2 * lxc: linux Container library
4 * (C) Copyright IBM Corp. 2007, 2009
7 * Daniel Lezcano <daniel.lezcano at free.fr>
9 * This library is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
14 * This library is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with this library; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
35 #include <sys/param.h>
36 #include <sys/socket.h>
42 #include "commands_utils.h"
55 * This file provides the different functions for clients to query/command the
56 * server. The client is typically some lxc tool and the server is typically the
57 * container (ie. lxc-start).
59 * Each command is transactional, the clients send a request to the server and
60 * the server answers the request with a message giving the request's status
61 * (zero or a negative errno value). Both the request and response may contain
64 * Each command is wrapped in a ancillary message in order to pass a credential
65 * making possible to the server to check if the client is allowed to ask for
66 * this command or not.
68 * IMPORTANTLY: Note that semantics for current commands are fixed. If you wish
69 * to make any changes to how, say, LXC_CMD_GET_CONFIG_ITEM works by adding
70 * information to the end of cmd.data, then you must introduce a new
71 * LXC_CMD_GET_CONFIG_ITEM_V2 define with a new number. You may wish to also
72 * mark LXC_CMD_GET_CONFIG_ITEM deprecated in commands.h.
74 * This is necessary in order to avoid having a newly compiled lxc command
75 * communicating with a running (old) monitor from crashing the running
79 lxc_log_define(lxc_commands
, lxc
);
81 static const char *lxc_cmd_str(lxc_cmd_t cmd
)
83 static const char *const cmdname
[LXC_CMD_MAX
] = {
84 [LXC_CMD_CONSOLE
] = "console",
85 [LXC_CMD_TERMINAL_WINCH
] = "terminal_winch",
86 [LXC_CMD_STOP
] = "stop",
87 [LXC_CMD_GET_STATE
] = "get_state",
88 [LXC_CMD_GET_INIT_PID
] = "get_init_pid",
89 [LXC_CMD_GET_CLONE_FLAGS
] = "get_clone_flags",
90 [LXC_CMD_GET_CGROUP
] = "get_cgroup",
91 [LXC_CMD_GET_CONFIG_ITEM
] = "get_config_item",
92 [LXC_CMD_GET_NAME
] = "get_name",
93 [LXC_CMD_GET_LXCPATH
] = "get_lxcpath",
94 [LXC_CMD_ADD_STATE_CLIENT
] = "add_state_client",
95 [LXC_CMD_CONSOLE_LOG
] = "console_log",
96 [LXC_CMD_SERVE_STATE_CLIENTS
] = "serve_state_clients",
99 if (cmd
>= LXC_CMD_MAX
)
100 return "Unknown cmd";
106 * lxc_cmd_rsp_recv: Receive a response to a command
108 * @sock : the socket connected to the container
109 * @cmd : command to put response in
111 * Returns the size of the response message or < 0 on failure
113 * Note that if the command response datalen > 0, then data is
114 * a malloc()ed buffer and should be free()ed by the caller. If
115 * the response data is <= a void * worth of data, it will be
116 * stored directly in data and datalen will be 0.
118 * As a special case, the response for LXC_CMD_CONSOLE is created
119 * here as it contains an fd for the master pty passed through the
122 static int lxc_cmd_rsp_recv(int sock
, struct lxc_cmd_rr
*cmd
)
125 struct lxc_cmd_rsp
*rsp
= &cmd
->rsp
;
127 ret
= lxc_abstract_unix_recv_fds(sock
, &rspfd
, 1, rsp
, sizeof(*rsp
));
129 WARN("%s - Failed to receive response for command \"%s\"",
130 strerror(errno
), lxc_cmd_str(cmd
->req
.cmd
));
131 if (errno
== ECONNRESET
)
136 TRACE("Command \"%s\" received response", lxc_cmd_str(cmd
->req
.cmd
));
138 if (cmd
->req
.cmd
== LXC_CMD_CONSOLE
) {
139 struct lxc_cmd_console_rsp_data
*rspdata
;
141 /* recv() returns 0 bytes when a tty cannot be allocated,
142 * rsp->ret is < 0 when the peer permission check failed
144 if (ret
== 0 || rsp
->ret
< 0)
147 rspdata
= malloc(sizeof(*rspdata
));
149 ERROR("Failed to allocate response buffer for command \"%s\"",
150 lxc_cmd_str(cmd
->req
.cmd
));
153 rspdata
->masterfd
= rspfd
;
154 rspdata
->ttynum
= PTR_TO_INT(rsp
->data
);
158 if (rsp
->datalen
== 0) {
159 DEBUG("Response data length for command \"%s\" is 0",
160 lxc_cmd_str(cmd
->req
.cmd
));
164 if ((rsp
->datalen
> LXC_CMD_DATA_MAX
) &&
165 (cmd
->req
.cmd
!= LXC_CMD_CONSOLE_LOG
)) {
167 ERROR("%s - Response data for command \"%s\" is too long: %d "
168 "bytes > %d", strerror(errno
), lxc_cmd_str(cmd
->req
.cmd
),
169 rsp
->datalen
, LXC_CMD_DATA_MAX
);
173 if (cmd
->req
.cmd
== LXC_CMD_CONSOLE_LOG
) {
174 rsp
->data
= malloc(rsp
->datalen
+ 1);
175 ((char *)rsp
->data
)[rsp
->datalen
] = '\0';
177 rsp
->data
= malloc(rsp
->datalen
);
181 ERROR("%s - Failed to allocate response buffer for command "
182 "\"%s\"", strerror(errno
), lxc_cmd_str(cmd
->req
.cmd
));
186 ret
= recv(sock
, rsp
->data
, rsp
->datalen
, 0);
187 if (ret
!= rsp
->datalen
) {
188 ERROR("%s - Failed to receive response data for command \"%s\"",
189 lxc_cmd_str(cmd
->req
.cmd
), strerror(errno
));
198 * lxc_cmd_rsp_send: Send a command response
200 * @fd : file descriptor of socket to send response on
201 * @rsp : response to send
203 * Returns 0 on success, < 0 on failure
205 static int lxc_cmd_rsp_send(int fd
, struct lxc_cmd_rsp
*rsp
)
209 ret
= send(fd
, rsp
, sizeof(*rsp
), 0);
210 if (ret
< 0 || (size_t)ret
!= sizeof(*rsp
)) {
211 ERROR("%s - Failed to send command response %zd",
212 strerror(errno
), ret
);
216 if (rsp
->datalen
<= 0)
219 ret
= send(fd
, rsp
->data
, rsp
->datalen
, 0);
220 if (ret
< 0 || ret
!= (ssize_t
)rsp
->datalen
) {
221 WARN("%s - Failed to send command response data %zd",
222 strerror(errno
), ret
);
229 static int lxc_cmd_send(const char *name
, struct lxc_cmd_rr
*cmd
,
230 const char *lxcpath
, const char *hashed_sock_name
)
235 client_fd
= lxc_cmd_connect(name
, lxcpath
, hashed_sock_name
, "command");
237 if (client_fd
== -ECONNREFUSED
)
238 return -ECONNREFUSED
;
243 ret
= lxc_abstract_unix_send_credential(client_fd
, &cmd
->req
,
245 if (ret
< 0 || (size_t)ret
!= sizeof(cmd
->req
)) {
257 if (cmd
->req
.datalen
<= 0)
260 ret
= send(client_fd
, cmd
->req
.data
, cmd
->req
.datalen
, MSG_NOSIGNAL
);
261 if (ret
< 0 || ret
!= (ssize_t
)cmd
->req
.datalen
) {
277 * lxc_cmd: Connect to the specified running container, send it a command
278 * request and collect the response
280 * @name : name of container to connect to
281 * @cmd : command with initialized request to send
282 * @stopped : output indicator if the container was not running
283 * @lxcpath : the lxcpath in which the container is running
285 * Returns the size of the response message on success, < 0 on failure
287 * Note that there is a special case for LXC_CMD_CONSOLE. For this command
288 * the fd cannot be closed because it is used as a placeholder to indicate
289 * that a particular tty slot is in use. The fd is also used as a signal to
290 * the container that when the caller dies or closes the fd, the container
291 * will notice the fd on its side of the socket in its mainloop select and
292 * then free the slot with lxc_cmd_fd_cleanup(). The socket fd will be
293 * returned in the cmd response structure.
295 static int lxc_cmd(const char *name
, struct lxc_cmd_rr
*cmd
, int *stopped
,
296 const char *lxcpath
, const char *hashed_sock_name
)
300 bool stay_connected
= false;
302 if (cmd
->req
.cmd
== LXC_CMD_CONSOLE
||
303 cmd
->req
.cmd
== LXC_CMD_ADD_STATE_CLIENT
)
304 stay_connected
= true;
308 client_fd
= lxc_cmd_send(name
, cmd
, lxcpath
, hashed_sock_name
);
310 TRACE("%s - Command \"%s\" failed to connect command socket",
311 strerror(errno
), lxc_cmd_str(cmd
->req
.cmd
));
312 if (client_fd
== -ECONNREFUSED
) {
317 if (client_fd
== -EPIPE
)
323 ret
= lxc_cmd_rsp_recv(client_fd
, cmd
);
324 if (ret
== -ECONNRESET
)
327 if (!stay_connected
|| ret
<= 0)
331 if (stay_connected
&& ret
> 0)
332 cmd
->rsp
.ret
= client_fd
;
341 int lxc_try_cmd(const char *name
, const char *lxcpath
)
344 struct lxc_cmd_rr cmd
= {
345 .req
= { .cmd
= LXC_CMD_GET_INIT_PID
},
348 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
351 if (ret
> 0 && cmd
.rsp
.ret
< 0) {
358 /* At this point we weren't denied access, and the container *was*
359 * started. There was some inexplicable error in the protocol. I'm not
360 * clear on whether we should return -1 here, but we didn't receive a
361 * -EACCES, so technically it's not that we're not allowed to control
362 * the container - it's just not behaving.
367 /* Implentations of the commands and their callbacks */
370 * lxc_cmd_get_init_pid: Get pid of the container's init process
372 * @name : name of container to connect to
373 * @lxcpath : the lxcpath in which the container is running
375 * Returns the pid on success, < 0 on failure
377 pid_t
lxc_cmd_get_init_pid(const char *name
, const char *lxcpath
)
380 struct lxc_cmd_rr cmd
= {
381 .req
= { .cmd
= LXC_CMD_GET_INIT_PID
},
384 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
388 return PTR_TO_INT(cmd
.rsp
.data
);
391 static int lxc_cmd_get_init_pid_callback(int fd
, struct lxc_cmd_req
*req
,
392 struct lxc_handler
*handler
)
394 struct lxc_cmd_rsp rsp
= { .data
= INT_TO_PTR(handler
->pid
) };
396 return lxc_cmd_rsp_send(fd
, &rsp
);
400 * lxc_cmd_get_clone_flags: Get clone flags container was spawned with
402 * @name : name of container to connect to
403 * @lxcpath : the lxcpath in which the container is running
405 * Returns the clone flags on success, < 0 on failure
407 int lxc_cmd_get_clone_flags(const char *name
, const char *lxcpath
)
410 struct lxc_cmd_rr cmd
= {
411 .req
= { .cmd
= LXC_CMD_GET_CLONE_FLAGS
},
414 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
418 return PTR_TO_INT(cmd
.rsp
.data
);
421 static int lxc_cmd_get_clone_flags_callback(int fd
, struct lxc_cmd_req
*req
,
422 struct lxc_handler
*handler
)
424 struct lxc_cmd_rsp rsp
= { .data
= INT_TO_PTR(handler
->ns_clone_flags
) };
426 return lxc_cmd_rsp_send(fd
, &rsp
);
430 * lxc_cmd_get_cgroup_path: Calculate a container's cgroup path for a
431 * particular subsystem. This is the cgroup path relative to the root
432 * of the cgroup filesystem.
434 * @name : name of container to connect to
435 * @lxcpath : the lxcpath in which the container is running
436 * @subsystem : the subsystem being asked about
438 * Returns the path on success, NULL on failure. The caller must free() the
441 char *lxc_cmd_get_cgroup_path(const char *name
, const char *lxcpath
,
442 const char *subsystem
)
445 struct lxc_cmd_rr cmd
= {
447 .cmd
= LXC_CMD_GET_CGROUP
,
453 cmd
.req
.data
= subsystem
;
456 cmd
.req
.datalen
= strlen(subsystem
) + 1;
458 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
465 if (cmd
.rsp
.ret
< 0 || cmd
.rsp
.datalen
< 0)
471 static int lxc_cmd_get_cgroup_callback(int fd
, struct lxc_cmd_req
*req
,
472 struct lxc_handler
*handler
)
475 struct lxc_cmd_rsp rsp
;
476 struct cgroup_ops
*cgroup_ops
= handler
->cgroup_ops
;
478 if (req
->datalen
> 0)
479 path
= cgroup_ops
->get_cgroup(cgroup_ops
, req
->data
);
481 path
= cgroup_ops
->get_cgroup(cgroup_ops
, NULL
);
486 rsp
.datalen
= strlen(path
) + 1;
487 rsp
.data
= (char *)path
;
489 return lxc_cmd_rsp_send(fd
, &rsp
);
493 * lxc_cmd_get_config_item: Get config item the running container
495 * @name : name of container to connect to
496 * @item : the configuration item to retrieve (ex: lxc.net.0.veth.pair)
497 * @lxcpath : the lxcpath in which the container is running
499 * Returns the item on success, NULL on failure. The caller must free() the
502 char *lxc_cmd_get_config_item(const char *name
, const char *item
,
506 struct lxc_cmd_rr cmd
= {
507 .req
= { .cmd
= LXC_CMD_GET_CONFIG_ITEM
,
509 .datalen
= strlen(item
) + 1,
513 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
517 if (cmd
.rsp
.ret
== 0)
523 static int lxc_cmd_get_config_item_callback(int fd
, struct lxc_cmd_req
*req
,
524 struct lxc_handler
*handler
)
528 struct lxc_config_t
*item
;
529 struct lxc_cmd_rsp rsp
;
531 memset(&rsp
, 0, sizeof(rsp
));
532 item
= lxc_get_config(req
->data
);
536 cilen
= item
->get(req
->data
, NULL
, 0, handler
->conf
, NULL
);
540 cidata
= alloca(cilen
+ 1);
541 if (item
->get(req
->data
, cidata
, cilen
+ 1, handler
->conf
, NULL
) != cilen
)
544 cidata
[cilen
] = '\0';
546 rsp
.datalen
= cilen
+ 1;
553 return lxc_cmd_rsp_send(fd
, &rsp
);
557 * lxc_cmd_get_state: Get current state of the container
559 * @name : name of container to connect to
560 * @lxcpath : the lxcpath in which the container is running
562 * Returns the state on success, < 0 on failure
564 int lxc_cmd_get_state(const char *name
, const char *lxcpath
)
567 struct lxc_cmd_rr cmd
= {
568 .req
= { .cmd
= LXC_CMD_GET_STATE
}
571 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
572 if (ret
< 0 && stopped
)
579 WARN("Container \"%s\" has stopped before sending its state", name
);
583 DEBUG("Container \"%s\" is in \"%s\" state", name
,
584 lxc_state2str(PTR_TO_INT(cmd
.rsp
.data
)));
586 return PTR_TO_INT(cmd
.rsp
.data
);
589 static int lxc_cmd_get_state_callback(int fd
, struct lxc_cmd_req
*req
,
590 struct lxc_handler
*handler
)
592 struct lxc_cmd_rsp rsp
= { .data
= INT_TO_PTR(handler
->state
) };
594 return lxc_cmd_rsp_send(fd
, &rsp
);
598 * lxc_cmd_stop: Stop the container previously started with lxc_start. All
599 * the processes running inside this container will be killed.
601 * @name : name of container to connect to
602 * @lxcpath : the lxcpath in which the container is running
604 * Returns 0 on success, < 0 on failure
606 int lxc_cmd_stop(const char *name
, const char *lxcpath
)
609 struct lxc_cmd_rr cmd
= {
610 .req
= { .cmd
= LXC_CMD_STOP
},
613 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
616 INFO("Container \"%s\" is already stopped", name
);
623 /* We do not expect any answer, because we wait for the connection to be
627 ERROR("%s - Failed to stop container \"%s\"",
628 strerror(-cmd
.rsp
.ret
), name
);
632 INFO("Container \"%s\" has stopped", name
);
636 static int lxc_cmd_stop_callback(int fd
, struct lxc_cmd_req
*req
,
637 struct lxc_handler
*handler
)
639 struct lxc_cmd_rsp rsp
;
640 int stopsignal
= SIGKILL
;
641 struct cgroup_ops
*cgroup_ops
= handler
->cgroup_ops
;
643 if (handler
->conf
->stopsignal
)
644 stopsignal
= handler
->conf
->stopsignal
;
645 memset(&rsp
, 0, sizeof(rsp
));
646 rsp
.ret
= kill(handler
->pid
, stopsignal
);
648 /* We can't just use lxc_unfreeze() since we are already in the
649 * context of handling the STOP cmd in lxc-start, and calling
650 * lxc_unfreeze() would do another cmd (GET_CGROUP) which would
653 if (cgroup_ops
->unfreeze(cgroup_ops
))
656 ERROR("Failed to unfreeze container \"%s\"", handler
->name
);
660 return lxc_cmd_rsp_send(fd
, &rsp
);
664 * lxc_cmd_terminal_winch: To process as if a SIGWINCH were received
666 * @name : name of container to connect to
667 * @lxcpath : the lxcpath in which the container is running
669 * Returns 0 on success, < 0 on failure
671 int lxc_cmd_terminal_winch(const char *name
, const char *lxcpath
)
674 struct lxc_cmd_rr cmd
= {
675 .req
= { .cmd
= LXC_CMD_TERMINAL_WINCH
},
678 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
685 static int lxc_cmd_terminal_winch_callback(int fd
, struct lxc_cmd_req
*req
,
686 struct lxc_handler
*handler
)
688 struct lxc_cmd_rsp rsp
= { .data
= 0 };
690 lxc_terminal_sigwinch(SIGWINCH
);
692 return lxc_cmd_rsp_send(fd
, &rsp
);
696 * lxc_cmd_console: Open an fd to a tty in the container
698 * @name : name of container to connect to
699 * @ttynum : in: the tty to open or -1 for next available
700 * : out: the tty allocated
701 * @fd : out: file descriptor for master side of pty
702 * @lxcpath : the lxcpath in which the container is running
704 * Returns fd holding tty allocated on success, < 0 on failure
706 int lxc_cmd_console(const char *name
, int *ttynum
, int *fd
, const char *lxcpath
)
709 struct lxc_cmd_console_rsp_data
*rspdata
;
710 struct lxc_cmd_rr cmd
= {
711 .req
= { .cmd
= LXC_CMD_CONSOLE
, .data
= INT_TO_PTR(*ttynum
) },
714 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
718 if (cmd
.rsp
.ret
< 0) {
719 ERROR("%s - Denied access to tty", strerror(-cmd
.rsp
.ret
));
725 ERROR("tty number %d invalid, busy or all ttys busy", *ttynum
);
730 rspdata
= cmd
.rsp
.data
;
731 if (rspdata
->masterfd
< 0) {
732 ERROR("Unable to allocate fd for tty %d", rspdata
->ttynum
);
736 ret
= cmd
.rsp
.ret
; /* socket fd */
737 *fd
= rspdata
->masterfd
;
738 *ttynum
= rspdata
->ttynum
;
739 INFO("Alloced fd %d for tty %d via socket %d", *fd
, rspdata
->ttynum
, ret
);
746 static int lxc_cmd_console_callback(int fd
, struct lxc_cmd_req
*req
,
747 struct lxc_handler
*handler
)
750 struct lxc_cmd_rsp rsp
;
751 int ttynum
= PTR_TO_INT(req
->data
);
753 masterfd
= lxc_terminal_allocate(handler
->conf
, fd
, &ttynum
);
757 memset(&rsp
, 0, sizeof(rsp
));
758 rsp
.data
= INT_TO_PTR(ttynum
);
759 ret
= lxc_abstract_unix_send_fds(fd
, &masterfd
, 1, &rsp
, sizeof(rsp
));
761 ERROR("Failed to send tty to client");
762 lxc_terminal_free(handler
->conf
, fd
);
769 /* Special indicator to lxc_cmd_handler() to close the fd and do
776 * lxc_cmd_get_name: Returns the name of the container
778 * @hashed_sock_name: hashed socket name
780 * Returns the name on success, NULL on failure.
782 char *lxc_cmd_get_name(const char *hashed_sock_name
)
785 struct lxc_cmd_rr cmd
= {
786 .req
= { .cmd
= LXC_CMD_GET_NAME
},
789 ret
= lxc_cmd(NULL
, &cmd
, &stopped
, NULL
, hashed_sock_name
);
793 if (cmd
.rsp
.ret
== 0)
799 static int lxc_cmd_get_name_callback(int fd
, struct lxc_cmd_req
*req
,
800 struct lxc_handler
*handler
)
802 struct lxc_cmd_rsp rsp
;
804 memset(&rsp
, 0, sizeof(rsp
));
806 rsp
.data
= (char *)handler
->name
;
807 rsp
.datalen
= strlen(handler
->name
) + 1;
810 return lxc_cmd_rsp_send(fd
, &rsp
);
814 * lxc_cmd_get_lxcpath: Returns the lxcpath of the container
816 * @hashed_sock_name: hashed socket name
818 * Returns the lxcpath on success, NULL on failure.
820 char *lxc_cmd_get_lxcpath(const char *hashed_sock_name
)
823 struct lxc_cmd_rr cmd
= {
824 .req
= { .cmd
= LXC_CMD_GET_LXCPATH
},
827 ret
= lxc_cmd(NULL
, &cmd
, &stopped
, NULL
, hashed_sock_name
);
831 if (cmd
.rsp
.ret
== 0)
837 static int lxc_cmd_get_lxcpath_callback(int fd
, struct lxc_cmd_req
*req
,
838 struct lxc_handler
*handler
)
840 struct lxc_cmd_rsp rsp
;
842 memset(&rsp
, 0, sizeof(rsp
));
845 rsp
.data
= (char *)handler
->lxcpath
;
846 rsp
.datalen
= strlen(handler
->lxcpath
) + 1;
848 return lxc_cmd_rsp_send(fd
, &rsp
);
851 int lxc_cmd_add_state_client(const char *name
, const char *lxcpath
,
852 lxc_state_t states
[MAX_STATE
],
853 int *state_client_fd
)
857 struct lxc_cmd_rr cmd
= {
859 .cmd
= LXC_CMD_ADD_STATE_CLIENT
,
861 .datalen
= (sizeof(lxc_state_t
) * MAX_STATE
)
865 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
866 if (states
[STOPPED
] != 0 && stopped
!= 0)
870 if (errno
!= ECONNREFUSED
)
871 ERROR("%s - Failed to execute command", strerror(errno
));
875 /* We should now be guaranteed to get an answer from the state sending
878 if (cmd
.rsp
.ret
< 0) {
879 ERROR("%s - Failed to receive socket fd", strerror(-cmd
.rsp
.ret
));
883 state
= PTR_TO_INT(cmd
.rsp
.data
);
884 if (state
< MAX_STATE
) {
885 TRACE("Container is already in requested state %s", lxc_state2str(state
));
890 *state_client_fd
= cmd
.rsp
.ret
;
891 TRACE("Added state client %d to state client list", cmd
.rsp
.ret
);
895 static int lxc_cmd_add_state_client_callback(int fd
, struct lxc_cmd_req
*req
,
896 struct lxc_handler
*handler
)
899 struct lxc_cmd_rsp rsp
= {0};
901 if (req
->datalen
< 0)
904 if (req
->datalen
> (sizeof(lxc_state_t
) * MAX_STATE
))
910 rsp
.ret
= lxc_add_state_client(fd
, handler
, (lxc_state_t
*)req
->data
);
914 rsp
.data
= INT_TO_PTR(rsp
.ret
);
916 ret
= lxc_cmd_rsp_send(fd
, &rsp
);
923 /* Special indicator to lxc_cmd_handler() to close the fd and do related
929 int lxc_cmd_console_log(const char *name
, const char *lxcpath
,
930 struct lxc_console_log
*log
)
933 struct lxc_cmd_console_log data
;
934 struct lxc_cmd_rr cmd
;
936 data
.clear
= log
->clear
;
937 data
.read
= log
->read
;
938 data
.read_max
= *log
->read_max
;
940 cmd
.req
.cmd
= LXC_CMD_CONSOLE_LOG
;
941 cmd
.req
.data
= &data
;
942 cmd
.req
.datalen
= sizeof(struct lxc_cmd_console_log
);
944 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
948 /* There is nothing to be read from the buffer. So clear any values we
949 * where passed to clearly indicate to the user that nothing went wrong.
951 if (cmd
.rsp
.ret
== -ENODATA
|| cmd
.rsp
.ret
== -EFAULT
|| cmd
.rsp
.ret
== -ENOENT
) {
956 /* This is a proper error so don't touch any values we were passed. */
960 *log
->read_max
= cmd
.rsp
.datalen
;
961 log
->data
= cmd
.rsp
.data
;
966 static int lxc_cmd_console_log_callback(int fd
, struct lxc_cmd_req
*req
,
967 struct lxc_handler
*handler
)
969 struct lxc_cmd_rsp rsp
;
970 uint64_t buffer_size
= handler
->conf
->console
.buffer_size
;
971 const struct lxc_cmd_console_log
*log
= req
->data
;
972 struct lxc_ringbuf
*buf
= &handler
->conf
->console
.ringbuf
;
977 if (buffer_size
<= 0)
980 if (log
->read
|| log
->write_logfile
)
981 rsp
.datalen
= lxc_ringbuf_used(buf
);
984 rsp
.data
= lxc_ringbuf_get_read_addr(buf
);
986 if (log
->read_max
> 0 && (log
->read_max
<= rsp
.datalen
))
987 rsp
.datalen
= log
->read_max
;
989 /* there's nothing to read */
991 if (log
->read
&& (buf
->r_off
== buf
->w_off
))
996 lxc_ringbuf_clear(buf
); /* clear the ringbuffer */
997 else if (rsp
.datalen
> 0)
998 lxc_ringbuf_move_read_addr(buf
, rsp
.datalen
);
1001 return lxc_cmd_rsp_send(fd
, &rsp
);
1004 int lxc_cmd_serve_state_clients(const char *name
, const char *lxcpath
,
1009 struct lxc_cmd_rr cmd
= {
1011 .cmd
= LXC_CMD_SERVE_STATE_CLIENTS
,
1012 .data
= INT_TO_PTR(state
)
1016 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
1018 ERROR("%s - Failed to execute command", strerror(errno
));
1025 static int lxc_cmd_serve_state_clients_callback(int fd
, struct lxc_cmd_req
*req
,
1026 struct lxc_handler
*handler
)
1029 lxc_state_t state
= PTR_TO_INT(req
->data
);
1030 struct lxc_cmd_rsp rsp
= {0};
1032 ret
= lxc_serve_state_clients(handler
->name
, handler
, state
);
1034 goto reap_client_fd
;
1036 ret
= lxc_cmd_rsp_send(fd
, &rsp
);
1038 goto reap_client_fd
;
1043 /* Special indicator to lxc_cmd_handler() to close the fd and do related
1049 static int lxc_cmd_process(int fd
, struct lxc_cmd_req
*req
,
1050 struct lxc_handler
*handler
)
1052 typedef int (*callback
)(int, struct lxc_cmd_req
*, struct lxc_handler
*);
1054 callback cb
[LXC_CMD_MAX
] = {
1055 [LXC_CMD_CONSOLE
] = lxc_cmd_console_callback
,
1056 [LXC_CMD_TERMINAL_WINCH
] = lxc_cmd_terminal_winch_callback
,
1057 [LXC_CMD_STOP
] = lxc_cmd_stop_callback
,
1058 [LXC_CMD_GET_STATE
] = lxc_cmd_get_state_callback
,
1059 [LXC_CMD_GET_INIT_PID
] = lxc_cmd_get_init_pid_callback
,
1060 [LXC_CMD_GET_CLONE_FLAGS
] = lxc_cmd_get_clone_flags_callback
,
1061 [LXC_CMD_GET_CGROUP
] = lxc_cmd_get_cgroup_callback
,
1062 [LXC_CMD_GET_CONFIG_ITEM
] = lxc_cmd_get_config_item_callback
,
1063 [LXC_CMD_GET_NAME
] = lxc_cmd_get_name_callback
,
1064 [LXC_CMD_GET_LXCPATH
] = lxc_cmd_get_lxcpath_callback
,
1065 [LXC_CMD_ADD_STATE_CLIENT
] = lxc_cmd_add_state_client_callback
,
1066 [LXC_CMD_CONSOLE_LOG
] = lxc_cmd_console_log_callback
,
1067 [LXC_CMD_SERVE_STATE_CLIENTS
] = lxc_cmd_serve_state_clients_callback
,
1070 if (req
->cmd
>= LXC_CMD_MAX
) {
1071 ERROR("Undefined command id %d", req
->cmd
);
1074 return cb
[req
->cmd
](fd
, req
, handler
);
1077 static void lxc_cmd_fd_cleanup(int fd
, struct lxc_handler
*handler
,
1078 struct lxc_epoll_descr
*descr
,
1079 const lxc_cmd_t cmd
)
1081 struct lxc_state_client
*client
;
1082 struct lxc_list
*cur
, *next
;
1084 lxc_terminal_free(handler
->conf
, fd
);
1085 lxc_mainloop_del_handler(descr
, fd
);
1086 if (cmd
!= LXC_CMD_ADD_STATE_CLIENT
) {
1091 lxc_list_for_each_safe(cur
, &handler
->conf
->state_clients
, next
) {
1093 if (client
->clientfd
!= fd
)
1096 /* kick client from list */
1098 close(client
->clientfd
);
1101 /* No need to walk the whole list. If we found the state client
1102 * fd there can't be a second one.
1108 static int lxc_cmd_handler(int fd
, uint32_t events
, void *data
,
1109 struct lxc_epoll_descr
*descr
)
1112 struct lxc_cmd_req req
;
1113 void *reqdata
= NULL
;
1114 struct lxc_handler
*handler
= data
;
1116 ret
= lxc_abstract_unix_rcv_credential(fd
, &req
, sizeof(req
));
1117 if (ret
== -EACCES
) {
1118 /* We don't care for the peer, just send and close. */
1119 struct lxc_cmd_rsp rsp
= {.ret
= ret
};
1121 lxc_cmd_rsp_send(fd
, &rsp
);
1126 SYSERROR("Failed to receive data on command socket for command "
1127 "\"%s\"", lxc_cmd_str(req
.cmd
));
1134 if (ret
!= sizeof(req
)) {
1135 WARN("Failed to receive full command request. Ignoring request "
1136 "for \"%s\"", lxc_cmd_str(req
.cmd
));
1141 if ((req
.datalen
> LXC_CMD_DATA_MAX
) &&
1142 (req
.cmd
!= LXC_CMD_CONSOLE_LOG
)) {
1143 ERROR("Received command data length %d is too large for "
1144 "command \"%s\"", req
.datalen
, lxc_cmd_str(req
.cmd
));
1150 if (req
.datalen
> 0) {
1151 /* LXC_CMD_CONSOLE_LOG needs to be able to allocate data
1152 * that exceeds LXC_CMD_DATA_MAX: use malloc() for that.
1154 if (req
.cmd
== LXC_CMD_CONSOLE_LOG
)
1155 reqdata
= malloc(req
.datalen
);
1157 reqdata
= alloca(req
.datalen
);
1159 ERROR("Failed to allocate memory for \"%s\" command",
1160 lxc_cmd_str(req
.cmd
));
1166 ret
= recv(fd
, reqdata
, req
.datalen
, 0);
1167 if (ret
!= req
.datalen
) {
1168 WARN("Failed to receive full command request. Ignoring "
1169 "request for \"%s\"", lxc_cmd_str(req
.cmd
));
1170 ret
= LXC_MAINLOOP_ERROR
;
1177 ret
= lxc_cmd_process(fd
, &req
, handler
);
1179 /* This is not an error, but only a request to close fd. */
1180 ret
= LXC_MAINLOOP_CONTINUE
;
1185 if (req
.cmd
== LXC_CMD_CONSOLE_LOG
&& reqdata
)
1191 lxc_cmd_fd_cleanup(fd
, handler
, descr
, req
.cmd
);
1195 static int lxc_cmd_accept(int fd
, uint32_t events
, void *data
,
1196 struct lxc_epoll_descr
*descr
)
1199 int opt
= 1, ret
= -1;
1201 connection
= accept(fd
, NULL
, 0);
1202 if (connection
< 0) {
1203 SYSERROR("Failed to accept connection to run command.");
1204 return LXC_MAINLOOP_ERROR
;
1207 ret
= fcntl(connection
, F_SETFD
, FD_CLOEXEC
);
1209 SYSERROR("Failed to set close-on-exec on incoming command connection");
1213 ret
= setsockopt(connection
, SOL_SOCKET
, SO_PASSCRED
, &opt
, sizeof(opt
));
1215 SYSERROR("Failed to enable necessary credentials on command socket");
1219 ret
= lxc_mainloop_add_handler(descr
, connection
, lxc_cmd_handler
, data
);
1221 ERROR("Failed to add command handler");
1233 int lxc_cmd_init(const char *name
, const char *lxcpath
, const char *suffix
)
1236 char path
[sizeof(((struct sockaddr_un
*)0)->sun_path
)] = {0};
1237 char *offset
= &path
[1];
1239 /* -2 here because this is an abstract unix socket so it needs a
1240 * leading \0, and we null terminate, so it needs a trailing \0.
1241 * Although null termination isn't required by the API, we do it anyway
1242 * because we print the sockname out sometimes.
1244 len
= sizeof(path
) - 2;
1245 ret
= lxc_make_abstract_socket_name(offset
, len
, name
, lxcpath
, NULL
, suffix
);
1248 TRACE("Creating abstract unix socket \"%s\"", offset
);
1250 fd
= lxc_abstract_unix_open(path
, SOCK_STREAM
, 0);
1252 ERROR("%s - Failed to create command socket %s",
1253 strerror(errno
), offset
);
1254 if (errno
== EADDRINUSE
)
1255 ERROR("Container \"%s\" appears to be already running", name
);
1259 ret
= fcntl(fd
, F_SETFD
, FD_CLOEXEC
);
1261 SYSERROR("Failed to set FD_CLOEXEC on command socket file descriptor");
1269 int lxc_cmd_mainloop_add(const char *name
, struct lxc_epoll_descr
*descr
,
1270 struct lxc_handler
*handler
)
1273 int fd
= handler
->conf
->maincmd_fd
;
1275 ret
= lxc_mainloop_add_handler(descr
, fd
, lxc_cmd_accept
, handler
);
1277 ERROR("Failed to add handler for command socket");