src/connectivity/pingnetid/ping.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. 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);
}