Initial revision

diff --git a/visudo.c b/visudo.c
new file mode 100644 (file)
index 0000000..d7cfc18
--- /dev/null
+++ b/visudo.c
@@ -0,0 +1,177 @@
+/*
+ *  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.
+ *
+ *  If you make modifications to the source, we would be happy to have
+ *  them to include in future releases.  Feel free to send them to:
+ *      Jeff Nieusma                       nieusma@rootgroup.com
+ *      3959 Arbol CT                      (303) 447-8093
+ *      Boulder, CO 80301-1752             
+ *
+********************************************************************************
+* visudo.c, sudo project
+* David R. Hieb
+* March 18, 1991
+*
+* edit, lock and parse the sudoers file in a fashion similiar to /etc/vipw.
+*******************************************************************************/
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/file.h>
+#include <stdio.h>
+#include <errno.h>
+#include <signal.h>
+
+#include "sudo.h"
+
+extern FILE *yyin, *yyout;
+extern int errno, yylineno;
+
+char   buffer[BUFSIZ];
+char   *sudoers = SUDOERS;
+int    status = 0, err_line_no = 0;
+char   *sudoers_tmp_file = TMPSUDOERS;
+FILE   *sudoers_tmp_fp, *sudoers_fp;
+
+void Exit()
+{
+fclose(sudoers_tmp_fp);
+unlink(sudoers_tmp_file);
+exit(1);
+}
+
+main(argc, argv)
+int argc;
+char **argv;
+{
+int fd;
+struct stat sbuf;
+
+/* handle the signals */
+signal(SIGILL, Exit);
+signal(SIGTRAP, Exit);
+signal(SIGBUS, Exit);
+signal(SIGSEGV, Exit);
+signal(SIGTERM, Exit);
+
+signal(SIGHUP, SIG_IGN);
+signal(SIGINT, SIG_IGN);
+signal(SIGQUIT, SIG_IGN);
+
+setbuf(stderr, NULL);
+
+/* we only want root to be able to read/write the sudoers_tmp_file */
+umask(077);
+
+/* open the sudoers file read only */
+if ((sudoers_fp = fopen(sudoers, "r")) == NULL) {
+    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) {
+        fprintf(stderr, "%s: sudoers file busy\n", *argv);
+        exit(1);
+        }
+    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) {
+    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);
+    }
+
+fclose(sudoers_fp);
+fclose(sudoers_tmp_fp);
+
+do {
+    /* build strings in buffer to be executed by system() */
+    sprintf(buffer, "%s +%d %s", EDITOR, err_line_no, sudoers_tmp_file);
+
+    /* edit the file */
+    if (system(buffer) == 0) {
+
+        /* can't stat file */
+        if (stat(sudoers_tmp_file, &sbuf) < 0) {
+            fprintf(stderr, "%s: can't stat temporary file, %s unchanged\n", 
+                sudoers, *argv);
+            Exit();
+            }
+        /* file has size == 0 */
+        if (sbuf.st_size == 0) {
+            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) {
+            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()) {
+            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;
+
+        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) {
+    fprintf(stderr, "%s: ", *argv), perror("rename");
+    }
+else {
+    if (chmod(sudoers, 0400) != 0) {
+        perror("chmod: failed");
+        }
+    exit(0);
+    }
+}