smsc_smpp.c -- some minor fixes

Here's a patch that fixes two deficiencies with Kannel's SMPP 
implementation.

*) UDH for MO messages is not supported in the unpatched driver.

This patch will correctly deal with the most common (SMPP 3.3-style) 
technique for sending MO's with UDH, namely esm_class |= 64 with the UDH 
placed in the short_message field.

*) Coding for some message types is broken.

I changed smsc_smpp.c to rely on the (dcs|fields)to(fields|dcs) 
functions in sms.c, and to only mess with the values if it does a 
transformation to UCS2 or iso-8859-1.

I have some minor qualms about the patch.

There was
pdu->u.deliver_sm.short_message = NULL;
in pdu_to_msg in smsc_smpp.c which I honestly don't understand.

Also, I'm not entirely clear on how memory is freed in Kannel from the 
Msg structure. Is there something like a destructor for the generated 
datastructures Kannel uses? Could someone give me a pointer (groan) 
where I should look to understand this?

So there is a small chance that it may leak a little memory. I suspect 
the usual segfault on a "free the dangling pointer" would have bit me by 
now if there were something wrong, but I don't want to rule that out 
until a few more eyes have a look at it.

Testing on my system(s) "works" -- i.e. no observed crashes or memory 
leak warnings, and correct handling of every kind of SMS data I could 
throw at it.

Have fun,

David WHITE
CONNECT AUSTRIA

-- PATCH --

===================================================================
RCS file: /home/cvs/gateway/gw/smsc/smsc_smpp.c,v
retrieving revision 1.22
diff -u -r1.22 smsc_smpp.c
--- gw/smsc/smsc_smpp.c	2 Jan 2003 14:43:00 -0000	1.22
+++ gw/smsc/smsc_smpp.c	11 Feb 2003 14:48:37 -0000
@@ -233,7 +233,8 @@

  static Msg *pdu_to_msg(SMPP *smpp, SMPP_PDU *pdu)
  {
-    Msg *msg;
+    Msg *msg;
+    int udh_offset = 0;

      gw_assert(pdu->type == deliver_sm);

@@ -242,10 +243,19 @@
      pdu->u.deliver_sm.source_addr = NULL;
      msg->sms.receiver = pdu->u.deliver_sm.destination_addr;
      pdu->u.deliver_sm.destination_addr = NULL;
-    msg->sms.msgdata = pdu->u.deliver_sm.short_message;
-    pdu->u.deliver_sm.short_message = NULL;
+    /*  msg->sms.msgdata = pdu->u.deliver_sm.short_message;  - done 
later -- DAVE
+	pdu->u.deliver_sm.short_message = NULL; */
      dcs_to_fields(&msg, pdu->u.deliver_sm.data_coding);

+    /* DAVE -- actually handle UDH */
+    if (pdu->u.deliver_sm.esm_class & 0x40) {
+      udh_offset = octstr_get_char(pdu->u.deliver_sm.short_message,0)+1;
+      msg->sms.udhdata = 
octstr_copy(pdu->u.deliver_sm.short_message,0,udh_offset);
+    }
+    info(0, "SMPP: pdu->u.deliver_sm.short_message = %x, udh_offset = 
%d",pdu->u.deliver_sm.short_message,udh_offset);
+    msg->sms.msgdata = 
octstr_copy(pdu->u.deliver_sm.short_message,udh_offset,octstr_len(pdu->u.deliver_sm.short_message)-udh_offset);
+
+
      /* handle default data coding */
      switch (pdu->u.deliver_sm.data_coding) {
          case 0x00: /* default SMSC alphabet */
@@ -257,11 +267,11 @@
                  if (charset_convert(msg->sms.msgdata, 
octstr_get_cstr(smpp->alt_charset), "ISO-8859-1") != 0)
                      error(0, "Failed to convert msgdata from charset 
<%s> to <%s>, will leave as is.",
                               octstr_get_cstr(smpp->alt_charset), 
"ISO-8859-1");-                msg->sms.coding = DC_7BIT;
+		msg->sms.coding = DC_7BIT;

              } else { /* assume GSM 03.38 7-bit alphabet */
                  charset_gsm_to_latin1(msg->sms.msgdata);
-                msg->sms.coding = DC_7BIT;
+                /* DAVE -- Don't do this, it was set OK by 
dcs_to_fields  msg->sms.coding = DC_7BIT;*/
              }
              break;
          case 0x01: /* ASCII or IA5 - not sure if I need to do anything */
@@ -269,7 +279,7 @@
          case 0x04: /* 8 bit binary - do nothing */
                  break;
          case 0x03: /* ISO-8859-1 - do nothing */
-                msg->sms.coding = DC_8BIT; break;
+                /* DAVE -- Don't do this, it was set OK by 
dcs_to_fields  msg->sms.coding = DC_8BIT;*/ break;
          case 0x05: /* JIS - what do I do with that ? */
                  break;
          case 0x06: /* Cyrllic - iso-8859-5, I'll convert to unicode */
@@ -288,7 +298,7 @@
               * you implement them if you feel like it
               */
          default:
-            msg->sms.coding = DC_7BIT;
+	  /* DAVE -- Don't do this, it was set OK by dcs_to_fields 
msg->sms.coding = DC_7BIT; */
      }
      msg->sms.pid = pdu->u.deliver_sm.protocol_id;