net/sched/act_pedit.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * net/sched/act_pedit.c	Generic packet editor
  *
  * Authors:	Jamal Hadi Salim (2002-4)
  */

 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/errno.h>
 #include <linux/skbuff.h>
 #include <linux/rtnetlink.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <net/netlink.h>
 #include <net/pkt_sched.h>
 #include <linux/tc_act/tc_pedit.h>
 #include <net/tc_act/tc_pedit.h>
 #include <uapi/linux/tc_act/tc_pedit.h>
 #include <net/pkt_cls.h>
 #include <net/tc_wrapper.h>

 static struct tc_action_ops act_pedit_ops;

 static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = {
 	[TCA_PEDIT_PARMS]	= { .len = sizeof(struct tc_pedit) },
 	[TCA_PEDIT_KEYS_EX]   = { .type = NLA_NESTED },
 };

 static const struct nla_policy pedit_key_ex_policy[TCA_PEDIT_KEY_EX_MAX + 1] = {
 	[TCA_PEDIT_KEY_EX_HTYPE] =
 		NLA_POLICY_MAX(NLA_U16, TCA_PEDIT_HDR_TYPE_MAX),
 	[TCA_PEDIT_KEY_EX_CMD] = NLA_POLICY_MAX(NLA_U16, TCA_PEDIT_CMD_MAX),
 };

 static struct tcf_pedit_key_ex *tcf_pedit_keys_ex_parse(struct nlattr *nla,
 							u8 n, struct netlink_ext_ack *extack)
 {
 	struct tcf_pedit_key_ex *keys_ex;
 	struct tcf_pedit_key_ex *k;
 	const struct nlattr *ka;
 	int err = -EINVAL;
 	int rem;

 	if (!nla)
 		return NULL;

 	keys_ex = kcalloc(n, sizeof(*k), GFP_KERNEL);
 	if (!keys_ex)
 		return ERR_PTR(-ENOMEM);

 	k = keys_ex;

 	nla_for_each_nested(ka, nla, rem) {
 		struct nlattr *tb[TCA_PEDIT_KEY_EX_MAX + 1];

 		if (!n) {
 			NL_SET_ERR_MSG_MOD(extack, "Can't parse more extended keys than requested");
 			err = -EINVAL;
 			goto err_out;
 		}
 		n--;

 		if (nla_type(ka) != TCA_PEDIT_KEY_EX) {
 			NL_SET_ERR_MSG_ATTR(extack, ka, "Unknown attribute, expected extended key");
 			err = -EINVAL;
 			goto err_out;
 		}

 		err = nla_parse_nested_deprecated(tb, TCA_PEDIT_KEY_EX_MAX,
 						  ka, pedit_key_ex_policy,
 						  NULL);
 		if (err)
 			goto err_out;

 		if (NL_REQ_ATTR_CHECK(extack, nla, tb, TCA_PEDIT_KEY_EX_HTYPE)) {
 			NL_SET_ERR_MSG(extack, "Missing required attribute");
 			err = -EINVAL;
 			goto err_out;
 		}

 		if (NL_REQ_ATTR_CHECK(extack, nla, tb, TCA_PEDIT_KEY_EX_CMD)) {
 			NL_SET_ERR_MSG(extack, "Missing required attribute");
 			err = -EINVAL;
 			goto err_out;
 		}

 		k->htype = nla_get_u16(tb[TCA_PEDIT_KEY_EX_HTYPE]);
 		k->cmd = nla_get_u16(tb[TCA_PEDIT_KEY_EX_CMD]);

 		k++;
 	}

 	if (n) {
 		NL_SET_ERR_MSG_MOD(extack, "Not enough extended keys to parse");
 		err = -EINVAL;
 		goto err_out;
 	}

 	return keys_ex;

 err_out:
 	kfree(keys_ex);
 	return ERR_PTR(err);
 }

 static int tcf_pedit_key_ex_dump(struct sk_buff *skb,
 				 struct tcf_pedit_key_ex *keys_ex, int n)
 {
 	struct nlattr *keys_start = nla_nest_start_noflag(skb,
 							  TCA_PEDIT_KEYS_EX);

 	if (!keys_start)
 		goto nla_failure;
 	for (; n > 0; n--) {
 		struct nlattr *key_start;

 		key_start = nla_nest_start_noflag(skb, TCA_PEDIT_KEY_EX);
 		if (!key_start)
 			goto nla_failure;

 		if (nla_put_u16(skb, TCA_PEDIT_KEY_EX_HTYPE, keys_ex->htype) ||
 		    nla_put_u16(skb, TCA_PEDIT_KEY_EX_CMD, keys_ex->cmd))
 			goto nla_failure;

 		nla_nest_end(skb, key_start);

 		keys_ex++;
 	}

 	nla_nest_end(skb, keys_start);

 	return 0;
 nla_failure:
 	nla_nest_cancel(skb, keys_start);
 	return -EINVAL;
 }

 static void tcf_pedit_cleanup_rcu(struct rcu_head *head)
 {
 	struct tcf_pedit_parms *parms =
 		container_of(head, struct tcf_pedit_parms, rcu);

 	kfree(parms->tcfp_keys_ex);
 	kfree(parms->tcfp_keys);

 	kfree(parms);
 }

 static int tcf_pedit_init(struct net *net, struct nlattr *nla,
 			  struct nlattr *est, struct tc_action **a,
 			  struct tcf_proto *tp, u32 flags,
 			  struct netlink_ext_ack *extack)
 {
 	struct tc_action_net *tn = net_generic(net, act_pedit_ops.net_id);
 	bool bind = flags & TCA_ACT_FLAGS_BIND;
 	struct tcf_chain *goto_ch = NULL;
 	struct tcf_pedit_parms *oparms, *nparms;
 	struct nlattr *tb[TCA_PEDIT_MAX + 1];
 	struct tc_pedit *parm;
 	struct nlattr *pattr;
 	struct tcf_pedit *p;
 	int ret = 0, err;
 	int i, ksize;
 	u32 index;

 	if (!nla) {
 		NL_SET_ERR_MSG_MOD(extack, "Pedit requires attributes to be passed");
 		return -EINVAL;
 	}

 	err = nla_parse_nested_deprecated(tb, TCA_PEDIT_MAX, nla,
 					  pedit_policy, NULL);
 	if (err < 0)
 		return err;

 	pattr = tb[TCA_PEDIT_PARMS];
 	if (!pattr)
 		pattr = tb[TCA_PEDIT_PARMS_EX];
 	if (!pattr) {
 		NL_SET_ERR_MSG_MOD(extack, "Missing required TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute");
 		return -EINVAL;
 	}

 	parm = nla_data(pattr);

 	index = parm->index;
 	err = tcf_idr_check_alloc(tn, &index, a, bind);
 	if (!err) {
 		ret = tcf_idr_create_from_flags(tn, index, est, a,
 						&act_pedit_ops, bind, flags);
 		if (ret) {
 			tcf_idr_cleanup(tn, index);
 			return ret;
 		}
 		ret = ACT_P_CREATED;
 	} else if (err > 0) {
 		if (bind)
 			return 0;
 		if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
 			ret = -EEXIST;
 			goto out_release;
 		}
 	} else {
 		return err;
 	}

 	if (!parm->nkeys) {
 		NL_SET_ERR_MSG_MOD(extack, "Pedit requires keys to be passed");
 		ret = -EINVAL;
 		goto out_release;
 	}
 	ksize = parm->nkeys * sizeof(struct tc_pedit_key);
 	if (nla_len(pattr) < sizeof(*parm) + ksize) {
 		NL_SET_ERR_MSG_ATTR(extack, pattr, "Length of TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute is invalid");
 		ret = -EINVAL;
 		goto out_release;
 	}

 	nparms = kzalloc(sizeof(*nparms), GFP_KERNEL);
 	if (!nparms) {
 		ret = -ENOMEM;
 		goto out_release;
 	}

 	nparms->tcfp_keys_ex =
 		tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys, extack);
 	if (IS_ERR(nparms->tcfp_keys_ex)) {
 		ret = PTR_ERR(nparms->tcfp_keys_ex);
 		goto out_free;
 	}

 	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
 	if (err < 0) {
 		ret = err;
 		goto out_free_ex;
 	}

 	nparms->tcfp_off_max_hint = 0;
 	nparms->tcfp_flags = parm->flags;
 	nparms->tcfp_nkeys = parm->nkeys;

 	nparms->tcfp_keys = kmalloc(ksize, GFP_KERNEL);
 	if (!nparms->tcfp_keys) {
 		ret = -ENOMEM;
 		goto put_chain;
 	}

 	memcpy(nparms->tcfp_keys, parm->keys, ksize);

 	for (i = 0; i < nparms->tcfp_nkeys; ++i) {
 		u32 offmask = nparms->tcfp_keys[i].offmask;
 		u32 cur = nparms->tcfp_keys[i].off;

 		/* The AT option can be added to static offsets in the datapath */
 		if (!offmask && cur % 4) {
 			NL_SET_ERR_MSG_MOD(extack, "Offsets must be on 32bit boundaries");
 			ret = -EINVAL;
 			goto put_chain;
 		}

 		/* sanitize the shift value for any later use */
 		nparms->tcfp_keys[i].shift = min_t(size_t,
 						   BITS_PER_TYPE(int) - 1,
 						   nparms->tcfp_keys[i].shift);

 		/* The AT option can read a single byte, we can bound the actual
 		 * value with uchar max.
 		 */
 		cur += (0xff & offmask) >> nparms->tcfp_keys[i].shift;

 		/* Each key touches 4 bytes starting from the computed offset */
 		nparms->tcfp_off_max_hint =
 			max(nparms->tcfp_off_max_hint, cur + 4);
 	}

 	p = to_pedit(*a);

 	spin_lock_bh(&p->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	oparms = rcu_replace_pointer(p->parms, nparms, 1);
 	spin_unlock_bh(&p->tcf_lock);

 	if (oparms)
 		call_rcu(&oparms->rcu, tcf_pedit_cleanup_rcu);

 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);

 	return ret;

 put_chain:
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);
 out_free_ex:
 	kfree(nparms->tcfp_keys_ex);
 out_free:
 	kfree(nparms);
 out_release:
 	tcf_idr_release(*a, bind);
 	return ret;
 }

 static void tcf_pedit_cleanup(struct tc_action *a)
 {
 	struct tcf_pedit *p = to_pedit(a);
 	struct tcf_pedit_parms *parms;

 	parms = rcu_dereference_protected(p->parms, 1);

 	if (parms)
 		call_rcu(&parms->rcu, tcf_pedit_cleanup_rcu);
 }

 static bool offset_valid(struct sk_buff *skb, int offset)
 {
 	if (offset > 0 && offset > skb->len)
 		return false;

 	if  (offset < 0 && -offset > skb_headroom(skb))
 		return false;

 	return true;
 }

 static void pedit_skb_hdr_offset(struct sk_buff *skb,
 				 enum pedit_header_type htype, int *hoffset)
 {
 	/* 'htype' is validated in the netlink parsing */
 	switch (htype) {
 	case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH:
 		if (skb_mac_header_was_set(skb))
 			*hoffset = skb_mac_offset(skb);
 		break;
 	case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK:
 	case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4:
 	case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6:
 		*hoffset = skb_network_offset(skb);
 		break;
 	case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP:
 	case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP:
 		if (skb_transport_header_was_set(skb))
 			*hoffset = skb_transport_offset(skb);
 		break;
 	default:
 		break;
 	}
 }

 TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
 				    const struct tc_action *a,
 				    struct tcf_result *res)
 {
 	enum pedit_header_type htype = TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK;
 	enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET;
 	struct tcf_pedit *p = to_pedit(a);
 	struct tcf_pedit_key_ex *tkey_ex;
 	struct tcf_pedit_parms *parms;
 	struct tc_pedit_key *tkey;
 	u32 max_offset;
 	int i;

 	parms = rcu_dereference_bh(p->parms);

 	max_offset = (skb_transport_header_was_set(skb) ?
 		      skb_transport_offset(skb) :
 		      skb_network_offset(skb)) +
 		     parms->tcfp_off_max_hint;
 	if (skb_ensure_writable(skb, min(skb->len, max_offset)))
 		goto done;

 	tcf_lastuse_update(&p->tcf_tm);
 	tcf_action_update_bstats(&p->common, skb);

 	tkey = parms->tcfp_keys;
 	tkey_ex = parms->tcfp_keys_ex;

 	for (i = parms->tcfp_nkeys; i > 0; i--, tkey++) {
 		int offset = tkey->off;
 		int hoffset = 0;
 		u32 *ptr, hdata;
 		u32 val;

 		if (tkey_ex) {
 			htype = tkey_ex->htype;
 			cmd = tkey_ex->cmd;

 			tkey_ex++;
 		}

 		pedit_skb_hdr_offset(skb, htype, &hoffset);

 		if (tkey->offmask) {
 			u8 *d, _d;

 			if (!offset_valid(skb, hoffset + tkey->at)) {
 				pr_info_ratelimited("tc action pedit 'at' offset %d out of bounds\n",
 						    hoffset + tkey->at);
 				goto bad;
 			}
 			d = skb_header_pointer(skb, hoffset + tkey->at,
 					       sizeof(_d), &_d);
 			if (!d)
 				goto bad;

 			offset += (*d & tkey->offmask) >> tkey->shift;
 			if (offset % 4) {
 				pr_info_ratelimited("tc action pedit offset must be on 32 bit boundaries\n");
 				goto bad;
 			}
 		}

 		if (!offset_valid(skb, hoffset + offset)) {
 			pr_info_ratelimited("tc action pedit offset %d out of bounds\n", hoffset + offset);
 			goto bad;
 		}

 		ptr = skb_header_pointer(skb, hoffset + offset,
 					 sizeof(hdata), &hdata);
 		if (!ptr)
 			goto bad;
 		/* just do it, baby */
 		switch (cmd) {
 		case TCA_PEDIT_KEY_EX_CMD_SET:
 			val = tkey->val;
 			break;
 		case TCA_PEDIT_KEY_EX_CMD_ADD:
 			val = (*ptr + tkey->val) & ~tkey->mask;
 			break;
 		default:
 			pr_info_ratelimited("tc action pedit bad command (%d)\n", cmd);
 			goto bad;
 		}

 		*ptr = ((*ptr & tkey->mask) ^ val);
 		if (ptr == &hdata)
 			skb_store_bits(skb, hoffset + offset, ptr, 4);
 	}

 	goto done;

 bad:
 	tcf_action_inc_overlimit_qstats(&p->common);
 done:
 	return p->tcf_action;
 }

 static void tcf_pedit_stats_update(struct tc_action *a, u64 bytes, u64 packets,
 				   u64 drops, u64 lastuse, bool hw)
 {
 	struct tcf_pedit *d = to_pedit(a);
 	struct tcf_t *tm = &d->tcf_tm;

 	tcf_action_update_stats(a, bytes, packets, drops, hw);
 	tm->lastuse = max_t(u64, tm->lastuse, lastuse);
 }

 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
 			  int bind, int ref)
 {
 	unsigned char *b = skb_tail_pointer(skb);
 	struct tcf_pedit *p = to_pedit(a);
 	struct tcf_pedit_parms *parms;
 	struct tc_pedit *opt;
 	struct tcf_t t;
 	int s;

 	spin_lock_bh(&p->tcf_lock);
 	parms = rcu_dereference_protected(p->parms, 1);
 	s = struct_size(opt, keys, parms->tcfp_nkeys);

 	opt = kzalloc(s, GFP_ATOMIC);
 	if (unlikely(!opt)) {
 		spin_unlock_bh(&p->tcf_lock);
 		return -ENOBUFS;
 	}

 	memcpy(opt->keys, parms->tcfp_keys,
 	       flex_array_size(opt, keys, parms->tcfp_nkeys));
 	opt->index = p->tcf_index;
 	opt->nkeys = parms->tcfp_nkeys;
 	opt->flags = parms->tcfp_flags;
 	opt->action = p->tcf_action;
 	opt->refcnt = refcount_read(&p->tcf_refcnt) - ref;
 	opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind;

 	if (parms->tcfp_keys_ex) {
 		if (tcf_pedit_key_ex_dump(skb, parms->tcfp_keys_ex,
 					  parms->tcfp_nkeys))
 			goto nla_put_failure;

 		if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt))
 			goto nla_put_failure;
 	} else {
 		if (nla_put(skb, TCA_PEDIT_PARMS, s, opt))
 			goto nla_put_failure;
 	}

 	tcf_tm_dump(&t, &p->tcf_tm);
 	if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD))
 		goto nla_put_failure;
 	spin_unlock_bh(&p->tcf_lock);

 	kfree(opt);
 	return skb->len;

 nla_put_failure:
 	spin_unlock_bh(&p->tcf_lock);
 	nlmsg_trim(skb, b);
 	kfree(opt);
 	return -1;
 }

 static int tcf_pedit_offload_act_setup(struct tc_action *act, void *entry_data,
 				       u32 *index_inc, bool bind,
 				       struct netlink_ext_ack *extack)
 {
 	if (bind) {
 		struct flow_action_entry *entry = entry_data;
 		int k;

 		for (k = 0; k < tcf_pedit_nkeys(act); k++) {
 			switch (tcf_pedit_cmd(act, k)) {
 			case TCA_PEDIT_KEY_EX_CMD_SET:
 				entry->id = FLOW_ACTION_MANGLE;
 				break;
 			case TCA_PEDIT_KEY_EX_CMD_ADD:
 				entry->id = FLOW_ACTION_ADD;
 				break;
 			default:
 				NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload");
 				return -EOPNOTSUPP;
 			}
 			entry->mangle.htype = tcf_pedit_htype(act, k);
 			entry->mangle.mask = tcf_pedit_mask(act, k);
 			entry->mangle.val = tcf_pedit_val(act, k);
 			entry->mangle.offset = tcf_pedit_offset(act, k);
 			entry->hw_stats = tc_act_hw_stats(act->hw_stats);
 			entry++;
 		}
 		*index_inc = k;
 	} else {
 		struct flow_offload_action *fl_action = entry_data;
 		u32 cmd = tcf_pedit_cmd(act, 0);
 		int k;

 		switch (cmd) {
 		case TCA_PEDIT_KEY_EX_CMD_SET:
 			fl_action->id = FLOW_ACTION_MANGLE;
 			break;
 		case TCA_PEDIT_KEY_EX_CMD_ADD:
 			fl_action->id = FLOW_ACTION_ADD;
 			break;
 		default:
 			NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload");
 			return -EOPNOTSUPP;
 		}

 		for (k = 1; k < tcf_pedit_nkeys(act); k++) {
 			if (cmd != tcf_pedit_cmd(act, k)) {
 				NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload");
 				return -EOPNOTSUPP;
 			}
 		}
 	}

 	return 0;
 }

 static struct tc_action_ops act_pedit_ops = {
 	.kind		=	"pedit",
 	.id		=	TCA_ID_PEDIT,
 	.owner		=	THIS_MODULE,
 	.act		=	tcf_pedit_act,
 	.stats_update	=	tcf_pedit_stats_update,
 	.dump		=	tcf_pedit_dump,
 	.cleanup	=	tcf_pedit_cleanup,
 	.init		=	tcf_pedit_init,
 	.offload_act_setup =	tcf_pedit_offload_act_setup,
 	.size		=	sizeof(struct tcf_pedit),
 };

 static __net_init int pedit_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, act_pedit_ops.net_id);

 	return tc_action_net_init(net, tn, &act_pedit_ops);
 }

 static void __net_exit pedit_exit_net(struct list_head *net_list)
 {
 	tc_action_net_exit(net_list, act_pedit_ops.net_id);
 }

 static struct pernet_operations pedit_net_ops = {
 	.init = pedit_init_net,
 	.exit_batch = pedit_exit_net,
 	.id   = &act_pedit_ops.net_id,
 	.size = sizeof(struct tc_action_net),
 };

 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
 MODULE_DESCRIPTION("Generic Packet Editor actions");
 MODULE_LICENSE("GPL");

 static int __init pedit_init_module(void)
 {
 	return tcf_register_action(&act_pedit_ops, &pedit_net_ops);
 }

 static void __exit pedit_cleanup_module(void)
 {
 	tcf_unregister_action(&act_pedit_ops, &pedit_net_ops);
 }

 module_init(pedit_init_module);
 module_exit(pedit_cleanup_module);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* net/sched/act_pedit.c Generic packet editor
	*
	* Authors: Jamal Hadi Salim (2002-4)
	*/

	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/string.h>
	#include <linux/errno.h>
	#include <linux/skbuff.h>
	#include <linux/rtnetlink.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/slab.h>
	#include <net/netlink.h>
	#include <net/pkt_sched.h>
	#include <linux/tc_act/tc_pedit.h>
	#include <net/tc_act/tc_pedit.h>
	#include <uapi/linux/tc_act/tc_pedit.h>
	#include <net/pkt_cls.h>
	#include <net/tc_wrapper.h>

	static struct tc_action_ops act_pedit_ops;

	static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = {
	[TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) },
	[TCA_PEDIT_KEYS_EX] = { .type = NLA_NESTED },
	};

	static const struct nla_policy pedit_key_ex_policy[TCA_PEDIT_KEY_EX_MAX + 1] = {
	[TCA_PEDIT_KEY_EX_HTYPE] =
	NLA_POLICY_MAX(NLA_U16, TCA_PEDIT_HDR_TYPE_MAX),
	[TCA_PEDIT_KEY_EX_CMD] = NLA_POLICY_MAX(NLA_U16, TCA_PEDIT_CMD_MAX),
	};

	static struct tcf_pedit_key_ex tcf_pedit_keys_ex_parse(struct nlattr nla,
	u8 n, struct netlink_ext_ack *extack)
	{
	struct tcf_pedit_key_ex *keys_ex;
	struct tcf_pedit_key_ex *k;
	const struct nlattr *ka;
	int err = -EINVAL;
	int rem;

	if (!nla)
	return NULL;

	keys_ex = kcalloc(n, sizeof(*k), GFP_KERNEL);
	if (!keys_ex)
	return ERR_PTR(-ENOMEM);

	k = keys_ex;

	nla_for_each_nested(ka, nla, rem) {
	struct nlattr *tb[TCA_PEDIT_KEY_EX_MAX + 1];

	if (!n) {
	NL_SET_ERR_MSG_MOD(extack, "Can't parse more extended keys than requested");
	err = -EINVAL;
	goto err_out;
	}
	n--;

	if (nla_type(ka) != TCA_PEDIT_KEY_EX) {
	NL_SET_ERR_MSG_ATTR(extack, ka, "Unknown attribute, expected extended key");
	err = -EINVAL;
	goto err_out;
	}

	err = nla_parse_nested_deprecated(tb, TCA_PEDIT_KEY_EX_MAX,
	ka, pedit_key_ex_policy,
	NULL);
	if (err)
	goto err_out;

	if (NL_REQ_ATTR_CHECK(extack, nla, tb, TCA_PEDIT_KEY_EX_HTYPE)) {
	NL_SET_ERR_MSG(extack, "Missing required attribute");
	err = -EINVAL;
	goto err_out;
	}

	if (NL_REQ_ATTR_CHECK(extack, nla, tb, TCA_PEDIT_KEY_EX_CMD)) {
	NL_SET_ERR_MSG(extack, "Missing required attribute");
	err = -EINVAL;
	goto err_out;
	}

	k->htype = nla_get_u16(tb[TCA_PEDIT_KEY_EX_HTYPE]);
	k->cmd = nla_get_u16(tb[TCA_PEDIT_KEY_EX_CMD]);

	k++;
	}

	if (n) {
	NL_SET_ERR_MSG_MOD(extack, "Not enough extended keys to parse");
	err = -EINVAL;
	goto err_out;
	}

	return keys_ex;

	err_out:
	kfree(keys_ex);
	return ERR_PTR(err);
	}

	static int tcf_pedit_key_ex_dump(struct sk_buff *skb,
	struct tcf_pedit_key_ex *keys_ex, int n)
	{
	struct nlattr *keys_start = nla_nest_start_noflag(skb,
	TCA_PEDIT_KEYS_EX);

	if (!keys_start)
	goto nla_failure;
	for (; n > 0; n--) {
	struct nlattr *key_start;

	key_start = nla_nest_start_noflag(skb, TCA_PEDIT_KEY_EX);
	if (!key_start)
	goto nla_failure;

	if (nla_put_u16(skb, TCA_PEDIT_KEY_EX_HTYPE, keys_ex->htype) \|\|
	nla_put_u16(skb, TCA_PEDIT_KEY_EX_CMD, keys_ex->cmd))
	goto nla_failure;

	nla_nest_end(skb, key_start);

	keys_ex++;
	}

	nla_nest_end(skb, keys_start);

	return 0;
	nla_failure:
	nla_nest_cancel(skb, keys_start);
	return -EINVAL;
	}

	static void tcf_pedit_cleanup_rcu(struct rcu_head *head)
	{
	struct tcf_pedit_parms *parms =
	container_of(head, struct tcf_pedit_parms, rcu);

	kfree(parms->tcfp_keys_ex);
	kfree(parms->tcfp_keys);

	kfree(parms);
	}

	static int tcf_pedit_init(struct net net, struct nlattr nla,
	struct nlattr est, struct tc_action *a,
	struct tcf_proto *tp, u32 flags,
	struct netlink_ext_ack *extack)
	{
	struct tc_action_net *tn = net_generic(net, act_pedit_ops.net_id);
	bool bind = flags & TCA_ACT_FLAGS_BIND;
	struct tcf_chain *goto_ch = NULL;
	struct tcf_pedit_parms oparms, nparms;
	struct nlattr *tb[TCA_PEDIT_MAX + 1];
	struct tc_pedit *parm;
	struct nlattr *pattr;
	struct tcf_pedit *p;
	int ret = 0, err;
	int i, ksize;
	u32 index;

	if (!nla) {
	NL_SET_ERR_MSG_MOD(extack, "Pedit requires attributes to be passed");
	return -EINVAL;
	}

	err = nla_parse_nested_deprecated(tb, TCA_PEDIT_MAX, nla,
	pedit_policy, NULL);
	if (err < 0)
	return err;

	pattr = tb[TCA_PEDIT_PARMS];
	if (!pattr)
	pattr = tb[TCA_PEDIT_PARMS_EX];
	if (!pattr) {
	NL_SET_ERR_MSG_MOD(extack, "Missing required TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute");
	return -EINVAL;
	}

	parm = nla_data(pattr);

	index = parm->index;
	err = tcf_idr_check_alloc(tn, &index, a, bind);
	if (!err) {
	ret = tcf_idr_create_from_flags(tn, index, est, a,
	&act_pedit_ops, bind, flags);
	if (ret) {
	tcf_idr_cleanup(tn, index);
	return ret;
	}
	ret = ACT_P_CREATED;
	} else if (err > 0) {
	if (bind)
	return 0;
	if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
	ret = -EEXIST;
	goto out_release;
	}
	} else {
	return err;
	}

	if (!parm->nkeys) {
	NL_SET_ERR_MSG_MOD(extack, "Pedit requires keys to be passed");
	ret = -EINVAL;
	goto out_release;
	}
	ksize = parm->nkeys * sizeof(struct tc_pedit_key);
	if (nla_len(pattr) < sizeof(*parm) + ksize) {
	NL_SET_ERR_MSG_ATTR(extack, pattr, "Length of TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute is invalid");
	ret = -EINVAL;
	goto out_release;
	}

	nparms = kzalloc(sizeof(*nparms), GFP_KERNEL);
	if (!nparms) {
	ret = -ENOMEM;
	goto out_release;
	}

	nparms->tcfp_keys_ex =
	tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys, extack);
	if (IS_ERR(nparms->tcfp_keys_ex)) {
	ret = PTR_ERR(nparms->tcfp_keys_ex);
	goto out_free;
	}

	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
	if (err < 0) {
	ret = err;
	goto out_free_ex;
	}

	nparms->tcfp_off_max_hint = 0;
	nparms->tcfp_flags = parm->flags;
	nparms->tcfp_nkeys = parm->nkeys;

	nparms->tcfp_keys = kmalloc(ksize, GFP_KERNEL);
	if (!nparms->tcfp_keys) {
	ret = -ENOMEM;
	goto put_chain;
	}

	memcpy(nparms->tcfp_keys, parm->keys, ksize);

	for (i = 0; i < nparms->tcfp_nkeys; ++i) {
	u32 offmask = nparms->tcfp_keys[i].offmask;
	u32 cur = nparms->tcfp_keys[i].off;

	/* The AT option can be added to static offsets in the datapath */
	if (!offmask && cur % 4) {
	NL_SET_ERR_MSG_MOD(extack, "Offsets must be on 32bit boundaries");
	ret = -EINVAL;
	goto put_chain;
	}

	/* sanitize the shift value for any later use */
	nparms->tcfp_keys[i].shift = min_t(size_t,
	BITS_PER_TYPE(int) - 1,
	nparms->tcfp_keys[i].shift);

	/* The AT option can read a single byte, we can bound the actual
	* value with uchar max.
	*/
	cur += (0xff & offmask) >> nparms->tcfp_keys[i].shift;

	/* Each key touches 4 bytes starting from the computed offset */
	nparms->tcfp_off_max_hint =
	max(nparms->tcfp_off_max_hint, cur + 4);
	}

	p = to_pedit(*a);

	spin_lock_bh(&p->tcf_lock);
	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
	oparms = rcu_replace_pointer(p->parms, nparms, 1);
	spin_unlock_bh(&p->tcf_lock);

	if (oparms)
	call_rcu(&oparms->rcu, tcf_pedit_cleanup_rcu);

	if (goto_ch)
	tcf_chain_put_by_act(goto_ch);

	return ret;

	put_chain:
	if (goto_ch)
	tcf_chain_put_by_act(goto_ch);
	out_free_ex:
	kfree(nparms->tcfp_keys_ex);
	out_free:
	kfree(nparms);
	out_release:
	tcf_idr_release(*a, bind);
	return ret;
	}

	static void tcf_pedit_cleanup(struct tc_action *a)
	{
	struct tcf_pedit *p = to_pedit(a);
	struct tcf_pedit_parms *parms;

	parms = rcu_dereference_protected(p->parms, 1);

	if (parms)
	call_rcu(&parms->rcu, tcf_pedit_cleanup_rcu);
	}

	static bool offset_valid(struct sk_buff *skb, int offset)
	{
	if (offset > 0 && offset > skb->len)
	return false;

	if (offset < 0 && -offset > skb_headroom(skb))
	return false;

	return true;
	}

	static void pedit_skb_hdr_offset(struct sk_buff *skb,
	enum pedit_header_type htype, int *hoffset)
	{
	/* 'htype' is validated in the netlink parsing */
	switch (htype) {
	case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH:
	if (skb_mac_header_was_set(skb))
	*hoffset = skb_mac_offset(skb);
	break;
	case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK:
	case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4:
	case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6:
	*hoffset = skb_network_offset(skb);
	break;
	case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP:
	case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP:
	if (skb_transport_header_was_set(skb))
	*hoffset = skb_transport_offset(skb);
	break;
	default:
	break;
	}
	}

	TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
	const struct tc_action *a,
	struct tcf_result *res)
	{
	enum pedit_header_type htype = TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK;
	enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET;
	struct tcf_pedit *p = to_pedit(a);
	struct tcf_pedit_key_ex *tkey_ex;
	struct tcf_pedit_parms *parms;
	struct tc_pedit_key *tkey;
	u32 max_offset;
	int i;

	parms = rcu_dereference_bh(p->parms);

	max_offset = (skb_transport_header_was_set(skb) ?
	skb_transport_offset(skb) :
	skb_network_offset(skb)) +
	parms->tcfp_off_max_hint;
	if (skb_ensure_writable(skb, min(skb->len, max_offset)))
	goto done;

	tcf_lastuse_update(&p->tcf_tm);
	tcf_action_update_bstats(&p->common, skb);

	tkey = parms->tcfp_keys;
	tkey_ex = parms->tcfp_keys_ex;

	for (i = parms->tcfp_nkeys; i > 0; i--, tkey++) {
	int offset = tkey->off;
	int hoffset = 0;
	u32 *ptr, hdata;
	u32 val;

	if (tkey_ex) {
	htype = tkey_ex->htype;
	cmd = tkey_ex->cmd;

	tkey_ex++;
	}

	pedit_skb_hdr_offset(skb, htype, &hoffset);

	if (tkey->offmask) {
	u8 *d, _d;

	if (!offset_valid(skb, hoffset + tkey->at)) {
	pr_info_ratelimited("tc action pedit 'at' offset %d out of bounds\n",
	hoffset + tkey->at);
	goto bad;
	}
	d = skb_header_pointer(skb, hoffset + tkey->at,
	sizeof(_d), &_d);
	if (!d)
	goto bad;

	offset += (*d & tkey->offmask) >> tkey->shift;
	if (offset % 4) {
	pr_info_ratelimited("tc action pedit offset must be on 32 bit boundaries\n");
	goto bad;
	}
	}

	if (!offset_valid(skb, hoffset + offset)) {
	pr_info_ratelimited("tc action pedit offset %d out of bounds\n", hoffset + offset);
	goto bad;
	}

	ptr = skb_header_pointer(skb, hoffset + offset,
	sizeof(hdata), &hdata);
	if (!ptr)
	goto bad;
	/* just do it, baby */
	switch (cmd) {
	case TCA_PEDIT_KEY_EX_CMD_SET:
	val = tkey->val;
	break;
	case TCA_PEDIT_KEY_EX_CMD_ADD:
	val = (*ptr + tkey->val) & ~tkey->mask;
	break;
	default:
	pr_info_ratelimited("tc action pedit bad command (%d)\n", cmd);
	goto bad;
	}

	ptr = ((ptr & tkey->mask) ^ val);
	if (ptr == &hdata)
	skb_store_bits(skb, hoffset + offset, ptr, 4);
	}

	goto done;

	bad:
	tcf_action_inc_overlimit_qstats(&p->common);
	done:
	return p->tcf_action;
	}

	static void tcf_pedit_stats_update(struct tc_action *a, u64 bytes, u64 packets,
	u64 drops, u64 lastuse, bool hw)
	{
	struct tcf_pedit *d = to_pedit(a);
	struct tcf_t *tm = &d->tcf_tm;

	tcf_action_update_stats(a, bytes, packets, drops, hw);
	tm->lastuse = max_t(u64, tm->lastuse, lastuse);
	}

	static int tcf_pedit_dump(struct sk_buff skb, struct tc_action a,
	int bind, int ref)
	{
	unsigned char *b = skb_tail_pointer(skb);
	struct tcf_pedit *p = to_pedit(a);
	struct tcf_pedit_parms *parms;
	struct tc_pedit *opt;
	struct tcf_t t;
	int s;

	spin_lock_bh(&p->tcf_lock);
	parms = rcu_dereference_protected(p->parms, 1);
	s = struct_size(opt, keys, parms->tcfp_nkeys);

	opt = kzalloc(s, GFP_ATOMIC);
	if (unlikely(!opt)) {
	spin_unlock_bh(&p->tcf_lock);
	return -ENOBUFS;
	}

	memcpy(opt->keys, parms->tcfp_keys,
	flex_array_size(opt, keys, parms->tcfp_nkeys));
	opt->index = p->tcf_index;
	opt->nkeys = parms->tcfp_nkeys;
	opt->flags = parms->tcfp_flags;
	opt->action = p->tcf_action;
	opt->refcnt = refcount_read(&p->tcf_refcnt) - ref;
	opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind;

	if (parms->tcfp_keys_ex) {
	if (tcf_pedit_key_ex_dump(skb, parms->tcfp_keys_ex,
	parms->tcfp_nkeys))
	goto nla_put_failure;

	if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt))
	goto nla_put_failure;
	} else {
	if (nla_put(skb, TCA_PEDIT_PARMS, s, opt))
	goto nla_put_failure;
	}

	tcf_tm_dump(&t, &p->tcf_tm);
	if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD))
	goto nla_put_failure;
	spin_unlock_bh(&p->tcf_lock);

	kfree(opt);
	return skb->len;

	nla_put_failure:
	spin_unlock_bh(&p->tcf_lock);
	nlmsg_trim(skb, b);
	kfree(opt);
	return -1;
	}

	static int tcf_pedit_offload_act_setup(struct tc_action act, void entry_data,
	u32 *index_inc, bool bind,
	struct netlink_ext_ack *extack)
	{
	if (bind) {
	struct flow_action_entry *entry = entry_data;
	int k;

	for (k = 0; k < tcf_pedit_nkeys(act); k++) {
	switch (tcf_pedit_cmd(act, k)) {
	case TCA_PEDIT_KEY_EX_CMD_SET:
	entry->id = FLOW_ACTION_MANGLE;
	break;
	case TCA_PEDIT_KEY_EX_CMD_ADD:
	entry->id = FLOW_ACTION_ADD;
	break;
	default:
	NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload");
	return -EOPNOTSUPP;
	}
	entry->mangle.htype = tcf_pedit_htype(act, k);
	entry->mangle.mask = tcf_pedit_mask(act, k);
	entry->mangle.val = tcf_pedit_val(act, k);
	entry->mangle.offset = tcf_pedit_offset(act, k);
	entry->hw_stats = tc_act_hw_stats(act->hw_stats);
	entry++;
	}
	*index_inc = k;
	} else {
	struct flow_offload_action *fl_action = entry_data;
	u32 cmd = tcf_pedit_cmd(act, 0);
	int k;

	switch (cmd) {
	case TCA_PEDIT_KEY_EX_CMD_SET:
	fl_action->id = FLOW_ACTION_MANGLE;
	break;
	case TCA_PEDIT_KEY_EX_CMD_ADD:
	fl_action->id = FLOW_ACTION_ADD;
	break;
	default:
	NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload");
	return -EOPNOTSUPP;
	}

	for (k = 1; k < tcf_pedit_nkeys(act); k++) {
	if (cmd != tcf_pedit_cmd(act, k)) {
	NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload");
	return -EOPNOTSUPP;
	}
	}
	}

	return 0;
	}

	static struct tc_action_ops act_pedit_ops = {
	.kind = "pedit",
	.id = TCA_ID_PEDIT,
	.owner = THIS_MODULE,
	.act = tcf_pedit_act,
	.stats_update = tcf_pedit_stats_update,
	.dump = tcf_pedit_dump,
	.cleanup = tcf_pedit_cleanup,
	.init = tcf_pedit_init,
	.offload_act_setup = tcf_pedit_offload_act_setup,
	.size = sizeof(struct tcf_pedit),
	};

	static __net_init int pedit_init_net(struct net *net)
	{
	struct tc_action_net *tn = net_generic(net, act_pedit_ops.net_id);

	return tc_action_net_init(net, tn, &act_pedit_ops);
	}

	static void __net_exit pedit_exit_net(struct list_head *net_list)
	{
	tc_action_net_exit(net_list, act_pedit_ops.net_id);
	}

	static struct pernet_operations pedit_net_ops = {
	.init = pedit_init_net,
	.exit_batch = pedit_exit_net,
	.id = &act_pedit_ops.net_id,
	.size = sizeof(struct tc_action_net),
	};

	MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
	MODULE_DESCRIPTION("Generic Packet Editor actions");
	MODULE_LICENSE("GPL");

	static int __init pedit_init_module(void)
	{
	return tcf_register_action(&act_pedit_ops, &pedit_net_ops);
	}

	static void __exit pedit_cleanup_module(void)
	{
	tcf_unregister_action(&act_pedit_ops, &pedit_net_ops);
	}

	module_init(pedit_init_module);
	module_exit(pedit_cleanup_module);