SMPP fixes

Hello, I have found a couple bugs in the read callback of smpp_smsc.c with regards to guarding against malformed packets. Please see attached patches for fixes. They are also published in openbsc branch daniel/smpp-fixes Regarding the last fix I don't think it is necessary to receive messages up to SSIZE_MAX, but since I don't have/know a value for the maximum sensible size I left it like that for now. Regards, Daniel -- - Daniel Willmann <dwillmann(a)sysmocom.de> http://www.sysmocom.de/ ======================================================================= * sysmocom - systems for mobile communications GmbH * Schivelbeiner Str. 5 * 10439 Berlin, Germany * Sitz / Registered office: Berlin, HRB 134158 B * Geschaeftsfuehrer / Managing Directors: Holger Freyther, Harald Welte