xref: /aosp_15_r20/external/libnl/src/nf-queue.c (revision 4dc78e53d49367fa8e61b07018507c90983a077d)
1 /* SPDX-License-Identifier: LGPL-2.1-only */
2 /*
3  * Copyright (c) 2007, 2008 Patrick McHardy <[email protected]>
4  * Copyright (c) 2010  Karl Hiramoto <[email protected]>
5  */
6 
7 #include "nl-default.h"
8 
9 #include <linux/netfilter.h>
10 #include <linux/netfilter/nfnetlink_queue.h>
11 #include <linux/netlink.h>
12 
13 #include <netlink/cli/utils.h>
14 #include <netlink/cli/link.h>
15 #include <netlink/netfilter/nfnl.h>
16 #include <netlink/netfilter/queue.h>
17 #include <netlink/netfilter/queue_msg.h>
18 
19 static struct nl_sock *nf_sock;
20 
alloc_queue(void)21 static struct nfnl_queue *alloc_queue(void)
22 {
23 	struct nfnl_queue *queue;
24 
25 	queue = nfnl_queue_alloc();
26 	if (!queue)
27 		nl_cli_fatal(ENOMEM, "Unable to allocate queue object");
28 
29 	return queue;
30 }
31 
32 
obj_input(struct nl_object * obj,void * arg)33 static void obj_input(struct nl_object *obj, void *arg)
34 {
35 	struct nfnl_queue_msg *msg = (struct nfnl_queue_msg *) obj;
36 	struct nl_dump_params dp = {
37 		.dp_type = NL_DUMP_STATS,
38 		.dp_fd = stdout,
39 		.dp_dump_msgtype = 1,
40 	};
41 
42 	nfnl_queue_msg_set_verdict(msg, NF_ACCEPT);
43 	nl_object_dump(obj, &dp);
44 	nfnl_queue_msg_send_verdict(nf_sock, msg);
45 }
46 
event_input(struct nl_msg * msg,void * arg)47 static int event_input(struct nl_msg *msg, void *arg)
48 {
49 	if (nl_msg_parse(msg, &obj_input, NULL) < 0)
50 		fprintf(stderr, "<<EVENT>> Unknown message type\n");
51 
52 	/* Exit nl_recvmsgs_def() and return to the main select() */
53 	return NL_STOP;
54 }
55 
main(int argc,char * argv[])56 int main(int argc, char *argv[])
57 {
58 	struct nl_sock *rt_sock;
59 	struct nfnl_queue *queue;
60 	int copy_mode;
61 	uint32_t copy_range;
62 	int err = 1;
63 	int family;
64 
65 	nf_sock = nfnl_queue_socket_alloc();
66 	if (nf_sock == NULL)
67 		nl_cli_fatal(ENOBUFS, "Unable to allocate netlink socket");
68 
69 	nl_socket_disable_seq_check(nf_sock);
70 	nl_socket_modify_cb(nf_sock, NL_CB_VALID, NL_CB_CUSTOM, event_input, NULL);
71 
72 	if ((argc > 1 && !strcasecmp(argv[1], "-h")) || argc < 3) {
73 		printf("Usage: nf-queue family group [ copy_mode ] "
74 		       "[ copy_range ]\n");
75 		printf("family: [ inet | inet6 | ... ] \n");
76 		printf("group: the --queue-num arg that you gave to iptables\n");
77 		printf("copy_mode: [ none | meta | packet ] \n");
78 		return 2;
79 	}
80 
81 	nl_cli_connect(nf_sock, NETLINK_NETFILTER);
82 
83 	if ((family = nl_str2af(argv[1])) == AF_UNSPEC)
84 		nl_cli_fatal(NLE_INVAL, "Unknown family \"%s\"", argv[1]);
85 
86 	nfnl_queue_pf_unbind(nf_sock, family);
87 	if ((err = nfnl_queue_pf_bind(nf_sock, family)) < 0)
88 		nl_cli_fatal(err, "Unable to bind logger: %s",
89 			     nl_geterror(err));
90 
91 	queue = alloc_queue();
92 	nfnl_queue_set_group(queue, atoi(argv[2]));
93 
94 	copy_mode = NFNL_QUEUE_COPY_PACKET;
95 	if (argc > 3) {
96 		copy_mode = nfnl_queue_str2copy_mode(argv[3]);
97 		if (copy_mode < 0)
98 			nl_cli_fatal(copy_mode,
99 				     "Unable to parse copy mode \"%s\": %s",
100 				     argv[3], nl_geterror(copy_mode));
101 	}
102 	nfnl_queue_set_copy_mode(queue, copy_mode);
103 
104 	copy_range = 0xFFFF;
105 	if (argc > 4)
106 		copy_range = atoi(argv[4]);
107 	nfnl_queue_set_copy_range(queue, copy_range);
108 
109 	if ((err = nfnl_queue_create(nf_sock, queue)) < 0)
110 		nl_cli_fatal(err, "Unable to bind queue: %s", nl_geterror(err));
111 
112 	rt_sock = nl_cli_alloc_socket();
113 	nl_cli_connect(rt_sock, NETLINK_ROUTE);
114 	nl_cli_link_alloc_cache(rt_sock);
115 
116 	nl_socket_set_buffer_size(nf_sock, 1024*127, 1024*127);
117 
118 	while (1) {
119 		fd_set rfds;
120 		int nffd, rtfd, maxfd, retval;
121 
122 		FD_ZERO(&rfds);
123 
124 		maxfd = nffd = nl_socket_get_fd(nf_sock);
125 		FD_SET(nffd, &rfds);
126 
127 		rtfd = nl_socket_get_fd(rt_sock);
128 		FD_SET(rtfd, &rfds);
129 		if (maxfd < rtfd)
130 			maxfd = rtfd;
131 
132 		/* wait for an incoming message on the netlink socket */
133 		retval = select(maxfd+1, &rfds, NULL, NULL, NULL);
134 
135 		if (retval) {
136 			if (FD_ISSET(nffd, &rfds))
137 				nl_recvmsgs_default(nf_sock);
138 			if (FD_ISSET(rtfd, &rfds))
139 				nl_recvmsgs_default(rt_sock);
140 		}
141 	}
142 
143 	return 0;
144 }
145