auto import from //depot/cupcake/@135843
diff --git a/slirp2/udp.c b/slirp2/udp.c
new file mode 100644
index 0000000..9305cfd
--- /dev/null
+++ b/slirp2/udp.c
@@ -0,0 +1,495 @@
+/*
+ * 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"
+#define SLIRP_COMPILATION  1
+#include "sockets.h"
+
+struct udpstat udpstat;
+
+struct socket udb;
+
+/*
+ * UDP protocol implementation.
+ * Per RFC 768, August, 1980.
+ */
+#ifndef	COMPAT_42
+int	udpcksum = 1;
+#else
+int	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 MBuf m;
+	int iphlen;
+{
+	register struct ip *ip;
+	register struct udphdr *uh;
+/*	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);
+
+	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, (MBuf )0);
+		iphlen = sizeof(struct ip);
+	}
+
+	/*
+	 * Get IP and UDP header together in first mbuf.
+	 */
+	ip = MBUF_TO(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;
+		}
+		mbuf_trim(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) {
+	  memset(&((struct ipovly *)ip)->ih_mbuf, 0, sizeof(struct mbuf_ptr));
+	  ((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))) {
+	    udpstat.udps_badsum++;
+	    goto bad;
+	  }
+	}
+
+        /*
+         *  handle DHCP/BOOTP
+         */
+        if (port_geth(uh->uh_dport) == BOOTP_SERVER) {
+            bootp_input(m);
+            goto bad;
+        }
+
+        /*
+         *  handle TFTP
+         */
+        if (port_geth(uh->uh_dport) == TFTP_SERVER) {
+            tftp_input(m);
+            goto bad;
+        }
+
+	/*
+	 * Locate pcb for datagram.
+	 */
+	so = udp_last_so;
+	if (so->so_laddr_port != port_geth(uh->uh_sport) ||
+	    so->so_laddr_ip   != ip_geth(ip->ip_src)) {
+		struct socket *tmp;
+
+		for (tmp = udb.so_next; tmp != &udb; tmp = tmp->so_next) {
+			if (tmp->so_laddr_port == port_geth(uh->uh_sport) &&
+			    tmp->so_laddr_ip   == ip_geth(ip->ip_src)) {
+				tmp->so_faddr_ip   = ip_geth(ip->ip_dst);
+				tmp->so_faddr_port = port_geth(uh->uh_dport);
+				so = tmp;
+				break;
+			}
+		}
+		if (tmp == &udb) {
+		  so = NULL;
+		} else {
+		  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,errno_str));
+	    sofree(so);
+	    goto bad;
+	  }
+
+	  /*
+	   * Setup fields
+	   */
+	  /* udp_last_so = so; */
+	  so->so_laddr_ip   = ip_geth(ip->ip_src);
+	  so->so_laddr_port = port_geth(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_geth(ip->ip_dst); /* XXX */
+        so->so_faddr_port = port_geth(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, errno_str));
+	  icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,errno_str);
+	}
+
+	mbuf_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:
+	mbuf_free(m);
+	/* if (opts) mbuf_free(opts); */
+	return;
+}
+
+int udp_output2_(struct socket*  so, MBuf  m, 
+                 const SockAddress*  saddr, 
+                 const SockAddress*  daddr,
+                 int  iptos)
+{
+    register struct udpiphdr *ui;
+    uint32_t  saddr_ip = sock_address_get_ip(saddr);
+    uint32_t  daddr_ip = sock_address_get_ip(daddr);
+    int       saddr_port = sock_address_get_port(saddr);
+    int       daddr_port = sock_address_get_port(daddr);
+    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_ip);
+    DEBUG_ARG("daddr = %lx", (long) daddr_ip);
+
+    /*
+        * 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 = MBUF_TO(m, struct udpiphdr *);
+    memset(&ui->ui_i.ih_mbuf, 0 , sizeof(struct mbuf_ptr));
+    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   = ip_seth(saddr_ip);
+    ui->ui_dst   = ip_seth(daddr_ip);
+    ui->ui_sport = port_seth(saddr_port);
+    ui->ui_dport = port_seth(daddr_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 = ip_defttl;
+    ((struct ip *)ui)->ip_tos = iptos;
+
+    udpstat.udps_opackets++;
+
+    error = ip_output(so, m);
+
+    return (error);
+}
+
+int udp_output_(struct socket *so, MBuf m, SockAddress* from)
+{
+    SockAddress  saddr, daddr;
+    uint32_t     saddr_ip;
+    uint16_t     saddr_port;
+
+    saddr_ip   = sock_address_get_ip(from);
+    saddr_port = sock_address_get_port(from);
+
+    if ((so->so_faddr_ip & 0xffffff00) == special_addr_ip) {
+        saddr_ip = so->so_faddr_ip;
+        if ((so->so_faddr_ip & 0x000000ff) == 0xff)
+            saddr_ip = alias_addr_ip;
+    }
+
+    sock_address_init_inet( &saddr, saddr_ip, saddr_port );
+    sock_address_init_inet( &daddr, so->so_laddr_ip, so->so_laddr_port );
+
+    return udp_output2_(so, m, &saddr, &daddr, so->so_iptos);
+}
+
+int
+udp_attach(so)
+     struct socket *so;
+{
+  so->s = socket_anyaddr_server( 0, SOCKET_DGRAM );
+  if (so->s != -1) {
+      /* success, insert in queue */
+      so->so_expire = curtime + SO_EXPIRE;
+      insque(so,&udb);
+  }
+  return(so->s);
+}
+
+void
+udp_detach(so)
+	struct socket *so;
+{
+	socket_close(so->s);
+	/* if (so->so_m) mbuf_free(so->so_m);    done by sofree */
+
+	sofree(so);
+}
+
+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}
+};
+
+u_int8_t
+udp_tos(so)
+	struct socket *so;
+{
+	int i = 0;
+
+	while(udptos[i].tos) {
+		if ((udptos[i].fport && so->so_faddr_port == udptos[i].fport) ||
+		    (udptos[i].lport && so->so_laddr_port == udptos[i].lport)) {
+		    	so->so_emu = udptos[i].emu;
+			return udptos[i].tos;
+		}
+		i++;
+	}
+
+	return 0;
+}
+
+/*
+ * Here, talk/ytalk/ntalk requests must be emulated
+ */
+void
+udp_emu(so, m)
+	struct socket *so;
+	MBuf m;
+{
+        SockAddress  sockaddr;
+
+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) {
+
+	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 (socket_get_address(so->s, &sockaddr) < 0)
+                            return;
+
+			cu_head = MBUF_TO(m, struct cu_header *);
+			cu_head->s_port  = htons( sock_address_get_port(&sockaddr));
+			cu_head->so_addr = htonl( sock_address_get_ip(&sockaddr));
+		}
+
+		return;
+	}
+}
+
+struct socket *
+udp_listen(port, laddr, lport, flags)
+	u_int port;
+	u_int32_t laddr;
+	u_int lport;
+	int flags;
+{
+	struct socket *so;
+	SockAddress    addr;
+	uint32_t       addr_ip;
+
+	if ((so = socreate()) == NULL) {
+		free(so);
+		return NULL;
+	}
+	so->s = socket_anyaddr_server( port, SOCKET_DGRAM );
+	so->so_expire = curtime + SO_EXPIRE;
+        so->so_haddr_port = port;
+	insque(so,&udb);
+
+	if (so->s < 0) {
+		udp_detach(so);
+		return NULL;
+	}
+
+        socket_get_address(so->s, &addr);
+
+	so->so_faddr_port = sock_address_get_port(&addr);
+	addr_ip = sock_address_get_ip(&addr);
+
+	if (addr_ip == 0 || addr_ip == loopback_addr_ip)
+	   so->so_faddr_ip = alias_addr_ip;
+	else
+	   so->so_faddr_ip = addr_ip;
+
+	so->so_laddr_port = lport;
+	so->so_laddr_ip   = laddr;
+	if (flags != SS_FACCEPTONCE)
+	   so->so_expire = 0;
+
+	so->so_state = SS_ISFCONNECTED;
+
+	return so;
+}
+
+int udp_unlisten (u_int port)
+{
+    struct socket *so;
+
+    for (so = udb.so_next; so != &udb; so = so->so_next) {
+        if (so->so_haddr_port == port) {
+            break;
+        }
+    }
+
+    if (so == &udb)
+        return -1;
+
+    sofcantrcvmore( so );
+    sofcantsendmore( so );
+    socket_close( so->s );
+    so->s = -1;
+    sofree( so );
+    return 0;
+}