[qemu.git] / slirp / udp.c

/*
 * Copyright (c) 1982, 1986, 1988, 1990, 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.
 *
 *	@(#)udp_usrreq.c	8.4 (Berkeley) 1/21/94
 * udp_usrreq.c,v 1.4 1994/10/02 17:48:45 phk Exp
 */

/*
 * Changes and additions relating to SLiRP
 * Copyright (c) 1995 Danny Gasparovski.
 *
 * Please read the file COPYRIGHT for the
 * terms and conditions of the copyright.
 */

#include <slirp.h>
#include "ip_icmp.h"

#ifdef LOG_ENABLED
struct udpstat udpstat;
#endif

struct socket udb;

static u_int8_t udp_tos(struct socket *so);
static void udp_emu(struct socket *so, struct mbuf *m);

/*
 * UDP protocol implementation.
 * Per RFC 768, August, 1980.
 */
#ifndef	COMPAT_42
#define UDPCKSUM 1
#else
#define UDPCKSUM 0 /* XXX */
#endif

struct	socket *udp_last_so = &udb;

void
udp_init()
{
	udb.so_next = udb.so_prev = &udb;
}
/* m->m_data  points at ip packet header
 * m->m_len   length ip packet
 * ip->ip_len length data (IPDU)
 */
void
udp_input(m, iphlen)
	register struct mbuf *m;
	int iphlen;
{
	register struct ip *ip;
	register struct udphdr *uh;
/*	struct mbuf *opts = 0;*/
	int len;
	struct ip save_ip;
	struct socket *so;

	DEBUG_CALL("udp_input");
	DEBUG_ARG("m = %lx", (long)m);
	DEBUG_ARG("iphlen = %d", iphlen);

	STAT(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 *);
	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) {
			STAT(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;
	save_ip.ip_len+= iphlen;         /* tcp_input subtracts this */

	/*
	 * Checksum extended UDP header and data.
	 */
	if (UDPCKSUM && uh->uh_sum) {
	  ((struct ipovly *)ip)->ih_next = 0;
	  ((struct ipovly *)ip)->ih_prev = 0;
	  ((struct ipovly *)ip)->ih_x1 = 0;
	  ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
	  /* keep uh_sum for ICMP reply
	   * uh->uh_sum = cksum(m, len + sizeof (struct ip));
	   * if (uh->uh_sum) {
	   */
	  if(cksum(m, len + sizeof(struct ip))) {
	    STAT(udpstat.udps_badsum++);
	    goto bad;
	  }
	}

        /*
         *  handle DHCP/BOOTP
         */
        if (ntohs(uh->uh_dport) == BOOTP_SERVER) {
            bootp_input(m);
            goto bad;
        }

        /*
         *  handle TFTP
         */
        if (ntohs(uh->uh_dport) == TFTP_SERVER) {
            tftp_input(m);
            goto bad;
        }

	/*
	 * Locate pcb for datagram.
	 */
	so = udp_last_so;
	if (so->so_lport != uh->uh_sport ||
	    so->so_laddr.s_addr != ip->ip_src.s_addr) {
		struct socket *tmp;

		for (tmp = udb.so_next; tmp != &udb; tmp = tmp->so_next) {
			if (tmp->so_lport == uh->uh_sport &&
			    tmp->so_laddr.s_addr == ip->ip_src.s_addr) {
				tmp->so_faddr.s_addr = ip->ip_dst.s_addr;
				tmp->so_fport = uh->uh_dport;
				so = tmp;
				break;
			}
		}
		if (tmp == &udb) {
		  so = NULL;
		} else {
		  STAT(udpstat.udpps_pcbcachemiss++);
		  udp_last_so = so;
		}
	}

	if (so == NULL) {
	  /*
	   * If there's no socket for this packet,
	   * create one
	   */
	  if ((so = socreate()) == NULL) goto bad;
	  if(udp_attach(so) == -1) {
	    DEBUG_MISC((dfd," udp_attach errno = %d-%s\n",
			errno,strerror(errno)));
	    sofree(so);
	    goto bad;
	  }

	  /*
	   * Setup fields
	   */
	  /* udp_last_so = so; */
	  so->so_laddr = ip->ip_src;
	  so->so_lport = uh->uh_sport;

	  if ((so->so_iptos = udp_tos(so)) == 0)
	    so->so_iptos = ip->ip_tos;

	  /*
	   * XXXXX Here, check if it's in udpexec_list,
	   * and if it is, do the fork_exec() etc.
	   */
	}

        so->so_faddr = ip->ip_dst; /* XXX */
        so->so_fport = uh->uh_dport; /* XXX */

	iphlen += sizeof(struct udphdr);
	m->m_len -= iphlen;
	m->m_data += iphlen;

	/*
	 * Now we sendto() the packet.
	 */
	if (so->so_emu)
	   udp_emu(so, m);

	if(sosendto(so,m) == -1) {
	  m->m_len += iphlen;
	  m->m_data -= iphlen;
	  *ip=save_ip;
	  DEBUG_MISC((dfd,"udp tx errno = %d-%s\n",errno,strerror(errno)));
	  icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));
	}

	m_free(so->so_m);   /* used for ICMP if error on sorecvfrom */

	/* restore the orig mbuf packet */
	m->m_len += iphlen;
	m->m_data -= iphlen;
	*ip=save_ip;
	so->so_m=m;         /* ICMP backup */

	return;
bad:
	m_freem(m);
	/* if (opts) m_freem(opts); */
	return;
}

int udp_output2(struct socket *so, struct mbuf *m,
                struct sockaddr_in *saddr, struct sockaddr_in *daddr,
                int iptos)
{
	register struct udpiphdr *ui;
	int error = 0;

	DEBUG_CALL("udp_output");
	DEBUG_ARG("so = %lx", (long)so);
	DEBUG_ARG("m = %lx", (long)m);
	DEBUG_ARG("saddr = %lx", (long)saddr->sin_addr.s_addr);
	DEBUG_ARG("daddr = %lx", (long)daddr->sin_addr.s_addr);

	/*
	 * Adjust for header
	 */
	m->m_data -= sizeof(struct udpiphdr);
	m->m_len += sizeof(struct udpiphdr);

	/*
	 * Fill in mbuf with extended UDP header
	 * and addresses and length put into network format.
	 */
	ui = mtod(m, struct udpiphdr *);
	ui->ui_next = ui->ui_prev = 0;
	ui->ui_x1 = 0;
	ui->ui_pr = IPPROTO_UDP;
	ui->ui_len = htons(m->m_len - sizeof(struct ip)); /* + sizeof (struct udphdr)); */
	/* XXXXX Check for from-one-location sockets, or from-any-location sockets */
        ui->ui_src = saddr->sin_addr;
	ui->ui_dst = daddr->sin_addr;
	ui->ui_sport = saddr->sin_port;
	ui->ui_dport = daddr->sin_port;
	ui->ui_ulen = ui->ui_len;

	/*
	 * Stuff checksum and output datagram.
	 */
	ui->ui_sum = 0;
	if (UDPCKSUM) {
	    if ((ui->ui_sum = cksum(m, /* sizeof (struct udpiphdr) + */ m->m_len)) == 0)
		ui->ui_sum = 0xffff;
	}
	((struct ip *)ui)->ip_len = m->m_len;

	((struct ip *)ui)->ip_ttl = IPDEFTTL;
	((struct ip *)ui)->ip_tos = iptos;

	STAT(udpstat.udps_opackets++);

	error = ip_output(so, m);

	return (error);
}

int udp_output(struct socket *so, struct mbuf *m,
               struct sockaddr_in *addr)

{
    struct sockaddr_in saddr, daddr;

    saddr = *addr;
    if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr) {
        if ((so->so_faddr.s_addr & htonl(0x000000ff)) == htonl(0xff))
            saddr.sin_addr.s_addr = alias_addr.s_addr;
        else if (addr->sin_addr.s_addr == loopback_addr.s_addr ||
                 (ntohl(so->so_faddr.s_addr) & 0xff) != CTL_ALIAS)
            saddr.sin_addr.s_addr = so->so_faddr.s_addr;
    }
    daddr.sin_addr = so->so_laddr;
    daddr.sin_port = so->so_lport;

    return udp_output2(so, m, &saddr, &daddr, so->so_iptos);
}

int
udp_attach(so)
     struct socket *so;
{
  struct sockaddr_in addr;

  if((so->s = socket(AF_INET,SOCK_DGRAM,0)) != -1) {
    /*
     * Here, we bind() the socket.  Although not really needed
     * (sendto() on an unbound socket will bind it), it's done
     * here so that emulation of ytalk etc. don't have to do it
     */
    addr.sin_family = AF_INET;
    addr.sin_port = 0;
    addr.sin_addr.s_addr = INADDR_ANY;
    if(bind(so->s, (struct sockaddr *)&addr, sizeof(addr))<0) {
      int lasterrno=errno;
      closesocket(so->s);
      so->s=-1;
#ifdef _WIN32
      WSASetLastError(lasterrno);
#else
      errno=lasterrno;
#endif
    } else {
      /* success, insert in queue */
      so->so_expire = curtime + SO_EXPIRE;
      insque(so,&udb);
    }
  }
  return(so->s);
}

void
udp_detach(so)
	struct socket *so;
{
	closesocket(so->s);
	/* if (so->so_m) m_free(so->so_m);    done by sofree */

	sofree(so);
}

static const struct tos_t udptos[] = {
	{0, 53, IPTOS_LOWDELAY, 0},			/* DNS */
	{517, 517, IPTOS_LOWDELAY, EMU_TALK},	/* talk */
	{518, 518, IPTOS_LOWDELAY, EMU_NTALK},	/* ntalk */
	{0, 7648, IPTOS_LOWDELAY, EMU_CUSEEME},	/* Cu-Seeme */
	{0, 0, 0, 0}
};

static u_int8_t
udp_tos(struct socket *so)
{
	int i = 0;

	while(udptos[i].tos) {
		if ((udptos[i].fport && ntohs(so->so_fport) == udptos[i].fport) ||
		    (udptos[i].lport && ntohs(so->so_lport) == udptos[i].lport)) {
		    	so->so_emu = udptos[i].emu;
			return udptos[i].tos;
		}
		i++;
	}

	return 0;
}

#ifdef EMULATE_TALK
#include "talkd.h"
#endif

/*
 * Here, talk/ytalk/ntalk requests must be emulated
 */
static void
udp_emu(struct socket *so, struct mbuf *m)
{
	struct sockaddr_in addr;
	socklen_t addrlen = sizeof(addr);
#ifdef EMULATE_TALK
	CTL_MSG_OLD *omsg;
	CTL_MSG *nmsg;
	char buff[sizeof(CTL_MSG)];
	u_char type;

struct talk_request {
	struct talk_request *next;
	struct socket *udp_so;
	struct socket *tcp_so;
} *req;

	static struct talk_request *req_tbl = 0;

#endif

struct cu_header {
	uint16_t	d_family;		// destination family
	uint16_t	d_port;			// destination port
	uint32_t	d_addr;			// destination address
	uint16_t	s_family;		// source family
	uint16_t	s_port;			// source port
	uint32_t	so_addr;		// source address
	uint32_t	seqn;			// sequence number
	uint16_t	message;		// message
	uint16_t	data_type;		// data type
	uint16_t	pkt_len;		// packet length
} *cu_head;

	switch(so->so_emu) {

#ifdef EMULATE_TALK
	 case EMU_TALK:
	 case EMU_NTALK:
		/*
		 * Talk emulation. We always change the ctl_addr to get
		 * some answers from the daemon. When an ANNOUNCE comes,
		 * we send LEAVE_INVITE to the local daemons. Also when a
		 * DELETE comes, we send copies to the local daemons.
		 */
		if (getsockname(so->s, (struct sockaddr *)&addr, &addrlen) < 0)
			return;

#define	IS_OLD	(so->so_emu == EMU_TALK)

#define COPY_MSG(dest, src) { dest->type = src->type; \
			      dest->id_num = src->id_num; \
			      dest->pid = src->pid; \
			      dest->addr = src->addr; \
			      dest->ctl_addr = src->ctl_addr; \
			      memcpy(&dest->l_name, &src->l_name, NAME_SIZE_OLD); \
			      memcpy(&dest->r_name, &src->r_name, NAME_SIZE_OLD); \
	         	      memcpy(&dest->r_tty, &src->r_tty, TTY_SIZE); }

#define OTOSIN(ptr, field) ((struct sockaddr_in *)&ptr->field)
/* old_sockaddr to sockaddr_in */


		if (IS_OLD) {  		/* old talk */
			omsg = mtod(m, CTL_MSG_OLD*);
			nmsg = (CTL_MSG *) buff;
			type = omsg->type;
			OTOSIN(omsg, ctl_addr)->sin_port = addr.sin_port;
			OTOSIN(omsg, ctl_addr)->sin_addr = our_addr;
                        pstrcpy(omsg->l_name, NAME_SIZE_OLD, getlogin());
		} else {		/* new talk */
			omsg = (CTL_MSG_OLD *) buff;
			nmsg = mtod(m, CTL_MSG *);
			type = nmsg->type;
			OTOSIN(nmsg, ctl_addr)->sin_port = addr.sin_port;
			OTOSIN(nmsg, ctl_addr)->sin_addr = our_addr;
                        pstrcpy(nmsg->l_name, NAME_SIZE_OLD, getlogin());
		}

		if (type == LOOK_UP)
			return;		/* for LOOK_UP this is enough */

		if (IS_OLD) {		/* make a copy of the message */
			COPY_MSG(nmsg, omsg);
			nmsg->vers = 1;
			nmsg->answer = 0;
		} else
			COPY_MSG(omsg, nmsg);

		/*
		 * If if is an ANNOUNCE message, we go through the
		 * request table to see if a tcp port has already
		 * been redirected for this socket. If not, we solisten()
		 * a new socket and add this entry to the table.
		 * The port number of the tcp socket and our IP
		 * are put to the addr field of the message structures.
		 * Then a LEAVE_INVITE is sent to both local daemon
		 * ports, 517 and 518. This is why we have two copies
		 * of the message, one in old talk and one in new talk
		 * format.
		 */

		if (type == ANNOUNCE) {
			int s;
			u_short temp_port;

			for(req = req_tbl; req; req = req->next)
				if (so == req->udp_so)
					break;  	/* found it */

			if (!req) {	/* no entry for so, create new */
				req = (struct talk_request *)
					malloc(sizeof(struct talk_request));
				req->udp_so = so;
				req->tcp_so = solisten(0,
					OTOSIN(omsg, addr)->sin_addr.s_addr,
					OTOSIN(omsg, addr)->sin_port,
					SS_FACCEPTONCE);
				req->next = req_tbl;
				req_tbl = req;
			}

			/* replace port number in addr field */
			addrlen = sizeof(addr);
			getsockname(req->tcp_so->s,
					(struct sockaddr *) &addr,
					&addrlen);
			OTOSIN(omsg, addr)->sin_port = addr.sin_port;
			OTOSIN(omsg, addr)->sin_addr = our_addr;
			OTOSIN(nmsg, addr)->sin_port = addr.sin_port;
			OTOSIN(nmsg, addr)->sin_addr = our_addr;

			/* send LEAVE_INVITEs */
			temp_port = OTOSIN(omsg, ctl_addr)->sin_port;
			OTOSIN(omsg, ctl_addr)->sin_port = 0;
			OTOSIN(nmsg, ctl_addr)->sin_port = 0;
			omsg->type = nmsg->type = LEAVE_INVITE;

			s = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
			addr.sin_addr = our_addr;
			addr.sin_family = AF_INET;
			addr.sin_port = htons(517);
			sendto(s, (char *)omsg, sizeof(*omsg), 0,
				(struct sockaddr *)&addr, sizeof(addr));
			addr.sin_port = htons(518);
			sendto(s, (char *)nmsg, sizeof(*nmsg), 0,
				(struct sockaddr *) &addr, sizeof(addr));
			closesocket(s) ;

			omsg->type = nmsg->type = ANNOUNCE;
			OTOSIN(omsg, ctl_addr)->sin_port = temp_port;
			OTOSIN(nmsg, ctl_addr)->sin_port = temp_port;
		}

		/*
		 * If it is a DELETE message, we send a copy to the
		 * local daemons. Then we delete the entry corresponding
		 * to our socket from the request table.
		 */

		if (type == DELETE) {
			struct talk_request *temp_req, *req_next;
			int s;
			u_short temp_port;

			temp_port = OTOSIN(omsg, ctl_addr)->sin_port;
			OTOSIN(omsg, ctl_addr)->sin_port = 0;
			OTOSIN(nmsg, ctl_addr)->sin_port = 0;

			s = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
			addr.sin_addr = our_addr;
			addr.sin_family = AF_INET;
			addr.sin_port = htons(517);
			sendto(s, (char *)omsg, sizeof(*omsg), 0,
				(struct sockaddr *)&addr, sizeof(addr));
			addr.sin_port = htons(518);
			sendto(s, (char *)nmsg, sizeof(*nmsg), 0,
				(struct sockaddr *)&addr, sizeof(addr));
			closesocket(s);

			OTOSIN(omsg, ctl_addr)->sin_port = temp_port;
			OTOSIN(nmsg, ctl_addr)->sin_port = temp_port;

			/* delete table entry */
			if (so == req_tbl->udp_so) {
				temp_req = req_tbl;
				req_tbl = req_tbl->next;
				free(temp_req);
			} else {
				temp_req = req_tbl;
				for(req = req_tbl->next; req; req = req_next) {
					req_next = req->next;
					if (so == req->udp_so) {
						temp_req->next = req_next;
						free(req);
						break;
					} else {
						temp_req = req;
					}
				}
			}
		}

		return;
#endif

	case EMU_CUSEEME:

		/*
		 * Cu-SeeMe emulation.
		 * Hopefully the packet is more that 16 bytes long. We don't
		 * do any other tests, just replace the address and port
		 * fields.
		 */
		if (m->m_len >= sizeof (*cu_head)) {
			if (getsockname(so->s, (struct sockaddr *)&addr, &addrlen) < 0)
				return;
			cu_head = mtod(m, struct cu_header *);
			cu_head->s_port = addr.sin_port;
			cu_head->so_addr = our_addr.s_addr;
		}

		return;
	}
}

struct socket *
udp_listen(port, laddr, lport, flags)
	u_int port;
	u_int32_t laddr;
	u_int lport;
	int flags;
{
	struct sockaddr_in addr;
	struct socket *so;
	socklen_t addrlen = sizeof(struct sockaddr_in), opt = 1;

	if ((so = socreate()) == NULL) {
		free(so);
		return NULL;
	}
	so->s = socket(AF_INET,SOCK_DGRAM,0);
	so->so_expire = curtime + SO_EXPIRE;
	insque(so,&udb);

	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = INADDR_ANY;
	addr.sin_port = port;

	if (bind(so->s,(struct sockaddr *)&addr, addrlen) < 0) {
		udp_detach(so);
		return NULL;
	}
	setsockopt(so->s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
/*	setsockopt(so->s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int)); */

	getsockname(so->s,(struct sockaddr *)&addr,&addrlen);
	so->so_fport = addr.sin_port;
	if (addr.sin_addr.s_addr == 0 || addr.sin_addr.s_addr == loopback_addr.s_addr)
	   so->so_faddr = alias_addr;
	else
	   so->so_faddr = addr.sin_addr;

	so->so_lport = lport;
	so->so_laddr.s_addr = laddr;
	if (flags != SS_FACCEPTONCE)
	   so->so_expire = 0;

	so->so_state = SS_ISFCONNECTED;

	return so;
}
Commit	Line	Data
f0cbd3ec FB	1	/*
	2	* Copyright (c) 1982, 1986, 1988, 1990, 1993
	3	* The Regents of the University of California. All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*
	33	* @(#)udp_usrreq.c 8.4 (Berkeley) 1/21/94
	34	* udp_usrreq.c,v 1.4 1994/10/02 17:48:45 phk Exp
	35	*/
	36
	37	/*
	38	* Changes and additions relating to SLiRP
	39	* Copyright (c) 1995 Danny Gasparovski.
5fafdf24 TS	40	*
5fafdf24 TS	41	* Please read the file COPYRIGHT for the
f0cbd3ec FB	42	* terms and conditions of the copyright.
	43	*/
	44
	45	#include <slirp.h>
	46	#include "ip_icmp.h"
	47
31a60e22	48	#ifdef LOG_ENABLED
f0cbd3ec	49	struct udpstat udpstat;
31a60e22	50	#endif
f0cbd3ec FB	51
	52	struct socket udb;
	53
9634d903 BS	54	static u_int8_t udp_tos(struct socket *so);
	55	static void udp_emu(struct socket so, struct mbuf m);
	56
f0cbd3ec FB	57	/*
	58	* UDP protocol implementation.
	59	* Per RFC 768, August, 1980.
	60	*/
	61	#ifndef COMPAT_42
9634d903	62	#define UDPCKSUM 1
f0cbd3ec	63	#else
9634d903	64	#define UDPCKSUM 0 /* XXX */
f0cbd3ec FB	65	#endif
	66
	67	struct socket *udp_last_so = &udb;
	68
	69	void
	70	udp_init()
	71	{
	72	udb.so_next = udb.so_prev = &udb;
	73	}
5fafdf24 TS	74	/* m->m_data points at ip packet header
5fafdf24 TS	75	* m->m_len length ip packet
f0cbd3ec FB	76	* ip->ip_len length data (IPDU)
	77	*/
	78	void
	79	udp_input(m, iphlen)
	80	register struct mbuf *m;
	81	int iphlen;
	82	{
	83	register struct ip *ip;
	84	register struct udphdr *uh;
	85	/* struct mbuf opts = 0;/
	86	int len;
5fafdf24	87	struct ip save_ip;
f0cbd3ec	88	struct socket *so;
5fafdf24	89
f0cbd3ec FB	90	DEBUG_CALL("udp_input");
	91	DEBUG_ARG("m = %lx", (long)m);
	92	DEBUG_ARG("iphlen = %d", iphlen);
5fafdf24	93
31a60e22	94	STAT(udpstat.udps_ipackets++);
f0cbd3ec FB	95
	96	/*
	97	* Strip IP options, if any; should skip this,
	98	* make available to user, and use on returned packets,
	99	* but we don't yet have a way to check the checksum
	100	* with options still present.
	101	*/
	102	if(iphlen > sizeof(struct ip)) {
	103	ip_stripoptions(m, (struct mbuf *)0);
	104	iphlen = sizeof(struct ip);
	105	}
	106
	107	/*
	108	* Get IP and UDP header together in first mbuf.
	109	*/
	110	ip = mtod(m, struct ip *);
	111	uh = (struct udphdr *)((caddr_t)ip + iphlen);
	112
	113	/*
	114	* Make mbuf data length reflect UDP length.
	115	* If not enough data to reflect UDP length, drop.
	116	*/
	117	len = ntohs((u_int16_t)uh->uh_ulen);
	118
	119	if (ip->ip_len != len) {
	120	if (len > ip->ip_len) {
31a60e22	121	STAT(udpstat.udps_badlen++);
f0cbd3ec FB	122	goto bad;
	123	}
	124	m_adj(m, len - ip->ip_len);
	125	ip->ip_len = len;
	126	}
5fafdf24	127
f0cbd3ec FB	128	/*
	129	* Save a copy of the IP header in case we want restore it
	130	* for sending an ICMP error message in response.
	131	*/
5fafdf24	132	save_ip = *ip;
f0cbd3ec FB	133	save_ip.ip_len+= iphlen; /* tcp_input subtracts this */
	134
	135	/*
	136	* Checksum extended UDP header and data.
	137	*/
9634d903	138	if (UDPCKSUM && uh->uh_sum) {
f0cbd3ec FB	139	((struct ipovly *)ip)->ih_next = 0;
	140	((struct ipovly *)ip)->ih_prev = 0;
	141	((struct ipovly *)ip)->ih_x1 = 0;
	142	((struct ipovly *)ip)->ih_len = uh->uh_ulen;
	143	/* keep uh_sum for ICMP reply
5fafdf24 TS	144	* uh->uh_sum = cksum(m, len + sizeof (struct ip));
5fafdf24 TS	145	* if (uh->uh_sum) {
f0cbd3ec FB	146	*/
f0cbd3ec FB	147	if(cksum(m, len + sizeof(struct ip))) {
31a60e22	148	STAT(udpstat.udps_badsum++);
f0cbd3ec FB	149	goto bad;
	150	}
	151	}
	152
	153	/*
	154	* handle DHCP/BOOTP
	155	*/
	156	if (ntohs(uh->uh_dport) == BOOTP_SERVER) {
	157	bootp_input(m);
	158	goto bad;
	159	}
	160
c7f74643 FB	161	/*
	162	* handle TFTP
	163	*/
	164	if (ntohs(uh->uh_dport) == TFTP_SERVER) {
	165	tftp_input(m);
	166	goto bad;
	167	}
	168
f0cbd3ec FB	169	/*
	170	* Locate pcb for datagram.
	171	*/
	172	so = udp_last_so;
	173	if (so->so_lport != uh->uh_sport \|\|
	174	so->so_laddr.s_addr != ip->ip_src.s_addr) {
	175	struct socket *tmp;
3b46e624	176
f0cbd3ec FB	177	for (tmp = udb.so_next; tmp != &udb; tmp = tmp->so_next) {
	178	if (tmp->so_lport == uh->uh_sport &&
	179	tmp->so_laddr.s_addr == ip->ip_src.s_addr) {
	180	tmp->so_faddr.s_addr = ip->ip_dst.s_addr;
	181	tmp->so_fport = uh->uh_dport;
	182	so = tmp;
	183	break;
	184	}
	185	}
	186	if (tmp == &udb) {
	187	so = NULL;
	188	} else {
31a60e22	189	STAT(udpstat.udpps_pcbcachemiss++);
f0cbd3ec FB	190	udp_last_so = so;
	191	}
	192	}
5fafdf24	193
f0cbd3ec FB	194	if (so == NULL) {
	195	/*
	196	* If there's no socket for this packet,
	197	* create one
	198	*/
	199	if ((so = socreate()) == NULL) goto bad;
	200	if(udp_attach(so) == -1) {
5fafdf24	201	DEBUG_MISC((dfd," udp_attach errno = %d-%s\n",
f0cbd3ec FB	202	errno,strerror(errno)));
	203	sofree(so);
	204	goto bad;
	205	}
3b46e624	206
f0cbd3ec FB	207	/*
	208	* Setup fields
	209	*/
	210	/* udp_last_so = so; */
	211	so->so_laddr = ip->ip_src;
	212	so->so_lport = uh->uh_sport;
3b46e624	213
f0cbd3ec FB	214	if ((so->so_iptos = udp_tos(so)) == 0)
f0cbd3ec FB	215	so->so_iptos = ip->ip_tos;
3b46e624	216
f0cbd3ec FB	217	/*
	218	* XXXXX Here, check if it's in udpexec_list,
	219	* and if it is, do the fork_exec() etc.
	220	*/
	221	}
	222
54fd9cdf TS	223	so->so_faddr = ip->ip_dst; /* XXX */
	224	so->so_fport = uh->uh_dport; /* XXX */
	225
f0cbd3ec FB	226	iphlen += sizeof(struct udphdr);
	227	m->m_len -= iphlen;
	228	m->m_data += iphlen;
	229
	230	/*
	231	* Now we sendto() the packet.
	232	*/
	233	if (so->so_emu)
	234	udp_emu(so, m);
	235
	236	if(sosendto(so,m) == -1) {
	237	m->m_len += iphlen;
	238	m->m_data -= iphlen;
	239	*ip=save_ip;
	240	DEBUG_MISC((dfd,"udp tx errno = %d-%s\n",errno,strerror(errno)));
3b46e624	241	icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));
f0cbd3ec FB	242	}
	243
	244	m_free(so->so_m); /* used for ICMP if error on sorecvfrom */
	245
	246	/* restore the orig mbuf packet */
	247	m->m_len += iphlen;
	248	m->m_data -= iphlen;
	249	*ip=save_ip;
	250	so->so_m=m; /* ICMP backup */
	251
	252	return;
	253	bad:
	254	m_freem(m);
	255	/* if (opts) m_freem(opts); */
	256	return;
	257	}
	258
5fafdf24	259	int udp_output2(struct socket so, struct mbuf m,
f0cbd3ec FB	260	struct sockaddr_in saddr, struct sockaddr_in daddr,
	261	int iptos)
	262	{
	263	register struct udpiphdr *ui;
	264	int error = 0;
	265
	266	DEBUG_CALL("udp_output");
	267	DEBUG_ARG("so = %lx", (long)so);
	268	DEBUG_ARG("m = %lx", (long)m);
	269	DEBUG_ARG("saddr = %lx", (long)saddr->sin_addr.s_addr);
	270	DEBUG_ARG("daddr = %lx", (long)daddr->sin_addr.s_addr);
	271
	272	/*
	273	* Adjust for header
	274	*/
	275	m->m_data -= sizeof(struct udpiphdr);
	276	m->m_len += sizeof(struct udpiphdr);
5fafdf24	277
f0cbd3ec FB	278	/*
	279	* Fill in mbuf with extended UDP header
	280	* and addresses and length put into network format.
	281	*/
	282	ui = mtod(m, struct udpiphdr *);
	283	ui->ui_next = ui->ui_prev = 0;
	284	ui->ui_x1 = 0;
	285	ui->ui_pr = IPPROTO_UDP;
	286	ui->ui_len = htons(m->m_len - sizeof(struct ip)); /* + sizeof (struct udphdr)); */
	287	/* XXXXX Check for from-one-location sockets, or from-any-location sockets */
	288	ui->ui_src = saddr->sin_addr;
	289	ui->ui_dst = daddr->sin_addr;
	290	ui->ui_sport = saddr->sin_port;
	291	ui->ui_dport = daddr->sin_port;
	292	ui->ui_ulen = ui->ui_len;
	293
	294	/*
	295	* Stuff checksum and output datagram.
	296	*/
	297	ui->ui_sum = 0;
9634d903	298	if (UDPCKSUM) {
f0cbd3ec FB	299	if ((ui->ui_sum = cksum(m, /* sizeof (struct udpiphdr) + */ m->m_len)) == 0)
	300	ui->ui_sum = 0xffff;
	301	}
	302	((struct ip *)ui)->ip_len = m->m_len;
	303
9634d903	304	((struct ip *)ui)->ip_ttl = IPDEFTTL;
f0cbd3ec	305	((struct ip *)ui)->ip_tos = iptos;
5fafdf24	306
31a60e22	307	STAT(udpstat.udps_opackets++);
5fafdf24	308
f0cbd3ec	309	error = ip_output(so, m);
5fafdf24	310
f0cbd3ec FB	311	return (error);
	312	}
	313
5fafdf24	314	int udp_output(struct socket so, struct mbuf m,
f0cbd3ec FB	315	struct sockaddr_in *addr)
	316
	317	{
	318	struct sockaddr_in saddr, daddr;
	319
	320	saddr = *addr;
f3ae0704	321	if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr) {
c904d61f FB	322	if ((so->so_faddr.s_addr & htonl(0x000000ff)) == htonl(0xff))
c904d61f FB	323	saddr.sin_addr.s_addr = alias_addr.s_addr;
f3ae0704	324	else if (addr->sin_addr.s_addr == loopback_addr.s_addr \|\|
242acf3a	325	(ntohl(so->so_faddr.s_addr) & 0xff) != CTL_ALIAS)
f3ae0704	326	saddr.sin_addr.s_addr = so->so_faddr.s_addr;
c904d61f	327	}
f0cbd3ec FB	328	daddr.sin_addr = so->so_laddr;
f0cbd3ec FB	329	daddr.sin_port = so->so_lport;
3b46e624	330
f0cbd3ec FB	331	return udp_output2(so, m, &saddr, &daddr, so->so_iptos);
	332	}
	333
	334	int
	335	udp_attach(so)
	336	struct socket *so;
	337	{
	338	struct sockaddr_in addr;
5fafdf24	339
f0cbd3ec FB	340	if((so->s = socket(AF_INET,SOCK_DGRAM,0)) != -1) {
	341	/*
	342	* Here, we bind() the socket. Although not really needed
	343	* (sendto() on an unbound socket will bind it), it's done
	344	* here so that emulation of ytalk etc. don't have to do it
	345	*/
	346	addr.sin_family = AF_INET;
	347	addr.sin_port = 0;
	348	addr.sin_addr.s_addr = INADDR_ANY;
	349	if(bind(so->s, (struct sockaddr *)&addr, sizeof(addr))<0) {
	350	int lasterrno=errno;
379ff53d	351	closesocket(so->s);
f0cbd3ec	352	so->s=-1;
02d2c54c FB	353	#ifdef _WIN32
	354	WSASetLastError(lasterrno);
	355	#else
f0cbd3ec	356	errno=lasterrno;
02d2c54c	357	#endif
f0cbd3ec FB	358	} else {
	359	/* success, insert in queue */
	360	so->so_expire = curtime + SO_EXPIRE;
	361	insque(so,&udb);
	362	}
	363	}
	364	return(so->s);
	365	}
	366
	367	void
	368	udp_detach(so)
	369	struct socket *so;
	370	{
379ff53d	371	closesocket(so->s);
f0cbd3ec FB	372	/* if (so->so_m) m_free(so->so_m); done by sofree */
	373
	374	sofree(so);
	375	}
	376
9634d903	377	static const struct tos_t udptos[] = {
f0cbd3ec FB	378	{0, 53, IPTOS_LOWDELAY, 0}, /* DNS */
	379	{517, 517, IPTOS_LOWDELAY, EMU_TALK}, /* talk */
	380	{518, 518, IPTOS_LOWDELAY, EMU_NTALK}, /* ntalk */
	381	{0, 7648, IPTOS_LOWDELAY, EMU_CUSEEME}, /* Cu-Seeme */
	382	{0, 0, 0, 0}
	383	};
	384
9634d903 BS	385	static u_int8_t
9634d903 BS	386	udp_tos(struct socket *so)
f0cbd3ec FB	387	{
f0cbd3ec FB	388	int i = 0;
5fafdf24	389
f0cbd3ec FB	390	while(udptos[i].tos) {
	391	if ((udptos[i].fport && ntohs(so->so_fport) == udptos[i].fport) \|\|
	392	(udptos[i].lport && ntohs(so->so_lport) == udptos[i].lport)) {
	393	so->so_emu = udptos[i].emu;
	394	return udptos[i].tos;
	395	}
	396	i++;
	397	}
5fafdf24	398
f0cbd3ec FB	399	return 0;
	400	}
	401
	402	#ifdef EMULATE_TALK
	403	#include "talkd.h"
	404	#endif
	405
	406	/*
	407	* Here, talk/ytalk/ntalk requests must be emulated
	408	*/
9634d903 BS	409	static void
9634d903 BS	410	udp_emu(struct socket so, struct mbuf m)
f0cbd3ec FB	411	{
f0cbd3ec FB	412	struct sockaddr_in addr;
242acf3a	413	socklen_t addrlen = sizeof(addr);
f0cbd3ec FB	414	#ifdef EMULATE_TALK
	415	CTL_MSG_OLD *omsg;
	416	CTL_MSG *nmsg;
	417	char buff[sizeof(CTL_MSG)];
	418	u_char type;
5fafdf24	419
f0cbd3ec FB	420	struct talk_request {
	421	struct talk_request *next;
	422	struct socket *udp_so;
	423	struct socket *tcp_so;
	424	} *req;
5fafdf24 TS	425
	426	static struct talk_request *req_tbl = 0;
	427
f0cbd3ec	428	#endif
5fafdf24	429
f0cbd3ec	430	struct cu_header {
101c5935 FB	431	uint16_t d_family; // destination family
	432	uint16_t d_port; // destination port
	433	uint32_t d_addr; // destination address
	434	uint16_t s_family; // source family
	435	uint16_t s_port; // source port
51a36cb2	436	uint32_t so_addr; // source address
101c5935 FB	437	uint32_t seqn; // sequence number
	438	uint16_t message; // message
	439	uint16_t data_type; // data type
	440	uint16_t pkt_len; // packet length
f0cbd3ec FB	441	} *cu_head;
	442
	443	switch(so->so_emu) {
	444
	445	#ifdef EMULATE_TALK
	446	case EMU_TALK:
	447	case EMU_NTALK:
	448	/*
	449	* Talk emulation. We always change the ctl_addr to get
	450	* some answers from the daemon. When an ANNOUNCE comes,
	451	* we send LEAVE_INVITE to the local daemons. Also when a
	452	* DELETE comes, we send copies to the local daemons.
	453	*/
	454	if (getsockname(so->s, (struct sockaddr *)&addr, &addrlen) < 0)
	455	return;
3b46e624	456
f0cbd3ec FB	457	#define IS_OLD (so->so_emu == EMU_TALK)
	458
	459	#define COPY_MSG(dest, src) { dest->type = src->type; \
	460	dest->id_num = src->id_num; \
	461	dest->pid = src->pid; \
	462	dest->addr = src->addr; \
	463	dest->ctl_addr = src->ctl_addr; \
	464	memcpy(&dest->l_name, &src->l_name, NAME_SIZE_OLD); \
	465	memcpy(&dest->r_name, &src->r_name, NAME_SIZE_OLD); \
	466	memcpy(&dest->r_tty, &src->r_tty, TTY_SIZE); }
	467
	468	#define OTOSIN(ptr, field) ((struct sockaddr_in *)&ptr->field)
	469	/* old_sockaddr to sockaddr_in */
	470
	471
	472	if (IS_OLD) { /* old talk */
	473	omsg = mtod(m, CTL_MSG_OLD*);
	474	nmsg = (CTL_MSG *) buff;
	475	type = omsg->type;
	476	OTOSIN(omsg, ctl_addr)->sin_port = addr.sin_port;
	477	OTOSIN(omsg, ctl_addr)->sin_addr = our_addr;
be15b141	478	pstrcpy(omsg->l_name, NAME_SIZE_OLD, getlogin());
5fafdf24	479	} else { /* new talk */
f0cbd3ec FB	480	omsg = (CTL_MSG_OLD *) buff;
	481	nmsg = mtod(m, CTL_MSG *);
	482	type = nmsg->type;
	483	OTOSIN(nmsg, ctl_addr)->sin_port = addr.sin_port;
	484	OTOSIN(nmsg, ctl_addr)->sin_addr = our_addr;
be15b141	485	pstrcpy(nmsg->l_name, NAME_SIZE_OLD, getlogin());
f0cbd3ec	486	}
3b46e624	487
5fafdf24	488	if (type == LOOK_UP)
f0cbd3ec	489	return; /* for LOOK_UP this is enough */
3b46e624	490
f0cbd3ec FB	491	if (IS_OLD) { /* make a copy of the message */
	492	COPY_MSG(nmsg, omsg);
	493	nmsg->vers = 1;
	494	nmsg->answer = 0;
	495	} else
	496	COPY_MSG(omsg, nmsg);
	497
	498	/*
	499	* If if is an ANNOUNCE message, we go through the
	500	* request table to see if a tcp port has already
	501	* been redirected for this socket. If not, we solisten()
	502	* a new socket and add this entry to the table.
	503	* The port number of the tcp socket and our IP
	504	* are put to the addr field of the message structures.
	505	* Then a LEAVE_INVITE is sent to both local daemon
	506	* ports, 517 and 518. This is why we have two copies
	507	* of the message, one in old talk and one in new talk
	508	* format.
5fafdf24	509	*/
f0cbd3ec FB	510
	511	if (type == ANNOUNCE) {
	512	int s;
	513	u_short temp_port;
3b46e624	514
f0cbd3ec FB	515	for(req = req_tbl; req; req = req->next)
	516	if (so == req->udp_so)
	517	break; /* found it */
3b46e624	518
f0cbd3ec FB	519	if (!req) { /* no entry for so, create new */
	520	req = (struct talk_request *)
	521	malloc(sizeof(struct talk_request));
	522	req->udp_so = so;
3b46e624	523	req->tcp_so = solisten(0,
5fafdf24	524	OTOSIN(omsg, addr)->sin_addr.s_addr,
f0cbd3ec FB	525	OTOSIN(omsg, addr)->sin_port,
	526	SS_FACCEPTONCE);
	527	req->next = req_tbl;
	528	req_tbl = req;
3b46e624 TS	529	}
3b46e624 TS	530
f0cbd3ec FB	531	/* replace port number in addr field */
f0cbd3ec FB	532	addrlen = sizeof(addr);
5fafdf24	533	getsockname(req->tcp_so->s,
f0cbd3ec	534	(struct sockaddr *) &addr,
3b46e624	535	&addrlen);
f0cbd3ec FB	536	OTOSIN(omsg, addr)->sin_port = addr.sin_port;
	537	OTOSIN(omsg, addr)->sin_addr = our_addr;
	538	OTOSIN(nmsg, addr)->sin_port = addr.sin_port;
3b46e624 TS	539	OTOSIN(nmsg, addr)->sin_addr = our_addr;
3b46e624 TS	540
f0cbd3ec FB	541	/* send LEAVE_INVITEs */
	542	temp_port = OTOSIN(omsg, ctl_addr)->sin_port;
	543	OTOSIN(omsg, ctl_addr)->sin_port = 0;
	544	OTOSIN(nmsg, ctl_addr)->sin_port = 0;
3b46e624 TS	545	omsg->type = nmsg->type = LEAVE_INVITE;
3b46e624 TS	546
f0cbd3ec FB	547	s = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
	548	addr.sin_addr = our_addr;
	549	addr.sin_family = AF_INET;
	550	addr.sin_port = htons(517);
5fafdf24	551	sendto(s, (char )omsg, sizeof(omsg), 0,
f0cbd3ec FB	552	(struct sockaddr *)&addr, sizeof(addr));
	553	addr.sin_port = htons(518);
	554	sendto(s, (char )nmsg, sizeof(nmsg), 0,
	555	(struct sockaddr *) &addr, sizeof(addr));
379ff53d	556	closesocket(s) ;
f0cbd3ec	557
5fafdf24	558	omsg->type = nmsg->type = ANNOUNCE;
f0cbd3ec FB	559	OTOSIN(omsg, ctl_addr)->sin_port = temp_port;
	560	OTOSIN(nmsg, ctl_addr)->sin_port = temp_port;
	561	}
3b46e624	562
5fafdf24	563	/*
f0cbd3ec FB	564	* If it is a DELETE message, we send a copy to the
	565	* local daemons. Then we delete the entry corresponding
	566	* to our socket from the request table.
	567	*/
3b46e624	568
f0cbd3ec FB	569	if (type == DELETE) {
	570	struct talk_request temp_req, req_next;
	571	int s;
	572	u_short temp_port;
3b46e624	573
f0cbd3ec FB	574	temp_port = OTOSIN(omsg, ctl_addr)->sin_port;
	575	OTOSIN(omsg, ctl_addr)->sin_port = 0;
	576	OTOSIN(nmsg, ctl_addr)->sin_port = 0;
3b46e624	577
f0cbd3ec FB	578	s = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
	579	addr.sin_addr = our_addr;
	580	addr.sin_family = AF_INET;
	581	addr.sin_port = htons(517);
	582	sendto(s, (char )omsg, sizeof(omsg), 0,
	583	(struct sockaddr *)&addr, sizeof(addr));
	584	addr.sin_port = htons(518);
	585	sendto(s, (char )nmsg, sizeof(nmsg), 0,
	586	(struct sockaddr *)&addr, sizeof(addr));
379ff53d	587	closesocket(s);
3b46e624	588
f0cbd3ec FB	589	OTOSIN(omsg, ctl_addr)->sin_port = temp_port;
	590	OTOSIN(nmsg, ctl_addr)->sin_port = temp_port;
	591
	592	/* delete table entry */
	593	if (so == req_tbl->udp_so) {
	594	temp_req = req_tbl;
	595	req_tbl = req_tbl->next;
	596	free(temp_req);
	597	} else {
	598	temp_req = req_tbl;
	599	for(req = req_tbl->next; req; req = req_next) {
	600	req_next = req->next;
	601	if (so == req->udp_so) {
	602	temp_req->next = req_next;
	603	free(req);
	604	break;
	605	} else {
	606	temp_req = req;
	607	}
	608	}
	609	}
	610	}
3b46e624 TS	611
3b46e624 TS	612	return;
f0cbd3ec	613	#endif
3b46e624	614
5fafdf24 TS	615	case EMU_CUSEEME:
5fafdf24 TS	616
f0cbd3ec FB	617	/*
	618	* Cu-SeeMe emulation.
	619	* Hopefully the packet is more that 16 bytes long. We don't
	620	* do any other tests, just replace the address and port
	621	* fields.
5fafdf24	622	*/
f0cbd3ec FB	623	if (m->m_len >= sizeof (*cu_head)) {
	624	if (getsockname(so->s, (struct sockaddr *)&addr, &addrlen) < 0)
	625	return;
	626	cu_head = mtod(m, struct cu_header *);
101c5935	627	cu_head->s_port = addr.sin_port;
51a36cb2	628	cu_head->so_addr = our_addr.s_addr;
f0cbd3ec	629	}
3b46e624	630
f0cbd3ec FB	631	return;
	632	}
	633	}
	634
	635	struct socket *
	636	udp_listen(port, laddr, lport, flags)
	637	u_int port;
	638	u_int32_t laddr;
	639	u_int lport;
	640	int flags;
	641	{
	642	struct sockaddr_in addr;
	643	struct socket *so;
242acf3a	644	socklen_t addrlen = sizeof(struct sockaddr_in), opt = 1;
5fafdf24	645
f0cbd3ec FB	646	if ((so = socreate()) == NULL) {
	647	free(so);
	648	return NULL;
	649	}
	650	so->s = socket(AF_INET,SOCK_DGRAM,0);
	651	so->so_expire = curtime + SO_EXPIRE;
	652	insque(so,&udb);
	653
	654	addr.sin_family = AF_INET;
	655	addr.sin_addr.s_addr = INADDR_ANY;
	656	addr.sin_port = port;
	657
	658	if (bind(so->s,(struct sockaddr *)&addr, addrlen) < 0) {
	659	udp_detach(so);
	660	return NULL;
	661	}
	662	setsockopt(so->s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
	663	/* setsockopt(so->s,SOL_SOCKET,SO_OOBINLINE,(char )&opt,sizeof(int)); /
5fafdf24	664
f0cbd3ec FB	665	getsockname(so->s,(struct sockaddr *)&addr,&addrlen);
	666	so->so_fport = addr.sin_port;
	667	if (addr.sin_addr.s_addr == 0 \|\| addr.sin_addr.s_addr == loopback_addr.s_addr)
8dbca8dd	668	so->so_faddr = alias_addr;
f0cbd3ec FB	669	else
f0cbd3ec FB	670	so->so_faddr = addr.sin_addr;
5fafdf24	671
f0cbd3ec FB	672	so->so_lport = lport;
	673	so->so_laddr.s_addr = laddr;
	674	if (flags != SS_FACCEPTONCE)
	675	so->so_expire = 0;
5fafdf24	676
f0cbd3ec	677	so->so_state = SS_ISFCONNECTED;
5fafdf24	678
f0cbd3ec FB	679	return so;
f0cbd3ec FB	680	}