| /* |
| * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * Development of this code funded by Astaro AG (http://www.astaro.com/) |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/netlink.h> |
| #include <linux/netfilter.h> |
| #include <linux/netfilter/nf_tables.h> |
| #include <net/netfilter/nf_tables_core.h> |
| #include <net/netfilter/nf_tables.h> |
| |
| struct nft_byteorder { |
| enum nft_registers sreg:8; |
| enum nft_registers dreg:8; |
| enum nft_byteorder_ops op:8; |
| u8 len; |
| u8 size; |
| }; |
| |
| static void nft_byteorder_eval(const struct nft_expr *expr, |
| struct nft_regs *regs, |
| const struct nft_pktinfo *pkt) |
| { |
| const struct nft_byteorder *priv = nft_expr_priv(expr); |
| u32 *src = ®s->data[priv->sreg]; |
| u32 *dst = ®s->data[priv->dreg]; |
| union { u32 u32; u16 u16; } *s, *d; |
| unsigned int i; |
| |
| s = (void *)src; |
| d = (void *)dst; |
| |
| switch (priv->size) { |
| case 4: |
| switch (priv->op) { |
| case NFT_BYTEORDER_NTOH: |
| for (i = 0; i < priv->len / 4; i++) |
| d[i].u32 = ntohl((__force __be32)s[i].u32); |
| break; |
| case NFT_BYTEORDER_HTON: |
| for (i = 0; i < priv->len / 4; i++) |
| d[i].u32 = (__force __u32)htonl(s[i].u32); |
| break; |
| } |
| break; |
| case 2: |
| switch (priv->op) { |
| case NFT_BYTEORDER_NTOH: |
| for (i = 0; i < priv->len / 2; i++) |
| d[i].u16 = ntohs((__force __be16)s[i].u16); |
| break; |
| case NFT_BYTEORDER_HTON: |
| for (i = 0; i < priv->len / 2; i++) |
| d[i].u16 = (__force __u16)htons(s[i].u16); |
| break; |
| } |
| break; |
| } |
| } |
| |
| static const struct nla_policy nft_byteorder_policy[NFTA_BYTEORDER_MAX + 1] = { |
| [NFTA_BYTEORDER_SREG] = { .type = NLA_U32 }, |
| [NFTA_BYTEORDER_DREG] = { .type = NLA_U32 }, |
| [NFTA_BYTEORDER_OP] = { .type = NLA_U32 }, |
| [NFTA_BYTEORDER_LEN] = { .type = NLA_U32 }, |
| [NFTA_BYTEORDER_SIZE] = { .type = NLA_U32 }, |
| }; |
| |
| static int nft_byteorder_init(const struct nft_ctx *ctx, |
| const struct nft_expr *expr, |
| const struct nlattr * const tb[]) |
| { |
| struct nft_byteorder *priv = nft_expr_priv(expr); |
| int err; |
| |
| if (tb[NFTA_BYTEORDER_SREG] == NULL || |
| tb[NFTA_BYTEORDER_DREG] == NULL || |
| tb[NFTA_BYTEORDER_LEN] == NULL || |
| tb[NFTA_BYTEORDER_SIZE] == NULL || |
| tb[NFTA_BYTEORDER_OP] == NULL) |
| return -EINVAL; |
| |
| priv->op = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_OP])); |
| switch (priv->op) { |
| case NFT_BYTEORDER_NTOH: |
| case NFT_BYTEORDER_HTON: |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| priv->size = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_SIZE])); |
| switch (priv->size) { |
| case 2: |
| case 4: |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| priv->sreg = nft_parse_register(tb[NFTA_BYTEORDER_SREG]); |
| priv->len = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_LEN])); |
| err = nft_validate_register_load(priv->sreg, priv->len); |
| if (err < 0) |
| return err; |
| |
| priv->dreg = nft_parse_register(tb[NFTA_BYTEORDER_DREG]); |
| return nft_validate_register_store(ctx, priv->dreg, NULL, |
| NFT_DATA_VALUE, priv->len); |
| } |
| |
| static int nft_byteorder_dump(struct sk_buff *skb, const struct nft_expr *expr) |
| { |
| const struct nft_byteorder *priv = nft_expr_priv(expr); |
| |
| if (nft_dump_register(skb, NFTA_BYTEORDER_SREG, priv->sreg)) |
| goto nla_put_failure; |
| if (nft_dump_register(skb, NFTA_BYTEORDER_DREG, priv->dreg)) |
| goto nla_put_failure; |
| if (nla_put_be32(skb, NFTA_BYTEORDER_OP, htonl(priv->op))) |
| goto nla_put_failure; |
| if (nla_put_be32(skb, NFTA_BYTEORDER_LEN, htonl(priv->len))) |
| goto nla_put_failure; |
| if (nla_put_be32(skb, NFTA_BYTEORDER_SIZE, htonl(priv->size))) |
| goto nla_put_failure; |
| return 0; |
| |
| nla_put_failure: |
| return -1; |
| } |
| |
| static struct nft_expr_type nft_byteorder_type; |
| static const struct nft_expr_ops nft_byteorder_ops = { |
| .type = &nft_byteorder_type, |
| .size = NFT_EXPR_SIZE(sizeof(struct nft_byteorder)), |
| .eval = nft_byteorder_eval, |
| .init = nft_byteorder_init, |
| .dump = nft_byteorder_dump, |
| }; |
| |
| static struct nft_expr_type nft_byteorder_type __read_mostly = { |
| .name = "byteorder", |
| .ops = &nft_byteorder_ops, |
| .policy = nft_byteorder_policy, |
| .maxattr = NFTA_BYTEORDER_MAX, |
| .owner = THIS_MODULE, |
| }; |
| |
| int __init nft_byteorder_module_init(void) |
| { |
| return nft_register_expr(&nft_byteorder_type); |
| } |
| |
| void nft_byteorder_module_exit(void) |
| { |
| nft_unregister_expr(&nft_byteorder_type); |
| } |