* 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/stat.h>
#include <sys/param.h>
-#include <string.h>
-#include <strings.h>
+#include <sys/stat.h>
+#include "sudo.h"
+
extern char *malloc();
extern char *getenv();
-
-extern char **Argv;
-char *find_path();
-static char *do_stat();
-static char *check_link();
-char *strdup();
-
+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()
+ * find_path()
*
- * this function finds the full pathname for a command
+ * this function finds the full pathname for a command
*/
char *find_path(file)
-char *file;
+ char *file;
{
-register char *n;
-char *path=NULL;
-char *cmd;
-
-if ( strlen ( file ) > MAXPATHLEN ) {
- fprintf ( stderr, "%s: path too long: %s\n", Argv[0], file );
- exit (1);
+ 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);
}
-
-if ( *file == '.' && *(file+1) == '/' || *file == '/' )
- return ( do_stat ( NULL, file ) );
-
-if ( ( path=getenv("PATH") ) == NULL ) return ( NULL ) ;
-if ( ( path=strdup(path) ) == NULL ) {
- perror ( "find_path: malloc" );
- exit (1);
- }
-
-while ( n = index ( path, ':' ) ) {
- *n='\0';
- if ( cmd = do_stat ( path, file ) ) return ( cmd );
- path=n+1;
- }
-
-if ( cmd = do_stat ( path, file ) )
- return ( cmd );
-else
- return ( NULL );
-}
-
-
-
-
-/**********************************************************************
- *
- * check_link()
- *
- * this function makes sure the argument is not a symbolic link.
- * it returns the pathname of the binary or NULL
- */
-
-static char *check_link(path)
-char *path;
-{
-char buf1[MAXPATHLEN+1]; /* is the link */
-char *s, *buf;
-register int rtn;
-
-/* the recursive buck stops here */
-if ( path == NULL ) return NULL ;
-
-/* I'd rather play with pointers than arrays... */
-buf = buf1;
+ /* do we need to search the path? */
+ if (index(file, '/'))
+ return (qualify(file));
-/* If this is NOT a sym link, return */
-if ( ( rtn=readlink(path, buf, MAXPATHLEN)) < 0 )
- return (path);
+ /* grab PATH out of environment and make a local copy */
+ if ((path = getenv("PATH") ) == NULL)
+ return (NULL);
-/* if it is a sym link, NULL terminate the string */
-buf[rtn]='\0';
-
-/* if the link points to an absolute path, start again... */
-if ( *buf == '/' ) return ( do_stat( NULL, buf ) );
-
-/* if the link points to ./something or something/ we need to
- * strip off the filename portion of the current path */
-if ( ( s=rindex(path,'/') ) == NULL ) {
- fprintf( stderr, "check_link: This path is very wierd: %s \n", path );
- exit (1);
+ if ((path = strdup(path)) == NULL) {
+ perror("find_path: malloc");
+ exit(1);
}
-else
- *s='\0';
-/* as long as the link has ./ or ../ in it, get rid of it... */
-while ( *buf == '.' ) {
-
- if ( strncmp(buf, "../", 3) == 0 ) {
- if ( ( s=rindex(path, '/')) ) {
- *s='\0';
- if ( *path == '\0' ) strcpy ( path, "/" );
- }
- buf += 3;
- continue;
+ 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 || errno == ENOTDIR)
+ path=n+1;
+ else {
+ perror("find_path: stat");
+ exit(1);
}
- else if ( strncmp(buf, "./", 2) == 0 ) {
- buf += 2;
- continue;
- }
- else
- break;
-
- }
-
-/* we have to copy the path buffer since do_stat() will bzero() it */
-if ( ( s = strdup ( path ) ) == NULL ) {
- perror ( "check_link: malloc" );
- exit (1);
}
-
-return ( do_stat ( s, buf ) );
+ return(NULL);
}
-
/******************************************************************
*
- * do_stat()
+ * qualify()
*
- * This function takes a path and a file and stat()s the file
- * If the file exists and is executable, the full path to that
- * file is returned otherwise NULL is returned.
+ * this function takes a path and makes it fully qualified and resolves
+ * all symbolic links, returning the fully qualfied path.
*/
-static char *do_stat( path, file )
-char *path, *file;
+char *qualify(n)
+ char *n; /* name to make fully qualified */
{
-static char buf[MAXPATHLEN+1];
-struct stat s;
-register char type;
-
-
-if (index(file, '/') && *file != '/' && strncmp(file, "./", 2)
- && strncmp(file, "../", 3))
- type=3;
-else if ( *file == '.' && *(file+1) == '/' )
- type=1;
-else if ( *file == '/' )
- type=2;
-else if ( path == NULL )
- type=2;
-else if ( *path == '.' && *(path+1) == (char)NULL )
- type=3;
-else
- type=0;
-
-
-switch ( type ) {
- case 1:
- file += 2;
- case 3:
- if ( (path=(char *)malloc(MAXPATHLEN+1)) == NULL ) {
- perror ("do_stat: malloc");
- exit (1);
- }
-#ifdef hpux
- if ( ! getcwd ( path, (size_t)(MAXPATHLEN+1) ) ) {
- perror ("do_stat: getcwd");
- exit (1);
- }
+ 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 ( path ) ) {
- perror ("do_stat: getwd");
- exit (1);
- }
+ if (!getwd(full)) {
#endif
- break;
- case 2:
- default:
- break;
- }
-
-
-if ( ( ( path? strlen(path) : 0 ) + strlen (file) ) > MAXPATHLEN - 1 ) {
- fprintf ( stderr, "%s: path too long: %s/%s\n", Argv[0], path, file );
- exit (1);
- }
+ 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 */
+ }
-bzero ( buf, MAXPATHLEN+1 );
-if ( path ) strcat ( buf, path );
-if ( *file != '/' && path [strlen(path)-1] != '/' ) strcat ( buf, "/" );
-strcat ( buf, file );
+ /* check for symbolic links */
+ if (lstat(full, &statbuf)) {
+ perror("qualify: lstat");
+ exit(1);
+ }
-/* make sure file exists and is executable */
-if ( ! stat ( buf, &s ) && (s.st_mode & 0000111) )
- return ( check_link ( buf ) );
-else
- return ( NULL );
+ 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()
*/
char *strdup(s1)
-char *s1;
+ char *s1;
{
-char *s;
-if ( ( s=(char *)malloc(strlen(s1)+1)) == NULL )
- return (NULL);
-strcpy(s,s1);
-return (s);
+ char *s;
+
+ if ((s = (char *) malloc(strlen(s1) + 1)) == NULL)
+ return (NULL);
+
+ (void)strcpy(s, s1);
+ return(s);
}
+#endif
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