text: /* vi: set sw=4 ts=4: */
  /* 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>
   *
   * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   */
  
  /*
   * 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 <magick@linux-fan.com>
   */
  
  //usage:#define ifconfig_trivial_usage
  //usage:	IF_FEATURE_IFCONFIG_STATUS("[-a]") " interface [address]"
  //usage:#define ifconfig_full_usage "\n\n"
  //usage:       "Configure a network interface\n"
  //usage:     "\n"
  //usage:	IF_FEATURE_IPV6(
  //usage:       "	[add ADDRESS[/PREFIXLEN]]\n")
  //usage:	IF_FEATURE_IPV6(
  //usage:       "	[del ADDRESS[/PREFIXLEN]]\n")
  //usage:       "	[[-]broadcast [ADDRESS]] [[-]pointopoint [ADDRESS]]\n"
  //usage:       "	[netmask ADDRESS] [dstaddr ADDRESS]\n"
  //usage:	IF_FEATURE_IFCONFIG_SLIP(
  //usage:       "	[outfill NN] [keepalive NN]\n")
  //usage:       "	" IF_FEATURE_IFCONFIG_HW("[hw ether" IF_FEATURE_HWIB("|infiniband")" ADDRESS] ") "[metric NN] [mtu NN]\n"
  //usage:       "	[[-]trailers] [[-]arp] [[-]allmulti]\n"
  //usage:       "	[multicast] [[-]promisc] [txqueuelen NN] [[-]dynamic]\n"
  //usage:	IF_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ(
  //usage:       "	[mem_start NN] [io_addr NN] [irq NN]\n")
  //usage:       "	[up|down] ..."
  
  #include "libbb.h"
  #include "inet_common.h"
  #include <net/if.h>
  #include <net/if_arp.h>
  #include <netinet/in.h>
  #ifdef HAVE_NET_ETHERNET_H
  # include <net/ethernet.h>
  #endif
  
  #if ENABLE_FEATURE_IFCONFIG_SLIP
  # include <net/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 ENABLE_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. */
  #if ENABLE_FEATURE_IFCONFIG_BROADCAST_PLUS
  #define A_HOSTNAME      0x100	/* Set if it is ip addr. */
  #define A_BROADCAST     0x200	/* Set if it is broadcast addr. */
  #else
  #define A_HOSTNAME          0
  #define A_BROADCAST         0
  #endif
  
  /*
   * 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 | A_BROADCAST)
  #define ARG_HW           (A_ARG_REQ | A_CAST_HOST_COPY_IN_ETHER)
  #define ARG_POINTOPOINT  (A_ARG_REQ | 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 | A_HOSTNAME)
  #define ARG_ADD_DEL      (A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER)
  
  
  struct arg1opt {
  	const char *name;
  	unsigned short selector;
  	unsigned short ifr_offset;
  };
  
  struct options {
  	const char *name;
  #if ENABLE_FEATURE_IFCONFIG_BROADCAST_PLUS
  	const unsigned int flags:6;
  	const unsigned int arg_flags:10;
  #else
  	const unsigned char flags;
  	const unsigned char arg_flags;
  #endif
  	const unsigned short selector;
  };
  
  #define ifreq_offsetof(x)  offsetof(struct ifreq, x)
  
  /*
   * Set up the tables.  Warning!  They must have corresponding order!
   */
  
  static const struct arg1opt Arg1Opt[] = {
  	{ "SIFMETRIC",  SIOCSIFMETRIC,  ifreq_offsetof(ifr_metric) },
  	{ "SIFMTU",     SIOCSIFMTU,     ifreq_offsetof(ifr_mtu) },
  	{ "SIFTXQLEN",  SIOCSIFTXQLEN,  ifreq_offsetof(ifr_qlen) },
  	{ "SIFDSTADDR", SIOCSIFDSTADDR, ifreq_offsetof(ifr_dstaddr) },
  	{ "SIFNETMASK", SIOCSIFNETMASK, ifreq_offsetof(ifr_netmask) },
  	{ "SIFBRDADDR", SIOCSIFBRDADDR, ifreq_offsetof(ifr_broadaddr) },
  #if ENABLE_FEATURE_IFCONFIG_HW
  	{ "SIFHWADDR",  SIOCSIFHWADDR,  ifreq_offsetof(ifr_hwaddr) },
  #endif
  	{ "SIFDSTADDR", SIOCSIFDSTADDR, ifreq_offsetof(ifr_dstaddr) },
  #ifdef SIOCSKEEPALIVE
  	{ "SKEEPALIVE", SIOCSKEEPALIVE, ifreq_offsetof(ifr_data) },
  #endif
  #ifdef SIOCSOUTFILL
  	{ "SOUTFILL",   SIOCSOUTFILL,   ifreq_offsetof(ifr_data) },
  #endif
  #if ENABLE_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
  	{ "SIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.mem_start) },
  	{ "SIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.base_addr) },
  	{ "SIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.irq) },
  #endif
  #if ENABLE_FEATURE_IPV6
  	{ "SIFADDR",    SIOCSIFADDR,    ifreq_offsetof(ifr_addr) }, /* IPv6 version ignores the offset */
  	{ "DIFADDR",    SIOCDIFADDR,    ifreq_offsetof(ifr_addr) }, /* IPv6 version ignores the offset */
  #endif
  	/* Last entry is for unmatched (assumed to be hostname/address) arg. */
  	{ "SIFADDR",    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 },
  #if ENABLE_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
  #if ENABLE_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 ENABLE_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) }
  };
  
  #if ENABLE_FEATURE_IFCONFIG_HW
  /* Input an Ethernet address and convert to binary. */
  static int in_ether(const char *bufp, struct sockaddr *sap)
  {
  	char *ptr;
  	int i, j;
  	unsigned char val;
  	unsigned char c;
  
  	sap->sa_family = ARPHRD_ETHER;
  	ptr = (char *) sap->sa_data;
  
  	i = 0;
  	do {
  		j = val = 0;
  
  		/* We might get a semicolon here - not required. */
  		if (i && (*bufp == ':')) {
  			bufp++;
  		}
  
  		do {
  			c = *bufp;
  			if (((unsigned char)(c - '0')) <= 9) {
  				c -= '0';
  			} else if ((unsigned char)((c|0x20) - 'a') <= 5) {
  				c = (unsigned char)((c|0x20) - 'a') + 10;
  			} else if (j && (c == ':' || c == 0)) {
  				break;
  			} else {
  				return -1;
  			}
  			++bufp;
  			val <<= 4;
  			val += c;
  		} while (++j < 2);
  		*ptr++ = val;
  	} while (++i < ETH_ALEN);
  
  	return *bufp; /* Error if we don't end at end of string. */
  }
  #endif
  
  int ifconfig_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  int ifconfig_main(int argc UNUSED_PARAM, char **argv)
  {
  	struct ifreq ifr;
  	struct sockaddr_in sai;
  #if ENABLE_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 selector;
  #if ENABLE_FEATURE_IFCONFIG_BROADCAST_PLUS
  	unsigned int mask;
  	unsigned int did_flags;
  	unsigned int sai_hostname, sai_netmask;
  #else
  	unsigned char mask;
  	unsigned char did_flags;
  #endif
  	char *p;
  	/*char host[128];*/
  	const char *host = NULL; /* make gcc happy */
  
  	did_flags = 0;
  #if ENABLE_FEATURE_IFCONFIG_BROADCAST_PLUS
  	sai_hostname = 0;
  	sai_netmask = 0;
  #endif
  
  	/* skip argv[0] */
  	++argv;
  
  #if ENABLE_FEATURE_IFCONFIG_STATUS
  	if (argv[0] && (argv[0][0] == '-' && argv[0][1] == 'a' && !argv[0][2])) {
  		interface_opt_a = 1;
  		++argv;
  	}
  #endif
  
  	if (!argv[0] || !argv[1]) { /* one or no args */
  #if ENABLE_FEATURE_IFCONFIG_STATUS
  		return display_interfaces(argv[0] /* can be NULL */);
  #else
  		bb_error_msg_and_die("no support for status display");
  #endif
  	}
  
  	/* Create a channel to the NET kernel. */
  	sockfd = xsocket(AF_INET, SOCK_DGRAM, 0);
  
  	/* get interface name */
  	strncpy_IFNAMSIZ(ifr.ifr_name, *argv);
  
  	/* Process the remaining arguments. */
  	while (*++argv != 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... */
  				mask &= op->flags;
  				if (mask)	/* set the mask and go. */
  					goto FOUND_ARG;
  				/* If we get here, there was a valid arg with an */
  				/* invalid '-' prefix. */
  				bb_error_msg_and_die("bad: '%s'", p-1);
  			}
  		}
  
  		/* We fell through, so treat as possible hostname. */
  		a1op = Arg1Opt + ARRAY_SIZE(Arg1Opt) - 1;
  		mask = op->arg_flags;
  		goto HOSTNAME;
  
   FOUND_ARG:
  		if (mask & ARG_MASK) {
  			mask = op->arg_flags;
  			if (mask & A_NETMASK & did_flags)
  				bb_show_usage();
  			a1op = Arg1Opt + (op - OptArray);
  			if (*++argv == NULL) {
  				if (mask & A_ARG_REQ)
  					bb_show_usage();
  				--argv;
  				mask &= A_SET_AFTER;	/* just for broadcast */
  			} else {	/* got an arg so process it */
   HOSTNAME:
  				did_flags |= (mask & (A_NETMASK|A_HOSTNAME));
  				if (mask & A_CAST_HOST_COPY) {
  #if ENABLE_FEATURE_IFCONFIG_HW
  					if (mask & A_CAST_RESOLVE) {
  #endif
  						host = *argv;
  						if (strcmp(host, "inet") == 0)
  							continue; /* compat stuff */
  						sai.sin_family = AF_INET;
  						sai.sin_port = 0;
  						if (strcmp(host, "default") == 0) {
  							/* Default is special, meaning 0.0.0.0. */
  							sai.sin_addr.s_addr = INADDR_ANY;
  						}
  #if ENABLE_FEATURE_IFCONFIG_BROADCAST_PLUS
  						else if ((host[0] == '+' && !host[1])
  						 && (mask & A_BROADCAST)
  						 && (did_flags & (A_NETMASK|A_HOSTNAME)) == (A_NETMASK|A_HOSTNAME)
  						) {
  							/* + is special, meaning broadcast is derived. */
  							sai.sin_addr.s_addr = (~sai_netmask) | (sai_hostname & sai_netmask);
  						}
  #endif
  						else {
  							len_and_sockaddr *lsa;
  #if ENABLE_FEATURE_IPV6
  							char *prefix;
  							int prefix_len = 0;
  							prefix = strchr(host, '/');
  							if (prefix) {
  								prefix_len = xatou_range(prefix + 1, 0, 128);
  								*prefix = '\0';
  							}
   resolve:
  #endif
  							lsa = xhost2sockaddr(host, 0);
  #if ENABLE_FEATURE_IPV6
  							if (lsa->u.sa.sa_family != AF_INET6 && prefix) {
  /* TODO: we do not support "ifconfig eth0 up 1.2.3.4/17".
   * For now, just make it fail instead of silently ignoring "/17" part:
   */
  								*prefix = '/';
  								goto resolve;
  							}
  							if (lsa->u.sa.sa_family == AF_INET6) {
  								int sockfd6;
  								struct in6_ifreq ifr6;
  
  								sockfd6 = xsocket(AF_INET6, SOCK_DGRAM, 0);
  								xioctl(sockfd6, SIOCGIFINDEX, &ifr);
  								ifr6.ifr6_ifindex = ifr.ifr_ifindex;
  								ifr6.ifr6_prefixlen = prefix_len;
  								memcpy(&ifr6.ifr6_addr,
  										&lsa->u.sin6.sin6_addr,
  										sizeof(struct in6_addr));
  								ioctl_or_perror_and_die(sockfd6, a1op->selector, &ifr6, "SIOC%s", a1op->name);
  								if (ENABLE_FEATURE_CLEAN_UP)
  									free(lsa);
  								continue;
  							}
  #endif
  							sai.sin_addr = lsa->u.sin.sin_addr;
  							if (ENABLE_FEATURE_CLEAN_UP)
  								free(lsa);
  						}
  #if ENABLE_FEATURE_IFCONFIG_BROADCAST_PLUS
  						if (mask & A_HOSTNAME)
  							sai_hostname = sai.sin_addr.s_addr;
  						if (mask & A_NETMASK)
  							sai_netmask = sai.sin_addr.s_addr;
  #endif
  						p = (char *) &sai;
  #if ENABLE_FEATURE_IFCONFIG_HW
  					} else {	/* A_CAST_HOST_COPY_IN_ETHER */
  						/* This is the "hw" arg case. */
  						smalluint hw_class = index_in_substrings("ether\0"
  								IF_FEATURE_HWIB("infiniband\0"), *argv) + 1;
  						if (!hw_class || !*++argv)
  							bb_show_usage();
  						host = *argv;
  						if (hw_class == 1 ? in_ether(host, &sa) : in_ib(host, &sa))
  							bb_error_msg_and_die("invalid hw-addr %s", host);
  						p = (char *) &sa;
  					}
  #endif
  					memcpy( ((char *)&ifr) + a1op->ifr_offset,
  						p, sizeof(struct sockaddr));
  				} else {
  					/* FIXME: error check?? */
  					unsigned long i = strtoul(*argv, NULL, 0);
  					p = ((char *)&ifr) + a1op->ifr_offset;
  #if ENABLE_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
  					if (mask & A_MAP_TYPE) {
  						xioctl(sockfd, SIOCGIFMAP, &ifr);
  						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;
  				}
  
  				ioctl_or_perror_and_die(sockfd, a1op->selector, &ifr, "SIOC%s", a1op->name);
  #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 (mask & ARG_MASK) */
  
  		xioctl(sockfd, SIOCGIFFLAGS, &ifr);
  		selector = op->selector;
  		if (mask & SET_MASK)
  			ifr.ifr_flags |= selector;
  		else
  			ifr.ifr_flags &= ~selector;
  		xioctl(sockfd, SIOCSIFFLAGS, &ifr);
  	} /* while () */
  
  	if (ENABLE_FEATURE_CLEAN_UP)
  		close(sockfd);
  	return 0;
  }
  