/* 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, <waltje@uwalt.nl.mugnet.org> * * 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 1.15 2002/10/22 22:14:29 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. */#include <stdio.h>#include <stdlib.h>#include <string.h>   // strcmp and friends#include <ctype.h>    // isdigit and friends#include <stddef.h>				/* offsetof */#include <sys/types.h>#include <sys/socket.h>#include <sys/ioctl.h>#include <netinet/in.h>#include <arpa/inet.h>#include <net/if.h>#include <net/if_arp.h>#include <linux/if_ether.h>#include "busybox.h"#ifdef BB_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/* * 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)/* * 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 BB_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 BB_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. */	{"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 BB_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 BB_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	{"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 BB_FEATURE_IFCONFIG_HWstatic int in_ether(char *bufp, struct sockaddr *sap);#endif#ifdef BB_FEATURE_IFCONFIG_STATUSextern 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;#ifdef BB_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];	unsigned char mask;	unsigned char did_flags;	goterr = 0;	did_flags = 0;	/* skip argv[0] */	++argv;	--argc;#ifdef BB_FEATURE_IFCONFIG_STATUS	if ((argc > 0) && (strcmp(*argv,"-a") == 0)) {		interface_opt_a = 1;		--argc;		++argv;	}#endif	if(argc <= 1) {#ifdef BB_FEATURE_IFCONFIG_STATUS		return display_interfaces(argc ? *argv : NULL);#else		error_msg_and_die( "ifconfig was not compiled with interface status display support.");#endif	}	/* Create a channel to the NET kernel. */	if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {		perror_msg_and_die("socket");	}	/* get interface name */	safe_strncpy(ifr.ifr_name, *argv, IFNAMSIZ);	/* Process the remaining arguments. */	while (*++argv != (char *) NULL) {		p = *argv;		mask = N_MASK;		if (*p == '-') {		/* If the arg starts with '-'... */			++p;				/*    advance past it and */			mask = M_MASK;		/*    set the appropriate mask. */		}		for (op = OptArray ; op->name ; op++) {	/* Find table entry. */			if (strcmp(p,op->name) == 0) { /* If name matches... */				if ((mask &= op->flags)) { /* set the mask and go. */				    goto FOUND_ARG;;				}				/* If we get here, there was a valid arg with an */				/* invalid '-' prefix. */				++goterr;				goto LOOP;			}		}				/* We fell through, so treat as possible hostname. */		a1op = Arg1Opt + (sizeof(Arg1Opt) / sizeof(Arg1Opt[0])) - 1;		mask = op->arg_flags;		goto HOSTNAME;	FOUND_ARG:		if (mask & ARG_MASK) {			mask = op->arg_flags;			a1op = Arg1Opt + (op - OptArray);			if (mask & A_NETMASK & did_flags) {				show_usage();			}			if (*++argv == NULL) {				if (mask & A_ARG_REQ) {					show_usage();				} else {					--argv;					mask &= A_SET_AFTER; /* just for broadcast */				}			} else {			/* got an arg so process it */			HOSTNAME:				did_flags |= (mask & A_NETMASK);				if (mask & A_CAST_HOST_COPY) {#ifdef BB_FEATURE_IFCONFIG_HW					if (mask & A_CAST_RESOLVE) {#endif						safe_strncpy(host, *argv, (sizeof host));						sai.sin_family = AF_INET;						sai.sin_port = 0;						if (!strcmp(host, "default")) {							/* Default is special, meaning 0.0.0.0. */							sai.sin_addr.s_addr = INADDR_ANY;						} else if (inet_aton(host, &sai.sin_addr) == 0) {							/* It's not a dotted quad. */							++goterr;							continue;						}						p = (char *) &sai;#ifdef BB_FEATURE_IFCONFIG_HW					} else { /* A_CAST_HOST_COPY_IN_ETHER */						/* This is the "hw" arg case. */						if (strcmp("ether", *argv) || (*++argv == NULL)) {							show_usage();						}						safe_strncpy(host, *argv, (sizeof host));						if (in_ether(host, &sa)) {							fprintf(stderr, "invalid hw-addr %s\n", host);							++goterr;							continue;						}						p = (char *) &sa;					}#endif					memcpy((((char *)(&ifr)) + a1op->ifr_offset),						   p, sizeof(struct sockaddr));				} else {					unsigned int i = strtoul(*argv,NULL,0);					p = ((char *)(&ifr)) + a1op->ifr_offset;#ifdef BB_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ					if (mask & A_MAP_TYPE) {						if (ioctl(sockfd, SIOCGIFMAP, &ifr) < 0) {							++goterr;							continue;						}						if ((mask & A_MAP_UCHAR) == A_MAP_UCHAR) {							*((unsigned char *) p) = i;						} else if (mask & A_MAP_USHORT) {							*((unsigned short *) p) = i;						} else {							*((unsigned long *) p) = i;						}					} else#endif					if (mask & A_CAST_CHAR_PTR) {						*((caddr_t *) p) = (caddr_t) i;					} else { /* A_CAST_INT */						*((int *) p) = i;					}				}										if (ioctl(sockfd, a1op->selector, &ifr) < 0) {					perror(a1op->name);					++goterr;					continue;				}#ifdef QUESTIONABLE_ALIAS_CASE				if (mask & A_COLON_CHK) {					/*					 * Don't do the set_flag() if the address is an alias with					 * a - at the end, since it's deleted already! - Roman					 *					 * Should really use regex.h here, not sure though how well					 * it'll go with the cross-platform support etc. 					 */					char *ptr;					short int found_colon = 0;					for (ptr = ifr.ifr_name; *ptr; ptr++ ) {						if (*ptr == ':') {							found_colon++;						}					}								if (found_colon && *(ptr - 1) == '-') {						continue;					}				}#endif			}			if (!(mask & A_SET_AFTER)) {				continue;			}			mask = N_SET;		}		if (ioctl(sockfd, SIOCGIFFLAGS, &ifr) < 0) {			perror("SIOCGIFFLAGS"); 			++goterr;		} else {			selector = op->selector;			if (mask & SET_MASK) {				ifr.ifr_flags |= selector;			} else {				ifr.ifr_flags &= ~selector;			}			if (ioctl(sockfd, SIOCSIFFLAGS, &ifr) < 0) {				perror("SIOCSIFFLAGS"); 				++goterr;			}		}	LOOP:		continue;	} /* end of while-loop */	return goterr;}#ifdef BB_FEATURE_IFCONFIG_HW/* Input an Ethernet address and convert to binary. */static intin_ether(char *bufp, struct sockaddr *sap){	unsigned char *ptr;	int i, j;	unsigned char val;	unsigned char c;		sap->sa_family = ARPHRD_ETHER;	ptr = sap->sa_data;		for (i = 0 ; i < ETH_ALEN ; i++) {		val = 0;		/* We might get a semicolon here - not required. */		if (i && (*bufp == ':')) {			bufp++;		}		for (j=0 ; j<2 ; j++) {			c = *bufp;			if (c >= '0' && c <= '9') {				c -= '0';			} else if (c >= 'a' && c <= 'f') {				c -= ('a' - 10);			} else if (c >= 'A' && c <= 'F') {				c -= ('A' - 10);			} else if (j && (c == ':' || c == 0)) {				break;			} else {				return -1;			}			++bufp;			val <<= 4;			val += c;		}		*ptr++ = val;	}	return (int) (*bufp);		/* Error if we don't end at end of string. */}#endif