1 /* Copyright (C) 2009 Pierre-Marc Fournier
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public
5 * License as published by the Free Software Foundation; either
6 * version 2.1 of the License, or (at your option) any later version.
8 * This library is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * Lesser General Public License for more details.
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 /* API used by UST components to communicate with each other via sockets. */
21 #include <sys/types.h>
24 #include <sys/socket.h>
38 #include "multipoll.h"
40 #define UNIX_PATH_MAX 108
42 static int mkdir_p(const char *path
, mode_t mode
)
51 tmp
= malloc(strlen(path
) + 1);
60 while (*path_p
!= '/') {
66 strncpy(tmp
, path
, path_p
- path
);
67 tmp
[path_p
-path
] = '\0';
68 if (tmp
[path_p
- path
- 1] != '/') {
69 result
= mkdir(tmp
, mode
);
71 if (!(errno
== EEXIST
|| errno
== EACCES
|| errno
== EROFS
)) {
72 /* Then this is a real error */
82 result
= mkdir(path
, mode
);
94 static int signal_process(pid_t pid
)
99 void ustcomm_init_connection(struct ustcomm_connection
*conn
)
101 conn
->recv_buf
= NULL
;
102 conn
->recv_buf_size
= 0;
103 conn
->recv_buf_alloc
= 0;
106 int pid_is_online(pid_t pid
) {
112 * @fd: file descriptor to send to
113 * @msg: a null-terminated string containing the message to send
117 * 0: connection closed
121 static int send_message_fd(int fd
, const char *msg
)
125 /* Send including the final \0 */
126 result
= patient_send(fd
, msg
, strlen(msg
)+1, MSG_NOSIGNAL
);
132 else if(result
== 0) {
136 DBG("sent message \"%s\"", msg
);
140 /* Called by an app to ask the consumer daemon to connect to it. */
142 int ustcomm_request_consumer(pid_t pid
, const char *channel
)
144 char path
[UNIX_PATH_MAX
];
148 struct ustcomm_connection conn
;
149 char *explicit_daemon_socket_path
;
151 explicit_daemon_socket_path
= getenv("UST_DAEMON_SOCKET");
152 if(explicit_daemon_socket_path
) {
153 /* user specified explicitly a socket path */
154 result
= snprintf(path
, UNIX_PATH_MAX
, "%s", explicit_daemon_socket_path
);
157 /* just use the default path */
158 result
= snprintf(path
, UNIX_PATH_MAX
, "%s/ustd", SOCK_DIR
);
161 if(result
>= UNIX_PATH_MAX
) {
162 ERR("string overflow allocating socket name");
166 asprintf(&msg
, "collect %d %s", pid
, channel
);
168 /* don't signal it because it's the daemon */
169 result
= ustcomm_connect_path(path
, &conn
, -1);
171 WARN("ustcomm_connect_path failed");
176 result
= ustcomm_send_request(&conn
, msg
, NULL
);
178 WARN("ustcomm_send_request failed");
184 ustcomm_disconnect(&conn
);
191 /* returns 1 to indicate a message was received
192 * returns 0 to indicate no message was received (end of stream)
193 * returns -1 to indicate an error
196 #define RECV_INCREMENT 1000
197 #define RECV_INITIAL_BUF_SIZE 10
199 static int recv_message_fd(int fd
, char **recv_buf
, int *recv_buf_size
, int *recv_buf_alloc
, char **msg
)
203 /* 1. Check if there is a message in the buf */
205 2.1 receive chunk and put it in buffer
206 2.2 process full message if there is one
207 -- while no message arrived
214 /* Search for full message in buffer */
215 for(i
=0; i
<*recv_buf_size
; i
++) {
216 if((*recv_buf
)[i
] == '\0') {
222 /* Process found message */
228 WARN("received empty message");
230 *msg
= strndup(*recv_buf
, i
);
232 /* Remove processed message from buffer */
233 newbuf
= (char *) malloc(*recv_buf_size
- (i
+1));
234 memcpy(newbuf
, *recv_buf
+ (i
+1), *recv_buf_size
- (i
+1));
237 *recv_buf_size
-= (i
+1);
238 *recv_buf_alloc
-= (i
+1);
243 /* Receive a chunk from the fd */
244 if(*recv_buf_alloc
- *recv_buf_size
< RECV_INCREMENT
) {
245 *recv_buf_alloc
+= RECV_INCREMENT
- (*recv_buf_alloc
- *recv_buf_size
);
246 *recv_buf
= (char *) realloc(*recv_buf
, *recv_buf_alloc
);
249 result
= recv(fd
, *recv_buf
+*recv_buf_size
, RECV_INCREMENT
, 0);
251 if(errno
== ECONNRESET
) {
255 else if(errno
== EINTR
) {
266 *recv_buf_size
+= result
;
268 /* Go back to the beginning to check if there is a full message in the buffer */
271 DBG("received message \"%s\"", *recv_buf
);
277 static int recv_message_conn(struct ustcomm_connection
*conn
, char **msg
)
279 return recv_message_fd(conn
->fd
, &conn
->recv_buf
, &conn
->recv_buf_size
, &conn
->recv_buf_alloc
, msg
);
282 int ustcomm_send_reply(struct ustcomm_server
*server
, char *msg
, struct ustcomm_source
*src
)
286 result
= send_message_fd(src
->fd
, msg
);
288 ERR("error in send_message_fd");
295 /* Called after a fork. */
297 int ustcomm_close_all_connections(struct ustcomm_server
*server
)
299 struct ustcomm_connection
*conn
;
300 struct ustcomm_connection
*deletable_conn
= NULL
;
302 list_for_each_entry(conn
, &server
->connections
, list
) {
303 free(deletable_conn
);
304 deletable_conn
= conn
;
305 ustcomm_close_app(conn
);
306 list_del(&conn
->list
);
312 /* @timeout: max blocking time in milliseconds, -1 means infinity
314 * returns 1 to indicate a message was received
315 * returns 0 to indicate no message was received
316 * returns -1 to indicate an error
319 int ustcomm_recv_message(struct ustcomm_server
*server
, char **msg
, struct ustcomm_source
*src
, int timeout
)
322 struct ustcomm_connection
**conn_table
;
323 struct ustcomm_connection
*conn
;
331 list_for_each_entry(conn
, &server
->connections
, list
) {
335 fds
= (struct pollfd
*) malloc(n_fds
* sizeof(struct pollfd
));
337 ERR("malloc returned NULL");
341 conn_table
= (struct ustcomm_connection
**) malloc(n_fds
* sizeof(struct ustcomm_connection
*));
342 if(conn_table
== NULL
) {
343 ERR("malloc returned NULL");
345 goto free_fds_return
;
348 /* special idx 0 is for listening socket */
349 fds
[idx
].fd
= server
->listen_fd
;
350 fds
[idx
].events
= POLLIN
;
353 list_for_each_entry(conn
, &server
->connections
, list
) {
354 fds
[idx
].fd
= conn
->fd
;
355 fds
[idx
].events
= POLLIN
;
356 conn_table
[idx
] = conn
;
360 result
= poll(fds
, n_fds
, timeout
);
361 if(result
== -1 && errno
== EINTR
) {
362 /* That's ok. ustd receives signals to notify it must shutdown. */
364 goto free_conn_table_return
;
366 else if(result
== -1) {
369 goto free_conn_table_return
;
371 else if(result
== 0) {
373 goto free_conn_table_return
;
377 struct ustcomm_connection
*newconn
;
380 result
= newfd
= accept(server
->listen_fd
, NULL
, NULL
);
384 goto free_conn_table_return
;
387 newconn
= (struct ustcomm_connection
*) malloc(sizeof(struct ustcomm_connection
));
388 if(newconn
== NULL
) {
389 ERR("malloc returned NULL");
393 ustcomm_init_connection(newconn
);
396 list_add(&newconn
->list
, &server
->connections
);
399 for(idx
=1; idx
<n_fds
; idx
++) {
400 if(fds
[idx
].revents
) {
401 retval
= recv_message_conn(conn_table
[idx
], msg
);
403 src
->fd
= fds
[idx
].fd
;
406 /* connection finished */
407 list_for_each_entry(conn
, &server
->connections
, list
) {
408 if(conn
->fd
== fds
[idx
].fd
) {
409 ustcomm_close_app(conn
);
410 list_del(&conn
->list
);
417 goto free_conn_table_return
;
426 free_conn_table_return
:
433 int ustcomm_ustd_recv_message(struct ustcomm_ustd
*ustd
, char **msg
, struct ustcomm_source
*src
, int timeout
)
435 return ustcomm_recv_message(&ustd
->server
, msg
, src
, timeout
);
438 int ustcomm_app_recv_message(struct ustcomm_app
*app
, char **msg
, struct ustcomm_source
*src
, int timeout
)
440 return ustcomm_recv_message(&app
->server
, msg
, src
, timeout
);
443 /* This removes src from the list of active connections of app.
446 int ustcomm_app_detach_client(struct ustcomm_app
*app
, struct ustcomm_source
*src
)
448 struct ustcomm_server
*server
= (struct ustcomm_server
*)app
;
449 struct ustcomm_connection
*conn
;
451 list_for_each_entry(conn
, &server
->connections
, list
) {
452 if(conn
->fd
== src
->fd
) {
453 list_del(&conn
->list
);
463 static int init_named_socket(const char *name
, char **path_out
)
468 struct sockaddr_un addr
;
470 result
= fd
= socket(PF_UNIX
, SOCK_STREAM
, 0);
476 addr
.sun_family
= AF_UNIX
;
478 strncpy(addr
.sun_path
, name
, UNIX_PATH_MAX
);
479 addr
.sun_path
[UNIX_PATH_MAX
-1] = '\0';
481 result
= access(name
, F_OK
);
484 result
= unlink(name
);
486 PERROR("unlink of socket file");
489 DBG("socket already exists; overwriting");
492 result
= bind(fd
, (struct sockaddr
*)&addr
, sizeof(addr
));
498 result
= listen(fd
, 1);
505 *path_out
= strdup(addr
.sun_path
);
518 * 0: Success, but no reply because recv() returned 0
522 * On error, the error message is printed, except on
523 * ECONNRESET, which is normal when the application dies.
526 int ustcomm_send_request(struct ustcomm_connection
*conn
, const char *req
, char **reply
)
530 /* Send including the final \0 */
531 result
= send_message_fd(conn
->fd
, req
);
538 result
= recv_message_conn(conn
, reply
);
542 else if(result
== 0) {
554 int ustcomm_connect_path(const char *path
, struct ustcomm_connection
*conn
, pid_t signalpid
)
558 struct sockaddr_un addr
;
560 ustcomm_init_connection(conn
);
562 result
= fd
= socket(PF_UNIX
, SOCK_STREAM
, 0);
568 addr
.sun_family
= AF_UNIX
;
570 result
= snprintf(addr
.sun_path
, UNIX_PATH_MAX
, "%s", path
);
571 if(result
>= UNIX_PATH_MAX
) {
572 ERR("string overflow allocating socket name");
577 result
= signal_process(signalpid
);
579 ERR("could not signal process");
584 result
= connect(fd
, (struct sockaddr
*)&addr
, sizeof(addr
));
586 PERROR("connect (path=%s)", path
);
595 int ustcomm_disconnect(struct ustcomm_connection
*conn
)
597 return close(conn
->fd
);
600 /* Open a connection to a traceable app.
607 int ustcomm_connect_app(pid_t pid
, struct ustcomm_connection
*conn
)
610 char path
[UNIX_PATH_MAX
];
613 result
= snprintf(path
, UNIX_PATH_MAX
, "%s/%d", SOCK_DIR
, pid
);
614 if(result
>= UNIX_PATH_MAX
) {
615 ERR("string overflow allocating socket name");
619 return ustcomm_connect_path(path
, conn
, pid
);
622 /* Close a connection to a traceable app. It frees the
623 * resources. It however does not free the
624 * ustcomm_connection itself.
627 int ustcomm_close_app(struct ustcomm_connection
*conn
)
630 free(conn
->recv_buf
);
635 static int ensure_dir_exists(const char *dir
)
643 result
= stat(dir
, &st
);
644 if(result
== -1 && errno
!= ENOENT
) {
647 else if(result
== -1) {
651 /* mkdir mode to 0777 */
652 result
= mkdir_p(dir
, S_IRWXU
| S_IRWXG
| S_IRWXO
);
654 ERR("executing in recursive creation of directory %s", dir
);
662 /* Called by an application to initialize its server so daemons can
666 int ustcomm_init_app(pid_t pid
, struct ustcomm_app
*handle
)
671 result
= asprintf(&name
, "%s/%d", SOCK_DIR
, (int)pid
);
672 if(result
>= UNIX_PATH_MAX
) {
673 ERR("string overflow allocating socket name");
677 result
= ensure_dir_exists(SOCK_DIR
);
679 ERR("Unable to create socket directory %s", SOCK_DIR
);
683 handle
->server
.listen_fd
= init_named_socket(name
, &(handle
->server
.socketpath
));
684 if(handle
->server
.listen_fd
< 0) {
685 ERR("Error initializing named socket (%s). Check that directory exists and that it is writable.", name
);
690 INIT_LIST_HEAD(&handle
->server
.connections
);
699 /* Used by the daemon to initialize its server so applications
703 int ustcomm_init_ustd(struct ustcomm_ustd
*handle
, const char *sock_path
)
709 asprintf(&name
, "%s", sock_path
);
714 /* Only check if socket dir exists if we are using the default directory */
715 result
= ensure_dir_exists(SOCK_DIR
);
717 ERR("Unable to create socket directory %s", SOCK_DIR
);
721 asprintf(&name
, "%s/%s", SOCK_DIR
, "ustd");
724 handle
->server
.listen_fd
= init_named_socket(name
, &handle
->server
.socketpath
);
725 if(handle
->server
.listen_fd
< 0) {
726 ERR("error initializing named socket at %s", name
);
731 INIT_LIST_HEAD(&handle
->server
.connections
);
739 static void ustcomm_fini_server(struct ustcomm_server
*server
, int keep_socket_file
)
744 if(!keep_socket_file
) {
746 result
= stat(server
->socketpath
, &st
);
748 PERROR("stat (%s)", server
->socketpath
);
752 /* Paranoid check before deleting. */
753 result
= S_ISSOCK(st
.st_mode
);
755 ERR("The socket we are about to delete is not a socket.");
759 result
= unlink(server
->socketpath
);
765 free(server
->socketpath
);
767 result
= close(server
->listen_fd
);
774 /* Free a traceable application server */
776 void ustcomm_fini_app(struct ustcomm_app
*handle
, int keep_socket_file
)
778 ustcomm_fini_server(&handle
->server
, keep_socket_file
);
781 /* Free a ustd server */
783 void ustcomm_fini_ustd(struct ustcomm_ustd
*handle
)
785 ustcomm_fini_server(&handle
->server
, 0);
788 static const char *find_tok(const char *str
)
800 static const char *find_sep(const char *str
)
812 int nth_token_is(const char *str
, const char *token
, int tok_no
)
818 for(i
=0; i
<=tok_no
; i
++) {
832 if(end
-start
!= strlen(token
))
835 if(strncmp(start
, token
, end
-start
))
841 char *nth_token(const char *str
, int tok_no
)
843 static char *retval
= NULL
;
848 for(i
=0; i
<=tok_no
; i
++) {
867 asprintf(&retval
, "%.*s", (int)(end
-start
), start
);
872 /* Callback from multipoll.
873 * Receive a new connection on the listening socket.
876 static int process_mp_incoming_conn(void *priv
, int fd
, short events
)
878 struct ustcomm_connection
*newconn
;
879 struct ustcomm_server
*server
= (struct ustcomm_server
*) priv
;
883 result
= newfd
= accept(server
->listen_fd
, NULL
, NULL
);
889 newconn
= (struct ustcomm_connection
*) malloc(sizeof(struct ustcomm_connection
));
890 if(newconn
== NULL
) {
891 ERR("malloc returned NULL");
895 ustcomm_init_connection(newconn
);
898 list_add(&newconn
->list
, &server
->connections
);
903 /* Callback from multipoll.
904 * Receive a message on an existing connection.
907 static int process_mp_conn_msg(void *priv
, int fd
, short revents
)
909 struct ustcomm_multipoll_conn_info
*mpinfo
= (struct ustcomm_multipoll_conn_info
*) priv
;
912 struct ustcomm_source src
;
917 result
= recv_message_conn(mpinfo
->conn
, &msg
);
919 ERR("error in recv_message_conn");
922 else if(result
== 0) {
923 /* connection finished */
924 ustcomm_close_app(mpinfo
->conn
);
925 list_del(&mpinfo
->conn
->list
);
929 mpinfo
->cb(msg
, &src
);
937 int free_ustcomm_client_poll(void *data
)
943 void ustcomm_mp_add_app_clients(struct mpentries
*ent
, struct ustcomm_app
*app
, int (*cb
)(char *recvbuf
, struct ustcomm_source
*src
))
945 struct ustcomm_connection
*conn
;
947 /* add listener socket */
948 multipoll_add(ent
, app
->server
.listen_fd
, POLLIN
, process_mp_incoming_conn
, &app
->server
, NULL
);
950 list_for_each_entry(conn
, &app
->server
.connections
, list
) {
951 struct ustcomm_multipoll_conn_info
*mpinfo
= (struct ustcomm_multipoll_conn_info
*) malloc(sizeof(struct ustcomm_multipoll_conn_info
));
954 multipoll_add(ent
, conn
->fd
, POLLIN
, process_mp_conn_msg
, mpinfo
, free_ustcomm_client_poll
);