| /*- |
| * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1994, 1995 |
| * The Regents of the University of California. All rights reserved. |
| * |
| * 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. |
| * 4. 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 <sys/bsd_cdefs.h> |
| //__FBSDID("$FreeBSD$"); |
| |
| #include "bsd_opt_inet.h" |
| #include "bsd_opt_inet6.h" |
| #include "bsd_opt_tcpdebug.h" |
| |
| #include <sys/bsd_param.h> |
| #include <sys/bsd_kernel.h> |
| #include <sys/bsd_malloc.h> |
| #include <sys/bsd_mbuf.h> |
| #include <sys/bsd_socket.h> |
| #include <sys/bsd_socketvar.h> |
| //baoyg//#include <sys/bsd_sysctl.h> |
| #include <sys/bsd_syslog.h> |
| #include <sys/bsd_systm.h> |
| |
| #include <vm/bsd_uma.h> |
| |
| #include <net/bsd_if.h> |
| #include <net/bsd_route.h> |
| #include <net/bsd_vnet.h> |
| |
| #include <netinet/bsd_in.h> |
| #include <netinet/bsd_in_pcb.h> |
| #include <netinet/bsd_in_systm.h> |
| #include <netinet/bsd_in_var.h> |
| #include <netinet/bsd_ip.h> |
| #include <netinet/bsd_ip_var.h> |
| #include <netinet/bsd_ip_options.h> |
| #include <netinet/bsd_ip6.h> |
| #include <netinet6/bsd_in6_pcb.h> |
| #include <netinet6/bsd_ip6_var.h> |
| #include <netinet6/bsd_nd6.h> |
| #include <netinet/bsd_tcp.h> |
| #include <netinet/bsd_tcp_fsm.h> |
| #include <netinet/bsd_tcp_seq.h> |
| #include <netinet/bsd_tcp_timer.h> |
| #include <netinet/bsd_tcp_var.h> |
| #include <netinet6/bsd_tcp6_var.h> |
| #include <netinet/bsd_tcpip.h> |
| #ifdef TCPDEBUG |
| #include <netinet/bsd_tcp_debug.h> |
| #endif /* TCPDEBUG */ |
| |
| static VNET_DEFINE(int, tcp_reass_maxseg); |
| VNET_DEFINE(int, tcp_reass_qsize); |
| static VNET_DEFINE(int, tcp_reass_maxqlen); |
| static VNET_DEFINE(int, tcp_reass_overflows); |
| |
| #define V_tcp_reass_maxseg VNET(tcp_reass_maxseg) |
| #define V_tcp_reass_maxqlen VNET(tcp_reass_maxqlen) |
| #define V_tcp_reass_overflows VNET(tcp_reass_overflows) |
| /* |
| SYSCTL_NODE(_net_inet_tcp, OID_AUTO, reass, CTLFLAG_RW, 0, |
| "TCP Segment Reassembly Queue"); |
| |
| SYSCTL_VNET_INT(_net_inet_tcp_reass, OID_AUTO, maxsegments, CTLFLAG_RDTUN, |
| &VNET_NAME(tcp_reass_maxseg), 0, |
| "Global maximum number of TCP Segments in Reassembly Queue"); |
| |
| SYSCTL_VNET_INT(_net_inet_tcp_reass, OID_AUTO, cursegments, CTLFLAG_RD, |
| &VNET_NAME(tcp_reass_qsize), 0, |
| "Global number of TCP Segments currently in Reassembly Queue"); |
| |
| SYSCTL_VNET_INT(_net_inet_tcp_reass, OID_AUTO, maxqlen, CTLFLAG_RW, |
| &VNET_NAME(tcp_reass_maxqlen), 0, |
| "Maximum number of TCP Segments per individual Reassembly Queue"); |
| |
| SYSCTL_VNET_INT(_net_inet_tcp_reass, OID_AUTO, overflows, CTLFLAG_RD, |
| &VNET_NAME(tcp_reass_overflows), 0, |
| "Global number of TCP Segment Reassembly Queue Overflows"); |
| */ |
| #if 0 |
| /* Initialize TCP reassembly queue */ |
| static void |
| tcp_reass_zone_change(void *tag) |
| { |
| |
| V_tcp_reass_maxseg = nmbclusters / 16; |
| uma_zone_set_max(V_tcp_reass_zone, V_tcp_reass_maxseg); |
| } |
| #endif |
| |
| VNET_DEFINE(uma_zone_t, tcp_reass_zone); |
| |
| void |
| tcp_reass_init(void) |
| { |
| |
| V_tcp_reass_maxseg = 0; |
| V_tcp_reass_qsize = 0; |
| V_tcp_reass_maxqlen = 48; |
| V_tcp_reass_overflows = 0; |
| |
| V_tcp_reass_maxseg = nmbclusters / 16; |
| //TUNABLE_INT_FETCH("net.inet.tcp.reass.maxsegments", |
| // &V_tcp_reass_maxseg); |
| V_tcp_reass_zone = uma_zcreate("tcpreass", sizeof (struct tseg_qent), |
| NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); |
| uma_zone_set_max(V_tcp_reass_zone, V_tcp_reass_maxseg); |
| // EVENTHANDLER_REGISTER(nmbclusters_change, |
| // tcp_reass_zone_change, NULL, EVENTHANDLER_PRI_ANY); |
| } |
| |
| int |
| tcp_reass(struct tcpcb *tp, struct tcphdr *th, int *tlenp, struct mbuf *m) |
| { |
| struct tseg_qent *q; |
| struct tseg_qent *p = NULL; |
| struct tseg_qent *nq; |
| struct tseg_qent *te = NULL; |
| struct socket *so = tp->t_inpcb->inp_socket; |
| int flags; |
| |
| INP_WLOCK_ASSERT(tp->t_inpcb); |
| |
| /* |
| * XXX: tcp_reass() is rather inefficient with its data structures |
| * and should be rewritten (see NetBSD for optimizations). |
| */ |
| |
| /* |
| * Call with th==NULL after become established to |
| * force pre-ESTABLISHED data up to user socket. |
| */ |
| if (th == NULL) |
| goto present; |
| |
| /* |
| * Limit the number of segments in the reassembly queue to prevent |
| * holding on to too many segments (and thus running out of mbufs). |
| * Make sure to let the missing segment through which caused this |
| * queue. Always keep one global queue entry spare to be able to |
| * process the missing segment. |
| */ |
| if (th->th_seq != tp->rcv_nxt && |
| (V_tcp_reass_qsize + 1 >= V_tcp_reass_maxseg || |
| tp->t_segqlen >= V_tcp_reass_maxqlen)) { |
| V_tcp_reass_overflows++; |
| TCPSTAT_INC(tcps_rcvmemdrop); |
| m_freem(m); |
| *tlenp = 0; |
| return (0); |
| } |
| |
| /* |
| * Allocate a new queue entry. If we can't, or hit the zone limit |
| * just drop the pkt. |
| */ |
| te = uma_zalloc(V_tcp_reass_zone, M_NOWAIT); |
| if (te == NULL) { |
| TCPSTAT_INC(tcps_rcvmemdrop); |
| m_freem(m); |
| *tlenp = 0; |
| return (0); |
| } |
| tp->t_segqlen++; |
| V_tcp_reass_qsize++; |
| |
| /* |
| * Find a segment which begins after this one does. |
| */ |
| LIST_FOREACH(q, &tp->t_segq, tqe_q) { |
| if (SEQ_GT(q->tqe_th->th_seq, th->th_seq)) |
| break; |
| p = q; |
| } |
| |
| /* |
| * If there is a preceding segment, it may provide some of |
| * our data already. If so, drop the data from the incoming |
| * segment. If it provides all of our data, drop us. |
| */ |
| if (p != NULL) { |
| int i; |
| /* conversion to int (in i) handles seq wraparound */ |
| i = p->tqe_th->th_seq + p->tqe_len - th->th_seq; |
| if (i > 0) { |
| if (i >= *tlenp) { |
| TCPSTAT_INC(tcps_rcvduppack); |
| TCPSTAT_ADD(tcps_rcvdupbyte, *tlenp); |
| m_freem(m); |
| uma_zfree(V_tcp_reass_zone, te); |
| tp->t_segqlen--; |
| V_tcp_reass_qsize--; |
| /* |
| * Try to present any queued data |
| * at the left window edge to the user. |
| * This is needed after the 3-WHS |
| * completes. |
| */ |
| goto present; /* ??? */ |
| } |
| m_adj(m, i); |
| *tlenp -= i; |
| th->th_seq += i; |
| } |
| } |
| TCPSTAT_INC(tcps_rcvoopack); |
| TCPSTAT_ADD(tcps_rcvoobyte, *tlenp); |
| |
| /* |
| * While we overlap succeeding segments trim them or, |
| * if they are completely covered, dequeue them. |
| */ |
| while (q) { |
| int i = (th->th_seq + *tlenp) - q->tqe_th->th_seq; |
| if (i <= 0) |
| break; |
| if (i < q->tqe_len) { |
| q->tqe_th->th_seq += i; |
| q->tqe_len -= i; |
| m_adj(q->tqe_m, i); |
| break; |
| } |
| |
| nq = LIST_NEXT(q, tqe_q); |
| LIST_REMOVE(q, tqe_q); |
| m_freem(q->tqe_m); |
| uma_zfree(V_tcp_reass_zone, q); |
| tp->t_segqlen--; |
| V_tcp_reass_qsize--; |
| q = nq; |
| } |
| |
| /* Insert the new segment queue entry into place. */ |
| te->tqe_m = m; |
| te->tqe_th = th; |
| te->tqe_len = *tlenp; |
| |
| if (p == NULL) { |
| LIST_INSERT_HEAD(&tp->t_segq, te, tqe_q); |
| } else { |
| LIST_INSERT_AFTER(p, te, tqe_q); |
| } |
| |
| present: |
| /* |
| * Present data to user, advancing rcv_nxt through |
| * completed sequence space. |
| */ |
| if (!TCPS_HAVEESTABLISHED(tp->t_state)) |
| return (0); |
| q = LIST_FIRST(&tp->t_segq); |
| if (!q || q->tqe_th->th_seq != tp->rcv_nxt) |
| return (0); |
| SOCKBUF_LOCK(&so->so_rcv); |
| do { |
| tp->rcv_nxt += q->tqe_len; |
| flags = q->tqe_th->th_flags & TH_FIN; |
| nq = LIST_NEXT(q, tqe_q); |
| LIST_REMOVE(q, tqe_q); |
| if (so->so_rcv.sb_state & SBS_CANTRCVMORE) |
| m_freem(q->tqe_m); |
| else |
| sbappendstream_locked(&so->so_rcv, q->tqe_m); |
| uma_zfree(V_tcp_reass_zone, q); |
| tp->t_segqlen--; |
| V_tcp_reass_qsize--; |
| q = nq; |
| } while (q && q->tqe_th->th_seq == tp->rcv_nxt); |
| ND6_HINT(tp); |
| sorwakeup_locked(so); |
| return (flags); |
| } |