network: make link become configured state when at least one dynamic protocol provide an address

Before this, to speed up the system boot with IPv4 only network,
we need to specify `IPv6AcceptRA=no`, as it is enabled by default.

Closes #15469.

meson_options.txt

@@ -58,7 +58,7 @@ option('debug-extra', type : 'array', choices : ['hashmap', 'mmap-cache', 'sipha
 option('memory-accounting-default', type : 'boolean',
        description : 'enable MemoryAccounting= by default')
 option('bump-proc-sys-fs-file-max', type : 'boolean',
-       description : 'bump /proc/sys/fs/file-max to ULONG_MAX')
+       description : 'bump /proc/sys/fs/file-max to LONG_MAX')
 option('bump-proc-sys-fs-nr-open', type : 'boolean',
        description : 'bump /proc/sys/fs/nr_open to INT_MAX')
 option('valgrind', type : 'boolean', value : false,

src/network/networkd-link.c

@@ -1133,16 +1133,14 @@ void link_check_ready(Link *link) {
                     in_addr_is_null(AF_INET6, (const union in_addr_union*) &link->ipv6ll_address))
                         return;
 
-                if ((link_dhcp4_enabled(link) || link_dhcp6_enabled(link)) &&
+                if ((link_dhcp4_enabled(link) || link_dhcp6_enabled(link) || link_ipv6_accept_ra_enabled(link)) &&
                     !link->dhcp4_configured &&
                     !link->dhcp6_configured &&
+                    !link->ndisc_configured &&
                     !(link_ipv4ll_enabled(link, ADDRESS_FAMILY_FALLBACK_IPV4) && link->ipv4ll_address))
-                        /* When DHCP is enabled, at least one protocol must provide an address, or
+                        /* When DHCP or RA is enabled, at least one protocol must provide an address, or
                          * an IPv4ll fallback address must be configured. */
                         return;
-
-                if (link_ipv6_accept_ra_enabled(link) && !link->ndisc_configured)
-                        return;
         }
 
         if (link->state != LINK_STATE_CONFIGURED)