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>
37 #include <common/common.h>
38 #include <common/runas.h>
39 #include <common/compat/getenv.h>
45 * Return a partial realpath(3) of the path even if the full path does not
46 * exist. For instance, with /tmp/test1/test2/test3, if test2/ does not exist
47 * but the /tmp/test1 does, the real path for /tmp/test1 is concatened with
48 * /test2/test3 then returned. In normal time, realpath(3) fails if the end
49 * point directory does not exist.
50 * In case resolved_path is NULL, the string returned was allocated in the
51 * function and thus need to be freed by the caller. The size argument allows
52 * to specify the size of the resolved_path argument if given, or the size to
56 char *utils_partial_realpath(const char *path
, char *resolved_path
, size_t size
)
58 char *cut_path
= NULL
, *try_path
= NULL
, *try_path_prev
= NULL
;
59 const char *next
, *prev
, *end
;
67 * Identify the end of the path, we don't want to treat the
68 * last char if it is a '/', we will just keep it on the side
69 * to be added at the end, and return a value coherent with
70 * the path given as argument
72 end
= path
+ strlen(path
);
73 if (*(end
-1) == '/') {
77 /* Initiate the values of the pointers before looping */
80 /* Only to ensure try_path is not NULL to enter the while */
81 try_path
= (char *)next
;
83 /* Resolve the canonical path of the first part of the path */
84 while (try_path
!= NULL
&& next
!= end
) {
86 * If there is not any '/' left, we want to try with
89 next
= strpbrk(next
+ 1, "/");
94 /* Cut the part we will be trying to resolve */
95 cut_path
= strndup(path
, next
- path
);
96 if (cut_path
== NULL
) {
101 /* Try to resolve this part */
102 try_path
= realpath((char *)cut_path
, NULL
);
103 if (try_path
== NULL
) {
105 * There was an error, we just want to be assured it
106 * is linked to an unexistent directory, if it's another
107 * reason, we spawn an error
111 /* Ignore the error */
114 PERROR("realpath (partial_realpath)");
119 /* Save the place we are before trying the next step */
121 try_path_prev
= try_path
;
125 /* Free the allocated memory */
130 /* Allocate memory for the resolved path if necessary */
131 if (resolved_path
== NULL
) {
132 resolved_path
= zmalloc(size
);
133 if (resolved_path
== NULL
) {
134 PERROR("zmalloc resolved path");
140 * If we were able to solve at least partially the path, we can concatenate
141 * what worked and what didn't work
143 if (try_path_prev
!= NULL
) {
144 /* If we risk to concatenate two '/', we remove one of them */
145 if (try_path_prev
[strlen(try_path_prev
) - 1] == '/' && prev
[0] == '/') {
146 try_path_prev
[strlen(try_path_prev
) - 1] = '\0';
150 * Duplicate the memory used by prev in case resolved_path and
151 * path are pointers for the same memory space
153 cut_path
= strdup(prev
);
154 if (cut_path
== NULL
) {
159 /* Concatenate the strings */
160 snprintf(resolved_path
, size
, "%s%s", try_path_prev
, cut_path
);
162 /* Free the allocated memory */
166 try_path_prev
= NULL
;
168 * Else, we just copy the path in our resolved_path to
172 strncpy(resolved_path
, path
, size
);
175 /* Then we return the 'partially' resolved path */
176 return resolved_path
;
185 * Make a full resolution of the given path even if it doesn't exist.
186 * This function uses the utils_partial_realpath function to resolve
187 * symlinks and relatives paths at the start of the string, and
188 * implements functionnalities to resolve the './' and '../' strings
189 * in the middle of a path. This function is only necessary because
190 * realpath(3) does not accept to resolve unexistent paths.
191 * The returned string was allocated in the function, it is thus of
192 * the responsibility of the caller to free this memory.
195 char *utils_expand_path(const char *path
)
197 char *next
, *previous
, *slash
, *start_path
, *absolute_path
= NULL
;
199 int is_dot
, is_dotdot
;
206 /* Allocate memory for the absolute_path */
207 absolute_path
= zmalloc(PATH_MAX
);
208 if (absolute_path
== NULL
) {
209 PERROR("zmalloc expand path");
214 * If the path is not already absolute nor explicitly relative,
215 * consider we're in the current directory
217 if (*path
!= '/' && strncmp(path
, "./", 2) != 0 &&
218 strncmp(path
, "../", 3) != 0) {
219 snprintf(absolute_path
, PATH_MAX
, "./%s", path
);
220 /* Else, we just copy the path */
222 strncpy(absolute_path
, path
, PATH_MAX
);
225 /* Resolve partially our path */
226 absolute_path
= utils_partial_realpath(absolute_path
,
227 absolute_path
, PATH_MAX
);
229 /* As long as we find '/./' in the working_path string */
230 while ((next
= strstr(absolute_path
, "/./"))) {
232 /* We prepare the start_path not containing it */
233 start_path
= strndup(absolute_path
, next
- absolute_path
);
238 /* And we concatenate it with the part after this string */
239 snprintf(absolute_path
, PATH_MAX
, "%s%s", start_path
, next
+ 2);
244 /* As long as we find '/../' in the working_path string */
245 while ((next
= strstr(absolute_path
, "/../"))) {
246 /* We find the last level of directory */
247 previous
= absolute_path
;
248 while ((slash
= strpbrk(previous
, "/")) && slash
!= next
) {
249 previous
= slash
+ 1;
252 /* Then we prepare the start_path not containing it */
253 start_path
= strndup(absolute_path
, previous
- absolute_path
);
259 /* And we concatenate it with the part after the '/../' */
260 snprintf(absolute_path
, PATH_MAX
, "%s%s", start_path
, next
+ 4);
262 /* We can free the memory used for the start path*/
265 /* Then we verify for symlinks using partial_realpath */
266 absolute_path
= utils_partial_realpath(absolute_path
,
267 absolute_path
, PATH_MAX
);
270 /* Identify the last token */
271 last_token
= strrchr(absolute_path
, '/');
273 /* Verify that this token is not a relative path */
274 is_dotdot
= (strcmp(last_token
, "/..") == 0);
275 is_dot
= (strcmp(last_token
, "/.") == 0);
277 /* If it is, take action */
278 if (is_dot
|| is_dotdot
) {
279 /* For both, remove this token */
282 /* If it was a reference to parent directory, go back one more time */
284 last_token
= strrchr(absolute_path
, '/');
286 /* If there was only one level left, we keep the first '/' */
287 if (last_token
== absolute_path
) {
295 return absolute_path
;
303 * Create a pipe in dst.
306 int utils_create_pipe(int *dst
)
316 PERROR("create pipe");
323 * Create pipe and set CLOEXEC flag to both fd.
325 * Make sure the pipe opened by this function are closed at some point. Use
326 * utils_close_pipe().
329 int utils_create_pipe_cloexec(int *dst
)
337 ret
= utils_create_pipe(dst
);
342 for (i
= 0; i
< 2; i
++) {
343 ret
= fcntl(dst
[i
], F_SETFD
, FD_CLOEXEC
);
345 PERROR("fcntl pipe cloexec");
355 * Create pipe and set fd flags to FD_CLOEXEC and O_NONBLOCK.
357 * Make sure the pipe opened by this function are closed at some point. Use
358 * utils_close_pipe(). Using pipe() and fcntl rather than pipe2() to
359 * support OSes other than Linux 2.6.23+.
362 int utils_create_pipe_cloexec_nonblock(int *dst
)
370 ret
= utils_create_pipe(dst
);
375 for (i
= 0; i
< 2; i
++) {
376 ret
= fcntl(dst
[i
], F_SETFD
, FD_CLOEXEC
);
378 PERROR("fcntl pipe cloexec");
382 * Note: we override any flag that could have been
383 * previously set on the fd.
385 ret
= fcntl(dst
[i
], F_SETFL
, O_NONBLOCK
);
387 PERROR("fcntl pipe nonblock");
397 * Close both read and write side of the pipe.
400 void utils_close_pipe(int *src
)
408 for (i
= 0; i
< 2; i
++) {
416 PERROR("close pipe");
422 * Create a new string using two strings range.
425 char *utils_strdupdelim(const char *begin
, const char *end
)
429 str
= zmalloc(end
- begin
+ 1);
431 PERROR("zmalloc strdupdelim");
435 memcpy(str
, begin
, end
- begin
);
436 str
[end
- begin
] = '\0';
443 * Set CLOEXEC flag to the give file descriptor.
446 int utils_set_fd_cloexec(int fd
)
455 ret
= fcntl(fd
, F_SETFD
, FD_CLOEXEC
);
457 PERROR("fcntl cloexec");
466 * Create pid file to the given path and filename.
469 int utils_create_pid_file(pid_t pid
, const char *filepath
)
476 fp
= fopen(filepath
, "w");
478 PERROR("open pid file %s", filepath
);
483 ret
= fprintf(fp
, "%d\n", pid
);
485 PERROR("fprintf pid file");
492 DBG("Pid %d written in file %s", pid
, filepath
);
499 * Create lock file to the given path and filename.
500 * Returns the associated file descriptor, -1 on error.
503 int utils_create_lock_file(const char *filepath
)
510 fd
= open(filepath
, O_CREAT
,
511 O_WRONLY
| S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
);
513 PERROR("open lock file %s", filepath
);
519 * Attempt to lock the file. If this fails, there is
520 * already a process using the same lock file running
521 * and we should exit.
523 ret
= flock(fd
, LOCK_EX
| LOCK_NB
);
525 ERR("Could not get lock file %s, another instance is running.",
528 PERROR("close lock file");
539 * Create directory using the given path and mode.
541 * On success, return 0 else a negative error code.
544 int utils_mkdir(const char *path
, mode_t mode
, int uid
, int gid
)
548 if (uid
< 0 || gid
< 0) {
549 ret
= mkdir(path
, mode
);
551 ret
= run_as_mkdir(path
, mode
, uid
, gid
);
554 if (errno
!= EEXIST
) {
555 PERROR("mkdir %s, uid %d, gid %d", path
? path
: "NULL",
566 * Internal version of mkdir_recursive. Runs as the current user.
567 * Don't call directly; use utils_mkdir_recursive().
569 * This function is ominously marked as "unsafe" since it should only
570 * be called by a caller that has transitioned to the uid and gid under which
571 * the directory creation should occur.
574 int _utils_mkdir_recursive_unsafe(const char *path
, mode_t mode
)
576 char *p
, tmp
[PATH_MAX
];
582 ret
= snprintf(tmp
, sizeof(tmp
), "%s", path
);
584 PERROR("snprintf mkdir");
589 if (tmp
[len
- 1] == '/') {
593 for (p
= tmp
+ 1; *p
; p
++) {
596 if (tmp
[strlen(tmp
) - 1] == '.' &&
597 tmp
[strlen(tmp
) - 2] == '.' &&
598 tmp
[strlen(tmp
) - 3] == '/') {
599 ERR("Using '/../' is not permitted in the trace path (%s)",
604 ret
= mkdir(tmp
, mode
);
606 if (errno
!= EEXIST
) {
607 PERROR("mkdir recursive");
616 ret
= mkdir(tmp
, mode
);
618 if (errno
!= EEXIST
) {
619 PERROR("mkdir recursive last element");
631 * Recursively create directory using the given path and mode, under the
632 * provided uid and gid.
634 * On success, return 0 else a negative error code.
637 int utils_mkdir_recursive(const char *path
, mode_t mode
, int uid
, int gid
)
641 if (uid
< 0 || gid
< 0) {
642 /* Run as current user. */
643 ret
= _utils_mkdir_recursive_unsafe(path
, mode
);
645 ret
= run_as_mkdir_recursive(path
, mode
, uid
, gid
);
648 PERROR("mkdir %s, uid %d, gid %d", path
? path
: "NULL",
656 * path is the output parameter. It needs to be PATH_MAX len.
658 * Return 0 on success or else a negative value.
660 static int utils_stream_file_name(char *path
,
661 const char *path_name
, const char *file_name
,
662 uint64_t size
, uint64_t count
,
666 char full_path
[PATH_MAX
];
667 char *path_name_suffix
= NULL
;
670 ret
= snprintf(full_path
, sizeof(full_path
), "%s/%s",
671 path_name
, file_name
);
673 PERROR("snprintf create output file");
677 /* Setup extra string if suffix or/and a count is needed. */
678 if (size
> 0 && suffix
) {
679 ret
= asprintf(&extra
, "_%" PRIu64
"%s", count
, suffix
);
680 } else if (size
> 0) {
681 ret
= asprintf(&extra
, "_%" PRIu64
, count
);
683 ret
= asprintf(&extra
, "%s", suffix
);
686 PERROR("Allocating extra string to name");
691 * If we split the trace in multiple files, we have to add the count at
692 * the end of the tracefile name.
695 ret
= asprintf(&path_name_suffix
, "%s%s", full_path
, extra
);
697 PERROR("Allocating path name with extra string");
698 goto error_free_suffix
;
700 strncpy(path
, path_name_suffix
, PATH_MAX
- 1);
701 path
[PATH_MAX
- 1] = '\0';
703 strncpy(path
, full_path
, PATH_MAX
- 1);
705 path
[PATH_MAX
- 1] = '\0';
708 free(path_name_suffix
);
716 * Create the stream file on disk.
718 * Return 0 on success or else a negative value.
721 int utils_create_stream_file(const char *path_name
, char *file_name
, uint64_t size
,
722 uint64_t count
, int uid
, int gid
, char *suffix
)
724 int ret
, flags
, mode
;
727 ret
= utils_stream_file_name(path
, path_name
, file_name
,
728 size
, count
, suffix
);
733 flags
= O_WRONLY
| O_CREAT
| O_TRUNC
;
734 /* Open with 660 mode */
735 mode
= S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
;
737 if (uid
< 0 || gid
< 0) {
738 ret
= open(path
, flags
, mode
);
740 ret
= run_as_open(path
, flags
, mode
, uid
, gid
);
743 PERROR("open stream path %s", path
);
750 * Unlink the stream tracefile from disk.
752 * Return 0 on success or else a negative value.
755 int utils_unlink_stream_file(const char *path_name
, char *file_name
, uint64_t size
,
756 uint64_t count
, int uid
, int gid
, char *suffix
)
761 ret
= utils_stream_file_name(path
, path_name
, file_name
,
762 size
, count
, suffix
);
766 if (uid
< 0 || gid
< 0) {
769 ret
= run_as_unlink(path
, uid
, gid
);
775 DBG("utils_unlink_stream_file %s returns %d", path
, ret
);
780 * Change the output tracefile according to the given size and count The
781 * new_count pointer is set during this operation.
783 * From the consumer, the stream lock MUST be held before calling this function
784 * because we are modifying the stream status.
786 * Return 0 on success or else a negative value.
789 int utils_rotate_stream_file(char *path_name
, char *file_name
, uint64_t size
,
790 uint64_t count
, int uid
, int gid
, int out_fd
, uint64_t *new_count
,
800 PERROR("Closing tracefile");
806 * In tracefile rotation, for the relay daemon we need
807 * to unlink the old file if present, because it may
808 * still be open in reading by the live thread, and we
809 * need to ensure that we do not overwrite the content
810 * between get_index and get_packet. Since we have no
811 * way to verify integrity of the data content compared
812 * to the associated index, we need to ensure the reader
813 * has exclusive access to the file content, and that
814 * the open of the data file is performed in get_index.
815 * Unlinking the old file rather than overwriting it
818 *new_count
= (*new_count
+ 1) % count
;
819 ret
= utils_unlink_stream_file(path_name
, file_name
,
820 size
, *new_count
, uid
, gid
, 0);
821 if (ret
< 0 && errno
!= ENOENT
) {
828 ret
= utils_create_stream_file(path_name
, file_name
, size
, *new_count
,
844 * Parse a string that represents a size in human readable format. It
845 * supports decimal integers suffixed by 'k', 'K', 'M' or 'G'.
847 * The suffix multiply the integer by:
852 * @param str The string to parse.
853 * @param size Pointer to a uint64_t that will be filled with the
856 * @return 0 on success, -1 on failure.
859 int utils_parse_size_suffix(const char * const str
, uint64_t * const size
)
868 DBG("utils_parse_size_suffix: received a NULL string.");
873 /* strtoull will accept a negative number, but we don't want to. */
874 if (strchr(str
, '-') != NULL
) {
875 DBG("utils_parse_size_suffix: invalid size string, should not contain '-'.");
880 /* str_end will point to the \0 */
881 str_end
= str
+ strlen(str
);
883 base_size
= strtoull(str
, &num_end
, 0);
885 PERROR("utils_parse_size_suffix strtoull");
890 if (num_end
== str
) {
891 /* strtoull parsed nothing, not good. */
892 DBG("utils_parse_size_suffix: strtoull had nothing good to parse.");
897 /* Check if a prefix is present. */
915 DBG("utils_parse_size_suffix: invalid suffix.");
920 /* Check for garbage after the valid input. */
921 if (num_end
!= str_end
) {
922 DBG("utils_parse_size_suffix: Garbage after size string.");
927 *size
= base_size
<< shift
;
929 /* Check for overflow */
930 if ((*size
>> shift
) != base_size
) {
931 DBG("utils_parse_size_suffix: oops, overflow detected.");
942 * fls: returns the position of the most significant bit.
943 * Returns 0 if no bit is set, else returns the position of the most
944 * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit).
946 #if defined(__i386) || defined(__x86_64)
947 static inline unsigned int fls_u32(uint32_t x
)
955 : "=r" (r
) : "rm" (x
));
962 static __attribute__((unused
)) unsigned int fls_u32(uint32_t x
)
969 if (!(x
& 0xFFFF0000U
)) {
973 if (!(x
& 0xFF000000U
)) {
977 if (!(x
& 0xF0000000U
)) {
981 if (!(x
& 0xC0000000U
)) {
985 if (!(x
& 0x80000000U
)) {
994 * Return the minimum order for which x <= (1UL << order).
995 * Return -1 if x is 0.
998 int utils_get_count_order_u32(uint32_t x
)
1004 return fls_u32(x
- 1);
1008 * Obtain the value of LTTNG_HOME environment variable, if exists.
1009 * Otherwise returns the value of HOME.
1012 char *utils_get_home_dir(void)
1017 val
= lttng_secure_getenv(DEFAULT_LTTNG_HOME_ENV_VAR
);
1021 val
= lttng_secure_getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR
);
1026 /* Fallback on the password file entry. */
1027 pwd
= getpwuid(getuid());
1033 DBG3("Home directory is '%s'", val
);
1040 * Get user's home directory. Dynamically allocated, must be freed
1044 char *utils_get_user_home_dir(uid_t uid
)
1047 struct passwd
*result
;
1048 char *home_dir
= NULL
;
1053 buflen
= sysconf(_SC_GETPW_R_SIZE_MAX
);
1058 buf
= zmalloc(buflen
);
1063 ret
= getpwuid_r(uid
, &pwd
, buf
, buflen
, &result
);
1064 if (ret
|| !result
) {
1065 if (ret
== ERANGE
) {
1073 home_dir
= strdup(pwd
.pw_dir
);
1080 * Obtain the value of LTTNG_KMOD_PROBES environment variable, if exists.
1081 * Otherwise returns NULL.
1084 char *utils_get_kmod_probes_list(void)
1086 return lttng_secure_getenv(DEFAULT_LTTNG_KMOD_PROBES
);
1090 * Obtain the value of LTTNG_EXTRA_KMOD_PROBES environment variable, if
1091 * exists. Otherwise returns NULL.
1094 char *utils_get_extra_kmod_probes_list(void)
1096 return lttng_secure_getenv(DEFAULT_LTTNG_EXTRA_KMOD_PROBES
);
1100 * With the given format, fill dst with the time of len maximum siz.
1102 * Return amount of bytes set in the buffer or else 0 on error.
1105 size_t utils_get_current_time_str(const char *format
, char *dst
, size_t len
)
1109 struct tm
*timeinfo
;
1114 /* Get date and time for session path */
1116 timeinfo
= localtime(&rawtime
);
1117 ret
= strftime(dst
, len
, format
, timeinfo
);
1119 ERR("Unable to strftime with format %s at dst %p of len %zu", format
,
1127 * Return the group ID matching name, else 0 if it cannot be found.
1130 gid_t
utils_get_group_id(const char *name
)
1134 grp
= getgrnam(name
);
1136 static volatile int warn_once
;
1139 WARN("No tracing group detected");
1148 * Return a newly allocated option string. This string is to be used as the
1149 * optstring argument of getopt_long(), see GETOPT(3). opt_count is the number
1150 * of elements in the long_options array. Returns NULL if the string's
1154 char *utils_generate_optstring(const struct option
*long_options
,
1158 size_t string_len
= opt_count
, str_pos
= 0;
1162 * Compute the necessary string length. One letter per option, two when an
1163 * argument is necessary, and a trailing NULL.
1165 for (i
= 0; i
< opt_count
; i
++) {
1166 string_len
+= long_options
[i
].has_arg
? 1 : 0;
1169 optstring
= zmalloc(string_len
);
1174 for (i
= 0; i
< opt_count
; i
++) {
1175 if (!long_options
[i
].name
) {
1176 /* Got to the trailing NULL element */
1180 if (long_options
[i
].val
!= '\0') {
1181 optstring
[str_pos
++] = (char) long_options
[i
].val
;
1182 if (long_options
[i
].has_arg
) {
1183 optstring
[str_pos
++] = ':';
1193 * Try to remove a hierarchy of empty directories, recursively. Don't unlink
1194 * any file. Try to rmdir any empty directory within the hierarchy.
1197 int utils_recursive_rmdir(const char *path
)
1200 int dir_fd
, ret
= 0, closeret
, is_empty
= 1;
1201 struct dirent
*entry
;
1203 /* Open directory */
1204 dir
= opendir(path
);
1206 PERROR("Cannot open '%s' path", path
);
1209 dir_fd
= dirfd(dir
);
1215 while ((entry
= readdir(dir
))) {
1216 if (!strcmp(entry
->d_name
, ".")
1217 || !strcmp(entry
->d_name
, ".."))
1219 switch (entry
->d_type
) {
1222 char subpath
[PATH_MAX
];
1224 strncpy(subpath
, path
, PATH_MAX
);
1225 subpath
[PATH_MAX
- 1] = '\0';
1226 strncat(subpath
, "/",
1227 PATH_MAX
- strlen(subpath
) - 1);
1228 strncat(subpath
, entry
->d_name
,
1229 PATH_MAX
- strlen(subpath
) - 1);
1230 if (utils_recursive_rmdir(subpath
)) {
1244 closeret
= closedir(dir
);
1249 DBG3("Attempting rmdir %s", path
);