20588b3bb2e8c00497c2bebd31e4dbac8d21c7a9
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/types.h>
28 #include <linux/time.h>
29 #include <linux/netlink.h>
30 #include <libltt/libltt.h>
34 /* Private interface */
55 #define LTTCTL_MAXERR LTTCTL_ERR_PROTOCOL
58 struct lttctl_errmap_t
{
62 { LTTCTL_ERR_NONE
, "Unknown error" },
63 { LTTCTL_ERR_IMPL
, "Implementation error" },
64 { LTTCTL_ERR_HANDLE
, "Unable to create netlink handle" },
65 { LTTCTL_ERR_SOCKET
, "Unable to create netlink socket" },
66 { LTTCTL_ERR_BIND
, "Unable to bind netlink socket" },
67 { LTTCTL_ERR_BUFFER
, "Unable to allocate buffer" },
68 { LTTCTL_ERR_RECV
, "Failed to receive netlink message" },
69 { LTTCTL_ERR_NLEOF
, "Received EOF on netlink socket" },
70 { LTTCTL_ERR_ADDRLEN
, "Invalid peer address length" },
71 { LTTCTL_ERR_STRUNC
, "Sent message truncated" },
72 { LTTCTL_ERR_RTRUNC
, "Received message truncated" },
73 { LTTCTL_ERR_NLRECV
, "Received error from netlink" },
74 { LTTCTL_ERR_SEND
, "Failed to send netlink message" },
75 { LTTCTL_ERR_SUPP
, "Operation not supported" },
76 { LTTCTL_ERR_RECVBUF
, "Receive buffer size invalid" },
77 { LTTCTL_ERR_TIMEOUT
, "Timeout"},
78 { LTTCTL_ERR_PROTOCOL
, "Invalid protocol specified" }
81 static int lttctl_errno
= LTTCTL_ERR_NONE
;
84 static ssize_t
lttctl_netlink_sendto(const struct lttctl_handle
*h
,
85 const void *msg
, size_t len
);
87 static ssize_t
lttctl_netlink_recvfrom(const struct lttctl_handle
*h
,
88 unsigned char *buf
, size_t len
,
91 static ssize_t
lttctl_netlink_sendmsg(const struct lttctl_handle
*h
,
92 const struct msghdr
*msg
,
95 static char *lttctl_strerror(int errcode
);
97 void lttctl_perror(const char *s
);
99 static ssize_t
lttctl_netlink_sendto(const struct lttctl_handle
*h
,
100 const void *msg
, size_t len
)
102 int status
= sendto(h
->fd
, msg
, len
, 0,
103 (struct sockaddr
*)&h
->peer
, sizeof(h
->peer
));
105 lttctl_errno
= LTTCTL_ERR_SEND
;
110 static ssize_t
lttctl_netlink_sendmsg(const struct lttctl_handle
*h
,
111 const struct msghdr
*msg
,
114 int status
= sendmsg(h
->fd
, msg
, flags
);
116 lttctl_errno
= LTTCTL_ERR_SEND
;
120 static ssize_t
lttctl_netlink_recvfrom(const struct lttctl_handle
*h
,
121 unsigned char *buf
, size_t len
,
125 struct nlmsghdr
*nlh
;
127 if (len
< sizeof(struct nlmsghdr
)) {
128 lttctl_errno
= LTTCTL_ERR_RECVBUF
;
129 lttctl_perror("Netlink recvfrom");
132 addrlen
= sizeof(h
->peer
);
140 /* non-block non-timeout */
144 tv
.tv_sec
= timeout
/ 1000000;
145 tv
.tv_usec
= timeout
% 1000000;
149 FD_SET(h
->fd
, &read_fds
);
150 ret
= select(h
->fd
+1, &read_fds
, NULL
, NULL
, &tv
);
152 if (errno
== EINTR
) {
156 lttctl_errno
= LTTCTL_ERR_RECV
;
157 lttctl_perror("Netlink recvfrom");
161 if (!FD_ISSET(h
->fd
, &read_fds
)) {
162 lttctl_errno
= LTTCTL_ERR_TIMEOUT
;
167 status
= recvfrom(h
->fd
, buf
, len
, 0,
168 (struct sockaddr
*)&h
->peer
, &addrlen
);
171 lttctl_errno
= LTTCTL_ERR_RECV
;
172 lttctl_perror("Netlink recvfrom");
175 if (addrlen
!= sizeof(h
->peer
)) {
176 lttctl_errno
= LTTCTL_ERR_RECV
;
177 lttctl_perror("Netlink recvfrom");
180 if (h
->peer
.nl_pid
!= 0) {
181 lttctl_errno
= LTTCTL_ERR_RECV
;
182 lttctl_perror("Netlink recvfrom");
186 lttctl_errno
= LTTCTL_ERR_NLEOF
;
187 lttctl_perror("Netlink recvfrom");
190 nlh
= (struct nlmsghdr
*)buf
;
191 if (nlh
->nlmsg_flags
& MSG_TRUNC
|| nlh
->nlmsg_len
> status
) {
192 lttctl_errno
= LTTCTL_ERR_RTRUNC
;
193 lttctl_perror("Netlink recvfrom");
202 static char *lttctl_strerror(int errcode
)
204 if (errcode
< 0 || errcode
> LTTCTL_MAXERR
)
205 errcode
= LTTCTL_ERR_IMPL
;
206 return lttctl_errmap
[errcode
].message
;
210 char *lttctl_errstr(void)
212 return lttctl_strerror(lttctl_errno
);
215 void lttctl_perror(const char *s
)
220 fputs("ERROR", stderr
);
222 fprintf(stderr
, ": %s", lttctl_errstr());
224 fprintf(stderr
, ": %s", strerror(errno
));
228 /* public interface */
231 * Create and initialise an lttctl handle.
233 struct lttctl_handle
*lttctl_create_handle(void)
236 struct lttctl_handle
*h
;
238 h
= (struct lttctl_handle
*)malloc(sizeof(struct lttctl_handle
));
240 lttctl_errno
= LTTCTL_ERR_HANDLE
;
241 lttctl_perror("Create handle");
245 memset(h
, 0, sizeof(struct lttctl_handle
));
247 h
->fd
= socket(PF_NETLINK
, SOCK_RAW
, NETLINK_LTT
);
250 lttctl_errno
= LTTCTL_ERR_SOCKET
;
251 lttctl_perror("Create handle");
254 memset(&h
->local
, 0, sizeof(struct sockaddr_nl
));
255 h
->local
.nl_family
= AF_NETLINK
;
256 h
->local
.nl_pid
= getpid();
257 h
->local
.nl_groups
= 0;
258 status
= bind(h
->fd
, (struct sockaddr
*)&h
->local
, sizeof(h
->local
));
260 lttctl_errno
= LTTCTL_ERR_BIND
;
261 lttctl_perror("Create handle");
264 memset(&h
->peer
, 0, sizeof(struct sockaddr_nl
));
265 h
->peer
.nl_family
= AF_NETLINK
;
267 h
->peer
.nl_groups
= 0;
270 /* Error condition */
280 * No error condition is checked here at this stage, but it may happen
281 * if/when reliable messaging is implemented.
283 int lttctl_destroy_handle(struct lttctl_handle
*h
)
293 int lttctl_create_trace(const struct lttctl_handle
*h
,
294 char *name
, enum trace_mode mode
)
300 lttctl_peer_msg_t msg
;
304 struct nlmsgerr nlerr
;
305 lttctl_peer_msg_t msg
;
308 memset(&req
, 0, sizeof(req
));
309 req
.nlh
.nlmsg_len
= NLMSG_LENGTH(sizeof(lttctl_peer_msg_t
));
310 req
.nlh
.nlmsg_flags
= NLM_F_REQUEST
|NLM_F_ACK
;
311 req
.nlh
.nlmsg_type
= LTTCTLM_CONTROL
;
312 req
.nlh
.nlmsg_pid
= h
->local
.nl_pid
;
313 req
.nlh
.nlmsg_seq
= 0;
315 strncpy(req
.msg
.trace_name
, name
, NAME_MAX
);
316 req
.msg
.op
= OP_CREATE
;
317 req
.msg
.args
.mode
= mode
;
319 err
= lttctl_netlink_sendto(h
, (void *)&req
, req
.nlh
.nlmsg_len
);
320 if(err
< 0) goto senderr
;
322 err
= lttctl_netlink_recvfrom(h
, (void*)&ack
, sizeof(ack
), 0);
323 if(err
< 0) goto senderr
;
325 err
= ack
.nlerr
.error
;
328 lttctl_perror("Create Trace Error");
335 lttctl_perror("Create Trace Error");
339 int lttctl_destroy_trace(const struct lttctl_handle
*h
,
344 lttctl_peer_msg_t msg
;
348 struct nlmsgerr nlerr
;
349 lttctl_peer_msg_t msg
;
353 memset(&req
, 0, sizeof(req
));
354 req
.nlh
.nlmsg_len
= NLMSG_LENGTH(sizeof(lttctl_peer_msg_t
));
355 req
.nlh
.nlmsg_flags
= NLM_F_REQUEST
;
356 req
.nlh
.nlmsg_type
= LTTCTLM_CONTROL
;
357 req
.nlh
.nlmsg_pid
= h
->local
.nl_pid
;
359 strncpy(req
.msg
.trace_name
, name
, NAME_MAX
);
360 req
.msg
.op
= OP_DESTROY
;
362 err
= lttctl_netlink_sendto(h
, (void *)&req
, req
.nlh
.nlmsg_len
);
363 if(err
< 0) goto senderr
;
365 err
= lttctl_netlink_recvfrom(h
, (void*)&ack
, sizeof(ack
), 0);
366 if(err
< 0) goto senderr
;
368 err
= ack
.nlerr
.error
;
371 lttctl_perror("Destroy Trace Channels Error");
378 lttctl_perror("Destroy Trace Channels Error");
383 int lttctl_start(const struct lttctl_handle
*h
,
388 lttctl_peer_msg_t msg
;
392 struct nlmsgerr nlerr
;
393 lttctl_peer_msg_t msg
;
398 memset(&req
, 0, sizeof(req
));
399 req
.nlh
.nlmsg_len
= NLMSG_LENGTH(sizeof(lttctl_peer_msg_t
));
400 req
.nlh
.nlmsg_flags
= NLM_F_REQUEST
;
401 req
.nlh
.nlmsg_type
= LTTCTLM_CONTROL
;
402 req
.nlh
.nlmsg_pid
= h
->local
.nl_pid
;
404 strncpy(req
.msg
.trace_name
, name
, NAME_MAX
);
405 req
.msg
.op
= OP_START
;
407 err
= lttctl_netlink_sendto(h
, (void *)&req
, req
.nlh
.nlmsg_len
);
408 if(err
< 0) goto senderr
;
410 err
= lttctl_netlink_recvfrom(h
, (void*)&ack
, sizeof(ack
), 0);
411 if(err
< 0) goto senderr
;
413 err
= ack
.nlerr
.error
;
416 lttctl_perror("Start Trace Error");
423 lttctl_perror("Start Trace Error");
428 int lttctl_stop(const struct lttctl_handle
*h
,
433 lttctl_peer_msg_t msg
;
437 struct nlmsgerr nlerr
;
438 lttctl_peer_msg_t msg
;
442 memset(&req
, 0, sizeof(req
));
443 req
.nlh
.nlmsg_len
= NLMSG_LENGTH(sizeof(lttctl_peer_msg_t
));
444 req
.nlh
.nlmsg_flags
= NLM_F_REQUEST
;
445 req
.nlh
.nlmsg_type
= LTTCTLM_CONTROL
;
446 req
.nlh
.nlmsg_pid
= h
->local
.nl_pid
;
448 strncpy(req
.msg
.trace_name
, name
, NAME_MAX
);
449 req
.msg
.op
= OP_STOP
;
451 err
= lttctl_netlink_sendto(h
, (void *)&req
, req
.nlh
.nlmsg_len
);
452 if(err
< 0) goto senderr
;
454 err
= lttctl_netlink_recvfrom(h
, (void*)&ack
, sizeof(ack
), 0);
455 if(err
< 0) goto senderr
;
457 err
= ack
.nlerr
.error
;
460 lttctl_perror("Stop Trace Error");
467 lttctl_perror("Stop Trace Error");
This page took 0.042797 seconds and 4 git commands to generate.