3 * Linux Trace Toolkit Netlink Control Library
5 * Controls the ltt-control kernel module through a netlink socket.
7 * Heavily inspired from libipq.c (iptables) made by
8 * James Morris <jmorris@intercode.com.au>
11 * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
26 #include <linux/socket.h>
27 #include <linux/in.h> // for broken Fedora Core 3
28 #include <linux/types.h>
29 #include <linux/time.h>
30 #include <linux/netlink.h>
31 #include <libltt/libltt.h>
32 #include <asm/socket.h>
37 /* Private interface */
58 #define LTTCTL_MAXERR LTTCTL_ERR_PROTOCOL
61 struct lttctl_errmap_t
{
65 { LTTCTL_ERR_NONE
, "Unknown error" },
66 { LTTCTL_ERR_IMPL
, "Implementation error" },
67 { LTTCTL_ERR_HANDLE
, "Unable to create netlink handle" },
68 { LTTCTL_ERR_SOCKET
, "Unable to create netlink socket" },
69 { LTTCTL_ERR_BIND
, "Unable to bind netlink socket" },
70 { LTTCTL_ERR_BUFFER
, "Unable to allocate buffer" },
71 { LTTCTL_ERR_RECV
, "Failed to receive netlink message" },
72 { LTTCTL_ERR_NLEOF
, "Received EOF on netlink socket" },
73 { LTTCTL_ERR_ADDRLEN
, "Invalid peer address length" },
74 { LTTCTL_ERR_STRUNC
, "Sent message truncated" },
75 { LTTCTL_ERR_RTRUNC
, "Received message truncated" },
76 { LTTCTL_ERR_NLRECV
, "Received error from netlink" },
77 { LTTCTL_ERR_SEND
, "Failed to send netlink message" },
78 { LTTCTL_ERR_SUPP
, "Operation not supported" },
79 { LTTCTL_ERR_RECVBUF
, "Receive buffer size invalid" },
80 { LTTCTL_ERR_TIMEOUT
, "Timeout"},
81 { LTTCTL_ERR_PROTOCOL
, "Invalid protocol specified" }
84 static int lttctl_errno
= LTTCTL_ERR_NONE
;
87 static ssize_t
lttctl_netlink_sendto(const struct lttctl_handle
*h
,
88 const void *msg
, size_t len
);
90 static ssize_t
lttctl_netlink_recvfrom(const struct lttctl_handle
*h
,
91 unsigned char *buf
, size_t len
,
94 static ssize_t
lttctl_netlink_sendmsg(const struct lttctl_handle
*h
,
95 const struct msghdr
*msg
,
98 static char *lttctl_strerror(int errcode
);
100 void lttctl_perror(const char *s
);
102 static ssize_t
lttctl_netlink_sendto(const struct lttctl_handle
*h
,
103 const void *msg
, size_t len
)
105 int status
= sendto(h
->fd
, msg
, len
, 0,
106 (struct sockaddr
*)&h
->peer
, sizeof(h
->peer
));
108 lttctl_errno
= LTTCTL_ERR_SEND
;
113 static ssize_t
lttctl_netlink_sendmsg(const struct lttctl_handle
*h
,
114 const struct msghdr
*msg
,
117 int status
= sendmsg(h
->fd
, msg
, flags
);
119 lttctl_errno
= LTTCTL_ERR_SEND
;
123 static ssize_t
lttctl_netlink_recvfrom(const struct lttctl_handle
*h
,
124 unsigned char *buf
, size_t len
,
128 struct nlmsghdr
*nlh
;
130 if (len
< sizeof(struct nlmsghdr
)) {
131 lttctl_errno
= LTTCTL_ERR_RECVBUF
;
132 lttctl_perror("Netlink recvfrom");
135 addrlen
= sizeof(h
->peer
);
143 /* non-block non-timeout */
147 tv
.tv_sec
= timeout
/ 1000000;
148 tv
.tv_usec
= timeout
% 1000000;
152 FD_SET(h
->fd
, &read_fds
);
153 ret
= select(h
->fd
+1, &read_fds
, NULL
, NULL
, &tv
);
155 if (errno
== EINTR
) {
159 lttctl_errno
= LTTCTL_ERR_RECV
;
160 lttctl_perror("Netlink recvfrom");
164 if (!FD_ISSET(h
->fd
, &read_fds
)) {
165 lttctl_errno
= LTTCTL_ERR_TIMEOUT
;
170 status
= recvfrom(h
->fd
, buf
, len
, 0,
171 (struct sockaddr
*)&h
->peer
, &addrlen
);
174 lttctl_errno
= LTTCTL_ERR_RECV
;
175 lttctl_perror("Netlink recvfrom");
178 if (addrlen
!= sizeof(h
->peer
)) {
179 lttctl_errno
= LTTCTL_ERR_RECV
;
180 lttctl_perror("Netlink recvfrom");
183 if (h
->peer
.nl_pid
!= 0) {
184 lttctl_errno
= LTTCTL_ERR_RECV
;
185 lttctl_perror("Netlink recvfrom");
189 lttctl_errno
= LTTCTL_ERR_NLEOF
;
190 lttctl_perror("Netlink recvfrom");
193 nlh
= (struct nlmsghdr
*)buf
;
194 if (nlh
->nlmsg_flags
& MSG_TRUNC
|| nlh
->nlmsg_len
> status
) {
195 lttctl_errno
= LTTCTL_ERR_RTRUNC
;
196 lttctl_perror("Netlink recvfrom");
205 static char *lttctl_strerror(int errcode
)
207 if (errcode
< 0 || errcode
> LTTCTL_MAXERR
)
208 errcode
= LTTCTL_ERR_IMPL
;
209 return lttctl_errmap
[errcode
].message
;
213 char *lttctl_errstr(void)
215 return lttctl_strerror(lttctl_errno
);
218 void lttctl_perror(const char *s
)
223 fputs("ERROR", stderr
);
225 fprintf(stderr
, ": %s", lttctl_errstr());
227 fprintf(stderr
, ": %s", strerror(errno
));
231 /* public interface */
234 * Create and initialise an lttctl handle.
236 struct lttctl_handle
*lttctl_create_handle(void)
239 struct lttctl_handle
*h
;
241 h
= (struct lttctl_handle
*)malloc(sizeof(struct lttctl_handle
));
243 lttctl_errno
= LTTCTL_ERR_HANDLE
;
244 lttctl_perror("Create handle");
248 memset(h
, 0, sizeof(struct lttctl_handle
));
250 h
->fd
= socket(PF_NETLINK
, SOCK_RAW
, NETLINK_LTT
);
253 lttctl_errno
= LTTCTL_ERR_SOCKET
;
254 lttctl_perror("Create handle");
257 memset(&h
->local
, 0, sizeof(struct sockaddr_nl
));
258 h
->local
.nl_family
= AF_NETLINK
;
259 h
->local
.nl_pid
= getpid();
260 h
->local
.nl_groups
= 0;
261 status
= bind(h
->fd
, (struct sockaddr
*)&h
->local
, sizeof(h
->local
));
263 lttctl_errno
= LTTCTL_ERR_BIND
;
264 lttctl_perror("Create handle");
267 memset(&h
->peer
, 0, sizeof(struct sockaddr_nl
));
268 h
->peer
.nl_family
= AF_NETLINK
;
270 h
->peer
.nl_groups
= 0;
273 /* Error condition */
283 * No error condition is checked here at this stage, but it may happen
284 * if/when reliable messaging is implemented.
286 int lttctl_destroy_handle(struct lttctl_handle
*h
)
296 int lttctl_create_trace(const struct lttctl_handle
*h
,
297 char *name
, enum trace_mode mode
)
303 lttctl_peer_msg_t msg
;
307 struct nlmsgerr nlerr
;
308 lttctl_peer_msg_t msg
;
311 memset(&req
, 0, sizeof(req
));
312 req
.nlh
.nlmsg_len
= NLMSG_LENGTH(sizeof(lttctl_peer_msg_t
));
313 req
.nlh
.nlmsg_flags
= NLM_F_REQUEST
|NLM_F_ACK
;
314 req
.nlh
.nlmsg_type
= LTTCTLM_CONTROL
;
315 req
.nlh
.nlmsg_pid
= h
->local
.nl_pid
;
316 req
.nlh
.nlmsg_seq
= 0;
318 strncpy(req
.msg
.trace_name
, name
, NAME_MAX
);
319 req
.msg
.op
= OP_CREATE
;
320 req
.msg
.args
.mode
= mode
;
322 err
= lttctl_netlink_sendto(h
, (void *)&req
, req
.nlh
.nlmsg_len
);
323 if(err
< 0) goto senderr
;
325 err
= lttctl_netlink_recvfrom(h
, (void*)&ack
, sizeof(ack
), 0);
326 if(err
< 0) goto senderr
;
328 err
= ack
.nlerr
.error
;
331 lttctl_perror("Create Trace Error");
338 lttctl_perror("Create Trace Error");
342 int lttctl_destroy_trace(const struct lttctl_handle
*h
,
347 lttctl_peer_msg_t msg
;
351 struct nlmsgerr nlerr
;
352 lttctl_peer_msg_t msg
;
356 memset(&req
, 0, sizeof(req
));
357 req
.nlh
.nlmsg_len
= NLMSG_LENGTH(sizeof(lttctl_peer_msg_t
));
358 req
.nlh
.nlmsg_flags
= NLM_F_REQUEST
;
359 req
.nlh
.nlmsg_type
= LTTCTLM_CONTROL
;
360 req
.nlh
.nlmsg_pid
= h
->local
.nl_pid
;
362 strncpy(req
.msg
.trace_name
, name
, NAME_MAX
);
363 req
.msg
.op
= OP_DESTROY
;
365 err
= lttctl_netlink_sendto(h
, (void *)&req
, req
.nlh
.nlmsg_len
);
366 if(err
< 0) goto senderr
;
368 err
= lttctl_netlink_recvfrom(h
, (void*)&ack
, sizeof(ack
), 0);
369 if(err
< 0) goto senderr
;
371 err
= ack
.nlerr
.error
;
374 lttctl_perror("Destroy Trace Channels Error");
381 lttctl_perror("Destroy Trace Channels Error");
386 int lttctl_start(const struct lttctl_handle
*h
,
391 lttctl_peer_msg_t msg
;
395 struct nlmsgerr nlerr
;
396 lttctl_peer_msg_t msg
;
401 memset(&req
, 0, sizeof(req
));
402 req
.nlh
.nlmsg_len
= NLMSG_LENGTH(sizeof(lttctl_peer_msg_t
));
403 req
.nlh
.nlmsg_flags
= NLM_F_REQUEST
;
404 req
.nlh
.nlmsg_type
= LTTCTLM_CONTROL
;
405 req
.nlh
.nlmsg_pid
= h
->local
.nl_pid
;
407 strncpy(req
.msg
.trace_name
, name
, NAME_MAX
);
408 req
.msg
.op
= OP_START
;
410 err
= lttctl_netlink_sendto(h
, (void *)&req
, req
.nlh
.nlmsg_len
);
411 if(err
< 0) goto senderr
;
413 err
= lttctl_netlink_recvfrom(h
, (void*)&ack
, sizeof(ack
), 0);
414 if(err
< 0) goto senderr
;
416 err
= ack
.nlerr
.error
;
419 lttctl_perror("Start Trace Error");
426 lttctl_perror("Start Trace Error");
431 int lttctl_stop(const struct lttctl_handle
*h
,
436 lttctl_peer_msg_t msg
;
440 struct nlmsgerr nlerr
;
441 lttctl_peer_msg_t msg
;
445 memset(&req
, 0, sizeof(req
));
446 req
.nlh
.nlmsg_len
= NLMSG_LENGTH(sizeof(lttctl_peer_msg_t
));
447 req
.nlh
.nlmsg_flags
= NLM_F_REQUEST
;
448 req
.nlh
.nlmsg_type
= LTTCTLM_CONTROL
;
449 req
.nlh
.nlmsg_pid
= h
->local
.nl_pid
;
451 strncpy(req
.msg
.trace_name
, name
, NAME_MAX
);
452 req
.msg
.op
= OP_STOP
;
454 err
= lttctl_netlink_sendto(h
, (void *)&req
, req
.nlh
.nlmsg_len
);
455 if(err
< 0) goto senderr
;
457 err
= lttctl_netlink_recvfrom(h
, (void*)&ack
, sizeof(ack
), 0);
458 if(err
< 0) goto senderr
;
460 err
= ack
.nlerr
.error
;
463 lttctl_perror("Stop Trace Error");
470 lttctl_perror("Stop Trace Error");
This page took 0.05137 seconds and 5 git commands to generate.