+
+LTTNG_HIDDEN
+int utils_change_working_directory(const char *path)
+{
+ int ret;
+
+ assert(path);
+
+ DBG("Changing working directory to \"%s\"", path);
+ ret = chdir(path);
+ if (ret) {
+ PERROR("Failed to change working directory to \"%s\"", path);
+ goto end;
+ }
+
+ /* Check for write access */
+ if (access(path, W_OK)) {
+ if (errno == EACCES) {
+ /*
+ * Do not treat this as an error since the permission
+ * might change in the lifetime of the process
+ */
+ DBG("Working directory \"%s\" is not writable", path);
+ } else {
+ PERROR("Failed to check if working directory \"%s\" is writable",
+ path);
+ }
+ }
+
+end:
+ return ret;
+}
+
+LTTNG_HIDDEN
+enum lttng_error_code utils_user_id_from_name(const char *user_name, uid_t *uid)
+{
+ struct passwd p, *pres;
+ int ret;
+ enum lttng_error_code ret_val = LTTNG_OK;
+ char *buf = NULL;
+ ssize_t buflen;
+
+ buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
+ if (buflen < 0) {
+ buflen = FALLBACK_USER_BUFLEN;
+ }
+
+ buf = zmalloc(buflen);
+ if (!buf) {
+ ret_val = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ for (;;) {
+ ret = getpwnam_r(user_name, &p, buf, buflen, &pres);
+ switch (ret) {
+ case EINTR:
+ continue;
+ case ERANGE:
+ buflen *= 2;
+ free(buf);
+ buf = zmalloc(buflen);
+ if (!buf) {
+ ret_val = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+ continue;
+ default:
+ goto end_loop;
+ }
+ }
+end_loop:
+
+ switch (ret) {
+ case 0:
+ if (pres == NULL) {
+ ret_val = LTTNG_ERR_USER_NOT_FOUND;
+ } else {
+ *uid = p.pw_uid;
+ DBG("Lookup of tracker UID/VUID: name '%s' maps to uid %" PRId64,
+ user_name, (int64_t) *uid);
+ ret_val = LTTNG_OK;
+ }
+ break;
+ case ENOENT:
+ case ESRCH:
+ case EBADF:
+ case EPERM:
+ ret_val = LTTNG_ERR_USER_NOT_FOUND;
+ break;
+ default:
+ ret_val = LTTNG_ERR_NOMEM;
+ }
+end:
+ free(buf);
+ return ret_val;
+}
+
+LTTNG_HIDDEN
+enum lttng_error_code utils_group_id_from_name(
+ const char *group_name, gid_t *gid)
+{
+ struct group g, *gres;
+ int ret;
+ enum lttng_error_code ret_val = LTTNG_OK;
+ char *buf = NULL;
+ ssize_t buflen;
+
+ buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
+ if (buflen < 0) {
+ buflen = FALLBACK_GROUP_BUFLEN;
+ }
+
+ buf = zmalloc(buflen);
+ if (!buf) {
+ ret_val = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ for (;;) {
+ ret = getgrnam_r(group_name, &g, buf, buflen, &gres);
+ switch (ret) {
+ case EINTR:
+ continue;
+ case ERANGE:
+ buflen *= 2;
+ free(buf);
+ buf = zmalloc(buflen);
+ if (!buf) {
+ ret_val = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+ continue;
+ default:
+ goto end_loop;
+ }
+ }
+end_loop:
+
+ switch (ret) {
+ case 0:
+ if (gres == NULL) {
+ ret_val = LTTNG_ERR_GROUP_NOT_FOUND;
+ } else {
+ *gid = g.gr_gid;
+ DBG("Lookup of tracker GID/GUID: name '%s' maps to gid %" PRId64,
+ group_name, (int64_t) *gid);
+ ret_val = LTTNG_OK;
+ }
+ break;
+ case ENOENT:
+ case ESRCH:
+ case EBADF:
+ case EPERM:
+ ret_val = LTTNG_ERR_GROUP_NOT_FOUND;
+ break;
+ default:
+ ret_val = LTTNG_ERR_NOMEM;
+ }
+end:
+ free(buf);
+ return ret_val;
+}
+
+LTTNG_HIDDEN
+int utils_parse_unsigned_long_long(const char *str,
+ unsigned long long *value)
+{
+ int ret;
+ char *endptr;
+
+ assert(str);
+ assert(value);
+
+ errno = 0;
+ *value = strtoull(str, &endptr, 10);
+
+ /* Conversion failed. Out of range? */
+ if (errno != 0) {
+ /* Don't print an error; allow the caller to log a better error. */
+ DBG("Failed to parse string as unsigned long long number: string = '%s', errno = %d",
+ str, errno);
+ ret = -1;
+ goto end;
+ }
+
+ /* Not the end of the string or empty string. */
+ if (*endptr || endptr == str) {
+ DBG("Failed to parse string as unsigned long long number: string = '%s'",
+ str);
+ ret = -1;
+ goto end;
+ }
+
+ ret = 0;
+
+end:
+ return ret;
+}