ifconfig.c

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/* ifconfig
 *
 * Similar to the standard Unix ifconfig, but with only the necessary
 * parts for AF_INET, and without any printing of if info (for now).
 *
 * Bjorn Wesen, Axis Communications AB
 *
 *
 * Authors of the original ifconfig was:      
 *              Fred N. van Kempen, <[e-mail]>
 *
 * This program is free software; you can redistribute it
 * and/or  modify it under  the terms of  the GNU General
 * Public  License as  published  by  the  Free  Software
 * Foundation;  either  version 2 of the License, or  (at
 * your option) any later version.
 *
 * $Id: ifconfig.c,v 1.18 2002/07/11 11:11:52 andersen Exp $
 *
 */

/*
 * Heavily modified by Manuel Novoa III       Mar 6, 2001
 *
 * From initial port to busybox, removed most of the redundancy by
 * converting to a table-driven approach.  Added several (optional)
 * args missing from initial port.
 *
 * Still missing:  media, tunnel.
 *
 * 2002-04-20
 * IPV6 support added by Bart Visscher <[e-mail]>
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>   // strcmp and friends
#include <ctype.h>    // isdigit and friends
#include <stddef.h>				/* offsetof */
#include <sys/ioctl.h>
#include <net/if_arp.h>
#include <netinet/in.h>
#include <linux/if_ether.h>
#include <net/if.h>
#include "inet_common.h"
#include "busybox.h"

#ifdef CONFIG_FEATURE_IFCONFIG_SLIP
#include <linux/if_slip.h>
#endif

/* I don't know if this is needed for busybox or not.  Anyone? */
#define QUESTIONABLE_ALIAS_CASE


/* Defines for glibc2.0 users. */
#ifndef SIOCSIFTXQLEN
#define SIOCSIFTXQLEN      0x8943
#define SIOCGIFTXQLEN      0x8942
#endif

/* ifr_qlen is ifru_ivalue, but it isn't present in 2.0 kernel headers */
#ifndef ifr_qlen
#define ifr_qlen        ifr_ifru.ifru_mtu
#endif

#ifndef IFF_DYNAMIC
#define IFF_DYNAMIC     0x8000  /* dialup device with changing addresses */
#endif

#if CONFIG_FEATURE_IPV6
struct in6_ifreq {
	struct in6_addr	ifr6_addr;
	uint32_t	ifr6_prefixlen;
	int		ifr6_ifindex; 
};
#endif

/*
 * Here are the bit masks for the "flags" member of struct options below.
 * N_ signifies no arg prefix; M_ signifies arg prefixed by '-'.
 * CLR clears the flag; SET sets the flag; ARG signifies (optional) arg.
 */
#define N_CLR            0x01
#define M_CLR            0x02
#define N_SET            0x04
#define M_SET            0x08
#define N_ARG            0x10
#define M_ARG            0x20

#define M_MASK           (M_CLR | M_SET | M_ARG)
#define N_MASK           (N_CLR | N_SET | N_ARG)
#define SET_MASK         (N_SET | M_SET)
#define CLR_MASK         (N_CLR | M_CLR)
#define SET_CLR_MASK     (SET_MASK | CLR_MASK)
#define ARG_MASK         (M_ARG | N_ARG)

/*
 * Here are the bit masks for the "arg_flags" member of struct options below.
 */

/*
 * cast type:
 *   00 int
 *   01 char *
 *   02 HOST_COPY in_ether
 *   03 HOST_COPY INET_resolve
 */
#define A_CAST_TYPE      0x03
/*
 * map type:
 *   00 not a map type (mem_start, io_addr, irq)
 *   04 memstart (unsigned long)
 *   08 io_addr  (unsigned short)
 *   0C irq      (unsigned char)
 */
#define A_MAP_TYPE       0x0C
#define A_ARG_REQ        0x10	/* Set if an arg is required. */
#define A_NETMASK        0x20	/* Set if netmask (check for multiple sets). */
#define A_SET_AFTER      0x40	/* Set a flag at the end. */
#define A_COLON_CHK      0x80	/* Is this needed?  See below. */

/*
 * These defines are for dealing with the A_CAST_TYPE field.
 */
#define A_CAST_CHAR_PTR  0x01
#define A_CAST_RESOLVE   0x01
#define A_CAST_HOST_COPY 0x02
#define A_CAST_HOST_COPY_IN_ETHER    A_CAST_HOST_COPY
#define A_CAST_HOST_COPY_RESOLVE     (A_CAST_HOST_COPY | A_CAST_RESOLVE)

/*
 * These defines are for dealing with the A_MAP_TYPE field.
 */
#define A_MAP_ULONG      0x04	/* memstart */
#define A_MAP_USHORT     0x08	/* io_addr */
#define A_MAP_UCHAR      0x0C	/* irq */

/*
 * Define the bit masks signifying which operations to perform for each arg.
 */

#define ARG_METRIC       (A_ARG_REQ /*| A_CAST_INT*/)
#define ARG_MTU          (A_ARG_REQ /*| A_CAST_INT*/)
#define ARG_TXQUEUELEN   (A_ARG_REQ /*| A_CAST_INT*/)
#define ARG_MEM_START    (A_ARG_REQ | A_MAP_ULONG)
#define ARG_IO_ADDR      (A_ARG_REQ | A_MAP_ULONG)
#define ARG_IRQ          (A_ARG_REQ | A_MAP_UCHAR)
#define ARG_DSTADDR      (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE)
#define ARG_NETMASK      (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE | A_NETMASK)
#define ARG_BROADCAST    (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER)
#define ARG_HW           (A_ARG_REQ | A_CAST_HOST_COPY_IN_ETHER)
#define ARG_POINTOPOINT  (A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER)
#define ARG_KEEPALIVE    (A_ARG_REQ | A_CAST_CHAR_PTR)
#define ARG_OUTFILL      (A_ARG_REQ | A_CAST_CHAR_PTR)
#define ARG_HOSTNAME     (A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER | A_COLON_CHK)
#define ARG_ADD_DEL      (A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER)


/*
 * Set up the tables.  Warning!  They must have corresponding order!
 */

struct arg1opt {
	const char *name;
	unsigned short selector;
	unsigned short ifr_offset;
};

struct options {
	const char *name;
	const unsigned char flags;
	const unsigned char arg_flags;
	const unsigned short selector;
};

#define ifreq_offsetof(x)  offsetof(struct ifreq, x)

static const struct arg1opt Arg1Opt[] = {
	{"SIOCSIFMETRIC",  SIOCSIFMETRIC,  ifreq_offsetof(ifr_metric)},
	{"SIOCSIFMTU",     SIOCSIFMTU,     ifreq_offsetof(ifr_mtu)},
	{"SIOCSIFTXQLEN",  SIOCSIFTXQLEN,  ifreq_offsetof(ifr_qlen)},
	{"SIOCSIFDSTADDR", SIOCSIFDSTADDR, ifreq_offsetof(ifr_dstaddr)},
	{"SIOCSIFNETMASK", SIOCSIFNETMASK, ifreq_offsetof(ifr_netmask)},
	{"SIOCSIFBRDADDR", SIOCSIFBRDADDR, ifreq_offsetof(ifr_broadaddr)},
#ifdef CONFIG_FEATURE_IFCONFIG_HW
	{"SIOCSIFHWADDR",  SIOCSIFHWADDR,  ifreq_offsetof(ifr_hwaddr)},
#endif
	{"SIOCSIFDSTADDR", SIOCSIFDSTADDR, ifreq_offsetof(ifr_dstaddr)},
#ifdef SIOCSKEEPALIVE
	{"SIOCSKEEPALIVE", SIOCSKEEPALIVE, ifreq_offsetof(ifr_data)},
#endif
#ifdef SIOCSOUTFILL
	{"SIOCSOUTFILL",   SIOCSOUTFILL,   ifreq_offsetof(ifr_data)},
#endif
#ifdef CONFIG_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
	{"SIOCSIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.mem_start)},
	{"SIOCSIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.base_addr)},
	{"SIOCSIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.irq)},
#endif
	/* Last entry if for unmatched (possibly hostname) arg. */
#if CONFIG_FEATURE_IPV6
	{"SIOCSIFADDR",    SIOCSIFADDR,    ifreq_offsetof(ifr_addr)}, /* IPv6 version ignores the offset */
	{"SIOCDIFADDR",    SIOCDIFADDR,    ifreq_offsetof(ifr_addr)}, /* IPv6 version ignores the offset */
#endif
	{"SIOCSIFADDR",    SIOCSIFADDR,    ifreq_offsetof(ifr_addr)},
};

static const struct options OptArray[] = {
	{"metric",       N_ARG,         ARG_METRIC,      0},
    {"mtu",          N_ARG,         ARG_MTU,         0},
	{"txqueuelen",   N_ARG,         ARG_TXQUEUELEN,  0},
	{"dstaddr",      N_ARG,         ARG_DSTADDR,     0},
	{"netmask",      N_ARG,         ARG_NETMASK,     0},
	{"broadcast",    N_ARG | M_CLR, ARG_BROADCAST,   IFF_BROADCAST},
#ifdef CONFIG_FEATURE_IFCONFIG_HW
	{"hw",           N_ARG,         ARG_HW,          0},
#endif
	{"pointopoint",  N_ARG | M_CLR, ARG_POINTOPOINT, IFF_POINTOPOINT},
#ifdef SIOCSKEEPALIVE
	{"keepalive",    N_ARG,         ARG_KEEPALIVE,   0},
#endif
#ifdef SIOCSOUTFILL
	{"outfill",      N_ARG,         ARG_OUTFILL,     0},
#endif
#ifdef CONFIG_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
	{"mem_start",    N_ARG,         ARG_MEM_START,   0},
	{"io_addr",      N_ARG,         ARG_IO_ADDR,     0},
	{"irq",          N_ARG,         ARG_IRQ,         0},
#endif
#if CONFIG_FEATURE_IPV6
	{"add",          N_ARG,         ARG_ADD_DEL,     0},
	{"del",          N_ARG,         ARG_ADD_DEL,     0},
#endif
	{"arp",          N_CLR | M_SET, 0,               IFF_NOARP},
	{"trailers",     N_CLR | M_SET, 0,               IFF_NOTRAILERS},
	{"promisc",      N_SET | M_CLR, 0,               IFF_PROMISC},
	{"multicast",    N_SET | M_CLR, 0,               IFF_MULTICAST},
	{"allmulti",     N_SET | M_CLR, 0,               IFF_ALLMULTI},
	{"dynamic",      N_SET | M_CLR, 0,               IFF_DYNAMIC},
	{"up",           N_SET        , 0,               (IFF_UP | IFF_RUNNING)},
	{"down",         N_CLR        , 0,               IFF_UP},
	{ NULL,          0,             ARG_HOSTNAME,    (IFF_UP | IFF_RUNNING)}
};

/*
 * A couple of prototypes.
 */

#ifdef CONFIG_FEATURE_IFCONFIG_HW
static int in_ether(char *bufp, struct sockaddr *sap);
#endif

#ifdef CONFIG_FEATURE_IFCONFIG_STATUS
extern int interface_opt_a;
extern int display_interfaces(char *ifname);
#endif

/*
 * Our main function.
 */

int ifconfig_main(int argc, char **argv)
{
	struct ifreq ifr;
	struct sockaddr_in sai;
#if CONFIG_FEATURE_IPV6
	struct sockaddr_in6 sai6;
#endif
#ifdef CONFIG_FEATURE_IFCONFIG_HW
	struct sockaddr sa;
#endif
	const struct arg1opt *a1op;
	const struct options *op;
	int sockfd;  /* socket fd we use to manipulate stuff with */
	int goterr;
	int selector;
	char *p;
	char host[128];