src/network/networkd-ipv4ll.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2013-2014 Tom Gundersen <teg@jklm.no>
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <netinet/ether.h>
  21 #include <linux/if.h>
  22
  23 #include "network-internal.h"
  24 #include "networkd-address.h"
  25 #include "networkd-manager.h"
  26 #include "networkd-link.h"
  27
  28 static int ipv4ll_address_lost(Link *link) {
  29         _cleanup_address_free_ Address *address = NULL;
  30         _cleanup_route_free_ Route *route = NULL;
  31         struct in_addr addr;
  32         int r;
  33
  34         assert(link);
  35
  36         link->ipv4ll_route = false;
  37         link->ipv4ll_address = false;
  38
  39         r = sd_ipv4ll_get_address(link->ipv4ll, &addr);
  40         if (r < 0)
  41                 return 0;
  42
  43         log_link_debug(link, "IPv4 link-local release %u.%u.%u.%u", ADDRESS_FMT_VAL(addr));
  44
  45         r = address_new(&address);
  46         if (r < 0) {
  47                 log_link_error_errno(link, r, "Could not allocate address: %m");
  48                 return r;
  49         }
  50
  51         address->family = AF_INET;
  52         address->in_addr.in = addr;
  53         address->prefixlen = 16;
  54         address->scope = RT_SCOPE_LINK;
  55
  56         address_remove(address, link, link_address_remove_handler);
  57
  58         r = route_new(&route);
  59         if (r < 0) {
  60                 log_link_error_errno(link, r, "Could not allocate route: %m");
  61                 return r;
  62         }
  63
  64         route->family = AF_INET;
  65         route->scope = RT_SCOPE_LINK;
  66         route->priority = IPV4LL_ROUTE_METRIC;
  67
  68         route_remove(route, link, link_route_remove_handler);
  69
  70         link_check_ready(link);
  71
  72         return 0;
  73 }
  74
  75 static int ipv4ll_route_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) {
  76         _cleanup_link_unref_ Link *link = userdata;
  77         int r;
  78
  79         assert(link);
  80         assert(!link->ipv4ll_route);
  81
  82         r = sd_netlink_message_get_errno(m);
  83         if (r < 0 && r != -EEXIST) {
  84                 log_link_error_errno(link, r, "could not set ipv4ll route: %m");
  85                 link_enter_failed(link);
  86         }
  87
  88         link->ipv4ll_route = true;
  89
  90         if (link->ipv4ll_address == true)
  91                 link_check_ready(link);
  92
  93         return 1;
  94 }
  95
  96 static int ipv4ll_address_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) {
  97         _cleanup_link_unref_ Link *link = userdata;
  98         int r;
  99
 100         assert(link);
 101         assert(!link->ipv4ll_address);
 102
 103         r = sd_netlink_message_get_errno(m);
 104         if (r < 0 && r != -EEXIST) {
 105                 log_link_error_errno(link, r, "could not set ipv4ll address: %m");
 106                 link_enter_failed(link);
 107         } else if (r >= 0)
 108                 manager_rtnl_process_address(rtnl, m, link->manager);
 109
 110         link->ipv4ll_address = true;
 111
 112         if (link->ipv4ll_route == true)
 113                 link_check_ready(link);
 114
 115         return 1;
 116 }
 117
 118 static int ipv4ll_address_claimed(sd_ipv4ll *ll, Link *link) {
 119         _cleanup_address_free_ Address *ll_addr = NULL;
 120         _cleanup_route_free_ Route *route = NULL;
 121         struct in_addr address;
 122         int r;
 123
 124         assert(ll);
 125         assert(link);
 126
 127         r = sd_ipv4ll_get_address(ll, &address);
 128         if (r == -ENOENT)
 129                 return 0;
 130         else if (r < 0)
 131                 return r;
 132
 133         log_link_debug(link, "IPv4 link-local claim %u.%u.%u.%u",
 134                        ADDRESS_FMT_VAL(address));
 135
 136         r = address_new(&ll_addr);
 137         if (r < 0)
 138                 return r;
 139
 140         ll_addr->family = AF_INET;
 141         ll_addr->in_addr.in = address;
 142         ll_addr->prefixlen = 16;
 143         ll_addr->broadcast.s_addr = ll_addr->in_addr.in.s_addr | htobe32(0xfffffffflu >> ll_addr->prefixlen);
 144         ll_addr->scope = RT_SCOPE_LINK;
 145
 146         r = address_configure(ll_addr, link, ipv4ll_address_handler, false);
 147         if (r < 0)
 148                 return r;
 149
 150         link->ipv4ll_address = false;
 151
 152         r = route_new(&route);
 153         if (r < 0)
 154                 return r;
 155
 156         route->family = AF_INET;
 157         route->scope = RT_SCOPE_LINK;
 158         route->protocol = RTPROT_STATIC;
 159         route->priority = IPV4LL_ROUTE_METRIC;
 160
 161         r = route_configure(route, link, ipv4ll_route_handler);
 162         if (r < 0)
 163                 return r;
 164
 165         link->ipv4ll_route = false;
 166
 167         return 0;
 168 }
 169
 170 static void ipv4ll_handler(sd_ipv4ll *ll, int event, void *userdata) {
 171         Link *link = userdata;
 172         int r;
 173
 174         assert(link);
 175         assert(link->network);
 176
 177         if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
 178                 return;
 179
 180         switch(event) {
 181                 case SD_IPV4LL_EVENT_STOP:
 182                         r = ipv4ll_address_lost(link);
 183                         if (r < 0) {
 184                                 link_enter_failed(link);
 185                                 return;
 186                         }
 187                         break;
 188                 case SD_IPV4LL_EVENT_CONFLICT:
 189                         r = ipv4ll_address_lost(link);
 190                         if (r < 0) {
 191                                 link_enter_failed(link);
 192                                 return;
 193                         }
 194
 195                         r = sd_ipv4ll_restart(ll);
 196                         if (r < 0)
 197                                 log_link_warning(link, "Could not acquire IPv4 link-local address");
 198                         break;
 199                 case SD_IPV4LL_EVENT_BIND:
 200                         r = ipv4ll_address_claimed(ll, link);
 201                         if (r < 0) {
 202                                 link_enter_failed(link);
 203                                 return;
 204                         }
 205                         break;
 206                 default:
 207                         log_link_warning(link, "IPv4 link-local unknown event: %d", event);
 208                         break;
 209         }
 210 }
 211
 212 int ipv4ll_configure(Link *link) {
 213         uint64_t seed;
 214         int r;
 215
 216         assert(link);
 217         assert(link->network);
 218         assert(link->network->link_local & ADDRESS_FAMILY_IPV4);
 219
 220         if (!link->ipv4ll) {
 221                 r = sd_ipv4ll_new(&link->ipv4ll);
 222                 if (r < 0)
 223                         return r;
 224         }
 225
 226         if (link->udev_device) {
 227                 r = net_get_unique_predictable_data(link->udev_device, &seed);
 228                 if (r >= 0) {
 229                         r = sd_ipv4ll_set_address_seed(link->ipv4ll, seed);
 230                         if (r < 0)
 231                                 return r;
 232                 }
 233         }
 234
 235         r = sd_ipv4ll_attach_event(link->ipv4ll, NULL, 0);
 236         if (r < 0)
 237                 return r;
 238
 239         r = sd_ipv4ll_set_mac(link->ipv4ll, &link->mac);
 240         if (r < 0)
 241                 return r;
 242
 243         r = sd_ipv4ll_set_ifindex(link->ipv4ll, link->ifindex);
 244         if (r < 0)
 245                 return r;
 246
 247         r = sd_ipv4ll_set_callback(link->ipv4ll, ipv4ll_handler, link);
 248         if (r < 0)
 249                 return r;
 250
 251         return 0;
 252 }