diff options
Diffstat (limited to 'net/ipv4/tcp_output.c')
| -rw-r--r-- | net/ipv4/tcp_output.c | 572 |
1 files changed, 421 insertions, 151 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 416fc4c2e7eb..dc7c096ddfef 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -37,6 +37,7 @@ #include <net/tcp.h> #include <linux/compiler.h> +#include <linux/gfp.h> #include <linux/module.h> /* People can turn this off for buggy TCP's found in printers etc. */ @@ -54,11 +55,16 @@ int sysctl_tcp_workaround_signed_windows __read_mostly = 0; 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; +int sysctl_tcp_base_mss __read_mostly = TCP_BASE_MSS; /* 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); + + +/* Account for new data that has been sent to the network. */ static void tcp_event_new_data_sent(struct sock *sk, struct sk_buff *skb) { struct tcp_sock *tp = tcp_sk(sk); @@ -113,9 +119,13 @@ static __u16 tcp_advertise_mss(struct sock *sk) struct dst_entry *dst = __sk_dst_get(sk); int mss = tp->advmss; - if (dst && dst_metric(dst, RTAX_ADVMSS) < mss) { - mss = dst_metric(dst, RTAX_ADVMSS); - tp->advmss = mss; + if (dst) { + unsigned int metric = dst_metric_advmss(dst); + + if (metric < mss) { + mss = metric; + tp->advmss = mss; + } } return (__u16)mss; @@ -142,6 +152,7 @@ static void tcp_cwnd_restart(struct sock *sk, struct dst_entry *dst) tp->snd_cwnd_used = 0; } +/* Congestion state accounting after a packet has been sent. */ static void tcp_event_data_sent(struct tcp_sock *tp, struct sk_buff *skb, struct sock *sk) { @@ -161,6 +172,7 @@ static void tcp_event_data_sent(struct tcp_sock *tp, icsk->icsk_ack.pingpong = 1; } +/* Account for an ACK we sent. */ static inline void tcp_event_ack_sent(struct sock *sk, unsigned int pkts) { tcp_dec_quickack_mode(sk, pkts); @@ -176,7 +188,8 @@ static inline void tcp_event_ack_sent(struct sock *sk, unsigned int pkts) */ void tcp_select_initial_window(int __space, __u32 mss, __u32 *rcv_wnd, __u32 *window_clamp, - int wscale_ok, __u8 *rcv_wscale) + int wscale_ok, __u8 *rcv_wscale, + __u32 init_rcv_wnd) { unsigned int space = (__space < 0 ? 0 : __space); @@ -215,23 +228,28 @@ void tcp_select_initial_window(int __space, __u32 mss, } } - /* Set initial window to value enough for senders, - * following RFC2414. Senders, not following this RFC, - * will be satisfied with 2. + /* Set initial window to a value enough for senders starting with + * initial congestion window of TCP_DEFAULT_INIT_RCVWND. Place + * a limit on the initial window when mss is larger than 1460. */ if (mss > (1 << *rcv_wscale)) { - int init_cwnd = 4; - 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; + int init_cwnd = TCP_DEFAULT_INIT_RCVWND; + if (mss > 1460) + init_cwnd = + max_t(u32, (1460 * TCP_DEFAULT_INIT_RCVWND) / mss, 2); + /* when initializing use the value from init_rcv_wnd + * rather than the default from above + */ + if (init_rcv_wnd) + *rcv_wnd = min(*rcv_wnd, init_rcv_wnd * mss); + else + *rcv_wnd = min(*rcv_wnd, init_cwnd * mss); } /* Set the clamp no higher than max representable value */ (*window_clamp) = min(65535U << (*rcv_wscale), *window_clamp); } +EXPORT_SYMBOL(tcp_select_initial_window); /* Chose a new window to advertise, update state in tcp_sock for the * socket, and return result with RFC1323 scaling applied. The return @@ -276,20 +294,22 @@ static u16 tcp_select_window(struct sock *sk) return new_win; } +/* Packet ECN state for a SYN-ACK */ static inline void TCP_ECN_send_synack(struct tcp_sock *tp, struct sk_buff *skb) { - TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_CWR; + TCP_SKB_CB(skb)->flags &= ~TCPHDR_CWR; if (!(tp->ecn_flags & TCP_ECN_OK)) - TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_ECE; + TCP_SKB_CB(skb)->flags &= ~TCPHDR_ECE; } +/* Packet ECN state for a SYN. */ 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 == 1) { - TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ECE | TCPCB_FLAG_CWR; + TCP_SKB_CB(skb)->flags |= TCPHDR_ECE | TCPHDR_CWR; tp->ecn_flags = TCP_ECN_OK; } } @@ -301,6 +321,9 @@ TCP_ECN_make_synack(struct request_sock *req, struct tcphdr *th) th->ece = 1; } +/* Set up ECN state for a packet on a ESTABLISHED socket that is about to + * be sent. + */ static inline void TCP_ECN_send(struct sock *sk, struct sk_buff *skb, int tcp_header_len) { @@ -330,6 +353,7 @@ static inline void TCP_ECN_send(struct sock *sk, struct sk_buff *skb, */ static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags) { + skb->ip_summed = CHECKSUM_PARTIAL; skb->csum = 0; TCP_SKB_CB(skb)->flags = flags; @@ -340,7 +364,7 @@ static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags) skb_shinfo(skb)->gso_type = 0; TCP_SKB_CB(skb)->seq = seq; - if (flags & (TCPCB_FLAG_SYN | TCPCB_FLAG_FIN)) + if (flags & (TCPHDR_SYN | TCPHDR_FIN)) seq++; TCP_SKB_CB(skb)->end_seq = seq; } @@ -353,16 +377,52 @@ static inline int tcp_urg_mode(const struct tcp_sock *tp) #define OPTION_SACK_ADVERTISE (1 << 0) #define OPTION_TS (1 << 1) #define OPTION_MD5 (1 << 2) +#define OPTION_WSCALE (1 << 3) +#define OPTION_COOKIE_EXTENSION (1 << 4) struct tcp_out_options { u8 options; /* bit field of OPTION_* */ u8 ws; /* window scale, 0 to disable */ u8 num_sack_blocks; /* number of SACK blocks to include */ + u8 hash_size; /* bytes in hash_location */ u16 mss; /* 0 to disable */ __u32 tsval, tsecr; /* need to include OPTION_TS */ + __u8 *hash_location; /* temporary pointer, overloaded */ }; -/* Beware: Something in the Internet is very sensitive to the ordering of +/* 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 * 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 @@ -374,17 +434,34 @@ struct tcp_out_options { * (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) { - if (unlikely(OPTION_MD5 & opts->options)) { - *ptr++ = htonl((TCPOPT_NOP << 24) | - (TCPOPT_NOP << 16) | - (TCPOPT_MD5SIG << 8) | - TCPOLEN_MD5SIG); - *md5_hash = (__u8 *)ptr; + struct tcp_out_options *opts) +{ + u8 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; + /* overload cookie hash location */ + opts->hash_location = (__u8 *)ptr; ptr += 4; - } else { - *md5_hash = NULL; } if (unlikely(opts->mss)) { @@ -393,12 +470,13 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp, opts->mss); } - if (likely(OPTION_TS & opts->options)) { - if (unlikely(OPTION_SACK_ADVERTISE & opts->options)) { + if (likely(OPTION_TS & options)) { + if (unlikely(OPTION_SACK_ADVERTISE & options)) { *ptr++ = htonl((TCPOPT_SACK_PERM << 24) | (TCPOLEN_SACK_PERM << 16) | (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP); + options &= ~OPTION_SACK_ADVERTISE; } else { *ptr++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | @@ -409,15 +487,52 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp, *ptr++ = htonl(opts->tsecr); } - if (unlikely(OPTION_SACK_ADVERTISE & opts->options && - !(OPTION_TS & opts->options))) { + /* 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) | (TCPOPT_SACK_PERM << 8) | TCPOLEN_SACK_PERM); } - if (unlikely(opts->ws)) { + if (unlikely(OPTION_WSCALE & options)) { *ptr++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_WINDOW << 16) | (TCPOLEN_WINDOW << 8) | @@ -445,17 +560,24 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp, } } +/* Compute TCP options for SYN packets. This is not the final + * network wire format yet. + */ static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb, struct tcp_out_options *opts, struct tcp_md5sig_key **md5) { struct tcp_sock *tp = tcp_sk(sk); - unsigned size = 0; + struct tcp_cookie_values *cvp = tp->cookie_values; + unsigned remaining = MAX_TCP_OPTION_SPACE; + u8 cookie_size = (!tp->rx_opt.cookie_out_never && cvp != NULL) ? + tcp_cookie_size_check(cvp->cookie_desired) : + 0; #ifdef CONFIG_TCP_MD5SIG *md5 = tp->af_specific->md5_lookup(sk, sk); if (*md5) { opts->options |= OPTION_MD5; - size += TCPOLEN_MD5SIG_ALIGNED; + remaining -= TCPOLEN_MD5SIG_ALIGNED; } #else *md5 = NULL; @@ -471,76 +593,154 @@ static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb, * SACKs don't matter, we never delay an ACK when we have any of those * going out. */ opts->mss = tcp_advertise_mss(sk); - size += TCPOLEN_MSS_ALIGNED; + remaining -= TCPOLEN_MSS_ALIGNED; if (likely(sysctl_tcp_timestamps && *md5 == NULL)) { opts->options |= OPTION_TS; opts->tsval = TCP_SKB_CB(skb)->when; opts->tsecr = tp->rx_opt.ts_recent; - size += TCPOLEN_TSTAMP_ALIGNED; + remaining -= TCPOLEN_TSTAMP_ALIGNED; } if (likely(sysctl_tcp_window_scaling)) { opts->ws = tp->rx_opt.rcv_wscale; - if (likely(opts->ws)) - size += TCPOLEN_WSCALE_ALIGNED; + opts->options |= OPTION_WSCALE; + remaining -= TCPOLEN_WSCALE_ALIGNED; } if (likely(sysctl_tcp_sack)) { opts->options |= OPTION_SACK_ADVERTISE; if (unlikely(!(OPTION_TS & opts->options))) - size += TCPOLEN_SACKPERM_ALIGNED; + remaining -= TCPOLEN_SACKPERM_ALIGNED; } - return size; + /* 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; } +/* Set up TCP options for SYN-ACKs. */ static unsigned tcp_synack_options(struct sock *sk, struct request_sock *req, unsigned mss, struct sk_buff *skb, struct tcp_out_options *opts, - struct tcp_md5sig_key **md5) { - unsigned size = 0; + struct tcp_md5sig_key **md5, + struct tcp_extend_values *xvp) +{ struct inet_request_sock *ireq = inet_rsk(req); - char doing_ts; + unsigned 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); if (*md5) { opts->options |= OPTION_MD5; - size += TCPOLEN_MD5SIG_ALIGNED; + remaining -= TCPOLEN_MD5SIG_ALIGNED; + + /* We can't fit any SACK blocks in a packet with MD5 + TS + * options. There was discussion about disabling SACK + * rather than TS in order to fit in better with old, + * buggy kernels, but that was deemed to be unnecessary. + */ + ireq->tstamp_ok &= !ireq->sack_ok; } #else *md5 = NULL; #endif - /* we can't fit any SACK blocks in a packet with MD5 + TS - options. There was discussion about disabling SACK rather than TS in - order to fit in better with old, buggy kernels, but that was deemed - to be unnecessary. */ - doing_ts = ireq->tstamp_ok && !(*md5 && ireq->sack_ok); - + /* We always send an MSS option. */ opts->mss = mss; - size += TCPOLEN_MSS_ALIGNED; + remaining -= TCPOLEN_MSS_ALIGNED; if (likely(ireq->wscale_ok)) { opts->ws = ireq->rcv_wscale; - if (likely(opts->ws)) - size += TCPOLEN_WSCALE_ALIGNED; + opts->options |= OPTION_WSCALE; + remaining -= TCPOLEN_WSCALE_ALIGNED; } - if (likely(doing_ts)) { + if (likely(ireq->tstamp_ok)) { opts->options |= OPTION_TS; opts->tsval = TCP_SKB_CB(skb)->when; opts->tsecr = req->ts_recent; - size += TCPOLEN_TSTAMP_ALIGNED; + remaining -= TCPOLEN_TSTAMP_ALIGNED; } if (likely(ireq->sack_ok)) { opts->options |= OPTION_SACK_ADVERTISE; - if (unlikely(!doing_ts)) - size += TCPOLEN_SACKPERM_ALIGNED; + if (unlikely(!ireq->tstamp_ok)) + remaining -= TCPOLEN_SACKPERM_ALIGNED; } - return size; + /* 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; } +/* Compute TCP options for ESTABLISHED sockets. This is not the + * final wire format yet. + */ static unsigned tcp_established_options(struct sock *sk, struct sk_buff *skb, struct tcp_out_options *opts, struct tcp_md5sig_key **md5) { @@ -601,7 +801,6 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, struct tcp_out_options opts; unsigned tcp_options_size, tcp_header_size; struct tcp_md5sig_key *md5; - __u8 *md5_hash_location; struct tcphdr *th; int err; @@ -627,15 +826,18 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, tcb = TCP_SKB_CB(skb); memset(&opts, 0, sizeof(opts)); - if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) + if (unlikely(tcb->flags & TCPHDR_SYN)) tcp_options_size = tcp_syn_options(sk, skb, &opts, &md5); else tcp_options_size = tcp_established_options(sk, skb, &opts, &md5); tcp_header_size = tcp_options_size + sizeof(struct tcphdr); - if (tcp_packets_in_flight(tp) == 0) + if (tcp_packets_in_flight(tp) == 0) { tcp_ca_event(sk, CA_EVENT_TX_START); + skb->ooo_okay = 1; + } else + skb->ooo_okay = 0; skb_push(skb, tcp_header_size); skb_reset_transport_header(skb); @@ -643,14 +845,14 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, /* Build TCP header and checksum it. */ th = tcp_hdr(skb); - th->source = inet->sport; - th->dest = inet->dport; + th->source = inet->inet_sport; + th->dest = inet->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)) { + if (unlikely(tcb->flags & TCPHDR_SYN)) { /* RFC1323: The window in SYN & SYN/ACK segments * is never scaled. */ @@ -667,36 +869,37 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, th->urg_ptr = htons(tp->snd_up - tcb->seq); th->urg = 1; } else if (after(tcb->seq + 0xFFFF, tp->snd_nxt)) { - th->urg_ptr = 0xFFFF; + th->urg_ptr = htons(0xFFFF); th->urg = 1; } } - tcp_options_write((__be32 *)(th + 1), tp, &opts, &md5_hash_location); - if (likely((tcb->flags & TCPCB_FLAG_SYN) == 0)) + tcp_options_write((__be32 *)(th + 1), tp, &opts); + if (likely((tcb->flags & TCPHDR_SYN) == 0)) 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) { - sk->sk_route_caps &= ~NETIF_F_GSO_MASK; - tp->af_specific->calc_md5_hash(md5_hash_location, + sk_nocaps_add(sk, NETIF_F_GSO_MASK); + tp->af_specific->calc_md5_hash(opts.hash_location, md5, sk, NULL, skb); } #endif - icsk->icsk_af_ops->send_check(sk, skb->len, skb); + icsk->icsk_af_ops->send_check(sk, skb); - if (likely(tcb->flags & TCPCB_FLAG_ACK)) + if (likely(tcb->flags & TCPHDR_ACK)) tcp_event_ack_sent(sk, tcp_skb_pcount(skb)); 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(sock_net(sk), TCP_MIB_OUTSEGS); + TCP_ADD_STATS(sock_net(sk), TCP_MIB_OUTSEGS, + tcp_skb_pcount(skb)); - err = icsk->icsk_af_ops->queue_xmit(skb, 0); + err = icsk->icsk_af_ops->queue_xmit(skb); if (likely(err <= 0)) return err; @@ -705,7 +908,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it, return net_xmit_eval(err); } -/* This routine just queue's the buffer +/* This routine just queues the buffer for sending. * * NOTE: probe0 timer is not checked, do not forget tcp_push_pending_frames, * otherwise socket can stall. @@ -722,10 +925,12 @@ static void tcp_queue_skb(struct sock *sk, struct sk_buff *skb) sk_mem_charge(sk, skb->truesize); } +/* Initialize TSO segments for a packet. */ static void tcp_set_skb_tso_segs(struct sock *sk, struct sk_buff *skb, unsigned int mss_now) { - if (skb->len <= mss_now || !sk_can_gso(sk)) { + if (skb->len <= mss_now || !sk_can_gso(sk) || + skb->ip_summed == CHECKSUM_NONE) { /* Avoid the costly divide in the normal * non-TSO case. */ @@ -827,7 +1032,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 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 & ~(TCPHDR_FIN | TCPHDR_PSH); TCP_SKB_CB(buff)->flags = flags; TCP_SKB_CB(buff)->sacked = TCP_SKB_CB(skb)->sacked; @@ -908,6 +1113,7 @@ static void __pskb_trim_head(struct sk_buff *skb, int len) skb->len = skb->data_len; } +/* Remove acked data from a packet in the transmit queue. */ 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)) @@ -936,7 +1142,7 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len) return 0; } -/* Not accounting for SACKs here. */ +/* Calculate MSS. Not accounting for SACKs here. */ int tcp_mtu_to_mss(struct sock *sk, int pmtu) { struct tcp_sock *tp = tcp_sk(sk); @@ -980,6 +1186,7 @@ int tcp_mss_to_mtu(struct sock *sk, int mss) return mtu; } +/* MTU probing init per socket */ void tcp_mtup_init(struct sock *sk) { struct tcp_sock *tp = tcp_sk(sk); @@ -991,6 +1198,7 @@ void tcp_mtup_init(struct sock *sk) icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, sysctl_tcp_base_mss); icsk->icsk_mtup.probe_size = 0; } +EXPORT_SYMBOL(tcp_mtup_init); /* This function synchronize snd mss to current pmtu/exthdr set. @@ -1034,6 +1242,7 @@ unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu) return mss_now; } +EXPORT_SYMBOL(tcp_sync_mss); /* Compute the current effective MSS, taking SACKs and IP options, * and even PMTU discovery events into account. @@ -1130,8 +1339,7 @@ static inline unsigned int tcp_cwnd_test(struct tcp_sock *tp, 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) && - tcp_skb_pcount(skb) == 1) + if ((TCP_SKB_CB(skb)->flags & TCPHDR_FIN) && tcp_skb_pcount(skb) == 1) return 1; in_flight = tcp_packets_in_flight(tp); @@ -1142,7 +1350,8 @@ static inline unsigned int tcp_cwnd_test(struct tcp_sock *tp, return 0; } -/* This must be invoked the first time we consider transmitting +/* Intialize TSO state of a skb. + * This must be invoked the first time we consider transmitting * SKB onto the wire. */ static int tcp_init_tso_segs(struct sock *sk, struct sk_buff *skb, @@ -1157,6 +1366,7 @@ static int tcp_init_tso_segs(struct sock *sk, struct sk_buff *skb, return tso_segs; } +/* Minshall's variant of the Nagle send check. */ static inline int tcp_minshall_check(const struct tcp_sock *tp) { return after(tp->snd_sml, tp->snd_una) && @@ -1174,9 +1384,9 @@ static inline int tcp_nagle_check(const struct tcp_sock *tp, const struct sk_buff *skb, unsigned mss_now, int nonagle) { - return (skb->len < mss_now && + return skb->len < mss_now && ((nonagle & TCP_NAGLE_CORK) || - (!nonagle && tp->packets_out && tcp_minshall_check(tp)))); + (!nonagle && tp->packets_out && tcp_minshall_check(tp))); } /* Return non-zero if the Nagle test allows this packet to be @@ -1198,7 +1408,7 @@ static inline int tcp_nagle_test(struct tcp_sock *tp, struct sk_buff *skb, * Nagle can be ignored during F-RTO too (see RFC4138). */ if (tcp_urg_mode(tp) || (tp->frto_counter == 2) || - (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)) + (TCP_SKB_CB(skb)->flags & TCPHDR_FIN)) return 1; if (!tcp_nagle_check(tp, skb, cur_mss, nonagle)) @@ -1241,15 +1451,16 @@ static unsigned int tcp_snd_test(struct sock *sk, struct sk_buff *skb, return cwnd_quota; } +/* Test if sending is allowed right now. */ int tcp_may_send_now(struct sock *sk) { struct tcp_sock *tp = tcp_sk(sk); struct sk_buff *skb = tcp_send_head(sk); - return (skb && + return skb && tcp_snd_test(sk, skb, tcp_current_mss(sk), (tcp_skb_is_last(sk, skb) ? - tp->nonagle : TCP_NAGLE_PUSH))); + tp->nonagle : TCP_NAGLE_PUSH)); } /* Trim TSO SKB to LEN bytes, put the remaining data into a new packet @@ -1260,7 +1471,7 @@ int tcp_may_send_now(struct sock *sk) * 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) + unsigned int mss_now, gfp_t gfp) { struct sk_buff *buff; int nlen = skb->len - len; @@ -1270,7 +1481,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len, if (skb->len != skb->data_len) return tcp_fragment(sk, skb, len, mss_now); - buff = sk_stream_alloc_skb(sk, 0, GFP_ATOMIC); + buff = sk_stream_alloc_skb(sk, 0, gfp); if (unlikely(buff == NULL)) return -ENOMEM; @@ -1286,7 +1497,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int 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 & ~(TCPHDR_FIN | TCPHDR_PSH); TCP_SKB_CB(buff)->flags = flags; /* This packet was never sent out yet, so no SACK bits. */ @@ -1316,8 +1527,9 @@ 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; + int win_divisor; - if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) + if (TCP_SKB_CB(skb)->flags & TCPHDR_FIN) goto send_now; if (icsk->icsk_ca_state != TCP_CA_Open) @@ -1347,13 +1559,14 @@ static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb) if ((skb != tcp_write_queue_tail(sk)) && (limit >= skb->len)) goto send_now; - if (sysctl_tcp_tso_win_divisor) { + win_divisor = ACCESS_ONCE(sysctl_tcp_tso_win_divisor); + if (win_divisor) { u32 chunk = min(tp->snd_wnd, tp->snd_cwnd * tp->mss_cache); /* If at least some fraction of a window is available, * just use it. */ - chunk /= sysctl_tcp_tso_win_divisor; + chunk /= win_divisor; if (limit >= chunk) goto send_now; } else { @@ -1377,6 +1590,10 @@ send_now: } /* Create a new MTU probe if we are ready. + * MTU probe is regularly attempting to increase the path MTU by + * deliberately sending larger packets. This discovers routing + * changes resulting in larger path MTUs. + * * Returns 0 if we should wait to probe (no cwnd available), * 1 if a probe was sent, * -1 otherwise @@ -1439,7 +1656,7 @@ static int tcp_mtu_probe(struct sock *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)->flags = TCPHDR_ACK; TCP_SKB_CB(nskb)->sacked = 0; nskb->csum = 0; nskb->ip_summed = skb->ip_summed; @@ -1464,7 +1681,7 @@ static int tcp_mtu_probe(struct sock *sk) sk_wmem_free_skb(sk, skb); } else { TCP_SKB_CB(nskb)->flags |= TCP_SKB_CB(skb)->flags & - ~(TCPCB_FLAG_FIN|TCPCB_FLAG_PSH); + ~(TCPHDR_FIN|TCPHDR_PSH); if (!skb_shinfo(skb)->nr_frags) { skb_pull(skb, copy); if (skb->ip_summed != CHECKSUM_PARTIAL) @@ -1564,7 +1781,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, cwnd_quota); if (skb->len > limit && - unlikely(tso_fragment(sk, skb, limit, mss_now))) + unlikely(tso_fragment(sk, skb, limit, mss_now, gfp))) break; TCP_SKB_CB(skb)->when = tcp_time_stamp; @@ -1598,11 +1815,6 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, int nonagle) { - struct sk_buff *skb = tcp_send_head(sk); - - if (!skb) - return; - /* If we are closed, the bytes will have to remain here. * In time closedown will finish, we empty the write queue and * all will be happy. @@ -1789,6 +2001,7 @@ static void tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb) sk_wmem_free_skb(sk, next_skb); } +/* Check if coalescing SKBs is legal. */ static int tcp_can_collapse(struct sock *sk, struct sk_buff *skb) { if (tcp_skb_pcount(skb) > 1) @@ -1807,6 +2020,9 @@ static int tcp_can_collapse(struct sock *sk, struct sk_buff *skb) return 1; } +/* Collapse packets in the retransmit queue to make to create + * less packets on the wire. This is only done on retransmission. + */ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to, int space) { @@ -1816,7 +2032,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to, if (!sysctl_tcp_retrans_collapse) return; - if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN) + if (TCP_SKB_CB(skb)->flags & TCPHDR_SYN) return; tcp_for_write_queue_from_safe(skb, tmp, sk) { @@ -1885,8 +2101,8 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb) * 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, tcp_wnd_end(tp)) - && TCP_SKB_CB(skb)->seq != tp->snd_una) + if (!before(TCP_SKB_CB(skb)->seq, tcp_wnd_end(tp)) && + TCP_SKB_CB(skb)->seq != tp->snd_una) return -EAGAIN; if (skb->len > cur_mss) { @@ -1908,7 +2124,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb) * 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) && + (TCP_SKB_CB(skb)->flags & TCPHDR_FIN) && tp->snd_una == (TCP_SKB_CB(skb)->end_seq - 1)) { if (!pskb_trim(skb, 0)) { /* Reuse, even though it does some unnecessary work */ @@ -1956,6 +2172,9 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb) return err; } +/* Check if we forward retransmits are possible in the current + * window/congestion state. + */ static int tcp_can_forward_retransmit(struct sock *sk) { const struct inet_connection_sock *icsk = inet_csk(sk); @@ -2001,6 +2220,9 @@ void tcp_xmit_retransmit_queue(struct sock *sk) int mib_idx; int fwd_rexmitting = 0; + if (!tp->packets_out) + return; + if (!tp->lost_out) tp->retransmit_high = tp->snd_una; @@ -2094,13 +2316,14 @@ void tcp_send_fin(struct sock *sk) mss_now = tcp_current_mss(sk); if (tcp_send_head(sk) != NULL) { - TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_FIN; + TCP_SKB_CB(skb)->flags |= TCPHDR_FIN; TCP_SKB_CB(skb)->end_seq++; tp->write_seq++; } else { /* Socket is locked, keep trying until memory is available. */ for (;;) { - skb = alloc_skb_fclone(MAX_TCP_HEADER, GFP_KERNEL); + skb = alloc_skb_fclone(MAX_TCP_HEADER, + sk->sk_allocation); if (skb) break; yield(); @@ -2110,7 +2333,7 @@ void tcp_send_fin(struct sock *sk) skb_reserve(skb, MAX_TCP_HEADER); /* FIN eats a sequence byte, write_seq advanced by tcp_queue_skb(). */ tcp_init_nondata_skb(skb, tp->write_seq, - TCPCB_FLAG_ACK | TCPCB_FLAG_FIN); + TCPHDR_ACK | TCPHDR_FIN); tcp_queue_skb(sk, skb); } __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_OFF); @@ -2135,7 +2358,7 @@ void tcp_send_active_reset(struct sock *sk, gfp_t priority) /* Reserve space for headers and prepare control bits. */ skb_reserve(skb, MAX_TCP_HEADER); tcp_init_nondata_skb(skb, tcp_acceptable_seq(sk), - TCPCB_FLAG_ACK | TCPCB_FLAG_RST); + TCPHDR_ACK | TCPHDR_RST); /* Send it off. */ TCP_SKB_CB(skb)->when = tcp_time_stamp; if (tcp_transmit_skb(sk, skb, 0, priority)) @@ -2144,7 +2367,8 @@ void tcp_send_active_reset(struct sock *sk, gfp_t priority) TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTRSTS); } -/* WARNING: This routine must only be called when we have already sent +/* Send a crossed SYN-ACK during socket establishment. + * WARNING: This routine must only be called when we have already sent * a SYN packet that crossed the incoming SYN that caused this routine * to get called. If this assumption fails then the initial rcv_wnd * and rcv_wscale values will not be correct. @@ -2154,11 +2378,11 @@ int tcp_send_synack(struct sock *sk) struct sk_buff *skb; skb = tcp_write_queue_head(sk); - if (skb == NULL || !(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN)) { + if (skb == NULL || !(TCP_SKB_CB(skb)->flags & TCPHDR_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 & TCPHDR_ACK)) { if (skb_cloned(skb)) { struct sk_buff *nskb = skb_copy(skb, GFP_ATOMIC); if (nskb == NULL) @@ -2172,30 +2396,33 @@ int tcp_send_synack(struct sock *sk) skb = nskb; } - TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ACK; + TCP_SKB_CB(skb)->flags |= TCPHDR_ACK; TCP_ECN_send_synack(tcp_sk(sk), skb); } TCP_SKB_CB(skb)->when = tcp_time_stamp; return tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC); } -/* - * Prepare a SYN-ACK. - */ +/* Prepare a SYN-ACK. */ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, - struct request_sock *req) + struct request_sock *req, + struct request_values *rvp) { + 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; - int tcp_header_size; - struct tcp_out_options opts; struct sk_buff *skb; struct tcp_md5sig_key *md5; - __u8 *md5_hash_location; + int tcp_header_size; int mss; + int s_data_desired = 0; - skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15, 1, GFP_ATOMIC); + if (cvp != NULL && cvp->s_data_constant && cvp->s_data_desired) + s_data_desired = cvp->s_data_desired; + skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15 + s_data_desired, 1, GFP_ATOMIC); if (skb == NULL) return NULL; @@ -2204,7 +2431,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, skb_dst_set(skb, dst_clone(dst)); - mss = dst_metric(dst, RTAX_ADVMSS); + mss = dst_metric_advmss(dst); if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss) mss = tp->rx_opt.user_mss; @@ -2212,13 +2439,20 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, __u8 rcv_wscale; /* Set this up on the first call only */ req->window_clamp = tp->window_clamp ? : dst_metric(dst, RTAX_WINDOW); + + /* limit the window selection if the user enforce a smaller rx buffer */ + if (sk->sk_userlocks & SOCK_RCVBUF_LOCK && + (req->window_clamp > tcp_full_space(sk) || req->window_clamp == 0)) + req->window_clamp = tcp_full_space(sk); + /* tcp_full_space because it is guaranteed to be the first packet */ tcp_select_initial_window(tcp_full_space(sk), mss - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0), &req->rcv_wnd, &req->window_clamp, ireq->wscale_ok, - &rcv_wscale); + &rcv_wscale, + dst_metric(dst, RTAX_INITRWND)); ireq->rcv_wscale = rcv_wscale; } @@ -2230,8 +2464,8 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, #endif TCP_SKB_CB(skb)->when = tcp_time_stamp; tcp_header_size = tcp_synack_options(sk, req, mss, - skb, &opts, &md5) + - sizeof(struct tcphdr); + skb, &opts, &md5, xvp) + + sizeof(*th); skb_push(skb, tcp_header_size); skb_reset_transport_header(skb); @@ -2247,30 +2481,64 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, * not even correctly set) */ tcp_init_nondata_skb(skb, tcp_rsk(req)->snt_isn, - TCPCB_FLAG_SYN | TCPCB_FLAG_ACK); + 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); th->ack_seq = htonl(tcp_rsk(req)->rcv_isn + 1); /* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */ th->window = htons(min(req->rcv_wnd, 65535U)); - tcp_options_write((__be32 *)(th + 1), tp, &opts, &md5_hash_location); + tcp_options_write((__be32 *)(th + 1), tp, &opts); th->doff = (tcp_header_size >> 2); - TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS); + TCP_ADD_STATS(sock_net(sk), TCP_MIB_OUTSEGS, tcp_skb_pcount(skb)); #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, + tcp_rsk(req)->af_specific->calc_md5_hash(opts.hash_location, md5, NULL, req, skb); } #endif return skb; } +EXPORT_SYMBOL(tcp_make_synack); -/* - * Do all connect socket setups that can be done AF independent. - */ +/* Do all connect socket setups that can be done AF independent. */ static void tcp_connect_init(struct sock *sk) { struct dst_entry *dst = __sk_dst_get(sk); @@ -2297,18 +2565,24 @@ static void tcp_connect_init(struct sock *sk) if (!tp->window_clamp) tp->window_clamp = dst_metric(dst, RTAX_WINDOW); - tp->advmss = dst_metric(dst, RTAX_ADVMSS); + tp->advmss = dst_metric_advmss(dst); 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); + /* limit the window selection if the user enforce a smaller rx buffer */ + if (sk->sk_userlocks & SOCK_RCVBUF_LOCK && + (tp->window_clamp > tcp_full_space(sk) || tp->window_clamp == 0)) + tp->window_clamp = tcp_full_space(sk); + tcp_select_initial_window(tcp_full_space(sk), tp->advmss - (tp->rx_opt.ts_recent_stamp ? tp->tcp_header_len - sizeof(struct tcphdr) : 0), &tp->rcv_wnd, &tp->window_clamp, sysctl_tcp_window_scaling, - &rcv_wscale); + &rcv_wscale, + dst_metric(dst, RTAX_INITRWND)); tp->rx_opt.rcv_wscale = rcv_wscale; tp->rcv_ssthresh = tp->rcv_wnd; @@ -2329,13 +2603,12 @@ static void tcp_connect_init(struct sock *sk) tcp_clear_retrans(tp); } -/* - * Build a SYN and send it off. - */ +/* Build a SYN and send it off. */ int tcp_connect(struct sock *sk) { struct tcp_sock *tp = tcp_sk(sk); struct sk_buff *buff; + int err; tcp_connect_init(sk); @@ -2347,7 +2620,7 @@ int tcp_connect(struct sock *sk) skb_reserve(buff, MAX_TCP_HEADER); tp->snd_nxt = tp->write_seq; - tcp_init_nondata_skb(buff, tp->write_seq++, TCPCB_FLAG_SYN); + tcp_init_nondata_skb(buff, tp->write_seq++, TCPHDR_SYN); TCP_ECN_send_syn(sk, buff); /* Send it off. */ @@ -2358,7 +2631,9 @@ int tcp_connect(struct sock *sk) sk->sk_wmem_queued += buff->truesize; sk_mem_charge(sk, buff->truesize); tp->packets_out += tcp_skb_pcount(buff); - tcp_transmit_skb(sk, buff, 1, GFP_KERNEL); + err = tcp_transmit_skb(sk, buff, 1, sk->sk_allocation); + if (err == -ECONNREFUSED) + return err; /* We change tp->snd_nxt after the tcp_transmit_skb() call * in order to make this packet get counted in tcpOutSegs. @@ -2372,6 +2647,7 @@ int tcp_connect(struct sock *sk) inet_csk(sk)->icsk_rto, TCP_RTO_MAX); return 0; } +EXPORT_SYMBOL(tcp_connect); /* Send out a delayed ack, the caller does the policy checking * to see if we should even be here. See tcp_input.c:tcp_ack_snd_check() @@ -2453,7 +2729,7 @@ void tcp_send_ack(struct sock *sk) /* 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); + tcp_init_nondata_skb(buff, tcp_acceptable_seq(sk), TCPHDR_ACK); /* Send it off, this clears delayed acks for us. */ TCP_SKB_CB(buff)->when = tcp_time_stamp; @@ -2487,11 +2763,12 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent) * end to send an ack. Don't queue or clone SKB, just * send it. */ - tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPCB_FLAG_ACK); + tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPHDR_ACK); TCP_SKB_CB(skb)->when = tcp_time_stamp; return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC); } +/* Initiate keepalive or window probe from timer. */ int tcp_write_wakeup(struct sock *sk) { struct tcp_sock *tp = tcp_sk(sk); @@ -2516,13 +2793,13 @@ int tcp_write_wakeup(struct sock *sk) 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)->flags |= TCPHDR_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); - TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH; + TCP_SKB_CB(skb)->flags |= TCPHDR_PSH; TCP_SKB_CB(skb)->when = tcp_time_stamp; err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC); if (!err) @@ -2575,10 +2852,3 @@ void tcp_send_probe0(struct sock *sk) TCP_RTO_MAX); } } - -EXPORT_SYMBOL(tcp_select_initial_window); -EXPORT_SYMBOL(tcp_connect); -EXPORT_SYMBOL(tcp_make_synack); -EXPORT_SYMBOL(tcp_simple_retransmit); -EXPORT_SYMBOL(tcp_sync_mss); -EXPORT_SYMBOL(tcp_mtup_init); |