[linux-2.6-block.git] / net / sched / act_pedit.c

// 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/ip.h>
#include <linux/ipv6.h>
#include <linux/slab.h>
#include <net/ipv6.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_PARMS_EX]	= { .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 ACT_P_BOUND;
		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 = kmemdup(parm->keys, ksize, GFP_KERNEL);
	if (!nparms->tcfp_keys) {
		ret = -ENOMEM;
		goto put_chain;
	}

	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 out_free_keys;
		}

		/* 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;

out_free_keys:
	kfree(nparms->tcfp_keys);
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 int pedit_l4_skb_offset(struct sk_buff *skb, int *hoffset, const int header_type)
{
	const int noff = skb_network_offset(skb);
	int ret = -EINVAL;
	struct iphdr _iph;

	switch (skb->protocol) {
	case htons(ETH_P_IP): {
		const struct iphdr *iph = skb_header_pointer(skb, noff, sizeof(_iph), &_iph);

		if (!iph)
			goto out;
		*hoffset = noff + iph->ihl * 4;
		ret = 0;
		break;
	}
	case htons(ETH_P_IPV6):
		ret = ipv6_find_hdr(skb, hoffset, header_type, NULL, NULL) == header_type ? 0 : -EINVAL;
		break;
	}
out:
	return ret;
}

static int pedit_skb_hdr_offset(struct sk_buff *skb,
				 enum pedit_header_type htype, int *hoffset)
{
	int ret = -EINVAL;
	/* '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);
			ret = 0;
		}
		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);
		ret = 0;
		break;
	case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP:
		ret = pedit_l4_skb_offset(skb, hoffset, IPPROTO_TCP);
		break;
	case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP:
		ret = pedit_l4_skb_offset(skb, hoffset, IPPROTO_UDP);
		break;
	default:
		break;
	}
	return ret;
}

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;
		int rc;

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

			tkey_ex++;
		}

		rc = pedit_skb_hdr_offset(skb, htype, &hoffset);
		if (rc) {
			pr_info_ratelimited("tc action pedit unable to extract header offset for header type (0x%x)\n", htype);
			goto bad;
		}

		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;
	}
	opt->nkeys = parms->tcfp_nkeys;

	memcpy(opt->keys, parms->tcfp_keys,
	       flex_array_size(opt, keys, parms->tcfp_nkeys));
	opt->index = p->tcf_index;
	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),
};
MODULE_ALIAS_NET_ACT("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);
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* net/sched/act_pedit.c Generic packet editor
	4	*
	5	* Authors: Jamal Hadi Salim (2002-4)
	6	*/
	7
	8	#include <linux/types.h>
	9	#include <linux/kernel.h>
	10	#include <linux/string.h>
	11	#include <linux/errno.h>
	12	#include <linux/skbuff.h>
	13	#include <linux/rtnetlink.h>
	14	#include <linux/module.h>
	15	#include <linux/init.h>
	16	#include <linux/ip.h>
	17	#include <linux/ipv6.h>
	18	#include <linux/slab.h>
	19	#include <net/ipv6.h>
	20	#include <net/netlink.h>
	21	#include <net/pkt_sched.h>
	22	#include <linux/tc_act/tc_pedit.h>
	23	#include <net/tc_act/tc_pedit.h>
	24	#include <uapi/linux/tc_act/tc_pedit.h>
	25	#include <net/pkt_cls.h>
	26	#include <net/tc_wrapper.h>
	27
	28	static struct tc_action_ops act_pedit_ops;
	29
	30	static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = {
	31	[TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) },
	32	[TCA_PEDIT_PARMS_EX] = { .len = sizeof(struct tc_pedit) },
	33	[TCA_PEDIT_KEYS_EX] = { .type = NLA_NESTED },
	34	};
	35
	36	static const struct nla_policy pedit_key_ex_policy[TCA_PEDIT_KEY_EX_MAX + 1] = {
	37	[TCA_PEDIT_KEY_EX_HTYPE] =
	38	NLA_POLICY_MAX(NLA_U16, TCA_PEDIT_HDR_TYPE_MAX),
	39	[TCA_PEDIT_KEY_EX_CMD] = NLA_POLICY_MAX(NLA_U16, TCA_PEDIT_CMD_MAX),
	40	};
	41
	42	static struct tcf_pedit_key_ex tcf_pedit_keys_ex_parse(struct nlattr nla,
	43	u8 n, struct netlink_ext_ack *extack)
	44	{
	45	struct tcf_pedit_key_ex *keys_ex;
	46	struct tcf_pedit_key_ex *k;
	47	const struct nlattr *ka;
	48	int err = -EINVAL;
	49	int rem;
	50
	51	if (!nla)
	52	return NULL;
	53
	54	keys_ex = kcalloc(n, sizeof(*k), GFP_KERNEL);
	55	if (!keys_ex)
	56	return ERR_PTR(-ENOMEM);
	57
	58	k = keys_ex;
	59
	60	nla_for_each_nested(ka, nla, rem) {
	61	struct nlattr *tb[TCA_PEDIT_KEY_EX_MAX + 1];
	62
	63	if (!n) {
	64	NL_SET_ERR_MSG_MOD(extack, "Can't parse more extended keys than requested");
	65	err = -EINVAL;
	66	goto err_out;
	67	}
	68	n--;
	69
	70	if (nla_type(ka) != TCA_PEDIT_KEY_EX) {
	71	NL_SET_ERR_MSG_ATTR(extack, ka, "Unknown attribute, expected extended key");
	72	err = -EINVAL;
	73	goto err_out;
	74	}
	75
	76	err = nla_parse_nested_deprecated(tb, TCA_PEDIT_KEY_EX_MAX,
	77	ka, pedit_key_ex_policy,
	78	NULL);
	79	if (err)
	80	goto err_out;
	81
	82	if (NL_REQ_ATTR_CHECK(extack, nla, tb, TCA_PEDIT_KEY_EX_HTYPE)) {
	83	NL_SET_ERR_MSG(extack, "Missing required attribute");
	84	err = -EINVAL;
	85	goto err_out;
	86	}
	87
	88	if (NL_REQ_ATTR_CHECK(extack, nla, tb, TCA_PEDIT_KEY_EX_CMD)) {
	89	NL_SET_ERR_MSG(extack, "Missing required attribute");
	90	err = -EINVAL;
	91	goto err_out;
	92	}
	93
	94	k->htype = nla_get_u16(tb[TCA_PEDIT_KEY_EX_HTYPE]);
	95	k->cmd = nla_get_u16(tb[TCA_PEDIT_KEY_EX_CMD]);
	96
	97	k++;
	98	}
	99
	100	if (n) {
	101	NL_SET_ERR_MSG_MOD(extack, "Not enough extended keys to parse");
	102	err = -EINVAL;
	103	goto err_out;
	104	}
	105
	106	return keys_ex;
	107
	108	err_out:
	109	kfree(keys_ex);
	110	return ERR_PTR(err);
	111	}
	112
	113	static int tcf_pedit_key_ex_dump(struct sk_buff *skb,
	114	struct tcf_pedit_key_ex *keys_ex, int n)
	115	{
	116	struct nlattr *keys_start = nla_nest_start_noflag(skb,
	117	TCA_PEDIT_KEYS_EX);
	118
	119	if (!keys_start)
	120	goto nla_failure;
	121	for (; n > 0; n--) {
	122	struct nlattr *key_start;
	123
	124	key_start = nla_nest_start_noflag(skb, TCA_PEDIT_KEY_EX);
	125	if (!key_start)
	126	goto nla_failure;
	127
	128	if (nla_put_u16(skb, TCA_PEDIT_KEY_EX_HTYPE, keys_ex->htype) \|\|
	129	nla_put_u16(skb, TCA_PEDIT_KEY_EX_CMD, keys_ex->cmd))
	130	goto nla_failure;
	131
	132	nla_nest_end(skb, key_start);
	133
	134	keys_ex++;
	135	}
	136
	137	nla_nest_end(skb, keys_start);
	138
	139	return 0;
	140	nla_failure:
	141	nla_nest_cancel(skb, keys_start);
	142	return -EINVAL;
	143	}
	144
	145	static void tcf_pedit_cleanup_rcu(struct rcu_head *head)
	146	{
	147	struct tcf_pedit_parms *parms =
	148	container_of(head, struct tcf_pedit_parms, rcu);
	149
	150	kfree(parms->tcfp_keys_ex);
	151	kfree(parms->tcfp_keys);
	152
	153	kfree(parms);
	154	}
	155
	156	static int tcf_pedit_init(struct net net, struct nlattr nla,
	157	struct nlattr est, struct tc_action *a,
	158	struct tcf_proto *tp, u32 flags,
	159	struct netlink_ext_ack *extack)
	160	{
	161	struct tc_action_net *tn = net_generic(net, act_pedit_ops.net_id);
	162	bool bind = flags & TCA_ACT_FLAGS_BIND;
	163	struct tcf_chain *goto_ch = NULL;
	164	struct tcf_pedit_parms oparms, nparms;
	165	struct nlattr *tb[TCA_PEDIT_MAX + 1];
	166	struct tc_pedit *parm;
	167	struct nlattr *pattr;
	168	struct tcf_pedit *p;
	169	int ret = 0, err;
	170	int i, ksize;
	171	u32 index;
	172
	173	if (!nla) {
	174	NL_SET_ERR_MSG_MOD(extack, "Pedit requires attributes to be passed");
	175	return -EINVAL;
	176	}
	177
	178	err = nla_parse_nested_deprecated(tb, TCA_PEDIT_MAX, nla,
	179	pedit_policy, NULL);
	180	if (err < 0)
	181	return err;
	182
	183	pattr = tb[TCA_PEDIT_PARMS];
	184	if (!pattr)
	185	pattr = tb[TCA_PEDIT_PARMS_EX];
	186	if (!pattr) {
	187	NL_SET_ERR_MSG_MOD(extack, "Missing required TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute");
	188	return -EINVAL;
	189	}
	190
	191	parm = nla_data(pattr);
	192
	193	index = parm->index;
	194	err = tcf_idr_check_alloc(tn, &index, a, bind);
	195	if (!err) {
	196	ret = tcf_idr_create_from_flags(tn, index, est, a,
	197	&act_pedit_ops, bind, flags);
	198	if (ret) {
	199	tcf_idr_cleanup(tn, index);
	200	return ret;
	201	}
	202	ret = ACT_P_CREATED;
	203	} else if (err > 0) {
	204	if (bind)
	205	return ACT_P_BOUND;
	206	if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
	207	ret = -EEXIST;
	208	goto out_release;
	209	}
	210	} else {
	211	return err;
	212	}
	213
	214	if (!parm->nkeys) {
	215	NL_SET_ERR_MSG_MOD(extack, "Pedit requires keys to be passed");
	216	ret = -EINVAL;
	217	goto out_release;
	218	}
	219	ksize = parm->nkeys * sizeof(struct tc_pedit_key);
	220	if (nla_len(pattr) < sizeof(*parm) + ksize) {
	221	NL_SET_ERR_MSG_ATTR(extack, pattr, "Length of TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute is invalid");
	222	ret = -EINVAL;
	223	goto out_release;
	224	}
	225
	226	nparms = kzalloc(sizeof(*nparms), GFP_KERNEL);
	227	if (!nparms) {
	228	ret = -ENOMEM;
	229	goto out_release;
	230	}
	231
	232	nparms->tcfp_keys_ex =
	233	tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys, extack);
	234	if (IS_ERR(nparms->tcfp_keys_ex)) {
	235	ret = PTR_ERR(nparms->tcfp_keys_ex);
	236	goto out_free;
	237	}
	238
	239	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
	240	if (err < 0) {
	241	ret = err;
	242	goto out_free_ex;
	243	}
	244
	245	nparms->tcfp_off_max_hint = 0;
	246	nparms->tcfp_flags = parm->flags;
	247	nparms->tcfp_nkeys = parm->nkeys;
	248
	249	nparms->tcfp_keys = kmemdup(parm->keys, ksize, GFP_KERNEL);
	250	if (!nparms->tcfp_keys) {
	251	ret = -ENOMEM;
	252	goto put_chain;
	253	}
	254
	255	for (i = 0; i < nparms->tcfp_nkeys; ++i) {
	256	u32 offmask = nparms->tcfp_keys[i].offmask;
	257	u32 cur = nparms->tcfp_keys[i].off;
	258
	259	/* The AT option can be added to static offsets in the datapath */
	260	if (!offmask && cur % 4) {
	261	NL_SET_ERR_MSG_MOD(extack, "Offsets must be on 32bit boundaries");
	262	ret = -EINVAL;
	263	goto out_free_keys;
	264	}
	265
	266	/* sanitize the shift value for any later use */
	267	nparms->tcfp_keys[i].shift = min_t(size_t,
	268	BITS_PER_TYPE(int) - 1,
	269	nparms->tcfp_keys[i].shift);
	270
	271	/* The AT option can read a single byte, we can bound the actual
	272	* value with uchar max.
	273	*/
	274	cur += (0xff & offmask) >> nparms->tcfp_keys[i].shift;
	275
	276	/* Each key touches 4 bytes starting from the computed offset */
	277	nparms->tcfp_off_max_hint =
	278	max(nparms->tcfp_off_max_hint, cur + 4);
	279	}
	280
	281	p = to_pedit(*a);
	282
	283	spin_lock_bh(&p->tcf_lock);
	284	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
	285	oparms = rcu_replace_pointer(p->parms, nparms, 1);
	286	spin_unlock_bh(&p->tcf_lock);
	287
	288	if (oparms)
	289	call_rcu(&oparms->rcu, tcf_pedit_cleanup_rcu);
	290
	291	if (goto_ch)
	292	tcf_chain_put_by_act(goto_ch);
	293
	294	return ret;
	295
	296	out_free_keys:
	297	kfree(nparms->tcfp_keys);
	298	put_chain:
	299	if (goto_ch)
	300	tcf_chain_put_by_act(goto_ch);
	301	out_free_ex:
	302	kfree(nparms->tcfp_keys_ex);
	303	out_free:
	304	kfree(nparms);
	305	out_release:
	306	tcf_idr_release(*a, bind);
	307	return ret;
	308	}
	309
	310	static void tcf_pedit_cleanup(struct tc_action *a)
	311	{
	312	struct tcf_pedit *p = to_pedit(a);
	313	struct tcf_pedit_parms *parms;
	314
	315	parms = rcu_dereference_protected(p->parms, 1);
	316
	317	if (parms)
	318	call_rcu(&parms->rcu, tcf_pedit_cleanup_rcu);
	319	}
	320
	321	static bool offset_valid(struct sk_buff *skb, int offset)
	322	{
	323	if (offset > 0 && offset > skb->len)
	324	return false;
	325
	326	if (offset < 0 && -offset > skb_headroom(skb))
	327	return false;
	328
	329	return true;
	330	}
	331
	332	static int pedit_l4_skb_offset(struct sk_buff skb, int hoffset, const int header_type)
	333	{
	334	const int noff = skb_network_offset(skb);
	335	int ret = -EINVAL;
	336	struct iphdr _iph;
	337
	338	switch (skb->protocol) {
	339	case htons(ETH_P_IP): {
	340	const struct iphdr *iph = skb_header_pointer(skb, noff, sizeof(_iph), &_iph);
	341
	342	if (!iph)
	343	goto out;
	344	hoffset = noff + iph->ihl 4;
	345	ret = 0;
	346	break;
	347	}
	348	case htons(ETH_P_IPV6):
	349	ret = ipv6_find_hdr(skb, hoffset, header_type, NULL, NULL) == header_type ? 0 : -EINVAL;
	350	break;
	351	}
	352	out:
	353	return ret;
	354	}
	355
	356	static int pedit_skb_hdr_offset(struct sk_buff *skb,
	357	enum pedit_header_type htype, int *hoffset)
	358	{
	359	int ret = -EINVAL;
	360	/* 'htype' is validated in the netlink parsing */
	361	switch (htype) {
	362	case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH:
	363	if (skb_mac_header_was_set(skb)) {
	364	*hoffset = skb_mac_offset(skb);
	365	ret = 0;
	366	}
	367	break;
	368	case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK:
	369	case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4:
	370	case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6:
	371	*hoffset = skb_network_offset(skb);
	372	ret = 0;
	373	break;
	374	case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP:
	375	ret = pedit_l4_skb_offset(skb, hoffset, IPPROTO_TCP);
	376	break;
	377	case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP:
	378	ret = pedit_l4_skb_offset(skb, hoffset, IPPROTO_UDP);
	379	break;
	380	default:
	381	break;
	382	}
	383	return ret;
	384	}
	385
	386	TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
	387	const struct tc_action *a,
	388	struct tcf_result *res)
	389	{
	390	enum pedit_header_type htype = TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK;
	391	enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET;
	392	struct tcf_pedit *p = to_pedit(a);
	393	struct tcf_pedit_key_ex *tkey_ex;
	394	struct tcf_pedit_parms *parms;
	395	struct tc_pedit_key *tkey;
	396	u32 max_offset;
	397	int i;
	398
	399	parms = rcu_dereference_bh(p->parms);
	400
	401	max_offset = (skb_transport_header_was_set(skb) ?
	402	skb_transport_offset(skb) :
	403	skb_network_offset(skb)) +
	404	parms->tcfp_off_max_hint;
	405	if (skb_ensure_writable(skb, min(skb->len, max_offset)))
	406	goto done;
	407
	408	tcf_lastuse_update(&p->tcf_tm);
	409	tcf_action_update_bstats(&p->common, skb);
	410
	411	tkey = parms->tcfp_keys;
	412	tkey_ex = parms->tcfp_keys_ex;
	413
	414	for (i = parms->tcfp_nkeys; i > 0; i--, tkey++) {
	415	int offset = tkey->off;
	416	int hoffset = 0;
	417	u32 *ptr, hdata;
	418	u32 val;
	419	int rc;
	420
	421	if (tkey_ex) {
	422	htype = tkey_ex->htype;
	423	cmd = tkey_ex->cmd;
	424
	425	tkey_ex++;
	426	}
	427
	428	rc = pedit_skb_hdr_offset(skb, htype, &hoffset);
	429	if (rc) {
	430	pr_info_ratelimited("tc action pedit unable to extract header offset for header type (0x%x)\n", htype);
	431	goto bad;
	432	}
	433
	434	if (tkey->offmask) {
	435	u8 *d, _d;
	436
	437	if (!offset_valid(skb, hoffset + tkey->at)) {
	438	pr_info_ratelimited("tc action pedit 'at' offset %d out of bounds\n",
	439	hoffset + tkey->at);
	440	goto bad;
	441	}
	442	d = skb_header_pointer(skb, hoffset + tkey->at,
	443	sizeof(_d), &_d);
	444	if (!d)
	445	goto bad;
	446
	447	offset += (*d & tkey->offmask) >> tkey->shift;
	448	if (offset % 4) {
	449	pr_info_ratelimited("tc action pedit offset must be on 32 bit boundaries\n");
	450	goto bad;
	451	}
	452	}
	453
	454	if (!offset_valid(skb, hoffset + offset)) {
	455	pr_info_ratelimited("tc action pedit offset %d out of bounds\n", hoffset + offset);
	456	goto bad;
	457	}
	458
	459	ptr = skb_header_pointer(skb, hoffset + offset,
	460	sizeof(hdata), &hdata);
	461	if (!ptr)
	462	goto bad;
	463	/* just do it, baby */
	464	switch (cmd) {
	465	case TCA_PEDIT_KEY_EX_CMD_SET:
	466	val = tkey->val;
	467	break;
	468	case TCA_PEDIT_KEY_EX_CMD_ADD:
	469	val = (*ptr + tkey->val) & ~tkey->mask;
	470	break;
	471	default:
	472	pr_info_ratelimited("tc action pedit bad command (%d)\n", cmd);
	473	goto bad;
	474	}
	475
	476	ptr = ((ptr & tkey->mask) ^ val);
	477	if (ptr == &hdata)
	478	skb_store_bits(skb, hoffset + offset, ptr, 4);
	479	}
	480
	481	goto done;
	482
	483	bad:
	484	tcf_action_inc_overlimit_qstats(&p->common);
	485	done:
	486	return p->tcf_action;
	487	}
	488
	489	static void tcf_pedit_stats_update(struct tc_action *a, u64 bytes, u64 packets,
	490	u64 drops, u64 lastuse, bool hw)
	491	{
	492	struct tcf_pedit *d = to_pedit(a);
	493	struct tcf_t *tm = &d->tcf_tm;
	494
	495	tcf_action_update_stats(a, bytes, packets, drops, hw);
	496	tm->lastuse = max_t(u64, tm->lastuse, lastuse);
	497	}
	498
	499	static int tcf_pedit_dump(struct sk_buff skb, struct tc_action a,
	500	int bind, int ref)
	501	{
	502	unsigned char *b = skb_tail_pointer(skb);
	503	struct tcf_pedit *p = to_pedit(a);
	504	struct tcf_pedit_parms *parms;
	505	struct tc_pedit *opt;
	506	struct tcf_t t;
	507	int s;
	508
	509	spin_lock_bh(&p->tcf_lock);
	510	parms = rcu_dereference_protected(p->parms, 1);
	511	s = struct_size(opt, keys, parms->tcfp_nkeys);
	512
	513	opt = kzalloc(s, GFP_ATOMIC);
	514	if (unlikely(!opt)) {
	515	spin_unlock_bh(&p->tcf_lock);
	516	return -ENOBUFS;
	517	}
	518	opt->nkeys = parms->tcfp_nkeys;
	519
	520	memcpy(opt->keys, parms->tcfp_keys,
	521	flex_array_size(opt, keys, parms->tcfp_nkeys));
	522	opt->index = p->tcf_index;
	523	opt->flags = parms->tcfp_flags;
	524	opt->action = p->tcf_action;
	525	opt->refcnt = refcount_read(&p->tcf_refcnt) - ref;
	526	opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind;
	527
	528	if (parms->tcfp_keys_ex) {
	529	if (tcf_pedit_key_ex_dump(skb, parms->tcfp_keys_ex,
	530	parms->tcfp_nkeys))
	531	goto nla_put_failure;
	532
	533	if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt))
	534	goto nla_put_failure;
	535	} else {
	536	if (nla_put(skb, TCA_PEDIT_PARMS, s, opt))
	537	goto nla_put_failure;
	538	}
	539
	540	tcf_tm_dump(&t, &p->tcf_tm);
	541	if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD))
	542	goto nla_put_failure;
	543	spin_unlock_bh(&p->tcf_lock);
	544
	545	kfree(opt);
	546	return skb->len;
	547
	548	nla_put_failure:
	549	spin_unlock_bh(&p->tcf_lock);
	550	nlmsg_trim(skb, b);
	551	kfree(opt);
	552	return -1;
	553	}
	554
	555	static int tcf_pedit_offload_act_setup(struct tc_action act, void entry_data,
	556	u32 *index_inc, bool bind,
	557	struct netlink_ext_ack *extack)
	558	{
	559	if (bind) {
	560	struct flow_action_entry *entry = entry_data;
	561	int k;
	562
	563	for (k = 0; k < tcf_pedit_nkeys(act); k++) {
	564	switch (tcf_pedit_cmd(act, k)) {
	565	case TCA_PEDIT_KEY_EX_CMD_SET:
	566	entry->id = FLOW_ACTION_MANGLE;
	567	break;
	568	case TCA_PEDIT_KEY_EX_CMD_ADD:
	569	entry->id = FLOW_ACTION_ADD;
	570	break;
	571	default:
	572	NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload");
	573	return -EOPNOTSUPP;
	574	}
	575	entry->mangle.htype = tcf_pedit_htype(act, k);
	576	entry->mangle.mask = tcf_pedit_mask(act, k);
	577	entry->mangle.val = tcf_pedit_val(act, k);
	578	entry->mangle.offset = tcf_pedit_offset(act, k);
	579	entry->hw_stats = tc_act_hw_stats(act->hw_stats);
	580	entry++;
	581	}
	582	*index_inc = k;
	583	} else {
	584	struct flow_offload_action *fl_action = entry_data;
	585	u32 cmd = tcf_pedit_cmd(act, 0);
	586	int k;
	587
	588	switch (cmd) {
	589	case TCA_PEDIT_KEY_EX_CMD_SET:
	590	fl_action->id = FLOW_ACTION_MANGLE;
	591	break;
	592	case TCA_PEDIT_KEY_EX_CMD_ADD:
	593	fl_action->id = FLOW_ACTION_ADD;
	594	break;
	595	default:
	596	NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload");
	597	return -EOPNOTSUPP;
	598	}
	599
	600	for (k = 1; k < tcf_pedit_nkeys(act); k++) {
	601	if (cmd != tcf_pedit_cmd(act, k)) {
	602	NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload");
	603	return -EOPNOTSUPP;
	604	}
	605	}
	606	}
	607
	608	return 0;
	609	}
	610
	611	static struct tc_action_ops act_pedit_ops = {
	612	.kind = "pedit",
	613	.id = TCA_ID_PEDIT,
	614	.owner = THIS_MODULE,
	615	.act = tcf_pedit_act,
	616	.stats_update = tcf_pedit_stats_update,
	617	.dump = tcf_pedit_dump,
	618	.cleanup = tcf_pedit_cleanup,
	619	.init = tcf_pedit_init,
	620	.offload_act_setup = tcf_pedit_offload_act_setup,
	621	.size = sizeof(struct tcf_pedit),
	622	};
	623	MODULE_ALIAS_NET_ACT("pedit");
	624
	625	static __net_init int pedit_init_net(struct net *net)
	626	{
	627	struct tc_action_net *tn = net_generic(net, act_pedit_ops.net_id);
	628
	629	return tc_action_net_init(net, tn, &act_pedit_ops);
	630	}
	631
	632	static void __net_exit pedit_exit_net(struct list_head *net_list)
	633	{
	634	tc_action_net_exit(net_list, act_pedit_ops.net_id);
	635	}
	636
	637	static struct pernet_operations pedit_net_ops = {
	638	.init = pedit_init_net,
	639	.exit_batch = pedit_exit_net,
	640	.id = &act_pedit_ops.net_id,
	641	.size = sizeof(struct tc_action_net),
	642	};
	643
	644	MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
	645	MODULE_DESCRIPTION("Generic Packet Editor actions");
	646	MODULE_LICENSE("GPL");
	647
	648	static int __init pedit_init_module(void)
	649	{
	650	return tcf_register_action(&act_pedit_ops, &pedit_net_ops);
	651	}
	652
	653	static void __exit pedit_cleanup_module(void)
	654	{
	655	tcf_unregister_action(&act_pedit_ops, &pedit_net_ops);
	656	}
	657
	658	module_init(pedit_init_module);
	659	module_exit(pedit_cleanup_module);