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File: [cvs.NetBSD.org] / src / sys / netinet / raw_ip.c (download)

Revision 1.78, Wed Nov 19 18:39:34 2003 UTC (10 years, 10 months ago) by jonathan
Branch: MAIN
CVS Tags: netbsd-2-0-base, BEFORE-IPF411
Branch point for: netbsd-2-0
Changes since 1.77: +3 -2 lines

Patch back support for (badly) randomized IP ids, by request:

* Include "opt_inet.h" everywhere IP-ids are generated with ip_newid(),
  so the RANDOM_IP_ID option is visible. Also in ip_id(), to ensure
  the prototype for ip_randomid() is made visible.

* Add new sysctl to enable randomized IP-ids, provided the kernel was
  configured with RANDOM_IP_ID. (The sysctl defaults to zero, and is
  a read-only zero if RANDOM_IP_ID is not configured).

Note that the implementation of randomized IP ids is still defective,
and should not be enabled at all (even if configured) without
very careful deliberation. Caveat emptor.

/*	$NetBSD: raw_ip.c,v 1.78 2003/11/19 18:39:34 jonathan Exp $	*/

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * 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.
 * 3. Neither the name of the project 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 PROJECT 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 PROJECT 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.
 */

/*
 * Copyright (c) 1982, 1986, 1988, 1993
 *	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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)raw_ip.c	8.7 (Berkeley) 5/15/95
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: raw_ip.c,v 1.78 2003/11/19 18:39:34 jonathan Exp $");

#include "opt_inet.h"
#include "opt_ipsec.h"
#include "opt_mrouting.h"

#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/systm.h>
#include <sys/proc.h>

#include <net/if.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/ip_mroute.h>
#include <netinet/ip_icmp.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>

#include <machine/stdarg.h>

#ifdef IPSEC
#include <netinet6/ipsec.h>
#endif /*IPSEC*/

#ifdef FAST_IPSEC
#include <netipsec/ipsec.h>
#endif	/* FAST_IPSEC*/

struct inpcbtable rawcbtable;

int	 rip_pcbnotify __P((struct inpcbtable *, struct in_addr,
    struct in_addr, int, int, void (*) __P((struct inpcb *, int))));
int	 rip_bind __P((struct inpcb *, struct mbuf *));
int	 rip_connect __P((struct inpcb *, struct mbuf *));
void	 rip_disconnect __P((struct inpcb *));

/*
 * Nominal space allocated to a raw ip socket.
 */
#define	RIPSNDQ		8192
#define	RIPRCVQ		8192

/*
 * Raw interface to IP protocol.
 */

/*
 * Initialize raw connection block q.
 */
void
rip_init()
{

	in_pcbinit(&rawcbtable, 1, 1);
}

/*
 * Setup generic address and protocol structures
 * for raw_input routine, then pass them along with
 * mbuf chain.
 */
void
#if __STDC__
rip_input(struct mbuf *m, ...)
#else
rip_input(m, va_alist)
	struct mbuf *m;
	va_dcl
#endif
{
	int proto;
	struct ip *ip = mtod(m, struct ip *);
	struct inpcb_hdr *inph;
	struct inpcb *inp;
	struct inpcb *last = 0;
	struct mbuf *opts = 0;
	struct sockaddr_in ripsrc;
	va_list ap;

	va_start(ap, m);
	(void)va_arg(ap, int);		/* ignore value, advance ap */
	proto = va_arg(ap, int);
	va_end(ap);

	ripsrc.sin_family = AF_INET;
	ripsrc.sin_len = sizeof(struct sockaddr_in);
	ripsrc.sin_addr = ip->ip_src;
	ripsrc.sin_port = 0;
	bzero((caddr_t)ripsrc.sin_zero, sizeof(ripsrc.sin_zero));

	/*
	 * XXX Compatibility: programs using raw IP expect ip_len
	 * XXX to have the header length subtracted, and in host order.
	 * XXX ip_off is also expected to be host order.
	 */
	ip->ip_len = ntohs(ip->ip_len) - (ip->ip_hl << 2);
	NTOHS(ip->ip_off);

	CIRCLEQ_FOREACH(inph, &rawcbtable.inpt_queue, inph_queue) {
		inp = (struct inpcb *)inph;
		if (inp->inp_af != AF_INET)
			continue;
		if (inp->inp_ip.ip_p && inp->inp_ip.ip_p != proto)
			continue;
		if (!in_nullhost(inp->inp_laddr) &&
		    !in_hosteq(inp->inp_laddr, ip->ip_dst))
			continue;
		if (!in_nullhost(inp->inp_faddr) &&
		    !in_hosteq(inp->inp_faddr, ip->ip_src))
			continue;
		if (last) {
			struct mbuf *n;

#if defined(IPSEC) || defined(FAST_IPSEC)
			/* check AH/ESP integrity. */
			if (ipsec4_in_reject_so(m, last->inp_socket)) {
				ipsecstat.in_polvio++;
				/* do not inject data to pcb */
			} else
#endif /*IPSEC*/
			if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
				if (last->inp_flags & INP_CONTROLOPTS ||
				    last->inp_socket->so_options & SO_TIMESTAMP)
					ip_savecontrol(last, &opts, ip, n);
				if (sbappendaddr(&last->inp_socket->so_rcv,
				    sintosa(&ripsrc), n, opts) == 0) {
					/* should notify about lost packet */
					m_freem(n);
					if (opts)
						m_freem(opts);
				} else
					sorwakeup(last->inp_socket);
				opts = NULL;
			}
		}
		last = inp;
	}
#if defined(IPSEC) || defined(FAST_IPSEC)
	/* check AH/ESP integrity. */
	if (last && ipsec4_in_reject_so(m, last->inp_socket)) {
		m_freem(m);
		ipsecstat.in_polvio++;
		ipstat.ips_delivered--;
		/* do not inject data to pcb */
	} else
#endif /*IPSEC*/
	if (last) {
		if (last->inp_flags & INP_CONTROLOPTS ||
		    last->inp_socket->so_options & SO_TIMESTAMP)
			ip_savecontrol(last, &opts, ip, m);
		if (sbappendaddr(&last->inp_socket->so_rcv,
		    sintosa(&ripsrc), m, opts) == 0) {
			m_freem(m);
			if (opts)
				m_freem(opts);
		} else
			sorwakeup(last->inp_socket);
	} else {
		if (inetsw[ip_protox[ip->ip_p]].pr_input == rip_input) {
			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PROTOCOL,
			    0, 0);
			ipstat.ips_noproto++;
			ipstat.ips_delivered--;
		} else
			m_freem(m);
	}
	return;
}

int
rip_pcbnotify(table, faddr, laddr, proto, errno, notify)
	struct inpcbtable *table;
	struct in_addr faddr, laddr;
	int proto;
	int errno;
	void (*notify) __P((struct inpcb *, int));
{
	struct inpcb *inp, *ninp;
	int nmatch;

	nmatch = 0;
	for (inp = (struct inpcb *)CIRCLEQ_FIRST(&table->inpt_queue);
	    inp != (struct inpcb *)&table->inpt_queue;
	    inp = ninp) {
		ninp = (struct inpcb *)inp->inp_queue.cqe_next;
		if (inp->inp_af != AF_INET)
			continue;
		if (inp->inp_ip.ip_p && inp->inp_ip.ip_p != proto)
			continue;
		if (in_hosteq(inp->inp_faddr, faddr) &&
		    in_hosteq(inp->inp_laddr, laddr)) {
			(*notify)(inp, errno);
			nmatch++;
		}
	}

	return nmatch;
}

void *
rip_ctlinput(cmd, sa, v)
	int cmd;
	struct sockaddr *sa;
	void *v;
{
	struct ip *ip = v;
	void (*notify) __P((struct inpcb *, int)) = in_rtchange;
	int errno;

	if (sa->sa_family != AF_INET ||
	    sa->sa_len != sizeof(struct sockaddr_in))
		return NULL;
	if ((unsigned)cmd >= PRC_NCMDS)
		return NULL;
	errno = inetctlerrmap[cmd];
	if (PRC_IS_REDIRECT(cmd))
		notify = in_rtchange, ip = 0;
	else if (cmd == PRC_HOSTDEAD)
		ip = 0;
	else if (errno == 0)
		return NULL;
	if (ip) {
		rip_pcbnotify(&rawcbtable, satosin(sa)->sin_addr,
		    ip->ip_src, ip->ip_p, errno, notify);

		/* XXX mapped address case */
	} else
		in_pcbnotifyall(&rawcbtable, satosin(sa)->sin_addr, errno,
		    notify);
	return NULL;
}

/*
 * Generate IP header and pass packet to ip_output.
 * Tack on options user may have setup with control call.
 */
int
#if __STDC__
rip_output(struct mbuf *m, ...)
#else
rip_output(m, va_alist)
	struct mbuf *m;
	va_dcl
#endif
{
	struct inpcb *inp;
	struct ip *ip;
	struct mbuf *opts;
	int flags;
	va_list ap;

	va_start(ap, m);
	inp = va_arg(ap, struct inpcb *);
	va_end(ap);

	flags =
	    (inp->inp_socket->so_options & SO_DONTROUTE) | IP_ALLOWBROADCAST
	    | IP_RETURNMTU;

	/*
	 * If the user handed us a complete IP packet, use it.
	 * Otherwise, allocate an mbuf for a header and fill it in.
	 */
	if ((inp->inp_flags & INP_HDRINCL) == 0) {
		if ((m->m_pkthdr.len + sizeof(struct ip)) > IP_MAXPACKET) {
			m_freem(m);
			return (EMSGSIZE);
		}
		M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
		if (!m)
			return (ENOBUFS);
		ip = mtod(m, struct ip *);
		ip->ip_tos = 0;
		ip->ip_off = htons(0);
		ip->ip_p = inp->inp_ip.ip_p;
		ip->ip_len = htons(m->m_pkthdr.len);
		ip->ip_src = inp->inp_laddr;
		ip->ip_dst = inp->inp_faddr;
		ip->ip_ttl = MAXTTL;
		opts = inp->inp_options;
	} else {
		if (m->m_pkthdr.len > IP_MAXPACKET) {
			m_freem(m);
			return (EMSGSIZE);
		}
		ip = mtod(m, struct ip *);

		/*
		 * If the mbuf is read-only, we need to allocate
		 * a new mbuf for the header, since we need to
		 * modify the header.
		 */
		if (M_READONLY(m)) {
			int hlen = ip->ip_hl << 2;

			m = m_copyup(m, hlen, (max_linkhdr + 3) & ~3);
			if (m == NULL)
				return (ENOMEM);	/* XXX */
			ip = mtod(m, struct ip *);
		}

		/* XXX userland passes ip_len and ip_off in host order */
		if (m->m_pkthdr.len != ip->ip_len) {
			m_freem(m);
			return (EINVAL);
		}
		HTONS(ip->ip_len);
		HTONS(ip->ip_off);
		if (ip->ip_id == 0)
			ip->ip_id = ip_newid();
		opts = NULL;
		/* XXX prevent ip_output from overwriting header fields */
		flags |= IP_RAWOUTPUT;
		ipstat.ips_rawout++;
	}
	return (ip_output(m, opts, &inp->inp_route, flags, inp->inp_moptions,
	     inp->inp_socket, &inp->inp_errormtu));
}

/*
 * Raw IP socket option processing.
 */
int
rip_ctloutput(op, so, level, optname, m)
	int op;
	struct socket *so;
	int level, optname;
	struct mbuf **m;
{
	struct inpcb *inp = sotoinpcb(so);
	int error = 0;

	if (level != IPPROTO_IP) {
		error = ENOPROTOOPT;
		if (op == PRCO_SETOPT && *m != 0)
			(void) m_free(*m);
	} else switch (op) {

	case PRCO_SETOPT:
		switch (optname) {
		case IP_HDRINCL:
			if (*m == 0 || (*m)->m_len < sizeof (int))
				error = EINVAL;
			else {
				if (*mtod(*m, int *))
					inp->inp_flags |= INP_HDRINCL;
				else
					inp->inp_flags &= ~INP_HDRINCL;
			}
			if (*m != 0)
				(void) m_free(*m);
			break;

#ifdef MROUTING
		case MRT_INIT:
		case MRT_DONE:
		case MRT_ADD_VIF:
		case MRT_DEL_VIF:
		case MRT_ADD_MFC:
		case MRT_DEL_MFC:
		case MRT_ASSERT:
			error = ip_mrouter_set(so, optname, m);
			break;
#endif

		default:
			error = ip_ctloutput(op, so, level, optname, m);
			break;
		}
		break;

	case PRCO_GETOPT:
		switch (optname) {
		case IP_HDRINCL:
			*m = m_get(M_WAIT, MT_SOOPTS);
			MCLAIM((*m), so->so_mowner);
			(*m)->m_len = sizeof (int);
			*mtod(*m, int *) = inp->inp_flags & INP_HDRINCL ? 1 : 0;
			break;

#ifdef MROUTING
		case MRT_VERSION:
		case MRT_ASSERT:
			error = ip_mrouter_get(so, optname, m);
			break;
#endif

		default:
			error = ip_ctloutput(op, so, level, optname, m);
			break;
		}
		break;
	}
	return (error);
}

int
rip_bind(inp, nam)
	struct inpcb *inp;
	struct mbuf *nam;
{
	struct sockaddr_in *addr = mtod(nam, struct sockaddr_in *);

	if (nam->m_len != sizeof(*addr))
		return (EINVAL);
	if (TAILQ_FIRST(&ifnet) == 0)
		return (EADDRNOTAVAIL);
	if (addr->sin_family != AF_INET &&
	    addr->sin_family != AF_IMPLINK)
		return (EAFNOSUPPORT);
	if (!in_nullhost(addr->sin_addr) &&
	    ifa_ifwithaddr(sintosa(addr)) == 0)
		return (EADDRNOTAVAIL);
	inp->inp_laddr = addr->sin_addr;
	return (0);
}

int
rip_connect(inp, nam)
	struct inpcb *inp;
	struct mbuf *nam;
{
	struct sockaddr_in *addr = mtod(nam, struct sockaddr_in *);

	if (nam->m_len != sizeof(*addr))
		return (EINVAL);
	if (TAILQ_FIRST(&ifnet) == 0)
		return (EADDRNOTAVAIL);
	if (addr->sin_family != AF_INET &&
	    addr->sin_family != AF_IMPLINK)
		return (EAFNOSUPPORT);
	inp->inp_faddr = addr->sin_addr;
	return (0);
}

void
rip_disconnect(inp)
	struct inpcb *inp;
{

	inp->inp_faddr = zeroin_addr;
}

u_long	rip_sendspace = RIPSNDQ;
u_long	rip_recvspace = RIPRCVQ;

/*ARGSUSED*/
int
rip_usrreq(so, req, m, nam, control, p)
	struct socket *so;
	int req;
	struct mbuf *m, *nam, *control;
	struct proc *p;
{
	struct inpcb *inp;
	int s;
	int error = 0;
#ifdef MROUTING
	extern struct socket *ip_mrouter;
#endif

	if (req == PRU_CONTROL)
		return (in_control(so, (long)m, (caddr_t)nam,
		    (struct ifnet *)control, p));

	if (req == PRU_PURGEIF) {
		in_pcbpurgeif0(&rawcbtable, (struct ifnet *)control);
		in_purgeif((struct ifnet *)control);
		in_pcbpurgeif(&rawcbtable, (struct ifnet *)control);
		return (0);
	}

	s = splsoftnet();
	inp = sotoinpcb(so);
#ifdef DIAGNOSTIC
	if (req != PRU_SEND && req != PRU_SENDOOB && control)
		panic("rip_usrreq: unexpected control mbuf");
#endif
	if (inp == 0 && req != PRU_ATTACH) {
		error = EINVAL;
		goto release;
	}

	switch (req) {

	case PRU_ATTACH:
		if (inp != 0) {
			error = EISCONN;
			break;
		}
		if (p == 0 || (error = suser(p->p_ucred, &p->p_acflag))) {
			error = EACCES;
			break;
		}
		if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
			error = soreserve(so, rip_sendspace, rip_recvspace);
			if (error)
				break;
		}
		error = in_pcballoc(so, &rawcbtable);
		if (error)
			break;
		inp = sotoinpcb(so);
		inp->inp_ip.ip_p = (long)nam;
		break;

	case PRU_DETACH:
#ifdef MROUTING
		if (so == ip_mrouter)
			ip_mrouter_done();
#endif
		in_pcbdetach(inp);
		break;

	case PRU_BIND:
		error = rip_bind(inp, nam);
		break;

	case PRU_LISTEN:
		error = EOPNOTSUPP;
		break;

	case PRU_CONNECT:
		error = rip_connect(inp, nam);
		if (error)
			break;
		soisconnected(so);
		break;

	case PRU_CONNECT2:
		error = EOPNOTSUPP;
		break;

	case PRU_DISCONNECT:
		soisdisconnected(so);
		rip_disconnect(inp);
		break;

	/*
	 * Mark the connection as being incapable of further input.
	 */
	case PRU_SHUTDOWN:
		socantsendmore(so);
		break;

	case PRU_RCVD:
		error = EOPNOTSUPP;
		break;

	/*
	 * Ship a packet out.  The appropriate raw output
	 * routine handles any massaging necessary.
	 */
	case PRU_SEND:
		if (control && control->m_len) {
			m_freem(control);
			m_freem(m);
			error = EINVAL;
			break;
		}
	{
		if (nam) {
			if ((so->so_state & SS_ISCONNECTED) != 0) {
				error = EISCONN;
				goto die;
			}
			error = rip_connect(inp, nam);
			if (error) {
			die:
				m_freem(m);
				break;
			}
		} else {
			if ((so->so_state & SS_ISCONNECTED) == 0) {
				error = ENOTCONN;
				goto die;
			}
		}
		error = rip_output(m, inp);
		if (nam)
			rip_disconnect(inp);
	}
		break;

	case PRU_SENSE:
		/*
		 * stat: don't bother with a blocksize.
		 */
		splx(s);
		return (0);

	case PRU_RCVOOB:
		error = EOPNOTSUPP;
		break;

	case PRU_SENDOOB:
		m_freem(control);
		m_freem(m);
		error = EOPNOTSUPP;
		break;

	case PRU_SOCKADDR:
		in_setsockaddr(inp, nam);
		break;

	case PRU_PEERADDR:
		in_setpeeraddr(inp, nam);
		break;

	default:
		panic("rip_usrreq");
	}

release:
	splx(s);
	return (error);
}