src/libsystemd-dhcp/dhcp-lease.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright (C) 2013 Intel Corporation. All rights reserved.
   5   Copyright (C) 2014 Tom Gundersen
   6
   7   systemd is free software; you can redistribute it and/or modify it
   8   under the terms of the GNU Lesser General Public License as published by
   9   the Free Software Foundation; either version 2.1 of the License, or
  10   (at your option) any later version.
  11
  12   systemd is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   Lesser General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public License
  18   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  19 ***/
  20
  21 #include <stdlib.h>
  22 #include <errno.h>
  23 #include <string.h>
  24 #include <stdio.h>
  25 #include <net/ethernet.h>
  26 #include <sys/param.h>
  27
  28 #include "util.h"
  29 #include "list.h"
  30
  31 #include "dhcp-protocol.h"
  32 #include "dhcp-internal.h"
  33 #include "dhcp-lease.h"
  34 #include "sd-dhcp-client.h"
  35
  36 int sd_dhcp_lease_get_address(sd_dhcp_lease *lease, struct in_addr *addr) {
  37         assert_return(lease, -EINVAL);
  38         assert_return(addr, -EINVAL);
  39
  40         addr->s_addr = lease->address;
  41
  42         return 0;
  43 }
  44
  45 int sd_dhcp_lease_get_mtu(sd_dhcp_lease *lease, uint16_t *mtu) {
  46         assert_return(lease, -EINVAL);
  47         assert_return(mtu, -EINVAL);
  48
  49         if (lease->mtu)
  50                 *mtu = lease->mtu;
  51         else
  52                 return -ENOENT;
  53
  54         return 0;
  55 }
  56
  57 int sd_dhcp_lease_get_dns(sd_dhcp_lease *lease, struct in_addr **addr, size_t *addr_size) {
  58         assert_return(lease, -EINVAL);
  59         assert_return(addr, -EINVAL);
  60         assert_return(addr_size, -EINVAL);
  61
  62         if (lease->dns_size) {
  63                 *addr_size = lease->dns_size;
  64                 *addr = lease->dns;
  65         } else
  66                 return -ENOENT;
  67
  68         return 0;
  69 }
  70
  71 int sd_dhcp_lease_get_domainname(sd_dhcp_lease *lease, const char **domainname) {
  72         assert_return(lease, -EINVAL);
  73         assert_return(domainname, -EINVAL);
  74
  75         if (lease->domainname)
  76                 *domainname = lease->domainname;
  77         else
  78                 return -ENOENT;
  79
  80         return 0;
  81 }
  82
  83 int sd_dhcp_lease_get_hostname(sd_dhcp_lease *lease, const char **hostname) {
  84         assert_return(lease, -EINVAL);
  85         assert_return(hostname, -EINVAL);
  86
  87         if (lease->hostname)
  88                 *hostname = lease->hostname;
  89         else
  90                 return -ENOENT;
  91
  92         return 0;
  93 }
  94
  95 int sd_dhcp_lease_get_router(sd_dhcp_lease *lease, struct in_addr *addr) {
  96         assert_return(lease, -EINVAL);
  97         assert_return(addr, -EINVAL);
  98
  99         addr->s_addr = lease->router;
 100
 101         return 0;
 102 }
 103
 104 int sd_dhcp_lease_get_netmask(sd_dhcp_lease *lease, struct in_addr *addr) {
 105         assert_return(lease, -EINVAL);
 106         assert_return(addr, -EINVAL);
 107
 108         addr->s_addr = lease->subnet_mask;
 109
 110         return 0;
 111 }
 112
 113 sd_dhcp_lease *sd_dhcp_lease_ref(sd_dhcp_lease *lease) {
 114         if (lease)
 115                 assert_se(REFCNT_INC(lease->n_ref) >= 2);
 116
 117         return lease;
 118 }
 119
 120 sd_dhcp_lease *sd_dhcp_lease_unref(sd_dhcp_lease *lease) {
 121         if (lease && REFCNT_DEC(lease->n_ref) <= 0) {
 122                 free(lease->hostname);
 123                 free(lease->domainname);
 124                 free(lease->dns);
 125                 free(lease);
 126         }
 127
 128         return NULL;
 129 }
 130
 131 int dhcp_lease_parse_options(uint8_t code, uint8_t len, const uint8_t *option,
 132                               void *user_data) {
 133         sd_dhcp_lease *lease = user_data;
 134         be32_t val;
 135
 136         switch(code) {
 137
 138         case DHCP_OPTION_IP_ADDRESS_LEASE_TIME:
 139                 if (len == 4) {
 140                         memcpy(&val, option, 4);
 141                         lease->lifetime = be32toh(val);
 142                 }
 143
 144                 break;
 145
 146         case DHCP_OPTION_SERVER_IDENTIFIER:
 147                 if (len >= 4)
 148                         memcpy(&lease->server_address, option, 4);
 149
 150                 break;
 151
 152         case DHCP_OPTION_SUBNET_MASK:
 153                 if (len >= 4)
 154                         memcpy(&lease->subnet_mask, option, 4);
 155
 156                 break;
 157
 158         case DHCP_OPTION_ROUTER:
 159                 if (len >= 4)
 160                         memcpy(&lease->router, option, 4);
 161
 162                 break;
 163
 164         case DHCP_OPTION_DOMAIN_NAME_SERVER:
 165                 if (len && !(len % 4)) {
 166                         unsigned i;
 167
 168                         lease->dns_size = len / 4;
 169
 170                         free(lease->dns);
 171                         lease->dns = new0(struct in_addr, lease->dns_size);
 172                         if (!lease->dns)
 173                                 return -ENOMEM;
 174
 175                         for (i = 0; i < lease->dns_size; i++) {
 176                                 memcpy(&lease->dns[i].s_addr, option + 4 * i, 4);
 177                         }
 178                 }
 179
 180                 break;
 181
 182         case DHCP_OPTION_INTERFACE_MTU:
 183                 if (len >= 2) {
 184                         be16_t mtu;
 185
 186                         memcpy(&mtu, option, 2);
 187                         lease->mtu = be16toh(mtu);
 188
 189                         if (lease->mtu < 68)
 190                                 lease->mtu = 0;
 191                 }
 192
 193                 break;
 194
 195         case DHCP_OPTION_DOMAIN_NAME:
 196                 if (len >= 1) {
 197                         free(lease->domainname);
 198                         lease->domainname = strndup((const char *)option, len);
 199                 }
 200
 201                 break;
 202
 203         case DHCP_OPTION_HOST_NAME:
 204                 if (len >= 1) {
 205                         free(lease->hostname);
 206                         lease->hostname = strndup((const char *)option, len);
 207                 }
 208
 209                 break;
 210
 211         case DHCP_OPTION_RENEWAL_T1_TIME:
 212                 if (len == 4) {
 213                         memcpy(&val, option, 4);
 214                         lease->t1 = be32toh(val);
 215                 }
 216
 217                 break;
 218
 219         case DHCP_OPTION_REBINDING_T2_TIME:
 220                 if (len == 4) {
 221                         memcpy(&val, option, 4);
 222                         lease->t2 = be32toh(val);
 223                 }
 224
 225                 break;
 226         }
 227
 228         return 0;
 229 }
 230
 231 int dhcp_lease_new(sd_dhcp_lease **ret) {
 232         _cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
 233
 234         lease = new0(sd_dhcp_lease, 1);
 235         if (!lease)
 236                 return -ENOMEM;
 237
 238         lease->n_ref = REFCNT_INIT;
 239
 240         *ret = lease;
 241         lease = NULL;
 242
 243         return 0;
 244 }