diff --git a/src/libcharon/plugins/kernel_libipsec/kernel_libipsec_ipsec.c b/src/libcharon/plugins/kernel_libipsec/kernel_libipsec_ipsec.c index c7fc56b71..efa519a83 100644 --- a/src/libcharon/plugins/kernel_libipsec/kernel_libipsec_ipsec.c +++ b/src/libcharon/plugins/kernel_libipsec/kernel_libipsec_ipsec.c @@ -18,6 +18,7 @@ #include #include #include +#include #include typedef struct private_kernel_libipsec_ipsec_t private_kernel_libipsec_ipsec_t; @@ -38,8 +39,173 @@ struct private_kernel_libipsec_ipsec_t { * TUN device */ tun_device_t *tun; + + /** + * Mutex to lock access to various lists + */ + mutex_t *mutex; + + /** + * List of installed policies (policy_entry_t) + */ + linked_list_t *policies; + + /** + * List of exclude routes (exclude_route_t) + */ + linked_list_t *excludes; }; +typedef struct exclude_route_t exclude_route_t; + +/** + * Exclude route definition + */ +struct exclude_route_t { + /** Destination address to exclude */ + host_t *dst; + /** Source address for route */ + host_t *src; + /** Nexthop exclude has been installed */ + host_t *gtw; + /** References to this route */ + int refs; +}; + +/** + * Clean up an exclude route entry + */ +static void exclude_route_destroy(exclude_route_t *this) +{ + this->dst->destroy(this->dst); + this->src->destroy(this->src); + this->gtw->destroy(this->gtw); + free(this); +} + +/** + * Find an exclude route entry by destination address + */ +static bool exclude_route_match(exclude_route_t *current, + host_t *dst) +{ + return dst->ip_equals(dst, current->dst); +} + +typedef struct route_entry_t route_entry_t; + +/** + * Installed routing entry + */ +struct route_entry_t { + /** Name of the interface the route is bound to */ + char *if_name; + /** Source ip of the route */ + host_t *src_ip; + /** Destination net */ + chunk_t dst_net; + /** Destination net prefixlen */ + u_int8_t prefixlen; + /** Reference to exclude route, if any */ + exclude_route_t *exclude; +}; + +/** + * Destroy a route_entry_t object + */ +static void route_entry_destroy(route_entry_t *this) +{ + free(this->if_name); + DESTROY_IF(this->src_ip); + chunk_free(&this->dst_net); + free(this); +} + +/** + * Compare two route_entry_t objects + */ +static bool route_entry_equals(route_entry_t *a, route_entry_t *b) +{ + return a->if_name && b->if_name && streq(a->if_name, b->if_name) && + a->src_ip->ip_equals(a->src_ip, b->src_ip) && + chunk_equals(a->dst_net, b->dst_net) && a->prefixlen == b->prefixlen; +} + +typedef struct policy_entry_t policy_entry_t; + +/** + * Installed policy + */ +struct policy_entry_t { + /** Direction of this policy: in, out, forward */ + u_int8_t direction; + /** Parameters of installed policy */ + struct { + /** Subnet and port */ + host_t *net; + /** Subnet mask */ + u_int8_t mask; + /** Protocol */ + u_int8_t proto; + } src, dst; + /** Associated route installed for this policy */ + route_entry_t *route; + /** References to this policy */ + int refs; +}; + +/** + * Create a policy_entry_t object + */ +static policy_entry_t *create_policy_entry(traffic_selector_t *src_ts, + traffic_selector_t *dst_ts, + policy_dir_t dir) +{ + policy_entry_t *this; + INIT(this, + .direction = dir, + ); + + src_ts->to_subnet(src_ts, &this->src.net, &this->src.mask); + dst_ts->to_subnet(dst_ts, &this->dst.net, &this->dst.mask); + + /* src or dest proto may be "any" (0), use more restrictive one */ + this->src.proto = max(src_ts->get_protocol(src_ts), + dst_ts->get_protocol(dst_ts)); + this->src.proto = this->src.proto ? this->src.proto : 0; + this->dst.proto = this->src.proto; + return this; +} + +/** + * Destroy a policy_entry_t object + */ +static void policy_entry_destroy(policy_entry_t *this) +{ + if (this->route) + { + route_entry_destroy(this->route); + } + DESTROY_IF(this->src.net); + DESTROY_IF(this->dst.net); + free(this); +} + +/** + * Compare two policy_entry_t objects + */ +static inline bool policy_entry_equals(policy_entry_t *a, + policy_entry_t *b) +{ + return a->direction == b->direction && + a->src.proto == b->src.proto && + a->dst.proto == b->dst.proto && + a->src.mask == b->src.mask && + a->dst.mask == b->dst.mask && + a->src.net->equals(a->src.net, b->src.net) && + a->dst.net->equals(a->dst.net, b->dst.net); +} + /** * Expiration callback */ @@ -106,14 +272,229 @@ METHOD(kernel_ipsec_t, flush_sas, status_t, return ipsec->sas->flush_sas(ipsec->sas); } +/** + * Add an explicit exclude route to a routing entry + */ +static void add_exclude_route(private_kernel_libipsec_ipsec_t *this, + route_entry_t *route, host_t *src, host_t *dst) +{ + exclude_route_t *exclude; + host_t *gtw; + + if (this->excludes->find_first(this->excludes, + (linked_list_match_t)exclude_route_match, + (void**)&exclude, dst) == SUCCESS) + { + route->exclude = exclude; + exclude->refs++; + } + + if (!route->exclude) + { + DBG2(DBG_KNL, "installing new exclude route for %H src %H", dst, src); + gtw = hydra->kernel_interface->get_nexthop(hydra->kernel_interface, + dst, NULL); + if (gtw) + { + char *if_name = NULL; + + if (hydra->kernel_interface->get_interface( + hydra->kernel_interface, src, &if_name) && + hydra->kernel_interface->add_route(hydra->kernel_interface, + dst->get_address(dst), + dst->get_family(dst) == AF_INET ? 32 : 128, + gtw, src, if_name) == SUCCESS) + { + INIT(exclude, + .dst = dst->clone(dst), + .src = src->clone(src), + .gtw = gtw->clone(gtw), + .refs = 1, + ); + route->exclude = exclude; + this->excludes->insert_last(this->excludes, exclude); + } + else + { + DBG1(DBG_KNL, "installing exclude route for %H failed", dst); + } + gtw->destroy(gtw); + free(if_name); + } + else + { + DBG1(DBG_KNL, "gateway lookup for %H failed", dst); + } + } +} + +/** + * Remove an exclude route attached to a routing entry + */ +static void remove_exclude_route(private_kernel_libipsec_ipsec_t *this, + route_entry_t *route) +{ + char *if_name = NULL; + host_t *dst; + + if (!route->exclude || --route->exclude->refs > 0) + { + return; + } + this->excludes->remove(this->excludes, route->exclude, NULL); + + dst = route->exclude->dst; + DBG2(DBG_KNL, "uninstalling exclude route for %H src %H", + dst, route->exclude->src); + if (hydra->kernel_interface->get_interface( + hydra->kernel_interface, + route->exclude->src, &if_name) && + hydra->kernel_interface->del_route(hydra->kernel_interface, + dst->get_address(dst), + dst->get_family(dst) == AF_INET ? 32 : 128, + route->exclude->gtw, route->exclude->src, + if_name) != SUCCESS) + { + DBG1(DBG_KNL, "uninstalling exclude route for %H failed", dst); + } + exclude_route_destroy(route->exclude); + route->exclude = NULL; + free(if_name); +} + +/** + * Install a route for the given policy + * + * this->mutex is released by this function + */ +static bool install_route(private_kernel_libipsec_ipsec_t *this, + host_t *src, host_t *dst, traffic_selector_t *src_ts, + traffic_selector_t *dst_ts, policy_entry_t *policy) +{ + route_entry_t *route, *old; + host_t *src_ip; + bool is_virtual; + + if (policy->direction != POLICY_OUT) + { + this->mutex->unlock(this->mutex); + return TRUE; + } + + if (hydra->kernel_interface->get_address_by_ts(hydra->kernel_interface, + src_ts, &src_ip, &is_virtual) != SUCCESS) + { + this->mutex->unlock(this->mutex); + return FALSE; + } + + INIT(route, + .if_name = strdup(this->tun->get_name(this->tun)), + .src_ip = src_ip, + .dst_net = chunk_clone(policy->dst.net->get_address(policy->dst.net)), + .prefixlen = policy->dst.mask, + ); + + if (policy->route) + { + old = policy->route; + + if (route_entry_equals(old, route)) + { /* such a route already exists */ + route_entry_destroy(route); + this->mutex->unlock(this->mutex); + return TRUE; + } + /* uninstall previously installed route */ + if (hydra->kernel_interface->del_route(hydra->kernel_interface, + old->dst_net, old->prefixlen, NULL, + old->src_ip, old->if_name) != SUCCESS) + { + DBG1(DBG_KNL, "error uninstalling route installed with policy " + "%R === %R %N", src_ts, dst_ts, policy_dir_names, + policy->direction); + } + route_entry_destroy(old); + policy->route = NULL; + } + + /* if remote traffic selector covers the IKE peer, add an exclude route */ + if (dst_ts->includes(dst_ts, dst)) + { + /* add exclude route for peer */ + add_exclude_route(this, route, src, dst); + } + + DBG2(DBG_KNL, "installing route: %R src %H dev %s", + dst_ts, route->src_ip, route->if_name); + + switch (hydra->kernel_interface->add_route(hydra->kernel_interface, + route->dst_net, route->prefixlen, NULL, + route->src_ip, route->if_name)) + { + case ALREADY_DONE: + /* route exists, do not uninstall */ + remove_exclude_route(this, route); + route_entry_destroy(route); + this->mutex->unlock(this->mutex); + return TRUE; + case SUCCESS: + /* cache the installed route */ + policy->route = route; + this->mutex->unlock(this->mutex); + return TRUE; + default: + DBG1(DBG_KNL, "installing route failed: %R src %H dev %s", + dst_ts, route->src_ip, route->if_name); + remove_exclude_route(this, route); + route_entry_destroy(route); + this->mutex->unlock(this->mutex); + return FALSE; + } +} + METHOD(kernel_ipsec_t, add_policy, status_t, private_kernel_libipsec_ipsec_t *this, host_t *src, host_t *dst, traffic_selector_t *src_ts, traffic_selector_t *dst_ts, policy_dir_t direction, policy_type_t type, ipsec_sa_cfg_t *sa, mark_t mark, policy_priority_t priority) { - return ipsec->policies->add_policy(ipsec->policies, src, dst, src_ts, - dst_ts, direction, type, sa, mark, priority); + policy_entry_t *policy, *found = NULL; + status_t status; + + if (type != POLICY_IPSEC) + { + return SUCCESS; + } + + status = ipsec->policies->add_policy(ipsec->policies, src, dst, src_ts, + dst_ts, direction, type, sa, mark, priority); + if (status != SUCCESS) + { + return status; + } + /* we track policies in order to install routes */ + policy = create_policy_entry(src_ts, dst_ts, direction); + + this->mutex->lock(this->mutex); + if (this->policies->find_first(this->policies, + (linked_list_match_t)policy_entry_equals, + (void**)&found, policy) == SUCCESS) + { + policy_entry_destroy(policy); + policy = found; + } + else + { /* use the new one, if we have no such policy */ + this->policies->insert_last(this->policies, policy); + } + policy->refs++; + + if (!install_route(this, src, dst, src_ts, dst_ts, policy)) + { + return FAILED; + } + return SUCCESS; } METHOD(kernel_ipsec_t, query_policy, status_t, @@ -129,19 +510,82 @@ METHOD(kernel_ipsec_t, del_policy, status_t, traffic_selector_t *dst_ts, policy_dir_t direction, u_int32_t reqid, mark_t mark, policy_priority_t priority) { - return ipsec->policies->del_policy(ipsec->policies, src_ts, dst_ts, - direction, reqid, mark, priority); + policy_entry_t *policy, *found = NULL; + status_t status; + + status = ipsec->policies->del_policy(ipsec->policies, src_ts, dst_ts, + direction, reqid, mark, priority); + + policy = create_policy_entry(src_ts, dst_ts, direction); + + this->mutex->lock(this->mutex); + if (this->policies->find_first(this->policies, + (linked_list_match_t)policy_entry_equals, + (void**)&found, policy) != SUCCESS) + { + policy_entry_destroy(policy); + this->mutex->unlock(this->mutex); + return status; + } + policy_entry_destroy(policy); + policy = found; + + if (--policy->refs > 0) + { /* policy is still in use */ + this->mutex->unlock(this->mutex); + return status; + } + + if (policy->route) + { + route_entry_t *route = policy->route; + + if (hydra->kernel_interface->del_route(hydra->kernel_interface, + route->dst_net, route->prefixlen, NULL, route->src_ip, + route->if_name) != SUCCESS) + { + DBG1(DBG_KNL, "error uninstalling route installed with " + "policy %R === %R %N", src_ts, dst_ts, + policy_dir_names, direction); + } + remove_exclude_route(this, route); + } + this->policies->remove(this->policies, policy, NULL); + policy_entry_destroy(policy); + this->mutex->unlock(this->mutex); + return status; } METHOD(kernel_ipsec_t, flush_policies, status_t, private_kernel_libipsec_ipsec_t *this) { - return ipsec->policies->flush_policies(ipsec->policies); + policy_entry_t *pol; + status_t status; + + status = ipsec->policies->flush_policies(ipsec->policies); + + this->mutex->lock(this->mutex); + while (this->policies->remove_first(this->policies, (void*)&pol) == SUCCESS) + { + if (pol->route) + { + route_entry_t *route = pol->route; + + hydra->kernel_interface->del_route(hydra->kernel_interface, + route->dst_net, route->prefixlen, NULL, route->src_ip, + route->if_name); + remove_exclude_route(this, route); + } + policy_entry_destroy(pol); + } + this->mutex->unlock(this->mutex); + return status; } METHOD(kernel_ipsec_t, bypass_socket, bool, private_kernel_libipsec_ipsec_t *this, int fd, int family) { + /* we use exclude routes for this */ return NOT_SUPPORTED; } @@ -155,6 +599,9 @@ METHOD(kernel_ipsec_t, destroy, void, private_kernel_libipsec_ipsec_t *this) { ipsec->events->unregister_listener(ipsec->events, &this->ipsec_listener); + this->policies->destroy_function(this->policies, (void*)policy_entry_destroy); + this->excludes->destroy(this->excludes); + this->mutex->destroy(this->mutex); free(this); } @@ -188,6 +635,9 @@ kernel_libipsec_ipsec_t *kernel_libipsec_ipsec_create() .expire = expire, }, .tun = lib->get(lib, "kernel-libipsec-tun"), + .mutex = mutex_create(MUTEX_TYPE_DEFAULT), + .policies = linked_list_create(), + .excludes = linked_list_create(), ); ipsec->events->register_listener(ipsec->events, &this->ipsec_listener);