/*
* Copyright (C) 2008-2019 Tobias Brunner
* Copyright (C) 2005-2008 Martin Willi
* HSR Hochschule fuer Technik Rapperswil
*
* 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. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* 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.
*/
/*
* Copyright (C) 2010 secunet Security Networks AG
* Copyright (C) 2010 Thomas Egerer
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <sys/socket.h>
#include <sys/utsname.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/if_addrlabel.h>
#include <unistd.h>
#include <errno.h>
#include <net/if.h>
#ifdef HAVE_LINUX_FIB_RULES_H
#include <linux/fib_rules.h>
#endif
#include "kernel_netlink_net.h"
#include "kernel_netlink_shared.h"
#include <daemon.h>
#include <utils/debug.h>
#include <threading/mutex.h>
#include <threading/rwlock.h>
#include <threading/rwlock_condvar.h>
#include <threading/spinlock.h>
#include <collections/hashtable.h>
#include <collections/linked_list.h>
#include <processing/jobs/callback_job.h>
/** delay before firing roam events (ms) */
#define ROAM_DELAY 100
/** delay before reinstalling routes (ms) */
#define ROUTE_DELAY 100
/** maximum recursion when searching for addresses in get_route() */
#define MAX_ROUTE_RECURSION 2
#ifndef ROUTING_TABLE
#define ROUTING_TABLE 0
#endif
#ifndef ROUTING_TABLE_PRIO
#define ROUTING_TABLE_PRIO 0
#endif
/** multicast groups (for groups > 31 setsockopt has to be used) */
#define nl_group(group) (1 << (group - 1))
ENUM(rt_msg_names, RTM_NEWLINK, RTM_GETRULE,
"RTM_NEWLINK",
"RTM_DELLINK",
"RTM_GETLINK",
"RTM_SETLINK",
"RTM_NEWADDR",
"RTM_DELADDR",
"RTM_GETADDR",
"23",
"RTM_NEWROUTE",
"RTM_DELROUTE",
"RTM_GETROUTE",
"27",
"RTM_NEWNEIGH",
"RTM_DELNEIGH",
"RTM_GETNEIGH",
"31",
"RTM_NEWRULE",
"RTM_DELRULE",
"RTM_GETRULE",
);
typedef struct addr_entry_t addr_entry_t;
/**
* IP address in an iface_entry_t
*/
struct addr_entry_t {
/** the ip address */
host_t *ip;
/** address flags */
u_char flags;
/** scope of the address */
u_char scope;
/** number of times this IP is used, if virtual (i.e. managed by us) */
u_int refcount;
/** TRUE once it is installed, if virtual */
bool installed;
};
/**
* destroy a addr_entry_t object
*/
static void addr_entry_destroy(addr_entry_t *this)
{
this->ip->destroy(this->ip);
free(this);
}
typedef struct iface_entry_t iface_entry_t;
/**
* A network interface on this system, containing addr_entry_t's
*/
struct iface_entry_t {
/** interface index */
int ifindex;
/** name of the interface */
char ifname[IFNAMSIZ];
/** interface flags, as in netdevice(7) SIOCGIFFLAGS */
u_int flags;
/** list of addresses as host_t */
linked_list_t *addrs;
/** TRUE if usable by config */
bool usable;
};
/**
* destroy an interface entry
*/
static void iface_entry_destroy(iface_entry_t *this)
{
this->addrs->destroy_function(this->addrs, (void*)addr_entry_destroy);
free(this);
}
CALLBACK(iface_entry_by_index, bool,
iface_entry_t *this, va_list args)
{
int ifindex;
VA_ARGS_VGET(args, ifindex);
return this->ifindex == ifindex;
}
CALLBACK(iface_entry_by_name, bool,
iface_entry_t *this, va_list args)
{
char *ifname;
VA_ARGS_VGET(args, ifname);
return streq(this->ifname, ifname);
}
/**
* check if an interface is up
*/
static inline bool iface_entry_up(iface_entry_t *iface)
{
return (iface->flags & IFF_UP) == IFF_UP;
}
/**
* check if an interface is up and usable
*/
static inline bool iface_entry_up_and_usable(iface_entry_t *iface)
{
return iface->usable && iface_entry_up(iface);
}
typedef struct addr_map_entry_t addr_map_entry_t;
/**
* Entry that maps an IP address to an interface entry
*/
struct addr_map_entry_t {
/** The IP address */
host_t *ip;
/** The address entry for this IP address */
addr_entry_t *addr;
/** The interface this address is installed on */
iface_entry_t *iface;
};
/**
* Hash a addr_map_entry_t object, all entries with the same IP address
* are stored in the same bucket
*/
static u_int addr_map_entry_hash(addr_map_entry_t *this)
{
return chunk_hash(this->ip->get_address(this->ip));
}
/**
* Compare two addr_map_entry_t objects, two entries are equal if they are
* installed on the same interface
*/
static bool addr_map_entry_equals(addr_map_entry_t *a, addr_map_entry_t *b)
{
return a->iface->ifindex == b->iface->ifindex &&
a->ip->ip_equals(a->ip, b->ip);
}
/**
* Used with get_match this finds an address entry if it is installed on
* an up and usable interface
*/
static bool addr_map_entry_match_up_and_usable(addr_map_entry_t *a,
addr_map_entry_t *b)
{
return iface_entry_up_and_usable(b->iface) &&
a->ip->ip_equals(a->ip, b->ip);
}
/**
* Used with get_match this finds an address entry if it is installed on
* any active local interface
*/
static bool addr_map_entry_match_up(addr_map_entry_t *a, addr_map_entry_t *b)
{
return iface_entry_up(b->iface) && a->ip->ip_equals(a->ip, b->ip);
}
/**
* Used with get_match this finds an address entry if it is installed on
* any local interface
*/
static bool addr_map_entry_match(addr_map_entry_t *a, addr_map_entry_t *b)
{
return a->ip->ip_equals(a->ip, b->ip);
}
typedef struct net_change_t net_change_t;
/**
* Queued network changes
*/
struct net_change_t {
/** Name of the interface that got activated (or an IP appeared on) */
char *if_name;
};
/**
* Destroy a net_change_t object
*/
static void net_change_destroy(net_change_t *this)
{
free(this->if_name);
free(this);
}
/**
* Hash a net_change_t object
*/
static u_int net_change_hash(net_change_t *this)
{
return chunk_hash(chunk_create(this->if_name, strlen(this->if_name)));
}
/**
* Compare two net_change_t objects
*/
static bool net_change_equals(net_change_t *a, net_change_t *b)
{
return streq(a->if_name, b->if_name);
}
typedef struct private_kernel_netlink_net_t private_kernel_netlink_net_t;
/**
* Private variables and functions of kernel_netlink_net class.
*/
struct private_kernel_netlink_net_t {
/**
* Public part of the kernel_netlink_net_t object.
*/
kernel_netlink_net_t public;
/**
* lock to access various lists and maps
*/
rwlock_t *lock;
/**
* condition variable to signal virtual IP add/removal
*/
rwlock_condvar_t *condvar;
/**
* Cached list of interfaces and its addresses (iface_entry_t)
*/
linked_list_t *ifaces;
/**
* Map for IP addresses to iface_entry_t objects (addr_map_entry_t)
*/
hashlist_t *addrs;
/**
* Map for virtual IP addresses to iface_entry_t objects (addr_map_entry_t)
*/
hashlist_t *vips;
/**
* netlink rt socket (routing)
*/
netlink_socket_t *socket;
/**
* Netlink rt socket to receive address change events
*/
int socket_events;
/**
* earliest time of the next roam event
*/
timeval_t next_roam;
/**
* roam event due to address change
*/
bool roam_address;
/**
* lock to check and update roam event time
*/
spinlock_t *roam_lock;
/**
* routing table to install routes
*/
uint32_t routing_table;
/**
* priority of used routing table
*/
uint32_t routing_table_prio;
/**
* installed routes
*/
hashlist_t *routes;
/**
* mutex for routes
*/
mutex_t *routes_lock;
/**
* interface changes which may trigger route reinstallation
*/
hashtable_t *net_changes;
/**
* mutex for route reinstallation triggers
*/
mutex_t *net_changes_lock;
/**
* time of last route reinstallation
*/
timeval_t last_route_reinstall;
/**
* whether to react to RTM_NEWROUTE or RTM_DELROUTE events
*/
bool process_route;
/**
* whether to react to RTM_NEWRULE or RTM_DELRULE events
*/
bool process_rules;
/**
* whether to trigger roam events
*/
bool roam_events;
/**
* whether to install IPsec policy routes
*/
bool install_routes;
/**
* whether to actually install virtual IPs
*/
bool install_virtual_ip;
/**
* the name of the interface virtual IP addresses are installed on
*/
char *install_virtual_ip_on;
/**
* whether preferred source addresses can be specified for IPv6 routes
*/
bool rta_prefsrc_for_ipv6;
/**
* whether marks can be used in route lookups
*/
bool rta_mark;
/**
* the mark excluded from the routing rule used for virtual IPs
*/
mark_t routing_mark;
/**
* whether to prefer temporary IPv6 addresses over public ones
*/
bool prefer_temporary_addrs;
/**
* list with routing tables to be excluded from route lookup
*/
linked_list_t *rt_exclude;
/**
* MTU to set on installed routes
*/
uint32_t mtu;
/**
* MSS to set on installed routes
*/
uint32_t mss;
};
/**
* Forward declaration
*/
static status_t manage_srcroute(private_kernel_netlink_net_t *this,
int nlmsg_type, int flags, chunk_t dst_net,
uint8_t prefixlen, host_t *gateway,
host_t *src_ip, char *if_name, bool pass);
/**
* Clear the queued network changes.
*/
static void net_changes_clear(private_kernel_netlink_net_t *this)
{
enumerator_t *enumerator;
net_change_t *change;
enumerator = this->net_changes->create_enumerator(this->net_changes);
while (enumerator->enumerate(enumerator, NULL, (void**)&change))
{
this->net_changes->remove_at(this->net_changes, enumerator);
net_change_destroy(change);
}
enumerator->destroy(enumerator);
}
/**
* Act upon queued network changes.
*/
static job_requeue_t reinstall_routes(private_kernel_netlink_net_t *this)
{
enumerator_t *enumerator;
route_entry_t *route;
this->net_changes_lock->lock(this->net_changes_lock);
this->routes_lock->lock(this->routes_lock);
enumerator = this->routes->ht.create_enumerator(&this->routes->ht);
while (enumerator->enumerate(enumerator, NULL, (void**)&route))
{
net_change_t *change, lookup = {
.if_name = route->if_name,
};
if (route->pass || !route->if_name)
{ /* no need to reinstall these, they don't reference interfaces */
continue;
}
/* check if a change for the outgoing interface is queued */
change = this->net_changes->get(this->net_changes, &lookup);
if (!change)
{ /* in case src_ip is not on the outgoing interface */
if (this->public.interface.get_interface(&this->public.interface,
route->src_ip, &lookup.if_name))
{
if (!streq(lookup.if_name, route->if_name))
{
change = this->net_changes->get(this->net_changes, &lookup);
}
free(lookup.if_name);
}
}
if (change)
{
manage_srcroute(this, RTM_NEWROUTE, NLM_F_CREATE | NLM_F_EXCL,
route->dst_net, route->prefixlen, route->gateway,
route->src_ip, route->if_name, route->pass);
}
}
enumerator->destroy(enumerator);
this->routes_lock->unlock(this->routes_lock);
net_changes_clear(this);
this->net_changes_lock->unlock(this->net_changes_lock);
return JOB_REQUEUE_NONE;
}
/**
* Queue route reinstallation caused by network changes for a given interface.
*
* The route reinstallation is delayed for a while and only done once for
* several calls during this delay, in order to avoid doing it too often.
* The interface name is freed.
*/
static void queue_route_reinstall(private_kernel_netlink_net_t *this,
char *if_name)
{
net_change_t *update, *found;
timeval_t now;
job_t *job;
INIT(update,
.if_name = if_name
);
this->net_changes_lock->lock(this->net_changes_lock);
found = this->net_changes->put(this->net_changes, update, update);
if (found)
{
net_change_destroy(found);
}
time_monotonic(&now);
if (timercmp(&now, &this->last_route_reinstall, >))
{
timeval_add_ms(&now, ROUTE_DELAY);
this->last_route_reinstall = now;
job = (job_t*)callback_job_create((callback_job_cb_t)reinstall_routes,
this, NULL, NULL);
lib->scheduler->schedule_job_ms(lib->scheduler, job, ROUTE_DELAY);
}
this->net_changes_lock->unlock(this->net_changes_lock);
}
/**
* check if the given IP is known as virtual IP and currently installed
*
* this function will also return TRUE if the virtual IP entry disappeared.
* in that case the returned entry will be NULL.
*
* this->lock must be held when calling this function
*/
static bool is_vip_installed_or_gone(private_kernel_netlink_net_t *this,
host_t *ip, addr_map_entry_t **entry)
{
addr_map_entry_t lookup = {
.ip = ip,
};
*entry = this->vips->get_match(this->vips, &lookup,
(void*)addr_map_entry_match);
if (*entry == NULL)
{ /* the virtual IP disappeared */
return TRUE;
}
return (*entry)->addr->installed;
}
/**
* check if the given IP is known as virtual IP
*
* this->lock must be held when calling this function
*/
static bool is_known_vip(private_kernel_netlink_net_t *this, host_t *ip)
{
addr_map_entry_t lookup = {
.ip = ip,
};
return this->vips->get_match(this->vips, &lookup,
(void*)addr_map_entry_match) != NULL;
}
/**
* Add an address map entry
*/
static void addr_map_entry_add(hashlist_t *map, addr_entry_t *addr,
iface_entry_t *iface)
{
addr_map_entry_t *entry;
INIT(entry,
.ip = addr->ip,
.addr = addr,
.iface = iface,
);
entry = map->ht.put(&map->ht, entry, entry);
free(entry);
}
/**
* Remove an address map entry
*/
static void addr_map_entry_remove(hashlist_t *map, addr_entry_t *addr,
iface_entry_t *iface)
{
addr_map_entry_t *entry, lookup = {
.ip = addr->ip,
.addr = addr,
.iface = iface,
};
entry = map->ht.remove(&map->ht, &lookup);
free(entry);
}
/**
* Check if an address or net (addr with prefix net bits) is in
* subnet (net with net_len net bits)
*/
static bool addr_in_subnet(chunk_t addr, int prefix, chunk_t net, int net_len)
{
static const u_char mask[] = { 0x00, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe };
int byte = 0;
if (net_len == 0)
{ /* any address matches a /0 network */
return TRUE;
}
if (addr.len != net.len || net_len > 8 * net.len || prefix < net_len)
{
return FALSE;
}
/* scan through all bytes in network order */
while (net_len > 0)
{
if (net_len < 8)
{
return (mask[net_len] & addr.ptr[byte]) == (mask[net_len] & net.ptr[byte]);
}
else
{
if (addr.ptr[byte] != net.ptr[byte])
{
return FALSE;
}
byte++;
net_len -= 8;
}
}
return TRUE;
}
/**
* Check if the given address is in subnet (net with net_len net bits)
*/
static bool host_in_subnet(host_t *host, chunk_t net, int net_len)
{
chunk_t addr;
addr = host->get_address(host);
return addr_in_subnet(addr, addr.len * 8, net, net_len);
}
/**
* Determine the type or scope of the given unicast IP address. This is not
* the same thing returned in rtm_scope/ifa_scope.
*
* We use return values as defined in RFC 6724 (referring to RFC 4291).
*/
static u_char get_scope(host_t *ip)
{
chunk_t addr;
addr = ip->get_address(ip);
switch (addr.len)
{
case 4:
/* we use the mapping defined in RFC 6724, 3.2 */
if (addr.ptr[0] == 127)
{ /* link-local, same as the IPv6 loopback address */
return 2;
}
if (addr.ptr[0] == 169 && addr.ptr[1] == 254)
{ /* link-local */
return 2;
}
break;
case 16:
if (IN6_IS_ADDR_LOOPBACK((struct in6_addr*)addr.ptr))
{ /* link-local, according to RFC 4291, 2.5.3 */
return 2;
}
if (IN6_IS_ADDR_LINKLOCAL((struct in6_addr*)addr.ptr))
{
return 2;
}
if (IN6_IS_ADDR_SITELOCAL((struct in6_addr*)addr.ptr))
{ /* deprecated, according to RFC 4291, 2.5.7 */
return 5;
}
break;
default:
break;
}
/* global */
return 14;
}
/**
* Determine the label of the given unicast IP address.
*
* We currently only support the default table given in RFC 6724:
*
* Prefix Precedence Label
* ::1/128 50 0
* ::/0 40 1
* ::ffff:0:0/96 35 4
* 2002::/16 30 2
* 2001::/32 5 5
* fc00::/7 3 13
* ::/96 1 3
* fec0::/10 1 11
* 3ffe::/16 1 12
*/
static u_char get_label(host_t *ip)
{
struct {
chunk_t net;
u_char prefix;
u_char label;
} priorities[] = {
/* priority table ordered by prefix */
/* ::1/128 */
{ chunk_from_chars(0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01), 128, 0 },
/* ::ffff:0:0/96 */
{ chunk_from_chars(0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00), 96, 4 },
/* ::/96 */
{ chunk_from_chars(0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00), 96, 3 },
/* 2001::/32 */
{ chunk_from_chars(0x20, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00), 32, 5 },
/* 2002::/16 */
{ chunk_from_chars(0x20, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00), 16, 2 },
/* 3ffe::/16 */
{ chunk_from_chars(0x3f, 0xfe, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00), 16, 12 },
/* fec0::/10 */
{ chunk_from_chars(0xfe, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00), 10, 11 },
/* fc00::/7 */
{ chunk_from_chars(0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00), 7, 13 },
};
int i;
for (i = 0; i < countof(priorities); i++)
{
if (host_in_subnet(ip, priorities[i].net, priorities[i].prefix))
{
return priorities[i].label;
}
}
/* ::/0 */
return 1;
}
/**
* Returns the length of the common prefix in bits up to the length of a's
* prefix, defined by RFC 6724 as the portion of the address not including the
* interface ID, which is 64-bit for most unicast addresses (see RFC 4291).
*/
static u_char common_prefix(host_t *a, host_t *b)
{
chunk_t aa, ba;
u_char byte, bits = 0, match;
aa = a->get_address(a);
ba = b->get_address(b);
for (byte = 0; byte < 8; byte++)
{
if (aa.ptr[byte] != ba.ptr[byte])
{
match = aa.ptr[byte] ^ ba.ptr[byte];
for (bits = 8; match; match >>= 1)
{
bits--;
}
break;
}
}
return byte * 8 + bits;
}
/**
* Compare two IP addresses and return TRUE if the second address is the better
* choice of the two to reach the destination.
* For IPv6 we approximately follow RFC 6724.
*/
static bool is_address_better(private_kernel_netlink_net_t *this,
addr_entry_t *a, addr_entry_t *b, host_t *d)
{
u_char sa, sb, sd, la, lb, ld, pa, pb;
/* rule 2: prefer appropriate scope */
if (d)
{
sa = get_scope(a->ip);
sb = get_scope(b->ip);
sd = get_scope(d);
if (sa < sb)
{
return sa < sd;
}
else if (sb < sa)
{
return sb >= sd;
}
}
if (a->ip->get_family(a->ip) == AF_INET)
{ /* stop here for IPv4, default to addresses found earlier */
return FALSE;
}
/* rule 3: avoid deprecated addresses (RFC 4862) */
if ((a->flags & IFA_F_DEPRECATED) != (b->flags & IFA_F_DEPRECATED))
{
return a->flags & IFA_F_DEPRECATED;
}
/* rule 4 is not applicable as we don't know if an address is a home or
* care-of addresses.
* rule 5 does not apply as we only compare addresses from one interface
*/
/* rule 6: prefer matching label */
if (d)
{
la = get_label(a->ip);
lb = get_label(b->ip);
ld = get_label(d);
if (la == ld && lb != ld)
{
return FALSE;
}
else if (lb == ld && la != ld)
{
return TRUE;
}
}
/* rule 7: prefer temporary addresses (WE REVERSE THIS BY DEFAULT!) */
if ((a->flags & IFA_F_TEMPORARY) != (b->flags & IFA_F_TEMPORARY))
{
if (this->prefer_temporary_addrs)
{
return b->flags & IFA_F_TEMPORARY;
}
return a->flags & IFA_F_TEMPORARY;
}
/* rule 8: use longest matching prefix */
if (d)
{
pa = common_prefix(a->ip, d);
pb = common_prefix(b->ip, d);
if (pa != pb)
{
return pb > pa;
}
}
/* default to addresses found earlier */
return FALSE;
}
/**
* Get a non-virtual IP address on the given interfaces and optionally in a
* given subnet.
*
* If a candidate address is given, we first search for that address and if not
* found return the address as above.
* Returned host is a clone, has to be freed by caller.
*
* this->lock must be held when calling this function.
*/
static host_t *get_matching_address(private_kernel_netlink_net_t *this,
int *ifindex, int family, chunk_t net,
uint8_t mask, host_t *dest,
host_t *candidate)
{
enumerator_t *ifaces, *addrs;
iface_entry_t *iface;
addr_entry_t *addr, *best = NULL;
bool candidate_matched = FALSE;
ifaces = this->ifaces->create_enumerator(this->ifaces);
while (ifaces->enumerate(ifaces, &iface))
{
if (iface->usable && (!ifindex || iface->ifindex == *ifindex))
{ /* only use matching interfaces not excluded by config */
addrs = iface->addrs->create_enumerator(iface->addrs);
while (addrs->enumerate(addrs, &addr))
{
if (addr->refcount ||
addr->ip->get_family(addr->ip) != family)
{ /* ignore virtual IP addresses and ensure family matches */
continue;
}
if (net.ptr && !host_in_subnet(addr->ip, net, mask))
{ /* optionally match a subnet */
continue;
}
if (candidate && candidate->ip_equals(candidate, addr->ip) &&
!(addr->flags & IFA_F_DEPRECATED))
{ /* stop if we find the candidate and it's not deprecated */
best = addr;
candidate_matched = TRUE;
break;
}
else if (!best || is_address_better(this, best, addr, dest))
{
best = addr;
}
}
addrs->destroy(addrs);
if (ifindex || candidate_matched)
{
break;
}
}
}
ifaces->destroy(ifaces);
return best ? best->ip->clone(best->ip) : NULL;
}
/**
* Get a non-virtual IP address on the given interface.
*
* If a candidate address is given, we first search for that address and if not
* found return the address as above.
* Returned host is a clone, has to be freed by caller.
*
* this->lock must be held when calling this function.
*/
static host_t *get_interface_address(private_kernel_netlink_net_t *this,
int ifindex, int family, host_t *dest,
host_t *candidate)
{
return get_matching_address(this, &ifindex, family, chunk_empty, 0, dest,
candidate);
}
/**
* Get a non-virtual IP address in the given subnet.
*
* If a candidate address is given, we first search for that address and if not
* found return the address as above.
* Returned host is a clone, has to be freed by caller.
*
* this->lock must be held when calling this function.
*/
static host_t *get_subnet_address(private_kernel_netlink_net_t *this,
int family, chunk_t net, uint8_t mask,
host_t *dest, host_t *candidate)
{
return get_matching_address(this, NULL, family, net, mask, dest, candidate);
}
/**
* callback function that raises the delayed roam event
*/
static job_requeue_t roam_event(private_kernel_netlink_net_t *this)
{
bool address;
this->roam_lock->lock(this->roam_lock);
address = this->roam_address;
this->roam_address = FALSE;
this->roam_lock->unlock(this->roam_lock);
charon->kernel->roam(charon->kernel, address);
return JOB_REQUEUE_NONE;
}
/**
* fire a roaming event. we delay it for a bit and fire only one event
* for multiple calls. otherwise we would create too many events.
*/
static void fire_roam_event(private_kernel_netlink_net_t *this, bool address)
{
timeval_t now;
job_t *job;
if (!this->roam_events)
{
return;
}
time_monotonic(&now);
this->roam_lock->lock(this->roam_lock);
this->roam_address |= address;
if (!timercmp(&now, &this->next_roam, >))
{
this->roam_lock->unlock(this->roam_lock);
return;
}
timeval_add_ms(&now, ROAM_DELAY);
this->next_roam = now;
this->roam_lock->unlock(this->roam_lock);
job = (job_t*)callback_job_create((callback_job_cb_t)roam_event,
this, NULL, NULL);
lib->scheduler->schedule_job_ms(lib->scheduler, job, ROAM_DELAY);
}
/**
* check if an interface with a given index is up and usable
*
* this->lock must be locked when calling this function
*/
static bool is_interface_up_and_usable(private_kernel_netlink_net_t *this,
int index)
{
iface_entry_t *iface;
if (this->ifaces->find_first(this->ifaces, iface_entry_by_index,
(void**)&iface, index))
{
return iface_entry_up_and_usable(iface);
}
return FALSE;
}
/**
* unregister the current addr_entry_t from the hashtable it is stored in
*
* this->lock must be locked when calling this function
*/
CALLBACK(addr_entry_unregister, void,
addr_entry_t *addr, va_list args)
{
private_kernel_netlink_net_t *this;
iface_entry_t *iface;
VA_ARGS_VGET(args, iface, this);
if (addr->refcount)
{
addr_map_entry_remove(this->vips, addr, iface);
this->condvar->broadcast(this->condvar);
return;
}
addr_map_entry_remove(this->addrs, addr, iface);
}
/**
* process RTM_NEWLINK/RTM_DELLINK from kernel
*/
static void process_link(private_kernel_netlink_net_t *this,
struct nlmsghdr *hdr, bool event)
{
struct ifinfomsg* msg = NLMSG_DATA(hdr);
struct rtattr *rta = IFLA_RTA(msg);
size_t rtasize = IFLA_PAYLOAD (hdr);
enumerator_t *enumerator;
iface_entry_t *current, *entry = NULL;
char *name = NULL;
bool update = FALSE, update_routes = FALSE;
while (RTA_OK(rta, rtasize))
{
switch (rta->rta_type)
{
case IFLA_IFNAME:
name = RTA_DATA(rta);
break;
}
rta = RTA_NEXT(rta, rtasize);
}
if (!name)
{
name = "(unknown)";
}
this->lock->write_lock(this->lock);
switch (hdr->nlmsg_type)
{
case RTM_NEWLINK:
{
if (!this->ifaces->find_first(this->ifaces, iface_entry_by_index,
(void**)&entry, msg->ifi_index))
{
INIT(entry,
.ifindex = msg->ifi_index,
.addrs = linked_list_create(),
);
this->ifaces->insert_last(this->ifaces, entry);
}
strncpy(entry->ifname, name, IFNAMSIZ);
entry->ifname[IFNAMSIZ-1] = '\0';
entry->usable = charon->kernel->is_interface_usable(charon->kernel,
name);
if (event && entry->usable)
{
if (!(entry->flags & IFF_UP) && (msg->ifi_flags & IFF_UP))
{
update = update_routes = TRUE;
DBG1(DBG_KNL, "interface %s activated", name);
}
if ((entry->flags & IFF_UP) && !(msg->ifi_flags & IFF_UP))
{
update = TRUE;
DBG1(DBG_KNL, "interface %s deactivated", name);
}
}
entry->flags = msg->ifi_flags;
break;
}
case RTM_DELLINK:
{
enumerator = this->ifaces->create_enumerator(this->ifaces);
while (enumerator->enumerate(enumerator, ¤t))
{
if (current->ifindex == msg->ifi_index)
{
if (event && current->usable)
{
update = TRUE;
DBG1(DBG_KNL, "interface %s deleted", current->ifname);
}
/* TODO: move virtual IPs installed on this interface to
* another interface? */
this->ifaces->remove_at(this->ifaces, enumerator);
current->addrs->invoke_function(current->addrs,
addr_entry_unregister, current, this);
iface_entry_destroy(current);
break;
}
}
enumerator->destroy(enumerator);
break;
}
}
this->lock->unlock(this->lock);
if (update_routes && event)
{
queue_route_reinstall(this, strdup(name));
}
if (update && event)
{
fire_roam_event(this, TRUE);
}
}
/**
* process RTM_NEWADDR/RTM_DELADDR from kernel
*/
static void process_addr(private_kernel_netlink_net_t *this,
struct nlmsghdr *hdr, bool event)
{
struct ifaddrmsg* msg = NLMSG_DATA(hdr);
struct rtattr *rta = IFA_RTA(msg);
size_t rtasize = IFA_PAYLOAD (hdr);
host_t *host = NULL;
iface_entry_t *iface;
chunk_t local = chunk_empty, address = chunk_empty;
char *route_ifname = NULL;
bool update = FALSE, found = FALSE, changed = FALSE;
while (RTA_OK(rta, rtasize))
{
switch (rta->rta_type)
{
case IFA_LOCAL:
local.ptr = RTA_DATA(rta);
local.len = RTA_PAYLOAD(rta);
break;
case IFA_ADDRESS:
address.ptr = RTA_DATA(rta);
address.len = RTA_PAYLOAD(rta);
break;
}
rta = RTA_NEXT(rta, rtasize);
}
/* For PPP interfaces, we need the IFA_LOCAL address,
* IFA_ADDRESS is the peers address. But IFA_LOCAL is
* not included in all cases (IPv6?), so fallback to IFA_ADDRESS. */
if (local.ptr)
{
host = host_create_from_chunk(msg->ifa_family, local, 0);
}
else if (address.ptr)
{
host = host_create_from_chunk(msg->ifa_family, address, 0);
}
if (host == NULL)
{ /* bad family? */
return;
}
this->lock->write_lock(this->lock);
if (this->ifaces->find_first(this->ifaces, iface_entry_by_index,
(void**)&iface, msg->ifa_index))
{
addr_map_entry_t *entry, lookup = {
.ip = host,
.iface = iface,
};
addr_entry_t *addr;
entry = this->vips->ht.get(&this->vips->ht, &lookup);
if (entry)
{
if (hdr->nlmsg_type == RTM_NEWADDR)
{ /* mark as installed and signal waiting threads */
entry->addr->installed = TRUE;
}
else
{ /* the address was already marked as uninstalled */
addr = entry->addr;
iface->addrs->remove(iface->addrs, addr, NULL);
addr_map_entry_remove(this->vips, addr, iface);
addr_entry_destroy(addr);
}
/* no roam events etc. for virtual IPs */
this->condvar->broadcast(this->condvar);
this->lock->unlock(this->lock);
host->destroy(host);
return;
}
entry = this->addrs->ht.get(&this->addrs->ht, &lookup);
if (entry)
{
if (hdr->nlmsg_type == RTM_DELADDR)
{
found = TRUE;
addr = entry->addr;
iface->addrs->remove(iface->addrs, addr, NULL);
if (iface->usable)
{
changed = TRUE;
DBG1(DBG_KNL, "%H disappeared from %s", host,
iface->ifname);
}
addr_map_entry_remove(this->addrs, addr, iface);
addr_entry_destroy(addr);
}
else if (entry->addr->flags != msg->ifa_flags)
{
found = TRUE;
entry->addr->flags = msg->ifa_flags;
if (event && iface->usable)
{
changed = TRUE;
DBG1(DBG_KNL, "flags changed for %H on %s", host,
iface->ifname);
}
}
}
else
{
if (hdr->nlmsg_type == RTM_NEWADDR)
{
found = TRUE;
changed = TRUE;
route_ifname = strdup(iface->ifname);
INIT(addr,
.ip = host->clone(host),
.flags = msg->ifa_flags,
.scope = msg->ifa_scope,
);
iface->addrs->insert_last(iface->addrs, addr);
addr_map_entry_add(this->addrs, addr, iface);
if (event && iface->usable)
{
DBG1(DBG_KNL, "%H appeared on %s", host, iface->ifname);
}
}
}
if (found && (iface->flags & IFF_UP))
{
update = TRUE;
}
if (!iface->usable)
{ /* ignore events for interfaces excluded by config */
update = changed = FALSE;
}
}
this->lock->unlock(this->lock);
if (update && event && route_ifname)
{
queue_route_reinstall(this, route_ifname);
}
else
{
free(route_ifname);
}
host->destroy(host);
/* send an update to all IKE_SAs */
if (update && event && changed)
{
fire_roam_event(this, TRUE);
}
}
/**
* process RTM_NEWROUTE and RTM_DELROUTE from kernel
*/
static void process_route(private_kernel_netlink_net_t *this,
struct nlmsghdr *hdr)
{
struct rtmsg* msg = NLMSG_DATA(hdr);
struct rtattr *rta = RTM_RTA(msg);
size_t rtasize = RTM_PAYLOAD(hdr);
uint32_t rta_oif = 0;
host_t *host = NULL;
/* ignore routes added by us or in the local routing table (local addrs) */
if (msg->rtm_table && (msg->rtm_table == this->routing_table ||
msg->rtm_table == RT_TABLE_LOCAL))
{
return;
}
else if (msg->rtm_flags & RTM_F_CLONED)
{ /* ignore cached routes, seem to be created a lot for IPv6 */
return;
}
while (RTA_OK(rta, rtasize))
{
switch (rta->rta_type)
{
#ifdef HAVE_RTA_TABLE
case RTA_TABLE:
/* also check against extended table ID */
if (RTA_PAYLOAD(rta) == sizeof(uint32_t) &&
this->routing_table == *(uint32_t*)RTA_DATA(rta))
{
return;
}
break;
#endif /* HAVE_RTA_TABLE */
case RTA_PREFSRC:
DESTROY_IF(host);
host = host_create_from_chunk(msg->rtm_family,
chunk_create(RTA_DATA(rta), RTA_PAYLOAD(rta)), 0);
break;
case RTA_OIF:
if (RTA_PAYLOAD(rta) == sizeof(rta_oif))
{
rta_oif = *(uint32_t*)RTA_DATA(rta);
}
break;
}
rta = RTA_NEXT(rta, rtasize);
}
this->lock->read_lock(this->lock);
if (rta_oif && !is_interface_up_and_usable(this, rta_oif))
{ /* ignore route changes for interfaces that are ignored or down */
this->lock->unlock(this->lock);
DESTROY_IF(host);
return;
}
if (!host && rta_oif)
{
host = get_interface_address(this, rta_oif, msg->rtm_family,
NULL, NULL);
}
if (!host || is_known_vip(this, host))
{ /* ignore routes added for virtual IPs */
this->lock->unlock(this->lock);
DESTROY_IF(host);
return;
}
this->lock->unlock(this->lock);
fire_roam_event(this, FALSE);
host->destroy(host);
}
/**
* process RTM_NEW|DELRULE from kernel
*/
static void process_rule(private_kernel_netlink_net_t *this,
struct nlmsghdr *hdr)
{
#ifdef HAVE_LINUX_FIB_RULES_H
struct rtmsg* msg = NLMSG_DATA(hdr);
struct rtattr *rta = RTM_RTA(msg);
size_t rtasize = RTM_PAYLOAD(hdr);
/* ignore rules added by us or in the local routing table (local addrs) */
if (msg->rtm_table && (msg->rtm_table == this->routing_table ||
msg->rtm_table == RT_TABLE_LOCAL))
{
return;
}
while (RTA_OK(rta, rtasize))
{
switch (rta->rta_type)
{
case FRA_TABLE:
/* also check against extended table ID */
if (RTA_PAYLOAD(rta) == sizeof(uint32_t) &&
this->routing_table == *(uint32_t*)RTA_DATA(rta))
{
return;
}
break;
}
rta = RTA_NEXT(rta, rtasize);
}
fire_roam_event(this, FALSE);
#endif
}
/**
* Receives events from kernel
*/
static bool receive_events(private_kernel_netlink_net_t *this, int fd,
watcher_event_t event)
{
char response[netlink_get_buflen()];
struct nlmsghdr *hdr = (struct nlmsghdr*)response;
struct sockaddr_nl addr;
socklen_t addr_len = sizeof(addr);
int len;
len = recvfrom(this->socket_events, response, sizeof(response),
MSG_DONTWAIT, (struct sockaddr*)&addr, &addr_len);
if (len < 0)
{
switch (errno)
{
case EINTR:
/* interrupted, try again */
return TRUE;
case EAGAIN:
/* no data ready, select again */
return TRUE;
default:
DBG1(DBG_KNL, "unable to receive from RT event socket %s (%d)",
strerror(errno), errno);
sleep(1);
return TRUE;
}
}
if (addr.nl_pid != 0)
{ /* not from kernel. not interested, try another one */
return TRUE;
}
while (NLMSG_OK(hdr, len))
{
/* looks good so far, dispatch netlink message */
switch (hdr->nlmsg_type)
{
case RTM_NEWADDR:
case RTM_DELADDR:
process_addr(this, hdr, TRUE);
break;
case RTM_NEWLINK:
case RTM_DELLINK:
process_link(this, hdr, TRUE);
break;
case RTM_NEWROUTE:
case RTM_DELROUTE:
if (this->process_route)
{
process_route(this, hdr);
}
break;
case RTM_NEWRULE:
case RTM_DELRULE:
if (this->process_rules)
{
process_rule(this, hdr);
}
break;
default:
break;
}
hdr = NLMSG_NEXT(hdr, len);
}
return TRUE;
}
/** enumerator over addresses */
typedef struct {
private_kernel_netlink_net_t* this;
/** which addresses to enumerate */
kernel_address_type_t which;
} address_enumerator_t;
CALLBACK(address_enumerator_destroy, void,
address_enumerator_t *data)
{
data->this->lock->unlock(data->this->lock);
free(data);
}
CALLBACK(filter_addresses, bool,
address_enumerator_t *data, enumerator_t *orig, va_list args)
{
addr_entry_t *addr;
host_t **out;
VA_ARGS_VGET(args, out);
while (orig->enumerate(orig, &addr))
{
if (!(data->which & ADDR_TYPE_VIRTUAL) && addr->refcount)
{ /* skip virtual interfaces added by us */
continue;
}
if (!(data->which & ADDR_TYPE_REGULAR) && !addr->refcount)
{ /* address is regular, but not requested */
continue;
}
if (addr->flags & IFA_F_DEPRECATED ||
addr->scope >= RT_SCOPE_LINK)
{ /* skip deprecated addresses or those with an unusable scope */
continue;
}
if (!addr->refcount && addr->ip->get_family(addr->ip) == AF_INET6)
{ /* handle non-VIP temporary IPv6 addresses according to config */
bool temporary = (addr->flags & IFA_F_TEMPORARY) == IFA_F_TEMPORARY;
if (data->this->prefer_temporary_addrs != temporary)
{
continue;
}
}
*out = addr->ip;
return TRUE;
}
return FALSE;
}
/**
* enumerator constructor for interfaces
*/
static enumerator_t *create_iface_enumerator(iface_entry_t *iface,
address_enumerator_t *data)
{
return enumerator_create_filter(
iface->addrs->create_enumerator(iface->addrs),
filter_addresses, data, NULL);
}
CALLBACK(filter_interfaces, bool,
address_enumerator_t *data, enumerator_t *orig, va_list args)
{
iface_entry_t *iface, **out;
VA_ARGS_VGET(args, out);
while (orig->enumerate(orig, &iface))
{
if (!(data->which & ADDR_TYPE_IGNORED) && !iface->usable)
{ /* skip interfaces excluded by config */
continue;
}
if (!(data->which & ADDR_TYPE_LOOPBACK) && (iface->flags & IFF_LOOPBACK))
{ /* ignore loopback devices */
continue;
}
if (!(data->which & ADDR_TYPE_DOWN) && !(iface->flags & IFF_UP))
{ /* skip interfaces not up */
continue;
}
*out = iface;
return TRUE;
}
return FALSE;
}
METHOD(kernel_net_t, create_address_enumerator, enumerator_t*,
private_kernel_netlink_net_t *this, kernel_address_type_t which)
{
address_enumerator_t *data;
INIT(data,
.this = this,
.which = which,
);
this->lock->read_lock(this->lock);
return enumerator_create_nested(
enumerator_create_filter(
this->ifaces->create_enumerator(this->ifaces),
filter_interfaces, data, NULL),
(void*)create_iface_enumerator, data,
address_enumerator_destroy);
}
METHOD(kernel_net_t, get_interface_name, bool,
private_kernel_netlink_net_t *this, host_t* ip, char **name)
{
addr_map_entry_t *entry, lookup = {
.ip = ip,
};
if (ip->is_anyaddr(ip))
{
return FALSE;
}
this->lock->read_lock(this->lock);
/* first try to find it on an up and usable interface */
entry = this->addrs->get_match(this->addrs, &lookup,
(void*)addr_map_entry_match_up_and_usable);
if (entry)
{
if (name)
{
*name = strdup(entry->iface->ifname);
DBG2(DBG_KNL, "%H is on interface %s", ip, *name);
}
this->lock->unlock(this->lock);
return TRUE;
}
/* in a second step, consider virtual IPs installed by us */
entry = this->vips->get_match(this->vips, &lookup,
(void*)addr_map_entry_match_up_and_usable);
if (entry)
{
if (name)
{
*name = strdup(entry->iface->ifname);
DBG2(DBG_KNL, "virtual IP %H is on interface %s", ip, *name);
}
this->lock->unlock(this->lock);
return TRUE;
}
/* maybe it is installed on an ignored interface */
entry = this->addrs->get_match(this->addrs, &lookup,
(void*)addr_map_entry_match_up);
if (!entry)
{
DBG2(DBG_KNL, "%H is not a local address or the interface is down", ip);
}
this->lock->unlock(this->lock);
return FALSE;
}
/**
* get the index of an interface by name
*/
static int get_interface_index(private_kernel_netlink_net_t *this, char* name)
{
iface_entry_t *iface;
int ifindex = 0;
DBG2(DBG_KNL, "getting iface index for %s", name);
this->lock->read_lock(this->lock);
if (this->ifaces->find_first(this->ifaces, iface_entry_by_name,
(void**)&iface, name))
{
ifindex = iface->ifindex;
}
this->lock->unlock(this->lock);
if (ifindex == 0)
{
DBG1(DBG_KNL, "unable to get interface index for %s", name);
}
return ifindex;
}
/**
* get the name of an interface by index (allocated)
*/
static char *get_interface_name_by_index(private_kernel_netlink_net_t *this,
int index)
{
iface_entry_t *iface;
char *name = NULL;
DBG2(DBG_KNL, "getting iface name for index %d", index);
this->lock->read_lock(this->lock);
if (this->ifaces->find_first(this->ifaces, iface_entry_by_index,
(void**)&iface, index))
{
name = strdup(iface->ifname);
}
this->lock->unlock(this->lock);
if (!name)
{
DBG1(DBG_KNL, "unable to get interface name for %d", index);
}
return name;
}
/**
* Store information about a route retrieved via RTNETLINK
*/
typedef struct {
chunk_t gtw;
chunk_t pref_src;
chunk_t dst;
chunk_t src;
host_t *src_host;
uint8_t dst_len;
uint8_t src_len;
uint32_t table;
uint32_t oif;
uint32_t priority;
} rt_entry_t;
/**
* Free a route entry
*/
static void rt_entry_destroy(rt_entry_t *this)
{
DESTROY_IF(this->src_host);
free(this);
}
/**
* Check if the route received with RTM_NEWROUTE is usable based on its type.
*/
static bool route_usable(struct nlmsghdr *hdr, bool allow_local)
{
struct rtmsg *msg;
msg = NLMSG_DATA(hdr);
switch (msg->rtm_type)
{
case RTN_BLACKHOLE:
case RTN_UNREACHABLE:
case RTN_PROHIBIT:
case RTN_THROW:
return FALSE;
case RTN_LOCAL:
return allow_local;
default:
return TRUE;
}
}
/**
* Parse route received with RTM_NEWROUTE. The given rt_entry_t object will be
* reused if not NULL.
*
* Returned chunks point to internal data of the Netlink message.
*/
static rt_entry_t *parse_route(struct nlmsghdr *hdr, rt_entry_t *route)
{
struct rtattr *rta;
struct rtmsg *msg;
size_t rtasize;
msg = NLMSG_DATA(hdr);
rta = RTM_RTA(msg);
rtasize = RTM_PAYLOAD(hdr);
if (route)
{
*route = (rt_entry_t){
.dst_len = msg->rtm_dst_len,
.src_len = msg->rtm_src_len,
.table = msg->rtm_table,
};
}
else
{
INIT(route,
.dst_len = msg->rtm_dst_len,
.src_len = msg->rtm_src_len,
.table = msg->rtm_table,
);
}
while (RTA_OK(rta, rtasize))
{
switch (rta->rta_type)
{
case RTA_PREFSRC:
route->pref_src = chunk_create(RTA_DATA(rta), RTA_PAYLOAD(rta));
break;
case RTA_GATEWAY:
route->gtw = chunk_create(RTA_DATA(rta), RTA_PAYLOAD(rta));
break;
case RTA_DST:
route->dst = chunk_create(RTA_DATA(rta), RTA_PAYLOAD(rta));
break;
case RTA_SRC:
route->src = chunk_create(RTA_DATA(rta), RTA_PAYLOAD(rta));
break;
case RTA_OIF:
if (RTA_PAYLOAD(rta) == sizeof(route->oif))
{
route->oif = *(uint32_t*)RTA_DATA(rta);
}
break;
case RTA_PRIORITY:
if (RTA_PAYLOAD(rta) == sizeof(route->priority))
{
route->priority = *(uint32_t*)RTA_DATA(rta);
}
break;
#ifdef HAVE_RTA_TABLE
case RTA_TABLE:
if (RTA_PAYLOAD(rta) == sizeof(route->table))
{
route->table = *(uint32_t*)RTA_DATA(rta);
}
break;
#endif /* HAVE_RTA_TABLE*/
}
rta = RTA_NEXT(rta, rtasize);
}
return route;
}
/**
* Get a route: If "nexthop", the nexthop is returned. source addr otherwise.
*/
static host_t *get_route(private_kernel_netlink_net_t *this, host_t *dest,
int prefix, bool nexthop, host_t *candidate,
char **iface, u_int recursion)
{
netlink_buf_t request;
struct nlmsghdr *hdr, *out, *current;
struct rtmsg *msg;
chunk_t chunk;
size_t len;
linked_list_t *routes;
rt_entry_t *route = NULL, *best = NULL;
enumerator_t *enumerator;
host_t *addr = NULL;
bool match_net;
int family;
if (recursion > MAX_ROUTE_RECURSION)
{
return NULL;
}
chunk = dest->get_address(dest);
len = chunk.len * 8;
prefix = prefix < 0 ? len : min(prefix, len);
match_net = prefix != len;
memset(&request, 0, sizeof(request));
family = dest->get_family(dest);
hdr = &request.hdr;
hdr->nlmsg_flags = NLM_F_REQUEST;
hdr->nlmsg_type = RTM_GETROUTE;
hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
msg = NLMSG_DATA(hdr);
msg->rtm_family = family;
if (!match_net && this->rta_mark && this->routing_mark.value)
{
/* if our routing rule excludes packets with a certain mark we can
* get the preferred route without having to dump all routes */
chunk = chunk_from_thing(this->routing_mark.value);
netlink_add_attribute(hdr, RTA_MARK, chunk, sizeof(request));
}
else if (family == AF_INET || this->rta_prefsrc_for_ipv6 ||
this->routing_table || match_net)
{ /* kernels prior to 3.0 do not support RTA_PREFSRC for IPv6 routes.
* as we want to ignore routes with virtual IPs we cannot use DUMP
* if these routes are not installed in a separate table */
if (this->install_routes)
{
hdr->nlmsg_flags |= NLM_F_DUMP;
}
}
if (candidate)
{
chunk = candidate->get_address(candidate);
if (hdr->nlmsg_flags & NLM_F_DUMP)
{
netlink_add_attribute(hdr, RTA_PREFSRC, chunk, sizeof(request));
}
else
{
netlink_add_attribute(hdr, RTA_SRC, chunk, sizeof(request));
}
}
/* we use this below to match against the routes */
chunk = dest->get_address(dest);
if (!match_net)
{
netlink_add_attribute(hdr, RTA_DST, chunk, sizeof(request));
}
if (this->socket->send(this->socket, hdr, &out, &len) != SUCCESS)
{
DBG2(DBG_KNL, "getting %s to reach %H/%d failed",
nexthop ? "nexthop" : "address", dest, prefix);
return NULL;
}
routes = linked_list_create();
this->lock->read_lock(this->lock);
for (current = out; NLMSG_OK(current, len);
current = NLMSG_NEXT(current, len))
{
switch (current->nlmsg_type)
{
case NLMSG_DONE:
break;
case RTM_NEWROUTE:
{
rt_entry_t *other;
uintptr_t table;
if (!route_usable(current, TRUE))
{
continue;
}
route = parse_route(current, route);
table = (uintptr_t)route->table;
if (this->rt_exclude->find_first(this->rt_exclude, NULL,
(void**)&table))
{ /* route is from an excluded routing table */
continue;
}
if (this->routing_table != 0 &&
route->table == this->routing_table)
{ /* route is from our own ipsec routing table */
continue;
}
if (route->oif && !is_interface_up_and_usable(this, route->oif))
{ /* interface is down */
continue;
}
if (!addr_in_subnet(chunk, prefix, route->dst, route->dst_len))
{ /* route destination does not contain dest */
continue;
}
if (route->pref_src.ptr)
{ /* verify source address, if any */
host_t *src = host_create_from_chunk(msg->rtm_family,
route->pref_src, 0);
if (src && is_known_vip(this, src))
{ /* ignore routes installed by us */
src->destroy(src);
continue;
}
route->src_host = src;
}
/* insert route, sorted by network prefix and priority */
enumerator = routes->create_enumerator(routes);
while (enumerator->enumerate(enumerator, &other))
{
if (route->dst_len > other->dst_len)
{
break;
}
if (route->dst_len == other->dst_len &&
route->priority < other->priority)
{
break;
}
}
routes->insert_before(routes, enumerator, route);
enumerator->destroy(enumerator);
route = NULL;
continue;
}
default:
continue;
}
break;
}
if (route)
{
rt_entry_destroy(route);
}
/* now we have a list of routes matching dest, sorted by net prefix.
* we will look for source addresses for these routes and select the one
* with the preferred source address, if possible */
enumerator = routes->create_enumerator(routes);
while (enumerator->enumerate(enumerator, &route))
{
if (route->src_host)
{ /* got a source address with the route, if no preferred source
* is given or it matches we are done, as this is the best route */
if (!candidate || candidate->ip_equals(candidate, route->src_host))
{
best = route;
break;
}
else if (route->oif)
{ /* no match yet, maybe it is assigned to the same interface */
host_t *src = get_interface_address(this, route->oif,
msg->rtm_family, dest, candidate);
if (src && src->ip_equals(src, candidate))
{
route->src_host->destroy(route->src_host);
route->src_host = src;
best = route;
break;
}
DESTROY_IF(src);
}
/* no luck yet with the source address. if this is the best (first)
* route we store it as fallback in case we don't find a route with
* the preferred source */
best = best ?: route;
continue;
}
if (route->src.ptr)
{ /* no src, but a source selector, try to find a matching address */
route->src_host = get_subnet_address(this, msg->rtm_family,
route->src, route->src_len, dest,
candidate);
if (route->src_host)
{ /* we handle this address the same as the one above */
if (!candidate ||
candidate->ip_equals(candidate, route->src_host))
{
best = route;
break;
}
best = best ?: route;
continue;
}
}
if (route->oif)
{ /* no src, but an interface - get address from it */
route->src_host = get_interface_address(this, route->oif,
msg->rtm_family, dest, candidate);
if (route->src_host)
{ /* more of the same */
if (!candidate ||
candidate->ip_equals(candidate, route->src_host))
{
best = route;
break;
}
best = best ?: route;
continue;
}
}
if (route->gtw.ptr)
{ /* no src, no iface, but a gateway - lookup src to reach gtw */
host_t *gtw;
gtw = host_create_from_chunk(msg->rtm_family, route->gtw, 0);
if (gtw && !gtw->ip_equals(gtw, dest))
{
route->src_host = get_route(this, gtw, -1, FALSE, candidate,
iface, recursion + 1);
}
DESTROY_IF(gtw);
if (route->src_host)
{ /* more of the same */
if (!candidate ||
candidate->ip_equals(candidate, route->src_host))
{
best = route;
break;
}
best = best ?: route;
}
}
}
enumerator->destroy(enumerator);
if (nexthop)
{ /* nexthop lookup, return gateway and oif if any */
if (iface)
{
*iface = NULL;
}
if (best || routes->get_first(routes, (void**)&best) == SUCCESS)
{
addr = host_create_from_chunk(msg->rtm_family, best->gtw, 0);
if (iface && best->oif)
{
*iface = get_interface_name_by_index(this, best->oif);
}
}
if (!addr && !match_net)
{ /* fallback to destination address */
addr = dest->clone(dest);
}
}
else
{
if (best)
{
addr = best->src_host->clone(best->src_host);
}
}
this->lock->unlock(this->lock);
routes->destroy_function(routes, (void*)rt_entry_destroy);
free(out);
if (addr)
{
if (nexthop && iface && *iface)
{
DBG2(DBG_KNL, "using %H as nexthop and %s as dev to reach %H/%d",
addr, *iface, dest, prefix);
}
else
{
DBG2(DBG_KNL, "using %H as %s to reach %H/%d", addr,
nexthop ? "nexthop" : "address", dest, prefix);
}
}
else if (!recursion)
{
DBG2(DBG_KNL, "no %s found to reach %H/%d",
nexthop ? "nexthop" : "address", dest, prefix);
}
return addr;
}
METHOD(kernel_net_t, get_source_addr, host_t*,
private_kernel_netlink_net_t *this, host_t *dest, host_t *src)
{
return get_route(this, dest, -1, FALSE, src, NULL, 0);
}
METHOD(kernel_net_t, get_nexthop, host_t*,
private_kernel_netlink_net_t *this, host_t *dest, int prefix, host_t *src,
char **iface)
{
return get_route(this, dest, prefix, TRUE, src, iface, 0);
}
/** enumerator over subnets */
typedef struct {
enumerator_t public;
private_kernel_netlink_net_t *private;
/** message from the kernel */
struct nlmsghdr *msg;
/** current message from the kernel */
struct nlmsghdr *current;
/** remaining length */
size_t len;
/** last subnet enumerated */
host_t *net;
/** interface of current net */
char ifname[IFNAMSIZ];
} subnet_enumerator_t;
METHOD(enumerator_t, destroy_subnet_enumerator, void,
subnet_enumerator_t *this)
{
DESTROY_IF(this->net);
free(this->msg);
free(this);
}
METHOD(enumerator_t, enumerate_subnets, bool,
subnet_enumerator_t *this, va_list args)
{
host_t **net;
uint8_t *mask;
char **ifname;
VA_ARGS_VGET(args, net, mask, ifname);
if (!this->current)
{
this->current = this->msg;
}
else
{
this->current = NLMSG_NEXT(this->current, this->len);
DESTROY_IF(this->net);
this->net = NULL;
}
while (NLMSG_OK(this->current, this->len))
{
switch (this->current->nlmsg_type)
{
case NLMSG_DONE:
break;
case RTM_NEWROUTE:
{
rt_entry_t route;
if (!route_usable(this->current, FALSE))
{
break;
}
parse_route(this->current, &route);
if (route.table && (
route.table == RT_TABLE_LOCAL ||
route.table == this->private->routing_table))
{ /* ignore our own and the local routing tables */
break;
}
else if (route.gtw.ptr)
{ /* ignore routes via gateway/next hop */
break;
}
if (route.dst.ptr && route.oif &&
if_indextoname(route.oif, this->ifname))
{
this->net = host_create_from_chunk(AF_UNSPEC, route.dst, 0);
*net = this->net;
*mask = route.dst_len;
*ifname = this->ifname;
return TRUE;
}
break;
}
default:
break;
}
this->current = NLMSG_NEXT(this->current, this->len);
}
return FALSE;
}
METHOD(kernel_net_t, create_local_subnet_enumerator, enumerator_t*,
private_kernel_netlink_net_t *this)
{
netlink_buf_t request;
struct nlmsghdr *hdr, *out;
struct rtmsg *msg;
size_t len;
subnet_enumerator_t *enumerator;
memset(&request, 0, sizeof(request));
hdr = &request.hdr;
hdr->nlmsg_flags = NLM_F_REQUEST;
hdr->nlmsg_type = RTM_GETROUTE;
hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
hdr->nlmsg_flags |= NLM_F_DUMP;
msg = NLMSG_DATA(hdr);
msg->rtm_scope = RT_SCOPE_LINK;
if (this->socket->send(this->socket, hdr, &out, &len) != SUCCESS)
{
DBG2(DBG_KNL, "enumerating local subnets failed");
return enumerator_create_empty();
}
INIT(enumerator,
.public = {
.enumerate = enumerator_enumerate_default,
.venumerate = _enumerate_subnets,
.destroy = _destroy_subnet_enumerator,
},
.private = this,
.msg = out,
.len = len,
);
return &enumerator->public;
}
/**
* Manages the creation and deletion of IPv6 address labels for virtual IPs.
* By setting the appropriate nlmsg_type the label is either added or removed.
*/
static status_t manage_addrlabel(private_kernel_netlink_net_t *this,
int nlmsg_type, host_t *ip)
{
netlink_buf_t request;
struct nlmsghdr *hdr;
struct ifaddrlblmsg *msg;
chunk_t chunk;
uint32_t label;
memset(&request, 0, sizeof(request));
chunk = ip->get_address(ip);
hdr = &request.hdr;
hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
if (nlmsg_type == RTM_NEWADDRLABEL)
{
hdr->nlmsg_flags |= NLM_F_CREATE | NLM_F_EXCL;
}
hdr->nlmsg_type = nlmsg_type;
hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrlblmsg));
msg = NLMSG_DATA(hdr);
msg->ifal_family = ip->get_family(ip);
msg->ifal_prefixlen = chunk.len * 8;
netlink_add_attribute(hdr, IFAL_ADDRESS, chunk, sizeof(request));
/* doesn't really matter as default labels are < 20 but this makes it kinda
* recognizable */
label = 220;
netlink_add_attribute(hdr, IFAL_LABEL, chunk_from_thing(label),
sizeof(request));
return this->socket->send_ack(this->socket, hdr);
}
/**
* Manages the creation and deletion of ip addresses on an interface.
* By setting the appropriate nlmsg_type, the ip will be set or unset.
*/
static status_t manage_ipaddr(private_kernel_netlink_net_t *this, int nlmsg_type,
int flags, int if_index, host_t *ip, int prefix)
{
netlink_buf_t request;
struct nlmsghdr *hdr;
struct ifaddrmsg *msg;
chunk_t chunk;
memset(&request, 0, sizeof(request));
chunk = ip->get_address(ip);
hdr = &request.hdr;
hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags;
hdr->nlmsg_type = nlmsg_type;
hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
msg = NLMSG_DATA(hdr);
msg->ifa_family = ip->get_family(ip);
msg->ifa_flags = 0;
msg->ifa_prefixlen = prefix < 0 ? chunk.len * 8 : prefix;
msg->ifa_scope = RT_SCOPE_UNIVERSE;
msg->ifa_index = if_index;
netlink_add_attribute(hdr, IFA_LOCAL, chunk, sizeof(request));
if (ip->get_family(ip) == AF_INET6)
{
#ifdef IFA_F_NODAD
msg->ifa_flags |= IFA_F_NODAD;
#endif
if (this->rta_prefsrc_for_ipv6)
{
/* if source routes are possible we set a label for this virtual IP
* so it gets only used if forced by our route, and not by the
* default IPv6 address selection */
int labelop = nlmsg_type == RTM_NEWADDR ? RTM_NEWADDRLABEL
: RTM_DELADDRLABEL;
if (manage_addrlabel(this, labelop, ip) != SUCCESS)
{
/* if we can't use address labels we let the virtual IP get
* deprecated immediately (but mark it as valid forever), which
* should also avoid that it gets used by the default address
* selection */
struct ifa_cacheinfo cache = {
.ifa_valid = 0xFFFFFFFF,
.ifa_prefered = 0,
};
netlink_add_attribute(hdr, IFA_CACHEINFO,
chunk_from_thing(cache), sizeof(request));
}
}
}
return this->socket->send_ack(this->socket, hdr);
}
METHOD(kernel_net_t, add_ip, status_t,
private_kernel_netlink_net_t *this, host_t *virtual_ip, int prefix,
char *iface_name)
{
addr_map_entry_t *entry, lookup = {
.ip = virtual_ip,
};
iface_entry_t *iface = NULL;
if (!this->install_virtual_ip)
{ /* disabled by config */
return SUCCESS;
}
this->lock->write_lock(this->lock);
/* the virtual IP might actually be installed as regular IP, in which case
* we don't track it as virtual IP */
entry = this->addrs->get_match(this->addrs, &lookup,
(void*)addr_map_entry_match);
if (!entry)
{ /* otherwise it might already be installed as virtual IP */
entry = this->vips->get_match(this->vips, &lookup,
(void*)addr_map_entry_match);
if (entry)
{ /* the vip we found can be in one of three states: 1) installed and
* ready, 2) just added by another thread, but not yet confirmed to
* be installed by the kernel, 3) just deleted, but not yet gone.
* Then while we wait below, several things could happen (as we
* release the lock). For instance, the interface could disappear,
* or the IP is finally deleted, and it reappears on a different
* interface. All these cases are handled by the call below. */
while (!is_vip_installed_or_gone(this, virtual_ip, &entry))
{
this->condvar->wait(this->condvar, this->lock);
}
if (entry)
{
entry->addr->refcount++;
}
}
}
if (entry)
{
DBG2(DBG_KNL, "virtual IP %H is already installed on %s", virtual_ip,
entry->iface->ifname);
this->lock->unlock(this->lock);
return SUCCESS;
}
/* try to find the target interface, either by config or via src ip */
if (!this->install_virtual_ip_on ||
!this->ifaces->find_first(this->ifaces, iface_entry_by_name,
(void**)&iface, this->install_virtual_ip_on))
{
if (!this->ifaces->find_first(this->ifaces, iface_entry_by_name,
(void**)&iface, iface_name))
{ /* if we don't find the requested interface we just use the first */
this->ifaces->get_first(this->ifaces, (void**)&iface);
}
}
if (iface)
{
addr_entry_t *addr;
char *ifname;
int ifi;
INIT(addr,
.ip = virtual_ip->clone(virtual_ip),
.refcount = 1,
.scope = RT_SCOPE_UNIVERSE,
);
iface->addrs->insert_last(iface->addrs, addr);
addr_map_entry_add(this->vips, addr, iface);
ifi = iface->ifindex;
this->lock->unlock(this->lock);
if (manage_ipaddr(this, RTM_NEWADDR, NLM_F_CREATE | NLM_F_EXCL,
ifi, virtual_ip, prefix) == SUCCESS)
{
this->lock->write_lock(this->lock);
while (!is_vip_installed_or_gone(this, virtual_ip, &entry))
{ /* wait until address appears */
this->condvar->wait(this->condvar, this->lock);
}
if (entry)
{ /* we fail if the interface got deleted in the meantime */
ifname = strdup(entry->iface->ifname);
this->lock->unlock(this->lock);
DBG2(DBG_KNL, "virtual IP %H installed on %s",
virtual_ip, ifname);
/* during IKEv1 reauthentication, children get moved from
* old the new SA before the virtual IP is available. This
* kills the route for our virtual IP, reinstall. */
queue_route_reinstall(this, ifname);
return SUCCESS;
}
this->lock->unlock(this->lock);
}
DBG1(DBG_KNL, "adding virtual IP %H failed", virtual_ip);
return FAILED;
}
this->lock->unlock(this->lock);
DBG1(DBG_KNL, "no interface available, unable to install virtual IP %H",
virtual_ip);
return FAILED;
}
METHOD(kernel_net_t, del_ip, status_t,
private_kernel_netlink_net_t *this, host_t *virtual_ip, int prefix,
bool wait)
{
addr_map_entry_t *entry, lookup = {
.ip = virtual_ip,
};
if (!this->install_virtual_ip)
{ /* disabled by config */
return SUCCESS;
}
DBG2(DBG_KNL, "deleting virtual IP %H", virtual_ip);
this->lock->write_lock(this->lock);
entry = this->vips->get_match(this->vips, &lookup,
(void*)addr_map_entry_match);
if (!entry)
{ /* we didn't install this IP as virtual IP */
entry = this->addrs->get_match(this->addrs, &lookup,
(void*)addr_map_entry_match);
if (entry)
{
DBG2(DBG_KNL, "not deleting existing IP %H on %s", virtual_ip,
entry->iface->ifname);
this->lock->unlock(this->lock);
return SUCCESS;
}
DBG2(DBG_KNL, "virtual IP %H not cached, unable to delete", virtual_ip);
this->lock->unlock(this->lock);
return FAILED;
}
if (entry->addr->refcount == 1)
{
status_t status;
int ifi;
/* we set this flag so that threads calling add_ip will block and wait
* until the entry is gone, also so we can wait below */
entry->addr->installed = FALSE;
ifi = entry->iface->ifindex;
this->lock->unlock(this->lock);
status = manage_ipaddr(this, RTM_DELADDR, 0, ifi, virtual_ip, prefix);
if (status == SUCCESS && wait)
{ /* wait until the address is really gone */
this->lock->write_lock(this->lock);
while (is_known_vip(this, virtual_ip))
{
this->condvar->wait(this->condvar, this->lock);
}
this->lock->unlock(this->lock);
}
return status;
}
else
{
entry->addr->refcount--;
}
DBG2(DBG_KNL, "virtual IP %H used by other SAs, not deleting",
virtual_ip);
this->lock->unlock(this->lock);
return SUCCESS;
}
/**
* Manages source routes in the routing table.
* By setting the appropriate nlmsg_type, the route gets added or removed.
*/
static status_t manage_srcroute(private_kernel_netlink_net_t *this,
int nlmsg_type, int flags, chunk_t dst_net,
uint8_t prefixlen, host_t *gateway,
host_t *src_ip, char *if_name, bool pass)
{
netlink_buf_t request;
struct nlmsghdr *hdr;
struct rtmsg *msg;
struct rtattr *rta;
int ifindex;
chunk_t chunk;
/* if route is 0.0.0.0/0, we can't install it, as it would
* overwrite the default route. Instead, we add two routes:
* 0.0.0.0/1 and 128.0.0.0/1 */
if (this->routing_table == 0 && prefixlen == 0)
{
chunk_t half_net;
uint8_t half_prefixlen;
status_t status;
half_net = chunk_alloca(dst_net.len);
memset(half_net.ptr, 0, half_net.len);
half_prefixlen = 1;
/* no throw routes in the main table */
status = manage_srcroute(this, nlmsg_type, flags, half_net,
half_prefixlen, gateway, src_ip, if_name, FALSE);
half_net.ptr[0] |= 0x80;
status |= manage_srcroute(this, nlmsg_type, flags, half_net,
half_prefixlen, gateway, src_ip, if_name, FALSE);
return status;
}
memset(&request, 0, sizeof(request));
hdr = &request.hdr;
hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags;
hdr->nlmsg_type = nlmsg_type;
hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
msg = NLMSG_DATA(hdr);
msg->rtm_family = (dst_net.len == 4) ? AF_INET : AF_INET6;
msg->rtm_dst_len = prefixlen;
msg->rtm_protocol = RTPROT_STATIC;
msg->rtm_type = pass ? RTN_THROW : RTN_UNICAST;
msg->rtm_scope = RT_SCOPE_UNIVERSE;
if (this->routing_table < 256)
{
msg->rtm_table = this->routing_table;
}
else
{
#ifdef HAVE_RTA_TABLE
chunk = chunk_from_thing(this->routing_table);
netlink_add_attribute(hdr, RTA_TABLE, chunk, sizeof(request));
#else
DBG1(DBG_KNL, "routing table IDs > 255 are not supported");
return FAILED;
#endif /* HAVE_RTA_TABLE */
}
netlink_add_attribute(hdr, RTA_DST, dst_net, sizeof(request));
/* only when installing regular routes do we need all the parameters,
* deletes are done by destination net (except if metrics are used, which
* we don't support), for throw routes we don't need any of them either */
if (nlmsg_type == RTM_NEWROUTE && !pass)
{
chunk = src_ip->get_address(src_ip);
netlink_add_attribute(hdr, RTA_PREFSRC, chunk, sizeof(request));
if (gateway && gateway->get_family(gateway) == src_ip->get_family(src_ip))
{
chunk = gateway->get_address(gateway);
netlink_add_attribute(hdr, RTA_GATEWAY, chunk, sizeof(request));
}
ifindex = get_interface_index(this, if_name);
chunk.ptr = (char*)&ifindex;
chunk.len = sizeof(ifindex);
netlink_add_attribute(hdr, RTA_OIF, chunk, sizeof(request));
if (this->mtu || this->mss)
{
chunk = chunk_alloca(RTA_LENGTH((sizeof(struct rtattr) +
sizeof(uint32_t)) * 2));
chunk.len = 0;
rta = (struct rtattr*)chunk.ptr;
if (this->mtu)
{
rta->rta_type = RTAX_MTU;
rta->rta_len = RTA_LENGTH(sizeof(uint32_t));
memcpy(RTA_DATA(rta), &this->mtu, sizeof(uint32_t));
chunk.len = rta->rta_len;
}
if (this->mss)
{
rta = (struct rtattr*)(chunk.ptr + RTA_ALIGN(chunk.len));
rta->rta_type = RTAX_ADVMSS;
rta->rta_len = RTA_LENGTH(sizeof(uint32_t));
memcpy(RTA_DATA(rta), &this->mss, sizeof(uint32_t));
chunk.len = RTA_ALIGN(chunk.len) + rta->rta_len;
}
netlink_add_attribute(hdr, RTA_METRICS, chunk, sizeof(request));
}
}
return this->socket->send_ack(this->socket, hdr);
}
/**
* Helper struct used to check routes
*/
typedef struct {
/** the entry we look for */
route_entry_t route;
/** kernel interface */
private_kernel_netlink_net_t *this;
} route_entry_lookup_t;
/**
* Check if a matching route entry has a VIP associated
*/
static bool route_with_vip(route_entry_lookup_t *a, route_entry_t *b)
{
if (chunk_equals(a->route.dst_net, b->dst_net) &&
a->route.prefixlen == b->prefixlen &&
is_known_vip(a->this, b->src_ip))
{
return TRUE;
}
return FALSE;
}
/**
* Check if there is any route entry with a matching destination
*/
static bool route_with_dst(route_entry_lookup_t *a, route_entry_t *b)
{
if (chunk_equals(a->route.dst_net, b->dst_net) &&
a->route.prefixlen == b->prefixlen)
{
return TRUE;
}
return FALSE;
}
METHOD(kernel_net_t, add_route, status_t,
private_kernel_netlink_net_t *this, chunk_t dst_net, uint8_t prefixlen,
host_t *gateway, host_t *src_ip, char *if_name, bool pass)
{
status_t status;
route_entry_t *found;
route_entry_lookup_t lookup = {
.route = {
.dst_net = dst_net,
.prefixlen = prefixlen,
.gateway = gateway,
.src_ip = src_ip,
.if_name = if_name,
.pass = pass,
},
.this = this,
};
if (!this->routing_table)
{ /* treat these as regular routes if installing in the main table */
pass = lookup.route.pass = FALSE;
}
this->routes_lock->lock(this->routes_lock);
found = this->routes->ht.get(&this->routes->ht, &lookup.route);
if (found)
{
this->routes_lock->unlock(this->routes_lock);
return ALREADY_DONE;
}
/* don't replace the route if we already have one with a VIP installed,
* but keep track of it in case that other route is uninstalled */
this->lock->read_lock(this->lock);
if (!is_known_vip(this, src_ip))
{
found = this->routes->get_match(this->routes, &lookup,
(void*)route_with_vip);
}
this->lock->unlock(this->lock);
if (found)
{
status = SUCCESS;
}
else
{
status = manage_srcroute(this, RTM_NEWROUTE, NLM_F_CREATE|NLM_F_REPLACE,
dst_net, prefixlen, gateway, src_ip, if_name,
pass);
}
if (status == SUCCESS)
{
found = route_entry_clone(&lookup.route);
this->routes->ht.put(&this->routes->ht, found, found);
}
this->routes_lock->unlock(this->routes_lock);
return status;
}
METHOD(kernel_net_t, del_route, status_t,
private_kernel_netlink_net_t *this, chunk_t dst_net, uint8_t prefixlen,
host_t *gateway, host_t *src_ip, char *if_name, bool pass)
{
status_t status;
route_entry_t *found;
route_entry_lookup_t lookup = {
.route = {
.dst_net = dst_net,
.prefixlen = prefixlen,
.gateway = gateway,
.src_ip = src_ip,
.if_name = if_name,
.pass = pass,
},
.this = this,
};
if (!this->routing_table)
{ /* treat these as regular routes if installing in the main table */
pass = lookup.route.pass = FALSE;
}
this->routes_lock->lock(this->routes_lock);
found = this->routes->ht.remove(&this->routes->ht, &lookup.route);
if (!found)
{
this->routes_lock->unlock(this->routes_lock);
return NOT_FOUND;
}
route_entry_destroy(found);
/* check if there are any other routes for the same destination and if
* so update the route, otherwise uninstall it */
this->lock->read_lock(this->lock);
found = this->routes->get_match(this->routes, &lookup,
(void*)route_with_vip);
this->lock->unlock(this->lock);
if (!found)
{
found = this->routes->get_match(this->routes, &lookup,
(void*)route_with_dst);
}
if (found)
{
status = manage_srcroute(this, RTM_NEWROUTE, NLM_F_CREATE|NLM_F_REPLACE,
found->dst_net, found->prefixlen, found->gateway,
found->src_ip, found->if_name, found->pass);
}
else
{
status = manage_srcroute(this, RTM_DELROUTE, 0, dst_net, prefixlen,
gateway, src_ip, if_name, pass);
}
this->routes_lock->unlock(this->routes_lock);
return status;
}
/**
* Initialize a list of local addresses.
*/
static status_t init_address_list(private_kernel_netlink_net_t *this)
{
netlink_buf_t request;
struct nlmsghdr *out, *current, *in;
struct rtgenmsg *msg;
size_t len;
enumerator_t *ifaces, *addrs;
iface_entry_t *iface;
addr_entry_t *addr;
DBG2(DBG_KNL, "known interfaces and IP addresses:");
memset(&request, 0, sizeof(request));
in = &request.hdr;
in->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg));
in->nlmsg_flags = NLM_F_REQUEST | NLM_F_MATCH | NLM_F_ROOT;
msg = NLMSG_DATA(in);
msg->rtgen_family = AF_UNSPEC;
/* get all links */
in->nlmsg_type = RTM_GETLINK;
if (this->socket->send(this->socket, in, &out, &len) != SUCCESS)
{
return FAILED;
}
current = out;
while (NLMSG_OK(current, len))
{
switch (current->nlmsg_type)
{
case NLMSG_DONE:
break;
case RTM_NEWLINK:
process_link(this, current, FALSE);
/* fall through */
default:
current = NLMSG_NEXT(current, len);
continue;
}
break;
}
free(out);
/* get all interface addresses */
in->nlmsg_type = RTM_GETADDR;
if (this->socket->send(this->socket, in, &out, &len) != SUCCESS)
{
return FAILED;
}
current = out;
while (NLMSG_OK(current, len))
{
switch (current->nlmsg_type)
{
case NLMSG_DONE:
break;
case RTM_NEWADDR:
process_addr(this, current, FALSE);
/* fall through */
default:
current = NLMSG_NEXT(current, len);
continue;
}
break;
}
free(out);
this->lock->read_lock(this->lock);
ifaces = this->ifaces->create_enumerator(this->ifaces);
while (ifaces->enumerate(ifaces, &iface))
{
if (iface_entry_up_and_usable(iface))
{
DBG2(DBG_KNL, " %s", iface->ifname);
addrs = iface->addrs->create_enumerator(iface->addrs);
while (addrs->enumerate(addrs, (void**)&addr))
{
DBG2(DBG_KNL, " %H", addr->ip);
}
addrs->destroy(addrs);
}
}
ifaces->destroy(ifaces);
this->lock->unlock(this->lock);
return SUCCESS;
}
/**
* create or delete a rule to use our routing table
*/
static status_t manage_rule(private_kernel_netlink_net_t *this, int nlmsg_type,
int family, uint32_t table, uint32_t prio)
{
netlink_buf_t request;
struct nlmsghdr *hdr;
struct rtmsg *msg;
chunk_t chunk;
char *fwmark;
memset(&request, 0, sizeof(request));
hdr = &request.hdr;
hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
hdr->nlmsg_type = nlmsg_type;
if (nlmsg_type == RTM_NEWRULE)
{
hdr->nlmsg_flags |= NLM_F_CREATE | NLM_F_EXCL;
}
hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
msg = NLMSG_DATA(hdr);
msg->rtm_family = family;
msg->rtm_protocol = RTPROT_BOOT;
msg->rtm_scope = RT_SCOPE_UNIVERSE;
msg->rtm_type = RTN_UNICAST;
if (this->routing_table < 256)
{
msg->rtm_table = table;
}
else
{
#ifdef HAVE_LINUX_FIB_RULES_H
chunk = chunk_from_thing(table);
netlink_add_attribute(hdr, FRA_TABLE, chunk, sizeof(request));
#else
DBG1(DBG_KNL, "routing table IDs > 255 are not supported");
return FAILED;
#endif /* HAVE_LINUX_FIB_RULES_H */
}
chunk = chunk_from_thing(prio);
netlink_add_attribute(hdr, RTA_PRIORITY, chunk, sizeof(request));
fwmark = lib->settings->get_str(lib->settings,
"%s.plugins.kernel-netlink.fwmark", NULL, lib->ns);
if (fwmark)
{
#ifdef HAVE_LINUX_FIB_RULES_H
mark_t mark;
if (fwmark[0] == '!')
{
msg->rtm_flags |= FIB_RULE_INVERT;
fwmark++;
}
if (mark_from_string(fwmark, MARK_OP_NONE, &mark))
{
chunk = chunk_from_thing(mark.value);
netlink_add_attribute(hdr, FRA_FWMARK, chunk, sizeof(request));
chunk = chunk_from_thing(mark.mask);
netlink_add_attribute(hdr, FRA_FWMASK, chunk, sizeof(request));
if (msg->rtm_flags & FIB_RULE_INVERT)
{
this->routing_mark = mark;
}
}
#else
DBG1(DBG_KNL, "setting firewall mark on routing rule is not supported");
#endif /* HAVE_LINUX_FIB_RULES_H */
}
return this->socket->send_ack(this->socket, hdr);
}
/**
* check for kernel features (currently only via version number)
*/
static void check_kernel_features(private_kernel_netlink_net_t *this)
{
struct utsname utsname;
int a, b, c;
if (uname(&utsname) == 0)
{
switch(sscanf(utsname.release, "%d.%d.%d", &a, &b, &c))
{
case 3:
if (a == 2)
{
if (b == 6 && c >= 36)
{
this->rta_mark = TRUE;
}
DBG2(DBG_KNL, "detected Linux %d.%d.%d, no support for "
"RTA_PREFSRC for IPv6 routes", a, b, c);
break;
}
/* fall-through */
case 2:
/* only 3.x+ uses two part version numbers */
this->rta_prefsrc_for_ipv6 = TRUE;
this->rta_mark = TRUE;
break;
default:
break;
}
}
}
/**
* Destroy an address to iface map
*/
static void addr_map_destroy(hashlist_t *map)
{
map->ht.destroy_function(&map->ht, (void*)free);
}
METHOD(kernel_net_t, destroy, void,
private_kernel_netlink_net_t *this)
{
enumerator_t *enumerator;
route_entry_t *route;
if (this->routing_table && this->socket)
{
manage_rule(this, RTM_DELRULE, AF_INET, this->routing_table,
this->routing_table_prio);
manage_rule(this, RTM_DELRULE, AF_INET6, this->routing_table,
this->routing_table_prio);
}
if (this->socket_events > 0)
{
lib->watcher->remove(lib->watcher, this->socket_events);
close(this->socket_events);
}
enumerator = this->routes->ht.create_enumerator(&this->routes->ht);
while (enumerator->enumerate(enumerator, NULL, (void**)&route))
{
manage_srcroute(this, RTM_DELROUTE, 0, route->dst_net, route->prefixlen,
route->gateway, route->src_ip, route->if_name,
route->pass);
route_entry_destroy(route);
}
enumerator->destroy(enumerator);
this->routes->destroy(this->routes);
this->routes_lock->destroy(this->routes_lock);
DESTROY_IF(this->socket);
net_changes_clear(this);
this->net_changes->destroy(this->net_changes);
this->net_changes_lock->destroy(this->net_changes_lock);
addr_map_destroy(this->addrs);
addr_map_destroy(this->vips);
this->ifaces->destroy_function(this->ifaces, (void*)iface_entry_destroy);
this->rt_exclude->destroy(this->rt_exclude);
this->roam_lock->destroy(this->roam_lock);
this->condvar->destroy(this->condvar);
this->lock->destroy(this->lock);
free(this);
}
/*
* Described in header.
*/
kernel_netlink_net_t *kernel_netlink_net_create()
{
private_kernel_netlink_net_t *this;
enumerator_t *enumerator;
bool register_for_events = TRUE;
char *exclude;
INIT(this,
.public = {
.interface = {
.get_interface = _get_interface_name,
.create_address_enumerator = _create_address_enumerator,
.create_local_subnet_enumerator = _create_local_subnet_enumerator,
.get_source_addr = _get_source_addr,
.get_nexthop = _get_nexthop,
.add_ip = _add_ip,
.del_ip = _del_ip,
.add_route = _add_route,
.del_route = _del_route,
.destroy = _destroy,
},
},
.socket = netlink_socket_create(NETLINK_ROUTE, rt_msg_names,
lib->settings->get_bool(lib->settings,
"%s.plugins.kernel-netlink.parallel_route", FALSE, lib->ns)),
.rt_exclude = linked_list_create(),
.routes = hashlist_create((hashtable_hash_t)route_entry_hash,
(hashtable_equals_t)route_entry_equals, 16),
.net_changes = hashtable_create(
(hashtable_hash_t)net_change_hash,
(hashtable_equals_t)net_change_equals, 16),
.addrs = hashlist_create(
(hashtable_hash_t)addr_map_entry_hash,
(hashtable_equals_t)addr_map_entry_equals, 16),
.vips = hashlist_create((hashtable_hash_t)addr_map_entry_hash,
(hashtable_equals_t)addr_map_entry_equals, 16),
.routes_lock = mutex_create(MUTEX_TYPE_DEFAULT),
.net_changes_lock = mutex_create(MUTEX_TYPE_DEFAULT),
.ifaces = linked_list_create(),
.lock = rwlock_create(RWLOCK_TYPE_DEFAULT),
.condvar = rwlock_condvar_create(),
.roam_lock = spinlock_create(),
.routing_table = lib->settings->get_int(lib->settings,
"%s.routing_table", ROUTING_TABLE, lib->ns),
.routing_table_prio = lib->settings->get_int(lib->settings,
"%s.routing_table_prio", ROUTING_TABLE_PRIO, lib->ns),
.process_route = lib->settings->get_bool(lib->settings,
"%s.process_route", TRUE, lib->ns),
.install_routes = lib->settings->get_bool(lib->settings,
"%s.install_routes", TRUE, lib->ns),
.install_virtual_ip = lib->settings->get_bool(lib->settings,
"%s.install_virtual_ip", TRUE, lib->ns),
.install_virtual_ip_on = lib->settings->get_str(lib->settings,
"%s.install_virtual_ip_on", NULL, lib->ns),
.prefer_temporary_addrs = lib->settings->get_bool(lib->settings,
"%s.prefer_temporary_addrs", FALSE, lib->ns),
.roam_events = lib->settings->get_bool(lib->settings,
"%s.plugins.kernel-netlink.roam_events", TRUE, lib->ns),
.process_rules = lib->settings->get_bool(lib->settings,
"%s.plugins.kernel-netlink.process_rules", FALSE, lib->ns),
.mtu = lib->settings->get_int(lib->settings,
"%s.plugins.kernel-netlink.mtu", 0, lib->ns),
.mss = lib->settings->get_int(lib->settings,
"%s.plugins.kernel-netlink.mss", 0, lib->ns),
);
timerclear(&this->last_route_reinstall);
timerclear(&this->next_roam);
check_kernel_features(this);
if (!this->socket)
{
destroy(this);
return NULL;
}
if (streq(lib->ns, "starter"))
{ /* starter has no threads, so we do not register for kernel events */
register_for_events = FALSE;
}
exclude = lib->settings->get_str(lib->settings,
"%s.ignore_routing_tables", NULL, lib->ns);
if (exclude)
{
char *token;
uintptr_t table;
enumerator = enumerator_create_token(exclude, " ", " ");
while (enumerator->enumerate(enumerator, &token))
{
errno = 0;
table = strtoul(token, NULL, 10);
if (errno == 0)
{
this->rt_exclude->insert_last(this->rt_exclude, (void*)table);
}
}
enumerator->destroy(enumerator);
}
if (register_for_events)
{
struct sockaddr_nl addr;
memset(&addr, 0, sizeof(addr));
addr.nl_family = AF_NETLINK;
/* create and bind RT socket for events (address/interface/route changes) */
this->socket_events = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
if (this->socket_events < 0)
{
DBG1(DBG_KNL, "unable to create RT event socket: %s (%d)",
strerror(errno), errno);
destroy(this);
return NULL;
}
addr.nl_groups = nl_group(RTNLGRP_IPV4_IFADDR) |
nl_group(RTNLGRP_IPV6_IFADDR) |
nl_group(RTNLGRP_LINK);
if (this->process_route)
{
addr.nl_groups |= nl_group(RTNLGRP_IPV4_ROUTE) |
nl_group(RTNLGRP_IPV6_ROUTE);
}
if (this->process_rules)
{
addr.nl_groups |= nl_group(RTNLGRP_IPV4_RULE) |
nl_group(RTNLGRP_IPV6_RULE);
}
if (bind(this->socket_events, (struct sockaddr*)&addr, sizeof(addr)))
{
DBG1(DBG_KNL, "unable to bind RT event socket: %s (%d)",
strerror(errno), errno);
destroy(this);
return NULL;
}
lib->watcher->add(lib->watcher, this->socket_events, WATCHER_READ,
(watcher_cb_t)receive_events, this);
}
if (init_address_list(this) != SUCCESS)
{
DBG1(DBG_KNL, "unable to get interface list");
destroy(this);
return NULL;
}
if (this->routing_table)
{
if (manage_rule(this, RTM_NEWRULE, AF_INET, this->routing_table,
this->routing_table_prio) != SUCCESS)
{
DBG1(DBG_KNL, "unable to create IPv4 routing table rule");
}
if (manage_rule(this, RTM_NEWRULE, AF_INET6, this->routing_table,
this->routing_table_prio) != SUCCESS)
{
DBG1(DBG_KNL, "unable to create IPv6 routing table rule");
}
}
return &this->public;
}
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