lib/libstand/udp.c

52 #include <netinet/ip.h>
60 /* Caller must leave room for ethernet, ip and udp headers in front!! */
68 	struct ip *ip;
85 	ip = (struct ip *)uh - 1;
86 	len += sizeof(*ip) + sizeof(*uh);
88 	bzero(ip, sizeof(*ip) + sizeof(*uh));
90 	ip->ip_v = IPVERSION;			/* half-char */
91 	ip->ip_hl = sizeof(*ip) >> 2;		/* half-char */
92 	ip->ip_len = htons(len);
93 	ip->ip_p = IPPROTO_UDP;			/* char */
94 	ip->ip_ttl = IPDEFTTL;			/* char */
95 	ip->ip_src = d->myip;
96 	ip->ip_dst = d->destip;
97 	ip->ip_sum = in_cksum(ip, sizeof(*ip));	 /* short, but special */
101 	uh->uh_ulen = htons(len - sizeof(*ip));
106 		struct ip tip;
108 		/* Calculate checksum (must save and restore ip header) */
109 		tip = *ip;
110 		ui = (struct udpiphdr *)ip;
114 		*ip = tip;
118 	if (ip->ip_dst.s_addr == INADDR_BROADCAST || ip->ip_src.s_addr == 0 ||
119 	    netmask == 0 || SAMENET(ip->ip_src, ip->ip_dst, netmask))
120 		ea = arpwhohas(d, ip->ip_dst);
124 	cc = sendether(d, ip, len, ea, ETHERTYPE_IP);
129 	return (cc - (sizeof(*ip) + sizeof(*uh)));
145 	struct ip *ip;
155 	ip = (struct ip *)uh - 1;
157 	n = readether(d, ip, len + sizeof(*ip) + sizeof(*uh), tleft, &etype);
158 	if (n == -1 || n < sizeof(*ip) + sizeof(*uh))
165 		struct arphdr *ah = (void *)ip;
181 	/* Check ip header */
182 	if (ip->ip_v != IPVERSION ||
183 	    ip->ip_p != IPPROTO_UDP) {	/* half char */
186 			printf("readudp: IP version or not UDP. ip_v=%d ip_p=%d\n", ip->ip_v, ip->ip_p);
191 	hlen = ip->ip_hl << 2;
192 	if (hlen < sizeof(*ip) ||
193 	    in_cksum(ip, hlen) != 0) {
200 	if (n < ntohs(ip->ip_len)) {
204 			       (int)n, ntohs(ip->ip_len));
208 	if (d->myip.s_addr && ip->ip_dst.s_addr != d->myip.s_addr) {
212 			printf("%s\n", inet_ntoa(ip->ip_dst));
218 	/* If there were ip options, make them go away */
219 	if (hlen != sizeof(*ip)) {
220 		bcopy(((u_char *)ip) + hlen, uh, len - hlen);
221 		ip->ip_len = htons(sizeof(*ip));
222 		n -= hlen - sizeof(*ip);
236 		struct ip tip;
238 		n = ntohs(uh->uh_ulen) + sizeof(*ip);
244 		/* Check checksum (must save and restore ip header) */
245 		tip = *ip;
246 		ui = (struct udpiphdr *)ip;
254 			*ip = tip;
257 		*ip = tip;