Merge pull request #23927 from AndreKalb/feature/ipv4-link-local-start-address

network: Feature IPv4 link-local start address

src/libsystemd-network/test-ipv4ll-manual.c

@@ -39,7 +39,7 @@ static void ll_handler(sd_ipv4ll *ll, int event, void *userdata) {
         }
 }
 
-static int client_run(int ifindex, const char *seed_str, const struct ether_addr *ha, sd_event *e) {
+static int client_run(int ifindex, const char *seed_str, const struct in_addr *start_address, const struct ether_addr *ha, sd_event *e) {
         sd_ipv4ll *ll;
 
         assert_se(sd_ipv4ll_new(&ll) >= 0);
@@ -57,6 +57,9 @@ static int client_run(int ifindex, const char *seed_str, const struct ether_addr
                 assert_se(sd_ipv4ll_set_address_seed(ll, seed) >= 0);
         }
 
+        if (start_address && in4_addr_is_set(start_address))
+                assert_se(sd_ipv4ll_set_address(ll, start_address) >= 0);
+
         log_info("starting IPv4LL client");
 
         assert_se(sd_ipv4ll_start(ll) >= 0);
@@ -68,7 +71,7 @@ static int client_run(int ifindex, const char *seed_str, const struct ether_addr
         return EXIT_SUCCESS;
 }
 
-static int test_ll(const char *ifname, const char *seed) {
+static int test_ll(const char *ifname, const char *seed, const struct in_addr *start_address) {
         _cleanup_(sd_event_unrefp) sd_event *e = NULL;
         _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL, *reply = NULL;
@@ -87,7 +90,7 @@ static int test_ll(const char *ifname, const char *seed) {
         assert_se(sd_rtnl_message_link_get_ifindex(reply, &ifindex) >= 0);
         assert_se(sd_netlink_message_read_ether_addr(reply, IFLA_ADDRESS, &ha) >= 0);
 
-        client_run(ifindex, seed, &ha, e);
+        client_run(ifindex, seed, start_address, &ha, e);
 
         return EXIT_SUCCESS;
 }
@@ -96,12 +99,19 @@ int main(int argc, char *argv[]) {
         test_setup_logging(LOG_DEBUG);
 
         if (argc == 2)
-                return test_ll(argv[1], NULL);
-        else if (argc == 3)
-                return test_ll(argv[1], argv[2]);
-        else {
+                return test_ll(argv[1], NULL, NULL);
+        else if (argc == 3) {
+                int r;
+                union in_addr_union a;
+
+                r = in_addr_from_string(AF_INET, argv[2], &a);
+                if (r < 0)
+                        return test_ll(argv[1], argv[2], NULL);
+                else
+                        return test_ll(argv[1], NULL, &a.in);
+        } else {
                 log_error("This program takes one or two arguments.\n"
-                          "\t %s <ifname> [<seed>]", program_invocation_short_name);
+                          "\t %s <ifname> [<seed>|<start_address>]", program_invocation_short_name);
                 return EXIT_FAILURE;
         }
 }

src/libsystemd-network/test-ipv4ll.c

@@ -122,7 +122,7 @@ static void test_public_api_setters(sd_event *e) {
         assert_se(sd_ipv4ll_unref(ll) == NULL);
 }
 
-static void test_basic_request(sd_event *e) {
+static void test_basic_request(sd_event *e, const struct in_addr *start_address) {
 
         sd_ipv4ll *ll;
         struct ether_arp arp;
@@ -133,6 +133,8 @@ static void test_basic_request(sd_event *e) {
                 printf("* %s\n", __func__);
 
         assert_se(sd_ipv4ll_new(&ll) == 0);
+        if (in4_addr_is_set(start_address))
+                assert_se(sd_ipv4ll_set_address(ll, start_address) >= 0);
         assert_se(sd_ipv4ll_start(ll) == -EINVAL);
 
         assert_se(sd_ipv4ll_attach_event(ll, e, 0) == 0);
@@ -168,6 +170,13 @@ static void test_basic_request(sd_event *e) {
 
                 sd_event_run(e, UINT64_MAX);
                 assert_se(basic_request_handler_bind == 1);
+
+                if (in4_addr_is_set(start_address)) {
+                        struct in_addr address;
+
+                        assert_se(sd_ipv4ll_get_address(ll, &address) >= 0);
+                        assert_se(start_address->s_addr == address.s_addr);
+                }
         }
 
         sd_ipv4ll_stop(ll);
@@ -179,6 +188,7 @@ static void test_basic_request(sd_event *e) {
 }
 
 int main(int argc, char *argv[]) {
+        struct in_addr start_address = {};
         _cleanup_(sd_event_unrefp) sd_event *e = NULL;
 
         test_setup_logging(LOG_DEBUG);
@@ -186,7 +196,12 @@ int main(int argc, char *argv[]) {
         assert_se(sd_event_new(&e) >= 0);
 
         test_public_api_setters(e);
-        test_basic_request(e);
+        test_basic_request(e, &start_address);
+
+        basic_request_handler_bind = 0;
+        basic_request_handler_stop = 0;
+        start_address.s_addr = htobe32(169U << 24 | 254U << 16 | 1U << 8 | 2U);
+        test_basic_request(e, &start_address);
 
         return 0;
 }

src/network/networkd-dhcp4.c

@@ -1071,6 +1071,12 @@ static int dhcp4_handler(sd_dhcp_client *client, int event, void *userdata) {
                         if (link->ipv4ll) {
                                 log_link_debug(link, "DHCP client is stopped. Acquiring IPv4 link-local address");
 
+                                if (in4_addr_is_set(&link->network->ipv4ll_start_address)) {
+                                        r = sd_ipv4ll_set_address(link->ipv4ll, &link->network->ipv4ll_start_address);
+                                        if (r < 0)
+                                                return log_link_warning_errno(link, r, "Could not set IPv4 link-local start address: %m");;
+                                }
+
                                 r = sd_ipv4ll_start(link->ipv4ll);
                                 if (r < 0)
                                         return log_link_warning_errno(link, r, "Could not acquire IPv4 link-local address: %m");
@@ -1154,6 +1160,12 @@ static int dhcp4_handler(sd_dhcp_client *client, int event, void *userdata) {
                         if (link->ipv4ll && !sd_ipv4ll_is_running(link->ipv4ll)) {
                                 log_link_debug(link, "Problems acquiring DHCP lease, acquiring IPv4 link-local address");
 
+                                if (in4_addr_is_set(&link->network->ipv4ll_start_address)) {
+                                        r = sd_ipv4ll_set_address(link->ipv4ll, &link->network->ipv4ll_start_address);
+                                        if (r < 0)
+                                                return log_link_warning_errno(link, r, "Could not set IPv4 link-local start address: %m");;
+                                }
+
                                 r = sd_ipv4ll_start(link->ipv4ll);
                                 if (r < 0)
                                         return log_link_warning_errno(link, r, "Could not acquire IPv4 link-local address: %m");

src/network/networkd-ipv4ll.c

@@ -263,3 +263,44 @@ int config_parse_ipv4ll(
 
         return 0;
 }
+
+int config_parse_ipv4ll_address(
+                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) {
+
+        union in_addr_union a;
+        struct in_addr *ipv4ll_address = ASSERT_PTR(data);
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        if (isempty(rvalue)) {
+                *ipv4ll_address = (struct in_addr) {};
+                return 0;
+        }
+
+        r = in_addr_from_string(AF_INET, rvalue, &a);
+        if (r < 0) {
+                log_syntax(unit, LOG_WARNING, filename, line, r,
+                           "Failed to parse %s=, ignoring assignment: %s", lvalue, rvalue);
+                return 0;
+        }
+        if (!in4_addr_is_link_local(&a.in)) {
+                log_syntax(unit, LOG_WARNING, filename, line, 0,
+                           "Not a IPv4 link local address, ignoring assignment: %s", rvalue);
+                return 0;
+        }
+
+        *ipv4ll_address = a.in;
+        return 0;
+}

src/network/networkd-ipv4ll.h

@@ -11,3 +11,4 @@ int ipv4ll_configure(Link *link);
 int ipv4ll_update_mac(Link *link);
 
 CONFIG_PARSER_PROTOTYPE(config_parse_ipv4ll);
+CONFIG_PARSER_PROTOTYPE(config_parse_ipv4ll_address);

src/network/networkd-link.c

@@ -611,6 +611,12 @@ static int link_acquire_dynamic_ipv4_conf(Link *link) {
                 log_link_debug(link, "Acquiring DHCPv4 lease.");
 
         } else if (link->ipv4ll) {
+                if (in4_addr_is_set(&link->network->ipv4ll_start_address)) {
+                        r = sd_ipv4ll_set_address(link->ipv4ll, &link->network->ipv4ll_start_address);
+                        if (r < 0)
+                                return log_link_warning_errno(link, r, "Could not set IPv4 link-local start address: %m");
+                }
+
                 r = sd_ipv4ll_start(link->ipv4ll);
                 if (r < 0)
                         return log_link_warning_errno(link, r, "Could not acquire IPv4 link-local address: %m");

src/network/networkd-network-gperf.gperf

@@ -106,6 +106,7 @@ Network.DHCPServer,                          config_parse_bool,
 Network.LinkLocalAddressing,                 config_parse_link_local_address_family,                   0,                             offsetof(Network, link_local)
 Network.IPv6LinkLocalAddressGenerationMode,  config_parse_ipv6_link_local_address_gen_mode,            0,                             offsetof(Network, ipv6ll_address_gen_mode)
 Network.IPv6StableSecretAddress,             config_parse_in_addr_non_null,                            AF_INET6,                      offsetof(Network, ipv6ll_stable_secret)
+Network.IPv4LLStartAddress,                  config_parse_ipv4ll_address,                              0,                             offsetof(Network, ipv4ll_start_address)
 Network.IPv4LLRoute,                         config_parse_bool,                                        0,                             offsetof(Network, ipv4ll_route)
 Network.DefaultRouteOnDevice,                config_parse_bool,                                        0,                             offsetof(Network, default_route_on_device)
 Network.LLDP,                                config_parse_lldp_mode,                                   0,                             offsetof(Network, lldp_mode)

src/network/networkd-network.h

@@ -208,6 +208,7 @@ struct Network {
         AddressFamily link_local;
         IPv6LinkLocalAddressGenMode ipv6ll_address_gen_mode;
         struct in6_addr ipv6ll_stable_secret;
+        struct in_addr ipv4ll_start_address;
         bool ipv4ll_route;
 
         /* IPv6 RA support */