/* By default, RFC2861 behavior. */
int sysctl_tcp_slow_start_after_idle __read_mostly = 1;
-int sysctl_tcp_cookie_size __read_mostly = 0; /* TCP_COOKIE_MAX */
-EXPORT_SYMBOL_GPL(sysctl_tcp_cookie_size);
-
static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
int push_one, gfp_t gfp);
/* Account for new data that has been sent to the network. */
static void tcp_event_new_data_sent(struct sock *sk, const struct sk_buff *skb)
{
+ struct inet_connection_sock *icsk = inet_csk(sk);
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;
- /* Don't override Nagle indefinitely with F-RTO */
- if (tp->frto_counter == 2)
- tp->frto_counter = 3;
-
tp->packets_out += tcp_skb_pcount(skb);
- if (!prior_packets || tp->early_retrans_delayed)
+ if (!prior_packets || icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS ||
+ icsk->icsk_pending == ICSK_TIME_LOSS_PROBE)
tcp_rearm_rto(sk);
}
#define OPTION_TS (1 << 1)
#define OPTION_MD5 (1 << 2)
#define OPTION_WSCALE (1 << 3)
-#define OPTION_COOKIE_EXTENSION (1 << 4)
#define OPTION_FAST_OPEN_COOKIE (1 << 8)
struct tcp_out_options {
struct tcp_fastopen_cookie *fastopen_cookie; /* Fast open cookie */
};
-/* The sysctl int routines are generic, so check consistency here.
- */
-static u8 tcp_cookie_size_check(u8 desired)
-{
- int cookie_size;
-
- if (desired > 0)
- /* previously specified */
- return desired;
-
- cookie_size = ACCESS_ONCE(sysctl_tcp_cookie_size);
- if (cookie_size <= 0)
- /* no default specified */
- return 0;
-
- if (cookie_size <= TCP_COOKIE_MIN)
- /* value too small, specify minimum */
- return TCP_COOKIE_MIN;
-
- if (cookie_size >= TCP_COOKIE_MAX)
- /* value too large, specify maximum */
- return TCP_COOKIE_MAX;
-
- if (cookie_size & 1)
- /* 8-bit multiple, illegal, fix it */
- cookie_size++;
-
- return (u8)cookie_size;
-}
-
/* Write previously computed TCP options to the packet.
*
* Beware: Something in the Internet is very sensitive to the ordering of
{
u16 options = opts->options; /* mungable copy */
- /* Having both authentication and cookies for security is redundant,
- * and there's certainly not enough room. Instead, the cookie-less
- * extension variant is proposed.
- *
- * Consider the pessimal case with authentication. The options
- * could look like:
- * COOKIE|MD5(20) + MSS(4) + SACK|TS(12) + WSCALE(4) == 40
- */
if (unlikely(OPTION_MD5 & options)) {
- if (unlikely(OPTION_COOKIE_EXTENSION & options)) {
- *ptr++ = htonl((TCPOPT_COOKIE << 24) |
- (TCPOLEN_COOKIE_BASE << 16) |
- (TCPOPT_MD5SIG << 8) |
- TCPOLEN_MD5SIG);
- } else {
- *ptr++ = htonl((TCPOPT_NOP << 24) |
- (TCPOPT_NOP << 16) |
- (TCPOPT_MD5SIG << 8) |
- TCPOLEN_MD5SIG);
- }
- options &= ~OPTION_COOKIE_EXTENSION;
+ *ptr++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
+ (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
/* overload cookie hash location */
opts->hash_location = (__u8 *)ptr;
ptr += 4;
*ptr++ = htonl(opts->tsecr);
}
- /* Specification requires after timestamp, so do it now.
- *
- * Consider the pessimal case without authentication. The options
- * could look like:
- * MSS(4) + SACK|TS(12) + COOKIE(20) + WSCALE(4) == 40
- */
- if (unlikely(OPTION_COOKIE_EXTENSION & options)) {
- __u8 *cookie_copy = opts->hash_location;
- u8 cookie_size = opts->hash_size;
-
- /* 8-bit multiple handled in tcp_cookie_size_check() above,
- * and elsewhere.
- */
- if (0x2 & cookie_size) {
- __u8 *p = (__u8 *)ptr;
-
- /* 16-bit multiple */
- *p++ = TCPOPT_COOKIE;
- *p++ = TCPOLEN_COOKIE_BASE + cookie_size;
- *p++ = *cookie_copy++;
- *p++ = *cookie_copy++;
- ptr++;
- cookie_size -= 2;
- } else {
- /* 32-bit multiple */
- *ptr++ = htonl(((TCPOPT_NOP << 24) |
- (TCPOPT_NOP << 16) |
- (TCPOPT_COOKIE << 8) |
- TCPOLEN_COOKIE_BASE) +
- cookie_size);
- }
-
- if (cookie_size > 0) {
- memcpy(ptr, cookie_copy, cookie_size);
- ptr += (cookie_size / 4);
- }
- }
-
if (unlikely(OPTION_SACK_ADVERTISE & options)) {
*ptr++ = htonl((TCPOPT_NOP << 24) |
(TCPOPT_NOP << 16) |
struct tcp_md5sig_key **md5)
{
struct tcp_sock *tp = tcp_sk(sk);
- struct tcp_cookie_values *cvp = tp->cookie_values;
unsigned int remaining = MAX_TCP_OPTION_SPACE;
- u8 cookie_size = (!tp->rx_opt.cookie_out_never && cvp != NULL) ?
- tcp_cookie_size_check(cvp->cookie_desired) :
- 0;
struct tcp_fastopen_request *fastopen = tp->fastopen_req;
#ifdef CONFIG_TCP_MD5SIG
tp->syn_fastopen = 1;
}
}
- /* Note that timestamps are required by the specification.
- *
- * Odd numbers of bytes are prohibited by the specification, ensuring
- * that the cookie is 16-bit aligned, and the resulting cookie pair is
- * 32-bit aligned.
- */
- if (*md5 == NULL &&
- (OPTION_TS & opts->options) &&
- cookie_size > 0) {
- int need = TCPOLEN_COOKIE_BASE + cookie_size;
-
- if (0x2 & need) {
- /* 32-bit multiple */
- need += 2; /* NOPs */
-
- if (need > remaining) {
- /* try shrinking cookie to fit */
- cookie_size -= 2;
- need -= 4;
- }
- }
- while (need > remaining && TCP_COOKIE_MIN <= cookie_size) {
- cookie_size -= 4;
- need -= 4;
- }
- if (TCP_COOKIE_MIN <= cookie_size) {
- opts->options |= OPTION_COOKIE_EXTENSION;
- opts->hash_location = (__u8 *)&cvp->cookie_pair[0];
- opts->hash_size = cookie_size;
-
- /* Remember for future incarnations. */
- cvp->cookie_desired = cookie_size;
-
- if (cvp->cookie_desired != cvp->cookie_pair_size) {
- /* Currently use random bytes as a nonce,
- * assuming these are completely unpredictable
- * by hostile users of the same system.
- */
- get_random_bytes(&cvp->cookie_pair[0],
- cookie_size);
- cvp->cookie_pair_size = cookie_size;
- }
- remaining -= need;
- }
- }
return MAX_TCP_OPTION_SPACE - remaining;
}
unsigned int mss, struct sk_buff *skb,
struct tcp_out_options *opts,
struct tcp_md5sig_key **md5,
- struct tcp_extend_values *xvp,
struct tcp_fastopen_cookie *foc)
{
struct inet_request_sock *ireq = inet_rsk(req);
unsigned int remaining = MAX_TCP_OPTION_SPACE;
- u8 cookie_plus = (xvp != NULL && !xvp->cookie_out_never) ?
- xvp->cookie_plus :
- 0;
#ifdef CONFIG_TCP_MD5SIG
*md5 = tcp_rsk(req)->af_specific->md5_lookup(sk, req);
remaining -= need;
}
}
- /* Similar rationale to tcp_syn_options() applies here, too.
- * If the <SYN> options fit, the same options should fit now!
- */
- if (*md5 == NULL &&
- ireq->tstamp_ok &&
- cookie_plus > TCPOLEN_COOKIE_BASE) {
- int need = cookie_plus; /* has TCPOLEN_COOKIE_BASE */
-
- if (0x2 & need) {
- /* 32-bit multiple */
- need += 2; /* NOPs */
- }
- if (need <= remaining) {
- opts->options |= OPTION_COOKIE_EXTENSION;
- opts->hash_size = cookie_plus - TCPOLEN_COOKIE_BASE;
- remaining -= need;
- } else {
- /* There's no error return, so flag it. */
- xvp->cookie_out_never = 1; /* true */
- opts->hash_size = 0;
- }
- }
+
return MAX_TCP_OPTION_SPACE - remaining;
}
* We cant xmit new skbs from this context, as we might already
* hold qdisc lock.
*/
-static void tcp_wfree(struct sk_buff *skb)
+void tcp_wfree(struct sk_buff *skb)
{
struct sock *sk = skb->sk;
struct tcp_sock *tp = tcp_sk(sk);
if (nonagle & TCP_NAGLE_PUSH)
return true;
- /* 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 (tcp_urg_mode(tp) || (tp->frto_counter == 2) ||
- (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN))
+ /* Don't use the nagle rule for urgent data (or for the final FIN). */
+ if (tcp_urg_mode(tp) || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN))
return true;
if (!tcp_nagle_check(tp, skb, cur_mss, nonagle))
goto send_now;
}
- /* Ok, it looks like it is advisable to defer. */
- tp->tso_deferred = 1 | (jiffies << 1);
+ /* Ok, it looks like it is advisable to defer.
+ * Do not rearm the timer if already set to not break TCP ACK clocking.
+ */
+ if (!tp->tso_deferred)
+ tp->tso_deferred = 1 | (jiffies << 1);
return true;
* snd_up-64k-mss .. snd_up cannot be large. However, taking into
* account rare use of URG, this is not a big flaw.
*
+ * Send at most one packet when push_one > 0. Temporarily ignore
+ * cwnd limit to force at most one packet out when push_one == 2.
+
* Returns true, if no segments are in flight and we have queued segments,
* but cannot send anything now because of SWS or another problem.
*/
goto repair; /* Skip network transmission */
cwnd_quota = tcp_cwnd_test(tp, skb);
- if (!cwnd_quota)
- break;
+ if (!cwnd_quota) {
+ if (push_one == 2)
+ /* Force out a loss probe pkt. */
+ cwnd_quota = 1;
+ else
+ break;
+ }
if (unlikely(!tcp_snd_wnd_test(tp, skb, mss_now)))
break;
if (likely(sent_pkts)) {
if (tcp_in_cwnd_reduction(sk))
tp->prr_out += sent_pkts;
+
+ /* Send one loss probe per tail loss episode. */
+ if (push_one != 2)
+ tcp_schedule_loss_probe(sk);
tcp_cwnd_validate(sk);
return false;
}
- return !tp->packets_out && tcp_send_head(sk);
+ return (push_one == 2) || (!tp->packets_out && tcp_send_head(sk));
+}
+
+bool tcp_schedule_loss_probe(struct sock *sk)
+{
+ struct inet_connection_sock *icsk = inet_csk(sk);
+ struct tcp_sock *tp = tcp_sk(sk);
+ u32 timeout, tlp_time_stamp, rto_time_stamp;
+ u32 rtt = tp->srtt >> 3;
+
+ if (WARN_ON(icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS))
+ return false;
+ /* No consecutive loss probes. */
+ if (WARN_ON(icsk->icsk_pending == ICSK_TIME_LOSS_PROBE)) {
+ tcp_rearm_rto(sk);
+ return false;
+ }
+ /* Don't do any loss probe on a Fast Open connection before 3WHS
+ * finishes.
+ */
+ if (sk->sk_state == TCP_SYN_RECV)
+ return false;
+
+ /* TLP is only scheduled when next timer event is RTO. */
+ if (icsk->icsk_pending != ICSK_TIME_RETRANS)
+ return false;
+
+ /* Schedule a loss probe in 2*RTT for SACK capable connections
+ * in Open state, that are either limited by cwnd or application.
+ */
+ if (sysctl_tcp_early_retrans < 3 || !rtt || !tp->packets_out ||
+ !tcp_is_sack(tp) || inet_csk(sk)->icsk_ca_state != TCP_CA_Open)
+ return false;
+
+ if ((tp->snd_cwnd > tcp_packets_in_flight(tp)) &&
+ tcp_send_head(sk))
+ return false;
+
+ /* Probe timeout is at least 1.5*rtt + TCP_DELACK_MAX to account
+ * for delayed ack when there's one outstanding packet.
+ */
+ timeout = rtt << 1;
+ if (tp->packets_out == 1)
+ timeout = max_t(u32, timeout,
+ (rtt + (rtt >> 1) + TCP_DELACK_MAX));
+ timeout = max_t(u32, timeout, msecs_to_jiffies(10));
+
+ /* If RTO is shorter, just schedule TLP in its place. */
+ tlp_time_stamp = tcp_time_stamp + timeout;
+ rto_time_stamp = (u32)inet_csk(sk)->icsk_timeout;
+ if ((s32)(tlp_time_stamp - rto_time_stamp) > 0) {
+ s32 delta = rto_time_stamp - tcp_time_stamp;
+ if (delta > 0)
+ timeout = delta;
+ }
+
+ inet_csk_reset_xmit_timer(sk, ICSK_TIME_LOSS_PROBE, timeout,
+ TCP_RTO_MAX);
+ return true;
+}
+
+/* When probe timeout (PTO) fires, send a new segment if one exists, else
+ * retransmit the last segment.
+ */
+void tcp_send_loss_probe(struct sock *sk)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct sk_buff *skb;
+ int pcount;
+ int mss = tcp_current_mss(sk);
+ int err = -1;
+
+ if (tcp_send_head(sk) != NULL) {
+ err = tcp_write_xmit(sk, mss, TCP_NAGLE_OFF, 2, GFP_ATOMIC);
+ goto rearm_timer;
+ }
+
+ /* At most one outstanding TLP retransmission. */
+ if (tp->tlp_high_seq)
+ goto rearm_timer;
+
+ /* Retransmit last segment. */
+ skb = tcp_write_queue_tail(sk);
+ if (WARN_ON(!skb))
+ goto rearm_timer;
+
+ pcount = tcp_skb_pcount(skb);
+ if (WARN_ON(!pcount))
+ goto rearm_timer;
+
+ if ((pcount > 1) && (skb->len > (pcount - 1) * mss)) {
+ if (unlikely(tcp_fragment(sk, skb, (pcount - 1) * mss, mss)))
+ goto rearm_timer;
+ skb = tcp_write_queue_tail(sk);
+ }
+
+ if (WARN_ON(!skb || !tcp_skb_pcount(skb)))
+ goto rearm_timer;
+
+ /* Probe with zero data doesn't trigger fast recovery. */
+ if (skb->len > 0)
+ err = __tcp_retransmit_skb(sk, skb);
+
+ /* Record snd_nxt for loss detection. */
+ if (likely(!err))
+ tp->tlp_high_seq = tp->snd_nxt;
+
+rearm_timer:
+ inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+ inet_csk(sk)->icsk_rto,
+ TCP_RTO_MAX);
+
+ if (likely(!err))
+ NET_INC_STATS_BH(sock_net(sk),
+ LINUX_MIB_TCPLOSSPROBES);
+ return;
}
/* Push out any pending frames which were held back due to
* sk: listener socket
* dst: dst entry attached to the SYNACK
* req: request_sock pointer
- * rvp: request_values pointer
*
* Allocate one skb and build a SYNACK packet.
* @dst is consumed : Caller should not use it again.
*/
struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
struct request_sock *req,
- struct request_values *rvp,
struct tcp_fastopen_cookie *foc)
{
struct tcp_out_options opts;
- struct tcp_extend_values *xvp = tcp_xv(rvp);
struct inet_request_sock *ireq = inet_rsk(req);
struct tcp_sock *tp = tcp_sk(sk);
- const struct tcp_cookie_values *cvp = tp->cookie_values;
struct tcphdr *th;
struct sk_buff *skb;
struct tcp_md5sig_key *md5;
int tcp_header_size;
int mss;
- int s_data_desired = 0;
- if (cvp != NULL && cvp->s_data_constant && cvp->s_data_desired)
- s_data_desired = cvp->s_data_desired;
- skb = alloc_skb(MAX_TCP_HEADER + 15 + s_data_desired,
- sk_gfp_atomic(sk, GFP_ATOMIC));
+ skb = alloc_skb(MAX_TCP_HEADER + 15, sk_gfp_atomic(sk, GFP_ATOMIC));
if (unlikely(!skb)) {
dst_release(dst);
return NULL;
else
#endif
TCP_SKB_CB(skb)->when = tcp_time_stamp;
- tcp_header_size = tcp_synack_options(sk, req, mss,
- skb, &opts, &md5, xvp, foc)
- + sizeof(*th);
+ tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts, &md5,
+ foc) + sizeof(*th);
skb_push(skb, tcp_header_size);
skb_reset_transport_header(skb);
tcp_init_nondata_skb(skb, tcp_rsk(req)->snt_isn,
TCPHDR_SYN | TCPHDR_ACK);
- if (OPTION_COOKIE_EXTENSION & opts.options) {
- if (s_data_desired) {
- u8 *buf = skb_put(skb, s_data_desired);
-
- /* copy data directly from the listening socket. */
- memcpy(buf, cvp->s_data_payload, s_data_desired);
- TCP_SKB_CB(skb)->end_seq += s_data_desired;
- }
-
- if (opts.hash_size > 0) {
- __u32 workspace[SHA_WORKSPACE_WORDS];
- u32 *mess = &xvp->cookie_bakery[COOKIE_DIGEST_WORDS];
- u32 *tail = &mess[COOKIE_MESSAGE_WORDS-1];
-
- /* Secret recipe depends on the Timestamp, (future)
- * Sequence and Acknowledgment Numbers, Initiator
- * Cookie, and others handled by IP variant caller.
- */
- *tail-- ^= opts.tsval;
- *tail-- ^= tcp_rsk(req)->rcv_isn + 1;
- *tail-- ^= TCP_SKB_CB(skb)->seq + 1;
-
- /* recommended */
- *tail-- ^= (((__force u32)th->dest << 16) | (__force u32)th->source);
- *tail-- ^= (u32)(unsigned long)cvp; /* per sockopt */
-
- sha_transform((__u32 *)&xvp->cookie_bakery[0],
- (char *)mess,
- &workspace[0]);
- opts.hash_location =
- (__u8 *)&xvp->cookie_bakery[0];
- }
- }
-
th->seq = htonl(TCP_SKB_CB(skb)->seq);
/* XXX data is queued and acked as is. No buffer/window check */
th->ack_seq = htonl(tcp_rsk(req)->rcv_nxt);
projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blobdiff