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author | Stéphane Veyret <sveyret@gmail.com> | 2019-05-31 18:51:45 +0200 |
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committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2019-06-19 13:11:34 +0200 |
commit | 7992160689ed70e1572cd63345cf0a123c462968 (patch) | |
tree | 4c1645328775dfd06862aef4c75a479da2daad71 /examples/nft-ct-expectation-get.c | |
parent | c4b6aa09b85d2604a07ad4b4464b1cbf6e7fa238 (diff) |
examples: add ct expectation examples
Add examples for ct expectations.
Add, list and delete ct expectation objects from specified table.
Add expectation object to rule.
Signed-off-by: Stéphane Veyret <sveyret@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'examples/nft-ct-expectation-get.c')
-rw-r--r-- | examples/nft-ct-expectation-get.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/examples/nft-ct-expectation-get.c b/examples/nft-ct-expectation-get.c new file mode 100644 index 0000000..12c1350 --- /dev/null +++ b/examples/nft-ct-expectation-get.c @@ -0,0 +1,142 @@ +/* + * (C) 2019 by Stéphane Veyret <sveyret@gmail.com> + * + * 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. + */ + +#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/object.h> + +static uint16_t parse_family(char *str, const char *option) +{ + if (strcmp(str, "ip") == 0) + return NFPROTO_IPV4; + else if (strcmp(str, "ip6") == 0) + return NFPROTO_IPV6; + else if (strcmp(str, "inet") == 0) + return NFPROTO_INET; + else if (strcmp(str, "arp") == 0) + return NFPROTO_INET; + fprintf(stderr, "Unknown %s: ip, ip6, inet, arp\n", option); + exit(EXIT_FAILURE); +} + +static struct nftnl_obj *obj_parse(int argc, char *argv[]) +{ + struct nftnl_obj *t; + uint16_t family; + + t = nftnl_obj_alloc(); + if (t == NULL) { + perror("OOM"); + return NULL; + } + + family = parse_family(argv[1], "family"); + nftnl_obj_set_u32(t, NFTNL_OBJ_FAMILY, family); + nftnl_obj_set_u32(t, NFTNL_OBJ_TYPE, NFT_OBJECT_CT_EXPECT); + nftnl_obj_set_str(t, NFTNL_OBJ_TABLE, argv[2]); + + if (argc > 3) + nftnl_obj_set_str(t, NFTNL_OBJ_NAME, argv[3]); + + return t; +} + +static int obj_cb(const struct nlmsghdr *nlh, void *data) +{ + uint32_t *type = data; + struct nftnl_obj *t; + char buf[4096]; + + t = nftnl_obj_alloc(); + if (t == NULL) { + perror("OOM"); + goto err; + } + + if (nftnl_obj_nlmsg_parse(nlh, t) < 0) { + perror("nftnl_obj_nlmsg_parse"); + goto err_free; + } + + nftnl_obj_snprintf(buf, sizeof(buf), t, *type, 0); + printf("%s\n", buf); + +err_free: + nftnl_obj_free(t); +err: + return MNL_CB_OK; +} + +int main(int argc, char *argv[]) +{ + struct mnl_socket *nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh; + uint32_t portid, seq, family; + struct nftnl_obj *t; + int ret; + uint32_t type = NFTNL_OUTPUT_DEFAULT; + uint16_t flags = NLM_F_ACK; + + if (argc < 3 || argc > 4) { + fprintf(stderr, "%s <family> <table> [<name>]\n", argv[0]); + return EXIT_FAILURE; + } + + t = obj_parse(argc, argv); + if (t == NULL) + exit(EXIT_FAILURE); + family = nftnl_obj_get_u32(t, NFTNL_OBJ_FAMILY); + + seq = time(NULL); + if (argc < 4) + flags = NLM_F_DUMP; + nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_GETOBJ, family, flags, seq); + nftnl_obj_nlmsg_build_payload(nlh, t); + nftnl_obj_free(t); + + 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, obj_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; +} |