Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 1 | /* |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 2 | * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 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> |
Florian Westphal | 8cfd23e | 2015-08-17 18:09:55 +0200 | [diff] [blame] | 12 | #include <linux/if_vlan.h> |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 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 | |
Florian Westphal | 8cfd23e | 2015-08-17 18:09:55 +0200 | [diff] [blame] | 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 | |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 68 | static void nft_payload_eval(const struct nft_expr *expr, |
Patrick McHardy | a55e22e | 2015-04-11 02:27:31 +0100 | [diff] [blame] | 69 | struct nft_regs *regs, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 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; |
Patrick McHardy | 49499c3 | 2015-04-11 02:27:37 +0100 | [diff] [blame] | 74 | u32 *dest = ®s->data[priv->dreg]; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 75 | int offset; |
| 76 | |
Florian Westphal | 8cfd23e | 2015-08-17 18:09:55 +0200 | [diff] [blame] | 77 | dest[priv->len / NFT_REG32_SIZE] = 0; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 78 | switch (priv->base) { |
| 79 | case NFT_PAYLOAD_LL_HEADER: |
| 80 | if (!skb_mac_header_was_set(skb)) |
| 81 | goto err; |
Florian Westphal | 8cfd23e | 2015-08-17 18:09:55 +0200 | [diff] [blame] | 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 | } |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 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: |
Pablo Neira Ayuso | c54032e | 2013-10-11 10:00:22 +0200 | [diff] [blame] | 95 | offset = pkt->xt.thoff; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 96 | break; |
| 97 | default: |
| 98 | BUG(); |
| 99 | } |
| 100 | offset += priv->offset; |
| 101 | |
Patrick McHardy | fad136e | 2015-04-11 02:27:33 +0100 | [diff] [blame] | 102 | if (skb_copy_bits(skb, offset, dest, priv->len) < 0) |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 103 | goto err; |
| 104 | return; |
| 105 | err: |
Patrick McHardy | a55e22e | 2015-04-11 02:27:31 +0100 | [diff] [blame] | 106 | regs->verdict.code = NFT_BREAK; |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 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); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 121 | |
Patrick McHardy | c29b72e | 2013-10-10 11:06:41 +0200 | [diff] [blame] | 122 | priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE])); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 123 | priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET])); |
| 124 | priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN])); |
Patrick McHardy | b1c96ed | 2015-04-11 02:27:36 +0100 | [diff] [blame] | 125 | priv->dreg = nft_parse_register(tb[NFTA_PAYLOAD_DREG]); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 126 | |
Patrick McHardy | 1ec1021 | 2015-04-11 02:27:27 +0100 | [diff] [blame] | 127 | return nft_validate_register_store(ctx, priv->dreg, NULL, |
| 128 | NFT_DATA_VALUE, priv->len); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 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 | |
Patrick McHardy | b1c96ed | 2015-04-11 02:27:36 +0100 | [diff] [blame] | 135 | if (nft_dump_register(skb, NFTA_PAYLOAD_DREG, priv->dreg) || |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 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 | |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 146 | static struct nft_expr_type nft_payload_type; |
| 147 | static const struct nft_expr_ops nft_payload_ops = { |
| 148 | .type = &nft_payload_type, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 149 | .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)), |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 150 | .eval = nft_payload_eval, |
| 151 | .init = nft_payload_init, |
| 152 | .dump = nft_payload_dump, |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 153 | }; |
| 154 | |
Patrick McHardy | c29b72e | 2013-10-10 11:06:41 +0200 | [diff] [blame] | 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 | |
Pablo Neira Ayuso | 0ca743a | 2013-10-14 00:06:06 +0200 | [diff] [blame] | 163 | static const struct nft_expr_ops * |
| 164 | nft_payload_select_ops(const struct nft_ctx *ctx, |
| 165 | const struct nlattr * const tb[]) |
Patrick McHardy | c29b72e | 2013-10-10 11:06:41 +0200 | [diff] [blame] | 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])); |
Patrick McHardy | 45d9bcd | 2015-04-11 02:27:26 +0100 | [diff] [blame] | 187 | len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN])); |
Patrick McHardy | c29b72e | 2013-10-10 11:06:41 +0200 | [diff] [blame] | 188 | |
Nikolay Aleksandrov | f627ed9 | 2014-02-16 14:01:58 +0100 | [diff] [blame] | 189 | if (len <= 4 && is_power_of_2(len) && IS_ALIGNED(offset, len) && |
| 190 | base != NFT_PAYLOAD_LL_HEADER) |
Patrick McHardy | c29b72e | 2013-10-10 11:06:41 +0200 | [diff] [blame] | 191 | return &nft_payload_fast_ops; |
| 192 | else |
| 193 | return &nft_payload_ops; |
| 194 | } |
| 195 | |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 196 | static struct nft_expr_type nft_payload_type __read_mostly = { |
| 197 | .name = "payload", |
Patrick McHardy | c29b72e | 2013-10-10 11:06:41 +0200 | [diff] [blame] | 198 | .select_ops = nft_payload_select_ops, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 199 | .policy = nft_payload_policy, |
| 200 | .maxattr = NFTA_PAYLOAD_MAX, |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 201 | .owner = THIS_MODULE, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 202 | }; |
| 203 | |
| 204 | int __init nft_payload_module_init(void) |
| 205 | { |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 206 | return nft_register_expr(&nft_payload_type); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 207 | } |
| 208 | |
| 209 | void nft_payload_module_exit(void) |
| 210 | { |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 211 | nft_unregister_expr(&nft_payload_type); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 212 | } |