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

Revision 1.46, Tue Jan 19 21:58:41 1999 UTC (15 years, 10 months ago) by mycroft
Branch: MAIN
Changes since 1.45: +2 -2 lines

Don't overwrite the checksum fields when checking them.  There's no reason to
do this, and it screws up ICMP replies.
XXX The returned IP checksum and length are still wrong.

/*	$NetBSD: udp_usrreq.c,v 1.46 1999/01/19 21:58:41 mycroft Exp $	*/

/*
 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
 *	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.
 *
 *	@(#)udp_usrreq.c	8.6 (Berkeley) 5/23/95
 */
#include "ipkdb.h"

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

#include <vm/vm.h>
#include <sys/sysctl.h>

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

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

#include <machine/stdarg.h>

/*
 * UDP protocol implementation.
 * Per RFC 768, August, 1980.
 */
#ifndef	COMPAT_42
int	udpcksum = 1;
#else
int	udpcksum = 0;		/* XXX */
#endif

static	void udp_notify __P((struct inpcb *, int));

#ifndef UDBHASHSIZE
#define	UDBHASHSIZE	128
#endif
int	udbhashsize = UDBHASHSIZE;

void
udp_init()
{

	in_pcbinit(&udbtable, udbhashsize, udbhashsize);
}

void
#if __STDC__
udp_input(struct mbuf *m, ...)
#else
udp_input(m, va_alist)
	struct mbuf *m;
	va_dcl
#endif
{
	register struct ip *ip;
	register struct udphdr *uh;
	register struct inpcb *inp;
	struct mbuf *opts = 0;
	int len;
	struct ip save_ip;
	int iphlen;
	va_list ap;
	struct sockaddr_in udpsrc;

	va_start(ap, m);
	iphlen = va_arg(ap, int);
	va_end(ap);

	udpstat.udps_ipackets++;

	/*
	 * Strip IP options, if any; should skip this,
	 * make available to user, and use on returned packets,
	 * but we don't yet have a way to check the checksum
	 * with options still present.
	 */
	if (iphlen > sizeof (struct ip)) {
		ip_stripoptions(m, (struct mbuf *)0);
		iphlen = sizeof(struct ip);
	}

	/*
	 * Get IP and UDP header together in first mbuf.
	 */
	ip = mtod(m, struct ip *);
	if (m->m_len < iphlen + sizeof(struct udphdr)) {
		if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
			udpstat.udps_hdrops++;
			return;
		}
		ip = mtod(m, struct ip *);
	}
	uh = (struct udphdr *)((caddr_t)ip + iphlen);

	/*
	 * Make mbuf data length reflect UDP length.
	 * If not enough data to reflect UDP length, drop.
	 */
	len = ntohs((u_int16_t)uh->uh_ulen);
	if (ip->ip_len != len) {
		if (len > ip->ip_len) {
			udpstat.udps_badlen++;
			goto bad;
		}
		m_adj(m, len - ip->ip_len);
		/* ip->ip_len = len; */
	}
	/*
	 * Save a copy of the IP header in case we want restore it
	 * for sending an ICMP error message in response.
	 */
	save_ip = *ip;

	/*
	 * Checksum extended UDP header and data.
	 */
	if (uh->uh_sum) {
		bzero(((struct ipovly *)ip)->ih_x1,
		    sizeof ((struct ipovly *)ip)->ih_x1);
		((struct ipovly *)ip)->ih_len = uh->uh_ulen;
		if (in_cksum(m, len + sizeof (struct ip)) != 0) {
			udpstat.udps_badsum++;
			m_freem(m);
			return;
		}
	}

	if (IN_MULTICAST(ip->ip_dst.s_addr) ||
	    in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) {
		struct inpcb *last;
		/*
		 * Deliver a multicast or broadcast datagram to *all* sockets
		 * for which the local and remote addresses and ports match
		 * those of the incoming datagram.  This allows more than
		 * one process to receive multi/broadcasts on the same port.
		 * (This really ought to be done for unicast datagrams as
		 * well, but that would cause problems with existing
		 * applications that open both address-specific sockets and
		 * a wildcard socket listening to the same port -- they would
		 * end up receiving duplicates of every unicast datagram.
		 * Those applications open the multiple sockets to overcome an
		 * inadequacy of the UDP socket interface, but for backwards
		 * compatibility we avoid the problem here rather than
		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
		 */

		/*
		 * Construct sockaddr format source address.
		 */
		udpsrc.sin_family = AF_INET;
		udpsrc.sin_len = sizeof(struct sockaddr_in);
		udpsrc.sin_addr = ip->ip_src;
		udpsrc.sin_port = uh->uh_sport;
		bzero((caddr_t)udpsrc.sin_zero, sizeof(udpsrc.sin_zero));

		iphlen += sizeof(struct udphdr);
		m->m_len -= iphlen;
		m->m_pkthdr.len -= iphlen;
		m->m_data += iphlen;
		/*
		 * Locate pcb(s) for datagram.
		 * (Algorithm copied from raw_intr().)
		 */
		last = NULL;
		for (inp = udbtable.inpt_queue.cqh_first;
		    inp != (struct inpcb *)&udbtable.inpt_queue;
		    inp = inp->inp_queue.cqe_next) {
			if (inp->inp_lport != uh->uh_dport)
				continue;
			if (!in_nullhost(inp->inp_laddr)) {
				if (!in_hosteq(inp->inp_laddr, ip->ip_dst))
					continue;
			}
			if (!in_nullhost(inp->inp_faddr)) {
				if (!in_hosteq(inp->inp_faddr, ip->ip_src) ||
				    inp->inp_fport != uh->uh_sport)
					continue;
			}

			if (last != NULL) {
				struct mbuf *n;

				if ((n = m_copy(m, 0, 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(&udpsrc), n, opts) == 0) {
						m_freem(n);
						if (opts)
							m_freem(opts);
					} else
						sorwakeup(last->inp_socket);
					opts = 0;
				}
			}
			last = inp;
			/*
			 * Don't look for additional matches if this one does
			 * not have either the SO_REUSEPORT or SO_REUSEADDR
			 * socket options set.  This heuristic avoids searching
			 * through all pcbs in the common case of a non-shared
			 * port.  It * assumes that an application will never
			 * clear these options after setting them.
			 */
			if ((last->inp_socket->so_options &
			    (SO_REUSEPORT|SO_REUSEADDR)) == 0)
				break;
		}

		if (last == NULL) {
			/*
			 * No matching pcb found; discard datagram.
			 * (No need to send an ICMP Port Unreachable
			 * for a broadcast or multicast datgram.)
			 */
			udpstat.udps_noportbcast++;
			goto bad;
		}
		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(&udpsrc), m, opts) == 0) {
			udpstat.udps_fullsock++;
			goto bad;
		}
		sorwakeup(last->inp_socket);
		return;
	}
	/*
	 * Locate pcb for datagram.
	 */
	inp = in_pcblookup_connect(&udbtable, ip->ip_src, uh->uh_sport,
	    ip->ip_dst, uh->uh_dport);
	if (inp == 0) {
		++udpstat.udps_pcbhashmiss;
		inp = in_pcblookup_bind(&udbtable, ip->ip_dst, uh->uh_dport);
		if (inp == 0) {
			udpstat.udps_noport++;
			if (m->m_flags & (M_BCAST | M_MCAST)) {
				udpstat.udps_noportbcast++;
				goto bad;
			}
			*ip = save_ip;
#if NIPKDB > 0
			if (checkipkdb(&ip->ip_src,
				       uh->uh_sport,
				       uh->uh_dport,
				       m,
				       iphlen + sizeof(struct udphdr),
				       len - sizeof(struct udphdr)))
			/* It was a debugger connect packet, just drop it now */
				goto bad;
#endif
			ip->ip_len += iphlen;
			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
			return;
		}
	}

	/*
	 * Construct sockaddr format source address.
	 * Stuff source address and datagram in user buffer.
	 */
	udpsrc.sin_family = AF_INET;
	udpsrc.sin_len = sizeof(struct sockaddr_in);
	udpsrc.sin_addr = ip->ip_src;
	udpsrc.sin_port = uh->uh_sport;
	bzero((caddr_t)udpsrc.sin_zero, sizeof(udpsrc.sin_zero));

	if (inp->inp_flags & INP_CONTROLOPTS ||
	    inp->inp_socket->so_options & SO_TIMESTAMP)
		ip_savecontrol(inp, &opts, ip, m);
	iphlen += sizeof(struct udphdr);
	m->m_len -= iphlen;
	m->m_pkthdr.len -= iphlen;
	m->m_data += iphlen;
	if (sbappendaddr(&inp->inp_socket->so_rcv, sintosa(&udpsrc), m,
	    opts) == 0) {
		udpstat.udps_fullsock++;
		goto bad;
	}
	sorwakeup(inp->inp_socket);
	return;
bad:
	m_freem(m);
	if (opts)
		m_freem(opts);
}

/*
 * Notify a udp user of an asynchronous error;
 * just wake up so that he can collect error status.
 */
static void
udp_notify(inp, errno)
	register struct inpcb *inp;
	int errno;
{

	inp->inp_socket->so_error = errno;
	sorwakeup(inp->inp_socket);
	sowwakeup(inp->inp_socket);
}

void *
udp_ctlinput(cmd, sa, v)
	int cmd;
	struct sockaddr *sa;
	void *v;
{
	register struct ip *ip = v;
	register struct udphdr *uh;
	extern int inetctlerrmap[];
	void (*notify) __P((struct inpcb *, int)) = udp_notify;
	int errno;

	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) {
		uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
		in_pcbnotify(&udbtable, satosin(sa)->sin_addr, uh->uh_dport,
		    ip->ip_src, uh->uh_sport, errno, notify);
	} else
		in_pcbnotifyall(&udbtable, satosin(sa)->sin_addr, errno,
		    notify);
	return NULL;
}

int
#if __STDC__
udp_output(struct mbuf *m, ...)
#else
udp_output(m, va_alist)
	struct mbuf *m;
	va_dcl
#endif
{
	register struct inpcb *inp;
	register struct udpiphdr *ui;
	register int len = m->m_pkthdr.len;
	int error = 0;
	va_list ap;

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

	/*
	 * Calculate data length and get a mbuf
	 * for UDP and IP headers.
	 */
	M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT);
	if (m == 0) {
		error = ENOBUFS;
		goto release;
	}

	/*
	 * Compute the packet length of the IP header, and
	 * punt if the length looks bogus.
	 */
	if ((len + sizeof(struct udpiphdr)) > IP_MAXPACKET) {
		error = EMSGSIZE;
		goto release;
	}

	/*
	 * Fill in mbuf with extended UDP header
	 * and addresses and length put into network format.
	 */
	ui = mtod(m, struct udpiphdr *);
	bzero(ui->ui_x1, sizeof ui->ui_x1);
	ui->ui_pr = IPPROTO_UDP;
	ui->ui_len = htons((u_int16_t)len + sizeof (struct udphdr));
	ui->ui_src = inp->inp_laddr;
	ui->ui_dst = inp->inp_faddr;
	ui->ui_sport = inp->inp_lport;
	ui->ui_dport = inp->inp_fport;
	ui->ui_ulen = ui->ui_len;

	/*
	 * Stuff checksum and output datagram.
	 */
	ui->ui_sum = 0;
	if (udpcksum) {
	    if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0)
		ui->ui_sum = 0xffff;
	}
	((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
	((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl;	/* XXX */
	((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos;	/* XXX */
	udpstat.udps_opackets++;
	return (ip_output(m, inp->inp_options, &inp->inp_route,
	    inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST),
	    inp->inp_moptions));

release:
	m_freem(m);
	return (error);
}

int	udp_sendspace = 9216;		/* really max datagram size */
int	udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in));
					/* 40 1K datagrams */

/*ARGSUSED*/
int
udp_usrreq(so, req, m, nam, control, p)
	struct socket *so;
	int req;
	struct mbuf *m, *nam, *control;
	struct proc *p;
{
	register struct inpcb *inp;
	int s;
	register int error = 0;

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

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

	/*
	 * Note: need to block udp_input while changing
	 * the udp pcb queue and/or pcb addresses.
	 */
	switch (req) {

	case PRU_ATTACH:
		if (inp != 0) {
			error = EISCONN;
			break;
		}
		if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
			error = soreserve(so, udp_sendspace, udp_recvspace);
			if (error)
				break;
		}
		error = in_pcballoc(so, &udbtable);
		if (error)
			break;
		inp = sotoinpcb(so);
		inp->inp_ip.ip_ttl = ip_defttl;
		break;

	case PRU_DETACH:
		in_pcbdetach(inp);
		break;

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

	case PRU_LISTEN:
		error = EOPNOTSUPP;
		break;

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

	case PRU_CONNECT2:
		error = EOPNOTSUPP;
		break;

	case PRU_DISCONNECT:
		/*soisdisconnected(so);*/
		so->so_state &= ~SS_ISCONNECTED;	/* XXX */
		in_pcbdisconnect(inp);
		inp->inp_laddr = zeroin_addr;		/* XXX */
		in_pcbstate(inp, INP_BOUND);		/* XXX */
		break;

	case PRU_SHUTDOWN:
		socantsendmore(so);
		break;

	case PRU_RCVD:
		error = EOPNOTSUPP;
		break;

	case PRU_SEND:
		if (control && control->m_len) {
			m_freem(control);
			m_freem(m);
			error = EINVAL;
			break;
		}
	{
		struct in_addr laddr;			/* XXX */

		if (nam) {
			laddr = inp->inp_laddr;		/* XXX */
			if ((so->so_state & SS_ISCONNECTED) != 0) {
				error = EISCONN;
				goto die;
			}
			error = in_pcbconnect(inp, nam);
			if (error) {
			die:
				m_freem(m);
				break;
			}
		} else {
			if ((so->so_state & SS_ISCONNECTED) == 0) {
				error = ENOTCONN;
				goto die;
			}
		}
		error = udp_output(m, inp);
		if (nam) {
			in_pcbdisconnect(inp);
			inp->inp_laddr = laddr;		/* XXX */
			in_pcbstate(inp, INP_BOUND);	/* XXX */
		}
	}
		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("udp_usrreq");
	}

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

/*
 * Sysctl for udp variables.
 */
int
udp_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
	int *name;
	u_int namelen;
	void *oldp;
	size_t *oldlenp;
	void *newp;
	size_t newlen;
{
	/* All sysctl names at this level are terminal. */
	if (namelen != 1)
		return (ENOTDIR);

	switch (name[0]) {
	case UDPCTL_CHECKSUM:
		return (sysctl_int(oldp, oldlenp, newp, newlen, &udpcksum));
	case UDPCTL_SENDSPACE:
		return (sysctl_int(oldp, oldlenp, newp, newlen,
		    &udp_sendspace));
	case UDPCTL_RECVSPACE:
		return (sysctl_int(oldp, oldlenp, newp, newlen, 
		    &udp_recvspace));
	default:
		return (ENOPROTOOPT);
	}
	/* NOTREACHED */
}