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Diffstat (limited to '')
| -rw-r--r-- | examples/nft-rule-get.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/examples/nft-rule-get.c b/examples/nft-rule-get.c new file mode 100644 index 0000000..8da5b59 --- /dev/null +++ b/examples/nft-rule-get.c @@ -0,0 +1,155 @@ +/* + * (C) 2012 by 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 as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This software has been sponsored by Sophos Astaro <http://www.sophos.com> + */ + +#include <stdlib.h> +#include <time.h> +#include <string.h> +#include <netinet/in.h> + +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> + +#include <libmnl/libmnl.h> +#include <libnftnl/rule.h> + +static int table_cb(const struct nlmsghdr *nlh, void *data) +{ + struct nftnl_rule *t; + char buf[4096]; + uint32_t *type = data; + + t = nftnl_rule_alloc(); + if (t == NULL) { + perror("OOM"); + goto err; + } + + if (nftnl_rule_nlmsg_parse(nlh, t) < 0) { + perror("nftnl_rule_nlmsg_parse"); + goto err_free; + } + + nftnl_rule_snprintf(buf, sizeof(buf), t, *type, 0); + printf("%s\n", buf); + +err_free: + nftnl_rule_free(t); +err: + return MNL_CB_OK; +} + +static struct nftnl_rule *setup_rule(uint8_t family, const char *table, + const char *chain, const char *handle) +{ + struct nftnl_rule *r; + uint64_t handle_num; + + r = nftnl_rule_alloc(); + if (r == NULL) + return NULL; + + if (table != NULL) + nftnl_rule_set_str(r, NFTNL_RULE_TABLE, table); + if (chain != NULL) + nftnl_rule_set_str(r, NFTNL_RULE_CHAIN, chain); + + nftnl_rule_set_u32(r, NFTNL_RULE_FAMILY, family); + + if (handle != NULL) { + handle_num = atoll(handle); + nftnl_rule_set_u64(r, NFTNL_RULE_POSITION, handle_num); + } + + return r; +} + +int main(int argc, char *argv[]) +{ + struct mnl_socket *nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh; + uint32_t portid, seq, type = NFTNL_OUTPUT_DEFAULT; + const char *table = NULL, *chain = NULL; + struct nftnl_rule *r; + int ret, family; + + if (argc < 2 || argc > 5) { + fprintf(stderr, "Usage: %s <family> [<table> <chain>]\n", + argv[0]); + exit(EXIT_FAILURE); + } + + if (strcmp(argv[1], "ip") == 0) + family = NFPROTO_IPV4; + else if (strcmp(argv[1], "ip6") == 0) + family = NFPROTO_IPV6; + else if (strcmp(argv[1], "inet") == 0) + family = NFPROTO_INET; + else if (strcmp(argv[1], "bridge") == 0) + family = NFPROTO_BRIDGE; + else if (strcmp(argv[1], "arp") == 0) + family = NFPROTO_ARP; + else if (strcmp(argv[1], "unspec") == 0) + family = NFPROTO_UNSPEC; + else { + fprintf(stderr, "Unknown family: ip, ip6, inet, bridge, arp, unspec\n"); + exit(EXIT_FAILURE); + } + + /* at least [<table> <chain>] specified */ + if (argc >= 4) { + table = argv[2]; + chain = argv[3]; + } + + seq = time(NULL); + nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_GETRULE, family, + NLM_F_DUMP, seq); + + r = setup_rule(family, table, chain, NULL); + if (!r) { + perror("setup_rule"); + exit(EXIT_FAILURE); + } + nftnl_rule_nlmsg_build_payload(nlh, r); + + 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); + } + portid = mnl_socket_get_portid(nl); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + perror("mnl_socket_send"); + exit(EXIT_FAILURE); + } + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret > 0) { + ret = mnl_cb_run(buf, ret, seq, portid, table_cb, &type); + if (ret <= 0) + break; + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + } + if (ret == -1) { + perror("error"); + exit(EXIT_FAILURE); + } + mnl_socket_close(nl); + + return EXIT_SUCCESS; +} |