1 files changed, 414 insertions, 0 deletions
diff --git a/src/mnl.c b/src/mnl.c
new file mode 100644
index 0000000..bd2227b
--- /dev/null
+++ b/src/mnl.c
@@ -0,0 +1,414 @@
+/*
+ * Copyright (c) 2013 Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
+ *
+ * Almost copied from 'nftables' project:
+ *
+ * Copyright (c) 2013 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 version 2 as
+ * published by the Free Software Foundation.
+ *
+ * TODO: provide abstract of these functions in libnftnl, later.
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+
+#include "mnl.h"
+#include "linux/netfilter/nf_tables.h"
+#include "linux/netfilter.h"
+
+static int seq;
+
+static int
+nfts_mnl_talk(struct mnl_socket *nf_sock, const void *data, unsigned int len,
+	      int (*cb)(const struct nlmsghdr *nlh, void *data), void *cb_data)
+{
+	char buf[MNL_SOCKET_BUFFER_SIZE];
+	uint32_t portid = mnl_socket_get_portid(nf_sock);
+	int ret;
+
+	if (mnl_socket_sendto(nf_sock, data, len) < 0)
+		return -1;
+
+	ret = mnl_socket_recvfrom(nf_sock, buf, sizeof(buf));
+	while (ret > 0) {
+		ret = mnl_cb_run(buf, ret, seq, portid, cb, cb_data);
+		if (ret <= 0)
+			goto out;
+
+		ret = mnl_socket_recvfrom(nf_sock, buf, sizeof(buf));
+	}
+out:
+	if (ret < 0 && errno == EAGAIN)
+		return 0;
+
+	return ret;
+}
+
+/*
+ * Rule
+ */
+static int rule_cb(const struct nlmsghdr *nlh, void *data)
+{
+	struct nft_rule_list *nlr_list = data;
+	struct nft_rule *r;
+
+	r = nft_rule_alloc();
+	if (r == NULL)
+		return -1;
+
+	if (nft_rule_nlmsg_parse(nlh, r) < 0)
+		goto err_free;
+
+	nft_rule_list_add_tail(r, nlr_list);
+	return MNL_CB_OK;
+
+err_free:
+	nft_rule_free(r);
+	return MNL_CB_OK;
+}
+
+struct nft_rule_list *mnl_rule_dump(struct mnl_socket *nf_sock, int family)
+{
+	char buf[MNL_SOCKET_BUFFER_SIZE];
+	struct nlmsghdr *nlh;
+	struct nft_rule_list *nlr_list;
+	int ret;
+
+	nlr_list = nft_rule_list_alloc();
+	if (nlr_list == NULL)
+		return NULL;
+
+	nlh = nft_rule_nlmsg_build_hdr(buf, NFT_MSG_GETRULE, family,
+				       NLM_F_DUMP, seq);
+
+	ret = nfts_mnl_talk(nf_sock, nlh, nlh->nlmsg_len, rule_cb, nlr_list);
+	if (ret < 0)
+		goto err;
+
+	return nlr_list;
+err:
+	nft_rule_list_free(nlr_list);
+	return NULL;
+}
+
+/*
+ * Chain
+ */
+static int chain_cb(const struct nlmsghdr *nlh, void *data)
+{
+	struct nft_chain_list *nlc_list = data;
+	struct nft_chain *c;
+
+	c = nft_chain_alloc();
+	if (c == NULL)
+		return -1;
+
+	if (nft_chain_nlmsg_parse(nlh, c) < 0)
+		goto err_free;
+
+	nft_chain_list_add_tail(c, nlc_list);
+	return MNL_CB_OK;
+
+err_free:
+	nft_chain_free(c);
+	return MNL_CB_OK;
+}
+
+struct nft_chain_list *mnl_chain_dump(struct mnl_socket *nf_sock, int family)
+{
+	char buf[MNL_SOCKET_BUFFER_SIZE];
+	struct nlmsghdr *nlh;
+	struct nft_chain_list *nlc_list;
+	int ret;
+
+	nlc_list = nft_chain_list_alloc();
+	if (nlc_list == NULL)
+		return NULL;
+
+	nlh = nft_chain_nlmsg_build_hdr(buf, NFT_MSG_GETCHAIN, family,
+					NLM_F_DUMP, seq);
+
+	ret = nfts_mnl_talk(nf_sock, nlh, nlh->nlmsg_len, chain_cb, nlc_list);
+	if (ret < 0)
+		goto err;
+
+	return nlc_list;
+err:
+	nft_chain_list_free(nlc_list);
+	return NULL;
+}
+
+/*
+ * Table
+ */
+
+static int table_cb(const struct nlmsghdr *nlh, void *data)
+{
+	struct nft_table_list *nlt_list = data;
+	struct nft_table *t;
+
+	t = nft_table_alloc();
+	if (t == NULL)
+		return -1;
+
+	if (nft_table_nlmsg_parse(nlh, t) < 0)
+		goto err_free;
+
+	nft_table_list_add_tail(t, nlt_list);
+	return MNL_CB_OK;
+
+err_free:
+	nft_table_free(t);
+	return MNL_CB_OK;
+}
+
+struct nft_table_list *mnl_table_dump(struct mnl_socket *nf_sock, int family)
+{
+	char buf[MNL_SOCKET_BUFFER_SIZE];
+	struct nlmsghdr *nlh;
+	struct nft_table_list *nlt_list;
+	int ret;
+
+	nlt_list = nft_table_list_alloc();
+	if (nlt_list == NULL)
+		return NULL;
+
+	nlh = nft_table_nlmsg_build_hdr(buf, NFT_MSG_GETTABLE, family,
+					NLM_F_DUMP, seq);
+
+	ret = nfts_mnl_talk(nf_sock, nlh, nlh->nlmsg_len, table_cb, nlt_list);
+	if (ret < 0)
+		goto err;
+
+	return nlt_list;
+err:
+	nft_table_list_free(nlt_list);
+	return NULL;
+}
+
+/*
+ * Set
+ */
+
+static int set_cb(const struct nlmsghdr *nlh, void *data)
+{
+	struct nft_set_list *nls_list = data;
+	struct nft_set *s;
+
+	s = nft_set_alloc();
+	if (s == NULL)
+		return -1;
+
+	if (nft_set_nlmsg_parse(nlh, s) < 0)
+		goto err_free;
+
+	nft_set_list_add_tail(s, nls_list);
+	return MNL_CB_OK;
+
+err_free:
+	nft_set_free(s);
+	return MNL_CB_OK;
+}
+
+struct nft_set_list *
+mnl_set_dump(struct mnl_socket *nf_sock, int family, const char *table)
+{
+	char buf[MNL_SOCKET_BUFFER_SIZE];
+	struct nlmsghdr *nlh;
+	struct nft_set *s;
+	struct nft_set_list *nls_list;
+	int ret;
+
+	s = nft_set_alloc();
+	if (s == NULL)
+		return NULL;
+
+	nlh = nft_set_nlmsg_build_hdr(buf, NFT_MSG_GETSET, family,
+				      NLM_F_DUMP|NLM_F_ACK, seq);
+	nft_set_attr_set(s, NFT_SET_ATTR_TABLE, table);
+	nft_set_nlmsg_build_payload(nlh, s);
+	nft_set_free(s);
+
+	nls_list = nft_set_list_alloc();
+	if (nls_list == NULL)
+		goto err;
+
+	ret = nfts_mnl_talk(nf_sock, nlh, nlh->nlmsg_len, set_cb, nls_list);
+	if (ret < 0)
+		goto err;
+
+	return nls_list;
+err:
+	nft_set_list_free(nls_list);
+	return NULL;
+}
+
+static void
+nft_set_list_merge(struct nft_set_list *dest, struct nft_set_list *orig)
+{
+	struct nft_set_list_iter *it;
+	struct nft_set *o;
+
+	it = nft_set_list_iter_create(orig);
+	if (it == NULL)
+		return;
+
+	o = nft_set_list_iter_next(it);
+	while (o != NULL) {
+		nft_set_list_add_tail(o, dest);
+		o = nft_set_list_iter_next(it);
+	}
+
+	nft_set_list_iter_destroy(it);
+}
+
+
+/*
+ * Set elements
+ */
+
+static int set_elem_cb(const struct nlmsghdr *nlh, void *data)
+{
+	nft_set_elems_nlmsg_parse(nlh, data);
+	return MNL_CB_OK;
+}
+
+int mnl_setelem_get(struct mnl_socket *nf_sock, struct nft_set *nls)
+{
+	char buf[MNL_SOCKET_BUFFER_SIZE];
+	struct nlmsghdr *nlh;
+	uint32_t family = nft_set_attr_get_u32(nls, NFT_SET_ATTR_FAMILY);
+
+	nlh = nft_set_nlmsg_build_hdr(buf, NFT_MSG_GETSETELEM, family,
+				      NLM_F_DUMP|NLM_F_ACK, seq);
+	nft_set_nlmsg_build_payload(nlh, nls);
+
+	return nfts_mnl_talk(nf_sock, nlh, nlh->nlmsg_len, set_elem_cb, nls);
+}
+
+/*
+ * ruleset
+ */
+
+struct nft_ruleset *mnl_ruleset_dump(struct mnl_socket *nf_sock)
+{
+	struct nft_ruleset *rs;
+	struct nft_rule_list *r;
+	struct nft_chain_list *c;
+	struct nft_set_list *complete_set_list = NULL, *s;
+	struct nft_table_list *t;
+	struct nft_table_list_iter *it;
+	struct nft_table *o;
+	const char *table;
+	uint16_t family;
+
+	t = mnl_table_dump(nf_sock, NFPROTO_UNSPEC);
+	if (t == NULL)
+		return NULL;
+
+	rs = nft_ruleset_alloc();
+	if (rs == NULL)
+		return NULL;
+
+	nft_ruleset_attr_set(rs, NFT_RULESET_ATTR_TABLELIST, t);
+
+	c = mnl_chain_dump(nf_sock, NFPROTO_UNSPEC);
+	if (c != NULL)
+		nft_ruleset_attr_set(rs, NFT_RULESET_ATTR_CHAINLIST, c);
+
+	r = mnl_rule_dump(nf_sock, NFPROTO_UNSPEC);
+	if (r != NULL)
+		nft_ruleset_attr_set(rs, NFT_RULESET_ATTR_RULELIST, r);
+
+	it = nft_table_list_iter_create(t);
+	if (it == NULL)
+		return NULL;
+
+	o = nft_table_list_iter_next(it);
+	while (o != NULL) {
+		table = nft_table_attr_get_str(o, NFT_TABLE_ATTR_NAME);
+		family = nft_table_attr_get_u32(o, NFT_TABLE_ATTR_FAMILY);
+
+		s = mnl_set_dump(nf_sock, family, table);
+		if (s != NULL) {
+			if (complete_set_list == NULL) {
+				complete_set_list = nft_set_list_alloc();
+				if (complete_set_list == NULL)
+					return NULL;
+			}
+
+			nft_set_list_merge(complete_set_list, s);
+			nft_set_list_free(s);
+		}
+		o = nft_table_list_iter_next(it);
+	}
+	nft_table_list_iter_destroy(it);
+
+	if (complete_set_list != NULL)
+		nft_ruleset_attr_set(rs, NFT_RULESET_ATTR_SETLIST,
+				     complete_set_list);
+
+	return rs;
+}
+
+/*
+ * netlink
+ */
+static struct mnl_socket *netlink_socket_open(void)
+{
+	return mnl_socket_open(NETLINK_NETFILTER);
+}
+
+int nfts_socket_open(struct nft_sync_inst *inst)
+{
+	struct mnl_socket *s = netlink_socket_open();
+	if (s == NULL)
+		return -1;
+
+	inst->nl_query_sock = s;
+	return 0;
+}
+
+void nfts_socket_close(struct nft_sync_inst *inst)
+{
+	mnl_socket_close(inst->nl_query_sock);
+}
+
+#define SNPRINTF_BUFSIZ 4096
+
+const char *netlink_dump_ruleset(struct mnl_socket *s)
+{
+	struct nft_ruleset *rs;
+	size_t bufsiz = SNPRINTF_BUFSIZ;
+	char *buf;
+	int ret;
+
+	buf = calloc(1, bufsiz);
+	if (buf == NULL)
+		return NULL;
+
+	rs = mnl_ruleset_dump(s);
+	if (rs == NULL) {
+		free(buf);
+		return NULL;
+	}
+
+	ret = nft_ruleset_snprintf(buf, bufsiz, rs, NFT_OUTPUT_XML, 0);
+	if (ret > SNPRINTF_BUFSIZ) {
+		free(buf);
+		buf = calloc(1, ret);
+		if (buf == NULL) {
+			nft_ruleset_free(rs);
+			return NULL;
+		}
+
+		bufsiz = ret;
+		ret = nft_ruleset_snprintf(buf, bufsiz, rs, NFT_OUTPUT_XML, 0);
+	}
+
+	nft_ruleset_free(rs);
+	return buf;
+}