src/network/networkd-ipv4ll.c

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