libnl  3.6.0
nf-log.c
1 /* SPDX-License-Identifier: LGPL-2.1-only */
2 /*
3  * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
4  * Copyright (c) 2007 Philip Craig <philipc@snapgear.com>
5  * Copyright (c) 2007 Secure Computing Corporation
6  */
7 
8 #include <netlink/cli/utils.h>
9 #include <netlink/cli/link.h>
10 #include <netlink/netfilter/nfnl.h>
11 #include <netlink/netfilter/log.h>
12 
13 #include <linux/netfilter/nfnetlink_log.h>
14 #include <linux/netlink.h>
15 
16 static struct nfnl_log *alloc_log(void)
17 {
18  struct nfnl_log *log;
19 
20  log = nfnl_log_alloc();
21  if (!log)
22  nl_cli_fatal(ENOMEM, "Unable to allocate log object");
23 
24  return log;
25 }
26 
27 static void obj_input(struct nl_object *obj, void *arg)
28 {
29  struct nl_dump_params dp = {
31  .dp_fd = stdout,
32  .dp_dump_msgtype = 1,
33  };
34 
35  nl_object_dump(obj, &dp);
36 }
37 
38 static int event_input(struct nl_msg *msg, void *arg)
39 {
40  if (nl_msg_parse(msg, &obj_input, NULL) < 0)
41  fprintf(stderr, "<<EVENT>> Unknown message type\n");
42 
43  /* Exit nl_recvmsgs_def() and return to the main select() */
44  return NL_STOP;
45 }
46 
47 int main(int argc, char *argv[])
48 {
49  struct nl_sock *nf_sock;
50  struct nl_sock *rt_sock;
51  struct nfnl_log *log;
52  int copy_mode;
53  uint32_t copy_range;
54  int err;
55  int family;
56 
57  nf_sock = nl_cli_alloc_socket();
59  nl_socket_modify_cb(nf_sock, NL_CB_VALID, NL_CB_CUSTOM, event_input, NULL);
60 
61  if ((argc > 1 && !strcasecmp(argv[1], "-h")) || argc < 3) {
62  printf("Usage: nf-log family group [ copy_mode ] "
63  "[copy_range] \n");
64  return 2;
65  }
66 
67  nl_cli_connect(nf_sock, NETLINK_NETFILTER);
68 
69  family = nl_str2af(argv[1]);
70  if (family == AF_UNSPEC)
71  nl_cli_fatal(NLE_INVAL, "Unknown family \"%s\": %s",
72  argv[1], nl_geterror(family));
73 
74  nfnl_log_pf_unbind(nf_sock, family);
75  if ((err = nfnl_log_pf_bind(nf_sock, family)) < 0)
76  nl_cli_fatal(err, "Unable to bind logger: %s",
77  nl_geterror(err));
78 
79  log = alloc_log();
80  nfnl_log_set_group(log, atoi(argv[2]));
81 
82  copy_mode = NFNL_LOG_COPY_META;
83  if (argc > 3) {
84  copy_mode = nfnl_log_str2copy_mode(argv[3]);
85  if (copy_mode < 0)
86  nl_cli_fatal(copy_mode,
87  "Unable to parse copy mode \"%s\": %s",
88  argv[3], nl_geterror(copy_mode));
89  }
90  nfnl_log_set_copy_mode(log, copy_mode);
91 
92  copy_range = 0xFFFF;
93  if (argc > 4)
94  copy_range = atoi(argv[4]);
95  nfnl_log_set_copy_range(log, copy_range);
96 
97  if ((err = nfnl_log_create(nf_sock, log)) < 0)
98  nl_cli_fatal(err, "Unable to bind instance: %s",
99  nl_geterror(err));
100 
101  {
102  struct nl_dump_params dp = {
104  .dp_fd = stdout,
105  .dp_dump_msgtype = 1,
106  };
107 
108  printf("log params: ");
109  nl_object_dump((struct nl_object *) log, &dp);
110  }
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  while (1) {
117  fd_set rfds;
118  int nffd, rtfd, maxfd, retval;
119 
120  FD_ZERO(&rfds);
121 
122  maxfd = nffd = nl_socket_get_fd(nf_sock);
123  FD_SET(nffd, &rfds);
124 
125  rtfd = nl_socket_get_fd(rt_sock);
126  FD_SET(rtfd, &rfds);
127  if (maxfd < rtfd)
128  maxfd = rtfd;
129 
130  /* wait for an incoming message on the netlink nf_socket */
131  retval = select(maxfd+1, &rfds, NULL, NULL, NULL);
132 
133  if (retval) {
134  if (FD_ISSET(nffd, &rfds))
135  nl_recvmsgs_default(nf_sock);
136  if (FD_ISSET(rtfd, &rfds))
137  nl_recvmsgs_default(rt_sock);
138  }
139  }
140 
141  return 0;
142 }
@ NL_STOP
Stop parsing altogether and discard remaining messages.
Definition: handlers.h:62
@ NL_CB_VALID
Message is valid.
Definition: handlers.h:89
@ NL_CB_CUSTOM
Customized handler specified by the user.
Definition: handlers.h:77
void nl_cli_fatal(int err, const char *fmt,...)
Print error message and quit application.
Definition: utils.c:71
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
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
int nl_socket_get_fd(const struct nl_sock *sk)
Return the file descriptor of the backing socket.
Definition: socket.c:577
void nl_socket_disable_seq_check(struct nl_sock *sk)
Disable sequence number checking.
Definition: socket.c:276
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:764
@ NL_DUMP_STATS
Dump all attributes including statistics.
Definition: types.h:18
Dumping parameters.
Definition: types.h:28
enum nl_dump_type dp_type
Specifies the type of dump that is requested.
Definition: types.h:32