xref: /freebsd/sys/netinet/raw_ip.c (revision f8f6cbba927c69012c21cc4922b799a377f52f4f)

/*
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)raw_ip.c	8.7 (Berkeley) 5/15/95
 *	$Id: raw_ip.c,v 1.48 1997/08/16 19:15:37 wollman Exp $
 */

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

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

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

#include <netinet/ip_fw.h>

#if !defined(COMPAT_IPFW) || COMPAT_IPFW == 1
#undef COMPAT_IPFW
#define COMPAT_IPFW 1
#else
#undef COMPAT_IPFW
#endif

static struct inpcbhead ripcb;
static struct inpcbinfo ripcbinfo;

/*
 * 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()
{
	LIST_INIT(&ripcb);
	ripcbinfo.listhead = &ripcb;
	/*
	 * XXX We don't use the hash list for raw IP, but it's easier
	 * to allocate a one entry hash list than it is to check all
	 * over the place for hashbase == NULL.
	 */
	ripcbinfo.hashbase = hashinit(1, M_PCB, &ripcbinfo.hashmask);
}

static struct	sockaddr_in ripsrc = { sizeof(ripsrc), AF_INET };
/*
 * Setup generic address and protocol structures
 * for raw_input routine, then pass them along with
 * mbuf chain.
 */
void
rip_input(m, iphlen)
	struct mbuf *m;
	int iphlen;
{
	register struct ip *ip = mtod(m, struct ip *);
	register struct inpcb *inp;
	struct inpcb *last = 0;
	struct mbuf *opts = 0;

	ripsrc.sin_addr = ip->ip_src;
	for (inp = ripcb.lh_first; inp != NULL; inp = inp->inp_list.le_next) {
		if (inp->inp_ip_p && inp->inp_ip_p != ip->ip_p)
			continue;
		if (inp->inp_laddr.s_addr &&
                  inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
			continue;
		if (inp->inp_faddr.s_addr &&
                  inp->inp_faddr.s_addr != ip->ip_src.s_addr)
			continue;
		if (last) {
			struct mbuf *n = m_copy(m, 0, (int)M_COPYALL);
			if (n) {
				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,
				    (struct sockaddr *)&ripsrc, n,
				    opts) == 0) {
					/* should notify about lost packet */
					m_freem(n);
					if (opts)
					    m_freem(opts);
				} else
					sorwakeup(last->inp_socket);
				opts = 0;
			}
		}
		last = inp;
	}
	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,
		    (struct sockaddr *)&ripsrc, m, opts) == 0) {
			m_freem(m);
			if (opts)
			    m_freem(opts);
		} else
			sorwakeup(last->inp_socket);
	} else {
		m_freem(m);
              ipstat.ips_noproto++;
              ipstat.ips_delivered--;
      }
}

/*
 * Generate IP header and pass packet to ip_output.
 * Tack on options user may have setup with control call.
 */
int
rip_output(m, so, dst)
	register struct mbuf *m;
	struct socket *so;
	u_long dst;
{
	register struct ip *ip;
	register struct inpcb *inp = sotoinpcb(so);
	int flags = (so->so_options & SO_DONTROUTE) | IP_ALLOWBROADCAST;

	/*
	 * 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_WAIT);
		ip = mtod(m, struct ip *);
		ip->ip_tos = 0;
		ip->ip_off = 0;
		ip->ip_p = inp->inp_ip_p;
		ip->ip_len = m->m_pkthdr.len;
		ip->ip_src = inp->inp_laddr;
		ip->ip_dst.s_addr = dst;
		ip->ip_ttl = MAXTTL;
	} else {
		if (m->m_pkthdr.len > IP_MAXPACKET) {
			m_freem(m);
			return(EMSGSIZE);
		}
		ip = mtod(m, struct ip *);
		/* don't allow both user specified and setsockopt options,
		   and don't allow packet length sizes that will crash */
		if (((IP_VHL_HL(ip->ip_vhl) != (sizeof (*ip) >> 2))
		     && inp->inp_options)
		    || (ip->ip_len > m->m_pkthdr.len)
		    || (ip->ip_len < (IP_VHL_HL(ip->ip_vhl) << 2))) {
			m_freem(m);
			return EINVAL;
		}
		if (ip->ip_id == 0)
			ip->ip_id = htons(ip_id++);
		/* XXX prevent ip_output from overwriting header fields */
		flags |= IP_RAWOUTPUT;
		ipstat.ips_rawout++;
	}
	return (ip_output(m, inp->inp_options, &inp->inp_route, flags,
			  inp->inp_moptions));
}

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

	if (level != IPPROTO_IP) {
		if (op == PRCO_SETOPT && *m)
			(void)m_free(*m);
		return (EINVAL);
	}

	switch (optname) {

	case IP_HDRINCL:
		error = 0;
		if (op == PRCO_SETOPT) {
			if (m == 0 || *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)
				(void)m_free(*m);
		} else {
			*m = m_get(M_WAIT, MT_SOOPTS);
			(*m)->m_len = sizeof (int);
			*mtod(*m, int *) = inp->inp_flags & INP_HDRINCL;
		}
		return (error);

#ifdef COMPAT_IPFW
	case IP_FW_GET:
		if (ip_fw_ctl_ptr == NULL || op == PRCO_SETOPT) {
			if (*m) (void)m_free(*m);
			return(EINVAL);
		}
		return (*ip_fw_ctl_ptr)(optname, m);

	case IP_FW_ADD:
	case IP_FW_DEL:
	case IP_FW_FLUSH:
	case IP_FW_ZERO:
		if (ip_fw_ctl_ptr == NULL || op != PRCO_SETOPT) {
			if (*m) (void)m_free(*m);
			return(EINVAL);
		}
		return (*ip_fw_ctl_ptr)(optname, m);

	case IP_NAT:
		if (ip_nat_ctl_ptr == NULL) {
			if (*m) (void)m_free(*m);
			return(EINVAL);
		}
		return (*ip_nat_ctl_ptr)(op, m);

#endif
	case IP_RSVP_ON:
		return ip_rsvp_init(so);
		break;

	case IP_RSVP_OFF:
		return ip_rsvp_done();
		break;

	case IP_RSVP_VIF_ON:
		return ip_rsvp_vif_init(so, *m);

	case IP_RSVP_VIF_OFF:
		return ip_rsvp_vif_done(so, *m);

	case MRT_INIT:
	case MRT_DONE:
	case MRT_ADD_VIF:
	case MRT_DEL_VIF:
	case MRT_ADD_MFC:
	case MRT_DEL_MFC:
	case MRT_VERSION:
	case MRT_ASSERT:
		if (op == PRCO_SETOPT) {
			error = ip_mrouter_set(optname, so, *m);
			if (*m)
				(void)m_free(*m);
		} else if (op == PRCO_GETOPT) {
			error = ip_mrouter_get(optname, so, m);
		} else
			error = EINVAL;
		return (error);
	}
	return (ip_ctloutput(op, so, level, optname, m, p));
}

/*
 * This function exists solely to receive the PRC_IFDOWN messages which
 * are sent by if_down().  It looks for an ifaddr whose ifa_addr is sa,
 * and calls in_ifadown() to remove all routes corresponding to that address.
 * It also receives the PRC_IFUP messages from if_up() and reinstalls the
 * interface routes.
 */
void
rip_ctlinput(cmd, sa, vip)
	int cmd;
	struct sockaddr *sa;
	void *vip;
{
	struct in_ifaddr *ia;
	struct ifnet *ifp;
	int err;
	int flags;

	switch(cmd) {
	case PRC_IFDOWN:
		for (ia = in_ifaddrhead.tqh_first; ia;
		     ia = ia->ia_link.tqe_next) {
			if (ia->ia_ifa.ifa_addr == sa
			    && (ia->ia_flags & IFA_ROUTE)) {
				/*
				 * in_ifscrub kills the interface route.
				 */
				in_ifscrub(ia->ia_ifp, ia);
				/*
				 * in_ifadown gets rid of all the rest of
				 * the routes.  This is not quite the right
				 * thing to do, but at least if we are running
				 * a routing process they will come back.
				 */
				in_ifadown(&ia->ia_ifa);
				break;
			}
		}
		break;

	case PRC_IFUP:
		for (ia = in_ifaddrhead.tqh_first; ia;
		     ia = ia->ia_link.tqe_next) {
			if (ia->ia_ifa.ifa_addr == sa)
				break;
		}
		if (ia == 0 || (ia->ia_flags & IFA_ROUTE))
			return;
		flags = RTF_UP;
		ifp = ia->ia_ifa.ifa_ifp;

		if ((ifp->if_flags & IFF_LOOPBACK)
		    || (ifp->if_flags & IFF_POINTOPOINT))
			flags |= RTF_HOST;

		err = rtinit(&ia->ia_ifa, RTM_ADD, flags);
		if (err == 0)
			ia->ia_flags |= IFA_ROUTE;
		break;
	}
}

static u_long	rip_sendspace = RIPSNDQ;
static u_long	rip_recvspace = RIPRCVQ;

SYSCTL_INT(_net_inet_raw, OID_AUTO, maxdgram, CTLFLAG_RW, &rip_sendspace,
	   0, "");
SYSCTL_INT(_net_inet_raw, OID_AUTO, recvspace, CTLFLAG_RW, &rip_recvspace,
	   0, "");

static int
rip_attach(struct socket *so, int proto, struct proc *p)
{
	struct inpcb *inp;
	int error;

	inp = sotoinpcb(so);
	if (inp)
		panic("rip_attach");
	if (p && (error = suser(p->p_ucred, &p->p_acflag)) != 0)
		return error;

	if ((error = soreserve(so, rip_sendspace, rip_recvspace)) ||
	    (error = in_pcballoc(so, &ripcbinfo, p)))
		return error;
	inp = (struct inpcb *)so->so_pcb;
	inp->inp_ip_p = proto;
	return 0;
}

static int
rip_detach(struct socket *so)
{
	struct inpcb *inp;

	inp = sotoinpcb(so);
	if (inp == 0)
		panic("rip_detach");
	if (so == ip_mrouter)
		ip_mrouter_done();
	ip_rsvp_force_done(so);
	if (so == ip_rsvpd)
		ip_rsvp_done();
	in_pcbdetach(inp);
	return 0;
}

static int
rip_abort(struct socket *so)
{
	soisdisconnected(so);
	return rip_detach(so);
}

static int
rip_disconnect(struct socket *so)
{
	if ((so->so_state & SS_ISCONNECTED) == 0)
		return ENOTCONN;
	return rip_abort(so);
}

static int
rip_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
{
	struct inpcb *inp = sotoinpcb(so);
	struct sockaddr_in *addr = (struct sockaddr_in *)nam;

	if (nam->sa_len != sizeof(*addr))
		return EINVAL;

	if (TAILQ_EMPTY(&ifnet) || ((addr->sin_family != AF_INET) &&
				    (addr->sin_family != AF_IMPLINK)) ||
	    (addr->sin_addr.s_addr &&
	     ifa_ifwithaddr((struct sockaddr *)addr) == 0))
		return EADDRNOTAVAIL;
	inp->inp_laddr = addr->sin_addr;
	return 0;
}

static int
rip_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
{
	struct inpcb *inp = sotoinpcb(so);
	struct sockaddr_in *addr = (struct sockaddr_in *)nam;

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

static int
rip_shutdown(struct socket *so)
{
	socantsendmore(so);
	return 0;
}

static int
rip_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
	 struct mbuf *control, struct proc *p)
{
	struct inpcb *inp = sotoinpcb(so);
	register u_long dst;

	if (so->so_state & SS_ISCONNECTED) {
		if (nam) {
			m_freem(m);
			return EISCONN;
		}
		dst = inp->inp_faddr.s_addr;
	} else {
		if (nam == NULL) {
			m_freem(m);
			return ENOTCONN;
		}
		dst = ((struct sockaddr_in *)nam)->sin_addr.s_addr;
	}
	return rip_output(m, so, dst);
}

struct pr_usrreqs rip_usrreqs = {
	rip_abort, pru_accept_notsupp, rip_attach, rip_bind, rip_connect,
	pru_connect2_notsupp, in_control, rip_detach, rip_disconnect,
	pru_listen_notsupp, in_setpeeraddr, pru_rcvd_notsupp,
	pru_rcvoob_notsupp, rip_send, pru_sense_null, rip_shutdown,
	in_setsockaddr, sosend, soreceive, sopoll
};