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], 48 be64_to_cpu((__force __be64)src64)); 49 } 50 break; 51 case NFT_BYTEORDER_HTON: 52 for (i = 0; i < priv->len / 8; i++) { 53 src64 = (__force __u64) 54 cpu_to_be64(nft_reg_load64(&src[i])); 55 nft_reg_store64(&dst[i], src64); 56 } 57 break; 58 } 59 break; 60 } 61 case 4: 62 switch (priv->op) { 63 case NFT_BYTEORDER_NTOH: 64 for (i = 0; i < priv->len / 4; i++) 65 d[i].u32 = ntohl((__force __be32)s[i].u32); 66 break; 67 case NFT_BYTEORDER_HTON: 68 for (i = 0; i < priv->len / 4; i++) 69 d[i].u32 = (__force __u32)htonl(s[i].u32); 70 break; 71 } 72 break; 73 case 2: 74 switch (priv->op) { 75 case NFT_BYTEORDER_NTOH: 76 for (i = 0; i < priv->len / 2; i++) 77 d[i].u16 = ntohs((__force __be16)s[i].u16); 78 break; 79 case NFT_BYTEORDER_HTON: 80 for (i = 0; i < priv->len / 2; i++) 81 d[i].u16 = (__force __u16)htons(s[i].u16); 82 break; 83 } 84 break; 85 } 86 } 87 88 static const struct nla_policy nft_byteorder_policy[NFTA_BYTEORDER_MAX + 1] = { 89 [NFTA_BYTEORDER_SREG] = { .type = NLA_U32 }, 90 [NFTA_BYTEORDER_DREG] = { .type = NLA_U32 }, 91 [NFTA_BYTEORDER_OP] = { .type = NLA_U32 }, 92 [NFTA_BYTEORDER_LEN] = { .type = NLA_U32 }, 93 [NFTA_BYTEORDER_SIZE] = { .type = NLA_U32 }, 94 }; 95 96 static int nft_byteorder_init(const struct nft_ctx *ctx, 97 const struct nft_expr *expr, 98 const struct nlattr * const tb[]) 99 { 100 struct nft_byteorder *priv = nft_expr_priv(expr); 101 u32 size, len; 102 int err; 103 104 if (tb[NFTA_BYTEORDER_SREG] == NULL || 105 tb[NFTA_BYTEORDER_DREG] == NULL || 106 tb[NFTA_BYTEORDER_LEN] == NULL || 107 tb[NFTA_BYTEORDER_SIZE] == NULL || 108 tb[NFTA_BYTEORDER_OP] == NULL) 109 return -EINVAL; 110 111 priv->op = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_OP])); 112 switch (priv->op) { 113 case NFT_BYTEORDER_NTOH: 114 case NFT_BYTEORDER_HTON: 115 break; 116 default: 117 return -EINVAL; 118 } 119 120 err = nft_parse_u32_check(tb[NFTA_BYTEORDER_SIZE], U8_MAX, &size); 121 if (err < 0) 122 return err; 123 124 priv->size = size; 125 126 switch (priv->size) { 127 case 2: 128 case 4: 129 case 8: 130 break; 131 default: 132 return -EINVAL; 133 } 134 135 err = nft_parse_u32_check(tb[NFTA_BYTEORDER_LEN], U8_MAX, &len); 136 if (err < 0) 137 return err; 138 139 priv->len = len; 140 141 err = nft_parse_register_load(tb[NFTA_BYTEORDER_SREG], &priv->sreg, 142 priv->len); 143 if (err < 0) 144 return err; 145 146 return nft_parse_register_store(ctx, tb[NFTA_BYTEORDER_DREG], 147 &priv->dreg, NULL, NFT_DATA_VALUE, 148 priv->len); 149 } 150 151 static int nft_byteorder_dump(struct sk_buff *skb, 152 const struct nft_expr *expr, bool reset) 153 { 154 const struct nft_byteorder *priv = nft_expr_priv(expr); 155 156 if (nft_dump_register(skb, NFTA_BYTEORDER_SREG, priv->sreg)) 157 goto nla_put_failure; 158 if (nft_dump_register(skb, NFTA_BYTEORDER_DREG, priv->dreg)) 159 goto nla_put_failure; 160 if (nla_put_be32(skb, NFTA_BYTEORDER_OP, htonl(priv->op))) 161 goto nla_put_failure; 162 if (nla_put_be32(skb, NFTA_BYTEORDER_LEN, htonl(priv->len))) 163 goto nla_put_failure; 164 if (nla_put_be32(skb, NFTA_BYTEORDER_SIZE, htonl(priv->size))) 165 goto nla_put_failure; 166 return 0; 167 168 nla_put_failure: 169 return -1; 170 } 171 172 static bool nft_byteorder_reduce(struct nft_regs_track *track, 173 const struct nft_expr *expr) 174 { 175 struct nft_byteorder *priv = nft_expr_priv(expr); 176 177 nft_reg_track_cancel(track, priv->dreg, priv->len); 178 179 return false; 180 } 181 182 static const struct nft_expr_ops nft_byteorder_ops = { 183 .type = &nft_byteorder_type, 184 .size = NFT_EXPR_SIZE(sizeof(struct nft_byteorder)), 185 .eval = nft_byteorder_eval, 186 .init = nft_byteorder_init, 187 .dump = nft_byteorder_dump, 188 .reduce = nft_byteorder_reduce, 189 }; 190 191 struct nft_expr_type nft_byteorder_type __read_mostly = { 192 .name = "byteorder", 193 .ops = &nft_byteorder_ops, 194 .policy = nft_byteorder_policy, 195 .maxattr = NFTA_BYTEORDER_MAX, 196 .owner = THIS_MODULE, 197 }; 198