/* Copyright (C) 1991-2016 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ #include <errno.h> #include <libc-lock.h> #include <pwd.h> #include <stdio.h> #include <stdlib.h> /* We need to protect the dynamic buffer handling. */ __libc_lock_define_initialized (static, lock); libc_freeres_ptr (static char *buffer); /* Read one entry from the given stream. */ struct passwd * fgetpwent (FILE *stream) { static size_t buffer_size; static struct passwd resbuf; fpos_t pos; struct passwd *result; int save; if (fgetpos (stream, &pos) != 0) return NULL; /* Get lock. */ __libc_lock_lock (lock); /* Allocate buffer if not yet available. */ if (buffer == NULL) { buffer_size = NSS_BUFLEN_PASSWD; buffer = malloc (buffer_size); } while (buffer != NULL && (__fgetpwent_r (stream, &resbuf, buffer, buffer_size, &result) == ERANGE)) { char *new_buf; buffer_size += NSS_BUFLEN_PASSWD; new_buf = realloc (buffer, buffer_size); if (new_buf == NULL) { /* We are out of memory. Free the current buffer so that the process gets a chance for a normal termination. */ save = errno; free (buffer); __set_errno (save); } buffer = new_buf; /* Reset the stream. */ if (fsetpos (stream, &pos) != 0) buffer = NULL; } if (buffer == NULL) result = NULL; /* Release lock. Preserve error value. */ save = errno; __libc_lock_unlock (lock); __set_errno (save); return result; }