1 files changed, 275 insertions, 0 deletions
diff --git a/lib/libstand/udp.c b/lib/libstand/udp.c
new file mode 100644
index 0000000..4953932
--- /dev/null
+++ b/lib/libstand/udp.c
@@ -0,0 +1,275 @@
+/* Taken from $NetBSD: net.c,v 1.20 1997/12/26 22:41:30 scottr Exp $	*/
+
+/*
+ * Copyright (c) 1992 Regents of the University of California.
+ * All rights reserved.
+ *
+ * This software was developed by the Computer Systems Engineering group
+ * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
+ * contributed to Berkeley.
+ *
+ * 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, Lawrence Berkeley Laboratory 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.
+ *
+ * @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp  (LBL)
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/socket.h>
+
+#include <string.h>
+
+#include <net/if.h>
+#include <netinet/in.h>
+#include <netinet/if_ether.h>
+#include <netinet/in_systm.h>
+
+#include <netinet/ip.h>
+#include <netinet/ip_var.h>
+#include <netinet/udp.h>
+#include <netinet/udp_var.h>
+
+#include "stand.h"
+#include "net.h"
+
+/* Caller must leave room for ethernet, ip and udp headers in front!! */
+ssize_t
+sendudp(d, pkt, len)
+	struct iodesc *d;
+	void *pkt;
+	size_t len;
+{
+	ssize_t cc;
+	struct ip *ip;
+	struct udphdr *uh;
+	u_char *ea;
+
+#ifdef NET_DEBUG
+ 	if (debug) {
+		printf("sendudp: d=%lx called.\n", (long)d);
+		if (d) {
+			printf("saddr: %s:%d",
+			    inet_ntoa(d->myip), ntohs(d->myport));
+			printf(" daddr: %s:%d\n",
+			    inet_ntoa(d->destip), ntohs(d->destport));
+		}
+	}
+#endif
+
+	uh = (struct udphdr *)pkt - 1;
+	ip = (struct ip *)uh - 1;
+	len += sizeof(*ip) + sizeof(*uh);
+
+	bzero(ip, sizeof(*ip) + sizeof(*uh));
+
+	ip->ip_v = IPVERSION;			/* half-char */
+	ip->ip_hl = sizeof(*ip) >> 2;		/* half-char */
+	ip->ip_len = htons(len);
+	ip->ip_p = IPPROTO_UDP;			/* char */
+	ip->ip_ttl = IP_TTL;			/* char */
+	ip->ip_src = d->myip;
+	ip->ip_dst = d->destip;
+	ip->ip_sum = in_cksum(ip, sizeof(*ip));	 /* short, but special */
+
+	uh->uh_sport = d->myport;
+	uh->uh_dport = d->destport;
+	uh->uh_ulen = htons(len - sizeof(*ip));
+
+#ifndef UDP_NO_CKSUM
+	{
+		struct udpiphdr *ui;
+		struct ip tip;
+
+		/* Calculate checksum (must save and restore ip header) */
+		tip = *ip;
+		ui = (struct udpiphdr *)ip;
+		bzero(&ui->ui_x1, sizeof(ui->ui_x1));
+		ui->ui_len = uh->uh_ulen;
+		uh->uh_sum = in_cksum(ui, len);
+		*ip = tip;
+	}
+#endif
+
+	if (ip->ip_dst.s_addr == INADDR_BROADCAST || ip->ip_src.s_addr == 0 ||
+	    netmask == 0 || SAMENET(ip->ip_src, ip->ip_dst, netmask))
+		ea = arpwhohas(d, ip->ip_dst);
+	else
+		ea = arpwhohas(d, gateip);
+
+	cc = sendether(d, ip, len, ea, ETHERTYPE_IP);
+	if (cc == -1)
+		return (-1);
+	if (cc != len)
+		panic("sendudp: bad write (%d != %d)", cc, len);
+	return (cc - (sizeof(*ip) + sizeof(*uh)));
+}
+
+/*
+ * Receive a UDP packet and validate it is for us.
+ * Caller leaves room for the headers (Ether, IP, UDP)
+ */
+ssize_t
+readudp(d, pkt, len, tleft)
+	struct iodesc *d;
+	void *pkt;
+	size_t len;
+	time_t tleft;
+{
+	ssize_t n;
+	size_t hlen;
+	struct ip *ip;
+	struct udphdr *uh;
+	u_int16_t etype;	/* host order */
+
+#ifdef NET_DEBUG
+	if (debug)
+		printf("readudp: called\n");
+#endif
+
+	uh = (struct udphdr *)pkt - 1;
+	ip = (struct ip *)uh - 1;
+
+	n = readether(d, ip, len + sizeof(*ip) + sizeof(*uh), tleft, &etype);
+	if (n == -1 || n < sizeof(*ip) + sizeof(*uh))
+		return -1;
+
+	/* Ethernet address checks now in readether() */
+
+	/* Need to respond to ARP requests. */
+	if (etype == ETHERTYPE_ARP) {
+		struct arphdr *ah = (void *)ip;
+		if (ah->ar_op == htons(ARPOP_REQUEST)) {
+			/* Send ARP reply */
+			arp_reply(d, ah);
+		}
+		return -1;
+	}
+
+	if (etype != ETHERTYPE_IP) {
+#ifdef NET_DEBUG
+		if (debug)
+			printf("readudp: not IP. ether_type=%x\n", etype);
+#endif
+		return -1;
+	}
+
+	/* Check ip header */
+	if (ip->ip_v != IPVERSION ||
+	    ip->ip_p != IPPROTO_UDP) {	/* half char */
+#ifdef NET_DEBUG
+		if (debug)
+			printf("readudp: IP version or not UDP. ip_v=%d ip_p=%d\n", ip->ip_v, ip->ip_p);
+#endif
+		return -1;
+	}
+
+	hlen = ip->ip_hl << 2;
+	if (hlen < sizeof(*ip) ||
+	    in_cksum(ip, hlen) != 0) {
+#ifdef NET_DEBUG
+		if (debug)
+			printf("readudp: short hdr or bad cksum.\n");
+#endif
+		return -1;
+	}
+	if (n < ntohs(ip->ip_len)) {
+#ifdef NET_DEBUG
+		if (debug)
+			printf("readudp: bad length %d < %d.\n",
+			       (int)n, ntohs(ip->ip_len));
+#endif
+		return -1;
+	}
+	if (d->myip.s_addr && ip->ip_dst.s_addr != d->myip.s_addr) {
+#ifdef NET_DEBUG
+		if (debug) {
+			printf("readudp: bad saddr %s != ", inet_ntoa(d->myip));
+			printf("%s\n", inet_ntoa(ip->ip_dst));
+		}
+#endif
+		return -1;
+	}
+
+	/* If there were ip options, make them go away */
+	if (hlen != sizeof(*ip)) {
+		bcopy(((u_char *)ip) + hlen, uh, len - hlen);
+		ip->ip_len = htons(sizeof(*ip));
+		n -= hlen - sizeof(*ip);
+	}
+	if (uh->uh_dport != d->myport) {
+#ifdef NET_DEBUG
+		if (debug)
+			printf("readudp: bad dport %d != %d\n",
+				d->myport, ntohs(uh->uh_dport));
+#endif
+		return -1;
+	}
+
+#ifndef UDP_NO_CKSUM
+	if (uh->uh_sum) {
+		struct udpiphdr *ui;
+		struct ip tip;
+
+		n = ntohs(uh->uh_ulen) + sizeof(*ip);
+		if (n > RECV_SIZE - ETHER_SIZE) {
+			printf("readudp: huge packet, udp len %d\n", (int)n);
+			return -1;
+		}
+
+		/* Check checksum (must save and restore ip header) */
+		tip = *ip;
+		ui = (struct udpiphdr *)ip;
+		bzero(&ui->ui_x1, sizeof(ui->ui_x1));
+		ui->ui_len = uh->uh_ulen;
+		if (in_cksum(ui, n) != 0) {
+#ifdef NET_DEBUG
+			if (debug)
+				printf("readudp: bad cksum\n");
+#endif
+			*ip = tip;
+			return -1;
+		}
+		*ip = tip;
+	}
+#endif
+	if (ntohs(uh->uh_ulen) < sizeof(*uh)) {
+#ifdef NET_DEBUG
+		if (debug)
+			printf("readudp: bad udp len %d < %d\n",
+				ntohs(uh->uh_ulen), (int)sizeof(*uh));
+#endif
+		return -1;
+	}
+
+	n = (n > (ntohs(uh->uh_ulen) - sizeof(*uh))) ? 
+	    ntohs(uh->uh_ulen) - sizeof(*uh) : n;
+	return (n);
+}