src/network/networkd-ipv4ll.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <netinet/ether.h>
   4 #include <linux/if.h>
   5
   6 #include "network-internal.h"
   7 #include "networkd-address.h"
   8 #include "networkd-manager.h"
   9 #include "networkd-link.h"
  10
  11 static int ipv4ll_address_lost(Link *link) {
  12         _cleanup_(address_freep) Address *address = NULL;
  13         _cleanup_(route_freep) Route *route = NULL;
  14         struct in_addr addr;
  15         int r;
  16
  17         assert(link);
  18
  19         link->ipv4ll_route = false;
  20         link->ipv4ll_address = false;
  21
  22         r = sd_ipv4ll_get_address(link->ipv4ll, &addr);
  23         if (r < 0)
  24                 return 0;
  25
  26         log_link_debug(link, "IPv4 link-local release %u.%u.%u.%u", ADDRESS_FMT_VAL(addr));
  27
  28         r = address_new(&address);
  29         if (r < 0)
  30                 return log_link_error_errno(link, r, "Could not allocate address: %m");
  31
  32         address->family = AF_INET;
  33         address->in_addr.in = addr;
  34         address->prefixlen = 16;
  35         address->scope = RT_SCOPE_LINK;
  36
  37         address_remove(address, link, NULL);
  38
  39         r = route_new(&route);
  40         if (r < 0)
  41                 return log_link_error_errno(link, r, "Could not allocate route: %m");
  42
  43         route->family = AF_INET;
  44         route->scope = RT_SCOPE_LINK;
  45         route->priority = IPV4LL_ROUTE_METRIC;
  46
  47         route_remove(route, link, NULL);
  48
  49         link_check_ready(link);
  50
  51         return 0;
  52 }
  53
  54 static int ipv4ll_route_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
  55         int r;
  56
  57         assert(link);
  58         assert(!link->ipv4ll_route);
  59
  60         r = sd_netlink_message_get_errno(m);
  61         if (r < 0 && r != -EEXIST) {
  62                 log_link_error_errno(link, r, "could not set ipv4ll route: %m");
  63                 link_enter_failed(link);
  64         }
  65
  66         link->ipv4ll_route = true;
  67
  68         link_check_ready(link);
  69
  70         return 1;
  71 }
  72
  73 static int ipv4ll_route_configure(Link *link) {
  74         _cleanup_(route_freep) Route *route = NULL;
  75         int r;
  76
  77         r = route_new(&route);
  78         if (r < 0)
  79                 return r;
  80
  81         route->family = AF_INET;
  82         route->scope = RT_SCOPE_LINK;
  83         route->protocol = RTPROT_STATIC;
  84         route->priority = IPV4LL_ROUTE_METRIC;
  85         route->table = link_get_vrf_table(link);
  86
  87         return route_configure(route, link, ipv4ll_route_handler);
  88 }
  89
  90 static int ipv4ll_address_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
  91         int r;
  92
  93         assert(link);
  94         assert(!link->ipv4ll_address);
  95
  96         r = sd_netlink_message_get_errno(m);
  97         if (r < 0 && r != -EEXIST) {
  98                 log_link_error_errno(link, r, "could not set ipv4ll address: %m");
  99                 link_enter_failed(link);
 100         } else if (r >= 0)
 101                 manager_rtnl_process_address(rtnl, m, link->manager);
 102
 103         link->ipv4ll_address = true;
 104
 105         r = ipv4ll_route_configure(link);
 106         if (r < 0) {
 107                 log_link_error_errno(link, r, "Failed to configure ipv4ll route: %m");
 108                 link_enter_failed(link);
 109         }
 110
 111         return 1;
 112 }
 113
 114 static int ipv4ll_address_claimed(sd_ipv4ll *ll, Link *link) {
 115         _cleanup_(address_freep) Address *ll_addr = NULL;
 116         struct in_addr address;
 117         int r;
 118
 119         assert(ll);
 120         assert(link);
 121
 122         link->ipv4ll_address = false;
 123         link->ipv4ll_route = false;
 124
 125         r = sd_ipv4ll_get_address(ll, &address);
 126         if (r == -ENOENT)
 127                 return 0;
 128         else if (r < 0)
 129                 return r;
 130
 131         log_link_debug(link, "IPv4 link-local claim %u.%u.%u.%u",
 132                        ADDRESS_FMT_VAL(address));
 133
 134         r = address_new(&ll_addr);
 135         if (r < 0)
 136                 return r;
 137
 138         ll_addr->family = AF_INET;
 139         ll_addr->in_addr.in = address;
 140         ll_addr->prefixlen = 16;
 141         ll_addr->broadcast.s_addr = ll_addr->in_addr.in.s_addr | htobe32(0xfffffffflu >> ll_addr->prefixlen);
 142         ll_addr->scope = RT_SCOPE_LINK;
 143
 144         r = address_configure(ll_addr, link, ipv4ll_address_handler, false);
 145         if (r < 0)
 146                 return r;
 147
 148         return 0;
 149 }
 150
 151 static void ipv4ll_handler(sd_ipv4ll *ll, int event, void *userdata) {
 152         Link *link = userdata;
 153         int r;
 154
 155         assert(link);
 156         assert(link->network);
 157
 158         if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
 159                 return;
 160
 161         switch(event) {
 162                 case SD_IPV4LL_EVENT_STOP:
 163                         r = ipv4ll_address_lost(link);
 164                         if (r < 0) {
 165                                 link_enter_failed(link);
 166                                 return;
 167                         }
 168                         break;
 169                 case SD_IPV4LL_EVENT_CONFLICT:
 170                         r = ipv4ll_address_lost(link);
 171                         if (r < 0) {
 172                                 link_enter_failed(link);
 173                                 return;
 174                         }
 175
 176                         r = sd_ipv4ll_restart(ll);
 177                         if (r < 0)
 178                                 log_link_warning(link, "Could not acquire IPv4 link-local address");
 179                         break;
 180                 case SD_IPV4LL_EVENT_BIND:
 181                         r = ipv4ll_address_claimed(ll, link);
 182                         if (r < 0) {
 183                                 log_link_error(link, "Failed to configure ipv4ll address: %m");
 184                                 link_enter_failed(link);
 185                                 return;
 186                         }
 187                         break;
 188                 default:
 189                         log_link_warning(link, "IPv4 link-local unknown event: %d", event);
 190                         break;
 191         }
 192 }
 193
 194 int ipv4ll_configure(Link *link) {
 195         uint64_t seed;
 196         int r;
 197
 198         assert(link);
 199         assert(link->network);
 200         assert(link->network->link_local & ADDRESS_FAMILY_IPV4);
 201
 202         if (!link->ipv4ll) {
 203                 r = sd_ipv4ll_new(&link->ipv4ll);
 204                 if (r < 0)
 205                         return r;
 206         }
 207
 208         if (link->sd_device &&
 209             net_get_unique_predictable_data(link->sd_device, &seed) >= 0) {
 210                 r = sd_ipv4ll_set_address_seed(link->ipv4ll, seed);
 211                 if (r < 0)
 212                         return r;
 213         }
 214
 215         r = sd_ipv4ll_attach_event(link->ipv4ll, NULL, 0);
 216         if (r < 0)
 217                 return r;
 218
 219         r = sd_ipv4ll_set_mac(link->ipv4ll, &link->mac);
 220         if (r < 0)
 221                 return r;
 222
 223         r = sd_ipv4ll_set_ifindex(link->ipv4ll, link->ifindex);
 224         if (r < 0)
 225                 return r;
 226
 227         r = sd_ipv4ll_set_callback(link->ipv4ll, ipv4ll_handler, link);
 228         if (r < 0)
 229                 return r;
 230
 231         return 0;
 232 }