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authorMáté Eckl <ecklm94@gmail.com>2018-05-28 09:15:32 +0200
committerPablo Neira Ayuso <pablo@netfilter.org>2018-06-01 10:20:49 +0200
commit038d226f2e6cc132de151cc295ea2e4b8805659a (patch)
tree7c5452ebbaf2baf94c76e810ae8de74d700caec4 /src/expr/socket.c
parent005369151ed52631b0e495268737f6915977dc20 (diff)
src: Add support for native socket matching
Signed-off-by: Máté Eckl <ecklm94@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'src/expr/socket.c')
-rw-r--r--src/expr/socket.c208
1 files changed, 208 insertions, 0 deletions
diff --git a/src/expr/socket.c b/src/expr/socket.c
new file mode 100644
index 0000000..db160a1
--- /dev/null
+++ b/src/expr/socket.c
@@ -0,0 +1,208 @@
+/*
+ * Copyright (c) 2018 Máté Eckl <ecklm94@gmail.com>
+ *
+ * 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 <string.h>
+#include <arpa/inet.h>
+#include <errno.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_socket {
+ enum nft_socket_keys key;
+ enum nft_registers dreg;
+};
+
+static int
+nftnl_expr_socket_set(struct nftnl_expr *e, uint16_t type,
+ const void *data, uint32_t data_len)
+{
+ struct nftnl_expr_socket *socket = nftnl_expr_data(e);
+
+ switch (type) {
+ case NFTNL_EXPR_SOCKET_KEY:
+ socket->key = *((uint32_t *)data);
+ break;
+ case NFTNL_EXPR_SOCKET_DREG:
+ socket->dreg = *((uint32_t *)data);
+ break;
+ default:
+ return -1;
+ }
+ return 0;
+}
+
+static const void *
+nftnl_expr_socket_get(const struct nftnl_expr *e, uint16_t type,
+ uint32_t *data_len)
+{
+ struct nftnl_expr_socket *socket = nftnl_expr_data(e);
+
+ switch (type) {
+ case NFTNL_EXPR_SOCKET_KEY:
+ *data_len = sizeof(socket->key);
+ return &socket->key;
+ case NFTNL_EXPR_SOCKET_DREG:
+ *data_len = sizeof(socket->dreg);
+ return &socket->dreg;
+ }
+ return NULL;
+}
+
+static int nftnl_expr_socket_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_SOCKET_MAX) < 0)
+ return MNL_CB_OK;
+
+ switch (type) {
+ case NFTA_SOCKET_KEY:
+ case NFTA_SOCKET_DREG:
+ if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
+ abi_breakage();
+ break;
+ }
+
+ tb[type] = attr;
+ return MNL_CB_OK;
+}
+
+static void
+nftnl_expr_socket_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
+{
+ struct nftnl_expr_socket *socket = nftnl_expr_data(e);
+
+ if (e->flags & (1 << NFTNL_EXPR_SOCKET_KEY))
+ mnl_attr_put_u32(nlh, NFTA_SOCKET_KEY, htonl(socket->key));
+ if (e->flags & (1 << NFTNL_EXPR_SOCKET_DREG))
+ mnl_attr_put_u32(nlh, NFTA_SOCKET_DREG, htonl(socket->dreg));
+}
+
+static int
+nftnl_expr_socket_parse(struct nftnl_expr *e, struct nlattr *attr)
+{
+ struct nftnl_expr_socket *socket = nftnl_expr_data(e);
+ struct nlattr *tb[NFTA_SOCKET_MAX+1] = {};
+
+ if (mnl_attr_parse_nested(attr, nftnl_expr_socket_cb, tb) < 0)
+ return -1;
+
+ if (tb[NFTA_SOCKET_KEY]) {
+ socket->key = ntohl(mnl_attr_get_u32(tb[NFTA_SOCKET_KEY]));
+ e->flags |= (1 << NFTNL_EXPR_SOCKET_KEY);
+ }
+ if (tb[NFTA_SOCKET_DREG]) {
+ socket->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_SOCKET_DREG]));
+ e->flags |= (1 << NFTNL_EXPR_SOCKET_DREG);
+ }
+
+ return 0;
+}
+
+static const char *socket_key2str_array[NFT_SOCKET_MAX + 1] = {
+ [NFT_SOCKET_TRANSPARENT] = "transparent",
+};
+
+static const char *socket_key2str(uint8_t key)
+{
+ if (key < NFT_SOCKET_MAX + 1)
+ return socket_key2str_array[key];
+
+ return "unknown";
+}
+
+static inline int str2socket_key(const char *str)
+{
+ int i;
+
+ for (i = 0; i < NFT_SOCKET_MAX + 1; i++) {
+ if (strcmp(str, socket_key2str_array[i]) == 0)
+ return i;
+ }
+
+ errno = EINVAL;
+ return -1;
+}
+
+static int
+nftnl_expr_socket_snprintf_default(char *buf, size_t len,
+ const struct nftnl_expr *e)
+{
+ struct nftnl_expr_socket *socket = nftnl_expr_data(e);
+
+ if (e->flags & (1 << NFTNL_EXPR_SOCKET_DREG)) {
+ return snprintf(buf, len, "load %s => reg %u ",
+ socket_key2str(socket->key), socket->dreg);
+ }
+ return 0;
+}
+
+static int nftnl_expr_socket_export(char *buf, size_t size,
+ const struct nftnl_expr *e, int type)
+{
+ struct nftnl_expr_socket *socket = nftnl_expr_data(e);
+ NFTNL_BUF_INIT(b, buf, size);
+
+ if (e->flags & (1 << NFTNL_EXPR_SOCKET_DREG))
+ nftnl_buf_u32(&b, type, socket->dreg, DREG);
+ if (e->flags & (1 << NFTNL_EXPR_SOCKET_KEY))
+ nftnl_buf_str(&b, type, socket_key2str(socket->key), KEY);
+
+ return nftnl_buf_done(&b);
+}
+
+static int
+nftnl_expr_socket_snprintf(char *buf, size_t len, uint32_t type,
+ uint32_t flags, const struct nftnl_expr *e)
+{
+ switch (type) {
+ case NFTNL_OUTPUT_DEFAULT:
+ return nftnl_expr_socket_snprintf_default(buf, len, e);
+ case NFTNL_OUTPUT_XML:
+ case NFTNL_OUTPUT_JSON:
+ return nftnl_expr_socket_export(buf, len, e, type);
+ default:
+ break;
+ }
+ return -1;
+}
+
+static bool nftnl_expr_socket_cmp(const struct nftnl_expr *e1,
+ const struct nftnl_expr *e2)
+{
+ struct nftnl_expr_socket *r1 = nftnl_expr_data(e1);
+ struct nftnl_expr_socket *r2 = nftnl_expr_data(e2);
+ bool eq = true;
+
+ if (e1->flags & (1 << NFTNL_EXPR_SOCKET_KEY))
+ eq &= (r1->key == r2->key);
+ if (e1->flags & (1 << NFTNL_EXPR_SOCKET_DREG))
+ eq &= (r1->dreg == r2->dreg);
+
+ return eq;
+}
+
+struct expr_ops expr_ops_socket = {
+ .name = "socket",
+ .alloc_len = sizeof(struct nftnl_expr_socket),
+ .max_attr = NFTA_SOCKET_MAX,
+ .cmp = nftnl_expr_socket_cmp,
+ .set = nftnl_expr_socket_set,
+ .get = nftnl_expr_socket_get,
+ .parse = nftnl_expr_socket_parse,
+ .build = nftnl_expr_socket_build,
+ .snprintf = nftnl_expr_socket_snprintf,
+};