libnl  3.7.0
nl-monitor.c
1 /* SPDX-License-Identifier: LGPL-2.1-only */
2 /*
3  * Copyright (c) 2003-2009 Thomas Graf <tgraf@suug.ch>
4  */
5 
6 #include <netlink/cli/utils.h>
7 #include <netlink/cli/link.h>
8 #include <netlink/cli/mdb.h>
9 
10 #include <linux/rtnetlink.h>
11 
12 static const struct {
13  enum rtnetlink_groups gr_id;
14  const char* gr_name;
15 } known_groups[] = {
16  { RTNLGRP_LINK, "link" },
17  { RTNLGRP_NOTIFY, "notify" },
18  { RTNLGRP_NEIGH, "neigh" },
19  { RTNLGRP_TC, "tc" },
20  { RTNLGRP_IPV4_IFADDR, "ipv4-ifaddr" },
21  { RTNLGRP_IPV4_MROUTE, "ipv4-mroute" },
22  { RTNLGRP_IPV4_ROUTE, "ipv4-route" },
23  { RTNLGRP_IPV6_IFADDR, "ipv6-ifaddr" },
24  { RTNLGRP_IPV6_MROUTE, "ipv6-mroute" },
25  { RTNLGRP_IPV6_ROUTE, "ipv6-route" },
26  { RTNLGRP_IPV6_IFINFO, "ipv6-ifinfo" },
27  { RTNLGRP_DECnet_IFADDR, "decnet-ifaddr" },
28  { RTNLGRP_DECnet_ROUTE, "decnet-route" },
29  { RTNLGRP_IPV6_PREFIX, "ipv6-prefix" },
30  { RTNLGRP_IPV4_NETCONF, "ipv4-netconf" },
31  { RTNLGRP_IPV6_NETCONF, "ipv6-netconf" },
32  { RTNLGRP_MPLS_NETCONF, "mpls-netconf" },
33  { RTNLGRP_MDB, "mdb" },
34  { RTNLGRP_NONE, NULL }
35 };
36 
37 static void obj_input(struct nl_object *obj, void *arg)
38 {
39  nl_object_dump(obj, arg);
40 }
41 
42 static int event_input(struct nl_msg *msg, void *arg)
43 {
44  if (nl_msg_parse(msg, &obj_input, arg) < 0)
45  fprintf(stderr, "<<EVENT>> Unknown message type\n");
46 
47  /* Exit nl_recvmsgs_def() and return to the main select() */
48  return NL_STOP;
49 }
50 
51 static void print_usage(void)
52 {
53  int i;
54 
55  printf(
56  "Usage: nl-monitor [OPTION] [<groups>]\n"
57  "\n"
58  "Options\n"
59  " -d, --debug=LEVEL Set libnl debug level { 0 - 7 }\n"
60  " -f, --format=TYPE Output format { brief | details | stats }\n"
61  " -h, --help Show this help.\n"
62  "\n"
63  );
64  printf("Known groups:");
65  for (i = 0; known_groups[i].gr_id != RTNLGRP_NONE; i++)
66  printf(" %s", known_groups[i].gr_name);
67  printf("\n");
68  exit(0);
69 }
70 
71 int main(int argc, char *argv[])
72 {
73  struct nl_dump_params dp = {
75  .dp_fd = stdout,
76  .dp_dump_msgtype = 1,
77  };
78 
79  struct nl_sock *sock;
80  int err = 1;
81  int i, idx;
82 
83  sock = nl_cli_alloc_socket();
85  nl_socket_modify_cb(sock, NL_CB_VALID, NL_CB_CUSTOM, event_input, &dp);
86 
87  for (;;) {
88  int c, optidx = 0;
89  static struct option long_opts[] = {
90  { "debug", 1, 0, 'd' },
91  { "format", 1, 0, 'f' },
92  { "help", 0, 0, 'h' },
93  { 0, 0, 0, 0 }
94  };
95 
96  c = getopt_long(argc, argv, "d:f:h", long_opts, &optidx);
97  if (c == -1)
98  break;
99 
100  switch (c) {
101  case 'd':
102  nl_debug = atoi(optarg);
103  break;
104  case 'f':
105  dp.dp_type = nl_cli_parse_dumptype(optarg);
106  break;
107  default:
108  print_usage();
109  break;
110  }
111  }
112 
113  nl_cli_connect(sock, NETLINK_ROUTE);
114 
115  for (idx = optind; argc > idx; idx++) {
116  for (i = 0; known_groups[i].gr_id != RTNLGRP_NONE; i++) {
117  if (!strcmp(argv[idx], known_groups[i].gr_name)) {
118 
119  if ((err = nl_socket_add_membership(sock, known_groups[i].gr_id)) < 0) {
120  nl_cli_fatal(err, "%s: %s\n", argv[idx],
121  nl_geterror(err));
122  }
123 
124  break;
125  }
126  }
127  if (known_groups[i].gr_id == RTNLGRP_NONE)
128  fprintf(stderr, "Warning: Unknown group: %s\n", argv[idx]);
129  }
130 
131  nl_cli_link_alloc_cache(sock);
132 
133  while (1) {
134  fd_set rfds;
135  int fd, retval;
136 
137  fd = nl_socket_get_fd(sock);
138 
139  FD_ZERO(&rfds);
140  FD_SET(fd, &rfds);
141  /* wait for an incoming message on the netlink socket */
142  retval = select(fd+1, &rfds, NULL, NULL, NULL);
143 
144  if (retval) {
145  /* FD_ISSET(fd, &rfds) will be true */
146  nl_recvmsgs_default(sock);
147  }
148  }
149 
150  return 0;
151 }
@ 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:578
void nl_socket_disable_seq_check(struct nl_sock *sk)
Disable sequence number checking.
Definition: socket.c:277
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
int nl_debug
Global variable indicating the desired level of debugging output.
Definition: utils.c:47
@ 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