1 3e0d8fb3 2005-12-27 devnull #include <u.h>
  2 3e0d8fb3 2005-12-27 devnull #include <libc.h>
  3 3e0d8fb3 2005-12-27 devnull #include <ip.h>
  4 3e0d8fb3 2005-12-27 devnull #include <bio.h>
  5 3e0d8fb3 2005-12-27 devnull #include <ndb.h>
  6 3e0d8fb3 2005-12-27 devnull #include "dns.h"
  7 3e0d8fb3 2005-12-27 devnull 
  8 3e0d8fb3 2005-12-27 devnull static RR*	doextquery(DNSmsg*, Request*, int);
  9 3e0d8fb3 2005-12-27 devnull static void	hint(RR**, RR*);
 10 3e0d8fb3 2005-12-27 devnull 
 11 3e0d8fb3 2005-12-27 devnull extern char *logfile;
 12 3e0d8fb3 2005-12-27 devnull 
 13 3e0d8fb3 2005-12-27 devnull /*
 14 3e0d8fb3 2005-12-27 devnull  *  answer a dns request
 15 3e0d8fb3 2005-12-27 devnull  */
 16 3e0d8fb3 2005-12-27 devnull void
 17 3e0d8fb3 2005-12-27 devnull dnserver(DNSmsg *reqp, DNSmsg *repp, Request *req)
 18 3e0d8fb3 2005-12-27 devnull {
 19 3e0d8fb3 2005-12-27 devnull 	RR *tp, *neg;
 20 3e0d8fb3 2005-12-27 devnull 	char *cp;
 21 3e0d8fb3 2005-12-27 devnull 	DN *nsdp, *dp;
 22 3e0d8fb3 2005-12-27 devnull 	Area *myarea;
 23 3e0d8fb3 2005-12-27 devnull 	char tname[32];
 24 3e0d8fb3 2005-12-27 devnull 
 25 3e0d8fb3 2005-12-27 devnull 	dncheck(nil, 1);
 26 3e0d8fb3 2005-12-27 devnull 
 27 3e0d8fb3 2005-12-27 devnull 	memset(repp, 0, sizeof(*repp));
 28 3e0d8fb3 2005-12-27 devnull 	repp->id = reqp->id;
 29 3e0d8fb3 2005-12-27 devnull 	repp->flags = Fresp | Fcanrec | Oquery;
 30 3e0d8fb3 2005-12-27 devnull 
 31 3e0d8fb3 2005-12-27 devnull 	/* move one question from reqp to repp */
 32 3e0d8fb3 2005-12-27 devnull 	tp = reqp->qd;
 33 3e0d8fb3 2005-12-27 devnull 	reqp->qd = tp->next;
 34 3e0d8fb3 2005-12-27 devnull 	tp->next = 0;
 35 3e0d8fb3 2005-12-27 devnull 	repp->qd = tp;
 36 3e0d8fb3 2005-12-27 devnull 
 37 3e0d8fb3 2005-12-27 devnull 	if(!rrsupported(repp->qd->type)){
 38 3e0d8fb3 2005-12-27 devnull 		syslog(0, logfile, "server: request %s", rrname(repp->qd->type, tname, sizeof tname));
 39 3e0d8fb3 2005-12-27 devnull 		repp->flags = Runimplimented | Fresp | Fcanrec | Oquery;
 40 3e0d8fb3 2005-12-27 devnull 		return;
 41 3e0d8fb3 2005-12-27 devnull 	}
 42 3e0d8fb3 2005-12-27 devnull 
 43 3e0d8fb3 2005-12-27 devnull 	if(repp->qd->owner->class != Cin){
 44 3e0d8fb3 2005-12-27 devnull 		syslog(0, logfile, "server: class %d", repp->qd->owner->class);
 45 3e0d8fb3 2005-12-27 devnull 		repp->flags = Runimplimented | Fresp | Fcanrec | Oquery;
 46 3e0d8fb3 2005-12-27 devnull 		return;
 47 3e0d8fb3 2005-12-27 devnull 	}
 48 3e0d8fb3 2005-12-27 devnull 
 49 3e0d8fb3 2005-12-27 devnull 	myarea = inmyarea(repp->qd->owner->name);
 50 3e0d8fb3 2005-12-27 devnull 	if(myarea != nil && (repp->qd->type == Tixfr || repp->qd->type == Taxfr)){
 51 3e0d8fb3 2005-12-27 devnull 		syslog(0, logfile, "server: request %s", rrname(repp->qd->type, tname, sizeof tname));
 52 3e0d8fb3 2005-12-27 devnull 		repp->flags = Runimplimented | Fresp | Fcanrec | Oquery;
 53 3e0d8fb3 2005-12-27 devnull 		return;
 54 3e0d8fb3 2005-12-27 devnull 	}
 55 3e0d8fb3 2005-12-27 devnull 
 56 3e0d8fb3 2005-12-27 devnull 	/*
 57 3e0d8fb3 2005-12-27 devnull 	 *  get the answer if we can
 58 3e0d8fb3 2005-12-27 devnull 	 */
 59 3e0d8fb3 2005-12-27 devnull 	if(reqp->flags & Frecurse)
 60 3e0d8fb3 2005-12-27 devnull 		neg = doextquery(repp, req, Recurse);
 61 3e0d8fb3 2005-12-27 devnull 	else
 62 3e0d8fb3 2005-12-27 devnull 		neg = doextquery(repp, req, Dontrecurse);
 63 3e0d8fb3 2005-12-27 devnull 
 64 3e0d8fb3 2005-12-27 devnull 	/* authority is transitive */
 65 3e0d8fb3 2005-12-27 devnull 	if(myarea != nil || (repp->an && repp->an->auth))
 66 3e0d8fb3 2005-12-27 devnull 		repp->flags |= Fauth;
 67 3e0d8fb3 2005-12-27 devnull 
 68 3e0d8fb3 2005-12-27 devnull 	/* pass on error codes */
 69 3e0d8fb3 2005-12-27 devnull 	if(repp->an == 0){
 70 3e0d8fb3 2005-12-27 devnull 		dp = dnlookup(repp->qd->owner->name, repp->qd->owner->class, 0);
 71 3e0d8fb3 2005-12-27 devnull 		if(dp->rr == 0)
 72 3e0d8fb3 2005-12-27 devnull 			if(reqp->flags & Frecurse)
 73 3e0d8fb3 2005-12-27 devnull 				repp->flags |= dp->nonexistent|Fauth;
 74 3e0d8fb3 2005-12-27 devnull 	}
 75 3e0d8fb3 2005-12-27 devnull 
 76 3e0d8fb3 2005-12-27 devnull 	if(myarea == nil){
 77 3e0d8fb3 2005-12-27 devnull 		/*
 78 3e0d8fb3 2005-12-27 devnull 		 *  add name server if we know
 79 3e0d8fb3 2005-12-27 devnull 		 */
 80 3e0d8fb3 2005-12-27 devnull 		for(cp = repp->qd->owner->name; cp; cp = walkup(cp)){
 81 3e0d8fb3 2005-12-27 devnull 			nsdp = dnlookup(cp, repp->qd->owner->class, 0);
 82 3e0d8fb3 2005-12-27 devnull 			if(nsdp == 0)
 83 3e0d8fb3 2005-12-27 devnull 				continue;
 84 3e0d8fb3 2005-12-27 devnull 	
 85 3e0d8fb3 2005-12-27 devnull 			repp->ns = rrlookup(nsdp, Tns, OKneg);
 86 3e0d8fb3 2005-12-27 devnull 			if(repp->ns){
 87 3e0d8fb3 2005-12-27 devnull 				/* don't pass on anything we know is wrong */
 88 3e0d8fb3 2005-12-27 devnull 				if(repp->ns->negative){
 89 3e0d8fb3 2005-12-27 devnull 					rrfreelist(repp->ns);
 90 3e0d8fb3 2005-12-27 devnull 					repp->ns = nil;
 91 3e0d8fb3 2005-12-27 devnull 				}
 92 3e0d8fb3 2005-12-27 devnull 				break;
 93 3e0d8fb3 2005-12-27 devnull 			}
 94 3e0d8fb3 2005-12-27 devnull 	
 95 3e0d8fb3 2005-12-27 devnull 			repp->ns = dblookup(cp, repp->qd->owner->class, Tns, 0, 0);
 96 3e0d8fb3 2005-12-27 devnull 			if(repp->ns)
 97 3e0d8fb3 2005-12-27 devnull 				break;
 98 3e0d8fb3 2005-12-27 devnull 		}
 99 3e0d8fb3 2005-12-27 devnull 	}
100 3e0d8fb3 2005-12-27 devnull 
101 3e0d8fb3 2005-12-27 devnull 	/*
102 3e0d8fb3 2005-12-27 devnull 	 *  add ip addresses as hints
103 3e0d8fb3 2005-12-27 devnull 	 */
104 3e0d8fb3 2005-12-27 devnull 	if(repp->qd->type != Taxfr && repp->qd->type != Tixfr){
105 3e0d8fb3 2005-12-27 devnull 		for(tp = repp->ns; tp; tp = tp->next)
106 3e0d8fb3 2005-12-27 devnull 			hint(&repp->ar, tp);
107 3e0d8fb3 2005-12-27 devnull 		for(tp = repp->an; tp; tp = tp->next)
108 3e0d8fb3 2005-12-27 devnull 			hint(&repp->ar, tp);
109 3e0d8fb3 2005-12-27 devnull 	}
110 3e0d8fb3 2005-12-27 devnull 
111 3e0d8fb3 2005-12-27 devnull 	/*
112 3e0d8fb3 2005-12-27 devnull 	 *  add an soa to the authority section to help client with negative caching
113 3e0d8fb3 2005-12-27 devnull 	 */
114 3e0d8fb3 2005-12-27 devnull 	if(repp->an == nil){
115 3e0d8fb3 2005-12-27 devnull 		if(myarea != nil){
116 3e0d8fb3 2005-12-27 devnull 			rrcopy(myarea->soarr, &tp);
117 3e0d8fb3 2005-12-27 devnull 			rrcat(&repp->ns, tp);
118 3e0d8fb3 2005-12-27 devnull 		} else if(neg != nil) {
119 3e0d8fb3 2005-12-27 devnull 			if(neg->negsoaowner != nil)
120 3e0d8fb3 2005-12-27 devnull 				rrcat(&repp->ns, rrlookup(neg->negsoaowner, Tsoa, NOneg));
121 3e0d8fb3 2005-12-27 devnull 			repp->flags |= neg->negrcode;
122 3e0d8fb3 2005-12-27 devnull 		}
123 3e0d8fb3 2005-12-27 devnull 	}
124 3e0d8fb3 2005-12-27 devnull 
125 3e0d8fb3 2005-12-27 devnull 	/*
126 3e0d8fb3 2005-12-27 devnull 	 *  get rid of duplicates
127 3e0d8fb3 2005-12-27 devnull 	 */
128 3e0d8fb3 2005-12-27 devnull 	unique(repp->an);
129 3e0d8fb3 2005-12-27 devnull 	unique(repp->ns);
130 3e0d8fb3 2005-12-27 devnull 	unique(repp->ar);
131 3e0d8fb3 2005-12-27 devnull 
132 3e0d8fb3 2005-12-27 devnull 	rrfreelist(neg);
133 3e0d8fb3 2005-12-27 devnull 
134 3e0d8fb3 2005-12-27 devnull 	dncheck(nil, 1);
135 3e0d8fb3 2005-12-27 devnull }
136 3e0d8fb3 2005-12-27 devnull 
137 3e0d8fb3 2005-12-27 devnull /*
138 3e0d8fb3 2005-12-27 devnull  *  satisfy a recursive request.  dnlookup will handle cnames.
139 3e0d8fb3 2005-12-27 devnull  */
140 3e0d8fb3 2005-12-27 devnull static RR*
141 3e0d8fb3 2005-12-27 devnull doextquery(DNSmsg *mp, Request *req, int recurse)
142 3e0d8fb3 2005-12-27 devnull {
143 3e0d8fb3 2005-12-27 devnull 	int type;
144 3e0d8fb3 2005-12-27 devnull 	char *name;
145 3e0d8fb3 2005-12-27 devnull 	RR *rp, *neg;
146 3e0d8fb3 2005-12-27 devnull 
147 3e0d8fb3 2005-12-27 devnull 	name = mp->qd->owner->name;
148 3e0d8fb3 2005-12-27 devnull 	type = mp->qd->type;
149 3e0d8fb3 2005-12-27 devnull 	rp = dnresolve(name, Cin, type, req, &mp->an, 0, recurse, 1, 0);
150 3e0d8fb3 2005-12-27 devnull 
151 3e0d8fb3 2005-12-27 devnull 	/* don't return soa hints as answers, it's wrong */
152 3e0d8fb3 2005-12-27 devnull 	if(rp && rp->db && !rp->auth && rp->type == Tsoa)
153 3e0d8fb3 2005-12-27 devnull 		rrfreelist(rp);
154 3e0d8fb3 2005-12-27 devnull 
155 3e0d8fb3 2005-12-27 devnull 	/* don't let negative cached entries escape */
156 3e0d8fb3 2005-12-27 devnull 	neg = rrremneg(&rp);
157 3e0d8fb3 2005-12-27 devnull 	rrcat(&mp->an, rp);
158 3e0d8fb3 2005-12-27 devnull 	return neg;
159 3e0d8fb3 2005-12-27 devnull }
160 3e0d8fb3 2005-12-27 devnull 
161 3e0d8fb3 2005-12-27 devnull static void
162 3e0d8fb3 2005-12-27 devnull hint(RR **last, RR *rp)
163 3e0d8fb3 2005-12-27 devnull {
164 3e0d8fb3 2005-12-27 devnull 	RR *hp;
165 3e0d8fb3 2005-12-27 devnull 
166 3e0d8fb3 2005-12-27 devnull 	switch(rp->type){
167 3e0d8fb3 2005-12-27 devnull 	case Tns:
168 3e0d8fb3 2005-12-27 devnull 	case Tmx:
169 3e0d8fb3 2005-12-27 devnull 	case Tmb:
170 3e0d8fb3 2005-12-27 devnull 	case Tmf:
171 3e0d8fb3 2005-12-27 devnull 	case Tmd:
172 3e0d8fb3 2005-12-27 devnull 		hp = rrlookup(rp->host, Ta, NOneg);
173 3e0d8fb3 2005-12-27 devnull 		if(hp == nil)
174 3e0d8fb3 2005-12-27 devnull 			hp = dblookup(rp->host->name, Cin, Ta, 0, 0);
175 3e0d8fb3 2005-12-27 devnull 		rrcat(last, hp);
176 3e0d8fb3 2005-12-27 devnull 		break;
177 3e0d8fb3 2005-12-27 devnull 	}
178 3e0d8fb3 2005-12-27 devnull }