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.
29 #include <sys/types.h>
36 #include <common/common.h>
37 #include <common/runas.h>
43 * Return a partial realpath(3) of the path even if the full path does not
44 * exist. For instance, with /tmp/test1/test2/test3, if test2/ does not exist
45 * but the /tmp/test1 does, the real path for /tmp/test1 is concatened with
46 * /test2/test3 then returned. In normal time, realpath(3) fails if the end
47 * point directory does not exist.
48 * In case resolved_path is NULL, the string returned was allocated in the
49 * function and thus need to be freed by the caller. The size argument allows
50 * to specify the size of the resolved_path argument if given, or the size to
54 char *utils_partial_realpath(const char *path
, char *resolved_path
, size_t size
)
56 char *cut_path
, *try_path
= NULL
, *try_path_prev
= NULL
;
57 const char *next
, *prev
, *end
;
65 * Identify the end of the path, we don't want to treat the
66 * last char if it is a '/', we will just keep it on the side
67 * to be added at the end, and return a value coherent with
68 * the path given as argument
70 end
= path
+ strlen(path
);
71 if (*(end
-1) == '/') {
75 /* Initiate the values of the pointers before looping */
78 /* Only to ensure try_path is not NULL to enter the while */
79 try_path
= (char *)next
;
81 /* Resolve the canonical path of the first part of the path */
82 while (try_path
!= NULL
&& next
!= end
) {
84 * If there is not any '/' left, we want to try with
87 next
= strpbrk(next
+ 1, "/");
92 /* Cut the part we will be trying to resolve */
93 cut_path
= strndup(path
, next
- path
);
94 if (cut_path
== NULL
) {
99 /* Try to resolve this part */
100 try_path
= realpath((char *)cut_path
, NULL
);
101 if (try_path
== NULL
) {
103 * There was an error, we just want to be assured it
104 * is linked to an unexistent directory, if it's another
105 * reason, we spawn an error
109 /* Ignore the error */
112 PERROR("realpath (partial_realpath)");
117 /* Save the place we are before trying the next step */
119 try_path_prev
= try_path
;
123 /* Free the allocated memory */
127 /* Allocate memory for the resolved path if necessary */
128 if (resolved_path
== NULL
) {
129 resolved_path
= zmalloc(size
);
130 if (resolved_path
== NULL
) {
131 PERROR("zmalloc resolved path");
137 * If we were able to solve at least partially the path, we can concatenate
138 * what worked and what didn't work
140 if (try_path_prev
!= NULL
) {
141 /* If we risk to concatenate two '/', we remove one of them */
142 if (try_path_prev
[strlen(try_path_prev
) - 1] == '/' && prev
[0] == '/') {
143 try_path_prev
[strlen(try_path_prev
) - 1] = '\0';
147 * Duplicate the memory used by prev in case resolved_path and
148 * path are pointers for the same memory space
150 cut_path
= strdup(prev
);
151 if (cut_path
== NULL
) {
156 /* Concatenate the strings */
157 snprintf(resolved_path
, size
, "%s%s", try_path_prev
, cut_path
);
159 /* Free the allocated memory */
163 * Else, we just copy the path in our resolved_path to
167 strncpy(resolved_path
, path
, size
);
170 /* Then we return the 'partially' resolved path */
171 return resolved_path
;
179 * Make a full resolution of the given path even if it doesn't exist.
180 * This function uses the utils_partial_realpath function to resolve
181 * symlinks and relatives paths at the start of the string, and
182 * implements functionnalities to resolve the './' and '../' strings
183 * in the middle of a path. This function is only necessary because
184 * realpath(3) does not accept to resolve unexistent paths.
185 * The returned string was allocated in the function, it is thus of
186 * the responsibility of the caller to free this memory.
189 char *utils_expand_path(const char *path
)
191 char *next
, *previous
, *slash
, *start_path
, *absolute_path
= NULL
;
193 int is_dot
, is_dotdot
;
200 /* Allocate memory for the absolute_path */
201 absolute_path
= zmalloc(PATH_MAX
);
202 if (absolute_path
== NULL
) {
203 PERROR("zmalloc expand path");
208 * If the path is not already absolute nor explicitly relative,
209 * consider we're in the current directory
211 if (*path
!= '/' && strncmp(path
, "./", 2) != 0 &&
212 strncmp(path
, "../", 3) != 0) {
213 snprintf(absolute_path
, PATH_MAX
, "./%s", path
);
214 /* Else, we just copy the path */
216 strncpy(absolute_path
, path
, PATH_MAX
);
219 /* Resolve partially our path */
220 absolute_path
= utils_partial_realpath(absolute_path
,
221 absolute_path
, PATH_MAX
);
223 /* As long as we find '/./' in the working_path string */
224 while ((next
= strstr(absolute_path
, "/./"))) {
226 /* We prepare the start_path not containing it */
227 start_path
= strndup(absolute_path
, next
- absolute_path
);
232 /* And we concatenate it with the part after this string */
233 snprintf(absolute_path
, PATH_MAX
, "%s%s", start_path
, next
+ 2);
238 /* As long as we find '/../' in the working_path string */
239 while ((next
= strstr(absolute_path
, "/../"))) {
240 /* We find the last level of directory */
241 previous
= absolute_path
;
242 while ((slash
= strpbrk(previous
, "/")) && slash
!= next
) {
243 previous
= slash
+ 1;
246 /* Then we prepare the start_path not containing it */
247 start_path
= strndup(absolute_path
, previous
- absolute_path
);
253 /* And we concatenate it with the part after the '/../' */
254 snprintf(absolute_path
, PATH_MAX
, "%s%s", start_path
, next
+ 4);
256 /* We can free the memory used for the start path*/
259 /* Then we verify for symlinks using partial_realpath */
260 absolute_path
= utils_partial_realpath(absolute_path
,
261 absolute_path
, PATH_MAX
);
264 /* Identify the last token */
265 last_token
= strrchr(absolute_path
, '/');
267 /* Verify that this token is not a relative path */
268 is_dotdot
= (strcmp(last_token
, "/..") == 0);
269 is_dot
= (strcmp(last_token
, "/.") == 0);
271 /* If it is, take action */
272 if (is_dot
|| is_dotdot
) {
273 /* For both, remove this token */
276 /* If it was a reference to parent directory, go back one more time */
278 last_token
= strrchr(absolute_path
, '/');
280 /* If there was only one level left, we keep the first '/' */
281 if (last_token
== absolute_path
) {
289 return absolute_path
;
297 * Create a pipe in dst.
300 int utils_create_pipe(int *dst
)
310 PERROR("create pipe");
317 * Create pipe and set CLOEXEC flag to both fd.
319 * Make sure the pipe opened by this function are closed at some point. Use
320 * utils_close_pipe().
323 int utils_create_pipe_cloexec(int *dst
)
331 ret
= utils_create_pipe(dst
);
336 for (i
= 0; i
< 2; i
++) {
337 ret
= fcntl(dst
[i
], F_SETFD
, FD_CLOEXEC
);
339 PERROR("fcntl pipe cloexec");
349 * Create pipe and set fd flags to FD_CLOEXEC and O_NONBLOCK.
351 * Make sure the pipe opened by this function are closed at some point. Use
352 * utils_close_pipe(). Using pipe() and fcntl rather than pipe2() to
353 * support OSes other than Linux 2.6.23+.
356 int utils_create_pipe_cloexec_nonblock(int *dst
)
364 ret
= utils_create_pipe(dst
);
369 for (i
= 0; i
< 2; i
++) {
370 ret
= fcntl(dst
[i
], F_SETFD
, FD_CLOEXEC
);
372 PERROR("fcntl pipe cloexec");
376 * Note: we override any flag that could have been
377 * previously set on the fd.
379 ret
= fcntl(dst
[i
], F_SETFL
, O_NONBLOCK
);
381 PERROR("fcntl pipe nonblock");
391 * Close both read and write side of the pipe.
394 void utils_close_pipe(int *src
)
402 for (i
= 0; i
< 2; i
++) {
410 PERROR("close pipe");
416 * Create a new string using two strings range.
419 char *utils_strdupdelim(const char *begin
, const char *end
)
423 str
= zmalloc(end
- begin
+ 1);
425 PERROR("zmalloc strdupdelim");
429 memcpy(str
, begin
, end
- begin
);
430 str
[end
- begin
] = '\0';
437 * Set CLOEXEC flag to the give file descriptor.
440 int utils_set_fd_cloexec(int fd
)
449 ret
= fcntl(fd
, F_SETFD
, FD_CLOEXEC
);
451 PERROR("fcntl cloexec");
460 * Create pid file to the given path and filename.
463 int utils_create_pid_file(pid_t pid
, const char *filepath
)
470 fp
= fopen(filepath
, "w");
472 PERROR("open pid file %s", filepath
);
477 ret
= fprintf(fp
, "%d\n", pid
);
479 PERROR("fprintf pid file");
483 DBG("Pid %d written in file %s", pid
, filepath
);
489 * Create lock file to the given path and filename.
490 * Returns the associated file descriptor, -1 on error.
493 int utils_create_lock_file(const char *filepath
)
500 fd
= open(filepath
, O_CREAT
,
501 O_WRONLY
| S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
);
503 PERROR("open lock file %s", filepath
);
509 * Attempt to lock the file. If this fails, there is
510 * already a process using the same lock file running
511 * and we should exit.
513 ret
= flock(fd
, LOCK_EX
| LOCK_NB
);
515 WARN("Could not get lock file %s, another instance is running.",
518 PERROR("close lock file");
529 * Recursively create directory using the given path and mode.
531 * On success, return 0 else a negative error code.
534 int utils_mkdir_recursive(const char *path
, mode_t mode
)
536 char *p
, tmp
[PATH_MAX
];
542 ret
= snprintf(tmp
, sizeof(tmp
), "%s", path
);
544 PERROR("snprintf mkdir");
549 if (tmp
[len
- 1] == '/') {
553 for (p
= tmp
+ 1; *p
; p
++) {
556 if (tmp
[strlen(tmp
) - 1] == '.' &&
557 tmp
[strlen(tmp
) - 2] == '.' &&
558 tmp
[strlen(tmp
) - 3] == '/') {
559 ERR("Using '/../' is not permitted in the trace path (%s)",
564 ret
= mkdir(tmp
, mode
);
566 if (errno
!= EEXIST
) {
567 PERROR("mkdir recursive");
576 ret
= mkdir(tmp
, mode
);
578 if (errno
!= EEXIST
) {
579 PERROR("mkdir recursive last piece");
591 * Create the stream tracefile on disk.
593 * Return 0 on success or else a negative value.
596 int utils_create_stream_file(const char *path_name
, char *file_name
, uint64_t size
,
597 uint64_t count
, int uid
, int gid
, char *suffix
)
599 int ret
, out_fd
, flags
, mode
;
600 char full_path
[PATH_MAX
], *path_name_suffix
= NULL
, *path
;
606 ret
= snprintf(full_path
, sizeof(full_path
), "%s/%s",
607 path_name
, file_name
);
609 PERROR("snprintf create output file");
613 /* Setup extra string if suffix or/and a count is needed. */
614 if (size
> 0 && suffix
) {
615 ret
= asprintf(&extra
, "_%" PRIu64
"%s", count
, suffix
);
616 } else if (size
> 0) {
617 ret
= asprintf(&extra
, "_%" PRIu64
, count
);
619 ret
= asprintf(&extra
, "%s", suffix
);
622 PERROR("Allocating extra string to name");
627 * If we split the trace in multiple files, we have to add the count at the
628 * end of the tracefile name
631 ret
= asprintf(&path_name_suffix
, "%s%s", full_path
, extra
);
633 PERROR("Allocating path name with extra string");
634 goto error_free_suffix
;
636 path
= path_name_suffix
;
641 flags
= O_WRONLY
| O_CREAT
| O_TRUNC
;
642 /* Open with 660 mode */
643 mode
= S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
;
645 if (uid
< 0 || gid
< 0) {
646 out_fd
= open(path
, flags
, mode
);
648 out_fd
= run_as_open(path
, flags
, mode
, uid
, gid
);
651 PERROR("open stream path %s", path
);
657 free(path_name_suffix
);
665 * Change the output tracefile according to the given size and count The
666 * new_count pointer is set during this operation.
668 * From the consumer, the stream lock MUST be held before calling this function
669 * because we are modifying the stream status.
671 * Return 0 on success or else a negative value.
674 int utils_rotate_stream_file(char *path_name
, char *file_name
, uint64_t size
,
675 uint64_t count
, int uid
, int gid
, int out_fd
, uint64_t *new_count
,
685 PERROR("Closing tracefile");
690 *new_count
= (*new_count
+ 1) % count
;
695 ret
= utils_create_stream_file(path_name
, file_name
, size
, *new_count
,
711 * Parse a string that represents a size in human readable format. It
712 * supports decimal integers suffixed by 'k', 'K', 'M' or 'G'.
714 * The suffix multiply the integer by:
719 * @param str The string to parse.
720 * @param size Pointer to a uint64_t that will be filled with the
723 * @return 0 on success, -1 on failure.
726 int utils_parse_size_suffix(const char * const str
, uint64_t * const size
)
735 DBG("utils_parse_size_suffix: received a NULL string.");
740 /* strtoull will accept a negative number, but we don't want to. */
741 if (strchr(str
, '-') != NULL
) {
742 DBG("utils_parse_size_suffix: invalid size string, should not contain '-'.");
747 /* str_end will point to the \0 */
748 str_end
= str
+ strlen(str
);
750 base_size
= strtoull(str
, &num_end
, 0);
752 PERROR("utils_parse_size_suffix strtoull");
757 if (num_end
== str
) {
758 /* strtoull parsed nothing, not good. */
759 DBG("utils_parse_size_suffix: strtoull had nothing good to parse.");
764 /* Check if a prefix is present. */
782 DBG("utils_parse_size_suffix: invalid suffix.");
787 /* Check for garbage after the valid input. */
788 if (num_end
!= str_end
) {
789 DBG("utils_parse_size_suffix: Garbage after size string.");
794 *size
= base_size
<< shift
;
796 /* Check for overflow */
797 if ((*size
>> shift
) != base_size
) {
798 DBG("utils_parse_size_suffix: oops, overflow detected.");
809 * fls: returns the position of the most significant bit.
810 * Returns 0 if no bit is set, else returns the position of the most
811 * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit).
813 #if defined(__i386) || defined(__x86_64)
814 static inline unsigned int fls_u32(uint32_t x
)
822 : "=r" (r
) : "rm" (x
));
829 static __attribute__((unused
)) unsigned int fls_u32(uint32_t x
)
836 if (!(x
& 0xFFFF0000U
)) {
840 if (!(x
& 0xFF000000U
)) {
844 if (!(x
& 0xF0000000U
)) {
848 if (!(x
& 0xC0000000U
)) {
852 if (!(x
& 0x80000000U
)) {
861 * Return the minimum order for which x <= (1UL << order).
862 * Return -1 if x is 0.
865 int utils_get_count_order_u32(uint32_t x
)
871 return fls_u32(x
- 1);
875 * Obtain the value of LTTNG_HOME environment variable, if exists.
876 * Otherwise returns the value of HOME.
879 char *utils_get_home_dir(void)
884 val
= getenv(DEFAULT_LTTNG_HOME_ENV_VAR
);
888 val
= getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR
);
893 /* Fallback on the password file entry. */
894 pwd
= getpwuid(getuid());
900 DBG3("Home directory is '%s'", val
);
907 * Get user's home directory. Dynamically allocated, must be freed
911 char *utils_get_user_home_dir(uid_t uid
)
914 struct passwd
*result
;
915 char *home_dir
= NULL
;
920 buflen
= sysconf(_SC_GETPW_R_SIZE_MAX
);
925 buf
= zmalloc(buflen
);
930 ret
= getpwuid_r(uid
, &pwd
, buf
, buflen
, &result
);
931 if (ret
|| !result
) {
940 home_dir
= strdup(pwd
.pw_dir
);
947 * Obtain the value of LTTNG_KMOD_PROBES environment variable, if exists.
948 * Otherwise returns NULL.
951 char *utils_get_kmod_probes_list(void)
953 return getenv(DEFAULT_LTTNG_KMOD_PROBES
);
957 * Obtain the value of LTTNG_EXTRA_KMOD_PROBES environment variable, if
958 * exists. Otherwise returns NULL.
961 char *utils_get_extra_kmod_probes_list(void)
963 return getenv(DEFAULT_LTTNG_EXTRA_KMOD_PROBES
);
967 * With the given format, fill dst with the time of len maximum siz.
969 * Return amount of bytes set in the buffer or else 0 on error.
972 size_t utils_get_current_time_str(const char *format
, char *dst
, size_t len
)
981 /* Get date and time for session path */
983 timeinfo
= localtime(&rawtime
);
984 ret
= strftime(dst
, len
, format
, timeinfo
);
986 ERR("Unable to strftime with format %s at dst %p of len %zu", format
,
994 * Return the group ID matching name, else 0 if it cannot be found.
997 gid_t
utils_get_group_id(const char *name
)
1001 grp
= getgrnam(name
);
1003 static volatile int warn_once
;
1006 WARN("No tracing group detected");
1015 * Return a newly allocated option string. This string is to be used as the
1016 * optstring argument of getopt_long(), see GETOPT(3). opt_count is the number
1017 * of elements in the long_options array. Returns NULL if the string's
1021 char *utils_generate_optstring(const struct option
*long_options
,
1025 size_t string_len
= opt_count
, str_pos
= 0;
1029 * Compute the necessary string length. One letter per option, two when an
1030 * argument is necessary, and a trailing NULL.
1032 for (i
= 0; i
< opt_count
; i
++) {
1033 string_len
+= long_options
[i
].has_arg
? 1 : 0;
1036 optstring
= zmalloc(string_len
);
1041 for (i
= 0; i
< opt_count
; i
++) {
1042 if (!long_options
[i
].name
) {
1043 /* Got to the trailing NULL element */
1047 optstring
[str_pos
++] = (char)long_options
[i
].val
;
1048 if (long_options
[i
].has_arg
) {
1049 optstring
[str_pos
++] = ':';