ifdef CONFIG_TCP_MD5SIG
+ /* Are we doing MD5 on this segment? If so - make room for it */
+ md5 = tcp_rsk(req)->af_specific->md5_lookup(sk, req);
+ if (md5)
+ tcp_header_size += TCPOLEN_MD5SIG_ALIGNED;
+#endif
+ skb_push(skb, tcp_header_size);
+ skb_reset_transport_header(skb);
+
+ th = tcp_hdr(skb);
memset(th, 0, sizeof(struct tcphdr));
th->syn = 1;
th->ack = 1;
- if (dst->dev->features&NETIF_F_TSO)
- ireq->ecn_ok = 0;
TCP_ECN_make_synack(req, th);
th->source = inet_sk(sk)->sport;
th->dest = ireq->rmt_port;
- TCP_SKB_CB(skb)->seq = tcp_rsk(req)->snt_isn;
- TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq + 1;
- TCP_SKB_CB(skb)->sacked = 0;
- skb_shinfo(skb)->tso_segs = 1;
- skb_shinfo(skb)->tso_size = 0;
+ /* Setting of flags are superfluous here for callers (and ECE is
+ * not even correctly set)
+ */
+ tcp_init_nondata_skb(skb, tcp_rsk(req)->snt_isn,
+ TCPCB_FLAG_SYN | TCPCB_FLAG_ACK);
th->seq = htonl(TCP_SKB_CB(skb)->seq);
th->ack_seq = htonl(tcp_rsk(req)->rcv_isn + 1);
if (req->rcv_wnd == 0) { /* ignored for retransmitted syns */
- __u8 rcv_wscale;
+ __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),
+ tcp_select_initial_window(tcp_full_space(sk),
dst_metric(dst, RTAX_ADVMSS) - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0),
&req->rcv_wnd,
&req->window_clamp,
ireq->wscale_ok,
&rcv_wscale);
- ireq->rcv_wscale = rcv_wscale;
+ ireq->rcv_wscale = rcv_wscale;
}
/* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
- th->window = htons(req->rcv_wnd);
+ th->window = htons(min(req->rcv_wnd, 65535U));
TCP_SKB_CB(skb)->when = tcp_time_stamp;
- tcp_syn_build_options((__u32 *)(th + 1), dst_metric(dst, RTAX_ADVMSS), ireq->tstamp_ok,
+ tcp_syn_build_options((__be32 *)(th + 1), dst_metric(dst, RTAX_ADVMSS), ireq->tstamp_ok,
ireq->sack_ok, ireq->wscale_ok, ireq->rcv_wscale,
TCP_SKB_CB(skb)->when,
- req->ts_recent);
+ req->ts_recent,
+ (
+#ifdef CONFIG_TCP_MD5SIG
+ md5 ? &md5_hash_location :
+#endif
+ NULL)
+ );
- skb->csum = 0;
th->doff = (tcp_header_size >> 2);
TCP_INC_STATS(TCP_MIB_OUTSEGS);
+
+#ifdef CONFIG_TCP_MD5SIG
+ /* Okay, we have all we need - do the md5 hash if needed */
+ if (md5) {
+ tp->af_specific->calc_md5_hash(md5_hash_location,
+ md5,
+ NULL, dst, req,
+ tcp_hdr(skb), sk->sk_protocol,
+ skb->len);
+ }
+#endif
+
return skb;
}
-/*
+/*
* Do all connect socket setups that can be done AF independent.
- */
-static inline void tcp_connect_init(struct sock *sk)
+ */
+static void tcp_connect_init(struct sock *sk)
{
struct dst_entry *dst = __sk_dst_get(sk);
struct tcp_sock *tp = tcp_sk(sk);
tp->tcp_header_len = sizeof(struct tcphdr) +
(sysctl_tcp_timestamps ? TCPOLEN_TSTAMP_ALIGNED : 0);
+#ifdef CONFIG_TCP_MD5SIG
+ if (tp->af_specific->md5_lookup(sk, sk) != NULL)
+ tp->tcp_header_len += TCPOLEN_MD5SIG_ALIGNED;
+#endif
+
/* If user gave his TCP_MAXSEG, record it to clamp */
if (tp->rx_opt.user_mss)
tp->rx_opt.mss_clamp = tp->rx_opt.user_mss;
tp->max_window = 0;
+ tcp_mtup_init(sk);
tcp_sync_mss(sk, dst_mtu(dst));
if (!tp->window_clamp)
/*
* Build a SYN and send it off.
- */
+ */
int tcp_connect(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
/* Reserve space for headers. */
skb_reserve(buff, MAX_TCP_HEADER);
- TCP_SKB_CB(buff)->flags = TCPCB_FLAG_SYN;
- TCP_ECN_send_syn(sk, tp, buff);
- TCP_SKB_CB(buff)->sacked = 0;
- skb_shinfo(buff)->tso_segs = 1;
- skb_shinfo(buff)->tso_size = 0;
- buff->csum = 0;
- TCP_SKB_CB(buff)->seq = tp->write_seq++;
- TCP_SKB_CB(buff)->end_seq = tp->write_seq;
tp->snd_nxt = tp->write_seq;
- tp->pushed_seq = tp->write_seq;
+ tcp_init_nondata_skb(buff, tp->write_seq++, TCPCB_FLAG_SYN);
+ TCP_ECN_send_syn(sk, buff);
/* Send it off. */
TCP_SKB_CB(buff)->when = tcp_time_stamp;
tp->retrans_stamp = TCP_SKB_CB(buff)->when;
skb_header_release(buff);
- __skb_queue_tail(&sk->sk_write_queue, buff);
- sk_charge_skb(sk, buff);
+ __tcp_add_write_queue_tail(sk, buff);
+ sk->sk_wmem_queued += buff->truesize;
+ sk_mem_charge(sk, buff->truesize);
tp->packets_out += tcp_skb_pcount(buff);
- tcp_transmit_skb(sk, skb_clone(buff, GFP_KERNEL));
+ tcp_transmit_skb(sk, buff, 1, GFP_KERNEL);
+
+ /* We change tp->snd_nxt after the tcp_transmit_skb() call
+ * in order to make this packet get counted in tcpOutSegs.
+ */
+ tp->snd_nxt = tp->write_seq;
+ tp->pushed_seq = tp->write_seq;
TCP_INC_STATS(TCP_MIB_ACTIVEOPENS);
/* Timer for repeating the SYN until an answer. */
if (ato > TCP_DELACK_MIN) {
const struct tcp_sock *tp = tcp_sk(sk);
- int max_ato = HZ/2;
+ int max_ato = HZ / 2;
- if (icsk->icsk_ack.pingpong || (icsk->icsk_ack.pending & ICSK_ACK_PUSHED))
+ if (icsk->icsk_ack.pingpong ||
+ (icsk->icsk_ack.pending & ICSK_ACK_PUSHED))
max_ato = TCP_DELACK_MAX;
/* Slow path, intersegment interval is "high". */
* directly.
*/
if (tp->srtt) {
- int rtt = max(tp->srtt>>3, TCP_DELACK_MIN);
+ int rtt = max(tp->srtt >> 3, TCP_DELACK_MIN);
if (rtt < max_ato)
max_ato = rtt;
/* This routine sends an ack and also updates the window. */
void tcp_send_ack(struct sock *sk)
{
- /* If we have been reset, we may not send again. */
- if (sk->sk_state != TCP_CLOSE) {
- struct tcp_sock *tp = tcp_sk(sk);
- struct sk_buff *buff;
+ struct sk_buff *buff;
- /* We are not putting this on the write queue, so
- * tcp_transmit_skb() will set the ownership to this
- * sock.
- */
- buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
- if (buff == NULL) {
- inet_csk_schedule_ack(sk);
- inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN;
- inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
- TCP_DELACK_MAX, TCP_RTO_MAX);
- return;
- }
+ /* If we have been reset, we may not send again. */
+ if (sk->sk_state == TCP_CLOSE)
+ return;
- /* Reserve space for headers and prepare control bits. */
- skb_reserve(buff, MAX_TCP_HEADER);
- buff->csum = 0;
- TCP_SKB_CB(buff)->flags = TCPCB_FLAG_ACK;
- TCP_SKB_CB(buff)->sacked = 0;
- skb_shinfo(buff)->tso_segs = 1;
- skb_shinfo(buff)->tso_size = 0;
-
- /* Send it off, this clears delayed acks for us. */
- TCP_SKB_CB(buff)->seq = TCP_SKB_CB(buff)->end_seq = tcp_acceptable_seq(sk, tp);
- TCP_SKB_CB(buff)->when = tcp_time_stamp;
- tcp_transmit_skb(sk, buff);
+ /* We are not putting this on the write queue, so
+ * tcp_transmit_skb() will set the ownership to this
+ * sock.
+ */
+ buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
+ if (buff == NULL) {
+ inet_csk_schedule_ack(sk);
+ inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN;
+ inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
+ TCP_DELACK_MAX, TCP_RTO_MAX);
+ return;
}
+
+ /* Reserve space for headers and prepare control bits. */
+ skb_reserve(buff, MAX_TCP_HEADER);
+ tcp_init_nondata_skb(buff, tcp_acceptable_seq(sk), TCPCB_FLAG_ACK);
+
+ /* Send it off, this clears delayed acks for us. */
+ TCP_SKB_CB(buff)->when = tcp_time_stamp;
+ tcp_transmit_skb(sk, buff, 0, GFP_ATOMIC);
}
/* This routine sends a packet with an out of date sequence
/* We don't queue it, tcp_transmit_skb() sets ownership. */
skb = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
- if (skb == NULL)
+ if (skb == NULL)
return -1;
/* Reserve space for headers and set control bits. */
skb_reserve(skb, MAX_TCP_HEADER);
- skb->csum = 0;
- TCP_SKB_CB(skb)->flags = TCPCB_FLAG_ACK;
- TCP_SKB_CB(skb)->sacked = urgent;
- skb_shinfo(skb)->tso_segs = 1;
- skb_shinfo(skb)->tso_size = 0;
-
/* Use a previous sequence. This should cause the other
* end to send an ack. Don't queue or clone SKB, just
* send it.
*/
- TCP_SKB_CB(skb)->seq = urgent ? tp->snd_una : tp->snd_una - 1;
- TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq;
+ tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPCB_FLAG_ACK);
TCP_SKB_CB(skb)->when = tcp_time_stamp;
- return tcp_transmit_skb(sk, skb);
+ return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC);
}
int tcp_write_wakeup(struct sock *sk)
{
- if (sk->sk_state != TCP_CLOSE) {
- struct tcp_sock *tp = tcp_sk(sk);
- struct sk_buff *skb;
-
- if ((skb = sk->sk_send_head) != NULL &&
- before(TCP_SKB_CB(skb)->seq, tp->snd_una+tp->snd_wnd)) {
- int err;
- unsigned int mss = tcp_current_mss(sk, 0);
- unsigned int seg_size = tp->snd_una+tp->snd_wnd-TCP_SKB_CB(skb)->seq;
-
- if (before(tp->pushed_seq, TCP_SKB_CB(skb)->end_seq))
- tp->pushed_seq = TCP_SKB_CB(skb)->end_seq;
-
- /* We are probing the opening of a window
- * but the window size is != 0
- * must have been a result SWS avoidance ( sender )
- */
- if (seg_size < TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq ||
- skb->len > mss) {
- seg_size = min(seg_size, mss);
- TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
- if (tcp_fragment(sk, skb, seg_size, mss))
- return -1;
- } else if (!tcp_skb_pcount(skb))
- tcp_set_skb_tso_segs(sk, skb, mss);
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct sk_buff *skb;
+ if (sk->sk_state == TCP_CLOSE)
+ return -1;
+
+ if ((skb = tcp_send_head(sk)) != NULL &&
+ before(TCP_SKB_CB(skb)->seq, tcp_wnd_end(tp))) {
+ int err;
+ unsigned int mss = tcp_current_mss(sk, 0);
+ unsigned int seg_size = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq;
+
+ if (before(tp->pushed_seq, TCP_SKB_CB(skb)->end_seq))
+ tp->pushed_seq = TCP_SKB_CB(skb)->end_seq;
+
+ /* We are probing the opening of a window
+ * but the window size is != 0
+ * must have been a result SWS avoidance ( sender )
+ */
+ if (seg_size < TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq ||
+ skb->len > mss) {
+ seg_size = min(seg_size, mss);
TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
- TCP_SKB_CB(skb)->when = tcp_time_stamp;
- err = tcp_transmit_skb(sk, skb_clone(skb, GFP_ATOMIC));
- if (!err) {
- update_send_head(sk, tp, skb);
- }
- return err;
- } else {
- if (tp->urg_mode &&
- between(tp->snd_up, tp->snd_una+1, tp->snd_una+0xFFFF))
- tcp_xmit_probe_skb(sk, TCPCB_URG);
- return tcp_xmit_probe_skb(sk, 0);
- }
+ if (tcp_fragment(sk, skb, seg_size, mss))
+ return -1;
+ } else if (!tcp_skb_pcount(skb))
+ tcp_set_skb_tso_segs(sk, skb, mss);
+
+ TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
+ TCP_SKB_CB(skb)->when = tcp_time_stamp;
+ err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
+ if (!err)
+ 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))
+ tcp_xmit_probe_skb(sk, 1);
+ return tcp_xmit_probe_skb(sk, 0);
}
- return -1;
}
/* A window probe timeout has occurred. If window is not closed send
err = tcp_write_wakeup(sk);
- if (tp->packets_out || !sk->sk_send_head) {
+ if (tp->packets_out || !tcp_send_head(sk)) {
/* Cancel probe timer, if it is not required. */
icsk->icsk_probes_out = 0;
icsk->icsk_backoff = 0;
if (icsk->icsk_backoff < sysctl_tcp_retries2)
icsk->icsk_backoff++;
icsk->icsk_probes_out++;
- inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
+ inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
min(icsk->icsk_rto << icsk->icsk_backoff, TCP_RTO_MAX),
TCP_RTO_MAX);
} else {
*/
if (!icsk->icsk_probes_out)
icsk->icsk_probes_out = 1;
- inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
+ inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
min(icsk->icsk_rto << icsk->icsk_backoff,
TCP_RESOURCE_PROBE_INTERVAL),
TCP_RTO_MAX);
EXPORT_SYMBOL(tcp_make_synack);
EXPORT_SYMBOL(tcp_simple_retransmit);
EXPORT_SYMBOL(tcp_sync_mss);
+EXPORT_SYMBOL(sysctl_tcp_tso_win_divisor);
+EXPORT_SYMBOL(tcp_mtup_init);