X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Futils.c;h=31596ddd36c3a3314daa2de1db6db19690b7800a;hp=57add319ba416b6eda1cb967fc126c008177f45f;hb=fb198a1138d32ac7218695c564909d96018eb1b7;hpb=5154230f59b7f66abe33166cf14ef49d2c4e2219 diff --git a/src/common/utils.c b/src/common/utils.c index 57add319b..31596ddd3 100644 --- a/src/common/utils.c +++ b/src/common/utils.c @@ -1,5 +1,7 @@ /* * Copyright (C) 2012 - David Goulet + * Copyright (C) 2013 - Raphaël Beamonte + * Copyright (C) 2013 - Jérémie Galarneau * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License, version 2 only, as @@ -28,6 +30,7 @@ #include #include #include +#include #include #include @@ -164,31 +167,51 @@ error: } /* - * Resolve the './' and '../' strings in the middle of a path using - * our very own way to do it, so that it works even if the directory - * does not exist + * Make a full resolution of the given path even if it doesn't exist. + * This function uses the utils_partial_realpath function to resolve + * symlinks and relatives paths at the start of the string, and + * implements functionnalities to resolve the './' and '../' strings + * in the middle of a path. This function is only necessary because + * realpath(3) does not accept to resolve unexistent paths. + * The returned string was allocated in the function, it is thus of + * the responsibility of the caller to free this memory. */ LTTNG_HIDDEN -char *utils_resolve_relative(const char *path) +char *utils_expand_path(const char *path) { char *next, *previous, *slash, *start_path, *absolute_path = NULL; + char *last_token; + int is_dot, is_dotdot; /* Safety net */ if (path == NULL) { goto error; } - /* Allocate memory for the absolute path */ + /* Allocate memory for the absolute_path */ absolute_path = zmalloc(PATH_MAX); if (absolute_path == NULL) { PERROR("zmalloc expand path"); goto error; } - /* Copy the path in the absolute path */ - strncpy(absolute_path, path, PATH_MAX); + /* + * 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 path string */ + /* As long as we find '/./' in the working_path string */ while ((next = strstr(absolute_path, "/./"))) { /* We prepare the start_path not containing it */ @@ -200,132 +223,57 @@ char *utils_resolve_relative(const char *path) free(start_path); } - /* As long as we find '/../' in the path string */ + /* As long as we find '/../' in the working_path string */ while ((next = strstr(absolute_path, "/../"))) { - /* If the path starts with '/../', there's a problem */ - if (next == absolute_path) { - ERR("%s: Path cannot be resolved", path); - goto error; - } - /* We find the last level of directory */ previous = absolute_path; - while ((slash = strpbrk(previous + 1, "/")) && slash != next) { - previous = slash; + while ((slash = strpbrk(previous, "/")) && slash != next) { + previous = slash + 1; } /* Then we prepare the start_path not containing it */ start_path = strndup(absolute_path, previous - absolute_path); /* And we concatenate it with the part after the '/../' */ - snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 3); + snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 4); + /* We can free the memory used for the start path*/ free(start_path); - } - - return absolute_path; - -error: - free(absolute_path); - return NULL; -} - - -/* - * Return the realpath(3) of the path even if the last directory token does not - * exist. For example, with /tmp/test1/test2, if test2/ does not exist but the - * /tmp/test1 does, the real path is returned. In normal time, realpath(3) - * fails if the end point directory does not exist. - */ -LTTNG_HIDDEN -char *utils_expand_path(const char *path) -{ - const char *end_path = NULL; - char *next, *cut_path = NULL, *expanded_path = NULL; - /* Safety net */ - if (path == NULL) { - goto error; + /* Then we verify for symlinks using partial_realpath */ + absolute_path = utils_partial_realpath(absolute_path, + absolute_path, PATH_MAX); } - /* Allocate memory for the expanded path */ - expanded_path = zmalloc(PATH_MAX); - if (expanded_path == NULL) { - PERROR("zmalloc expand path"); - goto error; - } + /* Identify the last token */ + last_token = strrchr(absolute_path, '/'); - /* If given path is already absolute */ - if (*path == '/') { - strncpy(expanded_path, path, PATH_MAX); - /* Else, we have some work to do */ - } else { - /* Pointer to the last char of the path */ - const char *last_char = path + strlen(path) - 1; + /* Verify that this token is not a relative path */ + is_dotdot = (strcmp(last_token, "/..") == 0); + is_dot = (strcmp(last_token, "/.") == 0); - end_path = path; + /* If it is, take action */ + if (is_dot || is_dotdot) { + /* For both, remove this token */ + *last_token = '\0'; - /* Split part that will be resolved by realpath (relative path from - * current directory using ./ or ../ only) and part that could not - * (directory names) - */ - while ((next = strpbrk(end_path, "/")) && (next != last_char)) { - end_path = next + 1; - if (strncmp(end_path, "./", 2) != 0 && - strncmp(end_path, "../", 3) != 0) { - break; - } - } + /* If it was a reference to parent directory, go back one more time */ + if (is_dotdot) { + last_token = strrchr(absolute_path, '/'); - /* If this is the end of the string, and we still can resolve it */ - if (strncmp(end_path, "..\0", 3) == 0 || - strncmp(end_path, ".\0", 2) == 0) { - end_path += strlen(end_path); - } - - /* If the end part is the whole path, we are in the current dir */ - if (end_path == path) { - cut_path = strdup("."); - /* Else, cut the resolvable part from original path */ - } else { - cut_path = strndup(path, end_path - path); - } - - /* Resolve the canonical path of the first part of the path */ - expanded_path = realpath((char *)cut_path, expanded_path); - if (expanded_path == NULL) { - switch (errno) { - case ENOENT: - ERR("%s: No such file or directory", cut_path); - break; - default: - PERROR("realpath utils expand path"); - break; + /* If there was only one level left, we keep the first '/' */ + if (last_token == absolute_path) { + last_token++; } - goto error; - } - /* Add end part to expanded path if not empty */ - if (*end_path != 0) { - strncat(expanded_path, "/", PATH_MAX - strlen(expanded_path) - 1); - strncat(expanded_path, end_path, - PATH_MAX - strlen(expanded_path) - 1); + *last_token = '\0'; } } - /* Resolve the internal './' and '../' strings */ - next = utils_resolve_relative(expanded_path); - if (next == NULL) { - goto error; - } - - free(expanded_path); - free(cut_path); - return next; + return absolute_path; error: - free(expanded_path); - free(cut_path); + free(absolute_path); return NULL; } @@ -907,6 +855,46 @@ char *utils_get_home_dir(void) return getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR); } +/** + * Get user's home directory. Dynamically allocated, must be freed + * by the caller. + */ +LTTNG_HIDDEN +char *utils_get_user_home_dir(uid_t uid) +{ + struct passwd pwd; + struct passwd *result; + char *home_dir = NULL; + char *buf = NULL; + long buflen; + int ret; + + buflen = sysconf(_SC_GETPW_R_SIZE_MAX); + if (buflen == -1) { + goto end; + } +retry: + buf = zmalloc(buflen); + if (!buf) { + goto end; + } + + ret = getpwuid_r(uid, &pwd, buf, buflen, &result); + if (ret || !result) { + if (ret == ERANGE) { + free(buf); + buflen *= 2; + goto retry; + } + goto end; + } + + home_dir = strdup(pwd.pw_dir); +end: + free(buf); + return home_dir; +} + /* * With the given format, fill dst with the time of len maximum siz. * @@ -954,3 +942,46 @@ gid_t utils_get_group_id(const char *name) } return grp->gr_gid; } + +/* + * Return a newly allocated option string. This string is to be used as the + * optstring argument of getopt_long(), see GETOPT(3). opt_count is the number + * of elements in the long_options array. Returns NULL if the string's + * allocation fails. + */ +LTTNG_HIDDEN +char *utils_generate_optstring(const struct option *long_options, + size_t opt_count) +{ + int i; + size_t string_len = opt_count, str_pos = 0; + char *optstring; + + /* + * Compute the necessary string length. One letter per option, two when an + * argument is necessary, and a trailing NULL. + */ + for (i = 0; i < opt_count; i++) { + string_len += long_options[i].has_arg ? 1 : 0; + } + + optstring = zmalloc(string_len); + if (!optstring) { + goto end; + } + + for (i = 0; i < opt_count; i++) { + if (!long_options[i].name) { + /* Got to the trailing NULL element */ + break; + } + + optstring[str_pos++] = (char)long_options[i].val; + if (long_options[i].has_arg) { + optstring[str_pos++] = ':'; + } + } + +end: + return optstring; +}