From 789c8da38e302dd1951ac1966c1788a850c668da Mon Sep 17 00:00:00 2001 From: Arturo Borrero Date: Mon, 8 Sep 2014 13:38:46 +0200 Subject: expr: add new nft_masq expression This patch adds userspace support to nft_masq, the new expression to perform masquerade. Signed-off-by: Arturo Borrero Gonzalez Signed-off-by: Pablo Neira Ayuso --- src/expr/masq.c | 208 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 208 insertions(+) create mode 100644 src/expr/masq.c (limited to 'src/expr/masq.c') diff --git a/src/expr/masq.c b/src/expr/masq.c new file mode 100644 index 0000000..6a1c609 --- /dev/null +++ b/src/expr/masq.c @@ -0,0 +1,208 @@ +/* + * (C) 2014 by Arturo Borrero Gonzalez + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published + * by the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include +#include +#include +#include +#include + +#include + +#include "internal.h" +#include +#include +#include +#include "expr_ops.h" + +struct nft_expr_masq { + uint32_t flags; +}; + +static int +nft_rule_expr_masq_set(struct nft_rule_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nft_expr_masq *masq = nft_expr_data(e); + + switch (type) { + case NFT_EXPR_MASQ_FLAGS: + masq->flags = *((uint32_t *)data); + break; + default: + return -1; + } + return 0; +} + +static const void * +nft_rule_expr_masq_get(const struct nft_rule_expr *e, uint16_t type, + uint32_t *data_len) +{ + struct nft_expr_masq *masq = nft_expr_data(e); + + switch (type) { + case NFT_EXPR_MASQ_FLAGS: + *data_len = sizeof(masq->flags); + return &masq->flags; + } + return NULL; +} + +static int nft_rule_expr_masq_cb(const struct nlattr *attr, void *data) +{ + const struct nlattr **tb = data; + int type = mnl_attr_get_type(attr); + + if (mnl_attr_type_valid(attr, NFTA_MASQ_MAX) < 0) + return MNL_CB_OK; + + switch (type) { + case NFTA_MASQ_FLAGS: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nft_rule_expr_masq_build(struct nlmsghdr *nlh, struct nft_rule_expr *e) +{ + struct nft_expr_masq *masq = nft_expr_data(e); + + if (e->flags & (1 << NFT_EXPR_MASQ_FLAGS)) + mnl_attr_put_u32(nlh, NFTA_MASQ_FLAGS, htobe32(masq->flags)); +} + +static int +nft_rule_expr_masq_parse(struct nft_rule_expr *e, struct nlattr *attr) +{ + struct nft_expr_masq *masq = nft_expr_data(e); + struct nlattr *tb[NFTA_MASQ_MAX+1] = {}; + + if (mnl_attr_parse_nested(attr, nft_rule_expr_masq_cb, tb) < 0) + return -1; + + if (tb[NFTA_MASQ_FLAGS]) { + masq->flags = be32toh(mnl_attr_get_u32(tb[NFTA_MASQ_FLAGS])); + e->flags |= (1 << NFT_EXPR_MASQ_FLAGS); + } + + return 0; +} + +static int +nft_rule_expr_masq_json_parse(struct nft_rule_expr *e, json_t *root, + struct nft_parse_err *err) +{ +#ifdef JSON_PARSING + uint32_t flags; + + if (nft_jansson_parse_val(root, "flags", NFT_TYPE_U32, &flags, + err) == 0) + nft_rule_expr_set_u32(e, NFT_EXPR_MASQ_FLAGS, flags); + + return 0; +#else + errno = EOPNOTSUPP; + return -1; +#endif +} + +static int +nft_rule_expr_masq_xml_parse(struct nft_rule_expr *e, mxml_node_t *tree, + struct nft_parse_err *err) +{ +#ifdef XML_PARSING + uint32_t flags; + + if (nft_mxml_num_parse(tree, "flags", MXML_DESCEND_FIRST, BASE_DEC, + &flags, NFT_TYPE_U32, NFT_XML_MAND, err) == 0) + nft_rule_expr_set_u32(e, NFT_EXPR_MASQ_FLAGS, flags); + + return 0; +#else + errno = EOPNOTSUPP; + return -1; +#endif +} +static int nft_rule_expr_masq_snprintf_json(char *buf, size_t len, + struct nft_rule_expr *e) +{ + int ret, size = len, offset = 0; + struct nft_expr_masq *masq = nft_expr_data(e); + + if (e->flags & (1 << NFT_EXPR_MASQ_FLAGS)) { + ret = snprintf(buf + offset, len, "\"flags\":%u", masq->flags); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + } + + return offset; +} + +static int nft_rule_expr_masq_snprintf_xml(char *buf, size_t len, + struct nft_rule_expr *e) +{ + int ret, size = len, offset = 0; + struct nft_expr_masq *masq = nft_expr_data(e); + + if (e->flags & (1 << NFT_EXPR_MASQ_FLAGS)) { + ret = snprintf(buf + offset, len, "%u", + masq->flags); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + } + + return offset; +} + +static int nft_rule_expr_masq_snprintf_default(char *buf, size_t len, + struct nft_rule_expr *e) +{ + struct nft_expr_masq *masq = nft_expr_data(e); + + return snprintf(buf, len, " flags %u ", + masq->flags); +} + +static int nft_rule_expr_masq_snprintf(char *buf, size_t len, uint32_t type, + uint32_t flags, struct nft_rule_expr *e) +{ + switch (type) { + case NFT_OUTPUT_DEFAULT: + return nft_rule_expr_masq_snprintf_default(buf, len, e); + case NFT_OUTPUT_XML: + return nft_rule_expr_masq_snprintf_xml(buf, len, e); + case NFT_OUTPUT_JSON: + return nft_rule_expr_masq_snprintf_json(buf, len, e); + default: + break; + } + return -1; +} + +struct expr_ops expr_ops_masq = { + .name = "masq", + .alloc_len = sizeof(struct nft_expr_masq), + .max_attr = NFTA_MASQ_MAX, + .set = nft_rule_expr_masq_set, + .get = nft_rule_expr_masq_get, + .parse = nft_rule_expr_masq_parse, + .build = nft_rule_expr_masq_build, + .snprintf = nft_rule_expr_masq_snprintf, + .xml_parse = nft_rule_expr_masq_xml_parse, + .json_parse = nft_rule_expr_masq_json_parse, +}; + +static void __init expr_masq_init(void) +{ + nft_expr_ops_register(&expr_ops_masq); +} -- cgit v1.2.3