diff options
Diffstat (limited to 'src/network/netdev/tuntap.c')
| -rw-r--r-- | src/network/netdev/tuntap.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/src/network/netdev/tuntap.c b/src/network/netdev/tuntap.c new file mode 100644 index 0000000..951138d --- /dev/null +++ b/src/network/netdev/tuntap.c @@ -0,0 +1,161 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include <errno.h> +#include <fcntl.h> +#include <linux/if_tun.h> +#include <net/if.h> +#include <netinet/if_ether.h> +#include <sys/ioctl.h> +#include <sys/stat.h> +#include <sys/types.h> + +#include "alloc-util.h" +#include "fd-util.h" +#include "netdev/tuntap.h" +#include "user-util.h" + +#define TUN_DEV "/dev/net/tun" + +static int netdev_fill_tuntap_message(NetDev *netdev, struct ifreq *ifr) { + TunTap *t; + + assert(netdev); + assert(netdev->ifname); + assert(ifr); + + if (netdev->kind == NETDEV_KIND_TAP) { + t = TAP(netdev); + ifr->ifr_flags |= IFF_TAP; + } else { + t = TUN(netdev); + ifr->ifr_flags |= IFF_TUN; + } + + if (!t->packet_info) + ifr->ifr_flags |= IFF_NO_PI; + + if (t->one_queue) + ifr->ifr_flags |= IFF_ONE_QUEUE; + + if (t->multi_queue) + ifr->ifr_flags |= IFF_MULTI_QUEUE; + + if (t->vnet_hdr) + ifr->ifr_flags |= IFF_VNET_HDR; + + strncpy(ifr->ifr_name, netdev->ifname, IFNAMSIZ-1); + + return 0; +} + +static int netdev_tuntap_add(NetDev *netdev, struct ifreq *ifr) { + _cleanup_close_ int fd; + TunTap *t = NULL; + const char *user; + const char *group; + uid_t uid; + gid_t gid; + int r; + + assert(netdev); + assert(ifr); + + fd = open(TUN_DEV, O_RDWR|O_CLOEXEC); + if (fd < 0) + return log_netdev_error_errno(netdev, -errno, "Failed to open tun dev: %m"); + + if (ioctl(fd, TUNSETIFF, ifr) < 0) + return log_netdev_error_errno(netdev, -errno, "TUNSETIFF failed on tun dev: %m"); + + if (netdev->kind == NETDEV_KIND_TAP) + t = TAP(netdev); + else + t = TUN(netdev); + + assert(t); + + if (t->user_name) { + user = t->user_name; + + r = get_user_creds(&user, &uid, NULL, NULL, NULL, USER_CREDS_ALLOW_MISSING); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Cannot resolve user name %s: %m", t->user_name); + + if (ioctl(fd, TUNSETOWNER, uid) < 0) + return log_netdev_error_errno(netdev, -errno, "TUNSETOWNER failed on tun dev: %m"); + } + + if (t->group_name) { + group = t->group_name; + + r = get_group_creds(&group, &gid, USER_CREDS_ALLOW_MISSING); + if (r < 0) + return log_netdev_error_errno(netdev, r, "Cannot resolve group name %s: %m", t->group_name); + + if (ioctl(fd, TUNSETGROUP, gid) < 0) + return log_netdev_error_errno(netdev, -errno, "TUNSETGROUP failed on tun dev: %m"); + + } + + if (ioctl(fd, TUNSETPERSIST, 1) < 0) + return log_netdev_error_errno(netdev, -errno, "TUNSETPERSIST failed on tun dev: %m"); + + return 0; +} + +static int netdev_create_tuntap(NetDev *netdev) { + struct ifreq ifr = {}; + int r; + + r = netdev_fill_tuntap_message(netdev, &ifr); + if (r < 0) + return r; + + return netdev_tuntap_add(netdev, &ifr); +} + +static void tuntap_done(NetDev *netdev) { + TunTap *t = NULL; + + assert(netdev); + + if (netdev->kind == NETDEV_KIND_TUN) + t = TUN(netdev); + else + t = TAP(netdev); + + assert(t); + + t->user_name = mfree(t->user_name); + t->group_name = mfree(t->group_name); +} + +static int tuntap_verify(NetDev *netdev, const char *filename) { + assert(netdev); + + if (netdev->mtu != 0) + log_netdev_warning(netdev, "MTU configured for %s, ignoring", netdev_kind_to_string(netdev->kind)); + + if (netdev->mac) + log_netdev_warning(netdev, "MAC configured for %s, ignoring", netdev_kind_to_string(netdev->kind)); + + return 0; +} + +const NetDevVTable tun_vtable = { + .object_size = sizeof(TunTap), + .sections = "Match\0NetDev\0Tun\0", + .config_verify = tuntap_verify, + .done = tuntap_done, + .create = netdev_create_tuntap, + .create_type = NETDEV_CREATE_INDEPENDENT, +}; + +const NetDevVTable tap_vtable = { + .object_size = sizeof(TunTap), + .sections = "Match\0NetDev\0Tap\0", + .config_verify = tuntap_verify, + .done = tuntap_done, + .create = netdev_create_tuntap, + .create_type = NETDEV_CREATE_INDEPENDENT, +}; |