diff options
Diffstat (limited to 'net/netfilter/nft_byteorder.c')
| -rw-r--r-- | net/netfilter/nft_byteorder.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/net/netfilter/nft_byteorder.c b/net/netfilter/nft_byteorder.c new file mode 100644 index 000000000000..c39ed8d29df1 --- /dev/null +++ b/net/netfilter/nft_byteorder.c @@ -0,0 +1,173 @@ +/* + * 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_data data[NFT_REG_MAX + 1], + const struct nft_pktinfo *pkt) +{ + const struct nft_byteorder *priv = nft_expr_priv(expr); + struct nft_data *src = &data[priv->sreg], *dst = &data[priv->dreg]; + union { u32 u32; u16 u16; } *s, *d; + unsigned int i; + + s = (void *)src->data; + d = (void *)dst->data; + + 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->sreg = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_SREG])); + err = nft_validate_input_register(priv->sreg); + if (err < 0) + return err; + + priv->dreg = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_DREG])); + err = nft_validate_output_register(priv->dreg); + if (err < 0) + return err; + err = nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE); + if (err < 0) + return err; + + 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->len = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_LEN])); + if (priv->len == 0 || priv->len > FIELD_SIZEOF(struct nft_data, data)) + return -EINVAL; + + priv->size = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_SIZE])); + switch (priv->size) { + case 2: + case 4: + break; + default: + return -EINVAL; + } + + return 0; +} + +static int nft_byteorder_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_byteorder *priv = nft_expr_priv(expr); + + if (nla_put_be32(skb, NFTA_BYTEORDER_SREG, htonl(priv->sreg))) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_BYTEORDER_DREG, htonl(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); +} |