From 44ab5902045a5cc0aad8e145d1a32f8a3b3cc157 Mon Sep 17 00:00:00 2001 From: Arturo Borrero Date: Mon, 23 Dec 2013 15:18:22 +0100 Subject: examples: add nft-ruleset-get This example prints the ruleset, using the ruleset API of nftables. The kernel patch c9c8e48 ("netfilter: nf_tables: dump sets in all existing families") is required. Signed-off-by: Arturo Borrero Gonzalez Signed-off-by: Pablo Neira Ayuso --- examples/nft-ruleset-get.c | 389 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 389 insertions(+) create mode 100644 examples/nft-ruleset-get.c (limited to 'examples/nft-ruleset-get.c') 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 + * + * based on previous code from: + * + * Copyright (c) 2013 Pablo Neira Ayuso + * + * 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 +#include +#include +#include +#include + +#include +#include + +#include +#include +#include +#include +#include +#include +#include + +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; +} -- cgit v1.2.3