1 #include <u.h>
2 #include <libc.h>
3 #include <ip.h>
4 #include "dat.h"
5 #include "protos.h"
6 
7 enum
8 {
9 	/* RR types */
10 	Ta=	1,
11 	Tns=	2,
12 	Tmd=	3,
13 	Tmf=	4,
14 	Tcname=	5,
15 	Tsoa=	6,
16 	Tmb=	7,
17 	Tmg=	8,
18 	Tmr=	9,
19 	Tnull=	10,
20 	Twks=	11,
21 	Tptr=	12,
22 	Thinfo=	13,
23 	Tminfo=	14,
24 	Tmx=	15,
25 	Ttxt=	16,
26 	Trp=	17,
27 	Tsig=	24,
28 	Tkey=	25,
29 	Taaaa=	28,
30 	Tcert=	37,
31 
32 	/* query types (all RR types are also queries) */
33 	Tixfr=	251,	/* incremental zone transfer */
34 	Taxfr=	252,	/* zone transfer */
35 	Tmailb=	253,	/* { Tmb, Tmg, Tmr } */
36 	Tall=	255,	/* all records */
37 
38 	/* classes */
39 	Csym=	0,	/* internal symbols */
40 	Cin=	1,	/* internet */
41 	Ccs,		/* CSNET (obsolete) */
42 	Cch,		/* Chaos net */
43 	Chs,		/* Hesiod (?) */
44 
45 	/* class queries (all class types are also queries) */
46 	Call=	255,	/* all classes */
47 
48 	/* opcodes */
49 	Oquery=		0<<11,		/* normal query */
50 	Oinverse=	1<<11,		/* inverse query */
51 	Ostatus=	2<<11,		/* status request */
52 	Onotify=	4<<11,		/* notify slaves of updates */
53 	Omask=		0xf<<11,	/* mask for opcode */
54 
55 	/* response codes */
56 	Rok=		0,
57 	Rformat=	1,	/* format error */
58 	Rserver=	2,	/* server failure (e.g. no answer from something) */
59 	Rname=		3,	/* bad name */
60 	Runimplimented=	4,	/* unimplemented */
61 	Rrefused=	5,	/* we don't like you */
62 	Rmask=		0xf,	/* mask for response */
63 	Rtimeout=	0x10,	/* timeout sending (for internal use only) */
64 
65 	/* bits in flag word (other than opcode and response) */
66 	Fresp=		1<<15,	/* message is a response */
67 	Fauth=		1<<10,	/* true if an authoritative response */
68 	Ftrunc=		1<<9,	/* truncated message */
69 	Frecurse=	1<<8,	/* request recursion */
70 	Fcanrec=	1<<7,	/* server can recurse */
71 };
72 
73 typedef struct Hdr	Hdr;
74 struct Hdr
75 {
76 	uchar	id[2];
77 	uchar	flags[2];
78 	uchar	qdcount[2];
79 	uchar	ancount[2];
80 	uchar	nscount[2];
81 	uchar	arcount[2];
82 };
83 
84 
85 static char*
86 getstr(uchar **pp, int *len, uchar *ep)
87 {
88 	uchar *p;
89 	int n;
90 
91 	p = *pp;
92 	n = *p++;
93 	if(p+n > ep)
94 		return nil;
95 	*len = n;
96 	*pp = p+n;
97 	return (char*)p;
98 }
99 
100 static char*
101 getname(uchar **pp, uchar *bp, uchar *ep)
102 {
103 	static char buf[2][512];
104 	static int toggle;
105 	char *tostart, *to;
106 	char *toend;
107 	int len, off, pointer, n;
108 	uchar *p;
109 
110 	to = buf[toggle^=1];
111 	toend = to+sizeof buf[0];
112 	tostart = to;
113 	p = *pp;
114 	len = 0;
115 	pointer = 0;
116 	while(p < ep && *p){
117 		if((*p & 0xc0) == 0xc0){
118 			/* pointer to another spot in message */
119 			if(pointer == 0)
120 				*pp = p + 2;
121 			if(pointer++ > 10)
122 				return nil;
123 			off = ((p[0]<<8) + p[1]) & 0x3ff;
124 			p = bp + off;
125 			if(p >= ep)
126 				return nil;
127 			n = 0;
128 			continue;
129 		}
130 		n = *p++;
131 		if(to+n >= toend || p+n > ep)
132 			return nil;
133 		memmove(to, p, n);
134 		to += n;
135 		p += n;
136 		if(*p){
137 			if(to >= toend)
138 				return nil;
139 			*to++ = '.';
140 		}
141 	}
142 	if(to >= toend || p >= ep)
143 		return nil;
144 	*to = 0;
145 	if(!pointer)
146 		*pp = ++p;
147 	return tostart;
148 }
149 
150 static char*
151 tname(int type)
152 {
153 	static char buf[20];
154 
155 	switch(type){
156 	case Ta:
157 		return "a";
158 	case Tns:
159 		return "ns";
160 	case Tmd:
161 		return "md";
162 	case Tmf:
163 		return "mf";
164 	case Tcname:
165 		return "cname";
166 	case Tsoa:
167 		return "soa";
168 	case Tmb:
169 		return "mb";
170 	case Tmg:
171 		return "mg";
172 	case Tmr:
173 		return "mr";
174 	case Tnull:
175 		return "null";
176 	case Twks:
177 		return "wks";
178 	case Tptr:
179 		return "ptr";
180 	case Thinfo:
181 		return "hinfo";
182 	case Tminfo:
183 		return "minfo";
184 	case Tmx:
185 		return "mx";
186 	case Ttxt:
187 		return "txt";
188 	case Trp:
189 		return "rp";
190 	case Tsig:
191 		return "sig";
192 	case Tkey:
193 		return "key";
194 	case Taaaa:
195 		return "aaaa";
196 	case Tcert:
197 		return "cert";
198 	case Tixfr:
199 		return "ixfr";
200 	case Taxfr:
201 		return "axfr";
202 	case Tmailb:
203 		return "mailb";
204 	case Tall:
205 		return "all";
206 	}
207 	snprint(buf, sizeof buf, "%d", type);
208 	return buf;
209 }
210 
211 static char*
212 cname(int class)
213 {
214 	static char buf[40];
215 
216 	if(class == Cin)
217 		return "";
218 
219 	snprint(buf, sizeof buf, "class=%d", class);
220 	return buf;
221 }
222 
223 #define PR(name, len) utfnlen(name, len), name
224 
225 extern int sflag;
226 
227 static int
228 p_seprint(Msg *m)
229 {
230 	int i, pref;
231 	Hdr *h;
232 	uchar *p, *ep;
233 	int an, ns, ar, rlen;
234 	char *name, *prefix;
235 	int len1, len2;
236 	char *sym1, *sym2, *sep;
237 	int type;
238 	static int first = 1;
239 
240 	if(first){
241 		first = 0;
242 		quotefmtinstall();
243 	}
244 
245 	if(m->pe - m->ps < sizeof(Hdr))
246 		return -1;
247 	h = (Hdr*)m->ps;
248 	m->pr = nil;
249 
250 	m->p = seprint(m->p, m->e, "id=%d flags=%04ux %d/%d/%d/%d",
251 			NetS(h->id), NetS(h->flags),
252 			NetS(h->qdcount), NetS(h->ancount),
253 			NetS(h->nscount), NetS(h->arcount));
254 	sep = ")\n\t";
255 	if(sflag)
256 		sep = ") ";
257 	p = m->ps + sizeof(Hdr);
258 	for(i=0; i<NetS(h->qdcount); i++){
259 		name = getname(&p, m->ps, m->pe);
260 		if(name == nil || p+4 > m->pe)
261 			goto error;
262 		m->p = seprint(m->p, m->e, "%sq=(%q %s%s",
263 			sep, name, tname(NetS(p)), cname(NetS(p+2)));
264 		p += 4;
265 	}
266 
267 	an = NetS(h->ancount);
268 	ns = NetS(h->nscount);
269 	ar = NetS(h->arcount);
270 	while(an+ns+ar > 0){
271 		if(an > 0){
272 			prefix = "an";
273 			an--;
274 		}else if(ns > 0){
275 			prefix = "ns";
276 			ns--;
277 		}else{
278 			prefix = "ar";
279 			ar--;
280 		}
281 		name = getname(&p, m->ps, m->pe);
282 		if(name == nil || p+10 > m->pe)
283 			goto error;
284 		type = NetS(p);
285 		rlen = NetS(p+8);
286 		ep = p+10+rlen;
287 		if(ep > m->pe)
288 			goto error;
289 		m->p = seprint(m->p, m->e, "%s%s=(%q %s%s | ttl=%lud",
290 			sep, prefix, name, tname(type), cname(NetS(p+2)), NetL(p+4), rlen);
291 		p += 10;
292 		switch(type){
293 		default:
294 			p = ep;
295 			break;
296 		case Thinfo:
297 			sym1 = getstr(&p, &len1, ep);
298 			if(sym1 == nil)
299 				goto error;
300 			sym2 = getstr(&p, &len2, ep);
301 			if(sym2 == nil)
302 				goto error;
303 			m->p = seprint(m->p, m->e, " cpu=%.*s os=%.*s",
304 				PR(sym1, len1),
305 				PR(sym2, len2));
306 			break;
307 		case Tcname:
308 		case Tmb:
309 		case Tmd:
310 		case Tmf:
311 		case Tns:
312 		case Tmg:
313 		case Tmr:
314 		case Tptr:
315 			sym1 = getname(&p, m->ps, m->pe);
316 			if(sym1 == nil)
317 				goto error;
318 			m->p = seprint(m->p, m->e, " %q", sym1);
319 			break;
320 		case Tminfo:
321 			sym1 = getname(&p, m->ps, m->pe);
322 			if(sym1 == nil)
323 				goto error;
324 			sym2 = getname(&p, m->ps, m->pe);
325 			if(sym2 == nil)
326 				goto error;
327 			m->p = seprint(m->p, m->e, " %q %q", sym1, sym2);
328 			break;
329 		case Tmx:
330 			if(p+2 >= ep)
331 				goto error;
332 			pref = NetS(p);
333 			p += 2;
334 			sym1 = getname(&p, m->ps, m->pe);
335 			if(sym1 == nil)
336 				goto error;
337 			break;
338 		case Ta:
339 			if(p+4 > ep)
340 				goto error;
341 			m->p = seprint(m->p, m->e, " %V", p);
342 			p += 4;
343 			break;
344 		case Taaaa:
345 			if(p+16 > ep)
346 				goto error;
347 			m->p = seprint(m->p, m->e, " %I", p);
348 			p += 16;
349 			break;
350 		case Tsoa:
351 			sym1 = getname(&p, m->ps, m->pe);
352 			if(sym1 == nil)
353 				goto error;
354 			sym2 = getname(&p, m->ps, m->pe);
355 			if(sym2 == nil)
356 				goto error;
357 			if(p+20 > ep)
358 				goto error;
359 			m->p = seprint(m->p, m->e, " host=%q rmb=%q serial=%lud refresh=%lud retry=%lud expire=%lud minttl=%lud",
360 				sym1, sym2, NetL(p), NetL(p+4),
361 				NetL(p+8), NetL(p+12), NetL(p+16));
362 			break;
363 		case Ttxt:
364 			while(p < ep){
365 				sym1 = getstr(&p, &len1, ep);
366 				if(sym1 == nil)
367 					goto error;
368 				m->p = seprint(m->p, m->e, " %.*q", PR(sym1, len1));
369 			}
370 			break;
371 		case Tnull:
372 			m->p = seprint(m->p, m->e, " %.*H", rlen, p);
373 			p += rlen;
374 			break;
375 		case Trp:
376 			sym1 = getname(&p, m->ps, m->pe);
377 			if(sym1 == nil)
378 				goto error;
379 			sym2 = getname(&p, m->ps, m->pe);
380 			if(sym2 == nil)
381 				goto error;
382 			m->p = seprint(m->p, m->e, " rmb=%q rp=%q", sym1, sym2);
383 			break;
384 		case Tkey:
385 			if(rlen < 4)
386 				goto error;
387 			m->p = seprint(m->p, m->e, " flags=%04ux proto=%d alg=%d %.*H",
388 				NetS(p), p[3], p[4], rlen-4, p+4);
389 			p += rlen;
390 			break;
391 
392 		case Tsig:
393 			if(rlen < 18)
394 				goto error;
395 			m->p = seprint(m->p, m->e, " type=%d alg=%d labels=%d ttl=%lud exp=%lud incep=%lud tag=%d %.*H",
396 				NetS(p), p[3], p[4], NetL(p+4), NetL(p+8), NetL(p+12), NetS(p+16),
397 				rlen-18, p+18);
398 			p += rlen;
399 			break;
400 
401 		case Tcert:
402 			if(rlen < 5)
403 				goto error;
404 			m->p = seprint(m->p, m->e, " type=%d tag=%d alg=%d %.*H",
405 				NetS(p), NetS(p+2), p[4], rlen-5, p+5);
406 			p += rlen;
407 			break;
408 		}
409 		if(p != ep)
410 			goto error;
411 	}
412 	return 0;
413 
414 error:
415 	m->p = seprint(m->p, m->e, " packet error!");
416 	return 0;
417 }
418 
419 Proto dns =
420 {
421 	"dns",
422 	nil,
423 	nil,
424 	p_seprint,
425 	nil,
426 	nil,
427 	nil,
428 	defaultframer
429 };