Current Path : /sys/netinet/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //sys/netinet/tcp_reass.c.orig |
/*- * 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/cdefs.h> __FBSDID("$FreeBSD: release/9.1.0/sys/netinet/tcp_reass.c 228058 2011-11-28 11:10:12Z lstewart $"); #include "opt_inet.h" #include "opt_inet6.h" #include "opt_tcpdebug.h" #include <sys/param.h> #include <sys/kernel.h> #include <sys/malloc.h> #include <sys/mbuf.h> #include <sys/socket.h> #include <sys/socketvar.h> #include <sys/sysctl.h> #include <sys/syslog.h> #include <sys/systm.h> #include <vm/uma.h> #include <net/if.h> #include <net/route.h> #include <net/vnet.h> #include <netinet/in.h> #include <netinet/in_pcb.h> #include <netinet/in_systm.h> #include <netinet/in_var.h> #include <netinet/ip.h> #include <netinet/ip_var.h> #include <netinet/ip_options.h> #include <netinet/ip6.h> #include <netinet6/in6_pcb.h> #include <netinet6/ip6_var.h> #include <netinet6/nd6.h> #include <netinet/tcp.h> #include <netinet/tcp_fsm.h> #include <netinet/tcp_seq.h> #include <netinet/tcp_timer.h> #include <netinet/tcp_var.h> #include <netinet6/tcp6_var.h> #include <netinet/tcpip.h> #ifdef TCPDEBUG #include <netinet/tcp_debug.h> #endif /* TCPDEBUG */ static int tcp_reass_sysctl_maxseg(SYSCTL_HANDLER_ARGS); static int tcp_reass_sysctl_qsize(SYSCTL_HANDLER_ARGS); SYSCTL_NODE(_net_inet_tcp, OID_AUTO, reass, CTLFLAG_RW, 0, "TCP Segment Reassembly Queue"); static VNET_DEFINE(int, tcp_reass_maxseg) = 0; #define V_tcp_reass_maxseg VNET(tcp_reass_maxseg) SYSCTL_VNET_PROC(_net_inet_tcp_reass, OID_AUTO, maxsegments, CTLTYPE_INT | CTLFLAG_RDTUN, &VNET_NAME(tcp_reass_maxseg), 0, &tcp_reass_sysctl_maxseg, "I", "Global maximum number of TCP Segments in Reassembly Queue"); static VNET_DEFINE(int, tcp_reass_qsize) = 0; #define V_tcp_reass_qsize VNET(tcp_reass_qsize) SYSCTL_VNET_PROC(_net_inet_tcp_reass, OID_AUTO, cursegments, CTLTYPE_INT | CTLFLAG_RD, &VNET_NAME(tcp_reass_qsize), 0, &tcp_reass_sysctl_qsize, "I", "Global number of TCP Segments currently in Reassembly Queue"); static VNET_DEFINE(int, tcp_reass_overflows) = 0; #define V_tcp_reass_overflows VNET(tcp_reass_overflows) SYSCTL_VNET_INT(_net_inet_tcp_reass, OID_AUTO, overflows, CTLTYPE_INT | CTLFLAG_RD, &VNET_NAME(tcp_reass_overflows), 0, "Global number of TCP Segment Reassembly Queue Overflows"); static VNET_DEFINE(uma_zone_t, tcp_reass_zone); #define V_tcp_reass_zone VNET(tcp_reass_zone) /* 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); } void tcp_reass_init(void) { 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); } #ifdef VIMAGE void tcp_reass_destroy(void) { uma_zdestroy(V_tcp_reass_zone); } #endif void tcp_reass_flush(struct tcpcb *tp) { struct tseg_qent *qe; INP_WLOCK_ASSERT(tp->t_inpcb); while ((qe = LIST_FIRST(&tp->t_segq)) != NULL) { LIST_REMOVE(qe, tqe_q); m_freem(qe->tqe_m); uma_zfree(V_tcp_reass_zone, qe); tp->t_segqlen--; } KASSERT((tp->t_segqlen == 0), ("TCP reass queue %p segment count is %d instead of 0 after flush.", tp, tp->t_segqlen)); } static int tcp_reass_sysctl_maxseg(SYSCTL_HANDLER_ARGS) { V_tcp_reass_maxseg = uma_zone_get_max(V_tcp_reass_zone); return (sysctl_handle_int(oidp, arg1, arg2, req)); } static int tcp_reass_sysctl_qsize(SYSCTL_HANDLER_ARGS) { V_tcp_reass_qsize = uma_zone_get_cur(V_tcp_reass_zone); return (sysctl_handle_int(oidp, arg1, arg2, req)); } 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; char *s = NULL; int flags; struct tseg_qent tqs; 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 that can be queued to reduce the * potential for mbuf exhaustion. For best performance, we want to be * able to queue a full window's worth of segments. The size of the * socket receive buffer determines our advertised window and grows * automatically when socket buffer autotuning is enabled. Use it as the * basis for our queue limit. * Always let the missing segment through which caused this queue. * NB: Access to the socket buffer is left intentionally unlocked as we * can tolerate stale information here. * * XXXLAS: Using sbspace(so->so_rcv) instead of so->so_rcv.sb_hiwat * should work but causes packets to be dropped when they shouldn't. * Investigate why and re-evaluate the below limit after the behaviour * is understood. */ if (th->th_seq != tp->rcv_nxt && tp->t_segqlen >= (so->so_rcv.sb_hiwat / tp->t_maxseg) + 1) { V_tcp_reass_overflows++; TCPSTAT_INC(tcps_rcvmemdrop); m_freem(m); *tlenp = 0; if ((s = tcp_log_addrs(&tp->t_inpcb->inp_inc, th, NULL, NULL))) { log(LOG_DEBUG, "%s; %s: queue limit reached, " "segment dropped\n", s, __func__); free(s, M_TCPLOG); } return (0); } /* * Allocate a new queue entry. If we can't, or hit the zone limit * just drop the pkt. * * Use a temporary structure on the stack for the missing segment * when the zone is exhausted. Otherwise we may get stuck. */ te = uma_zalloc(V_tcp_reass_zone, M_NOWAIT); if (te == NULL) { if (th->th_seq != tp->rcv_nxt) { TCPSTAT_INC(tcps_rcvmemdrop); m_freem(m); *tlenp = 0; if ((s = tcp_log_addrs(&tp->t_inpcb->inp_inc, th, NULL, NULL))) { log(LOG_DEBUG, "%s; %s: global zone limit " "reached, segment dropped\n", s, __func__); free(s, M_TCPLOG); } return (0); } else { bzero(&tqs, sizeof(struct tseg_qent)); te = &tqs; if ((s = tcp_log_addrs(&tp->t_inpcb->inp_inc, th, NULL, NULL))) { log(LOG_DEBUG, "%s; %s: global zone limit reached, using " "stack for missing segment\n", s, __func__); free(s, M_TCPLOG); } } } tp->t_segqlen++; /* * 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--; /* * 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; } } tp->t_rcvoopack++; 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--; 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 { KASSERT(te != &tqs, ("%s: temporary stack based entry not " "first element in queue", __func__)); 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); if (q != &tqs) uma_zfree(V_tcp_reass_zone, q); tp->t_segqlen--; q = nq; } while (q && q->tqe_th->th_seq == tp->rcv_nxt); ND6_HINT(tp); sorwakeup_locked(so); return (flags); }