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systemd/src/network/networkd-ndisc.c
T
Yu Watanabe e92f40c6b0 network/route: adjust configuration source based on Gateway= setting 
If Gateway=_dhcp4/_ra, the route will be anyway configured with
NETWORK_CONFIG_SOURCE_DHCP4/_NDISC. See dhcp4_request_route() and
ndisc_route_prepare().

This is mostly for avoiding link_drop_routes(), which drops unnecessary static
and/or foreign routes, unexpectedly filtering an existing route with the
route specified with Gateway=_dhcp4/_ra.
2025-01-27 06:29:26 +09:00

3148 lines
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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/***
Copyright © 2014 Intel Corporation. All rights reserved.
***/
#include <arpa/inet.h>
#include <netinet/icmp6.h>
#include <linux/if.h>
#include <linux/if_arp.h>
#include "sd-ndisc.h"
#include "event-util.h"
#include "missing_network.h"
#include "ndisc-router-internal.h"
#include "networkd-address-generation.h"
#include "networkd-address.h"
#include "networkd-dhcp6.h"
#include "networkd-manager.h"
#include "networkd-ndisc.h"
#include "networkd-nexthop.h"
#include "networkd-queue.h"
#include "networkd-route.h"
#include "networkd-state-file.h"
#include "networkd-sysctl.h"
#include "sort-util.h"
#include "string-table.h"
#include "string-util.h"
#include "strv.h"
#include "sysctl-util.h"
#define NDISC_DNSSL_MAX 64U
#define NDISC_RDNSS_MAX 64U
#define NDISC_ENCRYPTED_DNS_MAX 64U
/* Not defined in the RFC, but let's set an upper limit to make not consume much memory.
* This should be safe as typically there should be at most 1 portal per network. */
#define NDISC_CAPTIVE_PORTAL_MAX 64U
/* Neither defined in the RFC. Just for safety. Otherwise, malformed messages can make clients trigger OOM.
* Not sure if the threshold is high enough. Let's adjust later if not. */
#define NDISC_PREF64_MAX 64U
static int ndisc_drop_outdated(Link *link, const struct in6_addr *router, usec_t timestamp_usec);
bool link_ndisc_enabled(Link *link) {
assert(link);
if (!socket_ipv6_is_supported())
return false;
if (link->flags & IFF_LOOPBACK)
return false;
if (link->iftype == ARPHRD_CAN)
return false;
if (!link->network)
return false;
if (!link_may_have_ipv6ll(link, /* check_multicast = */ true))
return false;
/* Honor explicitly specified value. */
if (link->network->ndisc >= 0)
return link->network->ndisc;
/* Disable if RADV is enabled. */
if (link_radv_enabled(link))
return false;
/* Accept RAs if IPv6 forwarding is disabled, and ignore RAs if IPv6 forwarding is enabled. */
int t = link_get_ip_forwarding(link, AF_INET6);
if (t >= 0)
return !t;
/* Otherwise, defaults to true. */
return true;
}
void network_adjust_ndisc(Network *network) {
assert(network);
if (!FLAGS_SET(network->link_local, ADDRESS_FAMILY_IPV6)) {
if (network->ndisc > 0)
log_warning("%s: IPv6AcceptRA= is enabled but IPv6 link-local addressing is disabled or not supported. "
"Disabling IPv6AcceptRA=.", network->filename);
network->ndisc = false;
}
/* When RouterAllowList=, PrefixAllowList= or RouteAllowList= are specified, then
* RouterDenyList=, PrefixDenyList= or RouteDenyList= are ignored, respectively. */
if (!set_isempty(network->ndisc_allow_listed_router))
network->ndisc_deny_listed_router = set_free_free(network->ndisc_deny_listed_router);
if (!set_isempty(network->ndisc_allow_listed_prefix))
network->ndisc_deny_listed_prefix = set_free_free(network->ndisc_deny_listed_prefix);
if (!set_isempty(network->ndisc_allow_listed_route_prefix))
network->ndisc_deny_listed_route_prefix = set_free_free(network->ndisc_deny_listed_route_prefix);
}
static int ndisc_check_ready(Link *link);
static int ndisc_address_ready_callback(Address *address) {
Address *a;
assert(address);
assert(address->link);
SET_FOREACH(a, address->link->addresses)
if (a->source == NETWORK_CONFIG_SOURCE_NDISC)
a->callback = NULL;
return ndisc_check_ready(address->link);
}
static int ndisc_check_ready(Link *link) {
bool found = false, ready = false;
Address *address;
assert(link);
if (link->ndisc_messages > 0) {
log_link_debug(link, "%s(): SLAAC addresses and routes are not set.", __func__);
return 0;
}
SET_FOREACH(address, link->addresses) {
if (address->source != NETWORK_CONFIG_SOURCE_NDISC)
continue;
found = true;
if (address_is_ready(address)) {
ready = true;
break;
}
}
if (found && !ready) {
SET_FOREACH(address, link->addresses)
if (address->source == NETWORK_CONFIG_SOURCE_NDISC)
address->callback = ndisc_address_ready_callback;
log_link_debug(link, "%s(): no SLAAC address is ready.", __func__);
return 0;
}
link->ndisc_configured = true;
log_link_debug(link, "SLAAC addresses and routes set.");
link_check_ready(link);
return 0;
}
static int ndisc_remove_unused_nexthop(Link *link, NextHop *nexthop) {
int r;
assert(link);
assert(link->manager);
assert(link->ifindex > 0);
assert(nexthop);
if (nexthop->source != NETWORK_CONFIG_SOURCE_NDISC)
return 0;
if (nexthop->ifindex != link->ifindex)
return 0;
Route *route;
SET_FOREACH(route, nexthop->routes)
if (route_exists(route) || route_is_requesting(route))
return 0;
Request *req;
ORDERED_SET_FOREACH(req, link->manager->request_queue) {
if (req->type != REQUEST_TYPE_ROUTE)
continue;
route = ASSERT_PTR(req->userdata);
if (route->nexthop_id == nexthop->id)
return 0;
}
r = nexthop_remove_and_cancel(nexthop, link->manager);
if (r < 0)
return log_link_debug_errno(link, r, "Failed to remove unused nexthop: %m");
return 0;
}
static int ndisc_remove_unused_nexthop_by_id(Link *link, uint32_t id) {
assert(link);
assert(link->manager);
if (id == 0)
return 0;
NextHop *nexthop;
if (nexthop_get_by_id(link->manager, id, &nexthop) < 0)
return 0;
return ndisc_remove_unused_nexthop(link, nexthop);
}
static int ndisc_remove_unused_nexthops(Link *link) {
int ret = 0;
assert(link);
assert(link->manager);
NextHop *nexthop;
HASHMAP_FOREACH(nexthop, link->manager->nexthops_by_id)
RET_GATHER(ret, ndisc_remove_unused_nexthop(link, nexthop));
return ret;
}
#define NDISC_NEXTHOP_APP_ID SD_ID128_MAKE(76,d2,0f,1f,76,1e,44,d1,97,3a,52,5c,05,68,b5,0d)
static uint32_t ndisc_generate_nexthop_id(const NextHop *nexthop, Link *link, sd_id128_t app_id, uint64_t trial) {
assert(nexthop);
assert(link);
struct siphash state;
siphash24_init(&state, app_id.bytes);
siphash24_compress_typesafe(nexthop->protocol, &state);
siphash24_compress_string(link->ifname, &state);
siphash24_compress_typesafe(nexthop->gw.address.in6, &state);
siphash24_compress_typesafe(nexthop->provider.in6, &state);
uint64_t n = htole64(trial);
siphash24_compress_typesafe(n, &state);
uint64_t result = htole64(siphash24_finalize(&state));
return (uint32_t) ((result & 0xffffffff) ^ (result >> 32));
}
static bool ndisc_nexthop_equal(const NextHop *a, const NextHop *b) {
assert(a);
assert(b);
if (a->source != b->source)
return false;
if (a->protocol != b->protocol)
return false;
if (a->ifindex != b->ifindex)
return false;
if (!in6_addr_equal(&a->provider.in6, &b->provider.in6))
return false;
if (!in6_addr_equal(&a->gw.address.in6, &b->gw.address.in6))
return false;
return true;
}
static bool ndisc_take_nexthop_id(NextHop *nexthop, const NextHop *existing, Manager *manager) {
assert(nexthop);
assert(nexthop->id == 0);
assert(existing);
assert(existing->id > 0);
assert(manager);
if (!ndisc_nexthop_equal(nexthop, existing))
return false;
log_nexthop_debug(existing, "Found matching", manager);
nexthop->id = existing->id;
return true;
}
static int ndisc_nexthop_find_id(NextHop *nexthop, Link *link) {
NextHop *n;
Request *req;
int r;
assert(nexthop);
assert(link);
assert(link->manager);
sd_id128_t app_id;
r = sd_id128_get_machine_app_specific(NDISC_NEXTHOP_APP_ID, &app_id);
if (r < 0)
return r;
uint32_t id = ndisc_generate_nexthop_id(nexthop, link, app_id, 0);
if (nexthop_get_by_id(link->manager, id, &n) >= 0 &&
ndisc_take_nexthop_id(nexthop, n, link->manager))
return true;
if (nexthop_get_request_by_id(link->manager, id, &req) >= 0 &&
ndisc_take_nexthop_id(nexthop, req->userdata, link->manager))
return true;
HASHMAP_FOREACH(n, link->manager->nexthops_by_id)
if (ndisc_take_nexthop_id(nexthop, n, link->manager))
return true;
ORDERED_SET_FOREACH(req, link->manager->request_queue) {
if (req->type != REQUEST_TYPE_NEXTHOP)
continue;
if (ndisc_take_nexthop_id(nexthop, req->userdata, link->manager))
return true;
}
return false;
}
static int ndisc_nexthop_new(const Route *route, Link *link, NextHop **ret) {
_cleanup_(nexthop_unrefp) NextHop *nexthop = NULL;
int r;
assert(route);
assert(link);
assert(ret);
r = nexthop_new(&nexthop);
if (r < 0)
return r;
nexthop->source = NETWORK_CONFIG_SOURCE_NDISC;
nexthop->provider = route->provider;
nexthop->protocol = route->protocol == RTPROT_REDIRECT ? RTPROT_REDIRECT : RTPROT_RA;
nexthop->family = AF_INET6;
nexthop->gw.address = route->nexthop.gw;
nexthop->ifindex = link->ifindex;
r = ndisc_nexthop_find_id(nexthop, link);
if (r < 0)
return r;
*ret = TAKE_PTR(nexthop);
return 0;
}
static int ndisc_nexthop_acquire_id(NextHop *nexthop, Link *link) {
int r;
assert(nexthop);
assert(nexthop->id == 0);
assert(link);
assert(link->manager);
sd_id128_t app_id;
r = sd_id128_get_machine_app_specific(NDISC_NEXTHOP_APP_ID, &app_id);
if (r < 0)
return r;
for (uint64_t trial = 0; trial < 100; trial++) {
uint32_t id = ndisc_generate_nexthop_id(nexthop, link, app_id, trial);
if (id == 0)
continue;
if (set_contains(link->manager->nexthop_ids, UINT32_TO_PTR(id)))
continue; /* The ID is already used in a .network file. */
if (nexthop_get_by_id(link->manager, id, NULL) >= 0)
continue; /* The ID is already used by an existing nexthop. */
if (nexthop_get_request_by_id(link->manager, id, NULL) >= 0)
continue; /* The ID is already used by a nexthop being requested. */
log_link_debug(link, "Generated new ndisc nexthop ID for %s with trial %"PRIu64": %"PRIu32,
IN6_ADDR_TO_STRING(&nexthop->gw.address.in6), trial, id);
nexthop->id = id;
return 0;
}
return log_link_debug_errno(link, SYNTHETIC_ERRNO(EBUSY), "Cannot find free nexthop ID for %s.",
IN6_ADDR_TO_STRING(&nexthop->gw.address.in6));
}
static int ndisc_nexthop_handler(sd_netlink *rtnl, sd_netlink_message *m, Request *req, Link *link, NextHop *nexthop) {
int r;
assert(link);
r = nexthop_configure_handler_internal(m, link, "Could not set NDisc route");
if (r <= 0)
return r;
r = ndisc_check_ready(link);
if (r < 0)
link_enter_failed(link);
return 1;
}
static int ndisc_request_nexthop(NextHop *nexthop, Link *link) {
int r;
assert(nexthop);
assert(link);
if (nexthop->id > 0)
return 0;
r = ndisc_nexthop_acquire_id(nexthop, link);
if (r < 0)
return r;
r = link_request_nexthop(link, nexthop, &link->ndisc_messages, ndisc_nexthop_handler);
if (r < 0)
return r;
if (r > 0)
link->ndisc_configured = false;
return 0;
}
static int ndisc_set_route_nexthop(Route *route, Link *link, bool request) {
_cleanup_(nexthop_unrefp) NextHop *nexthop = NULL;
int r;
assert(route);
assert(link);
assert(link->manager);
if (!link->manager->manage_foreign_nexthops)
goto finalize;
if (route->nexthop.family != AF_INET6 || in6_addr_is_null(&route->nexthop.gw.in6))
goto finalize;
r = ndisc_nexthop_new(route, link, &nexthop);
if (r < 0)
return r;
if (nexthop->id == 0 && !request)
goto finalize;
r = ndisc_request_nexthop(nexthop, link);
if (r < 0)
return r;
route->nexthop = (RouteNextHop) {};
route->nexthop_id = nexthop->id;
finalize:
return route_adjust_nexthops(route, link);
}
static int ndisc_route_handler(sd_netlink *rtnl, sd_netlink_message *m, Request *req, Link *link, Route *route) {
int r;
assert(req);
assert(link);
r = route_configure_handler_internal(rtnl, m, req, "Could not set NDisc route");
if (r <= 0)
return r;
r = ndisc_check_ready(link);
if (r < 0)
link_enter_failed(link);
return 1;
}
static void ndisc_set_route_priority(Link *link, Route *route) {
assert(link);
assert(route);
if (route->priority_set)
return; /* explicitly configured. */
switch (route->pref) {
case SD_NDISC_PREFERENCE_LOW:
route->priority = link->network->ndisc_route_metric_low;
break;
case SD_NDISC_PREFERENCE_MEDIUM:
route->priority = link->network->ndisc_route_metric_medium;
break;
case SD_NDISC_PREFERENCE_HIGH:
route->priority = link->network->ndisc_route_metric_high;
break;
default:
assert_not_reached();
}
}
static int ndisc_request_route(Route *route, Link *link) {
int r;
assert(route);
assert(link);
assert(link->manager);
assert(link->network);
r = route_metric_set(&route->metric, RTAX_QUICKACK, link->network->ndisc_quickack);
if (r < 0)
return r;
r = ndisc_set_route_nexthop(route, link, /* request = */ true);
if (r < 0)
return r;
uint8_t pref, pref_original = route->pref;
FOREACH_ARGUMENT(pref, SD_NDISC_PREFERENCE_LOW, SD_NDISC_PREFERENCE_MEDIUM, SD_NDISC_PREFERENCE_HIGH) {
Route *existing;
Request *req;
/* If the preference is specified by the user config (that is, for semi-static routes),
* rather than RA, then only search conflicting routes that have the same preference. */
if (route->pref_set && pref != pref_original)
continue;
route->pref = pref;
ndisc_set_route_priority(link, route);
/* Note, here do not call route_remove_and_cancel() with 'route' directly, otherwise
* existing route(s) may be removed needlessly. */
/* First, check if a conflicting route is already requested. If there is an existing route,
* and also an existing pending request, then the source may be updated by the request. So,
* we first need to check the source of the requested route. */
if (route_get_request(link->manager, route, &req) >= 0) {
route->pref = pref_original;
ndisc_set_route_priority(link, route);
existing = ASSERT_PTR(req->userdata);
if (!route_can_update(existing, route)) {
if (existing->source == NETWORK_CONFIG_SOURCE_STATIC) {
log_link_debug(link, "Found a pending route request that conflicts with new request based on a received RA, ignoring request.");
return 0;
}
log_link_debug(link, "Found a pending route request that conflicts with new request based on a received RA, cancelling.");
r = route_remove_and_cancel(existing, link->manager);
if (r < 0)
return r;
}
}
route->pref = pref;
ndisc_set_route_priority(link, route);
/* Then, check if a conflicting route exists. */
if (route_get(link->manager, route, &existing) >= 0) {
route->pref = pref_original;
ndisc_set_route_priority(link, route);
if (!route_can_update(existing, route)) {
if (existing->source == NETWORK_CONFIG_SOURCE_STATIC) {
log_link_debug(link, "Found an existing route that conflicts with new route based on a received RA, ignoring request.");
return 0;
}
log_link_debug(link, "Found an existing route that conflicts with new route based on a received RA, removing.");
r = route_remove_and_cancel(existing, link->manager);
if (r < 0)
return r;
}
}
}
/* The preference (and priority) may be changed in the above loop. Restore it. */
route->pref = pref_original;
ndisc_set_route_priority(link, route);
bool is_new = route_get(link->manager, route, NULL) < 0;
r = link_request_route(link, route, &link->ndisc_messages, ndisc_route_handler);
if (r < 0)
return r;
if (r > 0 && is_new)
link->ndisc_configured = false;
return 0;
}
static void ndisc_route_prepare(Route *route, Link *link) {
assert(route);
assert(link);
route->source = NETWORK_CONFIG_SOURCE_NDISC;
if (!route->table_set)
route->table = link_get_ndisc_route_table(link);
}
static int ndisc_router_route_prepare(Route *route, Link *link, sd_ndisc_router *rt) {
assert(route);
assert(link);
assert(rt);
ndisc_route_prepare(route, link);
if (!route->protocol_set)
route->protocol = RTPROT_RA;
return sd_ndisc_router_get_sender_address(rt, &route->provider.in6);
}
static int ndisc_request_router_route(Route *route, Link *link, sd_ndisc_router *rt) {
int r;
assert(route);
assert(link);
assert(rt);
r = ndisc_router_route_prepare(route, link, rt);
if (r < 0)
return r;
return ndisc_request_route(route, link);
}
static int ndisc_remove_route(Route *route, Link *link) {
int r, ret = 0;
assert(route);
assert(link);
assert(link->manager);
r = ndisc_set_route_nexthop(route, link, /* request = */ false);
if (r < 0)
return r;
uint8_t pref, pref_original = route->pref;
FOREACH_ARGUMENT(pref, SD_NDISC_PREFERENCE_LOW, SD_NDISC_PREFERENCE_MEDIUM, SD_NDISC_PREFERENCE_HIGH) {
Route *existing;
Request *req;
/* If the preference is specified by the user config (that is, for semi-static routes),
* rather than RA, then only search conflicting routes that have the same preference. */
if (route->pref_set && pref != pref_original)
continue;
route->pref = pref;
ndisc_set_route_priority(link, route);
/* Unfortunately, we cannot directly pass 'route' to route_remove_and_cancel() here, as the
* same or similar route may be configured or requested statically. */
/* First, check if the route is already requested. If there is an existing route, and also an
* existing pending request, then the source may be updated by the request. So, we first need
* to check the source of the requested route. */
if (route_get_request(link->manager, route, &req) >= 0) {
existing = ASSERT_PTR(req->userdata);
if (existing->source == NETWORK_CONFIG_SOURCE_STATIC)
continue;
RET_GATHER(ret, route_remove_and_cancel(existing, link->manager));
}
/* Then, check if the route exists. */
if (route_get(link->manager, route, &existing) >= 0) {
if (existing->source == NETWORK_CONFIG_SOURCE_STATIC)
continue;
RET_GATHER(ret, route_remove_and_cancel(existing, link->manager));
}
}
return RET_GATHER(ret, ndisc_remove_unused_nexthop_by_id(link, route->nexthop_id));
}
static int ndisc_remove_router_route(Route *route, Link *link, sd_ndisc_router *rt) {
int r;
assert(route);
assert(link);
assert(rt);
r = ndisc_router_route_prepare(route, link, rt);
if (r < 0)
return r;
return ndisc_remove_route(route, link);
}
static int ndisc_address_handler(sd_netlink *rtnl, sd_netlink_message *m, Request *req, Link *link, Address *address) {
int r;
assert(link);
r = address_configure_handler_internal(rtnl, m, link, "Could not set NDisc address");
if (r <= 0)
return r;
r = ndisc_check_ready(link);
if (r < 0)
link_enter_failed(link);
return 1;
}
static int ndisc_request_address(Address *address, Link *link) {
bool is_new;
int r;
assert(address);
assert(link);
address->source = NETWORK_CONFIG_SOURCE_NDISC;
r = free_and_strdup_warn(&address->netlabel, link->network->ndisc_netlabel);
if (r < 0)
return r;
Address *existing;
if (address_get_harder(link, address, &existing) < 0)
is_new = true;
else if (address_can_update(existing, address))
is_new = false;
else if (existing->source == NETWORK_CONFIG_SOURCE_DHCP6) {
/* SLAAC address is preferred over DHCPv6 address. */
log_link_debug(link, "Conflicting DHCPv6 address %s exists, removing.",
IN_ADDR_PREFIX_TO_STRING(existing->family, &existing->in_addr, existing->prefixlen));
r = address_remove(existing, link);
if (r < 0)
return r;
is_new = true;
} else {
/* Conflicting static address is configured?? */
log_link_debug(link, "Conflicting address %s exists, ignoring request.",
IN_ADDR_PREFIX_TO_STRING(existing->family, &existing->in_addr, existing->prefixlen));
return 0;
}
r = link_request_address(link, address, &link->ndisc_messages,
ndisc_address_handler, NULL);
if (r < 0)
return r;
if (r > 0 && is_new)
link->ndisc_configured = false;
return 0;
}
int ndisc_reconfigure_address(Address *address, Link *link) {
int r;
assert(address);
assert(address->source == NETWORK_CONFIG_SOURCE_NDISC);
assert(link);
r = regenerate_address(address, link);
if (r <= 0)
return r;
r = ndisc_request_address(address, link);
if (r < 0)
return r;
if (!link->ndisc_configured)
link_set_state(link, LINK_STATE_CONFIGURING);
link_check_ready(link);
return 0;
}
static int ndisc_redirect_route_new(sd_ndisc_redirect *rd, Route **ret) {
_cleanup_(route_unrefp) Route *route = NULL;
struct in6_addr gateway, destination;
int r;
assert(rd);
assert(ret);
r = sd_ndisc_redirect_get_target_address(rd, &gateway);
if (r < 0)
return r;
r = sd_ndisc_redirect_get_destination_address(rd, &destination);
if (r < 0)
return r;
r = route_new(&route);
if (r < 0)
return r;
route->family = AF_INET6;
if (!in6_addr_equal(&gateway, &destination)) {
route->nexthop.gw.in6 = gateway;
route->nexthop.family = AF_INET6;
}
route->dst.in6 = destination;
route->dst_prefixlen = 128;
route->protocol = RTPROT_REDIRECT;
r = sd_ndisc_redirect_get_sender_address(rd, &route->provider.in6);
if (r < 0)
return r;
*ret = TAKE_PTR(route);
return 0;
}
static int ndisc_remove_redirect_route(Link *link, sd_ndisc_redirect *rd) {
_cleanup_(route_unrefp) Route *route = NULL;
int r;
assert(link);
assert(rd);
r = ndisc_redirect_route_new(rd, &route);
if (r < 0)
return r;
ndisc_route_prepare(route, link);
return ndisc_remove_route(route, link);
}
static void ndisc_redirect_hash_func(const sd_ndisc_redirect *x, struct siphash *state) {
struct in6_addr dest = {};
assert(x);
assert(state);
(void) sd_ndisc_redirect_get_destination_address((sd_ndisc_redirect*) x, &dest);
siphash24_compress_typesafe(dest, state);
}
static int ndisc_redirect_compare_func(const sd_ndisc_redirect *x, const sd_ndisc_redirect *y) {
struct in6_addr dest_x = {}, dest_y = {};
assert(x);
assert(y);
(void) sd_ndisc_redirect_get_destination_address((sd_ndisc_redirect*) x, &dest_x);
(void) sd_ndisc_redirect_get_destination_address((sd_ndisc_redirect*) y, &dest_y);
return memcmp(&dest_x, &dest_y, sizeof(dest_x));
}
DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
ndisc_redirect_hash_ops,
sd_ndisc_redirect,
ndisc_redirect_hash_func,
ndisc_redirect_compare_func,
sd_ndisc_redirect_unref);
static int ndisc_redirect_equal(sd_ndisc_redirect *x, sd_ndisc_redirect *y) {
struct in6_addr a, b;
int r;
assert(x);
assert(y);
r = sd_ndisc_redirect_get_destination_address(x, &a);
if (r < 0)
return r;
r = sd_ndisc_redirect_get_destination_address(y, &b);
if (r < 0)
return r;
if (!in6_addr_equal(&a, &b))
return false;
r = sd_ndisc_redirect_get_target_address(x, &a);
if (r < 0)
return r;
r = sd_ndisc_redirect_get_target_address(y, &b);
if (r < 0)
return r;
return in6_addr_equal(&a, &b);
}
static int ndisc_redirect_drop_conflict(Link *link, sd_ndisc_redirect *rd) {
_cleanup_(sd_ndisc_redirect_unrefp) sd_ndisc_redirect *existing = NULL;
int r;
assert(link);
assert(rd);
existing = set_remove(link->ndisc_redirects, rd);
if (!existing)
return 0;
r = ndisc_redirect_equal(rd, existing);
if (r != 0)
return r;
return ndisc_remove_redirect_route(link, existing);
}
static int ndisc_redirect_verify_sender(Link *link, sd_ndisc_redirect *rd) {
int r;
assert(link);
assert(rd);
/* RFC 4861 section 8.1
* The IP source address of the Redirect is the same as the current first-hop router for the specified
* ICMP Destination Address. */
struct in6_addr sender;
r = sd_ndisc_redirect_get_sender_address(rd, &sender);
if (r < 0)
return r;
/* We will reuse the sender's router lifetime as the lifetime of the redirect route. Hence, if we
* have not remembered an RA from the sender, refuse the Redirect message. */
sd_ndisc_router *router = hashmap_get(link->ndisc_routers_by_sender, &sender);
if (!router)
return false;
sd_ndisc_redirect *existing = set_get(link->ndisc_redirects, rd);
if (existing) {
struct in6_addr target, dest;
/* If we have received Redirect message for the host, the sender must be the previous target. */
r = sd_ndisc_redirect_get_target_address(existing, &target);
if (r < 0)
return r;
if (in6_addr_equal(&sender, &target))
return true;
/* If the existing redirect route is on-link, that is, the destination and target address are
* equivalent, then also accept Redirect message from the current default router. This is not
* mentioned by the RFC, but without this, we cannot update on-link redirect route. */
r = sd_ndisc_redirect_get_destination_address(existing, &dest);
if (r < 0)
return r;
if (!in6_addr_equal(&dest, &target))
return false;
}
/* Check if the sender is one of the known router with highest priority. */
uint8_t preference;
r = sd_ndisc_router_get_preference(router, &preference);
if (r < 0)
return r;
if (preference == SD_NDISC_PREFERENCE_HIGH)
return true;
sd_ndisc_router *rt;
HASHMAP_FOREACH(rt, link->ndisc_routers_by_sender) {
if (rt == router)
continue;
uint8_t pref;
if (sd_ndisc_router_get_preference(rt, &pref) < 0)
continue;
if (pref == SD_NDISC_PREFERENCE_HIGH ||
(pref == SD_NDISC_PREFERENCE_MEDIUM && preference == SD_NDISC_PREFERENCE_LOW))
return false;
}
return true;
}
static int ndisc_redirect_handler(Link *link, sd_ndisc_redirect *rd) {
int r;
assert(link);
assert(link->network);
assert(rd);
if (!link->network->ndisc_use_redirect)
return 0;
usec_t now_usec;
r = sd_event_now(link->manager->event, CLOCK_BOOTTIME, &now_usec);
if (r < 0)
return r;
r = ndisc_drop_outdated(link, /* router = */ NULL, now_usec);
if (r < 0)
return r;
r = ndisc_redirect_verify_sender(link, rd);
if (r <= 0)
return r;
/* First, drop conflicting redirect route, if exists. */
r = ndisc_redirect_drop_conflict(link, rd);
if (r < 0)
return r;
/* Then, remember the received message. */
r = set_ensure_put(&link->ndisc_redirects, &ndisc_redirect_hash_ops, rd);
if (r < 0)
return r;
sd_ndisc_redirect_ref(rd);
/* Finally, request the corresponding route. */
_cleanup_(route_unrefp) Route *route = NULL;
r = ndisc_redirect_route_new(rd, &route);
if (r < 0)
return r;
sd_ndisc_router *rt = hashmap_get(link->ndisc_routers_by_sender, &route->provider.in6);
if (!rt)
return -EADDRNOTAVAIL;
r = sd_ndisc_router_get_lifetime_timestamp(rt, CLOCK_BOOTTIME, &route->lifetime_usec);
if (r < 0)
return r;
ndisc_route_prepare(route, link);
return ndisc_request_route(route, link);
}
static int ndisc_drop_redirect(Link *link, const struct in6_addr *router) {
int r, ret = 0;
assert(link);
sd_ndisc_redirect *rd;
SET_FOREACH(rd, link->ndisc_redirects) {
if (router) {
struct in6_addr a;
if (!(sd_ndisc_redirect_get_sender_address(rd, &a) >= 0 && in6_addr_equal(&a, router)) &&
!(sd_ndisc_redirect_get_target_address(rd, &a) >= 0 && in6_addr_equal(&a, router)))
continue;
}
r = ndisc_remove_redirect_route(link, rd);
if (r < 0)
RET_GATHER(ret, log_link_warning_errno(link, r, "Failed to remove redirect route, ignoring: %m"));
sd_ndisc_redirect_unref(set_remove(link->ndisc_redirects, rd));
}
return ret;
}
static int ndisc_update_redirect_sender(Link *link, const struct in6_addr *original_address, const struct in6_addr *current_address) {
int r;
assert(link);
assert(original_address);
assert(current_address);
sd_ndisc_redirect *rd;
SET_FOREACH(rd, link->ndisc_redirects) {
struct in6_addr sender;
r = sd_ndisc_redirect_get_sender_address(rd, &sender);
if (r < 0)
return r;
if (!in6_addr_equal(&sender, original_address))
continue;
r = sd_ndisc_redirect_set_sender_address(rd, current_address);
if (r < 0)
return r;
}
return 0;
}
static int ndisc_router_drop_default(Link *link, sd_ndisc_router *rt) {
_cleanup_(route_unrefp) Route *route = NULL;
struct in6_addr gateway;
int r;
assert(link);
assert(link->network);
assert(rt);
r = sd_ndisc_router_get_sender_address(rt, &gateway);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get router address from RA: %m");
r = route_new(&route);
if (r < 0)
return log_oom();
route->family = AF_INET6;
route->nexthop.family = AF_INET6;
route->nexthop.gw.in6 = gateway;
r = ndisc_remove_router_route(route, link, rt);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to remove the default gateway configured by RA: %m");
Route *route_gw;
HASHMAP_FOREACH(route_gw, link->network->routes_by_section) {
_cleanup_(route_unrefp) Route *tmp = NULL;
if (route_gw->source != NETWORK_CONFIG_SOURCE_NDISC)
continue;
assert(route_gw->nexthop.family == AF_INET6);
r = route_dup(route_gw, NULL, &tmp);
if (r < 0)
return r;
tmp->nexthop.gw.in6 = gateway;
r = ndisc_remove_router_route(tmp, link, rt);
if (r < 0)
return log_link_warning_errno(link, r, "Could not remove semi-static gateway: %m");
}
return 0;
}
static int ndisc_router_process_default(Link *link, sd_ndisc_router *rt) {
usec_t lifetime_usec;
struct in6_addr gateway;
uint8_t preference;
int r;
assert(link);
assert(link->network);
assert(rt);
/* If the router lifetime is zero, the router should not be used as the default gateway. */
r = sd_ndisc_router_get_lifetime(rt, NULL);
if (r < 0)
return r;
if (r == 0)
return ndisc_router_drop_default(link, rt);
if (!link->network->ndisc_use_gateway &&
hashmap_isempty(link->network->routes_by_section))
return 0;
r = sd_ndisc_router_get_lifetime_timestamp(rt, CLOCK_BOOTTIME, &lifetime_usec);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get gateway lifetime from RA: %m");
r = sd_ndisc_router_get_sender_address(rt, &gateway);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
r = sd_ndisc_router_get_preference(rt, &preference);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get router preference from RA: %m");
if (link->network->ndisc_use_gateway) {
_cleanup_(route_unrefp) Route *route = NULL;
r = route_new(&route);
if (r < 0)
return log_oom();
route->family = AF_INET6;
route->pref = preference;
route->nexthop.family = AF_INET6;
route->nexthop.gw.in6 = gateway;
route->lifetime_usec = lifetime_usec;
r = ndisc_request_router_route(route, link, rt);
if (r < 0)
return log_link_warning_errno(link, r, "Could not request default route: %m");
}
Route *route_gw;
HASHMAP_FOREACH(route_gw, link->network->routes_by_section) {
_cleanup_(route_unrefp) Route *route = NULL;
if (route_gw->source != NETWORK_CONFIG_SOURCE_NDISC)
continue;
assert(route_gw->nexthop.family == AF_INET6);
r = route_dup(route_gw, NULL, &route);
if (r < 0)
return r;
route->nexthop.gw.in6 = gateway;
if (!route->pref_set)
route->pref = preference;
route->lifetime_usec = lifetime_usec;
r = ndisc_request_router_route(route, link, rt);
if (r < 0)
return log_link_warning_errno(link, r, "Could not request gateway: %m");
}
return 0;
}
DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(
ndisc_router_hash_ops,
struct in6_addr,
in6_addr_hash_func,
in6_addr_compare_func,
sd_ndisc_router,
sd_ndisc_router_unref);
static int ndisc_update_router_address(Link *link, const struct in6_addr *original_address, const struct in6_addr *current_address) {
_cleanup_(sd_ndisc_router_unrefp) sd_ndisc_router *rt = NULL;
int r;
assert(link);
assert(original_address);
assert(current_address);
rt = hashmap_remove(link->ndisc_routers_by_sender, original_address);
if (!rt)
return 0;
/* If we already received an RA from the new address, then forget the RA from the old address. */
if (hashmap_contains(link->ndisc_routers_by_sender, current_address))
return 0;
/* Otherwise, update the sender address of the previously received RA. */
r = sd_ndisc_router_set_sender_address(rt, current_address);
if (r < 0)
return r;
r = hashmap_put(link->ndisc_routers_by_sender, &rt->packet->sender_address, rt);
if (r < 0)
return r;
TAKE_PTR(rt);
return 0;
}
static int ndisc_drop_router_one(Link *link, sd_ndisc_router *rt, usec_t timestamp_usec) {
usec_t lifetime_usec;
int r;
assert(link);
assert(rt);
assert(rt->packet);
r = sd_ndisc_router_get_lifetime_timestamp(rt, CLOCK_BOOTTIME, &lifetime_usec);
if (r < 0)
return r;
if (lifetime_usec > timestamp_usec)
return 0;
r = ndisc_drop_redirect(link, &rt->packet->sender_address);
sd_ndisc_router_unref(hashmap_remove(link->ndisc_routers_by_sender, &rt->packet->sender_address));
return r;
}
static int ndisc_drop_routers(Link *link, const struct in6_addr *router, usec_t timestamp_usec) {
sd_ndisc_router *rt;
int ret = 0;
assert(link);
if (router) {
rt = hashmap_get(link->ndisc_routers_by_sender, router);
if (!rt)
return 0;
return ndisc_drop_router_one(link, rt, timestamp_usec);
}
HASHMAP_FOREACH_KEY(rt, router, link->ndisc_routers_by_sender)
RET_GATHER(ret, ndisc_drop_router_one(link, rt, timestamp_usec));
return ret;
}
static int ndisc_remember_router(Link *link, sd_ndisc_router *rt) {
int r;
assert(link);
assert(rt);
assert(rt->packet);
sd_ndisc_router_unref(hashmap_remove(link->ndisc_routers_by_sender, &rt->packet->sender_address));
/* Remember RAs with non-zero lifetime. */
r = sd_ndisc_router_get_lifetime(rt, NULL);
if (r <= 0)
return r;
r = hashmap_ensure_put(&link->ndisc_routers_by_sender, &ndisc_router_hash_ops, &rt->packet->sender_address, rt);
if (r < 0)
return r;
sd_ndisc_router_ref(rt);
return 0;
}
static int ndisc_router_process_reachable_time(Link *link, sd_ndisc_router *rt) {
usec_t reachable_time, msec;
int r;
assert(link);
assert(link->manager);
assert(link->network);
assert(rt);
if (!link->network->ndisc_use_reachable_time)
return 0;
r = sd_ndisc_router_get_reachable_time(rt, &reachable_time);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get reachable time from RA: %m");
/* 0 is the unspecified value and must not be set (see RFC4861, 6.3.4) */
if (!timestamp_is_set(reachable_time))
return 0;
msec = DIV_ROUND_UP(reachable_time, USEC_PER_MSEC);
if (msec <= 0 || msec > UINT32_MAX) {
log_link_debug(link, "Failed to get reachable time from RA - out of range (%"PRIu64"), ignoring", msec);
return 0;
}
/* Set the reachable time for Neighbor Solicitations. */
r = sysctl_write_ip_neighbor_property_uint32(AF_INET6, link->ifname, "base_reachable_time_ms", (uint32_t) msec, manager_get_sysctl_shadow(link->manager));
if (r < 0)
log_link_warning_errno(link, r, "Failed to apply neighbor reachable time (%"PRIu64"), ignoring: %m", msec);
return 0;
}
static int ndisc_router_process_retransmission_time(Link *link, sd_ndisc_router *rt) {
usec_t retrans_time, msec;
int r;
assert(link);
assert(link->manager);
assert(link->network);
assert(rt);
if (!link->network->ndisc_use_retransmission_time)
return 0;
r = sd_ndisc_router_get_retransmission_time(rt, &retrans_time);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get retransmission time from RA: %m");
/* 0 is the unspecified value and must not be set (see RFC4861, 6.3.4) */
if (!timestamp_is_set(retrans_time))
return 0;
msec = DIV_ROUND_UP(retrans_time, USEC_PER_MSEC);
if (msec <= 0 || msec > UINT32_MAX) {
log_link_debug(link, "Failed to get retransmission time from RA - out of range (%"PRIu64"), ignoring", msec);
return 0;
}
/* Set the retransmission time for Neighbor Solicitations. */
r = sysctl_write_ip_neighbor_property_uint32(AF_INET6, link->ifname, "retrans_time_ms", (uint32_t) msec, manager_get_sysctl_shadow(link->manager));
if (r < 0)
log_link_warning_errno(link, r, "Failed to apply neighbor retransmission time (%"PRIu64"), ignoring: %m", msec);
return 0;
}
static int ndisc_router_process_hop_limit(Link *link, sd_ndisc_router *rt) {
uint8_t hop_limit;
int r;
assert(link);
assert(link->manager);
assert(link->network);
assert(rt);
if (!link->network->ndisc_use_hop_limit)
return 0;
r = sd_ndisc_router_get_hop_limit(rt, &hop_limit);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get hop limit from RA: %m");
/* 0 is the unspecified value and must not be set (see RFC4861, 6.3.4):
*
* A Router Advertisement field (e.g., Cur Hop Limit, Reachable Time, and Retrans Timer) may contain
* a value denoting that it is unspecified. In such cases, the parameter should be ignored and the
* host should continue using whatever value it is already using. In particular, a host MUST NOT
* interpret the unspecified value as meaning change back to the default value that was in use before
* the first Router Advertisement was received.
*
* If the received Cur Hop Limit value is non-zero, the host SHOULD set
* its CurHopLimit variable to the received value. */
if (hop_limit <= 0)
return 0;
r = sysctl_write_ip_property_uint32(AF_INET6, link->ifname, "hop_limit", (uint32_t) hop_limit, manager_get_sysctl_shadow(link->manager));
if (r < 0)
log_link_warning_errno(link, r, "Failed to apply hop_limit (%u), ignoring: %m", hop_limit);
return 0;
}
static int ndisc_router_process_mtu(Link *link, sd_ndisc_router *rt) {
uint32_t mtu;
int r;
assert(link);
assert(link->network);
assert(rt);
if (!link->network->ndisc_use_mtu)
return 0;
r = sd_ndisc_router_get_mtu(rt, &mtu);
if (r == -ENODATA)
return 0;
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get MTU from RA: %m");
link->ndisc_mtu = mtu;
(void) link_set_ipv6_mtu(link, LOG_DEBUG);
return 0;
}
static int ndisc_address_set_lifetime(Address *address, Link *link, sd_ndisc_router *rt) {
Address *existing;
usec_t t;
int r;
assert(address);
assert(link);
assert(rt);
/* This is mostly based on RFC 4862 section 5.5.3 (e). However, the definition of 'RemainingLifetime'
* is ambiguous, and there is no clear explanation when the address is not assigned yet. If we assume
* that 'RemainingLifetime' is zero in that case, then IPv6 Core Conformance test [v6LC.3.2.5 Part C]
* fails. So, in such case, we skip the conditions about 'RemainingLifetime'. */
r = sd_ndisc_router_prefix_get_valid_lifetime_timestamp(rt, CLOCK_BOOTTIME, &address->lifetime_valid_usec);
if (r < 0)
return r;
r = sd_ndisc_router_prefix_get_preferred_lifetime_timestamp(rt, CLOCK_BOOTTIME, &address->lifetime_preferred_usec);
if (r < 0)
return r;
/* RFC 4862 section 5.5.3 (e)
* 1. If the received Valid Lifetime is greater than 2 hours or greater than RemainingLifetime,
* set the valid lifetime of the corresponding address to the advertised Valid Lifetime. */
r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &t);
if (r < 0)
return r;
if (t > 2 * USEC_PER_HOUR)
return 0;
if (address_get(link, address, &existing) < 0 || existing->source != NETWORK_CONFIG_SOURCE_NDISC)
return 0;
if (address->lifetime_valid_usec > existing->lifetime_valid_usec)
return 0;
/* 2. If RemainingLifetime is less than or equal to 2 hours, ignore the Prefix Information option
* with regards to the valid lifetime, unless the Router Advertisement from which this option was
* obtained has been authenticated (e.g., via Secure Neighbor Discovery [RFC3971]). If the Router
* Advertisement was authenticated, the valid lifetime of the corresponding address should be set
* to the Valid Lifetime in the received option.
*
* Currently, authentication is not supported. So check the lifetime of the existing address. */
r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, &t);
if (r < 0)
return r;
if (existing->lifetime_valid_usec <= usec_add(t, 2 * USEC_PER_HOUR)) {
address->lifetime_valid_usec = existing->lifetime_valid_usec;
return 0;
}
/* 3. Otherwise, reset the valid lifetime of the corresponding address to 2 hours. */
address->lifetime_valid_usec = usec_add(t, 2 * USEC_PER_HOUR);
return 0;
}
static int ndisc_router_process_autonomous_prefix(Link *link, sd_ndisc_router *rt) {
usec_t lifetime_valid_usec, lifetime_preferred_usec;
struct in6_addr prefix, router;
uint8_t prefixlen;
int r;
assert(link);
assert(link->network);
assert(rt);
if (!link->network->ndisc_use_autonomous_prefix)
return 0;
r = sd_ndisc_router_get_sender_address(rt, &router);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get router address: %m");
r = sd_ndisc_router_prefix_get_address(rt, &prefix);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get prefix address: %m");
r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get prefix length: %m");
/* ndisc_generate_addresses() below requires the prefix length <= 64. */
if (prefixlen > 64) {
log_link_debug(link, "Prefix is longer than 64, ignoring autonomous prefix %s.",
IN6_ADDR_PREFIX_TO_STRING(&prefix, prefixlen));
return 0;
}
r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_valid_usec);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get prefix valid lifetime: %m");
r = sd_ndisc_router_prefix_get_preferred_lifetime(rt, &lifetime_preferred_usec);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get prefix preferred lifetime: %m");
/* RFC 4862 section 5.5.3 (c)
* If the preferred lifetime is greater than the valid lifetime, silently ignore the Prefix
* Information option. */
if (lifetime_preferred_usec > lifetime_valid_usec)
return 0;
_cleanup_hashmap_free_ Hashmap *tokens_by_address = NULL;
r = ndisc_generate_addresses(link, &prefix, prefixlen, &tokens_by_address);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to generate SLAAC addresses: %m");
IPv6Token *token;
struct in6_addr *a;
HASHMAP_FOREACH_KEY(token, a, tokens_by_address) {
_cleanup_(address_unrefp) Address *address = NULL;
r = address_new(&address);
if (r < 0)
return log_oom();
address->provider.in6 = router;
address->family = AF_INET6;
address->in_addr.in6 = *a;
address->prefixlen = prefixlen;
address->flags = IFA_F_NOPREFIXROUTE|IFA_F_MANAGETEMPADDR;
address->token = ipv6_token_ref(token);
r = ndisc_address_set_lifetime(address, link, rt);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to set lifetime of SLAAC address: %m");
assert(address->lifetime_preferred_usec <= address->lifetime_valid_usec);
r = ndisc_request_address(address, link);
if (r < 0)
return log_link_warning_errno(link, r, "Could not request SLAAC address: %m");
}
return 0;
}
static int ndisc_router_process_onlink_prefix(Link *link, sd_ndisc_router *rt) {
_cleanup_(route_unrefp) Route *route = NULL;
uint8_t prefixlen, preference;
usec_t lifetime_usec;
struct in6_addr prefix;
int r;
assert(link);
assert(link->network);
assert(rt);
if (!link->network->ndisc_use_onlink_prefix)
return 0;
r = sd_ndisc_router_prefix_get_valid_lifetime_timestamp(rt, CLOCK_BOOTTIME, &lifetime_usec);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get prefix lifetime: %m");
r = sd_ndisc_router_prefix_get_address(rt, &prefix);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get prefix address: %m");
r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get prefix length: %m");
/* Prefix Information option does not have preference, hence we use the 'main' preference here */
r = sd_ndisc_router_get_preference(rt, &preference);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get router preference from RA: %m");
r = route_new(&route);
if (r < 0)
return log_oom();
route->family = AF_INET6;
route->dst.in6 = prefix;
route->dst_prefixlen = prefixlen;
route->pref = preference;
route->lifetime_usec = lifetime_usec;
/* RFC 4861 section 6.3.4:
* - If the prefix is not already present in the Prefix List, and the Prefix Information option's
* Valid Lifetime field is non-zero, create a new entry for the prefix and initialize its
* invalidation timer to the Valid Lifetime value in the Prefix Information option.
*
* - If the prefix is already present in the host's Prefix List as the result of a previously
* received advertisement, reset its invalidation timer to the Valid Lifetime value in the Prefix
* Information option. If the new Lifetime value is zero, timeout the prefix immediately. */
if (lifetime_usec == 0) {
r = ndisc_remove_router_route(route, link, rt);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to remove prefix route: %m");
} else {
r = ndisc_request_router_route(route, link, rt);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to request prefix route: %m");
}
return 0;
}
static int ndisc_router_process_prefix(Link *link, sd_ndisc_router *rt, bool zero_lifetime) {
uint8_t flags, prefixlen;
struct in6_addr a;
int r;
assert(link);
assert(link->network);
assert(rt);
usec_t lifetime_usec;
r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_usec);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get prefix lifetime: %m");
if ((lifetime_usec == 0) != zero_lifetime)
return 0;
r = sd_ndisc_router_prefix_get_address(rt, &a);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get prefix address: %m");
/* RFC 4861 Section 4.6.2:
* A router SHOULD NOT send a prefix option for the link-local prefix and a host SHOULD ignore such
* a prefix option. */
if (in6_addr_is_link_local(&a)) {
log_link_debug(link, "Received link-local prefix, ignoring prefix.");
return 0;
}
r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get prefix length: %m");
if (in6_prefix_is_filtered(&a, prefixlen, link->network->ndisc_allow_listed_prefix, link->network->ndisc_deny_listed_prefix)) {
if (set_isempty(link->network->ndisc_allow_listed_prefix))
log_link_debug(link, "Prefix '%s' is in deny list, ignoring.",
IN6_ADDR_PREFIX_TO_STRING(&a, prefixlen));
else
log_link_debug(link, "Prefix '%s' is not in allow list, ignoring.",
IN6_ADDR_PREFIX_TO_STRING(&a, prefixlen));
return 0;
}
r = sd_ndisc_router_prefix_get_flags(rt, &flags);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get RA prefix flags: %m");
if (FLAGS_SET(flags, ND_OPT_PI_FLAG_ONLINK)) {
r = ndisc_router_process_onlink_prefix(link, rt);
if (r < 0)
return r;
}
if (FLAGS_SET(flags, ND_OPT_PI_FLAG_AUTO)) {
r = ndisc_router_process_autonomous_prefix(link, rt);
if (r < 0)
return r;
}
return 0;
}
static int ndisc_router_process_route(Link *link, sd_ndisc_router *rt, bool zero_lifetime) {
_cleanup_(route_unrefp) Route *route = NULL;
uint8_t preference, prefixlen;
struct in6_addr gateway, dst;
usec_t lifetime_usec;
int r;
assert(link);
if (!link->network->ndisc_use_route_prefix)
return 0;
r = sd_ndisc_router_route_get_lifetime_timestamp(rt, CLOCK_BOOTTIME, &lifetime_usec);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get route lifetime from RA: %m");
if ((lifetime_usec == 0) != zero_lifetime)
return 0;
r = sd_ndisc_router_route_get_address(rt, &dst);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get route destination address: %m");
r = sd_ndisc_router_route_get_prefixlen(rt, &prefixlen);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get route prefix length: %m");
if (in6_prefix_is_filtered(&dst, prefixlen,
link->network->ndisc_allow_listed_route_prefix,
link->network->ndisc_deny_listed_route_prefix)) {
if (set_isempty(link->network->ndisc_allow_listed_route_prefix))
log_link_debug(link, "Route prefix '%s' is in deny list, ignoring.",
IN6_ADDR_PREFIX_TO_STRING(&dst, prefixlen));
else
log_link_debug(link, "Route prefix '%s' is not in allow list, ignoring.",
IN6_ADDR_PREFIX_TO_STRING(&dst, prefixlen));
return 0;
}
r = sd_ndisc_router_get_sender_address(rt, &gateway);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
if (link_get_ipv6_address(link, &gateway, NULL) >= 0) {
if (DEBUG_LOGGING)
log_link_debug(link, "Advertised route gateway %s is local to the link, ignoring route",
IN6_ADDR_TO_STRING(&gateway));
return 0;
}
r = sd_ndisc_router_route_get_preference(rt, &preference);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get router preference from RA: %m");
r = route_new(&route);
if (r < 0)
return log_oom();
route->family = AF_INET6;
route->pref = preference;
route->nexthop.gw.in6 = gateway;
route->nexthop.family = AF_INET6;
route->dst.in6 = dst;
route->dst_prefixlen = prefixlen;
route->lifetime_usec = lifetime_usec;
if (lifetime_usec != 0) {
r = ndisc_request_router_route(route, link, rt);
if (r < 0)
return log_link_warning_errno(link, r, "Could not request additional route: %m");
} else {
r = ndisc_remove_router_route(route, link, rt);
if (r < 0)
return log_link_warning_errno(link, r, "Could not remove additional route with zero lifetime: %m");
}
return 0;
}
static void ndisc_rdnss_hash_func(const NDiscRDNSS *x, struct siphash *state) {
siphash24_compress_typesafe(x->address, state);
}
static int ndisc_rdnss_compare_func(const NDiscRDNSS *a, const NDiscRDNSS *b) {
return memcmp(&a->address, &b->address, sizeof(a->address));
}
DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
ndisc_rdnss_hash_ops,
NDiscRDNSS,
ndisc_rdnss_hash_func,
ndisc_rdnss_compare_func,
free);
static int ndisc_router_process_rdnss(Link *link, sd_ndisc_router *rt, bool zero_lifetime) {
usec_t lifetime_usec;
const struct in6_addr *a;
struct in6_addr router;
bool updated = false, logged_about_too_many = false;
int n, r;
assert(link);
assert(link->network);
assert(rt);
if (!link_get_use_dns(link, NETWORK_CONFIG_SOURCE_NDISC))
return 0;
r = sd_ndisc_router_get_sender_address(rt, &router);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get router address from RA: %m");
r = sd_ndisc_router_rdnss_get_lifetime_timestamp(rt, CLOCK_BOOTTIME, &lifetime_usec);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get RDNSS lifetime: %m");
if ((lifetime_usec == 0) != zero_lifetime)
return 0;
n = sd_ndisc_router_rdnss_get_addresses(rt, &a);
if (n < 0)
return log_link_warning_errno(link, n, "Failed to get RDNSS addresses: %m");
for (int j = 0; j < n; j++) {
_cleanup_free_ NDiscRDNSS *x = NULL;
NDiscRDNSS *rdnss, d = {
.address = a[j],
};
if (lifetime_usec == 0) {
/* The entry is outdated. */
free(set_remove(link->ndisc_rdnss, &d));
updated = true;
continue;
}
rdnss = set_get(link->ndisc_rdnss, &d);
if (rdnss) {
rdnss->router = router;
rdnss->lifetime_usec = lifetime_usec;
continue;
}
if (set_size(link->ndisc_rdnss) >= NDISC_RDNSS_MAX) {
if (!logged_about_too_many)
log_link_warning(link, "Too many RDNSS records per link. Only first %u records will be used.", NDISC_RDNSS_MAX);
logged_about_too_many = true;
continue;
}
x = new(NDiscRDNSS, 1);
if (!x)
return log_oom();
*x = (NDiscRDNSS) {
.address = a[j],
.router = router,
.lifetime_usec = lifetime_usec,
};
r = set_ensure_consume(&link->ndisc_rdnss, &ndisc_rdnss_hash_ops, TAKE_PTR(x));
if (r < 0)
return log_oom();
assert(r > 0);
updated = true;
}
if (updated)
link_dirty(link);
return 0;
}
static void ndisc_dnssl_hash_func(const NDiscDNSSL *x, struct siphash *state) {
siphash24_compress_string(NDISC_DNSSL_DOMAIN(x), state);
}
static int ndisc_dnssl_compare_func(const NDiscDNSSL *a, const NDiscDNSSL *b) {
return strcmp(NDISC_DNSSL_DOMAIN(a), NDISC_DNSSL_DOMAIN(b));
}
DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
ndisc_dnssl_hash_ops,
NDiscDNSSL,
ndisc_dnssl_hash_func,
ndisc_dnssl_compare_func,
free);
static int ndisc_router_process_dnssl(Link *link, sd_ndisc_router *rt, bool zero_lifetime) {
char **l;
usec_t lifetime_usec;
struct in6_addr router;
bool updated = false, logged_about_too_many = false;
int r;
assert(link);
assert(link->network);
assert(rt);
if (link_get_use_domains(link, NETWORK_CONFIG_SOURCE_NDISC) <= 0)
return 0;
r = sd_ndisc_router_get_sender_address(rt, &router);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get router address from RA: %m");
r = sd_ndisc_router_dnssl_get_lifetime_timestamp(rt, CLOCK_BOOTTIME, &lifetime_usec);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get DNSSL lifetime: %m");
if ((lifetime_usec == 0) != zero_lifetime)
return 0;
r = sd_ndisc_router_dnssl_get_domains(rt, &l);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get DNSSL addresses: %m");
STRV_FOREACH(j, l) {
_cleanup_free_ NDiscDNSSL *s = NULL;
NDiscDNSSL *dnssl;
s = malloc0(ALIGN(sizeof(NDiscDNSSL)) + strlen(*j) + 1);
if (!s)
return log_oom();
strcpy(NDISC_DNSSL_DOMAIN(s), *j);
if (lifetime_usec == 0) {
/* The entry is outdated. */
free(set_remove(link->ndisc_dnssl, s));
updated = true;
continue;
}
dnssl = set_get(link->ndisc_dnssl, s);
if (dnssl) {
dnssl->router = router;
dnssl->lifetime_usec = lifetime_usec;
continue;
}
if (set_size(link->ndisc_dnssl) >= NDISC_DNSSL_MAX) {
if (!logged_about_too_many)
log_link_warning(link, "Too many DNSSL records per link. Only first %u records will be used.", NDISC_DNSSL_MAX);
logged_about_too_many = true;
continue;
}
s->router = router;
s->lifetime_usec = lifetime_usec;
r = set_ensure_consume(&link->ndisc_dnssl, &ndisc_dnssl_hash_ops, TAKE_PTR(s));
if (r < 0)
return log_oom();
assert(r > 0);
updated = true;
}
if (updated)
link_dirty(link);
return 0;
}
static NDiscCaptivePortal* ndisc_captive_portal_free(NDiscCaptivePortal *x) {
if (!x)
return NULL;
free(x->captive_portal);
return mfree(x);
}
DEFINE_TRIVIAL_CLEANUP_FUNC(NDiscCaptivePortal*, ndisc_captive_portal_free);
static void ndisc_captive_portal_hash_func(const NDiscCaptivePortal *x, struct siphash *state) {
assert(x);
siphash24_compress_string(x->captive_portal, state);
}
static int ndisc_captive_portal_compare_func(const NDiscCaptivePortal *a, const NDiscCaptivePortal *b) {
assert(a);
assert(b);
return strcmp_ptr(a->captive_portal, b->captive_portal);
}
DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
ndisc_captive_portal_hash_ops,
NDiscCaptivePortal,
ndisc_captive_portal_hash_func,
ndisc_captive_portal_compare_func,
ndisc_captive_portal_free);
static int ndisc_router_process_captive_portal(Link *link, sd_ndisc_router *rt, bool zero_lifetime) {
_cleanup_(ndisc_captive_portal_freep) NDiscCaptivePortal *new_entry = NULL;
_cleanup_free_ char *captive_portal = NULL;
const char *uri;
usec_t lifetime_usec;
NDiscCaptivePortal *exist;
struct in6_addr router;
int r;
assert(link);
assert(link->network);
assert(rt);
if (!link->network->ndisc_use_captive_portal)
return 0;
r = sd_ndisc_router_get_sender_address(rt, &router);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get router address from RA: %m");
/* RFC 4861 section 4.2. states that the lifetime in the message header should be used only for the
* default gateway, but the captive portal option does not have a lifetime field, hence, we use the
* main lifetime for the portal. */
r = sd_ndisc_router_get_lifetime_timestamp(rt, CLOCK_BOOTTIME, &lifetime_usec);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get lifetime of RA message: %m");
if ((lifetime_usec == 0) != zero_lifetime)
return 0;
r = sd_ndisc_router_get_captive_portal(rt, &uri);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get captive portal from RA: %m");
captive_portal = strdup(uri);
if (!captive_portal)
return log_oom();
if (lifetime_usec == 0) {
/* Drop the portal with zero lifetime. */
ndisc_captive_portal_free(set_remove(link->ndisc_captive_portals,
&(const NDiscCaptivePortal) {
.captive_portal = captive_portal,
}));
return 0;
}
exist = set_get(link->ndisc_captive_portals,
&(const NDiscCaptivePortal) {
.captive_portal = captive_portal,
});
if (exist) {
/* update existing entry */
exist->router = router;
exist->lifetime_usec = lifetime_usec;
return 1;
}
if (set_size(link->ndisc_captive_portals) >= NDISC_CAPTIVE_PORTAL_MAX) {
NDiscCaptivePortal *c, *target = NULL;
/* Find the portal who has the minimal lifetime and drop it to store new one. */
SET_FOREACH(c, link->ndisc_captive_portals)
if (!target || c->lifetime_usec < target->lifetime_usec)
target = c;
assert(target);
assert(set_remove(link->ndisc_captive_portals, target) == target);
ndisc_captive_portal_free(target);
}
new_entry = new(NDiscCaptivePortal, 1);
if (!new_entry)
return log_oom();
*new_entry = (NDiscCaptivePortal) {
.router = router,
.lifetime_usec = lifetime_usec,
.captive_portal = TAKE_PTR(captive_portal),
};
r = set_ensure_put(&link->ndisc_captive_portals, &ndisc_captive_portal_hash_ops, new_entry);
if (r < 0)
return log_oom();
assert(r > 0);
TAKE_PTR(new_entry);
link_dirty(link);
return 1;
}
static void ndisc_pref64_hash_func(const NDiscPREF64 *x, struct siphash *state) {
assert(x);
siphash24_compress_typesafe(x->prefix_len, state);
siphash24_compress_typesafe(x->prefix, state);
}
static int ndisc_pref64_compare_func(const NDiscPREF64 *a, const NDiscPREF64 *b) {
int r;
assert(a);
assert(b);
r = CMP(a->prefix_len, b->prefix_len);
if (r != 0)
return r;
return memcmp(&a->prefix, &b->prefix, sizeof(a->prefix));
}
DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
ndisc_pref64_hash_ops,
NDiscPREF64,
ndisc_pref64_hash_func,
ndisc_pref64_compare_func,
mfree);
static int ndisc_router_process_pref64(Link *link, sd_ndisc_router *rt, bool zero_lifetime) {
_cleanup_free_ NDiscPREF64 *new_entry = NULL;
usec_t lifetime_usec;
struct in6_addr a, router;
uint8_t prefix_len;
NDiscPREF64 *exist;
int r;
assert(link);
assert(link->network);
assert(rt);
if (!link->network->ndisc_use_pref64)
return 0;
r = sd_ndisc_router_get_sender_address(rt, &router);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get router address from RA: %m");
r = sd_ndisc_router_prefix64_get_prefix(rt, &a);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get pref64 prefix: %m");
r = sd_ndisc_router_prefix64_get_prefixlen(rt, &prefix_len);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get pref64 prefix length: %m");
r = sd_ndisc_router_prefix64_get_lifetime_timestamp(rt, CLOCK_BOOTTIME, &lifetime_usec);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get pref64 prefix lifetime: %m");
if ((lifetime_usec == 0) != zero_lifetime)
return 0;
if (lifetime_usec == 0) {
free(set_remove(link->ndisc_pref64,
&(NDiscPREF64) {
.prefix = a,
.prefix_len = prefix_len
}));
return 0;
}
exist = set_get(link->ndisc_pref64,
&(NDiscPREF64) {
.prefix = a,
.prefix_len = prefix_len
});
if (exist) {
/* update existing entry */
exist->router = router;
exist->lifetime_usec = lifetime_usec;
return 0;
}
if (set_size(link->ndisc_pref64) >= NDISC_PREF64_MAX) {
log_link_debug(link, "Too many PREF64 records received. Only first %u records will be used.", NDISC_PREF64_MAX);
return 0;
}
new_entry = new(NDiscPREF64, 1);
if (!new_entry)
return log_oom();
*new_entry = (NDiscPREF64) {
.router = router,
.lifetime_usec = lifetime_usec,
.prefix = a,
.prefix_len = prefix_len,
};
r = set_ensure_put(&link->ndisc_pref64, &ndisc_pref64_hash_ops, new_entry);
if (r < 0)
return log_oom();
assert(r > 0);
TAKE_PTR(new_entry);
return 0;
}
static NDiscDNR* ndisc_dnr_free(NDiscDNR *x) {
if (!x)
return NULL;
sd_dns_resolver_done(&x->resolver);
return mfree(x);
}
DEFINE_TRIVIAL_CLEANUP_FUNC(NDiscDNR*, ndisc_dnr_free);
static int ndisc_dnr_compare_func(const NDiscDNR *a, const NDiscDNR *b) {
return CMP(a->resolver.priority, b->resolver.priority) ||
strcmp_ptr(a->resolver.auth_name, b->resolver.auth_name) ||
CMP(a->resolver.transports, b->resolver.transports) ||
CMP(a->resolver.port, b->resolver.port) ||
strcmp_ptr(a->resolver.dohpath, b->resolver.dohpath) ||
CMP(a->resolver.family, b->resolver.family) ||
CMP(a->resolver.n_addrs, b->resolver.n_addrs) ||
memcmp(a->resolver.addrs, b->resolver.addrs, sizeof(a->resolver.addrs[0]) * a->resolver.n_addrs);
}
static void ndisc_dnr_hash_func(const NDiscDNR *x, struct siphash *state) {
assert(x);
siphash24_compress_resolver(&x->resolver, state);
}
DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
ndisc_dnr_hash_ops,
NDiscDNR,
ndisc_dnr_hash_func,
ndisc_dnr_compare_func,
ndisc_dnr_free);
static int sd_dns_resolver_copy(const sd_dns_resolver *a, sd_dns_resolver *b) {
int r;
assert(a);
assert(b);
_cleanup_(sd_dns_resolver_done) sd_dns_resolver c = {
.priority = a->priority,
.transports = a->transports,
.port = a->port,
/* .auth_name */
.family = a->family,
/* .addrs */
/* .n_addrs */
/* .dohpath */
};
/* auth_name */
r = strdup_to(&c.auth_name, a->auth_name);
if (r < 0)
return r;
/* addrs, n_addrs */
c.addrs = newdup(union in_addr_union, a->addrs, a->n_addrs);
if (!c.addrs)
return r;
c.n_addrs = a->n_addrs;
/* dohpath */
r = strdup_to(&c.dohpath, a->dohpath);
if (r < 0)
return r;
*b = TAKE_STRUCT(c);
return 0;
}
static int ndisc_router_process_encrypted_dns(Link *link, sd_ndisc_router *rt, bool zero_lifetime) {
int r;
assert(link);
assert(link->network);
assert(rt);
struct in6_addr router;
usec_t lifetime_usec;
sd_dns_resolver *res;
_cleanup_(ndisc_dnr_freep) NDiscDNR *new_entry = NULL;
if (!link_get_use_dnr(link, NETWORK_CONFIG_SOURCE_NDISC))
return 0;
r = sd_ndisc_router_get_sender_address(rt, &router);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get gateway address from RA: %m");
r = sd_ndisc_router_encrypted_dns_get_lifetime_timestamp(rt, CLOCK_BOOTTIME, &lifetime_usec);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get lifetime of RA message: %m");
if ((lifetime_usec == 0) != zero_lifetime)
return 0;
r = sd_ndisc_router_encrypted_dns_get_resolver(rt, &res);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get encrypted dns resolvers: %m");
NDiscDNR *dnr, d = { .resolver = *res };
if (lifetime_usec == 0) {
dnr = set_remove(link->ndisc_dnr, &d);
if (dnr) {
ndisc_dnr_free(dnr);
link_dirty(link);
}
return 0;
}
dnr = set_get(link->ndisc_dnr, &d);
if (dnr) {
dnr->router = router;
dnr->lifetime_usec = lifetime_usec;
return 0;
}
if (set_size(link->ndisc_dnr) >= NDISC_ENCRYPTED_DNS_MAX) {
log_link_warning(link, "Too many Encrypted DNS records received. Only first %u records will be used.", NDISC_ENCRYPTED_DNS_MAX);
return 0;
}
new_entry = new(NDiscDNR, 1);
if (!new_entry)
return log_oom();
*new_entry = (NDiscDNR) {
.router = router,
/* .resolver, */
.lifetime_usec = lifetime_usec,
};
r = sd_dns_resolver_copy(res, &new_entry->resolver);
if (r < 0)
return log_oom();
/* Not sorted by priority */
r = set_ensure_put(&link->ndisc_dnr, &ndisc_dnr_hash_ops, new_entry);
if (r < 0)
return log_oom();
assert(r > 0);
TAKE_PTR(new_entry);
link_dirty(link);
return 0;
}
static int ndisc_router_process_options(Link *link, sd_ndisc_router *rt, bool zero_lifetime) {
size_t n_captive_portal = 0;
int r;
assert(link);
assert(link->network);
assert(rt);
for (r = sd_ndisc_router_option_rewind(rt); ; r = sd_ndisc_router_option_next(rt)) {
uint8_t type;
if (r < 0)
return log_link_warning_errno(link, r, "Failed to iterate through options: %m");
if (r == 0) /* EOF */
return 0;
r = sd_ndisc_router_option_get_type(rt, &type);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get RA option type: %m");
switch (type) {
case SD_NDISC_OPTION_PREFIX_INFORMATION:
r = ndisc_router_process_prefix(link, rt, zero_lifetime);
break;
case SD_NDISC_OPTION_ROUTE_INFORMATION:
r = ndisc_router_process_route(link, rt, zero_lifetime);
break;
case SD_NDISC_OPTION_RDNSS:
r = ndisc_router_process_rdnss(link, rt, zero_lifetime);
break;
case SD_NDISC_OPTION_DNSSL:
r = ndisc_router_process_dnssl(link, rt, zero_lifetime);
break;
case SD_NDISC_OPTION_CAPTIVE_PORTAL:
if (n_captive_portal > 0) {
if (n_captive_portal == 1)
log_link_notice(link, "Received RA with multiple captive portals, only using the first one.");
n_captive_portal++;
continue;
}
r = ndisc_router_process_captive_portal(link, rt, zero_lifetime);
if (r > 0)
n_captive_portal++;
break;
case SD_NDISC_OPTION_PREF64:
r = ndisc_router_process_pref64(link, rt, zero_lifetime);
break;
case SD_NDISC_OPTION_ENCRYPTED_DNS:
r = ndisc_router_process_encrypted_dns(link, rt, zero_lifetime);
break;
}
if (r < 0 && r != -EBADMSG)
return r;
}
}
static int ndisc_drop_outdated(Link *link, const struct in6_addr *router, usec_t timestamp_usec) {
bool updated = false;
NDiscDNSSL *dnssl;
NDiscRDNSS *rdnss;
NDiscCaptivePortal *cp;
NDiscPREF64 *p64;
NDiscDNR *dnr;
Address *address;
Route *route;
int r, ret = 0;
assert(link);
assert(link->manager);
/* If an address or friends is already assigned, but not valid anymore, then refuse to update it,
* and let's immediately remove it.
* See RFC4862, section 5.5.3.e. But the following logic is deviated from RFC4862 by honoring all
* valid lifetimes to improve the reaction of SLAAC to renumbering events.
* See draft-ietf-6man-slaac-renum-02, section 4.2. */
r = ndisc_drop_routers(link, router, timestamp_usec);
if (r < 0)
RET_GATHER(ret, log_link_warning_errno(link, r, "Failed to drop outdated default router, ignoring: %m"));
SET_FOREACH(route, link->manager->routes) {
if (route->source != NETWORK_CONFIG_SOURCE_NDISC)
continue;
if (!route_is_bound_to_link(route, link))
continue;
if (route->protocol == RTPROT_REDIRECT)
continue; /* redirect route will be dropped by ndisc_drop_redirect(). */
if (route->lifetime_usec > timestamp_usec)
continue; /* the route is still valid */
if (router && !in6_addr_equal(&route->provider.in6, router))
continue;
r = route_remove_and_cancel(route, link->manager);
if (r < 0)
RET_GATHER(ret, log_link_warning_errno(link, r, "Failed to remove outdated SLAAC route, ignoring: %m"));
}
RET_GATHER(ret, ndisc_remove_unused_nexthops(link));
SET_FOREACH(address, link->addresses) {
if (address->source != NETWORK_CONFIG_SOURCE_NDISC)
continue;
if (address->lifetime_valid_usec > timestamp_usec)
continue; /* the address is still valid */
if (router && !in6_addr_equal(&address->provider.in6, router))
continue;
r = address_remove_and_cancel(address, link);
if (r < 0)
RET_GATHER(ret, log_link_warning_errno(link, r, "Failed to remove outdated SLAAC address, ignoring: %m"));
}
SET_FOREACH(rdnss, link->ndisc_rdnss) {
if (rdnss->lifetime_usec > timestamp_usec)
continue; /* the DNS server is still valid */
if (router && !in6_addr_equal(&rdnss->router, router))
continue;
free(set_remove(link->ndisc_rdnss, rdnss));
updated = true;
}
SET_FOREACH(dnssl, link->ndisc_dnssl) {
if (dnssl->lifetime_usec > timestamp_usec)
continue; /* the DNS domain is still valid */
if (router && !in6_addr_equal(&dnssl->router, router))
continue;
free(set_remove(link->ndisc_dnssl, dnssl));
updated = true;
}
SET_FOREACH(cp, link->ndisc_captive_portals) {
if (cp->lifetime_usec > timestamp_usec)
continue; /* the captive portal is still valid */
if (router && !in6_addr_equal(&cp->router, router))
continue;
ndisc_captive_portal_free(set_remove(link->ndisc_captive_portals, cp));
updated = true;
}
SET_FOREACH(p64, link->ndisc_pref64) {
if (p64->lifetime_usec > timestamp_usec)
continue; /* the pref64 prefix is still valid */
if (router && !in6_addr_equal(&p64->router, router))
continue;
free(set_remove(link->ndisc_pref64, p64));
/* The pref64 prefix is not exported through the state file, hence it is not necessary to set
* the 'updated' flag. */
}
SET_FOREACH(dnr, link->ndisc_dnr) {
if (dnr->lifetime_usec > timestamp_usec)
continue; /* The resolver is still valid */
ndisc_dnr_free(set_remove(link->ndisc_dnr, dnr));
updated = true;
}
RET_GATHER(ret, link_request_stacked_netdevs(link, NETDEV_LOCAL_ADDRESS_SLAAC));
if (updated)
link_dirty(link);
return ret;
}
static int ndisc_setup_expire(Link *link);
static int ndisc_expire_handler(sd_event_source *s, uint64_t usec, void *userdata) {
Link *link = ASSERT_PTR(userdata);
usec_t now_usec;
assert(link->manager);
assert_se(sd_event_now(link->manager->event, CLOCK_BOOTTIME, &now_usec) >= 0);
(void) ndisc_drop_outdated(link, /* router = */ NULL, now_usec);
(void) ndisc_setup_expire(link);
return 0;
}
static int ndisc_setup_expire(Link *link) {
usec_t lifetime_usec = USEC_INFINITY;
NDiscCaptivePortal *cp;
NDiscDNSSL *dnssl;
NDiscRDNSS *rdnss;
NDiscPREF64 *p64;
NDiscDNR *dnr;
Address *address;
Route *route;
int r;
assert(link);
assert(link->manager);
sd_ndisc_router *rt;
HASHMAP_FOREACH(rt, link->ndisc_routers_by_sender) {
usec_t t;
if (sd_ndisc_router_get_lifetime_timestamp(rt, CLOCK_BOOTTIME, &t) < 0)
continue;
lifetime_usec = MIN(lifetime_usec, t);
}
SET_FOREACH(route, link->manager->routes) {
if (route->source != NETWORK_CONFIG_SOURCE_NDISC)
continue;
if (!route_is_bound_to_link(route, link))
continue;
if (!route_exists(route))
continue;
lifetime_usec = MIN(lifetime_usec, route->lifetime_usec);
}
SET_FOREACH(address, link->addresses) {
if (address->source != NETWORK_CONFIG_SOURCE_NDISC)
continue;
if (!address_exists(address))
continue;
lifetime_usec = MIN(lifetime_usec, address->lifetime_valid_usec);
}
SET_FOREACH(rdnss, link->ndisc_rdnss)
lifetime_usec = MIN(lifetime_usec, rdnss->lifetime_usec);
SET_FOREACH(dnssl, link->ndisc_dnssl)
lifetime_usec = MIN(lifetime_usec, dnssl->lifetime_usec);
SET_FOREACH(cp, link->ndisc_captive_portals)
lifetime_usec = MIN(lifetime_usec, cp->lifetime_usec);
SET_FOREACH(p64, link->ndisc_pref64)
lifetime_usec = MIN(lifetime_usec, p64->lifetime_usec);
SET_FOREACH(dnr, link->ndisc_dnr)
lifetime_usec = MIN(lifetime_usec, dnr->lifetime_usec);
if (lifetime_usec == USEC_INFINITY)
return 0;
r = event_reset_time(link->manager->event, &link->ndisc_expire, CLOCK_BOOTTIME,
lifetime_usec, 0, ndisc_expire_handler, link, 0, "ndisc-expiration", true);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to update expiration timer for ndisc: %m");
return 0;
}
static int ndisc_start_dhcp6_client(Link *link, sd_ndisc_router *rt) {
int r;
assert(link);
assert(link->network);
switch (link->network->ndisc_start_dhcp6_client) {
case IPV6_ACCEPT_RA_START_DHCP6_CLIENT_NO:
return 0;
case IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES: {
uint64_t flags;
r = sd_ndisc_router_get_flags(rt, &flags);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get RA flags: %m");
if ((flags & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER)) == 0)
return 0;
/* (re)start DHCPv6 client in stateful or stateless mode according to RA flags.
* Note, if both "managed" and "other configuration" bits are set, then ignore
* "other configuration" bit. See RFC 4861. */
r = dhcp6_start_on_ra(link, !(flags & ND_RA_FLAG_MANAGED));
break;
}
case IPV6_ACCEPT_RA_START_DHCP6_CLIENT_ALWAYS:
/* When IPv6AcceptRA.DHCPv6Client=always, start dhcp6 client in solicit mode
* even if the router flags have neither M nor O flags. */
r = dhcp6_start_on_ra(link, /* information_request = */ false);
break;
default:
assert_not_reached();
}
if (r < 0)
return log_link_warning_errno(link, r, "Could not acquire DHCPv6 lease on NDisc request: %m");
log_link_debug(link, "Acquiring DHCPv6 lease on NDisc request");
return 0;
}
static int ndisc_router_handler(Link *link, sd_ndisc_router *rt) {
struct in6_addr router;
usec_t timestamp_usec;
int r;
assert(link);
assert(link->network);
assert(link->manager);
assert(rt);
r = sd_ndisc_router_get_sender_address(rt, &router);
if (r == -ENODATA) {
log_link_debug(link, "Received RA without router address, ignoring.");
return 0;
}
if (r < 0)
return log_link_warning_errno(link, r, "Failed to get router address from RA: %m");
if (in6_prefix_is_filtered(&router, 128, link->network->ndisc_allow_listed_router, link->network->ndisc_deny_listed_router)) {
if (!set_isempty(link->network->ndisc_allow_listed_router))
log_link_debug(link, "Router %s is not in allow list, ignoring.", IN6_ADDR_TO_STRING(&router));
else
log_link_debug(link, "Router %s is in deny list, ignoring.", IN6_ADDR_TO_STRING(&router));
return 0;
}
r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, &timestamp_usec);
if (r == -ENODATA) {
log_link_debug(link, "Received RA without timestamp, ignoring.");
return 0;
}
if (r < 0)
return r;
r = ndisc_drop_outdated(link, /* router = */ NULL, timestamp_usec);
if (r < 0)
return r;
r = ndisc_remember_router(link, rt);
if (r < 0)
return r;
r = ndisc_start_dhcp6_client(link, rt);
if (r < 0)
return r;
r = ndisc_router_process_reachable_time(link, rt);
if (r < 0)
return r;
r = ndisc_router_process_retransmission_time(link, rt);
if (r < 0)
return r;
r = ndisc_router_process_hop_limit(link, rt);
if (r < 0)
return r;
r = ndisc_router_process_mtu(link, rt);
if (r < 0)
return r;
r = ndisc_router_process_options(link, rt, /* zero_lifetime = */ true);
if (r < 0)
return r;
r = ndisc_router_process_default(link, rt);
if (r < 0)
return r;
r = ndisc_router_process_options(link, rt, /* zero_lifetime = */ false);
if (r < 0)
return r;
r = ndisc_setup_expire(link);
if (r < 0)
return r;
if (sd_ndisc_router_get_lifetime(rt, NULL) <= 0)
(void) ndisc_drop_redirect(link, &router);
if (link->ndisc_messages == 0)
link->ndisc_configured = true;
else
log_link_debug(link, "Setting SLAAC addresses and router.");
if (!link->ndisc_configured)
link_set_state(link, LINK_STATE_CONFIGURING);
link_check_ready(link);
return 0;
}
static int ndisc_neighbor_handle_non_router_message(Link *link, sd_ndisc_neighbor *na) {
struct in6_addr address;
int r;
assert(link);
assert(na);
/* Received Neighbor Advertisement message without Router flag. The node might have been a router,
* and now it is not. Let's drop all configurations based on RAs sent from the node. */
r = sd_ndisc_neighbor_get_target_address(na, &address);
if (r == -ENODATA)
return 0;
if (r < 0)
return r;
(void) ndisc_drop_outdated(link, /* router = */ &address, /* timestamp_usec = */ USEC_INFINITY);
(void) ndisc_drop_redirect(link, &address);
return 0;
}
static int ndisc_neighbor_handle_router_message(Link *link, sd_ndisc_neighbor *na) {
struct in6_addr current_address, original_address;
int r;
assert(link);
assert(link->manager);
assert(na);
/* Received Neighbor Advertisement message with Router flag. If the router address is changed, update
* the provider field of configurations. */
r = sd_ndisc_neighbor_get_sender_address(na, &current_address);
if (r == -ENODATA)
return 0;
if (r < 0)
return r;
r = sd_ndisc_neighbor_get_target_address(na, &original_address);
if (r == -ENODATA)
return 0;
if (r < 0)
return r;
if (in6_addr_equal(&current_address, &original_address))
return 0; /* the router address is not changed */
r = ndisc_update_router_address(link, &original_address, &current_address);
if (r < 0)
return r;
r = ndisc_update_redirect_sender(link, &original_address, &current_address);
if (r < 0)
return r;
Route *route;
SET_FOREACH(route, link->manager->routes) {
if (route->source != NETWORK_CONFIG_SOURCE_NDISC)
continue;
if (!route_is_bound_to_link(route, link))
continue;
if (!in6_addr_equal(&route->provider.in6, &original_address))
continue;
route->provider.in6 = current_address;
}
Address *address;
SET_FOREACH(address, link->addresses) {
if (address->source != NETWORK_CONFIG_SOURCE_NDISC)
continue;
if (!in6_addr_equal(&address->provider.in6, &original_address))
continue;
address->provider.in6 = current_address;
}
NDiscRDNSS *rdnss;
SET_FOREACH(rdnss, link->ndisc_rdnss) {
if (!in6_addr_equal(&rdnss->router, &original_address))
continue;
rdnss->router = current_address;
}
NDiscDNSSL *dnssl;
SET_FOREACH(dnssl, link->ndisc_dnssl) {
if (!in6_addr_equal(&dnssl->router, &original_address))
continue;
dnssl->router = current_address;
}
NDiscCaptivePortal *cp;
SET_FOREACH(cp, link->ndisc_captive_portals) {
if (!in6_addr_equal(&cp->router, &original_address))
continue;
cp->router = current_address;
}
NDiscPREF64 *p64;
SET_FOREACH(p64, link->ndisc_pref64) {
if (!in6_addr_equal(&p64->router, &original_address))
continue;
p64->router = current_address;
}
NDiscDNR *dnr;
SET_FOREACH(dnr, link->ndisc_dnr) {
if (!in6_addr_equal(&dnr->router, &original_address))
continue;
dnr->router = current_address;
}
return 0;
}
static int ndisc_neighbor_handler(Link *link, sd_ndisc_neighbor *na) {
int r;
assert(link);
assert(na);
r = sd_ndisc_neighbor_is_router(na);
if (r < 0)
return r;
if (r == 0)
r = ndisc_neighbor_handle_non_router_message(link, na);
else
r = ndisc_neighbor_handle_router_message(link, na);
if (r < 0)
return r;
return 0;
}
static void ndisc_handler(sd_ndisc *nd, sd_ndisc_event_t event, void *message, void *userdata) {
Link *link = ASSERT_PTR(userdata);
int r;
if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
return;
switch (event) {
case SD_NDISC_EVENT_ROUTER:
r = ndisc_router_handler(link, ASSERT_PTR(message));
if (r < 0 && r != -EBADMSG) {
link_enter_failed(link);
return;
}
break;
case SD_NDISC_EVENT_NEIGHBOR:
r = ndisc_neighbor_handler(link, ASSERT_PTR(message));
if (r < 0 && r != -EBADMSG) {
link_enter_failed(link);
return;
}
break;
case SD_NDISC_EVENT_REDIRECT:
r = ndisc_redirect_handler(link, ASSERT_PTR(message));
if (r < 0 && r != -EBADMSG) {
log_link_warning_errno(link, r, "Failed to process Redirect message: %m");
link_enter_failed(link);
return;
}
break;
case SD_NDISC_EVENT_TIMEOUT:
log_link_debug(link, "NDisc handler get timeout event");
if (link->ndisc_messages == 0) {
link->ndisc_configured = true;
link_check_ready(link);
}
break;
default:
log_link_debug(link, "Received unsupported NDisc event, ignoring.");
}
}
static int ndisc_configure(Link *link) {
int r;
assert(link);
if (!link_ndisc_enabled(link))
return 0;
if (link->ndisc)
return -EBUSY; /* Already configured. */
r = sd_ndisc_new(&link->ndisc);
if (r < 0)
return r;
r = sd_ndisc_attach_event(link->ndisc, link->manager->event, 0);
if (r < 0)
return r;
if (link->hw_addr.length == ETH_ALEN) {
r = sd_ndisc_set_mac(link->ndisc, &link->hw_addr.ether);
if (r < 0)
return r;
}
r = sd_ndisc_set_ifindex(link->ndisc, link->ifindex);
if (r < 0)
return r;
r = sd_ndisc_set_callback(link->ndisc, ndisc_handler, link);
if (r < 0)
return r;
return 0;
}
int ndisc_start(Link *link) {
int r;
assert(link);
if (!link->ndisc || !link->dhcp6_client)
return 0;
if (!link_has_carrier(link))
return 0;
if (in6_addr_is_null(&link->ipv6ll_address))
return 0;
r = sd_ndisc_set_link_local_address(link->ndisc, &link->ipv6ll_address);
if (r < 0)
return r;
log_link_debug(link, "Discovering IPv6 routers");
r = sd_ndisc_start(link->ndisc);
if (r < 0)
return r;
return 1;
}
static int ndisc_process_request(Request *req, Link *link, void *userdata) {
int r;
assert(link);
if (!link_is_ready_to_configure(link, /* allow_unmanaged = */ false))
return 0;
r = ndisc_configure(link);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to configure IPv6 Router Discovery: %m");
r = ndisc_start(link);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to start IPv6 Router Discovery: %m");
log_link_debug(link, "IPv6 Router Discovery is configured%s.",
r > 0 ? " and started" : "");
return 1;
}
int link_request_ndisc(Link *link) {
int r;
assert(link);
if (!link_ndisc_enabled(link))
return 0;
if (link->ndisc)
return 0;
r = link_queue_request(link, REQUEST_TYPE_NDISC, ndisc_process_request, NULL);
if (r < 0)
return log_link_warning_errno(link, r, "Failed to request configuring of the IPv6 Router Discovery: %m");
log_link_debug(link, "Requested configuring of the IPv6 Router Discovery.");
return 0;
}
int link_drop_ndisc_config(Link *link, Network *network) {
int r, ret = 0;
assert(link);
assert(link->network);
if (link->network == network)
return 0; /* .network file is unchanged. It is not necessary to reconfigure the client. */
if (!link_ndisc_enabled(link)) {
/* NDisc is disabled. Stop the client if it is running and flush configs. */
ret = ndisc_stop(link);
ndisc_flush(link);
link->ndisc = sd_ndisc_unref(link->ndisc);
return ret;
}
/* Even if the client was previously enabled and also enabled in the new .network file, detailed
* settings for the client may be different. Let's unref() the client. */
link->ndisc = sd_ndisc_unref(link->ndisc);
/* Get if NDisc was enabled or not. */
Network *current = link->network;
link->network = network;
bool enabled = link_ndisc_enabled(link);
link->network = current;
/* If previously explicitly disabled, there should be nothing to drop.
* If we do not know the previous setting of the client, e.g. when networkd is restarted, in that
* case we do not have the previous .network file assigned to the interface, then let's assume no
* detailed configuration is changed. Hopefully, unmatching configurations will be dropped after
* their lifetime. */
if (!enabled)
return 0;
assert(network);
/* Redirect messages will be ignored. Drop configurations based on the previously received redirect
* messages. */
if (!network->ndisc_use_redirect)
(void) ndisc_drop_redirect(link, /* router = */ NULL);
/* If one of the route setting is changed, drop all routes. */
if (link->network->ndisc_use_gateway != network->ndisc_use_gateway ||
link->network->ndisc_use_route_prefix != network->ndisc_use_route_prefix ||
link->network->ndisc_use_onlink_prefix != network->ndisc_use_onlink_prefix ||
link->network->ndisc_quickack != network->ndisc_quickack ||
link->network->ndisc_route_metric_high != network->ndisc_route_metric_high ||
link->network->ndisc_route_metric_medium != network->ndisc_route_metric_medium ||
link->network->ndisc_route_metric_low != network->ndisc_route_metric_low ||
!set_equal(link->network->ndisc_deny_listed_router, network->ndisc_deny_listed_router) ||
!set_equal(link->network->ndisc_allow_listed_router, network->ndisc_allow_listed_router) ||
!set_equal(link->network->ndisc_deny_listed_prefix, network->ndisc_deny_listed_prefix) ||
!set_equal(link->network->ndisc_allow_listed_prefix, network->ndisc_allow_listed_prefix) ||
!set_equal(link->network->ndisc_deny_listed_route_prefix, network->ndisc_deny_listed_route_prefix) ||
!set_equal(link->network->ndisc_allow_listed_route_prefix, network->ndisc_allow_listed_route_prefix)) {
Route *route;
SET_FOREACH(route, link->manager->routes) {
if (route->source != NETWORK_CONFIG_SOURCE_NDISC)
continue;
if (!route_is_bound_to_link(route, link))
continue;
if (route->protocol == RTPROT_REDIRECT)
continue; /* redirect route is handled by ndisc_drop_redirect(). */
r = route_remove_and_cancel(route, link->manager);
if (r < 0)
RET_GATHER(ret, log_link_warning_errno(link, r, "Failed to remove SLAAC route, ignoring: %m"));
}
RET_GATHER(ret, ndisc_remove_unused_nexthops(link));
}
/* If SLAAC address is disabled, drop all addresses. */
if (!network->ndisc_use_autonomous_prefix ||
!set_equal(link->network->ndisc_tokens, network->ndisc_tokens) ||
!set_equal(link->network->ndisc_deny_listed_prefix, network->ndisc_deny_listed_prefix) ||
!set_equal(link->network->ndisc_allow_listed_prefix, network->ndisc_allow_listed_prefix)) {
Address *address;
SET_FOREACH(address, link->addresses) {
if (address->source != NETWORK_CONFIG_SOURCE_NDISC)
continue;
r = address_remove_and_cancel(address, link);
if (r < 0)
RET_GATHER(ret, log_link_warning_errno(link, r, "Failed to remove SLAAC address, ignoring: %m"));
}
}
if (!network->ndisc_use_mtu)
link->ndisc_mtu = 0;
return ret;
}
int ndisc_stop(Link *link) {
assert(link);
link->ndisc_expire = sd_event_source_disable_unref(link->ndisc_expire);
return sd_ndisc_stop(link->ndisc);
}
void ndisc_flush(Link *link) {
assert(link);
/* Remove all addresses, routes, RDNSS, DNSSL, DNR, and Captive Portal entries, without exception. */
(void) ndisc_drop_outdated(link, /* router = */ NULL, /* timestamp_usec = */ USEC_INFINITY);
(void) ndisc_drop_redirect(link, /* router = */ NULL);
link->ndisc_routers_by_sender = hashmap_free(link->ndisc_routers_by_sender);
link->ndisc_rdnss = set_free(link->ndisc_rdnss);
link->ndisc_dnssl = set_free(link->ndisc_dnssl);
link->ndisc_captive_portals = set_free(link->ndisc_captive_portals);
link->ndisc_pref64 = set_free(link->ndisc_pref64);
link->ndisc_redirects = set_free(link->ndisc_redirects);
link->ndisc_dnr = set_free(link->ndisc_dnr);
link->ndisc_mtu = 0;
}
static const char* const ndisc_start_dhcp6_client_table[_IPV6_ACCEPT_RA_START_DHCP6_CLIENT_MAX] = {
[IPV6_ACCEPT_RA_START_DHCP6_CLIENT_NO] = "no",
[IPV6_ACCEPT_RA_START_DHCP6_CLIENT_ALWAYS] = "always",
[IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES] = "yes",
};
DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING_WITH_BOOLEAN(ndisc_start_dhcp6_client, IPv6AcceptRAStartDHCP6Client, IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES);
DEFINE_CONFIG_PARSE_ENUM(config_parse_ndisc_start_dhcp6_client, ndisc_start_dhcp6_client, IPv6AcceptRAStartDHCP6Client);
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