NetBSD/dist/openpam/lib/openpam_readline.c

155 lines
4.4 KiB
C

/*-
* Copyright (c) 2003 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by ThinkSec AS and
* Network Associates Laboratories, the Security Research Division of
* Network Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
* ("CBOSS"), as part of the DARPA CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $P4: //depot/projects/openpam/lib/openpam_readline.c#3 $
*/
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <security/pam_appl.h>
#include "openpam_impl.h"
#define MIN_LINE_LENGTH 128
/*
* OpenPAM extension
*
* Read a line from a file.
*/
char *
openpam_readline(FILE *f, int *lineno, size_t *lenp)
{
unsigned char *line;
size_t len, size;
int ch;
if ((line = malloc((size_t)MIN_LINE_LENGTH)) == NULL)
return (NULL);
size = MIN_LINE_LENGTH;
len = 0;
#define line_putch(ch) do { \
if (len >= size - 1) { \
unsigned char *tmp = realloc(line, size *= 2); \
if (tmp == NULL) \
goto fail; \
line = tmp; \
} \
line[len++] = ch; \
line[len] = '\0'; \
} while (/*CONSTCOND*/0)
for (;;) {
ch = fgetc(f);
/* strip comment */
if (ch == '#') {
do {
ch = fgetc(f);
} while (ch != EOF && ch != '\n');
}
/* eof */
if (ch == EOF) {
/* remove trailing whitespace */
while (len > 0 && isspace((unsigned char)line[len - 1]))
--len;
line[len] = '\0';
if (len == 0)
goto fail;
break;
}
/* eol */
if (ch == '\n') {
if (lineno != NULL)
++*lineno;
/* remove trailing whitespace */
while (len > 0 && isspace((unsigned char)line[len - 1]))
--len;
line[len] = '\0';
/* skip blank lines */
if (len == 0)
continue;
/* continuation */
if (line[len - 1] == '\\') {
line[--len] = '\0';
/* fall through to whitespace case */
} else {
break;
}
}
/* whitespace */
if (isspace(ch)) {
/* ignore leading whitespace */
/* collapse linear whitespace */
if (len > 0 && line[len - 1] != ' ')
line_putch(' ');
continue;
}
/* anything else */
line_putch(ch);
}
if (lenp != NULL)
*lenp = len;
return ((char *)line);
fail:
FREE(line);
return (NULL);
}
/**
* The =openpam_readline function reads a line from a file, and returns it
* in a NUL-terminated buffer allocated with =malloc.
*
* The =openpam_readline function performs a certain amount of processing
* on the data it reads.
* Comments (introduced by a hash sign) are stripped, as is leading and
* trailing whitespace.
* Any amount of linear whitespace is collapsed to a single space.
* Blank lines are ignored.
* If a line ends in a backslash, the backslash is stripped and the next
* line is appended.
*
* If =lineno is not =NULL, the integer variable it points to is
* incremented every time a newline character is read.
*
* If =lenp is not =NULL, the length of the line (not including the
* terminating NUL character) is stored in the variable it points to.
*
* The caller is responsible for releasing the returned buffer by passing
* it to =free.
*/