===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/cmp/cmp.c,v
retrieving revision 1.17
retrieving revision 1.18
diff -c -r1.17 -r1.18
*** src/usr.bin/cmp/cmp.c	2018/03/05 16:53:39	1.17
--- src/usr.bin/cmp/cmp.c	2018/03/05 16:57:37	1.18
***************
*** 1,4 ****
! /*      $OpenBSD: cmp.c,v 1.17 2018/03/05 16:53:39 cheloha Exp $      */
  /*      $NetBSD: cmp.c,v 1.7 1995/09/08 03:22:56 tls Exp $      */
  
  /*
--- 1,4 ----
! /*      $OpenBSD: cmp.c,v 1.18 2018/03/05 16:57:37 cheloha Exp $      */
  /*      $NetBSD: cmp.c,v 1.7 1995/09/08 03:22:56 tls Exp $      */
  
  /*
***************
*** 34,40 ****
--- 34,42 ----
  #include <sys/stat.h>
  
  #include <err.h>
+ #include <errno.h>
  #include <fcntl.h>
+ #include <limits.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
***************
*** 44,49 ****
--- 46,52 ----
  
  int	lflag, sflag;
  
+ static off_t get_skip(const char *, const char *);
  static void __dead usage(void);
  
  int
***************
*** 98,105 ****
  	if (pledge("stdio", NULL) == -1)
  		err(ERR_EXIT, "pledge");
  
! 	skip1 = argc > 2 ? strtoll(argv[2], NULL, 0) : 0;
! 	skip2 = argc == 4 ? strtoll(argv[3], NULL, 0) : 0;
  
  	if (!special) {
  		if (fstat(fd1, &sb1) == -1)
--- 101,108 ----
  	if (pledge("stdio", NULL) == -1)
  		err(ERR_EXIT, "pledge");
  
! 	skip1 = (argc > 2) ? get_skip(argv[2], "skip1") : 0;
! 	skip2 = (argc == 4) ? get_skip(argv[3], "skip2") : 0;
  
  	if (!special) {
  		if (fstat(fd1, &sb1) == -1)
***************
*** 120,125 ****
--- 123,145 ----
  		c_regular(fd1, file1, skip1, sb1.st_size,
  		    fd2, file2, skip2, sb2.st_size);
  	return 0;
+ }
+ 
+ static off_t
+ get_skip(const char *arg, const char *name)
+ {
+ 	off_t skip;
+ 	char *ep;
+ 
+ 	errno = 0;
+ 	skip = strtoll(arg, &ep, 0);
+ 	if (arg[0] == '\0' || *ep != '\0')
+ 		fatalx("%s is invalid: %s", name, arg);
+ 	if (skip < 0)
+ 		fatalx("%s is too small: %s", name, arg);
+ 	if (skip == LLONG_MAX && errno == ERANGE)
+ 		fatalx("%s is too large: %s", name, arg);
+ 	return skip;
  }
  
  static void __dead