diff options
Diffstat (limited to 'nss/fgetspent.c')
-rw-r--r-- | nss/fgetspent.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/nss/fgetspent.c b/nss/fgetspent.c new file mode 100644 index 0000000..541947b --- /dev/null +++ b/nss/fgetspent.c @@ -0,0 +1,90 @@ +/* Copyright (C) 1996-2023 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 + <https://www.gnu.org/licenses/>. */ + +#include <errno.h> +#include <libc-lock.h> +#include <shadow.h> +#include <stdio.h> +#include <stdlib.h> +#include <set-freeres.h> + + +/* A reasonable size for a buffer to start with. */ +#define BUFLEN_SPWD 1024 + +/* We need to protect the dynamic buffer handling. */ +__libc_lock_define_initialized (static, lock); + +static char *buffer; + +/* Read one shadow entry from the given stream. */ +struct spwd * +fgetspent (FILE *stream) +{ + static size_t buffer_size; + static struct spwd resbuf; + fpos_t pos; + struct spwd *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 = BUFLEN_SPWD; + buffer = malloc (buffer_size); + } + + while (buffer != NULL + && (__fgetspent_r (stream, &resbuf, buffer, buffer_size, &result) + == ERANGE)) + { + char *new_buf; + buffer_size += BUFLEN_SPWD; + 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; +} + +weak_alias (buffer, __libc_fgetspent_freemem_ptr); |