source: MondoRescue/branches/2.2.5/mindi-busybox/networking/libiproute/iplink.c@ 3332

/* vi: set sw=4 ts=4: */
/*
 * iplink.c "ip link".
 *
 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

//#include <sys/ioctl.h>
//#include <sys/socket.h>
#include <net/if.h>
#include <net/if_packet.h>
#include <netpacket/packet.h>
#include <net/ethernet.h>

#include "ip_common.h"  /* #include "libbb.h" is inside */
#include "rt_names.h"
#include "utils.h"

/* taken from linux/sockios.h */
#define SIOCSIFNAME 0x8923      /* set interface name */

static void on_off(const char *msg) ATTRIBUTE_NORETURN;
static void on_off(const char *msg)
{
    bb_error_msg_and_die("error: argument of \"%s\" must be \"on\" or \"off\"", msg);
}

/* Exits on error */
static int get_ctl_fd(void)
{
    int fd;

    fd = socket(PF_INET, SOCK_DGRAM, 0);
    if (fd >= 0)
        return fd;
    fd = socket(PF_PACKET, SOCK_DGRAM, 0);
    if (fd >= 0)
        return fd;
    return xsocket(PF_INET6, SOCK_DGRAM, 0);
}

/* Exits on error */
static void do_chflags(char *dev, uint32_t flags, uint32_t mask)
{
    struct ifreq ifr;
    int fd;

    strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
    fd = get_ctl_fd();
    xioctl(fd, SIOCGIFFLAGS, &ifr);
    if ((ifr.ifr_flags ^ flags) & mask) {
        ifr.ifr_flags &= ~mask;
        ifr.ifr_flags |= mask & flags;
        xioctl(fd, SIOCSIFFLAGS, &ifr);
    }
    close(fd);
}

/* Exits on error */
static void do_changename(char *dev, char *newdev)
{
    struct ifreq ifr;
    int fd;

    strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
    strncpy(ifr.ifr_newname, newdev, sizeof(ifr.ifr_newname));
    fd = get_ctl_fd();
    xioctl(fd, SIOCSIFNAME, &ifr);
    close(fd);
}

/* Exits on error */
static void set_qlen(char *dev, int qlen)
{
    struct ifreq ifr;
    int s;

    s = get_ctl_fd();
    memset(&ifr, 0, sizeof(ifr));
    strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
    ifr.ifr_qlen = qlen;
    xioctl(s, SIOCSIFTXQLEN, &ifr);
    close(s);
}

/* Exits on error */
static void set_mtu(char *dev, int mtu)
{
    struct ifreq ifr;
    int s;

    s = get_ctl_fd();
    memset(&ifr, 0, sizeof(ifr));
    strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
    ifr.ifr_mtu = mtu;
    xioctl(s, SIOCSIFMTU, &ifr);
    close(s);
}

/* Exits on error */
static int get_address(char *dev, int *htype)
{
    struct ifreq ifr;
    struct sockaddr_ll me;
    socklen_t alen;
    int s;

    s = xsocket(PF_PACKET, SOCK_DGRAM, 0);

    memset(&ifr, 0, sizeof(ifr));
    strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
    xioctl(s, SIOCGIFINDEX, &ifr);

    memset(&me, 0, sizeof(me));
    me.sll_family = AF_PACKET;
    me.sll_ifindex = ifr.ifr_ifindex;
    me.sll_protocol = htons(ETH_P_LOOP);
    xbind(s, (struct sockaddr*)&me, sizeof(me));

    alen = sizeof(me);
    if (getsockname(s, (struct sockaddr*)&me, &alen) == -1) {
        bb_perror_msg_and_die("getsockname");
    }
    close(s);
    *htype = me.sll_hatype;
    return me.sll_halen;
}

/* Exits on error */
static void parse_address(char *dev, int hatype, int halen, char *lla, struct ifreq *ifr)
{
    int alen;

    memset(ifr, 0, sizeof(*ifr));
    strncpy(ifr->ifr_name, dev, sizeof(ifr->ifr_name));
    ifr->ifr_hwaddr.sa_family = hatype;
    alen = ll_addr_a2n((unsigned char *)(ifr->ifr_hwaddr.sa_data), 14, lla);
    if (alen < 0)
        exit(1);
    if (alen != halen) {
        bb_error_msg_and_die("wrong address (%s) length: expected %d bytes", lla, halen);
    }
}

/* Exits on error */
static void set_address(struct ifreq *ifr, int brd)
{
    int s;

    s = get_ctl_fd();
    if (brd)
        xioctl(s, SIOCSIFHWBROADCAST, ifr);
    else
        xioctl(s, SIOCSIFHWADDR, ifr);
    close(s);
}


/* Return value becomes exitcode. It's okay to not return at all */
static int do_set(int argc, char **argv)
{
    char *dev = NULL;
    uint32_t mask = 0;
    uint32_t flags = 0;
    int qlen = -1;
    int mtu = -1;
    char *newaddr = NULL;
    char *newbrd = NULL;
    struct ifreq ifr0, ifr1;
    char *newname = NULL;
    int htype, halen;
    static const char keywords[] ALIGN1 =
        "up\0""down\0""name\0""mtu\0""multicast\0""arp\0""addr\0""dev\0"
        "on\0""off\0";
    enum { ARG_up = 1, ARG_down, ARG_name, ARG_mtu, ARG_multicast, ARG_arp,
        ARG_addr, ARG_dev, PARM_on, PARM_off };
    smalluint key;

    while (argc > 0) {
        key = index_in_strings(keywords, *argv) + 1;
        if (key == ARG_up) {
            mask |= IFF_UP;
            flags |= IFF_UP;
        } else if (key == ARG_down) {
            mask |= IFF_UP;
            flags &= ~IFF_UP;
        } else if (key == ARG_name) {
            NEXT_ARG();
            newname = *argv;
        } else if (key == ARG_mtu) {
            NEXT_ARG();
            if (mtu != -1)
                duparg("mtu", *argv);
            if (get_integer(&mtu, *argv, 0))
                invarg(*argv, "mtu");
        } else if (key == ARG_multicast) {
            NEXT_ARG();
            mask |= IFF_MULTICAST;
            key = index_in_strings(keywords, *argv) + 1;
            if (key == PARM_on) {
                flags |= IFF_MULTICAST;
            } else if (key == PARM_off) {
                flags &= ~IFF_MULTICAST;
            } else
                on_off("multicast");
        } else if (key == ARG_arp) {
            NEXT_ARG();
            mask |= IFF_NOARP;
            key = index_in_strings(keywords, *argv) + 1;
            if (key == PARM_on) {
                flags &= ~IFF_NOARP;
            } else if (key == PARM_off) {
                flags |= IFF_NOARP;
            } else
                on_off("arp");
        } else if (key == ARG_addr) {
            NEXT_ARG();
            newaddr = *argv;
        } else {
            if (key == ARG_dev) {
                NEXT_ARG();
            }
            if (dev)
                duparg2("dev", *argv);
            dev = *argv;
        }
        argc--; argv++;
    }

    if (!dev) {
        bb_error_msg_and_die(bb_msg_requires_arg, "\"dev\"");
    }

    if (newaddr || newbrd) {
        halen = get_address(dev, &htype);
        if (newaddr) {
            parse_address(dev, htype, halen, newaddr, &ifr0);
        }
        if (newbrd) {
            parse_address(dev, htype, halen, newbrd, &ifr1);
        }
    }

    if (newname && strcmp(dev, newname)) {
        do_changename(dev, newname);
        dev = newname;
    }
    if (qlen != -1) {
        set_qlen(dev, qlen);
    }
    if (mtu != -1) {
        set_mtu(dev, mtu);
    }
    if (newaddr || newbrd) {
        if (newbrd) {
            set_address(&ifr1, 1);
        }
        if (newaddr) {
            set_address(&ifr0, 0);
        }
    }
    if (mask)
        do_chflags(dev, flags, mask);
    return 0;
}

static int ipaddr_list_link(int argc, char **argv)
{
    preferred_family = AF_PACKET;
    return ipaddr_list_or_flush(argc, argv, 0);
}

/* Return value becomes exitcode. It's okay to not return at all */
int do_iplink(int argc, char **argv)
{
    static const char keywords[] ALIGN1 =
        "set\0""show\0""lst\0""list\0";
    smalluint key;
    if (argc <= 0)
        return ipaddr_list_link(0, NULL);
    key = index_in_substrings(keywords, *argv) + 1;
    if (key == 0)
        bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
    argc--; argv++;
    if (key == 1) /* set */
        return do_set(argc, argv);
    else /* show, lst, list */
        return ipaddr_list_link(argc, argv);
}