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_unrefp) 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_unrefp) Address *address = NULL;
  60         int r;
  61
  62         assert(link);
  63
  64         link->ipv4ll_address_configured = false;
  65
  66         r = address_new_from_ipv4ll(link, &address);
  67         if (r == -ENOENT)
  68                 return 0;
  69         if (r < 0)
  70                 return r;
  71
  72         log_link_debug(link, "IPv4 link-local release "IPV4_ADDRESS_FMT_STR,
  73                        IPV4_ADDRESS_FMT_VAL(address->in_addr.in));
  74
  75         return address_remove_and_cancel(address, link);
  76 }
  77
  78 static int ipv4ll_address_handler(sd_netlink *rtnl, sd_netlink_message *m, Request *req, Link *link, Address *address) {
  79         int r;
  80
  81         assert(link);
  82         assert(!link->ipv4ll_address_configured);
  83
  84         r = address_configure_handler_internal(rtnl, m, link, "Could not set ipv4ll address");
  85         if (r <= 0)
  86                 return r;
  87
  88         link->ipv4ll_address_configured = true;
  89         link_check_ready(link);
  90
  91         return 1;
  92 }
  93
  94 static int ipv4ll_address_claimed(sd_ipv4ll *ll, Link *link) {
  95         _cleanup_(address_unrefp) Address *address = NULL;
  96         int r;
  97
  98         assert(ll);
  99         assert(link);
 100
 101         link->ipv4ll_address_configured = false;
 102
 103         r = address_new_from_ipv4ll(link, &address);
 104         if (r == -ENOENT)
 105                 return 0;
 106         if (r < 0)
 107                 return r;
 108
 109         log_link_debug(link, "IPv4 link-local claim "IPV4_ADDRESS_FMT_STR,
 110                        IPV4_ADDRESS_FMT_VAL(address->in_addr.in));
 111
 112         return link_request_address(link, address, NULL, ipv4ll_address_handler, NULL);
 113 }
 114
 115 static void ipv4ll_handler(sd_ipv4ll *ll, int event, void *userdata) {
 116         Link *link = ASSERT_PTR(userdata);
 117         int r;
 118
 119         assert(link->network);
 120
 121         if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
 122                 return;
 123
 124         switch (event) {
 125                 case SD_IPV4LL_EVENT_STOP:
 126                         r = ipv4ll_address_lost(link);
 127                         if (r < 0) {
 128                                 link_enter_failed(link);
 129                                 return;
 130                         }
 131                         break;
 132                 case SD_IPV4LL_EVENT_CONFLICT:
 133                         r = ipv4ll_address_lost(link);
 134                         if (r < 0) {
 135                                 link_enter_failed(link);
 136                                 return;
 137                         }
 138
 139                         r = sd_ipv4ll_restart(ll);
 140                         if (r < 0) {
 141                                 log_link_warning_errno(link, r, "Could not acquire IPv4 link-local address: %m");
 142                                 link_enter_failed(link);
 143                         }
 144                         break;
 145                 case SD_IPV4LL_EVENT_BIND:
 146                         r = ipv4ll_address_claimed(ll, link);
 147                         if (r < 0) {
 148                                 log_link_error(link, "Failed to configure ipv4ll address: %m");
 149                                 link_enter_failed(link);
 150                                 return;
 151                         }
 152                         break;
 153                 default:
 154                         log_link_warning(link, "IPv4 link-local unknown event: %d", event);
 155                         break;
 156         }
 157 }
 158
 159 static int ipv4ll_check_mac(sd_ipv4ll *ll, const struct ether_addr *mac, void *userdata) {
 160         Manager *m = ASSERT_PTR(userdata);
 161         struct hw_addr_data hw_addr;
 162
 163         assert(mac);
 164
 165         hw_addr = (struct hw_addr_data) {
 166                 .length = ETH_ALEN,
 167                 .ether = *mac,
 168         };
 169
 170         return link_get_by_hw_addr(m, &hw_addr, NULL) >= 0;
 171 }
 172
 173 int ipv4ll_configure(Link *link) {
 174         uint64_t seed;
 175         int r;
 176
 177         assert(link);
 178
 179         if (!link_ipv4ll_enabled(link))
 180                 return 0;
 181
 182         if (link->ipv4ll)
 183                 return -EBUSY;
 184
 185         r = sd_ipv4ll_new(&link->ipv4ll);
 186         if (r < 0)
 187                 return r;
 188
 189         r = sd_ipv4ll_attach_event(link->ipv4ll, link->manager->event, 0);
 190         if (r < 0)
 191                 return r;
 192
 193         if (link->dev &&
 194             net_get_unique_predictable_data(link->dev, true, &seed) >= 0) {
 195                 r = sd_ipv4ll_set_address_seed(link->ipv4ll, seed);
 196                 if (r < 0)
 197                         return r;
 198         }
 199
 200         r = sd_ipv4ll_set_mac(link->ipv4ll, &link->hw_addr.ether);
 201         if (r < 0)
 202                 return r;
 203
 204         r = sd_ipv4ll_set_ifindex(link->ipv4ll, link->ifindex);
 205         if (r < 0)
 206                 return r;
 207
 208         r = sd_ipv4ll_set_callback(link->ipv4ll, ipv4ll_handler, link);
 209         if (r < 0)
 210                 return r;
 211
 212         return sd_ipv4ll_set_check_mac_callback(link->ipv4ll, ipv4ll_check_mac, link->manager);
 213 }
 214
 215 int ipv4ll_update_mac(Link *link) {
 216         assert(link);
 217
 218         if (link->hw_addr.length != ETH_ALEN)
 219                 return 0;
 220         if (ether_addr_is_null(&link->hw_addr.ether))
 221                 return 0;
 222         if (!link->ipv4ll)
 223                 return 0;
 224
 225         return sd_ipv4ll_set_mac(link->ipv4ll, &link->hw_addr.ether);
 226 }
 227
 228 int config_parse_ipv4ll(
 229                 const char* unit,
 230                 const char *filename,
 231                 unsigned line,
 232                 const char *section,
 233                 unsigned section_line,
 234                 const char *lvalue,
 235                 int ltype,
 236                 const char *rvalue,
 237                 void *data,
 238                 void *userdata) {
 239
 240         AddressFamily *link_local = ASSERT_PTR(data);
 241         int r;
 242
 243         assert(filename);
 244         assert(lvalue);
 245         assert(rvalue);
 246
 247         /* Note that this is mostly like
 248          * config_parse_address_family(), except that it
 249          * applies only to IPv4 */
 250
 251         r = parse_boolean(rvalue);
 252         if (r < 0) {
 253                 log_syntax(unit, LOG_WARNING, filename, line, r,
 254                            "Failed to parse %s=%s, ignoring assignment. "
 255                            "Note that the setting %s= is deprecated, please use LinkLocalAddressing= instead.",
 256                            lvalue, rvalue, lvalue);
 257                 return 0;
 258         }
 259
 260         SET_FLAG(*link_local, ADDRESS_FAMILY_IPV4, r);
 261
 262         log_syntax(unit, LOG_WARNING, filename, line, 0,
 263                    "%s=%s is deprecated, please use LinkLocalAddressing=%s instead.",
 264                    lvalue, rvalue, address_family_to_string(*link_local));
 265
 266         return 0;
 267 }
 268
 269 int config_parse_ipv4ll_address(
 270                 const char* unit,
 271                 const char *filename,
 272                 unsigned line,
 273                 const char *section,
 274                 unsigned section_line,
 275                 const char *lvalue,
 276                 int ltype,
 277                 const char *rvalue,
 278                 void *data,
 279                 void *userdata) {
 280
 281         union in_addr_union a;
 282         struct in_addr *ipv4ll_address = ASSERT_PTR(data);
 283         int r;
 284
 285         assert(filename);
 286         assert(lvalue);
 287         assert(rvalue);
 288
 289         if (isempty(rvalue)) {
 290                 *ipv4ll_address = (struct in_addr) {};
 291                 return 0;
 292         }
 293
 294         r = in_addr_from_string(AF_INET, rvalue, &a);
 295         if (r < 0) {
 296                 log_syntax(unit, LOG_WARNING, filename, line, r,
 297                            "Failed to parse %s=, ignoring assignment: %s", lvalue, rvalue);
 298                 return 0;
 299         }
 300         if (!in4_addr_is_link_local_dynamic(&a.in)) {
 301                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 302                            "Specified address cannot be used as an IPv4 link local address, ignoring assignment: %s",
 303                            rvalue);
 304                 return 0;
 305         }
 306
 307         *ipv4ll_address = a.in;
 308         return 0;
 309 }