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         if (t->vnet_hdr)
  55                 ifr->ifr_flags |= IFF_VNET_HDR;
  56
  57         strncpy(ifr->ifr_name, netdev->ifname, IFNAMSIZ-1);
  58
  59         return 0;
  60 }
  61
  62 static int netdev_tuntap_add(NetDev *netdev, struct ifreq *ifr) {
  63         _cleanup_close_ int fd;
  64         TunTap *t = NULL;
  65         const char *user;
  66         const char *group;
  67         uid_t uid;
  68         gid_t gid;
  69         int r;
  70
  71         assert(netdev);
  72         assert(ifr);
  73
  74         fd = open(TUN_DEV, O_RDWR);
  75         if (fd < 0)
  76                 return log_netdev_error_errno(netdev, -errno,  "Failed to open tun dev: %m");
  77
  78         r = ioctl(fd, TUNSETIFF, ifr);
  79         if (r < 0)
  80                 return log_netdev_error_errno(netdev, -errno, "TUNSETIFF failed on tun dev: %m");
  81
  82         if (netdev->kind == NETDEV_KIND_TAP)
  83                 t = TAP(netdev);
  84         else
  85                 t = TUN(netdev);
  86
  87         assert(t);
  88
  89         if(t->user_name) {
  90
  91                 user = t->user_name;
  92
  93                 r = get_user_creds(&user, &uid, NULL, NULL, NULL);
  94                 if (r < 0)
  95                         return log_netdev_error_errno(netdev, r, "Cannot resolve user name %s: %m", t->user_name);
  96
  97                 r = ioctl(fd, TUNSETOWNER, uid);
  98                 if (r < 0)
  99                         return log_netdev_error_errno(netdev, -errno, "TUNSETOWNER failed on tun dev: %m");
 100         }
 101
 102         if (t->group_name) {
 103
 104                 group = t->group_name;
 105
 106                 r = get_group_creds(&group, &gid);
 107                 if (r < 0)
 108                         return log_netdev_error_errno(netdev, r, "Cannot resolve group name %s: %m", t->group_name);
 109
 110                 r = ioctl(fd, TUNSETGROUP, gid);
 111                 if (r < 0)
 112                         return log_netdev_error_errno(netdev, -errno, "TUNSETGROUP failed on tun dev: %m");
 113
 114         }
 115
 116         r = ioctl(fd, TUNSETPERSIST, 1);
 117         if (r < 0)
 118                 return log_netdev_error_errno(netdev, -errno, "TUNSETPERSIST failed on tun dev: %m");
 119
 120         return 0;
 121 }
 122
 123 static int netdev_create_tuntap(NetDev *netdev) {
 124         struct ifreq ifr = {};
 125         int r;
 126
 127         r = netdev_fill_tuntap_message(netdev, &ifr);
 128         if(r < 0)
 129                 return r;
 130
 131         return netdev_tuntap_add(netdev, &ifr);
 132 }
 133
 134 static void tuntap_done(NetDev *netdev) {
 135         TunTap *t = NULL;
 136
 137         assert(netdev);
 138
 139         if (netdev->kind == NETDEV_KIND_TUN)
 140                 t = TUN(netdev);
 141         else
 142                 t = TAP(netdev);
 143
 144         assert(t);
 145
 146         t->user_name = mfree(t->user_name);
 147         t->group_name = mfree(t->group_name);
 148 }
 149
 150 static int tuntap_verify(NetDev *netdev, const char *filename) {
 151         assert(netdev);
 152
 153         if (netdev->mtu)
 154                 log_netdev_warning(netdev, "MTU configured for %s, ignoring", netdev_kind_to_string(netdev->kind));
 155
 156         if (netdev->mac)
 157                 log_netdev_warning(netdev, "MAC configured for %s, ignoring", netdev_kind_to_string(netdev->kind));
 158
 159         return 0;
 160 }
 161
 162 const NetDevVTable tun_vtable = {
 163         .object_size = sizeof(TunTap),
 164         .sections = "Match\0NetDev\0Tun\0",
 165         .config_verify = tuntap_verify,
 166         .done = tuntap_done,
 167         .create = netdev_create_tuntap,
 168         .create_type = NETDEV_CREATE_INDEPENDENT,
 169 };
 170
 171 const NetDevVTable tap_vtable = {
 172         .object_size = sizeof(TunTap),
 173         .sections = "Match\0NetDev\0Tap\0",
 174         .config_verify = tuntap_verify,
 175         .done = tuntap_done,
 176         .create = netdev_create_tuntap,
 177         .create_type = NETDEV_CREATE_INDEPENDENT,
 178 };