2 * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
3 * Copyright (C) 2013 - Raphaƫl Beamonte <raphael.beamonte@gmail.com>
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License, version 2 only, as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 51
16 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
27 #include <sys/types.h>
33 #include <common/common.h>
34 #include <common/runas.h>
40 * Return a partial realpath(3) of the path even if the full path does not
41 * exist. For instance, with /tmp/test1/test2/test3, if test2/ does not exist
42 * but the /tmp/test1 does, the real path for /tmp/test1 is concatened with
43 * /test2/test3 then returned. In normal time, realpath(3) fails if the end
44 * point directory does not exist.
45 * In case resolved_path is NULL, the string returned was allocated in the
46 * function and thus need to be freed by the caller. The size argument allows
47 * to specify the size of the resolved_path argument if given, or the size to
51 char *utils_partial_realpath(const char *path
, char *resolved_path
, size_t size
)
53 char *cut_path
, *try_path
= NULL
, *try_path_prev
= NULL
;
54 const char *next
, *prev
, *end
;
62 * Identify the end of the path, we don't want to treat the
63 * last char if it is a '/', we will just keep it on the side
64 * to be added at the end, and return a value coherent with
65 * the path given as argument
67 end
= path
+ strlen(path
);
68 if (*(end
-1) == '/') {
72 /* Initiate the values of the pointers before looping */
75 /* Only to ensure try_path is not NULL to enter the while */
76 try_path
= (char *)next
;
78 /* Resolve the canonical path of the first part of the path */
79 while (try_path
!= NULL
&& next
!= end
) {
81 * If there is not any '/' left, we want to try with
84 next
= strpbrk(next
+ 1, "/");
89 /* Cut the part we will be trying to resolve */
90 cut_path
= strndup(path
, next
- path
);
92 /* Try to resolve this part */
93 try_path
= realpath((char *)cut_path
, NULL
);
94 if (try_path
== NULL
) {
96 * There was an error, we just want to be assured it
97 * is linked to an unexistent directory, if it's another
98 * reason, we spawn an error
102 /* Ignore the error */
105 PERROR("realpath (partial_realpath)");
110 /* Save the place we are before trying the next step */
112 try_path_prev
= try_path
;
116 /* Free the allocated memory */
120 /* Allocate memory for the resolved path if necessary */
121 if (resolved_path
== NULL
) {
122 resolved_path
= zmalloc(size
);
123 if (resolved_path
== NULL
) {
124 PERROR("zmalloc resolved path");
130 * If we were able to solve at least partially the path, we can concatenate
131 * what worked and what didn't work
133 if (try_path_prev
!= NULL
) {
134 /* If we risk to concatenate two '/', we remove one of them */
135 if (try_path_prev
[strlen(try_path_prev
) - 1] == '/' && prev
[0] == '/') {
136 try_path_prev
[strlen(try_path_prev
) - 1] = '\0';
140 * Duplicate the memory used by prev in case resolved_path and
141 * path are pointers for the same memory space
143 cut_path
= strdup(prev
);
145 /* Concatenate the strings */
146 snprintf(resolved_path
, size
, "%s%s", try_path_prev
, cut_path
);
148 /* Free the allocated memory */
152 * Else, we just copy the path in our resolved_path to
156 strncpy(resolved_path
, path
, size
);
159 /* Then we return the 'partially' resolved path */
160 return resolved_path
;
168 * Make a full resolution of the given path even if it doesn't exist.
169 * This function uses the utils_partial_realpath function to resolve
170 * symlinks and relatives paths at the start of the string, and
171 * implements functionnalities to resolve the './' and '../' strings
172 * in the middle of a path. This function is only necessary because
173 * realpath(3) does not accept to resolve unexistent paths.
174 * The returned string was allocated in the function, it is thus of
175 * the responsibility of the caller to free this memory.
178 char *utils_expand_path(const char *path
)
180 char *next
, *previous
, *slash
, *start_path
, *absolute_path
= NULL
;
182 int is_dot
, is_dotdot
;
189 /* Allocate memory for the absolute_path */
190 absolute_path
= zmalloc(PATH_MAX
);
191 if (absolute_path
== NULL
) {
192 PERROR("zmalloc expand path");
197 * If the path is not already absolute nor explicitly relative,
198 * consider we're in the current directory
200 if (*path
!= '/' && strncmp(path
, "./", 2) != 0 &&
201 strncmp(path
, "../", 3) != 0) {
202 snprintf(absolute_path
, PATH_MAX
, "./%s", path
);
203 /* Else, we just copy the path */
205 strncpy(absolute_path
, path
, PATH_MAX
);
208 /* Resolve partially our path */
209 absolute_path
= utils_partial_realpath(absolute_path
,
210 absolute_path
, PATH_MAX
);
212 /* As long as we find '/./' in the working_path string */
213 while ((next
= strstr(absolute_path
, "/./"))) {
215 /* We prepare the start_path not containing it */
216 start_path
= strndup(absolute_path
, next
- absolute_path
);
218 /* And we concatenate it with the part after this string */
219 snprintf(absolute_path
, PATH_MAX
, "%s%s", start_path
, next
+ 2);
224 /* As long as we find '/../' in the working_path string */
225 while ((next
= strstr(absolute_path
, "/../"))) {
226 /* We find the last level of directory */
227 previous
= absolute_path
;
228 while ((slash
= strpbrk(previous
, "/")) && slash
!= next
) {
229 previous
= slash
+ 1;
232 /* Then we prepare the start_path not containing it */
233 start_path
= strndup(absolute_path
, previous
- absolute_path
);
235 /* And we concatenate it with the part after the '/../' */
236 snprintf(absolute_path
, PATH_MAX
, "%s%s", start_path
, next
+ 4);
238 /* We can free the memory used for the start path*/
241 /* Then we verify for symlinks using partial_realpath */
242 absolute_path
= utils_partial_realpath(absolute_path
,
243 absolute_path
, PATH_MAX
);
246 /* Identify the last token */
247 last_token
= strrchr(absolute_path
, '/');
249 /* Verify that this token is not a relative path */
250 is_dotdot
= (strcmp(last_token
, "/..") == 0);
251 is_dot
= (strcmp(last_token
, "/.") == 0);
253 /* If it is, take action */
254 if (is_dot
|| is_dotdot
) {
255 /* For both, remove this token */
258 /* If it was a reference to parent directory, go back one more time */
260 last_token
= strrchr(absolute_path
, '/');
262 /* If there was only one level left, we keep the first '/' */
263 if (last_token
== absolute_path
) {
271 return absolute_path
;
279 * Create a pipe in dst.
282 int utils_create_pipe(int *dst
)
292 PERROR("create pipe");
299 * Create pipe and set CLOEXEC flag to both fd.
301 * Make sure the pipe opened by this function are closed at some point. Use
302 * utils_close_pipe().
305 int utils_create_pipe_cloexec(int *dst
)
313 ret
= utils_create_pipe(dst
);
318 for (i
= 0; i
< 2; i
++) {
319 ret
= fcntl(dst
[i
], F_SETFD
, FD_CLOEXEC
);
321 PERROR("fcntl pipe cloexec");
331 * Create pipe and set fd flags to FD_CLOEXEC and O_NONBLOCK.
333 * Make sure the pipe opened by this function are closed at some point. Use
334 * utils_close_pipe(). Using pipe() and fcntl rather than pipe2() to
335 * support OSes other than Linux 2.6.23+.
338 int utils_create_pipe_cloexec_nonblock(int *dst
)
346 ret
= utils_create_pipe(dst
);
351 for (i
= 0; i
< 2; i
++) {
352 ret
= fcntl(dst
[i
], F_SETFD
, FD_CLOEXEC
);
354 PERROR("fcntl pipe cloexec");
358 * Note: we override any flag that could have been
359 * previously set on the fd.
361 ret
= fcntl(dst
[i
], F_SETFL
, O_NONBLOCK
);
363 PERROR("fcntl pipe nonblock");
373 * Close both read and write side of the pipe.
376 void utils_close_pipe(int *src
)
384 for (i
= 0; i
< 2; i
++) {
392 PERROR("close pipe");
398 * Create a new string using two strings range.
401 char *utils_strdupdelim(const char *begin
, const char *end
)
405 str
= zmalloc(end
- begin
+ 1);
407 PERROR("zmalloc strdupdelim");
411 memcpy(str
, begin
, end
- begin
);
412 str
[end
- begin
] = '\0';
419 * Set CLOEXEC flag to the give file descriptor.
422 int utils_set_fd_cloexec(int fd
)
431 ret
= fcntl(fd
, F_SETFD
, FD_CLOEXEC
);
433 PERROR("fcntl cloexec");
442 * Create pid file to the given path and filename.
445 int utils_create_pid_file(pid_t pid
, const char *filepath
)
452 fp
= fopen(filepath
, "w");
454 PERROR("open pid file %s", filepath
);
459 ret
= fprintf(fp
, "%d\n", pid
);
461 PERROR("fprintf pid file");
465 DBG("Pid %d written in file %s", pid
, filepath
);
471 * Recursively create directory using the given path and mode.
473 * On success, return 0 else a negative error code.
476 int utils_mkdir_recursive(const char *path
, mode_t mode
)
478 char *p
, tmp
[PATH_MAX
];
484 ret
= snprintf(tmp
, sizeof(tmp
), "%s", path
);
486 PERROR("snprintf mkdir");
491 if (tmp
[len
- 1] == '/') {
495 for (p
= tmp
+ 1; *p
; p
++) {
498 if (tmp
[strlen(tmp
) - 1] == '.' &&
499 tmp
[strlen(tmp
) - 2] == '.' &&
500 tmp
[strlen(tmp
) - 3] == '/') {
501 ERR("Using '/../' is not permitted in the trace path (%s)",
506 ret
= mkdir(tmp
, mode
);
508 if (errno
!= EEXIST
) {
509 PERROR("mkdir recursive");
518 ret
= mkdir(tmp
, mode
);
520 if (errno
!= EEXIST
) {
521 PERROR("mkdir recursive last piece");
533 * Create the stream tracefile on disk.
535 * Return 0 on success or else a negative value.
538 int utils_create_stream_file(const char *path_name
, char *file_name
, uint64_t size
,
539 uint64_t count
, int uid
, int gid
, char *suffix
)
541 int ret
, out_fd
, flags
, mode
;
542 char full_path
[PATH_MAX
], *path_name_suffix
= NULL
, *path
;
548 ret
= snprintf(full_path
, sizeof(full_path
), "%s/%s",
549 path_name
, file_name
);
551 PERROR("snprintf create output file");
555 /* Setup extra string if suffix or/and a count is needed. */
556 if (size
> 0 && suffix
) {
557 ret
= asprintf(&extra
, "_%" PRIu64
"%s", count
, suffix
);
558 } else if (size
> 0) {
559 ret
= asprintf(&extra
, "_%" PRIu64
, count
);
561 ret
= asprintf(&extra
, "%s", suffix
);
564 PERROR("Allocating extra string to name");
569 * If we split the trace in multiple files, we have to add the count at the
570 * end of the tracefile name
573 ret
= asprintf(&path_name_suffix
, "%s%s", full_path
, extra
);
575 PERROR("Allocating path name with extra string");
576 goto error_free_suffix
;
578 path
= path_name_suffix
;
583 flags
= O_WRONLY
| O_CREAT
| O_TRUNC
;
584 /* Open with 660 mode */
585 mode
= S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
;
587 if (uid
< 0 || gid
< 0) {
588 out_fd
= open(path
, flags
, mode
);
590 out_fd
= run_as_open(path
, flags
, mode
, uid
, gid
);
593 PERROR("open stream path %s", path
);
599 free(path_name_suffix
);
607 * Change the output tracefile according to the given size and count The
608 * new_count pointer is set during this operation.
610 * From the consumer, the stream lock MUST be held before calling this function
611 * because we are modifying the stream status.
613 * Return 0 on success or else a negative value.
616 int utils_rotate_stream_file(char *path_name
, char *file_name
, uint64_t size
,
617 uint64_t count
, int uid
, int gid
, int out_fd
, uint64_t *new_count
,
627 PERROR("Closing tracefile");
632 *new_count
= (*new_count
+ 1) % count
;
637 ret
= utils_create_stream_file(path_name
, file_name
, size
, *new_count
,
652 * Prints the error message corresponding to a regex error code.
654 * @param errcode The error code.
655 * @param regex The regex object that produced the error code.
657 static void regex_print_error(int errcode
, regex_t
*regex
)
659 /* Get length of error message and allocate accordingly */
663 assert(regex
!= NULL
);
665 length
= regerror(errcode
, regex
, NULL
, 0);
667 ERR("regerror returned a length of 0");
671 buffer
= zmalloc(length
);
673 ERR("regex_print_error: zmalloc failed");
677 /* Get and print error message */
678 regerror(errcode
, regex
, buffer
, length
);
679 ERR("regex error: %s\n", buffer
);
685 * Parse a string that represents a size in human readable format. It
686 * supports decimal integers suffixed by 'k', 'M' or 'G'.
688 * The suffix multiply the integer by:
693 * @param str The string to parse.
694 * @param size Pointer to a size_t that will be filled with the
697 * @return 0 on success, -1 on failure.
700 int utils_parse_size_suffix(char *str
, uint64_t *size
)
704 const int nmatch
= 3;
705 regmatch_t suffix_match
, matches
[nmatch
];
706 unsigned long long base_size
;
714 ret
= regcomp(®ex
, "^\\(0x\\)\\{0,1\\}[0-9][0-9]*\\([kKMG]\\{0,1\\}\\)$", 0);
716 regex_print_error(ret
, ®ex
);
722 ret
= regexec(®ex
, str
, nmatch
, matches
, 0);
728 /* There is a match ! */
730 base_size
= strtoull(str
, NULL
, 0);
737 /* Check if there is a suffix */
738 suffix_match
= matches
[2];
739 if (suffix_match
.rm_eo
- suffix_match
.rm_so
== 1) {
740 switch (*(str
+ suffix_match
.rm_so
)) {
752 ERR("parse_human_size: invalid suffix");
758 *size
= base_size
<< shift
;
760 /* Check for overflow */
761 if ((*size
>> shift
) != base_size
) {
762 ERR("parse_size_suffix: oops, overflow detected.");
776 * fls: returns the position of the most significant bit.
777 * Returns 0 if no bit is set, else returns the position of the most
778 * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit).
780 #if defined(__i386) || defined(__x86_64)
781 static inline unsigned int fls_u32(uint32_t x
)
789 : "=r" (r
) : "rm" (x
));
796 static __attribute__((unused
)) unsigned int fls_u32(uint32_t x
)
803 if (!(x
& 0xFFFF0000U
)) {
807 if (!(x
& 0xFF000000U
)) {
811 if (!(x
& 0xF0000000U
)) {
815 if (!(x
& 0xC0000000U
)) {
819 if (!(x
& 0x80000000U
)) {
828 * Return the minimum order for which x <= (1UL << order).
829 * Return -1 if x is 0.
832 int utils_get_count_order_u32(uint32_t x
)
838 return fls_u32(x
- 1);
842 * Obtain the value of LTTNG_HOME environment variable, if exists.
843 * Otherwise returns the value of HOME.
846 char *utils_get_home_dir(void)
849 val
= getenv(DEFAULT_LTTNG_HOME_ENV_VAR
);
853 return getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR
);
857 * With the given format, fill dst with the time of len maximum siz.
859 * Return amount of bytes set in the buffer or else 0 on error.
862 size_t utils_get_current_time_str(const char *format
, char *dst
, size_t len
)
871 /* Get date and time for session path */
873 timeinfo
= localtime(&rawtime
);
874 ret
= strftime(dst
, len
, format
, timeinfo
);
876 ERR("Unable to strftime with format %s at dst %p of len %lu", format
,
884 * Return the group ID matching name, else 0 if it cannot be found.
887 gid_t
utils_get_group_id(const char *name
)
891 grp
= getgrnam(name
);
893 static volatile int warn_once
;
896 WARN("No tracing group detected");