src/network/networkd-netdev-tuntap.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4     This file is part of systemd.
   5
   6     Copyright 2014 Susant Sahani <susant@redhat.com>
   7
   8     systemd is free software; you can redistribute it and/or modify it
   9     under the terms of the GNU Lesser General Public License as published by
  10     the Free Software Foundation; either version 2.1 of the License, or
  11     (at your option) any later version.
  12
  13     systemd is distributed in the hope that it will be useful, but
  14     WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16     Lesser General Public License for more details.
  17
  18     You should have received a copy of the GNU Lesser General Public License
  19     along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <sys/ioctl.h>
  23 #include <net/if.h>
  24 #include <linux/if_tun.h>
  25
  26 #include "networkd-netdev-tuntap.h"
  27
  28 #define TUN_DEV "/dev/net/tun"
  29
  30 static int netdev_fill_tuntap_message(NetDev *netdev, struct ifreq *ifr) {
  31         TunTap *t;
  32
  33         assert(netdev);
  34         assert(netdev->ifname);
  35         assert(ifr);
  36
  37         if (netdev->kind == NETDEV_KIND_TAP) {
  38                 t = TAP(netdev);
  39                 ifr->ifr_flags |= IFF_TAP;
  40         } else {
  41                 t = TUN(netdev);
  42                 ifr->ifr_flags |= IFF_TUN;
  43         }
  44
  45         if (!t->packet_info)
  46                 ifr->ifr_flags |= IFF_NO_PI;
  47
  48         if (t->one_queue)
  49                 ifr->ifr_flags |= IFF_ONE_QUEUE;
  50
  51         if (t->multi_queue)
  52                 ifr->ifr_flags |= IFF_MULTI_QUEUE;
  53
  54         strncpy(ifr->ifr_name, netdev->ifname, IFNAMSIZ-1);
  55
  56         return 0;
  57 }
  58
  59 static int netdev_tuntap_add(NetDev *netdev, struct ifreq *ifr) {
  60         _cleanup_close_ int fd;
  61         TunTap *t = NULL;
  62         const char *user;
  63         const char *group;
  64         uid_t uid;
  65         gid_t gid;
  66         int r;
  67
  68         assert(netdev);
  69         assert(ifr);
  70
  71         fd = open(TUN_DEV, O_RDWR);
  72         if (fd < 0) {
  73                 log_netdev_error(netdev, "Failed to open tun dev: %m");
  74                 return -errno;
  75         }
  76
  77         r = ioctl(fd, TUNSETIFF, ifr);
  78         if (r < 0) {
  79                 log_netdev_error(netdev,
  80                                  "TUNSETIFF failed on tun dev: %s",
  81                                  strerror(-r));
  82                 return r;
  83         }
  84
  85         if (netdev->kind == NETDEV_KIND_TAP)
  86                 t = TAP(netdev);
  87         else
  88                 t = TUN(netdev);
  89
  90         assert(t);
  91
  92         if(t->user_name) {
  93
  94                 user = t->user_name;
  95
  96                 r = get_user_creds(&user, &uid, NULL, NULL, NULL);
  97                 if (r < 0) {
  98                         log_error_errno(r, "Cannot resolve user name %s: %m",
  99                                         t->user_name);
 100                         return 0;
 101                 }
 102
 103                 r = ioctl(fd, TUNSETOWNER, uid);
 104                 if ( r < 0) {
 105                         log_netdev_error(netdev,
 106                                          "TUNSETOWNER failed on tun dev: %s",
 107                                          strerror(-r));
 108                 }
 109         }
 110
 111         if (t->group_name) {
 112
 113                 group = t->group_name;
 114
 115                 r = get_group_creds(&group, &gid);
 116                 if (r < 0) {
 117                         log_error_errno(r, "Cannot resolve group name %s: %m",
 118                                         t->group_name);
 119                         return 0;
 120                 }
 121
 122                 r = ioctl(fd, TUNSETGROUP, gid);
 123                 if( r < 0) {
 124                         log_netdev_error(netdev,
 125                                          "TUNSETGROUP failed on tun dev: %s",
 126                                          strerror(-r));
 127                         return r;
 128                 }
 129
 130         }
 131
 132         r = ioctl(fd, TUNSETPERSIST, 1);
 133         if (r < 0) {
 134                 log_netdev_error(netdev,
 135                                  "TUNSETPERSIST failed on tun dev: %s",
 136                                  strerror(-r));
 137                 return r;
 138         }
 139
 140         return 0;
 141 }
 142
 143 static int netdev_create_tuntap(NetDev *netdev) {
 144         struct ifreq ifr = {};
 145         int r;
 146
 147         r = netdev_fill_tuntap_message(netdev, &ifr);
 148         if(r < 0)
 149                 return r;
 150
 151         return netdev_tuntap_add(netdev, &ifr);
 152 }
 153
 154 static void tuntap_done(NetDev *netdev) {
 155         TunTap *t = NULL;
 156
 157         assert(netdev);
 158
 159         if (netdev->kind == NETDEV_KIND_TUN)
 160                 t = TUN(netdev);
 161         else
 162                 t = TAP(netdev);
 163
 164         assert(t);
 165
 166         free(t->user_name);
 167         t->user_name = NULL;
 168
 169         free(t->group_name);
 170         t->group_name = NULL;
 171 }
 172
 173 static int tuntap_verify(NetDev *netdev, const char *filename) {
 174         assert(netdev);
 175
 176         if (netdev->mtu)
 177                 log_netdev_warning(netdev, "MTU configured for %s, ignoring", netdev_kind_to_string(netdev->kind));
 178
 179         if (netdev->mac)
 180                 log_netdev_warning(netdev, "MAC configured for %s, ignoring", netdev_kind_to_string(netdev->kind));
 181
 182         return 0;
 183 }
 184
 185 const NetDevVTable tun_vtable = {
 186         .object_size = sizeof(TunTap),
 187         .sections = "Match\0NetDev\0Tun\0",
 188         .config_verify = tuntap_verify,
 189         .done = tuntap_done,
 190         .create = netdev_create_tuntap,
 191         .create_type = NETDEV_CREATE_INDEPENDENT,
 192 };
 193
 194 const NetDevVTable tap_vtable = {
 195         .object_size = sizeof(TunTap),
 196         .sections = "Match\0NetDev\0Tap\0",
 197         .config_verify = tuntap_verify,
 198         .done = tuntap_done,
 199         .create = netdev_create_tuntap,
 200         .create_type = NETDEV_CREATE_INDEPENDENT,
 201 };