1/*
2 * Copyright (c) 1989 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Mike Muuss.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#ifndef lint
38char copyright[] =
39"@(#) Copyright (c) 1989 The Regents of the University of California.\n\
40 All rights reserved.\n";
41#endif /* not lint */
42
43/*
44 *			P I N G . C
45 *
46 * Using the InterNet Control Message Protocol (ICMP) "ECHO" facility,
47 * measure round-trip-delays and packet loss across network paths.
48 *
49 * Author -
50 *	Mike Muuss
51 *	U. S. Army Ballistic Research Laboratory
52 *	December, 1983
53 *
54 * Status -
55 *	Public Domain.  Distribution Unlimited.
56 * Bugs -
57 *	More statistics could always be gathered.
58 *	This program has to run SUID to ROOT to access the ICMP socket.
59 */
60
61#include "ping_common.h"
62
63#include <netinet/ip.h>
64#include <netinet/ip_icmp.h>
65#ifndef WITHOUT_IFADDRS
66#include <ifaddrs.h>
67#endif
68
69#ifndef ICMP_FILTER
70#define ICMP_FILTER	1
71struct icmp_filter {
72	__u32	data;
73};
74#endif
75
76#define	MAXIPLEN	60
77#define	MAXICMPLEN	76
78#define	NROUTES		9		/* number of record route slots */
79#define TOS_MAX		255		/* 8-bit TOS field */
80#define MAX_HOSTNAMELEN	NI_MAXHOST
81
82
83static int ts_type;
84static int nroute = 0;
85static __u32 route[10];
86
87
88
89struct sockaddr_in whereto;	/* who to ping */
90int optlen = 0;
91int settos = 0;			/* Set TOS, Precendence or other QOS options */
92int icmp_sock;			/* socket file descriptor */
93u_char outpack[0x10000];
94int maxpacket = sizeof(outpack);
95
96static int broadcast_pings = 0;
97
98static char *pr_addr(__u32);
99static void pr_options(unsigned char * cp, int hlen);
100static void pr_iph(struct iphdr *ip);
101static void usage(void) __attribute__((noreturn));
102static u_short in_cksum(const u_short *addr, int len, u_short salt);
103static void pr_icmph(__u8 type, __u8 code, __u32 info, struct icmphdr *icp);
104static int parsetos(char *str);
105
106static struct {
107	struct cmsghdr cm;
108	struct in_pktinfo ipi;
109} cmsg = { {sizeof(struct cmsghdr) + sizeof(struct in_pktinfo), SOL_IP, IP_PKTINFO},
110	   {0, }};
111int cmsg_len;
112
113struct sockaddr_in source;
114char *device;
115int pmtudisc = -1;
116
117
118int
119main(int argc, char **argv)
120{
121	struct hostent *hp;
122	int ch, hold, packlen;
123	int socket_errno = 0;
124	u_char *packet;
125	char *target;
126#ifdef USE_IDN
127	char *hnamebuf = NULL;
128#else
129	char hnamebuf[MAX_HOSTNAMELEN];
130#endif
131	char rspace[3 + 4 * NROUTES + 1];	/* record route space */
132
133#ifdef ANDROID
134	android_check_security();
135#endif
136
137	limit_capabilities();
138
139#ifdef USE_IDN
140	setlocale(LC_ALL, "");
141#endif
142
143	icmp_sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
144	if (icmp_sock < 0) {
145		enable_capability_raw();
146		icmp_sock = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
147		socket_errno = errno;
148		disable_capability_raw();
149		using_ping_socket = 0;
150	}
151
152	source.sin_family = AF_INET;
153
154	preload = 1;
155	while ((ch = getopt(argc, argv, COMMON_OPTSTR "bRT:")) != EOF) {
156		switch(ch) {
157		case 'b':
158			broadcast_pings = 1;
159			break;
160		case 'Q':
161			settos = parsetos(optarg);
162			if (settos &&
163			    (setsockopt(icmp_sock, IPPROTO_IP, IP_TOS,
164					(char *)&settos, sizeof(int)) < 0)) {
165				perror("ping: error setting QOS sockopts");
166				exit(2);
167			}
168			break;
169		case 'R':
170			if (options & F_TIMESTAMP) {
171				fprintf(stderr, "Only one of -T or -R may be used\n");
172				exit(2);
173			}
174			options |= F_RROUTE;
175			break;
176		case 'T':
177			if (options & F_RROUTE) {
178				fprintf(stderr, "Only one of -T or -R may be used\n");
179				exit(2);
180			}
181			options |= F_TIMESTAMP;
182			if (strcmp(optarg, "tsonly") == 0)
183				ts_type = IPOPT_TS_TSONLY;
184			else if (strcmp(optarg, "tsandaddr") == 0)
185				ts_type = IPOPT_TS_TSANDADDR;
186			else if (strcmp(optarg, "tsprespec") == 0)
187				ts_type = IPOPT_TS_PRESPEC;
188			else {
189				fprintf(stderr, "Invalid timestamp type\n");
190				exit(2);
191			}
192			break;
193		case 'I':
194		{
195#if 0
196			char dummy;
197			int i1, i2, i3, i4;
198
199			if (sscanf(optarg, "%u.%u.%u.%u%c",
200				   &i1, &i2, &i3, &i4, &dummy) == 4) {
201				__u8 *ptr;
202				ptr = (__u8*)&source.sin_addr;
203				ptr[0] = i1;
204				ptr[1] = i2;
205				ptr[2] = i3;
206				ptr[3] = i4;
207				options |= F_STRICTSOURCE;
208			} else {
209				device = optarg;
210			}
211#else
212			if (inet_pton(AF_INET, optarg, &source.sin_addr) > 0)
213				options |= F_STRICTSOURCE;
214			else
215				device = optarg;
216#endif
217			break;
218		}
219		case 'M':
220			if (strcmp(optarg, "do") == 0)
221				pmtudisc = IP_PMTUDISC_DO;
222			else if (strcmp(optarg, "dont") == 0)
223				pmtudisc = IP_PMTUDISC_DONT;
224			else if (strcmp(optarg, "want") == 0)
225				pmtudisc = IP_PMTUDISC_WANT;
226			else {
227				fprintf(stderr, "ping: wrong value for -M: do, dont, want are valid ones.\n");
228				exit(2);
229			}
230			break;
231		case 'V':
232			printf("ping utility, iputils-%s\n", SNAPSHOT);
233			exit(0);
234		COMMON_OPTIONS
235			common_options(ch);
236			break;
237		default:
238			usage();
239		}
240	}
241	argc -= optind;
242	argv += optind;
243
244	if (argc == 0)
245		usage();
246	if (argc > 1) {
247		if (options & F_RROUTE)
248			usage();
249		else if (options & F_TIMESTAMP) {
250			if (ts_type != IPOPT_TS_PRESPEC)
251				usage();
252			if (argc > 5)
253				usage();
254		} else {
255			if (argc > 10)
256				usage();
257			options |= F_SOURCEROUTE;
258		}
259	}
260	while (argc > 0) {
261		target = *argv;
262
263		memset((char *)&whereto, 0, sizeof(whereto));
264		whereto.sin_family = AF_INET;
265		if (inet_aton(target, &whereto.sin_addr) == 1) {
266			hostname = target;
267			if (argc == 1)
268				options |= F_NUMERIC;
269		} else {
270			char *idn;
271#ifdef USE_IDN
272			int rc;
273
274			if (hnamebuf) {
275				free(hnamebuf);
276				hnamebuf = NULL;
277			}
278
279			rc = idna_to_ascii_lz(target, &idn, 0);
280			if (rc != IDNA_SUCCESS) {
281				fprintf(stderr, "ping: IDN encoding failed: %s\n", idna_strerror(rc));
282				exit(2);
283			}
284#else
285			idn = target;
286#endif
287			hp = gethostbyname(idn);
288			if (!hp) {
289				fprintf(stderr, "ping: unknown host %s\n", target);
290				exit(2);
291			}
292#ifdef USE_IDN
293			free(idn);
294#endif
295			memcpy(&whereto.sin_addr, hp->h_addr, 4);
296#ifdef USE_IDN
297			if (idna_to_unicode_lzlz(hp->h_name, &hnamebuf, 0) != IDNA_SUCCESS) {
298				hnamebuf = strdup(hp->h_name);
299				if (!hnamebuf) {
300					perror("ping: strdup");
301					exit(-1);
302				}
303			}
304#else
305			strncpy(hnamebuf, hp->h_name, sizeof(hnamebuf) - 1);
306			hnamebuf[sizeof(hnamebuf) - 1] = 0;
307#endif
308			hostname = hnamebuf;
309		}
310		if (argc > 1)
311			route[nroute++] = whereto.sin_addr.s_addr;
312		argc--;
313		argv++;
314	}
315
316	if (source.sin_addr.s_addr == 0) {
317		socklen_t alen;
318		struct sockaddr_in dst = whereto;
319		int probe_fd = socket(AF_INET, SOCK_DGRAM, 0);
320
321		if (probe_fd < 0) {
322			perror("socket");
323			exit(2);
324		}
325		if (device) {
326			struct ifreq ifr;
327			int rc;
328
329			memset(&ifr, 0, sizeof(ifr));
330			strncpy(ifr.ifr_name, device, IFNAMSIZ-1);
331
332			enable_capability_raw();
333			rc = setsockopt(probe_fd, SOL_SOCKET, SO_BINDTODEVICE, device, strlen(device)+1);
334			disable_capability_raw();
335
336			if (rc == -1) {
337				if (IN_MULTICAST(ntohl(dst.sin_addr.s_addr))) {
338					struct ip_mreqn imr;
339					if (ioctl(probe_fd, SIOCGIFINDEX, &ifr) < 0) {
340						fprintf(stderr, "ping: unknown iface %s\n", device);
341						exit(2);
342					}
343					memset(&imr, 0, sizeof(imr));
344					imr.imr_ifindex = ifr.ifr_ifindex;
345					if (setsockopt(probe_fd, SOL_IP, IP_MULTICAST_IF, &imr, sizeof(imr)) == -1) {
346						perror("ping: IP_MULTICAST_IF");
347						exit(2);
348					}
349				} else {
350					perror("ping: SO_BINDTODEVICE");
351					exit(2);
352				}
353			}
354		}
355
356		if (settos &&
357		    setsockopt(probe_fd, IPPROTO_IP, IP_TOS, (char *)&settos, sizeof(int)) < 0)
358			perror("Warning: error setting QOS sockopts");
359
360		dst.sin_port = htons(1025);
361		if (nroute)
362			dst.sin_addr.s_addr = route[0];
363
364		sock_setmark(probe_fd);
365
366		if (connect(probe_fd, (struct sockaddr*)&dst, sizeof(dst)) == -1) {
367			if (errno == EACCES) {
368				if (broadcast_pings == 0) {
369					fprintf(stderr, "Do you want to ping broadcast? Then -b\n");
370					exit(2);
371				}
372				fprintf(stderr, "WARNING: pinging broadcast address\n");
373				if (setsockopt(probe_fd, SOL_SOCKET, SO_BROADCAST,
374					       &broadcast_pings, sizeof(broadcast_pings)) < 0) {
375					perror ("can't set broadcasting");
376					exit(2);
377				}
378				if (connect(probe_fd, (struct sockaddr*)&dst, sizeof(dst)) == -1) {
379					perror("connect");
380					exit(2);
381				}
382			} else {
383				perror("connect");
384				exit(2);
385			}
386		}
387		alen = sizeof(source);
388		if (getsockname(probe_fd, (struct sockaddr*)&source, &alen) == -1) {
389			perror("getsockname");
390			exit(2);
391		}
392		source.sin_port = 0;
393
394#ifndef WITHOUT_IFADDRS
395		if (device) {
396			struct ifaddrs *ifa0, *ifa;
397			int ret;
398
399			ret = getifaddrs(&ifa0);
400			if (ret) {
401				fprintf(stderr, "gatifaddrs() failed.\n");
402				exit(2);
403			}
404			for (ifa = ifa0; ifa; ifa = ifa->ifa_next) {
405				if (!ifa->ifa_addr || ifa->ifa_addr->sa_family != AF_INET)
406					continue;
407				if (!strncmp(ifa->ifa_name, device, sizeof(device) - 1) &&
408				    !memcmp(&((struct sockaddr_in *)ifa->ifa_addr)->sin_addr,
409					    &source.sin_addr, sizeof(source.sin_addr)))
410					break;
411			}
412			freeifaddrs(ifa0);
413			if (!ifa)
414				fprintf(stderr, "ping: Warning: source address might be selected on device other than %s.\n", device);
415		}
416#endif
417		close(probe_fd);
418	} while (0);
419
420	if (whereto.sin_addr.s_addr == 0)
421		whereto.sin_addr.s_addr = source.sin_addr.s_addr;
422
423	if (icmp_sock < 0) {
424		errno = socket_errno;
425		perror("ping: icmp open socket");
426		exit(2);
427	}
428
429	if (device) {
430		struct ifreq ifr;
431
432		memset(&ifr, 0, sizeof(ifr));
433		strncpy(ifr.ifr_name, device, IFNAMSIZ-1);
434		if (ioctl(icmp_sock, SIOCGIFINDEX, &ifr) < 0) {
435			fprintf(stderr, "ping: unknown iface %s\n", device);
436			exit(2);
437		}
438		cmsg.ipi.ipi_ifindex = ifr.ifr_ifindex;
439		cmsg_len = sizeof(cmsg);
440	}
441
442	if (broadcast_pings || IN_MULTICAST(ntohl(whereto.sin_addr.s_addr))) {
443		if (uid) {
444			if (interval < 1000) {
445				fprintf(stderr, "ping: broadcast ping with too short interval.\n");
446				exit(2);
447			}
448			if (pmtudisc >= 0 && pmtudisc != IP_PMTUDISC_DO) {
449				fprintf(stderr, "ping: broadcast ping does not fragment.\n");
450				exit(2);
451			}
452		}
453		if (pmtudisc < 0)
454			pmtudisc = IP_PMTUDISC_DO;
455	}
456
457	if (pmtudisc >= 0) {
458		if (setsockopt(icmp_sock, SOL_IP, IP_MTU_DISCOVER, &pmtudisc, sizeof(pmtudisc)) == -1) {
459			perror("ping: IP_MTU_DISCOVER");
460			exit(2);
461		}
462	}
463
464	if ((options&F_STRICTSOURCE) &&
465	    bind(icmp_sock, (struct sockaddr*)&source, sizeof(source)) == -1) {
466		perror("bind");
467		exit(2);
468	}
469
470	if (!using_ping_socket) {
471		struct icmp_filter filt;
472		filt.data = ~((1<<ICMP_SOURCE_QUENCH)|
473			      (1<<ICMP_DEST_UNREACH)|
474			      (1<<ICMP_TIME_EXCEEDED)|
475			      (1<<ICMP_PARAMETERPROB)|
476			      (1<<ICMP_REDIRECT)|
477			      (1<<ICMP_ECHOREPLY));
478		if (setsockopt(icmp_sock, SOL_RAW, ICMP_FILTER, (char*)&filt, sizeof(filt)) == -1)
479			perror("WARNING: setsockopt(ICMP_FILTER)");
480	}
481
482	hold = 1;
483	if (setsockopt(icmp_sock, SOL_IP, IP_RECVERR, (char *)&hold, sizeof(hold)))
484		fprintf(stderr, "WARNING: your kernel is veeery old. No problems.\n");
485	if (using_ping_socket) {
486		if (setsockopt(icmp_sock, SOL_IP, IP_RECVTTL, (char *)&hold, sizeof(hold)))
487			perror("WARNING: setsockopt(IP_RECVTTL)");
488		if (setsockopt(icmp_sock, SOL_IP, IP_RETOPTS, (char *)&hold, sizeof(hold)))
489			perror("WARNING: setsockopt(IP_RETOPTS)");
490	}
491
492	/* record route option */
493	if (options & F_RROUTE) {
494		memset(rspace, 0, sizeof(rspace));
495		rspace[0] = IPOPT_NOP;
496		rspace[1+IPOPT_OPTVAL] = IPOPT_RR;
497		rspace[1+IPOPT_OLEN] = sizeof(rspace)-1;
498		rspace[1+IPOPT_OFFSET] = IPOPT_MINOFF;
499		optlen = 40;
500		if (setsockopt(icmp_sock, IPPROTO_IP, IP_OPTIONS, rspace, sizeof(rspace)) < 0) {
501			perror("ping: record route");
502			exit(2);
503		}
504	}
505	if (options & F_TIMESTAMP) {
506		memset(rspace, 0, sizeof(rspace));
507		rspace[0] = IPOPT_TIMESTAMP;
508		rspace[1] = (ts_type==IPOPT_TS_TSONLY ? 40 : 36);
509		rspace[2] = 5;
510		rspace[3] = ts_type;
511		if (ts_type == IPOPT_TS_PRESPEC) {
512			int i;
513			rspace[1] = 4+nroute*8;
514			for (i=0; i<nroute; i++)
515				*(__u32*)&rspace[4+i*8] = route[i];
516		}
517		if (setsockopt(icmp_sock, IPPROTO_IP, IP_OPTIONS, rspace, rspace[1]) < 0) {
518			rspace[3] = 2;
519			if (setsockopt(icmp_sock, IPPROTO_IP, IP_OPTIONS, rspace, rspace[1]) < 0) {
520				perror("ping: ts option");
521				exit(2);
522			}
523		}
524		optlen = 40;
525	}
526	if (options & F_SOURCEROUTE) {
527		int i;
528		memset(rspace, 0, sizeof(rspace));
529		rspace[0] = IPOPT_NOOP;
530		rspace[1+IPOPT_OPTVAL] = (options & F_SO_DONTROUTE) ? IPOPT_SSRR
531			: IPOPT_LSRR;
532		rspace[1+IPOPT_OLEN] = 3 + nroute*4;
533		rspace[1+IPOPT_OFFSET] = IPOPT_MINOFF;
534		for (i=0; i<nroute; i++)
535			*(__u32*)&rspace[4+i*4] = route[i];
536
537		if (setsockopt(icmp_sock, IPPROTO_IP, IP_OPTIONS, rspace, 4 + nroute*4) < 0) {
538			perror("ping: record route");
539			exit(2);
540		}
541		optlen = 40;
542	}
543
544	/* Estimate memory eaten by single packet. It is rough estimate.
545	 * Actually, for small datalen's it depends on kernel side a lot. */
546	hold = datalen + 8;
547	hold += ((hold+511)/512)*(optlen + 20 + 16 + 64 + 160);
548	sock_setbufs(icmp_sock, hold);
549
550	if (broadcast_pings) {
551		if (setsockopt(icmp_sock, SOL_SOCKET, SO_BROADCAST,
552			       &broadcast_pings, sizeof(broadcast_pings)) < 0) {
553			perror ("ping: can't set broadcasting");
554			exit(2);
555		}
556	}
557
558	if (options & F_NOLOOP) {
559		int loop = 0;
560		if (setsockopt(icmp_sock, IPPROTO_IP, IP_MULTICAST_LOOP,
561							&loop, 1) == -1) {
562			perror ("ping: can't disable multicast loopback");
563			exit(2);
564		}
565	}
566	if (options & F_TTL) {
567		int ittl = ttl;
568		if (setsockopt(icmp_sock, IPPROTO_IP, IP_MULTICAST_TTL,
569							&ttl, 1) == -1) {
570			perror ("ping: can't set multicast time-to-live");
571			exit(2);
572		}
573		if (setsockopt(icmp_sock, IPPROTO_IP, IP_TTL,
574							&ittl, sizeof(ittl)) == -1) {
575			perror ("ping: can't set unicast time-to-live");
576			exit(2);
577		}
578	}
579
580	if (datalen > 0xFFFF - 8 - optlen - 20) {
581		if (uid || datalen > sizeof(outpack)-8) {
582			fprintf(stderr, "Error: packet size %d is too large. Maximum is %d\n", datalen, 0xFFFF-8-20-optlen);
583			exit(2);
584		}
585		/* Allow small oversize to root yet. It will cause EMSGSIZE. */
586		fprintf(stderr, "WARNING: packet size %d is too large. Maximum is %d\n", datalen, 0xFFFF-8-20-optlen);
587	}
588
589	if (datalen >= sizeof(struct timeval))	/* can we time transfer */
590		timing = 1;
591	packlen = datalen + MAXIPLEN + MAXICMPLEN;
592	if (!(packet = (u_char *)malloc((u_int)packlen))) {
593		fprintf(stderr, "ping: out of memory.\n");
594		exit(2);
595	}
596
597	printf("PING %s (%s) ", hostname, inet_ntoa(whereto.sin_addr));
598	if (device || (options&F_STRICTSOURCE))
599		printf("from %s %s: ", inet_ntoa(source.sin_addr), device ?: "");
600	printf("%d(%d) bytes of data.\n", datalen, datalen+8+optlen+20);
601
602	setup(icmp_sock);
603
604	main_loop(icmp_sock, packet, packlen);
605}
606
607
608int receive_error_msg()
609{
610	int res;
611	char cbuf[512];
612	struct iovec  iov;
613	struct msghdr msg;
614	struct cmsghdr *cmsg;
615	struct sock_extended_err *e;
616	struct icmphdr icmph;
617	struct sockaddr_in target;
618	int net_errors = 0;
619	int local_errors = 0;
620	int saved_errno = errno;
621
622	iov.iov_base = &icmph;
623	iov.iov_len = sizeof(icmph);
624	msg.msg_name = (void*)&target;
625	msg.msg_namelen = sizeof(target);
626	msg.msg_iov = &iov;
627	msg.msg_iovlen = 1;
628	msg.msg_flags = 0;
629	msg.msg_control = cbuf;
630	msg.msg_controllen = sizeof(cbuf);
631
632	res = recvmsg(icmp_sock, &msg, MSG_ERRQUEUE|MSG_DONTWAIT);
633	if (res < 0)
634		goto out;
635
636	e = NULL;
637	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
638		if (cmsg->cmsg_level == SOL_IP) {
639			if (cmsg->cmsg_type == IP_RECVERR)
640				e = (struct sock_extended_err *)CMSG_DATA(cmsg);
641		}
642	}
643	if (e == NULL)
644		abort();
645
646	if (e->ee_origin == SO_EE_ORIGIN_LOCAL) {
647		local_errors++;
648		if (options & F_QUIET)
649			goto out;
650		if (options & F_FLOOD)
651			write_stdout("E", 1);
652		else if (e->ee_errno != EMSGSIZE)
653			fprintf(stderr, "ping: local error: %s\n", strerror(e->ee_errno));
654		else
655			fprintf(stderr, "ping: local error: Message too long, mtu=%u\n", e->ee_info);
656		nerrors++;
657	} else if (e->ee_origin == SO_EE_ORIGIN_ICMP) {
658		struct sockaddr_in *sin = (struct sockaddr_in*)(e+1);
659		int error_pkt;
660
661		if (res < sizeof(icmph) ||
662		    target.sin_addr.s_addr != whereto.sin_addr.s_addr ||
663		    icmph.type != ICMP_ECHO ||
664		    !is_ours(icmph.un.echo.id)) {
665			/* Not our error, not an error at all. Clear. */
666			saved_errno = 0;
667			goto out;
668		}
669
670		error_pkt = (e->ee_type != ICMP_REDIRECT &&
671			     e->ee_type != ICMP_SOURCE_QUENCH);
672		if (error_pkt) {
673			acknowledge(ntohs(icmph.un.echo.sequence));
674			net_errors++;
675			nerrors++;
676		}
677		else {
678			saved_errno = 0;
679		}
680
681		if (!using_ping_socket && !working_recverr) {
682			struct icmp_filter filt;
683			working_recverr = 1;
684			/* OK, it works. Add stronger filter. */
685			filt.data = ~((1<<ICMP_SOURCE_QUENCH)|
686				      (1<<ICMP_REDIRECT)|
687				      (1<<ICMP_ECHOREPLY));
688			if (setsockopt(icmp_sock, SOL_RAW, ICMP_FILTER, (char*)&filt, sizeof(filt)) == -1)
689				perror("\rWARNING: setsockopt(ICMP_FILTER)");
690		}
691
692		if (options & F_QUIET)
693			goto out;
694		if (options & F_FLOOD) {
695			if (error_pkt)
696				write_stdout("\bE", 2);
697		} else {
698			print_timestamp();
699			printf("From %s: icmp_seq=%u ", pr_addr(sin->sin_addr.s_addr), ntohs(icmph.un.echo.sequence));
700			pr_icmph(e->ee_type, e->ee_code, e->ee_info, NULL);
701			fflush(stdout);
702		}
703	}
704
705out:
706	errno = saved_errno;
707	return net_errors ? : -local_errors;
708}
709
710/*
711 * pinger --
712 * 	Compose and transmit an ICMP ECHO REQUEST packet.  The IP packet
713 * will be added on by the kernel.  The ID field is our UNIX process ID,
714 * and the sequence number is an ascending integer.  The first 8 bytes
715 * of the data portion are used to hold a UNIX "timeval" struct in VAX
716 * byte-order, to compute the round-trip time.
717 */
718int send_probe()
719{
720	struct icmphdr *icp;
721	int cc;
722	int i;
723
724	icp = (struct icmphdr *)outpack;
725	icp->type = ICMP_ECHO;
726	icp->code = 0;
727	icp->checksum = 0;
728	icp->un.echo.sequence = htons(ntransmitted+1);
729	icp->un.echo.id = ident;			/* ID */
730
731	rcvd_clear(ntransmitted+1);
732
733	if (timing) {
734		if (options&F_LATENCY) {
735			struct timeval tmp_tv;
736			gettimeofday(&tmp_tv, NULL);
737			memcpy(icp+1, &tmp_tv, sizeof(tmp_tv));
738		} else {
739			memset(icp+1, 0, sizeof(struct timeval));
740		}
741	}
742
743	cc = datalen + 8;			/* skips ICMP portion */
744
745	/* compute ICMP checksum here */
746	icp->checksum = in_cksum((u_short *)icp, cc, 0);
747
748	if (timing && !(options&F_LATENCY)) {
749		struct timeval tmp_tv;
750		gettimeofday(&tmp_tv, NULL);
751		memcpy(icp+1, &tmp_tv, sizeof(tmp_tv));
752		icp->checksum = in_cksum((u_short *)&tmp_tv, sizeof(tmp_tv), ~icp->checksum);
753	}
754
755	do {
756		static struct iovec iov = {outpack, 0};
757		static struct msghdr m = { &whereto, sizeof(whereto),
758						   &iov, 1, &cmsg, 0, 0 };
759		m.msg_controllen = cmsg_len;
760		iov.iov_len = cc;
761
762		i = sendmsg(icmp_sock, &m, confirm);
763		confirm = 0;
764	} while (0);
765
766	return (cc == i ? 0 : i);
767}
768
769/*
770 * parse_reply --
771 *	Print out the packet, if it came from us.  This logic is necessary
772 * because ALL readers of the ICMP socket get a copy of ALL ICMP packets
773 * which arrive ('tis only fair).  This permits multiple copies of this
774 * program to be run without having intermingled output (or statistics!).
775 */
776void pr_echo_reply(__u8 *_icp, int len)
777{
778	struct icmphdr *icp = (struct icmphdr *)_icp;
779	printf(" icmp_seq=%u", ntohs(icp->un.echo.sequence));
780}
781
782int
783parse_reply(struct msghdr *msg, int cc, void *addr, struct timeval *tv)
784{
785	struct sockaddr_in *from = addr;
786	__u8 *buf = msg->msg_iov->iov_base;
787	struct icmphdr *icp;
788	struct iphdr *ip;
789	int hlen;
790	int csfailed;
791	struct cmsghdr *cmsg;
792	int ttl;
793	__u8 *opts;
794	int optlen;
795
796	/* Check the IP header */
797	ip = (struct iphdr *)buf;
798	if (!using_ping_socket) {
799		hlen = ip->ihl*4;
800		if (cc < hlen + 8 || ip->ihl < 5) {
801			if (options & F_VERBOSE)
802				fprintf(stderr, "ping: packet too short (%d bytes) from %s\n", cc,
803					pr_addr(from->sin_addr.s_addr));
804			return 1;
805		}
806		ttl = ip->ttl;
807		opts = buf + sizeof(struct iphdr);
808		optlen = hlen - sizeof(struct iphdr);
809	} else {
810		hlen = 0;
811		ttl = 0;
812		opts = buf;
813		optlen = 0;
814		for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
815			if (cmsg->cmsg_level != SOL_IP)
816				continue;
817			if (cmsg->cmsg_type == IP_TTL) {
818				if (cmsg->cmsg_len < sizeof(int))
819					continue;
820				ttl = *(int *) CMSG_DATA(cmsg);
821			} else if (cmsg->cmsg_type == IP_RETOPTS) {
822				opts = (__u8 *) CMSG_DATA(cmsg);
823				optlen = cmsg->cmsg_len;
824			}
825		}
826	}
827
828	/* Now the ICMP part */
829	cc -= hlen;
830	icp = (struct icmphdr *)(buf + hlen);
831	csfailed = in_cksum((u_short *)icp, cc, 0);
832
833	if (icp->type == ICMP_ECHOREPLY) {
834		if (!is_ours(icp->un.echo.id))
835			return 1;			/* 'Twas not our ECHO */
836		if (gather_statistics((__u8*)icp, sizeof(*icp), cc,
837				      ntohs(icp->un.echo.sequence),
838				      ttl, 0, tv, pr_addr(from->sin_addr.s_addr),
839				      pr_echo_reply))
840			return 0;
841	} else {
842		/* We fall here when a redirect or source quench arrived.
843		 * Also this branch processes icmp errors, when IP_RECVERR
844		 * is broken. */
845
846		switch (icp->type) {
847		case ICMP_ECHO:
848			/* MUST NOT */
849			return 1;
850		case ICMP_SOURCE_QUENCH:
851		case ICMP_REDIRECT:
852		case ICMP_DEST_UNREACH:
853		case ICMP_TIME_EXCEEDED:
854		case ICMP_PARAMETERPROB:
855			{
856				struct iphdr * iph = (struct  iphdr *)(&icp[1]);
857				struct icmphdr *icp1 = (struct icmphdr*)((unsigned char *)iph + iph->ihl*4);
858				int error_pkt;
859				if (cc < 8+sizeof(struct iphdr)+8 ||
860				    cc < 8+iph->ihl*4+8)
861					return 1;
862				if (icp1->type != ICMP_ECHO ||
863				    iph->daddr != whereto.sin_addr.s_addr ||
864				    !is_ours(icp1->un.echo.id))
865					return 1;
866				error_pkt = (icp->type != ICMP_REDIRECT &&
867					     icp->type != ICMP_SOURCE_QUENCH);
868				if (error_pkt) {
869					acknowledge(ntohs(icp1->un.echo.sequence));
870					if (working_recverr) {
871						return 0;
872					} else {
873						static int once;
874						/* Sigh, IP_RECVERR for raw socket
875						 * was broken until 2.4.9. So, we ignore
876						 * the first error and warn on the second.
877						 */
878						if (once++ == 1)
879							fprintf(stderr, "\rWARNING: kernel is not very fresh, upgrade is recommended.\n");
880						if (once == 1)
881							return 0;
882					}
883				}
884				nerrors+=error_pkt;
885				if (options&F_QUIET)
886					return !error_pkt;
887				if (options & F_FLOOD) {
888					if (error_pkt)
889						write_stdout("\bE", 2);
890					return !error_pkt;
891				}
892				print_timestamp();
893				printf("From %s: icmp_seq=%u ",
894				       pr_addr(from->sin_addr.s_addr),
895				       ntohs(icp1->un.echo.sequence));
896				if (csfailed)
897					printf("(BAD CHECKSUM)");
898				pr_icmph(icp->type, icp->code, ntohl(icp->un.gateway), icp);
899				return !error_pkt;
900			}
901		default:
902			/* MUST NOT */
903			break;
904		}
905		if ((options & F_FLOOD) && !(options & (F_VERBOSE|F_QUIET))) {
906			if (!csfailed)
907				write_stdout("!E", 2);
908			else
909				write_stdout("!EC", 3);
910			return 0;
911		}
912		if (!(options & F_VERBOSE) || uid)
913			return 0;
914		if (options & F_PTIMEOFDAY) {
915			struct timeval recv_time;
916			gettimeofday(&recv_time, NULL);
917			printf("%lu.%06lu ", (unsigned long)recv_time.tv_sec, (unsigned long)recv_time.tv_usec);
918		}
919		printf("From %s: ", pr_addr(from->sin_addr.s_addr));
920		if (csfailed) {
921			printf("(BAD CHECKSUM)\n");
922			return 0;
923		}
924		pr_icmph(icp->type, icp->code, ntohl(icp->un.gateway), icp);
925		return 0;
926	}
927
928	if (!(options & F_FLOOD)) {
929		pr_options(opts, optlen + sizeof(struct iphdr));
930
931		if (options & F_AUDIBLE)
932			putchar('\a');
933		putchar('\n');
934		fflush(stdout);
935	} else {
936		putchar('\a');
937		fflush(stdout);
938	}
939	return 0;
940}
941
942
943#if BYTE_ORDER == LITTLE_ENDIAN
944# define ODDBYTE(v)	(v)
945#elif BYTE_ORDER == BIG_ENDIAN
946# define ODDBYTE(v)	((u_short)(v) << 8)
947#else
948# define ODDBYTE(v)	htons((u_short)(v) << 8)
949#endif
950
951u_short
952in_cksum(const u_short *addr, register int len, u_short csum)
953{
954	register int nleft = len;
955	const u_short *w = addr;
956	register u_short answer;
957	register int sum = csum;
958
959	/*
960	 *  Our algorithm is simple, using a 32 bit accumulator (sum),
961	 *  we add sequential 16 bit words to it, and at the end, fold
962	 *  back all the carry bits from the top 16 bits into the lower
963	 *  16 bits.
964	 */
965	while (nleft > 1)  {
966		sum += *w++;
967		nleft -= 2;
968	}
969
970	/* mop up an odd byte, if necessary */
971	if (nleft == 1)
972		sum += ODDBYTE(*(u_char *)w); /* le16toh() may be unavailable on old systems */
973
974	/*
975	 * add back carry outs from top 16 bits to low 16 bits
976	 */
977	sum = (sum >> 16) + (sum & 0xffff);	/* add hi 16 to low 16 */
978	sum += (sum >> 16);			/* add carry */
979	answer = ~sum;				/* truncate to 16 bits */
980	return (answer);
981}
982
983/*
984 * pr_icmph --
985 *	Print a descriptive string about an ICMP header.
986 */
987void pr_icmph(__u8 type, __u8 code, __u32 info, struct icmphdr *icp)
988{
989	switch(type) {
990	case ICMP_ECHOREPLY:
991		printf("Echo Reply\n");
992		/* XXX ID + Seq + Data */
993		break;
994	case ICMP_DEST_UNREACH:
995		switch(code) {
996		case ICMP_NET_UNREACH:
997			printf("Destination Net Unreachable\n");
998			break;
999		case ICMP_HOST_UNREACH:
1000			printf("Destination Host Unreachable\n");
1001			break;
1002		case ICMP_PROT_UNREACH:
1003			printf("Destination Protocol Unreachable\n");
1004			break;
1005		case ICMP_PORT_UNREACH:
1006			printf("Destination Port Unreachable\n");
1007			break;
1008		case ICMP_FRAG_NEEDED:
1009			printf("Frag needed and DF set (mtu = %u)\n", info);
1010			break;
1011		case ICMP_SR_FAILED:
1012			printf("Source Route Failed\n");
1013			break;
1014		case ICMP_NET_UNKNOWN:
1015			printf("Destination Net Unknown\n");
1016			break;
1017		case ICMP_HOST_UNKNOWN:
1018			printf("Destination Host Unknown\n");
1019			break;
1020		case ICMP_HOST_ISOLATED:
1021			printf("Source Host Isolated\n");
1022			break;
1023		case ICMP_NET_ANO:
1024			printf("Destination Net Prohibited\n");
1025			break;
1026		case ICMP_HOST_ANO:
1027			printf("Destination Host Prohibited\n");
1028			break;
1029		case ICMP_NET_UNR_TOS:
1030			printf("Destination Net Unreachable for Type of Service\n");
1031			break;
1032		case ICMP_HOST_UNR_TOS:
1033			printf("Destination Host Unreachable for Type of Service\n");
1034			break;
1035		case ICMP_PKT_FILTERED:
1036			printf("Packet filtered\n");
1037			break;
1038		case ICMP_PREC_VIOLATION:
1039			printf("Precedence Violation\n");
1040			break;
1041		case ICMP_PREC_CUTOFF:
1042			printf("Precedence Cutoff\n");
1043			break;
1044		default:
1045			printf("Dest Unreachable, Bad Code: %d\n", code);
1046			break;
1047		}
1048		if (icp && (options & F_VERBOSE))
1049			pr_iph((struct iphdr*)(icp + 1));
1050		break;
1051	case ICMP_SOURCE_QUENCH:
1052		printf("Source Quench\n");
1053		if (icp && (options & F_VERBOSE))
1054			pr_iph((struct iphdr*)(icp + 1));
1055		break;
1056	case ICMP_REDIRECT:
1057		switch(code) {
1058		case ICMP_REDIR_NET:
1059			printf("Redirect Network");
1060			break;
1061		case ICMP_REDIR_HOST:
1062			printf("Redirect Host");
1063			break;
1064		case ICMP_REDIR_NETTOS:
1065			printf("Redirect Type of Service and Network");
1066			break;
1067		case ICMP_REDIR_HOSTTOS:
1068			printf("Redirect Type of Service and Host");
1069			break;
1070		default:
1071			printf("Redirect, Bad Code: %d", code);
1072			break;
1073		}
1074		printf("(New nexthop: %s)\n", pr_addr(icp ? icp->un.gateway : info));
1075		if (icp && (options & F_VERBOSE))
1076			pr_iph((struct iphdr*)(icp + 1));
1077		break;
1078	case ICMP_ECHO:
1079		printf("Echo Request\n");
1080		/* XXX ID + Seq + Data */
1081		break;
1082	case ICMP_TIME_EXCEEDED:
1083		switch(code) {
1084		case ICMP_EXC_TTL:
1085			printf("Time to live exceeded\n");
1086			break;
1087		case ICMP_EXC_FRAGTIME:
1088			printf("Frag reassembly time exceeded\n");
1089			break;
1090		default:
1091			printf("Time exceeded, Bad Code: %d\n", code);
1092			break;
1093		}
1094		if (icp && (options & F_VERBOSE))
1095			pr_iph((struct iphdr*)(icp + 1));
1096		break;
1097	case ICMP_PARAMETERPROB:
1098		printf("Parameter problem: pointer = %u\n", icp ? (ntohl(icp->un.gateway)>>24) : info);
1099		if (icp && (options & F_VERBOSE))
1100			pr_iph((struct iphdr*)(icp + 1));
1101		break;
1102	case ICMP_TIMESTAMP:
1103		printf("Timestamp\n");
1104		/* XXX ID + Seq + 3 timestamps */
1105		break;
1106	case ICMP_TIMESTAMPREPLY:
1107		printf("Timestamp Reply\n");
1108		/* XXX ID + Seq + 3 timestamps */
1109		break;
1110	case ICMP_INFO_REQUEST:
1111		printf("Information Request\n");
1112		/* XXX ID + Seq */
1113		break;
1114	case ICMP_INFO_REPLY:
1115		printf("Information Reply\n");
1116		/* XXX ID + Seq */
1117		break;
1118#ifdef ICMP_MASKREQ
1119	case ICMP_MASKREQ:
1120		printf("Address Mask Request\n");
1121		break;
1122#endif
1123#ifdef ICMP_MASKREPLY
1124	case ICMP_MASKREPLY:
1125		printf("Address Mask Reply\n");
1126		break;
1127#endif
1128	default:
1129		printf("Bad ICMP type: %d\n", type);
1130	}
1131}
1132
1133void pr_options(unsigned char * cp, int hlen)
1134{
1135	int i, j;
1136	int optlen, totlen;
1137	unsigned char * optptr;
1138	static int old_rrlen;
1139	static char old_rr[MAX_IPOPTLEN];
1140
1141	totlen = hlen-sizeof(struct iphdr);
1142	optptr = cp;
1143
1144	while (totlen > 0) {
1145		if (*optptr == IPOPT_EOL)
1146			break;
1147		if (*optptr == IPOPT_NOP) {
1148			totlen--;
1149			optptr++;
1150			printf("\nNOP");
1151			continue;
1152		}
1153		cp = optptr;
1154		optlen = optptr[1];
1155		if (optlen < 2 || optlen > totlen)
1156			break;
1157
1158		switch (*cp) {
1159		case IPOPT_SSRR:
1160		case IPOPT_LSRR:
1161			printf("\n%cSRR: ", *cp==IPOPT_SSRR ? 'S' : 'L');
1162			j = *++cp;
1163			i = *++cp;
1164			i -= 4;
1165			cp++;
1166			if (j > IPOPT_MINOFF) {
1167				for (;;) {
1168					__u32 address;
1169					memcpy(&address, cp, 4);
1170					cp += 4;
1171					if (address == 0)
1172						printf("\t0.0.0.0");
1173					else
1174						printf("\t%s", pr_addr(address));
1175					j -= 4;
1176					putchar('\n');
1177					if (j <= IPOPT_MINOFF)
1178						break;
1179				}
1180			}
1181			break;
1182		case IPOPT_RR:
1183			j = *++cp;		/* get length */
1184			i = *++cp;		/* and pointer */
1185			if (i > j)
1186				i = j;
1187			i -= IPOPT_MINOFF;
1188			if (i <= 0)
1189				break;
1190			if (i == old_rrlen
1191			    && !memcmp(cp, old_rr, i)
1192			    && !(options & F_FLOOD)) {
1193				printf("\t(same route)");
1194				i = ((i + 3) / 4) * 4;
1195				cp += i;
1196				break;
1197			}
1198			old_rrlen = i;
1199			memcpy(old_rr, (char *)cp, i);
1200			printf("\nRR: ");
1201			cp++;
1202			for (;;) {
1203				__u32 address;
1204				memcpy(&address, cp, 4);
1205				cp += 4;
1206				if (address == 0)
1207					printf("\t0.0.0.0");
1208				else
1209					printf("\t%s", pr_addr(address));
1210				i -= 4;
1211				putchar('\n');
1212				if (i <= 0)
1213					break;
1214			}
1215			break;
1216		case IPOPT_TS:
1217		{
1218			int stdtime = 0, nonstdtime = 0;
1219			__u8 flags;
1220			j = *++cp;		/* get length */
1221			i = *++cp;		/* and pointer */
1222			if (i > j)
1223				i = j;
1224			i -= 5;
1225			if (i <= 0)
1226				break;
1227			flags = *++cp;
1228			printf("\nTS: ");
1229			cp++;
1230			for (;;) {
1231				long l;
1232
1233				if ((flags&0xF) != IPOPT_TS_TSONLY) {
1234					__u32 address;
1235					memcpy(&address, cp, 4);
1236					cp += 4;
1237					if (address == 0)
1238						printf("\t0.0.0.0");
1239					else
1240						printf("\t%s", pr_addr(address));
1241					i -= 4;
1242					if (i <= 0)
1243						break;
1244				}
1245				l = *cp++;
1246				l = (l<<8) + *cp++;
1247				l = (l<<8) + *cp++;
1248				l = (l<<8) + *cp++;
1249
1250				if  (l & 0x80000000) {
1251					if (nonstdtime==0)
1252						printf("\t%ld absolute not-standard", l&0x7fffffff);
1253					else
1254						printf("\t%ld not-standard", (l&0x7fffffff) - nonstdtime);
1255					nonstdtime = l&0x7fffffff;
1256				} else {
1257					if (stdtime==0)
1258						printf("\t%ld absolute", l);
1259					else
1260						printf("\t%ld", l - stdtime);
1261					stdtime = l;
1262				}
1263				i -= 4;
1264				putchar('\n');
1265				if (i <= 0)
1266					break;
1267			}
1268			if (flags>>4)
1269				printf("Unrecorded hops: %d\n", flags>>4);
1270			break;
1271		}
1272		default:
1273			printf("\nunknown option %x", *cp);
1274			break;
1275		}
1276		totlen -= optlen;
1277		optptr += optlen;
1278	}
1279}
1280
1281
1282/*
1283 * pr_iph --
1284 *	Print an IP header with options.
1285 */
1286void pr_iph(struct iphdr *ip)
1287{
1288	int hlen;
1289	u_char *cp;
1290
1291	hlen = ip->ihl << 2;
1292	cp = (u_char *)ip + 20;		/* point to options */
1293
1294	printf("Vr HL TOS  Len   ID Flg  off TTL Pro  cks      Src      Dst Data\n");
1295	printf(" %1x  %1x  %02x %04x %04x",
1296	       ip->version, ip->ihl, ip->tos, ip->tot_len, ip->id);
1297	printf("   %1x %04x", ((ip->frag_off) & 0xe000) >> 13,
1298	       (ip->frag_off) & 0x1fff);
1299	printf("  %02x  %02x %04x", ip->ttl, ip->protocol, ip->check);
1300	printf(" %s ", inet_ntoa(*(struct in_addr *)&ip->saddr));
1301	printf(" %s ", inet_ntoa(*(struct in_addr *)&ip->daddr));
1302	printf("\n");
1303	pr_options(cp, hlen);
1304}
1305
1306/*
1307 * pr_addr --
1308 *	Return an ascii host address as a dotted quad and optionally with
1309 * a hostname.
1310 */
1311char *
1312pr_addr(__u32 addr)
1313{
1314	struct hostent *hp;
1315	static char buf[4096];
1316
1317	in_pr_addr = !setjmp(pr_addr_jmp);
1318
1319	if (exiting || (options & F_NUMERIC) ||
1320	    !(hp = gethostbyaddr((char *)&addr, 4, AF_INET)))
1321		sprintf(buf, "%s", inet_ntoa(*(struct in_addr *)&addr));
1322	else {
1323		char *s;
1324#if USE_IDN
1325		if (idna_to_unicode_lzlz(hp->h_name, &s, 0) != IDNA_SUCCESS)
1326			s = NULL;
1327#else
1328		s = NULL;
1329#endif
1330		snprintf(buf, sizeof(buf), "%s (%s)", s ? s : hp->h_name,
1331			 inet_ntoa(*(struct in_addr *)&addr));
1332#if USE_IDN
1333		free(s);
1334#endif
1335	}
1336
1337	in_pr_addr = 0;
1338
1339	return(buf);
1340}
1341
1342
1343/* Set Type of Service (TOS) and other Quality of Service relating bits */
1344int parsetos(char *str)
1345{
1346	const char *cp;
1347	int tos;
1348	char *ep;
1349
1350	/* handle both hex and decimal values */
1351	if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X')) {
1352		cp = str + 2;
1353		tos = (int)strtol(cp, &ep, 16);
1354	} else
1355		tos = (int)strtol(str, &ep, 10);
1356
1357	/* doesn't look like decimal or hex, eh? */
1358	if (*ep != '\0') {
1359		fprintf(stderr, "ping: \"%s\" bad value for TOS\n", str);
1360		exit(2);
1361	}
1362
1363	if (tos > TOS_MAX) {
1364		fprintf(stderr, "ping: the decimal value of TOS bits must be 0-254 (or zero)\n");
1365		exit(2);
1366	}
1367	return(tos);
1368}
1369
1370#include <linux/filter.h>
1371
1372void install_filter(void)
1373{
1374	static int once;
1375	static struct sock_filter insns[] = {
1376		BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0), /* Skip IP header. F..g BSD... Look into ping6. */
1377		BPF_STMT(BPF_LD|BPF_H|BPF_IND, 4), /* Load icmp echo ident */
1378		BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0xAAAA, 0, 1), /* Ours? */
1379		BPF_STMT(BPF_RET|BPF_K, ~0U), /* Yes, it passes. */
1380		BPF_STMT(BPF_LD|BPF_B|BPF_IND, 0), /* Load icmp type */
1381		BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, ICMP_ECHOREPLY, 1, 0), /* Echo? */
1382		BPF_STMT(BPF_RET|BPF_K, 0xFFFFFFF), /* No. It passes. */
1383		BPF_STMT(BPF_RET|BPF_K, 0) /* Echo with wrong ident. Reject. */
1384	};
1385	static struct sock_fprog filter = {
1386		sizeof insns / sizeof(insns[0]),
1387		insns
1388	};
1389
1390	if (once || using_ping_socket)
1391		return;
1392	once = 1;
1393
1394	/* Patch bpflet for current identifier. */
1395	insns[2] = (struct sock_filter)BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, htons(ident), 0, 1);
1396
1397	if (setsockopt(icmp_sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)))
1398		perror("WARNING: failed to install socket filter\n");
1399}
1400
1401#define USAGE_NEWLINE	"\n           "
1402
1403void usage(void)
1404{
1405	fprintf(stderr,
1406		"Usage: ping"
1407		" [-"
1408			"aAbBdDfhLnOqrRUvV"
1409		"]"
1410		" [-c count]"
1411		" [-i interval]"
1412		" [-I interface]"
1413		USAGE_NEWLINE
1414		" [-m mark]"
1415		" [-M pmtudisc_option]"
1416		" [-l preload]"
1417		" [-p pattern]"
1418		" [-Q tos]"
1419		USAGE_NEWLINE
1420		" [-s packetsize]"
1421		" [-S sndbuf]"
1422		" [-t ttl]"
1423		" [-T timestamp_option]"
1424		USAGE_NEWLINE
1425		" [-w deadline]"
1426		" [-W timeout]"
1427		" [hop1 ...] destination"
1428		"\n"
1429	);
1430	exit(2);
1431}
1432