bug report 4.3BSD/ucb/148; null pointer dereference, syntax checking

on "hhmm" value, use stderr for error messages add Berkeley specific
header, originally written by Mark Horton.

SCCS-vsn: usr.bin/leave/leave.c 5.2

diff --git a/usr/src/usr.bin/leave/leave.c b/usr/src/usr.bin/leave/leave.c
index 96d2936..ce2e3b7 100644 (file)
--- a/usr/src/usr.bin/leave/leave.c
+++ b/usr/src/usr.bin/leave/leave.c
@@ -1,20 +1,27 @@
 /*
  * Copyright (c) 1980 Regents of the University of California.
 /*
  * Copyright (c) 1980 Regents of the University of California.

- * All rights reserved.  The Berkeley software License Agreement
- * specifies the terms and conditions for redistribution.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that this notice is preserved and that due credit is given
+ * to the University of California at Berkeley. The name of the University
+ * may not be used to endorse or promote products derived from this
+ * software without specific written prior permission. This software
+ * is provided ``as is'' without express or implied warranty.

  */
 
 #ifndef lint
 char copyright[] =
 "@(#) Copyright (c) 1980 Regents of the University of California.\n\
  All rights reserved.\n";
  */
 
 #ifndef lint
 char copyright[] =
 "@(#) Copyright (c) 1980 Regents of the University of California.\n\
  All rights reserved.\n";

-#endif not lint
+#endif /* not lint */

 
 #ifndef lint
 
 #ifndef lint

-static char sccsid[] = "@(#)leave.c    5.1 (Berkeley) %G%";
-#endif not lint
+static char sccsid[] = "@(#)leave.c    5.2 (Berkeley) %G%";
+#endif /* not lint */

 
 #include <stdio.h>
 
 #include <stdio.h>

+#include <ctype.h>

 #include <signal.h>
 /*
  * leave [[+]hhmm]
 #include <signal.h>
 /*
  * leave [[+]hhmm]


@@ -32,13 +39,17 @@ char buff[100];
 main(argc, argv)
 char **argv;
 {
 main(argc, argv)
 char **argv;
 {

-       long when, tod, now, diff, hours, minutes;
+       long when, now, diff, hours, minutes;

        char *cp;
        int *nv;
        char *cp;
        int *nv;

-       int atoi();
+       int gethm();

        int *localtime();
 
        int *localtime();
 

-       strcpy(origlogin, getlogin());
+       if ((cp = getlogin()) == NULL) {
+               fputs("leave: You are not logged in.\n", stderr);
+               exit(1);
+       }
+       strcpy(origlogin, cp);

        if (argc < 2) {
                printf("When do you have to leave? ");
                fflush(stdout);
        if (argc < 2) {
                printf("When do you have to leave? ");
                fflush(stdout);


@@ -50,26 +61,20 @@ char **argv;
                exit(0);
        if (*cp == '+') {
                cp++;
                exit(0);
        if (*cp == '+') {
                cp++;

-               if (*cp < '0' || *cp > '9')
+               if (!gethm(cp, &hours, &minutes))

                        usage();
                        usage();

-               tod = atoi(cp);
-               hours = tod / 100;
-               minutes = tod % 100;

                if (minutes < 0 || minutes > 59)
                        usage();
                diff = 60*hours+minutes;
                doalarm(diff);
                exit(0);
        }
                if (minutes < 0 || minutes > 59)
                        usage();
                diff = 60*hours+minutes;
                doalarm(diff);
                exit(0);
        }

-       if (*cp < '0' || *cp > '9')
+       if (!gethm(cp, &hours, &minutes))

                usage();
                usage();

-       tod = atoi(cp);
-       hours = tod / 100;

        if (hours > 12)
                hours -= 12;
        if (hours == 12)
                hours = 0;
        if (hours > 12)
                hours -= 12;
        if (hours == 12)
                hours = 0;

-       minutes = tod % 100;

 
        if (hours < 0 || hours > 12 || minutes < 0 || minutes > 59)
                usage();
 
        if (hours < 0 || hours > 12 || minutes < 0 || minutes > 59)
                usage();


@@ -84,7 +89,7 @@ char **argv;
        while (diff < 0)
                diff += 12*60;
        if (diff > 11*60) {
        while (diff < 0)
                diff += 12*60;
        if (diff > 11*60) {

-               printf("That time has already passed!\n");
+               fprintf(stderr, "That time has already passed!\n");

                exit(1);
        }
        doalarm(diff);
                exit(1);
        }
        doalarm(diff);


@@ -93,10 +98,29 @@ char **argv;
 
 usage()
 {
 
 usage()
 {

-       printf("usage: leave [[+]hhmm]\n");
+       fprintf(stderr, "usage: leave [[+]hhmm]\n");

        exit(1);
 }
 
        exit(1);
 }
 

+int
+gethm(cp, hp, mp)
+register char *cp;
+int *hp, *mp;
+{
+       register char c;
+       register int tod;
+
+       tod = 0;
+       while ((c = *cp++) != '\0') {
+               if (!isdigit(c))
+                       return(0);
+               tod = tod * 10 + (c - '0');
+       }
+       *hp = tod / 100;
+       *mp = tod % 100;
+       return(1);
+}
+

 doalarm(nmins)
 long nmins;
 {
 doalarm(nmins)
 long nmins;
 {


@@ -172,6 +196,7 @@ delay(secs)
 int secs;
 {
        int n;
 int secs;
 {
        int n;

+       register char *l;

 
        while (secs > 0) {
                n = 100;
 
        while (secs > 0) {
                n = 100;


@@ -180,7 +205,10 @@ int secs;
                secs -= n;
                if (n > 0)
                        sleep(n);
                secs -= n;
                if (n > 0)
                        sleep(n);

-               if (strcmp(origlogin, getlogin()))
+               l = getlogin();
+               if (l == NULL)
+                       exit(0);
+               if (strcmp(origlogin, l) != 0)

                        exit(0);
        }
 }
                        exit(0);
        }
 }