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_CONSOLE_WINCH
] = "console_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
->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
,
448 .datalen
= strlen(subsystem
) + 1,
453 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
460 if (cmd
.rsp
.ret
< 0 || cmd
.rsp
.datalen
< 0)
466 static int lxc_cmd_get_cgroup_callback(int fd
, struct lxc_cmd_req
*req
,
467 struct lxc_handler
*handler
)
470 struct lxc_cmd_rsp rsp
;
472 if (req
->datalen
< 1)
475 path
= cgroup_get_cgroup(handler
, req
->data
);
480 rsp
.datalen
= strlen(path
) + 1;
481 rsp
.data
= (char *)path
;
483 return lxc_cmd_rsp_send(fd
, &rsp
);
487 * lxc_cmd_get_config_item: Get config item the running container
489 * @name : name of container to connect to
490 * @item : the configuration item to retrieve (ex: lxc.net.0.veth.pair)
491 * @lxcpath : the lxcpath in which the container is running
493 * Returns the item on success, NULL on failure. The caller must free() the
496 char *lxc_cmd_get_config_item(const char *name
, const char *item
,
500 struct lxc_cmd_rr cmd
= {
501 .req
= { .cmd
= LXC_CMD_GET_CONFIG_ITEM
,
503 .datalen
= strlen(item
) + 1,
507 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
511 if (cmd
.rsp
.ret
== 0)
517 static int lxc_cmd_get_config_item_callback(int fd
, struct lxc_cmd_req
*req
,
518 struct lxc_handler
*handler
)
522 struct lxc_config_t
*item
;
523 struct lxc_cmd_rsp rsp
;
525 memset(&rsp
, 0, sizeof(rsp
));
526 item
= lxc_get_config(req
->data
);
530 cilen
= item
->get(req
->data
, NULL
, 0, handler
->conf
, NULL
);
534 cidata
= alloca(cilen
+ 1);
535 if (item
->get(req
->data
, cidata
, cilen
+ 1, handler
->conf
, NULL
) != cilen
)
538 cidata
[cilen
] = '\0';
540 rsp
.datalen
= cilen
+ 1;
547 return lxc_cmd_rsp_send(fd
, &rsp
);
551 * lxc_cmd_get_state: Get current state of the container
553 * @name : name of container to connect to
554 * @lxcpath : the lxcpath in which the container is running
556 * Returns the state on success, < 0 on failure
558 int lxc_cmd_get_state(const char *name
, const char *lxcpath
)
561 struct lxc_cmd_rr cmd
= {
562 .req
= { .cmd
= LXC_CMD_GET_STATE
}
565 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
566 if (ret
< 0 && stopped
)
573 WARN("Container \"%s\" has stopped before sending its state", name
);
577 DEBUG("Container \"%s\" is in \"%s\" state", name
,
578 lxc_state2str(PTR_TO_INT(cmd
.rsp
.data
)));
580 return PTR_TO_INT(cmd
.rsp
.data
);
583 static int lxc_cmd_get_state_callback(int fd
, struct lxc_cmd_req
*req
,
584 struct lxc_handler
*handler
)
586 struct lxc_cmd_rsp rsp
= { .data
= INT_TO_PTR(handler
->state
) };
588 return lxc_cmd_rsp_send(fd
, &rsp
);
592 * lxc_cmd_stop: Stop the container previously started with lxc_start. All
593 * the processes running inside this container will be killed.
595 * @name : name of container to connect to
596 * @lxcpath : the lxcpath in which the container is running
598 * Returns 0 on success, < 0 on failure
600 int lxc_cmd_stop(const char *name
, const char *lxcpath
)
603 struct lxc_cmd_rr cmd
= {
604 .req
= { .cmd
= LXC_CMD_STOP
},
607 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
610 INFO("Container \"%s\" is already stopped", name
);
617 /* We do not expect any answer, because we wait for the connection to be
621 ERROR("%s - Failed to stop container \"%s\"",
622 strerror(-cmd
.rsp
.ret
), name
);
626 INFO("Container \"%s\" has stopped", name
);
630 static int lxc_cmd_stop_callback(int fd
, struct lxc_cmd_req
*req
,
631 struct lxc_handler
*handler
)
633 struct lxc_cmd_rsp rsp
;
634 int stopsignal
= SIGKILL
;
636 if (handler
->conf
->stopsignal
)
637 stopsignal
= handler
->conf
->stopsignal
;
638 memset(&rsp
, 0, sizeof(rsp
));
639 rsp
.ret
= kill(handler
->pid
, stopsignal
);
641 /* We can't just use lxc_unfreeze() since we are already in the
642 * context of handling the STOP cmd in lxc-start, and calling
643 * lxc_unfreeze() would do another cmd (GET_CGROUP) which would
646 if (cgroup_unfreeze(handler
))
649 ERROR("Failed to unfreeze container \"%s\"", handler
->name
);
653 return lxc_cmd_rsp_send(fd
, &rsp
);
657 * lxc_cmd_console_winch: To process as if a SIGWINCH were received
659 * @name : name of container to connect to
660 * @lxcpath : the lxcpath in which the container is running
662 * Returns 0 on success, < 0 on failure
664 int lxc_cmd_console_winch(const char *name
, const char *lxcpath
)
667 struct lxc_cmd_rr cmd
= {
668 .req
= { .cmd
= LXC_CMD_CONSOLE_WINCH
},
671 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
678 static int lxc_cmd_console_winch_callback(int fd
, struct lxc_cmd_req
*req
,
679 struct lxc_handler
*handler
)
681 struct lxc_cmd_rsp rsp
= { .data
= 0 };
683 lxc_console_sigwinch(SIGWINCH
);
685 return lxc_cmd_rsp_send(fd
, &rsp
);
689 * lxc_cmd_console: Open an fd to a tty in the container
691 * @name : name of container to connect to
692 * @ttynum : in: the tty to open or -1 for next available
693 * : out: the tty allocated
694 * @fd : out: file descriptor for master side of pty
695 * @lxcpath : the lxcpath in which the container is running
697 * Returns fd holding tty allocated on success, < 0 on failure
699 int lxc_cmd_console(const char *name
, int *ttynum
, int *fd
, const char *lxcpath
)
702 struct lxc_cmd_console_rsp_data
*rspdata
;
703 struct lxc_cmd_rr cmd
= {
704 .req
= { .cmd
= LXC_CMD_CONSOLE
, .data
= INT_TO_PTR(*ttynum
) },
707 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
711 if (cmd
.rsp
.ret
< 0) {
712 ERROR("%s - Denied access to tty", strerror(-cmd
.rsp
.ret
));
718 ERROR("tty number %d invalid, busy or all ttys busy", *ttynum
);
723 rspdata
= cmd
.rsp
.data
;
724 if (rspdata
->masterfd
< 0) {
725 ERROR("Unable to allocate fd for tty %d", rspdata
->ttynum
);
729 ret
= cmd
.rsp
.ret
; /* socket fd */
730 *fd
= rspdata
->masterfd
;
731 *ttynum
= rspdata
->ttynum
;
732 INFO("Alloced fd %d for tty %d via socket %d", *fd
, rspdata
->ttynum
, ret
);
739 static int lxc_cmd_console_callback(int fd
, struct lxc_cmd_req
*req
,
740 struct lxc_handler
*handler
)
743 struct lxc_cmd_rsp rsp
;
744 int ttynum
= PTR_TO_INT(req
->data
);
746 masterfd
= lxc_console_allocate(handler
->conf
, fd
, &ttynum
);
750 memset(&rsp
, 0, sizeof(rsp
));
751 rsp
.data
= INT_TO_PTR(ttynum
);
752 ret
= lxc_abstract_unix_send_fds(fd
, &masterfd
, 1, &rsp
, sizeof(rsp
));
754 ERROR("Failed to send tty to client");
755 lxc_console_free(handler
->conf
, fd
);
762 /* Special indicator to lxc_cmd_handler() to close the fd and do
769 * lxc_cmd_get_name: Returns the name of the container
771 * @hashed_sock_name: hashed socket name
773 * Returns the name on success, NULL on failure.
775 char *lxc_cmd_get_name(const char *hashed_sock_name
)
778 struct lxc_cmd_rr cmd
= {
779 .req
= { .cmd
= LXC_CMD_GET_NAME
},
782 ret
= lxc_cmd(NULL
, &cmd
, &stopped
, NULL
, hashed_sock_name
);
786 if (cmd
.rsp
.ret
== 0)
792 static int lxc_cmd_get_name_callback(int fd
, struct lxc_cmd_req
*req
,
793 struct lxc_handler
*handler
)
795 struct lxc_cmd_rsp rsp
;
797 memset(&rsp
, 0, sizeof(rsp
));
799 rsp
.data
= (char *)handler
->name
;
800 rsp
.datalen
= strlen(handler
->name
) + 1;
803 return lxc_cmd_rsp_send(fd
, &rsp
);
807 * lxc_cmd_get_lxcpath: Returns the lxcpath of the container
809 * @hashed_sock_name: hashed socket name
811 * Returns the lxcpath on success, NULL on failure.
813 char *lxc_cmd_get_lxcpath(const char *hashed_sock_name
)
816 struct lxc_cmd_rr cmd
= {
817 .req
= { .cmd
= LXC_CMD_GET_LXCPATH
},
820 ret
= lxc_cmd(NULL
, &cmd
, &stopped
, NULL
, hashed_sock_name
);
824 if (cmd
.rsp
.ret
== 0)
830 static int lxc_cmd_get_lxcpath_callback(int fd
, struct lxc_cmd_req
*req
,
831 struct lxc_handler
*handler
)
833 struct lxc_cmd_rsp rsp
;
835 memset(&rsp
, 0, sizeof(rsp
));
838 rsp
.data
= (char *)handler
->lxcpath
;
839 rsp
.datalen
= strlen(handler
->lxcpath
) + 1;
841 return lxc_cmd_rsp_send(fd
, &rsp
);
844 int lxc_cmd_add_state_client(const char *name
, const char *lxcpath
,
845 lxc_state_t states
[MAX_STATE
],
846 int *state_client_fd
)
850 struct lxc_cmd_rr cmd
= {
852 .cmd
= LXC_CMD_ADD_STATE_CLIENT
,
854 .datalen
= (sizeof(lxc_state_t
) * MAX_STATE
)
858 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
859 if (states
[STOPPED
] != 0 && stopped
!= 0)
863 if (errno
!= ECONNREFUSED
)
864 ERROR("%s - Failed to execute command", strerror(errno
));
868 /* We should now be guaranteed to get an answer from the state sending
871 if (cmd
.rsp
.ret
< 0) {
872 ERROR("%s - Failed to receive socket fd", strerror(-cmd
.rsp
.ret
));
876 state
= PTR_TO_INT(cmd
.rsp
.data
);
877 if (state
< MAX_STATE
) {
878 TRACE("Container is already in requested state %s", lxc_state2str(state
));
883 *state_client_fd
= cmd
.rsp
.ret
;
884 TRACE("Added state client %d to state client list", cmd
.rsp
.ret
);
888 static int lxc_cmd_add_state_client_callback(int fd
, struct lxc_cmd_req
*req
,
889 struct lxc_handler
*handler
)
892 struct lxc_cmd_rsp rsp
= {0};
894 if (req
->datalen
< 0)
897 if (req
->datalen
> (sizeof(lxc_state_t
) * MAX_STATE
))
903 rsp
.ret
= lxc_add_state_client(fd
, handler
, (lxc_state_t
*)req
->data
);
907 rsp
.data
= INT_TO_PTR(rsp
.ret
);
909 ret
= lxc_cmd_rsp_send(fd
, &rsp
);
916 /* Special indicator to lxc_cmd_handler() to close the fd and do related
922 int lxc_cmd_console_log(const char *name
, const char *lxcpath
,
923 struct lxc_console_log
*log
)
926 struct lxc_cmd_console_log data
;
927 struct lxc_cmd_rr cmd
;
929 data
.clear
= log
->clear
;
930 data
.read
= log
->read
;
931 data
.read_max
= *log
->read_max
;
932 data
.write_logfile
= log
->write_logfile
;
934 cmd
.req
.cmd
= LXC_CMD_CONSOLE_LOG
;
935 cmd
.req
.data
= &data
;
936 cmd
.req
.datalen
= sizeof(struct lxc_cmd_console_log
);
938 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
942 /* There is nothing to be read from the buffer. So clear any values we
943 * where passed to clearly indicate to the user that nothing went wrong.
945 if (cmd
.rsp
.ret
== -ENODATA
|| cmd
.rsp
.ret
== -EFAULT
|| cmd
.rsp
.ret
== -ENOENT
) {
950 /* This is a proper error so don't touch any values we were passed. */
954 *log
->read_max
= cmd
.rsp
.datalen
;
955 log
->data
= cmd
.rsp
.data
;
960 static int lxc_cmd_console_log_callback(int fd
, struct lxc_cmd_req
*req
,
961 struct lxc_handler
*handler
)
963 struct lxc_cmd_rsp rsp
;
964 uint64_t buffer_size
= handler
->conf
->console
.buffer_size
;
965 const struct lxc_cmd_console_log
*log
= req
->data
;
966 struct lxc_console
*console
= &handler
->conf
->console
;
967 struct lxc_ringbuf
*buf
= &handler
->conf
->console
.ringbuf
;
972 if (buffer_size
<= 0)
975 if (log
->read
|| log
->write_logfile
)
976 rsp
.datalen
= lxc_ringbuf_used(buf
);
979 rsp
.data
= lxc_ringbuf_get_read_addr(buf
);
981 if (log
->read_max
> 0 && (log
->read_max
<= rsp
.datalen
))
982 rsp
.datalen
= log
->read_max
;
984 /* there's nothing to read */
986 if (log
->read
&& (buf
->r_off
== buf
->w_off
))
989 if (log
->write_logfile
&& rsp
.datalen
> 0) {
991 if (!console
->buffer_log_file
)
994 rsp
.ret
= lxc_console_write_ringbuffer(console
);
1005 /* clear the ringbuffer */
1006 lxc_ringbuf_clear(buf
);
1008 /* truncate the ringbuffer log file */
1009 if (console
->buffer_log_file
) {
1011 if (!file_exists(console
->buffer_log_file
))
1014 /* be very certain things are kosher */
1016 if (console
->buffer_log_file_fd
< 0)
1019 rsp
.ret
= lxc_unpriv(ftruncate(console
->buffer_log_file_fd
, 0));
1021 ERROR("%s - Failed to truncate console "
1022 "ringbuffer log file \"%s\"",
1023 strerror(errno
), console
->buffer_log_file
);
1028 /* rotate the console log file */
1029 if (!console
->log_path
|| console
->log_rotate
== 0)
1032 /* be very certain things are kosher */
1034 if (console
->log_fd
< 0)
1037 len
= strlen(console
->log_path
) + sizeof(".1");
1041 ret
= snprintf(tmp
, len
, "%s.1", console
->log_path
);
1042 if (ret
< 0 || (size_t)ret
>= len
)
1045 close(console
->log_fd
);
1046 console
->log_fd
= -1;
1047 rsp
.ret
= lxc_unpriv(rename(console
->log_path
, tmp
));
1051 rsp
.ret
= lxc_console_create_log_file(console
);
1052 } else if (rsp
.datalen
> 0) {
1053 lxc_ringbuf_move_read_addr(buf
, rsp
.datalen
);
1057 return lxc_cmd_rsp_send(fd
, &rsp
);
1060 int lxc_cmd_serve_state_clients(const char *name
, const char *lxcpath
,
1065 struct lxc_cmd_rr cmd
= {
1067 .cmd
= LXC_CMD_SERVE_STATE_CLIENTS
,
1068 .data
= INT_TO_PTR(state
)
1072 ret
= lxc_cmd(name
, &cmd
, &stopped
, lxcpath
, NULL
);
1074 ERROR("%s - Failed to execute command", strerror(errno
));
1081 static int lxc_cmd_serve_state_clients_callback(int fd
, struct lxc_cmd_req
*req
,
1082 struct lxc_handler
*handler
)
1085 lxc_state_t state
= PTR_TO_INT(req
->data
);
1086 struct lxc_cmd_rsp rsp
= {0};
1088 ret
= lxc_serve_state_clients(handler
->name
, handler
, state
);
1090 goto reap_client_fd
;
1092 ret
= lxc_cmd_rsp_send(fd
, &rsp
);
1094 goto reap_client_fd
;
1099 /* Special indicator to lxc_cmd_handler() to close the fd and do related
1105 static int lxc_cmd_process(int fd
, struct lxc_cmd_req
*req
,
1106 struct lxc_handler
*handler
)
1108 typedef int (*callback
)(int, struct lxc_cmd_req
*, struct lxc_handler
*);
1110 callback cb
[LXC_CMD_MAX
] = {
1111 [LXC_CMD_CONSOLE
] = lxc_cmd_console_callback
,
1112 [LXC_CMD_CONSOLE_WINCH
] = lxc_cmd_console_winch_callback
,
1113 [LXC_CMD_STOP
] = lxc_cmd_stop_callback
,
1114 [LXC_CMD_GET_STATE
] = lxc_cmd_get_state_callback
,
1115 [LXC_CMD_GET_INIT_PID
] = lxc_cmd_get_init_pid_callback
,
1116 [LXC_CMD_GET_CLONE_FLAGS
] = lxc_cmd_get_clone_flags_callback
,
1117 [LXC_CMD_GET_CGROUP
] = lxc_cmd_get_cgroup_callback
,
1118 [LXC_CMD_GET_CONFIG_ITEM
] = lxc_cmd_get_config_item_callback
,
1119 [LXC_CMD_GET_NAME
] = lxc_cmd_get_name_callback
,
1120 [LXC_CMD_GET_LXCPATH
] = lxc_cmd_get_lxcpath_callback
,
1121 [LXC_CMD_ADD_STATE_CLIENT
] = lxc_cmd_add_state_client_callback
,
1122 [LXC_CMD_CONSOLE_LOG
] = lxc_cmd_console_log_callback
,
1123 [LXC_CMD_SERVE_STATE_CLIENTS
] = lxc_cmd_serve_state_clients_callback
,
1126 if (req
->cmd
>= LXC_CMD_MAX
) {
1127 ERROR("Undefined command id %d", req
->cmd
);
1130 return cb
[req
->cmd
](fd
, req
, handler
);
1133 static void lxc_cmd_fd_cleanup(int fd
, struct lxc_handler
*handler
,
1134 struct lxc_epoll_descr
*descr
,
1135 const lxc_cmd_t cmd
)
1137 struct lxc_state_client
*client
;
1138 struct lxc_list
*cur
, *next
;
1140 lxc_console_free(handler
->conf
, fd
);
1141 lxc_mainloop_del_handler(descr
, fd
);
1142 if (cmd
!= LXC_CMD_ADD_STATE_CLIENT
) {
1148 lxc_list_for_each_safe(cur
, &handler
->conf
->state_clients
, next
) {
1150 if (client
->clientfd
!= fd
)
1153 /* kick client from list */
1154 close(client
->clientfd
);
1158 /* No need to walk the whole list. If we found the state client
1159 * fd there can't be a second one.
1166 static int lxc_cmd_handler(int fd
, uint32_t events
, void *data
,
1167 struct lxc_epoll_descr
*descr
)
1170 struct lxc_cmd_req req
;
1171 void *reqdata
= NULL
;
1172 struct lxc_handler
*handler
= data
;
1174 ret
= lxc_abstract_unix_rcv_credential(fd
, &req
, sizeof(req
));
1175 if (ret
== -EACCES
) {
1176 /* We don't care for the peer, just send and close. */
1177 struct lxc_cmd_rsp rsp
= {.ret
= ret
};
1179 lxc_cmd_rsp_send(fd
, &rsp
);
1184 SYSERROR("Failed to receive data on command socket for command "
1185 "\"%s\"", lxc_cmd_str(req
.cmd
));
1192 if (ret
!= sizeof(req
)) {
1193 WARN("Failed to receive full command request. Ignoring request "
1194 "for \"%s\"", lxc_cmd_str(req
.cmd
));
1199 if ((req
.datalen
> LXC_CMD_DATA_MAX
) &&
1200 (req
.cmd
!= LXC_CMD_CONSOLE_LOG
)) {
1201 ERROR("Received command data length %d is too large for "
1202 "command \"%s\"", req
.datalen
, lxc_cmd_str(req
.cmd
));
1208 if (req
.datalen
> 0) {
1209 /* LXC_CMD_CONSOLE_LOG needs to be able to allocate data
1210 * that exceeds LXC_CMD_DATA_MAX: use malloc() for that.
1212 if (req
.cmd
== LXC_CMD_CONSOLE_LOG
)
1213 reqdata
= malloc(req
.datalen
);
1215 reqdata
= alloca(req
.datalen
);
1217 ERROR("Failed to allocate memory for \"%s\" command",
1218 lxc_cmd_str(req
.cmd
));
1224 ret
= recv(fd
, reqdata
, req
.datalen
, 0);
1225 if (ret
!= req
.datalen
) {
1226 WARN("Failed to receive full command request. Ignoring "
1227 "request for \"%s\"", lxc_cmd_str(req
.cmd
));
1235 ret
= lxc_cmd_process(fd
, &req
, handler
);
1237 /* This is not an error, but only a request to close fd. */
1243 if (req
.cmd
== LXC_CMD_CONSOLE_LOG
&& reqdata
)
1249 lxc_cmd_fd_cleanup(fd
, handler
, descr
, req
.cmd
);
1253 static int lxc_cmd_accept(int fd
, uint32_t events
, void *data
,
1254 struct lxc_epoll_descr
*descr
)
1257 int opt
= 1, ret
= -1;
1259 connection
= accept(fd
, NULL
, 0);
1260 if (connection
< 0) {
1261 SYSERROR("Failed to accept connection to run command.");
1265 ret
= fcntl(connection
, F_SETFD
, FD_CLOEXEC
);
1267 SYSERROR("Failed to set close-on-exec on incoming command connection");
1271 ret
= setsockopt(connection
, SOL_SOCKET
, SO_PASSCRED
, &opt
, sizeof(opt
));
1273 SYSERROR("Failed to enable necessary credentials on command socket");
1277 ret
= lxc_mainloop_add_handler(descr
, connection
, lxc_cmd_handler
, data
);
1279 ERROR("Failed to add command handler");
1291 int lxc_cmd_init(const char *name
, const char *lxcpath
, const char *suffix
)
1294 char path
[sizeof(((struct sockaddr_un
*)0)->sun_path
)] = {0};
1295 char *offset
= &path
[1];
1297 /* -2 here because this is an abstract unix socket so it needs a
1298 * leading \0, and we null terminate, so it needs a trailing \0.
1299 * Although null termination isn't required by the API, we do it anyway
1300 * because we print the sockname out sometimes.
1302 len
= sizeof(path
) - 2;
1303 ret
= lxc_make_abstract_socket_name(offset
, len
, name
, lxcpath
, NULL
, suffix
);
1306 TRACE("Creating abstract unix socket \"%s\"", offset
);
1308 fd
= lxc_abstract_unix_open(path
, SOCK_STREAM
, 0);
1310 ERROR("%s - Failed to create command socket %s",
1311 strerror(errno
), offset
);
1312 if (errno
== EADDRINUSE
)
1313 ERROR("Container \"%s\" appears to be already running", name
);
1317 ret
= fcntl(fd
, F_SETFD
, FD_CLOEXEC
);
1319 SYSERROR("Failed to set FD_CLOEXEC on command socket file descriptor");
1327 int lxc_cmd_mainloop_add(const char *name
, struct lxc_epoll_descr
*descr
,
1328 struct lxc_handler
*handler
)
1331 int fd
= handler
->conf
->maincmd_fd
;
1333 ret
= lxc_mainloop_add_handler(descr
, fd
, lxc_cmd_accept
, handler
);
1335 ERROR("Failed to add handler for command socket");