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systemd/src/network/networkd-ndisc.c
Ronan Pigott 9747955d2d ndisc: parse RFC8910 captive portal ipv6ra option
2023-07-02 01:13:29 -07:00

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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 "networkd-address-generation.h"
#include "networkd-address.h"
#include "networkd-dhcp6.h"
#include "networkd-manager.h"
#include "networkd-ndisc.h"
#include "networkd-queue.h"
#include "networkd-route.h"
#include "networkd-state-file.h"
#include "string-table.h"
#include "string-util.h"
#include "strv.h"
#define NDISC_DNSSL_MAX 64U
#define NDISC_RDNSS_MAX 64U
bool link_ipv6_accept_ra_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;
assert(link->network->ipv6_accept_ra >= 0);
return link->network->ipv6_accept_ra;
}
void network_adjust_ipv6_accept_ra(Network *network) {
assert(network);
if (!FLAGS_SET(network->link_local, ADDRESS_FAMILY_IPV6)) {
if (network->ipv6_accept_ra > 0)
log_warning("%s: IPv6AcceptRA= is enabled but IPv6 link-local addressing is disabled or not supported. "
"Disabling IPv6AcceptRA=.", network->filename);
network->ipv6_accept_ra = false;
}
if (network->ipv6_accept_ra < 0)
/* default to accept RA if ip_forward is disabled and ignore RA if ip_forward is enabled */
network->ipv6_accept_ra = !FLAGS_SET(network->ip_forward, ADDRESS_FAMILY_IPV6);
/* 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_route_handler(sd_netlink *rtnl, sd_netlink_message *m, Request *req, Link *link, Route *route) {
int r;
assert(link);
r = route_configure_handler_internal(rtnl, 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 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->ipv6_accept_ra_route_metric_low;
break;
case SD_NDISC_PREFERENCE_MEDIUM:
route->priority = link->network->ipv6_accept_ra_route_metric_medium;
break;
case SD_NDISC_PREFERENCE_HIGH:
route->priority = link->network->ipv6_accept_ra_route_metric_high;
break;
default:
assert_not_reached();
}
}
static int ndisc_request_route(Route *in, Link *link, sd_ndisc_router *rt) {
_cleanup_(route_freep) Route *route = in;
struct in6_addr router;
bool is_new;
int r;
assert(route);
assert(link);
assert(link->network);
assert(rt);
r = sd_ndisc_router_get_address(rt, &router);
if (r < 0)
return r;
route->source = NETWORK_CONFIG_SOURCE_NDISC;
route->provider.in6 = router;
if (!route->table_set)
route->table = link_get_ipv6_accept_ra_route_table(link);
ndisc_set_route_priority(link, route);
if (!route->protocol_set)
route->protocol = RTPROT_RA;
if (route->quickack < 0)
route->quickack = link->network->ipv6_accept_ra_quickack;
is_new = route_get(NULL, link, route, NULL) < 0;
r = link_request_route(link, TAKE_PTR(route), true, &link->ndisc_messages,
ndisc_route_handler, NULL);
if (r < 0)
return r;
if (r > 0 && is_new)
link->ndisc_configured = false;
return 0;
}
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 *in, Link *link, sd_ndisc_router *rt) {
_cleanup_(address_freep) Address *address = in;
struct in6_addr router;
bool is_new;
int r;
assert(address);
assert(link);
assert(rt);
r = sd_ndisc_router_get_address(rt, &router);
if (r < 0)
return r;
address->source = NETWORK_CONFIG_SOURCE_NDISC;
address->provider.in6 = router;
r = free_and_strdup_warn(&address->netlabel, link->network->ndisc_netlabel);
if (r < 0)
return r;
is_new = address_get(link, address, NULL) < 0;
r = link_request_address(link, TAKE_PTR(address), true, &link->ndisc_messages,
ndisc_address_handler, NULL);
if (r < 0)
return r;
if (r > 0 && is_new)
link->ndisc_configured = false;
return 0;
}
static int ndisc_router_process_default(Link *link, sd_ndisc_router *rt) {
usec_t lifetime_usec, timestamp_usec;
struct in6_addr gateway;
uint16_t lifetime_sec;
unsigned preference;
uint32_t mtu = 0;
int r;
assert(link);
assert(link->network);
assert(rt);
if (!link->network->ipv6_accept_ra_use_gateway &&
hashmap_isempty(link->network->routes_by_section))
return 0;
r = sd_ndisc_router_get_lifetime(rt, &lifetime_sec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get gateway lifetime from RA: %m");
r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, &timestamp_usec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
lifetime_usec = sec16_to_usec(lifetime_sec, timestamp_usec);
r = sd_ndisc_router_get_address(rt, &gateway);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get gateway address from RA: %m");
if (link_get_ipv6_address(link, &gateway, 0, NULL) >= 0) {
if (DEBUG_LOGGING)
log_link_debug(link, "No NDisc route added, gateway %s matches local address",
IN6_ADDR_TO_STRING(&gateway));
return 0;
}
r = sd_ndisc_router_get_preference(rt, &preference);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get default router preference from RA: %m");
if (link->network->ipv6_accept_ra_use_mtu) {
r = sd_ndisc_router_get_mtu(rt, &mtu);
if (r < 0 && r != -ENODATA)
return log_link_error_errno(link, r, "Failed to get default router MTU from RA: %m");
}
if (link->network->ipv6_accept_ra_use_gateway) {
_cleanup_(route_freep) Route *route = NULL;
r = route_new(&route);
if (r < 0)
return log_oom();
route->family = AF_INET6;
route->pref = preference;
route->gw_family = AF_INET6;
route->gw.in6 = gateway;
route->lifetime_usec = lifetime_usec;
route->mtu = mtu;
r = ndisc_request_route(TAKE_PTR(route), link, rt);
if (r < 0)
return log_link_error_errno(link, r, "Could not request default route: %m");
}
Route *route_gw;
HASHMAP_FOREACH(route_gw, link->network->routes_by_section) {
_cleanup_(route_freep) Route *route = NULL;
if (!route_gw->gateway_from_dhcp_or_ra)
continue;
if (route_gw->gw_family != AF_INET6)
continue;
r = route_dup(route_gw, &route);
if (r < 0)
return r;
route->gw.in6 = gateway;
if (!route->pref_set)
route->pref = preference;
route->lifetime_usec = lifetime_usec;
if (route->mtu == 0)
route->mtu = mtu;
r = ndisc_request_route(TAKE_PTR(route), link, rt);
if (r < 0)
return log_link_error_errno(link, r, "Could not request gateway: %m");
}
return 0;
}
static int ndisc_router_process_autonomous_prefix(Link *link, sd_ndisc_router *rt) {
uint32_t lifetime_valid_sec, lifetime_preferred_sec;
usec_t lifetime_valid_usec, lifetime_preferred_usec, timestamp_usec;
_cleanup_set_free_ Set *addresses = NULL;
struct in6_addr prefix, *a;
unsigned prefixlen;
int r;
assert(link);
assert(link->network);
assert(rt);
if (!link->network->ipv6_accept_ra_use_autonomous_prefix)
return 0;
r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, &timestamp_usec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
r = sd_ndisc_router_prefix_get_address(rt, &prefix);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get prefix address: %m");
r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
if (r < 0)
return log_link_error_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_sec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get prefix valid lifetime: %m");
r = sd_ndisc_router_prefix_get_preferred_lifetime(rt, &lifetime_preferred_sec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get prefix preferred lifetime: %m");
/* The preferred lifetime is never greater than the valid lifetime */
if (lifetime_preferred_sec > lifetime_valid_sec)
return 0;
lifetime_valid_usec = sec_to_usec(lifetime_valid_sec, timestamp_usec);
lifetime_preferred_usec = sec_to_usec(lifetime_preferred_sec, timestamp_usec);
r = ndisc_generate_addresses(link, &prefix, prefixlen, &addresses);
if (r < 0)
return log_link_error_errno(link, r, "Failed to generate SLAAC addresses: %m");
SET_FOREACH(a, addresses) {
_cleanup_(address_freep) Address *address = NULL;
r = address_new(&address);
if (r < 0)
return log_oom();
address->family = AF_INET6;
address->in_addr.in6 = *a;
address->prefixlen = prefixlen;
address->flags = IFA_F_NOPREFIXROUTE|IFA_F_MANAGETEMPADDR;
address->lifetime_valid_usec = lifetime_valid_usec;
address->lifetime_preferred_usec = lifetime_preferred_usec;
r = ndisc_request_address(TAKE_PTR(address), link, rt);
if (r < 0)
return log_link_error_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_freep) Route *route = NULL;
usec_t timestamp_usec;
uint32_t lifetime_sec;
struct in6_addr prefix;
unsigned prefixlen;
int r;
assert(link);
assert(link->network);
assert(rt);
if (!link->network->ipv6_accept_ra_use_onlink_prefix)
return 0;
r = sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_sec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get prefix lifetime: %m");
r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, &timestamp_usec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
r = sd_ndisc_router_prefix_get_address(rt, &prefix);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get prefix address: %m");
r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get prefix length: %m");
r = route_new(&route);
if (r < 0)
return log_oom();
route->family = AF_INET6;
route->dst.in6 = prefix;
route->dst_prefixlen = prefixlen;
route->lifetime_usec = sec_to_usec(lifetime_sec, timestamp_usec);
r = ndisc_request_route(TAKE_PTR(route), link, rt);
if (r < 0)
return log_link_error_errno(link, r, "Could not request prefix route: %m");
return 0;
}
static int ndisc_router_process_prefix(Link *link, sd_ndisc_router *rt) {
unsigned prefixlen;
struct in6_addr a;
uint8_t flags;
int r;
assert(link);
assert(link->network);
assert(rt);
r = sd_ndisc_router_prefix_get_address(rt, &a);
if (r < 0)
return log_link_error_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 autonomous prefix.");
return 0;
}
r = sd_ndisc_router_prefix_get_prefixlen(rt, &prefixlen);
if (r < 0)
return log_link_error_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 (DEBUG_LOGGING)
log_link_debug(link, "Prefix '%s' is %s, ignoring",
!set_isempty(link->network->ndisc_allow_listed_prefix) ? "not in allow list"
: "in deny list",
IN6_ADDR_PREFIX_TO_STRING(&a, prefixlen));
return 0;
}
r = sd_ndisc_router_prefix_get_flags(rt, &flags);
if (r < 0)
return log_link_error_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) {
_cleanup_(route_freep) Route *route = NULL;
unsigned preference, prefixlen;
struct in6_addr gateway, dst;
uint32_t lifetime_sec;
usec_t timestamp_usec;
int r;
assert(link);
if (!link->network->ipv6_accept_ra_use_route_prefix)
return 0;
r = sd_ndisc_router_route_get_lifetime(rt, &lifetime_sec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get route lifetime from RA: %m");
r = sd_ndisc_router_route_get_address(rt, &dst);
if (r < 0)
return log_link_error_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_error_errno(link, r, "Failed to get route prefix length: %m");
if (in6_addr_is_null(&dst) && prefixlen == 0) {
log_link_debug(link, "Route prefix is ::/0, ignoring");
return 0;
}
if (in6_prefix_is_filtered(&dst, prefixlen,
link->network->ndisc_allow_listed_route_prefix,
link->network->ndisc_deny_listed_route_prefix)) {
if (DEBUG_LOGGING)
log_link_debug(link, "Route prefix %s is %s, ignoring",
!set_isempty(link->network->ndisc_allow_listed_route_prefix) ? "not in allow list"
: "in deny list",
IN6_ADDR_PREFIX_TO_STRING(&dst, prefixlen));
return 0;
}
r = sd_ndisc_router_get_address(rt, &gateway);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get gateway address from RA: %m");
if (link_get_ipv6_address(link, &gateway, 0, 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_error_errno(link, r, "Failed to get default router preference from RA: %m");
r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, &timestamp_usec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
r = route_new(&route);
if (r < 0)
return log_oom();
route->family = AF_INET6;
route->pref = preference;
route->gw.in6 = gateway;
route->gw_family = AF_INET6;
route->dst.in6 = dst;
route->dst_prefixlen = prefixlen;
route->lifetime_usec = sec_to_usec(lifetime_sec, timestamp_usec);
r = ndisc_request_route(TAKE_PTR(route), link, rt);
if (r < 0)
return log_link_error_errno(link, r, "Could not request additional route: %m");
return 0;
}
static void ndisc_rdnss_hash_func(const NDiscRDNSS *x, struct siphash *state) {
siphash24_compress(&x->address, sizeof(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) {
usec_t lifetime_usec, timestamp_usec;
uint32_t lifetime_sec;
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->network->ipv6_accept_ra_use_dns)
return 0;
r = sd_ndisc_router_get_address(rt, &router);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, &timestamp_usec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
r = sd_ndisc_router_rdnss_get_lifetime(rt, &lifetime_sec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get RDNSS lifetime: %m");
lifetime_usec = sec_to_usec(lifetime_sec, timestamp_usec);
n = sd_ndisc_router_rdnss_get_addresses(rt, &a);
if (n < 0)
return log_link_error_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_captive_portal(Link *link, sd_ndisc_router *rt) {
const char *uri;
_cleanup_free_ char *captive_portal = NULL;
size_t len;
int r;
assert(link);
assert(link->network);
assert(rt);
if (!link->network->ipv6_accept_ra_use_captive_portal)
return 0;
r = sd_ndisc_router_captive_portal_get_uri(rt, &uri, &len);
if (r < 0)
return r;
if (len == 0) {
mfree(link->ndisc_captive_portal);
return 0;
}
r = make_cstring(uri, len, MAKE_CSTRING_REFUSE_TRAILING_NUL, &captive_portal);
if (r < 0)
return r;
if (!in_charset(captive_portal, URI_VALID))
return -EINVAL;
if (!streq_ptr(link->ndisc_captive_portal, captive_portal)) {
free_and_replace(link->ndisc_captive_portal, captive_portal);
link_dirty(link);
}
return 0;
}
static int ndisc_router_process_dnssl(Link *link, sd_ndisc_router *rt) {
_cleanup_strv_free_ char **l = NULL;
usec_t lifetime_usec, timestamp_usec;
struct in6_addr router;
uint32_t lifetime_sec;
bool updated = false, logged_about_too_many = false;
int r;
assert(link);
assert(link->network);
assert(rt);
if (link->network->ipv6_accept_ra_use_domains == DHCP_USE_DOMAINS_NO)
return 0;
r = sd_ndisc_router_get_address(rt, &router);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get router address from RA: %m");
r = sd_ndisc_router_get_timestamp(rt, CLOCK_BOOTTIME, &timestamp_usec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get RA timestamp: %m");
r = sd_ndisc_router_dnssl_get_lifetime(rt, &lifetime_sec);
if (r < 0)
return log_link_error_errno(link, r, "Failed to get DNSSL lifetime: %m");
lifetime_usec = sec_to_usec(lifetime_sec, timestamp_usec);
r = sd_ndisc_router_dnssl_get_domains(rt, &l);
if (r < 0)
return log_link_error_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 int ndisc_router_process_options(Link *link, sd_ndisc_router *rt) {
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_error_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_error_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);
break;
case SD_NDISC_OPTION_ROUTE_INFORMATION:
r = ndisc_router_process_route(link, rt);
break;
case SD_NDISC_OPTION_RDNSS:
r = ndisc_router_process_rdnss(link, rt);
break;
case SD_NDISC_OPTION_DNSSL:
r = ndisc_router_process_dnssl(link, rt);
break;
case SD_NDISC_OPTION_CAPTIVE_PORTAL:
r = ndisc_router_process_captive_portal(link, rt);
break;
}
if (r < 0 && r != -EBADMSG)
return r;
}
}
static int ndisc_drop_outdated(Link *link, usec_t timestamp_usec) {
bool updated = false;
NDiscDNSSL *dnssl;
NDiscRDNSS *rdnss;
Address *address;
Route *route;
int r = 0, k;
assert(link);
/* 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. */
SET_FOREACH(route, link->routes) {
if (route->source != NETWORK_CONFIG_SOURCE_NDISC)
continue;
if (route->lifetime_usec >= timestamp_usec)
continue; /* the route is still valid */
k = route_remove_and_drop(route);
if (k < 0)
r = log_link_warning_errno(link, k, "Failed to remove outdated SLAAC route, ignoring: %m");
}
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 */
k = address_remove_and_drop(address);
if (k < 0)
r = log_link_warning_errno(link, k, "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 */
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 */
free(set_remove(link->ndisc_dnssl, dnssl));
updated = true;
}
if (updated)
link_dirty(link);
return r;
}
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, now_usec);
(void) ndisc_setup_expire(link);
return 0;
}
static int ndisc_setup_expire(Link *link) {
usec_t lifetime_usec = USEC_INFINITY;
NDiscDNSSL *dnssl;
NDiscRDNSS *rdnss;
Address *address;
Route *route;
int r;
assert(link);
assert(link->manager);
SET_FOREACH(route, link->routes) {
if (route->source != NETWORK_CONFIG_SOURCE_NDISC)
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);
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->ipv6_accept_ra_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_error_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_address(rt, &router);
if (r == -ENODATA) {
log_link_debug(link, "Received RA without router address, ignoring.");
return 0;
}
if (r < 0)
return log_link_error_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 (DEBUG_LOGGING) {
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, timestamp_usec);
if (r < 0)
return r;
r = ndisc_start_dhcp6_client(link, rt);
if (r < 0)
return r;
r = ndisc_router_process_default(link, rt);
if (r < 0)
return r;
r = ndisc_router_process_options(link, rt);
if (r < 0)
return r;
r = ndisc_setup_expire(link);
if (r < 0)
return r;
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 void ndisc_handler(sd_ndisc *nd, sd_ndisc_event_t event, sd_ndisc_router *rt, 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, rt);
if (r < 0 && r != -EBADMSG) {
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:
assert_not_reached();
}
}
static int ndisc_configure(Link *link) {
int r;
assert(link);
if (!link_ipv6_accept_ra_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;
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_ipv6_accept_ra_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 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);
/* Removes all RDNSS and DNSSL entries, without exception */
link->ndisc_rdnss = set_free(link->ndisc_rdnss);
link->ndisc_dnssl = set_free(link->ndisc_dnssl);
}
static const char* const ipv6_accept_ra_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(ipv6_accept_ra_start_dhcp6_client, IPv6AcceptRAStartDHCP6Client, IPV6_ACCEPT_RA_START_DHCP6_CLIENT_YES);
DEFINE_CONFIG_PARSE_ENUM(config_parse_ipv6_accept_ra_use_domains, dhcp_use_domains, DHCPUseDomains,
"Failed to parse UseDomains= setting");
DEFINE_CONFIG_PARSE_ENUM(config_parse_ipv6_accept_ra_start_dhcp6_client, ipv6_accept_ra_start_dhcp6_client, IPv6AcceptRAStartDHCP6Client,
"Failed to parse DHCPv6Client= setting");
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