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source: rtems/cpukit/libnetworking/libc/res_update.c @ 09fdb5e8

4.104.114.84.95

Last change on this file since 09fdb5e8 was 09fdb5e8, checked in by Ralf Corsepius <ralf.corsepius@…>, on 03/30/07 at 05:15:58
Eliminate SCCS, LINT. Add HAVE_CONFIG_H.
Property mode set to `100644`
File size: 13.8 KB

Line
1	/*
2	* Copyright (c) 1996 by Internet Software Consortium.
3	*
4	* Permission to use, copy, modify, and distribute this software for any
5	* purpose with or without fee is hereby granted, provided that the above
6	* copyright notice and this permission notice appear in all copies.
7	*
8	* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
9	* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
10	* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
11	* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
12	* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
13	* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
14	* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
15	* SOFTWARE.
16	*/
17
18	#if HAVE_CONFIG_H
19	#include "config.h"
20	#endif
21
22	/*
23	* Based on the Dynamic DNS reference implementation by Viraj Bais
24	* <viraj_bais@ccm.fm.intel.com>
25	*/
26
27	#include <sys/param.h>
28	#include <sys/socket.h>
29	#include <sys/time.h>
30	#include <netinet/in.h>
31	#include <arpa/inet.h>
32	#include <arpa/nameser.h>
33	#include <errno.h>
34	#include <limits.h>
35	#include <netdb.h>
36	#include <resolv.h>
37	#include <stdio.h>
38	#include <stdlib.h>
39	#include <string.h>
40
41	/*
42	* Separate a linked list of records into groups so that all records
43	* in a group will belong to a single zone on the nameserver.
44	* Create a dynamic update packet for each zone and send it to the
45	* nameservers for that zone, and await answer.
46	* Abort if error occurs in updating any zone.
47	* Return the number of zones updated on success, < 0 on error.
48	*
49	* On error, caller must deal with the unsynchronized zones
50	* eg. an A record might have been successfully added to the forward
51	* zone but the corresponding PTR record would be missing if error
52	* was encountered while updating the reverse zone.
53	*/
54
55	#define NSMAX 16
56
57	struct ns1 {
58	char nsname[MAXDNAME];
59	struct in_addr nsaddr1;
60	};
61
62	struct zonegrp {
63	char z_origin[MAXDNAME];
64	int16_t z_class;
65	char z_soardata[MAXDNAME + 5 * INT32SZ];
66	struct ns1 z_ns[NSMAX];
67	int z_nscount;
68	ns_updrec * z_rr;
69	struct zonegrp *z_next;
70	};
71
72
73	int
74	res_update(ns_updrec *rrecp_in) {
75	ns_updrec rrecp, tmprrecp;
76	u_char buf[PACKETSZ], answer[PACKETSZ], packet[2*PACKETSZ];
77	char name[MAXDNAME], zname[MAXDNAME], primary[MAXDNAME],
78	mailaddr[MAXDNAME];
79	u_char soardata[2MAXCDNAME+5INT32SZ];
80	char dname, svdname, cp1, target;
81	u_char cp, eom;
82	HEADER hp = (HEADER ) answer;
83	struct zonegrp zptr = NULL, tmpzptr, prevzptr, zgrp_start = NULL;
84	int i, j, k = 0, n, ancount, nscount, arcount, rcode, rdatasize,
85	newgroup, done, myzone, seen_before, numzones = 0;
86	u_int16_t dlen, class, qclass, type, qtype;
87	u_int32_t ttl;
88
89	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
90	h_errno = NETDB_INTERNAL;
91	return (-1);
92	}
93
94	for (rrecp = rrecp_in; rrecp; rrecp = rrecp->r_next) {
95	dname = rrecp->r_dname;
96	n = strlen(dname);
97	if (dname[n-1] == '.')
98	dname[n-1] = '\0';
99	qtype = T_SOA;
100	qclass = rrecp->r_class;
101	done = 0;
102	seen_before = 0;
103
104	while (!done && dname) {
105	if (qtype == T_SOA) {
106	for (tmpzptr = zgrp_start;
107	tmpzptr && !seen_before;
108	tmpzptr = tmpzptr->z_next) {
109	if (strcasecmp(dname,
110	tmpzptr->z_origin) == 0 &&
111	tmpzptr->z_class == qclass)
112	seen_before++;
113	for (tmprrecp = tmpzptr->z_rr;
114	tmprrecp && !seen_before;
115	tmprrecp = tmprrecp->r_grpnext)
116	if (strcasecmp(dname, tmprrecp->r_dname) == 0
117	&& tmprrecp->r_class == qclass) {
118	seen_before++;
119	break;
120	}
121	if (seen_before) {
122	/*
123	* Append to the end of
124	* current group.
125	*/
126	for (tmprrecp = tmpzptr->z_rr;
127	tmprrecp->r_grpnext;
128	tmprrecp = tmprrecp->r_grpnext)
129	(void)NULL;
130	tmprrecp->r_grpnext = rrecp;
131	rrecp->r_grpnext = NULL;
132	done = 1;
133	break;
134	}
135	}
136	} else if (qtype == T_A) {
137	for (tmpzptr = zgrp_start;
138	tmpzptr && !done;
139	tmpzptr = tmpzptr->z_next)
140	for (i = 0; i < tmpzptr->z_nscount; i++)
141	if (tmpzptr->z_class == qclass &&
142	strcasecmp(tmpzptr->z_ns[i].nsname,
143	dname) == 0 &&
144	tmpzptr->z_ns[i].nsaddr1.s_addr != 0) {
145	zptr->z_ns[k].nsaddr1.s_addr =
146	tmpzptr->z_ns[i].nsaddr1.s_addr;
147	done = 1;
148	break;
149	}
150	}
151	if (done)
152	break;
153	n = res_mkquery(QUERY, dname, qclass, qtype, NULL,
154	0, NULL, buf, sizeof buf);
155	if (n <= 0) {
156	fprintf(stderr, "res_update: mkquery failed\n");
157	return (n);
158	}
159	n = res_send(buf, n, answer, sizeof answer);
160	if (n < 0) {
161	fprintf(stderr, "res_update: send error for %s\n",
162	rrecp->r_dname);
163	return (n);
164	}
165	if (n < HFIXEDSZ)
166	return (-1);
167	ancount = ntohs(hp->ancount);
168	nscount = ntohs(hp->nscount);
169	arcount = ntohs(hp->arcount);
170	rcode = hp->rcode;
171	cp = answer + HFIXEDSZ;
172	eom = answer + n;
173	/* skip the question section */
174	n = dn_skipname(cp, eom);
175	if (n < 0 \|\| cp + n + 2 * INT16SZ > eom)
176	return (-1);
177	cp += n + 2 * INT16SZ;
178
179	if (qtype == T_SOA) {
180	if (ancount == 0 && nscount == 0 && arcount == 0) {
181	/*
182	* if (rcode == NOERROR) then the dname exists but
183	* has no soa record associated with it.
184	* if (rcode == NXDOMAIN) then the dname does not
185	* exist and the server is replying out of NCACHE.
186	* in either case, proceed with the next try
187	*/
188	dname = strchr(dname, '.');
189	if (dname != NULL)
190	dname++;
191	continue;
192	} else if ((rcode == NOERROR \|\| rcode == NXDOMAIN) &&
193	ancount == 0 &&
194	nscount == 1 && arcount == 0) {
195	/*
196	* name/data does not exist, soa record supplied in the
197	* authority section
198	*/
199	/* authority section must contain the soa record */
200	if ((n = dn_expand(answer, eom, cp, zname,
201	sizeof zname)) < 0)
202	return (n);
203	cp += n;
204	if (cp + 2 * INT16SZ > eom)
205	return (-1);
206	GETSHORT(type, cp);
207	GETSHORT(class, cp);
208	if (type != T_SOA \|\| class != qclass) {
209	fprintf(stderr, "unknown answer\n");
210	return (-1);
211	}
212	myzone = 0;
213	svdname = dname;
214	while (dname)
215	if (strcasecmp(dname, zname) == 0) {
216	myzone = 1;
217	break;
218	} else if ((dname = strchr(dname, '.')) != NULL)
219	dname++;
220	if (!myzone) {
221	dname = strchr(svdname, '.');
222	if (dname != NULL)
223	dname++;
224	continue;
225	}
226	nscount = 0;
227	/* fallthrough */
228	} else if (rcode == NOERROR && ancount == 1) {
229	/*
230	* found the zone name
231	* new servers will supply NS records for the zone
232	* in authority section and A records for those
233	* nameservers in the additional section
234	* older servers have to be explicitly queried for
235	* NS records for the zone
236	*/
237	/* answer section must contain the soa record */
238	if ((n = dn_expand(answer, eom, cp, zname,
239	sizeof zname)) < 0)
240	return (n);
241	else
242	cp += n;
243	if (cp + 2 * INT16SZ > eom)
244	return (-1);
245	GETSHORT(type, cp);
246	GETSHORT(class, cp);
247	if (type == T_CNAME) {
248	dname = strchr(dname, '.');
249	if (dname != NULL)
250	dname++;
251	continue;
252	}
253	if (strcasecmp(dname, zname) != 0 \|\|
254	type != T_SOA \|\|
255	class != rrecp->r_class) {
256	fprintf(stderr, "unknown answer\n");
257	return (-1);
258	}
259	/* FALLTHROUGH */
260	} else {
261	fprintf(stderr,
262	"unknown response: ans=%d, auth=%d, add=%d, rcode=%d\n",
263	ancount, nscount, arcount, hp->rcode);
264	return (-1);
265	}
266	if (cp + INT32SZ + INT16SZ > eom)
267	return (-1);
268	/* continue processing the soa record */
269	GETLONG(ttl, cp);
270	GETSHORT(dlen, cp);
271	if (cp + dlen > eom)
272	return (-1);
273	newgroup = 1;
274	zptr = zgrp_start;
275	prevzptr = NULL;
276	while (zptr) {
277	if (strcasecmp(zname, zptr->z_origin) == 0 &&
278	type == T_SOA && class == qclass) {
279	newgroup = 0;
280	break;
281	}
282	prevzptr = zptr;
283	zptr = zptr->z_next;
284	}
285	if (!newgroup) {
286	for (tmprrecp = zptr->z_rr;
287	tmprrecp->r_grpnext;
288	tmprrecp = tmprrecp->r_grpnext)
289	;
290	tmprrecp->r_grpnext = rrecp;
291	rrecp->r_grpnext = NULL;
292	done = 1;
293	cp += dlen;
294	break;
295	} else {
296	if ((n = dn_expand(answer, eom, cp, primary,
297	sizeof primary)) < 0)
298	return (n);
299	cp += n;
300	/*
301	* We don't have to bounds check here because the
302	* next use of 'cp' is in dn_expand().
303	*/
304	cp1 = (char *)soardata;
305	strcpy(cp1, primary);
306	cp1 += strlen(cp1) + 1;
307	if ((n = dn_expand(answer, eom, cp, mailaddr,
308	sizeof mailaddr)) < 0)
309	return (n);
310	cp += n;
311	strcpy(cp1, mailaddr);
312	cp1 += strlen(cp1) + 1;
313	if (cp + 5*INT32SZ > eom)
314	return (-1);
315	memcpy(cp1, cp, 5*INT32SZ);
316	cp += 5*INT32SZ;
317	cp1 += 5*INT32SZ;
318	rdatasize = (u_char *)cp1 - soardata;
319	zptr = calloc(1, sizeof(struct zonegrp));
320	if (zptr == NULL)
321	return (-1);
322	if (zgrp_start == NULL)
323	zgrp_start = zptr;
324	else
325	prevzptr->z_next = zptr;
326	zptr->z_rr = rrecp;
327	rrecp->r_grpnext = NULL;
328	strcpy(zptr->z_origin, zname);
329	zptr->z_class = class;
330	memcpy(zptr->z_soardata, soardata, rdatasize);
331	/* fallthrough to process NS and A records */
332	}
333	} else if (qtype == T_NS) {
334	if (rcode == NOERROR && ancount > 0) {
335	strcpy(zname, dname);
336	for (zptr = zgrp_start; zptr; zptr = zptr->z_next) {
337	if (strcasecmp(zname, zptr->z_origin) == 0)
338	break;
339	}
340	if (zptr == NULL)
341	/* should not happen */
342	return (-1);
343	if (nscount > 0) {
344	/*
345	* answer and authority sections contain
346	* the same information, skip answer section
347	*/
348	for (j = 0; j < ancount; j++) {
349	n = dn_skipname(cp, eom);
350	if (n < 0)
351	return (-1);
352	n += 2*INT16SZ + INT32SZ;
353	if (cp + n + INT16SZ > eom)
354	return (-1);
355	cp += n;
356	GETSHORT(dlen, cp);
357	cp += dlen;
358	}
359	} else
360	nscount = ancount;
361	/* fallthrough to process NS and A records */
362	} else {
363	fprintf(stderr, "cannot determine nameservers for %s:\
364	ans=%d, auth=%d, add=%d, rcode=%d\n",
365	dname, ancount, nscount, arcount, hp->rcode);
366	return (-1);
367	}
368	} else if (qtype == T_A) {
369	if (rcode == NOERROR && ancount > 0) {
370	arcount = ancount;
371	ancount = nscount = 0;
372	/* fallthrough to process A records */
373	} else {
374	fprintf(stderr, "cannot determine address for %s:\
375	ans=%d, auth=%d, add=%d, rcode=%d\n",
376	dname, ancount, nscount, arcount, hp->rcode);
377	return (-1);
378	}
379	}
380	/* process NS records for the zone */
381	j = 0;
382	for (i = 0; i < nscount; i++) {
383	if ((n = dn_expand(answer, eom, cp, name,
384	sizeof name)) < 0)
385	return (n);
386	cp += n;
387	if (cp + 3 * INT16SZ + INT32SZ > eom)
388	return (-1);
389	GETSHORT(type, cp);
390	GETSHORT(class, cp);
391	GETLONG(ttl, cp);
392	GETSHORT(dlen, cp);
393	if (cp + dlen > eom)
394	return (-1);
395	if (strcasecmp(name, zname) == 0 &&
396	type == T_NS && class == qclass) {
397	if ((n = dn_expand(answer, eom, cp,
398	name, sizeof name)) < 0)
399	return (n);
400	target = zptr->z_ns[j++].nsname;
401	strcpy(target, name);
402	}
403	cp += dlen;
404	}
405	if (zptr->z_nscount == 0)
406	zptr->z_nscount = j;
407	/* get addresses for the nameservers */
408	for (i = 0; i < arcount; i++) {
409	if ((n = dn_expand(answer, eom, cp, name,
410	sizeof name)) < 0)
411	return (n);
412	cp += n;
413	if (cp + 3 * INT16SZ + INT32SZ > eom)
414	return (-1);
415	GETSHORT(type, cp);
416	GETSHORT(class, cp);
417	GETLONG(ttl, cp);
418	GETSHORT(dlen, cp);
419	if (cp + dlen > eom)
420	return (-1);
421	if (type == T_A && dlen == INT32SZ && class == qclass) {
422	for (j = 0; j < zptr->z_nscount; j++)
423	if (strcasecmp(name, zptr->z_ns[j].nsname) == 0) {
424	memcpy(&zptr->z_ns[j].nsaddr1.s_addr, cp,
425	INT32SZ);
426	break;
427	}
428	}
429	cp += dlen;
430	}
431	if (zptr->z_nscount == 0) {
432	dname = zname;
433	qtype = T_NS;
434	continue;
435	}
436	done = 1;
437	for (k = 0; k < zptr->z_nscount; k++)
438	if (zptr->z_ns[k].nsaddr1.s_addr == 0) {
439	done = 0;
440	dname = zptr->z_ns[k].nsname;
441	qtype = T_A;
442	}
443
444	} /* while */
445	}
446
447	_res.options \|= RES_DEBUG;
448	for (zptr = zgrp_start; zptr; zptr = zptr->z_next) {
449
450	/* append zone section */
451	rrecp = res_mkupdrec(ns_s_zn, zptr->z_origin,
452	zptr->z_class, ns_t_soa, 0);
453	if (rrecp == NULL) {
454	fprintf(stderr, "saverrec error\n");
455	fflush(stderr);
456	return (-1);
457	}
458	rrecp->r_grpnext = zptr->z_rr;
459	zptr->z_rr = rrecp;
460
461	n = res_mkupdate(zptr->z_rr, packet, sizeof packet);
462	if (n < 0) {
463	fprintf(stderr, "res_mkupdate error\n");
464	fflush(stderr);
465	return (-1);
466	} else
467	fprintf(stdout, "res_mkupdate: packet size = %d\n", n);
468
469	/*
470	* Override the list of NS records from res_init() with
471	* the authoritative nameservers for the zone being updated.
472	* Sort primary to be the first in the list of nameservers.
473	*/
474	for (i = 0; i < zptr->z_nscount; i++) {
475	if (strcasecmp(zptr->z_ns[i].nsname,
476	zptr->z_soardata) == 0) {
477	struct in_addr tmpaddr;
478
479	if (i != 0) {
480	strcpy(zptr->z_ns[i].nsname,
481	zptr->z_ns[0].nsname);
482	strcpy(zptr->z_ns[0].nsname,
483	zptr->z_soardata);
484	tmpaddr = zptr->z_ns[i].nsaddr1;
485	zptr->z_ns[i].nsaddr1 =
486	zptr->z_ns[0].nsaddr1;
487	zptr->z_ns[0].nsaddr1 = tmpaddr;
488	}
489	break;
490	}
491	}
492	for (i = 0; i < MAXNS; i++) {
493	_res.nsaddr_list[i].sin_addr = zptr->z_ns[i].nsaddr1;
494	_res.nsaddr_list[i].sin_family = AF_INET;
495	_res.nsaddr_list[i].sin_port = htons(NAMESERVER_PORT);
496	}
497	_res.nscount = (zptr->z_nscount < MAXNS) ?
498	zptr->z_nscount : MAXNS;
499	n = res_send(packet, n, answer, sizeof(answer));
500	if (n < 0) {
501	fprintf(stderr, "res_send: send error, n=%d\n", n);
502	break;
503	} else
504	numzones++;
505	}
506
507	/* free malloc'ed memory */
508	while(zgrp_start) {
509	zptr = zgrp_start;
510	zgrp_start = zgrp_start->z_next;
511	res_freeupdrec(zptr->z_rr); /* Zone section we allocated. */
512	free((char *)zptr);
513	}
514
515	return (numzones);
516	}

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