/*      $NetBSD: if.c,v 1.109 2022/12/28 18:34:33 mrg Exp $     */

/*
 * Copyright (c) 1983, 1988, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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. 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.
 */

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "from: @(#)if.c  8.2 (Berkeley) 2/21/94";
#else
__RCSID("$NetBSD: if.c,v 1.109 2022/12/28 18:34:33 mrg Exp $");
#endif
#endif /* not lint */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/sysctl.h>
#include <sys/ioctl.h>

#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <arpa/inet.h>

#include <kvm.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <netdb.h>
#include <err.h>

#include "netstat.h"
#include "rtutil.h"
#include "prog_ops.h"

#define MAXIF   100

#define HUMBUF_SIZE 7

struct  iftot {
        char ift_name[IFNAMSIZ];        /* interface name */
        uint64_t ift_ip;                /* input packets */
        uint64_t ift_ib;                /* input bytes */
        uint64_t ift_ie;                /* input errors */
        uint64_t ift_iq;                /* input drops */
        uint64_t ift_op;                /* output packets */
        uint64_t ift_ob;                /* output bytes */
        uint64_t ift_oe;                /* output errors */
        uint64_t ift_oq;                /* output drops */
        uint64_t ift_co;                /* collisions */
};

struct if_data_ext {
        uint64_t ifi_oqdrops;
};

static void set_lines(void);
static void print_addr(const int, struct sockaddr *, struct sockaddr **,
    struct if_data *, struct ifnet *, struct if_data_ext *);
static void sidewaysintpr(u_int, u_long);

static void iftot_banner(struct iftot *);
static void iftot_print_sum(struct iftot *, struct iftot *);
static void iftot_print(struct iftot *, struct iftot *);

static void catchalarm(int);
static void get_rtaddrs(int, struct sockaddr *, struct sockaddr **);
static void fetchifs(void);

static int if_data_ext_get(const char *, struct if_data_ext *);
static void intpr_sysctl(void);
static void intpr_kvm(u_long, void (*)(const char *));

struct iftot iftot[MAXIF], ip_cur, ip_old, sum_cur, sum_old;
static sig_atomic_t signalled;          /* set when alarm goes off */

static unsigned redraw_lines = 21;

static void
set_lines(void)
{
        static bool first = true;
        struct ttysize ts;

        if (!first)
                return;
        first = false;
        if (ioctl(STDOUT_FILENO, TIOCGSIZE, &ts) != -1 && ts.ts_lines)
                redraw_lines = ts.ts_lines - 3;
}


/*
 * Print a description of the network interfaces.
 * NOTE: ifnetaddr is the location of the kernel global "ifnet",
 * which is a TAILQ_HEAD.
 */
void
intpr(int interval, u_long ifnetaddr, void (*pfunc)(const char *))
{

        if (interval) {
                sidewaysintpr((unsigned)interval, ifnetaddr);
                return;
        }

        if (use_sysctl)
                intpr_sysctl();
        else
                intpr_kvm(ifnetaddr, pfunc);
}

static void
intpr_header(void)
{

        if (!sflag && !pflag) {
                if (bflag) {
                        printf("%-5.5s %-5.5s %-13.13s %-17.17s "
                            "%10.10s %10.10s",
                            "Name", "Mtu", "Network", "Address",
                            "Ibytes", "Obytes");
                } else {
                        printf("%-5.5s %-5.5s %-13.13s %-17.17s "
                            "%8.8s %5.5s",
                            "Name", "Mtu", "Network", "Address", "Ipkts", "Ierrs");
                        if (dflag)
                                printf(" %6.6s", "Idrops");
                        printf(" %8.8s %5.5s %5.5s",
                            "Opkts", "Oerrs", "Colls");
                }
                if (dflag)
                        printf(" %6.6s", "Odrops");
                if (tflag)
                        printf(" %4.4s", "Time");
                putchar('\n');
        }
}

int
if_data_ext_get(const char *ifname, struct if_data_ext *dext)
{
        char namebuf[1024];
        size_t len;
        uint64_t drops;

        /* For sysctl */
        snprintf(namebuf, sizeof(namebuf),
            "net.interfaces.%s.sndq.drops", ifname);
        len = sizeof(drops);
        if (sysctlbyname(namebuf, &drops, &len, NULL, 0) == -1) {
                warn("%s", namebuf);
                dext->ifi_oqdrops = 0;
                return -1;
        } else
                dext->ifi_oqdrops = drops;

        return 0;
}

static void
intpr_sysctl(void)
{
        struct if_msghdr *ifm;
        int mib[6] = { CTL_NET, AF_ROUTE, 0, 0, NET_RT_IFLIST, 0 };
        static char *buf = NULL;
        static size_t olen;
        char *next, *lim, *cp;
        struct rt_msghdr *rtm;
        struct ifa_msghdr *ifam;
        struct if_data *ifd = NULL;
        struct sockaddr *sa, *rti_info[RTAX_MAX];
        struct sockaddr_dl *sdl;
        uint64_t total = 0;
        size_t len;
        int did = 1, rtax = 0, n;
        char name[IFNAMSIZ + 1];        /* + 1 for `*' */
        char origname[IFNAMSIZ];        /* without `*' */
        int ifindex = 0;

        if (prog_sysctl(mib, 6, NULL, &len, NULL, 0) == -1)
                err(1, "sysctl");
        if (len > olen) {
                free(buf);
                if ((buf = malloc(len)) == NULL)
                        err(1, NULL);
                olen = len;
        }
        if (prog_sysctl(mib, 6, buf, &len, NULL, 0) == -1)
                err(1, "sysctl");

        intpr_header();

        lim = buf + len;
        for (next = buf; next < lim; next += rtm->rtm_msglen) {
                struct if_data_ext dext;

                rtm = (struct rt_msghdr *)next;
                if (rtm->rtm_version != RTM_VERSION)
                        continue;
                switch (rtm->rtm_type) {
                case RTM_IFINFO:
                        total = 0;
                        ifm = (struct if_msghdr *)next;
                        ifd = &ifm->ifm_data;

                        sa = (struct sockaddr *)(ifm + 1);
                        get_rtaddrs(ifm->ifm_addrs, sa, rti_info);

                        sdl = (struct sockaddr_dl *)rti_info[RTAX_IFP];
                        if (sdl == NULL || sdl->sdl_family != AF_LINK)
                                continue;

                        bzero(name, sizeof(name));
                        if (sdl->sdl_nlen >= IFNAMSIZ)
                                memcpy(name, sdl->sdl_data, IFNAMSIZ - 1);
                        else if (sdl->sdl_nlen > 0)
                                memcpy(name, sdl->sdl_data, sdl->sdl_nlen);

                        if (interface != NULL && strcmp(name, interface) != 0)
                                continue;

                        ifindex = sdl->sdl_index;

                        /* Keep the original name */
                        strcpy(origname, name);

                        /* Mark inactive interfaces with a '*' */
                        cp = strchr(name, '\0');
                        if ((ifm->ifm_flags & IFF_UP) == 0) {
                                *cp++ = '*';
                                *cp = '\0';
                        }

                        if (qflag) {
                                total = ifd->ifi_ibytes + ifd->ifi_obytes +
                                    ifd->ifi_ipackets + ifd->ifi_ierrors +
                                    ifd->ifi_opackets + ifd->ifi_oerrors +
                                    ifd->ifi_collisions;
                                if (dflag)
                                        total += ifd->ifi_iqdrops;
                                if (total == 0)
                                        continue;
                        }
                        /* Skip the first one */
                        if (did) {
                                did = 0;
                                continue;
                        }
                        rtax = RTAX_IFP;
                        break;
                case RTM_NEWADDR:
                        if (qflag && total == 0)
                                continue;
                        if (interface != NULL && strcmp(name, interface) != 0)
                                continue;
                        ifam = (struct ifa_msghdr *)next;
                        if ((ifam->ifam_addrs & (RTA_NETMASK | RTA_IFA |
                            RTA_BRD)) == 0)
                                break;

                        sa = (struct sockaddr *)(ifam + 1);

                        get_rtaddrs(ifam->ifam_addrs, sa, rti_info);
                        rtax = RTAX_IFA;
                        did = 1;
                        break;
                default:
                        continue;
                }
                if (vflag)
                        n = strlen(name) < 5 ? 5 : strlen(name);
                else
                        n = 5;

                printf("%-*.*s %-5" PRIu64 " ", n, n, name, ifd->ifi_mtu);
                if (dflag)
                        if_data_ext_get(origname, &dext);

                print_addr(ifindex, rti_info[rtax], rti_info, ifd,
                    NULL, dflag ? &dext : NULL);
        }
}

union ifaddr_u {
        struct ifaddr ifa;
        struct in_ifaddr in;
#ifdef INET6
        struct in6_ifaddr in6;
#endif /* INET6 */
};

static void
ifname_to_ifdata(int s, const char *ifname, struct if_data * const ifd)
{
        struct ifdatareq ifdr;

        memset(ifd, 0, sizeof(*ifd));
        strlcpy(ifdr.ifdr_name, ifname, sizeof(ifdr.ifdr_name));
        if (ioctl(s, SIOCGIFDATA, &ifdr) != 0)
                return;
        memcpy(ifd, &ifdr.ifdr_data, sizeof(ifdr.ifdr_data));
}

static void
intpr_kvm(u_long ifnetaddr, void (*pfunc)(const char *))
{
        struct ifnet ifnet;
        struct if_data ifd;
        union ifaddr_u ifaddr;
        u_long ifaddraddr;
        struct ifnet_head ifhead;       /* TAILQ_HEAD */
        char name[IFNAMSIZ + 1];        /* + 1 for `*' */
        int s;

        if (ifnetaddr == 0) {
                printf("ifnet: symbol not defined\n");
                return;
        }

        /*
         * Find the pointer to the first ifnet structure.  Replace
         * the pointer to the TAILQ_HEAD with the actual pointer
         * to the first list element.
         */
        if (kread(ifnetaddr, (char *)&ifhead, sizeof ifhead))
                return;
        ifnetaddr = (u_long)ifhead.tqh_first;

        if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
                return;

        intpr_header();

        ifaddraddr = 0;
        while (ifnetaddr || ifaddraddr) {
                char *cp;
                int n;

                if (ifaddraddr == 0) {
                        if (kread(ifnetaddr, (char *)&ifnet, sizeof ifnet))
                                return;
                        memmove(name, ifnet.if_xname, IFNAMSIZ);
                        name[IFNAMSIZ - 1] = '\0';      /* sanity */
                        ifnetaddr = (u_long)ifnet.if_list.tqe_next;
                        if (interface != NULL && strcmp(name, interface) != 0)
                                continue;
                        cp = strchr(name, '\0');

                        if (pfunc) {
                                (*pfunc)(name);
                                continue;
                        }

                        if ((ifnet.if_flags & IFF_UP) == 0)
                                *cp++ = '*';
                        *cp = '\0';
                        ifaddraddr = (u_long)ifnet.if_addrlist.tqh_first;
                }
                if (vflag)
                        n = strlen(name) < 5 ? 5 : strlen(name);
                else
                        n = 5;
                printf("%-*.*s %-5llu ", n, n, name,
                    (unsigned long long)ifnet.if_mtu);
                if (ifaddraddr == 0) {
                        printf("%-13.13s ", "none");
                        printf("%-17.17s ", "none");
                } else {
                        struct sockaddr *sa;

                        if (kread(ifaddraddr, (char *)&ifaddr, sizeof ifaddr))
                        {
                                ifaddraddr = 0;
                                continue;
                        }
#define CP(x) ((char *)(x))
                        cp = (CP(ifaddr.ifa.ifa_addr) - CP(ifaddraddr)) +
                            CP(&ifaddr);
                        sa = (struct sockaddr *)cp;
                        ifname_to_ifdata(s, name, &ifd);
                        print_addr(ifnet.if_index, sa, (void *)&ifaddr,
                            &ifd, &ifnet, NULL);
                }
                ifaddraddr = (u_long)ifaddr.ifa.ifa_list.tqe_next;
        }
        close(s);
}

static void
mc_print(const int ifindex, const size_t ias, const char *oid, int *mcast_oids,
    void (*pr)(const void *))
{
        uint8_t *mcast_addrs, *p;
        const size_t incr = 2 * ias + sizeof(uint32_t);
        size_t len;

        if (mcast_oids[0] == 0) {
                size_t oidlen = 4;
                if (sysctlnametomib(oid, mcast_oids, &oidlen) == -1) {
                        warnx("'%s' not found", oid);
                        return;
                }
                if (oidlen != 3) {
                        warnx("Wrong OID path for '%s'", oid);
                        return;
                }
        }

        if (mcast_oids[3] == ifindex)
                return;
        mcast_oids[3] = ifindex;

        mcast_addrs = asysctl(mcast_oids, 4, &len);
        if (mcast_addrs == NULL && len != 0) {
                warn("failed to read '%s'", oid);
                return;
        }
        if (len) {
                p = mcast_addrs;
                while (len >= incr) {
                        (*pr)((p + ias));
                        p += incr;
                        len -= incr;
                }
        }
        free(mcast_addrs);
}

#ifdef INET6
static void
ia6_print(const struct in6_addr *ia)
{
        struct sockaddr_in6 as6;
        char hbuf[NI_MAXHOST];          /* for getnameinfo() */
        int n;

        memset(&as6, 0, sizeof(as6));
        as6.sin6_len = sizeof(struct sockaddr_in6);
        as6.sin6_family = AF_INET6;
        as6.sin6_addr = *ia;
        inet6_getscopeid(&as6, INET6_IS_ADDR_MC_LINKLOCAL);
        if (getnameinfo((struct sockaddr *)&as6, as6.sin6_len, hbuf,
            sizeof(hbuf), NULL, 0, NI_NUMERICHOST) != 0) {
                strlcpy(hbuf, "??", sizeof(hbuf));
        }
        if (vflag)
                n = strlen(hbuf) < 17 ? 17 : strlen(hbuf);
        else
                n = 17;
        printf("\n%25s %-*.*s ", "", n, n, hbuf);
}

static void
mc6_print(const int ifindex)
{
        static int mcast_oids[4];

        mc_print(ifindex, sizeof(struct in6_addr), "net.inet6.multicast",
            mcast_oids, (void (*)(const void *))ia6_print);
}
#endif

static void
ia4_print(const struct in_addr *ia)
{
        printf("\n%25s %-17.17s ", "", routename4(ia->s_addr, nflag));
}

static void
mc4_print(const int ifindex)
{
        static int mcast_oids[4];

        mc_print(ifindex, sizeof(struct in_addr), "net.inet.multicast",
            mcast_oids, (void (*)(const void *))ia4_print);
}

static void
print_addr(const int ifindex, struct sockaddr *sa, struct sockaddr **rtinfo,
    struct if_data *ifd, struct ifnet *ifnet, struct if_data_ext *dext)
{
        char hexsep = '.';              /* for hexprint */
        static const char hexfmt[] = "%02x%c";  /* for hexprint */
        char hbuf[NI_MAXHOST];          /* for getnameinfo() */
#ifdef INET6
        const int niflag = NI_NUMERICHOST;
        struct sockaddr_in6 *sin6, *netmask6;
#endif
        struct sockaddr_in netmask;
        struct sockaddr_in *sin;
        char *cp;
        int n, m;

        switch (sa->sa_family) {
        case AF_UNSPEC:
                printf("%-13.13s ", "none");
                printf("%-17.17s ", "none");
                break;
        case AF_INET:
                sin = (struct sockaddr_in *)sa;
                if (use_sysctl) {
                        netmask =
                            *((struct sockaddr_in *)rtinfo[RTAX_NETMASK]);
                } else {
                        struct in_ifaddr *ifaddr_in = (void *)rtinfo;
                        netmask.sin_addr.s_addr = ifaddr_in->ia_subnetmask;
                }
                cp = netname4(sin, &netmask, nflag);
                if (vflag)
                        n = strlen(cp) < 13 ? 13 : strlen(cp);
                else
                        n = 13;
                printf("%-*.*s ", n, n, cp);
                cp = routename4(sin->sin_addr.s_addr, nflag);
                if (vflag)
                        n = strlen(cp) < 17 ? 17 : strlen(cp);
                else
                        n = 17;
                printf("%-*.*s ", n, n, cp);

                if (!aflag)
                        break;
                if (ifnet) {
                        u_long multiaddr;
                        struct in_multi inm;
                        union ifaddr_u *ifaddr = (union ifaddr_u *)rtinfo;

                        multiaddr = (u_long)ifaddr->in.ia_multiaddrs.lh_first;
                        while (multiaddr != 0) {
                                kread(multiaddr, (char *)&inm, sizeof inm);
                                ia4_print(&inm.inm_addr);
                                multiaddr = (u_long)inm.inm_list.le_next;
                        }
                } else
                        mc4_print(ifindex);
                break;
#ifdef INET6
        case AF_INET6:
                sin6 = (struct sockaddr_in6 *)sa;
                inet6_getscopeid(sin6, INET6_IS_ADDR_LINKLOCAL);
#ifdef __KAME__
                if (!vflag)
                        sin6->sin6_scope_id = 0;
#endif

                if (use_sysctl)
                        netmask6 = (struct sockaddr_in6 *)rtinfo[RTAX_NETMASK];
                else {
                        struct in6_ifaddr *ifaddr_in6 = (void *)rtinfo;
                        netmask6 = &ifaddr_in6->ia_prefixmask;
                }

                cp = netname6(sin6, netmask6, nflag);
                if (vflag)
                        n = strlen(cp) < 13 ? 13 : strlen(cp);
                else
                        n = 13;
                printf("%-*.*s ", n, n, cp);
                if (getnameinfo((struct sockaddr *)sin6,
                                sin6->sin6_len,
                                hbuf, sizeof(hbuf), NULL, 0,
                                niflag) != 0) {
                        strlcpy(hbuf, "?", sizeof(hbuf));
                }
                cp = hbuf;
                if (vflag)
                        n = strlen(cp) < 17 ? 17 : strlen(cp);
                else
                        n = 17;
                printf("%-*.*s ", n, n, cp);

                if (!aflag)
                        break;
                if (ifnet) {
                        u_long multiaddr;
                        struct in6_multi inm;
                        union ifaddr_u *ifaddr = (union ifaddr_u *)rtinfo;

                        multiaddr = (u_long)ifaddr->in6._ia6_multiaddrs.lh_first;
                        while (multiaddr != 0) {
                                kread(multiaddr, (char *)&inm, sizeof inm);
                                ia6_print(&inm.in6m_addr);
                                multiaddr = (u_long)inm.in6m_entry.le_next;
                        }
                } else
                        mc6_print(ifindex);
                break;
#endif /*INET6*/
#ifndef SMALL
        case AF_APPLETALK:
                printf("atalk:%-7.7s ", atalk_print(sa, 0x10));
                printf("%-17.17s ", atalk_print(sa, 0x0b));
                break;
#endif
        case AF_LINK:
                printf("%-13.13s ", "<Link>");
                if (getnameinfo(sa, sa->sa_len,
                    hbuf, sizeof(hbuf), NULL, 0,
                    NI_NUMERICHOST) != 0) {
                        strlcpy(hbuf, "?", sizeof(hbuf));
                }
                cp = hbuf;
                if (vflag)
                        n = strlen(cp) < 17 ? 17 : strlen(cp);
                else
                        n = 17;
                printf("%-*.*s ", n, n, cp);
                break;

        default:
                m = printf("(%d)", sa->sa_family);
                for (cp = sa->sa_len + (char *)sa;
                        --cp > sa->sa_data && (*cp == 0);) {}
                n = cp - sa->sa_data + 1;
                cp = sa->sa_data;

                while (--n >= 0)
                        m += printf(hexfmt, *cp++ & 0xff,
                                    n > 0 ? hexsep : ' ');
                m = 32 - m;
                while (m-- > 0)
                        putchar(' ');
                break;
        }

        if (bflag) {
                char humbuf[HUMBUF_SIZE];

                if (hflag && humanize_number(humbuf, sizeof(humbuf),
                    ifd->ifi_ibytes, "", HN_AUTOSCALE, HN_NOSPACE | HN_B) > 0)
                        printf("%10s ", humbuf);
                else
                        printf("%10llu ", (unsigned long long)ifd->ifi_ibytes);

                if (hflag && humanize_number(humbuf, sizeof(humbuf),
                    ifd->ifi_obytes, "", HN_AUTOSCALE, HN_NOSPACE | HN_B) > 0)
                        printf("%10s", humbuf);
                else
                        printf("%10llu", (unsigned long long)ifd->ifi_obytes);
        } else {
                printf("%8llu %5llu",
                        (unsigned long long)ifd->ifi_ipackets,
                        (unsigned long long)ifd->ifi_ierrors);
                if (dflag)
                        printf(" %6" PRIu64, ifd->ifi_iqdrops);
                printf(" %8llu %5llu %5llu",
                        (unsigned long long)ifd->ifi_opackets,
                        (unsigned long long)ifd->ifi_oerrors,
                        (unsigned long long)ifd->ifi_collisions);
        }
        if (dflag)
                printf(" %6" PRIu64, ifnet ?
                    ifnet->if_snd.ifq_drops : dext->ifi_oqdrops);
        if (tflag)
                printf(" %4d", ifnet ? ifnet->if_timer : 0);
        putchar('\n');
}

static void
iftot_banner(struct iftot *ift)
{
        if (bflag)
                printf("%7.7s in %8.8s %6.6s out %5.5s",
                    ift->ift_name, " ",
                    ift->ift_name, " ");
        else
                printf("%5.5s in %5.5s%5.5s out %5.5s %5.5s",
                    ift->ift_name, " ",
                    ift->ift_name, " ", " ");
        if (dflag)
                printf(" %5.5s", " ");

        if (bflag)
                printf("  %7.7s in %8.8s %6.6s out %5.5s",
                    "total", " ", "total", " ");
        else
                printf("  %5.5s in %5.5s%5.5s out %5.5s %5.5s",
                    "total", " ", "total", " ", " ");
        if (dflag)
                printf(" %5.5s", " ");
        putchar('\n');
        if (bflag)
                printf("%10.10s %8.8s %10.10s %5.5s",
                    "bytes", " ", "bytes", " ");
        else
                printf("%8.8s %5.5s %8.8s %5.5s %5.5s",
                    "packets", "errs", "packets", "errs", "colls");
        if (dflag)
                printf(" %5.5s", "drops");

        if (bflag)
                printf("  %10.10s %8.8s %10.10s %5.5s",
                    "bytes", " ", "bytes", " ");
        else
                printf("  %8.8s %5.5s %8.8s %5.5s %5.5s",
                    "packets", "errs", "packets", "errs", "colls");
        if (dflag)
                printf(" %5.5s", "drops");
        putchar('\n');
        fflush(stdout);
}

static void
iftot_print(struct iftot *cur, struct iftot *old)
{
        if (bflag)
                printf("%10" PRIu64 " %8.8s %10" PRIu64 " %5.5s",
                    cur->ift_ib - old->ift_ib, " ",
                    cur->ift_ob - old->ift_ob, " ");
        else
                printf("%8" PRIu64 " %5" PRIu64 " %8" PRIu64 " %5" PRIu64 " %5" PRIu64,
                    cur->ift_ip - old->ift_ip,
                    cur->ift_ie - old->ift_ie,
                    cur->ift_op - old->ift_op,
                    cur->ift_oe - old->ift_oe,
                    cur->ift_co - old->ift_co);
        if (dflag)
                printf(" %5" PRIu64, cur->ift_oq - old->ift_oq);
}

static void
iftot_print_sum(struct iftot *cur, struct iftot *old)
{
        if (bflag)
                printf("  %10" PRIu64 " %8.8s %10" PRIu64 " %5.5s",
                    cur->ift_ib - old->ift_ib, " ",
                    cur->ift_ob - old->ift_ob, " ");
        else
                printf("  %8" PRIu64 " %5" PRIu64 " %8" PRIu64 " %5" PRIu64 " %5" PRIu64,
                    cur->ift_ip - old->ift_ip,
                    cur->ift_ie - old->ift_ie,
                    cur->ift_op - old->ift_op,
                    cur->ift_oe - old->ift_oe,
                    cur->ift_co - old->ift_co);

        if (dflag)
                printf(" %5" PRIu64, cur->ift_oq - old->ift_oq);
}

__dead static void
sidewaysintpr_sysctl(unsigned interval)
{
        struct itimerval it;
        sigset_t emptyset;
        sigset_t noalrm;
        unsigned line;

        set_lines();

        fetchifs();
        if (ip_cur.ift_name[0] == '\0') {
                fprintf(stderr, "%s: %s: unknown interface\n",
                    getprogname(), interface);
                exit(1);
        }

        sigemptyset(&emptyset);
        sigemptyset(&noalrm);
        sigaddset(&noalrm, SIGALRM);
        sigprocmask(SIG_SETMASK, &noalrm, NULL);

        signalled = 0;
        (void)signal(SIGALRM, catchalarm);

        it.it_interval.tv_sec = it.it_value.tv_sec = interval;
        it.it_interval.tv_usec = it.it_value.tv_usec = 0;
        setitimer(ITIMER_REAL, &it, NULL);

banner:
        iftot_banner(&ip_cur);

        line = 0;
        bzero(&ip_old, sizeof(ip_old));
        bzero(&sum_old, sizeof(sum_old));
loop:
        bzero(&sum_cur, sizeof(sum_cur));

        fetchifs();

        iftot_print(&ip_cur, &ip_old);

        ip_old = ip_cur;

        iftot_print_sum(&sum_cur, &sum_old);

        sum_old = sum_cur;

        putchar('\n');
        fflush(stdout);
        line++;
        if (signalled == 0)
                sigsuspend(&emptyset);

        signalled = 0;
        if (line == redraw_lines)
                goto banner;
        goto loop;
        /*NOTREACHED*/
}

static void
sidewaysintpr_kvm(unsigned interval, u_long off)
{
        struct itimerval it;
        sigset_t emptyset;
        sigset_t noalrm;
        struct ifnet ifnet;
        struct if_data ifd;
        u_long firstifnet;
        struct iftot *ip, *total;
        unsigned line;
        struct iftot *lastif, *sum, *interesting;
        struct ifnet_head ifhead;       /* TAILQ_HEAD */
        int s;

        set_lines();

        /*
         * Find the pointer to the first ifnet structure.  Replace
         * the pointer to the TAILQ_HEAD with the actual pointer
         * to the first list element.
         */
        if (kread(off, (char *)&ifhead, sizeof ifhead))
                return;
        firstifnet = (u_long)ifhead.tqh_first;

        if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
                return;

        lastif = iftot;
        sum = iftot + MAXIF - 1;
        total = sum - 1;
        interesting = (interface == NULL) ? iftot : NULL;
        for (off = firstifnet, ip = iftot; off;) {
                if (kread(off, (char *)&ifnet, sizeof ifnet))
                        break;
                memset(ip->ift_name, 0, sizeof(ip->ift_name));
                snprintf(ip->ift_name, IFNAMSIZ, "%s", ifnet.if_xname);
                if (interface && strcmp(ifnet.if_xname, interface) == 0)
                        interesting = ip;
                ip++;
                if (ip >= iftot + MAXIF - 2)
                        break;
                off = (u_long)ifnet.if_list.tqe_next;
        }
        if (interesting == NULL) {
                fprintf(stderr, "%s: %s: unknown interface\n",
                    getprogname(), interface);
                exit(1);
        }
        lastif = ip;

        sigemptyset(&emptyset);
        sigemptyset(&noalrm);
        sigaddset(&noalrm, SIGALRM);
        sigprocmask(SIG_SETMASK, &noalrm, NULL);

        signalled = 0;
        (void)signal(SIGALRM, catchalarm);

        it.it_interval.tv_sec = it.it_value.tv_sec = interval;
        it.it_interval.tv_usec = it.it_value.tv_usec = 0;
        setitimer(ITIMER_REAL, &it, NULL);

banner:
        if (bflag)
                printf("%7.7s in %8.8s %6.6s out %5.5s",
                    interesting->ift_name, " ",
                    interesting->ift_name, " ");
        else
                printf("%5.5s in %5.5s%5.5s out %5.5s %5.5s",
                    interesting->ift_name, " ",
                    interesting->ift_name, " ", " ");
        if (dflag)
                printf(" %5.5s", " ");
        if (lastif - iftot > 0) {
                if (bflag)
                        printf("  %7.7s in %8.8s %6.6s out %5.5s",
                            "total", " ", "total", " ");
                else
                        printf("  %5.5s in %5.5s%5.5s out %5.5s %5.5s",
                            "total", " ", "total", " ", " ");
                if (dflag)
                        printf(" %5.5s", " ");
        }
        for (ip = iftot; ip < iftot + MAXIF; ip++) {
                ip->ift_ip = 0;
                ip->ift_ib = 0;
                ip->ift_ie = 0;
                ip->ift_iq = 0;
                ip->ift_op = 0;
                ip->ift_ob = 0;
                ip->ift_oe = 0;
                ip->ift_oq = 0;
                ip->ift_co = 0;
        }
        putchar('\n');
        if (bflag)
                printf("%10.10s %8.8s %10.10s %5.5s",
                    "bytes", " ", "bytes", " ");
        else
                printf("%8.8s %5.5s %8.8s %5.5s %5.5s",
                    "packets", "errs", "packets", "errs", "colls");
        if (dflag)
                printf(" %5.5s", "drops");
        if (lastif - iftot > 0) {
                if (bflag)
                        printf("  %10.10s %8.8s %10.10s %5.5s",
                            "bytes", " ", "bytes", " ");
                else
                        printf("  %8.8s %5.5s %8.8s %5.5s %5.5s",
                            "packets", "errs", "packets", "errs", "colls");
                if (dflag)
                        printf(" %5.5s", "drops");
        }
        putchar('\n');
        fflush(stdout);
        line = 0;
loop:
        sum->ift_ip = 0;
        sum->ift_ib = 0;
        sum->ift_ie = 0;
        sum->ift_iq = 0;
        sum->ift_op = 0;
        sum->ift_ob = 0;
        sum->ift_oe = 0;
        sum->ift_oq = 0;
        sum->ift_co = 0;
        for (off = firstifnet, ip = iftot; off && ip < lastif; ip++) {
                if (kread(off, (char *)&ifnet, sizeof ifnet)) {
                        off = 0;
                        continue;
                }
                ifname_to_ifdata(s, ip->ift_name, &ifd);
                if (ip == interesting) {
                        if (bflag) {
                                char humbuf[HUMBUF_SIZE];

                                if (hflag && humanize_number(humbuf,
                                    sizeof(humbuf),
                                    ifd.ifi_ibytes - ip->ift_ib, "",
                                    HN_AUTOSCALE, HN_NOSPACE | HN_B) > 0)
                                        printf("%10s %8.8s ", humbuf, " ");
                                else
                                        printf("%10llu %8.8s ",
                                            (unsigned long long)
                                            (ifd.ifi_ibytes-ip->ift_ib), " ");

                                if (hflag && humanize_number(humbuf,
                                    sizeof(humbuf),
                                    ifd.ifi_obytes - ip->ift_ob, "",
                                    HN_AUTOSCALE, HN_NOSPACE | HN_B) > 0)
                                        printf("%10s %5.5s", humbuf, " ");
                                else
                                        printf("%10llu %5.5s",
                                            (unsigned long long)
                                            (ifd.ifi_obytes-ip->ift_ob), " ");
                        } else {
                                printf("%8llu %5llu %8llu %5llu %5llu",
                                    (unsigned long long)
                                        (ifd.ifi_ipackets - ip->ift_ip),
                                    (unsigned long long)
                                        (ifd.ifi_ierrors - ip->ift_ie),
                                    (unsigned long long)
                                        (ifd.ifi_opackets - ip->ift_op),
                                    (unsigned long long)
                                        (ifd.ifi_oerrors - ip->ift_oe),
                                    (unsigned long long)
                                        (ifd.ifi_collisions - ip->ift_co));
                        }
                        if (dflag)
                                printf(" %5" PRIu64,
                                        ifnet.if_snd.ifq_drops - ip->ift_oq);
                }
                ip->ift_ip = ifd.ifi_ipackets;
                ip->ift_ib = ifd.ifi_ibytes;
                ip->ift_ie = ifd.ifi_ierrors;
                ip->ift_op = ifd.ifi_opackets;
                ip->ift_ob = ifd.ifi_obytes;
                ip->ift_oe = ifd.ifi_oerrors;
                ip->ift_co = ifd.ifi_collisions;
                ip->ift_oq = ifnet.if_snd.ifq_drops;
                sum->ift_ip += ip->ift_ip;
                sum->ift_ib += ip->ift_ib;
                sum->ift_ie += ip->ift_ie;
                sum->ift_op += ip->ift_op;
                sum->ift_ob += ip->ift_ob;
                sum->ift_oe += ip->ift_oe;
                sum->ift_co += ip->ift_co;
                sum->ift_oq += ip->ift_oq;
                off = (u_long)ifnet.if_list.tqe_next;
        }
        if (lastif - iftot > 0) {
                if (bflag) {
                        char humbuf[HUMBUF_SIZE];

                        if (hflag && humanize_number(humbuf,
                            sizeof(humbuf), sum->ift_ib - total->ift_ib, "",
                            HN_AUTOSCALE, HN_NOSPACE | HN_B) > 0)
                                printf("  %10s %8.8s ", humbuf, " ");
                        else
                                printf("  %10llu %8.8s ",
                                    (unsigned long long)
                                    (sum->ift_ib - total->ift_ib), " ");

                        if (hflag && humanize_number(humbuf,
                            sizeof(humbuf), sum->ift_ob -  total->ift_ob, "",
                            HN_AUTOSCALE, HN_NOSPACE | HN_B) > 0)
                                printf("%10s %5.5s", humbuf, " ");
                        else
                                printf("%10llu %5.5s",
                                    (unsigned long long)
                                    (sum->ift_ob - total->ift_ob), " ");
                } else {
                        printf("  %8llu %5llu %8llu %5llu %5llu",
                            (unsigned long long)
                                (sum->ift_ip - total->ift_ip),
                            (unsigned long long)
                                (sum->ift_ie - total->ift_ie),
                            (unsigned long long)
                                (sum->ift_op - total->ift_op),
                            (unsigned long long)
                                (sum->ift_oe - total->ift_oe),
                            (unsigned long long)
                                (sum->ift_co - total->ift_co));
                }
                if (dflag)
                        printf(" %5llu",
                            (unsigned long long)(sum->ift_oq - total->ift_oq));
        }
        *total = *sum;
        putchar('\n');
        fflush(stdout);
        line++;
        if (signalled == 0)
                sigsuspend(&emptyset);

        signalled = 0;
        if (line == redraw_lines)
                goto banner;
        goto loop;
        /*NOTREACHED*/
}

/*
 * Print a running summary of interface statistics.
 * Repeat display every interval seconds, showing statistics
 * collected over that interval.  Assumes that interval is non-zero.
 * First line printed at top of screen is always cumulative.
 */
static void
sidewaysintpr(unsigned int interval, u_long off)
{

        if (use_sysctl)
                sidewaysintpr_sysctl(interval);
        else
                sidewaysintpr_kvm(interval, off);
}

/*
 * Called if an interval expires before sidewaysintpr has completed a loop.
 * Sets a flag to not wait for the alarm.
 */
static void
catchalarm(int signo)
{

        signalled = true;
}

static void
get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info)
{
        int i;

        for (i = 0; i < RTAX_MAX; i++) {
                if (addrs & (1 << i)) {
                        rti_info[i] = sa;
                        sa = (struct sockaddr *)((char *)(sa) +
                            RT_ROUNDUP(sa->sa_len));
                } else
                        rti_info[i] = NULL;
        }
}

static void
fetchifs(void)
{
        struct if_msghdr *ifm;
        int mib[6] = { CTL_NET, AF_ROUTE, 0, 0, NET_RT_IFLIST, 0 };
        struct rt_msghdr *rtm;
        struct if_data *ifd = NULL;
        struct sockaddr *sa, *rti_info[RTAX_MAX];
        struct sockaddr_dl *sdl;
        static char *buf = NULL;
        static size_t olen;
        struct if_data_ext dext;
        char *next, *lim;
        char name[IFNAMSIZ];
        size_t len;

        if (prog_sysctl(mib, 6, NULL, &len, NULL, 0) == -1)
                err(1, "sysctl");
        if (len > olen) {
                free(buf);
                if ((buf = malloc(len)) == NULL)
                        err(1, NULL);
                olen = len;
        }
        if (prog_sysctl(mib, 6, buf, &len, NULL, 0) == -1)
                err(1, "sysctl");

        memset(&dext, 0, sizeof(dext));
        lim = buf + len;
        for (next = buf; next < lim; next += rtm->rtm_msglen) {
                rtm = (struct rt_msghdr *)next;
                if (rtm->rtm_version != RTM_VERSION)
                        continue;
                switch (rtm->rtm_type) {
                case RTM_IFINFO:
                        ifm = (struct if_msghdr *)next;
                        ifd = &ifm->ifm_data;

                        sa = (struct sockaddr *)(ifm + 1);
                        get_rtaddrs(ifm->ifm_addrs, sa, rti_info);

                        sdl = (struct sockaddr_dl *)rti_info[RTAX_IFP];
                        if (sdl == NULL || sdl->sdl_family != AF_LINK)
                                continue;
                        bzero(name, sizeof(name));
                        if (sdl->sdl_nlen >= IFNAMSIZ)
                                memcpy(name, sdl->sdl_data, IFNAMSIZ - 1);
                        else if (sdl->sdl_nlen > 0)
                                memcpy(name, sdl->sdl_data, sdl->sdl_nlen);

                        if_data_ext_get(name, &dext);

                        if ((interface != NULL && !strcmp(name, interface)) ||
                            (interface == NULL &&
                            ((ip_cur.ift_ib + ip_cur.ift_ob) == 0 ||
                             (ip_cur.ift_ib + ip_cur.ift_ob <
                             ifd->ifi_ibytes + ifd->ifi_obytes)))) {
                                strlcpy(ip_cur.ift_name, name,
                                    sizeof(ip_cur.ift_name));
                                ip_cur.ift_ip = ifd->ifi_ipackets;
                                ip_cur.ift_ib = ifd->ifi_ibytes;
                                ip_cur.ift_ie = ifd->ifi_ierrors;
                                ip_cur.ift_op = ifd->ifi_opackets;
                                ip_cur.ift_ob = ifd->ifi_obytes;
                                ip_cur.ift_oe = ifd->ifi_oerrors;
                                ip_cur.ift_co = ifd->ifi_collisions;
                                ip_cur.ift_iq = ifd->ifi_iqdrops;
                                ip_cur.ift_oq = dext.ifi_oqdrops;
                        }

                        sum_cur.ift_ip += ifd->ifi_ipackets;
                        sum_cur.ift_ib += ifd->ifi_ibytes;
                        sum_cur.ift_ie += ifd->ifi_ierrors;
                        sum_cur.ift_op += ifd->ifi_opackets;
                        sum_cur.ift_ob += ifd->ifi_obytes;
                        sum_cur.ift_oe += ifd->ifi_oerrors;
                        sum_cur.ift_co += ifd->ifi_collisions;
                        sum_cur.ift_iq += ifd->ifi_iqdrops;
                        sum_cur.ift_oq += dext.ifi_oqdrops;
                        break;
                }
        }

        /*
         * If we picked an interface, be sure to keep using it for the rest
         * of this instance.
         */
        if (interface == NULL)
                interface = ip_cur.ift_name;
}