2 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 * Development of this code funded by Astaro AG (http://www.astaro.com/)
11 #include <linux/kernel.h>
12 #include <linux/if_vlan.h>
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/netlink.h>
16 #include <linux/netfilter.h>
17 #include <linux/netfilter/nf_tables.h>
18 #include <net/netfilter/nf_tables_core.h>
19 #include <net/netfilter/nf_tables.h>
21 /* add vlan header into the user buffer for if tag was removed by offloads */
23 nft_payload_copy_vlan(u32 *d, const struct sk_buff *skb, u8 offset, u8 len)
25 int mac_off = skb_mac_header(skb) - skb->data;
26 u8 vlan_len, *vlanh, *dst_u8 = (u8 *) d;
27 struct vlan_ethhdr veth;
30 if (offset < ETH_HLEN) {
31 u8 ethlen = min_t(u8, len, ETH_HLEN - offset);
33 if (skb_copy_bits(skb, mac_off, &veth, ETH_HLEN))
36 veth.h_vlan_proto = skb->vlan_proto;
38 memcpy(dst_u8, vlanh + offset, ethlen);
46 } else if (offset >= VLAN_ETH_HLEN) {
51 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
52 veth.h_vlan_encapsulated_proto = skb->protocol;
56 vlan_len = min_t(u8, len, VLAN_ETH_HLEN - offset);
57 memcpy(dst_u8, vlanh, vlan_len);
65 return skb_copy_bits(skb, offset + mac_off, dst_u8, len) == 0;
68 static void nft_payload_eval(const struct nft_expr *expr,
69 struct nft_regs *regs,
70 const struct nft_pktinfo *pkt)
72 const struct nft_payload *priv = nft_expr_priv(expr);
73 const struct sk_buff *skb = pkt->skb;
74 u32 *dest = ®s->data[priv->dreg];
77 if (priv->len % NFT_REG32_SIZE)
78 dest[priv->len / NFT_REG32_SIZE] = 0;
81 case NFT_PAYLOAD_LL_HEADER:
82 if (!skb_mac_header_was_set(skb))
85 if (skb_vlan_tag_present(skb)) {
86 if (!nft_payload_copy_vlan(dest, skb,
87 priv->offset, priv->len))
91 offset = skb_mac_header(skb) - skb->data;
93 case NFT_PAYLOAD_NETWORK_HEADER:
94 offset = skb_network_offset(skb);
96 case NFT_PAYLOAD_TRANSPORT_HEADER:
97 offset = pkt->xt.thoff;
102 offset += priv->offset;
104 if (skb_copy_bits(skb, offset, dest, priv->len) < 0)
108 regs->verdict.code = NFT_BREAK;
111 static const struct nla_policy nft_payload_policy[NFTA_PAYLOAD_MAX + 1] = {
112 [NFTA_PAYLOAD_DREG] = { .type = NLA_U32 },
113 [NFTA_PAYLOAD_BASE] = { .type = NLA_U32 },
114 [NFTA_PAYLOAD_OFFSET] = { .type = NLA_U32 },
115 [NFTA_PAYLOAD_LEN] = { .type = NLA_U32 },
118 static int nft_payload_init(const struct nft_ctx *ctx,
119 const struct nft_expr *expr,
120 const struct nlattr * const tb[])
122 struct nft_payload *priv = nft_expr_priv(expr);
124 priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
125 priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
126 priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
127 priv->dreg = nft_parse_register(tb[NFTA_PAYLOAD_DREG]);
129 return nft_validate_register_store(ctx, priv->dreg, NULL,
130 NFT_DATA_VALUE, priv->len);
133 static int nft_payload_dump(struct sk_buff *skb, const struct nft_expr *expr)
135 const struct nft_payload *priv = nft_expr_priv(expr);
137 if (nft_dump_register(skb, NFTA_PAYLOAD_DREG, priv->dreg) ||
138 nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) ||
139 nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) ||
140 nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len)))
141 goto nla_put_failure;
148 static struct nft_expr_type nft_payload_type;
149 static const struct nft_expr_ops nft_payload_ops = {
150 .type = &nft_payload_type,
151 .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)),
152 .eval = nft_payload_eval,
153 .init = nft_payload_init,
154 .dump = nft_payload_dump,
157 const struct nft_expr_ops nft_payload_fast_ops = {
158 .type = &nft_payload_type,
159 .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)),
160 .eval = nft_payload_eval,
161 .init = nft_payload_init,
162 .dump = nft_payload_dump,
165 static const struct nft_expr_ops *
166 nft_payload_select_ops(const struct nft_ctx *ctx,
167 const struct nlattr * const tb[])
169 enum nft_payload_bases base;
170 unsigned int offset, len;
172 if (tb[NFTA_PAYLOAD_DREG] == NULL ||
173 tb[NFTA_PAYLOAD_BASE] == NULL ||
174 tb[NFTA_PAYLOAD_OFFSET] == NULL ||
175 tb[NFTA_PAYLOAD_LEN] == NULL)
176 return ERR_PTR(-EINVAL);
178 base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
180 case NFT_PAYLOAD_LL_HEADER:
181 case NFT_PAYLOAD_NETWORK_HEADER:
182 case NFT_PAYLOAD_TRANSPORT_HEADER:
185 return ERR_PTR(-EOPNOTSUPP);
188 offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
189 len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
191 if (len <= 4 && is_power_of_2(len) && IS_ALIGNED(offset, len) &&
192 base != NFT_PAYLOAD_LL_HEADER)
193 return &nft_payload_fast_ops;
195 return &nft_payload_ops;
198 static struct nft_expr_type nft_payload_type __read_mostly = {
200 .select_ops = nft_payload_select_ops,
201 .policy = nft_payload_policy,
202 .maxattr = NFTA_PAYLOAD_MAX,
203 .owner = THIS_MODULE,
206 int __init nft_payload_module_init(void)
208 return nft_register_expr(&nft_payload_type);
211 void nft_payload_module_exit(void)
213 nft_unregister_expr(&nft_payload_type);