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 * Else, we just copy the path in our resolved_path to
170 strncpy(resolved_path
, path
, size
);
173 /* Then we return the 'partially' resolved path */
174 return resolved_path
;
183 * Make a full resolution of the given path even if it doesn't exist.
184 * This function uses the utils_partial_realpath function to resolve
185 * symlinks and relatives paths at the start of the string, and
186 * implements functionnalities to resolve the './' and '../' strings
187 * in the middle of a path. This function is only necessary because
188 * realpath(3) does not accept to resolve unexistent paths.
189 * The returned string was allocated in the function, it is thus of
190 * the responsibility of the caller to free this memory.
193 char *utils_expand_path(const char *path
)
195 char *next
, *previous
, *slash
, *start_path
, *absolute_path
= NULL
;
197 int is_dot
, is_dotdot
;
204 /* Allocate memory for the absolute_path */
205 absolute_path
= zmalloc(PATH_MAX
);
206 if (absolute_path
== NULL
) {
207 PERROR("zmalloc expand path");
212 * If the path is not already absolute nor explicitly relative,
213 * consider we're in the current directory
215 if (*path
!= '/' && strncmp(path
, "./", 2) != 0 &&
216 strncmp(path
, "../", 3) != 0) {
217 snprintf(absolute_path
, PATH_MAX
, "./%s", path
);
218 /* Else, we just copy the path */
220 strncpy(absolute_path
, path
, PATH_MAX
);
223 /* Resolve partially our path */
224 absolute_path
= utils_partial_realpath(absolute_path
,
225 absolute_path
, PATH_MAX
);
227 /* As long as we find '/./' in the working_path string */
228 while ((next
= strstr(absolute_path
, "/./"))) {
230 /* We prepare the start_path not containing it */
231 start_path
= strndup(absolute_path
, next
- absolute_path
);
236 /* And we concatenate it with the part after this string */
237 snprintf(absolute_path
, PATH_MAX
, "%s%s", start_path
, next
+ 2);
242 /* As long as we find '/../' in the working_path string */
243 while ((next
= strstr(absolute_path
, "/../"))) {
244 /* We find the last level of directory */
245 previous
= absolute_path
;
246 while ((slash
= strpbrk(previous
, "/")) && slash
!= next
) {
247 previous
= slash
+ 1;
250 /* Then we prepare the start_path not containing it */
251 start_path
= strndup(absolute_path
, previous
- absolute_path
);
257 /* And we concatenate it with the part after the '/../' */
258 snprintf(absolute_path
, PATH_MAX
, "%s%s", start_path
, next
+ 4);
260 /* We can free the memory used for the start path*/
263 /* Then we verify for symlinks using partial_realpath */
264 absolute_path
= utils_partial_realpath(absolute_path
,
265 absolute_path
, PATH_MAX
);
268 /* Identify the last token */
269 last_token
= strrchr(absolute_path
, '/');
271 /* Verify that this token is not a relative path */
272 is_dotdot
= (strcmp(last_token
, "/..") == 0);
273 is_dot
= (strcmp(last_token
, "/.") == 0);
275 /* If it is, take action */
276 if (is_dot
|| is_dotdot
) {
277 /* For both, remove this token */
280 /* If it was a reference to parent directory, go back one more time */
282 last_token
= strrchr(absolute_path
, '/');
284 /* If there was only one level left, we keep the first '/' */
285 if (last_token
== absolute_path
) {
293 return absolute_path
;
301 * Create a pipe in dst.
304 int utils_create_pipe(int *dst
)
314 PERROR("create pipe");
321 * Create pipe and set CLOEXEC flag to both fd.
323 * Make sure the pipe opened by this function are closed at some point. Use
324 * utils_close_pipe().
327 int utils_create_pipe_cloexec(int *dst
)
335 ret
= utils_create_pipe(dst
);
340 for (i
= 0; i
< 2; i
++) {
341 ret
= fcntl(dst
[i
], F_SETFD
, FD_CLOEXEC
);
343 PERROR("fcntl pipe cloexec");
353 * Create pipe and set fd flags to FD_CLOEXEC and O_NONBLOCK.
355 * Make sure the pipe opened by this function are closed at some point. Use
356 * utils_close_pipe(). Using pipe() and fcntl rather than pipe2() to
357 * support OSes other than Linux 2.6.23+.
360 int utils_create_pipe_cloexec_nonblock(int *dst
)
368 ret
= utils_create_pipe(dst
);
373 for (i
= 0; i
< 2; i
++) {
374 ret
= fcntl(dst
[i
], F_SETFD
, FD_CLOEXEC
);
376 PERROR("fcntl pipe cloexec");
380 * Note: we override any flag that could have been
381 * previously set on the fd.
383 ret
= fcntl(dst
[i
], F_SETFL
, O_NONBLOCK
);
385 PERROR("fcntl pipe nonblock");
395 * Close both read and write side of the pipe.
398 void utils_close_pipe(int *src
)
406 for (i
= 0; i
< 2; i
++) {
414 PERROR("close pipe");
420 * Create a new string using two strings range.
423 char *utils_strdupdelim(const char *begin
, const char *end
)
427 str
= zmalloc(end
- begin
+ 1);
429 PERROR("zmalloc strdupdelim");
433 memcpy(str
, begin
, end
- begin
);
434 str
[end
- begin
] = '\0';
441 * Set CLOEXEC flag to the give file descriptor.
444 int utils_set_fd_cloexec(int fd
)
453 ret
= fcntl(fd
, F_SETFD
, FD_CLOEXEC
);
455 PERROR("fcntl cloexec");
464 * Create pid file to the given path and filename.
467 int utils_create_pid_file(pid_t pid
, const char *filepath
)
474 fp
= fopen(filepath
, "w");
476 PERROR("open pid file %s", filepath
);
481 ret
= fprintf(fp
, "%d\n", pid
);
483 PERROR("fprintf pid file");
490 DBG("Pid %d written in file %s", pid
, filepath
);
497 * Create lock file to the given path and filename.
498 * Returns the associated file descriptor, -1 on error.
501 int utils_create_lock_file(const char *filepath
)
508 fd
= open(filepath
, O_CREAT
,
509 O_WRONLY
| S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
);
511 PERROR("open lock file %s", filepath
);
517 * Attempt to lock the file. If this fails, there is
518 * already a process using the same lock file running
519 * and we should exit.
521 ret
= flock(fd
, LOCK_EX
| LOCK_NB
);
523 ERR("Could not get lock file %s, another instance is running.",
526 PERROR("close lock file");
537 * On some filesystems (e.g. nfs), mkdir will validate access rights before
538 * checking for the existence of the path element. This means that on a setup
539 * where "/home/" is a mounted NFS share, and running as an unpriviledged user,
540 * recursively creating a path of the form "/home/my_user/trace/" will fail with
541 * EACCES on mkdir("/home", ...).
543 * Performing a stat(...) on the path to check for existence allows us to
544 * work around this behaviour.
547 int mkdir_check_exists(const char *path
, mode_t mode
)
552 ret
= stat(path
, &st
);
554 if (S_ISDIR(st
.st_mode
)) {
555 /* Directory exists, skip. */
558 /* Exists, but is not a directory. */
566 * Let mkdir handle other errors as the caller expects mkdir
569 ret
= mkdir(path
, mode
);
575 * Create directory using the given path and mode.
577 * On success, return 0 else a negative error code.
580 int utils_mkdir(const char *path
, mode_t mode
, int uid
, int gid
)
584 if (uid
< 0 || gid
< 0) {
585 ret
= mkdir_check_exists(path
, mode
);
587 ret
= run_as_mkdir(path
, mode
, uid
, gid
);
590 if (errno
!= EEXIST
) {
591 PERROR("mkdir %s, uid %d, gid %d", path
? path
: "NULL",
602 * Internal version of mkdir_recursive. Runs as the current user.
603 * Don't call directly; use utils_mkdir_recursive().
605 * This function is ominously marked as "unsafe" since it should only
606 * be called by a caller that has transitioned to the uid and gid under which
607 * the directory creation should occur.
610 int _utils_mkdir_recursive_unsafe(const char *path
, mode_t mode
)
612 char *p
, tmp
[PATH_MAX
];
618 ret
= snprintf(tmp
, sizeof(tmp
), "%s", path
);
620 PERROR("snprintf mkdir");
625 if (tmp
[len
- 1] == '/') {
629 for (p
= tmp
+ 1; *p
; p
++) {
632 if (tmp
[strlen(tmp
) - 1] == '.' &&
633 tmp
[strlen(tmp
) - 2] == '.' &&
634 tmp
[strlen(tmp
) - 3] == '/') {
635 ERR("Using '/../' is not permitted in the trace path (%s)",
640 ret
= mkdir_check_exists(tmp
, mode
);
642 if (errno
!= EACCES
) {
643 PERROR("mkdir recursive");
652 ret
= mkdir_check_exists(tmp
, mode
);
654 PERROR("mkdir recursive last element");
663 * Recursively create directory using the given path and mode, under the
664 * provided uid and gid.
666 * On success, return 0 else a negative error code.
669 int utils_mkdir_recursive(const char *path
, mode_t mode
, int uid
, int gid
)
673 if (uid
< 0 || gid
< 0) {
674 /* Run as current user. */
675 ret
= _utils_mkdir_recursive_unsafe(path
, mode
);
677 ret
= run_as_mkdir_recursive(path
, mode
, uid
, gid
);
680 PERROR("mkdir %s, uid %d, gid %d", path
? path
: "NULL",
688 * path is the output parameter. It needs to be PATH_MAX len.
690 * Return 0 on success or else a negative value.
692 static int utils_stream_file_name(char *path
,
693 const char *path_name
, const char *file_name
,
694 uint64_t size
, uint64_t count
,
698 char full_path
[PATH_MAX
];
699 char *path_name_suffix
= NULL
;
702 ret
= snprintf(full_path
, sizeof(full_path
), "%s/%s",
703 path_name
, file_name
);
705 PERROR("snprintf create output file");
709 /* Setup extra string if suffix or/and a count is needed. */
710 if (size
> 0 && suffix
) {
711 ret
= asprintf(&extra
, "_%" PRIu64
"%s", count
, suffix
);
712 } else if (size
> 0) {
713 ret
= asprintf(&extra
, "_%" PRIu64
, count
);
715 ret
= asprintf(&extra
, "%s", suffix
);
718 PERROR("Allocating extra string to name");
723 * If we split the trace in multiple files, we have to add the count at
724 * the end of the tracefile name.
727 ret
= asprintf(&path_name_suffix
, "%s%s", full_path
, extra
);
729 PERROR("Allocating path name with extra string");
730 goto error_free_suffix
;
732 strncpy(path
, path_name_suffix
, PATH_MAX
- 1);
733 path
[PATH_MAX
- 1] = '\0';
735 strncpy(path
, full_path
, PATH_MAX
- 1);
737 path
[PATH_MAX
- 1] = '\0';
740 free(path_name_suffix
);
748 * Create the stream file on disk.
750 * Return 0 on success or else a negative value.
753 int utils_create_stream_file(const char *path_name
, char *file_name
, uint64_t size
,
754 uint64_t count
, int uid
, int gid
, char *suffix
)
756 int ret
, flags
, mode
;
759 ret
= utils_stream_file_name(path
, path_name
, file_name
,
760 size
, count
, suffix
);
765 flags
= O_WRONLY
| O_CREAT
| O_TRUNC
;
766 /* Open with 660 mode */
767 mode
= S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
;
769 if (uid
< 0 || gid
< 0) {
770 ret
= open(path
, flags
, mode
);
772 ret
= run_as_open(path
, flags
, mode
, uid
, gid
);
775 PERROR("open stream path %s", path
);
782 * Unlink the stream tracefile from disk.
784 * Return 0 on success or else a negative value.
787 int utils_unlink_stream_file(const char *path_name
, char *file_name
, uint64_t size
,
788 uint64_t count
, int uid
, int gid
, char *suffix
)
793 ret
= utils_stream_file_name(path
, path_name
, file_name
,
794 size
, count
, suffix
);
798 if (uid
< 0 || gid
< 0) {
801 ret
= run_as_unlink(path
, uid
, gid
);
807 DBG("utils_unlink_stream_file %s returns %d", path
, ret
);
812 * Change the output tracefile according to the given size and count The
813 * new_count pointer is set during this operation.
815 * From the consumer, the stream lock MUST be held before calling this function
816 * because we are modifying the stream status.
818 * Return 0 on success or else a negative value.
821 int utils_rotate_stream_file(char *path_name
, char *file_name
, uint64_t size
,
822 uint64_t count
, int uid
, int gid
, int out_fd
, uint64_t *new_count
,
832 PERROR("Closing tracefile");
838 * In tracefile rotation, for the relay daemon we need
839 * to unlink the old file if present, because it may
840 * still be open in reading by the live thread, and we
841 * need to ensure that we do not overwrite the content
842 * between get_index and get_packet. Since we have no
843 * way to verify integrity of the data content compared
844 * to the associated index, we need to ensure the reader
845 * has exclusive access to the file content, and that
846 * the open of the data file is performed in get_index.
847 * Unlinking the old file rather than overwriting it
850 *new_count
= (*new_count
+ 1) % count
;
851 ret
= utils_unlink_stream_file(path_name
, file_name
,
852 size
, *new_count
, uid
, gid
, 0);
853 if (ret
< 0 && errno
!= ENOENT
) {
860 ret
= utils_create_stream_file(path_name
, file_name
, size
, *new_count
,
876 * Parse a string that represents a size in human readable format. It
877 * supports decimal integers suffixed by 'k', 'K', 'M' or 'G'.
879 * The suffix multiply the integer by:
884 * @param str The string to parse.
885 * @param size Pointer to a uint64_t that will be filled with the
888 * @return 0 on success, -1 on failure.
891 int utils_parse_size_suffix(const char * const str
, uint64_t * const size
)
900 DBG("utils_parse_size_suffix: received a NULL string.");
905 /* strtoull will accept a negative number, but we don't want to. */
906 if (strchr(str
, '-') != NULL
) {
907 DBG("utils_parse_size_suffix: invalid size string, should not contain '-'.");
912 /* str_end will point to the \0 */
913 str_end
= str
+ strlen(str
);
915 base_size
= strtoull(str
, &num_end
, 0);
917 PERROR("utils_parse_size_suffix strtoull");
922 if (num_end
== str
) {
923 /* strtoull parsed nothing, not good. */
924 DBG("utils_parse_size_suffix: strtoull had nothing good to parse.");
929 /* Check if a prefix is present. */
947 DBG("utils_parse_size_suffix: invalid suffix.");
952 /* Check for garbage after the valid input. */
953 if (num_end
!= str_end
) {
954 DBG("utils_parse_size_suffix: Garbage after size string.");
959 *size
= base_size
<< shift
;
961 /* Check for overflow */
962 if ((*size
>> shift
) != base_size
) {
963 DBG("utils_parse_size_suffix: oops, overflow detected.");
974 * fls: returns the position of the most significant bit.
975 * Returns 0 if no bit is set, else returns the position of the most
976 * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit).
978 #if defined(__i386) || defined(__x86_64)
979 static inline unsigned int fls_u32(uint32_t x
)
987 : "=r" (r
) : "rm" (x
));
994 static __attribute__((unused
)) unsigned int fls_u32(uint32_t x
)
1001 if (!(x
& 0xFFFF0000U
)) {
1005 if (!(x
& 0xFF000000U
)) {
1009 if (!(x
& 0xF0000000U
)) {
1013 if (!(x
& 0xC0000000U
)) {
1017 if (!(x
& 0x80000000U
)) {
1026 * Return the minimum order for which x <= (1UL << order).
1027 * Return -1 if x is 0.
1030 int utils_get_count_order_u32(uint32_t x
)
1036 return fls_u32(x
- 1);
1040 * Obtain the value of LTTNG_HOME environment variable, if exists.
1041 * Otherwise returns the value of HOME.
1044 char *utils_get_home_dir(void)
1049 val
= lttng_secure_getenv(DEFAULT_LTTNG_HOME_ENV_VAR
);
1053 val
= lttng_secure_getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR
);
1058 /* Fallback on the password file entry. */
1059 pwd
= getpwuid(getuid());
1065 DBG3("Home directory is '%s'", val
);
1072 * Get user's home directory. Dynamically allocated, must be freed
1076 char *utils_get_user_home_dir(uid_t uid
)
1079 struct passwd
*result
;
1080 char *home_dir
= NULL
;
1085 buflen
= sysconf(_SC_GETPW_R_SIZE_MAX
);
1090 buf
= zmalloc(buflen
);
1095 ret
= getpwuid_r(uid
, &pwd
, buf
, buflen
, &result
);
1096 if (ret
|| !result
) {
1097 if (ret
== ERANGE
) {
1105 home_dir
= strdup(pwd
.pw_dir
);
1112 * Obtain the value of LTTNG_KMOD_PROBES environment variable, if exists.
1113 * Otherwise returns NULL.
1116 char *utils_get_kmod_probes_list(void)
1118 return lttng_secure_getenv(DEFAULT_LTTNG_KMOD_PROBES
);
1122 * Obtain the value of LTTNG_EXTRA_KMOD_PROBES environment variable, if
1123 * exists. Otherwise returns NULL.
1126 char *utils_get_extra_kmod_probes_list(void)
1128 return lttng_secure_getenv(DEFAULT_LTTNG_EXTRA_KMOD_PROBES
);
1132 * With the given format, fill dst with the time of len maximum siz.
1134 * Return amount of bytes set in the buffer or else 0 on error.
1137 size_t utils_get_current_time_str(const char *format
, char *dst
, size_t len
)
1141 struct tm
*timeinfo
;
1146 /* Get date and time for session path */
1148 timeinfo
= localtime(&rawtime
);
1149 ret
= strftime(dst
, len
, format
, timeinfo
);
1151 ERR("Unable to strftime with format %s at dst %p of len %zu", format
,
1159 * Return the group ID matching name, else 0 if it cannot be found.
1162 gid_t
utils_get_group_id(const char *name
)
1166 grp
= getgrnam(name
);
1168 static volatile int warn_once
;
1171 WARN("No tracing group detected");
1180 * Return a newly allocated option string. This string is to be used as the
1181 * optstring argument of getopt_long(), see GETOPT(3). opt_count is the number
1182 * of elements in the long_options array. Returns NULL if the string's
1186 char *utils_generate_optstring(const struct option
*long_options
,
1190 size_t string_len
= opt_count
, str_pos
= 0;
1194 * Compute the necessary string length. One letter per option, two when an
1195 * argument is necessary, and a trailing NULL.
1197 for (i
= 0; i
< opt_count
; i
++) {
1198 string_len
+= long_options
[i
].has_arg
? 1 : 0;
1201 optstring
= zmalloc(string_len
);
1206 for (i
= 0; i
< opt_count
; i
++) {
1207 if (!long_options
[i
].name
) {
1208 /* Got to the trailing NULL element */
1212 if (long_options
[i
].val
!= '\0') {
1213 optstring
[str_pos
++] = (char) long_options
[i
].val
;
1214 if (long_options
[i
].has_arg
) {
1215 optstring
[str_pos
++] = ':';
1225 * Try to remove a hierarchy of empty directories, recursively. Don't unlink
1226 * any file. Try to rmdir any empty directory within the hierarchy.
1229 int utils_recursive_rmdir(const char *path
)
1232 int dir_fd
, ret
= 0, closeret
, is_empty
= 1;
1233 struct dirent
*entry
;
1235 /* Open directory */
1236 dir
= opendir(path
);
1238 PERROR("Cannot open '%s' path", path
);
1241 dir_fd
= dirfd(dir
);
1247 while ((entry
= readdir(dir
))) {
1248 if (!strcmp(entry
->d_name
, ".")
1249 || !strcmp(entry
->d_name
, ".."))
1251 switch (entry
->d_type
) {
1254 char subpath
[PATH_MAX
];
1256 strncpy(subpath
, path
, PATH_MAX
);
1257 subpath
[PATH_MAX
- 1] = '\0';
1258 strncat(subpath
, "/",
1259 PATH_MAX
- strlen(subpath
) - 1);
1260 strncat(subpath
, entry
->d_name
,
1261 PATH_MAX
- strlen(subpath
) - 1);
1262 if (utils_recursive_rmdir(subpath
)) {
1276 closeret
= closedir(dir
);
1281 DBG3("Attempting rmdir %s", path
);