diff --git a/man/systemd.network.xml b/man/systemd.network.xml index 862ad031bd..209787bf1b 100644 --- a/man/systemd.network.xml +++ b/man/systemd.network.xml @@ -308,18 +308,35 @@ IPv6Token= - Specifies an optional address generation mechanism and an optional address prefix. If - the mechanism is present, the two parts must be separated with a colon - type:prefix. The - address generation mechanism may be either prefixstable or - static. If not specified, static is assumed. When - set to prefixstable a method for generating IPv6 Interface Identifiers to - be used with IPv6 Stateless Address Autocon figuration (SLAAC). See - RFC 7217. When IPv6 address is set, - indicates the 64-bit interface part of SLAAC IPv6 addresses for this link. + Specifies an optional address generation mode and a required IPv6 address. If + the mode is present, the two parts must be separated with a colon + mode:address. The + address generation mode may be either prefixstable or + static. If not specified, static is assumed. + + When the mode is set to static, or unspecified, the lower bits of + the supplied address are combined with the upper bits of a prefix received in a Router Advertisement + message to form a complete address. Note that if multiple prefixes are received in an RA message, or in + multiple RA messages, addresses will be formed from each of them using the supplied address. This + mode implements SLAAC but uses a static interface identifier instead of an identifier generated + using the EUI-64 algorithm. Because the interface identifier is static, if Duplicate Address Detection + detects that the computed address is a duplicate (in use by another node on the link), then this + mode will fail to provide an address for that prefix. + + When the mode is set to prefixstable the RFC 7217 algorithm for generating + interface identifiers will be used, but only when a prefix received in an RA message matches the supplied address. + See RFC 7217. Prefix matching will be attempted + against each prefixstable IPv6Token variable provided in the configuration; if a received + prefix does not match any of the provided addresses, then the EUI-64 algorithm will be used to form + an interface identifier for that prefix. This mode is also SLAAC, but with a potentially stable interface + identifier which does not directly map to the interface's hardware address. - Note that the token is only ever used for SLAAC, and not for DHCPv6 addresses, even in - the case DHCP is requested by router advertisement. By default, the token is autogenerated. + Note that the prefixstable algorithm includes both the interface's name and + MAC address in the hash used to compute the interface identifier, so if either of those are changed the resulting + interface identifier (and address) will change, even if the prefix received in the RA message has not changed. + + Note that if multiple prefixstable IPv6Token variables are supplied with addresses that + match a prefix received in an RA message, only the first one will be used to generate addresses. diff --git a/src/network/networkd-address.c b/src/network/networkd-address.c index 88bafb4d20..59775869b6 100644 --- a/src/network/networkd-address.c +++ b/src/network/networkd-address.c @@ -187,7 +187,7 @@ static int address_compare_func(const Address *a1, const Address *a2) { } } -DEFINE_PRIVATE_HASH_OPS(address_hash_ops, Address, address_hash_func, address_compare_func); +DEFINE_HASH_OPS(address_hash_ops, Address, address_hash_func, address_compare_func); bool address_equal(Address *a1, Address *a2) { if (a1 == a2) diff --git a/src/network/networkd-address.h b/src/network/networkd-address.h index 76a30a54bc..6995c5c06e 100644 --- a/src/network/networkd-address.h +++ b/src/network/networkd-address.h @@ -67,6 +67,8 @@ int configure_ipv4_duplicate_address_detection(Link *link, Address *address); DEFINE_NETWORK_SECTION_FUNCTIONS(Address, address_free); +extern const struct hash_ops address_hash_ops; + CONFIG_PARSER_PROTOTYPE(config_parse_address); CONFIG_PARSER_PROTOTYPE(config_parse_broadcast); CONFIG_PARSER_PROTOTYPE(config_parse_label); diff --git a/src/network/networkd-ndisc.c b/src/network/networkd-ndisc.c index 12f8c1a1dc..c45fec5430 100644 --- a/src/network/networkd-ndisc.c +++ b/src/network/networkd-ndisc.c @@ -254,62 +254,109 @@ static int ndisc_router_process_default(Link *link, sd_ndisc_router *rt) { return 0; } -static int ndisc_router_generate_address(Link *link, unsigned prefixlen, uint32_t lifetime_preferred, Address *address) { - bool prefix = false; +static int ndisc_router_generate_addresses(Link *link, unsigned prefixlen, uint32_t lifetime_preferred, Address *address, Set **ret) { + _cleanup_set_free_free_ Set *addresses = NULL; struct in6_addr addr; IPv6Token *j; Iterator i; int r; - assert(address); assert(link); + assert(address); + assert(ret); + + addresses = set_new(&address_hash_ops); + if (!addresses) + return log_oom(); addr = address->in_addr.in6; - ORDERED_HASHMAP_FOREACH(j, link->network->ipv6_tokens, i) + ORDERED_HASHMAP_FOREACH(j, link->network->ipv6_tokens, i) { + bool have_address = false; + _cleanup_(address_freep) Address *new_address = NULL; + + r = address_new(&new_address); + if (r < 0) + return log_oom(); + + *new_address = *address; + if (j->address_generation_type == IPV6_TOKEN_ADDRESS_GENERATION_PREFIXSTABLE && memcmp(&j->prefix, &addr, FAMILY_ADDRESS_SIZE(address->family)) == 0) { + /* While this loop uses dad_counter and a retry limit as specified in RFC 7217, the loop + does not actually attempt Duplicate Address Detection; the counter will be incremented + only when the address generation algorithm produces an invalid address, and the loop + may exit with an address which ends up being unusable due to duplication on the link. + */ for (; j->dad_counter < DAD_CONFLICTS_IDGEN_RETRIES_RFC7217; j->dad_counter++) { - r = make_stableprivate_address(link, &j->prefix, prefixlen, j->dad_counter, &address->in_addr.in6); + r = make_stableprivate_address(link, &j->prefix, prefixlen, j->dad_counter, &new_address->in_addr.in6); if (r < 0) - return r; + break; - if (stableprivate_address_is_valid(&address->in_addr.in6)) { - prefix = true; + if (stableprivate_address_is_valid(&new_address->in_addr.in6)) { + have_address = true; break; } } } else if (j->address_generation_type == IPV6_TOKEN_ADDRESS_GENERATION_STATIC) { - memcpy(((uint8_t *)&address->in_addr.in6) + 8, ((uint8_t *) &j->prefix) + 8, 8); - prefix = true; - break; + memcpy(((uint8_t *)&new_address->in_addr.in6) + 8, ((uint8_t *) &j->prefix) + 8, 8); + have_address = true; } - /* fallback to eui64 if prefixstable or static do not match */ - if (!prefix) { - /* see RFC4291 section 2.5.1 */ - address->in_addr.in6.s6_addr[8] = link->mac.ether_addr_octet[0]; - address->in_addr.in6.s6_addr[8] ^= 1 << 1; - address->in_addr.in6.s6_addr[9] = link->mac.ether_addr_octet[1]; - address->in_addr.in6.s6_addr[10] = link->mac.ether_addr_octet[2]; - address->in_addr.in6.s6_addr[11] = 0xff; - address->in_addr.in6.s6_addr[12] = 0xfe; - address->in_addr.in6.s6_addr[13] = link->mac.ether_addr_octet[3]; - address->in_addr.in6.s6_addr[14] = link->mac.ether_addr_octet[4]; - address->in_addr.in6.s6_addr[15] = link->mac.ether_addr_octet[5]; + if (have_address) { + new_address->prefixlen = prefixlen; + new_address->flags = IFA_F_NOPREFIXROUTE|IFA_F_MANAGETEMPADDR; + new_address->cinfo.ifa_prefered = lifetime_preferred; + + r = set_put(addresses, new_address); + if (r < 0) + return log_link_warning_errno(link, r, "Failed to store address: %m"); + TAKE_PTR(new_address); + } } - address->prefixlen = prefixlen; - address->flags = IFA_F_NOPREFIXROUTE|IFA_F_MANAGETEMPADDR; - address->cinfo.ifa_prefered = lifetime_preferred; + /* fall back to EUI-64 if no tokens provided addresses */ + if (set_isempty(addresses)) { + _cleanup_(address_freep) Address *new_address = NULL; + + r = address_new(&new_address); + if (r < 0) + return log_oom(); + + *new_address = *address; + + /* see RFC4291 section 2.5.1 */ + new_address->in_addr.in6.s6_addr[8] = link->mac.ether_addr_octet[0]; + new_address->in_addr.in6.s6_addr[8] ^= 1 << 1; + new_address->in_addr.in6.s6_addr[9] = link->mac.ether_addr_octet[1]; + new_address->in_addr.in6.s6_addr[10] = link->mac.ether_addr_octet[2]; + new_address->in_addr.in6.s6_addr[11] = 0xff; + new_address->in_addr.in6.s6_addr[12] = 0xfe; + new_address->in_addr.in6.s6_addr[13] = link->mac.ether_addr_octet[3]; + new_address->in_addr.in6.s6_addr[14] = link->mac.ether_addr_octet[4]; + new_address->in_addr.in6.s6_addr[15] = link->mac.ether_addr_octet[5]; + new_address->prefixlen = prefixlen; + new_address->flags = IFA_F_NOPREFIXROUTE|IFA_F_MANAGETEMPADDR; + new_address->cinfo.ifa_prefered = lifetime_preferred; + + r = set_put(addresses, new_address); + if (r < 0) + return log_link_warning_errno(link, r, "Failed to store address: %m"); + TAKE_PTR(new_address); + } + + *ret = TAKE_PTR(addresses); return 0; } + static int ndisc_router_process_autonomous_prefix(Link *link, sd_ndisc_router *rt) { uint32_t lifetime_valid, lifetime_preferred, lifetime_remaining; + _cleanup_set_free_free_ Set *addresses = NULL; _cleanup_(address_freep) Address *address = NULL; - Address *existing_address; unsigned prefixlen; usec_t time_now; + Address *existing_address, *a; + Iterator i; int r; assert(link); @@ -344,36 +391,39 @@ static int ndisc_router_process_autonomous_prefix(Link *link, sd_ndisc_router *r if (r < 0) return log_link_error_errno(link, r, "Failed to get prefix address: %m"); - r = ndisc_router_generate_address(link, prefixlen, lifetime_preferred, address); + r = ndisc_router_generate_addresses(link, prefixlen, lifetime_preferred, address, &addresses); if (r < 0) - return log_link_error_errno(link, r, "Falied to generate prefix stable address: %m"); + return log_link_error_errno(link, r, "Failed to generate SLAAC addresses: %m"); - /* see RFC4862 section 5.5.3.e */ - r = address_get(link, address->family, &address->in_addr, address->prefixlen, &existing_address); - if (r > 0) { - lifetime_remaining = existing_address->cinfo.tstamp / 100 + existing_address->cinfo.ifa_valid - time_now / USEC_PER_SEC; - if (lifetime_valid > NDISC_PREFIX_LFT_MIN || lifetime_valid > lifetime_remaining) - address->cinfo.ifa_valid = lifetime_valid; - else if (lifetime_remaining <= NDISC_PREFIX_LFT_MIN) - address->cinfo.ifa_valid = lifetime_remaining; + SET_FOREACH(a, addresses, i) { + /* see RFC4862 section 5.5.3.e */ + r = address_get(link, a->family, &a->in_addr, a->prefixlen, &existing_address); + if (r > 0) { + lifetime_remaining = existing_address->cinfo.tstamp / 100 + existing_address->cinfo.ifa_valid - time_now / USEC_PER_SEC; + if (lifetime_valid > NDISC_PREFIX_LFT_MIN || lifetime_valid > lifetime_remaining) + a->cinfo.ifa_valid = lifetime_valid; + else if (lifetime_remaining <= NDISC_PREFIX_LFT_MIN) + a->cinfo.ifa_valid = lifetime_remaining; + else + a->cinfo.ifa_valid = NDISC_PREFIX_LFT_MIN; + } else if (lifetime_valid > 0) + a->cinfo.ifa_valid = lifetime_valid; else - address->cinfo.ifa_valid = NDISC_PREFIX_LFT_MIN; - } else if (lifetime_valid > 0) - address->cinfo.ifa_valid = lifetime_valid; - else - return 0; /* see RFC4862 section 5.5.3.d */ + return 0; /* see RFC4862 section 5.5.3.d */ - if (address->cinfo.ifa_valid == 0) - return 0; + if (a->cinfo.ifa_valid == 0) + continue; - r = address_configure(address, link, ndisc_netlink_address_message_handler, true); - if (r < 0) { - log_link_warning_errno(link, r, "Could not set SLAAC address: %m"); - link_enter_failed(link); - return r; + r = address_configure(a, link, ndisc_netlink_address_message_handler, true); + if (r < 0) { + log_link_warning_errno(link, r, "Could not set SLAAC address: %m"); + link_enter_failed(link); + return r; + } + + if (r > 0) + link->ndisc_messages++; } - if (r > 0) - link->ndisc_messages++; return 0; } diff --git a/test/test-network/conf/ipv6-prefix-veth-token-static-multiple.network b/test/test-network/conf/ipv6-prefix-veth-token-static-multiple.network new file mode 100644 index 0000000000..49c6f31e77 --- /dev/null +++ b/test/test-network/conf/ipv6-prefix-veth-token-static-multiple.network @@ -0,0 +1,7 @@ +[Match] +Name=veth99 + +[Network] +IPv6AcceptRA=true +IPv6Token=::1a:2b:3c:4d +IPv6Token=::fa:de:ca:fe diff --git a/test/test-network/systemd-networkd-tests.py b/test/test-network/systemd-networkd-tests.py index 7def8840be..b30385ce56 100755 --- a/test/test-network/systemd-networkd-tests.py +++ b/test/test-network/systemd-networkd-tests.py @@ -2685,6 +2685,7 @@ class NetworkdRATests(unittest.TestCase, Utilities): 'ipv6-prefix-veth.network', 'ipv6-prefix-veth-token-static.network', 'ipv6-prefix-veth-token-static-explicit.network', + 'ipv6-prefix-veth-token-static-multiple.network', 'ipv6-prefix-veth-token-prefixstable.network'] def setUp(self): @@ -2728,6 +2729,16 @@ class NetworkdRATests(unittest.TestCase, Utilities): print(output) self.assertRegex(output, '2002:da8:1:0:1a:2b:3c:4d') + def test_ipv6_token_static_multiple(self): + copy_unit_to_networkd_unit_path('25-veth.netdev', 'ipv6-prefix.network', 'ipv6-prefix-veth-token-static-multiple.network') + start_networkd() + self.wait_online(['veth99:routable', 'veth-peer:degraded']) + + output = check_output(*networkctl_cmd, '-n', '0', 'status', 'veth99', env=env) + print(output) + self.assertRegex(output, '2002:da8:1:0:1a:2b:3c:4d') + self.assertRegex(output, '2002:da8:1:0:fa:de:ca:fe') + def test_ipv6_token_prefixstable(self): copy_unit_to_networkd_unit_path('25-veth.netdev', 'ipv6-prefix.network', 'ipv6-prefix-veth-token-prefixstable.network') start_networkd()