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-rw-r--r--include/net/tc_act/tc_skbmod.h30
-rw-r--r--include/uapi/linux/tc_act/tc_skbmod.h39
-rw-r--r--net/sched/Kconfig11
-rw-r--r--net/sched/Makefile1
-rw-r--r--net/sched/act_skbmod.c301
5 files changed, 382 insertions, 0 deletions
diff --git a/include/net/tc_act/tc_skbmod.h b/include/net/tc_act/tc_skbmod.h
new file mode 100644
index 000000000000..644a2116b47b
--- /dev/null
+++ b/include/net/tc_act/tc_skbmod.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2016, Jamal Hadi Salim
+ *
+ * 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 __NET_TC_SKBMOD_H
+#define __NET_TC_SKBMOD_H
+
+#include <net/act_api.h>
+#include <linux/tc_act/tc_skbmod.h>
+
+struct tcf_skbmod_params {
+	struct rcu_head	rcu;
+	u64	flags; /*up to 64 types of operations; extend if needed */
+	u8	eth_dst[ETH_ALEN];
+	u16	eth_type;
+	u8	eth_src[ETH_ALEN];
+};
+
+struct tcf_skbmod {
+	struct tc_action	common;
+	struct tcf_skbmod_params __rcu *skbmod_p;
+};
+#define to_skbmod(a) ((struct tcf_skbmod *)a)
+
+#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 000000000000..10fc07da6c69
--- /dev/null
+++ b/include/uapi/linux/tc_act/tc_skbmod.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2016, Jamal Hadi Salim
+ *
+ * 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_SKBMOD_H
+#define __LINUX_TC_SKBMOD_H
+
+#include <linux/pkt_cls.h>
+
+#define TCA_ACT_SKBMOD 15
+
+#define SKBMOD_F_DMAC	0x1
+#define SKBMOD_F_SMAC	0x2
+#define SKBMOD_F_ETYPE	0x4
+#define SKBMOD_F_SWAPMAC 0x8
+
+struct tc_skbmod {
+	tc_gen;
+	__u64 flags;
+};
+
+enum {
+	TCA_SKBMOD_UNSPEC,
+	TCA_SKBMOD_TM,
+	TCA_SKBMOD_PARMS,
+	TCA_SKBMOD_DMAC,
+	TCA_SKBMOD_SMAC,
+	TCA_SKBMOD_ETYPE,
+	TCA_SKBMOD_PAD,
+	__TCA_SKBMOD_MAX
+};
+#define TCA_SKBMOD_MAX (__TCA_SKBMOD_MAX - 1)
+
+#endif
diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index 72e3426fa48f..7795d5a3f79a 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -749,6 +749,17 @@ config NET_ACT_CONNMARK
 	  To compile this code as a module, choose M here: the
 	  module will be called act_connmark.
 
+config NET_ACT_SKBMOD
+        tristate "skb data modification action"
+        depends on NET_CLS_ACT
+        ---help---
+         Say Y here to allow modification of skb data
+
+         If unsure, say N.
+
+         To compile this code as a module, choose M here: the
+         module will be called act_skbmod.
+
 config NET_ACT_IFE
         tristate "Inter-FE action based on IETF ForCES InterFE LFB"
         depends on NET_CLS_ACT
diff --git a/net/sched/Makefile b/net/sched/Makefile
index b9d046b9535a..148ae0d5ac2c 100644
--- a/net/sched/Makefile
+++ b/net/sched/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_NET_ACT_CSUM)	+= act_csum.o
 obj-$(CONFIG_NET_ACT_VLAN)	+= act_vlan.o
 obj-$(CONFIG_NET_ACT_BPF)	+= act_bpf.o
 obj-$(CONFIG_NET_ACT_CONNMARK)	+= act_connmark.o
+obj-$(CONFIG_NET_ACT_SKBMOD)	+= act_skbmod.o
 obj-$(CONFIG_NET_ACT_IFE)	+= act_ife.o
 obj-$(CONFIG_NET_IFE_SKBMARK)	+= act_meta_mark.o
 obj-$(CONFIG_NET_IFE_SKBPRIO)	+= act_meta_skbprio.o
diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c
new file mode 100644
index 000000000000..e7d96381c908
--- /dev/null
+++ b/net/sched/act_skbmod.c
@@ -0,0 +1,301 @@
+/*
+ * net/sched/act_skbmod.c  skb data modifier
+ *
+ * Copyright (c) 2016 Jamal Hadi Salim <jhs@mojatatu.com>
+ *
+ * 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.
+*/
+
+#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 struct tc_action_ops act_skbmod_ops;
+
+#define MAX_EDIT_LEN ETH_HLEN
+static int tcf_skbmod_run(struct sk_buff *skb, const struct tc_action *a,
+			  struct tcf_result *res)
+{
+	struct tcf_skbmod *d = to_skbmod(a);
+	int action;
+	struct tcf_skbmod_params *p;
+	u64 flags;
+	int err;
+
+	tcf_lastuse_update(&d->tcf_tm);
+	bstats_cpu_update(this_cpu_ptr(d->common.cpu_bstats), skb);
+
+	/* XXX: if you are going to edit more fields beyond ethernet header
+	 * (example when you add IP header replacement or vlan swap)
+	 * then MAX_EDIT_LEN needs to change appropriately
+	*/
+	err = skb_ensure_writable(skb, MAX_EDIT_LEN);
+	if (unlikely(err)) { /* best policy is to drop on the floor */
+		qstats_overlimit_inc(this_cpu_ptr(d->common.cpu_qstats));
+		return TC_ACT_SHOT;
+	}
+
+	rcu_read_lock();
+	action = READ_ONCE(d->tcf_action);
+	if (unlikely(action == TC_ACT_SHOT)) {
+		qstats_overlimit_inc(this_cpu_ptr(d->common.cpu_qstats));
+		rcu_read_unlock();
+		return action;
+	}
+
+	p = rcu_dereference(d->skbmod_p);
+	flags = p->flags;
+	if (flags & SKBMOD_F_DMAC)
+		ether_addr_copy(eth_hdr(skb)->h_dest, p->eth_dst);
+	if (flags & SKBMOD_F_SMAC)
+		ether_addr_copy(eth_hdr(skb)->h_source, p->eth_src);
+	if (flags & SKBMOD_F_ETYPE)
+		eth_hdr(skb)->h_proto = p->eth_type;
+	rcu_read_unlock();
+
+	if (flags & SKBMOD_F_SWAPMAC) {
+		u16 tmpaddr[ETH_ALEN / 2]; /* ether_addr_copy() requirement */
+		/*XXX: I am sure we can come up with more efficient swapping*/
+		ether_addr_copy((u8 *)tmpaddr, eth_hdr(skb)->h_dest);
+		ether_addr_copy(eth_hdr(skb)->h_dest, eth_hdr(skb)->h_source);
+		ether_addr_copy(eth_hdr(skb)->h_source, (u8 *)tmpaddr);
+	}
+
+	return 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 },
+	[TCA_SKBMOD_SMAC]		= { .len = ETH_ALEN },
+	[TCA_SKBMOD_ETYPE]		= { .type = NLA_U16 },
+};
+
+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 tcf_skbmod_params *p, *p_old;
+	struct tc_skbmod *parm;
+	struct tcf_skbmod *d;
+	bool exists = false;
+	u8 *daddr = NULL;
+	u8 *saddr = NULL;
+	u16 eth_type = 0;
+	u32 lflags = 0;
+	int ret = 0, err;
+
+	if (!nla)
+		return -EINVAL;
+
+	err = nla_parse_nested(tb, TCA_SKBMOD_MAX, nla, skbmod_policy);
+	if (err < 0)
+		return err;
+
+	if (!tb[TCA_SKBMOD_PARMS])
+		return -EINVAL;
+
+	if (tb[TCA_SKBMOD_DMAC]) {
+		daddr = nla_data(tb[TCA_SKBMOD_DMAC]);
+		lflags |= SKBMOD_F_DMAC;
+	}
+
+	if (tb[TCA_SKBMOD_SMAC]) {
+		saddr = nla_data(tb[TCA_SKBMOD_SMAC]);
+		lflags |= SKBMOD_F_SMAC;
+	}
+
+	if (tb[TCA_SKBMOD_ETYPE]) {
+		eth_type = nla_get_u16(tb[TCA_SKBMOD_ETYPE]);
+		lflags |= SKBMOD_F_ETYPE;
+	}
+
+	parm = nla_data(tb[TCA_SKBMOD_PARMS]);
+	if (parm->flags & SKBMOD_F_SWAPMAC)
+		lflags = SKBMOD_F_SWAPMAC;
+
+	exists = tcf_hash_check(tn, parm->index, a, bind);
+	if (exists && bind)
+		return 0;
+
+	if (!lflags)
+		return -EINVAL;
+
+	if (!exists) {
+		ret = tcf_hash_create(tn, parm->index, est, a,
+				      &act_skbmod_ops, bind, true);
+		if (ret)
+			return ret;
+
+		ret = ACT_P_CREATED;
+	} else {
+		tcf_hash_release(*a, bind);
+		if (!ovr)
+			return -EEXIST;
+	}
+
+	d = to_skbmod(*a);
+
+	ASSERT_RTNL();
+	p = kzalloc(sizeof(struct tcf_skbmod_params), GFP_KERNEL);
+	if (unlikely(!p)) {
+		if (ovr)
+			tcf_hash_release(*a, bind);
+		return -ENOMEM;
+	}
+
+	p->flags = lflags;
+	d->tcf_action = parm->action;
+
+	p_old = rtnl_dereference(d->skbmod_p);
+
+	if (ovr)
+		spin_lock_bh(&d->tcf_lock);
+
+	if (lflags & SKBMOD_F_DMAC)
+		ether_addr_copy(p->eth_dst, daddr);
+	if (lflags & SKBMOD_F_SMAC)
+		ether_addr_copy(p->eth_src, saddr);
+	if (lflags & SKBMOD_F_ETYPE)
+		p->eth_type = htons(eth_type);
+
+	rcu_assign_pointer(d->skbmod_p, p);
+	if (ovr)
+		spin_unlock_bh(&d->tcf_lock);
+
+	if (p_old)
+		kfree_rcu(p_old, rcu);
+
+	if (ret == ACT_P_CREATED)
+		tcf_hash_insert(tn, *a);
+	return ret;
+}
+
+static void tcf_skbmod_cleanup(struct tc_action *a, int bind)
+{
+	struct tcf_skbmod *d = to_skbmod(a);
+	struct tcf_skbmod_params  *p;
+
+	p = rcu_dereference_protected(d->skbmod_p, 1);
+	kfree_rcu(p, rcu);
+}
+
+static int tcf_skbmod_dump(struct sk_buff *skb, struct tc_action *a,
+			   int bind, int ref)
+{
+	struct tcf_skbmod *d = to_skbmod(a);
+	unsigned char *b = skb_tail_pointer(skb);
+	struct tcf_skbmod_params  *p = rtnl_dereference(d->skbmod_p);
+	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;
+
+	opt.flags  = p->flags;
+	if (nla_put(skb, TCA_SKBMOD_PARMS, sizeof(opt), &opt))
+		goto nla_put_failure;
+	if ((p->flags & SKBMOD_F_DMAC) &&
+	    nla_put(skb, TCA_SKBMOD_DMAC, ETH_ALEN, p->eth_dst))
+		goto nla_put_failure;
+	if ((p->flags & SKBMOD_F_SMAC) &&
+	    nla_put(skb, TCA_SKBMOD_SMAC, ETH_ALEN, p->eth_src))
+		goto nla_put_failure;
+	if ((p->flags & SKBMOD_F_ETYPE) &&
+	    nla_put_u16(skb, TCA_SKBMOD_ETYPE, ntohs(p->eth_type)))
+		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:
+	rcu_read_unlock();
+	nlmsg_trim(skb, b);
+	return -1;
+}
+
+static int tcf_skbmod_walker(struct net *net, struct sk_buff *skb,
+			     struct netlink_callback *cb, int type,
+			     const struct tc_action_ops *ops)
+{
+	struct tc_action_net *tn = net_generic(net, skbmod_net_id);
+
+	return tcf_generic_walker(tn, skb, cb, type, ops);
+}
+
+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,
+	.cleanup	=	tcf_skbmod_cleanup,
+	.walk		=	tcf_skbmod_walker,
+	.lookup		=	tcf_skbmod_search,
+	.size		=	sizeof(struct tcf_skbmod),
+};
+
+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, <jhs@mojatatu.com>");
+MODULE_DESCRIPTION("SKB data 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);
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-10-17 19:31:52 +0000