* _mailbox (pap +pap_mailbox822)
* _rp (pa)
* _soa (pa,mf,cs)
- * _srv* (qdpl,(pap),pa,mf,di,(csp),cs)
+ * _srv* (qdpl,(pap),pa,mf,di,(csp),cs,postsort)
* _flat (mf)
*
* within each section:
* mf_*
* csp_*
* cs_*
+ * postsort_*
*/
/*
}
/*
- * _srv* (pa*2,di,cs*2,qdpl)
+ * _srv* (pa*2,di,cs*2,qdpl,postsort)
*/
static adns_status qdpl_srv(adns_state ads,
}
static adns_status pap_srv_begin(const parseinfo *pai, int *cbyte_io, int max,
- adns_rr_srvraw *rrp
- /* might be adns_rr_srvha* */) {
+ adns_rr_srvha *rrp
+ /* might be adns_rr_srvraw* */) {
const byte *dgram= pai->dgram;
int ti, cbyte;
return 0;
}
-static adns_status csp_srv_begin(vbuf *vb, const adns_rr_srvraw *rrp
- /* might be adns_rr_srvha* */) {
+static adns_status csp_srv_begin(vbuf *vb, const adns_rr_srvha *rrp
+ /* might be adns_rr_srvraw* */) {
char buf[30];
sprintf(buf,"%u %u %u ", rrp->priority, rrp->weight, rrp->port);
CSP_ADDSTR(buf);
const adns_rr_srvraw *rrp= datap;
adns_status st;
- st= csp_srv_begin(vb,rrp); if (st) return st;
+ st= csp_srv_begin(vb,(const void*)rrp); if (st) return st;
return csp_domain(vb,rrp->host);
}
const adns_rr_srvha *rrp= datap;
adns_status st;
- st= csp_srv_begin(vb,datap); if (st) return st;
+ st= csp_srv_begin(vb,(const void*)datap); if (st) return st;
return csp_hostaddr(vb,&rrp->ha);
}
+static void postsort_srv(adns_state ads, void *array, int nrrs,
+ const struct typeinfo *typei) {
+ /* we treat everything in the array as if it were an adns_rr_srvha
+ * even though the array might be of adns_rr_srvraw. That's OK
+ * because they have the same prefix, which is all we access.
+ * We use typei->rrsz, too, rather than naive array indexing, of course.
+ */
+ char *workbegin, *workend, *search, *arrayend;
+ const adns_rr_srvha *rr;
+ union { adns_rr_srvha ha; adns_rr_srvraw raw; } rrtmp;
+ int cpriority, totalweight, runtotal;
+ long randval;
+
+ for (workbegin= array, arrayend= workbegin + typei->rrsz * nrrs;
+ workbegin < arrayend;
+ workbegin= workend) {
+ cpriority= (rr=(void*)workbegin)->priority;
+
+ for (workend= workbegin, totalweight= 0;
+ workend < arrayend && (rr=(void*)workend)->priority == cpriority;
+ workend += typei->rrsz) {
+ totalweight += rr->weight;
+ }
+
+ /* Now workbegin..(workend-1) incl. are exactly all of the RRs of
+ * cpriority. From now on, workbegin points to the `remaining'
+ * records: we select one record at a time (RFC2782 `Usage rules'
+ * and `Format of the SRV RR' subsection `Weight') to place at
+ * workbegin (swapping with the one that was there, and then
+ * advance workbegin. */
+ for (;
+ workbegin + typei->rrsz < workend; /* don't bother if just one */
+ workbegin += typei->rrsz) {
+
+ randval= nrand48(ads->rand48xsubi);
+ randval %= (totalweight + 1);
+ /* makes it into 0..totalweight inclusive; with 2^10 RRs,
+ * totalweight must be <= 2^26 so probability nonuniformity is
+ * no worse than 1 in 2^(31-26) ie 1 in 2^5, ie
+ * abs(log(P_intended(RR_i) / P_actual(RR_i)) <= log(2^-5).
+ */
+
+ for (search=workbegin, runtotal=0;
+ (runtotal += (rr=(void*)search)->weight) < randval;
+ search += typei->rrsz);
+ assert(search < arrayend);
+ totalweight -= rr->weight;
+ if (search != workbegin) {
+ memcpy(&rrtmp, workbegin, typei->rrsz);
+ memcpy(workbegin, search, typei->rrsz);
+ memcpy(search, &rrtmp, typei->rrsz);
+ }
+ }
+ }
+ /* tests:
+ * dig -t srv _srv._tcp.test.iwj.relativity.greenend.org.uk.
+ * ./adnshost_s -t srv- _sip._udp.voip.net.cam.ac.uk.
+ * ./adnshost_s -t srv- _jabber._tcp.jabber.org
+ */
+}
+
/*
* _flat (mf)
*/
#define DEEP_TYPE(code,rrt,fmt,memb,parser,comparer,printer) \
{ adns_r_##code, rrt,fmt,TYPESZ_M(memb), mf_##memb, \
- printer,parser,comparer, adns__qdpl_normal }
+ printer,parser,comparer, adns__qdpl_normal,0 }
#define FLAT_TYPE(code,rrt,fmt,memb,parser,comparer,printer) \
{ adns_r_##code, rrt,fmt,TYPESZ_M(memb), mf_flat, \
- printer,parser,comparer, adns__qdpl_normal }
-#define XTRA_TYPE(code,rrt,fmt,memb,parser,comparer,printer,qdpl) \
- { adns_r_##code, rrt,fmt,TYPESZ_M(memb), mf_##memb, \
- printer,parser,comparer,qdpl }
+ printer,parser,comparer, adns__qdpl_normal,0 }
+#define XTRA_TYPE(code,rrt,fmt,memb,parser,comparer,printer,qdpl,postsort) \
+ { adns_r_##code, rrt,fmt,TYPESZ_M(memb), mf_##memb, \
+ printer,parser,comparer,qdpl,postsort }
static const typeinfo typeinfos[] = {
/* Must be in ascending order of rrtype ! */
DEEP_TYPE(mx_raw, "MX", "raw",intstr, pa_mx_raw, di_mx_raw,cs_inthost ),
DEEP_TYPE(txt, "TXT", 0, manyistr,pa_txt, 0, cs_txt ),
DEEP_TYPE(rp_raw, "RP", "raw",strpair, pa_rp, 0, cs_rp ),
-XTRA_TYPE(srv_raw,"SRV", "raw",srvraw , pa_srvraw, di_srv,cs_srvraw,qdpl_srv),
+XTRA_TYPE(srv_raw,"SRV", "raw",srvraw , pa_srvraw, di_srv, cs_srvraw,
+ qdpl_srv, postsort_srv),
FLAT_TYPE(addr, "A", "addr", addr, pa_addr, di_addr, cs_addr ),
DEEP_TYPE(ns, "NS", "+addr",hostaddr,pa_hostaddr,di_hostaddr,cs_hostaddr ),
DEEP_TYPE(ptr, "PTR","checked",str, pa_ptr, 0, cs_domain ),
DEEP_TYPE(mx, "MX", "+addr",inthostaddr,pa_mx, di_mx, cs_inthostaddr),
-XTRA_TYPE(srv, "SRV","+addr",srvha, pa_srvha, di_srv,cs_srvha, qdpl_srv),
+XTRA_TYPE(srv, "SRV","+addr",srvha, pa_srvha, di_srv, cs_srvha,
+ qdpl_srv, postsort_srv),
DEEP_TYPE(soa, "SOA","822", soa, pa_soa, 0, cs_soa ),
DEEP_TYPE(rp, "RP", "822", strpair, pa_rp, 0, cs_rp ),
~ianmdlvl / adns.git / blobdiff