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         address_set_broadcast(address, link);
  54
  55         *ret = TAKE_PTR(address);
  56         return 0;
  57 }
  58
  59 static int ipv4ll_address_lost(Link *link) {
  60         _cleanup_(address_freep) Address *address = NULL;
  61         Address *existing;
  62         int r;
  63
  64         assert(link);
  65
  66         link->ipv4ll_address_configured = false;
  67
  68         r = address_new_from_ipv4ll(link, &address);
  69         if (r == -ENOENT)
  70                 return 0;
  71         if (r < 0)
  72                 return r;
  73
  74         if (address_get(link, address, &existing) < 0)
  75                 return 0;
  76
  77         if (existing->source != NETWORK_CONFIG_SOURCE_IPV4LL)
  78                 return 0;
  79
  80         if (!address_exists(existing))
  81                 return 0;
  82
  83         log_link_debug(link, "IPv4 link-local release "IPV4_ADDRESS_FMT_STR,
  84                        IPV4_ADDRESS_FMT_VAL(address->in_addr.in));
  85
  86         return address_remove(existing);
  87 }
  88
  89 static int ipv4ll_address_handler(sd_netlink *rtnl, sd_netlink_message *m, Request *req, Link *link, Address *address) {
  90         int r;
  91
  92         assert(link);
  93         assert(!link->ipv4ll_address_configured);
  94
  95         r = address_configure_handler_internal(rtnl, m, link, "Could not set ipv4ll address");
  96         if (r <= 0)
  97                 return r;
  98
  99         link->ipv4ll_address_configured = true;
 100         link_check_ready(link);
 101
 102         return 1;
 103 }
 104
 105 static int ipv4ll_address_claimed(sd_ipv4ll *ll, Link *link) {
 106         _cleanup_(address_freep) Address *address = NULL;
 107         int r;
 108
 109         assert(ll);
 110         assert(link);
 111
 112         link->ipv4ll_address_configured = false;
 113
 114         r = address_new_from_ipv4ll(link, &address);
 115         if (r == -ENOENT)
 116                 return 0;
 117         if (r < 0)
 118                 return r;
 119
 120         log_link_debug(link, "IPv4 link-local claim "IPV4_ADDRESS_FMT_STR,
 121                        IPV4_ADDRESS_FMT_VAL(address->in_addr.in));
 122
 123         return link_request_address(link, address, NULL, ipv4ll_address_handler, NULL);
 124 }
 125
 126 static void ipv4ll_handler(sd_ipv4ll *ll, int event, void *userdata) {
 127         Link *link = ASSERT_PTR(userdata);
 128         int r;
 129
 130         assert(link->network);
 131
 132         if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
 133                 return;
 134
 135         switch (event) {
 136                 case SD_IPV4LL_EVENT_STOP:
 137                         r = ipv4ll_address_lost(link);
 138                         if (r < 0) {
 139                                 link_enter_failed(link);
 140                                 return;
 141                         }
 142                         break;
 143                 case SD_IPV4LL_EVENT_CONFLICT:
 144                         r = ipv4ll_address_lost(link);
 145                         if (r < 0) {
 146                                 link_enter_failed(link);
 147                                 return;
 148                         }
 149
 150                         r = sd_ipv4ll_restart(ll);
 151                         if (r < 0) {
 152                                 log_link_warning_errno(link, r, "Could not acquire IPv4 link-local address: %m");
 153                                 link_enter_failed(link);
 154                         }
 155                         break;
 156                 case SD_IPV4LL_EVENT_BIND:
 157                         r = ipv4ll_address_claimed(ll, link);
 158                         if (r < 0) {
 159                                 log_link_error(link, "Failed to configure ipv4ll address: %m");
 160                                 link_enter_failed(link);
 161                                 return;
 162                         }
 163                         break;
 164                 default:
 165                         log_link_warning(link, "IPv4 link-local unknown event: %d", event);
 166                         break;
 167         }
 168 }
 169
 170 static int ipv4ll_check_mac(sd_ipv4ll *ll, const struct ether_addr *mac, void *userdata) {
 171         Manager *m = ASSERT_PTR(userdata);
 172         struct hw_addr_data hw_addr;
 173
 174         assert(mac);
 175
 176         hw_addr = (struct hw_addr_data) {
 177                 .length = ETH_ALEN,
 178                 .ether = *mac,
 179         };
 180
 181         return link_get_by_hw_addr(m, &hw_addr, NULL) >= 0;
 182 }
 183
 184 int ipv4ll_configure(Link *link) {
 185         uint64_t seed;
 186         int r;
 187
 188         assert(link);
 189
 190         if (!link_ipv4ll_enabled(link))
 191                 return 0;
 192
 193         if (link->ipv4ll)
 194                 return -EBUSY;
 195
 196         r = sd_ipv4ll_new(&link->ipv4ll);
 197         if (r < 0)
 198                 return r;
 199
 200         r = sd_ipv4ll_attach_event(link->ipv4ll, link->manager->event, 0);
 201         if (r < 0)
 202                 return r;
 203
 204         if (link->dev &&
 205             net_get_unique_predictable_data(link->dev, true, &seed) >= 0) {
 206                 r = sd_ipv4ll_set_address_seed(link->ipv4ll, seed);
 207                 if (r < 0)
 208                         return r;
 209         }
 210
 211         r = sd_ipv4ll_set_mac(link->ipv4ll, &link->hw_addr.ether);
 212         if (r < 0)
 213                 return r;
 214
 215         r = sd_ipv4ll_set_ifindex(link->ipv4ll, link->ifindex);
 216         if (r < 0)
 217                 return r;
 218
 219         r = sd_ipv4ll_set_callback(link->ipv4ll, ipv4ll_handler, link);
 220         if (r < 0)
 221                 return r;
 222
 223         return sd_ipv4ll_set_check_mac_callback(link->ipv4ll, ipv4ll_check_mac, link->manager);
 224 }
 225
 226 int ipv4ll_update_mac(Link *link) {
 227         assert(link);
 228
 229         if (link->hw_addr.length != ETH_ALEN)
 230                 return 0;
 231         if (ether_addr_is_null(&link->hw_addr.ether))
 232                 return 0;
 233         if (!link->ipv4ll)
 234                 return 0;
 235
 236         return sd_ipv4ll_set_mac(link->ipv4ll, &link->hw_addr.ether);
 237 }
 238
 239 int config_parse_ipv4ll(
 240                 const char* unit,
 241                 const char *filename,
 242                 unsigned line,
 243                 const char *section,
 244                 unsigned section_line,
 245                 const char *lvalue,
 246                 int ltype,
 247                 const char *rvalue,
 248                 void *data,
 249                 void *userdata) {
 250
 251         AddressFamily *link_local = ASSERT_PTR(data);
 252         int r;
 253
 254         assert(filename);
 255         assert(lvalue);
 256         assert(rvalue);
 257
 258         /* Note that this is mostly like
 259          * config_parse_address_family(), except that it
 260          * applies only to IPv4 */
 261
 262         r = parse_boolean(rvalue);
 263         if (r < 0) {
 264                 log_syntax(unit, LOG_WARNING, filename, line, r,
 265                            "Failed to parse %s=%s, ignoring assignment. "
 266                            "Note that the setting %s= is deprecated, please use LinkLocalAddressing= instead.",
 267                            lvalue, rvalue, lvalue);
 268                 return 0;
 269         }
 270
 271         SET_FLAG(*link_local, ADDRESS_FAMILY_IPV4, r);
 272
 273         log_syntax(unit, LOG_WARNING, filename, line, 0,
 274                    "%s=%s is deprecated, please use LinkLocalAddressing=%s instead.",
 275                    lvalue, rvalue, address_family_to_string(*link_local));
 276
 277         return 0;
 278 }
 279
 280 int config_parse_ipv4ll_address(
 281                 const char* unit,
 282                 const char *filename,
 283                 unsigned line,
 284                 const char *section,
 285                 unsigned section_line,
 286                 const char *lvalue,
 287                 int ltype,
 288                 const char *rvalue,
 289                 void *data,
 290                 void *userdata) {
 291
 292         union in_addr_union a;
 293         struct in_addr *ipv4ll_address = ASSERT_PTR(data);
 294         int r;
 295
 296         assert(filename);
 297         assert(lvalue);
 298         assert(rvalue);
 299
 300         if (isempty(rvalue)) {
 301                 *ipv4ll_address = (struct in_addr) {};
 302                 return 0;
 303         }
 304
 305         r = in_addr_from_string(AF_INET, rvalue, &a);
 306         if (r < 0) {
 307                 log_syntax(unit, LOG_WARNING, filename, line, r,
 308                            "Failed to parse %s=, ignoring assignment: %s", lvalue, rvalue);
 309                 return 0;
 310         }
 311         if (!in4_addr_is_link_local_dynamic(&a.in)) {
 312                 log_syntax(unit, LOG_WARNING, filename, line, 0,
 313                            "Specified address cannot be used as an IPv4 link local address, ignoring assignment: %s",
 314                            rvalue);
 315                 return 0;
 316         }
 317
 318         *ipv4ll_address = a.in;
 319         return 0;
 320 }