raw_ip.c

/*	$NetBSD: raw_ip.c,v 1.101.2.1 2007/12/26 19:57:41 ad 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 1.101.2.1 2007/12/26 19:57:41 ad Exp $");

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

#include <sys/param.h>
#include <sys/sysctl.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 <sys/kauth.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_proto.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>
#include <netipsec/ipsec_var.h>			/* XXX ipsecstat namespace */
#endif	/* FAST_IPSEC*/

struct inpcbtable rawcbtable;

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

	in_pcbinit(&rawcbtable, 1, 1);
}

static void
rip_sbappendaddr(struct inpcb *last, struct ip *ip, const struct sockaddr *sa,
    int hlen, struct mbuf *opts, struct mbuf *n)
{
	if (last->inp_flags & INP_NOHEADER)
		m_adj(n, hlen);
	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, sa, n, opts) == 0) {
		/* should notify about lost packet */
		m_freem(n);
		if (opts)
			m_freem(opts);
	} else
		sorwakeup(last->inp_socket);
}

/*
 * Setup generic address and protocol structures
 * for raw_input routine, then pass them along with
 * mbuf chain.
 */
void
rip_input(struct mbuf *m, ...)
{
	int hlen, proto;
	struct ip *ip = mtod(m, struct ip *);
	struct inpcb_hdr *inph;
	struct inpcb *inp;
	struct inpcb *last = NULL;
	struct mbuf *n, *opts = NULL;
	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);

	sockaddr_in_init(&ripsrc, &ip->ip_src, 0);

	/*
	 * 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.
	 */
	hlen = ip->ip_hl << 2;
	ip->ip_len = ntohs(ip->ip_len) - hlen;
	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 == NULL)
			;
#if defined(IPSEC) || defined(FAST_IPSEC)
		/* check AH/ESP integrity. */
		else if (ipsec4_in_reject_so(m, last->inp_socket)) {
			ipsecstat.in_polvio++;
			/* do not inject data to pcb */
		}
#endif /*IPSEC*/
		else if ((n = m_copypacket(m, M_DONTWAIT)) != NULL) {
			rip_sbappendaddr(last, ip, sintosa(&ripsrc), hlen, opts,
			    n);
			opts = NULL;
		}
		last = inp;
	}
#if defined(IPSEC) || defined(FAST_IPSEC)
	/* check AH/ESP integrity. */
	if (last != NULL && 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 != NULL)
		rip_sbappendaddr(last, ip, sintosa(&ripsrc), hlen, opts, m);
	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(struct inpcbtable *table,
    struct in_addr faddr, struct in_addr laddr, int proto, int errno,
    void (*notify)(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(int cmd, const struct sockaddr *sa, void *v)
{
	struct ip *ip = v;
	void (*notify)(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, satocsin(sa)->sin_addr,
		    ip->ip_src, ip->ip_p, errno, notify);

		/* XXX mapped address case */
	} else
		in_pcbnotifyall(&rawcbtable, satocsin(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
rip_output(struct mbuf *m, ...)
{
	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 && m->m_pkthdr.len >= IP_MINFRAGSIZE)
			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(int op, struct socket *so, int level, int optname,
    struct mbuf **m)
{
	struct inpcb *inp = sotoinpcb(so);
	int error = 0;

	if (level == SOL_SOCKET && optname == SO_NOHEADER) {
		if (op == PRCO_GETOPT) {
			*m = m_intopt(so,
			    (inp->inp_flags & INP_NOHEADER) ? 1 : 0);
			return 0;
		} else if (*m == NULL || (*m)->m_len != sizeof(int))
			error = EINVAL;
		else if (*mtod(*m, int *)) {
			inp->inp_flags &= ~INP_HDRINCL;
			inp->inp_flags |= INP_NOHEADER;
		} else
			inp->inp_flags &= ~INP_NOHEADER;
		goto free_m;
	} else if (level != IPPROTO_IP)
		return ip_ctloutput(op, so, level, optname, m);

	switch (op) {

	case PRCO_SETOPT:
		switch (optname) {
		case IP_HDRINCL:
			if (*m == NULL || (*m)->m_len != sizeof(int))
				error = EINVAL;
			else if (*mtod(*m, int *))
				inp->inp_flags |= INP_HDRINCL;
			else
				inp->inp_flags &= ~INP_HDRINCL;
			goto free_m;

#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:
		case MRT_API_CONFIG:
		case MRT_ADD_BW_UPCALL:
		case MRT_DEL_BW_UPCALL:
			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_intopt(so, inp->inp_flags & INP_HDRINCL ? 1 : 0);
			break;

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

		default:
			error = ip_ctloutput(op, so, level, optname, m);
			break;
		}
		break;
	}
	return error;
free_m:
	if (op == PRCO_SETOPT && *m != NULL)
		(void)m_free(*m);
	return error;
}

int
rip_bind(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(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(struct inpcb *inp)
{

	inp->inp_faddr = zeroin_addr;
}

u_long	rip_sendspace = RIPSNDQ;
u_long	rip_recvspace = RIPRCVQ;

/*ARGSUSED*/
int
rip_usrreq(struct socket *so, int req,
    struct mbuf *m, struct mbuf *nam, struct mbuf *control, struct lwp *l)
{
	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, (void *)nam,
		    (struct ifnet *)control, l));

	s = splsoftnet();

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

	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 (l == NULL) {
			error = EACCES;
			break;
		}

		/* XXX: raw socket permissions are checked in socreate() */

		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);
}

SYSCTL_SETUP(sysctl_net_inet_raw_setup, "sysctl net.inet.raw subtree setup")
{

	sysctl_createv(clog, 0, NULL, NULL,
		       CTLFLAG_PERMANENT,
		       CTLTYPE_NODE, "net", NULL,
		       NULL, 0, NULL, 0,
		       CTL_NET, CTL_EOL);
	sysctl_createv(clog, 0, NULL, NULL,
		       CTLFLAG_PERMANENT,
		       CTLTYPE_NODE, "inet", NULL,
		       NULL, 0, NULL, 0,
		       CTL_NET, PF_INET, CTL_EOL);
	sysctl_createv(clog, 0, NULL, NULL,
		       CTLFLAG_PERMANENT,
		       CTLTYPE_NODE, "raw",
		       SYSCTL_DESCR("Raw IPv4 settings"),
		       NULL, 0, NULL, 0,
		       CTL_NET, PF_INET, IPPROTO_RAW, CTL_EOL);

	sysctl_createv(clog, 0, NULL, NULL,
		       CTLFLAG_PERMANENT,
		       CTLTYPE_STRUCT, "pcblist",
		       SYSCTL_DESCR("Raw IPv4 control block list"),
		       sysctl_inpcblist, 0, &rawcbtable, 0,
		       CTL_NET, PF_INET, IPPROTO_RAW,
		       CTL_CREATE, CTL_EOL);
}