debian compatable ifup and ifdown commands

5 files changed, 1478 insertions, 0 deletions

diff --git a/include/applets.h b/include/applets.h
index e41a489..2de9c99 100644
--- a/include/applets.h
+++ b/include/applets.h
@@ -239,6 +239,12 @@
 #ifdef CONFIG_IFCONFIG
 	APPLET(ifconfig, ifconfig_main, _BB_DIR_SBIN, _BB_SUID_NEVER)
 #endif
+#ifdef CONFIG_IFUPDOWN
+	APPLET(ifdown, ifupdown_main, _BB_DIR_SBIN, _BB_SUID_NEVER)
+#endif
+#ifdef CONFIG_IFUPDOWN
+	APPLET(ifup, ifupdown_main, _BB_DIR_SBIN, _BB_SUID_NEVER)
+#endif
 #ifdef CONFIG_INIT
 	APPLET(init, init_main, _BB_DIR_SBIN, _BB_SUID_NEVER)
 #endif
diff --git a/include/usage.h b/include/usage.h
index 1d22806..2d20722 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -807,6 +807,34 @@
 	USAGE_IFCONFIG_MII("\t[mem_start <NN>]  [io_addr <NN>]  [irq <NN>]\n") \
 	"\t[up|down] ..."
 
+#define ifup_trivial_usage \
+	"<-ahinv> <ifaces...>"
+#define ifup_full_usage \
+	"Usage: ifup <options> <ifaces...>\n\n" \
+	"Options:\n" \
+	"\t-h, --help\t\tthis help\n" \
+	"\t-a, --all\t\tde/configure all interfaces automatically\n" \
+	"\t-i, --interfaces FILE\tuse FILE for interface definitions\n" \
+    "\t-n, --no-act\t\tprint out what would happen, but don't do it\n" \
+	"\t\t\t\t(note that this option doesn't disable mappings)\n" \
+    "\t-v, --verbose\t\tprint out what would happen before doing it\n" \
+	"\t--no-mappings\t\tdon't run any mappings\n" \
+	"\t--force\t\t\tforce de/configuration\n"
+
+#define ifdown_trivial_usage \
+	"<-ahinv> <ifaces...>"
+#define ifdown_full_usage \
+	"Usage: ifdown <options> <ifaces...>\n\n" \
+	"Options:\n" \
+	"\t-h, --help\t\tthis help\n" \
+	"\t-a, --all\t\tde/configure all interfaces automatically\n" \
+	"\t-i, --interfaces FILE\tuse FILE for interface definitions\n" \
+    "\t-n, --no-act\t\tprint out what would happen, but don't do it\n" \
+	"\t\t\t\t(note that this option doesn't disable mappings)\n" \
+    "\t-v, --verbose\t\tprint out what would happen before doing it\n" \
+	"\t--no-mappings\t\tdon't run any mappings\n" \
+	"\t--force\t\t\tforce de/configuration\n"
+	
 #define init_trivial_usage \
 	""
 #define init_full_usage \
diff --git a/networking/Makefile.in b/networking/Makefile.in
index d6c8592..743990b 100644
--- a/networking/Makefile.in
+++ b/networking/Makefile.in
@@ -25,6 +25,7 @@ endif
 NETWORKING-y:=
 NETWORKING-$(CONFIG_HOSTNAME)		+= hostname.o
 NETWORKING-$(CONFIG_IFCONFIG)		+= ifconfig.o
+NETWORKING-$(CONFIG_IFUPDOWN)		+= ifupdown.o
 NETWORKING-$(CONFIG_NC)			+= nc.o
 NETWORKING-$(CONFIG_NETSTAT)		+= netstat.o
 NETWORKING-$(CONFIG_NSLOOKUP)		+= nslookup.o
diff --git a/networking/config.in b/networking/config.in
index bc14940..09b2b5c 100644
--- a/networking/config.in
+++ b/networking/config.in
@@ -16,6 +16,12 @@ if [ "$CONFIG_IFCONFIG" = "y" ]; then
     bool '  Enable option "hw" (ether only)'						CONFIG_FEATURE_IFCONFIG_HW 
     bool '  Set the broadcast automatically'					CONFIG_FEATURE_IFCONFIG_BROADCAST_PLUS
 fi
+bool 'ifupdown'	    CONFIG_IFUPDOWN
+if [ "$CONFIG_IFUPDOWN" = "y" ]; then
+    bool '  Enable support for IPv4'	CONFIG_FEATURE_IFUPDOWN_IPV4
+    bool '  Enable support for IPv6 (requires ip command)' CONFIG_FEATURE_IFUPDOWN_IPV6
+    bool '  Enable support for IPX (requires ipx_interface command)' CONFIG_FEATURE_IFUPDOWN_IPX
+fi
 bool 'nc'	    CONFIG_NC
 bool 'netstat'	    CONFIG_NETSTAT
 bool 'nslookup'	    CONFIG_NSLOOKUP
diff --git a/networking/ifupdown.c b/networking/ifupdown.c
new file mode 100644
index 0000000..f56842d
--- /dev/null
+++ b/networking/ifupdown.c
@@ -0,0 +1,1437 @@
+/*
+ *  ifupdown for busybox
+ *  Based on ifupdown by Anthony Towns
+ *  Copyright (c) 1999 Anthony Towns <aj@azure.humbug.org.au>
+ *
+ *  Remove checks for kernel version, assume kernel version 2.2.0 or better
+ *
+ *  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.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <sys/stat.h>
+#include <sys/utsname.h>
+#include <sys/wait.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <fnmatch.h>
+#include <getopt.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "busybox.h"
+#include "config.h"
+
+#define IFUPDOWN_VERSION "0.6.4"
+
+typedef struct interface_defn interface_defn;
+
+typedef int (execfn)(char *command);
+typedef int (command_set)(interface_defn *ifd, execfn *e);
+
+typedef struct method {
+	char *name;
+	command_set *up;
+	command_set *down;
+} method;
+
+typedef struct address_family {
+	char *name;
+	int n_methods;
+	method *method;
+} address_family;
+
+typedef struct mapping_defn {
+	struct mapping_defn *next;
+
+	int max_matches;
+	int n_matches;
+	char **match;
+
+	char *script;
+
+	int max_mappings;
+	int n_mappings;
+	char **mapping;
+} mapping_defn;
+
+typedef struct variable {
+	char *name;
+	char *value;
+} variable;
+
+struct interface_defn {
+	struct interface_defn *next;
+
+	char *iface;
+	address_family *address_family;
+	method *method;
+
+	int automatic;
+
+	int max_options;
+	int n_options;
+	variable *option;
+};
+
+typedef struct interfaces_file {
+	int max_autointerfaces;
+	int n_autointerfaces;
+	char **autointerfaces;
+
+	interface_defn *ifaces;
+	mapping_defn *mappings;
+} interfaces_file;
+
+#define MAX_OPT_DEPTH 10
+#define EUNBALBRACK 10001
+#define EUNDEFVAR   10002
+#define MAX_VARNAME    32
+#define EUNBALPER   10000
+
+static int no_act = 0;
+static int verbose = 0;
+static char **environ = NULL;
+
+static int execable(char *program)
+{
+	struct stat buf;
+	if (0 == stat(program, &buf)) {
+		if (S_ISREG(buf.st_mode) && (S_IXUSR & buf.st_mode)) {
+			return(1);
+		}
+	}
+	return(0);
+}
+
+static void addstr(char **buf, size_t *len, size_t *pos, char *str, size_t str_length)
+{
+	if (*pos + str_length >= *len) {
+		char *newbuf;
+
+		newbuf = xrealloc(*buf, *len * 2 + str_length + 1);
+		*buf = newbuf;
+		*len = *len * 2 + str_length + 1;
+	}
+
+	while (str_length-- >= 1) {
+		(*buf)[(*pos)++] = *str;
+		str++;
+	}
+	(*buf)[*pos] = '\0';
+}
+
+static int strncmpz(char *l, char *r, size_t llen)
+{
+	int i = strncmp(l, r, llen);
+
+	if (i == 0) {
+		return(-r[llen]);
+	} else {
+		return(i);
+	}
+}
+
+static char *get_var(char *id, size_t idlen, interface_defn *ifd)
+{
+	int i;
+
+	if (strncmpz(id, "iface", idlen) == 0) {
+		return (ifd->iface);
+	} else {
+		for (i = 0; i < ifd->n_options; i++) {
+			if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
+				return (ifd->option[i].value);
+			}
+		}
+	}
+
+	return(NULL);
+}
+
+static char *parse(char *command, interface_defn *ifd)
+{
+
+	char *result = NULL;
+	size_t pos = 0, len = 0;
+	size_t old_pos[MAX_OPT_DEPTH] = { 0 };
+	int okay[MAX_OPT_DEPTH] = { 1 };
+	int opt_depth = 1;
+
+	while (*command) {
+		switch (*command) {
+
+		default:
+			addstr(&result, &len, &pos, command, 1);
+			command++;
+			break;
+		case '\\':
+			if (command[1]) {
+				addstr(&result, &len, &pos, command + 1, 1);
+				command += 2;
+			} else {
+				addstr(&result, &len, &pos, command, 1);
+				command++;
+			}
+			break;
+		case '[':
+			if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
+				old_pos[opt_depth] = pos;
+				okay[opt_depth] = 1;
+				opt_depth++;
+				command += 2;
+			} else {
+				addstr(&result, &len, &pos, "[", 1);
+				command++;
+			}
+			break;
+		case ']':
+			if (command[1] == ']' && opt_depth > 1) {
+				opt_depth--;
+				if (!okay[opt_depth]) {
+					pos = old_pos[opt_depth];
+					result[pos] = '\0';
+				}
+				command += 2;
+			} else {
+				addstr(&result, &len, &pos, "]", 1);
+				command++;
+			}
+			break;
+		case '%':
+		{
+			char *nextpercent;
+			char *varvalue;
+
+			command++;
+			nextpercent = strchr(command, '%');
+			if (!nextpercent) {
+				errno = EUNBALPER;
+				free(result);
+				return (NULL);
+			}
+
+			varvalue = get_var(command, nextpercent - command, ifd);
+
+			if (varvalue) {
+				addstr(&result, &len, &pos, varvalue, xstrlen(varvalue));
+			} else {
+				okay[opt_depth - 1] = 0;
+			}
+
+			command = nextpercent + 1;
+		}
+			break;
+		}
+	}
+
+	if (opt_depth > 1) {
+		errno = EUNBALBRACK;
+		free(result);
+		return(NULL);
+	}
+
+	if (!okay[0]) {
+		errno = EUNDEFVAR;
+		free(result);
+		return(NULL);
+	}
+
+	return(result);
+}
+
+static int execute(char *command, interface_defn *ifd, execfn *exec)
+{
+	char *out;
+	int ret;
+
+	out = parse(command, ifd);
+	if (!out) {
+		return(0);
+	}
+
+	ret = (*exec) (out);
+
+	free(out);
+	return(ret);
+}
+
+#ifdef CONFIG_FEATURE_IFUPDOWN_IPX
+static int static_up_ipx(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("ipx_interface add %iface% %frame% %netnum%", ifd, exec)) {
+		return(0);
+	}
+	return(1);
+}
+
+static int static_down_ipx(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("ipx_interface del %iface% %frame%", ifd, exec)) {
+		return(0);
+	}
+	return(1);
+}
+
+static int dynamic_up(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("ipx_interface add %iface% %frame%", ifd, exec)) {
+		return(0);
+	}
+	return(1);
+}
+
+static int dynamic_down(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("ipx_interface del %iface% %frame%", ifd, exec)) {
+		return(0);
+	}
+	return(1);
+}
+
+static method methods_ipx[] = {
+	{ "dynamic", dynamic_up, dynamic_down, },
+	{ "static", static_up_ipx, static_down_ipx, },
+};
+
+address_family addr_ipx = {
+	"ipx",
+	sizeof(methods_ipx) / sizeof(struct method),
+	methods_ipx
+};
+#endif /* IFUP_FEATURE_IPX */
+
+#ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
+static int loopback_up6(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("ifconfig %iface% add ::1", ifd, exec)) {
+		return(0);
+	}
+	return(1);
+}
+
+static int loopback_down6(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("ifconfig %iface% del ::1", ifd, exec))
+		return(0);
+	}
+	return(1);
+}
+
+static int static_up6(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("ifconfig %iface% [[media %media%]] [[hw %hwaddress%]] [[mtu %mtu%]] up", ifd, exec)) {
+		return(0);
+	}
+	if (!execute("ifconfig %iface% add %address%/%netmask%", ifd, exec)) {
+		return(0);
+	}
+	if (!execute("[[ route -A inet6 add ::/0 gw %gateway% ]]", ifd, exec)) {
+		return(0);
+	}
+	return(1);
+}
+
+static int static_down6(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("ifconfig %iface% down", ifd, exec)) {
+		return(0);
+	}
+	return(1);
+}
+
+static int v4tunnel_up(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("ip tunnel add %iface% mode sit remote %endpoint% [[local %local%]] [[ttl %ttl%]]", ifd, exec)) {
+		return(0);
+	}
+	if (!execute("ip link set %iface% up", ifd, exec)) {
+		return(0);
+	}
+	if (!execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec)) {
+		return(0);
+	}
+	if (!execute("[[ ip route add ::/0 via %gateway% ]]", ifd, exec)) {
+		return(0);
+	}
+	return(1);
+}
+
+static int v4tunnel_down(interface_defn * ifd, execfn * exec)
+{
+	if (!execute("ip tunnel del %iface%", ifd, exec)) {
+		return(0);
+	}
+	return(1);
+}
+
+static method methods6[] = {
+	{ "v4tunnel", v4tunnel_up, v4tunnel_down, },
+	{ "static", static_up6, static_down6, },
+	{ "loopback", loopback_up6, loopback_down6, },
+};
+
+address_family addr_inet6 = {
+	"inet6",
+	sizeof(methods6) / sizeof(struct method),
+	methods6
+};
+#endif /* CONFIG_FEATURE_IFUPDOWN_IPV6 */
+
+#ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
+static int loopback_up(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("ifconfig %iface% 127.0.0.1 up", ifd, exec)) {
+		return(0);
+	}
+	return(1);
+}
+
+static int loopback_down(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("ifconfig %iface% down", ifd, exec)) {
+		return(0);
+	}
+	return(1);
+}
+
+static int static_up(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("ifconfig %iface% %address% netmask %netmask% [[broadcast %broadcast%]] 	[[pointopoint %pointopoint%]] [[media %media%]] [[mtu %mtu%]] 	[[hw %hwaddress%]] up",
+		 ifd, exec)) {
+		return(0);
+	}
+	if (!execute("[[ route add default gw %gateway% %iface% ]]", ifd, exec)) {
+		return(0);
+	}
+	return(1);
+}
+
+static int static_down(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("[[ route del default gw %gateway% %iface% ]]", ifd, exec)) {
+		return(0);
+	}
+	if (!execute("ifconfig %iface% down", ifd, exec)) {
+		return(0);
+	}
+	return(1);
+}
+
+static int dhcp_up(interface_defn *ifd, execfn *exec)
+{
+	if (execable("/sbin/dhclient")) {
+		if (!execute("dhclient -pf /var/run/dhclient.%iface%.pid %iface%", ifd, exec)) {
+			return(0);
+		}
+	} else if (execable("/sbin/pump")) {
+		if (!execute("pump -i %iface% [[-h %hostname%]] [[-l %leasehours%]]", ifd, exec)) {
+			return(0);
+		}
+	} else if (execable("/sbin/udhcpc")) {
+		if (!execute("udhcpc -n -p /var/run/udhcpc.%iface%.pid -i %iface% [[-H %hostname%]] [[-c %clientid%]]", ifd, exec)) {
+			return 0;
+		}
+	} else if (execable("/sbin/dhcpcd")) {
+		if (!execute("dhcpcd [[-h %hostname%]] [[-i %vendor%]] [[-I %clientid%]] [[-l %leasetime%]] %iface%", ifd, exec)) {
+			return(0);
+		}
+	}
+	return(1);
+}
+
+static int dhcp_down(interface_defn *ifd, execfn *exec)
+{
+	if (execable("/sbin/dhclient")) {
+		if (!execute("cat /var/run/dhclient.%iface%.pid | xargs -i kill -TERM {}", ifd, exec)) {
+			return(0);
+		}
+	} else if (execable("/sbin/pump")) {
+		if (!execute("pump -i %iface% -k", ifd, exec)) {
+			return(0);
+		}
+	} else if (execable("/sbin/udhcpc")) {
+		if (!execute("cat /var/run/udhcpc.%iface%.pid | xargs -i kill -TERM {}", ifd, exec)) {
+			return(0);
+		}
+	} else if (execable("/sbin/dhcpcd")) {
+		if (!execute("dhcpcd -k %iface%", ifd, exec)) {
+			return(0);
+		}
+	}
+	if (!execute("ifconfig %iface% down", ifd, exec)) {
+		return(0);
+	}
+	return(1);
+}
+
+static int bootp_up(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("bootpc [[--bootfile %bootfile%]] --dev %iface% [[--server %server%]]            [[--hwaddr %hwaddr%]] --returniffail --serverbcast", ifd, exec)) {
+		return 0;
+	}
+	return 1;
+}
+
+static int bootp_down(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("ifconfig down %iface%", ifd, exec)) {
+		return 0;
+	}
+	return 1;
+}
+
+static int ppp_up(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("pon [[%provider%]]", ifd, exec)) {
+		return 0;
+	}
+	return 1;
+}
+
+static int ppp_down(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("poff [[%provider%]]", ifd, exec)) {
+		return 0;
+	}
+	return 1;
+}
+
+static int wvdial_up(interface_defn *ifd, execfn *exec)
+{
+	if (!execute("/sbin/start-stop-daemon --start -x /usr/bin/wvdial -p /var/run/wvdial.%iface% -b -m -- [[ %provider% ]]", ifd, exec)) {
+		return 0;
+	}
+	return 1;
+}
+
+static int wvdial_down(interface_defn *ifd, execfn *exec)
+{
+	if (!execute ("/sbin/start-stop-daemon --stop -x /usr/bin/wvdial -p /var/run/wvdial.%iface% -s 2", ifd, exec)) {
+		return 0;
+	}
+	return 1;
+}
+
+static method methods[] = {
+	{ "wvdial", wvdial_up, wvdial_down, },
+	{ "ppp", ppp_up, ppp_down, },
+	{ "static", static_up, static_down, },
+	{ "bootp", bootp_up, bootp_down, },
+	{ "dhcp", dhcp_up, dhcp_down, },
+	{ "loopback", loopback_up, loopback_down, },
+};
+
+address_family addr_inet = {
+	"inet",
+	sizeof(methods) / sizeof(struct method),
+	methods
+};
+
+#endif	/* ifdef CONFIG_FEATURE_IFUPDOWN_IPV4 */
+
+static char *next_word(char *buf, char *word, int maxlen)
+{
+	if (!buf)
+		return NULL;
+	if (!*buf)
+		return NULL;
+
+	while (!isspace(*buf) && *buf) {
+		if (maxlen-- > 1)
+			*word++ = *buf;
+		buf++;
+	}
+	if (maxlen > 0) {
+		*word = '\0';
+	}
+
+	while (isspace(*buf) && *buf) {
+		buf++;
+	}
+
+	return buf;
+}
+
+static address_family *get_address_family(address_family *af[], char *name)
+{
+	int i;
+
+	for (i = 0; af[i]; i++) {
+		if (strcmp(af[i]->name, name) == 0) {
+			return af[i];
+		}
+	}
+	return NULL;
+}
+
+static method *get_method(address_family *af, char *name)
+{
+	int i;
+
+	for (i = 0; i < af->n_methods; i++) {
+		if (strcmp(af->method[i].name, name) == 0) {
+			return &af->method[i];
+		}
+	}
+	return(NULL);
+}
+
+static int duplicate_if(interface_defn *ifa, interface_defn *ifb)
+{
+	if (strcmp(ifa->iface, ifb->iface) != 0) {
+		return(0);
+	}
+	if (ifa->address_family != ifb->address_family) {
+		return(0);
+	}
+	return(1);
+}
+
+static int get_line(char **result, size_t * result_len, FILE * f, int *line)
+{
+	size_t pos;
+
+	do {
+		pos = 0;
+		do {
+			if (*result_len - pos < 10) {
+				char *newstr = xrealloc(*result, *result_len * 2 + 80);
+				*result = newstr;
+				*result_len = *result_len * 2 + 80;
+			}
+
+			if (!fgets(*result + pos, *result_len - pos, f)) {
+				if (ferror(f) == 0 && pos == 0)
+					return 0;
+				if (ferror(f) != 0)
+					return 0;
+			}
+			pos += xstrlen(*result + pos);
+		} while (pos == *result_len - 1 && (*result)[pos - 1] != '\n');
+
+		if (pos != 0 && (*result)[pos - 1] == '\n') {
+			(*result)[--pos] = '\0';
+		}
+
+		(*line)++;
+		{
+			int first = 0;
+
+			while (isspace((*result)[first]) && (*result)[first]) {
+				first++;
+			}
+
+			memmove(*result, *result + first, pos - first + 1);
+			pos -= first;
+		}
+	} while ((*result)[0] == '#');
+
+	while ((*result)[pos - 1] == '\\') {
+		(*result)[--pos] = '\0';
+		do {
+			if (*result_len - pos < 10) {
+				char *newstr = xrealloc(*result, *result_len * 2 + 80);
+				*result = newstr;
+				*result_len = *result_len * 2 + 80;
+			}
+
+			if (!fgets(*result + pos, *result_len - pos, f)) {
+				if (ferror(f) == 0 && pos == 0)
+					return 0;
+				if (ferror(f) != 0)
+					return 0;
+			}
+			pos += xstrlen(*result + pos);
+		} while (pos == *result_len - 1 && (*result)[pos - 1] != '\n');
+
+		if (pos != 0 && (*result)[pos - 1] == '\n') {
+			(*result)[--pos] = '\0';
+		}
+		(*line)++;
+	}
+
+	while (isspace((*result)[pos - 1])) {	/* remove trailing whitespace */
+		pos--;
+	}
+	(*result)[pos] = '\0';
+
+	return 1;
+}
+
+static interfaces_file *read_interfaces(char *filename)
+{
+	interface_defn *currif = NULL;
+	interfaces_file *defn;
+	mapping_defn *currmap = NULL;
+	FILE *f;
+	char firstword[80];
+	char *buf = NULL;
+	char *rest;
+	int line;
+	size_t buf_len = 0;
+
+	enum { NONE, IFACE, MAPPING } currently_processing = NONE;
+
+	defn = xmalloc(sizeof(interfaces_file));
+	defn->max_autointerfaces = defn->n_autointerfaces = 0;
+	defn->autointerfaces = NULL;
+	defn->mappings = NULL;
+	defn->ifaces = NULL;
+	f = fopen(filename, "r");
+	if (f == NULL) {
+		return NULL;
+	}
+	line = 0;
+
+	while (get_line(&buf, &buf_len, f, &line)) {
+		rest = next_word(buf, firstword, 80);
+		if (rest == NULL) {
+			continue;	/* blank line */
+		}
+
+		if (strcmp(firstword, "mapping") == 0) {
+
+			currmap = xmalloc(sizeof(mapping_defn));
+			currmap->max_matches = 0;
+			currmap->n_matches = 0;
+			currmap->match = NULL;
+
+			while ((rest = next_word(rest, firstword, 80))) {
+				if (currmap->max_matches == currmap->n_matches) {
+					currmap->max_matches = currmap->max_matches * 2 + 1;
+					currmap->match = xrealloc(currmap->match, sizeof(currmap->match) * currmap->max_matches);
+				}
+
+				currmap->match[currmap->n_matches++] = xstrdup(firstword);
+			}
+			currmap->max_mappings = 0;
+			currmap->n_mappings = 0;
+			currmap->mapping = NULL;
+			currmap->script = NULL;
+			{
+				mapping_defn **where = &defn->mappings;
+				while (*where != NULL) {
+					where = &(*where)->next;
+				}
+				*where = currmap;
+				currmap->next = NULL;
+			}
+			currently_processing = MAPPING;
+		} else if (strcmp(firstword, "iface") == 0) {
+			{
+				char iface_name[80];
+				char address_family_name[80];
+				char method_name[80];
+				address_family *addr_fams[] = {
+#ifdef CONFIG_FEATURE_IFUPDOWN_IPV4
+					&addr_inet,
+#endif
+#ifdef CONFIG_FEATURE_IFUPDOWN_IPV6
+					&addr_inet6,
+#endif
+#ifdef CONFIG_FEATURE_IFUPDOWN_IPX
+					&addr_ipx,
+#endif
+					NULL
+				};
+
+				currif = xmalloc(sizeof(interface_defn));
+
+				rest = next_word(rest, iface_name, 80);
+				rest = next_word(rest, address_family_name, 80);
+				rest = next_word(rest, method_name, 80);
+
+				if (rest == NULL) {
+					error_msg("%s:%d: too few parameters for iface line", filename, line);
+					return NULL;
+				}
+
+				if (rest[0] != '\0') {
+					error_msg("%s:%d: too many parameters for iface line", filename, line);
+					return NULL;
+				}
+
+				currif->iface = xstrdup(iface_name);
+
+				currif->address_family = get_address_family(addr_fams, address_family_name);
+				if (!currif->address_family) {
+					error_msg("%s:%d: unknown address type", filename, line);
+					return NULL;
+				}
+
+				currif->method = get_method(currif->address_family, method_name);
+				if (!currif->method) {
+					error_msg("%s:%d: unknown method", filename, line);
+					return NULL;
+				}
+
+				currif->automatic = 1;
+				currif->max_options = 0;
+				currif->n_options = 0;
+				currif->option = NULL;
+
+
+				{
+					interface_defn **where = &defn->ifaces;
+
+					while (*where != NULL) {
+						if (duplicate_if(*where, currif)) {
+							error_msg("%s:%d: duplicate interface", filename, line);
+							return NULL;
+						}
+						where = &(*where)->next;
+					}
+
+					*where = currif;
+					currif->next = NULL;
+				}
+			}
+			currently_processing = IFACE;
+		} else if (strcmp(firstword, "auto") == 0) {
+			while ((rest = next_word(rest, firstword, 80))) {
+				int i;
+
+				for (i = 0; i < defn->n_autointerfaces; i++) {
+					if (strcmp(firstword, defn->autointerfaces[i]) == 0) {
+						perror_msg("%s:%d: interface declared auto twice", filename, line);
+						return NULL;
+					}
+				}
+
+				if (defn->n_autointerfaces == defn->max_autointerfaces) {
+					char **tmp;
+
+					defn->max_autointerfaces *= 2;
+					defn->max_autointerfaces++;
+					tmp = xrealloc(defn->autointerfaces, sizeof(*tmp) * defn->max_autointerfaces);
+					defn->autointerfaces = tmp;
+				}
+
+				defn->autointerfaces[defn->n_autointerfaces] = xstrdup(firstword);
+				defn->n_autointerfaces++;
+			}
+			currently_processing = NONE;
+		} else {
+			switch (currently_processing) {
+			case IFACE:
+			{
+				int i;
+
+				if (xstrlen(rest) == 0) {
+					error_msg("%s:%d: option with empty value", filename, line);
+					return NULL;
+				}
+
+				if (strcmp(firstword, "up") != 0
+					&& strcmp(firstword, "down") != 0
+					&& strcmp(firstword, "pre-up") != 0
+					&& strcmp(firstword, "post-down") != 0) {
+					for (i = 0; i < currif->n_options; i++) {
+						if (strcmp(currif->option[i].name, firstword) == 0) {
+							error_msg("%s:%d: duplicate option", filename, line);
+							return NULL;
+						}
+					}
+				}
+			}
+				if (currif->n_options >= currif->max_options) {
+					variable *opt;
+
+					currif->max_options = currif->max_options + 10;
+					opt = xrealloc(currif->option, sizeof(*opt) * currif->max_options);
+					currif->option = opt;
+				}
+				currif->option[currif->n_options].name = xstrdup(firstword);
+				currif->option[currif->n_options].value = xstrdup(rest);
+				if (!currif->option[currif->n_options].name) {
+					perror(filename);
+					return NULL;
+				}
+				if (!currif->option[currif->n_options].value) {
+					perror(filename);
+					return NULL;
+				}
+				currif->n_options++;
+				break;
+			case MAPPING:
+				if (strcmp(firstword, "script") == 0) {
+					if (currmap->script != NULL) {
+						error_msg("%s:%d: duplicate script in mapping", filename, line);
+						return NULL;
+					} else {
+						currmap->script = xstrdup(rest);
+					}
+				} else if (strcmp(firstword, "map") == 0) {
+					if (currmap->max_mappings == currmap->n_mappings) {
+						currmap->max_mappings = currmap->max_mappings * 2 + 1;
+						currmap->mapping = xrealloc(currmap->mapping, sizeof(char *) * currmap->max_mappings);
+					}
+					currmap->mapping[currmap->n_mappings] = xstrdup(rest);
+					currmap->n_mappings++;
+				} else {
+					error_msg("%s:%d: misplaced option", filename, line);
+					return NULL;
+				}
+				break;
+			case NONE:
+			default:
+				error_msg("%s:%d: misplaced option", filename, line);
+				return NULL;
+			}
+		}
+	}
+	if (ferror(f) != 0) {
+		perror_msg("%s", filename);
+		return NULL;
+	}
+	fclose(f);
+	line = -1;
+
+	return defn;
+}
+
+static int check(char *str)
+{
+	return (str != NULL);
+}
+
+static char *setlocalenv(char *format, char *name, char *value)
+{
+	char *result;
+	char *here;
+	char *there;
+
+	result = xmalloc(xstrlen(format) + xstrlen(name) + xstrlen(value) + 1);
+
+	sprintf(result, format, name, value);
+
+	for (here = there = result; *there != '=' && *there; there++) {
+		if (*there == '-')
+			*there = '_';
+		if (isalpha(*there))
+			*there = toupper(*there);
+
+		if (isalnum(*there) || *there == '_') {
+			*here = *there;
+			here++;
+		}
+	}
+	memmove(here, there, xstrlen(there) + 1);
+
+	return result;
+}
+
+static void set_environ(interface_defn *iface, char *mode)
+{
+	char **environend;
+	int i;
+	const int n_env_entries = iface->n_options + 5;
+	char **ppch;
+
+	if (environ != NULL) {
+		for (ppch = environ; *ppch; ppch++) {
+			free(*ppch);
+			*ppch = NULL;
+		}
+		free(environ);
+		environ = NULL;
+	}
+	environ = xmalloc(sizeof(char *) * (n_env_entries + 1 /* for final NULL */ ));
+	environend = environ;
+	*environend = NULL;
+
+	for (i = 0; i < iface->n_options; i++) {
+		if (strcmp(iface->option[i].name, "up") == 0
+			|| strcmp(iface->option[i].name, "down") == 0
+			|| strcmp(iface->option[i].name, "pre-up") == 0
+			|| strcmp(iface->option[i].name, "post-down") == 0) {
+			continue;
+		}
+		*(environend++) = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
+		*environend = NULL;
+	}
+
+	*(environend++) = setlocalenv("%s=%s", "IFACE", iface->iface);
+	*environend = NULL;
+	*(environend++) = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
+	*environend = NULL;
+	*(environend++) = setlocalenv("%s=%s", "METHOD", iface->method->name);
+	*environend = NULL;
+	*(environend++) = setlocalenv("%s=%s", "MODE", mode);
+	*environend = NULL;
+	*(environend++) = setlocalenv("%s=%s", "PATH", "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin");
+	*environend = NULL;
+}
+
+static int doit(char *str)
+{
+	if (verbose || no_act) {
+		error_msg("%s", str);
+	}
+	if (!no_act) {
+		pid_t child;
+		int status;
+
+		fflush(NULL);
+		switch (child = fork()) {
+		case -1:		/* failure */
+			return 0;
+		case 0:		/* child */
+			execle("/bin/sh", "/bin/sh", "-c", str, NULL, environ);
+			exit(127);
+		default:		/* parent */
+		}
+		waitpid(child, &status, 0);
+		if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+			return 0;
+		}
+	}
+	return (1);
+}
+
+static int execute_all(interface_defn *ifd, execfn *exec, char *opt)
+{
+	int i;
+	char buf[100];
+
+	for (i = 0; i < ifd->n_options; i++) {
+		if (strcmp(ifd->option[i].name, opt) == 0) {
+			if (!(*exec) (ifd->option[i].value)) {
+				return 0;
+			}
+		}
+	}
+
+	sprintf(buf, "run-parts /etc/network/if-%s.d", opt);
+	(*exec) (buf);
+
+	return (1);
+}
+
+static int iface_up(interface_defn *iface)
+{
+	if (!iface->method->up(iface, check)) {
+		return (-1);
+	}
+
+	set_environ(iface, "start");
+	if (!execute_all(iface, doit, "pre-up")) {
+		return (0);
+	}
+	if (!iface->method->up(iface, doit)) {
+		return (0);
+	}
+	if (!execute_all(iface, doit, "up")) {
+		return (0);
+	}
+
+	return (1);
+}
+
+static int iface_down(interface_defn *iface)
+{
+	if (!iface->method->down(iface, check)) {
+		return (-1);
+	}
+	set_environ(iface, "stop");
+	if (!execute_all(iface, doit, "down")) {
+		return (0);
+	}
+	if (!iface->method->down(iface, doit)) {
+		return (0);
+	}
+	if (!execute_all(iface, doit, "post-down")) {
+		return (0);
+	}
+	return (1);
+}
+
+static int popen2(FILE **in, FILE **out, char *command, ...)
+{
+	va_list ap;
+	char *argv[11] = { command };
+	int argc;
+	int infd[2], outfd[2];
+	pid_t pid;
+
+	argc = 1;
+	va_start(ap, command);
+	while ((argc < 10) && (argv[argc] = va_arg(ap, char *))) {
+		argc++;
+	}
+	argv[argc] = NULL;	/* make sure */
+	va_end(ap);
+
+	if (pipe(infd) != 0) {
+		return 0;
+	}
+
+	if (pipe(outfd) != 0) {
+		close(infd[0]);
+		close(infd[1]);
+		return 0;
+	}
+
+	fflush(NULL);
+	switch (pid = fork()) {
+	case -1:			/* failure */
+		close(infd[0]);
+		close(infd[1]);
+		close(outfd[0]);
+		close(outfd[1]);
+		return 0;
+	case 0:			/* child */
+		dup2(infd[0], 0);
+		dup2(outfd[1], 1);
+		close(infd[0]);
+		close(infd[1]);
+		close(outfd[0]);
+		close(outfd[1]);
+		execvp(command, argv);
+		exit(127);
+	default:			/* parent */
+		*in = fdopen(infd[1], "w");
+		*out = fdopen(outfd[0], "r");
+		close(infd[0]);
+		close(outfd[1]);
+		return pid;
+	}
+	/* unreached */
+}
+
+static int run_mapping(char *physical, char *logical, int len, mapping_defn * map)
+{
+	FILE *in, *out;
+	int i, status;
+	pid_t pid;
+
+
+	pid = popen2(&in, &out, map->script, physical, NULL);
+	if (pid == 0) {
+		return 0;
+	}
+	for (i = 0; i < map->n_mappings; i++) {
+		fprintf(in, "%s\n", map->mapping[i]);
+	}
+	fclose(in);
+	waitpid(pid, &status, 0);
+	if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
+		if (fgets(logical, len, out)) {
+			char *pch = logical + xstrlen(logical) - 1;
+
+			while (pch >= logical && isspace(*pch))
+				*(pch--) = '\0';
+		}
+	}
+	fclose(out);
+
+	return 1;
+}
+
+static int lookfor_iface(char **ifaces, int n_ifaces, char *iface)
+{
+	int i;
+
+	for (i = 0; i < n_ifaces; i++) {
+		if (strncmp(iface, ifaces[i], xstrlen(iface)) == 0) {
+			if (ifaces[i][xstrlen(iface)] == '=') {
+				return i;
+			}
+		}
+	}
+
+	return(-1);
+}
+
+static void add_to_state(char ***ifaces, int *n_ifaces, int *max_ifaces, char *new_iface)
+{
+	if (*max_ifaces == *n_ifaces) {
+		*max_ifaces = (*max_ifaces * 2) + 1;
+		*ifaces = xrealloc(*ifaces, sizeof(**ifaces) * *max_ifaces);
+	}
+
+	(*ifaces)[(*n_ifaces)++] = new_iface;
+}
+
+extern int ifupdown_main(int argc, char **argv)
+{
+	int (*cmds) (interface_defn *) = NULL;
+	struct option long_opts[] = {
+		{"help", no_argument, NULL, 'h'},
+		{"verbose", no_argument, NULL, 'v'},
+		{"all", no_argument, NULL, 'a'},
+		{"interfaces", required_argument, NULL, 'i'},
+		{"no-act", no_argument, NULL, 'n'},
+		{"no-mappings", no_argument, NULL, 1},
+		{"force", no_argument, NULL, 2},
+		{0, 0, 0, 0}
+	};
+	interfaces_file *defn;
+	FILE *state_fp = NULL;
+	char **target_iface = NULL;
+	char **state = NULL;	/* list of iface=liface */
+	char *interfaces = "/etc/network/interfaces";
+	char *statefile = "/etc/network/ifstate";
+
+	int do_all = 0;
+	int run_mappings = 1;
+	int force = 0;
+	int n_target_ifaces = 0;
+	int n_state = 0;
+	int max_state = 0;
+	int i;
+
+	if (applet_name[2] == 'u') {
+		/* ifup command */
+		cmds = iface_up;
+	} else {
+		/* ifdown command */
+		cmds = iface_down;
+	}
+
+	while ((i = getopt_long(argc, argv, "i:hvna", long_opts, NULL)) != EOF) {
+		switch (i) {
+		case 'i':
+			interfaces = xstrdup(optarg);
+			break;
+		case 'v':
+			verbose = 1;
+			break;
+		case 'a':
+			do_all = 1;
+			break;
+		case 'n':
+			no_act = 1;
+			break;
+		case 1:
+			run_mappings = 0;
+			break;
+		case 2:
+			force = 1;
+			break;
+		default:
+			show_usage();
+			break;
+		}
+	}
+
+	if (argc - optind > 0) {
+		if (do_all) {
+			show_usage();
+		}
+	} else {
+		if (!do_all) {
+			show_usage();
+		}
+	}			
+
+	defn = read_interfaces(interfaces);
+	if (!defn) {
+		error_msg_and_die("couldn't read interfaces file \"%s\"", interfaces);
+	}
+
+	state_fp = fopen(statefile, no_act ? "r" : "a+");
+	if (state_fp == NULL && !no_act) {
+		perror_msg_and_die("failed to open statefile %s", statefile);
+	}
+
+	if (state_fp != NULL) {
+		char buf[80];
+		char *p;
+
+		if (!no_act) {
+			int flags;
+			struct flock lock;
+			const int state_fd = fileno(state_fp);
+			
+			flags = fcntl(state_fd, F_GETFD);
+			if ((flags < 0) || (fcntl(state_fd, F_SETFD, flags | FD_CLOEXEC) < 0)) {
+				perror_msg_and_die("failed to set FD_CLOEXEC on statefile %s", statefile);
+			}
+
+			lock.l_type = F_WRLCK;
+			lock.l_whence = SEEK_SET;
+			lock.l_start = 0;
+			lock.l_len = 0;
+
+			if (fcntl(state_fd, F_SETLKW, &lock) < 0) {
+				perror_msg_and_die("failed to lock statefile %s", statefile);
+			}
+		}
+
+		rewind(state_fp);
+		while ((p = fgets(buf, sizeof buf, state_fp)) != NULL) {
+			char *pch;
+
+			pch = buf + xstrlen(buf) - 1;
+			while (pch > buf && isspace(*pch)) {
+				pch--;
+			}
+			*(pch + 1) = '\0';
+
+			pch = buf;
+			while (isspace(*pch)) {
+				pch++;
+			}
+
+			add_to_state(&state, &n_state, &max_state, xstrdup(pch));
+		}
+	}
+
+	if (do_all) {
+		if (cmds == iface_up) {
+			target_iface = defn->autointerfaces;
+			n_target_ifaces = defn->n_autointerfaces;
+		} else if (cmds == iface_down) {
+			target_iface = state;
+			n_target_ifaces = n_state;
+		}
+	} else {
+		target_iface = argv + optind;
+		n_target_ifaces = argc - optind;
+	}
+
+
+	for (i = 0; i < n_target_ifaces; i++) {
+		interface_defn *currif;
+		char iface[80];
+		char liface[80];
+		char *pch;
+		int okay = 0;
+
+		strncpy(iface, target_iface[i], sizeof(iface));
+		iface[sizeof(iface) - 1] = '\0';
+
+		if ((pch = strchr(iface, '='))) {
+			*pch = '\0';
+			strncpy(liface, pch + 1, sizeof(liface));
+			liface[sizeof(liface) - 1] = '\0';
+		} else {
+			strncpy(liface, iface, sizeof(liface));
+			liface[sizeof(liface) - 1] = '\0';
+		}
+		if (!force) {
+			int already_up = lookfor_iface(state, n_state, iface);;
+
+			if (cmds == iface_up) {
+				/* ifup */
+				if (already_up != -1) {
+					error_msg("interface %s already configured", iface);
+					continue;
+				}
+			} else {
+				/* ifdown */
+				if (already_up == -1) {
+					error_msg("interface %s not configured", iface);
+					continue;
+				}
+				strncpy(liface, strchr(state[already_up], '=') + 1, 80);
+				liface[79] = 0;
+			}
+		}
+
+		if ((cmds == iface_up) && run_mappings) {
+			mapping_defn *currmap;
+
+			for (currmap = defn->mappings; currmap; currmap = currmap->next) {
+
+				for (i = 0; i < currmap->n_matches; i++) {
+					if (fnmatch(currmap->match[i], liface, 0) != 0)
+						continue;
+					if (verbose) {
+						error_msg("Running mapping script %s on %s", currmap->script, liface);
+					}
+					run_mapping(iface, liface, sizeof(liface), currmap);
+					break;
+				}
+			}
+		}
+
+
+		for (currif = defn->ifaces; currif; currif = currif->next) {
+			if (strcmp(liface, currif->iface) == 0) {
+				char *oldiface = currif->iface;
+
+				okay = 1;
+
+				currif->iface = iface;
+
+				if (verbose) {
+					error_msg("Configuring interface %s=%s (%s)", iface, liface, currif->address_family->name);
+				}
+
+				switch (cmds(currif)) {
+				case -1:
+					printf
+						("Don't seem to be have all the variables for %s/%s.\n",
+						 liface, currif->address_family->name);
+					break;
+				case 0:
+					/* this wasn't entirely successful, should it be added to
+					 *      the state file?
+					 */
+				case 1:
+					/* successful */
+				}
+				currif->iface = oldiface;
+			}
+		}
+
+		if (!okay && !force) {
+			error_msg("Ignoring unknown interface %s=%s.", iface, liface);
+		} else {
+			int already_up = lookfor_iface(state, n_state, iface);
+
+			if (cmds == iface_up) {
+				char *newiface = xmalloc(xstrlen(iface) + 1 + xstrlen(liface) + 1);
+				sprintf(newiface, "%s=%s", iface, liface);
+				if (already_up == -1) {
+					add_to_state(&state, &n_state, &max_state, newiface);
+				} else {
+					free(state[already_up]);
+					state[already_up] = newiface;
+				}
+			} else if (cmds == iface_down) {
+				if (already_up != -1) {
+					state[already_up] = state[--n_state];
+				}
+			}
+		}
+		if (state_fp != NULL && !no_act) {
+			if (ftruncate(fileno(state_fp), 0) < 0) {
+				error_msg_and_die("failed to truncate statefile %s: %s", statefile, strerror(errno));
+			}
+
+			rewind(state_fp);
+			for (i = 0; i < n_state; i++) {
+				fputs(state[i], state_fp);
+				fputc('\n', state_fp);
+			}
+			fflush(state_fp);
+		}
+	}
+
+	if (state_fp != NULL) {
+		fclose(state_fp);
+		state_fp = NULL;
+	}
+
+	return 0;
+}