Commit | Line | Data |
---|---|---|
96518518 | 1 | /* |
ef1f7df9 | 2 | * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> |
96518518 PM |
3 | * |
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. | |
7 | * | |
8 | * Development of this code funded by Astaro AG (http://www.astaro.com/) | |
9 | */ | |
10 | ||
11 | #include <linux/kernel.h> | |
8cfd23e6 | 12 | #include <linux/if_vlan.h> |
96518518 PM |
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> | |
20 | ||
8cfd23e6 FW |
21 | /* add vlan header into the user buffer for if tag was removed by offloads */ |
22 | static bool | |
23 | nft_payload_copy_vlan(u32 *d, const struct sk_buff *skb, u8 offset, u8 len) | |
24 | { | |
25 | int mac_off = skb_mac_header(skb) - skb->data; | |
26 | u8 vlan_len, *vlanh, *dst_u8 = (u8 *) d; | |
27 | struct vlan_ethhdr veth; | |
28 | ||
29 | vlanh = (u8 *) &veth; | |
30 | if (offset < ETH_HLEN) { | |
31 | u8 ethlen = min_t(u8, len, ETH_HLEN - offset); | |
32 | ||
33 | if (skb_copy_bits(skb, mac_off, &veth, ETH_HLEN)) | |
34 | return false; | |
35 | ||
36 | veth.h_vlan_proto = skb->vlan_proto; | |
37 | ||
38 | memcpy(dst_u8, vlanh + offset, ethlen); | |
39 | ||
40 | len -= ethlen; | |
41 | if (len == 0) | |
42 | return true; | |
43 | ||
44 | dst_u8 += ethlen; | |
45 | offset = ETH_HLEN; | |
46 | } else if (offset >= VLAN_ETH_HLEN) { | |
47 | offset -= VLAN_HLEN; | |
48 | goto skip; | |
49 | } | |
50 | ||
51 | veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb)); | |
52 | veth.h_vlan_encapsulated_proto = skb->protocol; | |
53 | ||
54 | vlanh += offset; | |
55 | ||
56 | vlan_len = min_t(u8, len, VLAN_ETH_HLEN - offset); | |
57 | memcpy(dst_u8, vlanh, vlan_len); | |
58 | ||
59 | len -= vlan_len; | |
60 | if (!len) | |
61 | return true; | |
62 | ||
63 | dst_u8 += vlan_len; | |
64 | skip: | |
65 | return skb_copy_bits(skb, offset + mac_off, dst_u8, len) == 0; | |
66 | } | |
67 | ||
96518518 | 68 | static void nft_payload_eval(const struct nft_expr *expr, |
a55e22e9 | 69 | struct nft_regs *regs, |
96518518 PM |
70 | const struct nft_pktinfo *pkt) |
71 | { | |
72 | const struct nft_payload *priv = nft_expr_priv(expr); | |
73 | const struct sk_buff *skb = pkt->skb; | |
49499c3e | 74 | u32 *dest = ®s->data[priv->dreg]; |
96518518 PM |
75 | int offset; |
76 | ||
8cfd23e6 | 77 | dest[priv->len / NFT_REG32_SIZE] = 0; |
96518518 PM |
78 | switch (priv->base) { |
79 | case NFT_PAYLOAD_LL_HEADER: | |
80 | if (!skb_mac_header_was_set(skb)) | |
81 | goto err; | |
8cfd23e6 FW |
82 | |
83 | if (skb_vlan_tag_present(skb)) { | |
84 | if (!nft_payload_copy_vlan(dest, skb, | |
85 | priv->offset, priv->len)) | |
86 | goto err; | |
87 | return; | |
88 | } | |
96518518 PM |
89 | offset = skb_mac_header(skb) - skb->data; |
90 | break; | |
91 | case NFT_PAYLOAD_NETWORK_HEADER: | |
92 | offset = skb_network_offset(skb); | |
93 | break; | |
94 | case NFT_PAYLOAD_TRANSPORT_HEADER: | |
c54032e0 | 95 | offset = pkt->xt.thoff; |
96518518 PM |
96 | break; |
97 | default: | |
98 | BUG(); | |
99 | } | |
100 | offset += priv->offset; | |
101 | ||
fad136ea | 102 | if (skb_copy_bits(skb, offset, dest, priv->len) < 0) |
96518518 PM |
103 | goto err; |
104 | return; | |
105 | err: | |
a55e22e9 | 106 | regs->verdict.code = NFT_BREAK; |
96518518 PM |
107 | } |
108 | ||
109 | static const struct nla_policy nft_payload_policy[NFTA_PAYLOAD_MAX + 1] = { | |
110 | [NFTA_PAYLOAD_DREG] = { .type = NLA_U32 }, | |
111 | [NFTA_PAYLOAD_BASE] = { .type = NLA_U32 }, | |
112 | [NFTA_PAYLOAD_OFFSET] = { .type = NLA_U32 }, | |
113 | [NFTA_PAYLOAD_LEN] = { .type = NLA_U32 }, | |
114 | }; | |
115 | ||
116 | static int nft_payload_init(const struct nft_ctx *ctx, | |
117 | const struct nft_expr *expr, | |
118 | const struct nlattr * const tb[]) | |
119 | { | |
120 | struct nft_payload *priv = nft_expr_priv(expr); | |
96518518 | 121 | |
c29b72e0 | 122 | priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE])); |
96518518 PM |
123 | priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET])); |
124 | priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN])); | |
b1c96ed3 | 125 | priv->dreg = nft_parse_register(tb[NFTA_PAYLOAD_DREG]); |
96518518 | 126 | |
1ec10212 PM |
127 | return nft_validate_register_store(ctx, priv->dreg, NULL, |
128 | NFT_DATA_VALUE, priv->len); | |
96518518 PM |
129 | } |
130 | ||
131 | static int nft_payload_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
132 | { | |
133 | const struct nft_payload *priv = nft_expr_priv(expr); | |
134 | ||
b1c96ed3 | 135 | if (nft_dump_register(skb, NFTA_PAYLOAD_DREG, priv->dreg) || |
96518518 PM |
136 | nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) || |
137 | nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) || | |
138 | nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len))) | |
139 | goto nla_put_failure; | |
140 | return 0; | |
141 | ||
142 | nla_put_failure: | |
143 | return -1; | |
144 | } | |
145 | ||
ef1f7df9 PM |
146 | static struct nft_expr_type nft_payload_type; |
147 | static const struct nft_expr_ops nft_payload_ops = { | |
148 | .type = &nft_payload_type, | |
96518518 | 149 | .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)), |
96518518 PM |
150 | .eval = nft_payload_eval, |
151 | .init = nft_payload_init, | |
152 | .dump = nft_payload_dump, | |
ef1f7df9 PM |
153 | }; |
154 | ||
c29b72e0 PM |
155 | const struct nft_expr_ops nft_payload_fast_ops = { |
156 | .type = &nft_payload_type, | |
157 | .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)), | |
158 | .eval = nft_payload_eval, | |
159 | .init = nft_payload_init, | |
160 | .dump = nft_payload_dump, | |
161 | }; | |
162 | ||
0ca743a5 PNA |
163 | static const struct nft_expr_ops * |
164 | nft_payload_select_ops(const struct nft_ctx *ctx, | |
165 | const struct nlattr * const tb[]) | |
c29b72e0 PM |
166 | { |
167 | enum nft_payload_bases base; | |
168 | unsigned int offset, len; | |
169 | ||
170 | if (tb[NFTA_PAYLOAD_DREG] == NULL || | |
171 | tb[NFTA_PAYLOAD_BASE] == NULL || | |
172 | tb[NFTA_PAYLOAD_OFFSET] == NULL || | |
173 | tb[NFTA_PAYLOAD_LEN] == NULL) | |
174 | return ERR_PTR(-EINVAL); | |
175 | ||
176 | base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE])); | |
177 | switch (base) { | |
178 | case NFT_PAYLOAD_LL_HEADER: | |
179 | case NFT_PAYLOAD_NETWORK_HEADER: | |
180 | case NFT_PAYLOAD_TRANSPORT_HEADER: | |
181 | break; | |
182 | default: | |
183 | return ERR_PTR(-EOPNOTSUPP); | |
184 | } | |
185 | ||
186 | offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET])); | |
45d9bcda | 187 | len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN])); |
c29b72e0 | 188 | |
f627ed91 NA |
189 | if (len <= 4 && is_power_of_2(len) && IS_ALIGNED(offset, len) && |
190 | base != NFT_PAYLOAD_LL_HEADER) | |
c29b72e0 PM |
191 | return &nft_payload_fast_ops; |
192 | else | |
193 | return &nft_payload_ops; | |
194 | } | |
195 | ||
ef1f7df9 PM |
196 | static struct nft_expr_type nft_payload_type __read_mostly = { |
197 | .name = "payload", | |
c29b72e0 | 198 | .select_ops = nft_payload_select_ops, |
96518518 PM |
199 | .policy = nft_payload_policy, |
200 | .maxattr = NFTA_PAYLOAD_MAX, | |
ef1f7df9 | 201 | .owner = THIS_MODULE, |
96518518 PM |
202 | }; |
203 | ||
204 | int __init nft_payload_module_init(void) | |
205 | { | |
ef1f7df9 | 206 | return nft_register_expr(&nft_payload_type); |
96518518 PM |
207 | } |
208 | ||
209 | void nft_payload_module_exit(void) | |
210 | { | |
ef1f7df9 | 211 | nft_unregister_expr(&nft_payload_type); |
96518518 | 212 | } |