This example prints the ruleset, using the ruleset API of nftables.
The kernel patch [b63108a] (netfilter: nf_tables: allow to dump sets with
NFPROTO_UNSPEC) is required.
Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@xxxxxxxxx>
---
v1: initial release of this patch.
v2: refreshed against the current status of the lib: common.h, fprintf, etc..
examples/Makefile.am | 4
examples/nft-ruleset-get.c | 389 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 393 insertions(+)
create mode 100644 examples/nft-ruleset-get.c
diff --git a/examples/Makefile.am b/examples/Makefile.am
index 9965387..b909684 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -25,6 +25,7 @@ check_PROGRAMS = nft-table-add \
nft-set-elem-add \
nft-set-elem-get \
nft-set-elem-del \
+ nft-ruleset-get \
nft-compat-get
nft_table_add_SOURCES = nft-table-add.c
@@ -102,5 +103,8 @@ nft_set_elem_del_LDADD = ../src/libnftables.la ${LIBMNL_LIBS}
nft_set_elem_get_SOURCES = nft-set-elem-get.c
nft_set_elem_get_LDADD = ../src/libnftables.la ${LIBMNL_LIBS}
+nft_ruleset_get_SOURCES = nft-ruleset-get.c
+nft_ruleset_get_LDADD = ../src/libnftables.la ${LIBMNL_LIBS}
+
nft_compat_get_SOURCES = nft-compat-get.c
nft_compat_get_LDADD = ../src/libnftables.la ${LIBMNL_LIBS}
diff --git a/examples/nft-ruleset-get.c b/examples/nft-ruleset-get.c
new file mode 100644
index 0000000..25c6d7c
--- /dev/null
+++ b/examples/nft-ruleset-get.c
@@ -0,0 +1,389 @@
+/*
+ * Copyright (c) 2013 Arturo Borrero Gonzalez <arturo.borrero.glez@xxxxxxxxx>
+ *
+ * based on previous code from:
+ *
+ * Copyright (c) 2013 Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
+ *
+ * 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.
+ *
+ */
+
+#include <stdlib.h>
+#include <time.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <errno.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+
+#include <libmnl/libmnl.h>
+#include <libnftables/common.h>
+#include <libnftables/ruleset.h>
+#include <libnftables/table.h>
+#include <libnftables/chain.h>
+#include <libnftables/set.h>
+#include <libnftables/rule.h>
+
+static int seq;
+
+static void memory_allocation_error(void)
+{
+ perror("OOM");
+ exit(EXIT_FAILURE);
+}
+
+static int
+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)
+ memory_allocation_error();
+
+ 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;
+}
+
+static 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)
+ memory_allocation_error();
+
+ nlh = nft_rule_nlmsg_build_hdr(buf, NFT_MSG_GETRULE, family,
+ NLM_F_DUMP, seq);
+
+ ret = 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)
+ memory_allocation_error();
+
+ 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;
+}
+
+static 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)
+ memory_allocation_error();
+
+ nlh = nft_chain_nlmsg_build_hdr(buf, NFT_MSG_GETCHAIN, family,
+ NLM_F_DUMP, seq);
+
+ ret = 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)
+ memory_allocation_error();
+
+ 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;
+}
+
+static 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)
+ memory_allocation_error();
+
+ nlh = nft_table_nlmsg_build_hdr(buf, NFT_MSG_GETTABLE, family,
+ NLM_F_DUMP, seq);
+
+ ret = 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 elements
+ */
+static int set_elem_cb(const struct nlmsghdr *nlh, void *data)
+{
+ nft_set_elems_nlmsg_parse(nlh, data);
+ return MNL_CB_OK;
+}
+
+static 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 mnl_talk(nf_sock, nlh, nlh->nlmsg_len, set_elem_cb, nls);
+}
+
+/*
+ * 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)
+ memory_allocation_error();
+
+ 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;
+}
+
+static struct nft_set_list *
+mnl_set_dump(struct mnl_socket *nf_sock, int family)
+{
+ char buf[MNL_SOCKET_BUFFER_SIZE];
+ struct nlmsghdr *nlh;
+ struct nft_set *s;
+ struct nft_set_list *nls_list;
+ struct nft_set *si;
+ struct nft_set_list_iter *i;
+ int ret;
+
+ s = nft_set_alloc();
+ if (s == NULL)
+ memory_allocation_error();
+
+ nlh = nft_set_nlmsg_build_hdr(buf, NFT_MSG_GETSET, family,
+ NLM_F_DUMP|NLM_F_ACK, seq);
+ nft_set_nlmsg_build_payload(nlh, s);
+ nft_set_free(s);
+
+ nls_list = nft_set_list_alloc();
+ if (nls_list == NULL)
+ memory_allocation_error();
+
+ ret = mnl_talk(nf_sock, nlh, nlh->nlmsg_len, set_cb, nls_list);
+ if (ret < 0)
+ goto err;
+
+ i = nft_set_list_iter_create(nls_list);
+ if (i == NULL)
+ memory_allocation_error();
+
+ si = nft_set_list_iter_next(i);
+ while (si != NULL) {
+ if (mnl_setelem_get(nf_sock, si) != 0) {
+ perror("E: Unable to get set elements");
+ nft_set_list_iter_destroy(i);
+ goto err;
+ }
+ si = nft_set_list_iter_next(i);
+ }
+
+ nft_set_list_iter_destroy(i);
+
+ return nls_list;
+err:
+ nft_set_list_free(nls_list);
+ return NULL;
+}
+
+/*
+ * ruleset
+ */
+
+static struct nft_ruleset *mnl_ruleset_dump(struct mnl_socket *nf_sock)
+{
+ struct nft_ruleset *rs;
+ struct nft_table_list *t;
+ struct nft_chain_list *c;
+ struct nft_set_list *s;
+ struct nft_rule_list *r;
+
+ rs = nft_ruleset_alloc();
+ if (rs == NULL)
+ memory_allocation_error();
+
+ t = mnl_table_dump(nf_sock, NFPROTO_UNSPEC);
+ if (t != 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);
+
+ s = mnl_set_dump(nf_sock, NFPROTO_UNSPEC);
+ if (s != NULL)
+ nft_ruleset_attr_set(rs, NFT_RULESET_ATTR_SETLIST, s);
+
+ r = mnl_rule_dump(nf_sock, NFPROTO_UNSPEC);
+ if (r != NULL)
+ nft_ruleset_attr_set(rs, NFT_RULESET_ATTR_RULELIST, r);
+
+ return rs;
+}
+
+int main(int argc, char *argv[])
+{
+ struct mnl_socket *nl;
+ uint32_t type = NFT_OUTPUT_DEFAULT;
+ struct nft_ruleset *rs;
+ int ret;
+
+ if (argc > 2) {
+ fprintf(stderr, "%s {xml|json}\n",
+ argv[0]);
+ exit(EXIT_FAILURE);
+ }
+
+ if (argc == 2) {
+ if (strcmp(argv[1], "xml") == 0)
+ type = NFT_OUTPUT_XML;
+ else if (strcmp(argv[1], "json") == 0)
+ type = NFT_OUTPUT_JSON;
+ else {
+ fprintf(stderr, "Unknown type: {xml|json}\n");
+ exit(EXIT_FAILURE);
+ }
+ }
+
+ nl = mnl_socket_open(NETLINK_NETFILTER);
+ if (nl == NULL) {
+ perror("mnl_socket_open");
+ exit(EXIT_FAILURE);
+ }
+
+ if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
+ perror("mnl_socket_bind");
+ exit(EXIT_FAILURE);
+ }
+
+ seq = time(NULL);
+
+ rs = mnl_ruleset_dump(nl);
+ if (rs == NULL) {
+ perror("ruleset_dump");
+ exit(EXIT_FAILURE);
+ }
+
+ ret = nft_ruleset_fprintf(stdout, rs, type, 0);
+ fprintf(stdout, "\n");
+
+ if (ret == -1)
+ perror("E: Error during fprintf operations");
+
+ return 0;
+}
--
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