X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Futils.c;h=815965bc4ba25256de830f0794cf357f2150db70;hp=6938a5ae52f6cac2e12465b37e3caafe8ae61d23;hb=5983a922b5e591a0fd90800e482e1ab8b89a4281;hpb=116f95d94575a68aee90fff79c064119729d0d24 diff --git a/src/common/utils.c b/src/common/utils.c index 6938a5ae5..815965bc4 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 @@ -26,8 +28,8 @@ #include #include #include -#include #include +#include #include #include @@ -36,168 +38,241 @@ #include "defaults.h" /* - * 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 + * Return a partial realpath(3) of the path even if the full path does not + * exist. For instance, with /tmp/test1/test2/test3, if test2/ does not exist + * but the /tmp/test1 does, the real path for /tmp/test1 is concatened with + * /test2/test3 then returned. In normal time, realpath(3) fails if the end + * point directory does not exist. + * In case resolved_path is NULL, the string returned was allocated in the + * function and thus need to be freed by the caller. The size argument allows + * to specify the size of the resolved_path argument if given, or the size to + * allocate. */ LTTNG_HIDDEN -char *utils_resolve_relative(const char *path) +char *utils_partial_realpath(const char *path, char *resolved_path, size_t size) { - char *next, *previous, *slash, *start_path, *absolute_path = NULL; + char *cut_path, *try_path = NULL, *try_path_prev = NULL; + const char *next, *prev, *end; /* Safety net */ if (path == NULL) { goto error; } - /* Allocate memory for the absolute path */ - absolute_path = zmalloc(PATH_MAX); - if (absolute_path == NULL) { - PERROR("zmalloc expand path"); - goto error; + /* + * Identify the end of the path, we don't want to treat the + * last char if it is a '/', we will just keep it on the side + * to be added at the end, and return a value coherent with + * the path given as argument + */ + end = path + strlen(path); + if (*(end-1) == '/') { + end--; } - /* Copy the path in the absolute path */ - strncpy(absolute_path, path, PATH_MAX); - - /* As long as we find '/./' in the path string */ - while ((next = strstr(absolute_path, "/./"))) { + /* Initiate the values of the pointers before looping */ + next = path; + prev = next; + /* Only to ensure try_path is not NULL to enter the while */ + try_path = (char *)next; - /* We prepare the start_path not containing it */ - start_path = strndup(absolute_path, next - absolute_path); + /* Resolve the canonical path of the first part of the path */ + while (try_path != NULL && next != end) { + /* + * If there is not any '/' left, we want to try with + * the full path + */ + next = strpbrk(next + 1, "/"); + if (next == NULL) { + next = end; + } - /* And we concatenate it with the part after this string */ - snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 2); + /* Cut the part we will be trying to resolve */ + cut_path = strndup(path, next - path); + + /* Try to resolve this part */ + try_path = realpath((char *)cut_path, NULL); + if (try_path == NULL) { + /* + * There was an error, we just want to be assured it + * is linked to an unexistent directory, if it's another + * reason, we spawn an error + */ + switch (errno) { + case ENOENT: + /* Ignore the error */ + break; + default: + PERROR("realpath (partial_realpath)"); + goto error; + break; + } + } else { + /* Save the place we are before trying the next step */ + free(try_path_prev); + try_path_prev = try_path; + prev = next; + } - free(start_path); - } + /* Free the allocated memory */ + free(cut_path); + }; - /* As long as we find '/../' in the 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); + /* Allocate memory for the resolved path if necessary */ + if (resolved_path == NULL) { + resolved_path = zmalloc(size); + if (resolved_path == NULL) { + PERROR("zmalloc resolved path"); goto error; } + } - /* We find the last level of directory */ - previous = absolute_path; - while ((slash = strpbrk(previous + 1, "/")) && slash != next) { - previous = slash; + /* + * If we were able to solve at least partially the path, we can concatenate + * what worked and what didn't work + */ + if (try_path_prev != NULL) { + /* If we risk to concatenate two '/', we remove one of them */ + if (try_path_prev[strlen(try_path_prev) - 1] == '/' && prev[0] == '/') { + try_path_prev[strlen(try_path_prev) - 1] = '\0'; } - /* Then we prepare the start_path not containing it */ - start_path = strndup(absolute_path, previous - absolute_path); + /* + * Duplicate the memory used by prev in case resolved_path and + * path are pointers for the same memory space + */ + cut_path = strdup(prev); - /* And we concatenate it with the part after the '/../' */ - snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 3); + /* Concatenate the strings */ + snprintf(resolved_path, size, "%s%s", try_path_prev, cut_path); - free(start_path); + /* Free the allocated memory */ + free(cut_path); + free(try_path_prev); + /* + * Else, we just copy the path in our resolved_path to + * return it as is + */ + } else { + strncpy(resolved_path, path, size); } - return absolute_path; + /* Then we return the 'partially' resolved path */ + return resolved_path; error: - free(absolute_path); + free(resolved_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. + * 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_expand_path(const char *path) { - const char *end_path = NULL; - char *next, *cut_path = NULL, *expanded_path = NULL; + 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 expanded path */ - expanded_path = zmalloc(PATH_MAX); - if (expanded_path == NULL) { + /* Allocate memory for the absolute_path */ + absolute_path = zmalloc(PATH_MAX); + if (absolute_path == NULL) { PERROR("zmalloc expand path"); goto error; } - /* If given path is already absolute */ - if (*path == '/') { - strncpy(expanded_path, path, PATH_MAX); - /* Else, we have some work to do */ + /* + * 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 { - /* Pointer to the last char of the path */ - const char *last_char = path + strlen(path) - 1; + strncpy(absolute_path, path, PATH_MAX); + } - end_path = path; + /* Resolve partially our path */ + absolute_path = utils_partial_realpath(absolute_path, + absolute_path, PATH_MAX); - /* 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; - } - } + /* As long as we find '/./' in the working_path string */ + while ((next = strstr(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); - } + /* We prepare the start_path not containing it */ + start_path = strndup(absolute_path, next - absolute_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); - } + /* And we concatenate it with the part after this string */ + snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 2); - /* 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; - } - goto error; - } + free(start_path); + } - /* 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); + /* 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; } + + /* 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 + 4); + + /* We can free the memory used for the start path*/ + free(start_path); + + /* Then we verify for symlinks using partial_realpath */ + absolute_path = utils_partial_realpath(absolute_path, + absolute_path, PATH_MAX); } - /* Resolve the internal './' and '../' strings */ - next = utils_resolve_relative(expanded_path); - if (next == NULL) { - goto error; + /* Identify the last token */ + last_token = strrchr(absolute_path, '/'); + + /* Verify that this token is not a relative path */ + is_dotdot = (strcmp(last_token, "/..") == 0); + is_dot = (strcmp(last_token, "/.") == 0); + + /* If it is, take action */ + if (is_dot || is_dotdot) { + /* For both, remove this token */ + *last_token = '\0'; + + /* If it was a reference to parent directory, go back one more time */ + if (is_dotdot) { + last_token = strrchr(absolute_path, '/'); + + /* If there was only one level left, we keep the first '/' */ + if (last_token == absolute_path) { + last_token++; + } + + *last_token = '\0'; + } } - free(expanded_path); - free(cut_path); - return next; + return absolute_path; error: - free(expanded_path); - free(cut_path); + free(absolute_path); return NULL; } @@ -574,42 +649,10 @@ error: return ret; } -/** - * Prints the error message corresponding to a regex error code. - * - * @param errcode The error code. - * @param regex The regex object that produced the error code. - */ -static void regex_print_error(int errcode, regex_t *regex) -{ - /* Get length of error message and allocate accordingly */ - size_t length; - char *buffer; - - assert(regex != NULL); - - length = regerror(errcode, regex, NULL, 0); - if (length == 0) { - ERR("regerror returned a length of 0"); - return; - } - - buffer = zmalloc(length); - if (!buffer) { - ERR("regex_print_error: zmalloc failed"); - return; - } - - /* Get and print error message */ - regerror(errcode, regex, buffer, length); - ERR("regex error: %s\n", buffer); - free(buffer); - -} /** * Parse a string that represents a size in human readable format. It - * supports decimal integers suffixed by 'k', 'M' or 'G'. + * supports decimal integers suffixed by 'k', 'K', 'M' or 'G'. * * The suffix multiply the integer by: * 'k': 1024 @@ -617,83 +660,90 @@ static void regex_print_error(int errcode, regex_t *regex) * 'G': 1024^3 * * @param str The string to parse. - * @param size Pointer to a size_t that will be filled with the + * @param size Pointer to a uint64_t that will be filled with the * resulting size. * * @return 0 on success, -1 on failure. */ LTTNG_HIDDEN -int utils_parse_size_suffix(char *str, uint64_t *size) +int utils_parse_size_suffix(const char * const str, uint64_t * const size) { - regex_t regex; int ret; - const int nmatch = 3; - regmatch_t suffix_match, matches[nmatch]; - unsigned long long base_size; + uint64_t base_size; long shift = 0; + const char *str_end; + char *num_end; if (!str) { - return 0; - } - - /* Compile regex */ - ret = regcomp(®ex, "^\\(0x\\)\\{0,1\\}[0-9][0-9]*\\([kKMG]\\{0,1\\}\\)$", 0); - if (ret != 0) { - regex_print_error(ret, ®ex); + DBG("utils_parse_size_suffix: received a NULL string."); ret = -1; goto end; } - /* Match regex */ - ret = regexec(®ex, str, nmatch, matches, 0); - if (ret != 0) { + /* strtoull will accept a negative number, but we don't want to. */ + if (strchr(str, '-') != NULL) { + DBG("utils_parse_size_suffix: invalid size string, should not contain '-'."); ret = -1; - goto free; + goto end; } - /* There is a match ! */ + /* str_end will point to the \0 */ + str_end = str + strlen(str); errno = 0; - base_size = strtoull(str, NULL, 0); + base_size = strtoull(str, &num_end, 0); if (errno != 0) { - PERROR("strtoull"); + PERROR("utils_parse_size_suffix strtoull"); ret = -1; - goto free; + goto end; } - /* Check if there is a suffix */ - suffix_match = matches[2]; - if (suffix_match.rm_eo - suffix_match.rm_so == 1) { - switch (*(str + suffix_match.rm_so)) { - case 'K': - case 'k': - shift = KIBI_LOG2; - break; - case 'M': - shift = MEBI_LOG2; - break; - case 'G': - shift = GIBI_LOG2; - break; - default: - ERR("parse_human_size: invalid suffix"); - ret = -1; - goto free; - } + if (num_end == str) { + /* strtoull parsed nothing, not good. */ + DBG("utils_parse_size_suffix: strtoull had nothing good to parse."); + ret = -1; + goto end; + } + + /* Check if a prefix is present. */ + switch (*num_end) { + case 'G': + shift = GIBI_LOG2; + num_end++; + break; + case 'M': /* */ + shift = MEBI_LOG2; + num_end++; + break; + case 'K': + case 'k': + shift = KIBI_LOG2; + num_end++; + break; + case '\0': + break; + default: + DBG("utils_parse_size_suffix: invalid suffix."); + ret = -1; + goto end; + } + + /* Check for garbage after the valid input. */ + if (num_end != str_end) { + DBG("utils_parse_size_suffix: Garbage after size string."); + ret = -1; + goto end; } *size = base_size << shift; /* Check for overflow */ if ((*size >> shift) != base_size) { - ERR("parse_size_suffix: oops, overflow detected."); + DBG("utils_parse_size_suffix: oops, overflow detected."); ret = -1; - goto free; + goto end; } ret = 0; - -free: - regfree(®ex); end: return ret; } @@ -779,6 +829,46 @@ 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. * @@ -826,3 +916,46 @@ 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; +}