netsukuku/src/iptunnel.c

452 lines
11 KiB
C

/* This file is part of Netsukuku
* (c) Copyright 2005 Andrea Lo Pumo aka AlpT <alpt@freaknet.org>
*
* This source code 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 source code 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.
* Please refer to the GNU Public License for more details.
*
* You should have received a copy of the GNU Public License along with
* this source code; if not, write to:
* Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* --
* This code derives from iproute2/iprule.c, it was modified to fit in
* Netsukuku.
*
* 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
*/
#include "includes.h"
#include "inet.h"
#include <linux/ip.h>
#include <linux/if_tunnel.h>
#include "libnetlink.h"
#include "libnetlink.h"
#include "ll_map.h"
#include "krnl_route.h"
#include "route.h"
#include "iptunnel.h"
#include "common.h"
static int do_add(int cmd, inet_prefix *remote, inet_prefix *local, char *dev,
char *tunl_prefix, int tunl_number);
int do_del(inet_prefix *remote, inet_prefix *local, char *dev,
char *tunl_prefix, int tunl_number);
int tunnel_add(inet_prefix *remote, inet_prefix *local, char *dev,
char *tunl_prefix, int tunl_number)
{
return do_add(SIOCADDTUNNEL, remote, local, dev, tunl_prefix,
tunl_number);
}
int tunnel_change(inet_prefix *remote, inet_prefix *local, char *dev,
char *tunl_prefix, int tunl_number)
{
return do_add(SIOCGETTUNNEL, remote, local, dev, tunl_prefix,
tunl_number);
}
int tunnel_del(inet_prefix *remote, inet_prefix *local, char *dev,
char *tunl_prefix, int tunl_number)
{
return do_del(remote, local, dev, tunl_prefix, tunl_number);
}
static int do_ioctl_get_ifindex(const char *dev)
{
struct ifreq ifr;
int fd;
int err;
strncpy(ifr.ifr_name, dev, IFNAMSIZ);
fd = socket(AF_INET, SOCK_DGRAM, 0);
err = ioctl(fd, SIOCGIFINDEX, &ifr);
if (err) {
error(ERROR_MSG "ioctl: %s", ERROR_POS, strerror(errno));
return 0;
}
close(fd);
return ifr.ifr_ifindex;
}
#if 0
static int do_ioctl_get_iftype(const char *dev)
{
struct ifreq ifr;
int fd;
int err;
strncpy(ifr.ifr_name, dev, IFNAMSIZ);
fd = socket(AF_INET, SOCK_DGRAM, 0);
err = ioctl(fd, SIOCGIFHWADDR, &ifr);
if (err) {
error(ERROR_MSG "ioctl: %s",ERROR_POS, strerror(errno));
return -1;
}
close(fd);
return ifr.ifr_addr.sa_family;
}
static char * do_ioctl_get_ifname(int idx)
{
static struct ifreq ifr;
int fd;
int err;
ifr.ifr_ifindex = idx;
fd = socket(AF_INET, SOCK_DGRAM, 0);
err = ioctl(fd, SIOCGIFNAME, &ifr);
if (err) {
error(ERROR_MSG "ioctl: %s",ERROR_POS, strerror(errno));
return NULL;
}
close(fd);
return ifr.ifr_name;
}
#endif
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, IFNAMSIZ);
ifr.ifr_ifru.ifru_data = (void*)p;
fd = socket(AF_INET, SOCK_DGRAM, 0);
err = ioctl(fd, SIOCGETTUNNEL, &ifr);
/*
* if (err)
* error(ERROR_MSG "ioctl: %s",ERROR_POS, strerror(errno));
*/
close(fd);
return err;
}
static int do_add_ioctl(int cmd, const char *basedev, struct ip_tunnel_parm *p)
{
struct ifreq ifr;
int fd;
int err;
if (cmd == SIOCCHGTUNNEL && p->name[0])
strncpy(ifr.ifr_name, p->name, IFNAMSIZ);
else
strncpy(ifr.ifr_name, basedev, IFNAMSIZ);
ifr.ifr_ifru.ifru_data = (void*)p;
fd = socket(AF_INET, SOCK_DGRAM, 0);
err = ioctl(fd, cmd, &ifr);
error("Socket File Descriptor Is: %i cmd is: %i err is: %i ifr is: %s Errno is: %d", fd, cmd, err, &ifr, errno);
if (err)
error(ERROR_MSG "ioctl: %s",ERROR_POS, strerror(errno));
close(fd);
return err;
}
static int do_del_ioctl(const char *basedev, struct ip_tunnel_parm *p)
{
struct ifreq ifr;
int fd;
int err;
if (p->name[0])
strncpy(ifr.ifr_name, p->name, IFNAMSIZ);
else
strncpy(ifr.ifr_name, basedev, IFNAMSIZ);
ifr.ifr_ifru.ifru_data = (void*)p;
fd = socket(AF_INET, SOCK_DGRAM, 0);
err = ioctl(fd, SIOCDELTUNNEL, &ifr);
if (err)
error(ERROR_MSG "ioctl: %s",ERROR_POS, strerror(errno));
close(fd);
return err;
}
/*
* fill_tunnel_parm: fills the `p' struct.
* `remote' and `local' must be in host order
*/
static int fill_tunnel_parm(int cmd, inet_prefix *remote, inet_prefix *local,
char *dev, char *tunl_prefix, int tunl_number,
struct ip_tunnel_parm *p)
{
char medium[IFNAMSIZ];
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);
p->iph.protocol = IPPROTO_IPIP;
if(remote)
p->iph.daddr = htonl(remote->data[0]);
if(local)
p->iph.saddr = htonl(local->data[0]);
if(dev)
strncpy(medium, dev, IFNAMSIZ-1);
sprintf(p->name, TUNL_STRING, TUNL_N(tunl_prefix, tunl_number));
if (cmd == SIOCCHGTUNNEL) {
/* Change the old tunnel */
struct ip_tunnel_parm old_p;
memset(&old_p, 0, sizeof(old_p));
if (do_get_ioctl(p->name, &old_p))
return -1;
*p = old_p;
}
if (p->iph.protocol == IPPROTO_IPIP)
if ((p->i_flags & GRE_KEY) || (p->o_flags & GRE_KEY))
fatal("Keys are not allowed with ipip and sit.");
if (medium[0]) {
p->link = do_ioctl_get_ifindex(medium);
if (p->link == 0)
return -1;
}
if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr)
fatal("Broadcast tunnel requires a source address.");
return 0;
}
/*
* do_get: returns 1 if the tunnel named `dev' exists.
*/
int do_get(char *dev)
{
struct ip_tunnel_parm old_p;
memset(&old_p, 0, sizeof(old_p));
if (do_get_ioctl(dev, &old_p))
return 0;
return 1;
}
static int do_add(int cmd, inet_prefix *remote, inet_prefix *local, char *dev,
char *tunl_prefix, int tunl_number)
{
struct ip_tunnel_parm p;
if (fill_tunnel_parm(cmd, remote, local, dev, tunl_prefix,
tunl_number, &p) < 0)
return -1;
if (p.iph.ttl && p.iph.frag_off == 0)
fatal("ttl != 0 and noptmudisc are incompatible");
switch (p.iph.protocol) {
case IPPROTO_IPIP:
return do_add_ioctl(cmd, DEFAULT_TUNL_IF, &p);
default:
fatal("cannot determine tunnel mode (ipip, gre or sit)\n");
}
return -1;
}
int do_del(inet_prefix *remote, inet_prefix *local, char *dev, char *tunl_prefix,
int tunl_number)
{
struct ip_tunnel_parm p;
if (fill_tunnel_parm(SIOCDELTUNNEL, remote, local, dev, tunl_prefix,
tunl_number, &p) < 0)
return -1;
switch (p.iph.protocol) {
case IPPROTO_IPIP:
return do_del_ioctl(DEFAULT_TUNL_IF, &p);
default:
return do_del_ioctl(p.name, &p);
}
return -1;
}
/*
* tun_add_tunl: it adds in the `ifs' array a new struct which refers to
* the tunnel "tunlX", where X is a number equal to `tunl'.
*/
int tun_add_tunl(interface *ifs, char *tunl_prefix, u_char tunl_number)
{
char tunl_name[IFNAMSIZ];
sprintf(tunl_name, TUNL_STRING, TUNL_N(tunl_prefix, tunl_number));
strncpy(ifs->dev_name, tunl_name, IFNAMSIZ);
if(!(ifs->dev_idx=do_ioctl_get_ifindex(tunl_name)))
return -1;
return 0;
}
/*
* tun_del_tunl: it removes from the `ifs' array, which must have at least
* MAX_TUNNEL_IFS members, the struct which refers the tunnel "tunlX", where X
* is a number equal to `tunl'.
* If no such struct is found, -1 is returned.
*/
int tun_del_tunl(interface *ifs, char *tunl_prefix, u_char tunl_number)
{
char tunl_name[IFNAMSIZ];
int i;
sprintf(tunl_name, TUNL_STRING, TUNL_N(tunl_prefix, tunl_number));
for(i=0; i<MAX_TUNNEL_IFS; i++)
if(!strncmp(ifs[i].dev_name, tunl_name, IFNAMSIZ)) {
memset(&ifs[i], 0, sizeof(interface));
return 0;
}
return -1;
}
void init_tunnels_ifs(void)
{
memset(tunnel_ifs, 0, sizeof(interface)*MAX_TUNNEL_IFS);
}
/*
* first_free_tunnel_if: returns the position of the first member of the
* `tunnel_ifs' array which isn't used yet.
* If the whole array is full, -1 is returned.
*/
int first_free_tunnel_if(void)
{
int i;
for(i=0; i<MAX_TUNNEL_IFS; i++)
if(!*tunnel_ifs[i].dev_name && !tunnel_ifs[i].dev_idx)
return i;
return -1;
}
/*
* set_tunnel_ip: it brings down and up and set the `tunl_ip' IP to the
* "tunl`tunl_number'" tunnel device
*/
int set_tunnel_ip(char *tunl_prefix, int tunl_number, inet_prefix *tunl_ip)
{
const char *ntop;
ntop=inet_to_str(*tunl_ip);
set_all_ifs(&tunnel_ifs[tunl_number], 1, set_dev_down);
set_all_ifs(&tunnel_ifs[tunl_number], 1, set_dev_up);
if(set_all_dev_ip(*tunl_ip, &tunnel_ifs[tunl_number], 1) < 0) {
error("Cannot set the %s ip to " TUNL_STRING,
ntop, TUNL_N(tunl_prefix, tunl_number));
return -1;
}
return 0;
}
/*
* add_tunnel_if: creates a new tunnel, adds it in the `tunnel_ifs' array, and
* if `tunl_ip' isn't null, sets to the tunnel the IP `tunl_ip'.
*/
int add_tunnel_if(inet_prefix *remote, inet_prefix *local, char *dev,
char *tunl_prefix, int tunl_number, inet_prefix *tunl_ip)
{
char tunl_name[IFNAMSIZ];
/*
* tunl0 zero is a special tunnel, it cannot be created nor destroyed.
* It's pure energy.
*/
if(!strcmp(tunl_prefix, DEFAULT_TUNL_PREFIX) && !tunl_number)
goto skip_krnl_add_tunl;
if(tunnel_add(remote, local, dev, tunl_prefix, tunl_number) < 0) {
error("Cannot add the \"" TUNL_STRING "\" tunnel",
TUNL_N(tunl_prefix, tunl_number));
return -1;
}
skip_krnl_add_tunl:
if(tun_add_tunl(&tunnel_ifs[tunl_number], tunl_prefix, tunl_number) < 0)
return -1;
if(tunl_ip) {
/*
* ifconfig tunnel `tunl_ip' up
*/
if(set_tunnel_ip(tunl_prefix, tunl_number, tunl_ip) < 0)
return -1;
/*
* ip route append tunl_ip_subnet dev tunnel proto kernel \
* scope link src `tunl_ip'
*/
sprintf(tunl_name, TUNL_STRING, TUNL_N(tunl_prefix, tunl_number));
rt_append_subnet_src(tunl_ip, tunl_name);
if(route_rp_filter_all_dev(my_family, &tunnel_ifs[tunl_number],
1, 0) < 0)
return -1;
}
return 0;
}
/*
* del_tunnel_if: the inverse of add_tunnel_if() (see above)
*/
int del_tunnel_if(inet_prefix *remote, inet_prefix *local, char *dev,
char *tunl_prefix, int tunl_number)
{
/* tunl0 is a highlander */
if(!strcmp(tunl_prefix, DEFAULT_TUNL_PREFIX) && !tunl_number)
goto skip_krnl_del_tunl;
if(tunnel_del(remote, local, dev, tunl_prefix, tunl_number) < 0) {
error("Cannot delete the \"" TUNL_STRING "\" tunnel",
TUNL_N(tunl_prefix, tunl_number));
return -1;
}
skip_krnl_del_tunl:
tun_del_tunl(tunnel_ifs, tunl_prefix, tunl_number);
return 0;
}
void del_all_tunnel_ifs(inet_prefix *remote, inet_prefix *local, char *dev,
char *tunl_prefix)
{
char tunl_name[IFNAMSIZ];
int i;
for(i=0; i<MAX_TUNNEL_IFS; i++) {
sprintf(tunl_name, TUNL_STRING, TUNL_N(tunl_prefix, i));
if(do_get(tunl_name))
del_tunnel_if(remote, local, 0, tunl_prefix, i);
else
break;
}
}