Add mode setting to socket directory creation
[ust.git] / libustcomm / ustcomm.c
1 /* Copyright (C) 2009 Pierre-Marc Fournier
2 *
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.
7 *
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.
12 *
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
16 */
17
18 /* API used by UST components to communicate with each other via sockets. */
19
20 #define _GNU_SOURCE
21 #include <sys/types.h>
22 #include <signal.h>
23 #include <errno.h>
24 #include <sys/socket.h>
25 #include <sys/un.h>
26 #include <unistd.h>
27 #include <poll.h>
28 #include <sys/epoll.h>
29 #include <sys/stat.h>
30
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <execinfo.h>
35
36 #include "ustcomm.h"
37 #include "usterr.h"
38 #include "share.h"
39
40 static int mkdir_p(const char *path, mode_t mode)
41 {
42 const char *path_p;
43 char *tmp;
44
45 int retval = 0;
46 int result;
47 mode_t old_umask;
48
49 tmp = zmalloc(strlen(path) + 1);
50 if (tmp == NULL)
51 return -1;
52
53 /* skip first / */
54 path_p = path+1;
55
56 old_umask = umask(0);
57 for(;;) {
58 while (*path_p != '/') {
59 if(*path_p == 0)
60 break;
61 ++path_p;
62 }
63 if (*path_p == '/') {
64 strncpy(tmp, path, path_p - path);
65 tmp[path_p-path] = '\0';
66 if (tmp[path_p - path - 1] != '/') {
67 result = mkdir(tmp, mode);
68 if(result == -1) {
69 if (!(errno == EEXIST || errno == EACCES || errno == EROFS)) {
70 /* Then this is a real error */
71 retval = -1;
72 break;
73 }
74 }
75 }
76 /* pass / */
77 path_p++;
78 } else {
79 /* last component */
80 result = mkdir(path, mode);
81 if (result == -1)
82 retval = -1;
83 break;
84 }
85 }
86
87 free(tmp);
88 umask(old_umask);
89 return retval;
90 }
91
92 static struct sockaddr_un * create_sock_addr(const char *name,
93 size_t *sock_addr_size)
94 {
95 struct sockaddr_un * addr;
96 size_t alloc_size;
97
98 alloc_size = (size_t) (((struct sockaddr_un *) 0)->sun_path) +
99 strlen(name) + 1;
100
101 addr = malloc(alloc_size);
102 if (addr < 0) {
103 ERR("allocating addr failed");
104 return NULL;
105 }
106
107 addr->sun_family = AF_UNIX;
108 strcpy(addr->sun_path, name);
109
110 *sock_addr_size = alloc_size;
111
112 return addr;
113 }
114
115 struct ustcomm_sock * ustcomm_init_sock(int fd, int epoll_fd,
116 struct cds_list_head *list)
117 {
118 struct epoll_event ev;
119 struct ustcomm_sock *sock;
120
121 sock = malloc(sizeof(struct ustcomm_sock));
122 if (!sock) {
123 perror("malloc: couldn't allocate ustcomm_sock");
124 return NULL;
125 }
126
127 ev.events = EPOLLIN;
128 ev.data.ptr = sock;
129 sock->fd = fd;
130
131 if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock->fd, &ev) == -1) {
132 perror("epoll_ctl: failed to add socket\n");
133 free(sock);
134 return NULL;
135 }
136
137 sock->epoll_fd = epoll_fd;
138 if (list) {
139 cds_list_add(&sock->list, list);
140 } else {
141 CDS_INIT_LIST_HEAD(&sock->list);
142 }
143
144 return sock;
145 }
146
147 void ustcomm_del_sock(struct ustcomm_sock *sock, int keep_in_epoll)
148 {
149 cds_list_del(&sock->list);
150 if (!keep_in_epoll) {
151 if (epoll_ctl(sock->epoll_fd, EPOLL_CTL_DEL, sock->fd, NULL) == -1) {
152 PERROR("epoll_ctl: failed to delete socket");
153 }
154 }
155 close(sock->fd);
156 free(sock);
157 }
158
159 struct ustcomm_sock * ustcomm_init_named_socket(const char *name,
160 int epoll_fd)
161 {
162 int result;
163 int fd;
164 size_t sock_addr_size;
165 struct sockaddr_un * addr;
166 struct ustcomm_sock *sock;
167
168 fd = socket(PF_UNIX, SOCK_STREAM, 0);
169 if(fd == -1) {
170 PERROR("socket");
171 return NULL;
172 }
173
174 addr = create_sock_addr(name, &sock_addr_size);
175 if (addr == NULL) {
176 ERR("allocating addr, UST thread bailing");
177 goto close_sock;
178 }
179
180 result = access(name, F_OK);
181 if(result == 0) {
182 /* file exists */
183 result = unlink(name);
184 if(result == -1) {
185 PERROR("unlink of socket file");
186 goto free_addr;
187 }
188 DBG("socket already exists; overwriting");
189 }
190
191 result = bind(fd, (struct sockaddr *)addr, sock_addr_size);
192 if(result == -1) {
193 PERROR("bind");
194 goto free_addr;
195 }
196
197 result = listen(fd, 1);
198 if(result == -1) {
199 PERROR("listen");
200 goto free_addr;
201 }
202
203 sock = ustcomm_init_sock(fd, epoll_fd,
204 NULL);
205 if (!sock) {
206 ERR("failed to create ustcomm_sock");
207 goto free_addr;
208 }
209
210 free(addr);
211
212 return sock;
213
214 free_addr:
215 free(addr);
216 close_sock:
217 close(fd);
218
219 return NULL;
220 }
221
222 void ustcomm_del_named_sock(struct ustcomm_sock *sock,
223 int keep_socket_file)
224 {
225 int result, fd;
226 struct stat st;
227 struct sockaddr dummy;
228 struct sockaddr_un *sockaddr = NULL;
229 int alloc_size;
230
231 fd = sock->fd;
232
233 if(!keep_socket_file) {
234
235 /* Get the socket name */
236 alloc_size = sizeof(dummy);
237 if (getsockname(fd, &dummy, (socklen_t *)&alloc_size) < 0) {
238 PERROR("getsockname failed");
239 goto del_sock;
240 }
241
242 sockaddr = zmalloc(alloc_size);
243 if (!sockaddr) {
244 ERR("failed to allocate sockaddr");
245 goto del_sock;
246 }
247
248 if (getsockname(fd, sockaddr, (socklen_t *)&alloc_size) < 0) {
249 PERROR("getsockname failed");
250 goto free_sockaddr;
251 }
252
253 /* Destroy socket */
254 result = stat(sockaddr->sun_path, &st);
255 if(result < 0) {
256 PERROR("stat (%s)", sockaddr->sun_path);
257 goto free_sockaddr;
258 }
259
260 /* Paranoid check before deleting. */
261 result = S_ISSOCK(st.st_mode);
262 if(!result) {
263 ERR("The socket we are about to delete is not a socket.");
264 goto free_sockaddr;
265 }
266
267 result = unlink(sockaddr->sun_path);
268 if(result < 0) {
269 PERROR("unlink");
270 }
271 }
272
273 free_sockaddr:
274 free(sockaddr);
275
276 del_sock:
277 ustcomm_del_sock(sock, keep_socket_file);
278 }
279
280 int ustcomm_recv_alloc(int sock,
281 struct ustcomm_header *header,
282 char **data) {
283 int result;
284 struct ustcomm_header peek_header;
285 struct iovec iov[2];
286 struct msghdr msg;
287
288 /* Just to make the caller fail hard */
289 *data = NULL;
290
291 result = recv(sock, &peek_header, sizeof(peek_header),
292 MSG_PEEK | MSG_WAITALL);
293 if (result <= 0) {
294 if(errno == ECONNRESET) {
295 return 0;
296 } else if (errno == EINTR) {
297 return -1;
298 } else if (result < 0) {
299 PERROR("recv");
300 return -1;
301 }
302 return 0;
303 }
304
305 memset(&msg, 0, sizeof(msg));
306
307 iov[0].iov_base = (char *)header;
308 iov[0].iov_len = sizeof(struct ustcomm_header);
309
310 msg.msg_iov = iov;
311 msg.msg_iovlen = 1;
312
313 if (peek_header.size) {
314 *data = zmalloc(peek_header.size);
315 if (!*data) {
316 return -ENOMEM;
317 }
318
319 iov[1].iov_base = *data;
320 iov[1].iov_len = peek_header.size;
321
322 msg.msg_iovlen++;
323 }
324
325 result = recvmsg(sock, &msg, MSG_WAITALL);
326 if (result < 0) {
327 free(*data);
328 PERROR("recvmsg failed");
329 }
330
331 return result;
332 }
333
334 /* returns 1 to indicate a message was received
335 * returns 0 to indicate no message was received (end of stream)
336 * returns -1 to indicate an error
337 */
338 int ustcomm_recv_fd(int sock,
339 struct ustcomm_header *header,
340 char *data, int *fd)
341 {
342 int result;
343 struct ustcomm_header peek_header;
344 struct iovec iov[2];
345 struct msghdr msg;
346 struct cmsghdr *cmsg;
347 char buf[CMSG_SPACE(sizeof(int))];
348
349 result = recv(sock, &peek_header, sizeof(peek_header),
350 MSG_PEEK | MSG_WAITALL);
351 if (result <= 0) {
352 if(errno == ECONNRESET) {
353 return 0;
354 } else if (errno == EINTR) {
355 return -1;
356 } else if (result < 0) {
357 PERROR("recv");
358 return -1;
359 }
360 return 0;
361 }
362
363 memset(&msg, 0, sizeof(msg));
364
365 iov[0].iov_base = (char *)header;
366 iov[0].iov_len = sizeof(struct ustcomm_header);
367
368 msg.msg_iov = iov;
369 msg.msg_iovlen = 1;
370
371 if (peek_header.size && data) {
372 if (peek_header.size < 0 ||
373 peek_header.size > USTCOMM_DATA_SIZE) {
374 ERR("big peek header! %ld", peek_header.size);
375 return 0;
376 }
377
378 iov[1].iov_base = data;
379 iov[1].iov_len = peek_header.size;
380
381 msg.msg_iovlen++;
382 }
383
384 if (fd && peek_header.fd_included) {
385 msg.msg_control = buf;
386 msg.msg_controllen = sizeof(buf);
387 }
388
389 result = recvmsg(sock, &msg, MSG_WAITALL);
390 if (result <= 0) {
391 if (result < 0) {
392 PERROR("recvmsg failed");
393 }
394 return result;
395 }
396
397 if (fd && peek_header.fd_included) {
398 cmsg = CMSG_FIRSTHDR(&msg);
399 result = 0;
400 while (cmsg != NULL) {
401 if (cmsg->cmsg_level == SOL_SOCKET
402 && cmsg->cmsg_type == SCM_RIGHTS) {
403 *fd = *(int *) CMSG_DATA(cmsg);
404 result = 1;
405 break;
406 }
407 cmsg = CMSG_NXTHDR(&msg, cmsg);
408 }
409 if (!result) {
410 ERR("Failed to receive file descriptor\n");
411 }
412 }
413
414 return 1;
415 }
416
417 int ustcomm_recv(int sock,
418 struct ustcomm_header *header,
419 char *data)
420 {
421 return ustcomm_recv_fd(sock, header, data, NULL);
422 }
423
424
425 int ustcomm_send_fd(int sock,
426 const struct ustcomm_header *header,
427 const char *data,
428 int *fd)
429 {
430 struct iovec iov[2];
431 struct msghdr msg;
432 int result;
433 struct cmsghdr *cmsg;
434 char buf[CMSG_SPACE(sizeof(int))];
435
436 memset(&msg, 0, sizeof(msg));
437
438 iov[0].iov_base = (char *)header;
439 iov[0].iov_len = sizeof(struct ustcomm_header);
440
441 msg.msg_iov = iov;
442 msg.msg_iovlen = 1;
443
444 if (header->size && data) {
445 iov[1].iov_base = (char *)data;
446 iov[1].iov_len = header->size;
447
448 msg.msg_iovlen++;
449
450 }
451
452 if (fd && header->fd_included) {
453 msg.msg_control = buf;
454 msg.msg_controllen = sizeof(buf);
455 cmsg = CMSG_FIRSTHDR(&msg);
456 cmsg->cmsg_level = SOL_SOCKET;
457 cmsg->cmsg_type = SCM_RIGHTS;
458 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
459 *(int *) CMSG_DATA(cmsg) = *fd;
460 msg.msg_controllen = cmsg->cmsg_len;
461 }
462
463 result = sendmsg(sock, &msg, MSG_NOSIGNAL);
464 if (result < 0 && errno != EPIPE) {
465 PERROR("sendmsg failed");
466 }
467 return result;
468 }
469
470 int ustcomm_send(int sock,
471 const struct ustcomm_header *header,
472 const char *data)
473 {
474 return ustcomm_send_fd(sock, header, data, NULL);
475 }
476
477 int ustcomm_req(int sock,
478 const struct ustcomm_header *req_header,
479 const char *req_data,
480 struct ustcomm_header *res_header,
481 char *res_data)
482 {
483 int result;
484
485 result = ustcomm_send(sock, req_header, req_data);
486 if ( result <= 0) {
487 return result;
488 }
489
490 return ustcomm_recv(sock, res_header, res_data);
491 }
492
493 /* Return value:
494 * 0: success
495 * -1: error
496 */
497
498 int ustcomm_connect_path(const char *name, int *connection_fd)
499 {
500 int result, fd;
501 size_t sock_addr_size;
502 struct sockaddr_un *addr;
503
504 fd = socket(PF_UNIX, SOCK_STREAM, 0);
505 if(fd == -1) {
506 PERROR("socket");
507 return -1;
508 }
509
510 addr = create_sock_addr(name, &sock_addr_size);
511 if (addr == NULL) {
512 ERR("allocating addr failed");
513 goto close_sock;
514 }
515
516 result = connect(fd, (struct sockaddr *)addr, sock_addr_size);
517 if(result == -1) {
518 PERROR("connect (path=%s)", name);
519 goto free_sock_addr;
520 }
521
522 *connection_fd = fd;
523
524 free(addr);
525
526 return 0;
527
528 free_sock_addr:
529 free(addr);
530 close_sock:
531 close(fd);
532
533 return -1;
534 }
535
536 /* Returns the current users socket directory, must be freed */
537 char *ustcomm_user_sock_dir(void)
538 {
539 int result;
540 char *sock_dir = NULL;
541
542 result = asprintf(&sock_dir, "%s%s", USER_SOCK_DIR,
543 cuserid(NULL));
544 if (result < 0) {
545 ERR("string overflow allocating directory name");
546 return NULL;
547 }
548
549 return sock_dir;
550 }
551
552 /* Open a connection to a traceable app.
553 *
554 * Return value:
555 * 0: success
556 * -1: error
557 */
558
559 int ustcomm_connect_app(pid_t pid, int *app_fd)
560 {
561 int result;
562 int retval = 0;
563 char *dir_name, *sock_name;
564
565 dir_name = ustcomm_user_sock_dir();
566 if (!dir_name)
567 return -ENOMEM;
568
569 result = asprintf(&sock_name, "%s/%d", dir_name, pid);
570 if (result < 0) {
571 ERR("failed to allocate socket name");
572 retval = -1;
573 goto free_dir_name;
574 }
575
576 result = ustcomm_connect_path(sock_name, app_fd);
577 if (result < 0) {
578 ERR("failed to connect to app");
579 retval = -1;
580 goto free_sock_name;
581 }
582
583 free_sock_name:
584 free(sock_name);
585 free_dir_name:
586 free(dir_name);
587
588 return retval;
589 }
590
591 int ensure_dir_exists(const char *dir, mode_t mode)
592 {
593 struct stat st;
594 int result;
595
596 if (!strcmp(dir, ""))
597 return -1;
598
599 result = stat(dir, &st);
600 if (result < 0 && errno != ENOENT) {
601 return -1;
602 } else if (result < 0) {
603 /* ENOENT */
604 int result;
605
606 result = mkdir_p(dir, mode);
607 if(result != 0) {
608 ERR("executing in recursive creation of directory %s", dir);
609 return -1;
610 }
611 } else {
612 if (st.st_mode != mode) {
613 result = chmod(dir, mode);
614 if (result < 0) {
615 ERR("couldn't set directory mode on %s", dir);
616 return -1;
617 }
618 }
619 }
620
621 return 0;
622 }
623
624 char * ustcomm_print_data(char *data_field, int field_size,
625 int *offset, const char *format, ...)
626 {
627 va_list args;
628 int count, limit;
629 char *ptr = USTCOMM_POISON_PTR;
630
631 limit = field_size - *offset;
632 va_start(args, format);
633 count = vsnprintf(&data_field[*offset], limit, format, args);
634 va_end(args);
635
636 if (count < limit && count > -1) {
637 ptr = NULL + *offset;
638 *offset = *offset + count + 1;
639 }
640
641 return ptr;
642 }
643
644 char * ustcomm_restore_ptr(char *ptr, char *data_field, int data_field_size)
645 {
646 if ((unsigned long)ptr > data_field_size ||
647 ptr == USTCOMM_POISON_PTR) {
648 return NULL;
649 }
650
651 return data_field + (long)ptr;
652 }
653
654 int ustcomm_pack_single_field(struct ustcomm_header *header,
655 struct ustcomm_single_field *single_field,
656 const char *string)
657 {
658 int offset = 0;
659
660 single_field->field = ustcomm_print_data(single_field->data,
661 sizeof(single_field->data),
662 &offset,
663 string);
664
665 if (single_field->field == USTCOMM_POISON_PTR) {
666 return -ENOMEM;
667 }
668
669 header->size = COMPUTE_MSG_SIZE(single_field, offset);
670
671 return 0;
672 }
673
674 int ustcomm_unpack_single_field(struct ustcomm_single_field *single_field)
675 {
676 single_field->field = ustcomm_restore_ptr(single_field->field,
677 single_field->data,
678 sizeof(single_field->data));
679 if (!single_field->field) {
680 return -EINVAL;
681 }
682
683 return 0;
684 }
685
686 int ustcomm_pack_channel_info(struct ustcomm_header *header,
687 struct ustcomm_channel_info *ch_inf,
688 const char *trace,
689 const char *channel)
690 {
691 int offset = 0;
692
693 ch_inf->trace = ustcomm_print_data(ch_inf->data,
694 sizeof(ch_inf->data),
695 &offset,
696 trace);
697
698 if (ch_inf->trace == USTCOMM_POISON_PTR) {
699 return -ENOMEM;
700 }
701
702 ch_inf->channel = ustcomm_print_data(ch_inf->data,
703 sizeof(ch_inf->data),
704 &offset,
705 channel);
706
707 if (ch_inf->channel == USTCOMM_POISON_PTR) {
708 return -ENOMEM;
709 }
710
711 header->size = COMPUTE_MSG_SIZE(ch_inf, offset);
712
713 return 0;
714 }
715
716
717 int ustcomm_unpack_channel_info(struct ustcomm_channel_info *ch_inf)
718 {
719 ch_inf->trace = ustcomm_restore_ptr(ch_inf->trace,
720 ch_inf->data,
721 sizeof(ch_inf->data));
722 if (!ch_inf->trace) {
723 return -EINVAL;
724 }
725
726 ch_inf->channel = ustcomm_restore_ptr(ch_inf->channel,
727 ch_inf->data,
728 sizeof(ch_inf->data));
729 if (!ch_inf->channel) {
730 return -EINVAL;
731 }
732
733 return 0;
734 }
735
736 int ustcomm_pack_buffer_info(struct ustcomm_header *header,
737 struct ustcomm_buffer_info *buf_inf,
738 const char *trace,
739 const char *channel,
740 int channel_cpu)
741 {
742 int offset = 0;
743
744 buf_inf->trace = ustcomm_print_data(buf_inf->data,
745 sizeof(buf_inf->data),
746 &offset,
747 trace);
748
749 if (buf_inf->trace == USTCOMM_POISON_PTR) {
750 return -ENOMEM;
751 }
752
753 buf_inf->channel = ustcomm_print_data(buf_inf->data,
754 sizeof(buf_inf->data),
755 &offset,
756 channel);
757
758 if (buf_inf->channel == USTCOMM_POISON_PTR) {
759 return -ENOMEM;
760 }
761
762 buf_inf->ch_cpu = channel_cpu;
763
764 header->size = COMPUTE_MSG_SIZE(buf_inf, offset);
765
766 return 0;
767 }
768
769
770 int ustcomm_unpack_buffer_info(struct ustcomm_buffer_info *buf_inf)
771 {
772 buf_inf->trace = ustcomm_restore_ptr(buf_inf->trace,
773 buf_inf->data,
774 sizeof(buf_inf->data));
775 if (!buf_inf->trace) {
776 return -EINVAL;
777 }
778
779 buf_inf->channel = ustcomm_restore_ptr(buf_inf->channel,
780 buf_inf->data,
781 sizeof(buf_inf->data));
782 if (!buf_inf->channel) {
783 return -EINVAL;
784 }
785
786 return 0;
787 }
788
789 int ustcomm_pack_marker_info(struct ustcomm_header *header,
790 struct ustcomm_marker_info *marker_inf,
791 const char *trace,
792 const char *channel,
793 const char *marker)
794 {
795 int offset = 0;
796
797 marker_inf->trace = ustcomm_print_data(marker_inf->data,
798 sizeof(marker_inf->data),
799 &offset,
800 trace);
801
802 if (marker_inf->trace == USTCOMM_POISON_PTR) {
803 return -ENOMEM;
804 }
805
806
807 marker_inf->channel = ustcomm_print_data(marker_inf->data,
808 sizeof(marker_inf->data),
809 &offset,
810 channel);
811
812 if (marker_inf->channel == USTCOMM_POISON_PTR) {
813 return -ENOMEM;
814 }
815
816
817 marker_inf->marker = ustcomm_print_data(marker_inf->data,
818 sizeof(marker_inf->data),
819 &offset,
820 marker);
821
822 if (marker_inf->marker == USTCOMM_POISON_PTR) {
823 return -ENOMEM;
824 }
825
826 header->size = COMPUTE_MSG_SIZE(marker_inf, offset);
827
828 return 0;
829 }
830
831 int ustcomm_unpack_marker_info(struct ustcomm_marker_info *marker_inf)
832 {
833 marker_inf->trace = ustcomm_restore_ptr(marker_inf->trace,
834 marker_inf->data,
835 sizeof(marker_inf->data));
836 if (!marker_inf->trace) {
837 return -EINVAL;
838 }
839
840 marker_inf->channel = ustcomm_restore_ptr(marker_inf->channel,
841 marker_inf->data,
842 sizeof(marker_inf->data));
843 if (!marker_inf->channel) {
844 return -EINVAL;
845 }
846
847 marker_inf->marker = ustcomm_restore_ptr(marker_inf->marker,
848 marker_inf->data,
849 sizeof(marker_inf->data));
850 if (!marker_inf->marker) {
851 return -EINVAL;
852 }
853
854 return 0;
855 }
856
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