- RSSVAL(ubuf,offset,nmb->header.name_trn_id);
- ubuf[offset+2] = (nmb->header.opcode & 0xF) << 3;
- if (nmb->header.response)
- ubuf[offset+2] |= (1<<7);
- if (nmb->header.nm_flags.authoritative &&
- nmb->header.response)
- ubuf[offset+2] |= 0x4;
- if (nmb->header.nm_flags.trunc)
- ubuf[offset+2] |= 0x2;
- if (nmb->header.nm_flags.recursion_desired)
- ubuf[offset+2] |= 0x1;
- if (nmb->header.nm_flags.recursion_available &&
- nmb->header.response)
- ubuf[offset+3] |= 0x80;
- if (nmb->header.nm_flags.bcast)
- ubuf[offset+3] |= 0x10;
- ubuf[offset+3] |= (nmb->header.rcode & 0xF);
-
- RSSVAL(ubuf,offset+4,nmb->header.qdcount);
- RSSVAL(ubuf,offset+6,nmb->header.ancount);
- RSSVAL(ubuf,offset+8,nmb->header.nscount);
- RSSVAL(ubuf,offset+10,nmb->header.arcount);
-
+ if (buf) {
+ RSSVAL(ubuf,offset,nmb->header.name_trn_id);
+ ubuf[offset+2] = (nmb->header.opcode & 0xF) << 3;
+ if (nmb->header.response)
+ ubuf[offset+2] |= (1<<7);
+ if (nmb->header.nm_flags.authoritative &&
+ nmb->header.response)
+ ubuf[offset+2] |= 0x4;
+ if (nmb->header.nm_flags.trunc)
+ ubuf[offset+2] |= 0x2;
+ if (nmb->header.nm_flags.recursion_desired)
+ ubuf[offset+2] |= 0x1;
+ if (nmb->header.nm_flags.recursion_available &&
+ nmb->header.response)
+ ubuf[offset+3] |= 0x80;
+ if (nmb->header.nm_flags.bcast)
+ ubuf[offset+3] |= 0x10;
+ ubuf[offset+3] |= (nmb->header.rcode & 0xF);
+
+ RSSVAL(ubuf,offset+4,nmb->header.qdcount);
+ RSSVAL(ubuf,offset+6,nmb->header.ancount);
+ RSSVAL(ubuf,offset+8,nmb->header.nscount);
+ RSSVAL(ubuf,offset+10,nmb->header.arcount);
+ }
+