busybox/networking/ifupdown.c
Denys Vlasenko 0c4dbd481a regularize format of source file headers, no code changes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-09-18 16:28:43 +02:00

1519 lines
42 KiB
C

/* vi: set sw=4 ts=4: */
/*
* ifup/ifdown for busybox
* Copyright (c) 2002 Glenn McGrath
* Copyright (c) 2003-2004 Erik Andersen <andersen@codepoet.org>
*
* Based on ifupdown v 0.6.4 by Anthony Towns
* Copyright (c) 1999 Anthony Towns <aj@azure.humbug.org.au>
*
* Changes to upstream version
* Remove checks for kernel version, assume kernel version 2.2.0 or better.
* Lines in the interfaces file cannot wrap.
* To adhere to the FHS, the default state file is /var/run/ifstate
* (defined via CONFIG_IFUPDOWN_IFSTATE_PATH) and can be overridden by build
* configuration.
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//config:config IFUP
//config: bool "ifup (17 kb)"
//config: default y
//config: help
//config: Activate the specified interfaces. This applet makes use
//config: of either "ifconfig" and "route" or the "ip" command to actually
//config: configure network interfaces. Therefore, you will probably also want
//config: to enable either IFCONFIG and ROUTE, or enable
//config: FEATURE_IFUPDOWN_IP and the various IP options. Of
//config: course you could use non-busybox versions of these programs, so
//config: against my better judgement (since this will surely result in plenty
//config: of support questions on the mailing list), I do not force you to
//config: enable these additional options. It is up to you to supply either
//config: "ifconfig", "route" and "run-parts" or the "ip" command, either
//config: via busybox or via standalone utilities.
//config:
//config:config IFDOWN
//config: bool "ifdown (15 kb)"
//config: default y
//config: help
//config: Deactivate the specified interfaces.
//config:
//config:config IFUPDOWN_IFSTATE_PATH
//config: string "Absolute path to ifstate file"
//config: default "/var/run/ifstate"
//config: depends on IFUP || IFDOWN
//config: help
//config: ifupdown keeps state information in a file called ifstate.
//config: Typically it is located in /var/run/ifstate, however
//config: some distributions tend to put it in other places
//config: (debian, for example, uses /etc/network/run/ifstate).
//config: This config option defines location of ifstate.
//config:
//config:config FEATURE_IFUPDOWN_IP
//config: bool "Use ip tool (else ifconfig/route is used)"
//config: default y
//config: depends on IFUP || IFDOWN
//config: help
//config: Use the iproute "ip" command to implement "ifup" and "ifdown", rather
//config: than the default of using the older "ifconfig" and "route" utilities.
//config:
//config: If Y: you must install either the full-blown iproute2 package
//config: or enable "ip" applet in busybox, or the "ifup" and "ifdown" applets
//config: will not work.
//config:
//config: If N: you must install either the full-blown ifconfig and route
//config: utilities, or enable these applets in busybox.
//config:
//config:config FEATURE_IFUPDOWN_IPV4
//config: bool "Support IPv4"
//config: default y
//config: depends on IFUP || IFDOWN
//config: help
//config: If you want ifup/ifdown to talk IPv4, leave this on.
//config:
//config:config FEATURE_IFUPDOWN_IPV6
//config: bool "Support IPv6"
//config: default y
//config: depends on (IFUP || IFDOWN) && FEATURE_IPV6
//config: help
//config: If you need support for IPv6, turn this option on.
//config:
//UNUSED:
////////:config FEATURE_IFUPDOWN_IPX
////////: bool "Support IPX"
////////: default y
////////: depends on IFUP || IFDOWN
////////: help
////////: If this option is selected you can use busybox to work with IPX
////////: networks.
//config:
//config:config FEATURE_IFUPDOWN_MAPPING
//config: bool "Enable mapping support"
//config: default y
//config: depends on IFUP || IFDOWN
//config: help
//config: This enables support for the "mapping" stanza, unless you have
//config: a weird network setup you don't need it.
//config:
//config:config FEATURE_IFUPDOWN_EXTERNAL_DHCP
//config: bool "Support external DHCP clients"
//config: default n
//config: depends on IFUP || IFDOWN
//config: help
//config: This enables support for the external dhcp clients. Clients are
//config: tried in the following order: dhcpcd, dhclient, pump and udhcpc.
//config: Otherwise, if udhcpc applet is enabled, it is used.
//config: Otherwise, ifup/ifdown will have no support for DHCP.
// APPLET_ODDNAME:name main location suid_type help
//applet:IF_IFUP( APPLET_ODDNAME(ifup, ifupdown, BB_DIR_SBIN, BB_SUID_DROP, ifup))
//applet:IF_IFDOWN(APPLET_ODDNAME(ifdown, ifupdown, BB_DIR_SBIN, BB_SUID_DROP, ifdown))
//kbuild:lib-$(CONFIG_IFUP) += ifupdown.o
//kbuild:lib-$(CONFIG_IFDOWN) += ifupdown.o
//usage:#define ifup_trivial_usage
//usage: "[-an"IF_FEATURE_IFUPDOWN_MAPPING("m")"vf] [-i FILE] IFACE..."
//usage:#define ifup_full_usage "\n\n"
//usage: " -a Configure all interfaces"
//usage: "\n -i FILE Use FILE instead of /etc/network/interfaces"
//usage: "\n -n Print out what would happen, but don't do it"
//usage: IF_FEATURE_IFUPDOWN_MAPPING(
//usage: "\n (note: doesn't disable mappings)"
//usage: "\n -m Don't run any mappings"
//usage: )
//usage: "\n -v Print out what would happen before doing it"
//usage: "\n -f Force configuration"
//usage:
//usage:#define ifdown_trivial_usage
//usage: "[-an"IF_FEATURE_IFUPDOWN_MAPPING("m")"vf] [-i FILE] IFACE..."
//usage:#define ifdown_full_usage "\n\n"
//usage: " -a Deconfigure all interfaces"
//usage: "\n -i FILE Use FILE for interface definitions"
//usage: "\n -n Print out what would happen, but don't do it"
//usage: IF_FEATURE_IFUPDOWN_MAPPING(
//usage: "\n (note: doesn't disable mappings)"
//usage: "\n -m Don't run any mappings"
//usage: )
//usage: "\n -v Print out what would happen before doing it"
//usage: "\n -f Force deconfiguration"
#include "libbb.h"
#include "common_bufsiz.h"
/* After libbb.h, since it needs sys/types.h on some systems */
#include <sys/utsname.h>
#include <fnmatch.h>
#define MAX_OPT_DEPTH 10
#if ENABLE_FEATURE_IFUPDOWN_MAPPING
#define MAX_INTERFACE_LENGTH 10
#endif
#define UDHCPC_CMD_OPTIONS CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS
#define IFSTATE_FILE_PATH CONFIG_IFUPDOWN_IFSTATE_PATH
#define debug_noise(args...) /*fprintf(stderr, args)*/
/* Forward declaration */
struct interface_defn_t;
typedef int execfn(char *command);
struct method_t {
const char *name;
int (*up)(struct interface_defn_t *ifd, execfn *e) FAST_FUNC;
int (*down)(struct interface_defn_t *ifd, execfn *e) FAST_FUNC;
};
struct address_family_t {
const char *name;
int n_methods;
const struct method_t *method;
};
struct mapping_defn_t {
struct mapping_defn_t *next;
int max_matches;
int n_matches;
char **match;
char *script;
int n_mappings;
char **mapping;
};
struct variable_t {
char *name;
char *value;
};
struct interface_defn_t {
const struct address_family_t *address_family;
const struct method_t *method;
char *iface;
int n_options;
struct variable_t *option;
};
struct interfaces_file_t {
llist_t *autointerfaces;
llist_t *ifaces;
struct mapping_defn_t *mappings;
};
#define OPTION_STR "anvf" IF_FEATURE_IFUPDOWN_MAPPING("m") "i:"
enum {
OPT_do_all = 0x1,
OPT_no_act = 0x2,
OPT_verbose = 0x4,
OPT_force = 0x8,
OPT_no_mappings = 0x10,
};
#define DO_ALL (option_mask32 & OPT_do_all)
#define NO_ACT (option_mask32 & OPT_no_act)
#define VERBOSE (option_mask32 & OPT_verbose)
#define FORCE (option_mask32 & OPT_force)
#define NO_MAPPINGS (option_mask32 & OPT_no_mappings)
struct globals {
char **my_environ;
const char *startup_PATH;
char *shell;
} FIX_ALIASING;
#define G (*(struct globals*)bb_common_bufsiz1)
#define INIT_G() do { setup_common_bufsiz(); } while (0)
static const char keywords_up_down[] ALIGN1 =
"up\0"
"down\0"
"pre-up\0"
"post-down\0"
;
#if ENABLE_FEATURE_IFUPDOWN_IPV4 || ENABLE_FEATURE_IFUPDOWN_IPV6
static void addstr(char **bufp, const char *str, size_t str_length)
{
/* xasprintf trick will be smaller, but we are often
* called with str_length == 1 - don't want to have
* THAT much of malloc/freeing! */
char *buf = *bufp;
int len = (buf ? strlen(buf) : 0);
str_length++;
buf = xrealloc(buf, len + str_length);
/* copies at most str_length-1 chars! */
safe_strncpy(buf + len, str, str_length);
*bufp = buf;
}
static int strncmpz(const char *l, const char *r, size_t llen)
{
int i = strncmp(l, r, llen);
if (i == 0)
return - (unsigned char)r[llen];
return i;
}
static char *get_var(const char *id, size_t idlen, struct interface_defn_t *ifd)
{
int i;
if (strncmpz(id, "iface", idlen) == 0) {
// ubuntu's ifup doesn't do this:
//static char *label_buf;
//char *result;
//free(label_buf);
//label_buf = xstrdup(ifd->iface);
// Remove virtual iface suffix
//result = strchrnul(label_buf, ':');
//*result = '\0';
//return label_buf;
return ifd->iface;
}
if (strncmpz(id, "label", idlen) == 0) {
return ifd->iface;
}
for (i = 0; i < ifd->n_options; i++) {
if (strncmpz(id, ifd->option[i].name, idlen) == 0) {
return ifd->option[i].value;
}
}
return NULL;
}
# if ENABLE_FEATURE_IFUPDOWN_IP
static int count_netmask_bits(const char *dotted_quad)
{
// int result;
// unsigned a, b, c, d;
// /* Found a netmask... Check if it is dotted quad */
// if (sscanf(dotted_quad, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
// return -1;
// if ((a|b|c|d) >> 8)
// return -1; /* one of numbers is >= 256 */
// d |= (a << 24) | (b << 16) | (c << 8); /* IP */
// d = ~d; /* 11110000 -> 00001111 */
/* Shorter version */
int result;
struct in_addr ip;
unsigned d;
if (inet_aton(dotted_quad, &ip) == 0)
return -1; /* malformed dotted IP */
d = ntohl(ip.s_addr); /* IP in host order */
d = ~d; /* 11110000 -> 00001111 */
if (d & (d+1)) /* check that it is in 00001111 form */
return -1; /* no it is not */
result = 32;
while (d) {
d >>= 1;
result--;
}
return result;
}
# endif
static char *parse(const char *command, struct interface_defn_t *ifd)
{
size_t old_pos[MAX_OPT_DEPTH] = { 0 };
smallint okay[MAX_OPT_DEPTH] = { 1 };
int opt_depth = 1;
char *result = NULL;
while (*command) {
switch (*command) {
default:
addstr(&result, command, 1);
command++;
break;
case '\\':
if (command[1])
command++;
addstr(&result, command, 1);
command++;
break;
case '[':
if (command[1] == '[' && opt_depth < MAX_OPT_DEPTH) {
old_pos[opt_depth] = result ? strlen(result) : 0;
okay[opt_depth] = 1;
opt_depth++;
command += 2;
} else {
addstr(&result, command, 1);
command++;
}
break;
case ']':
if (command[1] == ']' && opt_depth > 1) {
opt_depth--;
if (!okay[opt_depth]) {
result[old_pos[opt_depth]] = '\0';
}
command += 2;
} else {
addstr(&result, command, 1);
command++;
}
break;
case '%':
{
char *nextpercent;
char *varvalue;
command++;
nextpercent = strchr(command, '%');
if (!nextpercent) {
/* Unterminated %var% */
free(result);
return NULL;
}
varvalue = get_var(command, nextpercent - command, ifd);
if (varvalue) {
# if ENABLE_FEATURE_IFUPDOWN_IP
/* "hwaddress <class> <address>":
* unlike ifconfig, ip doesnt want <class>
* (usually "ether" keyword). Skip it. */
if (is_prefixed_with(command, "hwaddress")) {
varvalue = skip_whitespace(skip_non_whitespace(varvalue));
}
# endif
addstr(&result, varvalue, strlen(varvalue));
} else {
# if ENABLE_FEATURE_IFUPDOWN_IP
/* Sigh... Add a special case for 'ip' to convert from
* dotted quad to bit count style netmasks. */
if (is_prefixed_with(command, "bnmask")) {
unsigned res;
varvalue = get_var("netmask", 7, ifd);
if (varvalue) {
res = count_netmask_bits(varvalue);
if (res > 0) {
const char *argument = utoa(res);
addstr(&result, argument, strlen(argument));
command = nextpercent + 1;
break;
}
}
}
# endif
okay[opt_depth - 1] = 0;
}
command = nextpercent + 1;
}
break;
}
}
if (opt_depth > 1) {
/* Unbalanced bracket */
free(result);
return NULL;
}
if (!okay[0]) {
/* Undefined variable and we aren't in a bracket */
free(result);
return NULL;
}
return result;
}
/* execute() returns 1 for success and 0 for failure */
static int execute(const char *command, struct interface_defn_t *ifd, execfn *exec)
{
char *out;
int ret;
out = parse(command, ifd);
if (!out) {
/* parse error? */
return 0;
}
/* out == "": parsed ok but not all needed variables known, skip */
ret = out[0] ? (*exec)(out) : 1;
free(out);
if (ret != 1) {
return 0;
}
return 1;
}
#endif /* FEATURE_IFUPDOWN_IPV4 || FEATURE_IFUPDOWN_IPV6 */
#if ENABLE_FEATURE_IFUPDOWN_IPV6
static int FAST_FUNC loopback_up6(struct interface_defn_t *ifd, execfn *exec)
{
# if ENABLE_FEATURE_IFUPDOWN_IP
int result;
result = execute("ip addr add ::1 dev %iface%", ifd, exec);
result += execute("ip link set %iface% up", ifd, exec);
return ((result == 2) ? 2 : 0);
# else
return execute("ifconfig %iface% add ::1", ifd, exec);
# endif
}
static int FAST_FUNC loopback_down6(struct interface_defn_t *ifd, execfn *exec)
{
# if ENABLE_FEATURE_IFUPDOWN_IP
return execute("ip link set %iface% down", ifd, exec);
# else
return execute("ifconfig %iface% del ::1", ifd, exec);
# endif
}
static int FAST_FUNC manual_up_down6(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
{
return 1;
}
static int FAST_FUNC static_up6(struct interface_defn_t *ifd, execfn *exec)
{
int result;
# if ENABLE_FEATURE_IFUPDOWN_IP
result = execute("ip addr add %address%/%netmask% dev %iface%[[ label %label%]]", ifd, exec);
result += execute("ip link set[[ mtu %mtu%]][[ addr %hwaddress%]] %iface% up", ifd, exec);
/* Reportedly, IPv6 needs "dev %iface%", but IPv4 does not: */
result += execute("[[ip route add ::/0 via %gateway% dev %iface%]][[ metric %metric%]]", ifd, exec);
# else
result = execute("ifconfig %iface%[[ media %media%]][[ hw %hwaddress%]][[ mtu %mtu%]] up", ifd, exec);
result += execute("ifconfig %iface% add %address%/%netmask%", ifd, exec);
result += execute("[[route -A inet6 add ::/0 gw %gateway%[[ metric %metric%]]]]", ifd, exec);
# endif
return ((result == 3) ? 3 : 0);
}
static int FAST_FUNC static_down6(struct interface_defn_t *ifd, execfn *exec)
{
# if ENABLE_FEATURE_IFUPDOWN_IP
return execute("ip link set %iface% down", ifd, exec);
# else
return execute("ifconfig %iface% down", ifd, exec);
# endif
}
# if ENABLE_FEATURE_IFUPDOWN_IP
static int FAST_FUNC v4tunnel_up(struct interface_defn_t *ifd, execfn *exec)
{
int result;
result = execute("ip tunnel add %iface% mode sit remote "
"%endpoint%[[ local %local%]][[ ttl %ttl%]]", ifd, exec);
result += execute("ip link set %iface% up", ifd, exec);
result += execute("ip addr add %address%/%netmask% dev %iface%", ifd, exec);
/* Reportedly, IPv6 needs "dev %iface%", but IPv4 does not: */
result += execute("[[ip route add ::/0 via %gateway% dev %iface%]]", ifd, exec);
return ((result == 4) ? 4 : 0);
}
static int FAST_FUNC v4tunnel_down(struct interface_defn_t * ifd, execfn * exec)
{
return execute("ip tunnel del %iface%", ifd, exec);
}
# endif
static const struct method_t methods6[] = {
# if ENABLE_FEATURE_IFUPDOWN_IP
{ "v4tunnel" , v4tunnel_up , v4tunnel_down , },
# endif
{ "static" , static_up6 , static_down6 , },
{ "manual" , manual_up_down6 , manual_up_down6 , },
{ "loopback" , loopback_up6 , loopback_down6 , },
};
static const struct address_family_t addr_inet6 = {
"inet6",
ARRAY_SIZE(methods6),
methods6
};
#endif /* FEATURE_IFUPDOWN_IPV6 */
#if ENABLE_FEATURE_IFUPDOWN_IPV4
static int FAST_FUNC loopback_up(struct interface_defn_t *ifd, execfn *exec)
{
# if ENABLE_FEATURE_IFUPDOWN_IP
int result;
result = execute("ip addr add 127.0.0.1/8 dev %iface%", ifd, exec);
result += execute("ip link set %iface% up", ifd, exec);
return ((result == 2) ? 2 : 0);
# else
return execute("ifconfig %iface% 127.0.0.1 up", ifd, exec);
# endif
}
static int FAST_FUNC loopback_down(struct interface_defn_t *ifd, execfn *exec)
{
# if ENABLE_FEATURE_IFUPDOWN_IP
int result;
result = execute("ip addr flush dev %iface%", ifd, exec);
result += execute("ip link set %iface% down", ifd, exec);
return ((result == 2) ? 2 : 0);
# else
return execute("ifconfig %iface% 127.0.0.1 down", ifd, exec);
# endif
}
static int FAST_FUNC static_up(struct interface_defn_t *ifd, execfn *exec)
{
int result;
# if ENABLE_FEATURE_IFUPDOWN_IP
result = execute("ip addr add %address%/%bnmask%[[ broadcast %broadcast%]] "
"dev %iface%[[ peer %pointopoint%]][[ label %label%]]", ifd, exec);
result += execute("ip link set[[ mtu %mtu%]][[ addr %hwaddress%]] %iface% up", ifd, exec);
result += execute("[[ip route add default via %gateway% dev %iface%[[ metric %metric%]]]]", ifd, exec);
return ((result == 3) ? 3 : 0);
# else
/* ifconfig said to set iface up before it processes hw %hwaddress%,
* which then of course fails. Thus we run two separate ifconfig */
result = execute("ifconfig %iface%[[ hw %hwaddress%]][[ media %media%]][[ mtu %mtu%]] up",
ifd, exec);
result += execute("ifconfig %iface% %address% netmask %netmask%"
"[[ broadcast %broadcast%]][[ pointopoint %pointopoint%]]",
ifd, exec);
result += execute("[[route add default gw %gateway%[[ metric %metric%]] %iface%]]", ifd, exec);
return ((result == 3) ? 3 : 0);
# endif
}
static int FAST_FUNC static_down(struct interface_defn_t *ifd, execfn *exec)
{
int result;
# if ENABLE_FEATURE_IFUPDOWN_IP
/* Optional "label LBL" is necessary if interface is an alias (eth0:0),
* otherwise "ip addr flush dev eth0:0" flushes all addresses on eth0.
*/
result = execute("ip addr flush dev %iface%[[ label %label%]]", ifd, exec);
result += execute("ip link set %iface% down", ifd, exec);
# else
/* result = execute("[[route del default gw %gateway% %iface%]]", ifd, exec); */
/* Bringing the interface down deletes the routes in itself.
Otherwise this fails if we reference 'gateway' when using this from dhcp_down */
result = 1;
result += execute("ifconfig %iface% down", ifd, exec);
# endif
return ((result == 2) ? 2 : 0);
}
# if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
struct dhcp_client_t {
const char *name;
const char *startcmd;
const char *stopcmd;
};
static const struct dhcp_client_t ext_dhcp_clients[] = {
{ "dhcpcd",
"dhcpcd[[ -h %hostname%]][[ -i %vendor%]][[ -I %client%]][[ -l %leasetime%]] %iface%",
"dhcpcd -k %iface%",
},
{ "dhclient",
"dhclient -pf /var/run/dhclient.%iface%.pid %iface%",
"kill -9 `cat /var/run/dhclient.%iface%.pid` 2>/dev/null",
},
{ "pump",
"pump -i %iface%[[ -h %hostname%]][[ -l %leasehours%]]",
"pump -i %iface% -k",
},
{ "udhcpc",
"udhcpc " UDHCPC_CMD_OPTIONS " -p /var/run/udhcpc.%iface%.pid -i %iface%[[ -x hostname:%hostname%]][[ -c %client%]]"
"[[ -s %script%]][[ %udhcpc_opts%]]",
"kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
},
};
# endif /* FEATURE_IFUPDOWN_EXTERNAL_DHCPC */
# if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd, execfn *exec)
{
unsigned i;
# if ENABLE_FEATURE_IFUPDOWN_IP
/* ip doesn't up iface when it configures it (unlike ifconfig) */
if (!execute("ip link set[[ addr %hwaddress%]] %iface% up", ifd, exec))
return 0;
# else
/* needed if we have hwaddress on dhcp iface */
if (!execute("ifconfig %iface%[[ hw %hwaddress%]] up", ifd, exec))
return 0;
# endif
for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
if (executable_exists(ext_dhcp_clients[i].name))
return execute(ext_dhcp_clients[i].startcmd, ifd, exec);
}
bb_error_msg("no dhcp clients found");
return 0;
}
# elif ENABLE_UDHCPC
static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd, execfn *exec)
{
# if ENABLE_FEATURE_IFUPDOWN_IP
/* ip doesn't up iface when it configures it (unlike ifconfig) */
if (!execute("ip link set[[ addr %hwaddress%]] %iface% up", ifd, exec))
return 0;
# else
/* needed if we have hwaddress on dhcp iface */
if (!execute("ifconfig %iface%[[ hw %hwaddress%]] up", ifd, exec))
return 0;
# endif
return execute("udhcpc " UDHCPC_CMD_OPTIONS " -p /var/run/udhcpc.%iface%.pid "
"-i %iface%[[ -x hostname:%hostname%]][[ -c %client%]][[ -s %script%]][[ %udhcpc_opts%]]",
ifd, exec);
}
# else
static int FAST_FUNC dhcp_up(struct interface_defn_t *ifd UNUSED_PARAM,
execfn *exec UNUSED_PARAM)
{
return 0; /* no dhcp support */
}
# endif
# if ENABLE_FEATURE_IFUPDOWN_EXTERNAL_DHCP
static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd, execfn *exec)
{
int result = 0;
unsigned i;
for (i = 0; i < ARRAY_SIZE(ext_dhcp_clients); i++) {
if (executable_exists(ext_dhcp_clients[i].name)) {
result = execute(ext_dhcp_clients[i].stopcmd, ifd, exec);
if (result)
break;
}
}
if (!result)
bb_error_msg("warning: no dhcp clients found and stopped");
/* Sleep a bit, otherwise static_down tries to bring down interface too soon,
and it may come back up because udhcpc is still shutting down */
usleep(100000);
result += static_down(ifd, exec);
return ((result == 3) ? 3 : 0);
}
# elif ENABLE_UDHCPC
static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd, execfn *exec)
{
int result;
result = execute(
"test -f /var/run/udhcpc.%iface%.pid && "
"kill `cat /var/run/udhcpc.%iface%.pid` 2>/dev/null",
ifd, exec);
/* Also bring the hardware interface down since
killing the dhcp client alone doesn't do it.
This enables consecutive ifup->ifdown->ifup */
/* Sleep a bit, otherwise static_down tries to bring down interface too soon,
and it may come back up because udhcpc is still shutting down */
usleep(100000);
result += static_down(ifd, exec);
return ((result == 3) ? 3 : 0);
}
# else
static int FAST_FUNC dhcp_down(struct interface_defn_t *ifd UNUSED_PARAM,
execfn *exec UNUSED_PARAM)
{
return 0; /* no dhcp support */
}
# endif
static int FAST_FUNC manual_up_down(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
{
return 1;
}
static int FAST_FUNC bootp_up(struct interface_defn_t *ifd, execfn *exec)
{
return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
"[[ --server %server%]][[ --hwaddr %hwaddr%]]"
" --returniffail --serverbcast", ifd, exec);
}
static int FAST_FUNC ppp_up(struct interface_defn_t *ifd, execfn *exec)
{
return execute("pon[[ %provider%]]", ifd, exec);
}
static int FAST_FUNC ppp_down(struct interface_defn_t *ifd, execfn *exec)
{
return execute("poff[[ %provider%]]", ifd, exec);
}
static int FAST_FUNC wvdial_up(struct interface_defn_t *ifd, execfn *exec)
{
return execute("start-stop-daemon --start -x wvdial "
"-p /var/run/wvdial.%iface% -b -m --[[ %provider%]]", ifd, exec);
}
static int FAST_FUNC wvdial_down(struct interface_defn_t *ifd, execfn *exec)
{
return execute("start-stop-daemon --stop -x wvdial "
"-p /var/run/wvdial.%iface% -s 2", ifd, exec);
}
static const struct method_t methods[] = {
{ "manual" , manual_up_down, manual_up_down, },
{ "wvdial" , wvdial_up , wvdial_down , },
{ "ppp" , ppp_up , ppp_down , },
{ "static" , static_up , static_down , },
{ "bootp" , bootp_up , static_down , },
{ "dhcp" , dhcp_up , dhcp_down , },
{ "loopback", loopback_up , loopback_down , },
};
static const struct address_family_t addr_inet = {
"inet",
ARRAY_SIZE(methods),
methods
};
#endif /* FEATURE_IFUPDOWN_IPV4 */
static int FAST_FUNC link_up_down(struct interface_defn_t *ifd UNUSED_PARAM, execfn *exec UNUSED_PARAM)
{
return 1;
}
static const struct method_t link_methods[] = {
{ "none", link_up_down, link_up_down }
};
static const struct address_family_t addr_link = {
"link", ARRAY_SIZE(link_methods), link_methods
};
/* Returns pointer to the next word, or NULL.
* In 1st case, advances *buf to the word after this one.
*/
static char *next_word(char **buf)
{
unsigned length;
char *word;
/* Skip over leading whitespace */
word = skip_whitespace(*buf);
/* Stop on EOL */
if (*word == '\0')
return NULL;
/* Find the length of this word (can't be 0) */
length = strcspn(word, " \t\n");
/* Unless we are already at NUL, store NUL and advance */
if (word[length] != '\0')
word[length++] = '\0';
*buf = skip_whitespace(word + length);
return word;
}
static const struct address_family_t *get_address_family(const struct address_family_t *const af[], char *name)
{
int i;
if (!name)
return NULL;
for (i = 0; af[i]; i++) {
if (strcmp(af[i]->name, name) == 0) {
return af[i];
}
}
return NULL;
}
static const struct method_t *get_method(const struct address_family_t *af, char *name)
{
int i;
if (!name)
return NULL;
/* TODO: use index_in_str_array() */
for (i = 0; i < af->n_methods; i++) {
if (strcmp(af->method[i].name, name) == 0) {
return &af->method[i];
}
}
return NULL;
}
static struct interfaces_file_t *read_interfaces(const char *filename, struct interfaces_file_t *defn)
{
/* Let's try to be compatible.
*
* "man 5 interfaces" says:
* Lines starting with "#" are ignored. Note that end-of-line
* comments are NOT supported, comments must be on a line of their own.
* A line may be extended across multiple lines by making
* the last character a backslash.
*
* Seen elsewhere in example config file:
* A first non-blank "#" character makes the rest of the line
* be ignored. Blank lines are ignored. Lines may be indented freely.
* A "\" character at the very end of the line indicates the next line
* should be treated as a continuation of the current one.
*
* Lines beginning with "source" are used to include stanzas from
* other files, so configuration can be split into many files.
* The word "source" is followed by the path of file to be sourced.
*/
#if ENABLE_FEATURE_IFUPDOWN_MAPPING
struct mapping_defn_t *currmap = NULL;
#endif
struct interface_defn_t *currif = NULL;
FILE *f;
char *buf;
char *first_word;
char *rest_of_line;
enum { NONE, IFACE, MAPPING } currently_processing = NONE;
if (!defn)
defn = xzalloc(sizeof(*defn));
debug_noise("reading %s file:\n", filename);
f = xfopen_for_read(filename);
while ((buf = xmalloc_fgetline(f)) != NULL) {
#if ENABLE_DESKTOP
/* Trailing "\" concatenates lines */
char *p;
while ((p = last_char_is(buf, '\\')) != NULL) {
*p = '\0';
rest_of_line = xmalloc_fgetline(f);
if (!rest_of_line)
break;
p = xasprintf("%s%s", buf, rest_of_line);
free(buf);
free(rest_of_line);
buf = p;
}
#endif
rest_of_line = buf;
first_word = next_word(&rest_of_line);
if (!first_word || *first_word == '#') {
free(buf);
continue; /* blank/comment line */
}
if (strcmp(first_word, "mapping") == 0) {
#if ENABLE_FEATURE_IFUPDOWN_MAPPING
currmap = xzalloc(sizeof(*currmap));
while ((first_word = next_word(&rest_of_line)) != NULL) {
currmap->match = xrealloc_vector(currmap->match, 4, currmap->n_matches);
currmap->match[currmap->n_matches++] = xstrdup(first_word);
}
/*currmap->n_mappings = 0;*/
/*currmap->mapping = NULL;*/
/*currmap->script = NULL;*/
{
struct mapping_defn_t **where = &defn->mappings;
while (*where != NULL) {
where = &(*where)->next;
}
*where = currmap;
/*currmap->next = NULL;*/
}
debug_noise("Added mapping\n");
#endif
currently_processing = MAPPING;
} else if (strcmp(first_word, "iface") == 0) {
static const struct address_family_t *const addr_fams[] = {
#if ENABLE_FEATURE_IFUPDOWN_IPV4
&addr_inet,
#endif
#if ENABLE_FEATURE_IFUPDOWN_IPV6
&addr_inet6,
#endif
&addr_link,
NULL
};
char *iface_name;
char *address_family_name;
char *method_name;
currif = xzalloc(sizeof(*currif));
iface_name = next_word(&rest_of_line);
address_family_name = next_word(&rest_of_line);
method_name = next_word(&rest_of_line);
if (method_name == NULL)
bb_error_msg_and_die("too few parameters for line \"%s\"", buf);
/* ship any trailing whitespace */
rest_of_line = skip_whitespace(rest_of_line);
if (rest_of_line[0] != '\0' /* && rest_of_line[0] != '#' */)
bb_error_msg_and_die("too many parameters \"%s\"", buf);
currif->iface = xstrdup(iface_name);
currif->address_family = get_address_family(addr_fams, address_family_name);
if (!currif->address_family)
bb_error_msg_and_die("unknown address type \"%s\"", address_family_name);
currif->method = get_method(currif->address_family, method_name);
if (!currif->method)
bb_error_msg_and_die("unknown method \"%s\"", method_name);
#if 0
// Allegedly, Debian allows a duplicate definition:
// iface eth0 inet static
// address 192.168.0.15
// netmask 255.255.0.0
// gateway 192.168.0.1
//
// iface eth0 inet static
// address 10.0.0.1
// netmask 255.255.255.0
//
// This adds *two* addresses to eth0 (probably requires use of "ip", not "ifconfig"
//
llist_t *iface_list;
for (iface_list = defn->ifaces; iface_list; iface_list = iface_list->link) {
struct interface_defn_t *tmp = (struct interface_defn_t *) iface_list->data;
if ((strcmp(tmp->iface, currif->iface) == 0)
&& (tmp->address_family == currif->address_family)
) {
bb_error_msg_and_die("duplicate interface \"%s\"", tmp->iface);
}
}
#endif
llist_add_to_end(&(defn->ifaces), (char*)currif);
debug_noise("iface %s %s %s\n", currif->iface, address_family_name, method_name);
currently_processing = IFACE;
} else if (strcmp(first_word, "auto") == 0) {
while ((first_word = next_word(&rest_of_line)) != NULL) {
/* Check the interface isnt already listed */
if (llist_find_str(defn->autointerfaces, first_word)) {
bb_perror_msg_and_die("interface declared auto twice \"%s\"", buf);
}
/* Add the interface to the list */
llist_add_to_end(&(defn->autointerfaces), xstrdup(first_word));
debug_noise("\nauto %s\n", first_word);
}
currently_processing = NONE;
} else if (strcmp(first_word, "source") == 0) {
read_interfaces(next_word(&rest_of_line), defn);
} else {
switch (currently_processing) {
case IFACE:
if (rest_of_line[0] == '\0')
bb_error_msg_and_die("option with empty value \"%s\"", buf);
if (strcmp(first_word, "post-up") == 0)
first_word += 5; /* "up" */
else if (strcmp(first_word, "pre-down") == 0)
first_word += 4; /* "down" */
/* If not one of "up", "down",... words... */
if (index_in_strings(keywords_up_down, first_word) < 0) {
int i;
for (i = 0; i < currif->n_options; i++) {
if (strcmp(currif->option[i].name, first_word) == 0)
bb_error_msg_and_die("duplicate option \"%s\"", buf);
}
}
debug_noise("\t%s=%s\n", first_word, rest_of_line);
currif->option = xrealloc_vector(currif->option, 4, currif->n_options);
currif->option[currif->n_options].name = xstrdup(first_word);
currif->option[currif->n_options].value = xstrdup(rest_of_line);
currif->n_options++;
break;
case MAPPING:
#if ENABLE_FEATURE_IFUPDOWN_MAPPING
if (strcmp(first_word, "script") == 0) {
if (currmap->script != NULL)
bb_error_msg_and_die("duplicate script in mapping \"%s\"", buf);
currmap->script = xstrdup(next_word(&rest_of_line));
} else if (strcmp(first_word, "map") == 0) {
currmap->mapping = xrealloc_vector(currmap->mapping, 2, currmap->n_mappings);
currmap->mapping[currmap->n_mappings] = xstrdup(next_word(&rest_of_line));
currmap->n_mappings++;
} else {
bb_error_msg_and_die("misplaced option \"%s\"", buf);
}
#endif
break;
case NONE:
default:
bb_error_msg_and_die("misplaced option \"%s\"", buf);
}
}
free(buf);
} /* while (fgets) */
if (ferror(f) != 0) {
/* ferror does NOT set errno! */
bb_error_msg_and_die("%s: I/O error", filename);
}
fclose(f);
debug_noise("\ndone reading %s\n\n", filename);
return defn;
}
static char *setlocalenv(const char *format, const char *name, const char *value)
{
char *result;
char *dst;
char *src;
char c;
result = xasprintf(format, name, value);
for (dst = src = result; (c = *src) != '=' && c; src++) {
if (c == '-')
c = '_';
if (c >= 'a' && c <= 'z')
c -= ('a' - 'A');
if (isalnum(c) || c == '_')
*dst++ = c;
}
overlapping_strcpy(dst, src);
return result;
}
static void set_environ(struct interface_defn_t *iface, const char *mode, const char *opt)
{
int i;
char **pp;
if (G.my_environ != NULL) {
for (pp = G.my_environ; *pp; pp++) {
free(*pp);
}
free(G.my_environ);
}
/* note: last element will stay NULL: */
G.my_environ = xzalloc(sizeof(char *) * (iface->n_options + 7));
pp = G.my_environ;
for (i = 0; i < iface->n_options; i++) {
if (index_in_strings(keywords_up_down, iface->option[i].name) >= 0) {
continue;
}
*pp++ = setlocalenv("IF_%s=%s", iface->option[i].name, iface->option[i].value);
}
*pp++ = setlocalenv("%s=%s", "IFACE", iface->iface);
*pp++ = setlocalenv("%s=%s", "ADDRFAM", iface->address_family->name);
*pp++ = setlocalenv("%s=%s", "METHOD", iface->method->name);
*pp++ = setlocalenv("%s=%s", "MODE", mode);
*pp++ = setlocalenv("%s=%s", "PHASE", opt);
if (G.startup_PATH)
*pp++ = setlocalenv("%s=%s", "PATH", G.startup_PATH);
}
static int doit(char *str)
{
if (option_mask32 & (OPT_no_act|OPT_verbose)) {
puts(str);
}
if (!(option_mask32 & OPT_no_act)) {
pid_t child;
int status;
fflush_all();
child = vfork();
if (child < 0) /* failure */
return 0;
if (child == 0) { /* child */
execle(G.shell, G.shell, "-c", str, (char *) NULL, G.my_environ);
_exit(127);
}
safe_waitpid(child, &status, 0);
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
return 0;
}
}
return 1;
}
static int execute_all(struct interface_defn_t *ifd, const char *opt)
{
int i;
char *buf;
for (i = 0; i < ifd->n_options; i++) {
if (strcmp(ifd->option[i].name, opt) == 0) {
if (!doit(ifd->option[i].value)) {
return 0;
}
}
}
/* Tested on Debian Squeeze: "standard" ifup runs this without
* checking that directory exists. If it doesn't, run-parts
* complains, and this message _is_ annoyingly visible.
* Don't "fix" this (unless newer Debian does).
*/
buf = xasprintf("run-parts /etc/network/if-%s.d", opt);
/* heh, we don't bother free'ing it */
return doit(buf);
}
static int check(char *str)
{
return str != NULL;
}
static int iface_up(struct interface_defn_t *iface)
{
if (!iface->method->up(iface, check)) return -1;
set_environ(iface, "start", "pre-up");
if (!execute_all(iface, "pre-up")) return 0;
if (!iface->method->up(iface, doit)) return 0;
set_environ(iface, "start", "post-up");
if (!execute_all(iface, "up")) return 0;
return 1;
}
static int iface_down(struct interface_defn_t *iface)
{
if (!iface->method->down(iface, check)) return -1;
set_environ(iface, "stop", "pre-down");
if (!execute_all(iface, "down")) return 0;
if (!iface->method->down(iface, doit)) return 0;
set_environ(iface, "stop", "post-down");
if (!execute_all(iface, "post-down")) return 0;
return 1;
}
#if ENABLE_FEATURE_IFUPDOWN_MAPPING
static int popen2(FILE **in, FILE **out, char *command, char *param)
{
char *argv[3] = { command, param, NULL };
struct fd_pair infd, outfd;
pid_t pid;
xpiped_pair(infd);
xpiped_pair(outfd);
fflush_all();
pid = xvfork();
if (pid == 0) {
/* Child */
/* NB: close _first_, then move fds! */
close(infd.wr);
close(outfd.rd);
xmove_fd(infd.rd, 0);
xmove_fd(outfd.wr, 1);
BB_EXECVP_or_die(argv);
}
/* parent */
close(infd.rd);
close(outfd.wr);
*in = xfdopen_for_write(infd.wr);
*out = xfdopen_for_read(outfd.rd);
return pid;
}
static char *run_mapping(char *physical, struct mapping_defn_t *map)
{
FILE *in, *out;
int i, status;
pid_t pid;
char *logical = xstrdup(physical);
/* Run the mapping script. Never fails. */
pid = popen2(&in, &out, map->script, physical);
/* Write mappings to stdin of mapping script. */
for (i = 0; i < map->n_mappings; i++) {
fprintf(in, "%s\n", map->mapping[i]);
}
fclose(in);
safe_waitpid(pid, &status, 0);
if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
/* If the mapping script exited successfully, try to
* grab a line of output and use that as the name of the
* logical interface. */
char *new_logical = xmalloc_fgetline(out);
if (new_logical) {
/* If we are able to read a line of output from the script,
* remove any trailing whitespace and use this value
* as the name of the logical interface. */
char *pch = new_logical + strlen(new_logical) - 1;
while (pch >= new_logical && isspace(*pch))
*(pch--) = '\0';
free(logical);
logical = new_logical;
}
}
fclose(out);
return logical;
}
#endif /* FEATURE_IFUPDOWN_MAPPING */
static llist_t *find_iface_state(llist_t *state_list, const char *iface)
{
llist_t *search = state_list;
while (search) {
char *after_iface = is_prefixed_with(search->data, iface);
if (after_iface
&& *after_iface == '='
) {
return search;
}
search = search->link;
}
return NULL;
}
/* read the previous state from the state file */
static llist_t *read_iface_state(void)
{
llist_t *state_list = NULL;
FILE *state_fp = fopen_for_read(IFSTATE_FILE_PATH);
if (state_fp) {
char *start, *end_ptr;
while ((start = xmalloc_fgets(state_fp)) != NULL) {
/* We should only need to check for a single character */
end_ptr = start + strcspn(start, " \t\n");
*end_ptr = '\0';
llist_add_to(&state_list, start);
}
fclose(state_fp);
}
return state_list;
}
/* read the previous state from the state file */
static FILE *open_new_state_file(void)
{
int fd, flags, cnt;
cnt = 0;
flags = (O_WRONLY | O_CREAT | O_EXCL);
for (;;) {
fd = open(IFSTATE_FILE_PATH".new", flags, 0666);
if (fd >= 0)
break;
if (errno != EEXIST
|| flags == (O_WRONLY | O_CREAT | O_TRUNC)
) {
bb_perror_msg_and_die("can't open '%s'",
IFSTATE_FILE_PATH".new");
}
/* Someone else created the .new file */
if (cnt > 30 * 1000) {
/* Waited for 30*30/2 = 450 milliseconds, still EEXIST.
* Assuming a stale file, rewriting it.
*/
flags = (O_WRONLY | O_CREAT | O_TRUNC);
continue;
}
usleep(cnt);
cnt += 1000;
}
return xfdopen_for_write(fd);
}
int ifupdown_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ifupdown_main(int argc UNUSED_PARAM, char **argv)
{
int (*cmds)(struct interface_defn_t *);
struct interfaces_file_t *defn;
llist_t *target_list = NULL;
const char *interfaces = "/etc/network/interfaces";
bool any_failures = 0;
INIT_G();
G.startup_PATH = getenv("PATH");
G.shell = xstrdup(get_shell_name());
if (ENABLE_IFUP
&& (!ENABLE_IFDOWN || applet_name[2] == 'u')
) {
/* ifup command */
cmds = iface_up;
} else {
cmds = iface_down;
}
getopt32(argv, OPTION_STR, &interfaces);
argv += optind;
if (argv[0]) {
if (DO_ALL) bb_show_usage();
} else {
if (!DO_ALL) bb_show_usage();
}
defn = read_interfaces(interfaces, NULL);
/* Create a list of interfaces to work on */
if (DO_ALL) {
target_list = defn->autointerfaces;
} else {
llist_add_to_end(&target_list, argv[0]);
}
/* Update the interfaces */
while (target_list) {
llist_t *iface_list;
struct interface_defn_t *currif;
char *iface;
char *liface;
char *pch;
bool okay = 0;
int cmds_ret;
bool curr_failure = 0;
iface = xstrdup(target_list->data);
target_list = target_list->link;
pch = strchr(iface, '=');
if (pch) {
*pch = '\0';
liface = xstrdup(pch + 1);
} else {
liface = xstrdup(iface);
}
if (!FORCE) {
llist_t *state_list = read_iface_state();
const llist_t *iface_state = find_iface_state(state_list, iface);
if (cmds == iface_up) {
/* ifup */
if (iface_state) {
bb_error_msg("interface %s already configured", iface);
goto next;
}
} else {
/* ifdown */
if (!iface_state) {
bb_error_msg("interface %s not configured", iface);
goto next;
}
}
llist_free(state_list, free);
}
#if ENABLE_FEATURE_IFUPDOWN_MAPPING
if ((cmds == iface_up) && !NO_MAPPINGS) {
struct mapping_defn_t *currmap;
for (currmap = defn->mappings; currmap; currmap = currmap->next) {
int i;
for (i = 0; i < currmap->n_matches; i++) {
if (fnmatch(currmap->match[i], liface, 0) != 0)
continue;
if (VERBOSE) {
printf("Running mapping script %s on %s\n", currmap->script, liface);
}
liface = run_mapping(iface, currmap);
break;
}
}
}
#endif
iface_list = defn->ifaces;
while (iface_list) {
currif = (struct interface_defn_t *) iface_list->data;
if (strcmp(liface, currif->iface) == 0) {
char *oldiface = currif->iface;
okay = 1;
currif->iface = iface;
debug_noise("\nConfiguring interface %s (%s)\n", liface, currif->address_family->name);
/* Call the cmds function pointer, does either iface_up() or iface_down() */
cmds_ret = cmds(currif);
if (cmds_ret == -1) {
bb_error_msg("don't have all variables for %s/%s",
liface, currif->address_family->name);
any_failures = curr_failure = 1;
} else if (cmds_ret == 0) {
any_failures = curr_failure = 1;
}
currif->iface = oldiface;
}
iface_list = iface_list->link;
}
if (VERBOSE) {
bb_putchar('\n');
}
if (!okay && !FORCE) {
bb_error_msg("ignoring unknown interface %s", liface);
any_failures = 1;
} else if (!NO_ACT) {
/* update the state file */
FILE *new_state_fp = open_new_state_file();
llist_t *state;
llist_t *state_list = read_iface_state();
llist_t *iface_state = find_iface_state(state_list, iface);
if (cmds == iface_up && !curr_failure) {
char *newiface = xasprintf("%s=%s", iface, liface);
if (!iface_state) {
llist_add_to_end(&state_list, newiface);
} else {
free(iface_state->data);
iface_state->data = newiface;
}
} else {
/* Remove an interface from state_list */
llist_unlink(&state_list, iface_state);
free(llist_pop(&iface_state));
}
/* Actually write the new state */
state = state_list;
while (state) {
if (state->data) {
fprintf(new_state_fp, "%s\n", state->data);
}
state = state->link;
}
fclose(new_state_fp);
xrename(IFSTATE_FILE_PATH".new", IFSTATE_FILE_PATH);
llist_free(state_list, free);
}
next:
free(iface);
free(liface);
}
return any_failures;
}