From: Jamal Hadi Salim <j...@mojatatu.com>
This action is intended to be an upgrade from a usability perspective
from pedit. Compare this:
sudo tc filter add dev $ETH parent 1: protocol ip prio 10 \
u32 match ip protocol 1 0xff flowid 1:2 \
action pedit munge offset -14 u8 set 0x02 \
munge offset -13 u8 set 0x15 \
munge offset -12 u8 set 0x15 \
munge offset -11 u8 set 0x15 \
munge offset -10 u16 set 0x1515 \
pipe
to:
sudo tc filter add dev $ETH parent 1: protocol ip prio 10 \
u32 match ip protocol 1 0xff flowid 1:2 \
action skbmod dstmac 02:15:15:15:15:15
The dump output is even more tricky.
pedit is a good starting point - but once you start going to a large
number of policies then from a programmability, ops and usability point
of view you need something with more succint params.
I have added only DST MAC - but for (ethernet) completion I will add SRC MAC
and ethertype.
Signed-off-by: Jamal Hadi Salim <j...@mojatatu.com>
---
include/net/tc_act/tc_skbmod.h | 33 ++++++
include/uapi/linux/tc_act/tc_skbmod.h | 43 +++++++
net/sched/act_skbmod.c | 216 ++++++++++++++++++++++++++++++++++
3 files changed, 292 insertions(+)
create mode 100644 include/net/tc_act/tc_skbmod.h
create mode 100644 include/uapi/linux/tc_act/tc_skbmod.h
create mode 100644 net/sched/act_skbmod.c
diff --git a/include/net/tc_act/tc_skbmod.h b/include/net/tc_act/tc_skbmod.h
new file mode 100644
index 0000000..4980960
--- /dev/null
+++ b/include/net/tc_act/tc_skbmod.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2016, Jamal Hadi Salim
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Jamal Hadi Salim <j...@mojatatu.com>
+ */
+
+#ifndef __NET_TC_SKBMOD_H
+#define __NET_TC_SKBMOD_H
+
+#include <net/act_api.h>
+#include <linux/tc_act/tc_skbmod.h>
+
+struct tcf_skbmod {
+ struct tcf_common common;
+ u32 flags;
+ u8 eth_dst[ETH_ALEN];
+};
+#define to_skbmod(a) \
+ container_of(a->priv, struct tcf_skbmod, common)
+
+#endif /* __NET_TC_SKBMOD_H */
diff --git a/include/uapi/linux/tc_act/tc_skbmod.h
b/include/uapi/linux/tc_act/tc_skbmod.h
new file mode 100644
index 0000000..e447240
--- /dev/null
+++ b/include/uapi/linux/tc_act/tc_skbmod.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2016, Jamal Hadi Salim
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * Author: Jamal Hadi Salim
+ */
+
+#ifndef __LINUX_TC_SKBMOD_H
+#define __LINUX_TC_SKBMOD_H
+
+#include <linux/pkt_cls.h>
+
+#define TCA_ACT_SKBMOD 15
+
+#define SKBMOD_F_DMAC 0x1
+
+struct tc_skbmod {
+ tc_gen;
+};
+
+enum {
+ TCA_SKBMOD_UNSPEC,
+ TCA_SKBMOD_TM,
+ TCA_SKBMOD_PARMS,
+ TCA_SKBMOD_DMAC,
+ TCA_SKBMOD_PAD,
+ __TCA_SKBMOD_MAX
+};
+#define TCA_SKBMOD_MAX (__TCA_SKBMOD_MAX - 1)
+
+#endif
diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c
new file mode 100644
index 0000000..81e470e
--- /dev/null
+++ b/net/sched/act_skbmod.c
@@ -0,0 +1,216 @@
+/*
+ * copyright Jamal Hadi Salim (2016)
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Jamal Hadi Salim <j...@mojatatu.com>
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+
+#include <linux/tc_act/tc_skbmod.h>
+#include <net/tc_act/tc_skbmod.h>
+
+#define SKBMOD_TAB_MASK 15
+
+static int skbmod_net_id;
+
+static int tcf_skbmod_run(struct sk_buff *skb, const struct tc_action *a,
+ struct tcf_result *res)
+{
+ struct tcf_skbmod *d = a->priv;
+
+ spin_lock(&d->tcf_lock);
+ tcf_lastuse_update(&d->tcf_tm);
+ bstats_update(&d->tcf_bstats, skb);
+
+ if (d->flags & SKBMOD_F_DMAC)
+ ether_addr_copy(eth_hdr(skb)->h_dest, m->eth_dst);
+
+ spin_unlock(&d->tcf_lock);
+ return d->tcf_action;
+}
+
+static const struct nla_policy skbmod_policy[TCA_SKBMOD_MAX + 1] = {
+ [TCA_SKBMOD_PARMS] = { .len = sizeof(struct tc_skbmod) },
+ [TCA_SKBMOD_DMAC] = { .len = ETH_ALEN },
+};
+
+static int tcf_skbmod_init(struct net *net, struct nlattr *nla,
+ struct nlattr *est, struct tc_action *a,
+ int ovr, int bind)
+{
+ struct tc_action_net *tn = net_generic(net, skbmod_net_id);
+ struct nlattr *tb[TCA_SKBMOD_MAX + 1];
+ struct tc_skbmod *parm;
+ struct tcf_skbmod *d;
+ u32 flags = 0, *priority = NULL, *mark = NULL;
+ u16 *queue_mapping = NULL, *ptype = NULL;
+ bool exists = false;
+ int ret = 0, err;
+
+ if (nla == NULL)
+ return -EINVAL;
+
+ err = nla_parse_nested(tb, TCA_SKBMOD_MAX, nla, skbmod_policy);
+ if (err < 0)
+ return err;
+
+ if (tb[TCA_SKBMOD_PARMS] == NULL)
+ return -EINVAL;
+
+ /*Allow zero valued dmac */
+ if (tb[TCA_SKBMOD_DMAC]) {
+ daddr = nla_data(tb[TCA_SKBMOD_DMAC]);
+ flags |= SKBMOD_F_DMAC;
+ }
+
+ if (!flags) {
+ return -EINVAL;
+ }
+
+ parm = nla_data(tb[TCA_SKBMOD_PARMS]);
+
+ exists = tcf_hash_check(tn, parm->index, a, bind);
+ if (exists && bind)
+ return 0;
+
+ if (!exists) {
+ ret = tcf_hash_create(tn, parm->index, est, a,
+ sizeof(*d), bind, false);
+ if (ret)
+ return ret;
+
+ d = to_skbmod(a);
+ ret = ACT_P_CREATED;
+ } else {
+ d = to_skbmod(a);
+ tcf_hash_release(a, bind);
+ if (!ovr)
+ return -EEXIST;
+ }
+
+ spin_lock_bh(&d->tcf_lock);
+
+ d->flags = flags;
+ if (flags & SKBMOD_F_DMAC)
+ ether_addr_copy(m->eth_dst, daddr);
+
+ d->tcf_action = parm->action;
+
+ spin_unlock_bh(&d->tcf_lock);
+
+ if (ret == ACT_P_CREATED)
+ tcf_hash_insert(tn, a);
+ return ret;
+}
+
+static int tcf_skbmod_dump(struct sk_buff *skb, struct tc_action *a,
+ int bind, int ref)
+{
+ unsigned char *b = skb_tail_pointer(skb);
+ struct tcf_skbmod *d = a->priv;
+ struct tc_skbmod opt = {
+ .index = d->tcf_index,
+ .refcnt = d->tcf_refcnt - ref,
+ .bindcnt = d->tcf_bindcnt - bind,
+ .action = d->tcf_action,
+ };
+ struct tcf_t t;
+
+ if (nla_put(skb, TCA_SKBMOD_PARMS, sizeof(opt), &opt))
+ goto nla_put_failure;
+ if ((d->flags & SKBMOD_F_DMAC) &&
+ nla_put(skb, TCA_SKBMOD_DMAC, ETH_ALEN, m->eth_dst))
+ goto nla_put_failure;
+
+ tcf_tm_dump(&t, &d->tcf_tm);
+ if (nla_put_64bit(skb, TCA_SKBMOD_TM, sizeof(t), &t, TCA_SKBMOD_PAD))
+ goto nla_put_failure;
+ return skb->len;
+
+nla_put_failure:
+ nlmsg_trim(skb, b);
+ return -1;
+}
+
+static int tcf_skbmod_walker(struct net *net, struct sk_buff *skb,
+ struct netlink_callback *cb, int type,
+ struct tc_action *a)
+{
+ struct tc_action_net *tn = net_generic(net, skbmod_net_id);
+
+ return tcf_generic_walker(tn, skb, cb, type, a);
+}
+
+static int tcf_skbmod_search(struct net *net, struct tc_action *a, u32 index)
+{
+ struct tc_action_net *tn = net_generic(net, skbmod_net_id);
+
+ return tcf_hash_search(tn, a, index);
+}
+
+static struct tc_action_ops act_skbmod_ops = {
+ .kind = "skbmod",
+ .type = TCA_ACT_SKBMOD,
+ .owner = THIS_MODULE,
+ .act = tcf_skbmod_run,
+ .dump = tcf_skbmod_dump,
+ .init = tcf_skbmod_init,
+ .walk = tcf_skbmod_walker,
+ .lookup = tcf_skbmod_search,
+};
+
+static __net_init int skbmod_init_net(struct net *net)
+{
+ struct tc_action_net *tn = net_generic(net, skbmod_net_id);
+
+ return tc_action_net_init(tn, &act_skbmod_ops, SKBMOD_TAB_MASK);
+}
+
+static void __net_exit skbmod_exit_net(struct net *net)
+{
+ struct tc_action_net *tn = net_generic(net, skbmod_net_id);
+
+ tc_action_net_exit(tn);
+}
+
+static struct pernet_operations skbmod_net_ops = {
+ .init = skbmod_init_net,
+ .exit = skbmod_exit_net,
+ .id = &skbmod_net_id,
+ .size = sizeof(struct tc_action_net),
+};
+
+MODULE_AUTHOR("Jamal Hadi Salim, <j...@mojatatu.com>");
+MODULE_DESCRIPTION("SKB mod-ing");
+MODULE_LICENSE("GPL");
+
+static int __init skbmod_init_module(void)
+{
+ return tcf_register_action(&act_skbmod_ops, &skbmod_net_ops);
+}
+
+static void __exit skbmod_cleanup_module(void)
+{
+ tcf_unregister_action(&act_skbmod_ops, &skbmod_net_ops);
+}
+
+module_init(skbmod_init_module);
+module_exit(skbmod_cleanup_module);
--
1.9.1
