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

Susant Sahani susant at redhat.com
Tue Jun 24 11:07:21 PDT 2014


On 06/24/2014 10:05 PM, Ronny Chevalier wrote:
> 2014-06-24 18:25 GMT+02:00 Susant Sahani <susant at redhat.com>:
>> This patch introduces tuntap support to networkd.
>>
>> Example conf
>>
>> file : tuntap.netdev
>>
>> [NetDev]
>> Name=tuntap-test
>> Kind=tuntap
>>
>> [TUNTAP]
>> 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
>> ---
>>   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) {
>> +                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;
> By using _cleanup_close_  you can avoid all the goto logic here.

Thanks :)

>
>> +        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
>>
>> _______________________________________________
>> systemd-devel mailing list
>> systemd-devel at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/systemd-devel
> _______________________________________________
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>

-- 
Susant


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