From 44dcf793ea4439978fbaae5b426912c4beb9425b Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Fri, 13 Apr 2012 17:15:27 +0200 Subject: examples: add example using libmnl and the new low-level API (conntrack) This patch adds the following examples: nfct-mnl-create nfct-mnl-del nfct-mnl-dump nfct-mnl-event nfct-mnl-flush nfct-mnl-get Basically, we re-use the existing object oriented handling and we provide full control on the netlink socket at the same time. Signed-off-by: Pablo Neira Ayuso --- examples/nfct-mnl-get.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) create mode 100644 examples/nfct-mnl-get.c (limited to 'examples/nfct-mnl-get.c') diff --git a/examples/nfct-mnl-get.c b/examples/nfct-mnl-get.c new file mode 100644 index 0000000..4858acf --- /dev/null +++ b/examples/nfct-mnl-get.c @@ -0,0 +1,100 @@ +#include +#include +#include +#include +#include + +#include +#include + +#include + +static int data_cb(const struct nlmsghdr *nlh, void *data) +{ + struct nf_conntrack *ct; + char buf[4096]; + + ct = nfct_new(); + if (ct == NULL) + return MNL_CB_OK; + + nfct_nlmsg_parse(nlh, ct); + + nfct_snprintf(buf, sizeof(buf), ct, NFCT_T_UNKNOWN, NFCT_O_DEFAULT, 0); + printf("%s\n", buf); + + nfct_destroy(ct); + + return MNL_CB_OK; +} + +int main(void) +{ + struct mnl_socket *nl; + struct nlmsghdr *nlh; + struct nfgenmsg *nfh; + char buf[MNL_SOCKET_BUFFER_SIZE]; + unsigned int seq, portid; + struct nf_conntrack *ct; + int ret; + + 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); + + nlh = mnl_nlmsg_put_header(buf); + nlh->nlmsg_type = (NFNL_SUBSYS_CTNETLINK << 8) | IPCTNL_MSG_CT_GET; + nlh->nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK; + nlh->nlmsg_seq = seq = time(NULL); + + nfh = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg)); + nfh->nfgen_family = AF_INET; + nfh->version = NFNETLINK_V0; + nfh->res_id = 0; + + ct = nfct_new(); + if (ct == NULL) { + perror("nfct_new"); + return 0; + } + + nfct_set_attr_u8(ct, ATTR_L3PROTO, AF_INET); + nfct_set_attr_u32(ct, ATTR_IPV4_SRC, inet_addr("1.1.1.1")); + nfct_set_attr_u32(ct, ATTR_IPV4_DST, inet_addr("2.2.2.2")); + + nfct_set_attr_u8(ct, ATTR_L4PROTO, IPPROTO_TCP); + nfct_set_attr_u16(ct, ATTR_PORT_SRC, htons(20)); + nfct_set_attr_u16(ct, ATTR_PORT_DST, htons(10)); + + nfct_nlmsg_build(nlh, ct); + + ret = mnl_socket_sendto(nl, nlh, nlh->nlmsg_len); + if (ret == -1) { + perror("mnl_socket_recvfrom"); + exit(EXIT_FAILURE); + } + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret > 0) { + ret = mnl_cb_run(buf, ret, seq, portid, data_cb, NULL); + if (ret <= MNL_CB_STOP) + break; + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + } + if (ret == -1) { + perror("mnl_socket_recvfrom"); + exit(EXIT_FAILURE); + } + + mnl_socket_close(nl); + + return 0; +} -- cgit v1.2.3