2 * Copyright (C) 2012 David Goulet <dgoulet@efficios.com>
3 * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com>
5 * SPDX-License-Identifier: LGPL-2.1-only
19 #include <sys/types.h>
22 #include <common/common.hpp>
23 #include <common/compat/directory-handle.hpp>
24 #include <common/compat/dirent.hpp>
25 #include <common/compat/getenv.hpp>
26 #include <common/compat/string.hpp>
27 #include <common/dynamic-buffer.hpp>
28 #include <common/readwrite.hpp>
29 #include <common/runas.hpp>
30 #include <common/string-utils/format.hpp>
31 #include <lttng/constant.h>
33 #include "defaults.hpp"
37 #define PROC_MEMINFO_PATH "/proc/meminfo"
38 #define PROC_MEMINFO_MEMAVAILABLE_LINE "MemAvailable:"
39 #define PROC_MEMINFO_MEMTOTAL_LINE "MemTotal:"
41 /* The length of the longest field of `/proc/meminfo`. */
42 #define PROC_MEMINFO_FIELD_MAX_NAME_LEN 20
44 #if (PROC_MEMINFO_FIELD_MAX_NAME_LEN == 20)
45 #define MAX_NAME_LEN_SCANF_IS_A_BROKEN_API "19"
47 #error MAX_NAME_LEN_SCANF_IS_A_BROKEN_API must be updated to match (PROC_MEMINFO_FIELD_MAX_NAME_LEN - 1)
50 #define FALLBACK_USER_BUFLEN 16384
51 #define FALLBACK_GROUP_BUFLEN 16384
54 * Create a pipe in dst.
56 int utils_create_pipe(int *dst
)
66 PERROR("create pipe");
73 * Create pipe and set CLOEXEC flag to both fd.
75 * Make sure the pipe opened by this function are closed at some point. Use
78 int utils_create_pipe_cloexec(int *dst
)
86 ret
= utils_create_pipe(dst
);
91 for (i
= 0; i
< 2; i
++) {
92 ret
= fcntl(dst
[i
], F_SETFD
, FD_CLOEXEC
);
94 PERROR("fcntl pipe cloexec");
104 * Create pipe and set fd flags to FD_CLOEXEC and O_NONBLOCK.
106 * Make sure the pipe opened by this function are closed at some point. Use
107 * utils_close_pipe(). Using pipe() and fcntl rather than pipe2() to
108 * support OSes other than Linux 2.6.23+.
110 int utils_create_pipe_cloexec_nonblock(int *dst
)
118 ret
= utils_create_pipe(dst
);
123 for (i
= 0; i
< 2; i
++) {
124 ret
= fcntl(dst
[i
], F_SETFD
, FD_CLOEXEC
);
126 PERROR("fcntl pipe cloexec");
130 * Note: we override any flag that could have been
131 * previously set on the fd.
133 ret
= fcntl(dst
[i
], F_SETFL
, O_NONBLOCK
);
135 PERROR("fcntl pipe nonblock");
145 * Close both read and write side of the pipe.
147 void utils_close_pipe(int *src
)
155 for (i
= 0; i
< 2; i
++) {
163 PERROR("close pipe");
170 * Create a new string using two strings range.
172 char *utils_strdupdelim(const char *begin
, const char *end
)
176 str
= (char *) zmalloc(end
- begin
+ 1);
178 PERROR("zmalloc strdupdelim");
182 memcpy(str
, begin
, end
- begin
);
183 str
[end
- begin
] = '\0';
190 * Set CLOEXEC flag to the give file descriptor.
192 int utils_set_fd_cloexec(int fd
)
201 ret
= fcntl(fd
, F_SETFD
, FD_CLOEXEC
);
203 PERROR("fcntl cloexec");
212 * Create pid file to the given path and filename.
214 int utils_create_pid_file(pid_t pid
, const char *filepath
)
219 LTTNG_ASSERT(filepath
);
221 fp
= fopen(filepath
, "w");
223 PERROR("open pid file %s", filepath
);
228 ret
= fprintf(fp
, "%d\n", (int) pid
);
230 PERROR("fprintf pid file");
237 DBG("Pid %d written in file %s", (int) pid
, filepath
);
244 * Create lock file to the given path and filename.
245 * Returns the associated file descriptor, -1 on error.
247 int utils_create_lock_file(const char *filepath
)
253 LTTNG_ASSERT(filepath
);
255 memset(&lock
, 0, sizeof(lock
));
256 fd
= open(filepath
, O_CREAT
| O_WRONLY
, S_IRUSR
| S_IWUSR
|
259 PERROR("open lock file %s", filepath
);
265 * Attempt to lock the file. If this fails, there is
266 * already a process using the same lock file running
267 * and we should exit.
269 lock
.l_whence
= SEEK_SET
;
270 lock
.l_type
= F_WRLCK
;
272 ret
= fcntl(fd
, F_SETLK
, &lock
);
274 PERROR("fcntl lock file");
275 ERR("Could not get lock file %s, another instance is running.",
278 PERROR("close lock file");
289 * Create directory using the given path and mode.
291 * On success, return 0 else a negative error code.
293 int utils_mkdir(const char *path
, mode_t mode
, int uid
, int gid
)
296 struct lttng_directory_handle
*handle
;
297 const struct lttng_credentials creds
= {
298 .uid
= LTTNG_OPTIONAL_INIT_VALUE((uid_t
) uid
),
299 .gid
= LTTNG_OPTIONAL_INIT_VALUE((gid_t
) gid
),
302 handle
= lttng_directory_handle_create(NULL
);
307 ret
= lttng_directory_handle_create_subdirectory_as_user(
309 (uid
>= 0 || gid
>= 0) ? &creds
: NULL
);
311 lttng_directory_handle_put(handle
);
316 * Recursively create directory using the given path and mode, under the
317 * provided uid and gid.
319 * On success, return 0 else a negative error code.
321 int utils_mkdir_recursive(const char *path
, mode_t mode
, int uid
, int gid
)
324 struct lttng_directory_handle
*handle
;
325 const struct lttng_credentials creds
= {
326 .uid
= LTTNG_OPTIONAL_INIT_VALUE((uid_t
) uid
),
327 .gid
= LTTNG_OPTIONAL_INIT_VALUE((gid_t
) gid
),
330 handle
= lttng_directory_handle_create(NULL
);
335 ret
= lttng_directory_handle_create_subdirectory_recursive_as_user(
337 (uid
>= 0 || gid
>= 0) ? &creds
: NULL
);
339 lttng_directory_handle_put(handle
);
344 * out_stream_path is the output parameter.
346 * Return 0 on success or else a negative value.
348 int utils_stream_file_path(const char *path_name
, const char *file_name
,
349 uint64_t size
, uint64_t count
, const char *suffix
,
350 char *out_stream_path
, size_t stream_path_len
)
353 char count_str
[MAX_INT_DEC_LEN(count
) + 1] = {};
354 const char *path_separator
;
356 if (path_name
&& (path_name
[0] == '\0' ||
357 path_name
[strlen(path_name
) - 1] == '/')) {
360 path_separator
= "/";
363 path_name
= path_name
? : "";
364 suffix
= suffix
? : "";
366 ret
= snprintf(count_str
, sizeof(count_str
), "_%" PRIu64
,
368 LTTNG_ASSERT(ret
> 0 && ret
< sizeof(count_str
));
371 ret
= snprintf(out_stream_path
, stream_path_len
, "%s%s%s%s%s",
372 path_name
, path_separator
, file_name
, count_str
,
374 if (ret
< 0 || ret
>= stream_path_len
) {
375 ERR("Truncation occurred while formatting stream path");
384 * Parse a string that represents a size in human readable format. It
385 * supports decimal integers suffixed by 'k', 'K', 'M' or 'G'.
387 * The suffix multiply the integer by:
392 * @param str The string to parse.
393 * @param size Pointer to a uint64_t that will be filled with the
396 * @return 0 on success, -1 on failure.
398 int utils_parse_size_suffix(const char * const str
, uint64_t * const size
)
407 DBG("utils_parse_size_suffix: received a NULL string.");
412 /* strtoull will accept a negative number, but we don't want to. */
413 if (strchr(str
, '-') != NULL
) {
414 DBG("utils_parse_size_suffix: invalid size string, should not contain '-'.");
419 /* str_end will point to the \0 */
420 str_end
= str
+ strlen(str
);
422 base_size
= strtoull(str
, &num_end
, 0);
424 PERROR("utils_parse_size_suffix strtoull");
429 if (num_end
== str
) {
430 /* strtoull parsed nothing, not good. */
431 DBG("utils_parse_size_suffix: strtoull had nothing good to parse.");
436 /* Check if a prefix is present. */
454 DBG("utils_parse_size_suffix: invalid suffix.");
459 /* Check for garbage after the valid input. */
460 if (num_end
!= str_end
) {
461 DBG("utils_parse_size_suffix: Garbage after size string.");
466 *size
= base_size
<< shift
;
468 /* Check for overflow */
469 if ((*size
>> shift
) != base_size
) {
470 DBG("utils_parse_size_suffix: oops, overflow detected.");
481 * Parse a string that represents a time in human readable format. It
482 * supports decimal integers suffixed by:
483 * "us" for microsecond,
484 * "ms" for millisecond,
489 * The suffix multiply the integer by:
496 * Note that unit-less numbers are assumed to be microseconds.
498 * @param str The string to parse, assumed to be NULL-terminated.
499 * @param time_us Pointer to a uint64_t that will be filled with the
500 * resulting time in microseconds.
502 * @return 0 on success, -1 on failure.
504 int utils_parse_time_suffix(char const * const str
, uint64_t * const time_us
)
508 uint64_t multiplier
= 1;
513 DBG("utils_parse_time_suffix: received a NULL string.");
518 /* strtoull will accept a negative number, but we don't want to. */
519 if (strchr(str
, '-') != NULL
) {
520 DBG("utils_parse_time_suffix: invalid time string, should not contain '-'.");
525 /* str_end will point to the \0 */
526 str_end
= str
+ strlen(str
);
528 base_time
= strtoull(str
, &num_end
, 10);
530 PERROR("utils_parse_time_suffix strtoull on string \"%s\"", str
);
535 if (num_end
== str
) {
536 /* strtoull parsed nothing, not good. */
537 DBG("utils_parse_time_suffix: strtoull had nothing good to parse.");
542 /* Check if a prefix is present. */
548 * Skip the "us" if the string matches the "us" suffix,
549 * otherwise let the check for the end of the string handle
550 * the error reporting.
552 if (*(num_end
+ 1) == 's') {
557 if (*(num_end
+ 1) == 's') {
558 /* Millisecond (ms) */
559 multiplier
= USEC_PER_MSEC
;
564 multiplier
= USEC_PER_MINUTE
;
570 multiplier
= USEC_PER_SEC
;
575 multiplier
= USEC_PER_HOURS
;
581 DBG("utils_parse_time_suffix: invalid suffix.");
586 /* Check for garbage after the valid input. */
587 if (num_end
!= str_end
) {
588 DBG("utils_parse_time_suffix: Garbage after time string.");
593 *time_us
= base_time
* multiplier
;
595 /* Check for overflow */
596 if ((*time_us
/ multiplier
) != base_time
) {
597 DBG("utils_parse_time_suffix: oops, overflow detected.");
608 * fls: returns the position of the most significant bit.
609 * Returns 0 if no bit is set, else returns the position of the most
610 * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit).
612 #if defined(__i386) || defined(__x86_64)
613 static inline unsigned int fls_u32(uint32_t x
)
621 : "=r" (r
) : "rm" (x
));
627 #if defined(__x86_64) && defined(__LP64__)
629 unsigned int fls_u64(uint64_t x
)
637 : "=r" (r
) : "rm" (x
));
644 static __attribute__((unused
))
645 unsigned int fls_u64(uint64_t x
)
652 if (!(x
& 0xFFFFFFFF00000000ULL
)) {
656 if (!(x
& 0xFFFF000000000000ULL
)) {
660 if (!(x
& 0xFF00000000000000ULL
)) {
664 if (!(x
& 0xF000000000000000ULL
)) {
668 if (!(x
& 0xC000000000000000ULL
)) {
672 if (!(x
& 0x8000000000000000ULL
)) {
681 static __attribute__((unused
)) unsigned int fls_u32(uint32_t x
)
688 if (!(x
& 0xFFFF0000U
)) {
692 if (!(x
& 0xFF000000U
)) {
696 if (!(x
& 0xF0000000U
)) {
700 if (!(x
& 0xC0000000U
)) {
704 if (!(x
& 0x80000000U
)) {
713 * Return the minimum order for which x <= (1UL << order).
714 * Return -1 if x is 0.
716 int utils_get_count_order_u32(uint32_t x
)
722 return fls_u32(x
- 1);
726 * Return the minimum order for which x <= (1UL << order).
727 * Return -1 if x is 0.
729 int utils_get_count_order_u64(uint64_t x
)
735 return fls_u64(x
- 1);
739 * Obtain the value of LTTNG_HOME environment variable, if exists.
740 * Otherwise returns the value of HOME.
742 const char *utils_get_home_dir(void)
747 val
= lttng_secure_getenv(DEFAULT_LTTNG_HOME_ENV_VAR
);
751 val
= lttng_secure_getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR
);
756 /* Fallback on the password file entry. */
757 pwd
= getpwuid(getuid());
763 DBG3("Home directory is '%s'", val
);
770 * Get user's home directory. Dynamically allocated, must be freed
773 char *utils_get_user_home_dir(uid_t uid
)
776 struct passwd
*result
;
777 char *home_dir
= NULL
;
782 buflen
= sysconf(_SC_GETPW_R_SIZE_MAX
);
787 buf
= (char *) zmalloc(buflen
);
792 ret
= getpwuid_r(uid
, &pwd
, buf
, buflen
, &result
);
793 if (ret
|| !result
) {
802 home_dir
= strdup(pwd
.pw_dir
);
809 * With the given format, fill dst with the time of len maximum siz.
811 * Return amount of bytes set in the buffer or else 0 on error.
813 size_t utils_get_current_time_str(const char *format
, char *dst
, size_t len
)
819 LTTNG_ASSERT(format
);
822 /* Get date and time for session path */
824 timeinfo
= localtime(&rawtime
);
826 DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL
827 ret
= strftime(dst
, len
, format
, timeinfo
);
830 ERR("Unable to strftime with format %s at dst %p of len %zu", format
,
838 * Return 0 on success and set *gid to the group_ID matching the passed name.
839 * Else -1 if it cannot be found or an error occurred.
841 int utils_get_group_id(const char *name
, bool warn
, gid_t
*gid
)
843 static volatile int warn_once
;
848 struct group
*result
;
849 struct lttng_dynamic_buffer buffer
;
851 /* Get the system limit, if it exists. */
852 sys_len
= sysconf(_SC_GETGR_R_SIZE_MAX
);
856 len
= (size_t) sys_len
;
859 lttng_dynamic_buffer_init(&buffer
);
860 ret
= lttng_dynamic_buffer_set_size(&buffer
, len
);
862 ERR("Failed to allocate group info buffer");
867 while ((ret
= getgrnam_r(name
, &grp
, buffer
.data
, buffer
.size
, &result
)) == ERANGE
) {
868 const size_t new_len
= 2 * buffer
.size
;
870 /* Buffer is not big enough, increase its size. */
871 if (new_len
< buffer
.size
) {
872 ERR("Group info buffer size overflow");
877 ret
= lttng_dynamic_buffer_set_size(&buffer
, new_len
);
879 ERR("Failed to grow group info buffer to %zu bytes",
887 DBG("Could not find group file entry for group name '%s'",
890 PERROR("Failed to get group file entry for group name '%s'",
898 /* Group not found. */
904 *gid
= result
->gr_gid
;
908 if (ret
&& warn
&& !warn_once
) {
909 WARN("No tracing group detected");
912 lttng_dynamic_buffer_reset(&buffer
);
917 * Return a newly allocated option string. This string is to be used as the
918 * optstring argument of getopt_long(), see GETOPT(3). opt_count is the number
919 * of elements in the long_options array. Returns NULL if the string's
922 char *utils_generate_optstring(const struct option
*long_options
,
926 size_t string_len
= opt_count
, str_pos
= 0;
930 * Compute the necessary string length. One letter per option, two when an
931 * argument is necessary, and a trailing NULL.
933 for (i
= 0; i
< opt_count
; i
++) {
934 string_len
+= long_options
[i
].has_arg
? 1 : 0;
937 optstring
= (char *) zmalloc(string_len
);
942 for (i
= 0; i
< opt_count
; i
++) {
943 if (!long_options
[i
].name
) {
944 /* Got to the trailing NULL element */
948 if (long_options
[i
].val
!= '\0') {
949 optstring
[str_pos
++] = (char) long_options
[i
].val
;
950 if (long_options
[i
].has_arg
) {
951 optstring
[str_pos
++] = ':';
961 * Try to remove a hierarchy of empty directories, recursively. Don't unlink
962 * any file. Try to rmdir any empty directory within the hierarchy.
964 int utils_recursive_rmdir(const char *path
)
967 struct lttng_directory_handle
*handle
;
969 handle
= lttng_directory_handle_create(NULL
);
974 ret
= lttng_directory_handle_remove_subdirectory(handle
, path
);
976 lttng_directory_handle_put(handle
);
980 int utils_truncate_stream_file(int fd
, off_t length
)
985 ret
= ftruncate(fd
, length
);
990 lseek_ret
= lseek(fd
, length
, SEEK_SET
);
1000 static const char *get_man_bin_path(void)
1002 char *env_man_path
= lttng_secure_getenv(DEFAULT_MAN_BIN_PATH_ENV
);
1005 return env_man_path
;
1008 return DEFAULT_MAN_BIN_PATH
;
1011 int utils_show_help(int section
, const char *page_name
,
1012 const char *help_msg
)
1014 char section_string
[8];
1015 const char *man_bin_path
= get_man_bin_path();
1019 printf("%s", help_msg
);
1023 /* Section integer -> section string */
1024 ret
= sprintf(section_string
, "%d", section
);
1025 LTTNG_ASSERT(ret
> 0 && ret
< 8);
1028 * Execute man pager.
1030 * We provide -M to man here because LTTng-tools can
1031 * be installed outside /usr, in which case its man pages are
1032 * not located in the default /usr/share/man directory.
1034 ret
= execlp(man_bin_path
, "man", "-M", MANPATH
,
1035 section_string
, page_name
, NULL
);
1042 int read_proc_meminfo_field(const char *field
, uint64_t *value
)
1046 char name
[PROC_MEMINFO_FIELD_MAX_NAME_LEN
] = {};
1048 proc_meminfo
= fopen(PROC_MEMINFO_PATH
, "r");
1049 if (!proc_meminfo
) {
1050 PERROR("Failed to fopen() " PROC_MEMINFO_PATH
);
1056 * Read the contents of /proc/meminfo line by line to find the right
1059 while (!feof(proc_meminfo
)) {
1062 ret
= fscanf(proc_meminfo
,
1063 "%" MAX_NAME_LEN_SCANF_IS_A_BROKEN_API
"s %" SCNu64
" kB\n",
1067 * fscanf() returning EOF can indicate EOF or an error.
1069 if (ferror(proc_meminfo
)) {
1070 PERROR("Failed to parse " PROC_MEMINFO_PATH
);
1075 if (ret
== 2 && strcmp(name
, field
) == 0) {
1077 * This number is displayed in kilo-bytes. Return the
1080 if (value_kb
> UINT64_MAX
/ 1024) {
1081 ERR("Overflow on kb to bytes conversion");
1085 *value
= value_kb
* 1024;
1090 /* Reached the end of the file without finding the right field. */
1094 fclose(proc_meminfo
);
1100 * Returns an estimate of the number of bytes of memory available based on the
1101 * the information in `/proc/meminfo`. The number returned by this function is
1104 int utils_get_memory_available(uint64_t *value
)
1106 return read_proc_meminfo_field(PROC_MEMINFO_MEMAVAILABLE_LINE
, value
);
1110 * Returns the total size of the memory on the system in bytes based on the
1111 * the information in `/proc/meminfo`.
1113 int utils_get_memory_total(uint64_t *value
)
1115 return read_proc_meminfo_field(PROC_MEMINFO_MEMTOTAL_LINE
, value
);
1118 int utils_change_working_directory(const char *path
)
1124 DBG("Changing working directory to \"%s\"", path
);
1127 PERROR("Failed to change working directory to \"%s\"", path
);
1131 /* Check for write access */
1132 if (access(path
, W_OK
)) {
1133 if (errno
== EACCES
) {
1135 * Do not treat this as an error since the permission
1136 * might change in the lifetime of the process
1138 DBG("Working directory \"%s\" is not writable", path
);
1140 PERROR("Failed to check if working directory \"%s\" is writable",
1149 enum lttng_error_code
utils_user_id_from_name(const char *user_name
, uid_t
*uid
)
1151 struct passwd p
, *pres
;
1153 enum lttng_error_code ret_val
= LTTNG_OK
;
1157 buflen
= sysconf(_SC_GETPW_R_SIZE_MAX
);
1159 buflen
= FALLBACK_USER_BUFLEN
;
1162 buf
= (char *) zmalloc(buflen
);
1164 ret_val
= LTTNG_ERR_NOMEM
;
1169 ret
= getpwnam_r(user_name
, &p
, buf
, buflen
, &pres
);
1176 buf
= (char *) zmalloc(buflen
);
1178 ret_val
= LTTNG_ERR_NOMEM
;
1191 ret_val
= LTTNG_ERR_USER_NOT_FOUND
;
1194 DBG("Lookup of tracker UID/VUID: name '%s' maps to uid %" PRId64
,
1195 user_name
, (int64_t) *uid
);
1203 ret_val
= LTTNG_ERR_USER_NOT_FOUND
;
1206 ret_val
= LTTNG_ERR_NOMEM
;
1213 enum lttng_error_code
utils_group_id_from_name(
1214 const char *group_name
, gid_t
*gid
)
1216 struct group g
, *gres
;
1218 enum lttng_error_code ret_val
= LTTNG_OK
;
1222 buflen
= sysconf(_SC_GETGR_R_SIZE_MAX
);
1224 buflen
= FALLBACK_GROUP_BUFLEN
;
1227 buf
= (char *) zmalloc(buflen
);
1229 ret_val
= LTTNG_ERR_NOMEM
;
1234 ret
= getgrnam_r(group_name
, &g
, buf
, buflen
, &gres
);
1241 buf
= (char *) zmalloc(buflen
);
1243 ret_val
= LTTNG_ERR_NOMEM
;
1256 ret_val
= LTTNG_ERR_GROUP_NOT_FOUND
;
1259 DBG("Lookup of tracker GID/GUID: name '%s' maps to gid %" PRId64
,
1260 group_name
, (int64_t) *gid
);
1268 ret_val
= LTTNG_ERR_GROUP_NOT_FOUND
;
1271 ret_val
= LTTNG_ERR_NOMEM
;
1278 int utils_parse_unsigned_long_long(const char *str
,
1279 unsigned long long *value
)
1285 LTTNG_ASSERT(value
);
1288 *value
= strtoull(str
, &endptr
, 10);
1290 /* Conversion failed. Out of range? */
1292 /* Don't print an error; allow the caller to log a better error. */
1293 DBG("Failed to parse string as unsigned long long number: string = '%s', errno = %d",
1299 /* Not the end of the string or empty string. */
1300 if (*endptr
|| endptr
== str
) {
1301 DBG("Failed to parse string as unsigned long long number: string = '%s'",