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
19 #include <sys/types.h>
22 #include <sys/socket.h>
36 #include "multipoll.h"
38 #define UNIX_PATH_MAX 108
40 static int mkdir_p(const char *path
, mode_t mode
)
48 tmp
= malloc(strlen(path
) + 1);
56 while (*path_p
!= '/') {
62 strncpy(tmp
, path
, path_p
- path
);
63 tmp
[path_p
-path
] = '\0';
64 if (tmp
[path_p
- path
- 1] != '/') {
65 result
= mkdir(tmp
, mode
);
67 if (!(errno
== EEXIST
|| errno
== EACCES
|| errno
== EROFS
)) {
68 /* Then this is a real error */
78 result
= mkdir(path
, mode
);
89 static int signal_process(pid_t pid
)
94 void ustcomm_init_connection(struct ustcomm_connection
*conn
)
96 conn
->recv_buf
= NULL
;
97 conn
->recv_buf_size
= 0;
98 conn
->recv_buf_alloc
= 0;
101 int pid_is_online(pid_t pid
) {
107 * @fd: file descriptor to send to
108 * @msg: a null-terminated string containing the message to send
112 * 0: connection closed
116 static int send_message_fd(int fd
, const char *msg
)
120 /* Send including the final \0 */
121 result
= patient_send(fd
, msg
, strlen(msg
)+1, MSG_NOSIGNAL
);
127 else if(result
== 0) {
131 DBG("sent message \"%s\"", msg
);
135 /* Called by an app to ask the consumer daemon to connect to it. */
137 int ustcomm_request_consumer(pid_t pid
, const char *channel
)
139 char path
[UNIX_PATH_MAX
];
143 struct ustcomm_connection conn
;
144 char *explicit_daemon_socket_path
;
146 explicit_daemon_socket_path
= getenv("UST_DAEMON_SOCKET");
147 if(explicit_daemon_socket_path
) {
148 /* user specified explicitly a socket path */
149 result
= snprintf(path
, UNIX_PATH_MAX
, "%s", explicit_daemon_socket_path
);
152 /* just use the default path */
153 result
= snprintf(path
, UNIX_PATH_MAX
, "%s/ustd", SOCK_DIR
);
156 if(result
>= UNIX_PATH_MAX
) {
157 ERR("string overflow allocating socket name");
161 asprintf(&msg
, "collect %d %s", pid
, channel
);
163 /* don't signal it because it's the daemon */
164 result
= ustcomm_connect_path(path
, &conn
, -1);
166 WARN("ustcomm_connect_path failed");
171 result
= ustcomm_send_request(&conn
, msg
, NULL
);
173 WARN("ustcomm_send_request failed");
179 ustcomm_disconnect(&conn
);
186 /* returns 1 to indicate a message was received
187 * returns 0 to indicate no message was received (end of stream)
188 * returns -1 to indicate an error
191 #define RECV_INCREMENT 1000
192 #define RECV_INITIAL_BUF_SIZE 10
194 static int recv_message_fd(int fd
, char **recv_buf
, int *recv_buf_size
, int *recv_buf_alloc
, char **msg
)
198 /* 1. Check if there is a message in the buf */
200 2.1 receive chunk and put it in buffer
201 2.2 process full message if there is one
202 -- while no message arrived
209 /* Search for full message in buffer */
210 for(i
=0; i
<*recv_buf_size
; i
++) {
211 if((*recv_buf
)[i
] == '\0') {
217 /* Process found message */
223 WARN("received empty message");
225 *msg
= strndup(*recv_buf
, i
);
227 /* Remove processed message from buffer */
228 newbuf
= (char *) malloc(*recv_buf_size
- (i
+1));
229 memcpy(newbuf
, *recv_buf
+ (i
+1), *recv_buf_size
- (i
+1));
232 *recv_buf_size
-= (i
+1);
233 *recv_buf_alloc
-= (i
+1);
238 /* Receive a chunk from the fd */
239 if(*recv_buf_alloc
- *recv_buf_size
< RECV_INCREMENT
) {
240 *recv_buf_alloc
+= RECV_INCREMENT
- (*recv_buf_alloc
- *recv_buf_size
);
241 *recv_buf
= (char *) realloc(*recv_buf
, *recv_buf_alloc
);
244 result
= recv(fd
, *recv_buf
+*recv_buf_size
, RECV_INCREMENT
, 0);
246 if(errno
== ECONNRESET
) {
250 else if(errno
== EINTR
) {
261 *recv_buf_size
+= result
;
263 /* Go back to the beginning to check if there is a full message in the buffer */
266 DBG("received message \"%s\"", *recv_buf
);
272 static int recv_message_conn(struct ustcomm_connection
*conn
, char **msg
)
274 return recv_message_fd(conn
->fd
, &conn
->recv_buf
, &conn
->recv_buf_size
, &conn
->recv_buf_alloc
, msg
);
277 int ustcomm_send_reply(struct ustcomm_server
*server
, char *msg
, struct ustcomm_source
*src
)
281 result
= send_message_fd(src
->fd
, msg
);
283 ERR("error in send_message_fd");
290 /* Called after a fork. */
292 int ustcomm_close_all_connections(struct ustcomm_server
*server
)
294 struct ustcomm_connection
*conn
;
295 struct ustcomm_connection
*deletable_conn
= NULL
;
297 list_for_each_entry(conn
, &server
->connections
, list
) {
298 free(deletable_conn
);
299 deletable_conn
= conn
;
300 ustcomm_close_app(conn
);
301 list_del(&conn
->list
);
307 /* @timeout: max blocking time in milliseconds, -1 means infinity
309 * returns 1 to indicate a message was received
310 * returns 0 to indicate no message was received
311 * returns -1 to indicate an error
314 int ustcomm_recv_message(struct ustcomm_server
*server
, char **msg
, struct ustcomm_source
*src
, int timeout
)
317 struct ustcomm_connection
**conn_table
;
318 struct ustcomm_connection
*conn
;
326 list_for_each_entry(conn
, &server
->connections
, list
) {
330 fds
= (struct pollfd
*) malloc(n_fds
* sizeof(struct pollfd
));
332 ERR("malloc returned NULL");
336 conn_table
= (struct ustcomm_connection
**) malloc(n_fds
* sizeof(struct ustcomm_connection
*));
337 if(conn_table
== NULL
) {
338 ERR("malloc returned NULL");
340 goto free_fds_return
;
343 /* special idx 0 is for listening socket */
344 fds
[idx
].fd
= server
->listen_fd
;
345 fds
[idx
].events
= POLLIN
;
348 list_for_each_entry(conn
, &server
->connections
, list
) {
349 fds
[idx
].fd
= conn
->fd
;
350 fds
[idx
].events
= POLLIN
;
351 conn_table
[idx
] = conn
;
355 result
= poll(fds
, n_fds
, timeout
);
356 if(result
== -1 && errno
== EINTR
) {
357 /* That's ok. ustd receives signals to notify it must shutdown. */
359 goto free_conn_table_return
;
361 else if(result
== -1) {
364 goto free_conn_table_return
;
366 else if(result
== 0) {
368 goto free_conn_table_return
;
372 struct ustcomm_connection
*newconn
;
375 result
= newfd
= accept(server
->listen_fd
, NULL
, NULL
);
379 goto free_conn_table_return
;
382 newconn
= (struct ustcomm_connection
*) malloc(sizeof(struct ustcomm_connection
));
383 if(newconn
== NULL
) {
384 ERR("malloc returned NULL");
388 ustcomm_init_connection(newconn
);
391 list_add(&newconn
->list
, &server
->connections
);
394 for(idx
=1; idx
<n_fds
; idx
++) {
395 if(fds
[idx
].revents
) {
396 retval
= recv_message_conn(conn_table
[idx
], msg
);
398 src
->fd
= fds
[idx
].fd
;
401 /* connection finished */
402 list_for_each_entry(conn
, &server
->connections
, list
) {
403 if(conn
->fd
== fds
[idx
].fd
) {
404 ustcomm_close_app(conn
);
405 list_del(&conn
->list
);
412 goto free_conn_table_return
;
421 free_conn_table_return
:
428 int ustcomm_ustd_recv_message(struct ustcomm_ustd
*ustd
, char **msg
, struct ustcomm_source
*src
, int timeout
)
430 return ustcomm_recv_message(&ustd
->server
, msg
, src
, timeout
);
433 int ustcomm_app_recv_message(struct ustcomm_app
*app
, char **msg
, struct ustcomm_source
*src
, int timeout
)
435 return ustcomm_recv_message(&app
->server
, msg
, src
, timeout
);
438 /* This removes src from the list of active connections of app.
441 int ustcomm_app_detach_client(struct ustcomm_app
*app
, struct ustcomm_source
*src
)
443 struct ustcomm_server
*server
= (struct ustcomm_server
*)app
;
444 struct ustcomm_connection
*conn
;
446 list_for_each_entry(conn
, &server
->connections
, list
) {
447 if(conn
->fd
== src
->fd
) {
448 list_del(&conn
->list
);
458 static int init_named_socket(const char *name
, char **path_out
)
463 struct sockaddr_un addr
;
465 result
= fd
= socket(PF_UNIX
, SOCK_STREAM
, 0);
471 addr
.sun_family
= AF_UNIX
;
473 strncpy(addr
.sun_path
, name
, UNIX_PATH_MAX
);
474 addr
.sun_path
[UNIX_PATH_MAX
-1] = '\0';
476 result
= access(name
, F_OK
);
479 result
= unlink(name
);
481 PERROR("unlink of socket file");
484 DBG("socket already exists; overwriting");
487 result
= bind(fd
, (struct sockaddr
*)&addr
, sizeof(addr
));
493 result
= listen(fd
, 1);
500 *path_out
= strdup(addr
.sun_path
);
513 * 0: Success, but no reply because recv() returned 0
517 * On error, the error message is printed, except on
518 * ECONNRESET, which is normal when the application dies.
521 int ustcomm_send_request(struct ustcomm_connection
*conn
, const char *req
, char **reply
)
525 /* Send including the final \0 */
526 result
= send_message_fd(conn
->fd
, req
);
533 result
= recv_message_conn(conn
, reply
);
537 else if(result
== 0) {
549 int ustcomm_connect_path(const char *path
, struct ustcomm_connection
*conn
, pid_t signalpid
)
553 struct sockaddr_un addr
;
555 ustcomm_init_connection(conn
);
557 result
= fd
= socket(PF_UNIX
, SOCK_STREAM
, 0);
563 addr
.sun_family
= AF_UNIX
;
565 result
= snprintf(addr
.sun_path
, UNIX_PATH_MAX
, "%s", path
);
566 if(result
>= UNIX_PATH_MAX
) {
567 ERR("string overflow allocating socket name");
572 result
= signal_process(signalpid
);
574 ERR("could not signal process");
579 result
= connect(fd
, (struct sockaddr
*)&addr
, sizeof(addr
));
581 PERROR("connect (path=%s)", path
);
590 int ustcomm_disconnect(struct ustcomm_connection
*conn
)
592 return close(conn
->fd
);
595 /* Open a connection to a traceable app.
602 int ustcomm_connect_app(pid_t pid
, struct ustcomm_connection
*conn
)
605 char path
[UNIX_PATH_MAX
];
608 result
= snprintf(path
, UNIX_PATH_MAX
, "%s/%d", SOCK_DIR
, pid
);
609 if(result
>= UNIX_PATH_MAX
) {
610 ERR("string overflow allocating socket name");
614 return ustcomm_connect_path(path
, conn
, pid
);
617 /* Close a connection to a traceable app. It frees the
618 * resources. It however does not free the
619 * ustcomm_connection itself.
622 int ustcomm_close_app(struct ustcomm_connection
*conn
)
625 free(conn
->recv_buf
);
630 static int ensure_dir_exists(const char *dir
)
638 result
= stat(dir
, &st
);
639 if(result
== -1 && errno
!= ENOENT
) {
642 else if(result
== -1) {
646 result
= mkdir_p(dir
, 0777);
648 ERR("executing in recursive creation of directory %s", dir
);
656 /* Called by an application to initialize its server so daemons can
660 int ustcomm_init_app(pid_t pid
, struct ustcomm_app
*handle
)
665 result
= asprintf(&name
, "%s/%d", SOCK_DIR
, (int)pid
);
666 if(result
>= UNIX_PATH_MAX
) {
667 ERR("string overflow allocating socket name");
671 result
= ensure_dir_exists(SOCK_DIR
);
673 ERR("Unable to create socket directory %s", SOCK_DIR
);
677 handle
->server
.listen_fd
= init_named_socket(name
, &(handle
->server
.socketpath
));
678 if(handle
->server
.listen_fd
< 0) {
679 ERR("Error initializing named socket (%s). Check that directory exists and that it is writable.", name
);
684 INIT_LIST_HEAD(&handle
->server
.connections
);
693 /* Used by the daemon to initialize its server so applications
697 int ustcomm_init_ustd(struct ustcomm_ustd
*handle
, const char *sock_path
)
703 asprintf(&name
, "%s", sock_path
);
708 /* Only check if socket dir exists if we are using the default directory */
709 result
= ensure_dir_exists(SOCK_DIR
);
711 ERR("Unable to create socket directory %s", SOCK_DIR
);
715 asprintf(&name
, "%s/%s", SOCK_DIR
, "ustd");
718 handle
->server
.listen_fd
= init_named_socket(name
, &handle
->server
.socketpath
);
719 if(handle
->server
.listen_fd
< 0) {
720 ERR("error initializing named socket at %s", name
);
725 INIT_LIST_HEAD(&handle
->server
.connections
);
733 static void ustcomm_fini_server(struct ustcomm_server
*server
, int keep_socket_file
)
738 if(!keep_socket_file
) {
740 result
= stat(server
->socketpath
, &st
);
742 PERROR("stat (%s)", server
->socketpath
);
746 /* Paranoid check before deleting. */
747 result
= S_ISSOCK(st
.st_mode
);
749 ERR("The socket we are about to delete is not a socket.");
753 result
= unlink(server
->socketpath
);
759 free(server
->socketpath
);
761 result
= close(server
->listen_fd
);
768 /* Free a traceable application server */
770 void ustcomm_fini_app(struct ustcomm_app
*handle
, int keep_socket_file
)
772 ustcomm_fini_server(&handle
->server
, keep_socket_file
);
775 /* Free a ustd server */
777 void ustcomm_fini_ustd(struct ustcomm_ustd
*handle
)
779 ustcomm_fini_server(&handle
->server
, 0);
782 static const char *find_tok(const char *str
)
794 static const char *find_sep(const char *str
)
806 int nth_token_is(const char *str
, const char *token
, int tok_no
)
812 for(i
=0; i
<=tok_no
; i
++) {
826 if(end
-start
!= strlen(token
))
829 if(strncmp(start
, token
, end
-start
))
835 char *nth_token(const char *str
, int tok_no
)
837 static char *retval
= NULL
;
842 for(i
=0; i
<=tok_no
; i
++) {
861 asprintf(&retval
, "%.*s", (int)(end
-start
), start
);
866 /* Callback from multipoll.
867 * Receive a new connection on the listening socket.
870 static int process_mp_incoming_conn(void *priv
, int fd
, short events
)
872 struct ustcomm_connection
*newconn
;
873 struct ustcomm_server
*server
= (struct ustcomm_server
*) priv
;
877 result
= newfd
= accept(server
->listen_fd
, NULL
, NULL
);
883 newconn
= (struct ustcomm_connection
*) malloc(sizeof(struct ustcomm_connection
));
884 if(newconn
== NULL
) {
885 ERR("malloc returned NULL");
889 ustcomm_init_connection(newconn
);
892 list_add(&newconn
->list
, &server
->connections
);
897 /* Callback from multipoll.
898 * Receive a message on an existing connection.
901 static int process_mp_conn_msg(void *priv
, int fd
, short revents
)
903 struct ustcomm_multipoll_conn_info
*mpinfo
= (struct ustcomm_multipoll_conn_info
*) priv
;
906 struct ustcomm_source src
;
911 result
= recv_message_conn(mpinfo
->conn
, &msg
);
913 ERR("error in recv_message_conn");
916 else if(result
== 0) {
917 /* connection finished */
918 ustcomm_close_app(mpinfo
->conn
);
919 list_del(&mpinfo
->conn
->list
);
923 mpinfo
->cb(msg
, &src
);
931 int free_ustcomm_client_poll(void *data
)
937 void ustcomm_mp_add_app_clients(struct mpentries
*ent
, struct ustcomm_app
*app
, int (*cb
)(char *recvbuf
, struct ustcomm_source
*src
))
939 struct ustcomm_connection
*conn
;
941 /* add listener socket */
942 multipoll_add(ent
, app
->server
.listen_fd
, POLLIN
, process_mp_incoming_conn
, &app
->server
, NULL
);
944 list_for_each_entry(conn
, &app
->server
.connections
, list
) {
945 struct ustcomm_multipoll_conn_info
*mpinfo
= (struct ustcomm_multipoll_conn_info
*) malloc(sizeof(struct ustcomm_multipoll_conn_info
));
948 multipoll_add(ent
, conn
->fd
, POLLIN
, process_mp_conn_msg
, mpinfo
, free_ustcomm_client_poll
);