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/*
* CU sudo version 1.3.1 (based on Root Group sudo version 1.1)
*
* This software comes with no waranty whatsoever, use at your own risk.
*
* Please send bugs, changes, problems to sudo-bugs.cs.colorado.edu
*
*/
/*
* sudo version 1.1 allows users to execute commands as root
* Copyright (C) 1991 The Root Group, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 1, or (at your option)
* any later version.
*
* 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*
**************************************************************************
* visudo.c, sudo project
* David R. Hieb
* March 18, 1991
*
* edit, lock and parse the sudoers file in a fashion similiar to /etc/vipw.
*/
#ifndef lint
static char rcsid[] = "$Id$";
#endif /* lint */
#include "config.h"
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <stdio.h>
#ifdef STDC_HEADERS
#include <stdlib.h>
#endif /* STDC_HEADERS */
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif /* HAVE_UNISTD_H */
#include <errno.h>
#include <signal.h>
#include "sudo.h"
#ifndef STDC_HEADERS
extern char *getenv();
#endif /* !STDC_HEADERS */
extern FILE *yyin, *yyout;
extern int errno, yylineno;
char buffer[BUFSIZ];
char *sudoers = _PATH_SUDO_SUDOERS;
int status = 0, err_line_no = 0;
char *sudoers_tmp_file = _PATH_SUDO_STMP;
FILE *sudoers_tmp_fp=NULL, *sudoers_fp=NULL;
RETSIGTYPE Exit()
{
if (sudoers_tmp_fp)
(void) fclose(sudoers_tmp_fp);
(void) unlink(sudoers_tmp_file);
exit(1);
}
main(argc, argv)
int argc;
char **argv;
{
int fd;
struct stat sbuf;
#ifdef ENV_EDITOR
char * Editor;
#endif /* ENV_EDITOR */
/*
* handle the signals
*/
(void) signal(SIGILL, Exit);
(void) signal(SIGTRAP, Exit);
(void) signal(SIGBUS, Exit);
(void) signal(SIGSEGV, Exit);
(void) signal(SIGTERM, Exit);
(void) signal(SIGHUP, SIG_IGN);
(void) signal(SIGINT, SIG_IGN);
(void) signal(SIGQUIT, SIG_IGN);
setbuf(stderr, NULL);
/*
* we only want root to be able to read/write the sudoers_tmp_file
*/
umask(077);
#ifdef ENV_EDITOR
/*
* set up the Editor variable correctly
*/
if ( (Editor = getenv("EDITOR")) == NULL)
if ( (Editor = getenv("VISUAL")) == NULL )
Editor = EDITOR;
#endif /* ENV_EDITOR */
/*
* open the sudoers file read only
*/
if ((sudoers_fp = fopen(sudoers, "r")) == NULL) {
(void) fprintf(stderr, "%s: ", *argv);
perror(sudoers);
Exit();
}
/*
* open the temporary sudoers file with the correct flags
*/
if ((fd = open(sudoers_tmp_file, O_WRONLY | O_CREAT | O_EXCL, 0600)) < 0) {
if (errno == EEXIST) {
(void) fprintf(stderr, "%s: sudoers file busy\n", *argv);
exit(1);
}
(void) fprintf(stderr, "%s: ", *argv);
perror(sudoers_tmp_file);
exit(1);
}
/*
* get a STREAM file pointer to the temporary sudoers file
*/
if ((sudoers_tmp_fp = fdopen(fd, "w")) == NULL) {
(void) fprintf(stderr, "%s: ", *argv);
perror(sudoers_tmp_file);
Exit();
}
/*
* transfer the contents of the sudoers file to the temporary sudoers file
*/
while (fgets(buffer, sizeof(buffer) - 1, sudoers_fp) != NULL) {
fputs(buffer, sudoers_tmp_fp);
}
(void) fclose(sudoers_fp);
(void) fclose(sudoers_tmp_fp);
do {
/*
* build strings in buffer to be executed by system()
*/
#ifdef ENV_EDITOR
(void) sprintf(buffer, "%s +%d %s", Editor, err_line_no,
sudoers_tmp_file);
#else
(void) sprintf(buffer, "%s +%d %s", EDITOR, err_line_no,
sudoers_tmp_file);
#endif /* ENV_EDITOR */
/* edit the file */
if (system(buffer) == 0) {
/* can't stat file */
if (stat(sudoers_tmp_file, &sbuf) < 0) {
(void) fprintf(stderr, "%s: can't stat temporary file, %s unchanged\n",
sudoers, *argv);
Exit();
}
/* file has size == 0 */
if (sbuf.st_size == 0) {
(void) fprintf(stderr, "%s: bad temporary file, %s unchanged\n",
sudoers, *argv);
Exit();
}
/* re-open the sudoers file for parsing */
if ((sudoers_tmp_fp = fopen(sudoers_tmp_file, "r")) == NULL) {
(void) fprintf(stderr, "%s: can't re-open temporary file, %s unchanged\n",
sudoers, *argv);
Exit();
}
yyin = sudoers_tmp_fp;
yyout = stdout;
/* parse the file */
if (yyparse()) {
(void) fprintf(stderr, "yyparse() failed\n");
Exit();
}
/*
* the first time we get an error, set status to yylineno which
* will be the line number after the line with the error. then,
* if we have gotten an error, set err_line_no to the correct
* line so that when we edit the file err_line_no will be
* correct. at this time we also reset status and yylineno to
* their default values so that the next time yyparse() is
* called, they will be initialized correctly.
*/
err_line_no = (status == 0) ? 0 : status - 1;
status = 0;
yylineno = 1;
(void) fclose(sudoers_tmp_fp);
}
} while (err_line_no);
/*
* once the temporary sudoers file is gramatically correct, we can
* rename it to the real sudoers file.
*/
if (rename(sudoers_tmp_file, sudoers) != 0) {
(void) fprintf(stderr, "%s: ", *argv);
perror("rename");
} else {
if (chmod(sudoers, 0400) != 0)
perror("chmod: failed");
exit(0);
}
}
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