diff options
Diffstat (limited to 'src/network/networkd-dhcp-prefix-delegation.c')
| -rw-r--r-- | src/network/networkd-dhcp-prefix-delegation.c | 1298 |
1 files changed, 1298 insertions, 0 deletions
diff --git a/src/network/networkd-dhcp-prefix-delegation.c b/src/network/networkd-dhcp-prefix-delegation.c new file mode 100644 index 0000000..084f1c3 --- /dev/null +++ b/src/network/networkd-dhcp-prefix-delegation.c @@ -0,0 +1,1298 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <linux/ipv6_route.h> + +#include "sd-dhcp6-client.h" + +#include "hashmap.h" +#include "in-addr-prefix-util.h" +#include "networkd-address-generation.h" +#include "networkd-address.h" +#include "networkd-dhcp-prefix-delegation.h" +#include "networkd-dhcp6.h" +#include "networkd-link.h" +#include "networkd-manager.h" +#include "networkd-queue.h" +#include "networkd-radv.h" +#include "networkd-route.h" +#include "networkd-setlink.h" +#include "parse-util.h" +#include "string-util.h" +#include "strv.h" +#include "tunnel.h" + +bool link_dhcp_pd_is_enabled(Link *link) { + assert(link); + + if (!link->network) + return false; + + return link->network->dhcp_pd; +} + +bool dhcp_pd_is_uplink(Link *link, Link *target, bool accept_auto) { + assert(link); + assert(target); + + if (!link_dhcp_pd_is_enabled(link)) + return false; + + if (link->network->dhcp_pd_uplink_name) + return streq_ptr(target->ifname, link->network->dhcp_pd_uplink_name) || + strv_contains(target->alternative_names, link->network->dhcp_pd_uplink_name); + + if (link->network->dhcp_pd_uplink_index > 0) + return target->ifindex == link->network->dhcp_pd_uplink_index; + + if (link->network->dhcp_pd_uplink_index == UPLINK_INDEX_SELF) + return link == target; + + assert(link->network->dhcp_pd_uplink_index == UPLINK_INDEX_AUTO); + return accept_auto; +} + +bool dhcp4_lease_has_pd_prefix(sd_dhcp_lease *lease) { + if (!lease) + return false; + + return sd_dhcp_lease_get_6rd(lease, NULL, NULL, NULL, NULL, NULL) >= 0; +} + +bool dhcp6_lease_has_pd_prefix(sd_dhcp6_lease *lease) { + uint32_t lifetime_preferred_sec, lifetime_valid_sec; + struct in6_addr pd_prefix; + uint8_t pd_prefix_len; + + if (!lease) + return false; + + sd_dhcp6_lease_reset_pd_prefix_iter(lease); + + return sd_dhcp6_lease_get_pd(lease, &pd_prefix, &pd_prefix_len, &lifetime_preferred_sec, &lifetime_valid_sec) >= 0; +} + +static void link_remove_dhcp_pd_subnet_prefix(Link *link, const struct in6_addr *prefix) { + void *key; + + assert(link); + assert(link->manager); + assert(prefix); + + if (hashmap_get(link->manager->links_by_dhcp_pd_subnet_prefix, prefix) != link) + return; + + hashmap_remove2(link->manager->links_by_dhcp_pd_subnet_prefix, prefix, &key); + free(key); +} + +static int link_add_dhcp_pd_subnet_prefix(Link *link, const struct in6_addr *prefix) { + _cleanup_free_ struct in6_addr *copy = NULL; + int r; + + assert(link); + assert(prefix); + + copy = newdup(struct in6_addr, prefix, 1); + if (!copy) + return -ENOMEM; + + r = hashmap_ensure_put(&link->manager->links_by_dhcp_pd_subnet_prefix, &in6_addr_hash_ops_free, copy, link); + if (r < 0) + return r; + if (r > 0) + TAKE_PTR(copy); + + return 0; +} + +static int link_get_by_dhcp_pd_subnet_prefix(Manager *manager, const struct in6_addr *prefix, Link **ret) { + Link *link; + + assert(manager); + assert(prefix); + + link = hashmap_get(manager->links_by_dhcp_pd_subnet_prefix, prefix); + if (!link) + return -ENODEV; + + if (ret) + *ret = link; + return 0; +} + +static int dhcp_pd_get_assigned_subnet_prefix(Link *link, const struct in6_addr *pd_prefix, uint8_t pd_prefix_len, struct in6_addr *ret) { + assert(link); + assert(pd_prefix); + + if (!link_dhcp_pd_is_enabled(link)) + return -ENOENT; + + if (link->network->dhcp_pd_assign) { + Address *address; + + SET_FOREACH(address, link->addresses) { + if (address->source != NETWORK_CONFIG_SOURCE_DHCP_PD) + continue; + assert(address->family == AF_INET6); + + if (in6_addr_prefix_covers(pd_prefix, pd_prefix_len, &address->in_addr.in6) <= 0) + continue; + + if (ret) { + struct in6_addr prefix = address->in_addr.in6; + + in6_addr_mask(&prefix, 64); + *ret = prefix; + } + return 0; + } + } else { + Route *route; + + SET_FOREACH(route, link->routes) { + if (route->source != NETWORK_CONFIG_SOURCE_DHCP_PD) + continue; + assert(route->family == AF_INET6); + + if (in6_addr_prefix_covers(pd_prefix, pd_prefix_len, &route->dst.in6) > 0) { + if (ret) + *ret = route->dst.in6; + return 0; + } + } + } + + return -ENOENT; +} + +int dhcp_pd_remove(Link *link, bool only_marked) { + int k, r = 0; + + assert(link); + assert(link->manager); + + if (!link_dhcp_pd_is_enabled(link)) + return 0; + + if (!only_marked) + link->dhcp_pd_configured = false; + + if (!link->network->dhcp_pd_assign) { + Route *route; + + SET_FOREACH(route, link->routes) { + if (route->source != NETWORK_CONFIG_SOURCE_DHCP_PD) + continue; + if (only_marked && !route_is_marked(route)) + continue; + + if (link->radv) + sd_radv_remove_prefix(link->radv, &route->dst.in6, 64); + + link_remove_dhcp_pd_subnet_prefix(link, &route->dst.in6); + + k = route_remove(route); + if (k < 0) + r = k; + + route_cancel_request(route, link); + } + } else { + Address *address; + + SET_FOREACH(address, link->addresses) { + struct in6_addr prefix; + + if (address->source != NETWORK_CONFIG_SOURCE_DHCP_PD) + continue; + if (only_marked && !address_is_marked(address)) + continue; + + prefix = address->in_addr.in6; + in6_addr_mask(&prefix, 64); + + if (link->radv) + sd_radv_remove_prefix(link->radv, &prefix, 64); + + link_remove_dhcp_pd_subnet_prefix(link, &prefix); + + k = address_remove(address); + if (k < 0) + r = k; + + address_cancel_request(address); + } + } + + return r; +} + +static int dhcp_pd_check_ready(Link *link); + +static int dhcp_pd_address_ready_callback(Address *address) { + Address *a; + + assert(address); + assert(address->link); + + SET_FOREACH(a, address->link->addresses) + if (a->source == NETWORK_CONFIG_SOURCE_DHCP_PD) + a->callback = NULL; + + return dhcp_pd_check_ready(address->link); +} + +static int dhcp_pd_check_ready(Link *link) { + int r; + + assert(link); + assert(link->network); + + if (link->dhcp_pd_messages > 0) { + log_link_debug(link, "%s(): DHCP-PD addresses and routes are not set.", __func__); + return 0; + } + + if (link->network->dhcp_pd_assign) { + bool has_ready = false; + Address *address; + + SET_FOREACH(address, link->addresses) { + if (address->source != NETWORK_CONFIG_SOURCE_DHCP_PD) + continue; + if (address_is_ready(address)) { + has_ready = true; + break; + } + } + + if (!has_ready) { + SET_FOREACH(address, link->addresses) + if (address->source == NETWORK_CONFIG_SOURCE_DHCP_PD) + address->callback = dhcp_pd_address_ready_callback; + + log_link_debug(link, "%s(): no DHCP-PD address is ready.", __func__); + return 0; + } + } + + link->dhcp_pd_configured = true; + + log_link_debug(link, "DHCP-PD addresses and routes set."); + + r = dhcp_pd_remove(link, /* only_marked = */ true); + if (r < 0) + return r; + + link_check_ready(link); + return 1; +} + +static int dhcp_pd_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, "Failed to add prefix route for DHCP delegated subnet prefix"); + if (r <= 0) + return r; + + r = dhcp_pd_check_ready(link); + if (r < 0) + link_enter_failed(link); + + return 1; +} + +static int dhcp_pd_request_route(Link *link, const struct in6_addr *prefix, usec_t lifetime_usec) { + _cleanup_(route_freep) Route *route = NULL; + Route *existing; + int r; + + assert(link); + assert(link->network); + assert(prefix); + + if (link->network->dhcp_pd_assign) + return 0; + + r = route_new(&route); + if (r < 0) + return r; + + route->source = NETWORK_CONFIG_SOURCE_DHCP_PD; + route->family = AF_INET6; + route->dst.in6 = *prefix; + route->dst_prefixlen = 64; + route->protocol = RTPROT_DHCP; + route->priority = link->network->dhcp_pd_route_metric; + route->lifetime_usec = lifetime_usec; + + if (route_get(NULL, link, route, &existing) < 0) + link->dhcp_pd_configured = false; + else + route_unmark(existing); + + r = link_request_route(link, TAKE_PTR(route), true, &link->dhcp_pd_messages, + dhcp_pd_route_handler, NULL); + if (r < 0) + return log_link_error_errno(link, r, "Failed to request DHCP-PD prefix route: %m"); + + return 0; +} + +static int dhcp_pd_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 DHCP-PD address"); + if (r <= 0) + return r; + + r = dhcp_pd_check_ready(link); + if (r < 0) + link_enter_failed(link); + + return 1; +} + +static void log_dhcp_pd_address(Link *link, const Address *address) { + assert(address); + assert(address->family == AF_INET6); + + int log_level = address_get(link, address, NULL) >= 0 ? LOG_DEBUG : LOG_INFO; + + if (log_level < log_get_max_level()) + return; + + log_link_full(link, log_level, "DHCP-PD address %s (valid %s, preferred %s)", + IN6_ADDR_PREFIX_TO_STRING(&address->in_addr.in6, address->prefixlen), + FORMAT_LIFETIME(address->lifetime_valid_usec), + FORMAT_LIFETIME(address->lifetime_preferred_usec)); +} + +static int dhcp_pd_request_address( + Link *link, + const struct in6_addr *prefix, + usec_t lifetime_preferred_usec, + usec_t lifetime_valid_usec) { + + _cleanup_set_free_ Set *addresses = NULL; + struct in6_addr *a; + int r; + + assert(link); + assert(link->network); + assert(prefix); + + if (!link->network->dhcp_pd_assign) + return 0; + + r = dhcp_pd_generate_addresses(link, prefix, &addresses); + if (r < 0) + return log_link_warning_errno(link, r, "Failed to generate addresses for acquired DHCP delegated prefix: %m"); + + SET_FOREACH(a, addresses) { + _cleanup_(address_freep) Address *address = NULL; + Address *existing; + + r = address_new(&address); + if (r < 0) + return log_link_error_errno(link, r, "Failed to allocate address for DHCP delegated prefix: %m"); + + address->source = NETWORK_CONFIG_SOURCE_DHCP_PD; + address->family = AF_INET6; + address->in_addr.in6 = *a; + address->prefixlen = 64; + address->lifetime_preferred_usec = lifetime_preferred_usec; + address->lifetime_valid_usec = lifetime_valid_usec; + SET_FLAG(address->flags, IFA_F_MANAGETEMPADDR, link->network->dhcp_pd_manage_temporary_address); + address->route_metric = link->network->dhcp_pd_route_metric; + + log_dhcp_pd_address(link, address); + + r = free_and_strdup_warn(&address->netlabel, link->network->dhcp_pd_netlabel); + if (r < 0) + return r; + + if (address_get(link, address, &existing) < 0) + link->dhcp_pd_configured = false; + else + address_unmark(existing); + + r = link_request_address(link, TAKE_PTR(address), true, &link->dhcp_pd_messages, + dhcp_pd_address_handler, NULL); + if (r < 0) + return log_link_error_errno(link, r, "Failed to request DHCP delegated prefix address: %m"); + } + + return 0; +} + +static int dhcp_pd_calculate_subnet_prefix( + const struct in6_addr *pd_prefix, + uint8_t pd_prefix_len, + uint64_t subnet_id, + struct in6_addr *ret) { + + struct in6_addr prefix; + + assert(pd_prefix); + assert(pd_prefix_len <= 64); + assert(ret); + + if (subnet_id >= UINT64_C(1) << (64 - pd_prefix_len)) + return -ERANGE; + + prefix = *pd_prefix; + + if (pd_prefix_len < 32) + prefix.s6_addr32[0] |= htobe32(subnet_id >> 32); + + prefix.s6_addr32[1] |= htobe32(subnet_id & 0xffffffff); + + *ret = prefix; + return 0; +} + +static int dhcp_pd_get_preferred_subnet_prefix( + Link *link, + const struct in6_addr *pd_prefix, + uint8_t pd_prefix_len, + struct in6_addr *ret) { + + struct in6_addr prefix; + Link *assigned_link; + int r; + + assert(link); + assert(link->manager); + assert(link->network); + assert(pd_prefix); + + if (link->network->dhcp_pd_subnet_id >= 0) { + /* If the link has a preference for a particular subnet id try to allocate that */ + + r = dhcp_pd_calculate_subnet_prefix(pd_prefix, pd_prefix_len, link->network->dhcp_pd_subnet_id, &prefix); + if (r < 0) + return log_link_warning_errno(link, r, + "subnet id %" PRIi64 " is out of range. Only have %" PRIu64 " subnets.", + link->network->dhcp_pd_subnet_id, UINT64_C(1) << (64 - pd_prefix_len)); + + *ret = prefix; + return 0; + } + + if (dhcp_pd_get_assigned_subnet_prefix(link, pd_prefix, pd_prefix_len, ret) >= 0) + return 0; + + for (uint64_t n = 0; ; n++) { + /* If we do not have an allocation preference just iterate + * through the address space and return the first free prefix. */ + + r = dhcp_pd_calculate_subnet_prefix(pd_prefix, pd_prefix_len, n, &prefix); + if (r < 0) + return log_link_warning_errno(link, r, + "Couldn't find a suitable prefix. Ran out of address space."); + + /* Do not use explicitly requested subnet IDs. Note that the corresponding link may not + * appear yet. So, we need to check the ID is not used in any .network files. */ + if (set_contains(link->manager->dhcp_pd_subnet_ids, &n)) + continue; + + /* Check that the prefix is not assigned to another link. */ + if (link_get_by_dhcp_pd_subnet_prefix(link->manager, &prefix, &assigned_link) < 0 || + assigned_link == link) + break; + } + + r = link_add_dhcp_pd_subnet_prefix(link, &prefix); + if (r < 0) + return log_link_warning_errno(link, r, "Failed to save acquired free subnet prefix: %m"); + + *ret = prefix; + return 0; +} + +static int dhcp_pd_assign_subnet_prefix( + Link *link, + const struct in6_addr *pd_prefix, + uint8_t pd_prefix_len, + usec_t lifetime_preferred_usec, + usec_t lifetime_valid_usec, + bool is_uplink) { + + struct in6_addr prefix; + int r; + + assert(link); + assert(link->network); + assert(pd_prefix); + + r = dhcp_pd_get_preferred_subnet_prefix(link, pd_prefix, pd_prefix_len, &prefix); + if (r < 0) + return r == -ERANGE ? 0 : r; + + const char *pretty = IN6_ADDR_PREFIX_TO_STRING(&prefix, 64); + + if (link_radv_enabled(link) && link->network->dhcp_pd_announce) { + if (is_uplink) + log_link_debug(link, "Ignoring Announce= setting on upstream interface."); + else { + r = radv_add_prefix(link, &prefix, 64, lifetime_preferred_usec, lifetime_valid_usec); + if (r < 0) + return log_link_warning_errno(link, r, + "Failed to assign/update prefix %s to IPv6 Router Advertisement: %m", + pretty); + } + } + + r = dhcp_pd_request_route(link, &prefix, lifetime_valid_usec); + if (r < 0) + return log_link_warning_errno(link, r, + "Failed to assign/update route for prefix %s: %m", pretty); + + r = dhcp_pd_request_address(link, &prefix, lifetime_preferred_usec, lifetime_valid_usec); + if (r < 0) + return log_link_warning_errno(link, r, + "Failed to assign/update address for prefix %s: %m", pretty); + + log_link_debug(link, "Assigned prefix %s", pretty); + return 1; +} + +static int dhcp_pd_prepare(Link *link) { + if (!IN_SET(link->state, LINK_STATE_CONFIGURING, LINK_STATE_CONFIGURED)) + return 0; + + if (!link_dhcp_pd_is_enabled(link)) + return 0; + + if (link_radv_enabled(link) && link->network->dhcp_pd_announce && !link->radv) + return 0; + + link_mark_addresses(link, NETWORK_CONFIG_SOURCE_DHCP_PD); + link_mark_routes(link, NETWORK_CONFIG_SOURCE_DHCP_PD); + + return 1; +} + +static int dhcp_pd_finalize(Link *link) { + int r; + + if (!IN_SET(link->state, LINK_STATE_CONFIGURING, LINK_STATE_CONFIGURED)) + return 0; + + if (link->dhcp_pd_messages == 0) { + link->dhcp_pd_configured = false; + + r = dhcp_pd_remove(link, /* only_marked = */ true); + if (r < 0) + return r; + } + + if (!link->dhcp_pd_configured) + link_set_state(link, LINK_STATE_CONFIGURING); + + link_check_ready(link); + return 0; +} + +void dhcp_pd_prefix_lost(Link *uplink) { + Route *route; + Link *link; + int r; + + assert(uplink); + assert(uplink->manager); + + HASHMAP_FOREACH(link, uplink->manager->links_by_index) { + if (!dhcp_pd_is_uplink(link, uplink, /* accept_auto = */ true)) + continue; + + r = dhcp_pd_remove(link, /* only_marked = */ false); + if (r < 0) + link_enter_failed(link); + } + + SET_FOREACH(route, uplink->manager->routes) { + if (!IN_SET(route->source, NETWORK_CONFIG_SOURCE_DHCP4, NETWORK_CONFIG_SOURCE_DHCP6)) + continue; + if (route->family != AF_INET6) + continue; + if (route->type != RTN_UNREACHABLE) + continue; + if (!set_contains(uplink->dhcp_pd_prefixes, + &(struct in_addr_prefix) { + .family = AF_INET6, + .prefixlen = route->dst_prefixlen, + .address = route->dst })) + continue; + + (void) route_remove(route); + + route_cancel_request(route, uplink); + } + + set_clear(uplink->dhcp_pd_prefixes); +} + +void dhcp4_pd_prefix_lost(Link *uplink) { + Link *tunnel; + + dhcp_pd_prefix_lost(uplink); + + if (uplink->dhcp4_6rd_tunnel_name && + link_get_by_name(uplink->manager, uplink->dhcp4_6rd_tunnel_name, &tunnel) >= 0) + (void) link_remove(tunnel); +} + +static int dhcp4_unreachable_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, "Failed to set unreachable route for DHCPv4 delegated prefix"); + if (r <= 0) + return r; + + r = dhcp4_check_ready(link); + if (r < 0) + link_enter_failed(link); + + return 1; +} + +static int dhcp6_unreachable_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, "Failed to set unreachable route for DHCPv6 delegated prefix"); + if (r <= 0) + return r; + + r = dhcp6_check_ready(link); + if (r < 0) + link_enter_failed(link); + + return 1; +} + +static int dhcp_request_unreachable_route( + Link *link, + const struct in6_addr *addr, + uint8_t prefixlen, + usec_t lifetime_usec, + NetworkConfigSource source, + const union in_addr_union *server_address, + unsigned *counter, + route_netlink_handler_t callback, + bool *configured) { + + _cleanup_(route_freep) Route *route = NULL; + Route *existing; + int r; + + assert(link); + assert(addr); + assert(IN_SET(source, NETWORK_CONFIG_SOURCE_DHCP4, NETWORK_CONFIG_SOURCE_DHCP6)); + assert(server_address); + assert(counter); + assert(callback); + assert(configured); + + if (prefixlen >= 64) { + log_link_debug(link, "Not adding a blocking route for DHCP delegated prefix %s since the prefix has length >= 64.", + IN6_ADDR_PREFIX_TO_STRING(addr, prefixlen)); + return 0; + } + + r = route_new(&route); + if (r < 0) + return log_oom(); + + route->source = source; + route->provider = *server_address; + route->family = AF_INET6; + route->dst.in6 = *addr; + route->dst_prefixlen = prefixlen; + route->type = RTN_UNREACHABLE; + route->protocol = RTPROT_DHCP; + route->priority = IP6_RT_PRIO_USER; + route->lifetime_usec = lifetime_usec; + + if (route_get(link->manager, NULL, route, &existing) < 0) + *configured = false; + else + route_unmark(existing); + + r = link_request_route(link, TAKE_PTR(route), true, counter, callback, NULL); + if (r < 0) + return log_link_error_errno(link, r, "Failed to request unreachable route for DHCP delegated prefix %s: %m", + IN6_ADDR_PREFIX_TO_STRING(addr, prefixlen)); + + return 0; +} + +static int dhcp4_request_unreachable_route( + Link *link, + const struct in6_addr *addr, + uint8_t prefixlen, + usec_t lifetime_usec, + const union in_addr_union *server_address) { + + return dhcp_request_unreachable_route(link, addr, prefixlen, lifetime_usec, + NETWORK_CONFIG_SOURCE_DHCP4, server_address, + &link->dhcp4_messages, dhcp4_unreachable_route_handler, + &link->dhcp4_configured); +} + +static int dhcp6_request_unreachable_route( + Link *link, + const struct in6_addr *addr, + uint8_t prefixlen, + usec_t lifetime_usec, + const union in_addr_union *server_address) { + + return dhcp_request_unreachable_route(link, addr, prefixlen, lifetime_usec, + NETWORK_CONFIG_SOURCE_DHCP6, server_address, + &link->dhcp6_messages, dhcp6_unreachable_route_handler, + &link->dhcp6_configured); +} + +static int dhcp_pd_prefix_add(Link *link, const struct in6_addr *prefix, uint8_t prefixlen) { + struct in_addr_prefix *p; + int r; + + assert(link); + assert(prefix); + + p = new(struct in_addr_prefix, 1); + if (!p) + return log_oom(); + + *p = (struct in_addr_prefix) { + .family = AF_INET6, + .prefixlen = prefixlen, + .address.in6 = *prefix, + }; + + int log_level = set_contains(link->dhcp_pd_prefixes, p) ? LOG_DEBUG : + prefixlen > 64 || prefixlen < 48 ? LOG_WARNING : LOG_INFO; + log_link_full(link, + log_level, + "DHCP: received delegated prefix %s%s", + IN6_ADDR_PREFIX_TO_STRING(prefix, prefixlen), + prefixlen > 64 ? " with prefix length > 64, ignoring." : + prefixlen < 48 ? " with prefix length < 48, looks unusual.": ""); + + /* Store PD prefix even if prefixlen > 64, not to make logged at warning level so frequently. */ + r = set_ensure_consume(&link->dhcp_pd_prefixes, &in_addr_prefix_hash_ops_free, p); + if (r < 0) + return log_link_error_errno(link, r, "Failed to store DHCP delegated prefix %s: %m", + IN6_ADDR_PREFIX_TO_STRING(prefix, prefixlen)); + return 0; +} + +static int dhcp4_pd_request_default_gateway_on_6rd_tunnel(Link *link, const struct in_addr *br_address, usec_t lifetime_usec) { + _cleanup_(route_freep) Route *route = NULL; + Route *existing; + int r; + + assert(link); + assert(br_address); + + r = route_new(&route); + if (r < 0) + return log_link_debug_errno(link, r, "Failed to allocate default gateway for DHCP delegated prefix: %m"); + + route->source = NETWORK_CONFIG_SOURCE_DHCP_PD; + route->family = AF_INET6; + route->gw_family = AF_INET6; + route->gw.in6.s6_addr32[3] = br_address->s_addr; + route->scope = RT_SCOPE_UNIVERSE; + route->protocol = RTPROT_DHCP; + route->priority = IP6_RT_PRIO_USER; + route->lifetime_usec = lifetime_usec; + + if (route_get(NULL, link, route, &existing) < 0) /* This is a new route. */ + link->dhcp_pd_configured = false; + else + route_unmark(existing); + + r = link_request_route(link, TAKE_PTR(route), true, &link->dhcp_pd_messages, + dhcp_pd_route_handler, NULL); + if (r < 0) + return log_link_debug_errno(link, r, "Failed to request default gateway for DHCP delegated prefix: %m"); + + return 0; +} + +static void dhcp4_calculate_pd_prefix( + const struct in_addr *ipv4address, + uint8_t ipv4masklen, + const struct in6_addr *sixrd_prefix, + uint8_t sixrd_prefixlen, + struct in6_addr *ret_pd_prefix, + uint8_t *ret_pd_prefixlen) { + + struct in6_addr pd_prefix; + + assert(ipv4address); + assert(ipv4masklen <= 32); + assert(sixrd_prefix); + assert(32 - ipv4masklen + sixrd_prefixlen <= 128); + assert(ret_pd_prefix); + + pd_prefix = *sixrd_prefix; + for (unsigned i = 0; i < (unsigned) (32 - ipv4masklen); i++) + if (ipv4address->s_addr & htobe32(UINT32_C(1) << (32 - ipv4masklen - i - 1))) + pd_prefix.s6_addr[(i + sixrd_prefixlen) / 8] |= 1 << (7 - (i + sixrd_prefixlen) % 8); + + *ret_pd_prefix = pd_prefix; + if (ret_pd_prefixlen) + *ret_pd_prefixlen = 32 - ipv4masklen + sixrd_prefixlen; +} + +static int dhcp4_pd_assign_subnet_prefix(Link *link, Link *uplink) { + uint8_t ipv4masklen, sixrd_prefixlen, pd_prefixlen; + struct in6_addr sixrd_prefix, pd_prefix; + const struct in_addr *br_addresses; + struct in_addr ipv4address; + uint32_t lifetime_sec; + usec_t lifetime_usec, now_usec; + int r; + + assert(link); + assert(uplink); + assert(uplink->manager); + assert(uplink->dhcp_lease); + + r = sd_dhcp_lease_get_address(uplink->dhcp_lease, &ipv4address); + if (r < 0) + return log_link_warning_errno(uplink, r, "Failed to get DHCPv4 address: %m"); + + r = sd_dhcp_lease_get_lifetime(uplink->dhcp_lease, &lifetime_sec); + if (r < 0) + return log_link_warning_errno(uplink, r, "Failed to get lifetime of DHCPv4 lease: %m"); + + assert_se(sd_event_now(uplink->manager->event, CLOCK_BOOTTIME, &now_usec) >= 0); + lifetime_usec = sec_to_usec(lifetime_sec, now_usec); + + r = sd_dhcp_lease_get_6rd(uplink->dhcp_lease, &ipv4masklen, &sixrd_prefixlen, &sixrd_prefix, &br_addresses, NULL); + if (r < 0) + return log_link_warning_errno(uplink, r, "Failed to get DHCPv4 6rd option: %m"); + + dhcp4_calculate_pd_prefix(&ipv4address, ipv4masklen, &sixrd_prefix, sixrd_prefixlen, &pd_prefix, &pd_prefixlen); + + if (pd_prefixlen > 64) + return 0; + + r = dhcp_pd_prepare(link); + if (r <= 0) + return r; + + if (streq_ptr(uplink->dhcp4_6rd_tunnel_name, link->ifname)) { + r = dhcp4_pd_request_default_gateway_on_6rd_tunnel(link, &br_addresses[0], lifetime_usec); + if (r < 0) + return r; + } + + r = dhcp_pd_assign_subnet_prefix(link, &pd_prefix, pd_prefixlen, lifetime_usec, lifetime_usec, /* is_uplink = */ false); + if (r < 0) + return r; + + return dhcp_pd_finalize(link); +} + +static int dhcp4_pd_6rd_tunnel_create_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) { + int r; + + assert(m); + assert(link); + assert(link->manager); + assert(link->dhcp4_6rd_tunnel_name); + + if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER)) + return 0; + + r = sd_netlink_message_get_errno(m); + if (r < 0) { + log_link_message_warning_errno(link, m, r, "Failed to create tunnel device for DHCPv4 6rd"); + link_enter_failed(link); + return 0; + } + + return 0; +} + +int dhcp4_pd_prefix_acquired(Link *uplink) { + _cleanup_free_ char *tunnel_name = NULL; + uint8_t ipv4masklen, sixrd_prefixlen, pd_prefixlen; + struct in6_addr sixrd_prefix, pd_prefix; + struct in_addr ipv4address; + union in_addr_union server_address; + const struct in_addr *br_addresses; + uint32_t lifetime_sec; + usec_t lifetime_usec, now_usec; + Link *link; + int r; + + assert(uplink); + assert(uplink->manager); + assert(uplink->dhcp_lease); + + r = sd_dhcp_lease_get_address(uplink->dhcp_lease, &ipv4address); + if (r < 0) + return log_link_warning_errno(uplink, r, "Failed to get DHCPv4 address: %m"); + + r = sd_dhcp_lease_get_lifetime(uplink->dhcp_lease, &lifetime_sec); + if (r < 0) + return log_link_warning_errno(uplink, r, "Failed to get lifetime of DHCPv4 lease: %m"); + + assert_se(sd_event_now(uplink->manager->event, CLOCK_BOOTTIME, &now_usec) >= 0); + lifetime_usec = sec_to_usec(lifetime_sec, now_usec); + + r = sd_dhcp_lease_get_server_identifier(uplink->dhcp_lease, &server_address.in); + if (r < 0) + return log_link_warning_errno(uplink, r, "Failed to get server address of DHCPv4 lease: %m"); + + r = sd_dhcp_lease_get_6rd(uplink->dhcp_lease, &ipv4masklen, &sixrd_prefixlen, &sixrd_prefix, &br_addresses, NULL); + if (r < 0) + return log_link_warning_errno(uplink, r, "Failed to get DHCPv4 6rd option: %m"); + + if (DEBUG_LOGGING) + log_link_debug(uplink, "DHCPv4: 6rd option is acquired: IPv4_masklen=%u, 6rd_prefix=%s, br_address="IPV4_ADDRESS_FMT_STR, + ipv4masklen, + IN6_ADDR_PREFIX_TO_STRING(&sixrd_prefix, sixrd_prefixlen), + IPV4_ADDRESS_FMT_VAL(*br_addresses)); + + /* Calculate PD prefix */ + dhcp4_calculate_pd_prefix(&ipv4address, ipv4masklen, &sixrd_prefix, sixrd_prefixlen, &pd_prefix, &pd_prefixlen); + + /* Register and log PD prefix */ + r = dhcp_pd_prefix_add(uplink, &pd_prefix, pd_prefixlen); + if (r < 0) + return r; + + /* Request unreachable route */ + r = dhcp4_request_unreachable_route(uplink, &pd_prefix, pd_prefixlen, lifetime_usec, &server_address); + if (r < 0) + return r; + + /* Generate 6rd SIT tunnel device name. */ + r = dhcp4_pd_create_6rd_tunnel_name(uplink, &tunnel_name); + if (r < 0) + return r; + + /* Remove old tunnel device if exists. */ + if (!streq_ptr(uplink->dhcp4_6rd_tunnel_name, tunnel_name)) { + Link *old_tunnel; + + if (uplink->dhcp4_6rd_tunnel_name && + link_get_by_name(uplink->manager, uplink->dhcp4_6rd_tunnel_name, &old_tunnel) >= 0) + (void) link_remove(old_tunnel); + + free_and_replace(uplink->dhcp4_6rd_tunnel_name, tunnel_name); + } + + /* Create 6rd SIT tunnel device if it does not exist yet. */ + if (link_get_by_name(uplink->manager, uplink->dhcp4_6rd_tunnel_name, NULL) < 0) { + r = dhcp4_pd_create_6rd_tunnel(uplink, dhcp4_pd_6rd_tunnel_create_handler); + if (r < 0) + return r; + } + + /* Then, assign subnet prefixes to downstream interfaces. */ + HASHMAP_FOREACH(link, uplink->manager->links_by_index) { + if (!dhcp_pd_is_uplink(link, uplink, /* accept_auto = */ true)) + continue; + + r = dhcp4_pd_assign_subnet_prefix(link, uplink); + if (r < 0) { + /* When failed on the upstream interface (i.e., the case link == uplink), + * immediately abort the assignment of the prefixes. As, the all assigned + * prefixes will be dropped soon in link_enter_failed(), and it is meaningless + * to continue the assignment. */ + if (link == uplink) + return r; + + link_enter_failed(link); + } + } + + return 0; +} + +static int dhcp6_pd_assign_subnet_prefixes(Link *link, Link *uplink) { + usec_t timestamp_usec; + int r; + + assert(link); + assert(uplink); + assert(uplink->dhcp6_lease); + + r = dhcp_pd_prepare(link); + if (r <= 0) + return r; + + r = sd_dhcp6_lease_get_timestamp(uplink->dhcp6_lease, CLOCK_BOOTTIME, ×tamp_usec); + if (r < 0) + return r; + + for (sd_dhcp6_lease_reset_pd_prefix_iter(uplink->dhcp6_lease);;) { + uint32_t lifetime_preferred_sec, lifetime_valid_sec; + struct in6_addr pd_prefix; + uint8_t pd_prefix_len; + + r = sd_dhcp6_lease_get_pd(uplink->dhcp6_lease, &pd_prefix, &pd_prefix_len, + &lifetime_preferred_sec, &lifetime_valid_sec); + if (r < 0) + break; + + if (pd_prefix_len > 64) + continue; + + /* Mask prefix for safety. */ + r = in6_addr_mask(&pd_prefix, pd_prefix_len); + if (r < 0) + return r; + + r = dhcp_pd_assign_subnet_prefix(link, &pd_prefix, pd_prefix_len, + sec_to_usec(lifetime_preferred_sec, timestamp_usec), + sec_to_usec(lifetime_valid_sec, timestamp_usec), + /* is_uplink = */ link == uplink); + if (r < 0) + return r; + } + + return dhcp_pd_finalize(link); +} + +int dhcp6_pd_prefix_acquired(Link *uplink) { + union in_addr_union server_address; + usec_t timestamp_usec; + Link *link; + int r; + + assert(uplink); + assert(uplink->dhcp6_lease); + + r = sd_dhcp6_lease_get_server_address(uplink->dhcp6_lease, &server_address.in6); + if (r < 0) + return log_link_warning_errno(uplink, r, "Failed to get server address of DHCPv6 lease: %m"); + + r = sd_dhcp6_lease_get_timestamp(uplink->dhcp6_lease, CLOCK_BOOTTIME, ×tamp_usec); + if (r < 0) + return log_link_warning_errno(uplink, r, "Failed to get timestamp of DHCPv6 lease: %m"); + + /* First, logs acquired prefixes and request unreachable routes. */ + for (sd_dhcp6_lease_reset_pd_prefix_iter(uplink->dhcp6_lease);;) { + uint32_t lifetime_preferred_sec, lifetime_valid_sec; + struct in6_addr pd_prefix; + uint8_t pd_prefix_len; + + r = sd_dhcp6_lease_get_pd(uplink->dhcp6_lease, &pd_prefix, &pd_prefix_len, + &lifetime_preferred_sec, &lifetime_valid_sec); + if (r < 0) + break; + + /* Mask prefix for safety. */ + r = in6_addr_mask(&pd_prefix, pd_prefix_len); + if (r < 0) + return log_link_error_errno(uplink, r, "Failed to mask DHCPv6 delegated prefix: %m"); + + r = dhcp_pd_prefix_add(uplink, &pd_prefix, pd_prefix_len); + if (r < 0) + return r; + + r = dhcp6_request_unreachable_route(uplink, &pd_prefix, pd_prefix_len, + sec_to_usec(lifetime_valid_sec, timestamp_usec), + &server_address); + if (r < 0) + return r; + } + + /* Then, assign subnet prefixes. */ + HASHMAP_FOREACH(link, uplink->manager->links_by_index) { + if (!dhcp_pd_is_uplink(link, uplink, /* accept_auto = */ true)) + continue; + + r = dhcp6_pd_assign_subnet_prefixes(link, uplink); + if (r < 0) { + /* When failed on the upstream interface (i.e., the case link == uplink), + * immediately abort the assignment of the prefixes. As, the all assigned + * prefixes will be dropped soon in link_enter_failed(), and it is meaningless + * to continue the assignment. */ + if (link == uplink) + return r; + + link_enter_failed(link); + } + } + + return 0; +} + +static bool dhcp4_pd_uplink_is_ready(Link *link) { + assert(link); + + if (!link->network) + return false; + + if (!link->network->dhcp_use_6rd) + return false; + + if (!IN_SET(link->state, LINK_STATE_CONFIGURING, LINK_STATE_CONFIGURED)) + return false; + + if (!link->dhcp_client) + return false; + + if (sd_dhcp_client_is_running(link->dhcp_client) <= 0) + return false; + + if (!link->dhcp_lease) + return false; + + return dhcp4_lease_has_pd_prefix(link->dhcp_lease); +} + +static bool dhcp6_pd_uplink_is_ready(Link *link) { + assert(link); + + if (!link->network) + return false; + + if (!link->network->dhcp6_use_pd_prefix) + return false; + + if (!IN_SET(link->state, LINK_STATE_CONFIGURING, LINK_STATE_CONFIGURED)) + return false; + + if (!link->dhcp6_client) + return false; + + if (sd_dhcp6_client_is_running(link->dhcp6_client) <= 0) + return false; + + if (!link->dhcp6_lease) + return false; + + return dhcp6_lease_has_pd_prefix(link->dhcp6_lease); +} + +int dhcp_pd_find_uplink(Link *link, Link **ret) { + Link *uplink = NULL; + int r = 0; + + assert(link); + assert(link->manager); + assert(link_dhcp_pd_is_enabled(link)); + assert(ret); + + if (link->network->dhcp_pd_uplink_name) + r = link_get_by_name(link->manager, link->network->dhcp_pd_uplink_name, &uplink); + else if (link->network->dhcp_pd_uplink_index > 0) + r = link_get_by_index(link->manager, link->network->dhcp_pd_uplink_index, &uplink); + else if (link->network->dhcp_pd_uplink_index == UPLINK_INDEX_SELF) + uplink = link; + if (r < 0) + return r; + + if (uplink) { + if (dhcp4_pd_uplink_is_ready(uplink)) { + *ret = uplink; + return AF_INET; + } + + if (dhcp6_pd_uplink_is_ready(uplink)) { + *ret = uplink; + return AF_INET6; + } + + return -EBUSY; + } + + HASHMAP_FOREACH(uplink, link->manager->links_by_index) { + /* Assume that there exists at most one link which acquired delegated prefixes. */ + if (dhcp4_pd_uplink_is_ready(uplink)) { + *ret = uplink; + return AF_INET; + } + + if (dhcp6_pd_uplink_is_ready(uplink)) { + *ret = uplink; + return AF_INET6; + } + } + + return -ENODEV; +} + +int dhcp_request_prefix_delegation(Link *link) { + Link *uplink; + int r; + + assert(link); + + if (!link_dhcp_pd_is_enabled(link)) + return 0; + + r = dhcp_pd_find_uplink(link, &uplink); + if (r < 0) + return 0; + + log_link_debug(link, "Requesting subnets of delegated prefixes acquired by DHCPv%c client on %s", + r == AF_INET ? '4' : '6', uplink->ifname); + + return r == AF_INET ? + dhcp4_pd_assign_subnet_prefix(link, uplink) : + dhcp6_pd_assign_subnet_prefixes(link, uplink); +} + +int config_parse_dhcp_pd_subnet_id( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + int64_t *p = ASSERT_PTR(data); + uint64_t t; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + + if (isempty(rvalue) || streq(rvalue, "auto")) { + *p = -1; + return 0; + } + + r = safe_atoux64(rvalue, &t); + if (r < 0) { + log_syntax(unit, LOG_WARNING, filename, line, r, + "Failed to parse %s=, ignoring assignment: %s", + lvalue, rvalue); + return 0; + } + if (t > INT64_MAX) { + log_syntax(unit, LOG_WARNING, filename, line, 0, + "Invalid subnet id '%s', ignoring assignment.", + rvalue); + return 0; + } + + *p = (int64_t) t; + + return 0; +} |