source: MondoRescue/branches/3.2/mindi-busybox/networking/libiproute/iplink.c@ 3232

/* vi: set sw=4 ts=4: */
/*
 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */
#include <net/if.h>
#include <net/if_packet.h>
#include <netpacket/packet.h>
#include <netinet/if_ether.h>

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

#ifndef IFLA_LINKINFO
# define IFLA_LINKINFO 18
# define IFLA_INFO_KIND 1
#endif

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

/* 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_IFNAMSIZ(ifr.ifr_name, dev);
    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_IFNAMSIZ(ifr.ifr_name, dev);
    strncpy_IFNAMSIZ(ifr.ifr_newname, newdev);
    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_IFNAMSIZ(ifr.ifr_name, dev);
    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_IFNAMSIZ(ifr.ifr_name, dev);
    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_IFNAMSIZ(ifr.ifr_name, dev);
    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);
    getsockname(s, (struct sockaddr*)&me, &alen);
    //never happens:
    //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_IFNAMSIZ(ifr->ifr_name, dev);
    ifr->ifr_hwaddr.sa_family = hatype;

    alen = hatype == 1/*ARPHRD_ETHER*/ ? 14/*ETH_HLEN*/ : 19/*INFINIBAND_HLEN*/;
    alen = ll_addr_a2n((unsigned char *)(ifr->ifr_hwaddr.sa_data), alen, lla);
    if (alen < 0)
        exit(EXIT_FAILURE);
    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);
}


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

/* Return value becomes exitcode. It's okay to not return at all */
static int do_set(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""qlen\0""multicast\0"
        "arp\0""address\0""dev\0";
    enum { ARG_up = 0, ARG_down, ARG_name, ARG_mtu, ARG_qlen, ARG_multicast,
        ARG_arp, ARG_addr, ARG_dev };
    static const char str_on_off[] ALIGN1 = "on\0""off\0";
    enum { PARM_on = 0, PARM_off };
    smalluint key;

    while (*argv) {
        /* substring search ensures that e.g. "addr" and "address"
         * are both accepted */
        key = index_in_substrings(keywords, *argv);
        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);
            mtu = get_unsigned(*argv, "mtu");
        } else if (key == ARG_qlen) {
            NEXT_ARG();
            if (qlen != -1)
                duparg("qlen", *argv);
            qlen = get_unsigned(*argv, "qlen");
        } else if (key == ARG_addr) {
            NEXT_ARG();
            newaddr = *argv;
        } else if (key >= ARG_dev) {
            if (key == ARG_dev) {
                NEXT_ARG();
            }
            if (dev)
                duparg2("dev", *argv);
            dev = *argv;
        } else {
            int param;
            NEXT_ARG();
            param = index_in_strings(str_on_off, *argv);
            if (key == ARG_multicast) {
                if (param < 0)
                    die_must_be_on_off("multicast");
                mask |= IFF_MULTICAST;
                if (param == PARM_on)
                    flags |= IFF_MULTICAST;
                else
                    flags &= ~IFF_MULTICAST;
            } else if (key == ARG_arp) {
                if (param < 0)
                    die_must_be_on_off("arp");
                mask |= IFF_NOARP;
                if (param == PARM_on)
                    flags &= ~IFF_NOARP;
                else
                    flags |= IFF_NOARP;
            }
        }
        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);
            set_address(&ifr0, 0);
        }
        if (newbrd) {
            parse_address(dev, htype, halen, newbrd, &ifr1);
            set_address(&ifr1, 1);
        }
    }

    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 (mask)
        do_chflags(dev, flags, mask);
    return 0;
}

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

#ifndef NLMSG_TAIL
#define NLMSG_TAIL(nmsg) \
    ((struct rtattr *) (((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
#endif
/* Return value becomes exitcode. It's okay to not return at all */
static int do_change(char **argv, const unsigned rtm)
{
    static const char keywords[] ALIGN1 =
        "link\0""name\0""type\0""dev\0";
    enum {
        ARG_link,
        ARG_name,
        ARG_type,
        ARG_dev,
    };
    struct rtnl_handle rth;
    struct {
        struct nlmsghdr  n;
        struct ifinfomsg i;
        char             buf[1024];
    } req;
    smalluint arg;
    char *name_str = NULL, *link_str = NULL, *type_str = NULL, *dev_str = NULL;

    memset(&req, 0, sizeof(req));

    req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
    req.n.nlmsg_flags = NLM_F_REQUEST;
    req.n.nlmsg_type = rtm;
    req.i.ifi_family = preferred_family;
    if (rtm == RTM_NEWLINK)
        req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;

    while (*argv) {
        arg = index_in_substrings(keywords, *argv);
        if (arg == ARG_link) {
            NEXT_ARG();
            link_str = *argv;
        } else if (arg == ARG_name) {
            NEXT_ARG();
            name_str = *argv;
        } else if (arg == ARG_type) {
            NEXT_ARG();
            type_str = *argv;
        } else {
            if (arg == ARG_dev) {
                if (dev_str)
                    duparg(*argv, "dev");
                NEXT_ARG();
            }
            dev_str = *argv;
        }
        argv++;
    }
    xrtnl_open(&rth);
    ll_init_map(&rth);
    if (type_str) {
        struct rtattr *linkinfo = NLMSG_TAIL(&req.n);

        addattr_l(&req.n, sizeof(req), IFLA_LINKINFO, NULL, 0);
        addattr_l(&req.n, sizeof(req), IFLA_INFO_KIND, type_str,
                strlen(type_str));
        linkinfo->rta_len = (void *)NLMSG_TAIL(&req.n) - (void *)linkinfo;
    }
    if (rtm != RTM_NEWLINK) {
        if (!dev_str)
            return 1; /* Need a device to delete */
        req.i.ifi_index = xll_name_to_index(dev_str);
    } else {
        if (!name_str)
            name_str = dev_str;
        if (link_str) {
            int idx = xll_name_to_index(link_str);
            addattr_l(&req.n, sizeof(req), IFLA_LINK, &idx, 4);
        }
    }
    if (name_str) {
        const size_t name_len = strlen(name_str) + 1;
        if (name_len < 2 || name_len > IFNAMSIZ)
            invarg(name_str, "name");
        addattr_l(&req.n, sizeof(req), IFLA_IFNAME, name_str, name_len);
    }
    if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
        return 2;
    return 0;
}

/* Return value becomes exitcode. It's okay to not return at all */
int FAST_FUNC do_iplink(char **argv)
{
    static const char keywords[] ALIGN1 =
        "add\0""delete\0""set\0""show\0""lst\0""list\0";
    if (*argv) {
        smalluint key = index_in_substrings(keywords, *argv);
        if (key > 5) /* invalid argument */
            bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
        argv++;
        if (key <= 1) /* add/delete */
            return do_change(argv, key ? RTM_DELLINK : RTM_NEWLINK);
        else if (key == 2) /* set */
            return do_set(argv);
    }
    /* show, lst, list */
    return ipaddr_list_link(argv);
}