X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Futils.c;h=08139e5e2cb23d691c92c6800cef841e2362bc57;hp=e9fb552ac1011fc37569865baacb6fdbe29ca2de;hb=2daf65025e0fe5c15179dc4bfb26f875e3d31a26;hpb=072ede5941482a4d2727d2b41af7ea2557fed4d9 diff --git a/src/common/utils.c b/src/common/utils.c index e9fb552ac..08139e5e2 100644 --- a/src/common/utils.c +++ b/src/common/utils.c @@ -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. */ @@ -1549,3 +1646,38 @@ int utils_show_help(int section, const char *page_name, end: return ret; } + +LTTNG_HIDDEN +int timespec_to_ms(struct timespec ts, unsigned long *ms) +{ + unsigned long res, remain_ms; + + if (ts.tv_sec > ULONG_MAX / MSEC_PER_SEC) { + errno = EOVERFLOW; + return -1; /* multiplication overflow */ + } + res = ts.tv_sec * MSEC_PER_SEC; + remain_ms = ULONG_MAX - res; + if (ts.tv_nsec / NSEC_PER_MSEC > remain_ms) { + errno = EOVERFLOW; + return -1; /* addition overflow */ + } + res += ts.tv_nsec / NSEC_PER_MSEC; + *ms = res; + return 0; +} + +LTTNG_HIDDEN +struct timespec timespec_abs_diff(struct timespec t1, struct timespec t2) +{ + uint64_t ts1 = (uint64_t) t1.tv_sec * (uint64_t) NSEC_PER_SEC + + (uint64_t) t1.tv_nsec; + uint64_t ts2 = (uint64_t) t2.tv_sec * (uint64_t) NSEC_PER_SEC + + (uint64_t) t2.tv_nsec; + uint64_t diff = max(ts1, ts2) - min(ts1, ts2); + struct timespec res; + + res.tv_sec = diff / (uint64_t) NSEC_PER_SEC; + res.tv_nsec = diff % (uint64_t) NSEC_PER_SEC; + return res; +}