busybox/networking/libiproute/iptunnel.c

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/* vi: set sw=4 ts=4: */
/*
* iptunnel.c "ip tunnel"
*
* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
*
* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
*
*
* Changes:
*
* Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses
* Rani Assaf <rani@magic.metawire.com> 980930: do not allow key for ipip/sit
* Phil Karn <karn@ka9q.ampr.org> 990408: "pmtudisc" flag
*/
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#include <netinet/ip.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <asm/types.h>
#ifndef __constant_htons
#define __constant_htons htons
#endif
#include <linux/if_tunnel.h>
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#include "ip_common.h" /* #include "libbb.h" is inside */
#include "rt_names.h"
#include "utils.h"
/* Dies on error */
static int do_ioctl_get_ifindex(char *dev)
{
struct ifreq ifr;
int fd;
strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
fd = xsocket(AF_INET, SOCK_DGRAM, 0);
xioctl(fd, SIOCGIFINDEX, &ifr);
close(fd);
return ifr.ifr_ifindex;
}
static int do_ioctl_get_iftype(char *dev)
{
struct ifreq ifr;
int fd;
int err;
strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
fd = xsocket(AF_INET, SOCK_DGRAM, 0);
err = ioctl_or_warn(fd, SIOCGIFHWADDR, &ifr);
close(fd);
return err ? -1 : ifr.ifr_addr.sa_family;
}
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static char *do_ioctl_get_ifname(int idx)
{
struct ifreq ifr;
int fd;
int err;
ifr.ifr_ifindex = idx;
fd = xsocket(AF_INET, SOCK_DGRAM, 0);
err = ioctl_or_warn(fd, SIOCGIFNAME, &ifr);
close(fd);
return err ? NULL : xstrndup(ifr.ifr_name, sizeof(ifr.ifr_name));
}
static int do_get_ioctl(const char *basedev, struct ip_tunnel_parm *p)
{
struct ifreq ifr;
int fd;
int err;
strncpy(ifr.ifr_name, basedev, sizeof(ifr.ifr_name));
ifr.ifr_ifru.ifru_data = (void*)p;
fd = xsocket(AF_INET, SOCK_DGRAM, 0);
err = ioctl_or_warn(fd, SIOCGETTUNNEL, &ifr);
close(fd);
return err;
}
/* Dies on error, otherwise returns 0 */
static int do_add_ioctl(int cmd, const char *basedev, struct ip_tunnel_parm *p)
{
struct ifreq ifr;
int fd;
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if (cmd == SIOCCHGTUNNEL && p->name[0]) {
strncpy(ifr.ifr_name, p->name, sizeof(ifr.ifr_name));
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} else {
strncpy(ifr.ifr_name, basedev, sizeof(ifr.ifr_name));
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}
ifr.ifr_ifru.ifru_data = (void*)p;
fd = xsocket(AF_INET, SOCK_DGRAM, 0);
#if ENABLE_IOCTL_HEX2STR_ERROR
/* #define magic will turn ioctl# into string */
if (cmd == SIOCCHGTUNNEL)
xioctl(fd, SIOCCHGTUNNEL, &ifr);
else
xioctl(fd, SIOCADDTUNNEL, &ifr);
#else
xioctl(fd, cmd, &ifr);
#endif
close(fd);
return 0;
}
/* Dies on error, otherwise returns 0 */
static int do_del_ioctl(const char *basedev, struct ip_tunnel_parm *p)
{
struct ifreq ifr;
int fd;
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if (p->name[0]) {
strncpy(ifr.ifr_name, p->name, sizeof(ifr.ifr_name));
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} else {
strncpy(ifr.ifr_name, basedev, sizeof(ifr.ifr_name));
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}
ifr.ifr_ifru.ifru_data = (void*)p;
fd = xsocket(AF_INET, SOCK_DGRAM, 0);
xioctl(fd, SIOCDELTUNNEL, &ifr);
close(fd);
return 0;
}
/* Dies on error */
static void parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
{
static const char keywords[] ALIGN1 =
"mode\0""ipip\0""ip/ip\0""gre\0""gre/ip\0""sit\0""ipv6/ip\0"
"key\0""ikey\0""okey\0""seq\0""iseq\0""oseq\0"
"csum\0""icsum\0""ocsum\0""nopmtudisc\0""pmtudisc\0"
"remote\0""any\0""local\0""dev\0"
"ttl\0""inherit\0""tos\0""dsfield\0"
"name\0";
enum {
ARG_mode, ARG_ipip, ARG_ip_ip, ARG_gre, ARG_gre_ip, ARG_sit, ARG_ip6_ip,
ARG_key, ARG_ikey, ARG_okey, ARG_seq, ARG_iseq, ARG_oseq,
ARG_csum, ARG_icsum, ARG_ocsum, ARG_nopmtudisc, ARG_pmtudisc,
ARG_remote, ARG_any, ARG_local, ARG_dev,
ARG_ttl, ARG_inherit, ARG_tos, ARG_dsfield,
ARG_name
};
int count = 0;
char medium[IFNAMSIZ];
int key;
memset(p, 0, sizeof(*p));
memset(&medium, 0, sizeof(medium));
p->iph.version = 4;
p->iph.ihl = 5;
#ifndef IP_DF
#define IP_DF 0x4000 /* Flag: "Don't Fragment" */
#endif
p->iph.frag_off = htons(IP_DF);
while (argc > 0) {
key = index_in_strings(keywords, *argv);
if (key == ARG_mode) {
NEXT_ARG();
key = index_in_strings(keywords, *argv);
if (key == ARG_ipip ||
key == ARG_ip_ip) {
if (p->iph.protocol && p->iph.protocol != IPPROTO_IPIP) {
bb_error_msg_and_die("you managed to ask for more than one tunnel mode");
}
p->iph.protocol = IPPROTO_IPIP;
} else if (key == ARG_gre ||
key == ARG_gre_ip) {
if (p->iph.protocol && p->iph.protocol != IPPROTO_GRE) {
bb_error_msg_and_die("you managed to ask for more than one tunnel mode");
}
p->iph.protocol = IPPROTO_GRE;
} else if (key == ARG_sit ||
key == ARG_ip6_ip) {
if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) {
bb_error_msg_and_die("you managed to ask for more than one tunnel mode");
}
p->iph.protocol = IPPROTO_IPV6;
} else {
bb_error_msg_and_die("cannot guess tunnel mode");
}
} else if (key == ARG_key) {
unsigned uval;
NEXT_ARG();
p->i_flags |= GRE_KEY;
p->o_flags |= GRE_KEY;
if (strchr(*argv, '.'))
p->i_key = p->o_key = get_addr32(*argv);
else {
if (get_unsigned(&uval, *argv, 0)<0) {
bb_error_msg_and_die("invalid value of \"key\"");
}
p->i_key = p->o_key = htonl(uval);
}
} else if (key == ARG_ikey) {
unsigned uval;
NEXT_ARG();
p->i_flags |= GRE_KEY;
if (strchr(*argv, '.'))
p->o_key = get_addr32(*argv);
else {
if (get_unsigned(&uval, *argv, 0)<0) {
bb_error_msg_and_die("invalid value of \"ikey\"");
}
p->i_key = htonl(uval);
}
} else if (key == ARG_okey) {
unsigned uval;
NEXT_ARG();
p->o_flags |= GRE_KEY;
if (strchr(*argv, '.'))
p->o_key = get_addr32(*argv);
else {
if (get_unsigned(&uval, *argv, 0)<0) {
bb_error_msg_and_die("invalid value of \"okey\"");
}
p->o_key = htonl(uval);
}
} else if (key == ARG_seq) {
p->i_flags |= GRE_SEQ;
p->o_flags |= GRE_SEQ;
} else if (key == ARG_iseq) {
p->i_flags |= GRE_SEQ;
} else if (key == ARG_oseq) {
p->o_flags |= GRE_SEQ;
} else if (key == ARG_csum) {
p->i_flags |= GRE_CSUM;
p->o_flags |= GRE_CSUM;
} else if (key == ARG_icsum) {
p->i_flags |= GRE_CSUM;
} else if (key == ARG_ocsum) {
p->o_flags |= GRE_CSUM;
} else if (key == ARG_nopmtudisc) {
p->iph.frag_off = 0;
} else if (key == ARG_pmtudisc) {
p->iph.frag_off = htons(IP_DF);
} else if (key == ARG_remote) {
NEXT_ARG();
key = index_in_strings(keywords, *argv);
if (key == ARG_any)
p->iph.daddr = get_addr32(*argv);
} else if (key == ARG_local) {
NEXT_ARG();
key = index_in_strings(keywords, *argv);
if (key == ARG_any)
p->iph.saddr = get_addr32(*argv);
} else if (key == ARG_dev) {
NEXT_ARG();
strncpy(medium, *argv, IFNAMSIZ-1);
} else if (key == ARG_ttl) {
unsigned uval;
NEXT_ARG();
key = index_in_strings(keywords, *argv);
if (key != ARG_inherit) {
if (get_unsigned(&uval, *argv, 0))
invarg(*argv, "TTL");
if (uval > 255)
invarg(*argv, "TTL must be <=255");
p->iph.ttl = uval;
}
} else if (key == ARG_tos ||
key == ARG_dsfield) {
uint32_t uval;
NEXT_ARG();
key = index_in_strings(keywords, *argv);
if (key != ARG_inherit) {
if (rtnl_dsfield_a2n(&uval, *argv))
invarg(*argv, "TOS");
p->iph.tos = uval;
} else
p->iph.tos = 1;
} else {
if (key == ARG_name) {
NEXT_ARG();
}
if (p->name[0])
duparg2("name", *argv);
strncpy(p->name, *argv, IFNAMSIZ);
if (cmd == SIOCCHGTUNNEL && count == 0) {
struct ip_tunnel_parm old_p;
memset(&old_p, 0, sizeof(old_p));
if (do_get_ioctl(*argv, &old_p))
exit(1);
*p = old_p;
}
}
count++;
argc--;
argv++;
}
if (p->iph.protocol == 0) {
if (memcmp(p->name, "gre", 3) == 0)
p->iph.protocol = IPPROTO_GRE;
else if (memcmp(p->name, "ipip", 4) == 0)
p->iph.protocol = IPPROTO_IPIP;
else if (memcmp(p->name, "sit", 3) == 0)
p->iph.protocol = IPPROTO_IPV6;
}
if (p->iph.protocol == IPPROTO_IPIP || p->iph.protocol == IPPROTO_IPV6) {
if ((p->i_flags & GRE_KEY) || (p->o_flags & GRE_KEY)) {
bb_error_msg_and_die("keys are not allowed with ipip and sit");
}
}
if (medium[0]) {
p->link = do_ioctl_get_ifindex(medium);
}
if (p->i_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
p->i_key = p->iph.daddr;
p->i_flags |= GRE_KEY;
}
if (p->o_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
p->o_key = p->iph.daddr;
p->o_flags |= GRE_KEY;
}
if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr) {
bb_error_msg_and_die("broadcast tunnel requires a source address");
}
}
/* Return value becomes exitcode. It's okay to not return at all */
static int do_add(int cmd, int argc, char **argv)
{
struct ip_tunnel_parm p;
parse_args(argc, argv, cmd, &p);
if (p.iph.ttl && p.iph.frag_off == 0) {
bb_error_msg_and_die("ttl != 0 and noptmudisc are incompatible");
}
switch (p.iph.protocol) {
case IPPROTO_IPIP:
return do_add_ioctl(cmd, "tunl0", &p);
case IPPROTO_GRE:
return do_add_ioctl(cmd, "gre0", &p);
case IPPROTO_IPV6:
return do_add_ioctl(cmd, "sit0", &p);
default:
bb_error_msg_and_die("cannot determine tunnel mode (ipip, gre or sit)");
}
}
/* Return value becomes exitcode. It's okay to not return at all */
static int do_del(int argc, char **argv)
{
struct ip_tunnel_parm p;
parse_args(argc, argv, SIOCDELTUNNEL, &p);
switch (p.iph.protocol) {
case IPPROTO_IPIP:
return do_del_ioctl("tunl0", &p);
case IPPROTO_GRE:
return do_del_ioctl("gre0", &p);
case IPPROTO_IPV6:
return do_del_ioctl("sit0", &p);
default:
return do_del_ioctl(p.name, &p);
}
}
static void print_tunnel(struct ip_tunnel_parm *p)
{
char s1[256];
char s2[256];
char s3[64];
char s4[64];
format_host(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1));
format_host(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2));
inet_ntop(AF_INET, &p->i_key, s3, sizeof(s3));
inet_ntop(AF_INET, &p->o_key, s4, sizeof(s4));
printf("%s: %s/ip remote %s local %s ",
p->name,
p->iph.protocol == IPPROTO_IPIP ? "ip" :
(p->iph.protocol == IPPROTO_GRE ? "gre" :
(p->iph.protocol == IPPROTO_IPV6 ? "ipv6" : "unknown")),
p->iph.daddr ? s1 : "any", p->iph.saddr ? s2 : "any");
if (p->link) {
char *n = do_ioctl_get_ifname(p->link);
if (n) {
printf(" dev %s ", n);
free(n);
}
}
if (p->iph.ttl)
printf(" ttl %d ", p->iph.ttl);
else
printf(" ttl inherit ");
if (p->iph.tos) {
SPRINT_BUF(b1);
printf(" tos");
if (p->iph.tos & 1)
printf(" inherit");
if (p->iph.tos & ~1)
printf("%c%s ", p->iph.tos & 1 ? '/' : ' ',
rtnl_dsfield_n2a(p->iph.tos & ~1, b1, sizeof(b1)));
}
if (!(p->iph.frag_off & htons(IP_DF)))
printf(" nopmtudisc");
if ((p->i_flags & GRE_KEY) && (p->o_flags & GRE_KEY) && p->o_key == p->i_key)
printf(" key %s", s3);
else if ((p->i_flags | p->o_flags) & GRE_KEY) {
if (p->i_flags & GRE_KEY)
printf(" ikey %s ", s3);
if (p->o_flags & GRE_KEY)
printf(" okey %s ", s4);
}
if (p->i_flags & GRE_SEQ)
printf("%c Drop packets out of sequence.\n", _SL_);
if (p->i_flags & GRE_CSUM)
printf("%c Checksum in received packet is required.", _SL_);
if (p->o_flags & GRE_SEQ)
printf("%c Sequence packets on output.", _SL_);
if (p->o_flags & GRE_CSUM)
printf("%c Checksum output packets.", _SL_);
}
static void do_tunnels_list(struct ip_tunnel_parm *p)
{
char name[IFNAMSIZ];
unsigned long rx_bytes, rx_packets, rx_errs, rx_drops,
rx_fifo, rx_frame,
tx_bytes, tx_packets, tx_errs, tx_drops,
tx_fifo, tx_colls, tx_carrier, rx_multi;
int type;
struct ip_tunnel_parm p1;
char buf[512];
FILE *fp = fopen_or_warn("/proc/net/dev", "r");
if (fp == NULL) {
return;
}
fgets(buf, sizeof(buf), fp);
fgets(buf, sizeof(buf), fp);
while (fgets(buf, sizeof(buf), fp) != NULL) {
char *ptr;
/*buf[sizeof(buf) - 1] = 0; - fgets is safe anyway */
ptr = strchr(buf, ':');
if (ptr == NULL ||
(*ptr++ = 0, sscanf(buf, "%s", name) != 1)) {
bb_error_msg("wrong format of /proc/net/dev");
return;
}
if (sscanf(ptr, "%lu%lu%lu%lu%lu%lu%lu%*d%lu%lu%lu%lu%lu%lu%lu",
&rx_bytes, &rx_packets, &rx_errs, &rx_drops,
&rx_fifo, &rx_frame, &rx_multi,
&tx_bytes, &tx_packets, &tx_errs, &tx_drops,
&tx_fifo, &tx_colls, &tx_carrier) != 14)
continue;
if (p->name[0] && strcmp(p->name, name))
continue;
type = do_ioctl_get_iftype(name);
if (type == -1) {
bb_error_msg("cannot get type of [%s]", name);
continue;
}
if (type != ARPHRD_TUNNEL && type != ARPHRD_IPGRE && type != ARPHRD_SIT)
continue;
memset(&p1, 0, sizeof(p1));
if (do_get_ioctl(name, &p1))
continue;
if ((p->link && p1.link != p->link) ||
(p->name[0] && strcmp(p1.name, p->name)) ||
(p->iph.daddr && p1.iph.daddr != p->iph.daddr) ||
(p->iph.saddr && p1.iph.saddr != p->iph.saddr) ||
(p->i_key && p1.i_key != p->i_key))
continue;
print_tunnel(&p1);
puts("");
}
}
/* Return value becomes exitcode. It's okay to not return at all */
static int do_show(int argc, char **argv)
{
int err;
struct ip_tunnel_parm p;
parse_args(argc, argv, SIOCGETTUNNEL, &p);
switch (p.iph.protocol) {
case IPPROTO_IPIP:
err = do_get_ioctl(p.name[0] ? p.name : "tunl0", &p);
break;
case IPPROTO_GRE:
err = do_get_ioctl(p.name[0] ? p.name : "gre0", &p);
break;
case IPPROTO_IPV6:
err = do_get_ioctl(p.name[0] ? p.name : "sit0", &p);
break;
default:
do_tunnels_list(&p);
return 0;
}
if (err)
return -1;
print_tunnel(&p);
puts("");
return 0;
}
/* Return value becomes exitcode. It's okay to not return at all */
int do_iptunnel(int argc, char **argv)
{
static const char keywords[] ALIGN1 =
"add\0""change\0""delete\0""show\0""list\0""lst\0";
enum { ARG_add = 0, ARG_change, ARG_del, ARG_show, ARG_list, ARG_lst };
int key;
if (argc) {
key = index_in_substrings(keywords, *argv);
if (key < 0)
bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
--argc;
++argv;
if (key == ARG_add)
return do_add(SIOCADDTUNNEL, argc, argv);
if (key == ARG_change)
return do_add(SIOCCHGTUNNEL, argc, argv);
if (key == ARG_del)
return do_del(argc, argv);
}
return do_show(argc, argv);
}