summaryrefslogtreecommitdiffstats
path: root/src/expr/immediate.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/expr/immediate.c')
-rw-r--r--src/expr/immediate.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/src/expr/immediate.c b/src/expr/immediate.c
new file mode 100644
index 0000000..68c27ec
--- /dev/null
+++ b/src/expr/immediate.c
@@ -0,0 +1,215 @@
+/*
+ * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * 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.
+ *
+ * This code has been sponsored by Sophos Astaro <http://www.sophos.com>
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <arpa/inet.h>
+
+#include "internal.h"
+#include <libmnl/libmnl.h>
+#include <linux/netfilter/nf_tables.h>
+#include <libnftables/expr.h>
+#include "expr_ops.h"
+#include "data_reg.h"
+
+struct nft_expr_immediate {
+ union nft_data_reg data;
+ enum nft_registers dreg;
+};
+
+static int
+nft_rule_expr_immediate_set(struct nft_rule_expr *e, uint16_t type,
+ const void *data, size_t data_len)
+{
+ struct nft_expr_immediate *imm = (struct nft_expr_immediate *)e->data;
+
+ switch(type) {
+ case NFT_EXPR_IMM_DREG:
+ imm->dreg = *((uint32_t *)data);
+ break;
+ case NFT_EXPR_IMM_DATA:
+ memcpy(&imm->data.val, data, data_len);
+ imm->data.len = data_len;
+ break;
+ case NFT_EXPR_IMM_VERDICT:
+ imm->data.verdict = *((uint32_t *)data);
+ break;
+ case NFT_EXPR_IMM_CHAIN:
+ if (imm->data.chain)
+ free(imm->data.chain);
+
+ imm->data.chain = strdup(data);
+ break;
+ default:
+ return -1;
+ }
+ return 0;
+}
+
+static const void *
+nft_rule_expr_immediate_get(struct nft_rule_expr *e, uint16_t type,
+ size_t *data_len)
+{
+ struct nft_expr_immediate *imm = (struct nft_expr_immediate *)e->data;
+
+ switch(type) {
+ case NFT_EXPR_IMM_DREG:
+ if (e->flags & (1 << NFT_EXPR_IMM_DREG)) {
+ *data_len = sizeof(imm->dreg);
+ return &imm->dreg;
+ } else
+ return NULL;
+ break;
+ case NFT_EXPR_IMM_DATA:
+ if (e->flags & (1 << NFT_EXPR_IMM_DATA)) {
+ *data_len = imm->data.len;
+ return &imm->data.val;
+ } else
+ return NULL;
+ break;
+ case NFT_EXPR_IMM_VERDICT:
+ if (e->flags & (1 << NFT_EXPR_IMM_VERDICT)) {
+ *data_len = sizeof(imm->data.verdict);
+ return &imm->data.verdict;
+ } else
+ return NULL;
+ break;
+ case NFT_EXPR_IMM_CHAIN:
+ if (e->flags & (1 << NFT_EXPR_IMM_CHAIN)) {
+ *data_len = strlen(imm->data.chain)+1;
+ return imm->data.chain;
+ } else
+ return NULL;
+ break;
+ default:
+ break;
+ }
+ return NULL;
+}
+
+static int nft_rule_expr_immediate_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_IMMEDIATE_MAX) < 0)
+ return MNL_CB_OK;
+
+ switch(type) {
+ case NFTA_IMMEDIATE_DREG:
+ if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
+ perror("mnl_attr_validate");
+ return MNL_CB_ERROR;
+ }
+ break;
+ case NFTA_IMMEDIATE_DATA:
+ if (mnl_attr_validate(attr, MNL_TYPE_BINARY) < 0) {
+ perror("mnl_attr_validate");
+ return MNL_CB_ERROR;
+ }
+ break;
+ }
+
+ tb[type] = attr;
+ return MNL_CB_OK;
+}
+
+static void
+nft_rule_expr_immediate_build(struct nlmsghdr *nlh, struct nft_rule_expr *e)
+{
+ struct nft_expr_immediate *imm = (struct nft_expr_immediate *)e->data;
+
+ if (e->flags & (1 << NFT_EXPR_IMM_DREG))
+ mnl_attr_put_u32(nlh, NFTA_IMMEDIATE_DREG, htonl(imm->dreg));
+
+ /* Sane configurations allows you to set ONLY one of these two below */
+ if (e->flags & (1 << NFT_EXPR_IMM_DATA)) {
+ struct nlattr *nest;
+
+ nest = mnl_attr_nest_start(nlh, NFTA_IMMEDIATE_DATA);
+ mnl_attr_put(nlh, NFTA_DATA_VALUE, imm->data.len, imm->data.val);
+ mnl_attr_nest_end(nlh, nest);
+
+ } else if (e->flags & (1 << NFT_EXPR_IMM_VERDICT)) {
+ struct nlattr *nest1, *nest2;
+
+ nest1 = mnl_attr_nest_start(nlh, NFTA_IMMEDIATE_DATA);
+ nest2 = mnl_attr_nest_start(nlh, NFTA_DATA_VERDICT);
+ mnl_attr_put_u32(nlh, NFTA_VERDICT_CODE, htonl(imm->data.verdict));
+ if (e->flags & (1 << NFT_EXPR_IMM_CHAIN))
+ mnl_attr_put_strz(nlh, NFTA_VERDICT_CHAIN, imm->data.chain);
+
+ mnl_attr_nest_end(nlh, nest1);
+ mnl_attr_nest_end(nlh, nest2);
+ }
+}
+
+static int
+nft_rule_expr_immediate_parse(struct nft_rule_expr *e, struct nlattr *attr)
+{
+ struct nft_expr_immediate *imm = (struct nft_expr_immediate *)e->data;
+ struct nlattr *tb[NFTA_IMMEDIATE_MAX+1] = {};
+ int ret = 0;
+
+ if (mnl_attr_parse_nested(attr, nft_rule_expr_immediate_cb, tb) < 0)
+ return -1;
+
+ if (tb[NFTA_IMMEDIATE_DREG]) {
+ imm->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_IMMEDIATE_DREG]));
+ e->flags |= (1 << NFT_EXPR_IMM_DREG);
+ }
+ if (tb[NFTA_IMMEDIATE_DATA]) {
+ int type;
+
+ ret = nft_parse_data(&imm->data, tb[NFTA_IMMEDIATE_DATA], &type);
+ if (ret < 0)
+ return ret;
+
+ switch(type) {
+ case DATA_VALUE:
+ /* real immediate data to be loaded to destination */
+ e->flags |= (1 << NFT_EXPR_IMM_DATA);
+ break;
+ case DATA_VERDICT:
+ /* NF_ACCEPT, NF_DROP, NF_QUEUE and NFT_RETURN case */
+ e->flags |= (1 << NFT_EXPR_IMM_VERDICT);
+ break;
+ case DATA_CHAIN:
+ /* NFT_GOTO and NFT_JUMP case */
+ e->flags |= (1 << NFT_EXPR_IMM_VERDICT) |
+ (1 << NFT_EXPR_IMM_CHAIN);
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static int
+nft_rule_expr_immediate_snprintf(char *buf, size_t len, struct nft_rule_expr *e)
+{
+ struct nft_expr_immediate *imm = (struct nft_expr_immediate *)e->data;
+
+ return snprintf(buf, len, "dreg=%u data=%u ",
+ imm->dreg, imm->data.val[0]);
+}
+
+struct expr_ops expr_ops_immediate = {
+ .name = "immediate",
+ .alloc_len = sizeof(struct nft_expr_immediate),
+ .max_attr = NFTA_IMMEDIATE_MAX,
+ .set = nft_rule_expr_immediate_set,
+ .get = nft_rule_expr_immediate_get,
+ .parse = nft_rule_expr_immediate_parse,
+ .build = nft_rule_expr_immediate_build,
+ .snprintf = nft_rule_expr_immediate_snprintf,
+};