[Feature]add MT2731_MP2_MR2_SVN388 baseline version

Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/connectivity/pingnetid/ping.c b/src/connectivity/pingnetid/ping.c
new file mode 100644
index 0000000..40df3b0
--- /dev/null
+++ b/src/connectivity/pingnetid/ping.c
@@ -0,0 +1,1428 @@
+/*
+ * 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. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *  This product includes software developed by the University of
+ *  California, Berkeley and its contributors.
+ * 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.
+ */
+
+#ifndef lint
+char copyright[] =
+"@(#) Copyright (c) 1989 The Regents of the University of California.\n\
+ All rights reserved.\n";
+#endif /* not lint */
+
+/*
+ *          P I N G . C
+ *
+ * Using the InterNet Control Message Protocol (ICMP) "ECHO" facility,
+ * measure round-trip-delays and packet loss across network paths.
+ *
+ * Author -
+ *  Mike Muuss
+ *  U. S. Army Ballistic Research Laboratory
+ *  December, 1983
+ *
+ * Status -
+ *  Public Domain.  Distribution Unlimited.
+ * Bugs -
+ *  More statistics could always be gathered.
+ *  This program has to run SUID to ROOT to access the ICMP socket.
+ */
+
+#include "ping_common.h"
+
+#include <netinet/ip.h>
+#include <netinet/ip_icmp.h>
+#ifndef WITHOUT_IFADDRS
+#include <ifaddrs.h>
+#endif
+
+#ifndef ICMP_FILTER
+#define ICMP_FILTER 1
+struct icmp_filter {
+    __u32   data;
+};
+#endif
+
+#define MAXIPLEN    60
+#define MAXICMPLEN  76
+#define NROUTES     9       /* number of record route slots */
+#define TOS_MAX     255     /* 8-bit TOS field */
+#define MAX_HOSTNAMELEN NI_MAXHOST
+
+
+static int ts_type;
+static int nroute = 0;
+static __u32 route[10];
+
+
+
+struct sockaddr_in whereto; /* who to ping */
+int optlen = 0;
+int settos = 0;         /* Set TOS, Precendence or other QOS options */
+int icmp_sock;          /* socket file descriptor */
+u_char outpack[0x10000];
+int maxpacket = sizeof(outpack);
+
+static int broadcast_pings = 0;
+
+static char *pr_addr(__u32);
+static void pr_options(unsigned char * cp, int hlen);
+static void pr_iph(struct iphdr *ip);
+static void usage(void) __attribute__((noreturn));
+static u_short in_cksum(const u_short *addr, int len, u_short salt);
+static void pr_icmph(__u8 type, __u8 code, __u32 info, struct icmphdr *icp);
+static int parsetos(char *str);
+
+static struct {
+    struct cmsghdr cm;
+    struct in_pktinfo ipi;
+} cmsg = { {sizeof(struct cmsghdr) + sizeof(struct in_pktinfo), SOL_IP, IP_PKTINFO},
+       {0, }};
+int cmsg_len;
+
+struct sockaddr_in source;
+char *device;
+int pmtudisc = -1;
+
+
+int
+main(int argc, char **argv)
+{
+    struct hostent *hp;
+    int ch, hold, packlen;
+    int socket_errno = 0;
+    u_char *packet;
+    char *target;
+    struct sockaddr_in *addr_in;
+    int ret;
+
+#ifdef USE_IDN
+    char *hnamebuf = NULL;
+#else
+    char hnamebuf[MAX_HOSTNAMELEN];
+#endif
+    char rspace[3 + 4 * NROUTES + 1];   /* record route space */
+
+#ifdef ANDROID
+    android_check_security();
+#endif
+
+    limit_capabilities();
+
+#ifdef USE_IDN
+    setlocale(LC_ALL, "");
+#endif
+
+    icmp_sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
+    if (icmp_sock < 0) {
+        enable_capability_raw();
+        icmp_sock = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
+        socket_errno = errno;
+        disable_capability_raw();
+        using_ping_socket = 0;
+    }
+
+    source.sin_family = AF_INET;
+
+    preload = 1;
+    while ((ch = getopt(argc, argv, COMMON_OPTSTR "bRT:")) != EOF) {
+        switch(ch) {
+        case 'b':
+            broadcast_pings = 1;
+            break;
+        case 'Q':
+            settos = parsetos(optarg);
+            if (settos &&
+                (setsockopt(icmp_sock, IPPROTO_IP, IP_TOS,
+                    (char *)&settos, sizeof(int)) < 0)) {
+                perror("ping: error setting QOS sockopts");
+                exit(2);
+            }
+            break;
+        case 'R':
+            if (options & F_TIMESTAMP) {
+                fprintf(stderr, "Only one of -T or -R may be used\n");
+                exit(2);
+            }
+            options |= F_RROUTE;
+            break;
+        case 'T':
+            if (options & F_RROUTE) {
+                fprintf(stderr, "Only one of -T or -R may be used\n");
+                exit(2);
+            }
+            options |= F_TIMESTAMP;
+            if (strcmp(optarg, "tsonly") == 0)
+                ts_type = IPOPT_TS_TSONLY;
+            else if (strcmp(optarg, "tsandaddr") == 0)
+                ts_type = IPOPT_TS_TSANDADDR;
+            else if (strcmp(optarg, "tsprespec") == 0)
+                ts_type = IPOPT_TS_PRESPEC;
+            else {
+                fprintf(stderr, "Invalid timestamp type\n");
+                exit(2);
+            }
+            break;
+        case 'I':
+        {
+#if 0
+            char dummy;
+            int i1, i2, i3, i4;
+
+            if (sscanf(optarg, "%u.%u.%u.%u%c",
+                   &i1, &i2, &i3, &i4, &dummy) == 4) {
+                __u8 *ptr;
+                ptr = (__u8*)&source.sin_addr;
+                ptr[0] = i1;
+                ptr[1] = i2;
+                ptr[2] = i3;
+                ptr[3] = i4;
+                options |= F_STRICTSOURCE;
+            } else {
+                device = optarg;
+            }
+#else
+            if (inet_pton(AF_INET, optarg, &source.sin_addr) > 0)
+                options |= F_STRICTSOURCE;
+            else
+                device = optarg;
+#endif
+            break;
+        }
+        case 'M':
+            if (strcmp(optarg, "do") == 0)
+                pmtudisc = IP_PMTUDISC_DO;
+            else if (strcmp(optarg, "dont") == 0)
+                pmtudisc = IP_PMTUDISC_DONT;
+            else if (strcmp(optarg, "want") == 0)
+                pmtudisc = IP_PMTUDISC_WANT;
+            else {
+                fprintf(stderr, "ping: wrong value for -M: do, dont, want are valid ones.\n");
+                exit(2);
+            }
+            break;
+        case 'V':
+            //printf("ping utility, iputils-%s\n", SNAPSHOT);
+            exit(0);
+        COMMON_OPTIONS
+            common_options(ch);
+            break;
+        default:
+            usage();
+        }
+    }
+    argc -= optind;
+    argv += optind;
+
+    if (argc == 0)
+        usage();
+    if (argc > 1) {
+        if (options & F_RROUTE)
+            usage();
+        else if (options & F_TIMESTAMP) {
+            if (ts_type != IPOPT_TS_PRESPEC)
+                usage();
+            if (argc > 5)
+                usage();
+        } else {
+            if (argc > 10)
+                usage();
+            options |= F_SOURCEROUTE;
+        }
+    }
+    while (argc > 0) {
+        target = *argv;
+
+        memset((char *)&whereto, 0, sizeof(whereto));
+        whereto.sin_family = AF_INET;
+        if (inet_aton(target, &whereto.sin_addr) == 1) {
+            hostname = target;
+            if (argc == 1)
+                options |= F_NUMERIC;
+        } else {
+            char *idn;
+#ifdef USE_IDN
+            int rc;
+
+            if (hnamebuf) {
+                free(hnamebuf);
+                hnamebuf = NULL;
+            }
+
+            rc = idna_to_ascii_lz(target, &idn, 0);
+            if (rc != IDNA_SUCCESS) {
+                fprintf(stderr, "ping: IDN encoding failed: %s\n", idna_strerror(rc));
+                exit(2);
+            }
+#else
+            idn = target;
+#endif
+            ret = ping_netid_getaddrinfo_android(idn, &addr_in);
+            if (ret != 0)
+            {
+                fprintf(stderr, "ping: unknown host %s\n", target);
+                exit(2);
+            }
+
+            whereto.sin_family = AF_INET;
+            whereto.sin_addr.s_addr = addr_in->sin_addr.s_addr;
+
+            hostname = inet_ntoa(addr_in->sin_addr);
+            strcpy(target, hostname);
+        }
+        if (argc > 1)
+            route[nroute++] = whereto.sin_addr.s_addr;
+        argc--;
+        argv++;
+    }
+
+    if (source.sin_addr.s_addr == 0) {
+        socklen_t alen;
+        struct sockaddr_in dst = whereto;
+        int probe_fd = socket(AF_INET, SOCK_DGRAM, 0);
+
+        if (probe_fd < 0) {
+            perror("socket");
+            exit(2);
+        }
+        if (device) {
+            struct ifreq ifr;
+            int rc;
+
+            memset(&ifr, 0, sizeof(ifr));
+            strncpy(ifr.ifr_name, device, IFNAMSIZ-1);
+
+            enable_capability_raw();
+            rc = setsockopt(probe_fd, SOL_SOCKET, SO_BINDTODEVICE, device, strlen(device)+1);
+            disable_capability_raw();
+
+            if (rc == -1) {
+                if (IN_MULTICAST(ntohl(dst.sin_addr.s_addr))) {
+                    struct ip_mreqn imr;
+                    if (ioctl(probe_fd, SIOCGIFINDEX, &ifr) < 0) {
+                        fprintf(stderr, "ping: unknown iface %s\n", device);
+                        exit(2);
+                    }
+                    memset(&imr, 0, sizeof(imr));
+                    imr.imr_ifindex = ifr.ifr_ifindex;
+                    if (setsockopt(probe_fd, SOL_IP, IP_MULTICAST_IF, &imr, sizeof(imr)) == -1) {
+                        perror("ping: IP_MULTICAST_IF");
+                        exit(2);
+                    }
+                } else {
+                    perror("ping: SO_BINDTODEVICE");
+                    exit(2);
+                }
+            }
+        }
+
+        if (settos &&
+            setsockopt(probe_fd, IPPROTO_IP, IP_TOS, (char *)&settos, sizeof(int)) < 0)
+            perror("Warning: error setting QOS sockopts");
+
+        dst.sin_port = htons(1025);
+        if (nroute)
+            dst.sin_addr.s_addr = route[0];
+
+        sock_setmark(probe_fd);
+
+        if (connect(probe_fd, (struct sockaddr*)&dst, sizeof(dst)) == -1) {
+            if (errno == EACCES) {
+                if (broadcast_pings == 0) {
+                    fprintf(stderr, "Do you want to ping broadcast? Then -b\n");
+                    exit(2);
+                }
+                fprintf(stderr, "WARNING: pinging broadcast address\n");
+                if (setsockopt(probe_fd, SOL_SOCKET, SO_BROADCAST,
+                           &broadcast_pings, sizeof(broadcast_pings)) < 0) {
+                    perror ("can't set broadcasting");
+                    exit(2);
+                }
+                if (connect(probe_fd, (struct sockaddr*)&dst, sizeof(dst)) == -1) {
+                    perror("connect");
+                    exit(2);
+                }
+            } else {
+                perror("connect");
+                exit(2);
+            }
+        }
+        alen = sizeof(source);
+        if (getsockname(probe_fd, (struct sockaddr*)&source, &alen) == -1) {
+            perror("getsockname");
+            exit(2);
+        }
+        source.sin_port = 0;
+
+#ifndef WITHOUT_IFADDRS
+        if (device) {
+            struct ifaddrs *ifa0, *ifa;
+            int ret;
+
+            ret = getifaddrs(&ifa0);
+            if (ret) {
+                fprintf(stderr, "gatifaddrs() failed.\n");
+                exit(2);
+            }
+            for (ifa = ifa0; ifa; ifa = ifa->ifa_next) {
+                if (!ifa->ifa_addr || ifa->ifa_addr->sa_family != AF_INET)
+                    continue;
+                if (!strncmp(ifa->ifa_name, device, sizeof(device) - 1) &&
+                    !memcmp(&((struct sockaddr_in *)ifa->ifa_addr)->sin_addr,
+                        &source.sin_addr, sizeof(source.sin_addr)))
+                    break;
+            }
+            freeifaddrs(ifa0);
+            if (!ifa)
+                fprintf(stderr, "ping: Warning: source address might be selected on device other than %s.\n", device);
+        }
+#endif
+        close(probe_fd);
+    } while (0);
+
+    if (whereto.sin_addr.s_addr == 0)
+        whereto.sin_addr.s_addr = source.sin_addr.s_addr;
+
+    if (icmp_sock < 0) {
+        errno = socket_errno;
+        perror("ping: icmp open socket");
+        exit(2);
+    }
+
+    if (device) {
+        struct ifreq ifr;
+
+        memset(&ifr, 0, sizeof(ifr));
+        strncpy(ifr.ifr_name, device, IFNAMSIZ-1);
+        if (ioctl(icmp_sock, SIOCGIFINDEX, &ifr) < 0) {
+            fprintf(stderr, "ping: unknown iface %s\n", device);
+            exit(2);
+        }
+        cmsg.ipi.ipi_ifindex = ifr.ifr_ifindex;
+        cmsg_len = sizeof(cmsg);
+    }
+
+    if (broadcast_pings || IN_MULTICAST(ntohl(whereto.sin_addr.s_addr))) {
+        if (uid) {
+            if (interval < 1000) {
+                fprintf(stderr, "ping: broadcast ping with too short interval.\n");
+                exit(2);
+            }
+            if (pmtudisc >= 0 && pmtudisc != IP_PMTUDISC_DO) {
+                fprintf(stderr, "ping: broadcast ping does not fragment.\n");
+                exit(2);
+            }
+        }
+        if (pmtudisc < 0)
+            pmtudisc = IP_PMTUDISC_DO;
+    }
+
+    if (pmtudisc >= 0) {
+        if (setsockopt(icmp_sock, SOL_IP, IP_MTU_DISCOVER, &pmtudisc,
+            sizeof(pmtudisc)) == -1) {
+            perror("ping: IP_MTU_DISCOVER");
+            exit(2);
+        }
+    }
+
+    if ((options&F_STRICTSOURCE) &&
+        bind(icmp_sock, (struct sockaddr*)&source, sizeof(source)) == -1) {
+        perror("bind");
+        exit(2);
+    }
+
+    if (!using_ping_socket) {
+        struct icmp_filter filt;
+        filt.data = ~((1<<ICMP_SOURCE_QUENCH)|
+                  (1<<ICMP_DEST_UNREACH)|
+                  (1<<ICMP_TIME_EXCEEDED)|
+                  (1<<ICMP_PARAMETERPROB)|
+                  (1<<ICMP_REDIRECT)|
+                  (1<<ICMP_ECHOREPLY));
+        if (setsockopt(icmp_sock, SOL_RAW, ICMP_FILTER, (char*)&filt, sizeof(filt)) == -1)
+            perror("WARNING: setsockopt(ICMP_FILTER)");
+    }
+
+    hold = 1;
+    if (setsockopt(icmp_sock, SOL_IP, IP_RECVERR, (char *)&hold, sizeof(hold)))
+        fprintf(stderr, "WARNING: your kernel is veeery old. No problems.\n");
+    if (using_ping_socket) {
+        if (setsockopt(icmp_sock, SOL_IP, IP_RECVTTL, (char *)&hold, sizeof(hold)))
+            perror("WARNING: setsockopt(IP_RECVTTL)");
+        if (setsockopt(icmp_sock, SOL_IP, IP_RETOPTS, (char *)&hold, sizeof(hold)))
+            perror("WARNING: setsockopt(IP_RETOPTS)");
+    }
+
+    /* record route option */
+    if (options & F_RROUTE) {
+        memset(rspace, 0, sizeof(rspace));
+        rspace[0] = IPOPT_NOP;
+        rspace[1+IPOPT_OPTVAL] = IPOPT_RR;
+        rspace[1+IPOPT_OLEN] = sizeof(rspace)-1;
+        rspace[1+IPOPT_OFFSET] = IPOPT_MINOFF;
+        optlen = 40;
+        if (setsockopt(icmp_sock, IPPROTO_IP, IP_OPTIONS, rspace, sizeof(rspace)) < 0) {
+            perror("ping: record route");
+            exit(2);
+        }
+    }
+    if (options & F_TIMESTAMP) {
+        memset(rspace, 0, sizeof(rspace));
+        rspace[0] = IPOPT_TIMESTAMP;
+        rspace[1] = (ts_type==IPOPT_TS_TSONLY ? 40 : 36);
+        rspace[2] = 5;
+        rspace[3] = ts_type;
+        if (ts_type == IPOPT_TS_PRESPEC) {
+            int i;
+            rspace[1] = 4+nroute*8;
+            for (i=0; i<nroute; i++)
+                *(__u32*)&rspace[4+i*8] = route[i];
+        }
+        if (setsockopt(icmp_sock, IPPROTO_IP, IP_OPTIONS, rspace, rspace[1]) < 0) {
+            rspace[3] = 2;
+            if (setsockopt(icmp_sock, IPPROTO_IP, IP_OPTIONS, rspace, rspace[1]) < 0) {
+                perror("ping: ts option");
+                exit(2);
+            }
+        }
+        optlen = 40;
+    }
+    if (options & F_SOURCEROUTE) {
+        int i;
+        memset(rspace, 0, sizeof(rspace));
+        rspace[0] = IPOPT_NOOP;
+        rspace[1+IPOPT_OPTVAL] = (options & F_SO_DONTROUTE) ? IPOPT_SSRR
+            : IPOPT_LSRR;
+        rspace[1+IPOPT_OLEN] = 3 + nroute*4;
+        rspace[1+IPOPT_OFFSET] = IPOPT_MINOFF;
+        for (i=0; i<nroute; i++)
+            *(__u32*)&rspace[4+i*4] = route[i];
+
+        if (setsockopt(icmp_sock, IPPROTO_IP, IP_OPTIONS, rspace, 4 + nroute*4) < 0) {
+            perror("ping: record route");
+            exit(2);
+        }
+        optlen = 40;
+    }
+
+    /* Estimate memory eaten by single packet. It is rough estimate.
+     * Actually, for small datalen's it depends on kernel side a lot. */
+    hold = datalen + 8;
+    hold += ((hold+511)/512)*(optlen + 20 + 16 + 64 + 160);
+    sock_setbufs(icmp_sock, hold);
+
+    if (broadcast_pings) {
+        if (setsockopt(icmp_sock, SOL_SOCKET, SO_BROADCAST,
+                   &broadcast_pings, sizeof(broadcast_pings)) < 0) {
+            perror ("ping: can't set broadcasting");
+            exit(2);
+        }
+    }
+
+    if (options & F_NOLOOP) {
+        int loop = 0;
+        if (setsockopt(icmp_sock, IPPROTO_IP, IP_MULTICAST_LOOP,
+                            &loop, 1) == -1) {
+            perror ("ping: can't disable multicast loopback");
+            exit(2);
+        }
+    }
+    if (options & F_TTL) {
+        int ittl = ttl;
+        if (setsockopt(icmp_sock, IPPROTO_IP, IP_MULTICAST_TTL,
+                            &ttl, 1) == -1) {
+            perror ("ping: can't set multicast time-to-live");
+            exit(2);
+        }
+        if (setsockopt(icmp_sock, IPPROTO_IP, IP_TTL,
+                            &ittl, sizeof(ittl)) == -1) {
+            perror ("ping: can't set unicast time-to-live");
+            exit(2);
+        }
+    }
+
+    if (datalen > 0xFFFF - 8 - optlen - 20) {
+        if (uid || datalen > sizeof(outpack)-8) {
+            fprintf(stderr, "Error: packet size %d is too large. Maximum is %d\n",
+            datalen, 0xFFFF-8-20-optlen);
+            exit(2);
+        }
+        /* Allow small oversize to root yet. It will cause EMSGSIZE. */
+        fprintf(stderr, "WARNING: packet size %d is too large. Maximum is %d\n",
+        datalen, 0xFFFF-8-20-optlen);
+    }
+
+    if (datalen >= sizeof(struct timeval))  /* can we time transfer */
+        timing = 1;
+    packlen = datalen + MAXIPLEN + MAXICMPLEN;
+    if (!(packet = (u_char *)malloc((u_int)packlen))) {
+        fprintf(stderr, "ping: out of memory.\n");
+        exit(2);
+    }
+
+    printf("PING %s (%s) ", hostname, inet_ntoa(whereto.sin_addr));
+    if (device || (options&F_STRICTSOURCE))
+        printf("from %s %s: ", inet_ntoa(source.sin_addr), device ?: "");
+    printf("%d(%d) bytes of data.\n", datalen, datalen+8+optlen+20);
+
+    setup(icmp_sock);
+
+    main_loop(icmp_sock, packet, packlen);
+}
+
+
+int receive_error_msg()
+{
+    int res;
+    char cbuf[512];
+    struct iovec  iov;
+    struct msghdr msg;
+    struct cmsghdr *cmsg;
+    struct sock_extended_err *e;
+    struct icmphdr icmph;
+    struct sockaddr_in target;
+    int net_errors = 0;
+    int local_errors = 0;
+    int saved_errno = errno;
+
+    iov.iov_base = &icmph;
+    iov.iov_len = sizeof(icmph);
+    msg.msg_name = (void*)&target;
+    msg.msg_namelen = sizeof(target);
+    msg.msg_iov = &iov;
+    msg.msg_iovlen = 1;
+    msg.msg_flags = 0;
+    msg.msg_control = cbuf;
+    msg.msg_controllen = sizeof(cbuf);
+
+    res = recvmsg(icmp_sock, &msg, MSG_ERRQUEUE|MSG_DONTWAIT);
+    if (res < 0)
+        goto out;
+
+    e = NULL;
+    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+        if (cmsg->cmsg_level == SOL_IP) {
+            if (cmsg->cmsg_type == IP_RECVERR)
+                e = (struct sock_extended_err *)CMSG_DATA(cmsg);
+        }
+    }
+    if (e == NULL)
+        abort();
+
+    if (e->ee_origin == SO_EE_ORIGIN_LOCAL) {
+        local_errors++;
+        if (options & F_QUIET)
+            goto out;
+        if (options & F_FLOOD)
+            write_stdout("E", 1);
+        else if (e->ee_errno != EMSGSIZE)
+            fprintf(stderr, "ping: local error: %s\n", strerror(e->ee_errno));
+        else
+            fprintf(stderr, "ping: local error: Message too long, mtu=%u\n", e->ee_info);
+        nerrors++;
+    } else if (e->ee_origin == SO_EE_ORIGIN_ICMP) {
+        struct sockaddr_in *sin = (struct sockaddr_in*)(e+1);
+        int error_pkt;
+
+        if (res < sizeof(icmph) ||
+            target.sin_addr.s_addr != whereto.sin_addr.s_addr ||
+            icmph.type != ICMP_ECHO ||
+            !is_ours(icmph.un.echo.id)) {
+            /* Not our error, not an error at all. Clear. */
+            saved_errno = 0;
+            goto out;
+        }
+
+        error_pkt = (e->ee_type != ICMP_REDIRECT &&
+                 e->ee_type != ICMP_SOURCE_QUENCH);
+        if (error_pkt) {
+            acknowledge(ntohs(icmph.un.echo.sequence));
+            net_errors++;
+            nerrors++;
+        }
+        else {
+            saved_errno = 0;
+        }
+
+        if (!using_ping_socket && !working_recverr) {
+            struct icmp_filter filt;
+            working_recverr = 1;
+            /* OK, it works. Add stronger filter. */
+            filt.data = ~((1<<ICMP_SOURCE_QUENCH)|
+                      (1<<ICMP_REDIRECT)|
+                      (1<<ICMP_ECHOREPLY));
+            if (setsockopt(icmp_sock, SOL_RAW, ICMP_FILTER, (char*)&filt, sizeof(filt)) == -1)
+                perror("\rWARNING: setsockopt(ICMP_FILTER)");
+        }
+
+        if (options & F_QUIET)
+            goto out;
+        if (options & F_FLOOD) {
+            if (error_pkt)
+                write_stdout("\bE", 2);
+        } else {
+            print_timestamp();
+            printf("From %s: icmp_seq=%u ", pr_addr(sin->sin_addr.s_addr),
+            ntohs(icmph.un.echo.sequence));
+            pr_icmph(e->ee_type, e->ee_code, e->ee_info, NULL);
+            fflush(stdout);
+        }
+    }
+
+out:
+    errno = saved_errno;
+    return net_errors ? : -local_errors;
+}
+
+/*
+ * pinger --
+ *  Compose and transmit an ICMP ECHO REQUEST packet.  The IP packet
+ * will be added on by the kernel.  The ID field is our UNIX process ID,
+ * and the sequence number is an ascending integer.  The first 8 bytes
+ * of the data portion are used to hold a UNIX "timeval" struct in VAX
+ * byte-order, to compute the round-trip time.
+ */
+int send_probe()
+{
+    struct icmphdr *icp;
+    int cc;
+    int i;
+
+    icp = (struct icmphdr *)outpack;
+    icp->type = ICMP_ECHO;
+    icp->code = 0;
+    icp->checksum = 0;
+    icp->un.echo.sequence = htons(ntransmitted+1);
+    icp->un.echo.id = ident;            /* ID */
+
+    rcvd_clear(ntransmitted+1);
+
+    if (timing) {
+        if (options&F_LATENCY) {
+            struct timeval tmp_tv;
+            gettimeofday(&tmp_tv, NULL);
+            memcpy(icp+1, &tmp_tv, sizeof(tmp_tv));
+        } else {
+            memset(icp+1, 0, sizeof(struct timeval));
+        }
+    }
+
+    cc = datalen + 8;           /* skips ICMP portion */
+
+    /* compute ICMP checksum here */
+    icp->checksum = in_cksum((u_short *)icp, cc, 0);
+
+    if (timing && !(options&F_LATENCY)) {
+        struct timeval tmp_tv;
+        gettimeofday(&tmp_tv, NULL);
+        memcpy(icp+1, &tmp_tv, sizeof(tmp_tv));
+        icp->checksum = in_cksum((u_short *)&tmp_tv, sizeof(tmp_tv), ~icp->checksum);
+    }
+
+    do {
+        static struct iovec iov = {outpack, 0};
+        static struct msghdr m = { &whereto, sizeof(whereto),
+                           &iov, 1, &cmsg, 0, 0 };
+        m.msg_controllen = cmsg_len;
+        iov.iov_len = cc;
+
+        i = sendmsg(icmp_sock, &m, confirm);
+        confirm = 0;
+    } while (0);
+
+    return (cc == i ? 0 : i);
+}
+
+/*
+ * parse_reply --
+ *  Print out the packet, if it came from us.  This logic is necessary
+ * because ALL readers of the ICMP socket get a copy of ALL ICMP packets
+ * which arrive ('tis only fair).  This permits multiple copies of this
+ * program to be run without having intermingled output (or statistics!).
+ */
+void pr_echo_reply(__u8 *_icp, int len)
+{
+    struct icmphdr *icp = (struct icmphdr *)_icp;
+    printf(" icmp_seq=%u", ntohs(icp->un.echo.sequence));
+}
+
+int
+parse_reply(struct msghdr *msg, int cc, void *addr, struct timeval *tv)
+{
+    struct sockaddr_in *from = addr;
+    __u8 *buf = msg->msg_iov->iov_base;
+    struct icmphdr *icp;
+    struct iphdr *ip;
+    int hlen;
+    int csfailed;
+    struct cmsghdr *cmsg;
+    int ttl;
+    __u8 *opts;
+    int optlen;
+
+    /* Check the IP header */
+    ip = (struct iphdr *)buf;
+    if (!using_ping_socket) {
+        hlen = ip->ihl*4;
+        if (cc < hlen + 8 || ip->ihl < 5) {
+            if (options & F_VERBOSE)
+                fprintf(stderr, "ping: packet too short (%d bytes) from %s\n", cc,
+                    pr_addr(from->sin_addr.s_addr));
+            return 1;
+        }
+        ttl = ip->ttl;
+        opts = buf + sizeof(struct iphdr);
+        optlen = hlen - sizeof(struct iphdr);
+    } else {
+        hlen = 0;
+        ttl = 0;
+        opts = buf;
+        optlen = 0;
+        for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
+            if (cmsg->cmsg_level != SOL_IP)
+                continue;
+            if (cmsg->cmsg_type == IP_TTL) {
+                if (cmsg->cmsg_len < sizeof(int))
+                    continue;
+                ttl = *(int *) CMSG_DATA(cmsg);
+            } else if (cmsg->cmsg_type == IP_RETOPTS) {
+                opts = (__u8 *) CMSG_DATA(cmsg);
+                optlen = cmsg->cmsg_len;
+            }
+        }
+    }
+
+    /* Now the ICMP part */
+    cc -= hlen;
+    icp = (struct icmphdr *)(buf + hlen);
+    csfailed = in_cksum((u_short *)icp, cc, 0);
+
+    if (icp->type == ICMP_ECHOREPLY) {
+        if (!is_ours(icp->un.echo.id))
+            return 1;           /* 'Twas not our ECHO */
+        if (gather_statistics((__u8*)icp, sizeof(*icp), cc,
+                      ntohs(icp->un.echo.sequence),
+                      ttl, 0, tv, pr_addr(from->sin_addr.s_addr),
+                      pr_echo_reply))
+            return 0;
+    } else {
+        /* We fall here when a redirect or source quench arrived.
+         * Also this branch processes icmp errors, when IP_RECVERR
+         * is broken. */
+
+        switch (icp->type) {
+        case ICMP_ECHO:
+            /* MUST NOT */
+            return 1;
+        case ICMP_SOURCE_QUENCH:
+        case ICMP_REDIRECT:
+        case ICMP_DEST_UNREACH:
+        case ICMP_TIME_EXCEEDED:
+        case ICMP_PARAMETERPROB:
+            {
+                struct iphdr * iph = (struct  iphdr *)(&icp[1]);
+                struct icmphdr *icp1 = (struct icmphdr*)((unsigned char *)iph + iph->ihl*4);
+                int error_pkt;
+                if (cc < 8+sizeof(struct iphdr)+8 ||
+                    cc < 8+iph->ihl*4+8)
+                    return 1;
+                if (icp1->type != ICMP_ECHO ||
+                    iph->daddr != whereto.sin_addr.s_addr ||
+                    !is_ours(icp1->un.echo.id))
+                    return 1;
+                error_pkt = (icp->type != ICMP_REDIRECT &&
+                         icp->type != ICMP_SOURCE_QUENCH);
+                if (error_pkt) {
+                    acknowledge(ntohs(icp1->un.echo.sequence));
+                    if (working_recverr) {
+                        return 0;
+                    } else {
+                        static int once;
+                        /* Sigh, IP_RECVERR for raw socket
+                         * was broken until 2.4.9. So, we ignore
+                         * the first error and warn on the second.
+                         */
+                        if (once++ == 1)
+                            fprintf(stderr, "\rWARNING: kernel is not very fresh, upgrade is recommended.\n");
+                        if (once == 1)
+                            return 0;
+                    }
+                }
+                nerrors+=error_pkt;
+                if (options&F_QUIET)
+                    return !error_pkt;
+                if (options & F_FLOOD) {
+                    if (error_pkt)
+                        write_stdout("\bE", 2);
+                    return !error_pkt;
+                }
+                print_timestamp();
+                printf("From %s: icmp_seq=%u ",
+                       pr_addr(from->sin_addr.s_addr),
+                       ntohs(icp1->un.echo.sequence));
+                if (csfailed)
+                    printf("(BAD CHECKSUM)");
+                pr_icmph(icp->type, icp->code, ntohl(icp->un.gateway), icp);
+                return !error_pkt;
+            }
+        default:
+            /* MUST NOT */
+            break;
+        }
+        if ((options & F_FLOOD) && !(options & (F_VERBOSE|F_QUIET))) {
+            if (!csfailed)
+                write_stdout("!E", 2);
+            else
+                write_stdout("!EC", 3);
+            return 0;
+        }
+        if (!(options & F_VERBOSE) || uid)
+            return 0;
+        if (options & F_PTIMEOFDAY) {
+            struct timeval recv_time;
+            gettimeofday(&recv_time, NULL);
+            printf("%lu.%06lu ", (unsigned long)recv_time.tv_sec, (unsigned long)recv_time.tv_usec);
+        }
+        printf("From %s: ", pr_addr(from->sin_addr.s_addr));
+        if (csfailed) {
+            printf("(BAD CHECKSUM)\n");
+            return 0;
+        }
+        pr_icmph(icp->type, icp->code, ntohl(icp->un.gateway), icp);
+        return 0;
+    }
+
+    if (!(options & F_FLOOD)) {
+        pr_options(opts, optlen + sizeof(struct iphdr));
+
+        if (options & F_AUDIBLE)
+            putchar('\a');
+        putchar('\n');
+        fflush(stdout);
+    } else {
+        putchar('\a');
+        fflush(stdout);
+    }
+    return 0;
+}
+
+
+#if BYTE_ORDER == LITTLE_ENDIAN
+# define ODDBYTE(v) (v)
+#elif BYTE_ORDER == BIG_ENDIAN
+# define ODDBYTE(v) ((u_short)(v) << 8)
+#else
+# define ODDBYTE(v) htons((u_short)(v) << 8)
+#endif
+
+u_short
+in_cksum(const u_short *addr, register int len, u_short csum)
+{
+    register int nleft = len;
+    const u_short *w = addr;
+    register u_short answer;
+    register int sum = csum;
+
+    /*
+     *  Our algorithm is simple, using a 32 bit accumulator (sum),
+     *  we add sequential 16 bit words to it, and at the end, fold
+     *  back all the carry bits from the top 16 bits into the lower
+     *  16 bits.
+     */
+    while (nleft > 1)  {
+        sum += *w++;
+        nleft -= 2;
+    }
+
+    /* mop up an odd byte, if necessary */
+    if (nleft == 1)
+        sum += ODDBYTE(*(u_char *)w); /* le16toh() may be unavailable on old systems */
+
+    /*
+     * add back carry outs from top 16 bits to low 16 bits
+     */
+    sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
+    sum += (sum >> 16);         /* add carry */
+    answer = ~sum;              /* truncate to 16 bits */
+    return (answer);
+}
+
+/*
+ * pr_icmph --
+ *  Print a descriptive string about an ICMP header.
+ */
+void pr_icmph(__u8 type, __u8 code, __u32 info, struct icmphdr *icp)
+{
+    switch(type) {
+    case ICMP_ECHOREPLY:
+        printf("Echo Reply\n");
+        /* XXX ID + Seq + Data */
+        break;
+    case ICMP_DEST_UNREACH:
+        switch(code) {
+        case ICMP_NET_UNREACH:
+            printf("Destination Net Unreachable\n");
+            break;
+        case ICMP_HOST_UNREACH:
+            printf("Destination Host Unreachable\n");
+            break;
+        case ICMP_PROT_UNREACH:
+            printf("Destination Protocol Unreachable\n");
+            break;
+        case ICMP_PORT_UNREACH:
+            printf("Destination Port Unreachable\n");
+            break;
+        case ICMP_FRAG_NEEDED:
+            printf("Frag needed and DF set (mtu = %u)\n", info);
+            break;
+        case ICMP_SR_FAILED:
+            printf("Source Route Failed\n");
+            break;
+        case ICMP_NET_UNKNOWN:
+            printf("Destination Net Unknown\n");
+            break;
+        case ICMP_HOST_UNKNOWN:
+            printf("Destination Host Unknown\n");
+            break;
+        case ICMP_HOST_ISOLATED:
+            printf("Source Host Isolated\n");
+            break;
+        case ICMP_NET_ANO:
+            printf("Destination Net Prohibited\n");
+            break;
+        case ICMP_HOST_ANO:
+            printf("Destination Host Prohibited\n");
+            break;
+        case ICMP_NET_UNR_TOS:
+            printf("Destination Net Unreachable for Type of Service\n");
+            break;
+        case ICMP_HOST_UNR_TOS:
+            printf("Destination Host Unreachable for Type of Service\n");
+            break;
+        case ICMP_PKT_FILTERED:
+            printf("Packet filtered\n");
+            break;
+        case ICMP_PREC_VIOLATION:
+            printf("Precedence Violation\n");
+            break;
+        case ICMP_PREC_CUTOFF:
+            printf("Precedence Cutoff\n");
+            break;
+        default:
+            printf("Dest Unreachable, Bad Code: %d\n", code);
+            break;
+        }
+        if (icp && (options & F_VERBOSE))
+            pr_iph((struct iphdr*)(icp + 1));
+        break;
+    case ICMP_SOURCE_QUENCH:
+        printf("Source Quench\n");
+        if (icp && (options & F_VERBOSE))
+            pr_iph((struct iphdr*)(icp + 1));
+        break;
+    case ICMP_REDIRECT:
+        switch(code) {
+        case ICMP_REDIR_NET:
+            printf("Redirect Network");
+            break;
+        case ICMP_REDIR_HOST:
+            printf("Redirect Host");
+            break;
+        case ICMP_REDIR_NETTOS:
+            printf("Redirect Type of Service and Network");
+            break;
+        case ICMP_REDIR_HOSTTOS:
+            printf("Redirect Type of Service and Host");
+            break;
+        default:
+            printf("Redirect, Bad Code: %d", code);
+            break;
+        }
+        printf("(New nexthop: %s)\n", pr_addr(icp ? icp->un.gateway : info));
+        if (icp && (options & F_VERBOSE))
+            pr_iph((struct iphdr*)(icp + 1));
+        break;
+    case ICMP_ECHO:
+        printf("Echo Request\n");
+        /* XXX ID + Seq + Data */
+        break;
+    case ICMP_TIME_EXCEEDED:
+        switch(code) {
+        case ICMP_EXC_TTL:
+            printf("Time to live exceeded\n");
+            break;
+        case ICMP_EXC_FRAGTIME:
+            printf("Frag reassembly time exceeded\n");
+            break;
+        default:
+            printf("Time exceeded, Bad Code: %d\n", code);
+            break;
+        }
+        if (icp && (options & F_VERBOSE))
+            pr_iph((struct iphdr*)(icp + 1));
+        break;
+    case ICMP_PARAMETERPROB:
+        printf("Parameter problem: pointer = %u\n", icp ? (ntohl(icp->un.gateway)>>24) : info);
+        if (icp && (options & F_VERBOSE))
+            pr_iph((struct iphdr*)(icp + 1));
+        break;
+    case ICMP_TIMESTAMP:
+        printf("Timestamp\n");
+        /* XXX ID + Seq + 3 timestamps */
+        break;
+    case ICMP_TIMESTAMPREPLY:
+        printf("Timestamp Reply\n");
+        /* XXX ID + Seq + 3 timestamps */
+        break;
+    case ICMP_INFO_REQUEST:
+        printf("Information Request\n");
+        /* XXX ID + Seq */
+        break;
+    case ICMP_INFO_REPLY:
+        printf("Information Reply\n");
+        /* XXX ID + Seq */
+        break;
+#ifdef ICMP_MASKREQ
+    case ICMP_MASKREQ:
+        printf("Address Mask Request\n");
+        break;
+#endif
+#ifdef ICMP_MASKREPLY
+    case ICMP_MASKREPLY:
+        printf("Address Mask Reply\n");
+        break;
+#endif
+    default:
+        printf("Bad ICMP type: %d\n", type);
+    }
+}
+
+void pr_options(unsigned char * cp, int hlen)
+{
+    int i, j;
+    int optlen, totlen;
+    unsigned char * optptr;
+    static int old_rrlen;
+    static char old_rr[MAX_IPOPTLEN];
+
+    totlen = hlen-sizeof(struct iphdr);
+    optptr = cp;
+
+    while (totlen > 0) {
+        if (*optptr == IPOPT_EOL)
+            break;
+        if (*optptr == IPOPT_NOP) {
+            totlen--;
+            optptr++;
+            printf("\nNOP");
+            continue;
+        }
+        cp = optptr;
+        optlen = optptr[1];
+        if (optlen < 2 || optlen > totlen)
+            break;
+
+        switch (*cp) {
+        case IPOPT_SSRR:
+        case IPOPT_LSRR:
+            printf("\n%cSRR: ", *cp==IPOPT_SSRR ? 'S' : 'L');
+            j = *++cp;
+            i = *++cp;
+            i -= 4;
+            cp++;
+            if (j > IPOPT_MINOFF) {
+                for (;;) {
+                    __u32 address;
+                    memcpy(&address, cp, 4);
+                    cp += 4;
+                    if (address == 0)
+                        printf("\t0.0.0.0");
+                    else
+                        printf("\t%s", pr_addr(address));
+                    j -= 4;
+                    putchar('\n');
+                    if (j <= IPOPT_MINOFF)
+                        break;
+                }
+            }
+            break;
+        case IPOPT_RR:
+            j = *++cp;      /* get length */
+            i = *++cp;      /* and pointer */
+            if (i > j)
+                i = j;
+            i -= IPOPT_MINOFF;
+            if (i <= 0)
+                break;
+            if (i == old_rrlen
+                && !memcmp(cp, old_rr, i)
+                && !(options & F_FLOOD)) {
+                printf("\t(same route)");
+                i = ((i + 3) / 4) * 4;
+                cp += i;
+                break;
+            }
+            old_rrlen = i;
+            memcpy(old_rr, (char *)cp, i);
+            printf("\nRR: ");
+            cp++;
+            for (;;) {
+                __u32 address;
+                memcpy(&address, cp, 4);
+                cp += 4;
+                if (address == 0)
+                    printf("\t0.0.0.0");
+                else
+                    printf("\t%s", pr_addr(address));
+                i -= 4;
+                putchar('\n');
+                if (i <= 0)
+                    break;
+            }
+            break;
+        case IPOPT_TS:
+        {
+            int stdtime = 0, nonstdtime = 0;
+            __u8 flags;
+            j = *++cp;      /* get length */
+            i = *++cp;      /* and pointer */
+            if (i > j)
+                i = j;
+            i -= 5;
+            if (i <= 0)
+                break;
+            flags = *++cp;
+            printf("\nTS: ");
+            cp++;
+            for (;;) {
+                long l;
+
+                if ((flags&0xF) != IPOPT_TS_TSONLY) {
+                    __u32 address;
+                    memcpy(&address, cp, 4);
+                    cp += 4;
+                    if (address == 0)
+                        printf("\t0.0.0.0");
+                    else
+                        printf("\t%s", pr_addr(address));
+                    i -= 4;
+                    if (i <= 0)
+                        break;
+                }
+                l = *cp++;
+                l = (l<<8) + *cp++;
+                l = (l<<8) + *cp++;
+                l = (l<<8) + *cp++;
+
+                if  (l & 0x80000000) {
+                    if (nonstdtime==0)
+                        printf("\t%ld absolute not-standard", l&0x7fffffff);
+                    else
+                        printf("\t%ld not-standard", (l&0x7fffffff) - nonstdtime);
+                    nonstdtime = l&0x7fffffff;
+                } else {
+                    if (stdtime==0)
+                        printf("\t%ld absolute", l);
+                    else
+                        printf("\t%ld", l - stdtime);
+                    stdtime = l;
+                }
+                i -= 4;
+                putchar('\n');
+                if (i <= 0)
+                    break;
+            }
+            if (flags>>4)
+                printf("Unrecorded hops: %d\n", flags>>4);
+            break;
+        }
+        default:
+            printf("\nunknown option %x", *cp);
+            break;
+        }
+        totlen -= optlen;
+        optptr += optlen;
+    }
+}
+
+
+/*
+ * pr_iph --
+ *  Print an IP header with options.
+ */
+void pr_iph(struct iphdr *ip)
+{
+    int hlen;
+    u_char *cp;
+
+    hlen = ip->ihl << 2;
+    cp = (u_char *)ip + 20;     /* point to options */
+
+    printf("Vr HL TOS  Len   ID Flg  off TTL Pro  cks      Src      Dst Data\n");
+    printf(" %1x  %1x  %02x %04x %04x",
+           ip->version, ip->ihl, ip->tos, ip->tot_len, ip->id);
+    printf("   %1x %04x", ((ip->frag_off) & 0xe000) >> 13,
+           (ip->frag_off) & 0x1fff);
+    printf("  %02x  %02x %04x", ip->ttl, ip->protocol, ip->check);
+    printf(" %s ", inet_ntoa(*(struct in_addr *)&ip->saddr));
+    printf(" %s ", inet_ntoa(*(struct in_addr *)&ip->daddr));
+    printf("\n");
+    pr_options(cp, hlen);
+}
+
+/*
+ * pr_addr --
+ *  Return an ascii host address as a dotted quad and optionally with
+ * a hostname.
+ */
+char *
+pr_addr(__u32 addr)
+{
+    struct hostent *hp;
+    static char buf[4096];
+
+    in_pr_addr = !setjmp(pr_addr_jmp);
+
+    if (exiting || (options & F_NUMERIC) ||
+        !(hp = gethostbyaddr((char *)&addr, 4, AF_INET)))
+        sprintf(buf, "%s", inet_ntoa(*(struct in_addr *)&addr));
+    else {
+        char *s;
+#if USE_IDN
+        if (idna_to_unicode_lzlz(hp->h_name, &s, 0) != IDNA_SUCCESS)
+            s = NULL;
+#else
+        s = NULL;
+#endif
+        snprintf(buf, sizeof(buf), "%s (%s)", s ? s : hp->h_name,
+             inet_ntoa(*(struct in_addr *)&addr));
+#if USE_IDN
+        free(s);
+#endif
+    }
+
+    in_pr_addr = 0;
+
+    return(buf);
+}
+
+
+/* Set Type of Service (TOS) and other Quality of Service relating bits */
+int parsetos(char *str)
+{
+    const char *cp;
+    int tos;
+    char *ep;
+
+    /* handle both hex and decimal values */
+    if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X')) {
+        cp = str + 2;
+        tos = (int)strtol(cp, &ep, 16);
+    } else
+        tos = (int)strtol(str, &ep, 10);
+
+    /* doesn't look like decimal or hex, eh? */
+    if (*ep != '\0') {
+        fprintf(stderr, "ping: \"%s\" bad value for TOS\n", str);
+        exit(2);
+    }
+
+    if (tos > TOS_MAX) {
+        fprintf(stderr, "ping: the decimal value of TOS bits must be 0-254 (or zero)\n");
+        exit(2);
+    }
+    return(tos);
+}
+
+#include <linux/filter.h>
+
+void install_filter(void)
+{
+    static int once;
+    static struct sock_filter insns[] = {
+        BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0), /* Skip IP header. F..g BSD... Look into ping6. */
+        BPF_STMT(BPF_LD|BPF_H|BPF_IND, 4), /* Load icmp echo ident */
+        BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0xAAAA, 0, 1), /* Ours? */
+        BPF_STMT(BPF_RET|BPF_K, ~0U), /* Yes, it passes. */
+        BPF_STMT(BPF_LD|BPF_B|BPF_IND, 0), /* Load icmp type */
+        BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, ICMP_ECHOREPLY, 1, 0), /* Echo? */
+        BPF_STMT(BPF_RET|BPF_K, 0xFFFFFFF), /* No. It passes. */
+        BPF_STMT(BPF_RET|BPF_K, 0) /* Echo with wrong ident. Reject. */
+    };
+    static struct sock_fprog filter = {
+        sizeof insns / sizeof(insns[0]),
+        insns
+    };
+
+    if (once || using_ping_socket)
+        return;
+    once = 1;
+
+    /* Patch bpflet for current identifier. */
+    insns[2] = (struct sock_filter)BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, htons(ident), 0, 1);
+
+    if (setsockopt(icmp_sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)))
+        perror("WARNING: failed to install socket filter\n");
+}
+
+#define USAGE_NEWLINE   "\n           "
+
+void usage(void)
+{
+    fprintf(stderr,
+        "Usage: ping"
+        " [-"
+            "aAbBdDfhLnOqrRUvV"
+        "]"
+        " [-c count]"
+        " [-i interval]"
+        " [-I interface]"
+        USAGE_NEWLINE
+        " [-m mark]"
+        " [-M pmtudisc_option]"
+        " [-l preload]"
+        " [-p pattern]"
+        " [-Q tos]"
+        USAGE_NEWLINE
+        " [-s packetsize]"
+        " [-S sndbuf]"
+        " [-t ttl]"
+        " [-T timestamp_option]"
+        USAGE_NEWLINE
+        " [-w deadline]"
+        " [-W timeout]"
+        " [hop1 ...] destination"
+        "\n"
+    );
+    exit(2);
+}