Support minute and hour as time suffixes
[lttng-tools.git] / src / common / utils.c
index 1e52ae0aa073640a34f8b035376bb6b5119d5660..a092d940f422979b724fa5a61a72365c54b83ad7 100644 (file)
@@ -41,6 +41,7 @@
 
 #include "utils.h"
 #include "defaults.h"
+#include "time.h"
 
 /*
  * Return a partial realpath(3) of the path even if the full path does not
@@ -196,6 +197,106 @@ error:
        return NULL;
 }
 
+static
+int expand_double_slashes_dot_and_dotdot(char *path)
+{
+       size_t expanded_path_len, path_len;
+       const char *curr_char, *path_last_char, *next_slash, *prev_slash;
+
+       path_len = strlen(path);
+       path_last_char = &path[path_len];
+
+       if (path_len == 0) {
+               goto error;
+       }
+
+       expanded_path_len = 0;
+
+       /* We iterate over the provided path to expand the "//", "../" and "./" */
+       for (curr_char = path; curr_char <= path_last_char; curr_char = next_slash + 1) {
+               /* Find the next forward slash. */
+               size_t curr_token_len;
+
+               if (curr_char == path_last_char) {
+                       expanded_path_len++;
+                       break;
+               }
+
+               next_slash = memchr(curr_char, '/', path_last_char - curr_char);
+               if (next_slash == NULL) {
+                       /* Reached the end of the provided path. */
+                       next_slash = path_last_char;
+               }
+
+               /* Compute how long is the previous token. */
+               curr_token_len = next_slash - curr_char;
+               switch(curr_token_len) {
+               case 0:
+                       /*
+                        * The pointer has not move meaning that curr_char is
+                        * pointing to a slash. It that case there is no token
+                        * to copy, so continue the iteration to find the next
+                        * token
+                        */
+                       continue;
+               case 1:
+                       /*
+                        * The pointer moved 1 character. Check if that
+                        * character is a dot ('.'), if it is: omit it, else
+                        * copy the token to the normalized path.
+                        */
+                       if (curr_char[0] == '.') {
+                               continue;
+                       }
+                       break;
+               case 2:
+                       /*
+                        * The pointer moved 2 characters. Check if these
+                        * characters are double dots ('..'). If that is the
+                        * case, we need to remove the last token of the
+                        * normalized path.
+                        */
+                       if (curr_char[0] == '.' && curr_char[1] == '.') {
+                               /*
+                                * Find the previous path component by
+                                * using the memrchr function to find the
+                                * previous forward slash and substract that
+                                * len to the resulting path.
+                                */
+                               prev_slash = lttng_memrchr(path, '/', expanded_path_len);
+                               /*
+                                * If prev_slash is NULL, we reached the
+                                * beginning of the path. We can't go back any
+                                * further.
+                                */
+                               if (prev_slash != NULL) {
+                                       expanded_path_len = prev_slash - path;
+                               }
+                               continue;
+                       }
+                       break;
+               default:
+                       break;
+               }
+
+               /*
+                * Copy the current token which is neither a '.' nor a '..'.
+                */
+               path[expanded_path_len++] = '/';
+               memcpy(&path[expanded_path_len], curr_char, curr_token_len);
+               expanded_path_len += curr_token_len;
+       }
+
+       if (expanded_path_len == 0) {
+               path[expanded_path_len++] = '/';
+       }
+
+       path[expanded_path_len] = '\0';
+       return 0;
+error:
+       return -1;
+}
+
 /*
  * Make a full resolution of the given path even if it doesn't exist.
  * This function uses the utils_partial_realpath function to resolve
@@ -207,11 +308,12 @@ error:
  * the responsibility of the caller to free this memory.
  */
 LTTNG_HIDDEN
-char *utils_expand_path(const char *path)
+char *_utils_expand_path(const char *path, bool keep_symlink)
 {
-       char *next, *previous, *slash, *start_path, *absolute_path = NULL;
+       int ret;
+       char *absolute_path = NULL;
        char *last_token;
-       int is_dot, is_dotdot;
+       bool is_dot, is_dotdot;
 
        /* Safety net */
        if (path == NULL) {
@@ -219,67 +321,52 @@ char *utils_expand_path(const char *path)
        }
 
        /* Allocate memory for the absolute_path */
-       absolute_path = zmalloc(PATH_MAX);
+       absolute_path = zmalloc(LTTNG_PATH_MAX);
        if (absolute_path == NULL) {
                PERROR("zmalloc expand path");
                goto error;
        }
 
-       /*
-        * If the path is not already absolute nor explicitly relative,
-        * consider we're in the current directory
-        */
-       if (*path != '/' && strncmp(path, "./", 2) != 0 &&
-                       strncmp(path, "../", 3) != 0) {
-               snprintf(absolute_path, PATH_MAX, "./%s", path);
-       /* Else, we just copy the path */
-       } else {
-               strncpy(absolute_path, path, PATH_MAX);
-       }
-
-       /* Resolve partially our path */
-       absolute_path = utils_partial_realpath(absolute_path,
-                       absolute_path, PATH_MAX);
-
-       /* As long as we find '/./' in the working_path string */
-       while ((next = strstr(absolute_path, "/./"))) {
-
-               /* We prepare the start_path not containing it */
-               start_path = lttng_strndup(absolute_path, next - absolute_path);
-               if (!start_path) {
-                       PERROR("lttng_strndup");
+       if (path[0] == '/') {
+               ret = lttng_strncpy(absolute_path, path, LTTNG_PATH_MAX);
+               if (ret) {
+                       ERR("Path exceeds maximal size of %i bytes", LTTNG_PATH_MAX);
                        goto error;
                }
-               /* And we concatenate it with the part after this string */
-               snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 2);
-
-               free(start_path);
-       }
+       } else {
+               /*
+                * This is a relative path. We need to get the present working
+                * directory and start the path walk from there.
+                */
+               char current_working_dir[LTTNG_PATH_MAX];
+               char *cwd_ret;
 
-       /* As long as we find '/../' in the working_path string */
-       while ((next = strstr(absolute_path, "/../"))) {
-               /* We find the last level of directory */
-               previous = absolute_path;
-               while ((slash = strpbrk(previous, "/")) && slash != next) {
-                       previous = slash + 1;
+               cwd_ret = getcwd(current_working_dir, sizeof(current_working_dir));
+               if (!cwd_ret) {
+                       goto error;
                }
-
-               /* Then we prepare the start_path not containing it */
-               start_path = lttng_strndup(absolute_path, previous - absolute_path);
-               if (!start_path) {
-                       PERROR("lttng_strndup");
+               /*
+                * Get the number of character in the CWD and allocate an array
+                * to can hold it and the path provided by the caller.
+                */
+               ret = snprintf(absolute_path, LTTNG_PATH_MAX, "%s/%s",
+                               current_working_dir, path);
+               if (ret >= LTTNG_PATH_MAX) {
+                       ERR("Concatenating current working directory %s and path %s exceeds maximal size of %i bytes",
+                                       current_working_dir, path, LTTNG_PATH_MAX);
                        goto error;
                }
+       }
 
-               /* And we concatenate it with the part after the '/../' */
-               snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 4);
-
-               /* We can free the memory used for the start path*/
-               free(start_path);
-
-               /* Then we verify for symlinks using partial_realpath */
+       if (keep_symlink) {
+               /* Resolve partially our path */
                absolute_path = utils_partial_realpath(absolute_path,
-                               absolute_path, PATH_MAX);
+                               absolute_path, LTTNG_PATH_MAX);
+       }
+
+       ret = expand_double_slashes_dot_and_dotdot(absolute_path);
+       if (ret) {
+               goto error;
        }
 
        /* Identify the last token */
@@ -313,7 +400,17 @@ error:
        free(absolute_path);
        return NULL;
 }
+LTTNG_HIDDEN
+char *utils_expand_path(const char *path)
+{
+       return _utils_expand_path(path, true);
+}
 
+LTTNG_HIDDEN
+char *utils_expand_path_keep_symlink(const char *path)
+{
+       return _utils_expand_path(path, false);
+}
 /*
  * Create a pipe in dst.
  */
@@ -528,7 +625,7 @@ int utils_create_lock_file(const char *filepath)
                S_IRGRP | S_IWGRP);
        if (fd < 0) {
                PERROR("open lock file %s", filepath);
-               ret = -1;
+               fd = -1;
                goto error;
        }
 
@@ -755,7 +852,11 @@ static int utils_stream_file_name(char *path,
                strncpy(path, path_name_suffix, PATH_MAX - 1);
                path[PATH_MAX - 1] = '\0';
        } else {
-               strncpy(path, full_path, PATH_MAX - 1);
+               ret = lttng_strncpy(path, full_path, PATH_MAX);
+               if (ret) {
+                       ERR("Failed to copy stream file name");
+                       goto error_free_suffix;
+               }
        }
        path[PATH_MAX - 1] = '\0';
        ret = 0;
@@ -785,7 +886,11 @@ int utils_create_stream_file(const char *path_name, char *file_name, uint64_t si
                goto error;
        }
 
-       flags = O_WRONLY | O_CREAT | O_TRUNC;
+       /*
+        * With the session rotation feature on the relay, we might need to seek
+        * and truncate a tracefile, so we need read and write access.
+        */
+       flags = O_RDWR | O_CREAT | O_TRUNC;
        /* Open with 660 mode */
        mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
 
@@ -997,6 +1102,134 @@ end:
        return ret;
 }
 
+/**
+ * Parse a string that represents a time in human readable format. It
+ * supports decimal integers suffixed by:
+ *     "us" for microsecond,
+ *     "ms" for millisecond,
+ *     "s"  for second,
+ *     "m"  for minute,
+ *     "h"  for hour
+ *
+ * The suffix multiply the integer by:
+ *     "us" : 1
+ *     "ms" : 1000
+ *     "s"  : 1000000
+ *     "m"  : 60000000
+ *     "h"  : 3600000000
+ *
+ * Note that unit-less numbers are assumed to be microseconds.
+ *
+ * @param str          The string to parse, assumed to be NULL-terminated.
+ * @param time_us      Pointer to a uint64_t that will be filled with the
+ *                     resulting time in microseconds.
+ *
+ * @return 0 on success, -1 on failure.
+ */
+LTTNG_HIDDEN
+int utils_parse_time_suffix(char const * const str, uint64_t * const time_us)
+{
+       int ret;
+       uint64_t base_time;
+       uint64_t multiplier = 1;
+       const char *str_end;
+       char *num_end;
+
+       if (!str) {
+               DBG("utils_parse_time_suffix: received a NULL string.");
+               ret = -1;
+               goto end;
+       }
+
+       /* strtoull will accept a negative number, but we don't want to. */
+       if (strchr(str, '-') != NULL) {
+               DBG("utils_parse_time_suffix: invalid time string, should not contain '-'.");
+               ret = -1;
+               goto end;
+       }
+
+       /* str_end will point to the \0 */
+       str_end = str + strlen(str);
+       errno = 0;
+       base_time = strtoull(str, &num_end, 10);
+       if (errno != 0) {
+               PERROR("utils_parse_time_suffix strtoull on string \"%s\"", str);
+               ret = -1;
+               goto end;
+       }
+
+       if (num_end == str) {
+               /* strtoull parsed nothing, not good. */
+               DBG("utils_parse_time_suffix: strtoull had nothing good to parse.");
+               ret = -1;
+               goto end;
+       }
+
+       /* Check if a prefix is present. */
+       switch (*num_end) {
+       case 'u':
+               /*
+                * Microsecond (us)
+                *
+                * Skip the "us" if the string matches the "us" suffix,
+                * otherwise let the check for the end of the string handle
+                * the error reporting.
+                */
+               if (*(num_end + 1) == 's') {
+                       num_end += 2;
+               }
+               break;
+       case 'm':
+               if (*(num_end + 1) == 's') {
+                       /* Millisecond (ms) */
+                       multiplier = USEC_PER_MSEC;
+                       /* Skip the 's' */
+                       num_end++;
+               } else {
+                       /* Minute (m) */
+                       multiplier = USEC_PER_MINUTE;
+               }
+               num_end++;
+               break;
+       case 's':
+               /* Second */
+               multiplier = USEC_PER_SEC;
+               num_end++;
+               break;
+       case 'h':
+               /* Hour */
+               multiplier = USEC_PER_HOURS;
+               num_end++;
+               break;
+       case '\0':
+               break;
+       default:
+               DBG("utils_parse_time_suffix: invalid suffix.");
+               ret = -1;
+               goto end;
+       }
+
+       /* Check for garbage after the valid input. */
+       if (num_end != str_end) {
+               DBG("utils_parse_time_suffix: Garbage after time string.");
+               ret = -1;
+               goto end;
+       }
+
+       *time_us = base_time * multiplier;
+
+       /* Check for overflow */
+       if ((*time_us / multiplier) != base_time) {
+               DBG("utils_parse_time_suffix: oops, overflow detected.");
+               ret = -1;
+               goto end;
+       }
+
+       ret = 0;
+end:
+       return ret;
+}
+
 /*
  * fls: returns the position of the most significant bit.
  * Returns 0 if no bit is set, else returns the position of the most
@@ -1017,6 +1250,59 @@ static inline unsigned int fls_u32(uint32_t x)
 #define HAS_FLS_U32
 #endif
 
+#if defined(__x86_64)
+static inline
+unsigned int fls_u64(uint64_t x)
+{
+       long r;
+
+       asm("bsrq %1,%0\n\t"
+           "jnz 1f\n\t"
+           "movq $-1,%0\n\t"
+           "1:\n\t"
+           : "=r" (r) : "rm" (x));
+       return r + 1;
+}
+#define HAS_FLS_U64
+#endif
+
+#ifndef HAS_FLS_U64
+static __attribute__((unused))
+unsigned int fls_u64(uint64_t x)
+{
+       unsigned int r = 64;
+
+       if (!x)
+               return 0;
+
+       if (!(x & 0xFFFFFFFF00000000ULL)) {
+               x <<= 32;
+               r -= 32;
+       }
+       if (!(x & 0xFFFF000000000000ULL)) {
+               x <<= 16;
+               r -= 16;
+       }
+       if (!(x & 0xFF00000000000000ULL)) {
+               x <<= 8;
+               r -= 8;
+       }
+       if (!(x & 0xF000000000000000ULL)) {
+               x <<= 4;
+               r -= 4;
+       }
+       if (!(x & 0xC000000000000000ULL)) {
+               x <<= 2;
+               r -= 2;
+       }
+       if (!(x & 0x8000000000000000ULL)) {
+               x <<= 1;
+               r -= 1;
+       }
+       return r;
+}
+#endif
+
 #ifndef HAS_FLS_U32
 static __attribute__((unused)) unsigned int fls_u32(uint32_t x)
 {
@@ -1063,6 +1349,20 @@ int utils_get_count_order_u32(uint32_t x)
        return fls_u32(x - 1);
 }
 
+/*
+ * Return the minimum order for which x <= (1UL << order).
+ * Return -1 if x is 0.
+ */
+LTTNG_HIDDEN
+int utils_get_count_order_u64(uint64_t x)
+{
+       if (!x) {
+               return -1;
+       }
+
+       return fls_u64(x - 1);
+}
+
 /**
  * Obtain the value of LTTNG_HOME environment variable, if exists.
  * Otherwise returns the value of HOME.
@@ -1135,26 +1435,6 @@ end:
        return home_dir;
 }
 
-/*
- * Obtain the value of LTTNG_KMOD_PROBES environment variable, if exists.
- * Otherwise returns NULL.
- */
-LTTNG_HIDDEN
-char *utils_get_kmod_probes_list(void)
-{
-       return lttng_secure_getenv(DEFAULT_LTTNG_KMOD_PROBES);
-}
-
-/*
- * Obtain the value of LTTNG_EXTRA_KMOD_PROBES environment variable, if
- * exists. Otherwise returns NULL.
- */
-LTTNG_HIDDEN
-char *utils_get_extra_kmod_probes_list(void)
-{
-       return lttng_secure_getenv(DEFAULT_LTTNG_EXTRA_KMOD_PROBES);
-}
-
 /*
  * With the given format, fill dst with the time of len maximum siz.
  *
@@ -1335,15 +1615,17 @@ LTTNG_HIDDEN
 int utils_truncate_stream_file(int fd, off_t length)
 {
        int ret;
+       off_t lseek_ret;
 
        ret = ftruncate(fd, length);
        if (ret < 0) {
                PERROR("ftruncate");
                goto end;
        }
-       ret = lseek(fd, length, SEEK_SET);
-       if (ret < 0) {
+       lseek_ret = lseek(fd, length, SEEK_SET);
+       if (lseek_ret < 0) {
                PERROR("lseek");
+               ret = -1;
                goto end;
        }
 end:
@@ -1362,11 +1644,17 @@ static const char *get_man_bin_path(void)
 }
 
 LTTNG_HIDDEN
-int utils_show_man_page(int section, const char *page_name)
+int utils_show_help(int section, const char *page_name,
+               const char *help_msg)
 {
        char section_string[8];
        const char *man_bin_path = get_man_bin_path();
-       int ret;
+       int ret = 0;
+
+       if (help_msg) {
+               printf("%s", help_msg);
+               goto end;
+       }
 
        /* Section integer -> section string */
        ret = sprintf(section_string, "%d", section);
@@ -1375,11 +1663,13 @@ int utils_show_man_page(int section, const char *page_name)
        /*
         * Execute man pager.
         *
-        * We provide --manpath to man here because LTTng-tools can
+        * We provide -M to man here because LTTng-tools can
         * be installed outside /usr, in which case its man pages are
         * not located in the default /usr/share/man directory.
         */
-       ret = execlp(man_bin_path, "man", "--manpath", MANPATH,
+       ret = execlp(man_bin_path, "man", "-M", MANPATH,
                section_string, page_name, NULL);
+
+end:
        return ret;
 }
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