busybox/networking/libiproute/iplink.c
Denis Vlasenko 6ca409e0e4 trylink: produce even more info about final link stage
trylink: explain how to modify link and drastically decrease amount
  of padding (unfortunately, needs hand editing ATM).
*: add ALIGN1 / ALIGN2 to global strings and arrays of bytes and shorts

size saving: 0.5k
2007-08-12 20:58:27 +00:00

292 lines
6.3 KiB
C

/* 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);
}