From 7992160689ed70e1572cd63345cf0a123c462968 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?St=C3=A9phane=20Veyret?= Date: Fri, 31 May 2019 18:51:45 +0200 Subject: examples: add ct expectation examples MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Pablo Neira Ayuso --- examples/nft-rule-ct-expectation-add.c | 163 +++++++++++++++++++++++++++++++++ 1 file changed, 163 insertions(+) create mode 100644 examples/nft-rule-ct-expectation-add.c (limited to 'examples/nft-rule-ct-expectation-add.c') diff --git a/examples/nft-rule-ct-expectation-add.c b/examples/nft-rule-ct-expectation-add.c new file mode 100644 index 0000000..238e224 --- /dev/null +++ b/examples/nft-rule-ct-expectation-add.c @@ -0,0 +1,163 @@ +/* + * (C) 2019 by Stéphane Veyret + * + * 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 +#include +#include +#include /* for offsetof */ +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include +#include +#include + +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 void add_ct_expect(struct nftnl_rule *r, const char *obj_name) +{ + struct nftnl_expr *e; + + e = nftnl_expr_alloc("objref"); + if (e == NULL) { + perror("expr objref oom"); + exit(EXIT_FAILURE); + } + nftnl_expr_set_str(e, NFTNL_EXPR_OBJREF_IMM_NAME, obj_name); + nftnl_expr_set_u32(e, NFTNL_EXPR_OBJREF_IMM_TYPE, NFT_OBJECT_CT_EXPECT); + + nftnl_rule_add_expr(r, e); +} + +static struct nftnl_rule *setup_rule(uint8_t family, const char *table, + const char *chain, const char *handle, + const char *obj_name) +{ + struct nftnl_rule *r = NULL; + uint64_t handle_num; + + r = nftnl_rule_alloc(); + if (r == NULL) { + perror("OOM"); + exit(EXIT_FAILURE); + } + + nftnl_rule_set(r, NFTNL_RULE_TABLE, table); + nftnl_rule_set(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); + } + + add_ct_expect(r, obj_name); + + return r; +} + +int main(int argc, char *argv[]) +{ + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct mnl_nlmsg_batch *batch; + uint32_t seq = time(NULL); + struct mnl_socket *nl; + struct nftnl_rule *r; + struct nlmsghdr *nlh; + uint8_t family; + int ret; + + if (argc < 5 || argc > 6) { + fprintf(stderr, + "Usage: %s [] \n", + argv[0]); + exit(EXIT_FAILURE); + } + family = parse_family(argv[1], "family"); + + if (argc < 6) + r = setup_rule(family, argv[2], argv[3], NULL, argv[4]); + else + r = setup_rule(family, argv[2], argv[3], argv[4], argv[5]); + + 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); + } + + batch = mnl_nlmsg_batch_start(buf, sizeof(buf)); + + nftnl_batch_begin(mnl_nlmsg_batch_current(batch), seq++); + mnl_nlmsg_batch_next(batch); + + nlh = nftnl_rule_nlmsg_build_hdr(mnl_nlmsg_batch_current(batch), + NFT_MSG_NEWRULE, + nftnl_rule_get_u32(r, NFTNL_RULE_FAMILY), + NLM_F_APPEND|NLM_F_CREATE|NLM_F_ACK, + seq++); + + nftnl_rule_nlmsg_build_payload(nlh, r); + nftnl_rule_free(r); + mnl_nlmsg_batch_next(batch); + + nftnl_batch_end(mnl_nlmsg_batch_current(batch), seq++); + mnl_nlmsg_batch_next(batch); + + ret = mnl_socket_sendto(nl, mnl_nlmsg_batch_head(batch), + mnl_nlmsg_batch_size(batch)); + if (ret == -1) { + perror("mnl_socket_sendto"); + exit(EXIT_FAILURE); + } + + mnl_nlmsg_batch_stop(batch); + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + if (ret == -1) { + perror("mnl_socket_recvfrom"); + exit(EXIT_FAILURE); + } + + ret = mnl_cb_run(buf, ret, 0, mnl_socket_get_portid(nl), NULL, NULL); + if (ret < 0) { + perror("mnl_cb_run"); + exit(EXIT_FAILURE); + } + + mnl_socket_close(nl); + + return EXIT_SUCCESS; +} -- cgit v1.2.3