terry@wsccs.UUCP (terry) (02/23/88)
Why is it that when I get a System V port open using the partial open hack, it works OK until I get a HI to LO transition of the carrier detect, at which point it will continue to transmit out the port, but not read? In addition, since there is no signal to a proccess whose controlling tty is NOT the tty that the CD was lost on (ie: cu, Kermit, TERM), I can't tell it's gone (except from the fact that I now get an EOF when I attempt to read it... it comes back with a correctly terminated read which read 0 characters), and if someone then calls in, it crashes the system (isn't this *NOT* supposed to be possible, no matter what mistakes the user makes, short of being priveledged and doing something like kludging /dev/mem, etc.). I can demonstrate this on the following operating systems: AT&T 3B1 (PC 7300) All UNIX versions AT&T 3B2 All UNIX versions Microport UNIX 386 version only ISC Unix 386 verion (only one I had access to) L/F Technologies cubix 5.2 (?) All NCR boxes All Unisys boxes Arete 1100 Burroughs XE550 Doesn't anybody test these things? I am using a modified dial.c (simpleist case, apparently) to just 1) open the port and 2) sit there forever, constantly queing single character reads. PLEASE PLEASE PLEASE PLEASE PLEASE fix this so I don't get any more calls. I can pin-point it within 10 lines of code in tty.c, but since I no longer am a student at the college I went to, I cannot access the source any more without incurring a 65,000 dollar fee (isn't that what they're charging these days?). I can't post a fix (same reason). I won't post a source that does it (if you can't hack one yourself, you probably shouldn't be doing it anyway) because the dial.c is proprietary. If you can mail me, and prove you're AT&T, I'll talk, but don't expect a quick reply; I'm too busy answering calls. PS: we have a workaround, but I shouldn't have to work around. Mail from AT&T welcome at: | Terry Lambert UUCP: ...!decvax!utah-cs!century!terry | | @ Century Software or : ...utah-cs!uplherc!sp7040!obie!wsccs!terry | | SLC, Utah | | These opinions are not my companies, but if you find them | | useful, send a $20.00 donation to Brisbane Australia... | | 'There are monkey boys in the facility. Do not be alarmed; you are secure' |