Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 335 insertions, 0 deletions

diff --git a/src/network/networkd-sysctl.c b/src/network/networkd-sysctl.c
new file mode 100644
index 0000000..2b226b2
--- /dev/null
+++ b/src/network/networkd-sysctl.c
@@ -0,0 +1,335 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <netinet/in.h>
+#include <linux/if.h>
+#include <linux/if_arp.h>
+
+#include "missing_network.h"
+#include "networkd-link.h"
+#include "networkd-manager.h"
+#include "networkd-network.h"
+#include "networkd-sysctl.h"
+#include "socket-util.h"
+#include "string-table.h"
+#include "sysctl-util.h"
+
+static bool link_is_configured_for_family(Link *link, int family) {
+        assert(link);
+
+        if (!link->network)
+                return false;
+
+        if (link->flags & IFF_LOOPBACK)
+                return false;
+
+        /* CAN devices do not support IP layer. Most of the functions below are never called for CAN devices,
+         * but link_set_ipv6_mtu() may be called after setting interface MTU, and warn about the failure. For
+         * safety, let's unconditionally check if the interface is not a CAN device. */
+        if (IN_SET(family, AF_INET, AF_INET6) && link->iftype == ARPHRD_CAN)
+                return false;
+
+        if (family == AF_INET6 && !socket_ipv6_is_supported())
+                return false;
+
+        return true;
+}
+
+static int link_update_ipv6_sysctl(Link *link) {
+        assert(link);
+
+        if (!link_is_configured_for_family(link, AF_INET6))
+                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_is_configured_for_family(link, AF_INET))
+                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 (!link_is_configured_for_family(link, family))
+                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_ipv4_rp_filter(Link *link) {
+        assert(link);
+
+        if (!link_is_configured_for_family(link, AF_INET))
+                return 0;
+
+        if (link->network->ipv4_rp_filter < 0)
+                return 0;
+
+        return sysctl_write_ip_property_int(AF_INET, link->ifname, "rp_filter", link->network->ipv4_rp_filter);
+}
+
+static int link_set_ipv6_privacy_extensions(Link *link) {
+        IPv6PrivacyExtensions val;
+
+        assert(link);
+        assert(link->manager);
+
+        if (!link_is_configured_for_family(link, AF_INET6))
+                return 0;
+
+        val = link->network->ipv6_privacy_extensions;
+        if (val < 0) /* If not specified, then use the global setting. */
+                val = link->manager->ipv6_privacy_extensions;
+
+        /* When "kernel", do not update the setting. */
+        if (val == IPV6_PRIVACY_EXTENSIONS_KERNEL)
+                return 0;
+
+        return sysctl_write_ip_property_int(AF_INET6, link->ifname, "use_tempaddr", (int) val);
+}
+
+static int link_set_ipv6_accept_ra(Link *link) {
+        assert(link);
+
+        if (!link_is_configured_for_family(link, AF_INET6))
+                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);
+
+        if (!link_is_configured_for_family(link, AF_INET6))
+                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);
+
+        if (!link_is_configured_for_family(link, AF_INET6))
+                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 (!link_is_configured_for_family(link, AF_INET6))
+                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);
+
+        if (!link_is_configured_for_family(link, AF_INET6))
+                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_ipv4_accept_local(Link *link) {
+        assert(link);
+
+        if (!link_is_configured_for_family(link, AF_INET))
+                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_is_configured_for_family(link, AF_INET))
+                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);
+}
+
+static int link_set_ipv4_promote_secondaries(Link *link) {
+        assert(link);
+
+        if (!link_is_configured_for_family(link, AF_INET))
+                return 0;
+
+        /* 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 */
+        return sysctl_write_ip_property_boolean(AF_INET, link->ifname, "promote_secondaries", true);
+}
+
+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");
+
+        r = link_set_ipv4_rp_filter(link);
+        if (r < 0)
+                log_link_warning_errno(link, r, "Cannot set IPv4 reverse path filtering for interface, ignoring: %m");
+
+        r = link_set_ipv4_promote_secondaries(link);
+        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",
+        [IPV6_PRIVACY_EXTENSIONS_KERNEL]        = "kernel",
+};
+
+DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(ipv6_privacy_extensions, IPv6PrivacyExtensions,
+                                        IPV6_PRIVACY_EXTENSIONS_YES);
+DEFINE_CONFIG_PARSE_ENUM(config_parse_ipv6_privacy_extensions, ipv6_privacy_extensions, IPv6PrivacyExtensions,
+                         "Failed to parse IPv6 privacy extensions option");
+
+static const char* const ip_reverse_path_filter_table[_IP_REVERSE_PATH_FILTER_MAX] = {
+        [IP_REVERSE_PATH_FILTER_NO]     = "no",
+        [IP_REVERSE_PATH_FILTER_STRICT] = "strict",
+        [IP_REVERSE_PATH_FILTER_LOOSE]  = "loose",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(ip_reverse_path_filter, IPReversePathFilter);
+DEFINE_CONFIG_PARSE_ENUM(config_parse_ip_reverse_path_filter, ip_reverse_path_filter, IPReversePathFilter,
+                         "Failed to parse IP reverse path filter option");