1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> 4 * 5 * Development of this code funded by Astaro AG (http://www.astaro.com/) 6 */ 7 8 #include <asm/unaligned.h> 9 #include <linux/kernel.h> 10 #include <linux/init.h> 11 #include <linux/module.h> 12 #include <linux/netlink.h> 13 #include <linux/netfilter.h> 14 #include <linux/netfilter/nf_tables.h> 15 #include <net/netfilter/nf_tables_core.h> 16 #include <net/netfilter/nf_tables.h> 17 18 struct nft_byteorder { 19 u8 sreg; 20 u8 dreg; 21 enum nft_byteorder_ops op:8; 22 u8 len; 23 u8 size; 24 }; 25 26 void nft_byteorder_eval(const struct nft_expr *expr, 27 struct nft_regs *regs, 28 const struct nft_pktinfo *pkt) 29 { 30 const struct nft_byteorder *priv = nft_expr_priv(expr); 31 u32 *src = ®s->data[priv->sreg]; 32 u32 *dst = ®s->data[priv->dreg]; 33 union { u32 u32; u16 u16; } *s, *d; 34 unsigned int i; 35 36 s = (void *)src; 37 d = (void *)dst; 38 39 switch (priv->size) { 40 case 8: { 41 u64 src64; 42 43 switch (priv->op) { 44 case NFT_BYTEORDER_NTOH: 45 for (i = 0; i < priv->len / 8; i++) { 46 src64 = nft_reg_load64(&src[i]); 47 nft_reg_store64(&dst[i], be64_to_cpu(src64)); 48 } 49 break; 50 case NFT_BYTEORDER_HTON: 51 for (i = 0; i < priv->len / 8; i++) { 52 src64 = (__force __u64) 53 cpu_to_be64(nft_reg_load64(&src[i])); 54 nft_reg_store64(&dst[i], src64); 55 } 56 break; 57 } 58 break; 59 } 60 case 4: 61 switch (priv->op) { 62 case NFT_BYTEORDER_NTOH: 63 for (i = 0; i < priv->len / 4; i++) 64 d[i].u32 = ntohl((__force __be32)s[i].u32); 65 break; 66 case NFT_BYTEORDER_HTON: 67 for (i = 0; i < priv->len / 4; i++) 68 d[i].u32 = (__force __u32)htonl(s[i].u32); 69 break; 70 } 71 break; 72 case 2: 73 switch (priv->op) { 74 case NFT_BYTEORDER_NTOH: 75 for (i = 0; i < priv->len / 2; i++) 76 d[i].u16 = ntohs((__force __be16)s[i].u16); 77 break; 78 case NFT_BYTEORDER_HTON: 79 for (i = 0; i < priv->len / 2; i++) 80 d[i].u16 = (__force __u16)htons(s[i].u16); 81 break; 82 } 83 break; 84 } 85 } 86 87 static const struct nla_policy nft_byteorder_policy[NFTA_BYTEORDER_MAX + 1] = { 88 [NFTA_BYTEORDER_SREG] = { .type = NLA_U32 }, 89 [NFTA_BYTEORDER_DREG] = { .type = NLA_U32 }, 90 [NFTA_BYTEORDER_OP] = { .type = NLA_U32 }, 91 [NFTA_BYTEORDER_LEN] = { .type = NLA_U32 }, 92 [NFTA_BYTEORDER_SIZE] = { .type = NLA_U32 }, 93 }; 94 95 static int nft_byteorder_init(const struct nft_ctx *ctx, 96 const struct nft_expr *expr, 97 const struct nlattr * const tb[]) 98 { 99 struct nft_byteorder *priv = nft_expr_priv(expr); 100 u32 size, len; 101 int err; 102 103 if (tb[NFTA_BYTEORDER_SREG] == NULL || 104 tb[NFTA_BYTEORDER_DREG] == NULL || 105 tb[NFTA_BYTEORDER_LEN] == NULL || 106 tb[NFTA_BYTEORDER_SIZE] == NULL || 107 tb[NFTA_BYTEORDER_OP] == NULL) 108 return -EINVAL; 109 110 priv->op = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_OP])); 111 switch (priv->op) { 112 case NFT_BYTEORDER_NTOH: 113 case NFT_BYTEORDER_HTON: 114 break; 115 default: 116 return -EINVAL; 117 } 118 119 err = nft_parse_u32_check(tb[NFTA_BYTEORDER_SIZE], U8_MAX, &size); 120 if (err < 0) 121 return err; 122 123 priv->size = size; 124 125 switch (priv->size) { 126 case 2: 127 case 4: 128 case 8: 129 break; 130 default: 131 return -EINVAL; 132 } 133 134 err = nft_parse_u32_check(tb[NFTA_BYTEORDER_LEN], U8_MAX, &len); 135 if (err < 0) 136 return err; 137 138 priv->len = len; 139 140 err = nft_parse_register_load(tb[NFTA_BYTEORDER_SREG], &priv->sreg, 141 priv->len); 142 if (err < 0) 143 return err; 144 145 return nft_parse_register_store(ctx, tb[NFTA_BYTEORDER_DREG], 146 &priv->dreg, NULL, NFT_DATA_VALUE, 147 priv->len); 148 } 149 150 static int nft_byteorder_dump(struct sk_buff *skb, const struct nft_expr *expr) 151 { 152 const struct nft_byteorder *priv = nft_expr_priv(expr); 153 154 if (nft_dump_register(skb, NFTA_BYTEORDER_SREG, priv->sreg)) 155 goto nla_put_failure; 156 if (nft_dump_register(skb, NFTA_BYTEORDER_DREG, priv->dreg)) 157 goto nla_put_failure; 158 if (nla_put_be32(skb, NFTA_BYTEORDER_OP, htonl(priv->op))) 159 goto nla_put_failure; 160 if (nla_put_be32(skb, NFTA_BYTEORDER_LEN, htonl(priv->len))) 161 goto nla_put_failure; 162 if (nla_put_be32(skb, NFTA_BYTEORDER_SIZE, htonl(priv->size))) 163 goto nla_put_failure; 164 return 0; 165 166 nla_put_failure: 167 return -1; 168 } 169 170 static bool nft_byteorder_reduce(struct nft_regs_track *track, 171 const struct nft_expr *expr) 172 { 173 struct nft_byteorder *priv = nft_expr_priv(expr); 174 175 nft_reg_track_cancel(track, priv->dreg, priv->len); 176 177 return false; 178 } 179 180 static const struct nft_expr_ops nft_byteorder_ops = { 181 .type = &nft_byteorder_type, 182 .size = NFT_EXPR_SIZE(sizeof(struct nft_byteorder)), 183 .eval = nft_byteorder_eval, 184 .init = nft_byteorder_init, 185 .dump = nft_byteorder_dump, 186 .reduce = nft_byteorder_reduce, 187 }; 188 189 struct nft_expr_type nft_byteorder_type __read_mostly = { 190 .name = "byteorder", 191 .ops = &nft_byteorder_ops, 192 .policy = nft_byteorder_policy, 193 .maxattr = NFTA_BYTEORDER_MAX, 194 .owner = THIS_MODULE, 195 }; 196