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> |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/netlink.h> |
| 15 | #include <linux/netfilter.h> |
| 16 | #include <linux/netfilter/nf_tables.h> |
| 17 | #include <net/dst.h> |
| 18 | #include <net/sock.h> |
| 19 | #include <net/tcp_states.h> /* for TCP_TIME_WAIT */ |
| 20 | #include <net/netfilter/nf_tables.h> |
| 21 | |
| 22 | struct nft_meta { |
| 23 | enum nft_meta_keys key:8; |
| 24 | enum nft_registers dreg:8; |
| 25 | }; |
| 26 | |
| 27 | static void nft_meta_eval(const struct nft_expr *expr, |
| 28 | struct nft_data data[NFT_REG_MAX + 1], |
| 29 | const struct nft_pktinfo *pkt) |
| 30 | { |
| 31 | const struct nft_meta *priv = nft_expr_priv(expr); |
| 32 | const struct sk_buff *skb = pkt->skb; |
| 33 | const struct net_device *in = pkt->in, *out = pkt->out; |
| 34 | struct nft_data *dest = &data[priv->dreg]; |
| 35 | |
| 36 | switch (priv->key) { |
| 37 | case NFT_META_LEN: |
| 38 | dest->data[0] = skb->len; |
| 39 | break; |
| 40 | case NFT_META_PROTOCOL: |
| 41 | *(__be16 *)dest->data = skb->protocol; |
| 42 | break; |
| 43 | case NFT_META_PRIORITY: |
| 44 | dest->data[0] = skb->priority; |
| 45 | break; |
| 46 | case NFT_META_MARK: |
| 47 | dest->data[0] = skb->mark; |
| 48 | break; |
| 49 | case NFT_META_IIF: |
| 50 | if (in == NULL) |
| 51 | goto err; |
| 52 | dest->data[0] = in->ifindex; |
| 53 | break; |
| 54 | case NFT_META_OIF: |
| 55 | if (out == NULL) |
| 56 | goto err; |
| 57 | dest->data[0] = out->ifindex; |
| 58 | break; |
| 59 | case NFT_META_IIFNAME: |
| 60 | if (in == NULL) |
| 61 | goto err; |
| 62 | strncpy((char *)dest->data, in->name, sizeof(dest->data)); |
| 63 | break; |
| 64 | case NFT_META_OIFNAME: |
| 65 | if (out == NULL) |
| 66 | goto err; |
| 67 | strncpy((char *)dest->data, out->name, sizeof(dest->data)); |
| 68 | break; |
| 69 | case NFT_META_IIFTYPE: |
| 70 | if (in == NULL) |
| 71 | goto err; |
| 72 | *(u16 *)dest->data = in->type; |
| 73 | break; |
| 74 | case NFT_META_OIFTYPE: |
| 75 | if (out == NULL) |
| 76 | goto err; |
| 77 | *(u16 *)dest->data = out->type; |
| 78 | break; |
| 79 | case NFT_META_SKUID: |
| 80 | if (skb->sk == NULL || skb->sk->sk_state == TCP_TIME_WAIT) |
| 81 | goto err; |
| 82 | |
| 83 | read_lock_bh(&skb->sk->sk_callback_lock); |
| 84 | if (skb->sk->sk_socket == NULL || |
| 85 | skb->sk->sk_socket->file == NULL) { |
| 86 | read_unlock_bh(&skb->sk->sk_callback_lock); |
| 87 | goto err; |
| 88 | } |
| 89 | |
| 90 | dest->data[0] = |
| 91 | from_kuid_munged(&init_user_ns, |
| 92 | skb->sk->sk_socket->file->f_cred->fsuid); |
| 93 | read_unlock_bh(&skb->sk->sk_callback_lock); |
| 94 | break; |
| 95 | case NFT_META_SKGID: |
| 96 | if (skb->sk == NULL || skb->sk->sk_state == TCP_TIME_WAIT) |
| 97 | goto err; |
| 98 | |
| 99 | read_lock_bh(&skb->sk->sk_callback_lock); |
| 100 | if (skb->sk->sk_socket == NULL || |
| 101 | skb->sk->sk_socket->file == NULL) { |
| 102 | read_unlock_bh(&skb->sk->sk_callback_lock); |
| 103 | goto err; |
| 104 | } |
| 105 | dest->data[0] = |
| 106 | from_kgid_munged(&init_user_ns, |
| 107 | skb->sk->sk_socket->file->f_cred->fsgid); |
| 108 | read_unlock_bh(&skb->sk->sk_callback_lock); |
| 109 | break; |
| 110 | #ifdef CONFIG_NET_CLS_ROUTE |
| 111 | case NFT_META_RTCLASSID: { |
| 112 | const struct dst_entry *dst = skb_dst(skb); |
| 113 | |
| 114 | if (dst == NULL) |
| 115 | goto err; |
| 116 | dest->data[0] = dst->tclassid; |
| 117 | break; |
| 118 | } |
| 119 | #endif |
| 120 | #ifdef CONFIG_NETWORK_SECMARK |
| 121 | case NFT_META_SECMARK: |
| 122 | dest->data[0] = skb->secmark; |
| 123 | break; |
| 124 | #endif |
| 125 | default: |
| 126 | WARN_ON(1); |
| 127 | goto err; |
| 128 | } |
| 129 | return; |
| 130 | |
| 131 | err: |
| 132 | data[NFT_REG_VERDICT].verdict = NFT_BREAK; |
| 133 | } |
| 134 | |
| 135 | static const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = { |
| 136 | [NFTA_META_DREG] = { .type = NLA_U32 }, |
| 137 | [NFTA_META_KEY] = { .type = NLA_U32 }, |
| 138 | }; |
| 139 | |
| 140 | static int nft_meta_init(const struct nft_ctx *ctx, const struct nft_expr *expr, |
| 141 | const struct nlattr * const tb[]) |
| 142 | { |
| 143 | struct nft_meta *priv = nft_expr_priv(expr); |
| 144 | int err; |
| 145 | |
| 146 | if (tb[NFTA_META_DREG] == NULL || |
| 147 | tb[NFTA_META_KEY] == NULL) |
| 148 | return -EINVAL; |
| 149 | |
| 150 | priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY])); |
| 151 | switch (priv->key) { |
| 152 | case NFT_META_LEN: |
| 153 | case NFT_META_PROTOCOL: |
| 154 | case NFT_META_PRIORITY: |
| 155 | case NFT_META_MARK: |
| 156 | case NFT_META_IIF: |
| 157 | case NFT_META_OIF: |
| 158 | case NFT_META_IIFNAME: |
| 159 | case NFT_META_OIFNAME: |
| 160 | case NFT_META_IIFTYPE: |
| 161 | case NFT_META_OIFTYPE: |
| 162 | case NFT_META_SKUID: |
| 163 | case NFT_META_SKGID: |
| 164 | #ifdef CONFIG_NET_CLS_ROUTE |
| 165 | case NFT_META_RTCLASSID: |
| 166 | #endif |
| 167 | #ifdef CONFIG_NETWORK_SECMARK |
| 168 | case NFT_META_SECMARK: |
| 169 | #endif |
| 170 | break; |
| 171 | default: |
| 172 | return -EOPNOTSUPP; |
| 173 | } |
| 174 | |
| 175 | priv->dreg = ntohl(nla_get_be32(tb[NFTA_META_DREG])); |
| 176 | err = nft_validate_output_register(priv->dreg); |
| 177 | if (err < 0) |
| 178 | return err; |
| 179 | return nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE); |
| 180 | } |
| 181 | |
| 182 | static int nft_meta_dump(struct sk_buff *skb, const struct nft_expr *expr) |
| 183 | { |
| 184 | const struct nft_meta *priv = nft_expr_priv(expr); |
| 185 | |
| 186 | if (nla_put_be32(skb, NFTA_META_DREG, htonl(priv->dreg))) |
| 187 | goto nla_put_failure; |
| 188 | if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key))) |
| 189 | goto nla_put_failure; |
| 190 | return 0; |
| 191 | |
| 192 | nla_put_failure: |
| 193 | return -1; |
| 194 | } |
| 195 | |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 196 | static struct nft_expr_type nft_meta_type; |
| 197 | static const struct nft_expr_ops nft_meta_ops = { |
| 198 | .type = &nft_meta_type, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 199 | .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)), |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 200 | .eval = nft_meta_eval, |
| 201 | .init = nft_meta_init, |
| 202 | .dump = nft_meta_dump, |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 203 | }; |
| 204 | |
| 205 | static struct nft_expr_type nft_meta_type __read_mostly = { |
| 206 | .name = "meta", |
| 207 | .ops = &nft_meta_ops, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 208 | .policy = nft_meta_policy, |
| 209 | .maxattr = NFTA_META_MAX, |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 210 | .owner = THIS_MODULE, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 211 | }; |
| 212 | |
| 213 | static int __init nft_meta_module_init(void) |
| 214 | { |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 215 | return nft_register_expr(&nft_meta_type); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 216 | } |
| 217 | |
| 218 | static void __exit nft_meta_module_exit(void) |
| 219 | { |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 220 | nft_unregister_expr(&nft_meta_type); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 221 | } |
| 222 | |
| 223 | module_init(nft_meta_module_init); |
| 224 | module_exit(nft_meta_module_exit); |
| 225 | |
| 226 | MODULE_LICENSE("GPL"); |
| 227 | MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |
| 228 | MODULE_ALIAS_NFT_EXPR("meta"); |