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Diffstat (limited to 'examples/nft-chain-add.c')
| -rw-r--r-- | examples/nft-chain-add.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/examples/nft-chain-add.c b/examples/nft-chain-add.c new file mode 100644 index 0000000..13be982 --- /dev/null +++ b/examples/nft-chain-add.c @@ -0,0 +1,148 @@ +/* + * (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/chain.h> + +static struct nftnl_chain *chain_add_parse(int argc, char *argv[]) +{ + struct nftnl_chain *t; + int hooknum = 0; + + if (argc == 6) { + /* This is a base chain, set the hook number */ + if (strcmp(argv[4], "NF_INET_LOCAL_IN") == 0) + hooknum = NF_INET_LOCAL_IN; + else if (strcmp(argv[4], "NF_INET_LOCAL_OUT") == 0) + hooknum = NF_INET_LOCAL_OUT; + else if (strcmp(argv[4], "NF_INET_PRE_ROUTING") == 0) + hooknum = NF_INET_PRE_ROUTING; + else if (strcmp(argv[4], "NF_INET_POST_ROUTING") == 0) + hooknum = NF_INET_POST_ROUTING; + else if (strcmp(argv[4], "NF_INET_FORWARD") == 0) + hooknum = NF_INET_FORWARD; + else { + fprintf(stderr, "Unknown hook: %s\n", argv[4]); + return NULL; + } + } + + t = nftnl_chain_alloc(); + if (t == NULL) { + perror("OOM"); + return NULL; + } + nftnl_chain_set_str(t, NFTNL_CHAIN_TABLE, argv[2]); + nftnl_chain_set_str(t, NFTNL_CHAIN_NAME, argv[3]); + if (argc == 6) { + nftnl_chain_set_u32(t, NFTNL_CHAIN_HOOKNUM, hooknum); + nftnl_chain_set_u32(t, NFTNL_CHAIN_PRIO, atoi(argv[5])); + } + + return t; +} + +int main(int argc, char *argv[]) +{ + struct mnl_socket *nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh; + uint32_t portid, seq, chain_seq; + int ret, family; + struct nftnl_chain *t; + struct mnl_nlmsg_batch *batch; + + if (argc != 4 && argc != 6) { + fprintf(stderr, "Usage: %s <family> <table> <chain> " + "[<hooknum> <prio>]\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 { + fprintf(stderr, "Unknown family: ip, ip6, inet, bridge, arp\n"); + exit(EXIT_FAILURE); + } + + t = chain_add_parse(argc, argv); + if (t == NULL) + exit(EXIT_FAILURE); + + seq = time(NULL); + batch = mnl_nlmsg_batch_start(buf, sizeof(buf)); + + nftnl_batch_begin(mnl_nlmsg_batch_current(batch), seq++); + mnl_nlmsg_batch_next(batch); + + chain_seq = seq; + nlh = nftnl_nlmsg_build_hdr(mnl_nlmsg_batch_current(batch), + NFT_MSG_NEWCHAIN, family, + NLM_F_CREATE | NLM_F_ACK, seq++); + nftnl_chain_nlmsg_build_payload(nlh, t); + nftnl_chain_free(t); + mnl_nlmsg_batch_next(batch); + + nftnl_batch_end(mnl_nlmsg_batch_current(batch), seq++); + mnl_nlmsg_batch_next(batch); + + 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, mnl_nlmsg_batch_head(batch), + mnl_nlmsg_batch_size(batch)) < 0) { + perror("mnl_socket_send"); + exit(EXIT_FAILURE); + } + + mnl_nlmsg_batch_stop(batch); + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret > 0) { + ret = mnl_cb_run(buf, ret, chain_seq, portid, NULL, NULL); + 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; +} |