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