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-rw-r--r--src/expr/masq.c167
1 files changed, 167 insertions, 0 deletions
diff --git a/src/expr/masq.c b/src/expr/masq.c
new file mode 100644
index 0000000..e6e528d
--- /dev/null
+++ b/src/expr/masq.c
@@ -0,0 +1,167 @@
+/*
+ * (C) 2014 by Arturo Borrero Gonzalez <arturo@debian.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.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <inttypes.h>
+
+#include <linux/netfilter/nf_tables.h>
+
+#include "internal.h"
+#include <libmnl/libmnl.h>
+#include <libnftnl/expr.h>
+#include <libnftnl/rule.h>
+
+struct nftnl_expr_masq {
+ uint32_t flags;
+ enum nft_registers sreg_proto_min;
+ enum nft_registers sreg_proto_max;
+};
+
+static int
+nftnl_expr_masq_set(struct nftnl_expr *e, uint16_t type,
+ const void *data, uint32_t data_len)
+{
+ struct nftnl_expr_masq *masq = nftnl_expr_data(e);
+
+ switch (type) {
+ case NFTNL_EXPR_MASQ_FLAGS:
+ memcpy(&masq->flags, data, sizeof(masq->flags));
+ break;
+ case NFTNL_EXPR_MASQ_REG_PROTO_MIN:
+ memcpy(&masq->sreg_proto_min, data, sizeof(masq->sreg_proto_min));
+ break;
+ case NFTNL_EXPR_MASQ_REG_PROTO_MAX:
+ memcpy(&masq->sreg_proto_max, data, sizeof(masq->sreg_proto_max));
+ break;
+ default:
+ return -1;
+ }
+ return 0;
+}
+
+static const void *
+nftnl_expr_masq_get(const struct nftnl_expr *e, uint16_t type,
+ uint32_t *data_len)
+{
+ struct nftnl_expr_masq *masq = nftnl_expr_data(e);
+
+ switch (type) {
+ case NFTNL_EXPR_MASQ_FLAGS:
+ *data_len = sizeof(masq->flags);
+ return &masq->flags;
+ case NFTNL_EXPR_MASQ_REG_PROTO_MIN:
+ *data_len = sizeof(masq->sreg_proto_min);
+ return &masq->sreg_proto_min;
+ case NFTNL_EXPR_MASQ_REG_PROTO_MAX:
+ *data_len = sizeof(masq->sreg_proto_max);
+ return &masq->sreg_proto_max;
+ }
+ return NULL;
+}
+
+static int nftnl_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_REG_PROTO_MIN:
+ case NFTA_MASQ_REG_PROTO_MAX:
+ 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
+nftnl_expr_masq_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
+{
+ struct nftnl_expr_masq *masq = nftnl_expr_data(e);
+
+ if (e->flags & (1 << NFTNL_EXPR_MASQ_FLAGS))
+ mnl_attr_put_u32(nlh, NFTA_MASQ_FLAGS, htobe32(masq->flags));
+ if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MIN))
+ mnl_attr_put_u32(nlh, NFTA_MASQ_REG_PROTO_MIN,
+ htobe32(masq->sreg_proto_min));
+ if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MAX))
+ mnl_attr_put_u32(nlh, NFTA_MASQ_REG_PROTO_MAX,
+ htobe32(masq->sreg_proto_max));
+}
+
+static int
+nftnl_expr_masq_parse(struct nftnl_expr *e, struct nlattr *attr)
+{
+ struct nftnl_expr_masq *masq = nftnl_expr_data(e);
+ struct nlattr *tb[NFTA_MASQ_MAX+1] = {};
+
+ if (mnl_attr_parse_nested(attr, nftnl_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 << NFTNL_EXPR_MASQ_FLAGS);
+ }
+ if (tb[NFTA_MASQ_REG_PROTO_MIN]) {
+ masq->sreg_proto_min =
+ be32toh(mnl_attr_get_u32(tb[NFTA_MASQ_REG_PROTO_MIN]));
+ e->flags |= (1 << NFTNL_EXPR_MASQ_REG_PROTO_MIN);
+ }
+ if (tb[NFTA_MASQ_REG_PROTO_MAX]) {
+ masq->sreg_proto_max =
+ be32toh(mnl_attr_get_u32(tb[NFTA_MASQ_REG_PROTO_MAX]));
+ e->flags |= (1 << NFTNL_EXPR_MASQ_REG_PROTO_MAX);
+ }
+
+ return 0;
+}
+
+static int nftnl_expr_masq_snprintf(char *buf, size_t remain,
+ uint32_t flags, const struct nftnl_expr *e)
+{
+ struct nftnl_expr_masq *masq = nftnl_expr_data(e);
+ int offset = 0, ret = 0;
+
+ if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MIN)) {
+ ret = snprintf(buf + offset, remain, "proto_min reg %u ",
+ masq->sreg_proto_min);
+ SNPRINTF_BUFFER_SIZE(ret, remain, offset);
+ }
+ if (e->flags & (1 << NFTNL_EXPR_MASQ_REG_PROTO_MAX)) {
+ ret = snprintf(buf + offset, remain, "proto_max reg %u ",
+ masq->sreg_proto_max);
+ SNPRINTF_BUFFER_SIZE(ret, remain, offset);
+ }
+ if (e->flags & (1 << NFTNL_EXPR_MASQ_FLAGS)) {
+ ret = snprintf(buf + offset, remain, "flags 0x%x ", masq->flags);
+ SNPRINTF_BUFFER_SIZE(ret, remain, offset);
+ }
+
+ return offset;
+}
+
+struct expr_ops expr_ops_masq = {
+ .name = "masq",
+ .alloc_len = sizeof(struct nftnl_expr_masq),
+ .max_attr = NFTA_MASQ_MAX,
+ .set = nftnl_expr_masq_set,
+ .get = nftnl_expr_masq_get,
+ .parse = nftnl_expr_masq_parse,
+ .build = nftnl_expr_masq_build,
+ .output = nftnl_expr_masq_snprintf,
+};