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 enum nft_registers sreg:8; 20 enum nft_registers dreg:8; 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 = get_unaligned((u64 *)&src[i]); 47 put_unaligned_be64(src64, &dst[i]); 48 } 49 break; 50 case NFT_BYTEORDER_HTON: 51 for (i = 0; i < priv->len / 8; i++) { 52 src64 = get_unaligned_be64(&src[i]); 53 put_unaligned(src64, (u64 *)&dst[i]); 54 } 55 break; 56 } 57 break; 58 } 59 case 4: 60 switch (priv->op) { 61 case NFT_BYTEORDER_NTOH: 62 for (i = 0; i < priv->len / 4; i++) 63 d[i].u32 = ntohl((__force __be32)s[i].u32); 64 break; 65 case NFT_BYTEORDER_HTON: 66 for (i = 0; i < priv->len / 4; i++) 67 d[i].u32 = (__force __u32)htonl(s[i].u32); 68 break; 69 } 70 break; 71 case 2: 72 switch (priv->op) { 73 case NFT_BYTEORDER_NTOH: 74 for (i = 0; i < priv->len / 2; i++) 75 d[i].u16 = ntohs((__force __be16)s[i].u16); 76 break; 77 case NFT_BYTEORDER_HTON: 78 for (i = 0; i < priv->len / 2; i++) 79 d[i].u16 = (__force __u16)htons(s[i].u16); 80 break; 81 } 82 break; 83 } 84 } 85 86 static const struct nla_policy nft_byteorder_policy[NFTA_BYTEORDER_MAX + 1] = { 87 [NFTA_BYTEORDER_SREG] = { .type = NLA_U32 }, 88 [NFTA_BYTEORDER_DREG] = { .type = NLA_U32 }, 89 [NFTA_BYTEORDER_OP] = { .type = NLA_U32 }, 90 [NFTA_BYTEORDER_LEN] = { .type = NLA_U32 }, 91 [NFTA_BYTEORDER_SIZE] = { .type = NLA_U32 }, 92 }; 93 94 static int nft_byteorder_init(const struct nft_ctx *ctx, 95 const struct nft_expr *expr, 96 const struct nlattr * const tb[]) 97 { 98 struct nft_byteorder *priv = nft_expr_priv(expr); 99 u32 size, len; 100 int err; 101 102 if (tb[NFTA_BYTEORDER_SREG] == NULL || 103 tb[NFTA_BYTEORDER_DREG] == NULL || 104 tb[NFTA_BYTEORDER_LEN] == NULL || 105 tb[NFTA_BYTEORDER_SIZE] == NULL || 106 tb[NFTA_BYTEORDER_OP] == NULL) 107 return -EINVAL; 108 109 priv->op = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_OP])); 110 switch (priv->op) { 111 case NFT_BYTEORDER_NTOH: 112 case NFT_BYTEORDER_HTON: 113 break; 114 default: 115 return -EINVAL; 116 } 117 118 err = nft_parse_u32_check(tb[NFTA_BYTEORDER_SIZE], U8_MAX, &size); 119 if (err < 0) 120 return err; 121 122 priv->size = size; 123 124 switch (priv->size) { 125 case 2: 126 case 4: 127 case 8: 128 break; 129 default: 130 return -EINVAL; 131 } 132 133 priv->sreg = nft_parse_register(tb[NFTA_BYTEORDER_SREG]); 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_validate_register_load(priv->sreg, priv->len); 141 if (err < 0) 142 return err; 143 144 priv->dreg = nft_parse_register(tb[NFTA_BYTEORDER_DREG]); 145 return nft_validate_register_store(ctx, priv->dreg, NULL, 146 NFT_DATA_VALUE, priv->len); 147 } 148 149 static int nft_byteorder_dump(struct sk_buff *skb, const struct nft_expr *expr) 150 { 151 const struct nft_byteorder *priv = nft_expr_priv(expr); 152 153 if (nft_dump_register(skb, NFTA_BYTEORDER_SREG, priv->sreg)) 154 goto nla_put_failure; 155 if (nft_dump_register(skb, NFTA_BYTEORDER_DREG, priv->dreg)) 156 goto nla_put_failure; 157 if (nla_put_be32(skb, NFTA_BYTEORDER_OP, htonl(priv->op))) 158 goto nla_put_failure; 159 if (nla_put_be32(skb, NFTA_BYTEORDER_LEN, htonl(priv->len))) 160 goto nla_put_failure; 161 if (nla_put_be32(skb, NFTA_BYTEORDER_SIZE, htonl(priv->size))) 162 goto nla_put_failure; 163 return 0; 164 165 nla_put_failure: 166 return -1; 167 } 168 169 static const struct nft_expr_ops nft_byteorder_ops = { 170 .type = &nft_byteorder_type, 171 .size = NFT_EXPR_SIZE(sizeof(struct nft_byteorder)), 172 .eval = nft_byteorder_eval, 173 .init = nft_byteorder_init, 174 .dump = nft_byteorder_dump, 175 }; 176 177 struct nft_expr_type nft_byteorder_type __read_mostly = { 178 .name = "byteorder", 179 .ops = &nft_byteorder_ops, 180 .policy = nft_byteorder_policy, 181 .maxattr = NFTA_BYTEORDER_MAX, 182 .owner = THIS_MODULE, 183 }; 184