tc/act_tunnel: Introduce ip tunnel action

This action could be used before redirecting packets to a shared tunnel
device, or when redirecting packets arriving from a such a device.

The 'unset' action is optional. It is used to explicitly unset the
metadata created by the tunnel device during decap. If not used, the
metadata will be released automatically by the kernel.
The 'set' operation, will set the metadata with the specified values for
the encap.

For example, the following flower filter will forward all ICMP packets
destined to 11.11.11.2 through the shared vxlan device 'vxlan0'. Before
redirecting, a metadata for the vxlan tunnel is created using the
tunnel_key action and it's arguments:

$ tc filter add dev net0 protocol ip parent ffff: \
    flower \
      ip_proto 1 \
      dst_ip 11.11.11.2 \
    action tunnel_key set \
      src_ip 11.11.0.1 \
      dst_ip 11.11.0.2 \
      id 11 \
    action mirred egress redirect dev vxlan0

Signed-off-by: Amir Vadai <amir@vadai.me>
This commit is contained in:
Amir Vadai 2016-12-02 13:25:15 +02:00 committed by Stephen Hemminger
parent bb9b63b18e
commit d57639a475
4 changed files with 413 additions and 0 deletions

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@ -0,0 +1,42 @@
/*
* Copyright (c) 2016, Amir Vadai <amir@vadai.me>
* Copyright (c) 2016, Mellanox Technologies. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#ifndef __LINUX_TC_TUNNEL_KEY_H
#define __LINUX_TC_TUNNEL_KEY_H
#include <linux/pkt_cls.h>
#define TCA_ACT_TUNNEL_KEY 17
#define TCA_TUNNEL_KEY_ACT_SET 1
#define TCA_TUNNEL_KEY_ACT_RELEASE 2
struct tc_tunnel_key {
tc_gen;
int t_action;
};
enum {
TCA_TUNNEL_KEY_UNSPEC,
TCA_TUNNEL_KEY_TM,
TCA_TUNNEL_KEY_PARMS,
TCA_TUNNEL_KEY_ENC_IPV4_SRC, /* be32 */
TCA_TUNNEL_KEY_ENC_IPV4_DST, /* be32 */
TCA_TUNNEL_KEY_ENC_IPV6_SRC, /* struct in6_addr */
TCA_TUNNEL_KEY_ENC_IPV6_DST, /* struct in6_addr */
TCA_TUNNEL_KEY_ENC_KEY_ID, /* be64 */
TCA_TUNNEL_KEY_PAD,
__TCA_TUNNEL_KEY_MAX,
};
#define TCA_TUNNEL_KEY_MAX (__TCA_TUNNEL_KEY_MAX - 1)
#endif

112
man/man8/tc-tunnel_key.8 Normal file
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.TH "Tunnel metadata manipulation action in tc" 8 "10 Nov 2016" "iproute2" "Linux"
.SH NAME
tunnel_key - Tunnel metadata manipulation
.SH SYNOPSIS
.in +8
.ti -8
.BR tc " ... " "action tunnel_key" " { " unset " | "
.IR SET " }"
.ti -8
.IR SET " := "
.BR set " " src_ip
.IR ADDRESS
.BR dst_ip
.IR ADDRESS
.BI id " KEY_ID"
.SH DESCRIPTION
The
.B tunnel_key
action combined with a shared IP tunnel device, allows to perform IP tunnel en-
or decapsulation on a packet, reflected by
the operation modes
.IR UNSET " and " SET .
The
.I UNSET
mode is optional - even without using it, the metadata information will be
released automatically when packet processing will be finished.
.IR UNSET
function could be used in cases when traffic is forwarded between two tunnels,
where the metadata from the first tunnel will be used for encapsulation done by
the second tunnel.
.IR SET
mode requires the source and destination ip
.I ADDRESS
and the tunnel key id
.I KEY_ID
which will be used by the ip tunnel shared device to create the tunnel header. The
.B tunnel_key
action is useful only in combination with a
.B mirred redirect
action to a shared IP tunnel device which will use the metadata (for
.I SET
) and unset the metadata created by it (for
.I UNSET
).
.SH OPTIONS
.TP
.B unset
Unset the tunnel metadata created by the IP tunnel device. This function is
not mandatory and might be used only in some specific use cases (as explained
above).
.TP
.B set
Set tunnel metadata to be used by the IP tunnel device. Requires
.B id
,
.B src_ip
and
.B dst_ip
options.
.RS
.TP
.B id
Tunnel ID (for example VNI in VXLAN tunnel)
.TP
.B src_ip
Outer header source IP address (IPv4 or IPv6)
.TP
.B dst_ip
Outer header destination IP address (IPv4 or IPv6)
.RE
.SH EXAMPLES
The following example encapsulates incoming ICMP packets on eth0 into a vxlan
tunnel, by setting metadata to VNI 11, source IP 11.11.0.1 and destination IP
11.11.0.2, and by redirecting the packet with the metadata to device vxlan0,
which will do the actual encapsulation using the metadata:
.RS
.EX
#tc qdisc add dev eth0 handle ffff: ingress
#tc filter add dev eth0 protocol ip parent ffff: \\
flower \\
ip_proto icmp \\
action tunnel_key set \\
src_ip 11.11.0.1 \\
dst_ip 11.11.0.2 \\
id 11 \\
action mirred egress redirect dev vxlan0
.EE
.RE
Here is an example of the
.B unset
function: Incoming VXLAN traffic with outer IP's and VNI 11 is decapsulated by
vxlan0 and metadata is unset before redirecting to tunl1 device:
.RS
.EX
#tc qdisc add dev eth0 handle ffff: ingress
#tc filter add dev vxlan0 protocol ip parent ffff: \
flower \\
enc_src_ip 11.11.0.2 enc_dst_ip 11.11.0.1 enc_key_id 11 \
action tunnel_key unset \
action mirred egress redirect dev tunl1
.EE
.RE
.SH SEE ALSO
.BR tc (8)

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@ -50,6 +50,7 @@ TCMODULES += m_simple.o
TCMODULES += m_vlan.o
TCMODULES += m_connmark.o
TCMODULES += m_bpf.o
TCMODULES += m_tunnel_key.o
TCMODULES += p_ip.o
TCMODULES += p_icmp.o
TCMODULES += p_tcp.o

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tc/m_tunnel_key.c Normal file
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/*
* m_tunnel_key.c ip tunnel manipulation module
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: Amir Vadai <amir@vadai.me>
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <linux/if_ether.h>
#include "utils.h"
#include "rt_names.h"
#include "tc_util.h"
#include <linux/tc_act/tc_tunnel_key.h>
static void explain(void)
{
fprintf(stderr, "Usage: tunnel_key unset\n");
fprintf(stderr, " tunnel_key set id TUNNELID src_ip IP dst_ip IP\n");
}
static void usage(void)
{
explain();
exit(-1);
}
static int tunnel_key_parse_ip_addr(const char *str, int addr4_type,
int addr6_type, struct nlmsghdr *n)
{
inet_prefix addr;
int ret;
ret = get_addr(&addr, str, AF_UNSPEC);
if (ret)
return ret;
addattr_l(n, MAX_MSG, addr.family == AF_INET ? addr4_type : addr6_type,
addr.data, addr.bytelen);
return 0;
}
static int tunnel_key_parse_key_id(const char *str, int type,
struct nlmsghdr *n)
{
__be32 key_id;
int ret;
ret = get_be32(&key_id, str, 10);
if (!ret)
addattr32(n, MAX_MSG, type, key_id);
return ret;
}
static int parse_tunnel_key(struct action_util *a, int *argc_p, char ***argv_p,
int tca_id, struct nlmsghdr *n)
{
struct tc_tunnel_key parm = { .action = TC_ACT_PIPE };
char **argv = *argv_p;
int argc = *argc_p;
struct rtattr *tail;
int action = 0;
int ret;
int has_src_ip = 0;
int has_dst_ip = 0;
int has_key_id = 0;
if (matches(*argv, "tunnel_key") != 0)
return -1;
tail = NLMSG_TAIL(n);
addattr_l(n, MAX_MSG, tca_id, NULL, 0);
NEXT_ARG();
while (argc > 0) {
if (matches(*argv, "unset") == 0) {
if (action) {
fprintf(stderr, "unexpected \"%s\" - action already specified\n",
*argv);
explain();
return -1;
}
action = TCA_TUNNEL_KEY_ACT_RELEASE;
} else if (matches(*argv, "set") == 0) {
if (action) {
fprintf(stderr, "unexpected \"%s\" - action already specified\n",
*argv);
explain();
return -1;
}
action = TCA_TUNNEL_KEY_ACT_SET;
} else if (matches(*argv, "src_ip") == 0) {
NEXT_ARG();
ret = tunnel_key_parse_ip_addr(*argv,
TCA_TUNNEL_KEY_ENC_IPV4_SRC,
TCA_TUNNEL_KEY_ENC_IPV6_SRC,
n);
if (ret < 0) {
fprintf(stderr, "Illegal \"src_ip\"\n");
return -1;
}
has_src_ip = 1;
} else if (matches(*argv, "dst_ip") == 0) {
NEXT_ARG();
ret = tunnel_key_parse_ip_addr(*argv,
TCA_TUNNEL_KEY_ENC_IPV4_DST,
TCA_TUNNEL_KEY_ENC_IPV6_DST,
n);
if (ret < 0) {
fprintf(stderr, "Illegal \"dst_ip\"\n");
return -1;
}
has_dst_ip = 1;
} else if (matches(*argv, "id") == 0) {
NEXT_ARG();
ret = tunnel_key_parse_key_id(*argv, TCA_TUNNEL_KEY_ENC_KEY_ID, n);
if (ret < 0) {
fprintf(stderr, "Illegal \"id\"\n");
return -1;
}
has_key_id = 1;
} else if (matches(*argv, "help") == 0) {
usage();
} else {
break;
}
NEXT_ARG_FWD();
}
if (argc && !action_a2n(*argv, &parm.action, false))
NEXT_ARG_FWD();
if (argc) {
if (matches(*argv, "index") == 0) {
NEXT_ARG();
if (get_u32(&parm.index, *argv, 10)) {
fprintf(stderr, "tunnel_key: Illegal \"index\"\n");
return -1;
}
NEXT_ARG_FWD();
}
}
if (action == TCA_TUNNEL_KEY_ACT_SET &&
(!has_src_ip || !has_dst_ip || !has_key_id)) {
fprintf(stderr, "set needs tunnel_key parameters\n");
explain();
return -1;
}
parm.t_action = action;
addattr_l(n, MAX_MSG, TCA_TUNNEL_KEY_PARMS, &parm, sizeof(parm));
tail->rta_len = (char *)NLMSG_TAIL(n) - (char *)tail;
*argc_p = argc;
*argv_p = argv;
return 0;
}
static void tunnel_key_print_ip_addr(FILE *f, const char *name,
struct rtattr *attr)
{
int family;
size_t len;
if (!attr)
return;
len = RTA_PAYLOAD(attr);
if (len == 4)
family = AF_INET;
else if (len == 16)
family = AF_INET6;
else
return;
fprintf(f, "\n\t%s %s", name, rt_addr_n2a_rta(family, attr));
}
static void tunnel_key_print_key_id(FILE *f, const char *name,
struct rtattr *attr)
{
if (!attr)
return;
fprintf(f, "\n\t%s %d", name, rta_getattr_be32(attr));
}
static int print_tunnel_key(struct action_util *au, FILE *f, struct rtattr *arg)
{
struct rtattr *tb[TCA_TUNNEL_KEY_MAX + 1];
struct tc_tunnel_key *parm;
if (!arg)
return -1;
parse_rtattr_nested(tb, TCA_TUNNEL_KEY_MAX, arg);
if (!tb[TCA_TUNNEL_KEY_PARMS]) {
fprintf(f, "[NULL tunnel_key parameters]");
return -1;
}
parm = RTA_DATA(tb[TCA_TUNNEL_KEY_PARMS]);
fprintf(f, "tunnel_key");
switch (parm->t_action) {
case TCA_TUNNEL_KEY_ACT_RELEASE:
fprintf(f, " unset");
break;
case TCA_TUNNEL_KEY_ACT_SET:
fprintf(f, " set");
tunnel_key_print_ip_addr(f, "src_ip",
tb[TCA_TUNNEL_KEY_ENC_IPV4_SRC]);
tunnel_key_print_ip_addr(f, "dst_ip",
tb[TCA_TUNNEL_KEY_ENC_IPV4_DST]);
tunnel_key_print_ip_addr(f, "src_ip",
tb[TCA_TUNNEL_KEY_ENC_IPV6_SRC]);
tunnel_key_print_ip_addr(f, "dst_ip",
tb[TCA_TUNNEL_KEY_ENC_IPV6_DST]);
tunnel_key_print_key_id(f, "key_id",
tb[TCA_TUNNEL_KEY_ENC_KEY_ID]);
break;
}
fprintf(f, " %s", action_n2a(parm->action));
fprintf(f, "\n\tindex %d ref %d bind %d", parm->index, parm->refcnt,
parm->bindcnt);
if (show_stats) {
if (tb[TCA_TUNNEL_KEY_TM]) {
struct tcf_t *tm = RTA_DATA(tb[TCA_TUNNEL_KEY_TM]);
print_tm(f, tm);
}
}
fprintf(f, "\n ");
return 0;
}
struct action_util tunnel_key_action_util = {
.id = "tunnel_key",
.parse_aopt = parse_tunnel_key,
.print_aopt = print_tunnel_key,
};