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