src/network/networkd-ipv4ll.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2013-2014 Tom Gundersen <teg@jklm.no>
   6 ***/
   7
   8 #include <netinet/ether.h>
   9 #include <linux/if.h>
  10
  11 #include "network-internal.h"
  12 #include "networkd-address.h"
  13 #include "networkd-manager.h"
  14 #include "networkd-link.h"
  15
  16 static int ipv4ll_address_lost(Link *link) {
  17         _cleanup_(address_freep) Address *address = NULL;
  18         _cleanup_(route_freep) Route *route = NULL;
  19         struct in_addr addr;
  20         int r;
  21
  22         assert(link);
  23
  24         link->ipv4ll_route = false;
  25         link->ipv4ll_address = false;
  26
  27         r = sd_ipv4ll_get_address(link->ipv4ll, &addr);
  28         if (r < 0)
  29                 return 0;
  30
  31         log_link_debug(link, "IPv4 link-local release %u.%u.%u.%u", ADDRESS_FMT_VAL(addr));
  32
  33         r = address_new(&address);
  34         if (r < 0) {
  35                 log_link_error_errno(link, r, "Could not allocate address: %m");
  36                 return r;
  37         }
  38
  39         address->family = AF_INET;
  40         address->in_addr.in = addr;
  41         address->prefixlen = 16;
  42         address->scope = RT_SCOPE_LINK;
  43
  44         address_remove(address, link, link_address_remove_handler);
  45
  46         r = route_new(&route);
  47         if (r < 0) {
  48                 log_link_error_errno(link, r, "Could not allocate route: %m");
  49                 return r;
  50         }
  51
  52         route->family = AF_INET;
  53         route->scope = RT_SCOPE_LINK;
  54         route->priority = IPV4LL_ROUTE_METRIC;
  55
  56         route_remove(route, link, link_route_remove_handler);
  57
  58         link_check_ready(link);
  59
  60         return 0;
  61 }
  62
  63 static int ipv4ll_route_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) {
  64         _cleanup_(link_unrefp) Link *link = userdata;
  65         int r;
  66
  67         assert(link);
  68         assert(!link->ipv4ll_route);
  69
  70         r = sd_netlink_message_get_errno(m);
  71         if (r < 0 && r != -EEXIST) {
  72                 log_link_error_errno(link, r, "could not set ipv4ll route: %m");
  73                 link_enter_failed(link);
  74         }
  75
  76         link->ipv4ll_route = true;
  77
  78         if (link->ipv4ll_address == true)
  79                 link_check_ready(link);
  80
  81         return 1;
  82 }
  83
  84 static int ipv4ll_address_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) {
  85         _cleanup_(link_unrefp) Link *link = userdata;
  86         int r;
  87
  88         assert(link);
  89         assert(!link->ipv4ll_address);
  90
  91         r = sd_netlink_message_get_errno(m);
  92         if (r < 0 && r != -EEXIST) {
  93                 log_link_error_errno(link, r, "could not set ipv4ll address: %m");
  94                 link_enter_failed(link);
  95         } else if (r >= 0)
  96                 manager_rtnl_process_address(rtnl, m, link->manager);
  97
  98         link->ipv4ll_address = true;
  99
 100         if (link->ipv4ll_route)
 101                 link_check_ready(link);
 102
 103         return 1;
 104 }
 105
 106 static int ipv4ll_address_claimed(sd_ipv4ll *ll, Link *link) {
 107         _cleanup_(address_freep) Address *ll_addr = NULL;
 108         _cleanup_(route_freep) Route *route = NULL;
 109         struct in_addr address;
 110         int r;
 111
 112         assert(ll);
 113         assert(link);
 114
 115         r = sd_ipv4ll_get_address(ll, &address);
 116         if (r == -ENOENT)
 117                 return 0;
 118         else if (r < 0)
 119                 return r;
 120
 121         log_link_debug(link, "IPv4 link-local claim %u.%u.%u.%u",
 122                        ADDRESS_FMT_VAL(address));
 123
 124         r = address_new(&ll_addr);
 125         if (r < 0)
 126                 return r;
 127
 128         ll_addr->family = AF_INET;
 129         ll_addr->in_addr.in = address;
 130         ll_addr->prefixlen = 16;
 131         ll_addr->broadcast.s_addr = ll_addr->in_addr.in.s_addr | htobe32(0xfffffffflu >> ll_addr->prefixlen);
 132         ll_addr->scope = RT_SCOPE_LINK;
 133
 134         r = address_configure(ll_addr, link, ipv4ll_address_handler, false);
 135         if (r < 0)
 136                 return r;
 137
 138         link->ipv4ll_address = false;
 139
 140         r = route_new(&route);
 141         if (r < 0)
 142                 return r;
 143
 144         route->family = AF_INET;
 145         route->scope = RT_SCOPE_LINK;
 146         route->protocol = RTPROT_STATIC;
 147         route->priority = IPV4LL_ROUTE_METRIC;
 148
 149         r = route_configure(route, link, ipv4ll_route_handler);
 150         if (r < 0)
 151                 return r;
 152
 153         link->ipv4ll_route = false;
 154
 155         return 0;
 156 }
 157
 158 static void ipv4ll_handler(sd_ipv4ll *ll, int event, void *userdata) {
 159         Link *link = userdata;
 160         int r;
 161
 162         assert(link);
 163         assert(link->network);
 164
 165         if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
 166                 return;
 167
 168         switch(event) {
 169                 case SD_IPV4LL_EVENT_STOP:
 170                         r = ipv4ll_address_lost(link);
 171                         if (r < 0) {
 172                                 link_enter_failed(link);
 173                                 return;
 174                         }
 175                         break;
 176                 case SD_IPV4LL_EVENT_CONFLICT:
 177                         r = ipv4ll_address_lost(link);
 178                         if (r < 0) {
 179                                 link_enter_failed(link);
 180                                 return;
 181                         }
 182
 183                         r = sd_ipv4ll_restart(ll);
 184                         if (r < 0)
 185                                 log_link_warning(link, "Could not acquire IPv4 link-local address");
 186                         break;
 187                 case SD_IPV4LL_EVENT_BIND:
 188                         r = ipv4ll_address_claimed(ll, link);
 189                         if (r < 0) {
 190                                 link_enter_failed(link);
 191                                 return;
 192                         }
 193                         break;
 194                 default:
 195                         log_link_warning(link, "IPv4 link-local unknown event: %d", event);
 196                         break;
 197         }
 198 }
 199
 200 int ipv4ll_configure(Link *link) {
 201         uint64_t seed;
 202         int r;
 203
 204         assert(link);
 205         assert(link->network);
 206         assert(link->network->link_local & ADDRESS_FAMILY_IPV4);
 207
 208         if (!link->ipv4ll) {
 209                 r = sd_ipv4ll_new(&link->ipv4ll);
 210                 if (r < 0)
 211                         return r;
 212         }
 213
 214         if (link->udev_device) {
 215                 r = net_get_unique_predictable_data(link->udev_device, &seed);
 216                 if (r >= 0) {
 217                         r = sd_ipv4ll_set_address_seed(link->ipv4ll, seed);
 218                         if (r < 0)
 219                                 return r;
 220                 }
 221         }
 222
 223         r = sd_ipv4ll_attach_event(link->ipv4ll, NULL, 0);
 224         if (r < 0)
 225                 return r;
 226
 227         r = sd_ipv4ll_set_mac(link->ipv4ll, &link->mac);
 228         if (r < 0)
 229                 return r;
 230
 231         r = sd_ipv4ll_set_ifindex(link->ipv4ll, link->ifindex);
 232         if (r < 0)
 233                 return r;
 234
 235         r = sd_ipv4ll_set_callback(link->ipv4ll, ipv4ll_handler, link);
 236         if (r < 0)
 237                 return r;
 238
 239         return 0;
 240 }