Messages in this thread | | | Date | Mon, 12 May 2003 15:13:12 -0700 | From | Frank Cusack <> | Subject | Re: MPPE in kernel? |
| |
On Mon, May 12, 2003 at 11:07:20PM +1000, Paul Mackerras wrote: > Frank Cusack writes: > > > I have the compressor return a 3-valued return code (<0, 0, >0) instead of > > two-valued (>0, other). A negative value tells ppp_generic to drop the > > packet. 0 means the same as it does now--the compressor failed for some > > reason. (All current compressors always return 0 or >0, so the negative > > return is compatible.) > > > > 0 could also mean that CCP isn't up yet, but pppd userland doesn't allow > > NCP's to come up until CCP completes (iff trying to negotiate MPPE). > > Hmmm, and are you sure that nothing can cause CCP to go down? If it > does then ppp_generic will send data uncompressed. What would happen > if an attacker managed to insert a CCP terminate-request into the > receive stream somehow?
When (if) CCP goes down, pppd shuts down LCP if MPPE was running. This could move into the kernel if you think it's better that way, but I think userland is ok.
static void ccp_input(unit, p, len) { ... #ifdef MPPE if (ccp_gotoptions[unit].mppe) { error("MPPE disabled, closing LCP"); lcp_close(unit, "MPPE disabled by peer"); } #endif }
/fc - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |