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Path MTU discovery based on NetBSD but with the decision to use the DF
flag delayed to ip_output(). That halves the code and reduces most of the route lookups. okay deraadt@
This commit is contained in:
provos
parent
27142ee4fb
commit
62c4355e0f
@ -1,4 +1,4 @@
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/* $OpenBSD: in.h,v 1.40 2000/06/18 07:06:13 itojun Exp $ */
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/* $OpenBSD: in.h,v 1.41 2000/09/18 22:06:36 provos Exp $ */
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/* $NetBSD: in.h,v 1.20 1996/02/13 23:41:47 christos Exp $ */
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/*
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@ -447,7 +447,9 @@ struct ip_mreq {
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#define IPCTL_IPSEC_FIRSTUSE 24
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#define IPCTL_IPSEC_ENC_ALGORITHM 25
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#define IPCTL_IPSEC_AUTH_ALGORITHM 26
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#define IPCTL_MAXID 27
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#define IPCTL_MTUDISC 27 /* allow path MTU discovery */
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#define IPCTL_MTUDISCTIMEOUT 28 /* allow path MTU discovery */
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#define IPCTL_MAXID 29
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#define IPCTL_NAMES { \
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{ 0, 0 }, \
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@ -477,6 +479,8 @@ struct ip_mreq {
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{ "ipsec-firstuse", CTLTYPE_INT }, \
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{ "ipsec-enc-alg", CTLTYPE_STRING }, \
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{ "ipsec-auth-alg", CTLTYPE_STRING }, \
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{ "mtudisc", CTLTYPE_INT }, \
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{ "mtudisctimeout", CTLTYPE_INT }, \
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}
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/* INET6 stuff */
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@ -1,4 +1,4 @@
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/* $OpenBSD: in_pcb.c,v 1.42 2000/04/27 09:23:21 itojun Exp $ */
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/* $OpenBSD: in_pcb.c,v 1.43 2000/09/18 22:06:37 provos Exp $ */
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/* $NetBSD: in_pcb.c,v 1.25 1996/02/13 23:41:53 christos Exp $ */
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/*
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@ -859,6 +859,43 @@ in_pcblookup(table, faddrp, fport_arg, laddrp, lport_arg, flags)
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return (match);
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}
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struct rtentry *
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in_pcbrtentry(inp)
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struct inpcb *inp;
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{
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struct route *ro;
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ro = &inp->inp_route;
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/*
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* No route yet, so try to acquire one.
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*/
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if (ro->ro_rt == NULL) {
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switch(sotopf(inp->inp_socket)) {
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#ifdef INET6
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case PF_INET6:
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if (IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
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break;
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ro->ro_dst.sa_family = AF_INET6;
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ro->ro_dst.sa_len = sizeof(struct sockaddr_in6);
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((struct sockaddr_in6 *) &ro->ro_dst)->sin6_addr =
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inp->inp_faddr6;
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rtalloc(ro);
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break;
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#endif /* INET6 */
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case PF_INET:
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if (inp->inp_faddr.s_addr != INADDR_ANY)
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break;
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ro->ro_dst.sa_family = AF_INET;
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ro->ro_dst.sa_len = sizeof(ro->ro_dst);
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satosin(&ro->ro_dst)->sin_addr = inp->inp_faddr;
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rtalloc(ro);
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break;
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}
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}
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return (ro->ro_rt);
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}
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struct sockaddr_in *
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in_selectsrc(sin, ro, soopts, mopts, errorp)
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struct sockaddr_in *sin;
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@ -1,4 +1,4 @@
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/* $OpenBSD: in_pcb.h,v 1.25 2000/06/18 17:32:48 itojun Exp $ */
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/* $OpenBSD: in_pcb.h,v 1.26 2000/09/18 22:06:37 provos Exp $ */
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/* $NetBSD: in_pcb.h,v 1.14 1996/02/13 23:42:00 christos Exp $ */
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/*
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@ -260,6 +260,8 @@ void in_setsockaddr __P((struct inpcb *, struct mbuf *));
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int in_baddynamic __P((u_int16_t, u_int16_t));
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extern struct sockaddr_in *in_selectsrc __P((struct sockaddr_in *,
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struct route *, int, struct ip_moptions *, int *));
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struct rtentry *
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in_pcbrtentry __P((struct inpcb *));
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/* INET6 stuff */
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int in6_pcbnotify __P((struct inpcbtable *, struct sockaddr *,
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@ -1,4 +1,4 @@
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/* $OpenBSD: ip_icmp.c,v 1.21 2000/05/15 11:07:32 itojun Exp $ */
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/* $OpenBSD: ip_icmp.c,v 1.22 2000/09/18 22:06:37 provos Exp $ */
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/* $NetBSD: ip_icmp.c,v 1.19 1996/02/13 23:42:22 christos Exp $ */
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/*
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@ -92,6 +92,9 @@ static int ip_next_mtu __P((int, int));
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/*static*/ int ip_next_mtu __P((int, int));
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#endif
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void icmp_mtudisc __P((struct icmp *));
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void icmp_mtudisc_timeout __P((struct rtentry *, struct rttimer *));
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extern struct protosw inetsw[];
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/*
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@ -391,6 +394,8 @@ icmp_input(m, va_alist)
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printf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
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#endif
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icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
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if (code == PRC_MSGSIZE && ip_mtudisc)
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icmp_mtudisc(icp);
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/*
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* XXX if the packet contains [IPv4 AH TCP], we can't make a
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* notification to TCP layer.
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@ -712,3 +717,147 @@ icmp_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
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}
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/* NOTREACHED */
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}
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void
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icmp_mtudisc(icp)
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struct icmp *icp;
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{
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struct rtentry *rt;
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struct sockaddr *dst = sintosa(&icmpsrc);
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u_long mtu = ntohs(icp->icmp_nextmtu); /* Why a long? IPv6 */
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int error;
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/* Table of common MTUs: */
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static u_short mtu_table[] = {65535, 65280, 32000, 17914, 9180, 8166,
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4352, 2002, 1492, 1006, 508, 296, 68, 0};
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rt = rtalloc1(dst, 1);
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if (rt == 0)
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return;
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/* If we didn't get a host route, allocate one */
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if ((rt->rt_flags & RTF_HOST) == 0) {
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struct rtentry *nrt;
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error = rtrequest((int) RTM_ADD, dst,
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(struct sockaddr *) rt->rt_gateway,
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(struct sockaddr *) 0,
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RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt);
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if (error) {
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rtfree(rt);
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rtfree(nrt);
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return;
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}
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nrt->rt_rmx = rt->rt_rmx;
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rtfree(rt);
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rt = nrt;
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}
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error = rt_timer_add(rt, icmp_mtudisc_timeout, ip_mtudisc_timeout_q);
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if (error) {
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rtfree(rt);
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return;
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}
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if (mtu == 0) {
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int i = 0;
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mtu = icp->icmp_ip.ip_len; /* NTOHS happened in deliver: */
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/* Some 4.2BSD-based routers incorrectly adjust the ip_len */
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if (mtu > rt->rt_rmx.rmx_mtu && rt->rt_rmx.rmx_mtu != 0)
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mtu -= (icp->icmp_ip.ip_hl << 2);
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/* If we still can't guess a value, try the route */
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if (mtu == 0) {
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mtu = rt->rt_rmx.rmx_mtu;
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/* If no route mtu, default to the interface mtu */
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if (mtu == 0)
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mtu = rt->rt_ifp->if_mtu;
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}
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for (i = 0; i < sizeof(mtu_table) / sizeof(mtu_table[0]); i++)
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if (mtu > mtu_table[i]) {
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mtu = mtu_table[i];
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break;
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}
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}
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/*
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* XXX: RTV_MTU is overloaded, since the admin can set it
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* to turn off PMTU for a route, and the kernel can
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* set it to indicate a serious problem with PMTU
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* on a route. We should be using a separate flag
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* for the kernel to indicate this.
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*/
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if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) {
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if (mtu < 296 || mtu > rt->rt_ifp->if_mtu)
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rt->rt_rmx.rmx_locks |= RTV_MTU;
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else if (rt->rt_rmx.rmx_mtu > mtu ||
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rt->rt_rmx.rmx_mtu == 0)
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rt->rt_rmx.rmx_mtu = mtu;
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}
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if (rt)
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rtfree(rt);
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}
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/*
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* Return the next larger or smaller MTU plateau (table from RFC 1191)
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* given current value MTU. If DIR is less than zero, a larger plateau
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* is returned; otherwise, a smaller value is returned.
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*/
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int
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ip_next_mtu(mtu, dir) /* XXX */
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int mtu;
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int dir;
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{
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static u_short mtutab[] = {
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65535, 32000, 17914, 8166, 4352, 2002, 1492, 1006, 508, 296,
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68, 0
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};
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int i;
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for (i = 0; i < (sizeof mtutab) / (sizeof mtutab[0]); i++) {
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if (mtu >= mtutab[i])
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break;
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}
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if (dir < 0) {
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if (i == 0) {
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return 0;
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} else {
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return mtutab[i - 1];
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}
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} else {
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if (mtutab[i] == 0) {
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return 0;
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} else if(mtu > mtutab[i]) {
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return mtutab[i];
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} else {
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return mtutab[i + 1];
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}
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}
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}
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void
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icmp_mtudisc_timeout(rt, r)
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struct rtentry *rt;
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struct rttimer *r;
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{
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if (rt == NULL)
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panic("icmp_mtudisc_timeout: bad route to timeout");
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if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) ==
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(RTF_DYNAMIC | RTF_HOST)) {
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rtrequest((int) RTM_DELETE, (struct sockaddr *)rt_key(rt),
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rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
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} else {
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if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) {
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rt->rt_rmx.rmx_mtu = 0;
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}
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}
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}
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@ -1,4 +1,4 @@
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/* $OpenBSD: ip_input.c,v 1.56 2000/05/15 11:07:33 itojun Exp $ */
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/* $OpenBSD: ip_input.c,v 1.57 2000/09/18 22:06:37 provos Exp $ */
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/* $NetBSD: ip_input.c,v 1.30 1996/03/16 23:53:58 christos Exp $ */
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/*
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@ -76,6 +76,12 @@
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#ifndef IPSENDREDIRECTS
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#define IPSENDREDIRECTS 1
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#endif
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#ifndef IPMTUDISC
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#define IPMTUDISC 0
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#endif
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#ifndef IPMTUDISCTIMEOUT
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#define IPMTUDISCTIMEOUT (10 * 60) /* as per RFC 1191 */
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#endif
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int encdebug = 0;
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int ipsec_acl = 1;
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@ -107,11 +113,15 @@ int ipforwarding = IPFORWARDING;
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int ipsendredirects = IPSENDREDIRECTS;
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int ip_dosourceroute = 0; /* no src-routing unless sysctl'd to enable */
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int ip_defttl = IPDEFTTL;
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int ip_mtudisc = IPMTUDISC;
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u_int ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
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int ip_directedbcast = IPDIRECTEDBCAST;
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#ifdef DIAGNOSTIC
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int ipprintfs = 0;
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#endif
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struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
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int ipsec_auth_default_level = IPSEC_AUTH_LEVEL_DEFAULT;
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int ipsec_esp_trans_default_level = IPSEC_ESP_TRANS_LEVEL_DEFAULT;
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int ipsec_esp_network_default_level = IPSEC_ESP_NETWORK_LEVEL_DEFAULT;
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@ -224,6 +234,9 @@ ip_init()
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LIST_INIT(&ipq);
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ipintrq.ifq_maxlen = ipqmaxlen;
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TAILQ_INIT(&in_ifaddr);
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if (ip_mtudisc != 0)
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ip_mtudisc_timeout_q =
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rt_timer_queue_create(ip_mtudisc_timeout);
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/* Fill in list of ports not to allocate dynamically. */
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bzero((void *)&baddynamicports, sizeof(baddynamicports));
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@ -1469,6 +1482,8 @@ ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
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void *newp;
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size_t newlen;
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{
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int error;
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/* All sysctl names at this level are terminal. */
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if (namelen != 1)
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return (ENOTDIR);
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@ -1496,6 +1511,24 @@ ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
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case IPCTL_DIRECTEDBCAST:
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return (sysctl_int(oldp, oldlenp, newp, newlen,
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&ip_directedbcast));
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case IPCTL_MTUDISC:
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error = sysctl_int(oldp, oldlenp, newp, newlen,
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&ip_mtudisc);
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if (ip_mtudisc != 0 && ip_mtudisc_timeout_q == NULL) {
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ip_mtudisc_timeout_q =
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rt_timer_queue_create(ip_mtudisc_timeout);
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} else if (ip_mtudisc == 0 && ip_mtudisc_timeout_q != NULL) {
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rt_timer_queue_destroy(ip_mtudisc_timeout_q, TRUE);
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ip_mtudisc_timeout_q = NULL;
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}
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return error;
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case IPCTL_MTUDISCTIMEOUT:
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error = sysctl_int(oldp, oldlenp, newp, newlen,
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&ip_mtudisc_timeout);
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if (ip_mtudisc_timeout_q != NULL)
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rt_timer_queue_change(ip_mtudisc_timeout_q,
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ip_mtudisc_timeout);
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return (error);
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case IPCTL_IPPORT_FIRSTAUTO:
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return (sysctl_int(oldp, oldlenp, newp, newlen,
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&ipport_firstauto));
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@ -1,4 +1,4 @@
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/* $OpenBSD: ip_output.c,v 1.79 2000/07/29 22:51:22 angelos Exp $ */
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/* $OpenBSD: ip_output.c,v 1.80 2000/09/18 22:06:37 provos Exp $ */
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/* $NetBSD: ip_output.c,v 1.28 1996/02/13 23:43:07 christos Exp $ */
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/*
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@ -545,6 +545,14 @@ ip_output(m0, va_alist)
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m->m_flags &= ~M_BCAST;
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sendit:
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/*
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* If we're doing Path MTU discovery, we need to set DF unless
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* the route's MTU is locked.
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*/
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if ((flags & IP_MTUDISC) && ro->ro_rt &&
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(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0)
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ip->ip_off |= IP_DF;
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#ifdef IPSEC
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/*
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* Check if the packet needs encapsulation.
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@ -1,4 +1,4 @@
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/* $OpenBSD: ip_var.h,v 1.13 2000/01/02 09:00:19 angelos Exp $ */
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/* $OpenBSD: ip_var.h,v 1.14 2000/09/18 22:06:38 provos Exp $ */
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/* $NetBSD: ip_var.h,v 1.16 1996/02/13 23:43:20 christos Exp $ */
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/*
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@ -154,12 +154,17 @@ struct ipstat {
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#define IP_RAWOUTPUT 0x2 /* raw ip header exists */
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#define IP_ROUTETOIF SO_DONTROUTE /* bypass routing tables */
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#define IP_ALLOWBROADCAST SO_BROADCAST /* can send broadcast packets */
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#define IP_MTUDISC 0x0400 /* pmtu discovery, set DF */
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#define IP_ENCAPSULATED 0x0800 /* encapsulated already */
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struct ipstat ipstat;
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LIST_HEAD(ipqhead, ipq) ipq; /* ip reass. queue */
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int ip_defttl; /* default IP ttl */
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int ip_mtudisc; /* mtu discovery */
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u_int ip_mtudisc_timeout; /* seconds to timeout mtu discovery */
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struct rttimer_queue *ip_mtudisc_timeout_q;
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int ip_ctloutput __P((int, struct socket *, int, int, struct mbuf **));
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int ip_dooptions __P((struct mbuf *));
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void ip_drain __P((void));
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@ -1,4 +1,4 @@
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/* $OpenBSD: tcp_input.c,v 1.69 2000/09/05 21:57:41 provos Exp $ */
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/* $OpenBSD: tcp_input.c,v 1.70 2000/09/18 22:06:38 provos Exp $ */
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/* $NetBSD: tcp_input.c,v 1.23 1996/02/13 23:43:44 christos Exp $ */
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/*
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@ -2743,13 +2743,14 @@ tcp_xmit_timer(tp, rtt)
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int
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tcp_mss(tp, offer)
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register struct tcpcb *tp;
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u_int offer;
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int offer;
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{
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struct route *ro;
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register struct rtentry *rt;
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struct ifnet *ifp;
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register int rtt, mss;
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register int rtt, mss, mssopt;
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u_long bufsize;
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int iphlen, is_ipv6 = 0;
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struct inpcb *inp;
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struct socket *so;
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@ -2796,6 +2797,23 @@ tcp_mss(tp, offer)
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}
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ifp = rt->rt_ifp;
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mssopt = mss = tcp_mssdflt;
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switch (tp->pf) {
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#ifdef INET6
|
||||
case AF_INET6:
|
||||
iphlen = sizeof(struct ip6_hdr);
|
||||
is_ipv6 = 1;
|
||||
break;
|
||||
#endif
|
||||
case AF_INET:
|
||||
iphlen = sizeof(struct ip);
|
||||
break;
|
||||
default:
|
||||
/* the family does not support path MTU discovery */
|
||||
goto out;
|
||||
}
|
||||
|
||||
#ifdef RTV_MTU /* if route characteristics exist ... */
|
||||
/*
|
||||
* While we're here, check if there's an initial rtt
|
||||
@ -2823,58 +2841,52 @@ tcp_mss(tp, offer)
|
||||
((tp->t_srtt >> 2) + tp->t_rttvar) >> 1,
|
||||
tp->t_rttmin, TCPTV_REXMTMAX);
|
||||
}
|
||||
|
||||
/*
|
||||
* if there's an mtu associated with the route and we support
|
||||
* path MTU discovery for the underlying protocol family, use it.
|
||||
*/
|
||||
/*
|
||||
* XXX It's wrong to use PMTU values to determine the MSS we
|
||||
* are going to advertise; we should only use the input interface's
|
||||
* MTU instead (see draft-ietf-tcpimpl-pmtud-03.txt). tcp_mss()
|
||||
* should be changed to be aware whether it's called for input or
|
||||
* output MSS calculation, and act accordingly.
|
||||
*/
|
||||
if (rt->rt_rmx.rmx_mtu) {
|
||||
/*
|
||||
* One may wish to lower MSS to take into account options,
|
||||
* especially security-related options.
|
||||
*/
|
||||
mss = rt->rt_rmx.rmx_mtu - sizeof(struct tcphdr);
|
||||
switch (tp->pf) {
|
||||
#ifdef INET6
|
||||
case AF_INET6:
|
||||
mss -= sizeof(struct ip6_hdr);
|
||||
break;
|
||||
#endif
|
||||
#ifdef notdef /* no IPv4 path MTU discovery yet */
|
||||
case AF_INET:
|
||||
mss -= sizeof(struct ip);
|
||||
break;
|
||||
#endif
|
||||
default:
|
||||
/* the family does not support path MTU discovery */
|
||||
mss = 0;
|
||||
break;
|
||||
}
|
||||
mss = rt->rt_rmx.rmx_mtu - iphlen - sizeof(struct tcphdr);
|
||||
} else
|
||||
mss = 0;
|
||||
#else
|
||||
mss = 0;
|
||||
#endif /* RTV_MTU */
|
||||
if (mss == 0) {
|
||||
if (!ifp)
|
||||
/*
|
||||
* ifp may be null and rmx_mtu may be zero in certain
|
||||
* v6 cases (e.g., if ND wasn't able to resolve the
|
||||
* destination host.
|
||||
*/
|
||||
mss = ifp ? ifp->if_mtu - sizeof(struct tcpiphdr) : 0;
|
||||
switch (tp->pf) {
|
||||
case AF_INET:
|
||||
if (!in_localaddr(inp->inp_faddr))
|
||||
mss = min(mss, tcp_mssdflt);
|
||||
break;
|
||||
goto out;
|
||||
else if (ip_mtudisc || ifp->if_flags & IFF_LOOPBACK)
|
||||
mss = ifp->if_mtu - iphlen - sizeof(struct tcphdr);
|
||||
#ifdef INET6
|
||||
else if (is_ipv6) {
|
||||
if (IN6_IS_ADDR_V4MAPPED(&inp->inp_faddr6)) {
|
||||
/* mapped addr case */
|
||||
struct in_addr d;
|
||||
bcopy(&inp->inp_faddr6.s6_addr32[3], &d, sizeof(d));
|
||||
if (in_localaddr(d))
|
||||
mss = ifp->if_mtu - iphlen - sizeof(struct tcphdr);
|
||||
} else {
|
||||
if (in6_localaddr(&inp->inp_faddr6))
|
||||
mss = ifp->if_mtu - iphlen - sizeof(struct tcphdr);
|
||||
}
|
||||
}
|
||||
#endif /* INET6 */
|
||||
else if (inp && in_localaddr(inp->inp_faddr))
|
||||
mss = ifp->if_mtu - iphlen - sizeof(struct tcphdr);
|
||||
|
||||
/* Calculate the value that we offer in TCPOPT_MAXSEG */
|
||||
if (offer != -1) {
|
||||
mssopt = ifp->if_mtu - iphlen - sizeof(struct tcphdr);
|
||||
mssopt = max(tcp_mssdflt, mssopt);
|
||||
}
|
||||
|
||||
out:
|
||||
/*
|
||||
* The current mss, t_maxseg, is initialized to the default value.
|
||||
* If we compute a smaller value, reduce the current mss.
|
||||
@ -2883,7 +2895,7 @@ tcp_mss(tp, offer)
|
||||
* unless we received an offer at least that large from peer.
|
||||
* However, do not accept offers under 32 bytes.
|
||||
*/
|
||||
if (offer)
|
||||
if (offer && offer != -1)
|
||||
mss = min(mss, offer);
|
||||
mss = max(mss, 64); /* sanity - at least max opt. space */
|
||||
/*
|
||||
@ -2953,7 +2965,8 @@ tcp_mss(tp, offer)
|
||||
tp->snd_ssthresh = max(2 * mss, rt->rt_rmx.rmx_ssthresh);
|
||||
}
|
||||
#endif /* RTV_MTU */
|
||||
return (mss);
|
||||
|
||||
return (offer != -1 ? mssopt : mss);
|
||||
}
|
||||
#endif /* TUBA_INCLUDE */
|
||||
|
||||
|
||||
@ -1,4 +1,4 @@
|
||||
/* $OpenBSD: tcp_output.c,v 1.31 2000/09/05 21:57:41 provos Exp $ */
|
||||
/* $OpenBSD: tcp_output.c,v 1.32 2000/09/18 22:06:38 provos Exp $ */
|
||||
/* $NetBSD: tcp_output.c,v 1.16 1997/06/03 16:17:09 kml Exp $ */
|
||||
|
||||
/*
|
||||
@ -1033,7 +1033,9 @@ send:
|
||||
ip->ip_tos = tp->t_inpcb->inp_ip.ip_tos;
|
||||
}
|
||||
error = ip_output(m, tp->t_inpcb->inp_options,
|
||||
&tp->t_inpcb->inp_route, so->so_options & SO_DONTROUTE,
|
||||
&tp->t_inpcb->inp_route,
|
||||
(ip_mtudisc ? IP_MTUDISC : 0) |
|
||||
(so->so_options & SO_DONTROUTE),
|
||||
0, tp->t_inpcb);
|
||||
break;
|
||||
#endif /* INET */
|
||||
|
||||
@ -1,4 +1,4 @@
|
||||
/* $OpenBSD: tcp_subr.c,v 1.30 2000/07/11 19:18:17 provos Exp $ */
|
||||
/* $OpenBSD: tcp_subr.c,v 1.31 2000/09/18 22:06:38 provos Exp $ */
|
||||
/* $NetBSD: tcp_subr.c,v 1.22 1996/02/13 23:44:00 christos Exp $ */
|
||||
|
||||
/*
|
||||
@ -406,7 +406,8 @@ tcp_respond(tp, template, m, ack, seq, flags)
|
||||
th->th_sum = in_cksum(m, tlen);
|
||||
((struct ip *)ti)->ip_len = tlen;
|
||||
((struct ip *)ti)->ip_ttl = ip_defttl;
|
||||
ip_output(m, NULL, ro, 0, NULL, tp ? tp->t_inpcb : NULL);
|
||||
ip_output(m, NULL, ro, ip_mtudisc ? IP_MTUDISC : 0, NULL,
|
||||
tp ? tp->t_inpcb : NULL);
|
||||
}
|
||||
}
|
||||
|
||||
@ -729,10 +730,8 @@ tcp6_ctlinput(cmd, sa, d)
|
||||
return;
|
||||
if (cmd == PRC_QUENCH)
|
||||
notify = tcp_quench;
|
||||
#if 0
|
||||
else if (cmd == PRC_MSGSIZE)
|
||||
notify = tcp_mtudisc;
|
||||
#endif
|
||||
else if (!PRC_IS_REDIRECT(cmd) &&
|
||||
((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0))
|
||||
return;
|
||||
@ -809,6 +808,8 @@ tcp_ctlinput(cmd, sa, v)
|
||||
notify = tcp_quench;
|
||||
else if (PRC_IS_REDIRECT(cmd))
|
||||
notify = in_rtchange, ip = 0;
|
||||
else if (cmd == PRC_MSGSIZE && ip_mtudisc)
|
||||
notify = tcp_mtudisc, ip = 0;
|
||||
else if (cmd == PRC_HOSTDEAD)
|
||||
ip = 0;
|
||||
else if (errno == 0)
|
||||
@ -839,6 +840,52 @@ tcp_quench(inp, errno)
|
||||
tp->snd_cwnd = tp->t_maxseg;
|
||||
}
|
||||
|
||||
/*
|
||||
* On receipt of path MTU corrections, flush old route and replace it
|
||||
* with the new one. Retransmit all unacknowledged packets, to ensure
|
||||
* that all packets will be received.
|
||||
*/
|
||||
void
|
||||
tcp_mtudisc(inp, errno)
|
||||
struct inpcb *inp;
|
||||
int errno;
|
||||
{
|
||||
struct tcpcb *tp = intotcpcb(inp);
|
||||
struct rtentry *rt = in_pcbrtentry(inp);
|
||||
|
||||
if (tp != 0) {
|
||||
if (rt != 0) {
|
||||
/*
|
||||
* If this was not a host route, remove and realloc.
|
||||
*/
|
||||
if ((rt->rt_flags & RTF_HOST) == 0) {
|
||||
in_rtchange(inp, errno);
|
||||
if ((rt = in_pcbrtentry(inp)) == 0)
|
||||
return;
|
||||
}
|
||||
|
||||
/*
|
||||
* Slow start out of the error condition. We
|
||||
* use the MTU because we know it's smaller
|
||||
* than the previously transmitted segment.
|
||||
*
|
||||
* Note: This is more conservative than the
|
||||
* suggestion in RFC 2414
|
||||
*/
|
||||
if (rt->rt_rmx.rmx_mtu != 0) {
|
||||
tcp_mss(tp, -1);
|
||||
tp->snd_cwnd = rt->rt_rmx.rmx_mtu;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Resend unacknowledged packets.
|
||||
*/
|
||||
tp->snd_nxt = tp->snd_una;
|
||||
tcp_output(tp);
|
||||
}
|
||||
}
|
||||
|
||||
#ifdef TCP_SIGNATURE
|
||||
int
|
||||
tcp_signature_tdb_attach()
|
||||
|
||||
@ -1,4 +1,4 @@
|
||||
/* $OpenBSD: tcp_timer.c,v 1.16 1999/12/21 17:49:28 provos Exp $ */
|
||||
/* $OpenBSD: tcp_timer.c,v 1.17 2000/09/18 22:06:38 provos Exp $ */
|
||||
/* $NetBSD: tcp_timer.c,v 1.14 1996/02/13 23:44:09 christos Exp $ */
|
||||
|
||||
/*
|
||||
@ -236,6 +236,24 @@ tcp_timers(tp, timer)
|
||||
rto * tcp_backoff[tp->t_rxtshift],
|
||||
tp->t_rttmin, TCPTV_REXMTMAX);
|
||||
tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
|
||||
#if 0
|
||||
/*
|
||||
* If we are losing and we are trying path MTU discovery,
|
||||
* try turning it off. This will avoid black holes in
|
||||
* the network which suppress or fail to send "packet
|
||||
* too big" ICMP messages. We should ideally do
|
||||
* lots more sophisticated searching to find the right
|
||||
* value here...
|
||||
*/
|
||||
if (ip_mtudisc && tp->t_rxtshift > TCP_MAXRXTSHIFT / 6) {
|
||||
struct rtentry *rt = NULL;
|
||||
|
||||
if (tp->t_inpcb)
|
||||
rt = in_pcbrtentry(tp->t_inpcb);
|
||||
|
||||
/* XXX: Black hole recovery code goes here */
|
||||
}
|
||||
#endif
|
||||
/*
|
||||
* If losing, let the lower level know and try for
|
||||
* a better route. Also, if we backed off this far,
|
||||
|
||||
@ -1,4 +1,4 @@
|
||||
/* $OpenBSD: tcp_var.h,v 1.29 2000/07/11 16:53:22 provos Exp $ */
|
||||
/* $OpenBSD: tcp_var.h,v 1.30 2000/09/18 22:06:38 provos Exp $ */
|
||||
/* $NetBSD: tcp_var.h,v 1.17 1996/02/13 23:44:24 christos Exp $ */
|
||||
|
||||
/*
|
||||
@ -342,7 +342,8 @@ void tcp_init __P((void));
|
||||
int tcp6_input __P((struct mbuf **, int *, int));
|
||||
#endif
|
||||
void tcp_input __P((struct mbuf *, ...));
|
||||
int tcp_mss __P((struct tcpcb *, u_int));
|
||||
int tcp_mss __P((struct tcpcb *, int));
|
||||
void tcp_mtudisc __P((struct inpcb *, int));
|
||||
struct tcpcb *
|
||||
tcp_newtcpcb __P((struct inpcb *));
|
||||
void tcp_notify __P((struct inpcb *, int));
|
||||
|
||||
Loading…
Reference in New Issue
Block a user