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/netfilter/nf_tables_core.h> |
| 18 | #include <net/netfilter/nf_tables.h> |
| 19 | |
| 20 | struct nft_cmp_expr { |
| 21 | struct nft_data data; |
| 22 | enum nft_registers sreg:8; |
| 23 | u8 len; |
| 24 | enum nft_cmp_ops op:8; |
| 25 | }; |
| 26 | |
| 27 | static void nft_cmp_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_cmp_expr *priv = nft_expr_priv(expr); |
| 32 | int d; |
| 33 | |
| 34 | d = nft_data_cmp(&data[priv->sreg], &priv->data, priv->len); |
| 35 | switch (priv->op) { |
| 36 | case NFT_CMP_EQ: |
| 37 | if (d != 0) |
| 38 | goto mismatch; |
| 39 | break; |
| 40 | case NFT_CMP_NEQ: |
| 41 | if (d == 0) |
| 42 | goto mismatch; |
| 43 | break; |
| 44 | case NFT_CMP_LT: |
| 45 | if (d == 0) |
| 46 | goto mismatch; |
| 47 | case NFT_CMP_LTE: |
| 48 | if (d > 0) |
| 49 | goto mismatch; |
| 50 | break; |
| 51 | case NFT_CMP_GT: |
| 52 | if (d == 0) |
| 53 | goto mismatch; |
| 54 | case NFT_CMP_GTE: |
| 55 | if (d < 0) |
| 56 | goto mismatch; |
| 57 | break; |
| 58 | } |
| 59 | return; |
| 60 | |
| 61 | mismatch: |
| 62 | data[NFT_REG_VERDICT].verdict = NFT_BREAK; |
| 63 | } |
| 64 | |
| 65 | static const struct nla_policy nft_cmp_policy[NFTA_CMP_MAX + 1] = { |
| 66 | [NFTA_CMP_SREG] = { .type = NLA_U32 }, |
| 67 | [NFTA_CMP_OP] = { .type = NLA_U32 }, |
| 68 | [NFTA_CMP_DATA] = { .type = NLA_NESTED }, |
| 69 | }; |
| 70 | |
| 71 | static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr, |
| 72 | const struct nlattr * const tb[]) |
| 73 | { |
| 74 | struct nft_cmp_expr *priv = nft_expr_priv(expr); |
| 75 | struct nft_data_desc desc; |
| 76 | int err; |
| 77 | |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 78 | priv->sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG])); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 79 | priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP])); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 80 | |
| 81 | err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_CMP_DATA]); |
Patrick McHardy | cb7dbfd | 2013-10-10 23:35:40 +0200 | [diff] [blame] | 82 | BUG_ON(err < 0); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 83 | |
| 84 | priv->len = desc.len; |
| 85 | return 0; |
| 86 | } |
| 87 | |
| 88 | static int nft_cmp_dump(struct sk_buff *skb, const struct nft_expr *expr) |
| 89 | { |
| 90 | const struct nft_cmp_expr *priv = nft_expr_priv(expr); |
| 91 | |
| 92 | if (nla_put_be32(skb, NFTA_CMP_SREG, htonl(priv->sreg))) |
| 93 | goto nla_put_failure; |
| 94 | if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op))) |
| 95 | goto nla_put_failure; |
| 96 | |
| 97 | if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data, |
| 98 | NFT_DATA_VALUE, priv->len) < 0) |
| 99 | goto nla_put_failure; |
| 100 | return 0; |
| 101 | |
| 102 | nla_put_failure: |
| 103 | return -1; |
| 104 | } |
| 105 | |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 106 | static struct nft_expr_type nft_cmp_type; |
| 107 | static const struct nft_expr_ops nft_cmp_ops = { |
| 108 | .type = &nft_cmp_type, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 109 | .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)), |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 110 | .eval = nft_cmp_eval, |
| 111 | .init = nft_cmp_init, |
| 112 | .dump = nft_cmp_dump, |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 113 | }; |
| 114 | |
Patrick McHardy | cb7dbfd | 2013-10-10 23:35:40 +0200 | [diff] [blame] | 115 | static int nft_cmp_fast_init(const struct nft_ctx *ctx, |
| 116 | const struct nft_expr *expr, |
| 117 | const struct nlattr * const tb[]) |
| 118 | { |
| 119 | struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); |
| 120 | struct nft_data_desc desc; |
| 121 | struct nft_data data; |
| 122 | u32 mask; |
| 123 | int err; |
| 124 | |
| 125 | priv->sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG])); |
| 126 | |
| 127 | err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]); |
| 128 | BUG_ON(err < 0); |
| 129 | desc.len *= BITS_PER_BYTE; |
| 130 | |
Patrick McHardy | b855d41 | 2014-04-12 13:17:57 +0200 | [diff] [blame^] | 131 | mask = nft_cmp_fast_mask(desc.len); |
Patrick McHardy | cb7dbfd | 2013-10-10 23:35:40 +0200 | [diff] [blame] | 132 | priv->data = data.data[0] & mask; |
| 133 | priv->len = desc.len; |
| 134 | return 0; |
| 135 | } |
| 136 | |
| 137 | static int nft_cmp_fast_dump(struct sk_buff *skb, const struct nft_expr *expr) |
| 138 | { |
| 139 | const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); |
| 140 | struct nft_data data; |
| 141 | |
| 142 | if (nla_put_be32(skb, NFTA_CMP_SREG, htonl(priv->sreg))) |
| 143 | goto nla_put_failure; |
| 144 | if (nla_put_be32(skb, NFTA_CMP_OP, htonl(NFT_CMP_EQ))) |
| 145 | goto nla_put_failure; |
| 146 | |
| 147 | data.data[0] = priv->data; |
| 148 | if (nft_data_dump(skb, NFTA_CMP_DATA, &data, |
| 149 | NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0) |
| 150 | goto nla_put_failure; |
| 151 | return 0; |
| 152 | |
| 153 | nla_put_failure: |
| 154 | return -1; |
| 155 | } |
| 156 | |
| 157 | const struct nft_expr_ops nft_cmp_fast_ops = { |
| 158 | .type = &nft_cmp_type, |
| 159 | .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)), |
| 160 | .eval = NULL, /* inlined */ |
| 161 | .init = nft_cmp_fast_init, |
| 162 | .dump = nft_cmp_fast_dump, |
| 163 | }; |
| 164 | |
Pablo Neira Ayuso | 0ca743a | 2013-10-14 00:06:06 +0200 | [diff] [blame] | 165 | static const struct nft_expr_ops * |
| 166 | nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[]) |
Patrick McHardy | cb7dbfd | 2013-10-10 23:35:40 +0200 | [diff] [blame] | 167 | { |
| 168 | struct nft_data_desc desc; |
| 169 | struct nft_data data; |
| 170 | enum nft_registers sreg; |
| 171 | enum nft_cmp_ops op; |
| 172 | int err; |
| 173 | |
| 174 | if (tb[NFTA_CMP_SREG] == NULL || |
| 175 | tb[NFTA_CMP_OP] == NULL || |
| 176 | tb[NFTA_CMP_DATA] == NULL) |
| 177 | return ERR_PTR(-EINVAL); |
| 178 | |
| 179 | sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG])); |
| 180 | err = nft_validate_input_register(sreg); |
| 181 | if (err < 0) |
| 182 | return ERR_PTR(err); |
| 183 | |
| 184 | op = ntohl(nla_get_be32(tb[NFTA_CMP_OP])); |
| 185 | switch (op) { |
| 186 | case NFT_CMP_EQ: |
| 187 | case NFT_CMP_NEQ: |
| 188 | case NFT_CMP_LT: |
| 189 | case NFT_CMP_LTE: |
| 190 | case NFT_CMP_GT: |
| 191 | case NFT_CMP_GTE: |
| 192 | break; |
| 193 | default: |
| 194 | return ERR_PTR(-EINVAL); |
| 195 | } |
| 196 | |
| 197 | err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]); |
| 198 | if (err < 0) |
| 199 | return ERR_PTR(err); |
| 200 | |
| 201 | if (desc.len <= sizeof(u32) && op == NFT_CMP_EQ) |
| 202 | return &nft_cmp_fast_ops; |
| 203 | else |
| 204 | return &nft_cmp_ops; |
| 205 | } |
| 206 | |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 207 | static struct nft_expr_type nft_cmp_type __read_mostly = { |
| 208 | .name = "cmp", |
Patrick McHardy | cb7dbfd | 2013-10-10 23:35:40 +0200 | [diff] [blame] | 209 | .select_ops = nft_cmp_select_ops, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 210 | .policy = nft_cmp_policy, |
| 211 | .maxattr = NFTA_CMP_MAX, |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 212 | .owner = THIS_MODULE, |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 213 | }; |
| 214 | |
| 215 | int __init nft_cmp_module_init(void) |
| 216 | { |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 217 | return nft_register_expr(&nft_cmp_type); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 218 | } |
| 219 | |
| 220 | void nft_cmp_module_exit(void) |
| 221 | { |
Patrick McHardy | ef1f7df | 2013-10-10 11:41:20 +0200 | [diff] [blame] | 222 | nft_unregister_expr(&nft_cmp_type); |
Patrick McHardy | 9651851 | 2013-10-14 11:00:02 +0200 | [diff] [blame] | 223 | } |