| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #include <netinet/in.h> |
| #include <linux/if.h> |
| |
| #include "missing_network.h" |
| #include "networkd-link.h" |
| #include "networkd-network.h" |
| #include "networkd-sysctl.h" |
| #include "socket-util.h" |
| #include "string-table.h" |
| #include "sysctl-util.h" |
| |
| #define STABLE_SECRET_APP_ID_1 SD_ID128_MAKE(aa,05,1d,94,43,68,45,07,b9,73,f1,e8,e4,b7,34,52) |
| #define STABLE_SECRET_APP_ID_2 SD_ID128_MAKE(52,c4,40,a0,9f,2f,48,58,a9,3a,f6,29,25,ba,7a,7d) |
| |
| static int link_update_ipv6_sysctl(Link *link) { |
| assert(link); |
| |
| if (link->flags & IFF_LOOPBACK) |
| return 0; |
| |
| if (!link_ipv6_enabled(link)) |
| return 0; |
| |
| return sysctl_write_ip_property_boolean(AF_INET6, link->ifname, "disable_ipv6", false); |
| } |
| |
| static int link_set_proxy_arp(Link *link) { |
| assert(link); |
| |
| if (link->flags & IFF_LOOPBACK) |
| return 0; |
| |
| if (!link->network) |
| return 0; |
| |
| if (link->network->proxy_arp < 0) |
| return 0; |
| |
| return sysctl_write_ip_property_boolean(AF_INET, link->ifname, "proxy_arp", link->network->proxy_arp > 0); |
| } |
| |
| static bool link_ip_forward_enabled(Link *link, int family) { |
| assert(link); |
| assert(IN_SET(family, AF_INET, AF_INET6)); |
| |
| if (family == AF_INET6 && !socket_ipv6_is_supported()) |
| return false; |
| |
| if (link->flags & IFF_LOOPBACK) |
| return false; |
| |
| if (!link->network) |
| return false; |
| |
| return link->network->ip_forward & (family == AF_INET ? ADDRESS_FAMILY_IPV4 : ADDRESS_FAMILY_IPV6); |
| } |
| |
| static int link_set_ipv4_forward(Link *link) { |
| assert(link); |
| |
| if (!link_ip_forward_enabled(link, AF_INET)) |
| return 0; |
| |
| /* We propagate the forwarding flag from one interface to the |
| * global setting one way. This means: as long as at least one |
| * interface was configured at any time that had IP forwarding |
| * enabled the setting will stay on for good. We do this |
| * primarily to keep IPv4 and IPv6 packet forwarding behaviour |
| * somewhat in sync (see below). */ |
| |
| return sysctl_write_ip_property(AF_INET, NULL, "ip_forward", "1"); |
| } |
| |
| static int link_set_ipv6_forward(Link *link) { |
| assert(link); |
| |
| if (!link_ip_forward_enabled(link, AF_INET6)) |
| return 0; |
| |
| /* On Linux, the IPv6 stack does not know a per-interface |
| * packet forwarding setting: either packet forwarding is on |
| * for all, or off for all. We hence don't bother with a |
| * per-interface setting, but simply propagate the interface |
| * flag, if it is set, to the global flag, one-way. Note that |
| * while IPv4 would allow a per-interface flag, we expose the |
| * same behaviour there and also propagate the setting from |
| * one to all, to keep things simple (see above). */ |
| |
| return sysctl_write_ip_property(AF_INET6, "all", "forwarding", "1"); |
| } |
| |
| static int link_set_ipv6_privacy_extensions(Link *link) { |
| assert(link); |
| |
| if (!socket_ipv6_is_supported()) |
| return 0; |
| |
| if (link->flags & IFF_LOOPBACK) |
| return 0; |
| |
| if (!link->network) |
| return 0; |
| |
| // this is the special "kernel" value |
| if (link->network->ipv6_privacy_extensions == _IPV6_PRIVACY_EXTENSIONS_INVALID) |
| return 0; |
| |
| return sysctl_write_ip_property_int(AF_INET6, link->ifname, "use_tempaddr", (int) link->network->ipv6_privacy_extensions); |
| } |
| |
| static int link_set_ipv6_accept_ra(Link *link) { |
| assert(link); |
| |
| /* Make this a NOP if IPv6 is not available */ |
| if (!socket_ipv6_is_supported()) |
| return 0; |
| |
| if (link->flags & IFF_LOOPBACK) |
| return 0; |
| |
| if (!link->network) |
| return 0; |
| |
| return sysctl_write_ip_property(AF_INET6, link->ifname, "accept_ra", "0"); |
| } |
| |
| static int link_set_ipv6_dad_transmits(Link *link) { |
| assert(link); |
| |
| /* Make this a NOP if IPv6 is not available */ |
| if (!socket_ipv6_is_supported()) |
| return 0; |
| |
| if (link->flags & IFF_LOOPBACK) |
| return 0; |
| |
| if (!link->network) |
| return 0; |
| |
| if (link->network->ipv6_dad_transmits < 0) |
| return 0; |
| |
| return sysctl_write_ip_property_int(AF_INET6, link->ifname, "dad_transmits", link->network->ipv6_dad_transmits); |
| } |
| |
| static int link_set_ipv6_hop_limit(Link *link) { |
| assert(link); |
| |
| /* Make this a NOP if IPv6 is not available */ |
| if (!socket_ipv6_is_supported()) |
| return 0; |
| |
| if (link->flags & IFF_LOOPBACK) |
| return 0; |
| |
| if (!link->network) |
| return 0; |
| |
| if (link->network->ipv6_hop_limit < 0) |
| return 0; |
| |
| return sysctl_write_ip_property_int(AF_INET6, link->ifname, "hop_limit", link->network->ipv6_hop_limit); |
| } |
| |
| static int link_set_ipv6_proxy_ndp(Link *link) { |
| bool v; |
| |
| assert(link); |
| |
| if (!socket_ipv6_is_supported()) |
| return 0; |
| |
| if (link->flags & IFF_LOOPBACK) |
| return 0; |
| |
| if (!link->network) |
| return 0; |
| |
| if (link->network->ipv6_proxy_ndp >= 0) |
| v = link->network->ipv6_proxy_ndp; |
| else |
| v = !set_isempty(link->network->ipv6_proxy_ndp_addresses); |
| |
| return sysctl_write_ip_property_boolean(AF_INET6, link->ifname, "proxy_ndp", v); |
| } |
| |
| int link_set_ipv6_mtu(Link *link) { |
| uint32_t mtu; |
| |
| assert(link); |
| |
| /* Make this a NOP if IPv6 is not available */ |
| if (!socket_ipv6_is_supported()) |
| return 0; |
| |
| if (link->flags & IFF_LOOPBACK) |
| return 0; |
| |
| if (!link->network) |
| return 0; |
| |
| if (link->network->ipv6_mtu == 0) |
| return 0; |
| |
| mtu = link->network->ipv6_mtu; |
| if (mtu > link->max_mtu) { |
| log_link_warning(link, "Reducing requested IPv6 MTU %"PRIu32" to the interface's maximum MTU %"PRIu32".", |
| mtu, link->max_mtu); |
| mtu = link->max_mtu; |
| } |
| |
| return sysctl_write_ip_property_uint32(AF_INET6, link->ifname, "mtu", mtu); |
| } |
| |
| static int link_set_ipv6ll_stable_secret(Link *link) { |
| _cleanup_free_ char *str = NULL; |
| struct in6_addr a; |
| int r; |
| |
| assert(link); |
| assert(link->network); |
| |
| if (link->network->ipv6ll_address_gen_mode != IPV6_LINK_LOCAL_ADDRESSS_GEN_MODE_STABLE_PRIVACY) |
| return 0; |
| |
| if (in6_addr_is_set(&link->network->ipv6ll_stable_secret)) |
| a = link->network->ipv6ll_stable_secret; |
| else { |
| sd_id128_t key; |
| le64_t v; |
| |
| /* Generate a stable secret address from machine-ID and the interface name. */ |
| |
| r = sd_id128_get_machine_app_specific(STABLE_SECRET_APP_ID_1, &key); |
| if (r < 0) |
| return log_link_debug_errno(link, r, "Failed to generate key: %m"); |
| |
| v = htole64(siphash24_string(link->ifname, key.bytes)); |
| memcpy(a.s6_addr, &v, sizeof(v)); |
| |
| r = sd_id128_get_machine_app_specific(STABLE_SECRET_APP_ID_2, &key); |
| if (r < 0) |
| return log_link_debug_errno(link, r, "Failed to generate key: %m"); |
| |
| v = htole64(siphash24_string(link->ifname, key.bytes)); |
| assert_cc(sizeof(v) * 2 == sizeof(a.s6_addr)); |
| memcpy(a.s6_addr + sizeof(v), &v, sizeof(v)); |
| } |
| |
| r = in6_addr_to_string(&a, &str); |
| if (r < 0) |
| return r; |
| |
| return sysctl_write_ip_property(AF_INET6, link->ifname, "stable_secret", str); |
| } |
| |
| static int link_set_ipv4_accept_local(Link *link) { |
| assert(link); |
| |
| if (link->flags & IFF_LOOPBACK) |
| return 0; |
| |
| if (link->network->ipv4_accept_local < 0) |
| return 0; |
| |
| return sysctl_write_ip_property_boolean(AF_INET, link->ifname, "accept_local", link->network->ipv4_accept_local > 0); |
| } |
| |
| static int link_set_ipv4_route_localnet(Link *link) { |
| assert(link); |
| |
| if (link->flags & IFF_LOOPBACK) |
| return 0; |
| |
| if (link->network->ipv4_route_localnet < 0) |
| return 0; |
| |
| return sysctl_write_ip_property_boolean(AF_INET, link->ifname, "route_localnet", link->network->ipv4_route_localnet > 0); |
| } |
| |
| int link_set_sysctl(Link *link) { |
| int r; |
| |
| assert(link); |
| |
| /* If IPv6 configured that is static IPv6 address and IPv6LL autoconfiguration is enabled |
| * for this interface, then enable IPv6 */ |
| r = link_update_ipv6_sysctl(link); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Cannot enable IPv6, ignoring: %m"); |
| |
| r = link_set_proxy_arp(link); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Cannot configure proxy ARP for interface, ignoring: %m"); |
| |
| r = link_set_ipv4_forward(link); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Cannot turn on IPv4 packet forwarding, ignoring: %m"); |
| |
| r = link_set_ipv6_forward(link); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Cannot configure IPv6 packet forwarding, ignoring: %m");; |
| |
| r = link_set_ipv6_privacy_extensions(link); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Cannot configure IPv6 privacy extensions for interface, ignoring: %m"); |
| |
| r = link_set_ipv6_accept_ra(link); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Cannot disable kernel IPv6 accept_ra for interface, ignoring: %m"); |
| |
| r = link_set_ipv6_dad_transmits(link); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Cannot set IPv6 dad transmits for interface, ignoring: %m"); |
| |
| r = link_set_ipv6_hop_limit(link); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Cannot set IPv6 hop limit for interface, ignoring: %m"); |
| |
| r = link_set_ipv6_proxy_ndp(link); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Cannot set IPv6 proxy NDP, ignoring: %m"); |
| |
| r = link_set_ipv6_mtu(link); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Cannot set IPv6 MTU, ignoring: %m"); |
| |
| r = link_set_ipv6ll_stable_secret(link); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Cannot set stable secret address for IPv6 link local address: %m"); |
| |
| r = link_set_ipv4_accept_local(link); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Cannot set IPv4 accept_local flag for interface, ignoring: %m"); |
| |
| r = link_set_ipv4_route_localnet(link); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Cannot set IPv4 route_localnet flag for interface, ignoring: %m"); |
| |
| /* If promote_secondaries is not set, DHCP will work only as long as the IP address does not |
| * changes between leases. The kernel will remove all secondary IP addresses of an interface |
| * otherwise. The way systemd-networkd works is that the new IP of a lease is added as a |
| * secondary IP and when the primary one expires it relies on the kernel to promote the |
| * secondary IP. See also https://github.com/systemd/systemd/issues/7163 */ |
| r = sysctl_write_ip_property_boolean(AF_INET, link->ifname, "promote_secondaries", true); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Cannot enable promote_secondaries for interface, ignoring: %m"); |
| |
| return 0; |
| } |
| |
| static const char* const ipv6_privacy_extensions_table[_IPV6_PRIVACY_EXTENSIONS_MAX] = { |
| [IPV6_PRIVACY_EXTENSIONS_NO] = "no", |
| [IPV6_PRIVACY_EXTENSIONS_PREFER_PUBLIC] = "prefer-public", |
| [IPV6_PRIVACY_EXTENSIONS_YES] = "yes", |
| }; |
| |
| DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(ipv6_privacy_extensions, IPv6PrivacyExtensions, |
| IPV6_PRIVACY_EXTENSIONS_YES); |
| |
| int config_parse_ipv6_privacy_extensions( |
| 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) { |
| |
| IPv6PrivacyExtensions s, *ipv6_privacy_extensions = data; |
| |
| assert(filename); |
| assert(lvalue); |
| assert(rvalue); |
| assert(ipv6_privacy_extensions); |
| |
| s = ipv6_privacy_extensions_from_string(rvalue); |
| if (s < 0) { |
| if (streq(rvalue, "kernel")) |
| s = _IPV6_PRIVACY_EXTENSIONS_INVALID; |
| else { |
| log_syntax(unit, LOG_WARNING, filename, line, 0, |
| "Failed to parse IPv6 privacy extensions option, ignoring: %s", rvalue); |
| return 0; |
| } |
| } |
| |
| *ipv6_privacy_extensions = s; |
| |
| return 0; |
| } |
