libnl: /data/src/libnl3/src/nf-queue.c Source File

libnl 3.7.0

nf-queue.c
1 /* SPDX-License-Identifier: LGPL-2.1-only */
2 /*
3 * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
4 * Copyright (c) 2010 Karl Hiramoto <karl@hiramoto.org>
5 */
6
7 #include <netlink/cli/utils.h>
8 #include <netlink/cli/link.h>
9 #include <netinet/in.h>
10 #include <linux/netfilter.h>
11 #include <linux/netfilter/nfnetlink_queue.h>
12 #include <netlink/netfilter/nfnl.h>
13 #include <netlink/netfilter/queue.h>
14 #include <netlink/netfilter/queue_msg.h>
15
16 #include <linux/netlink.h>
17
18 static struct nl_sock *nf_sock;
19
20 static struct nfnl_queue *alloc_queue(void)
21 {
22 struct nfnl_queue *queue;
23
24 queue = nfnl_queue_alloc();
25 if (!queue)
26 nl_cli_fatal(ENOMEM, "Unable to allocate queue object");
27
28 return queue;
29 }
30
31
32 static void obj_input(struct nl_object *obj, void *arg)
33 {
34 struct nfnl_queue_msg *msg = (struct nfnl_queue_msg *) obj;
35 struct nl_dump_params dp = {
36 .dp_type = NL_DUMP_STATS,
37 .dp_fd = stdout,
38 .dp_dump_msgtype = 1,
39 };
40
41 nfnl_queue_msg_set_verdict(msg, NF_ACCEPT);
42 nl_object_dump(obj, &dp);
43 nfnl_queue_msg_send_verdict(nf_sock, msg);
44 }
45
46 static int event_input(struct nl_msg *msg, void *arg)
47 {
48 if (nl_msg_parse(msg, &obj_input, NULL) < 0)
49 fprintf(stderr, "<<EVENT>> Unknown message type\n");
50
51 /* Exit nl_recvmsgs_def() and return to the main select() */
52 return NL_STOP;
53 }
54
55 int main(int argc, char *argv[])
56 {
57 struct nl_sock *rt_sock;
58 struct nfnl_queue *queue;
59 int copy_mode;
60 uint32_t copy_range;
61 int err = 1;
62 int family;
63
64 nf_sock = nfnl_queue_socket_alloc();
65 if (nf_sock == NULL)
66 nl_cli_fatal(ENOBUFS, "Unable to allocate netlink socket");
67
68 nl_socket_disable_seq_check(nf_sock);
69 nl_socket_modify_cb(nf_sock, NL_CB_VALID, NL_CB_CUSTOM, event_input, NULL);
70
71 if ((argc > 1 && !strcasecmp(argv[1], "-h")) || argc < 3) {
72 printf("Usage: nf-queue family group [ copy_mode ] "
73 "[ copy_range ]\n");
74 printf("family: [ inet | inet6 | ... ] \n");
75 printf("group: the --queue-num arg that you gave to iptables\n");
76 printf("copy_mode: [ none | meta | packet ] \n");
77 return 2;
78 }
79
80 nl_cli_connect(nf_sock, NETLINK_NETFILTER);
81
82 if ((family = nl_str2af(argv[1])) == AF_UNSPEC)
83 nl_cli_fatal(NLE_INVAL, "Unknown family \"%s\"", argv[1]);
84
85 nfnl_queue_pf_unbind(nf_sock, family);
86 if ((err = nfnl_queue_pf_bind(nf_sock, family)) < 0)
87 nl_cli_fatal(err, "Unable to bind logger: %s",
88 nl_geterror(err));
89
90 queue = alloc_queue();
91 nfnl_queue_set_group(queue, atoi(argv[2]));
92
93 copy_mode = NFNL_QUEUE_COPY_PACKET;
94 if (argc > 3) {
95 copy_mode = nfnl_queue_str2copy_mode(argv[3]);
96 if (copy_mode < 0)
97 nl_cli_fatal(copy_mode,
98 "Unable to parse copy mode \"%s\": %s",
99 argv[3], nl_geterror(copy_mode));
100 }
101 nfnl_queue_set_copy_mode(queue, copy_mode);
102
103 copy_range = 0xFFFF;
104 if (argc > 4)
105 copy_range = atoi(argv[4]);
106 nfnl_queue_set_copy_range(queue, copy_range);
107
108 if ((err = nfnl_queue_create(nf_sock, queue)) < 0)
109 nl_cli_fatal(err, "Unable to bind queue: %s", nl_geterror(err));
110
111 rt_sock = nl_cli_alloc_socket();
112 nl_cli_connect(rt_sock, NETLINK_ROUTE);
113 nl_cli_link_alloc_cache(rt_sock);
114
115 nl_socket_set_buffer_size(nf_sock, 1024*127, 1024*127);
116
117 while (1) {
118 fd_set rfds;
119 int nffd, rtfd, maxfd, retval;
120
121 FD_ZERO(&rfds);
122
123 maxfd = nffd = nl_socket_get_fd(nf_sock);
124 FD_SET(nffd, &rfds);
125
126 rtfd = nl_socket_get_fd(rt_sock);
127 FD_SET(rtfd, &rfds);
128 if (maxfd < rtfd)
129 maxfd = rtfd;
130
131 /* wait for an incoming message on the netlink socket */
132 retval = select(maxfd+1, &rfds, NULL, NULL, NULL);
133
134 if (retval) {
135 if (FD_ISSET(nffd, &rfds))
136 nl_recvmsgs_default(nf_sock);
137 if (FD_ISSET(rtfd, &rfds))
138 nl_recvmsgs_default(rt_sock);
139 }
140 }
141
142 return 0;
143 }
NL_STOP
@ NL_STOP
Stop parsing altogether and discard remaining messages.
Definition: handlers.h:62
NL_CB_VALID
@ NL_CB_VALID
Message is valid.
Definition: handlers.h:89
NL_CB_CUSTOM
@ NL_CB_CUSTOM
Customized handler specified by the user.
Definition: handlers.h:77
nl_cli_fatal
void nl_cli_fatal(int err, const char *fmt,...)
Print error message and quit application.
Definition: utils.c:71
nl_object_dump
void nl_object_dump(struct nl_object *obj, struct nl_dump_params *params)
Dump this object according to the specified parameters.
Definition: object.c:287
nl_recvmsgs_default
int nl_recvmsgs_default(struct nl_sock *sk)
Receive a set of message from a netlink socket using handlers in nl_sock.
Definition: nl.c:1087
nl_socket_get_fd
int nl_socket_get_fd(const struct nl_sock *sk)
Return the file descriptor of the backing socket.
Definition: socket.c:578
nl_socket_disable_seq_check
void nl_socket_disable_seq_check(struct nl_sock *sk)
Disable sequence number checking.
Definition: socket.c:277
nl_socket_set_buffer_size
int nl_socket_set_buffer_size(struct nl_sock *sk, int rxbuf, int txbuf)
Set socket buffer size of netlink socket.
Definition: socket.c:807
nl_socket_modify_cb
int nl_socket_modify_cb(struct nl_sock *sk, enum nl_cb_type type, enum nl_cb_kind kind, nl_recvmsg_msg_cb_t func, void *arg)
Modify the callback handler associated with the socket.
Definition: socket.c:765
NL_DUMP_STATS
@ NL_DUMP_STATS
Dump all attributes including statistics.
Definition: types.h:18
nl_dump_params
Dumping parameters.
Definition: types.h:28
nl_dump_params::dp_type
enum nl_dump_type dp_type
Specifies the type of dump that is requested.
Definition: types.h:32