X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Futils.c;h=732a30bf114fb89551bf322451dca89afbef10cf;hp=84d42f4638e53f37fc139c4b1c6d5d6b1c30b375;hb=93bed9fe8f48c11b7bb1224db36d82404cea080d;hpb=4b223a6755662f272f7db155ee380528728e5dd1 diff --git a/src/common/utils.c b/src/common/utils.c index 84d42f463..732a30bf1 100644 --- a/src/common/utils.c +++ b/src/common/utils.c @@ -33,14 +33,32 @@ #include #include +#include #include #include #include #include +#include +#include +#include #include #include "utils.h" #include "defaults.h" +#include "time.h" + +#define PROC_MEMINFO_PATH "/proc/meminfo" +#define PROC_MEMINFO_MEMAVAILABLE_LINE "MemAvailable:" +#define PROC_MEMINFO_MEMTOTAL_LINE "MemTotal:" + +/* The length of the longest field of `/proc/meminfo`. */ +#define PROC_MEMINFO_FIELD_MAX_NAME_LEN 20 + +#if (PROC_MEMINFO_FIELD_MAX_NAME_LEN == 20) +#define MAX_NAME_LEN_SCANF_IS_A_BROKEN_API "19" +#else +#error MAX_NAME_LEN_SCANF_IS_A_BROKEN_API must be updated to match (PROC_MEMINFO_FIELD_MAX_NAME_LEN - 1) +#endif /* * Return a partial realpath(3) of the path even if the full path does not @@ -197,7 +215,7 @@ error: } static -char *expand_double_slashes_dot_and_dotdot(char *path) +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; @@ -206,7 +224,6 @@ char *expand_double_slashes_dot_and_dotdot(char *path) path_last_char = &path[path_len]; if (path_len == 0) { - path = NULL; goto error; } @@ -292,9 +309,9 @@ char *expand_double_slashes_dot_and_dotdot(char *path) } path[expanded_path_len] = '\0'; - + return 0; error: - return path; + return -1; } /* @@ -310,9 +327,10 @@ error: LTTNG_HIDDEN char *_utils_expand_path(const char *path, bool keep_symlink) { + int ret; char *absolute_path = NULL; char *last_token; - int is_dot, is_dotdot; + bool is_dot, is_dotdot; /* Safety net */ if (path == NULL) { @@ -320,41 +338,51 @@ char *_utils_expand_path(const char *path, bool keep_symlink) } /* 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 (path[0] == '/') { - strncpy(absolute_path, path, PATH_MAX); + ret = lttng_strncpy(absolute_path, path, LTTNG_PATH_MAX); + if (ret) { + ERR("Path exceeds maximal size of %i bytes", LTTNG_PATH_MAX); + goto error; + } } 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[PATH_MAX]; + char current_working_dir[LTTNG_PATH_MAX]; char *cwd_ret; + cwd_ret = getcwd(current_working_dir, sizeof(current_working_dir)); if (!cwd_ret) { - absolute_path = NULL; goto error; } /* * Get the number of character in the CWD and allocate an array * to can hold it and the path provided by the caller. */ - snprintf(absolute_path, PATH_MAX, "%s/%s", current_working_dir, path); + 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; + } } if (keep_symlink) { /* Resolve partially our path */ absolute_path = utils_partial_realpath(absolute_path, - absolute_path, PATH_MAX); + absolute_path, LTTNG_PATH_MAX); } - absolute_path = expand_double_slashes_dot_and_dotdot(absolute_path); - if (!absolute_path) { + ret = expand_double_slashes_dot_and_dotdot(absolute_path); + if (ret) { goto error; } @@ -642,44 +670,6 @@ error: return fd; } -/* - * On some filesystems (e.g. nfs), mkdir will validate access rights before - * checking for the existence of the path element. This means that on a setup - * where "/home/" is a mounted NFS share, and running as an unpriviledged user, - * recursively creating a path of the form "/home/my_user/trace/" will fail with - * EACCES on mkdir("/home", ...). - * - * Performing a stat(...) on the path to check for existence allows us to - * work around this behaviour. - */ -static -int mkdir_check_exists(const char *path, mode_t mode) -{ - int ret = 0; - struct stat st; - - ret = stat(path, &st); - if (ret == 0) { - if (S_ISDIR(st.st_mode)) { - /* Directory exists, skip. */ - goto end; - } else { - /* Exists, but is not a directory. */ - errno = ENOTDIR; - ret = -1; - goto end; - } - } - - /* - * Let mkdir handle other errors as the caller expects mkdir - * semantics. - */ - ret = mkdir(path, mode); -end: - return ret; -} - /* * Create directory using the given path and mode. * @@ -689,82 +679,21 @@ LTTNG_HIDDEN int utils_mkdir(const char *path, mode_t mode, int uid, int gid) { int ret; - - if (uid < 0 || gid < 0) { - ret = mkdir_check_exists(path, mode); - } else { - ret = run_as_mkdir(path, mode, uid, gid); - } - if (ret < 0) { - if (errno != EEXIST) { - PERROR("mkdir %s, uid %d, gid %d", path ? path : "NULL", - uid, gid); - } else { - ret = 0; - } - } - - return ret; -} - -/* - * Internal version of mkdir_recursive. Runs as the current user. - * Don't call directly; use utils_mkdir_recursive(). - * - * This function is ominously marked as "unsafe" since it should only - * be called by a caller that has transitioned to the uid and gid under which - * the directory creation should occur. - */ -LTTNG_HIDDEN -int _utils_mkdir_recursive_unsafe(const char *path, mode_t mode) -{ - char *p, tmp[PATH_MAX]; - size_t len; - int ret; - - assert(path); - - ret = snprintf(tmp, sizeof(tmp), "%s", path); - if (ret < 0) { - PERROR("snprintf mkdir"); - goto error; - } - - len = ret; - if (tmp[len - 1] == '/') { - tmp[len - 1] = 0; - } - - for (p = tmp + 1; *p; p++) { - if (*p == '/') { - *p = 0; - if (tmp[strlen(tmp) - 1] == '.' && - tmp[strlen(tmp) - 2] == '.' && - tmp[strlen(tmp) - 3] == '/') { - ERR("Using '/../' is not permitted in the trace path (%s)", - tmp); - ret = -1; - goto error; - } - ret = mkdir_check_exists(tmp, mode); - if (ret < 0) { - if (errno != EACCES) { - PERROR("mkdir recursive"); - ret = -errno; - goto error; - } - } - *p = '/'; - } - } - - ret = mkdir_check_exists(tmp, mode); - if (ret < 0) { - PERROR("mkdir recursive last element"); - ret = -errno; + struct lttng_directory_handle handle; + const struct lttng_credentials creds = { + .uid = (uid_t) uid, + .gid = (gid_t) gid, + }; + + ret = lttng_directory_handle_init(&handle, NULL); + if (ret) { + goto end; } - -error: + ret = lttng_directory_handle_create_subdirectory_as_user( + &handle, path, mode, + (uid >= 0 || gid >= 0) ? &creds : NULL); + lttng_directory_handle_fini(&handle); +end: return ret; } @@ -778,82 +707,61 @@ LTTNG_HIDDEN int utils_mkdir_recursive(const char *path, mode_t mode, int uid, int gid) { int ret; - - if (uid < 0 || gid < 0) { - /* Run as current user. */ - ret = _utils_mkdir_recursive_unsafe(path, mode); - } else { - ret = run_as_mkdir_recursive(path, mode, uid, gid); - } - if (ret < 0) { - PERROR("mkdir %s, uid %d, gid %d", path ? path : "NULL", - uid, gid); + struct lttng_directory_handle handle; + const struct lttng_credentials creds = { + .uid = (uid_t) uid, + .gid = (gid_t) gid, + }; + + ret = lttng_directory_handle_init(&handle, NULL); + if (ret) { + goto end; } - + ret = lttng_directory_handle_create_subdirectory_recursive_as_user( + &handle, path, mode, + (uid >= 0 || gid >= 0) ? &creds : NULL); + lttng_directory_handle_fini(&handle); +end: return ret; } /* - * path is the output parameter. It needs to be PATH_MAX len. + * out_stream_path is the output parameter. * * Return 0 on success or else a negative value. */ -static int utils_stream_file_name(char *path, - const char *path_name, const char *file_name, - uint64_t size, uint64_t count, - const char *suffix) +LTTNG_HIDDEN +int utils_stream_file_path(const char *path_name, const char *file_name, + uint64_t size, uint64_t count, const char *suffix, + char *out_stream_path, size_t stream_path_len) { int ret; - char full_path[PATH_MAX]; - char *path_name_suffix = NULL; - char *extra = NULL; + char count_str[MAX_INT_DEC_LEN(count) + 1] = {}; + const char *path_separator; - ret = snprintf(full_path, sizeof(full_path), "%s/%s", - path_name, file_name); - if (ret < 0) { - PERROR("snprintf create output file"); - goto error; + if (path_name && path_name[strlen(path_name) - 1] == '/') { + path_separator = ""; + } else { + path_separator = "/"; } - /* Setup extra string if suffix or/and a count is needed. */ - if (size > 0 && suffix) { - ret = asprintf(&extra, "_%" PRIu64 "%s", count, suffix); - } else if (size > 0) { - ret = asprintf(&extra, "_%" PRIu64, count); - } else if (suffix) { - ret = asprintf(&extra, "%s", suffix); - } - if (ret < 0) { - PERROR("Allocating extra string to name"); - goto error; + path_name = path_name ? : ""; + suffix = suffix ? : ""; + if (size > 0) { + ret = snprintf(count_str, sizeof(count_str), "_%" PRIu64, + count); + assert(ret > 0 && ret < sizeof(count_str)); } - /* - * If we split the trace in multiple files, we have to add the count at - * the end of the tracefile name. - */ - if (extra) { - ret = asprintf(&path_name_suffix, "%s%s", full_path, extra); - if (ret < 0) { - PERROR("Allocating path name with extra string"); - goto error_free_suffix; - } - strncpy(path, path_name_suffix, PATH_MAX - 1); - path[PATH_MAX - 1] = '\0'; + ret = snprintf(out_stream_path, stream_path_len, "%s%s%s%s%s", + path_name, path_separator, file_name, count_str, + suffix); + if (ret < 0 || ret >= stream_path_len) { + ERR("Truncation occurred while formatting stream path"); + ret = -1; } else { - ret = lttng_strncpy(path, full_path, PATH_MAX); - if (ret) { - ERR("Failed to copy stream file name"); - goto error_free_suffix; - } + ret = 0; } - path[PATH_MAX - 1] = '\0'; - ret = 0; - - free(path_name_suffix); -error_free_suffix: - free(extra); -error: return ret; } @@ -867,10 +775,10 @@ int utils_create_stream_file(const char *path_name, char *file_name, uint64_t si uint64_t count, int uid, int gid, char *suffix) { int ret, flags, mode; - char path[PATH_MAX]; + char path[LTTNG_PATH_MAX]; - ret = utils_stream_file_name(path, path_name, file_name, - size, count, suffix); + ret = utils_stream_file_path(path_name, file_name, + size, count, suffix, path, sizeof(path)); if (ret < 0) { goto error; } @@ -905,10 +813,10 @@ int utils_unlink_stream_file(const char *path_name, char *file_name, uint64_t si uint64_t count, int uid, int gid, char *suffix) { int ret; - char path[PATH_MAX]; + char path[LTTNG_PATH_MAX]; - ret = utils_stream_file_name(path, path_name, file_name, - size, count, suffix); + ret = utils_stream_file_path(path_name, file_name, size, count, suffix, + path, sizeof(path)); if (ret < 0) { goto error; } @@ -1093,12 +1001,19 @@ end: /** * Parse a string that represents a time in human readable format. It - * supports decimal integers suffixed by 's', 'u', 'm', 'us', and 'ms'. + * 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: - * 'u'/'us': 1 - * 'm'/'ms': 1000 - * 's': 1000000 + * "us" : 1 + * "ms" : 1000 + * "s" : 1000000 + * "m" : 60000000 + * "h" : 3600000000 * * Note that unit-less numbers are assumed to be microseconds. * @@ -1113,7 +1028,7 @@ int utils_parse_time_suffix(char const * const str, uint64_t * const time_us) { int ret; uint64_t base_time; - long multiplier = 1; + uint64_t multiplier = 1; const char *str_end; char *num_end; @@ -1150,17 +1065,37 @@ int utils_parse_time_suffix(char const * const str, uint64_t * const time_us) /* Check if a prefix is present. */ switch (*num_end) { case 'u': - multiplier = 1; - /* Skip another letter in the 'us' case. */ - num_end += (*(num_end + 1) == 's') ? 2 : 1; + /* + * 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': - multiplier = 1000; - /* Skip another letter in the 'ms' case. */ - num_end += (*(num_end + 1) == 's') ? 2 : 1; + 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': - multiplier = 1000000; + /* Second */ + multiplier = USEC_PER_SEC; + num_end++; + break; + case 'h': + /* Hour */ + multiplier = USEC_PER_HOURS; num_end++; break; case '\0': @@ -1425,24 +1360,77 @@ size_t utils_get_current_time_str(const char *format, char *dst, size_t len) } /* - * Return the group ID matching name, else 0 if it cannot be found. + * Return 0 on success and set *gid to the group_ID matching the passed name. + * Else -1 if it cannot be found or an error occurred. */ LTTNG_HIDDEN -gid_t utils_get_group_id(const char *name) +int utils_get_group_id(const char *name, bool warn, gid_t *gid) { - struct group *grp; + static volatile int warn_once; + int ret; + long sys_len; + size_t len; + struct group grp; + struct group *result; + struct lttng_dynamic_buffer buffer; + + /* Get the system limit, if it exists. */ + sys_len = sysconf(_SC_GETGR_R_SIZE_MAX); + if (sys_len == -1) { + len = 1024; + } else { + len = (size_t) sys_len; + } - grp = getgrnam(name); - if (!grp) { - static volatile int warn_once; + lttng_dynamic_buffer_init(&buffer); + ret = lttng_dynamic_buffer_set_size(&buffer, len); + if (ret) { + ERR("Failed to allocate group info buffer"); + ret = -1; + goto error; + } + + while ((ret = getgrnam_r(name, &grp, buffer.data, buffer.size, &result)) == ERANGE) { + const size_t new_len = 2 * buffer.size; - if (!warn_once) { - WARN("No tracing group detected"); - warn_once = 1; + /* Buffer is not big enough, increase its size. */ + if (new_len < buffer.size) { + ERR("Group info buffer size overflow"); + ret = -1; + goto error; + } + + ret = lttng_dynamic_buffer_set_size(&buffer, new_len); + if (ret) { + ERR("Failed to grow group info buffer to %zu bytes", + new_len); + ret = -1; + goto error; } - return 0; } - return grp->gr_gid; + if (ret) { + PERROR("Failed to get group file entry for group name \"%s\"", + name); + ret = -1; + goto error; + } + + /* Group not found. */ + if (!result) { + ret = -1; + goto error; + } + + *gid = result->gr_gid; + ret = 0; + +error: + if (ret && warn && !warn_once) { + WARN("No tracing group detected"); + warn_once = 1; + } + lttng_dynamic_buffer_reset(&buffer); + return ret; } /* @@ -1497,79 +1485,16 @@ end: LTTNG_HIDDEN int utils_recursive_rmdir(const char *path) { - DIR *dir; - size_t path_len; - int dir_fd, ret = 0, closeret, is_empty = 1; - struct dirent *entry; - - /* Open directory */ - dir = opendir(path); - if (!dir) { - PERROR("Cannot open '%s' path", path); - return -1; - } - dir_fd = lttng_dirfd(dir); - if (dir_fd < 0) { - PERROR("lttng_dirfd"); - return -1; - } - - path_len = strlen(path); - while ((entry = readdir(dir))) { - struct stat st; - size_t name_len; - char filename[PATH_MAX]; - - if (!strcmp(entry->d_name, ".") - || !strcmp(entry->d_name, "..")) { - continue; - } - - name_len = strlen(entry->d_name); - if (path_len + name_len + 2 > sizeof(filename)) { - ERR("Failed to remove file: path name too long (%s/%s)", - path, entry->d_name); - continue; - } - if (snprintf(filename, sizeof(filename), "%s/%s", - path, entry->d_name) < 0) { - ERR("Failed to format path."); - continue; - } - - if (stat(filename, &st)) { - PERROR("stat"); - continue; - } + int ret; + struct lttng_directory_handle handle; - if (S_ISDIR(st.st_mode)) { - char subpath[PATH_MAX]; - - strncpy(subpath, path, PATH_MAX); - subpath[PATH_MAX - 1] = '\0'; - strncat(subpath, "/", - PATH_MAX - strlen(subpath) - 1); - strncat(subpath, entry->d_name, - PATH_MAX - strlen(subpath) - 1); - if (utils_recursive_rmdir(subpath)) { - is_empty = 0; - } - } else if (S_ISREG(st.st_mode)) { - is_empty = 0; - } else { - ret = -EINVAL; - goto end; - } + ret = lttng_directory_handle_init(&handle, NULL); + if (ret) { + goto end; } + ret = lttng_directory_handle_remove_subdirectory(&handle, path); + lttng_directory_handle_fini(&handle); end: - closeret = closedir(dir); - if (closeret) { - PERROR("closedir"); - } - if (is_empty) { - DBG3("Attempting rmdir %s", path); - ret = rmdir(path); - } return ret; } @@ -1635,3 +1560,77 @@ int utils_show_help(int section, const char *page_name, end: return ret; } + +static +int read_proc_meminfo_field(const char *field, size_t *value) +{ + int ret; + FILE *proc_meminfo; + char name[PROC_MEMINFO_FIELD_MAX_NAME_LEN] = {}; + + proc_meminfo = fopen(PROC_MEMINFO_PATH, "r"); + if (!proc_meminfo) { + PERROR("Failed to fopen() " PROC_MEMINFO_PATH); + ret = -1; + goto fopen_error; + } + + /* + * Read the contents of /proc/meminfo line by line to find the right + * field. + */ + while (!feof(proc_meminfo)) { + unsigned long value_kb; + + ret = fscanf(proc_meminfo, + "%" MAX_NAME_LEN_SCANF_IS_A_BROKEN_API "s %lu kB\n", + name, &value_kb); + if (ret == EOF) { + /* + * fscanf() returning EOF can indicate EOF or an error. + */ + if (ferror(proc_meminfo)) { + PERROR("Failed to parse " PROC_MEMINFO_PATH); + } + break; + } + + if (ret == 2 && strcmp(name, field) == 0) { + /* + * This number is displayed in kilo-bytes. Return the + * number of bytes. + */ + *value = ((size_t) value_kb) * 1024; + ret = 0; + goto found; + } + } + /* Reached the end of the file without finding the right field. */ + ret = -1; + +found: + fclose(proc_meminfo); +fopen_error: + return ret; +} + +/* + * Returns an estimate of the number of bytes of memory available based on the + * the information in `/proc/meminfo`. The number returned by this function is + * a best guess. + */ +LTTNG_HIDDEN +int utils_get_memory_available(size_t *value) +{ + return read_proc_meminfo_field(PROC_MEMINFO_MEMAVAILABLE_LINE, value); +} + +/* + * Returns the total size of the memory on the system in bytes based on the + * the information in `/proc/meminfo`. + */ +LTTNG_HIDDEN +int utils_get_memory_total(size_t *value) +{ + return read_proc_meminfo_field(PROC_MEMINFO_MEMTOTAL_LINE, value); +}