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/*
* 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
*
*******************************************************************
*
* This module contains the find_path() command that returns
* a pointer to a static area with the absolute path of the
* command or NULL if the command is not found in the path
*
* I also added the strdup() function in here after I found most
* systems don't have it...
*
* Jeff Nieusma Thu Mar 21 23:11:23 MST 1991
*/
/*
* Most of this code has been rewritten to fix bugs and bears little
* resemblence to the original. As such, this file conforms to my
* personal coding style.
*
* Todd C. Miller (millert@colorado.edu) Sat Sep 4 12:22:04 MDT 1993
*/
#include <stdio.h>
#include <strings.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include "sudo.h"
extern char *malloc();
extern char *getenv();
extern char *strcpy();
extern int fprintf();
extern int readlink();
extern int stat();
extern int lstat();
#ifdef USE_CWD
extern char *getcwd();
#else
extern char *getwd();
#endif
/*******************************************************************
*
* find_path()
*
* this function finds the full pathname for a command
*/
char *find_path(file)
char *file;
{
register char *n; /* for traversing path */
char *path = NULL; /* contents of PATH env var */
char fn[MAXPATHLEN+1]; /* filename (path + file) */
struct stat statbuf; /* for stat() */
char *qualify();
if (strlen(file) > MAXPATHLEN) {
fprintf(stderr, "%s: path too long: %s\n", Argv[0], file);
exit(1);
}
/* do we need to search the path? */
if (index(file, '/'))
return (qualify(file));
/* grab PATH out of environment and make a local copy */
if ((path = getenv("PATH") ) == NULL)
return (NULL);
if ((path = strdup(path)) == NULL) {
perror("find_path: malloc");
exit(1);
}
while ((n = index(path, ':'))) {
*n='\0';
strcpy(fn, path);
strcat(fn, "/");
strcat(fn, file);
/* stat the file to make sure it exists and is executable */
if (!stat(fn, &statbuf) && (statbuf.st_mode & 0000111))
return (qualify(fn));
else if (errno == ENOENT)
path=n+1;
else {
perror("find_path: stat");
exit(1);
}
}
return(NULL);
}
/******************************************************************
*
* qualify()
*
* this function takes a path and makes it fully qualified and resolves
* all symbolic links, returning the fully qualfied path.
*/
char *qualify(n)
char *n; /* name to make fully qualified */
{
char *beg = NULL; /* begining of a path component */
char *end; /* end of a path component */
static char full[MAXPATHLEN+1]; /* the fully qualified name */
char name[MAXPATHLEN+1]; /* local copy of n */
struct stat statbuf; /* for lstat() */
char *tmp; /* temporary pointer */
/* is it a bogus path? */
if (stat(n, &statbuf)) {
if (errno == ENOENT)
return(NULL);
else {
perror("qualify: stat");
exit(1);
}
}
/* if n is relative, fill full with working dir */
if (*n != '/') {
#ifdef USE_CWD
if (!getcwd(full, (size_t)(MAXPATHLEN+1))) {
#else
if (!getwd(full)) {
#endif
fprintf(stderr, "%s: Can't get working directory!\n", Argv[0]);
exit(1);
}
} else
full[0] = '\0';
(void)strcpy(name, n); /* working copy... */
do { /* while (end) */
if (beg)
beg = end + 1; /* skip past the NULL */
else
beg = name; /* just starting out... */
/* find and terminate end of path component */
if ((end = index(beg, '/')))
*end = '\0';
if (beg == end)
continue;
else if (!strcmp(beg, "."))
; /* ignore "." */
else if (!strcmp(beg, "..")) {
tmp = rindex(full, '/');
if (tmp && tmp != &full[0])
*tmp = '\0';
} else {
strcat(full, "/");
strcat(full, beg); /* copy in new component */
}
/* check for symbolic links */
if (lstat(full, &statbuf)) {
perror("qualify: lstat");
exit(1);
}
if ((statbuf.st_mode & S_IFMT) == S_IFLNK) {
int linklen; /* length of link contents */
char newname[MAXPATHLEN+1]; /* temp storage to build new name */
linklen = readlink(full, newname, sizeof(newname));
newname[linklen] = '\0';
/* check to make sure we don't go past MAXPATHLEN */
++end;
if (end != (char *)1) {
if (linklen + strlen(end) >= MAXPATHLEN) {
fprintf(stderr, "%s: path too long: %s/%s\n", Argv[0],
newname, end);
exit(1);
}
strcat(newname, "/");
strcat(newname, end); /* copy what's left of end */
}
if (newname[0] == '/') /* reset full if necesary */
full[0] = '\0';
else
if ((tmp = rindex(full, '/'))) /* remove component from full */
*tmp = '\0';
strcpy(name, newname); /* reset name with new path */
beg = NULL; /* since we have a new name */
}
} while (end);
return((char *)full);
}
#ifdef NEED_STRDUP
/******************************************************************
*
* strdup()
*
* this function returns a pointer a string copied into
* a malloc()ed buffer
*/
char *strdup(s1)
char *s1;
{
char *s;
if ((s = (char *) malloc(strlen(s1) + 1)) == NULL)
return (NULL);
(void)strcpy(s, s1);
return(s);
}
#endif
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