ifconfig.c

一个基于linux的TCP/IP协议栈的实现

/* ifconfig.c copied from net-tools
 * [e-mail]
 * 2006-10-19
 */
 
#define DFLT_AF "myinet"

#include "config.h"
#include "af_inet.h"
#include "log.h"

#include <features.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <netdb.h>
#include <stdio.h>

/* Ugh.  But libc5 doesn't provide POSIX types.  */
#include <asm/types.h>


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

#include "interface.h"
#include "sockets.h"
#include "net-support.h"
#include "util.h"

extern struct aftype myinet_aftype;

char *Release = "ipv4-module 2.0", *Version = "ifconfig 1.42 (2006-10-19)";

int opt_a = 0;			/* show all interfaces          */
int opt_i = 0;			/* show the statistics          */
int opt_v = 0;			/* debugging output flag        */

int addr_family = 0;		/* currently selected AF        */

static int if_print(char *ifname)
{
	int res;
	if( ife_short )
		printf( "Iface   MTU Met    RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg\n" );
	if( !ifname ){
		res = for_all_interfaces( do_if_print, &opt_a );
	}else{
		struct interface *ife;
		ife = lookup_interface(ifname);
		res = do_if_fetch(ife); 
		if (res >= 0) 
			ife_print(ife);
	}
	return res; 
}

static void version(void)
{
	fprintf(stderr, "%s\n%s\n", Release, Version);
	exit(0);
}

static void usage(void)
{
	fprintf(stderr, "Usage:\n  ifconfig [-a] [-i] [-v] [-s] <interface> [[<AF>] <address>]\n");
	fprintf(stderr, "  [add <address>[/<prefixlen>]]\n");
	fprintf(stderr, "  [del <address>[/<prefixlen>]]\n");
	fprintf(stderr, "  [[-]broadcast [<address>]]  [[-]pointopoint [<address>]]\n");
	fprintf(stderr, "  [netmask <address>]  [dstaddr <address>]  [tunnel <address>]\n");
	fprintf(stderr, "  [hw <HW> <address>]  [metric <NN>]  [mtu <NN>]\n");
	fprintf(stderr, "  [[-]trailers]  [[-]arp]  [[-]allmulti]\n");
	fprintf(stderr, "  [multicast]  [[-]promisc]\n");
	fprintf(stderr, "  [mem_start <NN>]  [io_addr <NN>]  [irq <NN>]  [media <type>]\n");
	fprintf(stderr, "  [txqueuelen <NN>]\n");
	fprintf(stderr, "  [[-]dynamic]\n");
	fprintf(stderr, "  [up|down] ...\n\n");
	fprintf(stderr, "  <HW>=Hardware Type.\n");
	fprintf(stderr, "  List of possible hardware types:\n");
	print_hwlist(0); /* 1 = ARPable */
	fprintf(stderr, "  <AF>=Address family. Default: %s\n", DFLT_AF);
	fprintf(stderr, "  List of possible address families:\n");
	print_aflist(0); /* 1 = routeable */
	exit(E_USAGE);
}

static int set_flag(char *ifname, short flag)
{
	struct ifreq ifr;

	safe_strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
	if( ioctl(skfd, SIOCGIFFLAGS, &ifr) < 0 ){
		PR_ERR( "%s: unknown interface: %s\n", ifname, strerror(errno) );
		return (-1);
	}
	safe_strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
	ifr.ifr_flags |= flag;
	if( ioctl(skfd, SIOCSIFFLAGS, &ifr) < 0 ){
		PR_ERR( "SIOCSIFFLAGS: %s", strerror(errno) );
		return -1;
	}
	return (0);
}

static int clr_flag(char *ifname, short flag)
{
	struct ifreq ifr;
	int fd;

	if( strchr(ifname, ':') ){
		fd = get_socket_for_af( MY_AF_INET);
		if (fd < 0) {
			PR_ERR( "No support for MYINET on this system.\n" );
			return -1;
		}
	}else
		fd = skfd;

	safe_strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
	if (ioctl(fd, SIOCGIFFLAGS, &ifr) < 0) {
		PR_ERR( "%s: unknown interface: %s\n", ifname, strerror(errno) );
		return -1;
	}
	safe_strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
	ifr.ifr_flags &= ~flag;
	if( ioctl(fd, SIOCSIFFLAGS, &ifr) < 0 ){
		PR_ERR( "SIOCSIFFLAGS: %s", strerror(errno) );
		return -1;
	}
	return (0);
}

static int set_netmask(int skfd, struct ifreq *ifr, struct sockaddr *sa)
{
	int err = 0;
	memcpy((char *) &ifr->ifr_netmask, (char *) sa, sizeof(struct sockaddr));
	if( ioctl(skfd, SIOCSIFNETMASK, ifr) < 0 ){
		fprintf(stderr, "SIOCSIFNETMASK: %s\n", strerror(errno));
		err = 1;
	}
	return 0;
}

static int get_nmbc_parent(char *parent, unsigned long *nm, unsigned long *bc)
{
	struct interface *i;
	struct sockaddr_in *sin;

	i = lookup_interface( parent );
	if( !i )
		return -1;
	if( do_if_fetch(i) < 0 )
		return 0;
	sin = (struct sockaddr_in *)&i->netmask;
	memcpy( nm, &sin->sin_addr.s_addr, sizeof(unsigned long) );
	sin = (struct sockaddr_in *)&i->broadaddr;
	memcpy( bc, &sin->sin_addr.s_addr, sizeof(unsigned long) );
	return 0;
}

struct ifcmd {
	int flag;
	unsigned long addr;
	char *base;
	int baselen;
};

static unsigned char searcher[256];

static int set_ip_using(const char *name, int c, unsigned long ip)
{
	struct ifreq ifr;
	struct sockaddr_in sin;

	safe_strncpy( ifr.ifr_name, name, IFNAMSIZ );
	memset(&sin, 0, sizeof(struct sockaddr));
	sin.sin_family = MY_AF_INET;
	sin.sin_addr.s_addr = ip;
	memcpy(&ifr.ifr_addr, &sin, sizeof(struct sockaddr));
	if( ioctl(skfd, c, &ifr) < 0 )
		return -1;
	return 0;
}

static int do_ifcmd(struct interface *x, struct ifcmd *ptr)
{
	char *z, *e;
	struct sockaddr_in *sin;
	int i;

	if (do_if_fetch(x) < 0)
		return 0;
	if( strncmp(x->name, ptr->base, ptr->baselen) != 0 )
		return 0;
	z = strchr(x->name, ':');
	if( !z || !*z )
		return 0;
	z++;
	for( e = z; *e; e++ )
		if( *e == '-' )
			return 0;
	i = atoi(z);
	if (i < 0 || i > 255)
		abort();
	searcher[i] = 1;

	sin = (struct sockaddr_in *)&x->dstaddr;
	if( sin->sin_addr.s_addr != ptr->addr ){
		return 0;
	}
	if( ptr->flag ){
		if (set_flag(x->name, IFF_UP | IFF_RUNNING) == -1)
			return -1;
	}else{
		if( clr_flag(x->name, IFF_UP) == -1 )
			return -1;
	}
	return 1;
}

static int set_ifstate(char *parent, unsigned long ip,
				unsigned long nm, unsigned long bc,
				int flag)
{
	char buf[IFNAMSIZ];
	struct ifcmd pt;
	int i;

	pt.base = parent;
	pt.baselen = strlen(parent);
	pt.addr = ip;
	pt.flag = flag;
	memset(searcher, 0, sizeof(searcher));
	i = for_all_interfaces((int (*)(struct interface *,void *))do_ifcmd,
					&pt);
	if( i == -1 )
		return -1;
	if( i == 1 )
		return 0;

	for( i = 0; i < 256; i++ )
		if( searcher[i] == 0 )
			break;
	if( i == 256 )
		return -1;
	if( snprintf(buf, IFNAMSIZ, "%s:%d", parent, i) > IFNAMSIZ )
		return -1;
	if( set_ip_using(buf, SIOCSIFADDR, ip) == -1 )
		return -1;
	if( set_ip_using(buf, SIOCSIFNETMASK, nm) == -1 )
		return -1;
	if( set_ip_using(buf, SIOCSIFBRDADDR, bc) == -1 )
		return -1;
	if( set_flag(buf, IFF_BROADCAST) == -1 )
		return -1;
	return 0;
}

int main( int argc, char **argv )
{
	struct sockaddr sa;
	struct sockaddr_in sin;
	char **spp;
	struct ifreq ifr;
	struct aftype *ap;
	struct hwtype *hw;
	int goterr = 0, didnetmask = 0;
	char host[128];
	int fd;

	argc--;
	argv++;
	while( argc && *argv[0] == '-' ){
		if( !strcmp(*argv, "-a") )
			opt_a = 1;
		else if( !strcmp(*argv, "-s") )
			ife_short = 1;
		else if (!strcmp(*argv, "-v"))
        	opt_v = 1;
		else if( !strcmp(*argv, "-V") || !strcmp(*argv, "-version") ||
						!strcmp(*argv, "--version"))
			version();
		else if( !strcmp(*argv, "-?") || !strcmp(*argv, "-h") ||
						!strcmp(*argv, "-help") || !strcmp(*argv, "--help") )
			usage();
		else{
			fprintf(stderr, "ifconfig: option `%s' not recognised.\n", argv[0]);
			fprintf(stderr, "ifconfig: `--help' gives usage information.\n");
			exit(1);
		}
		argv++;
		argc--;
	}

	if( (skfd = sockets_open(0)) < 0 ){
		PR_ERR( "socket: %s\n", strerror(errno) );
		exit(1);
	}

	if( argc == 0 ){
		int err = if_print( (char *) NULL );
		(void)close(skfd);
		exit(err < 0);
	}

	spp = argv;
	safe_strncpy(ifr.ifr_name, *spp++, IFNAMSIZ);
	if( *spp == (char *) NULL ){
		int err = if_print( ifr.ifr_name );
		(void) close(skfd);
		exit(err < 0);
	}

	if( (ap = get_aftype(*spp)) != NULL )
		spp++;
	else
		ap = get_aftype(DFLT_AF);
	if( ap ){
		addr_family = ap->af;
		skfd = ap->fd;
	}

	while( *spp != (char *) NULL ){
		if( !strcmp(*spp, "arp") ){
			goterr |= clr_flag(ifr.ifr_name, IFF_NOARP);
			spp++;
			continue;
		}
		if( !strcmp(*spp, "-arp") ){
			goterr |= set_flag(ifr.ifr_name, IFF_NOARP);
			spp++;
			continue;
		}

		if (!strcmp(*spp, "trailers")) {
			goterr |= clr_flag(ifr.ifr_name, IFF_NOTRAILERS);
			spp++;
			continue;
		}
		if (!strcmp(*spp, "-trailers")) {
			goterr |= set_flag(ifr.ifr_name, IFF_NOTRAILERS);
			spp++;
			continue;
		}
		if( !strcmp(*spp, "promisc") ){