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 int	udpannounce(char*);
  9 3e0d8fb3 2005-12-27 devnull static void	reply(int, uchar*, DNSmsg*, Request*);
 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 static void
 14 3e0d8fb3 2005-12-27 devnull ding(void *x, char *msg)
 15 3e0d8fb3 2005-12-27 devnull {
 16 3e0d8fb3 2005-12-27 devnull 	USED(x);
 17 3e0d8fb3 2005-12-27 devnull 	if(strcmp(msg, "alarm") == 0)
 18 3e0d8fb3 2005-12-27 devnull 		noted(NCONT);
 19 3e0d8fb3 2005-12-27 devnull 	else
 20 3e0d8fb3 2005-12-27 devnull 		noted(NDFLT);
 21 3e0d8fb3 2005-12-27 devnull }
 22 3e0d8fb3 2005-12-27 devnull 
 23 3e0d8fb3 2005-12-27 devnull typedef struct Inprogress Inprogress;
 24 3e0d8fb3 2005-12-27 devnull struct Inprogress
 25 3e0d8fb3 2005-12-27 devnull {
 26 3e0d8fb3 2005-12-27 devnull 	int	inuse;
 27 3e0d8fb3 2005-12-27 devnull 	OUdphdr	uh;
 28 3e0d8fb3 2005-12-27 devnull 	DN	*owner;
 29 3e0d8fb3 2005-12-27 devnull 	int	type;
 30 3e0d8fb3 2005-12-27 devnull 	int	id;
 31 3e0d8fb3 2005-12-27 devnull };
 32 3e0d8fb3 2005-12-27 devnull Inprogress inprog[Maxactive+2];
 33 3e0d8fb3 2005-12-27 devnull 
 34 3e0d8fb3 2005-12-27 devnull /*
 35 3e0d8fb3 2005-12-27 devnull  *  record client id and ignore retransmissions.
 36 3e0d8fb3 2005-12-27 devnull  *  we're still single thread at this point.
 37 3e0d8fb3 2005-12-27 devnull  */
 38 3e0d8fb3 2005-12-27 devnull static Inprogress*
 39 3e0d8fb3 2005-12-27 devnull clientrxmit(DNSmsg *req, uchar *buf)
 40 3e0d8fb3 2005-12-27 devnull {
 41 3e0d8fb3 2005-12-27 devnull 	Inprogress *p, *empty;
 42 3e0d8fb3 2005-12-27 devnull 	OUdphdr *uh;
 43 3e0d8fb3 2005-12-27 devnull 
 44 3e0d8fb3 2005-12-27 devnull 	uh = (OUdphdr *)buf;
 45 3e0d8fb3 2005-12-27 devnull 	empty = 0;
 46 3e0d8fb3 2005-12-27 devnull 	for(p = inprog; p < &inprog[Maxactive]; p++){
 47 3e0d8fb3 2005-12-27 devnull 		if(p->inuse == 0){
 48 3e0d8fb3 2005-12-27 devnull 			if(empty == 0)
 49 3e0d8fb3 2005-12-27 devnull 				empty = p;
 50 3e0d8fb3 2005-12-27 devnull 			continue;
 51 3e0d8fb3 2005-12-27 devnull 		}
 52 3e0d8fb3 2005-12-27 devnull 		if(req->id == p->id)
 53 3e0d8fb3 2005-12-27 devnull 		if(req->qd->owner == p->owner)
 54 3e0d8fb3 2005-12-27 devnull 		if(req->qd->type == p->type)
 55 3e0d8fb3 2005-12-27 devnull 		if(memcmp(uh, &p->uh, OUdphdrsize) == 0)
 56 3e0d8fb3 2005-12-27 devnull 			return 0;
 57 3e0d8fb3 2005-12-27 devnull 	}
 58 3e0d8fb3 2005-12-27 devnull 	if(empty == 0)
 59 3e0d8fb3 2005-12-27 devnull 		return 0;	/* shouldn't happen - see slave() and definition of Maxactive */
 60 3e0d8fb3 2005-12-27 devnull 
 61 3e0d8fb3 2005-12-27 devnull 	empty->id = req->id;
 62 3e0d8fb3 2005-12-27 devnull 	empty->owner = req->qd->owner;
 63 3e0d8fb3 2005-12-27 devnull 	empty->type = req->qd->type;
 64 3e0d8fb3 2005-12-27 devnull 	memmove(&empty->uh, uh, OUdphdrsize);
 65 3e0d8fb3 2005-12-27 devnull 	empty->inuse = 1;
 66 3e0d8fb3 2005-12-27 devnull 	return empty;
 67 3e0d8fb3 2005-12-27 devnull }
 68 3e0d8fb3 2005-12-27 devnull 
 69 3e0d8fb3 2005-12-27 devnull /*
 70 3e0d8fb3 2005-12-27 devnull  *  a process to act as a dns server for outside reqeusts
 71 3e0d8fb3 2005-12-27 devnull  */
 72 3e0d8fb3 2005-12-27 devnull void
 73 3e0d8fb3 2005-12-27 devnull dnudpserver(char *mntpt)
 74 3e0d8fb3 2005-12-27 devnull {
 75 3e0d8fb3 2005-12-27 devnull 	int fd, len, op;
 76 3e0d8fb3 2005-12-27 devnull 	Request req;
 77 3e0d8fb3 2005-12-27 devnull 	DNSmsg reqmsg, repmsg;
 78 3e0d8fb3 2005-12-27 devnull 	uchar buf[OUdphdrsize + Maxudp + 1024];
 79 3e0d8fb3 2005-12-27 devnull 	char *err;
 80 3e0d8fb3 2005-12-27 devnull 	Inprogress *p;
 81 3e0d8fb3 2005-12-27 devnull 	char tname[32];
 82 3e0d8fb3 2005-12-27 devnull 	OUdphdr *uh;
 83 3e0d8fb3 2005-12-27 devnull 
 84 3e0d8fb3 2005-12-27 devnull 	/* fork sharing text, data, and bss with parent */
 85 3e0d8fb3 2005-12-27 devnull 	switch(rfork(RFPROC|RFNOTEG|RFMEM|RFNOWAIT)){
 86 3e0d8fb3 2005-12-27 devnull 	case -1:
 87 3e0d8fb3 2005-12-27 devnull 		break;
 88 3e0d8fb3 2005-12-27 devnull 	case 0:
 89 3e0d8fb3 2005-12-27 devnull 		break;
 90 3e0d8fb3 2005-12-27 devnull 	default:
 91 3e0d8fb3 2005-12-27 devnull 		return;
 92 3e0d8fb3 2005-12-27 devnull 	}
 93 3e0d8fb3 2005-12-27 devnull 
 94 3e0d8fb3 2005-12-27 devnull 	fd = -1;
 95 3e0d8fb3 2005-12-27 devnull 	notify(ding);
 96 3e0d8fb3 2005-12-27 devnull restart:
 97 3e0d8fb3 2005-12-27 devnull 	if(fd >= 0)
 98 3e0d8fb3 2005-12-27 devnull 		close(fd);
 99 3e0d8fb3 2005-12-27 devnull 	while((fd = udpannounce(mntpt)) < 0)
100 3e0d8fb3 2005-12-27 devnull 		sleep(5000);
101 3e0d8fb3 2005-12-27 devnull 	if(setjmp(req.mret))
102 3e0d8fb3 2005-12-27 devnull 		putactivity();
103 3e0d8fb3 2005-12-27 devnull 	req.isslave = 0;
104 3e0d8fb3 2005-12-27 devnull 
105 3e0d8fb3 2005-12-27 devnull 	/* loop on requests */
106 3e0d8fb3 2005-12-27 devnull 	for(;; putactivity()){
107 3e0d8fb3 2005-12-27 devnull 		memset(&repmsg, 0, sizeof(repmsg));
108 3e0d8fb3 2005-12-27 devnull 		memset(&reqmsg, 0, sizeof(reqmsg));
109 3e0d8fb3 2005-12-27 devnull 		alarm(60*1000);
110 3e0d8fb3 2005-12-27 devnull 		len = udpread(fd, (OUdphdr*)buf, buf+OUdphdrsize, sizeof(buf)-OUdphdrsize);
111 3e0d8fb3 2005-12-27 devnull 		alarm(0);
112 3e0d8fb3 2005-12-27 devnull 		if(len <= 0)
113 3e0d8fb3 2005-12-27 devnull 			goto restart;
114 3e0d8fb3 2005-12-27 devnull 		uh = (OUdphdr*)buf;
115 3e0d8fb3 2005-12-27 devnull 		getactivity(&req);
116 3e0d8fb3 2005-12-27 devnull 		req.aborttime = now + 30;	/* don't spend more than 30 seconds */
117 3e0d8fb3 2005-12-27 devnull 		err = convM2DNS(&buf[OUdphdrsize], len, &reqmsg);
118 3e0d8fb3 2005-12-27 devnull 		if(err){
119 3e0d8fb3 2005-12-27 devnull 			syslog(0, logfile, "server: input error: %s from %I", err, buf);
120 3e0d8fb3 2005-12-27 devnull 			continue;
121 3e0d8fb3 2005-12-27 devnull 		}
122 3e0d8fb3 2005-12-27 devnull 		if(reqmsg.qdcount < 1){
123 3e0d8fb3 2005-12-27 devnull 			syslog(0, logfile, "server: no questions from %I", buf);
124 3e0d8fb3 2005-12-27 devnull 			goto freereq;
125 3e0d8fb3 2005-12-27 devnull 		}
126 3e0d8fb3 2005-12-27 devnull 		if(reqmsg.flags & Fresp){
127 3e0d8fb3 2005-12-27 devnull 			syslog(0, logfile, "server: reply not request from %I", buf);
128 3e0d8fb3 2005-12-27 devnull 			goto freereq;
129 3e0d8fb3 2005-12-27 devnull 		}
130 3e0d8fb3 2005-12-27 devnull 		op = reqmsg.flags & Omask;
131 3e0d8fb3 2005-12-27 devnull 		if(op != Oquery && op != Onotify){
132 3e0d8fb3 2005-12-27 devnull 			syslog(0, logfile, "server: op %d from %I", reqmsg.flags & Omask, buf);
133 3e0d8fb3 2005-12-27 devnull 			goto freereq;
134 3e0d8fb3 2005-12-27 devnull 		}
135 3e0d8fb3 2005-12-27 devnull 
136 3e0d8fb3 2005-12-27 devnull 		if(debug || (trace && subsume(trace, reqmsg.qd->owner->name))){
137 3e0d8fb3 2005-12-27 devnull 			syslog(0, logfile, "%d: serve (%I/%d) %d %s %s",
138 3e0d8fb3 2005-12-27 devnull 				req.id, buf, ((uh->rport[0])<<8)+uh->rport[1],
139 3e0d8fb3 2005-12-27 devnull 				reqmsg.id,
140 3e0d8fb3 2005-12-27 devnull 				reqmsg.qd->owner->name,
141 3e0d8fb3 2005-12-27 devnull 				rrname(reqmsg.qd->type, tname, sizeof tname));
142 3e0d8fb3 2005-12-27 devnull 		}
143 3e0d8fb3 2005-12-27 devnull 
144 3e0d8fb3 2005-12-27 devnull 		p = clientrxmit(&reqmsg, buf);
145 3e0d8fb3 2005-12-27 devnull 		if(p == 0){
146 3e0d8fb3 2005-12-27 devnull 			if(debug)
147 3e0d8fb3 2005-12-27 devnull 				syslog(0, logfile, "%d: duplicate", req.id);
148 3e0d8fb3 2005-12-27 devnull 			goto freereq;
149 3e0d8fb3 2005-12-27 devnull 		}
150 3e0d8fb3 2005-12-27 devnull 
151 3e0d8fb3 2005-12-27 devnull 		/* loop through each question */
152 3e0d8fb3 2005-12-27 devnull 		while(reqmsg.qd){
153 3e0d8fb3 2005-12-27 devnull 			memset(&repmsg, 0, sizeof(repmsg));
154 3e0d8fb3 2005-12-27 devnull 			switch(op){
155 3e0d8fb3 2005-12-27 devnull 			case Oquery:
156 3e0d8fb3 2005-12-27 devnull 				dnserver(&reqmsg, &repmsg, &req);
157 3e0d8fb3 2005-12-27 devnull 				break;
158 3e0d8fb3 2005-12-27 devnull 			case Onotify:
159 3e0d8fb3 2005-12-27 devnull 				dnnotify(&reqmsg, &repmsg, &req);
160 3e0d8fb3 2005-12-27 devnull 				break;
161 3e0d8fb3 2005-12-27 devnull 			}
162 3e0d8fb3 2005-12-27 devnull 			reply(fd, buf, &repmsg, &req);
163 3e0d8fb3 2005-12-27 devnull 			rrfreelist(repmsg.qd);
164 3e0d8fb3 2005-12-27 devnull 			rrfreelist(repmsg.an);
165 3e0d8fb3 2005-12-27 devnull 			rrfreelist(repmsg.ns);
166 3e0d8fb3 2005-12-27 devnull 			rrfreelist(repmsg.ar);
167 3e0d8fb3 2005-12-27 devnull 		}
168 3e0d8fb3 2005-12-27 devnull 
169 3e0d8fb3 2005-12-27 devnull 		p->inuse = 0;
170 3e0d8fb3 2005-12-27 devnull 
171 3e0d8fb3 2005-12-27 devnull freereq:
172 3e0d8fb3 2005-12-27 devnull 		rrfreelist(reqmsg.qd);
173 3e0d8fb3 2005-12-27 devnull 		rrfreelist(reqmsg.an);
174 3e0d8fb3 2005-12-27 devnull 		rrfreelist(reqmsg.ns);
175 3e0d8fb3 2005-12-27 devnull 		rrfreelist(reqmsg.ar);
176 3e0d8fb3 2005-12-27 devnull 
177 3e0d8fb3 2005-12-27 devnull 		if(req.isslave){
178 3e0d8fb3 2005-12-27 devnull 			putactivity();
179 3e0d8fb3 2005-12-27 devnull 			_exits(0);
180 3e0d8fb3 2005-12-27 devnull 		}
181 3e0d8fb3 2005-12-27 devnull 
182 3e0d8fb3 2005-12-27 devnull 	}
183 3e0d8fb3 2005-12-27 devnull }
184 3e0d8fb3 2005-12-27 devnull 
185 3e0d8fb3 2005-12-27 devnull /*
186 3e0d8fb3 2005-12-27 devnull  *  announce on udp port
187 3e0d8fb3 2005-12-27 devnull  */
188 3e0d8fb3 2005-12-27 devnull static int
189 3e0d8fb3 2005-12-27 devnull udpannounce(char *mntpt)
190 3e0d8fb3 2005-12-27 devnull {
191 3e0d8fb3 2005-12-27 devnull 	int fd;
192 3e0d8fb3 2005-12-27 devnull 	char buf[40];
193 3e0d8fb3 2005-12-27 devnull 	
194 3e0d8fb3 2005-12-27 devnull 	USED(mntpt);
195 3e0d8fb3 2005-12-27 devnull 	
196 3e0d8fb3 2005-12-27 devnull 	if((fd=announce("udp!*!nameserver", buf)) < 0)
197 3e0d8fb3 2005-12-27 devnull 		warning("can't announce on dns udp port");
198 3e0d8fb3 2005-12-27 devnull 	return fd;
199 3e0d8fb3 2005-12-27 devnull }
200 3e0d8fb3 2005-12-27 devnull 
201 3e0d8fb3 2005-12-27 devnull static void
202 3e0d8fb3 2005-12-27 devnull reply(int fd, uchar *buf, DNSmsg *rep, Request *reqp)
203 3e0d8fb3 2005-12-27 devnull {
204 3e0d8fb3 2005-12-27 devnull 	int len;
205 3e0d8fb3 2005-12-27 devnull 	char tname[32];
206 3e0d8fb3 2005-12-27 devnull 	RR *rp;
207 3e0d8fb3 2005-12-27 devnull 
208 3e0d8fb3 2005-12-27 devnull 	if(debug || (trace && subsume(trace, rep->qd->owner->name)))
209 3e0d8fb3 2005-12-27 devnull 		syslog(0, logfile, "%d: reply (%I/%d) %d %s %s an %R ns %R ar %R",
210 3e0d8fb3 2005-12-27 devnull 			reqp->id, buf, ((buf[4])<<8)+buf[5],
211 3e0d8fb3 2005-12-27 devnull 			rep->id, rep->qd->owner->name,
212 3e0d8fb3 2005-12-27 devnull 			rrname(rep->qd->type, tname, sizeof tname), rep->an, rep->ns, rep->ar);
213 3e0d8fb3 2005-12-27 devnull 
214 3e0d8fb3 2005-12-27 devnull 	len = convDNS2M(rep, &buf[OUdphdrsize], Maxudp);
215 3e0d8fb3 2005-12-27 devnull 	if(len <= 0){
216 3e0d8fb3 2005-12-27 devnull 		syslog(0, logfile, "error converting reply: %s %d", rep->qd->owner->name,
217 3e0d8fb3 2005-12-27 devnull 			rep->qd->type);
218 3e0d8fb3 2005-12-27 devnull 		for(rp = rep->an; rp; rp = rp->next)
219 3e0d8fb3 2005-12-27 devnull 			syslog(0, logfile, "an %R", rp);
220 3e0d8fb3 2005-12-27 devnull 		for(rp = rep->ns; rp; rp = rp->next)
221 3e0d8fb3 2005-12-27 devnull 			syslog(0, logfile, "ns %R", rp);
222 3e0d8fb3 2005-12-27 devnull 		for(rp = rep->ar; rp; rp = rp->next)
223 3e0d8fb3 2005-12-27 devnull 			syslog(0, logfile, "ar %R", rp);
224 3e0d8fb3 2005-12-27 devnull 		return;
225 3e0d8fb3 2005-12-27 devnull 	}
226 3e0d8fb3 2005-12-27 devnull 	if(udpwrite(fd, (OUdphdr*)buf, buf+OUdphdrsize, len) != len)
227 3e0d8fb3 2005-12-27 devnull 		syslog(0, logfile, "error sending reply: %r");
228 3e0d8fb3 2005-12-27 devnull }