[systemd-devel] [PATCH] networkd: Introduce tuntap device

Tom Gundersen teg at jklm.no
Tue Jun 24 10:01:42 PDT 2014


Looks great, just minor comments below.

On Tue, Jun 24, 2014 at 6:25 PM, Susant Sahani <susant at redhat.com> wrote:
> This patch introduces tuntap support to networkd.
>
> Example conf
>
> file : tuntap.netdev
>
> [NetDev]
> Name=tuntap-test
> Kind=tuntap
>
> [TUNTAP]

Hm, maybe call this TunTap instead?

> Mode=tap
> OneQueue=true
> MultiQueue=true
> PacketInfo=true
>
> Added:
>   1. file networkd-tuntap.c
>   2. enum TunTapKind
>   3. NETDEV_KIND_TUNTAP
>   4. TUNTAP Section to parse conf and gperf conf parameters
>
>   TODO:
>   1. Add  user(uid) group(gid) parameters

Yeah, this would be great to have as well.

> ---
>  Makefile.am                             |   1 +
>  src/network/networkd-netdev-gperf.gperf |   4 ++
>  src/network/networkd-netdev.c           |  40 +++++++++---
>  src/network/networkd-tuntap.c           | 106 ++++++++++++++++++++++++++++++++
>  src/network/networkd.h                  |  19 ++++++
>  5 files changed, 163 insertions(+), 7 deletions(-)
>  create mode 100644 src/network/networkd-tuntap.c
>
> diff --git a/Makefile.am b/Makefile.am
> index 37a164e..d9cba3b 100644
> --- a/Makefile.am
> +++ b/Makefile.am
> @@ -4479,6 +4479,7 @@ libsystemd_networkd_core_la_SOURCES = \
>         src/network/networkd-tunnel.c \
>         src/network/networkd-veth.c \
>         src/network/networkd-vxlan.c \
> +       src/network/networkd-tuntap.c \
>         src/network/networkd-network.c \
>         src/network/networkd-address.c \
>         src/network/networkd-route.c \
> diff --git a/src/network/networkd-netdev-gperf.gperf b/src/network/networkd-netdev-gperf.gperf
> index 9125e1d..d29e41d 100644
> --- a/src/network/networkd-netdev-gperf.gperf
> +++ b/src/network/networkd-netdev-gperf.gperf
> @@ -38,3 +38,7 @@ VXLAN.Group,             config_parse_tunnel_address,        0,
>  VXLAN.TOS,               config_parse_unsigned,              0,                             offsetof(NetDev, tos)
>  VXLAN.TTL,               config_parse_unsigned,              0,                             offsetof(NetDev, ttl)
>  VXLAN.MacLearning,       config_parse_bool,                  0,                             offsetof(NetDev, learning)
> +TUNTAP.Mode,             config_parse_tuntap_kind,           0,                             offsetof(NetDev, tuntap_kind)
> +TUNTAP.OneQueue,         config_parse_bool,                  0,                             offsetof(NetDev, one_queue)
> +TUNTAP.MultiQueue,       config_parse_bool,                  0,                             offsetof(NetDev, multi_queue)
> +TUNTAP.PacketInfo,       config_parse_bool,                  0,                             offsetof(NetDev, packet_info)
> diff --git a/src/network/networkd-netdev.c b/src/network/networkd-netdev.c
> index dcf7596..41db707 100644
> --- a/src/network/networkd-netdev.c
> +++ b/src/network/networkd-netdev.c
> @@ -41,7 +41,8 @@ static const char* const netdev_kind_table[_NETDEV_KIND_MAX] = {
>          [NETDEV_KIND_GRE] = "gre",
>          [NETDEV_KIND_SIT] = "sit",
>          [NETDEV_KIND_VETH] = "veth",
> -        [NETDEV_KIND_VTI] = "vti"
> +        [NETDEV_KIND_VTI] = "vti",
> +        [NETDEV_KIND_TUNTAP] = "tuntap"
>  };
>
>  DEFINE_STRING_TABLE_LOOKUP(netdev_kind, NetDevKind);
> @@ -57,6 +58,14 @@ static const char* const macvlan_mode_table[_NETDEV_MACVLAN_MODE_MAX] = {
>  DEFINE_STRING_TABLE_LOOKUP(macvlan_mode, MacVlanMode);
>  DEFINE_CONFIG_PARSE_ENUM(config_parse_macvlan_mode, macvlan_mode, MacVlanMode, "Failed to parse macvlan mode");
>
> +static const char* const tuntap_kind_table[_TUNTAP_KIND_MAX] = {
> +        [TUNTAP_KIND_TAP] = "tap",
> +        [TUNTAP_KIND_TUNNEL] = "tunnel",
> +};
> +
> +DEFINE_STRING_TABLE_LOOKUP(tuntap_kind, TunTapKind);
> +DEFINE_CONFIG_PARSE_ENUM(config_parse_tuntap_kind, tuntap_kind, TunTapKind, "Failed to parse tuntap kind");
> +
>  static void netdev_cancel_callbacks(NetDev *netdev) {
>          _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL;
>          netdev_enslave_callback *callback;
> @@ -521,11 +530,13 @@ int netdev_set_ifindex(NetDev *netdev, sd_rtnl_message *message) {
>                  return -EINVAL;
>          }
>
> -        if (!streq(kind, received_kind)) {
> -                log_error_netdev(netdev, "Received newlink with wrong KIND %s, "
> -                                 "expected %s", received_kind, kind);
> -                netdev_enter_failed(netdev);
> -                return r;
> +        if (netdev->kind != NETDEV_KIND_TUNTAP) {

Probably better explain why tuntap needs special casing in a comment here.

> +                if (!streq(kind, received_kind)) {
> +                        log_error_netdev(netdev, "Received newlink with wrong KIND %s, "
> +                                         "expected %s", received_kind, kind);
> +                        netdev_enter_failed(netdev);
> +                        return r;
> +                }
>          }
>
>          netdev->ifindex = ifindex;
> @@ -612,14 +623,16 @@ static int netdev_load_one(Manager *manager, const char *filename) {
>          netdev->manager = manager;
>          netdev->state = _NETDEV_STATE_INVALID;
>          netdev->kind = _NETDEV_KIND_INVALID;
> +        netdev->tuntap_kind = _TUNTAP_KIND_INVALID;
>          netdev->macvlan_mode = _NETDEV_MACVLAN_MODE_INVALID;
>          netdev->vlanid = VLANID_MAX + 1;
>          netdev->vxlanid = VXLAN_VID_MAX + 1;
>          netdev->tunnel_pmtudisc = true;
>          netdev->learning = true;
> +        netdev->packet_info = true;
>
>          r = config_parse(NULL, filename, file,
> -                         "Match\0NetDev\0VLAN\0MACVLAN\0VXLAN\0Tunnel\0Peer\0",
> +                         "Match\0NetDev\0VLAN\0MACVLAN\0VXLAN\0Tunnel\0Peer\0TUNTAP\0",
>                           config_item_perf_lookup, (void*) network_netdev_gperf_lookup,
>                           false, false, netdev);
>          if (r < 0) {
> @@ -666,6 +679,12 @@ static int netdev_load_one(Manager *manager, const char *filename) {
>                  return 0;
>          }
>
> +        if (netdev->kind == NETDEV_KIND_TUNTAP &&
> +            netdev->tuntap_kind == _TUNTAP_KIND_INVALID) {
> +                log_warning("TunTap without Mode configured in %s. Ignoring", filename);
> +                return 0;
> +        }
> +
>          netdev->filename = strdup(filename);
>          if (!netdev->filename)
>                  return log_oom();
> @@ -719,6 +738,13 @@ static int netdev_load_one(Manager *manager, const char *filename) {
>                  if (r < 0)
>                          return r;
>                  break;
> +
> +        case NETDEV_KIND_TUNTAP:
> +                r = netdev_create_tuntap(netdev);
> +                if (r < 0)
> +                        return r;
> +                break;
> +
>          default:
>                  break;
>          }
> diff --git a/src/network/networkd-tuntap.c b/src/network/networkd-tuntap.c
> new file mode 100644
> index 0000000..f138b8a
> --- /dev/null
> +++ b/src/network/networkd-tuntap.c
> @@ -0,0 +1,106 @@
> +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
> +
> +/***
> +    This file is part of systemd.
> +
> +    Copyright 2014 Susant Sahani <susant at redhat.com>
> +
> +    systemd is free software; you can redistribute it and/or modify it
> +    under the terms of the GNU Lesser General Public License as published by
> +    the Free Software Foundation; either version 2.1 of the License, or
> +    (at your option) any later version.
> +
> +    systemd is distributed in the hope that it will be useful, but
> +    WITHOUT ANY WARRANTY; without even the implied warranty of
> +    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> +    Lesser General Public License for more details.
> +
> +    You should have received a copy of the GNU Lesser General Public License
> +    along with systemd; If not, see <http://www.gnu.org/licenses/>.
> +***/
> +
> +#include <sys/ioctl.h>
> +#include <net/if.h>
> +#include <linux/if_tun.h>
> +
> +#include "networkd.h"
> +
> +#define TUN_DEV "/dev/net/tun"
> +
> +
> +static int netdev_fill_tuntap_message(NetDev *netdev, struct ifreq *ifr) {
> +
> +        assert(netdev);
> +        assert(ifr);
> +
> +        memset(ifr, 0, sizeof(*ifr));
> +
> +        if(netdev->tuntap_kind == TUNTAP_KIND_TAP)
> +                ifr->ifr_flags |= IFF_TAP;
> +        else
> +                ifr->ifr_flags |= IFF_TUN;
> +
> +        if(!netdev->packet_info)
> +                ifr->ifr_flags &= ~IFF_NO_PI;
> +        else
> +                ifr->ifr_flags |= IFF_NO_PI;
> +
> +        if(netdev->one_queue)
> +                ifr->ifr_flags |= IFF_ONE_QUEUE;
> +
> +        if(netdev->multi_queue)
> +                ifr->ifr_flags |= IFF_MULTI_QUEUE;
> +
> +        strncpy(ifr->ifr_name, netdev->ifname, IFNAMSIZ-1);
> +
> +        return 0;
> +}
> +
> +static int netdev_tuntap_add(struct ifreq *ifr)
> +{
> +        int fd;
> +        int r = 0;
> +
> +        fd = open(TUN_DEV, O_RDWR);
> +        if (fd < 0) {
> +                r = -errno;
> +                goto fail;
> +        }
> +
> +        r = ioctl(fd, TUNSETIFF, ifr);
> +        if (r < 0) {
> +                r = -errno;
> +                goto  fail;
> +        }
> +
> +        r = ioctl(fd, TUNSETPERSIST, 1);
> +        if (r < 0) {
> +                r = -errno;
> +                goto fail;
> +        }
> +
> + fail:
> +        close(fd);
> +
> +        return r;
> +}
> +
> +int netdev_create_tuntap(NetDev *netdev) {
> +        int r;
> +        struct ifreq ifr;
> +
> +        assert(netdev);
> +        assert(netdev->ifname);
> +
> +        if(netdev->kind != NETDEV_KIND_TUNTAP)
> +                return -ENOTSUP;
> +
> +        r = netdev_fill_tuntap_message(netdev, &ifr);
> +        if(r < 0)
> +                return r;
> +
> +        log_debug_netdev(netdev, "Creating tuntap netdev: %s",
> +                         netdev_kind_to_string(netdev->kind));
> +
> +        return netdev_tuntap_add(&ifr);
> +}
> diff --git a/src/network/networkd.h b/src/network/networkd.h
> index b7b1d90..ab1ca4e 100644
> --- a/src/network/networkd.h
> +++ b/src/network/networkd.h
> @@ -80,6 +80,7 @@ typedef enum NetDevKind {
>          NETDEV_KIND_SIT,
>          NETDEV_KIND_VETH,
>          NETDEV_KIND_VTI,
> +        NETDEV_KIND_TUNTAP,
>          _NETDEV_KIND_MAX,
>          _NETDEV_KIND_INVALID = -1
>  } NetDevKind;
> @@ -93,6 +94,13 @@ typedef enum NetDevState {
>          _NETDEV_STATE_INVALID = -1,
>  } NetDevState;
>
> +typedef enum TunTapKind {
> +        TUNTAP_KIND_TAP,
> +        TUNTAP_KIND_TUNNEL,
> +        _TUNTAP_KIND_MAX,
> +        _TUNTAP_KIND_INVALID = -1
> +} TunTapKind;
> +
>  struct NetDev {
>          Manager *manager;
>
> @@ -112,6 +120,7 @@ struct NetDev {
>          struct ether_addr *mac;
>          struct ether_addr *mac_peer;
>          NetDevKind kind;
> +        TunTapKind tuntap_kind;
>
>          uint64_t vlanid;
>          uint64_t vxlanid;
> @@ -122,6 +131,10 @@ struct NetDev {
>
>          bool tunnel_pmtudisc;
>          bool learning;
> +        bool one_queue;
> +        bool multi_queue;
> +        bool packet_info;
> +
>          unsigned ttl;
>          unsigned tos;
>          struct in_addr local;
> @@ -342,6 +355,7 @@ int netdev_enslave(NetDev *netdev, Link *link, sd_rtnl_message_handler_t cb);
>  int netdev_create_tunnel(Link *link, sd_rtnl_message_handler_t callback);
>  int netdev_create_veth(NetDev *netdev, sd_rtnl_message_handler_t callback);
>  int netdev_create_vxlan(NetDev *netdev, Link *link, sd_rtnl_message_handler_t callback);
> +int netdev_create_tuntap(NetDev *netdev);
>
>  const char *netdev_kind_to_string(NetDevKind d) _const_;
>  NetDevKind netdev_kind_from_string(const char *d) _pure_;
> @@ -349,10 +363,15 @@ NetDevKind netdev_kind_from_string(const char *d) _pure_;
>  const char *macvlan_mode_to_string(MacVlanMode d) _const_;
>  MacVlanMode macvlan_mode_from_string(const char *d) _pure_;
>
> +const char *tuntap_kind_to_string(TunTapKind d) _const_;
> +TunTapKind tuntap_kind_from_string(const char *d) _pure_;
> +
>  int config_parse_netdev_kind(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
>
>  int config_parse_macvlan_mode(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
>
> +int config_parse_tuntap_kind(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
> +
>  /* gperf */
>  const struct ConfigPerfItem* network_netdev_gperf_lookup(const char *key, unsigned length);
>
> --
> 1.9.3
>


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