summaryrefslogtreecommitdiffstats
path: root/src/expr/payload.c
diff options
context:
space:
mode:
authorPablo Neira Ayuso <pablo@netfilter.org>2012-08-03 17:31:48 +0200
committerPablo Neira Ayuso <pablo@netfilter.org>2012-10-11 15:15:02 +0200
commit00c179b4c9f9f9394cc6f79e5f2a68410631fd72 (patch)
tree00057636d125f3c89e2b9485c67c4283a98d91b2 /src/expr/payload.c
initial version of libnftables
It adds support for table, chain and rule handling. This also includes expression handling for each rule. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'src/expr/payload.c')
-rw-r--r--src/expr/payload.c185
1 files changed, 185 insertions, 0 deletions
diff --git a/src/expr/payload.c b/src/expr/payload.c
new file mode 100644
index 0000000..746a127
--- /dev/null
+++ b/src/expr/payload.c
@@ -0,0 +1,185 @@
+/*
+ * (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 "internal.h"
+
+#include <stdio.h>
+#include <stdint.h>
+#include <arpa/inet.h>
+
+#include <libmnl/libmnl.h>
+
+#include <linux/netfilter/nf_tables.h>
+
+#include <libnftables/expr.h>
+
+#include "expr_ops.h"
+
+struct nft_expr_payload {
+ enum nft_registers dreg;
+ enum nft_payload_bases base;
+ unsigned int offset;
+ unsigned int len;
+};
+
+static int
+nft_rule_expr_payload_set(struct nft_rule_expr *e, uint16_t type,
+ const void *data, size_t data_len)
+{
+ struct nft_expr_payload *payload = (struct nft_expr_payload *)e->data;
+
+ switch(type) {
+ case NFT_EXPR_PAYLOAD_DREG:
+ payload->dreg = *((uint32_t *)data);
+ break;
+ case NFT_EXPR_PAYLOAD_BASE:
+ payload->base = *((uint32_t *)data);
+ break;
+ case NFT_EXPR_PAYLOAD_OFFSET:
+ payload->offset = *((unsigned int *)data);
+ break;
+ case NFT_EXPR_PAYLOAD_LEN:
+ payload->len = *((unsigned int *)data);
+ break;
+ default:
+ return -1;
+ }
+ return 0;
+}
+
+static const void *
+nft_rule_expr_payload_get(struct nft_rule_expr *e, uint16_t type, size_t *data_len)
+{
+ struct nft_expr_payload *payload = (struct nft_expr_payload *)e->data;
+
+ switch(type) {
+ case NFT_EXPR_PAYLOAD_DREG:
+ if (e->flags & (1 << NFT_EXPR_PAYLOAD_DREG)) {
+ *data_len = sizeof(payload->dreg);
+ return &payload->dreg;
+ } else
+ return NULL;
+ break;
+ case NFT_EXPR_PAYLOAD_BASE:
+ if (e->flags & (1 << NFT_EXPR_PAYLOAD_BASE)) {
+ *data_len = sizeof(payload->base);
+ return &payload->base;
+ } else
+ return NULL;
+ break;
+ case NFT_EXPR_PAYLOAD_OFFSET:
+ if (e->flags & (1 << NFT_EXPR_PAYLOAD_OFFSET)) {
+ *data_len = sizeof(payload->offset);
+ return &payload->offset;
+ } else
+ return NULL;
+ break;
+ case NFT_EXPR_PAYLOAD_LEN:
+ if (e->flags & (1 << NFT_EXPR_PAYLOAD_LEN)) {
+ *data_len = sizeof(payload->len);
+ return &payload->len;
+ } else
+ return NULL;
+ break;
+ default:
+ break;
+ }
+ return NULL;
+}
+
+static int nft_rule_expr_payload_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_PAYLOAD_MAX) < 0)
+ return MNL_CB_OK;
+
+ switch(type) {
+ case NFTA_PAYLOAD_DREG:
+ case NFTA_PAYLOAD_BASE:
+ case NFTA_PAYLOAD_OFFSET:
+ case NFTA_PAYLOAD_LEN:
+ if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
+ perror("mnl_attr_validate");
+ return MNL_CB_ERROR;
+ }
+ break;
+ }
+
+ tb[type] = attr;
+ return MNL_CB_OK;
+}
+
+static void
+nft_rule_expr_payload_build(struct nlmsghdr *nlh, struct nft_rule_expr *e)
+{
+ struct nft_expr_payload *payload = (struct nft_expr_payload *)e->data;
+
+ if (e->flags & (1 << NFT_EXPR_PAYLOAD_DREG))
+ mnl_attr_put_u32(nlh, NFTA_PAYLOAD_DREG, htonl(payload->dreg));
+ if (e->flags & (1 << NFT_EXPR_PAYLOAD_BASE))
+ mnl_attr_put_u32(nlh, NFTA_PAYLOAD_BASE, htonl(payload->base));
+ if (e->flags & (1 << NFT_EXPR_PAYLOAD_OFFSET))
+ mnl_attr_put_u32(nlh, NFTA_PAYLOAD_OFFSET, htonl(payload->offset));
+ if (e->flags & (1 << NFT_EXPR_PAYLOAD_LEN))
+ mnl_attr_put_u32(nlh, NFTA_PAYLOAD_LEN, htonl(payload->len));
+}
+
+static int
+nft_rule_expr_payload_parse(struct nft_rule_expr *e, struct nlattr *attr)
+{
+ struct nft_expr_payload *payload = (struct nft_expr_payload *)e->data;
+ struct nlattr *tb[NFTA_PAYLOAD_MAX+1] = {};
+
+ if (mnl_attr_parse_nested(attr, nft_rule_expr_payload_cb, tb) < 0)
+ return -1;
+
+ if (tb[NFTA_PAYLOAD_DREG]) {
+ payload->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_PAYLOAD_DREG]));
+ e->flags |= (1 << NFT_EXPR_PAYLOAD_DREG);
+ }
+ if (tb[NFTA_PAYLOAD_BASE]) {
+ payload->base = ntohl(mnl_attr_get_u32(tb[NFTA_PAYLOAD_BASE]));
+ e->flags |= (1 << NFT_EXPR_PAYLOAD_BASE);
+ }
+ if (tb[NFTA_PAYLOAD_OFFSET]) {
+ payload->offset = ntohl(mnl_attr_get_u32(tb[NFTA_PAYLOAD_OFFSET]));
+ e->flags |= (1 << NFT_EXPR_PAYLOAD_OFFSET);
+ }
+ if (tb[NFTA_PAYLOAD_LEN]) {
+ payload->len = ntohl(mnl_attr_get_u32(tb[NFTA_PAYLOAD_LEN]));
+ e->flags |= (1 << NFT_EXPR_PAYLOAD_LEN);
+ }
+
+ return 0;
+}
+
+static int
+nft_rule_expr_payload_snprintf(char *buf, size_t len, struct nft_rule_expr *e)
+{
+ struct nft_expr_payload *payload = (struct nft_expr_payload *)e->data;
+
+ return snprintf(buf, len, "dreg=%u base=%u offset=%u len=%u ",
+ payload->dreg, payload->base,
+ payload->offset, payload->len);
+}
+
+struct expr_ops expr_ops_payload = {
+ .name = "payload",
+ .alloc_len = sizeof(struct nft_expr_payload),
+ .max_attr = NFTA_PAYLOAD_MAX,
+ .set = nft_rule_expr_payload_set,
+ .get = nft_rule_expr_payload_get,
+ .parse = nft_rule_expr_payload_parse,
+ .build = nft_rule_expr_payload_build,
+ .snprintf = nft_rule_expr_payload_snprintf,
+};