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
));
343 * Get the number of character in the CWD and allocate an array
344 * to can hold it and the path provided by the caller.
346 snprintf(absolute_path
, PATH_MAX
, "%s/%s", current_working_dir
, path
);
350 /* Resolve partially our path */
351 absolute_path
= utils_partial_realpath(absolute_path
,
352 absolute_path
, PATH_MAX
);
355 absolute_path
= expand_double_slashes_dot_and_dotdot(absolute_path
);
356 if (!absolute_path
) {
360 /* Identify the last token */
361 last_token
= strrchr(absolute_path
, '/');
363 /* Verify that this token is not a relative path */
364 is_dotdot
= (strcmp(last_token
, "/..") == 0);
365 is_dot
= (strcmp(last_token
, "/.") == 0);
367 /* If it is, take action */
368 if (is_dot
|| is_dotdot
) {
369 /* For both, remove this token */
372 /* If it was a reference to parent directory, go back one more time */
374 last_token
= strrchr(absolute_path
, '/');
376 /* If there was only one level left, we keep the first '/' */
377 if (last_token
== absolute_path
) {
385 return absolute_path
;
392 char *utils_expand_path(const char *path
)
394 return _utils_expand_path(path
, true);
398 char *utils_expand_path_keep_symlink(const char *path
)
400 return _utils_expand_path(path
, false);
403 * Create a pipe in dst.
406 int utils_create_pipe(int *dst
)
416 PERROR("create pipe");
423 * Create pipe and set CLOEXEC flag to both fd.
425 * Make sure the pipe opened by this function are closed at some point. Use
426 * utils_close_pipe().
429 int utils_create_pipe_cloexec(int *dst
)
437 ret
= utils_create_pipe(dst
);
442 for (i
= 0; i
< 2; i
++) {
443 ret
= fcntl(dst
[i
], F_SETFD
, FD_CLOEXEC
);
445 PERROR("fcntl pipe cloexec");
455 * Create pipe and set fd flags to FD_CLOEXEC and O_NONBLOCK.
457 * Make sure the pipe opened by this function are closed at some point. Use
458 * utils_close_pipe(). Using pipe() and fcntl rather than pipe2() to
459 * support OSes other than Linux 2.6.23+.
462 int utils_create_pipe_cloexec_nonblock(int *dst
)
470 ret
= utils_create_pipe(dst
);
475 for (i
= 0; i
< 2; i
++) {
476 ret
= fcntl(dst
[i
], F_SETFD
, FD_CLOEXEC
);
478 PERROR("fcntl pipe cloexec");
482 * Note: we override any flag that could have been
483 * previously set on the fd.
485 ret
= fcntl(dst
[i
], F_SETFL
, O_NONBLOCK
);
487 PERROR("fcntl pipe nonblock");
497 * Close both read and write side of the pipe.
500 void utils_close_pipe(int *src
)
508 for (i
= 0; i
< 2; i
++) {
516 PERROR("close pipe");
522 * Create a new string using two strings range.
525 char *utils_strdupdelim(const char *begin
, const char *end
)
529 str
= zmalloc(end
- begin
+ 1);
531 PERROR("zmalloc strdupdelim");
535 memcpy(str
, begin
, end
- begin
);
536 str
[end
- begin
] = '\0';
543 * Set CLOEXEC flag to the give file descriptor.
546 int utils_set_fd_cloexec(int fd
)
555 ret
= fcntl(fd
, F_SETFD
, FD_CLOEXEC
);
557 PERROR("fcntl cloexec");
566 * Create pid file to the given path and filename.
569 int utils_create_pid_file(pid_t pid
, const char *filepath
)
576 fp
= fopen(filepath
, "w");
578 PERROR("open pid file %s", filepath
);
583 ret
= fprintf(fp
, "%d\n", (int) pid
);
585 PERROR("fprintf pid file");
592 DBG("Pid %d written in file %s", (int) pid
, filepath
);
599 * Create lock file to the given path and filename.
600 * Returns the associated file descriptor, -1 on error.
603 int utils_create_lock_file(const char *filepath
)
611 memset(&lock
, 0, sizeof(lock
));
612 fd
= open(filepath
, O_CREAT
| O_WRONLY
, S_IRUSR
| S_IWUSR
|
615 PERROR("open lock file %s", filepath
);
621 * Attempt to lock the file. If this fails, there is
622 * already a process using the same lock file running
623 * and we should exit.
625 lock
.l_whence
= SEEK_SET
;
626 lock
.l_type
= F_WRLCK
;
628 ret
= fcntl(fd
, F_SETLK
, &lock
);
630 PERROR("fcntl lock file");
631 ERR("Could not get lock file %s, another instance is running.",
634 PERROR("close lock file");
645 * On some filesystems (e.g. nfs), mkdir will validate access rights before
646 * checking for the existence of the path element. This means that on a setup
647 * where "/home/" is a mounted NFS share, and running as an unpriviledged user,
648 * recursively creating a path of the form "/home/my_user/trace/" will fail with
649 * EACCES on mkdir("/home", ...).
651 * Performing a stat(...) on the path to check for existence allows us to
652 * work around this behaviour.
655 int mkdir_check_exists(const char *path
, mode_t mode
)
660 ret
= stat(path
, &st
);
662 if (S_ISDIR(st
.st_mode
)) {
663 /* Directory exists, skip. */
666 /* Exists, but is not a directory. */
674 * Let mkdir handle other errors as the caller expects mkdir
677 ret
= mkdir(path
, mode
);
683 * Create directory using the given path and mode.
685 * On success, return 0 else a negative error code.
688 int utils_mkdir(const char *path
, mode_t mode
, int uid
, int gid
)
692 if (uid
< 0 || gid
< 0) {
693 ret
= mkdir_check_exists(path
, mode
);
695 ret
= run_as_mkdir(path
, mode
, uid
, gid
);
698 if (errno
!= EEXIST
) {
699 PERROR("mkdir %s, uid %d, gid %d", path
? path
: "NULL",
710 * Internal version of mkdir_recursive. Runs as the current user.
711 * Don't call directly; use utils_mkdir_recursive().
713 * This function is ominously marked as "unsafe" since it should only
714 * be called by a caller that has transitioned to the uid and gid under which
715 * the directory creation should occur.
718 int _utils_mkdir_recursive_unsafe(const char *path
, mode_t mode
)
720 char *p
, tmp
[PATH_MAX
];
726 ret
= snprintf(tmp
, sizeof(tmp
), "%s", path
);
728 PERROR("snprintf mkdir");
733 if (tmp
[len
- 1] == '/') {
737 for (p
= tmp
+ 1; *p
; p
++) {
740 if (tmp
[strlen(tmp
) - 1] == '.' &&
741 tmp
[strlen(tmp
) - 2] == '.' &&
742 tmp
[strlen(tmp
) - 3] == '/') {
743 ERR("Using '/../' is not permitted in the trace path (%s)",
748 ret
= mkdir_check_exists(tmp
, mode
);
750 if (errno
!= EACCES
) {
751 PERROR("mkdir recursive");
760 ret
= mkdir_check_exists(tmp
, mode
);
762 PERROR("mkdir recursive last element");
771 * Recursively create directory using the given path and mode, under the
772 * provided uid and gid.
774 * On success, return 0 else a negative error code.
777 int utils_mkdir_recursive(const char *path
, mode_t mode
, int uid
, int gid
)
781 if (uid
< 0 || gid
< 0) {
782 /* Run as current user. */
783 ret
= _utils_mkdir_recursive_unsafe(path
, mode
);
785 ret
= run_as_mkdir_recursive(path
, mode
, uid
, gid
);
788 PERROR("mkdir %s, uid %d, gid %d", path
? path
: "NULL",
796 * path is the output parameter. It needs to be PATH_MAX len.
798 * Return 0 on success or else a negative value.
800 static int utils_stream_file_name(char *path
,
801 const char *path_name
, const char *file_name
,
802 uint64_t size
, uint64_t count
,
806 char full_path
[PATH_MAX
];
807 char *path_name_suffix
= NULL
;
810 ret
= snprintf(full_path
, sizeof(full_path
), "%s/%s",
811 path_name
, file_name
);
813 PERROR("snprintf create output file");
817 /* Setup extra string if suffix or/and a count is needed. */
818 if (size
> 0 && suffix
) {
819 ret
= asprintf(&extra
, "_%" PRIu64
"%s", count
, suffix
);
820 } else if (size
> 0) {
821 ret
= asprintf(&extra
, "_%" PRIu64
, count
);
823 ret
= asprintf(&extra
, "%s", suffix
);
826 PERROR("Allocating extra string to name");
831 * If we split the trace in multiple files, we have to add the count at
832 * the end of the tracefile name.
835 ret
= asprintf(&path_name_suffix
, "%s%s", full_path
, extra
);
837 PERROR("Allocating path name with extra string");
838 goto error_free_suffix
;
840 strncpy(path
, path_name_suffix
, PATH_MAX
- 1);
841 path
[PATH_MAX
- 1] = '\0';
843 ret
= lttng_strncpy(path
, full_path
, PATH_MAX
);
845 ERR("Failed to copy stream file name");
846 goto error_free_suffix
;
849 path
[PATH_MAX
- 1] = '\0';
852 free(path_name_suffix
);
860 * Create the stream file on disk.
862 * Return 0 on success or else a negative value.
865 int utils_create_stream_file(const char *path_name
, char *file_name
, uint64_t size
,
866 uint64_t count
, int uid
, int gid
, char *suffix
)
868 int ret
, flags
, mode
;
871 ret
= utils_stream_file_name(path
, path_name
, file_name
,
872 size
, count
, suffix
);
878 * With the session rotation feature on the relay, we might need to seek
879 * and truncate a tracefile, so we need read and write access.
881 flags
= O_RDWR
| O_CREAT
| O_TRUNC
;
882 /* Open with 660 mode */
883 mode
= S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
;
885 if (uid
< 0 || gid
< 0) {
886 ret
= open(path
, flags
, mode
);
888 ret
= run_as_open(path
, flags
, mode
, uid
, gid
);
891 PERROR("open stream path %s", path
);
898 * Unlink the stream tracefile from disk.
900 * Return 0 on success or else a negative value.
903 int utils_unlink_stream_file(const char *path_name
, char *file_name
, uint64_t size
,
904 uint64_t count
, int uid
, int gid
, char *suffix
)
909 ret
= utils_stream_file_name(path
, path_name
, file_name
,
910 size
, count
, suffix
);
914 if (uid
< 0 || gid
< 0) {
917 ret
= run_as_unlink(path
, uid
, gid
);
923 DBG("utils_unlink_stream_file %s returns %d", path
, ret
);
928 * Change the output tracefile according to the given size and count The
929 * new_count pointer is set during this operation.
931 * From the consumer, the stream lock MUST be held before calling this function
932 * because we are modifying the stream status.
934 * Return 0 on success or else a negative value.
937 int utils_rotate_stream_file(char *path_name
, char *file_name
, uint64_t size
,
938 uint64_t count
, int uid
, int gid
, int out_fd
, uint64_t *new_count
,
947 PERROR("Closing tracefile");
954 * In tracefile rotation, for the relay daemon we need
955 * to unlink the old file if present, because it may
956 * still be open in reading by the live thread, and we
957 * need to ensure that we do not overwrite the content
958 * between get_index and get_packet. Since we have no
959 * way to verify integrity of the data content compared
960 * to the associated index, we need to ensure the reader
961 * has exclusive access to the file content, and that
962 * the open of the data file is performed in get_index.
963 * Unlinking the old file rather than overwriting it
967 *new_count
= (*new_count
+ 1) % count
;
969 ret
= utils_unlink_stream_file(path_name
, file_name
, size
,
970 new_count
? *new_count
: 0, uid
, gid
, 0);
971 if (ret
< 0 && errno
!= ENOENT
) {
980 ret
= utils_create_stream_file(path_name
, file_name
, size
,
981 new_count
? *new_count
: 0, uid
, gid
, 0);
996 * Parse a string that represents a size in human readable format. It
997 * supports decimal integers suffixed by 'k', 'K', 'M' or 'G'.
999 * The suffix multiply the integer by:
1004 * @param str The string to parse.
1005 * @param size Pointer to a uint64_t that will be filled with the
1008 * @return 0 on success, -1 on failure.
1011 int utils_parse_size_suffix(const char * const str
, uint64_t * const size
)
1016 const char *str_end
;
1020 DBG("utils_parse_size_suffix: received a NULL string.");
1025 /* strtoull will accept a negative number, but we don't want to. */
1026 if (strchr(str
, '-') != NULL
) {
1027 DBG("utils_parse_size_suffix: invalid size string, should not contain '-'.");
1032 /* str_end will point to the \0 */
1033 str_end
= str
+ strlen(str
);
1035 base_size
= strtoull(str
, &num_end
, 0);
1037 PERROR("utils_parse_size_suffix strtoull");
1042 if (num_end
== str
) {
1043 /* strtoull parsed nothing, not good. */
1044 DBG("utils_parse_size_suffix: strtoull had nothing good to parse.");
1049 /* Check if a prefix is present. */
1067 DBG("utils_parse_size_suffix: invalid suffix.");
1072 /* Check for garbage after the valid input. */
1073 if (num_end
!= str_end
) {
1074 DBG("utils_parse_size_suffix: Garbage after size string.");
1079 *size
= base_size
<< shift
;
1081 /* Check for overflow */
1082 if ((*size
>> shift
) != base_size
) {
1083 DBG("utils_parse_size_suffix: oops, overflow detected.");
1094 * Parse a string that represents a time in human readable format. It
1095 * supports decimal integers suffixed by 's', 'u', 'm', 'us', and 'ms'.
1097 * The suffix multiply the integer by:
1102 * Note that unit-less numbers are assumed to be microseconds.
1104 * @param str The string to parse, assumed to be NULL-terminated.
1105 * @param time_us Pointer to a uint64_t that will be filled with the
1106 * resulting time in microseconds.
1108 * @return 0 on success, -1 on failure.
1111 int utils_parse_time_suffix(char const * const str
, uint64_t * const time_us
)
1115 long multiplier
= 1;
1116 const char *str_end
;
1120 DBG("utils_parse_time_suffix: received a NULL string.");
1125 /* strtoull will accept a negative number, but we don't want to. */
1126 if (strchr(str
, '-') != NULL
) {
1127 DBG("utils_parse_time_suffix: invalid time string, should not contain '-'.");
1132 /* str_end will point to the \0 */
1133 str_end
= str
+ strlen(str
);
1135 base_time
= strtoull(str
, &num_end
, 10);
1137 PERROR("utils_parse_time_suffix strtoull on string \"%s\"", str
);
1142 if (num_end
== str
) {
1143 /* strtoull parsed nothing, not good. */
1144 DBG("utils_parse_time_suffix: strtoull had nothing good to parse.");
1149 /* Check if a prefix is present. */
1153 /* Skip another letter in the 'us' case. */
1154 num_end
+= (*(num_end
+ 1) == 's') ? 2 : 1;
1158 /* Skip another letter in the 'ms' case. */
1159 num_end
+= (*(num_end
+ 1) == 's') ? 2 : 1;
1162 multiplier
= 1000000;
1168 DBG("utils_parse_time_suffix: invalid suffix.");
1173 /* Check for garbage after the valid input. */
1174 if (num_end
!= str_end
) {
1175 DBG("utils_parse_time_suffix: Garbage after time string.");
1180 *time_us
= base_time
* multiplier
;
1182 /* Check for overflow */
1183 if ((*time_us
/ multiplier
) != base_time
) {
1184 DBG("utils_parse_time_suffix: oops, overflow detected.");
1195 * fls: returns the position of the most significant bit.
1196 * Returns 0 if no bit is set, else returns the position of the most
1197 * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit).
1199 #if defined(__i386) || defined(__x86_64)
1200 static inline unsigned int fls_u32(uint32_t x
)
1204 asm("bsrl %1,%0\n\t"
1208 : "=r" (r
) : "rm" (x
));
1214 #if defined(__x86_64)
1216 unsigned int fls_u64(uint64_t x
)
1220 asm("bsrq %1,%0\n\t"
1224 : "=r" (r
) : "rm" (x
));
1231 static __attribute__((unused
))
1232 unsigned int fls_u64(uint64_t x
)
1234 unsigned int r
= 64;
1239 if (!(x
& 0xFFFFFFFF00000000ULL
)) {
1243 if (!(x
& 0xFFFF000000000000ULL
)) {
1247 if (!(x
& 0xFF00000000000000ULL
)) {
1251 if (!(x
& 0xF000000000000000ULL
)) {
1255 if (!(x
& 0xC000000000000000ULL
)) {
1259 if (!(x
& 0x8000000000000000ULL
)) {
1268 static __attribute__((unused
)) unsigned int fls_u32(uint32_t x
)
1270 unsigned int r
= 32;
1275 if (!(x
& 0xFFFF0000U
)) {
1279 if (!(x
& 0xFF000000U
)) {
1283 if (!(x
& 0xF0000000U
)) {
1287 if (!(x
& 0xC0000000U
)) {
1291 if (!(x
& 0x80000000U
)) {
1300 * Return the minimum order for which x <= (1UL << order).
1301 * Return -1 if x is 0.
1304 int utils_get_count_order_u32(uint32_t x
)
1310 return fls_u32(x
- 1);
1314 * Return the minimum order for which x <= (1UL << order).
1315 * Return -1 if x is 0.
1318 int utils_get_count_order_u64(uint64_t x
)
1324 return fls_u64(x
- 1);
1328 * Obtain the value of LTTNG_HOME environment variable, if exists.
1329 * Otherwise returns the value of HOME.
1332 char *utils_get_home_dir(void)
1337 val
= lttng_secure_getenv(DEFAULT_LTTNG_HOME_ENV_VAR
);
1341 val
= lttng_secure_getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR
);
1346 /* Fallback on the password file entry. */
1347 pwd
= getpwuid(getuid());
1353 DBG3("Home directory is '%s'", val
);
1360 * Get user's home directory. Dynamically allocated, must be freed
1364 char *utils_get_user_home_dir(uid_t uid
)
1367 struct passwd
*result
;
1368 char *home_dir
= NULL
;
1373 buflen
= sysconf(_SC_GETPW_R_SIZE_MAX
);
1378 buf
= zmalloc(buflen
);
1383 ret
= getpwuid_r(uid
, &pwd
, buf
, buflen
, &result
);
1384 if (ret
|| !result
) {
1385 if (ret
== ERANGE
) {
1393 home_dir
= strdup(pwd
.pw_dir
);
1400 * With the given format, fill dst with the time of len maximum siz.
1402 * Return amount of bytes set in the buffer or else 0 on error.
1405 size_t utils_get_current_time_str(const char *format
, char *dst
, size_t len
)
1409 struct tm
*timeinfo
;
1414 /* Get date and time for session path */
1416 timeinfo
= localtime(&rawtime
);
1417 ret
= strftime(dst
, len
, format
, timeinfo
);
1419 ERR("Unable to strftime with format %s at dst %p of len %zu", format
,
1427 * Return the group ID matching name, else 0 if it cannot be found.
1430 gid_t
utils_get_group_id(const char *name
)
1434 grp
= getgrnam(name
);
1436 static volatile int warn_once
;
1439 WARN("No tracing group detected");
1448 * Return a newly allocated option string. This string is to be used as the
1449 * optstring argument of getopt_long(), see GETOPT(3). opt_count is the number
1450 * of elements in the long_options array. Returns NULL if the string's
1454 char *utils_generate_optstring(const struct option
*long_options
,
1458 size_t string_len
= opt_count
, str_pos
= 0;
1462 * Compute the necessary string length. One letter per option, two when an
1463 * argument is necessary, and a trailing NULL.
1465 for (i
= 0; i
< opt_count
; i
++) {
1466 string_len
+= long_options
[i
].has_arg
? 1 : 0;
1469 optstring
= zmalloc(string_len
);
1474 for (i
= 0; i
< opt_count
; i
++) {
1475 if (!long_options
[i
].name
) {
1476 /* Got to the trailing NULL element */
1480 if (long_options
[i
].val
!= '\0') {
1481 optstring
[str_pos
++] = (char) long_options
[i
].val
;
1482 if (long_options
[i
].has_arg
) {
1483 optstring
[str_pos
++] = ':';
1493 * Try to remove a hierarchy of empty directories, recursively. Don't unlink
1494 * any file. Try to rmdir any empty directory within the hierarchy.
1497 int utils_recursive_rmdir(const char *path
)
1501 int dir_fd
, ret
= 0, closeret
, is_empty
= 1;
1502 struct dirent
*entry
;
1504 /* Open directory */
1505 dir
= opendir(path
);
1507 PERROR("Cannot open '%s' path", path
);
1510 dir_fd
= lttng_dirfd(dir
);
1512 PERROR("lttng_dirfd");
1516 path_len
= strlen(path
);
1517 while ((entry
= readdir(dir
))) {
1520 char filename
[PATH_MAX
];
1522 if (!strcmp(entry
->d_name
, ".")
1523 || !strcmp(entry
->d_name
, "..")) {
1527 name_len
= strlen(entry
->d_name
);
1528 if (path_len
+ name_len
+ 2 > sizeof(filename
)) {
1529 ERR("Failed to remove file: path name too long (%s/%s)",
1530 path
, entry
->d_name
);
1533 if (snprintf(filename
, sizeof(filename
), "%s/%s",
1534 path
, entry
->d_name
) < 0) {
1535 ERR("Failed to format path.");
1539 if (stat(filename
, &st
)) {
1544 if (S_ISDIR(st
.st_mode
)) {
1545 char subpath
[PATH_MAX
];
1547 strncpy(subpath
, path
, PATH_MAX
);
1548 subpath
[PATH_MAX
- 1] = '\0';
1549 strncat(subpath
, "/",
1550 PATH_MAX
- strlen(subpath
) - 1);
1551 strncat(subpath
, entry
->d_name
,
1552 PATH_MAX
- strlen(subpath
) - 1);
1553 if (utils_recursive_rmdir(subpath
)) {
1556 } else if (S_ISREG(st
.st_mode
)) {
1564 closeret
= closedir(dir
);
1569 DBG3("Attempting rmdir %s", path
);
1576 int utils_truncate_stream_file(int fd
, off_t length
)
1581 ret
= ftruncate(fd
, length
);
1583 PERROR("ftruncate");
1586 lseek_ret
= lseek(fd
, length
, SEEK_SET
);
1587 if (lseek_ret
< 0) {
1596 static const char *get_man_bin_path(void)
1598 char *env_man_path
= lttng_secure_getenv(DEFAULT_MAN_BIN_PATH_ENV
);
1601 return env_man_path
;
1604 return DEFAULT_MAN_BIN_PATH
;
1608 int utils_show_help(int section
, const char *page_name
,
1609 const char *help_msg
)
1611 char section_string
[8];
1612 const char *man_bin_path
= get_man_bin_path();
1616 printf("%s", help_msg
);
1620 /* Section integer -> section string */
1621 ret
= sprintf(section_string
, "%d", section
);
1622 assert(ret
> 0 && ret
< 8);
1625 * Execute man pager.
1627 * We provide -M to man here because LTTng-tools can
1628 * be installed outside /usr, in which case its man pages are
1629 * not located in the default /usr/share/man directory.
1631 ret
= execlp(man_bin_path
, "man", "-M", MANPATH
,
1632 section_string
, page_name
, NULL
);