network/traceroute/traceroute.c

23  * traceroute host  - trace the route ip packets follow going to "host".
25  * Attempt to trace the route an ip packet would follow to some
31  * defaults to net.inet.ip.ttl hops & can be changed with the -m flag).
146  * system available from Berkeley:  A raw ip socket using proto
147  * IPPROTO_RAW must interpret the data sent as an ip datagram (as
148  * opposed to data to be wrapped in an ip datagram).  See the README
159  * udp header (the ip id could be used but there's no way to
160  * interlock with the kernel's assignment of ip id's and, anyway,
162  * code to set the ip id).  So, to allow two or more users to
210 #include <netinet/ip.h>
307 struct ip *outip;		/* last output ip packet */
310 struct ip *hip = NULL;		/* Quoted IP header */
323 int minpacket;			/* min ip packet size */
324 int maxpacket = 32 * 1024;	/* max ip packet size */
348 int doipcksum = 0;		/* don't calculate ip checksums by default */
350 int doipcksum = 1;		/* calculate ip checksums by default */
352 int optlen;			/* length of ip options */
374 u_short p_cksum(struct ip *, u_short *, int, int);
571 			perror("sysctl(net.inet.ip.ttl)");
675 			 * set the ip source address of the outbound
726 		Fprintf(stderr, "%s: Warning: ip checksums disabled\n", prog);
772 	outip = (struct ip *)malloc((unsigned)packlen);
1042 			register struct ip *ip;
1121 					ip = (struct ip *)packet;
1122 					if (ip->ip_ttl <= 1)
1136 					ip = (struct ip *)packet;
1137 					if (ip->ip_ttl <= 1)
1397 	register struct ip *ip;
1399 	ip = (struct ip *) buf;
1400 	hlen = ip->ip_hl << 2;
1444 		    inet_ntoa(ip->ip_dst), type, pr_type(type), icp->icmp_code);
1693 	register struct ip *ip;
1697 	ip = (struct ip *) buf;
1698 	hlen = ip->ip_hl << 2;
1712 		Printf(" %d bytes to %s", cc, inet_ntoa(ip->ip_dst));
1719 p_cksum(struct ip *ip, u_short *data, int len, int cov)
1724 	ipo.ih_pr = ip->ip_p;
1726 	ipo.ih_src = ip->ip_src;
1727 	ipo.ih_dst = ip->ip_dst;
1729 	sum[1] = in_cksum((u_short *)&ipo, sizeof(ipo)); /* pseudo ip hdr cksum */