src/network/networkd-ipv4ll.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <netinet/in.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         r = address_remove(address, link, NULL);
  38         if (r < 0)
  39                 return r;
  40
  41         r = route_new(&route);
  42         if (r < 0)
  43                 return log_link_error_errno(link, r, "Could not allocate route: %m");
  44
  45         route->family = AF_INET;
  46         route->scope = RT_SCOPE_LINK;
  47         route->priority = IPV4LL_ROUTE_METRIC;
  48
  49         r = route_remove(route, link, NULL);
  50         if (r < 0)
  51                 return r;
  52
  53         link_check_ready(link);
  54
  55         return 0;
  56 }
  57
  58 static int ipv4ll_route_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
  59         int r;
  60
  61         assert(link);
  62         assert(!link->ipv4ll_route);
  63
  64         r = sd_netlink_message_get_errno(m);
  65         if (r < 0 && r != -EEXIST) {
  66                 log_link_error_errno(link, r, "could not set ipv4ll route: %m");
  67                 link_enter_failed(link);
  68         }
  69
  70         link->ipv4ll_route = true;
  71
  72         link_check_ready(link);
  73
  74         return 1;
  75 }
  76
  77 static int ipv4ll_route_configure(Link *link) {
  78         _cleanup_(route_freep) Route *route = NULL;
  79         int r;
  80
  81         r = route_new(&route);
  82         if (r < 0)
  83                 return r;
  84
  85         route->family = AF_INET;
  86         route->scope = RT_SCOPE_LINK;
  87         route->protocol = RTPROT_STATIC;
  88         route->priority = IPV4LL_ROUTE_METRIC;
  89         route->table = link_get_vrf_table(link);
  90
  91         return route_configure(route, link, ipv4ll_route_handler);
  92 }
  93
  94 static int ipv4ll_address_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
  95         int r;
  96
  97         assert(link);
  98         assert(!link->ipv4ll_address);
  99
 100         r = sd_netlink_message_get_errno(m);
 101         if (r < 0 && r != -EEXIST) {
 102                 log_link_error_errno(link, r, "could not set ipv4ll address: %m");
 103                 link_enter_failed(link);
 104         } else if (r >= 0)
 105                 manager_rtnl_process_address(rtnl, m, link->manager);
 106
 107         link->ipv4ll_address = true;
 108
 109         r = ipv4ll_route_configure(link);
 110         if (r < 0) {
 111                 log_link_error_errno(link, r, "Failed to configure ipv4ll route: %m");
 112                 link_enter_failed(link);
 113         }
 114
 115         return 1;
 116 }
 117
 118 static int ipv4ll_address_claimed(sd_ipv4ll *ll, Link *link) {
 119         _cleanup_(address_freep) Address *ll_addr = NULL;
 120         struct in_addr address;
 121         int r;
 122
 123         assert(ll);
 124         assert(link);
 125
 126         link->ipv4ll_address = false;
 127         link->ipv4ll_route = false;
 128
 129         r = sd_ipv4ll_get_address(ll, &address);
 130         if (r == -ENOENT)
 131                 return 0;
 132         else if (r < 0)
 133                 return r;
 134
 135         log_link_debug(link, "IPv4 link-local claim %u.%u.%u.%u",
 136                        ADDRESS_FMT_VAL(address));
 137
 138         r = address_new(&ll_addr);
 139         if (r < 0)
 140                 return r;
 141
 142         ll_addr->family = AF_INET;
 143         ll_addr->in_addr.in = address;
 144         ll_addr->prefixlen = 16;
 145         ll_addr->broadcast.s_addr = ll_addr->in_addr.in.s_addr | htobe32(0xfffffffflu >> ll_addr->prefixlen);
 146         ll_addr->scope = RT_SCOPE_LINK;
 147
 148         r = address_configure(ll_addr, link, ipv4ll_address_handler, false);
 149         if (r < 0)
 150                 return r;
 151
 152         return 0;
 153 }
 154
 155 static void ipv4ll_handler(sd_ipv4ll *ll, int event, void *userdata) {
 156         Link *link = userdata;
 157         int r;
 158
 159         assert(link);
 160         assert(link->network);
 161
 162         if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
 163                 return;
 164
 165         switch(event) {
 166                 case SD_IPV4LL_EVENT_STOP:
 167                         r = ipv4ll_address_lost(link);
 168                         if (r < 0) {
 169                                 link_enter_failed(link);
 170                                 return;
 171                         }
 172                         break;
 173                 case SD_IPV4LL_EVENT_CONFLICT:
 174                         r = ipv4ll_address_lost(link);
 175                         if (r < 0) {
 176                                 link_enter_failed(link);
 177                                 return;
 178                         }
 179
 180                         r = sd_ipv4ll_restart(ll);
 181                         if (r < 0)
 182                                 log_link_warning_errno(link, r, "Could not acquire IPv4 link-local address: %m");
 183                         break;
 184                 case SD_IPV4LL_EVENT_BIND:
 185                         r = ipv4ll_address_claimed(ll, link);
 186                         if (r < 0) {
 187                                 log_link_error(link, "Failed to configure ipv4ll address: %m");
 188                                 link_enter_failed(link);
 189                                 return;
 190                         }
 191                         break;
 192                 default:
 193                         log_link_warning(link, "IPv4 link-local unknown event: %d", event);
 194                         break;
 195         }
 196 }
 197
 198 int ipv4ll_configure(Link *link) {
 199         uint64_t seed;
 200         int r;
 201
 202         assert(link);
 203         assert(link->network);
 204         assert(link->network->link_local & (ADDRESS_FAMILY_IPV4 | ADDRESS_FAMILY_FALLBACK_IPV4));
 205
 206         if (!link->ipv4ll) {
 207                 r = sd_ipv4ll_new(&link->ipv4ll);
 208                 if (r < 0)
 209                         return r;
 210         }
 211
 212         if (link->sd_device &&
 213             net_get_unique_predictable_data(link->sd_device, true, &seed) >= 0) {
 214                 r = sd_ipv4ll_set_address_seed(link->ipv4ll, seed);
 215                 if (r < 0)
 216                         return r;
 217         }
 218
 219         r = sd_ipv4ll_attach_event(link->ipv4ll, NULL, 0);
 220         if (r < 0)
 221                 return r;
 222
 223         r = sd_ipv4ll_set_mac(link->ipv4ll, &link->mac);
 224         if (r < 0)
 225                 return r;
 226
 227         r = sd_ipv4ll_set_ifindex(link->ipv4ll, link->ifindex);
 228         if (r < 0)
 229                 return r;
 230
 231         r = sd_ipv4ll_set_callback(link->ipv4ll, ipv4ll_handler, link);
 232         if (r < 0)
 233                 return r;
 234
 235         return 0;
 236 }