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- /* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License, version 2.0,
- as published by the Free Software Foundation.
- This program is also distributed with certain software (including
- but not limited to OpenSSL) that is licensed under separate terms,
- as designated in a particular file or component or in included license
- documentation. The authors of MySQL hereby grant you an additional
- permission to link the program and your derivative works with the
- separately licensed software that they have included with MySQL.
- Without limiting anything contained in the foregoing, this file,
- which is part of C Driver for MySQL (Connector/C), is also subject to the
- Universal FOSS Exception, version 1.0, a copy of which can be found at
- http://oss.oracle.com/licenses/universal-foss-exception.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License, version 2.0, for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
- /**
- @file mysys/my_getpwnam.cc
- */
- #include "my_getpwnam.h"
- #include <atomic>
- #include <vector>
- #include <errno.h>
- #include <unistd.h>
- namespace {
- std::size_t start_bufsz() {
- long scsz = sysconf(_SC_GETPW_R_SIZE_MAX);
- return (scsz == -1L ? 256 : scsz);
- }
- template <class GETPW_CLOS>
- PasswdValue my_getpw_(GETPW_CLOS &&getpwfunc) {
- passwd pwd;
- std::size_t bufsz = start_bufsz();
- std::vector<char> buf(bufsz);
- passwd *resptr = nullptr;
- while (true) {
- errno = getpwfunc(&pwd, &buf, &resptr);
- switch (errno) {
- case ERANGE:
- bufsz *= 2;
- buf.resize(bufsz);
- // fallthrough
- case EINTR:
- continue;
- default:
- break;
- }
- break;
- }
- return resptr ? PasswdValue{pwd} : PasswdValue{};
- }
- } // namespace
- /**
- Wrapper around the getpwnam_r() POSIX function which places the
- contents of the passwd struct into an object with value semantics
- and returns this.
- @param name Symbolic user id
- @retval PasswdValue representing user's passwd entry.
- PasswdValue::IsVoid() returns true if no such user exists or an error
- occured. In the latter case errno is set.
- */
- PasswdValue my_getpwnam(const char *name) {
- return my_getpw_(
- [&name](passwd *pwd, std::vector<char> *bufp, passwd **resptr) {
- return getpwnam_r(name, pwd, &bufp->front(), bufp->size(), resptr);
- });
- }
- /**
- Wrapper around the getpwuid_r() POSIX function which places the
- contents of the passwd struct into an object with value semantics
- and returns this.
- @param uid Numeric user id
- @retval PasswdValue representing user's passwd entry.
- PasswdValue::IsVoid() returns true if no such user exists or an error
- occured. In the latter case errno is set.
- */
- PasswdValue my_getpwuid(uid_t uid) {
- return my_getpw_(
- [uid](passwd *pwd, std::vector<char> *bufp, passwd **resptr) {
- return getpwuid_r(uid, pwd, &bufp->front(), bufp->size(), resptr);
- });
- }
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