Re: Add more errnos to ober_read_elements

[Martijn van Duren]

Apparently I missed one...

On Thu, 2020-09-03 at 18:00 +0200, Martijn van Duren wrote:
> Just reminded myself of this one.
> The manpage says nothing about ober_read_elements setting errno upon
> failure, yet it does in most cases. Furthermore, applications like
> snmpd use errno in ober_read_elements to determine if a read is
> incomplete (checking for ECANCELED), without initializing errno to
> 0.
> 
> The danger here is that since some stale errno might linger and a
> return from ober_read_elements with NULL could test against an old
> errno.
> 
> Diff below tries to remedy this.
> 
> OK?
> 
> martijn@

Index: ber.c
===================================================================
RCS file: /cvs/src/lib/libutil/ber.c,v
retrieving revision 1.16
diff -u -p -r1.16 ber.c
--- ber.c       3 Sep 2020 17:01:15 -0000       1.16
+++ ber.c       3 Sep 2020 18:47:38 -0000
@@ -1258,8 +1258,10 @@ ober_read_element(struct ber *ber, struc
                }
        case BER_TYPE_INTEGER:
        case BER_TYPE_ENUMERATED:
-               if (len > (ssize_t)sizeof(long long))
+               if (len > (ssize_t)sizeof(long long)) {
+                       errno = ERANGE;
                        return -1;
+               }
                for (i = 0; i < len; i++) {
                        if (ober_getc(ber, &c) != 1)
                                return -1;