2 * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
3 * Copyright (C) 2013 - Raphaël Beamonte <raphael.beamonte@gmail.com>
4 * Copyright (C) 2013 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License, version 2 only, as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
27 #include <sys/types.h>
35 #include <common/common.h>
36 #include <common/runas.h>
37 #include <common/compat/getenv.h>
38 #include <common/compat/string.h>
39 #include <common/compat/dirent.h>
40 #include <lttng/constant.h>
46 * Return a partial realpath(3) of the path even if the full path does not
47 * exist. For instance, with /tmp/test1/test2/test3, if test2/ does not exist
48 * but the /tmp/test1 does, the real path for /tmp/test1 is concatened with
49 * /test2/test3 then returned. In normal time, realpath(3) fails if the end
50 * point directory does not exist.
51 * In case resolved_path is NULL, the string returned was allocated in the
52 * function and thus need to be freed by the caller. The size argument allows
53 * to specify the size of the resolved_path argument if given, or the size to
57 char *utils_partial_realpath(const char *path
, char *resolved_path
, size_t size
)
59 char *cut_path
= NULL
, *try_path
= NULL
, *try_path_prev
= NULL
;
60 const char *next
, *prev
, *end
;
68 * Identify the end of the path, we don't want to treat the
69 * last char if it is a '/', we will just keep it on the side
70 * to be added at the end, and return a value coherent with
71 * the path given as argument
73 end
= path
+ strlen(path
);
74 if (*(end
-1) == '/') {
78 /* Initiate the values of the pointers before looping */
81 /* Only to ensure try_path is not NULL to enter the while */
82 try_path
= (char *)next
;
84 /* Resolve the canonical path of the first part of the path */
85 while (try_path
!= NULL
&& next
!= end
) {
86 char *try_path_buf
= NULL
;
89 * If there is not any '/' left, we want to try with
92 next
= strpbrk(next
+ 1, "/");
97 /* Cut the part we will be trying to resolve */
98 cut_path
= lttng_strndup(path
, next
- path
);
99 if (cut_path
== NULL
) {
100 PERROR("lttng_strndup");
104 try_path_buf
= zmalloc(LTTNG_PATH_MAX
);
110 /* Try to resolve this part */
111 try_path
= realpath((char *) cut_path
, try_path_buf
);
112 if (try_path
== NULL
) {
115 * There was an error, we just want to be assured it
116 * is linked to an unexistent directory, if it's another
117 * reason, we spawn an error
121 /* Ignore the error */
124 PERROR("realpath (partial_realpath)");
129 /* Save the place we are before trying the next step */
132 try_path_prev
= try_path
;
136 /* Free the allocated memory */
141 /* Allocate memory for the resolved path if necessary */
142 if (resolved_path
== NULL
) {
143 resolved_path
= zmalloc(size
);
144 if (resolved_path
== NULL
) {
145 PERROR("zmalloc resolved path");
151 * If we were able to solve at least partially the path, we can concatenate
152 * what worked and what didn't work
154 if (try_path_prev
!= NULL
) {
155 /* If we risk to concatenate two '/', we remove one of them */
156 if (try_path_prev
[strlen(try_path_prev
) - 1] == '/' && prev
[0] == '/') {
157 try_path_prev
[strlen(try_path_prev
) - 1] = '\0';
161 * Duplicate the memory used by prev in case resolved_path and
162 * path are pointers for the same memory space
164 cut_path
= strdup(prev
);
165 if (cut_path
== NULL
) {
170 /* Concatenate the strings */
171 snprintf(resolved_path
, size
, "%s%s", try_path_prev
, cut_path
);
173 /* Free the allocated memory */
177 try_path_prev
= NULL
;
179 * Else, we just copy the path in our resolved_path to
183 strncpy(resolved_path
, path
, size
);
186 /* Then we return the 'partially' resolved path */
187 return resolved_path
;
193 if (try_path_prev
!= try_path
) {
200 char *expand_double_slashes_dot_and_dotdot(char *path
)
202 size_t expanded_path_len
, path_len
;
203 const char *curr_char
, *path_last_char
, *next_slash
, *prev_slash
;
205 path_len
= strlen(path
);
206 path_last_char
= &path
[path_len
];
213 expanded_path_len
= 0;
215 /* We iterate over the provided path to expand the "//", "../" and "./" */
216 for (curr_char
= path
; curr_char
<= path_last_char
; curr_char
= next_slash
+ 1) {
217 /* Find the next forward slash. */
218 size_t curr_token_len
;
220 if (curr_char
== path_last_char
) {
225 next_slash
= memchr(curr_char
, '/', path_last_char
- curr_char
);
226 if (next_slash
== NULL
) {
227 /* Reached the end of the provided path. */
228 next_slash
= path_last_char
;
231 /* Compute how long is the previous token. */
232 curr_token_len
= next_slash
- curr_char
;
233 switch(curr_token_len
) {
236 * The pointer has not move meaning that curr_char is
237 * pointing to a slash. It that case there is no token
238 * to copy, so continue the iteration to find the next
244 * The pointer moved 1 character. Check if that
245 * character is a dot ('.'), if it is: omit it, else
246 * copy the token to the normalized path.
248 if (curr_char
[0] == '.') {
254 * The pointer moved 2 characters. Check if these
255 * characters are double dots ('..'). If that is the
256 * case, we need to remove the last token of the
259 if (curr_char
[0] == '.' && curr_char
[1] == '.') {
261 * Find the previous path component by
262 * using the memrchr function to find the
263 * previous forward slash and substract that
264 * len to the resulting path.
266 prev_slash
= lttng_memrchr(path
, '/', expanded_path_len
);
268 * If prev_slash is NULL, we reached the
269 * beginning of the path. We can't go back any
272 if (prev_slash
!= NULL
) {
273 expanded_path_len
= prev_slash
- path
;
283 * Copy the current token which is neither a '.' nor a '..'.
285 path
[expanded_path_len
++] = '/';
286 memcpy(&path
[expanded_path_len
], curr_char
, curr_token_len
);
287 expanded_path_len
+= curr_token_len
;
290 if (expanded_path_len
== 0) {
291 path
[expanded_path_len
++] = '/';
294 path
[expanded_path_len
] = '\0';
301 * Make a full resolution of the given path even if it doesn't exist.
302 * This function uses the utils_partial_realpath function to resolve
303 * symlinks and relatives paths at the start of the string, and
304 * implements functionnalities to resolve the './' and '../' strings
305 * in the middle of a path. This function is only necessary because
306 * realpath(3) does not accept to resolve unexistent paths.
307 * The returned string was allocated in the function, it is thus of
308 * the responsibility of the caller to free this memory.
311 char *_utils_expand_path(const char *path
, bool keep_symlink
)
313 char *absolute_path
= NULL
;
315 int is_dot
, is_dotdot
;
322 /* Allocate memory for the absolute_path */
323 absolute_path
= zmalloc(PATH_MAX
);
324 if (absolute_path
== NULL
) {
325 PERROR("zmalloc expand path");
329 if (path
[0] == '/') {
330 strncpy(absolute_path
, path
, PATH_MAX
);
333 * This is a relative path. We need to get the present working
334 * directory and start the path walk from there.
336 char current_working_dir
[PATH_MAX
];
338 cwd_ret
= getcwd(current_working_dir
, sizeof(current_working_dir
));
340 absolute_path
= NULL
;
344 * Get the number of character in the CWD and allocate an array
345 * to can hold it and the path provided by the caller.
347 snprintf(absolute_path
, PATH_MAX
, "%s/%s", current_working_dir
, path
);
351 /* Resolve partially our path */
352 absolute_path
= utils_partial_realpath(absolute_path
,
353 absolute_path
, PATH_MAX
);
356 absolute_path
= expand_double_slashes_dot_and_dotdot(absolute_path
);
357 if (!absolute_path
) {
361 /* Identify the last token */
362 last_token
= strrchr(absolute_path
, '/');
364 /* Verify that this token is not a relative path */
365 is_dotdot
= (strcmp(last_token
, "/..") == 0);
366 is_dot
= (strcmp(last_token
, "/.") == 0);
368 /* If it is, take action */
369 if (is_dot
|| is_dotdot
) {
370 /* For both, remove this token */
373 /* If it was a reference to parent directory, go back one more time */
375 last_token
= strrchr(absolute_path
, '/');
377 /* If there was only one level left, we keep the first '/' */
378 if (last_token
== absolute_path
) {
386 return absolute_path
;
393 char *utils_expand_path(const char *path
)
395 return _utils_expand_path(path
, true);
399 char *utils_expand_path_keep_symlink(const char *path
)
401 return _utils_expand_path(path
, false);
404 * Create a pipe in dst.
407 int utils_create_pipe(int *dst
)
417 PERROR("create pipe");
424 * Create pipe and set CLOEXEC flag to both fd.
426 * Make sure the pipe opened by this function are closed at some point. Use
427 * utils_close_pipe().
430 int utils_create_pipe_cloexec(int *dst
)
438 ret
= utils_create_pipe(dst
);
443 for (i
= 0; i
< 2; i
++) {
444 ret
= fcntl(dst
[i
], F_SETFD
, FD_CLOEXEC
);
446 PERROR("fcntl pipe cloexec");
456 * Create pipe and set fd flags to FD_CLOEXEC and O_NONBLOCK.
458 * Make sure the pipe opened by this function are closed at some point. Use
459 * utils_close_pipe(). Using pipe() and fcntl rather than pipe2() to
460 * support OSes other than Linux 2.6.23+.
463 int utils_create_pipe_cloexec_nonblock(int *dst
)
471 ret
= utils_create_pipe(dst
);
476 for (i
= 0; i
< 2; i
++) {
477 ret
= fcntl(dst
[i
], F_SETFD
, FD_CLOEXEC
);
479 PERROR("fcntl pipe cloexec");
483 * Note: we override any flag that could have been
484 * previously set on the fd.
486 ret
= fcntl(dst
[i
], F_SETFL
, O_NONBLOCK
);
488 PERROR("fcntl pipe nonblock");
498 * Close both read and write side of the pipe.
501 void utils_close_pipe(int *src
)
509 for (i
= 0; i
< 2; i
++) {
517 PERROR("close pipe");
523 * Create a new string using two strings range.
526 char *utils_strdupdelim(const char *begin
, const char *end
)
530 str
= zmalloc(end
- begin
+ 1);
532 PERROR("zmalloc strdupdelim");
536 memcpy(str
, begin
, end
- begin
);
537 str
[end
- begin
] = '\0';
544 * Set CLOEXEC flag to the give file descriptor.
547 int utils_set_fd_cloexec(int fd
)
556 ret
= fcntl(fd
, F_SETFD
, FD_CLOEXEC
);
558 PERROR("fcntl cloexec");
567 * Create pid file to the given path and filename.
570 int utils_create_pid_file(pid_t pid
, const char *filepath
)
577 fp
= fopen(filepath
, "w");
579 PERROR("open pid file %s", filepath
);
584 ret
= fprintf(fp
, "%d\n", (int) pid
);
586 PERROR("fprintf pid file");
593 DBG("Pid %d written in file %s", (int) pid
, filepath
);
600 * Create lock file to the given path and filename.
601 * Returns the associated file descriptor, -1 on error.
604 int utils_create_lock_file(const char *filepath
)
612 memset(&lock
, 0, sizeof(lock
));
613 fd
= open(filepath
, O_CREAT
| O_WRONLY
, S_IRUSR
| S_IWUSR
|
616 PERROR("open lock file %s", filepath
);
622 * Attempt to lock the file. If this fails, there is
623 * already a process using the same lock file running
624 * and we should exit.
626 lock
.l_whence
= SEEK_SET
;
627 lock
.l_type
= F_WRLCK
;
629 ret
= fcntl(fd
, F_SETLK
, &lock
);
631 PERROR("fcntl lock file");
632 ERR("Could not get lock file %s, another instance is running.",
635 PERROR("close lock file");
646 * On some filesystems (e.g. nfs), mkdir will validate access rights before
647 * checking for the existence of the path element. This means that on a setup
648 * where "/home/" is a mounted NFS share, and running as an unpriviledged user,
649 * recursively creating a path of the form "/home/my_user/trace/" will fail with
650 * EACCES on mkdir("/home", ...).
652 * Performing a stat(...) on the path to check for existence allows us to
653 * work around this behaviour.
656 int mkdir_check_exists(const char *path
, mode_t mode
)
661 ret
= stat(path
, &st
);
663 if (S_ISDIR(st
.st_mode
)) {
664 /* Directory exists, skip. */
667 /* Exists, but is not a directory. */
675 * Let mkdir handle other errors as the caller expects mkdir
678 ret
= mkdir(path
, mode
);
684 * Create directory using the given path and mode.
686 * On success, return 0 else a negative error code.
689 int utils_mkdir(const char *path
, mode_t mode
, int uid
, int gid
)
693 if (uid
< 0 || gid
< 0) {
694 ret
= mkdir_check_exists(path
, mode
);
696 ret
= run_as_mkdir(path
, mode
, uid
, gid
);
699 if (errno
!= EEXIST
) {
700 PERROR("mkdir %s, uid %d, gid %d", path
? path
: "NULL",
711 * Internal version of mkdir_recursive. Runs as the current user.
712 * Don't call directly; use utils_mkdir_recursive().
714 * This function is ominously marked as "unsafe" since it should only
715 * be called by a caller that has transitioned to the uid and gid under which
716 * the directory creation should occur.
719 int _utils_mkdir_recursive_unsafe(const char *path
, mode_t mode
)
721 char *p
, tmp
[PATH_MAX
];
727 ret
= snprintf(tmp
, sizeof(tmp
), "%s", path
);
729 PERROR("snprintf mkdir");
734 if (tmp
[len
- 1] == '/') {
738 for (p
= tmp
+ 1; *p
; p
++) {
741 if (tmp
[strlen(tmp
) - 1] == '.' &&
742 tmp
[strlen(tmp
) - 2] == '.' &&
743 tmp
[strlen(tmp
) - 3] == '/') {
744 ERR("Using '/../' is not permitted in the trace path (%s)",
749 ret
= mkdir_check_exists(tmp
, mode
);
751 if (errno
!= EACCES
) {
752 PERROR("mkdir recursive");
761 ret
= mkdir_check_exists(tmp
, mode
);
763 PERROR("mkdir recursive last element");
772 * Recursively create directory using the given path and mode, under the
773 * provided uid and gid.
775 * On success, return 0 else a negative error code.
778 int utils_mkdir_recursive(const char *path
, mode_t mode
, int uid
, int gid
)
782 if (uid
< 0 || gid
< 0) {
783 /* Run as current user. */
784 ret
= _utils_mkdir_recursive_unsafe(path
, mode
);
786 ret
= run_as_mkdir_recursive(path
, mode
, uid
, gid
);
789 PERROR("mkdir %s, uid %d, gid %d", path
? path
: "NULL",
797 * path is the output parameter. It needs to be PATH_MAX len.
799 * Return 0 on success or else a negative value.
801 static int utils_stream_file_name(char *path
,
802 const char *path_name
, const char *file_name
,
803 uint64_t size
, uint64_t count
,
807 char full_path
[PATH_MAX
];
808 char *path_name_suffix
= NULL
;
811 ret
= snprintf(full_path
, sizeof(full_path
), "%s/%s",
812 path_name
, file_name
);
814 PERROR("snprintf create output file");
818 /* Setup extra string if suffix or/and a count is needed. */
819 if (size
> 0 && suffix
) {
820 ret
= asprintf(&extra
, "_%" PRIu64
"%s", count
, suffix
);
821 } else if (size
> 0) {
822 ret
= asprintf(&extra
, "_%" PRIu64
, count
);
824 ret
= asprintf(&extra
, "%s", suffix
);
827 PERROR("Allocating extra string to name");
832 * If we split the trace in multiple files, we have to add the count at
833 * the end of the tracefile name.
836 ret
= asprintf(&path_name_suffix
, "%s%s", full_path
, extra
);
838 PERROR("Allocating path name with extra string");
839 goto error_free_suffix
;
841 strncpy(path
, path_name_suffix
, PATH_MAX
- 1);
842 path
[PATH_MAX
- 1] = '\0';
844 ret
= lttng_strncpy(path
, full_path
, PATH_MAX
);
846 ERR("Failed to copy stream file name");
847 goto error_free_suffix
;
850 path
[PATH_MAX
- 1] = '\0';
853 free(path_name_suffix
);
861 * Create the stream file on disk.
863 * Return 0 on success or else a negative value.
866 int utils_create_stream_file(const char *path_name
, char *file_name
, uint64_t size
,
867 uint64_t count
, int uid
, int gid
, char *suffix
)
869 int ret
, flags
, mode
;
872 ret
= utils_stream_file_name(path
, path_name
, file_name
,
873 size
, count
, suffix
);
879 * With the session rotation feature on the relay, we might need to seek
880 * and truncate a tracefile, so we need read and write access.
882 flags
= O_RDWR
| O_CREAT
| O_TRUNC
;
883 /* Open with 660 mode */
884 mode
= S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
;
886 if (uid
< 0 || gid
< 0) {
887 ret
= open(path
, flags
, mode
);
889 ret
= run_as_open(path
, flags
, mode
, uid
, gid
);
892 PERROR("open stream path %s", path
);
899 * Unlink the stream tracefile from disk.
901 * Return 0 on success or else a negative value.
904 int utils_unlink_stream_file(const char *path_name
, char *file_name
, uint64_t size
,
905 uint64_t count
, int uid
, int gid
, char *suffix
)
910 ret
= utils_stream_file_name(path
, path_name
, file_name
,
911 size
, count
, suffix
);
915 if (uid
< 0 || gid
< 0) {
918 ret
= run_as_unlink(path
, uid
, gid
);
924 DBG("utils_unlink_stream_file %s returns %d", path
, ret
);
929 * Change the output tracefile according to the given size and count The
930 * new_count pointer is set during this operation.
932 * From the consumer, the stream lock MUST be held before calling this function
933 * because we are modifying the stream status.
935 * Return 0 on success or else a negative value.
938 int utils_rotate_stream_file(char *path_name
, char *file_name
, uint64_t size
,
939 uint64_t count
, int uid
, int gid
, int out_fd
, uint64_t *new_count
,
948 PERROR("Closing tracefile");
955 * In tracefile rotation, for the relay daemon we need
956 * to unlink the old file if present, because it may
957 * still be open in reading by the live thread, and we
958 * need to ensure that we do not overwrite the content
959 * between get_index and get_packet. Since we have no
960 * way to verify integrity of the data content compared
961 * to the associated index, we need to ensure the reader
962 * has exclusive access to the file content, and that
963 * the open of the data file is performed in get_index.
964 * Unlinking the old file rather than overwriting it
968 *new_count
= (*new_count
+ 1) % count
;
970 ret
= utils_unlink_stream_file(path_name
, file_name
, size
,
971 new_count
? *new_count
: 0, uid
, gid
, 0);
972 if (ret
< 0 && errno
!= ENOENT
) {
981 ret
= utils_create_stream_file(path_name
, file_name
, size
,
982 new_count
? *new_count
: 0, uid
, gid
, 0);
997 * Parse a string that represents a size in human readable format. It
998 * supports decimal integers suffixed by 'k', 'K', 'M' or 'G'.
1000 * The suffix multiply the integer by:
1005 * @param str The string to parse.
1006 * @param size Pointer to a uint64_t that will be filled with the
1009 * @return 0 on success, -1 on failure.
1012 int utils_parse_size_suffix(const char * const str
, uint64_t * const size
)
1017 const char *str_end
;
1021 DBG("utils_parse_size_suffix: received a NULL string.");
1026 /* strtoull will accept a negative number, but we don't want to. */
1027 if (strchr(str
, '-') != NULL
) {
1028 DBG("utils_parse_size_suffix: invalid size string, should not contain '-'.");
1033 /* str_end will point to the \0 */
1034 str_end
= str
+ strlen(str
);
1036 base_size
= strtoull(str
, &num_end
, 0);
1038 PERROR("utils_parse_size_suffix strtoull");
1043 if (num_end
== str
) {
1044 /* strtoull parsed nothing, not good. */
1045 DBG("utils_parse_size_suffix: strtoull had nothing good to parse.");
1050 /* Check if a prefix is present. */
1068 DBG("utils_parse_size_suffix: invalid suffix.");
1073 /* Check for garbage after the valid input. */
1074 if (num_end
!= str_end
) {
1075 DBG("utils_parse_size_suffix: Garbage after size string.");
1080 *size
= base_size
<< shift
;
1082 /* Check for overflow */
1083 if ((*size
>> shift
) != base_size
) {
1084 DBG("utils_parse_size_suffix: oops, overflow detected.");
1095 * Parse a string that represents a time in human readable format. It
1096 * supports decimal integers suffixed by 's', 'u', 'm', 'us', and 'ms'.
1098 * The suffix multiply the integer by:
1103 * Note that unit-less numbers are assumed to be microseconds.
1105 * @param str The string to parse, assumed to be NULL-terminated.
1106 * @param time_us Pointer to a uint64_t that will be filled with the
1107 * resulting time in microseconds.
1109 * @return 0 on success, -1 on failure.
1112 int utils_parse_time_suffix(char const * const str
, uint64_t * const time_us
)
1116 long multiplier
= 1;
1117 const char *str_end
;
1121 DBG("utils_parse_time_suffix: received a NULL string.");
1126 /* strtoull will accept a negative number, but we don't want to. */
1127 if (strchr(str
, '-') != NULL
) {
1128 DBG("utils_parse_time_suffix: invalid time string, should not contain '-'.");
1133 /* str_end will point to the \0 */
1134 str_end
= str
+ strlen(str
);
1136 base_time
= strtoull(str
, &num_end
, 10);
1138 PERROR("utils_parse_time_suffix strtoull on string \"%s\"", str
);
1143 if (num_end
== str
) {
1144 /* strtoull parsed nothing, not good. */
1145 DBG("utils_parse_time_suffix: strtoull had nothing good to parse.");
1150 /* Check if a prefix is present. */
1154 /* Skip another letter in the 'us' case. */
1155 num_end
+= (*(num_end
+ 1) == 's') ? 2 : 1;
1159 /* Skip another letter in the 'ms' case. */
1160 num_end
+= (*(num_end
+ 1) == 's') ? 2 : 1;
1163 multiplier
= 1000000;
1169 DBG("utils_parse_time_suffix: invalid suffix.");
1174 /* Check for garbage after the valid input. */
1175 if (num_end
!= str_end
) {
1176 DBG("utils_parse_time_suffix: Garbage after time string.");
1181 *time_us
= base_time
* multiplier
;
1183 /* Check for overflow */
1184 if ((*time_us
/ multiplier
) != base_time
) {
1185 DBG("utils_parse_time_suffix: oops, overflow detected.");
1196 * fls: returns the position of the most significant bit.
1197 * Returns 0 if no bit is set, else returns the position of the most
1198 * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit).
1200 #if defined(__i386) || defined(__x86_64)
1201 static inline unsigned int fls_u32(uint32_t x
)
1205 asm("bsrl %1,%0\n\t"
1209 : "=r" (r
) : "rm" (x
));
1215 #if defined(__x86_64)
1217 unsigned int fls_u64(uint64_t x
)
1221 asm("bsrq %1,%0\n\t"
1225 : "=r" (r
) : "rm" (x
));
1232 static __attribute__((unused
))
1233 unsigned int fls_u64(uint64_t x
)
1235 unsigned int r
= 64;
1240 if (!(x
& 0xFFFFFFFF00000000ULL
)) {
1244 if (!(x
& 0xFFFF000000000000ULL
)) {
1248 if (!(x
& 0xFF00000000000000ULL
)) {
1252 if (!(x
& 0xF000000000000000ULL
)) {
1256 if (!(x
& 0xC000000000000000ULL
)) {
1260 if (!(x
& 0x8000000000000000ULL
)) {
1269 static __attribute__((unused
)) unsigned int fls_u32(uint32_t x
)
1271 unsigned int r
= 32;
1276 if (!(x
& 0xFFFF0000U
)) {
1280 if (!(x
& 0xFF000000U
)) {
1284 if (!(x
& 0xF0000000U
)) {
1288 if (!(x
& 0xC0000000U
)) {
1292 if (!(x
& 0x80000000U
)) {
1301 * Return the minimum order for which x <= (1UL << order).
1302 * Return -1 if x is 0.
1305 int utils_get_count_order_u32(uint32_t x
)
1311 return fls_u32(x
- 1);
1315 * Return the minimum order for which x <= (1UL << order).
1316 * Return -1 if x is 0.
1319 int utils_get_count_order_u64(uint64_t x
)
1325 return fls_u64(x
- 1);
1329 * Obtain the value of LTTNG_HOME environment variable, if exists.
1330 * Otherwise returns the value of HOME.
1333 char *utils_get_home_dir(void)
1338 val
= lttng_secure_getenv(DEFAULT_LTTNG_HOME_ENV_VAR
);
1342 val
= lttng_secure_getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR
);
1347 /* Fallback on the password file entry. */
1348 pwd
= getpwuid(getuid());
1354 DBG3("Home directory is '%s'", val
);
1361 * Get user's home directory. Dynamically allocated, must be freed
1365 char *utils_get_user_home_dir(uid_t uid
)
1368 struct passwd
*result
;
1369 char *home_dir
= NULL
;
1374 buflen
= sysconf(_SC_GETPW_R_SIZE_MAX
);
1379 buf
= zmalloc(buflen
);
1384 ret
= getpwuid_r(uid
, &pwd
, buf
, buflen
, &result
);
1385 if (ret
|| !result
) {
1386 if (ret
== ERANGE
) {
1394 home_dir
= strdup(pwd
.pw_dir
);
1401 * With the given format, fill dst with the time of len maximum siz.
1403 * Return amount of bytes set in the buffer or else 0 on error.
1406 size_t utils_get_current_time_str(const char *format
, char *dst
, size_t len
)
1410 struct tm
*timeinfo
;
1415 /* Get date and time for session path */
1417 timeinfo
= localtime(&rawtime
);
1418 ret
= strftime(dst
, len
, format
, timeinfo
);
1420 ERR("Unable to strftime with format %s at dst %p of len %zu", format
,
1428 * Return the group ID matching name, else 0 if it cannot be found.
1431 gid_t
utils_get_group_id(const char *name
)
1435 grp
= getgrnam(name
);
1437 static volatile int warn_once
;
1440 WARN("No tracing group detected");
1449 * Return a newly allocated option string. This string is to be used as the
1450 * optstring argument of getopt_long(), see GETOPT(3). opt_count is the number
1451 * of elements in the long_options array. Returns NULL if the string's
1455 char *utils_generate_optstring(const struct option
*long_options
,
1459 size_t string_len
= opt_count
, str_pos
= 0;
1463 * Compute the necessary string length. One letter per option, two when an
1464 * argument is necessary, and a trailing NULL.
1466 for (i
= 0; i
< opt_count
; i
++) {
1467 string_len
+= long_options
[i
].has_arg
? 1 : 0;
1470 optstring
= zmalloc(string_len
);
1475 for (i
= 0; i
< opt_count
; i
++) {
1476 if (!long_options
[i
].name
) {
1477 /* Got to the trailing NULL element */
1481 if (long_options
[i
].val
!= '\0') {
1482 optstring
[str_pos
++] = (char) long_options
[i
].val
;
1483 if (long_options
[i
].has_arg
) {
1484 optstring
[str_pos
++] = ':';
1494 * Try to remove a hierarchy of empty directories, recursively. Don't unlink
1495 * any file. Try to rmdir any empty directory within the hierarchy.
1498 int utils_recursive_rmdir(const char *path
)
1502 int dir_fd
, ret
= 0, closeret
, is_empty
= 1;
1503 struct dirent
*entry
;
1505 /* Open directory */
1506 dir
= opendir(path
);
1508 PERROR("Cannot open '%s' path", path
);
1511 dir_fd
= lttng_dirfd(dir
);
1513 PERROR("lttng_dirfd");
1517 path_len
= strlen(path
);
1518 while ((entry
= readdir(dir
))) {
1521 char filename
[PATH_MAX
];
1523 if (!strcmp(entry
->d_name
, ".")
1524 || !strcmp(entry
->d_name
, "..")) {
1528 name_len
= strlen(entry
->d_name
);
1529 if (path_len
+ name_len
+ 2 > sizeof(filename
)) {
1530 ERR("Failed to remove file: path name too long (%s/%s)",
1531 path
, entry
->d_name
);
1534 if (snprintf(filename
, sizeof(filename
), "%s/%s",
1535 path
, entry
->d_name
) < 0) {
1536 ERR("Failed to format path.");
1540 if (stat(filename
, &st
)) {
1545 if (S_ISDIR(st
.st_mode
)) {
1546 char subpath
[PATH_MAX
];
1548 strncpy(subpath
, path
, PATH_MAX
);
1549 subpath
[PATH_MAX
- 1] = '\0';
1550 strncat(subpath
, "/",
1551 PATH_MAX
- strlen(subpath
) - 1);
1552 strncat(subpath
, entry
->d_name
,
1553 PATH_MAX
- strlen(subpath
) - 1);
1554 if (utils_recursive_rmdir(subpath
)) {
1557 } else if (S_ISREG(st
.st_mode
)) {
1565 closeret
= closedir(dir
);
1570 DBG3("Attempting rmdir %s", path
);
1577 int utils_truncate_stream_file(int fd
, off_t length
)
1582 ret
= ftruncate(fd
, length
);
1584 PERROR("ftruncate");
1587 lseek_ret
= lseek(fd
, length
, SEEK_SET
);
1588 if (lseek_ret
< 0) {
1597 static const char *get_man_bin_path(void)
1599 char *env_man_path
= lttng_secure_getenv(DEFAULT_MAN_BIN_PATH_ENV
);
1602 return env_man_path
;
1605 return DEFAULT_MAN_BIN_PATH
;
1609 int utils_show_help(int section
, const char *page_name
,
1610 const char *help_msg
)
1612 char section_string
[8];
1613 const char *man_bin_path
= get_man_bin_path();
1617 printf("%s", help_msg
);
1621 /* Section integer -> section string */
1622 ret
= sprintf(section_string
, "%d", section
);
1623 assert(ret
> 0 && ret
< 8);
1626 * Execute man pager.
1628 * We provide -M to man here because LTTng-tools can
1629 * be installed outside /usr, in which case its man pages are
1630 * not located in the default /usr/share/man directory.
1632 ret
= execlp(man_bin_path
, "man", "-M", MANPATH
,
1633 section_string
, page_name
, NULL
);