502 lines
12 KiB
C
502 lines
12 KiB
C
/*
|
|
* 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.
|
|
*
|
|
**************************************************************************
|
|
*
|
|
* parse.c, sudo project
|
|
* David R. Hieb
|
|
* March 18, 1991
|
|
*
|
|
* routines to implement and maintain the parsing and list management.
|
|
*/
|
|
|
|
#ifndef lint
|
|
static char rcsid[] = "$Id$";
|
|
#endif /* lint */
|
|
|
|
#include "config.h"
|
|
|
|
#include <stdio.h>
|
|
#ifdef HAVE_UNISTD_H
|
|
#include <unistd.h>
|
|
#endif /* HAVE_UNISTD_H */
|
|
#ifdef HAVE_STRING_H
|
|
#include <string.h>
|
|
#endif /* HAVE_STRING_H */
|
|
#ifdef HAVE_STRINGS_H
|
|
#include <strings.h>
|
|
#endif /* HAVE_STRINGS_H */
|
|
#ifdef HAVE_MALLOC_H
|
|
#include <malloc.h>
|
|
#endif /* HAVE_MALLOC_H */
|
|
#include <ctype.h>
|
|
#include <sys/param.h>
|
|
#include <sys/types.h>
|
|
|
|
#include "sudo.h"
|
|
|
|
/*
|
|
* there are 3 main lists (User, Host_Alias, Cmnd_Alias) and 1 extra list
|
|
*/
|
|
#define NUM_LISTS 3+1
|
|
|
|
extern FILE *yyin, *yyout;
|
|
|
|
int user_list_found = FALSE;
|
|
int list_num, new_list[NUM_LISTS];
|
|
int parse_error = FALSE, found_user = FALSE;
|
|
int next_type, num_host_alias = 0, num_cmnd_alias = 0;
|
|
LINK tmp_ptr, reset_ptr, save_ptr, list_ptr[NUM_LISTS];
|
|
|
|
|
|
/*
|
|
* inserts a node into list 'list_num' and updates list_ptr[list_num]
|
|
*/
|
|
|
|
void insert_member(list_num, token_type, op_type, data_string)
|
|
int token_type, list_num;
|
|
char op_type;
|
|
char *data_string;
|
|
{
|
|
tmp_ptr = (LINK) malloc(sizeof(LIST));
|
|
tmp_ptr -> type = token_type;
|
|
tmp_ptr -> op = op_type;
|
|
tmp_ptr -> data = (char *) malloc(strlen(data_string) + 1);
|
|
strcpy(tmp_ptr -> data, data_string);
|
|
tmp_ptr -> next = (new_list[list_num] == TRUE) ? NULL : list_ptr[list_num];
|
|
|
|
list_ptr[list_num] = list_ptr[EXTRA_LIST] = tmp_ptr;
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* diagnostic list printing utility that prints list 'list_num'
|
|
*/
|
|
|
|
void print_list(list_num)
|
|
int list_num;
|
|
{
|
|
LINK tmptmp_ptr;
|
|
|
|
tmptmp_ptr = list_ptr[list_num];
|
|
|
|
while (list_ptr[list_num] != NULL) {
|
|
(void) printf("type = %d, op = %c, data = %s\n",
|
|
list_ptr[list_num] -> type,
|
|
list_ptr[list_num] -> op, list_ptr[list_num] -> data);
|
|
tmp_ptr = list_ptr[list_num];
|
|
list_ptr[list_num] = tmp_ptr -> next;
|
|
}
|
|
list_ptr[list_num] = tmptmp_ptr;
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* delete list utility that deletes list 'list_num'
|
|
*/
|
|
|
|
void delete_list(list_num)
|
|
int list_num;
|
|
{
|
|
while (list_ptr[list_num] != NULL) {
|
|
tmp_ptr = list_ptr[list_num];
|
|
list_ptr[list_num] = tmp_ptr -> next;
|
|
/* free(tmp_ptr); */
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* this routine is what the lex/yacc code calls to build the different lists.
|
|
* once the lists are all built, control eventually returns to validate().
|
|
*/
|
|
|
|
int call_back(token_type, op_type, data_string)
|
|
int token_type;
|
|
char op_type;
|
|
char *data_string;
|
|
{
|
|
/*
|
|
* all nodes start out in the extra list since the node name
|
|
* is received last
|
|
*/
|
|
list_num = EXTRA_LIST;
|
|
|
|
/*
|
|
* if the last received node is TYPE1, then we can classify the list
|
|
* and effectively transfer the extra list to the correct list type.
|
|
*/
|
|
if (token_type == TYPE1) {
|
|
/*
|
|
* we have just build a "Host_Alias" list
|
|
*/
|
|
if (strcmp(data_string, "Host_Alias") == 0) {
|
|
list_num = HOST_LIST;
|
|
if (num_host_alias > 0) {
|
|
reset_ptr -> next = list_ptr[HOST_LIST];
|
|
}
|
|
num_host_alias++;
|
|
}
|
|
/*
|
|
* we have just build a "Cmnd_Alias" list
|
|
*/
|
|
else if (strcmp(data_string, "Cmnd_Alias") == 0) {
|
|
list_num = CMND_LIST;
|
|
if (num_cmnd_alias > 0) {
|
|
reset_ptr -> next = list_ptr[CMND_LIST];
|
|
}
|
|
num_cmnd_alias++;
|
|
}
|
|
/*
|
|
* we have just build a "User" list
|
|
*/
|
|
else {
|
|
list_num = USER_LIST;
|
|
user_list_found = TRUE;
|
|
}
|
|
new_list[EXTRA_LIST] = TRUE;
|
|
new_list[list_num] = FALSE;
|
|
list_ptr[list_num] = list_ptr[EXTRA_LIST];
|
|
}
|
|
/*
|
|
* actually link the new node into list 'list_num'
|
|
*/
|
|
insert_member(list_num, token_type, op_type, data_string);
|
|
|
|
if (new_list[list_num] == TRUE) {
|
|
reset_ptr = list_ptr[list_num];
|
|
new_list[list_num] = FALSE;
|
|
}
|
|
/*
|
|
* we process one user record at a time from the sudoers file. if we
|
|
* find the user were looking for, we return to lex/yacc declaring
|
|
* that we have done so. otherwise, we reset the user list, delete the
|
|
* nodes and start over again looking for the user.
|
|
*/
|
|
if (user_list_found == TRUE) {
|
|
if (list_ptr[list_num] -> type == TYPE1 &&
|
|
strcmp(list_ptr[list_num] -> data, user) == 0) {
|
|
return (FOUND_USER);
|
|
} else {
|
|
new_list[list_num] = TRUE;
|
|
user_list_found = FALSE;
|
|
delete_list(list_num);
|
|
}
|
|
}
|
|
return (NOT_FOUND_USER);
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* this routine is called from cmnd_check() to resolve whether or not
|
|
* a user is permitted to perform a to-yet-be-determined command for
|
|
* a certain host name.
|
|
*/
|
|
|
|
int host_type_ok()
|
|
{
|
|
/*
|
|
* check for the reserved keyword 'ALL'. if so, don't check the host name
|
|
*/
|
|
if (strcmp(list_ptr[USER_LIST] -> data, "ALL") == 0) {
|
|
return (TRUE);
|
|
}
|
|
/*
|
|
* this case is the normal lowercase hostname
|
|
*/
|
|
else if (isupper(list_ptr[USER_LIST] -> data[0]) == FALSE) {
|
|
return (strcmp(list_ptr[USER_LIST] -> data, host) == 0);
|
|
}
|
|
/*
|
|
* by now we have a Host_Alias that will have to be expanded
|
|
*/
|
|
else {
|
|
save_ptr = list_ptr[HOST_LIST];
|
|
while (list_ptr[HOST_LIST] != NULL) {
|
|
if ((list_ptr[HOST_LIST] -> type == TYPE2) &&
|
|
(strcmp(list_ptr[HOST_LIST] -> data,
|
|
list_ptr[USER_LIST] -> data) == 0)) {
|
|
next_type = list_ptr[HOST_LIST] -> next -> type;
|
|
tmp_ptr = list_ptr[HOST_LIST];
|
|
list_ptr[HOST_LIST] = tmp_ptr -> next;
|
|
while (next_type == TYPE3) {
|
|
if (strcmp(list_ptr[HOST_LIST] -> data, host) == 0) {
|
|
list_ptr[HOST_LIST] = save_ptr;
|
|
return (TRUE);
|
|
}
|
|
if (list_ptr[HOST_LIST] -> next != NULL) {
|
|
next_type = list_ptr[HOST_LIST] -> next -> type;
|
|
tmp_ptr = list_ptr[HOST_LIST];
|
|
list_ptr[HOST_LIST] = tmp_ptr -> next;
|
|
} else {
|
|
next_type = ~TYPE3;
|
|
}
|
|
}
|
|
} else {
|
|
tmp_ptr = list_ptr[HOST_LIST];
|
|
list_ptr[HOST_LIST] = tmp_ptr -> next;
|
|
}
|
|
}
|
|
list_ptr[HOST_LIST] = save_ptr;
|
|
return (FALSE);
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* this routine is called from cmnd_check() to resolve whether or not
|
|
* a user is permitted to perform a certain command on the already
|
|
* established host.
|
|
*/
|
|
|
|
int cmnd_type_ok()
|
|
{
|
|
/*
|
|
* check for the reserved keyword 'ALL'.
|
|
*/
|
|
if (strcmp(list_ptr[USER_LIST] -> data, "ALL") == 0) {
|
|
/* if the command has an absolute path, let them do it */
|
|
if (cmnd[0] == '/') {
|
|
return (MATCH);
|
|
}
|
|
/* if the command does not have an absolute path, forget it */
|
|
else {
|
|
return (NO_MATCH);
|
|
}
|
|
}
|
|
/*
|
|
* if the command has an absolute path, check it out
|
|
*/
|
|
else if (list_ptr[USER_LIST] -> data[0] == '/') {
|
|
/*
|
|
* op | data | return value
|
|
* ---------------------------------
|
|
* ' ' | No Match | return(NO_MATCH)
|
|
* '!' | No Match | return(NO_MATCH)
|
|
* ' ' | A Match | return(MATCH)
|
|
* '!' | A Match | return(QUIT_NOW)
|
|
*
|
|
* these special cases are important in subtracting from the Universe
|
|
* of commands in something like:
|
|
* user machine=ALL,!/bin/rm,!/etc/named ...
|
|
*/
|
|
|
|
/*
|
|
* Check to see if a directory is being permitted
|
|
*/
|
|
if (list_ptr[USER_LIST]->data[strlen(list_ptr[USER_LIST]->data)-1]
|
|
== '/') {
|
|
/* we have a directory spec */
|
|
if (strncmp(list_ptr[USER_LIST]->data, cmnd,
|
|
strlen(list_ptr[USER_LIST]->data)) == 0)
|
|
return(MATCH);
|
|
else
|
|
return(NO_MATCH);
|
|
}
|
|
|
|
if (strcmp(list_ptr[USER_LIST] -> data, cmnd) == 0) {
|
|
if (list_ptr[USER_LIST] -> op == '!') {
|
|
return (QUIT_NOW);
|
|
} else {
|
|
return (MATCH);
|
|
}
|
|
} else {
|
|
return (NO_MATCH);
|
|
}
|
|
}
|
|
/*
|
|
* by now we have a Cmnd_Alias that will have to be expanded
|
|
*/
|
|
else {
|
|
save_ptr = list_ptr[CMND_LIST];
|
|
while (list_ptr[CMND_LIST] != NULL) {
|
|
if ((list_ptr[CMND_LIST] -> type == TYPE2) &&
|
|
(strcmp(list_ptr[CMND_LIST] -> data,
|
|
list_ptr[USER_LIST] -> data) == 0)) {
|
|
next_type = list_ptr[CMND_LIST] -> next -> type;
|
|
tmp_ptr = list_ptr[CMND_LIST];
|
|
list_ptr[CMND_LIST] = tmp_ptr -> next;
|
|
while (next_type == TYPE3) {
|
|
/*
|
|
* Check to see if a directory is being permitted
|
|
*/
|
|
if (list_ptr[CMND_LIST]->
|
|
data[strlen(list_ptr[CMND_LIST]->data)-1] == '/' ) {
|
|
/* we have a directory spec */
|
|
if (strncmp(list_ptr[CMND_LIST]->data, cmnd,
|
|
strlen(list_ptr[CMND_LIST]->data)) == 0)
|
|
return(MATCH);
|
|
else
|
|
return(NO_MATCH);
|
|
}
|
|
|
|
if (strcmp(list_ptr[CMND_LIST] -> data, cmnd) == 0) {
|
|
if (list_ptr[USER_LIST] -> op == '!') {
|
|
list_ptr[CMND_LIST] = save_ptr;
|
|
return (QUIT_NOW);
|
|
} else {
|
|
list_ptr[CMND_LIST] = save_ptr;
|
|
return (MATCH);
|
|
}
|
|
}
|
|
if (list_ptr[CMND_LIST] -> next != NULL) {
|
|
next_type = list_ptr[CMND_LIST] -> next -> type;
|
|
tmp_ptr = list_ptr[CMND_LIST];
|
|
list_ptr[CMND_LIST] = tmp_ptr -> next;
|
|
} else {
|
|
next_type = ~TYPE3;
|
|
}
|
|
}
|
|
} else {
|
|
tmp_ptr = list_ptr[CMND_LIST];
|
|
list_ptr[CMND_LIST] = tmp_ptr -> next;
|
|
}
|
|
}
|
|
list_ptr[CMND_LIST] = save_ptr;
|
|
return (NO_MATCH);
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* this routine is called from validate() after the call_back() routine
|
|
* has built all the possible lists. this routine steps thru the user list
|
|
* calling on host_type_ok() and cmnd_type_ok() trying to resolve whether
|
|
* or not the user will be able to execute the command on the host.
|
|
*/
|
|
|
|
int cmnd_check()
|
|
{
|
|
int return_code;
|
|
|
|
while (list_ptr[USER_LIST] != NULL) {
|
|
if ((list_ptr[USER_LIST] -> type == TYPE2) && host_type_ok()) {
|
|
next_type = list_ptr[USER_LIST] -> next -> type;
|
|
tmp_ptr = list_ptr[USER_LIST];
|
|
list_ptr[USER_LIST] = tmp_ptr -> next;
|
|
while (next_type == TYPE3) {
|
|
return_code = cmnd_type_ok();
|
|
if (return_code == MATCH) {
|
|
return (VALIDATE_OK);
|
|
} else if (return_code == QUIT_NOW) {
|
|
return (VALIDATE_NOT_OK);
|
|
}
|
|
if (list_ptr[USER_LIST] -> next != NULL) {
|
|
next_type = list_ptr[USER_LIST] -> next -> type;
|
|
tmp_ptr = list_ptr[USER_LIST];
|
|
list_ptr[USER_LIST] = tmp_ptr -> next;
|
|
} else {
|
|
next_type = ~TYPE3;
|
|
}
|
|
}
|
|
} else {
|
|
tmp_ptr = list_ptr[USER_LIST];
|
|
list_ptr[USER_LIST] = tmp_ptr -> next;
|
|
}
|
|
}
|
|
return (VALIDATE_NOT_OK);
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* this routine is called from the sudo.c module and tries to validate
|
|
* the user, host and command triplet.
|
|
*/
|
|
|
|
int validate()
|
|
{
|
|
FILE *sudoers_fp;
|
|
int i, return_code;
|
|
|
|
/* become root */
|
|
be_root();
|
|
|
|
if ((sudoers_fp = fopen(_PATH_SUDO_SUDOERS, "r")) == NULL) {
|
|
perror(_PATH_SUDO_SUDOERS);
|
|
log_error(NO_SUDOERS_FILE);
|
|
exit(1);
|
|
}
|
|
yyin = sudoers_fp;
|
|
yyout = stdout;
|
|
|
|
for (i = 0; i < NUM_LISTS; i++)
|
|
new_list[i] = TRUE;
|
|
|
|
/*
|
|
* yyparse() returns with one of 3 values: 0) yyparse() worked fine;
|
|
* 1) yyparse() failed; FOUND_USER) the user was found and yyparse()
|
|
* was returned from prematurely.
|
|
*/
|
|
return_code = yyparse();
|
|
|
|
/*
|
|
* don't need to keep this open...
|
|
*/
|
|
(void) fclose(sudoers_fp);
|
|
|
|
/* relinquish root */
|
|
be_user();
|
|
|
|
/*
|
|
* if a parsing error occurred, set return_code accordingly
|
|
*/
|
|
if (parse_error == TRUE) {
|
|
return_code = PARSE_ERROR;
|
|
}
|
|
/*
|
|
* if the user was not found, set the return_code accordingly
|
|
*/
|
|
if (found_user == FALSE) {
|
|
return_code = NOT_FOUND_USER;
|
|
}
|
|
/*
|
|
* handle the 3 cases individually
|
|
*/
|
|
switch (return_code) {
|
|
case FOUND_USER:
|
|
return_code = cmnd_check();
|
|
delete_list(USER_LIST);
|
|
delete_list(HOST_LIST);
|
|
delete_list(CMND_LIST);
|
|
return (return_code);
|
|
break;
|
|
case NOT_FOUND_USER:
|
|
return (VALIDATE_NO_USER);
|
|
break;
|
|
case PARSE_ERROR:
|
|
return (VALIDATE_ERROR);
|
|
break;
|
|
}
|
|
}
|