Ticket12: Fix buffer overflow in Keithley 2k

[ghost]

Description of Work Done

• Fixes the buffer overflow of pvname into close_format if pvname is longer than 40 characters (can be 60) by changing pvname to be a char array of size MAX_LENGTH_OF_PV_NAME.
• Changed strcpy to strncpy to copy strings safer.

Issue this addresses

12

[ghost]

Updated using PVNAME_STRINGSZ.

[MarkRivers]

strncpy() will not 0 terminate the destination if the size of the source is >= N. I think those statements should be sizeof(model)-1 and sizeof(close_format)-1 in order to guarantee that the destination is 0 terminated.

I realized strncpy with sizeof(model)-1 also does not 0 terminate the string. I changed back to sizeof(model), and then explicitly make the last character be 0 in case the size was >=sizeof(model). I did the same for close_format.

            P = macValueGet("P");
            Dmm = macValueGet("Dmm");
            strncpy(model, macValueGet("model"), sizeof(model));
            model[sizeof(model)-1] = 0;
            pvPut(model);
            channels = atoi(macValueGet("channels"));
            pvPut(channels);
            if (strcmp(model, "2000") == 0) {
               strncpy(close_format, "rout:clos (@%d)", sizeof(close_format));
            } else {
               strncpy(close_format, "rout:clos (@1%2.2d)", sizeof(close_format));
            }
            close_format[sizeof(close_format)-1] = 0;
        } state monitor_mode_changes

I made these same changes in Keithley2kDMM_mf40.st and Keithley65xxEM.st and pushed to master branch.