676 lines
13 KiB
C
676 lines
13 KiB
C
/* $NetBSD: if_tun.c,v 1.32 1997/09/25 13:11:58 matt Exp $ */
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/*
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* Copyright (c) 1988, Julian Onions <jpo@cs.nott.ac.uk>
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* Nottingham University 1987.
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*
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* This source may be freely distributed, however I would be interested
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* in any changes that are made.
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*
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* This driver takes packets off the IP i/f and hands them up to a
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* user process to have its wicked way with. This driver has its
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* roots in a similar driver written by Phil Cockcroft (formerly) at
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* UCL. This driver is based much more on read/write/poll mode of
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* operation though.
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*/
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#include "tun.h"
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#if NTUN > 0
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#include <sys/param.h>
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#include <sys/proc.h>
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#include <sys/systm.h>
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#include <sys/mbuf.h>
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#include <sys/buf.h>
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#include <sys/protosw.h>
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#include <sys/socket.h>
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#include <sys/ioctl.h>
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#include <sys/errno.h>
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#include <sys/syslog.h>
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#include <sys/select.h>
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#include <sys/poll.h>
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#include <sys/file.h>
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#include <sys/signalvar.h>
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#include <sys/conf.h>
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#include <machine/cpu.h>
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#include <net/if.h>
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#include <net/if_ether.h>
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#include <net/netisr.h>
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#include <net/route.h>
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#ifdef INET
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/in_var.h>
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#include <netinet/ip.h>
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#include <netinet/if_inarp.h>
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#endif
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#ifdef NS
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#include <netns/ns.h>
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#include <netns/ns_if.h>
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#endif
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#include "bpfilter.h"
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#if NBPFILTER > 0
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#include <sys/time.h>
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#include <net/bpf.h>
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#endif
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#include <net/if_tun.h>
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#define TUNDEBUG if (tundebug) printf
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int tundebug = 0;
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struct tun_softc tunctl[NTUN];
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extern int ifqmaxlen;
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void tunattach __P((int));
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int tun_ioctl __P((struct ifnet *, u_long, caddr_t));
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int tun_output __P((struct ifnet *, struct mbuf *, struct sockaddr *,
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struct rtentry *rt));
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static void tuninit __P((struct tun_softc *));
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void
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tunattach(unused)
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int unused;
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{
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register int i;
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struct ifnet *ifp;
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for (i = 0; i < NTUN; i++) {
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tunctl[i].tun_flags = TUN_INITED;
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ifp = &tunctl[i].tun_if;
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sprintf(ifp->if_xname, "tun%d", i);
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ifp->if_softc = &tunctl[i];
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ifp->if_mtu = TUNMTU;
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ifp->if_ioctl = tun_ioctl;
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ifp->if_output = tun_output;
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ifp->if_flags = IFF_POINTOPOINT;
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ifp->if_snd.ifq_maxlen = ifqmaxlen;
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ifp->if_collisions = 0;
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ifp->if_ierrors = 0;
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ifp->if_oerrors = 0;
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ifp->if_ipackets = 0;
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ifp->if_opackets = 0;
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if_attach(ifp);
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#if NBPFILTER > 0
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bpfattach(&tunctl[i].tun_bpf, ifp, DLT_NULL, sizeof(u_int32_t));
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#endif
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}
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}
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/*
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* tunnel open - must be superuser & the device must be
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* configured in
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*/
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int
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tunopen(dev, flag, mode, p)
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dev_t dev;
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int flag, mode;
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struct proc *p;
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{
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struct ifnet *ifp;
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struct tun_softc *tp;
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register int unit, error;
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if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
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return (error);
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if ((unit = minor(dev)) >= NTUN)
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return (ENXIO);
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tp = &tunctl[unit];
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if (tp->tun_flags & TUN_OPEN)
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return ENXIO;
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ifp = &tp->tun_if;
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tp->tun_flags |= TUN_OPEN;
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TUNDEBUG("%s: open\n", ifp->if_xname);
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return (0);
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}
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/*
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* tunclose - close the device - mark i/f down & delete
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* routing info
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*/
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int
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tunclose(dev, flag, mode, p)
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dev_t dev;
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int flag;
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int mode;
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struct proc *p;
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{
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register int unit = minor(dev), s;
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struct tun_softc *tp = &tunctl[unit];
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struct ifnet *ifp = &tp->tun_if;
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struct mbuf *m;
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tp->tun_flags &= ~TUN_OPEN;
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/*
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* junk all pending output
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*/
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do {
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s = splimp();
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IF_DEQUEUE(&ifp->if_snd, m);
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splx(s);
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if (m)
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m_freem(m);
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} while (m);
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if (ifp->if_flags & IFF_UP) {
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s = splimp();
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if_down(ifp);
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if (ifp->if_flags & IFF_RUNNING) {
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/* find internet addresses and delete routes */
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register struct ifaddr *ifa;
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for (ifa = ifp->if_addrlist.tqh_first; ifa != 0;
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ifa = ifa->ifa_list.tqe_next) {
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if (ifa->ifa_addr->sa_family == AF_INET) {
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rtinit(ifa, (int)RTM_DELETE,
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tp->tun_flags & TUN_DSTADDR
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? RTF_HOST
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: 0);
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}
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}
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}
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splx(s);
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}
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tp->tun_pgrp = 0;
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selwakeup(&tp->tun_rsel);
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TUNDEBUG ("%s: closed\n", ifp->if_xname);
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return (0);
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}
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static void
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tuninit(tp)
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struct tun_softc *tp;
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{
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struct ifnet *ifp = &tp->tun_if;
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register struct ifaddr *ifa;
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TUNDEBUG("%s: tuninit\n", ifp->if_xname);
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ifp->if_flags |= IFF_UP | IFF_RUNNING;
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tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR);
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for (ifa = ifp->if_addrlist.tqh_first; ifa != 0;
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ifa = ifa->ifa_list.tqe_next) {
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if (ifa->ifa_addr->sa_family == AF_INET) {
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struct sockaddr_in *sin;
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sin = satosin(ifa->ifa_addr);
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if (sin && sin->sin_addr.s_addr)
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tp->tun_flags |= TUN_IASET;
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if (ifp->if_flags & IFF_POINTOPOINT) {
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sin = satosin(ifa->ifa_dstaddr);
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if (sin && sin->sin_addr.s_addr)
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tp->tun_flags |= TUN_DSTADDR;
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}
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}
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}
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return;
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}
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/*
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* Process an ioctl request.
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*/
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int
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tun_ioctl(ifp, cmd, data)
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struct ifnet *ifp;
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u_long cmd;
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caddr_t data;
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{
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int error = 0, s;
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s = splimp();
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switch(cmd) {
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case SIOCSIFADDR:
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tuninit((struct tun_softc *)(ifp->if_softc));
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TUNDEBUG("%s: address set\n", ifp->if_xname);
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break;
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case SIOCSIFDSTADDR:
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tuninit((struct tun_softc *)(ifp->if_softc));
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TUNDEBUG("%s: destination address set\n", ifp->if_xname);
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break;
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case SIOCSIFBRDADDR:
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TUNDEBUG("%s: broadcast address set\n", ifp->if_xname);
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break;
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case SIOCSIFMTU: {
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struct ifreq *ifr = (struct ifreq *) data;
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if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) {
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error = EINVAL;
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break;
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}
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TUNDEBUG("%s: interface mtu set\n", ifp->if_xname);
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ifp->if_mtu = ifr->ifr_mtu;
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break;
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}
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case SIOCADDMULTI:
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case SIOCDELMULTI: {
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struct ifreq *ifr = (struct ifreq *) data;
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if (ifr == 0) {
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error = EAFNOSUPPORT; /* XXX */
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break;
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}
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switch (ifr->ifr_addr.sa_family) {
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#ifdef INET
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case AF_INET:
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break;
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#endif
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default:
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error = EAFNOSUPPORT;
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break;
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}
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break;
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}
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default:
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error = EINVAL;
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}
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splx(s);
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return (error);
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}
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/*
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* tun_output - queue packets from higher level ready to put out.
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*/
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int
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tun_output(ifp, m0, dst, rt)
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struct ifnet *ifp;
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struct mbuf *m0;
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struct sockaddr *dst;
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struct rtentry *rt;
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{
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struct tun_softc *tp = ifp->if_softc;
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struct proc *p;
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int s;
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TUNDEBUG ("%s: tun_output\n", ifp->if_xname);
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if ((tp->tun_flags & TUN_READY) != TUN_READY) {
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TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname,
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tp->tun_flags);
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m_freem (m0);
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return (EHOSTDOWN);
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}
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#if NBPFILTER > 0
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if (tp->tun_bpf) {
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/*
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* We need to prepend the address family as
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* a four byte field. Cons up a dummy header
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* to pacify bpf. This is safe because bpf
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* will only read from the mbuf (i.e., it won't
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* try to free it or keep a pointer to it).
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*/
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struct mbuf m;
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u_int32_t af = dst->sa_family;
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m.m_next = m0;
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m.m_len = sizeof(af);
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m.m_data = (char *)⁡
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bpf_mtap(tp->tun_bpf, &m);
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}
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#endif
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switch(dst->sa_family) {
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#ifdef INET
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case AF_INET:
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if (tp->tun_flags & TUN_PREPADDR) {
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/* Simple link-layer header */
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M_PREPEND(m0, dst->sa_len, M_DONTWAIT);
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if (m0 == NULL) {
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IF_DROP(&ifp->if_snd);
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return (ENOBUFS);
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}
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bcopy(dst, mtod(m0, char *), dst->sa_len);
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}
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s = splimp();
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if (IF_QFULL(&ifp->if_snd)) {
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IF_DROP(&ifp->if_snd);
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m_freem(m0);
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splx(s);
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ifp->if_collisions++;
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return (ENOBUFS);
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}
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IF_ENQUEUE(&ifp->if_snd, m0);
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splx(s);
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ifp->if_opackets++;
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break;
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#endif
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default:
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m_freem(m0);
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return (EAFNOSUPPORT);
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}
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if (tp->tun_flags & TUN_RWAIT) {
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tp->tun_flags &= ~TUN_RWAIT;
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wakeup((caddr_t)tp);
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}
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if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) {
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if (tp->tun_pgrp > 0)
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gsignal(tp->tun_pgrp, SIGIO);
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else if ((p = pfind(-tp->tun_pgrp)) != NULL)
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psignal(p, SIGIO);
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}
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selwakeup(&tp->tun_rsel);
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return (0);
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}
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/*
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* the cdevsw interface is now pretty minimal.
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*/
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int
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tunioctl(dev, cmd, data, flag, p)
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dev_t dev;
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u_long cmd;
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caddr_t data;
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int flag;
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struct proc *p;
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{
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int unit = minor(dev), s;
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struct tun_softc *tp = &tunctl[unit];
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switch (cmd) {
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case TUNSDEBUG:
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tundebug = *(int *)data;
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break;
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case TUNGDEBUG:
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*(int *)data = tundebug;
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break;
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case TUNSIFMODE:
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switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) {
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case IFF_POINTOPOINT:
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case IFF_BROADCAST:
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s = splimp();
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if (tp->tun_if.if_flags & IFF_UP) {
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splx(s);
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return (EBUSY);
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}
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tp->tun_if.if_flags &=
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~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
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tp->tun_if.if_flags |= *(int *)data;
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splx(s);
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break;
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default:
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return (EINVAL);
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break;
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}
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break;
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case TUNSLMODE:
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if (*(int *)data)
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tp->tun_flags |= TUN_PREPADDR;
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else
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tp->tun_flags &= ~TUN_PREPADDR;
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break;
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case FIONBIO:
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if (*(int *)data)
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tp->tun_flags |= TUN_NBIO;
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else
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tp->tun_flags &= ~TUN_NBIO;
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break;
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case FIOASYNC:
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if (*(int *)data)
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tp->tun_flags |= TUN_ASYNC;
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else
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tp->tun_flags &= ~TUN_ASYNC;
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break;
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case FIONREAD:
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s = splimp();
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if (tp->tun_if.if_snd.ifq_head)
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*(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len;
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else
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*(int *)data = 0;
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splx(s);
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break;
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case TIOCSPGRP:
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tp->tun_pgrp = *(int *)data;
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break;
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case TIOCGPGRP:
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*(int *)data = tp->tun_pgrp;
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break;
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default:
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return (ENOTTY);
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}
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return (0);
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}
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/*
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* The cdevsw read interface - reads a packet at a time, or at
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* least as much of a packet as can be read.
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*/
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int
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tunread(dev, uio, ioflag)
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dev_t dev;
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struct uio *uio;
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int ioflag;
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{
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int unit = minor(dev);
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struct tun_softc *tp = &tunctl[unit];
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struct ifnet *ifp = &tp->tun_if;
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struct mbuf *m, *m0;
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int error=0, len, s;
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TUNDEBUG ("%s: read\n", ifp->if_xname);
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if ((tp->tun_flags & TUN_READY) != TUN_READY) {
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TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags);
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return EHOSTDOWN;
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}
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tp->tun_flags &= ~TUN_RWAIT;
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s = splimp();
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do {
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IF_DEQUEUE(&ifp->if_snd, m0);
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if (m0 == 0) {
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if (tp->tun_flags & TUN_NBIO) {
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splx(s);
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return (EWOULDBLOCK);
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}
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tp->tun_flags |= TUN_RWAIT;
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if (tsleep((caddr_t)tp, PZERO|PCATCH, "tunread", 0)) {
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splx(s);
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return (EINTR);
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}
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}
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} while (m0 == 0);
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splx(s);
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while (m0 && uio->uio_resid > 0 && error == 0) {
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len = min(uio->uio_resid, m0->m_len);
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if (len == 0)
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break;
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error = uiomove(mtod(m0, caddr_t), len, uio);
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MFREE(m0, m);
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m0 = m;
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}
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if (m0) {
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TUNDEBUG("Dropping mbuf\n");
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m_freem(m0);
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}
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if (error)
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ifp->if_ierrors++;
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return (error);
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}
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/*
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* the cdevsw write interface - an atomic write is a packet - or else!
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*/
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int
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tunwrite(dev, uio, ioflag)
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dev_t dev;
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struct uio *uio;
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int ioflag;
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{
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int unit = minor (dev);
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struct tun_softc *tp = &tunctl[unit];
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struct ifnet *ifp = &tp->tun_if;
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struct mbuf *top, **mp, *m;
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struct ifqueue *ifq;
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struct sockaddr dst;
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int isr, error=0, s, tlen, mlen;
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TUNDEBUG("%s: tunwrite\n", ifp->if_xname);
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if (tp->tun_flags & TUN_PREPADDR) {
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if (uio->uio_resid < sizeof(dst))
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return (EIO);
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error = uiomove((caddr_t)&dst, sizeof(dst), uio);
|
|
if (dst.sa_len > sizeof(dst)) {
|
|
/* Duh.. */
|
|
char discard;
|
|
int n = dst.sa_len - sizeof(dst);
|
|
while (n--)
|
|
if ((error = uiomove(&discard, 1, uio)) != 0)
|
|
return (error);
|
|
}
|
|
} else {
|
|
#ifdef INET
|
|
dst.sa_family = AF_INET;
|
|
#endif
|
|
}
|
|
|
|
if (uio->uio_resid < 0 || uio->uio_resid > TUNMTU) {
|
|
TUNDEBUG("%s: len=%d!\n", ifp->if_xname, uio->uio_resid);
|
|
return (EIO);
|
|
}
|
|
|
|
switch (dst.sa_family) {
|
|
#ifdef INET
|
|
case AF_INET:
|
|
ifq = &ipintrq;
|
|
isr = NETISR_IP;
|
|
break;
|
|
#endif
|
|
default:
|
|
return (EAFNOSUPPORT);
|
|
}
|
|
|
|
tlen = uio->uio_resid;
|
|
|
|
/* get a header mbuf */
|
|
MGETHDR(m, M_DONTWAIT, MT_DATA);
|
|
if (m == NULL)
|
|
return (ENOBUFS);
|
|
mlen = MHLEN;
|
|
|
|
top = 0;
|
|
mp = ⊤
|
|
while (error == 0 && uio->uio_resid > 0) {
|
|
m->m_len = min(mlen, uio->uio_resid);
|
|
error = uiomove(mtod (m, caddr_t), m->m_len, uio);
|
|
*mp = m;
|
|
mp = &m->m_next;
|
|
if (uio->uio_resid > 0) {
|
|
MGET (m, M_DONTWAIT, MT_DATA);
|
|
if (m == 0) {
|
|
error = ENOBUFS;
|
|
break;
|
|
}
|
|
mlen = MLEN;
|
|
}
|
|
}
|
|
if (error) {
|
|
if (top)
|
|
m_freem (top);
|
|
ifp->if_ierrors++;
|
|
return (error);
|
|
}
|
|
|
|
top->m_pkthdr.len = tlen;
|
|
top->m_pkthdr.rcvif = ifp;
|
|
|
|
#if NBPFILTER > 0
|
|
if (tp->tun_bpf) {
|
|
/*
|
|
* We need to prepend the address family as
|
|
* a four byte field. Cons up a dummy header
|
|
* to pacify bpf. This is safe because bpf
|
|
* will only read from the mbuf (i.e., it won't
|
|
* try to free it or keep a pointer to it).
|
|
*/
|
|
struct mbuf m;
|
|
u_int32_t af = AF_INET;
|
|
|
|
m.m_next = top;
|
|
m.m_len = sizeof(af);
|
|
m.m_data = (char *)⁡
|
|
|
|
bpf_mtap(tp->tun_bpf, &m);
|
|
}
|
|
#endif
|
|
|
|
s = splimp();
|
|
if (IF_QFULL(ifq)) {
|
|
IF_DROP(ifq);
|
|
splx(s);
|
|
ifp->if_collisions++;
|
|
m_freem(top);
|
|
return (ENOBUFS);
|
|
}
|
|
IF_ENQUEUE(ifq, top);
|
|
splx(s);
|
|
ifp->if_ipackets++;
|
|
schednetisr(isr);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* tunpoll - the poll interface, this is only useful on reads
|
|
* really. The write detect always returns true, write never blocks
|
|
* anyway, it either accepts the packet or drops it.
|
|
*/
|
|
int
|
|
tunpoll(dev, events, p)
|
|
dev_t dev;
|
|
int events;
|
|
struct proc *p;
|
|
{
|
|
int unit = minor(dev), s;
|
|
struct tun_softc *tp = &tunctl[unit];
|
|
struct ifnet *ifp = &tp->tun_if;
|
|
int revents = 0;
|
|
|
|
s = splimp();
|
|
TUNDEBUG("%s: tunpoll\n", ifp->if_xname);
|
|
|
|
if (events & (POLLIN | POLLRDNORM))
|
|
if (ifp->if_snd.ifq_len > 0) {
|
|
TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname,
|
|
ifp->if_snd.ifq_len);
|
|
revents |= events & (POLLIN | POLLRDNORM);
|
|
} else {
|
|
TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname);
|
|
selrecord(p, &tp->tun_rsel);
|
|
}
|
|
|
|
if (events & (POLLOUT | POLLWRNORM))
|
|
revents |= events & (POLLOUT | POLLWRNORM);
|
|
|
|
splx(s);
|
|
return (revents);
|
|
}
|
|
|
|
#endif /* NTUN */
|