Index: head/sys/modules/tcp/fastpath/Makefile =================================================================== --- head/sys/modules/tcp/fastpath/Makefile (revision 336671) +++ head/sys/modules/tcp/fastpath/Makefile (nonexistent) @@ -1,18 +0,0 @@ -# -# $FreeBSD$ -# - -.PATH: ${SRCTOP}/sys/netinet/tcp_stacks - -KMOD= fastpath -SRCS= fastpath.c - -SRCS+= opt_inet.h opt_inet6.h opt_ipsec.h -SRCS+= opt_tcpdebug.h - -# -# Enable full debugging -# -#CFLAGS += -g - -.include Property changes on: head/sys/modules/tcp/fastpath/Makefile ___________________________________________________________________ Deleted: svn:eol-style ## -1 +0,0 ## -native \ No newline at end of property Deleted: svn:keywords ## -1 +0,0 ## -FreeBSD=%H \ No newline at end of property Deleted: svn:mime-type ## -1 +0,0 ## -text/plain \ No newline at end of property Index: head/sys/modules/tcp/Makefile =================================================================== --- head/sys/modules/tcp/Makefile (revision 336671) +++ head/sys/modules/tcp/Makefile (revision 336672) @@ -1,25 +1,23 @@ # # $FreeBSD$ # SYSDIR?=${SRCTOP}/sys .include "${SYSDIR}/conf/kern.opts.mk" SUBDIR= \ - ${_tcp_fastpath} \ ${_tcp_rack} \ ${_tcpmd5} \ .if ${MK_EXTRA_TCP_STACKS} != "no" || defined(ALL_MODULES) -_tcp_fastpath= fastpath _tcp_rack= rack .endif .if (${MK_INET_SUPPORT} != "no" || ${MK_INET6_SUPPORT} != "no") || \ defined(ALL_MODULES) .if ${MK_IPSEC_SUPPORT} != "no" _tcpmd5= tcpmd5 .endif .endif .include Index: head/sys/netinet/tcp_stacks/fastpath.c =================================================================== --- head/sys/netinet/tcp_stacks/fastpath.c (revision 336671) +++ head/sys/netinet/tcp_stacks/fastpath.c (nonexistent) @@ -1,2360 +0,0 @@ -/*- - * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1994, 1995 - * The Regents of the University of California. All rights reserved. - * Copyright (c) 2007-2008,2010 - * Swinburne University of Technology, Melbourne, Australia. - * Copyright (c) 2009-2010 Lawrence Stewart - * Copyright (c) 2010 The FreeBSD Foundation - * Copyright (c) 2010-2011 Juniper Networks, Inc. - * Copyright (c) 2015 Netflix Inc. - * All rights reserved. - * - * Portions of this software were developed at the Centre for Advanced Internet - * Architectures, Swinburne University of Technology, by Lawrence Stewart, - * James Healy and David Hayes, made possible in part by a grant from the Cisco - * University Research Program Fund at Community Foundation Silicon Valley. - * - * Portions of this software were developed at the Centre for Advanced - * Internet Architectures, Swinburne University of Technology, Melbourne, - * Australia by David Hayes under sponsorship from the FreeBSD Foundation. - * - * Portions of this software were developed by Robert N. M. Watson under - * contract to Juniper Networks, Inc. - * - * Portions of this software were developed by Randall R. Stewart while - * working for Netflix Inc. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - * - * @(#)tcp_input.c 8.12 (Berkeley) 5/24/95 - */ - -#include -__FBSDID("$FreeBSD$"); - -#include "opt_inet.h" -#include "opt_inet6.h" -#include "opt_tcpdebug.h" - -#include -#include -#include -#include -#include -#ifdef TCP_HHOOK -#include -#endif -#include -#include -#include /* for proc0 declaration */ -#include -#include -#include -#include -#include -#include -#include -#include - -#include /* before tcp_seq.h, for tcp_random18() */ - -#include - -#include -#include - -#define TCPSTATES /* for logging */ - -#include -#include -#include -#include -#include -#include /* required for icmp_var.h */ -#include /* for ICMP_BANDLIM */ -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#ifdef TCPDEBUG -#include -#endif /* TCPDEBUG */ -#ifdef TCP_OFFLOAD -#include -#endif - -#include - -#include - -static void tcp_do_segment_fastslow(struct mbuf *, struct tcphdr *, - struct socket *, struct tcpcb *, int, int, uint8_t); - -static void tcp_do_segment_fastack(struct mbuf *, struct tcphdr *, - struct socket *, struct tcpcb *, int, int, uint8_t); - -/* - * Indicate whether this ack should be delayed. We can delay the ack if - * following conditions are met: - * - There is no delayed ack timer in progress. - * - Our last ack wasn't a 0-sized window. We never want to delay - * the ack that opens up a 0-sized window. - * - LRO wasn't used for this segment. We make sure by checking that the - * segment size is not larger than the MSS. - */ -#define DELAY_ACK(tp, tlen) \ - ((!tcp_timer_active(tp, TT_DELACK) && \ - (tp->t_flags & TF_RXWIN0SENT) == 0) && \ - (tlen <= tp->t_maxseg) && \ - (V_tcp_delack_enabled || (tp->t_flags & TF_NEEDSYN))) - -/* - * So how is this faster than the normal fast ack? - * It basically allows us to also stay in the fastpath - * when a window-update ack also arrives. In testing - * we saw only 25-30% of connections doing fastpath - * due to the fact that along with moving forward - * in sequence the window was also updated. - */ -static void -tcp_do_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so, - struct tcpcb *tp, struct tcpopt *to, int drop_hdrlen, int tlen, - uint32_t tiwin) -{ - int acked; - uint16_t nsegs; - int winup_only=0; - - nsegs = max(1, m->m_pkthdr.lro_nsegs); -#ifdef TCPDEBUG - /* - * The size of tcp_saveipgen must be the size of the max ip header, - * now IPv6. - */ - u_char tcp_saveipgen[IP6_HDR_LEN]; - struct tcphdr tcp_savetcp; - short ostate = 0; -#endif - - /* - * The following if statement will be true if - * we are doing the win_up_in_fp - * - We have more new data (SEQ_LT(tp->snd_wl1, th->th_seq)) - * - No more new data, but we have an ack for new data - * (tp->snd_wl1 == th->th_seq && SEQ_LT(tp->snd_wl2, th->th_ack)) - * - No more new data, the same ack point but the window grew - * (tp->snd_wl1 == th->th_seq && tp->snd_wl2 == th->th_ack && twin > tp->snd_wnd) - */ - if ((SEQ_LT(tp->snd_wl1, th->th_seq) || - (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) || - (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) { - /* keep track of pure window updates */ - if (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd) { - winup_only = 1; - TCPSTAT_INC(tcps_rcvwinupd); - } - tp->snd_wnd = tiwin; - tp->snd_wl1 = th->th_seq; - tp->snd_wl2 = th->th_ack; - if (tp->snd_wnd > tp->max_sndwnd) - tp->max_sndwnd = tp->snd_wnd; - } - /* - * If last ACK falls within this segment's sequence numbers, - * record the timestamp. - * NOTE that the test is modified according to the latest - * proposal of the tcplw@cray.com list (Braden 1993/04/26). - */ - if ((to->to_flags & TOF_TS) != 0 && - SEQ_LEQ(th->th_seq, tp->last_ack_sent)) { - tp->ts_recent_age = tcp_ts_getticks(); - tp->ts_recent = to->to_tsval; - } - /* - * This is a pure ack for outstanding data. - */ - TCPSTAT_INC(tcps_predack); - - /* - * "bad retransmit" recovery. - */ - if (tp->t_rxtshift == 1 && - tp->t_flags & TF_PREVVALID && - (int)(ticks - tp->t_badrxtwin) < 0) { - cc_cong_signal(tp, th, CC_RTO_ERR); - } - - /* - * Recalculate the transmit timer / rtt. - * - * Some boxes send broken timestamp replies - * during the SYN+ACK phase, ignore - * timestamps of 0 or we could calculate a - * huge RTT and blow up the retransmit timer. - */ - if ((to->to_flags & TOF_TS) != 0 && - to->to_tsecr) { - uint32_t t; - - t = tcp_ts_getticks() - to->to_tsecr; - if (!tp->t_rttlow || tp->t_rttlow > t) - tp->t_rttlow = t; - tcp_xmit_timer(tp, - TCP_TS_TO_TICKS(t) + 1); - } else if (tp->t_rtttime && - SEQ_GT(th->th_ack, tp->t_rtseq)) { - if (!tp->t_rttlow || - tp->t_rttlow > ticks - tp->t_rtttime) - tp->t_rttlow = ticks - tp->t_rtttime; - tcp_xmit_timer(tp, - ticks - tp->t_rtttime); - } - if (winup_only == 0) { - acked = BYTES_THIS_ACK(tp, th); - -#ifdef TCP_HHOOK - /* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */ - hhook_run_tcp_est_in(tp, th, to); -#endif - - TCPSTAT_ADD(tcps_rcvackbyte, acked); - sbdrop(&so->so_snd, acked); - if (SEQ_GT(tp->snd_una, tp->snd_recover) && - SEQ_LEQ(th->th_ack, tp->snd_recover)) - tp->snd_recover = th->th_ack - 1; - - /* - * Let the congestion control algorithm update - * congestion control related information. This - * typically means increasing the congestion - * window. - */ - cc_ack_received(tp, th, nsegs, CC_ACK); - - tp->snd_una = th->th_ack; - /* - * Pull snd_wl2 up to prevent seq wrap relative - * to th_ack. - */ - tp->snd_wl2 = th->th_ack; - tp->t_dupacks = 0; - - /* - * If all outstanding data are acked, stop - * retransmit timer, otherwise restart timer - * using current (possibly backed-off) value. - * If process is waiting for space, - * wakeup/selwakeup/signal. If data - * are ready to send, let tcp_output - * decide between more output or persist. - */ -#ifdef TCPDEBUG - if (so->so_options & SO_DEBUG) - tcp_trace(TA_INPUT, ostate, tp, - (void *)tcp_saveipgen, - &tcp_savetcp, 0); -#endif - TCP_PROBE3(debug__input, tp, th, m); - m_freem(m); - if (tp->snd_una == tp->snd_max) - tcp_timer_activate(tp, TT_REXMT, 0); - else if (!tcp_timer_active(tp, TT_PERSIST)) - tcp_timer_activate(tp, TT_REXMT, - tp->t_rxtcur); - } else { - /* - * Window update only, just free the mbufs and - * send out whatever we can. - */ - m_freem(m); - } - sowwakeup(so); - if (sbavail(&so->so_snd)) - (void) tcp_output(tp); - INP_WLOCK_ASSERT(tp->t_inpcb); - - if (tp->t_flags & TF_DELACK) { - tp->t_flags &= ~TF_DELACK; - tcp_timer_activate(tp, TT_DELACK, tcp_delacktime); - } - INP_WUNLOCK(tp->t_inpcb); -} - -/* - * Here nothing is really faster, its just that we - * have broken out the fast-data path also just like - * the fast-ack. - */ -static void -tcp_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so, - struct tcpcb *tp, struct tcpopt *to, int drop_hdrlen, int tlen, - uint32_t tiwin) -{ - int newsize = 0; /* automatic sockbuf scaling */ -#ifdef TCPDEBUG - /* - * The size of tcp_saveipgen must be the size of the max ip header, - * now IPv6. - */ - u_char tcp_saveipgen[IP6_HDR_LEN]; - struct tcphdr tcp_savetcp; - short ostate = 0; -#endif - /* - * If last ACK falls within this segment's sequence numbers, - * record the timestamp. - * NOTE that the test is modified according to the latest - * proposal of the tcplw@cray.com list (Braden 1993/04/26). - */ - if ((to->to_flags & TOF_TS) != 0 && - SEQ_LEQ(th->th_seq, tp->last_ack_sent)) { - tp->ts_recent_age = tcp_ts_getticks(); - tp->ts_recent = to->to_tsval; - } - - /* Clean receiver SACK report if present */ - if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks) - tcp_clean_sackreport(tp); - TCPSTAT_INC(tcps_preddat); - tp->rcv_nxt += tlen; - /* - * Pull snd_wl1 up to prevent seq wrap relative to - * th_seq. - */ - tp->snd_wl1 = th->th_seq; - /* - * Pull rcv_up up to prevent seq wrap relative to - * rcv_nxt. - */ - tp->rcv_up = tp->rcv_nxt; - TCPSTAT_ADD(tcps_rcvbyte, tlen); -#ifdef TCPDEBUG - if (so->so_options & SO_DEBUG) - tcp_trace(TA_INPUT, ostate, tp, - (void *)tcp_saveipgen, &tcp_savetcp, 0); -#endif - TCP_PROBE3(debug__input, tp, th, m); - - newsize = tcp_autorcvbuf(m, th, so, tp, tlen); - - /* Add data to socket buffer. */ - SOCKBUF_LOCK(&so->so_rcv); - if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { - m_freem(m); - } else { - /* - * Set new socket buffer size. - * Give up when limit is reached. - */ - if (newsize) - if (!sbreserve_locked(&so->so_rcv, - newsize, so, NULL)) - so->so_rcv.sb_flags &= ~SB_AUTOSIZE; - m_adj(m, drop_hdrlen); /* delayed header drop */ - sbappendstream_locked(&so->so_rcv, m, 0); - } - /* NB: sorwakeup_locked() does an implicit unlock. */ - sorwakeup_locked(so); - if (DELAY_ACK(tp, tlen)) { - tp->t_flags |= TF_DELACK; - } else { - tp->t_flags |= TF_ACKNOW; - tcp_output(tp); - } - INP_WLOCK_ASSERT(tp->t_inpcb); - - if (tp->t_flags & TF_DELACK) { - tp->t_flags &= ~TF_DELACK; - tcp_timer_activate(tp, TT_DELACK, tcp_delacktime); - } - INP_WUNLOCK(tp->t_inpcb); -} - -/* - * The slow-path is the clone of the long long part - * of tcp_do_segment past all the fast-path stuff. We - * use it here by two different callers, the fast/slow and - * the fastack only. - */ -static void -tcp_do_slowpath(struct mbuf *m, struct tcphdr *th, struct socket *so, - struct tcpcb *tp, struct tcpopt *to, int drop_hdrlen, int tlen, - uint32_t tiwin, int thflags) -{ - int acked, ourfinisacked, needoutput = 0; - int rstreason, todrop, win; - uint16_t nsegs; - char *s; - struct in_conninfo *inc; - struct mbuf *mfree = NULL; - - nsegs = max(1, m->m_pkthdr.lro_nsegs); -#ifdef TCPDEBUG - /* - * The size of tcp_saveipgen must be the size of the max ip header, - * now IPv6. - */ - u_char tcp_saveipgen[IP6_HDR_LEN]; - struct tcphdr tcp_savetcp; - short ostate = 0; -#endif - /* - * Calculate amount of space in receive window, - * and then do TCP input processing. - * Receive window is amount of space in rcv queue, - * but not less than advertised window. - */ - inc = &tp->t_inpcb->inp_inc; - win = sbspace(&so->so_rcv); - if (win < 0) - win = 0; - tp->rcv_wnd = imax(win, (int)(tp->rcv_adv - tp->rcv_nxt)); - switch (tp->t_state) { - - /* - * If the state is SYN_RECEIVED: - * if seg contains an ACK, but not for our SYN/ACK, send a RST. - */ - case TCPS_SYN_RECEIVED: - if ((thflags & TH_ACK) && - (SEQ_LEQ(th->th_ack, tp->snd_una) || - SEQ_GT(th->th_ack, tp->snd_max))) { - rstreason = BANDLIM_RST_OPENPORT; - goto dropwithreset; - } - break; - - /* - * If the state is SYN_SENT: - * if seg contains a RST with valid ACK (SEQ.ACK has already - * been verified), then drop the connection. - * if seg contains a RST without an ACK, drop the seg. - * if seg does not contain SYN, then drop the seg. - * Otherwise this is an acceptable SYN segment - * initialize tp->rcv_nxt and tp->irs - * if seg contains ack then advance tp->snd_una - * if seg contains an ECE and ECN support is enabled, the stream - * is ECN capable. - * if SYN has been acked change to ESTABLISHED else SYN_RCVD state - * arrange for segment to be acked (eventually) - * continue processing rest of data/controls, beginning with URG - */ - case TCPS_SYN_SENT: - if ((thflags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) { - TCP_PROBE5(connect__refused, NULL, tp, m, tp, th); - tp = tcp_drop(tp, ECONNREFUSED); - } - if (thflags & TH_RST) - goto drop; - if (!(thflags & TH_SYN)) - goto drop; - - tp->irs = th->th_seq; - tcp_rcvseqinit(tp); - if (thflags & TH_ACK) { - TCPSTAT_INC(tcps_connects); - soisconnected(so); -#ifdef MAC - mac_socketpeer_set_from_mbuf(m, so); -#endif - /* Do window scaling on this connection? */ - if ((tp->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) == - (TF_RCVD_SCALE|TF_REQ_SCALE)) { - tp->rcv_scale = tp->request_r_scale; - } - tp->rcv_adv += min(tp->rcv_wnd, - TCP_MAXWIN << tp->rcv_scale); - tp->snd_una++; /* SYN is acked */ - /* - * If there's data, delay ACK; if there's also a FIN - * ACKNOW will be turned on later. - */ - if (DELAY_ACK(tp, tlen) && tlen != 0) - tcp_timer_activate(tp, TT_DELACK, - tcp_delacktime); - else - tp->t_flags |= TF_ACKNOW; - - if ((thflags & TH_ECE) && V_tcp_do_ecn) { - tp->t_flags |= TF_ECN_PERMIT; - TCPSTAT_INC(tcps_ecn_shs); - } - - /* - * Received in SYN_SENT[*] state. - * Transitions: - * SYN_SENT --> ESTABLISHED - * SYN_SENT* --> FIN_WAIT_1 - */ - tp->t_starttime = ticks; - if (tp->t_flags & TF_NEEDFIN) { - tcp_state_change(tp, TCPS_FIN_WAIT_1); - tp->t_flags &= ~TF_NEEDFIN; - thflags &= ~TH_SYN; - } else { - tcp_state_change(tp, TCPS_ESTABLISHED); - TCP_PROBE5(connect__established, NULL, tp, - m, tp, th); - cc_conn_init(tp); - tcp_timer_activate(tp, TT_KEEP, - TP_KEEPIDLE(tp)); - } - } else { - /* - * Received initial SYN in SYN-SENT[*] state => - * simultaneous open. - * If it succeeds, connection is * half-synchronized. - * Otherwise, do 3-way handshake: - * SYN-SENT -> SYN-RECEIVED - * SYN-SENT* -> SYN-RECEIVED* - */ - tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN); - tcp_timer_activate(tp, TT_REXMT, 0); - tcp_state_change(tp, TCPS_SYN_RECEIVED); - } - - INP_INFO_RLOCK_ASSERT(&V_tcbinfo); - INP_WLOCK_ASSERT(tp->t_inpcb); - - /* - * Advance th->th_seq to correspond to first data byte. - * If data, trim to stay within window, - * dropping FIN if necessary. - */ - th->th_seq++; - if (tlen > tp->rcv_wnd) { - todrop = tlen - tp->rcv_wnd; - m_adj(m, -todrop); - tlen = tp->rcv_wnd; - thflags &= ~TH_FIN; - TCPSTAT_INC(tcps_rcvpackafterwin); - TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop); - } - tp->snd_wl1 = th->th_seq - 1; - tp->rcv_up = th->th_seq; - /* - * Client side of transaction: already sent SYN and data. - * If the remote host used T/TCP to validate the SYN, - * our data will be ACK'd; if so, enter normal data segment - * processing in the middle of step 5, ack processing. - * Otherwise, goto step 6. - */ - if (thflags & TH_ACK) - goto process_ACK; - - goto step6; - - /* - * If the state is LAST_ACK or CLOSING or TIME_WAIT: - * do normal processing. - * - * NB: Leftover from RFC1644 T/TCP. Cases to be reused later. - */ - case TCPS_LAST_ACK: - case TCPS_CLOSING: - break; /* continue normal processing */ - } - - /* - * States other than LISTEN or SYN_SENT. - * First check the RST flag and sequence number since reset segments - * are exempt from the timestamp and connection count tests. This - * fixes a bug introduced by the Stevens, vol. 2, p. 960 bugfix - * below which allowed reset segments in half the sequence space - * to fall though and be processed (which gives forged reset - * segments with a random sequence number a 50 percent chance of - * killing a connection). - * Then check timestamp, if present. - * Then check the connection count, if present. - * Then check that at least some bytes of segment are within - * receive window. If segment begins before rcv_nxt, - * drop leading data (and SYN); if nothing left, just ack. - */ - if (thflags & TH_RST) { - /* - * RFC5961 Section 3.2 - * - * - RST drops connection only if SEG.SEQ == RCV.NXT. - * - If RST is in window, we send challenge ACK. - * - * Note: to take into account delayed ACKs, we should - * test against last_ack_sent instead of rcv_nxt. - * Note 2: we handle special case of closed window, not - * covered by the RFC. - */ - if ((SEQ_GEQ(th->th_seq, tp->last_ack_sent) && - SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) || - (tp->rcv_wnd == 0 && tp->last_ack_sent == th->th_seq)) { - INP_INFO_RLOCK_ASSERT(&V_tcbinfo); - KASSERT(tp->t_state != TCPS_SYN_SENT, - ("%s: TH_RST for TCPS_SYN_SENT th %p tp %p", - __func__, th, tp)); - - if (V_tcp_insecure_rst || - tp->last_ack_sent == th->th_seq) { - TCPSTAT_INC(tcps_drops); - /* Drop the connection. */ - switch (tp->t_state) { - case TCPS_SYN_RECEIVED: - so->so_error = ECONNREFUSED; - goto close; - case TCPS_ESTABLISHED: - case TCPS_FIN_WAIT_1: - case TCPS_FIN_WAIT_2: - case TCPS_CLOSE_WAIT: - case TCPS_CLOSING: - case TCPS_LAST_ACK: - so->so_error = ECONNRESET; - close: - /* FALLTHROUGH */ - default: - tp = tcp_close(tp); - } - } else { - TCPSTAT_INC(tcps_badrst); - /* Send challenge ACK. */ - tcp_respond(tp, mtod(m, void *), th, m, - tp->rcv_nxt, tp->snd_nxt, TH_ACK); - tp->last_ack_sent = tp->rcv_nxt; - m = NULL; - } - } - goto drop; - } - - /* - * RFC5961 Section 4.2 - * Send challenge ACK for any SYN in synchronized state. - */ - if ((thflags & TH_SYN) && tp->t_state != TCPS_SYN_SENT) { - INP_INFO_RLOCK_ASSERT(&V_tcbinfo); - - TCPSTAT_INC(tcps_badsyn); - if (V_tcp_insecure_syn && - SEQ_GEQ(th->th_seq, tp->last_ack_sent) && - SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) { - tp = tcp_drop(tp, ECONNRESET); - rstreason = BANDLIM_UNLIMITED; - } else { - /* Send challenge ACK. */ - tcp_respond(tp, mtod(m, void *), th, m, tp->rcv_nxt, - tp->snd_nxt, TH_ACK); - tp->last_ack_sent = tp->rcv_nxt; - m = NULL; - } - goto drop; - } - - /* - * RFC 1323 PAWS: If we have a timestamp reply on this segment - * and it's less than ts_recent, drop it. - */ - if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent && - TSTMP_LT(to->to_tsval, tp->ts_recent)) { - - /* Check to see if ts_recent is over 24 days old. */ - if (tcp_ts_getticks() - tp->ts_recent_age > TCP_PAWS_IDLE) { - /* - * Invalidate ts_recent. If this segment updates - * ts_recent, the age will be reset later and ts_recent - * will get a valid value. If it does not, setting - * ts_recent to zero will at least satisfy the - * requirement that zero be placed in the timestamp - * echo reply when ts_recent isn't valid. The - * age isn't reset until we get a valid ts_recent - * because we don't want out-of-order segments to be - * dropped when ts_recent is old. - */ - tp->ts_recent = 0; - } else { - TCPSTAT_INC(tcps_rcvduppack); - TCPSTAT_ADD(tcps_rcvdupbyte, tlen); - TCPSTAT_INC(tcps_pawsdrop); - if (tlen) - goto dropafterack; - goto drop; - } - } - - /* - * In the SYN-RECEIVED state, validate that the packet belongs to - * this connection before trimming the data to fit the receive - * window. Check the sequence number versus IRS since we know - * the sequence numbers haven't wrapped. This is a partial fix - * for the "LAND" DoS attack. - */ - if (tp->t_state == TCPS_SYN_RECEIVED && SEQ_LT(th->th_seq, tp->irs)) { - rstreason = BANDLIM_RST_OPENPORT; - goto dropwithreset; - } - - todrop = tp->rcv_nxt - th->th_seq; - if (todrop > 0) { - if (thflags & TH_SYN) { - thflags &= ~TH_SYN; - th->th_seq++; - if (th->th_urp > 1) - th->th_urp--; - else - thflags &= ~TH_URG; - todrop--; - } - /* - * Following if statement from Stevens, vol. 2, p. 960. - */ - if (todrop > tlen - || (todrop == tlen && (thflags & TH_FIN) == 0)) { - /* - * Any valid FIN must be to the left of the window. - * At this point the FIN must be a duplicate or out - * of sequence; drop it. - */ - thflags &= ~TH_FIN; - - /* - * Send an ACK to resynchronize and drop any data. - * But keep on processing for RST or ACK. - */ - tp->t_flags |= TF_ACKNOW; - todrop = tlen; - TCPSTAT_INC(tcps_rcvduppack); - TCPSTAT_ADD(tcps_rcvdupbyte, todrop); - } else { - TCPSTAT_INC(tcps_rcvpartduppack); - TCPSTAT_ADD(tcps_rcvpartdupbyte, todrop); - } - drop_hdrlen += todrop; /* drop from the top afterwards */ - th->th_seq += todrop; - tlen -= todrop; - if (th->th_urp > todrop) - th->th_urp -= todrop; - else { - thflags &= ~TH_URG; - th->th_urp = 0; - } - } - - /* - * If new data are received on a connection after the - * user processes are gone, then RST the other end. - */ - if ((so->so_state & SS_NOFDREF) && - tp->t_state > TCPS_CLOSE_WAIT && tlen) { - INP_INFO_RLOCK_ASSERT(&V_tcbinfo); - - if ((s = tcp_log_addrs(inc, th, NULL, NULL))) { - log(LOG_DEBUG, "%s; %s: %s: Received %d bytes of data " - "after socket was closed, " - "sending RST and removing tcpcb\n", - s, __func__, tcpstates[tp->t_state], tlen); - free(s, M_TCPLOG); - } - tp = tcp_close(tp); - TCPSTAT_INC(tcps_rcvafterclose); - rstreason = BANDLIM_UNLIMITED; - goto dropwithreset; - } - - /* - * If segment ends after window, drop trailing data - * (and PUSH and FIN); if nothing left, just ACK. - */ - todrop = (th->th_seq + tlen) - (tp->rcv_nxt + tp->rcv_wnd); - if (todrop > 0) { - TCPSTAT_INC(tcps_rcvpackafterwin); - if (todrop >= tlen) { - TCPSTAT_ADD(tcps_rcvbyteafterwin, tlen); - /* - * If window is closed can only take segments at - * window edge, and have to drop data and PUSH from - * incoming segments. Continue processing, but - * remember to ack. Otherwise, drop segment - * and ack. - */ - if (tp->rcv_wnd == 0 && th->th_seq == tp->rcv_nxt) { - tp->t_flags |= TF_ACKNOW; - TCPSTAT_INC(tcps_rcvwinprobe); - } else - goto dropafterack; - } else - TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop); - m_adj(m, -todrop); - tlen -= todrop; - thflags &= ~(TH_PUSH|TH_FIN); - } - - /* - * If last ACK falls within this segment's sequence numbers, - * record its timestamp. - * NOTE: - * 1) That the test incorporates suggestions from the latest - * proposal of the tcplw@cray.com list (Braden 1993/04/26). - * 2) That updating only on newer timestamps interferes with - * our earlier PAWS tests, so this check should be solely - * predicated on the sequence space of this segment. - * 3) That we modify the segment boundary check to be - * Last.ACK.Sent <= SEG.SEQ + SEG.Len - * instead of RFC1323's - * Last.ACK.Sent < SEG.SEQ + SEG.Len, - * This modified check allows us to overcome RFC1323's - * limitations as described in Stevens TCP/IP Illustrated - * Vol. 2 p.869. In such cases, we can still calculate the - * RTT correctly when RCV.NXT == Last.ACK.Sent. - */ - if ((to->to_flags & TOF_TS) != 0 && - SEQ_LEQ(th->th_seq, tp->last_ack_sent) && - SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen + - ((thflags & (TH_SYN|TH_FIN)) != 0))) { - tp->ts_recent_age = tcp_ts_getticks(); - tp->ts_recent = to->to_tsval; - } - - /* - * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN - * flag is on (half-synchronized state), then queue data for - * later processing; else drop segment and return. - */ - if ((thflags & TH_ACK) == 0) { - if (tp->t_state == TCPS_SYN_RECEIVED || - (tp->t_flags & TF_NEEDSYN)) - goto step6; - else if (tp->t_flags & TF_ACKNOW) - goto dropafterack; - else - goto drop; - } - - /* - * Ack processing. - */ - switch (tp->t_state) { - - /* - * In SYN_RECEIVED state, the ack ACKs our SYN, so enter - * ESTABLISHED state and continue processing. - * The ACK was checked above. - */ - case TCPS_SYN_RECEIVED: - - TCPSTAT_INC(tcps_connects); - soisconnected(so); - /* Do window scaling? */ - if ((tp->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) == - (TF_RCVD_SCALE|TF_REQ_SCALE)) { - tp->rcv_scale = tp->request_r_scale; - tp->snd_wnd = tiwin; - } - /* - * Make transitions: - * SYN-RECEIVED -> ESTABLISHED - * SYN-RECEIVED* -> FIN-WAIT-1 - */ - tp->t_starttime = ticks; - if (tp->t_flags & TF_NEEDFIN) { - tcp_state_change(tp, TCPS_FIN_WAIT_1); - tp->t_flags &= ~TF_NEEDFIN; - } else { - tcp_state_change(tp, TCPS_ESTABLISHED); - TCP_PROBE5(accept__established, NULL, tp, - m, tp, th); - cc_conn_init(tp); - tcp_timer_activate(tp, TT_KEEP, TP_KEEPIDLE(tp)); - } - /* - * If segment contains data or ACK, will call tcp_reass() - * later; if not, do so now to pass queued data to user. - */ - if (tlen == 0 && (thflags & TH_FIN) == 0) - (void) tcp_reass(tp, (struct tcphdr *)0, 0, - (struct mbuf *)0); - tp->snd_wl1 = th->th_seq - 1; - /* FALLTHROUGH */ - - /* - * In ESTABLISHED state: drop duplicate ACKs; ACK out of range - * ACKs. If the ack is in the range - * tp->snd_una < th->th_ack <= tp->snd_max - * then advance tp->snd_una to th->th_ack and drop - * data from the retransmission queue. If this ACK reflects - * more up to date window information we update our window information. - */ - case TCPS_ESTABLISHED: - case TCPS_FIN_WAIT_1: - case TCPS_FIN_WAIT_2: - case TCPS_CLOSE_WAIT: - case TCPS_CLOSING: - case TCPS_LAST_ACK: - if (SEQ_GT(th->th_ack, tp->snd_max)) { - TCPSTAT_INC(tcps_rcvacktoomuch); - goto dropafterack; - } - if ((tp->t_flags & TF_SACK_PERMIT) && - ((to->to_flags & TOF_SACK) || - !TAILQ_EMPTY(&tp->snd_holes))) - tcp_sack_doack(tp, to, th->th_ack); - else - /* - * Reset the value so that previous (valid) value - * from the last ack with SACK doesn't get used. - */ - tp->sackhint.sacked_bytes = 0; - -#ifdef TCP_HHOOK - /* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */ - hhook_run_tcp_est_in(tp, th, to); -#endif - - if (SEQ_LEQ(th->th_ack, tp->snd_una)) { - if (tlen == 0 && tiwin == tp->snd_wnd) { - /* - * If this is the first time we've seen a - * FIN from the remote, this is not a - * duplicate and it needs to be processed - * normally. This happens during a - * simultaneous close. - */ - if ((thflags & TH_FIN) && - (TCPS_HAVERCVDFIN(tp->t_state) == 0)) { - tp->t_dupacks = 0; - break; - } - TCPSTAT_INC(tcps_rcvdupack); - /* - * If we have outstanding data (other than - * a window probe), this is a completely - * duplicate ack (ie, window info didn't - * change and FIN isn't set), - * the ack is the biggest we've - * seen and we've seen exactly our rexmt - * threshold of them, assume a packet - * has been dropped and retransmit it. - * Kludge snd_nxt & the congestion - * window so we send only this one - * packet. - * - * We know we're losing at the current - * window size so do congestion avoidance - * (set ssthresh to half the current window - * and pull our congestion window back to - * the new ssthresh). - * - * Dup acks mean that packets have left the - * network (they're now cached at the receiver) - * so bump cwnd by the amount in the receiver - * to keep a constant cwnd packets in the - * network. - * - * When using TCP ECN, notify the peer that - * we reduced the cwnd. - */ - if (!tcp_timer_active(tp, TT_REXMT) || - th->th_ack != tp->snd_una) - tp->t_dupacks = 0; - else if (++tp->t_dupacks > tcprexmtthresh || - IN_FASTRECOVERY(tp->t_flags)) { - cc_ack_received(tp, th, nsegs, - CC_DUPACK); - if ((tp->t_flags & TF_SACK_PERMIT) && - IN_FASTRECOVERY(tp->t_flags)) { - int awnd; - - /* - * Compute the amount of data in flight first. - * We can inject new data into the pipe iff - * we have less than 1/2 the original window's - * worth of data in flight. - */ - if (V_tcp_do_rfc6675_pipe) - awnd = tcp_compute_pipe(tp); - else - awnd = (tp->snd_nxt - tp->snd_fack) + - tp->sackhint.sack_bytes_rexmit; - - if (awnd < tp->snd_ssthresh) { - tp->snd_cwnd += tp->t_maxseg; - if (tp->snd_cwnd > tp->snd_ssthresh) - tp->snd_cwnd = tp->snd_ssthresh; - } - } else - tp->snd_cwnd += tp->t_maxseg; - (void) tp->t_fb->tfb_tcp_output(tp); - goto drop; - } else if (tp->t_dupacks == tcprexmtthresh) { - tcp_seq onxt = tp->snd_nxt; - - /* - * If we're doing sack, check to - * see if we're already in sack - * recovery. If we're not doing sack, - * check to see if we're in newreno - * recovery. - */ - if (tp->t_flags & TF_SACK_PERMIT) { - if (IN_FASTRECOVERY(tp->t_flags)) { - tp->t_dupacks = 0; - break; - } - } else { - if (SEQ_LEQ(th->th_ack, - tp->snd_recover)) { - tp->t_dupacks = 0; - break; - } - } - /* Congestion signal before ack. */ - cc_cong_signal(tp, th, CC_NDUPACK); - cc_ack_received(tp, th, nsegs, - CC_DUPACK); - tcp_timer_activate(tp, TT_REXMT, 0); - tp->t_rtttime = 0; - if (tp->t_flags & TF_SACK_PERMIT) { - TCPSTAT_INC( - tcps_sack_recovery_episode); - tp->sack_newdata = tp->snd_nxt; - tp->snd_cwnd = tp->t_maxseg; - (void) tp->t_fb->tfb_tcp_output(tp); - goto drop; - } - tp->snd_nxt = th->th_ack; - tp->snd_cwnd = tp->t_maxseg; - (void) tp->t_fb->tfb_tcp_output(tp); - KASSERT(tp->snd_limited <= 2, - ("%s: tp->snd_limited too big", - __func__)); - tp->snd_cwnd = tp->snd_ssthresh + - tp->t_maxseg * - (tp->t_dupacks - tp->snd_limited); - if (SEQ_GT(onxt, tp->snd_nxt)) - tp->snd_nxt = onxt; - goto drop; - } else if (V_tcp_do_rfc3042) { - /* - * Process first and second duplicate - * ACKs. Each indicates a segment - * leaving the network, creating room - * for more. Make sure we can send a - * packet on reception of each duplicate - * ACK by increasing snd_cwnd by one - * segment. Restore the original - * snd_cwnd after packet transmission. - */ - cc_ack_received(tp, th, nsegs, - CC_DUPACK); - uint32_t oldcwnd = tp->snd_cwnd; - tcp_seq oldsndmax = tp->snd_max; - u_int sent; - int avail; - - KASSERT(tp->t_dupacks == 1 || - tp->t_dupacks == 2, - ("%s: dupacks not 1 or 2", - __func__)); - if (tp->t_dupacks == 1) - tp->snd_limited = 0; - tp->snd_cwnd = - (tp->snd_nxt - tp->snd_una) + - (tp->t_dupacks - tp->snd_limited) * - tp->t_maxseg; - /* - * Only call tcp_output when there - * is new data available to be sent. - * Otherwise we would send pure ACKs. - */ - SOCKBUF_LOCK(&so->so_snd); - avail = sbavail(&so->so_snd) - - (tp->snd_nxt - tp->snd_una); - SOCKBUF_UNLOCK(&so->so_snd); - if (avail > 0) - (void) tp->t_fb->tfb_tcp_output(tp); - sent = tp->snd_max - oldsndmax; - if (sent > tp->t_maxseg) { - KASSERT((tp->t_dupacks == 2 && - tp->snd_limited == 0) || - (sent == tp->t_maxseg + 1 && - tp->t_flags & TF_SENTFIN), - ("%s: sent too much", - __func__)); - tp->snd_limited = 2; - } else if (sent > 0) - ++tp->snd_limited; - tp->snd_cwnd = oldcwnd; - goto drop; - } - } else - tp->t_dupacks = 0; - break; - } - - KASSERT(SEQ_GT(th->th_ack, tp->snd_una), - ("%s: th_ack <= snd_una", __func__)); - - /* - * If the congestion window was inflated to account - * for the other side's cached packets, retract it. - */ - if (IN_FASTRECOVERY(tp->t_flags)) { - if (SEQ_LT(th->th_ack, tp->snd_recover)) { - if (tp->t_flags & TF_SACK_PERMIT) - tcp_sack_partialack(tp, th); - else - tcp_newreno_partial_ack(tp, th); - } else - cc_post_recovery(tp, th); - } - tp->t_dupacks = 0; - /* - * If we reach this point, ACK is not a duplicate, - * i.e., it ACKs something we sent. - */ - if (tp->t_flags & TF_NEEDSYN) { - /* - * T/TCP: Connection was half-synchronized, and our - * SYN has been ACK'd (so connection is now fully - * synchronized). Go to non-starred state, - * increment snd_una for ACK of SYN, and check if - * we can do window scaling. - */ - tp->t_flags &= ~TF_NEEDSYN; - tp->snd_una++; - /* Do window scaling? */ - if ((tp->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) == - (TF_RCVD_SCALE|TF_REQ_SCALE)) { - tp->rcv_scale = tp->request_r_scale; - /* Send window already scaled. */ - } - } - -process_ACK: - INP_WLOCK_ASSERT(tp->t_inpcb); - - acked = BYTES_THIS_ACK(tp, th); - TCPSTAT_INC(tcps_rcvackpack); - TCPSTAT_ADD(tcps_rcvackbyte, acked); - - /* - * If we just performed our first retransmit, and the ACK - * arrives within our recovery window, then it was a mistake - * to do the retransmit in the first place. Recover our - * original cwnd and ssthresh, and proceed to transmit where - * we left off. - */ - if (tp->t_rxtshift == 1 && tp->t_flags & TF_PREVVALID && - (int)(ticks - tp->t_badrxtwin) < 0) - cc_cong_signal(tp, th, CC_RTO_ERR); - - /* - * If we have a timestamp reply, update smoothed - * round trip time. If no timestamp is present but - * transmit timer is running and timed sequence - * number was acked, update smoothed round trip time. - * Since we now have an rtt measurement, cancel the - * timer backoff (cf., Phil Karn's retransmit alg.). - * Recompute the initial retransmit timer. - * - * Some boxes send broken timestamp replies - * during the SYN+ACK phase, ignore - * timestamps of 0 or we could calculate a - * huge RTT and blow up the retransmit timer. - */ - if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) { - uint32_t t; - - t = tcp_ts_getticks() - to->to_tsecr; - if (!tp->t_rttlow || tp->t_rttlow > t) - tp->t_rttlow = t; - tcp_xmit_timer(tp, TCP_TS_TO_TICKS(t) + 1); - } else if (tp->t_rtttime && SEQ_GT(th->th_ack, tp->t_rtseq)) { - if (!tp->t_rttlow || tp->t_rttlow > ticks - tp->t_rtttime) - tp->t_rttlow = ticks - tp->t_rtttime; - tcp_xmit_timer(tp, ticks - tp->t_rtttime); - } - - /* - * If all outstanding data is acked, stop retransmit - * timer and remember to restart (more output or persist). - * If there is more data to be acked, restart retransmit - * timer, using current (possibly backed-off) value. - */ - if (th->th_ack == tp->snd_max) { - tcp_timer_activate(tp, TT_REXMT, 0); - needoutput = 1; - } else if (!tcp_timer_active(tp, TT_PERSIST)) - tcp_timer_activate(tp, TT_REXMT, tp->t_rxtcur); - - /* - * If no data (only SYN) was ACK'd, - * skip rest of ACK processing. - */ - if (acked == 0) - goto step6; - - /* - * Let the congestion control algorithm update congestion - * control related information. This typically means increasing - * the congestion window. - */ - cc_ack_received(tp, th, nsegs, CC_ACK); - - SOCKBUF_LOCK(&so->so_snd); - if (acked > sbavail(&so->so_snd)) { - tp->snd_wnd -= sbavail(&so->so_snd); - mfree = sbcut_locked(&so->so_snd, - (int)sbavail(&so->so_snd)); - ourfinisacked = 1; - } else { - mfree = sbcut_locked(&so->so_snd, acked); - tp->snd_wnd -= acked; - ourfinisacked = 0; - } - /* NB: sowwakeup_locked() does an implicit unlock. */ - sowwakeup_locked(so); - m_freem(mfree); - /* Detect una wraparound. */ - if (!IN_RECOVERY(tp->t_flags) && - SEQ_GT(tp->snd_una, tp->snd_recover) && - SEQ_LEQ(th->th_ack, tp->snd_recover)) - tp->snd_recover = th->th_ack - 1; - /* XXXLAS: Can this be moved up into cc_post_recovery? */ - if (IN_RECOVERY(tp->t_flags) && - SEQ_GEQ(th->th_ack, tp->snd_recover)) { - EXIT_RECOVERY(tp->t_flags); - } - tp->snd_una = th->th_ack; - if (tp->t_flags & TF_SACK_PERMIT) { - if (SEQ_GT(tp->snd_una, tp->snd_recover)) - tp->snd_recover = tp->snd_una; - } - if (SEQ_LT(tp->snd_nxt, tp->snd_una)) - tp->snd_nxt = tp->snd_una; - - switch (tp->t_state) { - - /* - * In FIN_WAIT_1 STATE in addition to the processing - * for the ESTABLISHED state if our FIN is now acknowledged - * then enter FIN_WAIT_2. - */ - case TCPS_FIN_WAIT_1: - if (ourfinisacked) { - /* - * If we can't receive any more - * data, then closing user can proceed. - * Starting the timer is contrary to the - * specification, but if we don't get a FIN - * we'll hang forever. - * - * XXXjl: - * we should release the tp also, and use a - * compressed state. - */ - if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { - soisdisconnected(so); - tcp_timer_activate(tp, TT_2MSL, - (tcp_fast_finwait2_recycle ? - tcp_finwait2_timeout : - TP_MAXIDLE(tp))); - } - tcp_state_change(tp, TCPS_FIN_WAIT_2); - } - break; - - /* - * In CLOSING STATE in addition to the processing for - * the ESTABLISHED state if the ACK acknowledges our FIN - * then enter the TIME-WAIT state, otherwise ignore - * the segment. - */ - case TCPS_CLOSING: - if (ourfinisacked) { - INP_INFO_RLOCK_ASSERT(&V_tcbinfo); - tcp_twstart(tp); - m_freem(m); - return; - } - break; - - /* - * In LAST_ACK, we may still be waiting for data to drain - * and/or to be acked, as well as for the ack of our FIN. - * If our FIN is now acknowledged, delete the TCB, - * enter the closed state and return. - */ - case TCPS_LAST_ACK: - if (ourfinisacked) { - INP_INFO_RLOCK_ASSERT(&V_tcbinfo); - tp = tcp_close(tp); - goto drop; - } - break; - } - } - -step6: - INP_WLOCK_ASSERT(tp->t_inpcb); - - /* - * Update window information. - * Don't look at window if no ACK: TAC's send garbage on first SYN. - */ - if ((thflags & TH_ACK) && - (SEQ_LT(tp->snd_wl1, th->th_seq) || - (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) || - (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) { - /* keep track of pure window updates */ - if (tlen == 0 && - tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd) - TCPSTAT_INC(tcps_rcvwinupd); - tp->snd_wnd = tiwin; - tp->snd_wl1 = th->th_seq; - tp->snd_wl2 = th->th_ack; - if (tp->snd_wnd > tp->max_sndwnd) - tp->max_sndwnd = tp->snd_wnd; - needoutput = 1; - } - - /* - * Process segments with URG. - */ - if ((thflags & TH_URG) && th->th_urp && - TCPS_HAVERCVDFIN(tp->t_state) == 0) { - /* - * This is a kludge, but if we receive and accept - * random urgent pointers, we'll crash in - * soreceive. It's hard to imagine someone - * actually wanting to send this much urgent data. - */ - SOCKBUF_LOCK(&so->so_rcv); - if (th->th_urp + sbavail(&so->so_rcv) > sb_max) { - th->th_urp = 0; /* XXX */ - thflags &= ~TH_URG; /* XXX */ - SOCKBUF_UNLOCK(&so->so_rcv); /* XXX */ - goto dodata; /* XXX */ - } - /* - * If this segment advances the known urgent pointer, - * then mark the data stream. This should not happen - * in CLOSE_WAIT, CLOSING, LAST_ACK or TIME_WAIT STATES since - * a FIN has been received from the remote side. - * In these states we ignore the URG. - * - * According to RFC961 (Assigned Protocols), - * the urgent pointer points to the last octet - * of urgent data. We continue, however, - * to consider it to indicate the first octet - * of data past the urgent section as the original - * spec states (in one of two places). - */ - if (SEQ_GT(th->th_seq+th->th_urp, tp->rcv_up)) { - tp->rcv_up = th->th_seq + th->th_urp; - so->so_oobmark = sbavail(&so->so_rcv) + - (tp->rcv_up - tp->rcv_nxt) - 1; - if (so->so_oobmark == 0) - so->so_rcv.sb_state |= SBS_RCVATMARK; - sohasoutofband(so); - tp->t_oobflags &= ~(TCPOOB_HAVEDATA | TCPOOB_HADDATA); - } - SOCKBUF_UNLOCK(&so->so_rcv); - /* - * Remove out of band data so doesn't get presented to user. - * This can happen independent of advancing the URG pointer, - * but if two URG's are pending at once, some out-of-band - * data may creep in... ick. - */ - if (th->th_urp <= (uint32_t)tlen && - !(so->so_options & SO_OOBINLINE)) { - /* hdr drop is delayed */ - tcp_pulloutofband(so, th, m, drop_hdrlen); - } - } else { - /* - * If no out of band data is expected, - * pull receive urgent pointer along - * with the receive window. - */ - if (SEQ_GT(tp->rcv_nxt, tp->rcv_up)) - tp->rcv_up = tp->rcv_nxt; - } -dodata: /* XXX */ - INP_WLOCK_ASSERT(tp->t_inpcb); - - /* - * Process the segment text, merging it into the TCP sequencing queue, - * and arranging for acknowledgment of receipt if necessary. - * This process logically involves adjusting tp->rcv_wnd as data - * is presented to the user (this happens in tcp_usrreq.c, - * case PRU_RCVD). If a FIN has already been received on this - * connection then we just ignore the text. - */ - if ((tlen || (thflags & TH_FIN)) && - TCPS_HAVERCVDFIN(tp->t_state) == 0) { - tcp_seq save_start = th->th_seq; - m_adj(m, drop_hdrlen); /* delayed header drop */ - /* - * Insert segment which includes th into TCP reassembly queue - * with control block tp. Set thflags to whether reassembly now - * includes a segment with FIN. This handles the common case - * inline (segment is the next to be received on an established - * connection, and the queue is empty), avoiding linkage into - * and removal from the queue and repetition of various - * conversions. - * Set DELACK for segments received in order, but ack - * immediately when segments are out of order (so - * fast retransmit can work). - */ - if (th->th_seq == tp->rcv_nxt && - LIST_EMPTY(&tp->t_segq) && - TCPS_HAVEESTABLISHED(tp->t_state)) { - if (DELAY_ACK(tp, tlen)) - tp->t_flags |= TF_DELACK; - else - tp->t_flags |= TF_ACKNOW; - tp->rcv_nxt += tlen; - thflags = th->th_flags & TH_FIN; - TCPSTAT_INC(tcps_rcvpack); - TCPSTAT_ADD(tcps_rcvbyte, tlen); - SOCKBUF_LOCK(&so->so_rcv); - if (so->so_rcv.sb_state & SBS_CANTRCVMORE) - m_freem(m); - else - sbappendstream_locked(&so->so_rcv, m, 0); - /* NB: sorwakeup_locked() does an implicit unlock. */ - sorwakeup_locked(so); - } else { - /* - * XXX: Due to the header drop above "th" is - * theoretically invalid by now. Fortunately - * m_adj() doesn't actually frees any mbufs - * when trimming from the head. - */ - thflags = tcp_reass(tp, th, &tlen, m); - tp->t_flags |= TF_ACKNOW; - } - if (tlen > 0 && (tp->t_flags & TF_SACK_PERMIT)) - tcp_update_sack_list(tp, save_start, save_start + tlen); -#if 0 - /* - * Note the amount of data that peer has sent into - * our window, in order to estimate the sender's - * buffer size. - * XXX: Unused. - */ - if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) - len = so->so_rcv.sb_hiwat - (tp->rcv_adv - tp->rcv_nxt); - else - len = so->so_rcv.sb_hiwat; -#endif - } else { - m_freem(m); - thflags &= ~TH_FIN; - } - - /* - * If FIN is received ACK the FIN and let the user know - * that the connection is closing. - */ - if (thflags & TH_FIN) { - if (TCPS_HAVERCVDFIN(tp->t_state) == 0) { - socantrcvmore(so); - /* - * If connection is half-synchronized - * (ie NEEDSYN flag on) then delay ACK, - * so it may be piggybacked when SYN is sent. - * Otherwise, since we received a FIN then no - * more input can be expected, send ACK now. - */ - if (tp->t_flags & TF_NEEDSYN) - tp->t_flags |= TF_DELACK; - else - tp->t_flags |= TF_ACKNOW; - tp->rcv_nxt++; - } - switch (tp->t_state) { - - /* - * In SYN_RECEIVED and ESTABLISHED STATES - * enter the CLOSE_WAIT state. - */ - case TCPS_SYN_RECEIVED: - tp->t_starttime = ticks; - /* FALLTHROUGH */ - case TCPS_ESTABLISHED: - tcp_state_change(tp, TCPS_CLOSE_WAIT); - break; - - /* - * If still in FIN_WAIT_1 STATE FIN has not been acked so - * enter the CLOSING state. - */ - case TCPS_FIN_WAIT_1: - tcp_state_change(tp, TCPS_CLOSING); - break; - - /* - * In FIN_WAIT_2 state enter the TIME_WAIT state, - * starting the time-wait timer, turning off the other - * standard timers. - */ - case TCPS_FIN_WAIT_2: - INP_INFO_RLOCK_ASSERT(&V_tcbinfo); - tcp_twstart(tp); - return; - } - } -#ifdef TCPDEBUG - if (so->so_options & SO_DEBUG) - tcp_trace(TA_INPUT, ostate, tp, (void *)tcp_saveipgen, - &tcp_savetcp, 0); -#endif - TCP_PROBE3(debug__input, tp, th, m); - - /* - * Return any desired output. - */ - if (needoutput || (tp->t_flags & TF_ACKNOW)) - (void) tp->t_fb->tfb_tcp_output(tp); - - INP_WLOCK_ASSERT(tp->t_inpcb); - - if (tp->t_flags & TF_DELACK) { - tp->t_flags &= ~TF_DELACK; - tcp_timer_activate(tp, TT_DELACK, tcp_delacktime); - } - INP_WUNLOCK(tp->t_inpcb); - return; - -dropafterack: - /* - * Generate an ACK dropping incoming segment if it occupies - * sequence space, where the ACK reflects our state. - * - * We can now skip the test for the RST flag since all - * paths to this code happen after packets containing - * RST have been dropped. - * - * In the SYN-RECEIVED state, don't send an ACK unless the - * segment we received passes the SYN-RECEIVED ACK test. - * If it fails send a RST. This breaks the loop in the - * "LAND" DoS attack, and also prevents an ACK storm - * between two listening ports that have been sent forged - * SYN segments, each with the source address of the other. - */ - if (tp->t_state == TCPS_SYN_RECEIVED && (thflags & TH_ACK) && - (SEQ_GT(tp->snd_una, th->th_ack) || - SEQ_GT(th->th_ack, tp->snd_max)) ) { - rstreason = BANDLIM_RST_OPENPORT; - goto dropwithreset; - } -#ifdef TCPDEBUG - if (so->so_options & SO_DEBUG) - tcp_trace(TA_DROP, ostate, tp, (void *)tcp_saveipgen, - &tcp_savetcp, 0); -#endif - TCP_PROBE3(debug__drop, tp, th, m); - tp->t_flags |= TF_ACKNOW; - (void) tp->t_fb->tfb_tcp_output(tp); - INP_WUNLOCK(tp->t_inpcb); - m_freem(m); - return; - -dropwithreset: - if (tp != NULL) { - tcp_dropwithreset(m, th, tp, tlen, rstreason); - INP_WUNLOCK(tp->t_inpcb); - } else - tcp_dropwithreset(m, th, NULL, tlen, rstreason); - return; - -drop: - /* - * Drop space held by incoming segment and return. - */ -#ifdef TCPDEBUG - if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) - tcp_trace(TA_DROP, ostate, tp, (void *)tcp_saveipgen, - &tcp_savetcp, 0); -#endif - TCP_PROBE3(debug__drop, tp, th, m); - if (tp != NULL) - INP_WUNLOCK(tp->t_inpcb); - m_freem(m); -} - - -/* - * Do fast slow is a combination of the original - * tcp_dosegment and a split fastpath, one function - * for the fast-ack which also includes allowing fastpath - * for window advanced in sequence acks. And also a - * sub-function that handles the insequence data. - */ -void -tcp_do_segment_fastslow(struct mbuf *m, struct tcphdr *th, struct socket *so, - struct tcpcb *tp, int drop_hdrlen, int tlen, uint8_t iptos) -{ - int thflags; - uint32_t tiwin; - char *s; - uint16_t nsegs; - int can_enter; - struct in_conninfo *inc; - struct tcpopt to; - - thflags = th->th_flags; - inc = &tp->t_inpcb->inp_inc; - nsegs = max(1, m->m_pkthdr.lro_nsegs); - /* - * If this is either a state-changing packet or current state isn't - * established, we require a write lock on tcbinfo. Otherwise, we - * allow the tcbinfo to be in either alocked or unlocked, as the - * caller may have unnecessarily acquired a write lock due to a race. - */ - if ((thflags & (TH_SYN | TH_FIN | TH_RST)) != 0 || - tp->t_state != TCPS_ESTABLISHED) { - INP_INFO_RLOCK_ASSERT(&V_tcbinfo); - } - INP_WLOCK_ASSERT(tp->t_inpcb); - KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN", - __func__)); - KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT", - __func__)); - - if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) { - if ((s = tcp_log_addrs(inc, th, NULL, NULL))) { - log(LOG_DEBUG, "%s; %s: " - "SYN|FIN segment ignored (based on " - "sysctl setting)\n", s, __func__); - free(s, M_TCPLOG); - } - INP_WUNLOCK(tp->t_inpcb); - m_freem(m); - return; - } - - /* - * If a segment with the ACK-bit set arrives in the SYN-SENT state - * check SEQ.ACK first. - */ - if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) && - (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) { - tcp_dropwithreset(m, th, tp, tlen, BANDLIM_UNLIMITED); - INP_WUNLOCK(tp->t_inpcb); - return; - } - - tp->sackhint.last_sack_ack = 0; - - /* - * Segment received on connection. - * Reset idle time and keep-alive timer. - * XXX: This should be done after segment - * validation to ignore broken/spoofed segs. - */ - tp->t_rcvtime = ticks; - - /* - * Unscale the window into a 32-bit value. - * For the SYN_SENT state the scale is zero. - */ - tiwin = th->th_win << tp->snd_scale; - - /* - * TCP ECN processing. - */ - if (tp->t_flags & TF_ECN_PERMIT) { - if (thflags & TH_CWR) - tp->t_flags &= ~TF_ECN_SND_ECE; - switch (iptos & IPTOS_ECN_MASK) { - case IPTOS_ECN_CE: - tp->t_flags |= TF_ECN_SND_ECE; - TCPSTAT_INC(tcps_ecn_ce); - break; - case IPTOS_ECN_ECT0: - TCPSTAT_INC(tcps_ecn_ect0); - break; - case IPTOS_ECN_ECT1: - TCPSTAT_INC(tcps_ecn_ect1); - break; - } - /* Congestion experienced. */ - if (thflags & TH_ECE) { - cc_cong_signal(tp, th, CC_ECN); - } - } - - /* - * Parse options on any incoming segment. - */ - tcp_dooptions(&to, (u_char *)(th + 1), - (th->th_off << 2) - sizeof(struct tcphdr), - (thflags & TH_SYN) ? TO_SYN : 0); - - /* - * If echoed timestamp is later than the current time, - * fall back to non RFC1323 RTT calculation. Normalize - * timestamp if syncookies were used when this connection - * was established. - */ - if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) { - to.to_tsecr -= tp->ts_offset; - if (TSTMP_GT(to.to_tsecr, tcp_ts_getticks())) - to.to_tsecr = 0; - } - - /* - * Process options only when we get SYN/ACK back. The SYN case - * for incoming connections is handled in tcp_syncache. - * According to RFC1323 the window field in a SYN (i.e., a - * or ) segment itself is never scaled. - * XXX this is traditional behavior, may need to be cleaned up. - */ - if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) { - if ((to.to_flags & TOF_SCALE) && - (tp->t_flags & TF_REQ_SCALE)) { - tp->t_flags |= TF_RCVD_SCALE; - tp->snd_scale = to.to_wscale; - } - /* - * Initial send window. It will be updated with - * the next incoming segment to the scaled value. - */ - tp->snd_wnd = th->th_win; - if (to.to_flags & TOF_TS) { - tp->t_flags |= TF_RCVD_TSTMP; - tp->ts_recent = to.to_tsval; - tp->ts_recent_age = tcp_ts_getticks(); - } - if (to.to_flags & TOF_MSS) - tcp_mss(tp, to.to_mss); - if ((tp->t_flags & TF_SACK_PERMIT) && - (to.to_flags & TOF_SACKPERM) == 0) - tp->t_flags &= ~TF_SACK_PERMIT; - if (IS_FASTOPEN(tp->t_flags)) { - if (to.to_flags & TOF_FASTOPEN) { - uint16_t mss; - - if (to.to_flags & TOF_MSS) - mss = to.to_mss; - else - if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) - mss = TCP6_MSS; - else - mss = TCP_MSS; - tcp_fastopen_update_cache(tp, mss, - to.to_tfo_len, to.to_tfo_cookie); - } else - tcp_fastopen_disable_path(tp); - } - } - - /* - * If timestamps were negotiated during SYN/ACK they should - * appear on every segment during this session and vice versa. - */ - if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS)) { - if ((s = tcp_log_addrs(inc, th, NULL, NULL))) { - log(LOG_DEBUG, "%s; %s: Timestamp missing, " - "no action\n", s, __func__); - free(s, M_TCPLOG); - } - } - if (!(tp->t_flags & TF_RCVD_TSTMP) && (to.to_flags & TOF_TS)) { - if ((s = tcp_log_addrs(inc, th, NULL, NULL))) { - log(LOG_DEBUG, "%s; %s: Timestamp not expected, " - "no action\n", s, __func__); - free(s, M_TCPLOG); - } - } - - can_enter = 0; - if (__predict_true((tlen == 0))) { - /* - * The ack moved forward and we have a window (non-zero) - * - * The ack did not move forward, but the window increased. - */ - if (__predict_true((SEQ_GT(th->th_ack, tp->snd_una) && tiwin) || - ((th->th_ack == tp->snd_una) && tiwin && (tiwin > tp->snd_wnd)))) { - can_enter = 1; - } - } else { - /* - * Data incoming, use the old entry criteria - * for fast-path with data. - */ - if ((tiwin && tiwin == tp->snd_wnd)) { - can_enter = 1; - } - } - /* - * Header prediction: check for the two common cases - * of a uni-directional data xfer. If the packet has - * no control flags, is in-sequence, the window didn't - * change and we're not retransmitting, it's a - * candidate. If the length is zero and the ack moved - * forward, we're the sender side of the xfer. Just - * free the data acked & wake any higher level process - * that was blocked waiting for space. If the length - * is non-zero and the ack didn't move, we're the - * receiver side. If we're getting packets in-order - * (the reassembly queue is empty), add the data to - * the socket buffer and note that we need a delayed ack. - * Make sure that the hidden state-flags are also off. - * Since we check for TCPS_ESTABLISHED first, it can only - * be TH_NEEDSYN. - */ - if (__predict_true(tp->t_state == TCPS_ESTABLISHED && - th->th_seq == tp->rcv_nxt && - (thflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK)) == TH_ACK && - tp->snd_nxt == tp->snd_max && - can_enter && - ((tp->t_flags & (TF_NEEDSYN|TF_NEEDFIN)) == 0) && - LIST_EMPTY(&tp->t_segq) && - ((to.to_flags & TOF_TS) == 0 || - TSTMP_GEQ(to.to_tsval, tp->ts_recent)))) { - if (__predict_true((tlen == 0) && - (SEQ_LEQ(th->th_ack, tp->snd_max) && - !IN_RECOVERY(tp->t_flags) && - (to.to_flags & TOF_SACK) == 0 && - TAILQ_EMPTY(&tp->snd_holes)))) { - /* We are done */ - tcp_do_fastack(m, th, so, tp, &to, drop_hdrlen, tlen, - tiwin); - return; - } else if ((tlen) && - (th->th_ack == tp->snd_una && - tlen <= sbspace(&so->so_rcv))) { - tcp_do_fastnewdata(m, th, so, tp, &to, drop_hdrlen, tlen, - tiwin); - /* We are done */ - return; - } - } - tcp_do_slowpath(m, th, so, tp, &to, drop_hdrlen, tlen, - tiwin, thflags); -} - - -/* - * This subfunction is used to try to highly optimize the - * fast path. We again allow window updates that are - * in sequence to remain in the fast-path. We also add - * in the __predict's to attempt to help the compiler. - * Note that if we return a 0, then we can *not* process - * it and the caller should push the packet into the - * slow-path. - */ -static int -tcp_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so, - struct tcpcb *tp, struct tcpopt *to, int drop_hdrlen, int tlen, - uint32_t tiwin) -{ - int acked; - uint16_t nsegs; - int winup_only=0; - - nsegs = max(1, m->m_pkthdr.lro_nsegs); -#ifdef TCPDEBUG - /* - * The size of tcp_saveipgen must be the size of the max ip header, - * now IPv6. - */ - u_char tcp_saveipgen[IP6_HDR_LEN]; - struct tcphdr tcp_savetcp; - short ostate = 0; -#endif - - - if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) { - /* Old ack, behind (or duplicate to) the last one rcv'd */ - return (0); - } - if (__predict_false(th->th_ack == tp->snd_una) && - __predict_false(tiwin <= tp->snd_wnd)) { - /* duplicate ack a shrinking dup ack with shrinking window */ - return (0); - } - if (__predict_false(tiwin == 0)) { - /* zero window */ - return (0); - } - if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) { - /* Above what we have sent? */ - return (0); - } - if (__predict_false(tp->snd_nxt != tp->snd_max)) { - /* We are retransmitting */ - return (0); - } - if (__predict_false(tp->t_flags & (TF_NEEDSYN|TF_NEEDFIN))) { - /* We need a SYN or a FIN, unlikely.. */ - return (0); - } - if((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) { - /* Timestamp is behind .. old ack with seq wrap? */ - return (0); - } - if (__predict_false(IN_RECOVERY(tp->t_flags))) { - /* Still recovering */ - return (0); - } - if (__predict_false(to->to_flags & TOF_SACK)) { - /* Sack included in the ack.. */ - return (0); - } - if (!TAILQ_EMPTY(&tp->snd_holes)) { - /* We have sack holes on our scoreboard */ - return (0); - } - /* Ok if we reach here, we can process a fast-ack */ - - /* Did the window get updated? */ - if (tiwin != tp->snd_wnd) { - /* keep track of pure window updates */ - if (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd) { - winup_only = 1; - TCPSTAT_INC(tcps_rcvwinupd); - } - tp->snd_wnd = tiwin; - tp->snd_wl1 = th->th_seq; - if (tp->snd_wnd > tp->max_sndwnd) - tp->max_sndwnd = tp->snd_wnd; - } - /* - * Pull snd_wl2 up to prevent seq wrap relative - * to th_ack. - */ - tp->snd_wl2 = th->th_ack; - /* - * If last ACK falls within this segment's sequence numbers, - * record the timestamp. - * NOTE that the test is modified according to the latest - * proposal of the tcplw@cray.com list (Braden 1993/04/26). - */ - if ((to->to_flags & TOF_TS) != 0 && - SEQ_LEQ(th->th_seq, tp->last_ack_sent)) { - tp->ts_recent_age = tcp_ts_getticks(); - tp->ts_recent = to->to_tsval; - } - /* - * This is a pure ack for outstanding data. - */ - TCPSTAT_INC(tcps_predack); - - /* - * "bad retransmit" recovery. - */ - if (tp->t_rxtshift == 1 && - tp->t_flags & TF_PREVVALID && - (int)(ticks - tp->t_badrxtwin) < 0) { - cc_cong_signal(tp, th, CC_RTO_ERR); - } - - /* - * Recalculate the transmit timer / rtt. - * - * Some boxes send broken timestamp replies - * during the SYN+ACK phase, ignore - * timestamps of 0 or we could calculate a - * huge RTT and blow up the retransmit timer. - */ - if ((to->to_flags & TOF_TS) != 0 && - to->to_tsecr) { - uint32_t t; - - t = tcp_ts_getticks() - to->to_tsecr; - if (!tp->t_rttlow || tp->t_rttlow > t) - tp->t_rttlow = t; - tcp_xmit_timer(tp, - TCP_TS_TO_TICKS(t) + 1); - } else if (tp->t_rtttime && - SEQ_GT(th->th_ack, tp->t_rtseq)) { - if (!tp->t_rttlow || - tp->t_rttlow > ticks - tp->t_rtttime) - tp->t_rttlow = ticks - tp->t_rtttime; - tcp_xmit_timer(tp, - ticks - tp->t_rtttime); - } - if (winup_only == 0) { - acked = BYTES_THIS_ACK(tp, th); - -#ifdef TCP_HHOOK - /* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */ - hhook_run_tcp_est_in(tp, th, to); -#endif - - TCPSTAT_ADD(tcps_rcvackbyte, acked); - sbdrop(&so->so_snd, acked); - if (SEQ_GT(tp->snd_una, tp->snd_recover) && - SEQ_LEQ(th->th_ack, tp->snd_recover)) - tp->snd_recover = th->th_ack - 1; - - /* - * Let the congestion control algorithm update - * congestion control related information. This - * typically means increasing the congestion - * window. - */ - cc_ack_received(tp, th, nsegs, CC_ACK); - - tp->snd_una = th->th_ack; - tp->t_dupacks = 0; - - /* - * If all outstanding data are acked, stop - * retransmit timer, otherwise restart timer - * using current (possibly backed-off) value. - * If process is waiting for space, - * wakeup/selwakeup/signal. If data - * are ready to send, let tcp_output - * decide between more output or persist. - */ -#ifdef TCPDEBUG - if (so->so_options & SO_DEBUG) - tcp_trace(TA_INPUT, ostate, tp, - (void *)tcp_saveipgen, - &tcp_savetcp, 0); -#endif - TCP_PROBE3(debug__input, tp, th, m); - m_freem(m); - if (tp->snd_una == tp->snd_max) - tcp_timer_activate(tp, TT_REXMT, 0); - else if (!tcp_timer_active(tp, TT_PERSIST)) - tcp_timer_activate(tp, TT_REXMT, - tp->t_rxtcur); - /* Wake up the socket if we have room to write more */ - sowwakeup(so); - } else { - /* - * Window update only, just free the mbufs and - * send out whatever we can. - */ - m_freem(m); - } - if (sbavail(&so->so_snd)) - (void) tcp_output(tp); - INP_WLOCK_ASSERT(tp->t_inpcb); - - if (tp->t_flags & TF_DELACK) { - tp->t_flags &= ~TF_DELACK; - tcp_timer_activate(tp, TT_DELACK, tcp_delacktime); - } - INP_WUNLOCK(tp->t_inpcb); - return (1); -} - -/* - * This tcp-do-segment concentrates on making the fastest - * ack processing path. It does not have a fast-path for - * data (it possibly could which would then eliminate the - * need for fast-slow above). For a content distributor having - * large outgoing elephants and very very little coming in - * having no fastpath for data does not really help (since you - * don't get much data in). The most important thing is - * processing ack's quickly and getting the rest of the data - * output to the peer as quickly as possible. This routine - * seems to be about an overall 3% faster then the old - * tcp_do_segment and keeps us in the fast-path for packets - * much more (by allowing window updates to also stay in the fastpath). - */ -void -tcp_do_segment_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so, - struct tcpcb *tp, int drop_hdrlen, int tlen, uint8_t iptos) -{ - int thflags; - uint32_t tiwin; - char *s; - struct in_conninfo *inc; - struct tcpopt to; - - thflags = th->th_flags; - inc = &tp->t_inpcb->inp_inc; - /* - * If this is either a state-changing packet or current state isn't - * established, we require a write lock on tcbinfo. Otherwise, we - * allow the tcbinfo to be in either alocked or unlocked, as the - * caller may have unnecessarily acquired a write lock due to a race. - */ - if ((thflags & (TH_SYN | TH_FIN | TH_RST)) != 0 || - tp->t_state != TCPS_ESTABLISHED) { - INP_INFO_RLOCK_ASSERT(&V_tcbinfo); - } - INP_WLOCK_ASSERT(tp->t_inpcb); - KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN", - __func__)); - KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT", - __func__)); - - if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) { - if ((s = tcp_log_addrs(inc, th, NULL, NULL))) { - log(LOG_DEBUG, "%s; %s: " - "SYN|FIN segment ignored (based on " - "sysctl setting)\n", s, __func__); - free(s, M_TCPLOG); - } - INP_WUNLOCK(tp->t_inpcb); - m_freem(m); - return; - } - - /* - * If a segment with the ACK-bit set arrives in the SYN-SENT state - * check SEQ.ACK first. - */ - if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) && - (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) { - tcp_dropwithreset(m, th, tp, tlen, BANDLIM_UNLIMITED); - INP_WUNLOCK(tp->t_inpcb); - return; - } - - tp->sackhint.last_sack_ack = 0; - - /* - * Segment received on connection. - * Reset idle time and keep-alive timer. - * XXX: This should be done after segment - * validation to ignore broken/spoofed segs. - */ - tp->t_rcvtime = ticks; - - /* - * Unscale the window into a 32-bit value. - * For the SYN_SENT state the scale is zero. - */ - tiwin = th->th_win << tp->snd_scale; - - /* - * TCP ECN processing. - */ - if (tp->t_flags & TF_ECN_PERMIT) { - if (thflags & TH_CWR) - tp->t_flags &= ~TF_ECN_SND_ECE; - switch (iptos & IPTOS_ECN_MASK) { - case IPTOS_ECN_CE: - tp->t_flags |= TF_ECN_SND_ECE; - TCPSTAT_INC(tcps_ecn_ce); - break; - case IPTOS_ECN_ECT0: - TCPSTAT_INC(tcps_ecn_ect0); - break; - case IPTOS_ECN_ECT1: - TCPSTAT_INC(tcps_ecn_ect1); - break; - } - /* Congestion experienced. */ - if (thflags & TH_ECE) { - cc_cong_signal(tp, th, CC_ECN); - } - } - - /* - * Parse options on any incoming segment. - */ - tcp_dooptions(&to, (u_char *)(th + 1), - (th->th_off << 2) - sizeof(struct tcphdr), - (thflags & TH_SYN) ? TO_SYN : 0); - - /* - * If echoed timestamp is later than the current time, - * fall back to non RFC1323 RTT calculation. Normalize - * timestamp if syncookies were used when this connection - * was established. - */ - if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) { - to.to_tsecr -= tp->ts_offset; - if (TSTMP_GT(to.to_tsecr, tcp_ts_getticks())) - to.to_tsecr = 0; - } - - /* - * Process options only when we get SYN/ACK back. The SYN case - * for incoming connections is handled in tcp_syncache. - * According to RFC1323 the window field in a SYN (i.e., a - * or ) segment itself is never scaled. - * XXX this is traditional behavior, may need to be cleaned up. - */ - if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) { - if ((to.to_flags & TOF_SCALE) && - (tp->t_flags & TF_REQ_SCALE)) { - tp->t_flags |= TF_RCVD_SCALE; - tp->snd_scale = to.to_wscale; - } - /* - * Initial send window. It will be updated with - * the next incoming segment to the scaled value. - */ - tp->snd_wnd = th->th_win; - if (to.to_flags & TOF_TS) { - tp->t_flags |= TF_RCVD_TSTMP; - tp->ts_recent = to.to_tsval; - tp->ts_recent_age = tcp_ts_getticks(); - } - if (to.to_flags & TOF_MSS) - tcp_mss(tp, to.to_mss); - if ((tp->t_flags & TF_SACK_PERMIT) && - (to.to_flags & TOF_SACKPERM) == 0) - tp->t_flags &= ~TF_SACK_PERMIT; - if (IS_FASTOPEN(tp->t_flags)) { - if (to.to_flags & TOF_FASTOPEN) { - uint16_t mss; - - if (to.to_flags & TOF_MSS) - mss = to.to_mss; - else - if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) - mss = TCP6_MSS; - else - mss = TCP_MSS; - tcp_fastopen_update_cache(tp, mss, - to.to_tfo_len, to.to_tfo_cookie); - } else - tcp_fastopen_disable_path(tp); - } - } - - /* - * If timestamps were negotiated during SYN/ACK they should - * appear on every segment during this session and vice versa. - */ - if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS)) { - if ((s = tcp_log_addrs(inc, th, NULL, NULL))) { - log(LOG_DEBUG, "%s; %s: Timestamp missing, " - "no action\n", s, __func__); - free(s, M_TCPLOG); - } - } - if (!(tp->t_flags & TF_RCVD_TSTMP) && (to.to_flags & TOF_TS)) { - if ((s = tcp_log_addrs(inc, th, NULL, NULL))) { - log(LOG_DEBUG, "%s; %s: Timestamp not expected, " - "no action\n", s, __func__); - free(s, M_TCPLOG); - } - } - - /* - * Header prediction: check for the two common cases - * of a uni-directional data xfer. If the packet has - * no control flags, is in-sequence, the window didn't - * change and we're not retransmitting, it's a - * candidate. If the length is zero and the ack moved - * forward, we're the sender side of the xfer. Just - * free the data acked & wake any higher level process - * that was blocked waiting for space. If the length - * is non-zero and the ack didn't move, we're the - * receiver side. If we're getting packets in-order - * (the reassembly queue is empty), add the data to - * the socket buffer and note that we need a delayed ack. - * Make sure that the hidden state-flags are also off. - * Since we check for TCPS_ESTABLISHED first, it can only - * be TH_NEEDSYN. - */ - if (__predict_true(tp->t_state == TCPS_ESTABLISHED) && - __predict_true(((to.to_flags & TOF_SACK) == 0)) && - __predict_true(tlen == 0) && - __predict_true((thflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK)) == TH_ACK) && - __predict_true(LIST_EMPTY(&tp->t_segq)) && - __predict_true(th->th_seq == tp->rcv_nxt)) { - if (tcp_fastack(m, th, so, tp, &to, drop_hdrlen, tlen, - tiwin)) { - return; - } - } - tcp_do_slowpath(m, th, so, tp, &to, drop_hdrlen, tlen, - tiwin, thflags); -} - -struct tcp_function_block __tcp_fastslow = { - .tfb_tcp_block_name = "fastslow", - .tfb_tcp_output = tcp_output, - .tfb_tcp_do_segment = tcp_do_segment_fastslow, - .tfb_tcp_ctloutput = tcp_default_ctloutput, -}; - -struct tcp_function_block __tcp_fastack = { - .tfb_tcp_block_name = "fastack", - .tfb_tcp_output = tcp_output, - .tfb_tcp_do_segment = tcp_do_segment_fastack, - .tfb_tcp_ctloutput = tcp_default_ctloutput -}; - -static int -tcp_addfastpaths(module_t mod, int type, void *data) -{ - int err = 0; - - switch (type) { - case MOD_LOAD: - err = register_tcp_functions(&__tcp_fastack, M_WAITOK); - if (err) { - printf("Failed to register fastack module -- err:%d\n", err); - return(err); - } - err = register_tcp_functions(&__tcp_fastslow, M_WAITOK); - if (err) { - printf("Failed to register fastslow module -- err:%d\n", err); - deregister_tcp_functions(&__tcp_fastack, false, true); - return(err); - } - break; - case MOD_QUIESCE: - if ((__tcp_fastslow.tfb_refcnt) ||( __tcp_fastack.tfb_refcnt)) { - return(EBUSY); - } - err = deregister_tcp_functions(&__tcp_fastack, true, false); - err = deregister_tcp_functions(&__tcp_fastslow, true, false); - break; - case MOD_UNLOAD: - err = deregister_tcp_functions(&__tcp_fastack, false, true); - err = deregister_tcp_functions(&__tcp_fastslow, false, true); - if (err == EBUSY) - break; - err = 0; - break; - default: - return (EOPNOTSUPP); - } - return (err); -} - -static moduledata_t new_tcp_fastpaths = { - .name = "tcp_fastpaths", - .evhand = tcp_addfastpaths, - .priv = 0 -}; - -MODULE_VERSION(kern_tcpfastpaths, 1); -DECLARE_MODULE(kern_tcpfastpaths, new_tcp_fastpaths, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY); Property changes on: head/sys/netinet/tcp_stacks/fastpath.c ___________________________________________________________________ Deleted: svn:eol-style ## -1 +0,0 ## -native \ No newline at end of property Deleted: svn:keywords ## -1 +0,0 ## -FreeBSD=%H \ No newline at end of property Deleted: svn:mime-type ## -1 +0,0 ## -text/plain \ No newline at end of property