udhcp: fix config help text
[oweals/busybox.git] / networking / ping.c
index 518265668fe46c75a3cf5479711fd62339bfe2c7..2991486411beec9338ac8fbeab7a2bf0e0b19b1b 100644 (file)
@@ -1,36 +1,43 @@
 /* vi: set sw=4 ts=4: */
 /*
- * $Id: ping.c,v 1.56 2004/03/15 08:28:48 andersen Exp $
  * 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.
- * Derived from software contributed to Berkeley by Mike Muuss.
+ * 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 <sys/param.h>
-#include <sys/socket.h>
-#include <sys/file.h>
-#include <sys/times.h>
-#include <signal.h>
-
-#include <netinet/in.h>
-#include <netinet/ip.h>
+#include <net/if.h>
 #include <netinet/ip_icmp.h>
-#include <arpa/inet.h>
-#include <netdb.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <errno.h>
-#include <unistd.h>
-#include <string.h>
-#include <stdlib.h>
-#include "busybox.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,
@@ -39,20 +46,11 @@ enum {
        MAXPACKET = 65468,
        MAX_DUP_CHK = (8 * 128),
        MAXWAIT = 10,
-       PINGINTERVAL = 1                /* second */
+       PINGINTERVAL = 1, /* 1 second */
 };
 
-#define O_QUIET         (1 << 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 ping(const char *host);
-
 /* common routines */
+
 static int in_cksum(unsigned short *buf, int sz)
 {
        int nleft = sz;
@@ -73,60 +71,49 @@ static int in_cksum(unsigned short *buf, int sz)
        sum = (sum >> 16) + (sum & 0xFFFF);
        sum += (sum >> 16);
        ans = ~sum;
-       return (ans);
+       return ans;
 }
 
+#if !ENABLE_FEATURE_FANCY_PING
+
 /* simple version */
-#ifndef CONFIG_FEATURE_FANCY_PING
-static char *hostname = NULL;
-static void noresp(int ign)
+
+static char *hostname;
+
+static void noresp(int ign ATTRIBUTE_UNUSED)
 {
        printf("No response from %s\n", hostname);
        exit(EXIT_FAILURE);
 }
 
-static void ping(const char *host)
+static void ping4(len_and_sockaddr *lsa)
 {
-       struct hostent *h;
        struct sockaddr_in pingaddr;
        struct icmp *pkt;
        int pingsock, c;
        char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN];
 
        pingsock = create_icmp_socket();
-
-       memset(&pingaddr, 0, sizeof(struct sockaddr_in));
-
-       pingaddr.sin_family = AF_INET;
-       h = xgethostbyname(host);
-       memcpy(&pingaddr.sin_addr, h->h_addr, sizeof(pingaddr.sin_addr));
-       hostname = h->h_name;
+       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 = sendto(pingsock, packet, DEFDATALEN + ICMP_MINLEN, 0,
-                          (struct sockaddr *) &pingaddr, sizeof(struct sockaddr_in));
-
-       if (c < 0) {
-               if (ENABLE_FEATURE_CLEAN_UP) close(pingsock);
-               bb_perror_msg_and_die("sendto");
-       }
+       c = xsendto(pingsock, packet, DEFDATALEN + ICMP_MINLEN,
+                          (struct sockaddr *) &pingaddr, sizeof(pingaddr));
 
-       signal(SIGALRM, noresp);
-       alarm(5);                                       /* give the host 5000ms to respond */
        /* listen for replies */
        while (1) {
                struct sockaddr_in from;
                socklen_t fromlen = sizeof(from);
 
-               if ((c = recvfrom(pingsock, packet, sizeof(packet), 0,
-                                                 (struct sockaddr *) &from, &fromlen)) < 0) {
-                       if (errno == EINTR)
-                               continue;
-                       bb_perror_msg("recvfrom");
+               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 */
@@ -137,290 +124,682 @@ static void ping(const char *host)
                                break;
                }
        }
-       if (ENABLE_FEATURE_CLEAN_UP) close(pingsock);
-       printf("%s is alive!\n", hostname);
-       return;
+       if (ENABLE_FEATURE_CLEAN_UP)
+               close(pingsock);
 }
 
-int ping_main(int argc, char **argv)
+#if ENABLE_PING6
+static void ping6(len_and_sockaddr *lsa)
 {
-       argc--;
+       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 ATTRIBUTE_UNUSED, 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++;
-       if (argc < 1)
+#endif
+
+       hostname = *argv;
+       if (!hostname)
                bb_show_usage();
-       ping(*argv);
+
+#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 /* ! CONFIG_FEATURE_FANCY_PING */
+
+#else /* FEATURE_FANCY_PING */
+
+
 /* full(er) version */
-static struct sockaddr_in pingaddr;
-static int pingsock = -1;
-static int datalen; /* intentionally uninitialized to work around gcc bug */
 
-static long ntransmitted, nreceived, nrepeats, pingcount;
-static int myid, options;
-static unsigned long tmin = ULONG_MAX, tmax, tsum;
-static char rcvd_tbl[MAX_DUP_CHK / 8];
+#define OPT_STRING ("qvc:s:w:W:I:4" USE_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,
+};
 
-#ifndef CONFIG_FEATURE_FANCY_PING6
-static
+
+struct globals {
+       int pingsock;
+       int if_index;
+       char *opt_I;
+       len_and_sockaddr *source_lsa;
+       unsigned datalen;
+       unsigned long ntransmitted, nreceived, nrepeats, pingcount;
+       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
-       struct hostent *hostent;
+       } 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 opt_I        (G.opt_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)
 
-static void sendping(int);
-static void pingstats(int);
-static void unpack(char *, int, struct sockaddr_in *);
+
+#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 pingstats(int junk)
+static void print_stats_and_exit(int junk) ATTRIBUTE_NORETURN;
+static void print_stats_and_exit(int junk ATTRIBUTE_UNUSED)
 {
-       int status;
-
        signal(SIGINT, SIG_IGN);
 
-       printf("\n--- %s ping statistics ---\n", hostent->h_name);
-       printf("%ld packets transmitted, ", ntransmitted);
-       printf("%ld packets received, ", nreceived);
+       printf("\n--- %s ping statistics ---\n", hostname);
+       printf("%lu packets transmitted, ", ntransmitted);
+       printf("%lu packets received, ", nreceived);
        if (nrepeats)
-               printf("%ld duplicates, ", nrepeats);
+               printf("%lu duplicates, ", nrepeats);
        if (ntransmitted)
-               printf("%ld%% packet loss\n",
-                          (ntransmitted - nreceived) * 100 / ntransmitted);
-       if (nreceived)
-               printf("round-trip min/avg/max = %lu.%lu/%lu.%lu/%lu.%lu ms\n",
-                          tmin / 10, tmin % 10,
-                          (tsum / (nreceived + nrepeats)) / 10,
-                          (tsum / (nreceived + nrepeats)) % 10, tmax / 10, tmax % 10);
-       if (nreceived != 0)
-               status = EXIT_SUCCESS;
-       else
-               status = EXIT_FAILURE;
-       exit(status);
+               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(int junk)
+static void sendping_tail(void (*sp)(int), const void *pkt, int size_pkt)
 {
-       struct icmp *pkt;
-       int i;
-       char packet[datalen + ICMP_MINLEN];
+       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);
+       }
+}
 
-       pkt = (struct icmp *) packet;
+static void sendping4(int junk ATTRIBUTE_UNUSED)
+{
+       /* +4 reserves a place for timestamp, which may end up sitting
+        * *after* packet. Saves one if() */
+       struct icmp *pkt = alloca(datalen + ICMP_MINLEN + 4);
 
        pkt->icmp_type = ICMP_ECHO;
        pkt->icmp_code = 0;
        pkt->icmp_cksum = 0;
-       pkt->icmp_seq = htons(ntransmitted++);
+       pkt->icmp_seq = htons(ntransmitted); /* don't ++ here, it can be a macro */
        pkt->icmp_id = myid;
-       CLR(ntohs(pkt->icmp_seq) % MAX_DUP_CHK);
 
-       gettimeofday((struct timeval *) &pkt->icmp_dun, NULL);
-       pkt->icmp_cksum = in_cksum((unsigned short *) pkt, sizeof(packet));
+       /* 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);
 
-       i = sendto(pingsock, packet, sizeof(packet), 0,
-                          (struct sockaddr *) &pingaddr, sizeof(struct sockaddr_in));
+       sendping_tail(sendping4, pkt, datalen + ICMP_MINLEN);
+}
+#if ENABLE_PING6
+static void sendping6(int junk ATTRIBUTE_UNUSED)
+{
+       struct icmp6_hdr *pkt = alloca(datalen + sizeof(struct icmp6_hdr) + 4);
 
-       if (i < 0)
-               bb_perror_msg_and_die("sendto");
-       else if ((size_t)i != sizeof(packet))
-               bb_error_msg_and_die("ping wrote %d chars; %d expected", i,
-                          (int)sizeof(packet));
+       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;
 
-       signal(SIGALRM, sendping);
-       if (pingcount == 0 || ntransmitted < pingcount) {       /* schedule next in 1s */
-               alarm(PINGINTERVAL);
-       } else {                                        /* done, wait for the last ping to come back */
-               /* todo, don't necessarily need to wait so long... */
-               signal(SIGALRM, pingstats);
-               alarm(MAXWAIT);
-       }
+       /*if (datalen >= 4)*/
+               *(uint32_t*)(&pkt->icmp6_data8[4]) = monotonic_us();
+
+       sendping_tail(sendping6, pkt, datalen + sizeof(struct icmp6_hdr));
 }
+#endif
 
-static char *icmp_type_name (int id)
+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 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";
+       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;
+       }
 
-static void unpack(char *buf, int sz, struct sockaddr_in *from)
+       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;
-       struct timeval tv, *tp;
-       int hlen, dupflag;
-       unsigned long triptime;
+       int hlen;
 
-       gettimeofday(&tv, NULL);
-
-       /* check IP header */
-       iphdr = (struct iphdr *) buf;
-       hlen = iphdr->ihl << 2;
        /* 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 */
+               return;                         /* not our ping */
 
        if (icmppkt->icmp_type == ICMP_ECHOREPLY) {
-               u_int16_t recv_seq = ntohs(icmppkt->icmp_seq);
-           ++nreceived;
-               tp = (struct timeval *) icmppkt->icmp_data;
-
-               if ((tv.tv_usec -= tp->tv_usec) < 0) {
-                       --tv.tv_sec;
-                       tv.tv_usec += 1000000;
-               }
-               tv.tv_sec -= tp->tv_sec;
-
-               triptime = tv.tv_sec * 10000 + (tv.tv_usec / 100);
-               tsum += triptime;
-               if (triptime < tmin)
-                       tmin = triptime;
-               if (triptime > tmax)
-                       tmax = triptime;
+               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];
 
-               if (TST(recv_seq % MAX_DUP_CHK)) {
-                       ++nrepeats;
-                       --nreceived;
-                       dupflag = 1;
-               } else {
-                       SET(recv_seq % MAX_DUP_CHK);
-                       dupflag = 0;
-               }
+       /* discard if too short */
+       if (sz < (datalen + sizeof(struct icmp6_hdr)))
+               return;
 
-               if (options & O_QUIET)
-                       return;
-
-               printf("%d bytes from %s: icmp_seq=%u", sz,
-                          inet_ntoa(*(struct in_addr *) &from->sin_addr.s_addr),
-                          recv_seq);
-               printf(" ttl=%d", iphdr->ttl);
-               printf(" time=%lu.%lu ms", triptime / 10, triptime % 10);
-               if (dupflag)
-                       printf(" (DUP!)");
-               printf("\n");
-       } else
-               if (icmppkt->icmp_type != ICMP_ECHO)
-                       bb_error_msg("Warning: Got ICMP %d (%s)",
-                                       icmppkt->icmp_type, icmp_type_name (icmppkt->icmp_type));
-       fflush(stdout);
+       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 ping(const char *host)
+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 (opt_I)
+               setsockopt(pingsock, SOL_SOCKET, SO_BINDTODEVICE, opt_I, strlen(opt_I) + 1);
+
+       /* enable broadcast pings */
+       setsockopt_broadcast(pingsock);
+
+       /* set recv buf for broadcast pings */
+       sockopt = 48 * 1024; /* explain why 48k? */
+       setsockopt(pingsock, SOL_SOCKET, SO_RCVBUF, &sockopt, sizeof(sockopt));
 
-       memset(&pingaddr, 0, sizeof(struct sockaddr_in));
+       signal(SIGINT, print_stats_and_exit);
 
-       pingaddr.sin_family = AF_INET;
-       hostent = xgethostbyname(host);
-       if (hostent->h_addrtype != AF_INET)
-               bb_error_msg_and_die("unknown address type; only AF_INET is currently supported.");
+       /* 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;
 
-       memcpy(&pingaddr.sin_addr, hostent->h_addr, sizeof(pingaddr.sin_addr));
+               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 (opt_I)
+               setsockopt(pingsock, SOL_SOCKET, SO_BINDTODEVICE, opt_I, strlen(opt_I) + 1);
+
+#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 */
-       sockopt = 1;
-       setsockopt(pingsock, SOL_SOCKET, SO_BROADCAST, (char *) &sockopt,
-                          sizeof(sockopt));
+       setsockopt_broadcast(pingsock);
 
        /* set recv buf for broadcast pings */
-       sockopt = 48 * 1024;
-       setsockopt(pingsock, SOL_SOCKET, SO_RCVBUF, (char *) &sockopt,
-                          sizeof(sockopt));
+       sockopt = 48 * 1024; /* explain why 48k? */
+       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));
 
-       printf("PING %s (%s): %d data bytes\n",
-                  hostent->h_name,
-                  inet_ntoa(*(struct in_addr *) &pingaddr.sin_addr.s_addr),
-                  datalen);
+       if (if_index)
+               pingaddr.sin6.sin6_scope_id = if_index;
 
-       signal(SIGINT, pingstats);
+       signal(SIGINT, print_stats_and_exit);
 
        /* start the ping's going ... */
-       sendping(0);
+       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) {
-               struct sockaddr_in from;
-               socklen_t fromlen = (socklen_t) sizeof(from);
                int c;
-
-               if ((c = recvfrom(pingsock, packet, sizeof(packet), 0,
-                                                 (struct sockaddr *) &from, &fromlen)) < 0) {
-                       if (errno == EINTR)
-                               continue;
-                       bb_perror_msg("recvfrom");
+               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;
                }
-               unpack(packet, c, &from);
-               if (pingcount > 0 && nreceived >= pingcount)
+               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;
        }
-       pingstats(0);
 }
+#endif
 
-int ping_main(int argc, char **argv)
+static void ping(len_and_sockaddr *lsa)
 {
-       char *thisarg;
+       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);
 
-       datalen = DEFDATALEN; /* initialized here rather than in global scope to work around gcc bug */
+#if ENABLE_PING6
+       if (lsa->u.sa.sa_family == AF_INET6)
+               ping6(lsa);
+       else
+#endif
+               ping4(lsa);
+}
 
-       argc--;
-       argv++;
-       options = 0;
-       /* Parse any options */
-       while (argc >= 1 && **argv == '-') {
-               thisarg = *argv;
-               thisarg++;
-               switch (*thisarg) {
-               case 'q':
-                       options |= O_QUIET;
-                       break;
-               case 'c':
-                       if (--argc <= 0)
-                               bb_show_usage();
-                       argv++;
-                       pingcount = atoi(*argv);
-                       break;
-               case 's':
-                       if (--argc <= 0)
-                               bb_show_usage();
-                       argv++;
-                       datalen = atoi(*argv);
-                       break;
-               default:
-                       bb_show_usage();
+int ping_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int ping_main(int argc ATTRIBUTE_UNUSED, char **argv)
+{
+       len_and_sockaddr *lsa;
+       char *opt_c, *opt_s;
+       USE_PING6(sa_family_t af = AF_UNSPEC;)
+
+       INIT_G();
+
+       /* exactly one argument needed; -v and -q don't mix; -w NUM, -W NUM */
+       opt_complementary = "=1:q--v:v--q:w+:W+";
+       getopt32(argv, OPT_STRING, &opt_c, &opt_s, &deadline, &timeout, &opt_I);
+       if (option_mask32 & OPT_c)
+               pingcount = xatoul(opt_c); // -c
+       if (option_mask32 & OPT_s)
+               datalen = xatou16(opt_s); // -s
+       if (option_mask32 & OPT_I) { // -I
+               if_index = if_nametoindex(opt_I);
+               if (!if_index) {
+                       /* TODO: I'm not sure it takes IPv6 unless in [XX:XX..] format */
+                       source_lsa = xdotted2sockaddr(opt_I, 0);
+                       opt_I = NULL; /* don't try to bind to device later */
                }
-               argc--;
-               argv++;
        }
-       if (argc < 1)
-               bb_show_usage();
+       myid = (uint16_t) getpid();
+       hostname = argv[optind];
+#if ENABLE_PING6
+       if (option_mask32 & OPT_IPV4)
+               af = AF_INET;
+       if (option_mask32 & OPT_IPV6)
+               af = AF_INET6;
+       lsa = xhost_and_af2sockaddr(hostname, 0, af);
+#else
+       lsa = xhost_and_af2sockaddr(hostname, 0, AF_INET);
+#endif
 
-       myid = getpid() & 0xFFFF;
-       ping(*argv);
-       return EXIT_SUCCESS;
+       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(0);
+       /*return EXIT_SUCCESS;*/
 }
-#endif /* ! CONFIG_FEATURE_FANCY_PING */
+#endif /* FEATURE_FANCY_PING */
+
+
+#if ENABLE_PING6
+int ping6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int ping6_main(int argc, char **argv)
+{
+       argv[0] = (char*)"-6";
+       return ping_main(argc + 1, 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.
+ */