src/network/networkd-ipv4ll.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <netinet/in.h>
   4 #include <linux/if.h>
   5
   6 #include "netif-util.h"
   7 #include "networkd-address.h"
   8 #include "networkd-ipv4acd.h"
   9 #include "networkd-ipv4ll.h"
  10 #include "networkd-link.h"
  11 #include "networkd-manager.h"
  12 #include "networkd-queue.h"
  13 #include "parse-util.h"
  14
  15 bool link_ipv4ll_enabled(Link *link) {
  16         assert(link);
  17
  18         if (!link_ipv4acd_supported(link))
  19                 return false;
  20
  21         if (!link->network)
  22                 return false;
  23
  24         if (link->network->bond)
  25                 return false;
  26
  27         return link->network->link_local & ADDRESS_FAMILY_IPV4;
  28 }
  29
  30 static int address_new_from_ipv4ll(Link *link, Address **ret) {
  31         _cleanup_(address_freep) Address *address = NULL;
  32         struct in_addr addr;
  33         int r;
  34
  35         assert(link);
  36         assert(link->ipv4ll);
  37         assert(ret);
  38
  39         r = sd_ipv4ll_get_address(link->ipv4ll, &addr);
  40         if (r < 0)
  41                 return r;
  42
  43         r = address_new(&address);
  44         if (r < 0)
  45                 return -ENOMEM;
  46
  47         address->source = NETWORK_CONFIG_SOURCE_IPV4LL;
  48         address->family = AF_INET;
  49         address->in_addr.in = addr;
  50         address->prefixlen = 16;
  51         address->scope = RT_SCOPE_LINK;
  52         address->route_metric = IPV4LL_ROUTE_METRIC;
  53
  54         *ret = TAKE_PTR(address);
  55         return 0;
  56 }
  57
  58 static int ipv4ll_address_lost(Link *link) {
  59         _cleanup_(address_freep) Address *address = NULL;
  60         Address *existing;
  61         int r;
  62
  63         assert(link);
  64
  65         link->ipv4ll_address_configured = false;
  66
  67         r = address_new_from_ipv4ll(link, &address);
  68         if (r == -ENOENT)
  69                 return 0;
  70         if (r < 0)
  71                 return r;
  72
  73         if (address_get(link, address, &existing) < 0)
  74                 return 0;
  75
  76         if (existing->source != NETWORK_CONFIG_SOURCE_IPV4LL)
  77                 return 0;
  78
  79         if (!address_exists(existing))
  80                 return 0;
  81
  82         log_link_debug(link, "IPv4 link-local release "IPV4_ADDRESS_FMT_STR,
  83                        IPV4_ADDRESS_FMT_VAL(address->in_addr.in));
  84
  85         return address_remove(existing);
  86 }
  87
  88 static int ipv4ll_address_handler(sd_netlink *rtnl, sd_netlink_message *m, Request *req, Link *link, Address *address) {
  89         int r;
  90
  91         assert(link);
  92         assert(!link->ipv4ll_address_configured);
  93
  94         r = address_configure_handler_internal(rtnl, m, link, "Could not set ipv4ll address");
  95         if (r <= 0)
  96                 return r;
  97
  98         link->ipv4ll_address_configured = true;
  99         link_check_ready(link);
 100
 101         return 1;
 102 }
 103
 104 static int ipv4ll_address_claimed(sd_ipv4ll *ll, Link *link) {
 105         _cleanup_(address_freep) Address *address = NULL;
 106         int r;
 107
 108         assert(ll);
 109         assert(link);
 110
 111         link->ipv4ll_address_configured = false;
 112
 113         r = address_new_from_ipv4ll(link, &address);
 114         if (r == -ENOENT)
 115                 return 0;
 116         if (r < 0)
 117                 return r;
 118
 119         log_link_debug(link, "IPv4 link-local claim "IPV4_ADDRESS_FMT_STR,
 120                        IPV4_ADDRESS_FMT_VAL(address->in_addr.in));
 121
 122         return link_request_address(link, address, NULL, ipv4ll_address_handler, NULL);
 123 }
 124
 125 static void ipv4ll_handler(sd_ipv4ll *ll, int event, void *userdata) {
 126         Link *link = ASSERT_PTR(userdata);
 127         int r;
 128
 129         assert(link->network);
 130
 131         if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
 132                 return;
 133
 134         switch (event) {
 135                 case SD_IPV4LL_EVENT_STOP:
 136                         r = ipv4ll_address_lost(link);
 137                         if (r < 0) {
 138                                 link_enter_failed(link);
 139                                 return;
 140                         }
 141                         break;
 142                 case SD_IPV4LL_EVENT_CONFLICT:
 143                         r = ipv4ll_address_lost(link);
 144                         if (r < 0) {
 145                                 link_enter_failed(link);
 146                                 return;
 147                         }
 148
 149                         r = sd_ipv4ll_restart(ll);
 150                         if (r < 0) {
 151                                 log_link_warning_errno(link, r, "Could not acquire IPv4 link-local address: %m");
 152                                 link_enter_failed(link);
 153                         }
 154                         break;
 155                 case SD_IPV4LL_EVENT_BIND:
 156                         r = ipv4ll_address_claimed(ll, link);
 157                         if (r < 0) {
 158                                 log_link_error(link, "Failed to configure ipv4ll address: %m");
 159                                 link_enter_failed(link);
 160                                 return;
 161                         }
 162                         break;
 163                 default:
 164                         log_link_warning(link, "IPv4 link-local unknown event: %d", event);
 165                         break;
 166         }
 167 }
 168
 169 static int ipv4ll_check_mac(sd_ipv4ll *ll, const struct ether_addr *mac, void *userdata) {
 170         Manager *m = ASSERT_PTR(userdata);
 171         struct hw_addr_data hw_addr;
 172
 173         assert(mac);
 174
 175         hw_addr = (struct hw_addr_data) {
 176                 .length = ETH_ALEN,
 177                 .ether = *mac,
 178         };
 179
 180         return link_get_by_hw_addr(m, &hw_addr, NULL) >= 0;
 181 }
 182
 183 int ipv4ll_configure(Link *link) {
 184         uint64_t seed;
 185         int r;
 186
 187         assert(link);
 188
 189         if (!link_ipv4ll_enabled(link))
 190                 return 0;
 191
 192         if (link->ipv4ll)
 193                 return -EBUSY;
 194
 195         r = sd_ipv4ll_new(&link->ipv4ll);
 196         if (r < 0)
 197                 return r;
 198
 199         r = sd_ipv4ll_attach_event(link->ipv4ll, link->manager->event, 0);
 200         if (r < 0)
 201                 return r;
 202
 203         if (link->dev &&
 204             net_get_unique_predictable_data(link->dev, true, &seed) >= 0) {
 205                 r = sd_ipv4ll_set_address_seed(link->ipv4ll, seed);
 206                 if (r < 0)
 207                         return r;
 208         }
 209
 210         r = sd_ipv4ll_set_mac(link->ipv4ll, &link->hw_addr.ether);
 211         if (r < 0)
 212                 return r;
 213
 214         r = sd_ipv4ll_set_ifindex(link->ipv4ll, link->ifindex);
 215         if (r < 0)
 216                 return r;
 217
 218         r = sd_ipv4ll_set_callback(link->ipv4ll, ipv4ll_handler, link);
 219         if (r < 0)
 220                 return r;
 221
 222         return sd_ipv4ll_set_check_mac_callback(link->ipv4ll, ipv4ll_check_mac, link->manager);
 223 }
 224
 225 int ipv4ll_update_mac(Link *link) {
 226         assert(link);
 227
 228         if (link->hw_addr.length != ETH_ALEN)
 229                 return 0;
 230         if (ether_addr_is_null(&link->hw_addr.ether))
 231                 return 0;
 232         if (!link->ipv4ll)
 233                 return 0;
 234
 235         return sd_ipv4ll_set_mac(link->ipv4ll, &link->hw_addr.ether);
 236 }
 237
 238 int config_parse_ipv4ll(
 239                 const char* unit,
 240                 const char *filename,
 241                 unsigned line,
 242                 const char *section,
 243                 unsigned section_line,
 244                 const char *lvalue,
 245                 int ltype,
 246                 const char *rvalue,
 247                 void *data,
 248                 void *userdata) {
 249
 250         AddressFamily *link_local = ASSERT_PTR(data);
 251         int r;
 252
 253         assert(filename);
 254         assert(lvalue);
 255         assert(rvalue);
 256
 257         /* Note that this is mostly like
 258          * config_parse_address_family(), except that it
 259          * applies only to IPv4 */
 260
 261         r = parse_boolean(rvalue);
 262         if (r < 0) {
 263                 log_syntax(unit, LOG_WARNING, filename, line, r,
 264                            "Failed to parse %s=%s, ignoring assignment. "
 265                            "Note that the setting %s= is deprecated, please use LinkLocalAddressing= instead.",
 266                            lvalue, rvalue, lvalue);
 267                 return 0;
 268         }
 269
 270         SET_FLAG(*link_local, ADDRESS_FAMILY_IPV4, r);
 271
 272         log_syntax(unit, LOG_WARNING, filename, line, 0,
 273                    "%s=%s is deprecated, please use LinkLocalAddressing=%s instead.",
 274                    lvalue, rvalue, address_family_to_string(*link_local));
 275
 276         return 0;
 277 }
 278
 279 int config_parse_ipv4ll_address(
 280                 const char* unit,
 281                 const char *filename,
 282                 unsigned line,
 283                 const char *section,
 284                 unsigned section_line,
 285                 const char *lvalue,
 286                 int ltype,
 287                 const char *rvalue,
 288                 void *data,
 289                 void *userdata) {
 290
 291         union in_addr_union a;
 292         struct in_addr *ipv4ll_address = ASSERT_PTR(data);
 293         int r;
 294
 295         assert(filename);
 296         assert(lvalue);
 297         assert(rvalue);
 298
 299         if (isempty(rvalue)) {
 300                 *ipv4ll_address = (struct in_addr) {};
 301                 return 0;
 302         }
 303
 304         r = in_addr_from_string(AF_INET, rvalue, &a);
 305         if (r < 0) {
 306                 log_syntax(unit, LOG_WARNING, filename, line, r,
 307                            "Failed to parse %s=, ignoring assignment: %s", lvalue, rvalue);
 308                 return 0;
 309         }
 310         if (!in4_addr_is_link_local_dynamic(&a.in)) {
 311                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 312                            "Specified address cannot be used as an IPv4 link local address, ignoring assignment: %s",
 313                            rvalue);
 314                 return 0;
 315         }
 316
 317         *ipv4ll_address = a.in;
 318         return 0;
 319 }