text: /* vi: set sw=4 ts=4: */
  /*
   * Mini ping implementation for busybox
   *
   * Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
   *
   * Adapted from the ping in netkit-base 0.10:
   * Copyright (c) 1989 The Regents of the University of California.
   * All rights reserved.
   *
   * This code is derived from software contributed to Berkeley by
   * Mike Muuss.
   *
   * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   */
  /* from ping6.c:
   * Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
   *
   * This version of ping is adapted from the ping in netkit-base 0.10,
   * which is:
   *
   * Original copyright notice is retained at the end of this file.
   *
   * This version is an adaptation of ping.c from busybox.
   * The code was modified by Bart Visscher <magick@linux-fan.com>
   */
  //config:config PING
  //config:	bool "ping (9.5 kb)"
  //config:	default y
  //config:	select PLATFORM_LINUX
  //config:	help
  //config:	ping uses the ICMP protocol's mandatory ECHO_REQUEST datagram to
  //config:	elicit an ICMP ECHO_RESPONSE from a host or gateway.
  //config:
  //config:config PING6
  //config:	bool "ping6 (10 kb)"
  //config:	default y
  //config:	depends on FEATURE_IPV6
  //config:	help
  //config:	Alias to "ping -6".
  //config:
  //config:config FEATURE_FANCY_PING
  //config:	bool "Enable fancy ping output"
  //config:	default y
  //config:	depends on PING || PING6
  //config:	help
  //config:	With this option off, ping will say "HOST is alive!"
  //config:	or terminate with SIGALRM in 5 seconds otherwise.
  //config:	No command-line options will be recognized.
  
  /* Needs socket(AF_INET, SOCK_RAW, IPPROTO_ICMP), therefore BB_SUID_MAYBE: */
  //applet:IF_PING(APPLET(ping, BB_DIR_BIN, BB_SUID_MAYBE))
  //applet:IF_PING6(APPLET(ping6, BB_DIR_BIN, BB_SUID_MAYBE))
  
  //kbuild:lib-$(CONFIG_PING)  += ping.o
  //kbuild:lib-$(CONFIG_PING6) += ping.o
  
  //usage:#if !ENABLE_FEATURE_FANCY_PING
  //usage:# define ping_trivial_usage
  //usage:       "HOST"
  //usage:# define ping_full_usage "\n\n"
  //usage:       "Send ICMP ECHO_REQUEST packets to network hosts"
  //usage:# define ping6_trivial_usage
  //usage:       "HOST"
  //usage:# define ping6_full_usage "\n\n"
  //usage:       "Send ICMP ECHO_REQUEST packets to network hosts"
  //usage:#else
  //usage:# define ping_trivial_usage
  //usage:       "[OPTIONS] HOST"
  //usage:# define ping_full_usage "\n\n"
  //usage:       "Send ICMP ECHO_REQUEST packets to network hosts\n"
  //usage:	IF_PING6(
  //usage:     "\n	-4,-6		Force IP or IPv6 name resolution"
  //usage:	)
  //usage:     "\n	-c CNT		Send only CNT pings"
  //usage:     "\n	-s SIZE		Send SIZE data bytes in packets (default 56)"
  //usage:     "\n	-t TTL		Set TTL"
  //usage:     "\n	-I IFACE/IP	Source interface or IP address"
  //usage:     "\n	-W SEC		Seconds to wait for the first response (default 10)"
  //usage:     "\n			(after all -c CNT packets are sent)"
  //usage:     "\n	-w SEC		Seconds until ping exits (default:infinite)"
  //usage:     "\n			(can exit earlier with -c CNT)"
  //usage:     "\n	-q		Quiet, only display output at start"
  //usage:     "\n			and when finished"
  //usage:     "\n	-p HEXBYTE	Pattern to use for payload"
  //usage:
  //usage:# define ping6_trivial_usage
  //usage:       "[OPTIONS] HOST"
  //usage:# define ping6_full_usage "\n\n"
  //usage:       "Send ICMP ECHO_REQUEST packets to network hosts\n"
  //usage:     "\n	-c CNT		Send only CNT pings"
  //usage:     "\n	-s SIZE		Send SIZE data bytes in packets (default 56)"
  //usage:     "\n	-I IFACE/IP	Source interface or IP address"
  //usage:     "\n	-q		Quiet, only display output at start"
  //usage:     "\n			and when finished"
  //usage:     "\n	-p HEXBYTE	Pattern to use for payload"
  //usage:
  //usage:#endif
  //usage:
  //usage:#define ping_example_usage
  //usage:       "$ ping localhost\n"
  //usage:       "PING slag (127.0.0.1): 56 data bytes\n"
  //usage:       "64 bytes from 127.0.0.1: icmp_seq=0 ttl=255 time=20.1 ms\n"
  //usage:       "\n"
  //usage:       "--- debian ping statistics ---\n"
  //usage:       "1 packets transmitted, 1 packets received, 0% packet loss\n"
  //usage:       "round-trip min/avg/max = 20.1/20.1/20.1 ms\n"
  //usage:#define ping6_example_usage
  //usage:       "$ ping6 ip6-localhost\n"
  //usage:       "PING ip6-localhost (::1): 56 data bytes\n"
  //usage:       "64 bytes from ::1: icmp6_seq=0 ttl=64 time=20.1 ms\n"
  //usage:       "\n"
  //usage:       "--- ip6-localhost ping statistics ---\n"
  //usage:       "1 packets transmitted, 1 packets received, 0% packet loss\n"
  //usage:       "round-trip min/avg/max = 20.1/20.1/20.1 ms\n"
  
  #include <net/if.h>
  #include <netinet/ip_icmp.h>
  #include "libbb.h"
  #include "common_bufsiz.h"
  
  #ifdef __BIONIC__
  /* should be in netinet/ip_icmp.h */
  # define ICMP_DEST_UNREACH    3  /* Destination Unreachable  */
  # define ICMP_SOURCE_QUENCH   4  /* Source Quench    */
  # define ICMP_REDIRECT        5  /* Redirect (change route)  */
  # define ICMP_ECHO            8  /* Echo Request      */
  # define ICMP_TIME_EXCEEDED  11  /* Time Exceeded    */
  # define ICMP_PARAMETERPROB  12  /* Parameter Problem    */
  # define ICMP_TIMESTAMP      13  /* Timestamp Request    */
  # define ICMP_TIMESTAMPREPLY 14  /* Timestamp Reply    */
  # define ICMP_INFO_REQUEST   15  /* Information Request    */
  # define ICMP_INFO_REPLY     16  /* Information Reply    */
  # define ICMP_ADDRESS        17  /* Address Mask Request    */
  # define ICMP_ADDRESSREPLY   18  /* Address Mask Reply    */
  #endif
  
  /* Some operating systems, like GNU/Hurd, don't define SOL_RAW, but do have
   * IPPROTO_RAW. Since the IPPROTO definitions are also valid to use for
   * setsockopt (and take the same value as their corresponding SOL definitions,
   * if they exist), we can just fall back on IPPROTO_RAW. */
  #ifndef SOL_RAW
  # define SOL_RAW IPPROTO_RAW
  #endif
  
  #if ENABLE_PING6
  # include <netinet/icmp6.h>
  /* I see RENUMBERED constants in bits/in.h - !!?
   * What a fuck is going on with libc? Is it a glibc joke? */
  # ifdef IPV6_2292HOPLIMIT
  #  undef IPV6_HOPLIMIT
  #  define IPV6_HOPLIMIT IPV6_2292HOPLIMIT
  # endif
  #endif
  
  enum {
  	DEFDATALEN = 56,
  	MAXIPLEN = 60,
  	MAXICMPLEN = 76,
  	MAX_DUP_CHK = (8 * 128),
  	MAXWAIT = 10,
  	PINGINTERVAL = 1, /* 1 second */
  	pingsock = 0,
  };
  
  static void
  #if ENABLE_PING6
  create_icmp_socket(len_and_sockaddr *lsa)
  #else
  create_icmp_socket(void)
  #define create_icmp_socket(lsa) create_icmp_socket()
  #endif
  {
  	int sock;
  #if ENABLE_PING6
  	if (lsa->u.sa.sa_family == AF_INET6)
  		sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
  	else
  #endif
  		sock = socket(AF_INET, SOCK_RAW, 1); /* 1 == ICMP */
  	if (sock < 0) {
  		if (errno == EPERM)
  			bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
  		bb_perror_msg_and_die(bb_msg_can_not_create_raw_socket);
  	}
  
  	xmove_fd(sock, pingsock);
  }
  
  #if !ENABLE_FEATURE_FANCY_PING
  
  /* Simple version */
  
  struct globals {
  	char *hostname;
  	char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN];
  	uint16_t myid;
  } FIX_ALIASING;
  #define G (*(struct globals*)bb_common_bufsiz1)
  #define INIT_G() do { setup_common_bufsiz(); } while (0)
  
  static void noresp(int ign UNUSED_PARAM)
  {
  	printf("No response from %s\n", G.hostname);
  	exit(EXIT_FAILURE);
  }
  
  static void ping4(len_and_sockaddr *lsa)
  {
  	struct icmp *pkt;
  	int c;
  
  	pkt = (struct icmp *) G.packet;
  	/*memset(pkt, 0, sizeof(G.packet)); already is */
  	pkt->icmp_type = ICMP_ECHO;
  	pkt->icmp_id = G.myid;
  	pkt->icmp_cksum = inet_cksum((uint16_t *) pkt, sizeof(G.packet));
  
  	xsendto(pingsock, G.packet, DEFDATALEN + ICMP_MINLEN, &lsa->u.sa, lsa->len);
  
  	/* listen for replies */
  	while (1) {
  #if 0
  		struct sockaddr_in from;
  		socklen_t fromlen = sizeof(from);
  
  		c = recvfrom(pingsock, G.packet, sizeof(G.packet), 0,
  				(struct sockaddr *) &from, &fromlen);
  #else
  		c = recv(pingsock, G.packet, sizeof(G.packet), 0);
  #endif
  		if (c < 0) {
  			if (errno != EINTR)
  				bb_perror_msg("recvfrom");
  			continue;
  		}
  		if (c >= 76) {			/* ip + icmp */
  			struct iphdr *iphdr = (struct iphdr *) G.packet;
  
  			pkt = (struct icmp *) (G.packet + (iphdr->ihl << 2));	/* skip ip hdr */
  			if (pkt->icmp_id != G.myid)
  				continue; /* not our ping */
  			if (pkt->icmp_type == ICMP_ECHOREPLY)
  				break;
  		}
  	}
  }
  
  #if ENABLE_PING6
  static void ping6(len_and_sockaddr *lsa)
  {
  	struct icmp6_hdr *pkt;
  	int c;
  	int sockopt;
  
  	pkt = (struct icmp6_hdr *) G.packet;
  	/*memset(pkt, 0, sizeof(G.packet)); already is */
  	pkt->icmp6_type = ICMP6_ECHO_REQUEST;
  	pkt->icmp6_id = G.myid;
  
  	sockopt = offsetof(struct icmp6_hdr, icmp6_cksum);
  	setsockopt_int(pingsock, SOL_RAW, IPV6_CHECKSUM, sockopt);
  
  	xsendto(pingsock, G.packet, DEFDATALEN + sizeof(struct icmp6_hdr), &lsa->u.sa, lsa->len);
  
  	/* listen for replies */
  	while (1) {
  #if 0
  		struct sockaddr_in6 from;
  		socklen_t fromlen = sizeof(from);
  
  		c = recvfrom(pingsock, G.packet, sizeof(G.packet), 0,
  				(struct sockaddr *) &from, &fromlen);
  #else
  		c = recv(pingsock, G.packet, sizeof(G.packet), 0);
  #endif
  		if (c < 0) {
  			if (errno != EINTR)
  				bb_perror_msg("recvfrom");
  			continue;
  		}
  		if (c >= ICMP_MINLEN) {	/* icmp6_hdr */
  			if (pkt->icmp6_id != G.myid)
  				continue; /* not our ping */
  			if (pkt->icmp6_type == ICMP6_ECHO_REPLY)
  				break;
  		}
  	}
  }
  #endif
  
  #if !ENABLE_PING6
  # define common_ping_main(af, argv) common_ping_main(argv)
  #endif
  static int common_ping_main(sa_family_t af, char **argv)
  {
  	len_and_sockaddr *lsa;
  
  	INIT_G();
  
  #if ENABLE_PING6
  	while ((++argv)[0] && argv[0][0] == '-') {
  		if (argv[0][1] == '4') {
  			af = AF_INET;
  			continue;
  		}
  		if (argv[0][1] == '6') {
  			af = AF_INET6;
  			continue;
  		}
  		bb_show_usage();
  	}
  #else
  	argv++;
  #endif
  
  	G.hostname = *argv;
  	if (!G.hostname)
  		bb_show_usage();
  
  #if ENABLE_PING6
  	lsa = xhost_and_af2sockaddr(G.hostname, 0, af);
  #else
  	lsa = xhost_and_af2sockaddr(G.hostname, 0, AF_INET);
  #endif
  	/* Set timer _after_ DNS resolution */
  	signal(SIGALRM, noresp);
  	alarm(5); /* give the host 5000ms to respond */
  
  	create_icmp_socket(lsa);
  	G.myid = (uint16_t) getpid();
  #if ENABLE_PING6
  	if (lsa->u.sa.sa_family == AF_INET6)
  		ping6(lsa);
  	else
  #endif
  		ping4(lsa);
  	if (ENABLE_FEATURE_CLEAN_UP)
  		close(pingsock);
  	printf("%s is alive!\n", G.hostname);
  	return EXIT_SUCCESS;
  }
  
  
  #else /* FEATURE_FANCY_PING */
  
  
  /* Full(er) version */
  
  /* -c NUM, -t NUM, -w NUM, -W NUM */
  #define OPT_STRING "qvc:+s:t:+w:+W:+I:np:4"IF_PING6("6")
  enum {
  	OPT_QUIET = 1 << 0,
  	OPT_VERBOSE = 1 << 1,
  	OPT_c = 1 << 2,
  	OPT_s = 1 << 3,
  	OPT_t = 1 << 4,
  	OPT_w = 1 << 5,
  	OPT_W = 1 << 6,
  	OPT_I = 1 << 7,
  	/*OPT_n = 1 << 8, - ignored */
  	OPT_p = 1 << 9,
  	OPT_IPV4 = 1 << 10,
  	OPT_IPV6 = (1 << 11) * ENABLE_PING6,
  };
  
  
  struct globals {
  	int if_index;
  	char *str_I;
  	len_and_sockaddr *source_lsa;
  	unsigned datalen;
  	unsigned pingcount; /* must be int-sized */
  	unsigned opt_ttl;
  	unsigned long ntransmitted, nreceived, nrepeats;
  	uint16_t myid;
  	uint8_t pattern;
  	unsigned tmin, tmax; /* in us */
  	unsigned long long tsum; /* in us, sum of all times */
  	unsigned deadline;
  	unsigned timeout;
  	unsigned total_secs;
  	unsigned sizeof_rcv_packet;
  	char *rcv_packet; /* [datalen + MAXIPLEN + MAXICMPLEN] */
  	void *snd_packet; /* [datalen + ipv4/ipv6_const] */
  	const char *hostname;
  	const char *dotted;
  	union {
  		struct sockaddr sa;
  		struct sockaddr_in sin;
  #if ENABLE_PING6
  		struct sockaddr_in6 sin6;
  #endif
  	} pingaddr;
  	unsigned char rcvd_tbl[MAX_DUP_CHK / 8];
  } FIX_ALIASING;
  #define G (*(struct globals*)bb_common_bufsiz1)
  #define if_index     (G.if_index    )
  #define source_lsa   (G.source_lsa  )
  #define str_I        (G.str_I       )
  #define datalen      (G.datalen     )
  #define pingcount    (G.pingcount   )
  #define opt_ttl      (G.opt_ttl     )
  #define myid         (G.myid        )
  #define tmin         (G.tmin        )
  #define tmax         (G.tmax        )
  #define tsum         (G.tsum        )
  #define deadline     (G.deadline    )
  #define timeout      (G.timeout     )
  #define total_secs   (G.total_secs  )
  #define hostname     (G.hostname    )
  #define dotted       (G.dotted      )
  #define pingaddr     (G.pingaddr    )
  #define rcvd_tbl     (G.rcvd_tbl    )
  #define INIT_G() do { \
  	setup_common_bufsiz(); \
  	BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
  	datalen = DEFDATALEN; \
  	timeout = MAXWAIT; \
  	tmin = UINT_MAX; \
  } while (0)
  
  
  #define BYTE(bit)	rcvd_tbl[(bit)>>3]
  #define MASK(bit)	(1 << ((bit) & 7))
  #define SET(bit)	(BYTE(bit) |= MASK(bit))
  #define CLR(bit)	(BYTE(bit) &= (~MASK(bit)))
  #define TST(bit)	(BYTE(bit) & MASK(bit))
  
  static void print_stats_and_exit(int junk) NORETURN;
  static void print_stats_and_exit(int junk UNUSED_PARAM)
  {
  	unsigned long ul;
  	unsigned long nrecv;
  
  	signal(SIGINT, SIG_IGN);
  
  	nrecv = G.nreceived;
  	printf("\n--- %s ping statistics ---\n"
  		"%lu packets transmitted, "
  		"%lu packets received, ",
  		hostname, G.ntransmitted, nrecv
  	);
  	if (G.nrepeats)
  		printf("%lu duplicates, ", G.nrepeats);
  	ul = G.ntransmitted;
  	if (ul != 0)
  		ul = (ul - nrecv) * 100 / ul;
  	printf("%lu%% packet loss\n", ul);
  	if (tmin != UINT_MAX) {
  		unsigned tavg = tsum / (nrecv + G.nrepeats);
  		printf("round-trip min/avg/max = %u.%03u/%u.%03u/%u.%03u ms\n",
  			tmin / 1000, tmin % 1000,
  			tavg / 1000, tavg % 1000,
  			tmax / 1000, tmax % 1000);
  	}
  	/* if condition is true, exit with 1 -- 'failure' */
  	exit(nrecv == 0 || (deadline && nrecv < pingcount));
  }
  
  static void sendping_tail(void (*sp)(int), int size_pkt)
  {
  	int sz;
  
  	CLR((uint16_t)G.ntransmitted % MAX_DUP_CHK);
  	G.ntransmitted++;
  
  	size_pkt += datalen;
  
  	/* sizeof(pingaddr) can be larger than real sa size, but I think
  	 * it doesn't matter */
  	sz = xsendto(pingsock, G.snd_packet, size_pkt, &pingaddr.sa, sizeof(pingaddr));
  	if (sz != size_pkt)
  		bb_error_msg_and_die(bb_msg_write_error);
  
  	if (pingcount == 0 || deadline || G.ntransmitted < pingcount) {
  		/* Didn't send all pings yet - schedule next in 1s */
  		signal(SIGALRM, sp);
  		if (deadline) {
  			total_secs += PINGINTERVAL;
  			if (total_secs >= deadline)
  				signal(SIGALRM, print_stats_and_exit);
  		}
  		alarm(PINGINTERVAL);
  	} else { /* -c NN, and all NN are sent (and no deadline) */
  		/* Wait for the last ping to come back.
  		 * -W timeout: wait for a response in seconds.
  		 * Affects only timeout in absence of any responses,
  		 * otherwise ping waits for two RTTs. */
  		unsigned expire = timeout;
  
  		if (G.nreceived) {
  			/* approx. 2*tmax, in seconds (2 RTT) */
  			expire = tmax / (512*1024);
  			if (expire == 0)
  				expire = 1;
  		}
  		signal(SIGALRM, print_stats_and_exit);
  		alarm(expire);
  	}
  }
  
  static void sendping4(int junk UNUSED_PARAM)
  {
  	struct icmp *pkt = G.snd_packet;
  
  	memset(pkt, G.pattern, datalen + ICMP_MINLEN + 4);
  	pkt->icmp_type = ICMP_ECHO;
  	/*pkt->icmp_code = 0;*/
  	pkt->icmp_cksum = 0; /* cksum is calculated with this field set to 0 */
  	pkt->icmp_seq = htons(G.ntransmitted); /* don't ++ here, it can be a macro */
  	pkt->icmp_id = myid;
  
  	/* If datalen < 4, we store timestamp _past_ the packet,
  	 * but it's ok - we allocated 4 extra bytes in xzalloc() just in case.
  	 */
  	/*if (datalen >= 4)*/
  		/* No hton: we'll read it back on the same machine */
  		*(uint32_t*)&pkt->icmp_dun = monotonic_us();
  
  	pkt->icmp_cksum = inet_cksum((uint16_t *) pkt, datalen + ICMP_MINLEN);
  
  	sendping_tail(sendping4, ICMP_MINLEN);
  }
  #if ENABLE_PING6
  static void sendping6(int junk UNUSED_PARAM)
  {
  	struct icmp6_hdr *pkt = G.snd_packet;
  
  	memset(pkt, G.pattern, datalen + sizeof(struct icmp6_hdr) + 4);
  	pkt->icmp6_type = ICMP6_ECHO_REQUEST;
  	/*pkt->icmp6_code = 0;*/
  	/*pkt->icmp6_cksum = 0;*/
  	pkt->icmp6_seq = htons(G.ntransmitted); /* don't ++ here, it can be a macro */
  	pkt->icmp6_id = myid;
  
  	/*if (datalen >= 4)*/
  		*(bb__aliased_uint32_t*)(&pkt->icmp6_data8[4]) = monotonic_us();
  
  	//TODO? pkt->icmp_cksum = inet_cksum(...);
  
  	sendping_tail(sendping6, sizeof(struct icmp6_hdr));
  }
  #endif
  
  static const char *icmp_type_name(int id)
  {
  	switch (id) {
  	case ICMP_ECHOREPLY:      return "Echo Reply";
  	case ICMP_DEST_UNREACH:   return "Destination Unreachable";
  	case ICMP_SOURCE_QUENCH:  return "Source Quench";
  	case ICMP_REDIRECT:       return "Redirect (change route)";
  	case ICMP_ECHO:           return "Echo Request";
  	case ICMP_TIME_EXCEEDED:  return "Time Exceeded";
  	case ICMP_PARAMETERPROB:  return "Parameter Problem";
  	case ICMP_TIMESTAMP:      return "Timestamp Request";
  	case ICMP_TIMESTAMPREPLY: return "Timestamp Reply";
  	case ICMP_INFO_REQUEST:   return "Information Request";
  	case ICMP_INFO_REPLY:     return "Information Reply";
  	case ICMP_ADDRESS:        return "Address Mask Request";
  	case ICMP_ADDRESSREPLY:   return "Address Mask Reply";
  	default:                  return "unknown ICMP type";
  	}
  }
  #if ENABLE_PING6
  /* RFC3542 changed some definitions from RFC2292 for no good reason, whee!
   * the newer 3542 uses a MLD_ prefix where as 2292 uses ICMP6_ prefix */
  #ifndef MLD_LISTENER_QUERY
  # define MLD_LISTENER_QUERY ICMP6_MEMBERSHIP_QUERY
  #endif
  #ifndef MLD_LISTENER_REPORT
  # define MLD_LISTENER_REPORT ICMP6_MEMBERSHIP_REPORT
  #endif
  #ifndef MLD_LISTENER_REDUCTION
  # define MLD_LISTENER_REDUCTION ICMP6_MEMBERSHIP_REDUCTION
  #endif
  static const char *icmp6_type_name(int id)
  {
  	switch (id) {
  	case ICMP6_DST_UNREACH:      return "Destination Unreachable";
  	case ICMP6_PACKET_TOO_BIG:   return "Packet too big";
  	case ICMP6_TIME_EXCEEDED:    return "Time Exceeded";
  	case ICMP6_PARAM_PROB:       return "Parameter Problem";
  	case ICMP6_ECHO_REPLY:       return "Echo Reply";
  	case ICMP6_ECHO_REQUEST:     return "Echo Request";
  	case MLD_LISTENER_QUERY:     return "Listener Query";
  	case MLD_LISTENER_REPORT:    return "Listener Report";
  	case MLD_LISTENER_REDUCTION: return "Listener Reduction";
  	default:                     return "unknown ICMP type";
  	}
  }
  #endif
  
  static void unpack_tail(int sz, uint32_t *tp,
  		const char *from_str,
  		uint16_t recv_seq, int ttl)
  {
  	unsigned char *b, m;
  	const char *dupmsg = " (DUP!)";
  	unsigned triptime = triptime; /* for gcc */
  
  	if (tp) {
  		/* (int32_t) cast is for hypothetical 64-bit unsigned */
  		/* (doesn't hurt 32-bit real-world anyway) */
  		triptime = (int32_t) ((uint32_t)monotonic_us() - *tp);
  		tsum += triptime;
  		if (triptime < tmin)
  			tmin = triptime;
  		if (triptime > tmax)
  			tmax = triptime;
  	}
  
  	b = &BYTE(recv_seq % MAX_DUP_CHK);
  	m = MASK(recv_seq % MAX_DUP_CHK);
  	/*if TST(recv_seq % MAX_DUP_CHK):*/
  	if (*b & m) {
  		++G.nrepeats;
  	} else {
  		/*SET(recv_seq % MAX_DUP_CHK):*/
  		*b |= m;
  		++G.nreceived;
  		dupmsg += 7;
  	}
  
  	if (option_mask32 & OPT_QUIET)
  		return;
  
  	printf("%d bytes from %s: seq=%u ttl=%d", sz,
  		from_str, recv_seq, ttl);
  	if (tp)
  		printf(" time=%u.%03u ms", triptime / 1000, triptime % 1000);
  	puts(dupmsg);
  	fflush_all();
  }
  static void unpack4(char *buf, int sz, struct sockaddr_in *from)
  {
  	struct icmp *icmppkt;
  	struct iphdr *iphdr;
  	int hlen;
  
  	/* discard if too short */
  	if (sz < (datalen + ICMP_MINLEN))
  		return;
  
  	/* check IP header */
  	iphdr = (struct iphdr *) buf;
  	hlen = iphdr->ihl << 2;
  	sz -= hlen;
  	icmppkt = (struct icmp *) (buf + hlen);
  	if (icmppkt->icmp_id != myid)
  		return;				/* not our ping */
  
  	if (icmppkt->icmp_type == ICMP_ECHOREPLY) {
  		uint16_t recv_seq = ntohs(icmppkt->icmp_seq);
  		uint32_t *tp = NULL;
  
  		if (sz >= ICMP_MINLEN + sizeof(uint32_t))
  			tp = (uint32_t *) icmppkt->icmp_data;
  		unpack_tail(sz, tp,
  			inet_ntoa(*(struct in_addr *) &from->sin_addr.s_addr),
  			recv_seq, iphdr->ttl);
  	} else if (icmppkt->icmp_type != ICMP_ECHO) {
  		bb_error_msg("warning: got ICMP %d (%s)",
  				icmppkt->icmp_type,
  				icmp_type_name(icmppkt->icmp_type));
  	}
  }
  #if ENABLE_PING6
  static void unpack6(char *packet, int sz, struct sockaddr_in6 *from, int hoplimit)
  {
  	struct icmp6_hdr *icmppkt;
  	char buf[INET6_ADDRSTRLEN];
  
  	/* discard if too short */
  	if (sz < (datalen + sizeof(struct icmp6_hdr)))
  		return;
  
  	icmppkt = (struct icmp6_hdr *) packet;
  	if (icmppkt->icmp6_id != myid)
  		return;				/* not our ping */
  
  	if (icmppkt->icmp6_type == ICMP6_ECHO_REPLY) {
  		uint16_t recv_seq = ntohs(icmppkt->icmp6_seq);
  		uint32_t *tp = NULL;
  
  		if (sz >= sizeof(struct icmp6_hdr) + sizeof(uint32_t))
  			tp = (uint32_t *) &icmppkt->icmp6_data8[4];
  		unpack_tail(sz, tp,
  			inet_ntop(AF_INET6, &from->sin6_addr,
  					buf, sizeof(buf)),
  			recv_seq, hoplimit);
  	} else if (icmppkt->icmp6_type != ICMP6_ECHO_REQUEST) {
  		bb_error_msg("warning: got ICMP %d (%s)",
  				icmppkt->icmp6_type,
  				icmp6_type_name(icmppkt->icmp6_type));
  	}
  }
  #endif
  
  static void ping4(len_and_sockaddr *lsa)
  {
  	int sockopt;
  
  	pingaddr.sin = lsa->u.sin;
  	if (source_lsa) {
  		if (setsockopt(pingsock, IPPROTO_IP, IP_MULTICAST_IF,
  				&source_lsa->u.sa, source_lsa->len))
  			bb_error_msg_and_die("can't set multicast source interface");
  		xbind(pingsock, &source_lsa->u.sa, source_lsa->len);
  	}
  
  	/* enable broadcast pings */
  	setsockopt_broadcast(pingsock);
  
  	/* set recv buf (needed if we can get lots of responses: flood ping,
  	 * broadcast ping etc) */
  	sockopt = (datalen * 2) + 7 * 1024; /* giving it a bit of extra room */
  	setsockopt_SOL_SOCKET_int(pingsock, SO_RCVBUF, sockopt);
  
  	if (opt_ttl != 0) {
  		setsockopt_int(pingsock, IPPROTO_IP, IP_TTL, opt_ttl);
  		/* above doesn't affect packets sent to bcast IP, so... */
  		setsockopt_int(pingsock, IPPROTO_IP, IP_MULTICAST_TTL, opt_ttl);
  	}
  
  	signal(SIGINT, print_stats_and_exit);
  
  	/* start the ping's going ... */
  	sendping4(0);
  
  	/* listen for replies */
  	while (1) {
  		struct sockaddr_in from;
  		socklen_t fromlen = (socklen_t) sizeof(from);
  		int c;
  
  		c = recvfrom(pingsock, G.rcv_packet, G.sizeof_rcv_packet, 0,
  				(struct sockaddr *) &from, &fromlen);
  		if (c < 0) {
  			if (errno != EINTR)
  				bb_perror_msg("recvfrom");
  			continue;
  		}
  		unpack4(G.rcv_packet, c, &from);
  		if (pingcount && G.nreceived >= pingcount)
  			break;
  	}
  }
  #if ENABLE_PING6
  static void ping6(len_and_sockaddr *lsa)
  {
  	int sockopt;
  	struct msghdr msg;
  	struct sockaddr_in6 from;
  	struct iovec iov;
  	char control_buf[CMSG_SPACE(36)];
  
  	pingaddr.sin6 = lsa->u.sin6;
  	if (source_lsa)
  		xbind(pingsock, &source_lsa->u.sa, source_lsa->len);
  
  #ifdef ICMP6_FILTER
  	{
  		struct icmp6_filter filt;
  		if (!(option_mask32 & OPT_VERBOSE)) {
  			ICMP6_FILTER_SETBLOCKALL(&filt);
  			ICMP6_FILTER_SETPASS(ICMP6_ECHO_REPLY, &filt);
  		} else {
  			ICMP6_FILTER_SETPASSALL(&filt);
  		}
  		if (setsockopt(pingsock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
  					sizeof(filt)) < 0)
  			bb_error_msg_and_die("setsockopt(%s)", "ICMP6_FILTER");
  	}
  #endif /*ICMP6_FILTER*/
  
  	/* enable broadcast pings */
  	setsockopt_broadcast(pingsock);
  
  	/* set recv buf (needed if we can get lots of responses: flood ping,
  	 * broadcast ping etc) */
  	sockopt = (datalen * 2) + 7 * 1024; /* giving it a bit of extra room */
  	setsockopt_SOL_SOCKET_int(pingsock, SO_RCVBUF, sockopt);
  
  	sockopt = offsetof(struct icmp6_hdr, icmp6_cksum);
  	BUILD_BUG_ON(offsetof(struct icmp6_hdr, icmp6_cksum) != 2);
  	setsockopt_int(pingsock, SOL_RAW, IPV6_CHECKSUM, sockopt);
  
  	/* request ttl info to be returned in ancillary data */
  	setsockopt_1(pingsock, SOL_IPV6, IPV6_HOPLIMIT);
  
  	if (if_index)
  		pingaddr.sin6.sin6_scope_id = if_index;
  
  	signal(SIGINT, print_stats_and_exit);
  
  	/* start the ping's going ... */
  	sendping6(0);
  
  	/* listen for replies */
  	msg.msg_name = &from;
  	msg.msg_namelen = sizeof(from);
  	msg.msg_iov = &iov;
  	msg.msg_iovlen = 1;
  	msg.msg_control = control_buf;
  	iov.iov_base = G.rcv_packet;
  	iov.iov_len = G.sizeof_rcv_packet;
  	while (1) {
  		int c;
  		struct cmsghdr *mp;
  		int hoplimit = -1;
  		msg.msg_controllen = sizeof(control_buf);
  
  		c = recvmsg(pingsock, &msg, 0);
  		if (c < 0) {
  			if (errno != EINTR)
  				bb_perror_msg("recvfrom");
  			continue;
  		}
  		for (mp = CMSG_FIRSTHDR(&msg); mp; mp = CMSG_NXTHDR(&msg, mp)) {
  			if (mp->cmsg_level == SOL_IPV6
  			 && mp->cmsg_type == IPV6_HOPLIMIT
  			 /* don't check len - we trust the kernel: */
  			 /* && mp->cmsg_len >= CMSG_LEN(sizeof(int)) */
  			) {
  				/*hoplimit = *(int*)CMSG_DATA(mp); - unaligned access */
  				move_from_unaligned_int(hoplimit, CMSG_DATA(mp));
  			}
  		}
  		unpack6(G.rcv_packet, c, &from, hoplimit);
  		if (pingcount && G.nreceived >= pingcount)
  			break;
  	}
  }
  #endif
  
  static void ping(len_and_sockaddr *lsa)
  {
  	printf("PING %s (%s)", hostname, dotted);
  	if (source_lsa) {
  		printf(" from %s",
  			xmalloc_sockaddr2dotted_noport(&source_lsa->u.sa));
  	}
  	printf(": %d data bytes\n", datalen);
  
  	create_icmp_socket(lsa);
  	/* untested whether "-I addr" really works for IPv6: */
  	if (str_I)
  		setsockopt_bindtodevice(pingsock, str_I);
  
  	G.sizeof_rcv_packet = datalen + MAXIPLEN + MAXICMPLEN;
  	G.rcv_packet = xzalloc(G.sizeof_rcv_packet);
  #if ENABLE_PING6
  	if (lsa->u.sa.sa_family == AF_INET6) {
  		/* +4 reserves a place for timestamp, which may end up sitting
  		 * _after_ packet. Saves one if() - see sendping4/6() */
  		G.snd_packet = xzalloc(datalen + sizeof(struct icmp6_hdr) + 4);
  		ping6(lsa);
  	} else
  #endif
  	{
  		G.snd_packet = xzalloc(datalen + ICMP_MINLEN + 4);
  		ping4(lsa);
  	}
  }
  
  static int common_ping_main(int opt, char **argv)
  {
  	len_and_sockaddr *lsa;
  	char *str_s, *str_p;
  
  	INIT_G();
  
  	opt |= getopt32(argv, "^"
  			OPT_STRING
  			/* exactly one arg; -v and -q don't mix */
  			"\0" "=1:q--v:v--q",
  			&pingcount, &str_s, &opt_ttl, &deadline, &timeout, &str_I, &str_p
  	);
  	if (opt & OPT_s)
  		datalen = xatou16(str_s); // -s
  	if (opt & OPT_I) { // -I
  		if_index = if_nametoindex(str_I);
  		if (!if_index) {
  			/* TODO: I'm not sure it takes IPv6 unless in [XX:XX..] format */
  			source_lsa = xdotted2sockaddr(str_I, 0);
  			str_I = NULL; /* don't try to bind to device later */
  		}
  	}
  	if (opt & OPT_p)
  		G.pattern = xstrtou_range(str_p, 16, 0, 255);
  
  	myid = (uint16_t) getpid();
  	hostname = argv[optind];
  #if ENABLE_PING6
  	{
  		sa_family_t af = AF_UNSPEC;
  		if (opt & OPT_IPV4)
  			af = AF_INET;
  		if (opt & OPT_IPV6)
  			af = AF_INET6;
  		lsa = xhost_and_af2sockaddr(hostname, 0, af);
  	}
  #else
  	lsa = xhost_and_af2sockaddr(hostname, 0, AF_INET);
  #endif
  
  	if (source_lsa && source_lsa->u.sa.sa_family != lsa->u.sa.sa_family)
  		/* leaking it here... */
  		source_lsa = NULL;
  
  	dotted = xmalloc_sockaddr2dotted_noport(&lsa->u.sa);
  	ping(lsa);
  	print_stats_and_exit(EXIT_SUCCESS);
  	/*return EXIT_SUCCESS;*/
  }
  #endif /* FEATURE_FANCY_PING */
  
  
  #if ENABLE_PING
  int ping_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  int ping_main(int argc UNUSED_PARAM, char **argv)
  {
  # if !ENABLE_FEATURE_FANCY_PING
  	return common_ping_main(AF_UNSPEC, argv);
  # else
  	return common_ping_main(0, argv);
  # endif
  }
  #endif
  
  #if ENABLE_PING6
  int ping6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  int ping6_main(int argc UNUSED_PARAM, char **argv)
  {
  # if !ENABLE_FEATURE_FANCY_PING
  	return common_ping_main(AF_INET6, argv);
  # else
  	return common_ping_main(OPT_IPV6, argv);
  # endif
  }
  #endif
  
  /* from ping6.c:
   * Copyright (c) 1989 The Regents of the University of California.
   * All rights reserved.
   *
   * This code is derived from software contributed to Berkeley by
   * Mike Muuss.
   *
   * 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. <BSD Advertising Clause omitted per the July 22, 1999 licensing change
   *		ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change>
   *
   * 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.
   */
  