/* 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 tarball for details.
 */
/* 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>
 */

#include <net/if.h>
#include <netinet/ip_icmp.h>
#include "libbb.h"

#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,
        MAXPACKET = 65468,
        MAX_DUP_CHK = (8 * 128),
        MAXWAIT = 10,
        PINGINTERVAL = 1, /* 1 second */
};

/* common routines */

static int in_cksum(unsigned short *buf, int sz)
{
        int nleft = sz;
        int sum = 0;
        unsigned short *w = buf;
        unsigned short ans = 0;

        while (nleft > 1) {
                sum += *w++;
                nleft -= 2;
        }

        if (nleft == 1) {
                *(unsigned char *) (&ans) = *(unsigned char *) w;
                sum += ans;
        }

        sum = (sum >> 16) + (sum & 0xFFFF);
        sum += (sum >> 16);
        ans = ~sum;
        return ans;
}

#if !ENABLE_FEATURE_FANCY_PING

/* simple version */

static char *hostname;

static void noresp(int ign UNUSED_PARAM)
{
        printf("No response from %s\n", hostname);
        exit(EXIT_FAILURE);
}

static void ping4(len_and_sockaddr *lsa)
{
        struct sockaddr_in pingaddr;
        struct icmp *pkt;
        int pingsock, c;
        char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN];

        pingsock = create_icmp_socket();
        pingaddr = lsa->u.sin;

        pkt = (struct icmp *) packet;
        memset(pkt, 0, sizeof(packet));
        pkt->icmp_type = ICMP_ECHO;
        pkt->icmp_cksum = in_cksum((unsigned short *) pkt, sizeof(packet));

        c = xsendto(pingsock, packet, DEFDATALEN + ICMP_MINLEN,
                           (struct sockaddr *) &pingaddr, sizeof(pingaddr));

        /* listen for replies */
        while (1) {
                struct sockaddr_in from;
                socklen_t fromlen = sizeof(from);

                c = recvfrom(pingsock, packet, sizeof(packet), 0,
                                (struct sockaddr *) &from, &fromlen);
                if (c < 0) {
                        if (errno != EINTR)
                                bb_perror_msg("recvfrom");
                        continue;
                }
                if (c >= 76) {                  /* ip + icmp */
                        struct iphdr *iphdr = (struct iphdr *) packet;

                        pkt = (struct icmp *) (packet + (iphdr->ihl << 2));     /* skip ip hdr */
                        if (pkt->icmp_type == ICMP_ECHOREPLY)
                                break;
                }
        }
        if (ENABLE_FEATURE_CLEAN_UP)
                close(pingsock);
}

#if ENABLE_PING6
static void ping6(len_and_sockaddr *lsa)
{
        struct sockaddr_in6 pingaddr;
        struct icmp6_hdr *pkt;
        int pingsock, c;
        int sockopt;
        char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN];

        pingsock = create_icmp6_socket();
        pingaddr = lsa->u.sin6;

        pkt = (struct icmp6_hdr *) packet;
        memset(pkt, 0, sizeof(packet));
        pkt->icmp6_type = ICMP6_ECHO_REQUEST;

        sockopt = offsetof(struct icmp6_hdr, icmp6_cksum);
        setsockopt(pingsock, SOL_RAW, IPV6_CHECKSUM, &sockopt, sizeof(sockopt));

        c = xsendto(pingsock, packet, DEFDATALEN + sizeof (struct icmp6_hdr),
                           (struct sockaddr *) &pingaddr, sizeof(pingaddr));

        /* listen for replies */
        while (1) {
                struct sockaddr_in6 from;
                socklen_t fromlen = sizeof(from);

                c = recvfrom(pingsock, packet, sizeof(packet), 0,
                                (struct sockaddr *) &from, &fromlen);
                if (c < 0) {
                        if (errno != EINTR)
                                bb_perror_msg("recvfrom");
                        continue;
                }
                if (c >= 8) {                   /* icmp6_hdr */
                        pkt = (struct icmp6_hdr *) packet;
                        if (pkt->icmp6_type == ICMP6_ECHO_REPLY)
                                break;
                }
        }
        if (ENABLE_FEATURE_CLEAN_UP)
                close(pingsock);
}
#endif

int ping_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ping_main(int argc UNUSED_PARAM, char **argv)
{
        len_and_sockaddr *lsa;
#if ENABLE_PING6
        sa_family_t af = AF_UNSPEC;

        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

        hostname = *argv;
        if (!hostname)
                bb_show_usage();

#if ENABLE_PING6
        lsa = xhost_and_af2sockaddr(hostname, 0, af);
#else
        lsa = xhost_and_af2sockaddr(hostname, 0, AF_INET);
#endif
        /* Set timer _after_ DNS resolution */
        signal(SIGALRM, noresp);
        alarm(5); /* give the host 5000ms to respond */

#if ENABLE_PING6
        if (lsa->u.sa.sa_family == AF_INET6)
                ping6(lsa);
        else
#endif
                ping4(lsa);
        printf("%s is alive!\n", hostname);
        return EXIT_SUCCESS;
}


#else /* FEATURE_FANCY_PING */


/* full(er) version */

#define OPT_STRING ("qvc:s:w:W:I:4" IF_PING6("6"))
enum {
        OPT_QUIET = 1 << 0,
        OPT_VERBOSE = 1 << 1,
        OPT_c = 1 << 2,
        OPT_s = 1 << 3,
        OPT_w = 1 << 4,
        OPT_W = 1 << 5,
        OPT_I = 1 << 6,
        OPT_IPV4 = 1 << 7,
        OPT_IPV6 = (1 << 8) * ENABLE_PING6,
};


struct globals {
        int pingsock;
        int if_index;
        char *str_I;
        len_and_sockaddr *source_lsa;
        unsigned datalen;
        unsigned pingcount; /* must be int-sized */
        unsigned long ntransmitted, nreceived, nrepeats;
        uint16_t myid;
        unsigned tmin, tmax; /* in us */
        unsigned long long tsum; /* in us, sum of all times */
        unsigned deadline;
        unsigned timeout;
        unsigned total_secs;
        const char *hostname;
        const char *dotted;
        union {
                struct sockaddr sa;
                struct sockaddr_in sin;
#if ENABLE_PING6
                struct sockaddr_in6 sin6;
#endif
        } pingaddr;
        char rcvd_tbl[MAX_DUP_CHK / 8];
};
#define G (*(struct globals*)&bb_common_bufsiz1)
#define pingsock     (G.pingsock    )
#define if_index     (G.if_index    )
#define source_lsa   (G.source_lsa  )
#define str_I        (G.str_I       )
#define datalen      (G.datalen     )
#define ntransmitted (G.ntransmitted)
#define nreceived    (G.nreceived   )
#define nrepeats     (G.nrepeats    )
#define pingcount    (G.pingcount   )
#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    )
void BUG_ping_globals_too_big(void);
#define INIT_G() do { \
        if (sizeof(G) > COMMON_BUFSIZE) \
                BUG_ping_globals_too_big(); \
        pingsock = -1; \
        datalen = DEFDATALEN; \
        timeout = MAXWAIT; \
        tmin = UINT_MAX; \
} while (0)


#define A(bit)          rcvd_tbl[(bit)>>3]      /* identify byte in array */
#define B(bit)          (1 << ((bit) & 0x07))   /* identify bit in byte */
#define SET(bit)        (A(bit) |= B(bit))
#define CLR(bit)        (A(bit) &= (~B(bit)))
#define TST(bit)        (A(bit) & B(bit))

/**************************************************************************/

static void print_stats_and_exit(int junk) NORETURN;
static void print_stats_and_exit(int junk UNUSED_PARAM)
{
        signal(SIGINT, SIG_IGN);

        printf("\n--- %s ping statistics ---\n", hostname);
        printf("%lu packets transmitted, ", ntransmitted);
        printf("%lu packets received, ", nreceived);
        if (nrepeats)
                printf("%lu duplicates, ", nrepeats);
        if (ntransmitted)
                ntransmitted = (ntransmitted - nreceived) * 100 / ntransmitted;
        printf("%lu%% packet loss\n", ntransmitted);
        if (tmin != UINT_MAX) {
                unsigned tavg = tsum / (nreceived + 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(nreceived == 0 || (deadline && nreceived < pingcount));
}

static void sendping_tail(void (*sp)(int), const void *pkt, int size_pkt)
{
        int sz;

        CLR((uint16_t)ntransmitted % MAX_DUP_CHK);
        ntransmitted++;

        /* sizeof(pingaddr) can be larger than real sa size, but I think
         * it doesn't matter */
        sz = xsendto(pingsock, pkt, size_pkt, &pingaddr.sa, sizeof(pingaddr));
        if (sz != size_pkt)
                bb_error_msg_and_die(bb_msg_write_error);

        if (pingcount == 0 || deadline || 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 absense of any responses,
                 * otherwise ping waits for two RTTs. */
                unsigned expire = timeout;

                if (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)
{
        /* +4 reserves a place for timestamp, which may end up sitting
         * *after* packet. Saves one if() */
        struct icmp *pkt = alloca(datalen + ICMP_MINLEN + 4);

        memset(pkt, 0, datalen + ICMP_MINLEN + 4);
        pkt->icmp_type = ICMP_ECHO;
        /*pkt->icmp_code = 0;*/
        /*pkt->icmp_cksum = 0;*/
        pkt->icmp_seq = htons(ntransmitted); /* don't ++ here, it can be a macro */
        pkt->icmp_id = myid;

        /* We don't do hton, because we will read it back on the same machine */
        /*if (datalen >= 4)*/
                *(uint32_t*)&pkt->icmp_dun = monotonic_us();

        pkt->icmp_cksum = in_cksum((unsigned short *) pkt, datalen + ICMP_MINLEN);

        sendping_tail(sendping4, pkt, datalen + ICMP_MINLEN);
}
#if ENABLE_PING6
static void sendping6(int junk UNUSED_PARAM)
{
        struct icmp6_hdr *pkt = alloca(datalen + sizeof(struct icmp6_hdr) + 4);

        memset(pkt, 0, datalen + sizeof(struct icmp6_hdr) + 4);
        pkt->icmp6_type = ICMP6_ECHO_REQUEST;
        /*pkt->icmp6_code = 0;*/
        /*pkt->icmp6_cksum = 0;*/
        pkt->icmp6_seq = htons(ntransmitted); /* don't ++ here, it can be a macro */
        pkt->icmp6_id = myid;

        /*if (datalen >= 4)*/
                *(uint32_t*)(&pkt->icmp6_data8[4]) = monotonic_us();

        sendping_tail(sendping6, pkt, datalen + 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)
{
        const char *dupmsg = " (DUP!)";
        unsigned triptime = triptime; /* for gcc */

        ++nreceived;

        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;
        }

        if (TST(recv_seq % MAX_DUP_CHK)) {
                ++nrepeats;
                --nreceived;
        } else {
                SET(recv_seq % MAX_DUP_CHK);
                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(stdout);
}
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, &pingaddr.sin6.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)
{
        char packet[datalen + MAXIPLEN + MAXICMPLEN];
        int sockopt;

        pingsock = create_icmp_socket();
        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);
        }
        if (str_I)
                setsockopt_bindtodevice(pingsock, str_I);

        /* 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(pingsock, SOL_SOCKET, SO_RCVBUF, &sockopt, sizeof(sockopt));

        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, packet, sizeof(packet), 0,
                                (struct sockaddr *) &from, &fromlen);
                if (c < 0) {
                        if (errno != EINTR)
                                bb_perror_msg("recvfrom");
                        continue;
                }
                unpack4(packet, c, &from);
                if (pingcount && nreceived >= pingcount)
                        break;
        }
}
#if ENABLE_PING6
extern int BUG_bad_offsetof_icmp6_cksum(void);
static void ping6(len_and_sockaddr *lsa)
{
        char packet[datalen + MAXIPLEN + MAXICMPLEN];
        int sockopt;
        struct msghdr msg;
        struct sockaddr_in6 from;
        struct iovec iov;
        char control_buf[CMSG_SPACE(36)];

        pingsock = create_icmp6_socket();
        pingaddr.sin6 = lsa->u.sin6;
        /* untested whether "-I addr" really works for IPv6: */
        if (source_lsa)
                xbind(pingsock, &source_lsa->u.sa, source_lsa->len);
        if (str_I)
                setsockopt_bindtodevice(pingsock, str_I);

#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(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(pingsock, SOL_SOCKET, SO_RCVBUF, &sockopt, sizeof(sockopt));

        sockopt = offsetof(struct icmp6_hdr, icmp6_cksum);
        if (offsetof(struct icmp6_hdr, icmp6_cksum) != 2)
                BUG_bad_offsetof_icmp6_cksum();
        setsockopt(pingsock, SOL_RAW, IPV6_CHECKSUM, &sockopt, sizeof(sockopt));

        /* request ttl info to be returned in ancillary data */
        setsockopt(pingsock, SOL_IPV6, IPV6_HOPLIMIT, &const_int_1, sizeof(const_int_1));

        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 = packet;
        iov.iov_len = sizeof(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);
                        }
                }
                unpack6(packet, c, /*&from,*/ hoplimit);
                if (pingcount && 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);

#if ENABLE_PING6
        if (lsa->u.sa.sa_family == AF_INET6)
                ping6(lsa);
        else
#endif
                ping4(lsa);
}

int ping_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ping_main(int argc UNUSED_PARAM, char **argv)
{
        len_and_sockaddr *lsa;
        char *str_s;
        int opt;

        INIT_G();

        /* exactly one argument needed; -v and -q don't mix; -c NUM, -w NUM, -W NUM */
        opt_complementary = "=1:q--v:v--q:c+:w+:W+";
        opt = getopt32(argv, OPT_STRING, &pingcount, &str_s, &deadline, &timeout, &str_I);
        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 */
                }
        }
        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_PING6
int ping6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ping6_main(int argc UNUSED_PARAM, char **argv)
{
        argv[0] = (char*)"-6";
        return ping_main(0 /* argc+1 - but it's unused anyway */,
                        argv - 1);
}
#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.
 */