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busybox/networking/ifconfig.c
Denys Vlasenko 6cc4962b60 decrease padding: gcc-9.3.1 slaps 32-byte alignment on arrays willy-nilly 
text	   data	    bss	    dec	    hex	filename
1021236	    559	   5052	1026847	  fab1f	busybox_old
1021120	    559	   5052	1026731	  faaab	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-11-30 14:58:02 +01:00

556 lines
18 KiB
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/* 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>
*/
//config:config IFCONFIG
//config: bool "ifconfig (12 kb)"
//config: default y
//config: help
//config: Ifconfig is used to configure the kernel-resident network interfaces.
//config:
//config:config FEATURE_IFCONFIG_STATUS
//config: bool "Enable status reporting output (+7k)"
//config: default y
//config: depends on IFCONFIG
//config: help
//config: If ifconfig is called with no arguments it will display the status
//config: of the currently active interfaces.
//config:
//config:config FEATURE_IFCONFIG_SLIP
//config: bool "Enable slip-specific options \"keepalive\" and \"outfill\""
//config: default y
//config: depends on IFCONFIG
//config: help
//config: Allow "keepalive" and "outfill" support for SLIP. If you're not
//config: planning on using serial lines, leave this unchecked.
//config:
//config:config FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
//config: bool "Enable options \"mem_start\", \"io_addr\", and \"irq\""
//config: default y
//config: depends on IFCONFIG
//config: help
//config: Allow the start address for shared memory, start address for I/O,
//config: and/or the interrupt line used by the specified device.
//config:
//config:config FEATURE_IFCONFIG_HW
//config: bool "Enable option \"hw\" (ether only)"
//config: default y
//config: depends on IFCONFIG
//config: help
//config: Set the hardware address of this interface, if the device driver
//config: supports this operation. Currently, we only support the 'ether'
//config: class.
//config:
//config:config FEATURE_IFCONFIG_BROADCAST_PLUS
//config: bool "Set the broadcast automatically"
//config: default y
//config: depends on IFCONFIG
//config: help
//config: Setting this will make ifconfig attempt to find the broadcast
//config: automatically if the value '+' is used.
//applet:IF_IFCONFIG(APPLET(ifconfig, BB_DIR_SBIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_IFCONFIG) += ifconfig.o interface.o
//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 <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 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[] ALIGN_PTR = {
{ "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[] ALIGN_PTR = {
{ "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) }
};
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 */
IF_FEATURE_IFCONFIG_STATUS(char *show_all_param;)
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
show_all_param = NULL;
if (argv[0] && argv[0][0] == '-' && argv[0][1] == 'a' && !argv[0][2]) {
++argv;
show_all_param = IFNAME_SHOW_DOWNED_TOO;
}
#endif
if (!argv[0] || !argv[1]) { /* one or no args */
#if ENABLE_FEATURE_IFCONFIG_STATUS
return display_interfaces(argv[0] ? argv[0] : show_all_param);
#else
bb_simple_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;
}
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