update.c
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1 /* update.c
2  *
3  * Functions for RFC 2136 Dynamic Update
4  *
5  * Copyright (c) 2005-2008, NLnet Labs. All rights reserved.
6  *
7  * See LICENSE for the license.
8  */
9 
10 #include <ldns/config.h>
11 
12 #include <ldns/ldns.h>
13 
14 #include <strings.h>
15 #include <stdlib.h>
16 #include <limits.h>
17 
18 /*
19  * RFC 2136 sections mapped to RFC 1035:
20  * zone/ZO -- QD/question
21  * prerequisites/PR -- AN/answers
22  * updates/UP -- NS/authority records
23  * additional data/AD -- AR/additional records
24  */
25 
26 ldns_pkt *
28  const ldns_rr_list *pr_rrlist, const ldns_rr_list *up_rrlist, const ldns_rr_list *ad_rrlist)
29 {
30  ldns_pkt *p;
31 
32  if (!zone_rdf || !up_rrlist) {
33  return NULL;
34  }
35 
36  if (c == 0) {
37  c = LDNS_RR_CLASS_IN;
38  }
39 
40  /* Create packet, fill in Zone Section. */
41  p = ldns_pkt_query_new(zone_rdf, LDNS_RR_TYPE_SOA, c, LDNS_RD);
42  if (!p) {
43  return NULL;
44  }
45  zone_rdf = NULL; /* No longer safe to use. */
46 
48 
50 
52 
54 
55  if (pr_rrlist) {
56  ldns_rr_list_deep_free(p->_answer); /*XXX access function */
59  }
60 
61  if (ad_rrlist) {
65  }
66  return p;
67 }
68 
71 {
72 #ifdef HAVE_SSL
73  uint16_t fudge = 300; /* Recommended fudge. [RFC2845 6.4] */
78 #else
79  /* do nothing */
80  (void)p;
81  (void)r;
82 #endif /* HAVE_SSL */
83  /* No TSIG to do. */
84  return LDNS_STATUS_OK;
85 }
86 
87 /* Move to higher.c or similar? */
88 /* XXX doc */
91  ldns_rr_class c, ldns_rdf **mname)
92 {
93  ldns_rr *soa_rr;
94  ldns_pkt *query, *resp;
95 
96  /* Nondestructive, so clone 'zone' here */
98  c, LDNS_RD);
99  if (!query) {
100  return LDNS_STATUS_ERR;
101  }
102 
103  ldns_pkt_set_random_id(query);
104  if (ldns_resolver_send_pkt(&resp, r, query) != LDNS_STATUS_OK) {
105  ldns_pkt_free(query);
106  return LDNS_STATUS_ERR;
107  }
108  ldns_pkt_free(query);
109  if (!resp) {
110  return LDNS_STATUS_ERR;
111  }
112 
113  /* Expect a SOA answer. */
114  *mname = NULL;
115  while ((soa_rr = ldns_rr_list_pop_rr(ldns_pkt_answer(resp)))) {
116  if (ldns_rr_get_type(soa_rr) != LDNS_RR_TYPE_SOA
117  || ldns_rr_rdf(soa_rr, 0) == NULL)
118  continue;
119  /* [RFC1035 3.3.13] */
120  *mname = ldns_rdf_clone(ldns_rr_rdf(soa_rr, 0));
121  break;
122  }
123  ldns_pkt_free(resp);
124 
125  return *mname ? LDNS_STATUS_OK : LDNS_STATUS_ERR;
126 }
127 
128 /* Try to get zone and MNAME from SOA queries. */
131  ldns_rr_class c, ldns_rdf **zone_rdf, ldns_rdf **mname_rdf)
132 {
133  ldns_rr *soa_rr, *rr;
134  ldns_rdf *soa_zone = NULL, *soa_mname = NULL;
135  ldns_rdf *ipaddr, *fqdn_rdf, *tmp;
136  ldns_rdf **nslist;
137  ldns_pkt *query, *resp;
138  ldns_resolver *tmp_r;
139  size_t i;
140 
141  /*
142  * XXX Ok, this cannot be the best way to find this...?
143  * XXX (I run into weird cache-related stuff here)
144  */
145 
146  /* Step 1 - first find a nameserver that should know *something* */
147  fqdn_rdf = ldns_dname_new_frm_str(fqdn);
148  query = ldns_pkt_query_new(fqdn_rdf, LDNS_RR_TYPE_SOA, c, LDNS_RD);
149  if (!query) {
150  return LDNS_STATUS_ERR;
151  }
152  fqdn_rdf = NULL;
153 
154  ldns_pkt_set_random_id(query);
155  if (ldns_resolver_send_pkt(&resp, r, query) != LDNS_STATUS_OK) {
156  ldns_pkt_free(query);
157  return LDNS_STATUS_ERR;
158  }
159  ldns_pkt_free(query);
160  if (!resp) {
161  return LDNS_STATUS_ERR;
162  }
163 
164  /* XXX Is it safe to only look in authority section here? */
165  while ((soa_rr = ldns_rr_list_pop_rr(ldns_pkt_authority(resp)))) {
166  if (ldns_rr_get_type(soa_rr) != LDNS_RR_TYPE_SOA
167  || ldns_rr_rdf(soa_rr, 0) == NULL)
168  continue;
169  /* [RFC1035 3.3.13] */
170  soa_mname = ldns_rdf_clone(ldns_rr_rdf(soa_rr, 0));
171  break;
172  }
173  ldns_pkt_free(resp);
174  if (!soa_rr) {
175  return LDNS_STATUS_ERR;
176  }
177 
178  /* Step 2 - find SOA MNAME IP address, add to resolver */
179  query = ldns_pkt_query_new(soa_mname, LDNS_RR_TYPE_A, c, LDNS_RD);
180  if (!query) {
181  return LDNS_STATUS_ERR;
182  }
183  soa_mname = NULL;
184 
185  ldns_pkt_set_random_id(query);
186  if (ldns_resolver_send_pkt(&resp, r, query) != LDNS_STATUS_OK) {
187  ldns_pkt_free(query);
188  return LDNS_STATUS_ERR;
189  }
190  ldns_pkt_free(query);
191  if (!resp) {
192  return LDNS_STATUS_ERR;
193  }
194 
195  if (ldns_pkt_ancount(resp) == 0) {
196  ldns_pkt_free(resp);
197  return LDNS_STATUS_ERR;
198  }
199 
200  /* XXX There may be more than one answer RR here. */
202  ipaddr = ldns_rr_rdf(rr, 0);
203 
204  /* Put the SOA mname IP first in the nameserver list. */
205  if (!(tmp_r = ldns_resolver_clone(r))) {
206  return LDNS_STATUS_MEM_ERR;
207  }
208  nslist = ldns_resolver_nameservers(tmp_r);
209  for (i = 0; i < ldns_resolver_nameserver_count(tmp_r); i++) {
210  if (ldns_rdf_compare(ipaddr, nslist[i]) == 0) {
211  if (i) {
212  tmp = nslist[0];
213  nslist[0] = nslist[i];
214  nslist[i] = tmp;
215  }
216  break;
217  }
218  }
219  if (i >= ldns_resolver_nameserver_count(tmp_r)) {
220  /* SOA mname was not part of the resolver so add it first. */
221  (void) ldns_resolver_push_nameserver(tmp_r, ipaddr);
222  nslist = ldns_resolver_nameservers(tmp_r);
223  i = ldns_resolver_nameserver_count(tmp_r) - 1;
224  tmp = nslist[0];
225  nslist[0] = nslist[i];
226  nslist[i] = tmp;
227  }
228  ldns_pkt_free(resp);
229 
230  /* Make sure to ask the first in the list, i.e SOA mname */
231  ldns_resolver_set_random(tmp_r, false);
232 
233  /* Step 3 - Redo SOA query, sending to SOA MNAME directly. */
234  fqdn_rdf = ldns_dname_new_frm_str(fqdn);
235  query = ldns_pkt_query_new(fqdn_rdf, LDNS_RR_TYPE_SOA, c, LDNS_RD);
236  if (!query) {
237  ldns_resolver_free(tmp_r);
238  return LDNS_STATUS_ERR;
239  }
240  fqdn_rdf = NULL;
241 
242  ldns_pkt_set_random_id(query);
243  if (ldns_resolver_send_pkt(&resp, tmp_r, query) != LDNS_STATUS_OK) {
244  ldns_pkt_free(query);
245  ldns_resolver_free(tmp_r);
246  return LDNS_STATUS_ERR;
247  }
248  ldns_resolver_free(tmp_r);
249  ldns_pkt_free(query);
250  if (!resp) {
251  return LDNS_STATUS_ERR;
252  }
253 
254  /* XXX Is it safe to only look in authority section here, too? */
255  while ((soa_rr = ldns_rr_list_pop_rr(ldns_pkt_authority(resp)))) {
256  if (ldns_rr_get_type(soa_rr) != LDNS_RR_TYPE_SOA
257  || ldns_rr_rdf(soa_rr, 0) == NULL)
258  continue;
259  /* [RFC1035 3.3.13] */
260  soa_mname = ldns_rdf_clone(ldns_rr_rdf(soa_rr, 0));
261  soa_zone = ldns_rdf_clone(ldns_rr_owner(soa_rr));
262  break;
263  }
264  ldns_pkt_free(resp);
265  if (!soa_rr) {
266  return LDNS_STATUS_ERR;
267  }
268 
269  /* That seems to have worked, pass results to caller. */
270  *zone_rdf = soa_zone;
271  *mname_rdf = soa_mname;
272  return LDNS_STATUS_OK;
273 }
274 
275 /*
276  * ldns_update_{get,set}_{zo,pr,up,ad}count
277  */
278 
279 uint16_t
281 {
282  return ldns_pkt_qdcount(p);
283 }
284 
285 uint16_t
287 {
288  return ldns_pkt_ancount(p);
289 }
290 
291 uint16_t
293 {
294  return ldns_pkt_nscount(p);
295 }
296 
297 uint16_t
299 {
300  return ldns_pkt_arcount(p);
301 }
302 
303 void
305 {
306  ldns_pkt_set_qdcount(p, v);
307 }
308 
309 void
311 {
312  ldns_pkt_set_ancount(p, v);
313 }
314 
315 void
317 {
318  ldns_pkt_set_nscount(p, v);
319 }
320 
321 void
323 {
324  ldns_pkt_set_arcount(p, v);
325 }
ldns_rdf * ldns_dname_new_frm_str(const char *str)
creates a new dname rdf from a string.
Definition: dname.c:268
@ LDNS_STATUS_ERR
Definition: error.h:37
@ LDNS_STATUS_MEM_ERR
Definition: error.h:34
@ LDNS_STATUS_OK
Definition: error.h:26
enum ldns_enum_status ldns_status
Definition: error.h:146
Including this file will include all ldns files, and define some lookup tables.
void ldns_pkt_free(ldns_pkt *packet)
frees the packet structure and all data that it contains.
Definition: packet.c:895
void ldns_pkt_set_ancount(ldns_pkt *packet, uint16_t ancount)
Set the packet's an count.
Definition: packet.c:569
void ldns_pkt_set_opcode(ldns_pkt *packet, ldns_pkt_opcode opcode)
Set the packet's opcode.
Definition: packet.c:551
void ldns_pkt_set_additional(ldns_pkt *p, ldns_rr_list *rr)
directly set the additional section
Definition: packet.c:509
void ldns_pkt_set_random_id(ldns_pkt *packet)
Set the packet's id to a random value.
Definition: packet.c:477
uint16_t ldns_pkt_arcount(const ldns_pkt *packet)
Return the packet's ar count.
Definition: packet.c:118
void ldns_pkt_set_nscount(ldns_pkt *packet, uint16_t nscount)
Set the packet's ns count.
Definition: packet.c:575
void ldns_pkt_set_authority(ldns_pkt *p, ldns_rr_list *rr)
directly set the authority section
Definition: packet.c:527
ldns_rr_list * ldns_pkt_authority(const ldns_pkt *packet)
Return the packet's authority section.
Definition: packet.c:136
uint16_t ldns_pkt_ancount(const ldns_pkt *packet)
Return the packet's an count.
Definition: packet.c:106
void ldns_pkt_set_answer(ldns_pkt *p, ldns_rr_list *rr)
directly set the answer section
Definition: packet.c:521
void ldns_pkt_set_qdcount(ldns_pkt *packet, uint16_t qdcount)
Set the packet's qd count.
Definition: packet.c:563
ldns_rr_list * ldns_pkt_answer(const ldns_pkt *packet)
Return the packet's answer section.
Definition: packet.c:130
uint16_t ldns_pkt_nscount(const ldns_pkt *packet)
Return the packet's ns count.
Definition: packet.c:112
uint16_t ldns_pkt_qdcount(const ldns_pkt *packet)
Return the packet's qd count.
Definition: packet.c:100
void ldns_pkt_set_arcount(ldns_pkt *packet, uint16_t arcount)
Set the packet's arcount.
Definition: packet.c:581
ldns_pkt * ldns_pkt_query_new(ldns_rdf *rr_name, ldns_rr_type rr_type, ldns_rr_class rr_class, uint16_t flags)
creates a packet with a query in it for the given name, type and class.
Definition: packet.c:1148
@ LDNS_PACKET_UPDATE
Definition: packet.h:51
#define LDNS_RD
Definition: packet.h:30
int ldns_rdf_compare(const ldns_rdf *rd1, const ldns_rdf *rd2)
compares two rdf's on their wire formats.
Definition: rdata.c:657
ldns_rdf * ldns_rdf_clone(const ldns_rdf *rd)
clones a rdf structure.
Definition: rdata.c:222
void ldns_resolver_set_random(ldns_resolver *r, bool b)
Should the nameserver list be randomized before each use.
Definition: resolver.c:601
const char * ldns_resolver_tsig_algorithm(const ldns_resolver *r)
Return the tsig algorithm as used by the nameserver.
Definition: resolver.c:213
const char * ldns_resolver_tsig_keydata(const ldns_resolver *r)
Return the tsig keydata as used by the nameserver.
Definition: resolver.c:219
size_t ldns_resolver_nameserver_count(const ldns_resolver *r)
How many nameserver are configured in the resolver.
Definition: resolver.c:114
void ldns_resolver_free(ldns_resolver *res)
Frees the allocated space for this resolver.
Definition: resolver.c:1033
ldns_status ldns_resolver_push_nameserver(ldns_resolver *r, const ldns_rdf *n)
Push a new nameserver to the resolver.
Definition: resolver.c:288
const char * ldns_resolver_tsig_keyname(const ldns_resolver *r)
Return the tsig keyname as used by the nameserver.
Definition: resolver.c:207
ldns_rdf ** ldns_resolver_nameservers(const ldns_resolver *r)
Return the configured nameserver ip address.
Definition: resolver.c:108
ldns_resolver * ldns_resolver_clone(ldns_resolver *src)
Clone a resolver.
Definition: resolver.c:665
ldns_status ldns_resolver_send_pkt(ldns_pkt **answer, ldns_resolver *r, ldns_pkt *query_pkt)
Send the given packet to a nameserver.
Definition: resolver.c:1206
ldns_rr * ldns_rr_list_pop_rr(ldns_rr_list *rr_list)
pops the last rr from an rrlist.
Definition: rr.c:1177
ldns_rdf * ldns_rr_owner(const ldns_rr *rr)
returns the owner name of an rr structure.
Definition: rr.c:919
void ldns_rr_list_deep_free(ldns_rr_list *rr_list)
frees an rr_list structure and all rrs contained therein.
Definition: rr.c:1020
size_t ldns_rr_list_rr_count(const ldns_rr_list *rr_list)
returns the number of rr's in an rr_list.
Definition: rr.c:957
ldns_rr_type ldns_rr_get_type(const ldns_rr *rr)
returns the type of the rr.
Definition: rr.c:943
ldns_rr_list * ldns_rr_list_clone(const ldns_rr_list *rrlist)
clones an rrlist.
Definition: rr.c:1431
ldns_rdf * ldns_rr_rdf(const ldns_rr *rr, size_t nr)
returns the rdata field member counter.
Definition: rr.c:909
@ LDNS_RR_TYPE_A
a host address
Definition: rr.h:80
@ LDNS_RR_TYPE_SOA
marks the start of a zone of authority
Definition: rr.h:90
enum ldns_enum_rr_class ldns_rr_class
Definition: rr.h:61
@ LDNS_RR_CLASS_IN
the Internet
Definition: rr.h:47
DNS packet.
Definition: packet.h:235
ldns_rr_list * _authority
Authority section.
Definition: packet.h:268
ldns_rr_list * _answer
Answer section.
Definition: packet.h:266
ldns_rr_list * _additional
Additional section.
Definition: packet.h:270
Resource record data field.
Definition: rdata.h:197
DNS stub resolver structure.
Definition: resolver.h:60
List or Set of Resource Records.
Definition: rr.h:338
Resource Record.
Definition: rr.h:310
ldns_status ldns_pkt_tsig_sign(ldns_pkt *pkt, const char *key_name, const char *key_data, uint16_t fudge, const char *algorithm_name, const ldns_rdf *query_mac)
creates a tsig rr for the given packet and key.
Definition: tsig.c:376
uint16_t ldns_update_ad(const ldns_pkt *p)
Get the zo count.
Definition: update.c:298
void ldns_update_set_zo(ldns_pkt *p, uint16_t v)
Set the zo count.
Definition: update.c:304
void ldns_update_set_adcount(ldns_pkt *p, uint16_t v)
Set the ad count.
Definition: update.c:322
uint16_t ldns_update_upcount(const ldns_pkt *p)
Get the zo count.
Definition: update.c:292
uint16_t ldns_update_zocount(const ldns_pkt *p)
Get the zo count.
Definition: update.c:280
ldns_status ldns_update_soa_zone_mname(const char *fqdn, ldns_resolver *r, ldns_rr_class c, ldns_rdf **zone_rdf, ldns_rdf **mname_rdf)
Definition: update.c:130
ldns_pkt * ldns_update_pkt_new(ldns_rdf *zone_rdf, ldns_rr_class c, const ldns_rr_list *pr_rrlist, const ldns_rr_list *up_rrlist, const ldns_rr_list *ad_rrlist)
create an update packet from zone name, class and the rr lists
Definition: update.c:27
uint16_t ldns_update_prcount(const ldns_pkt *p)
Get the zo count.
Definition: update.c:286
void ldns_update_set_prcount(ldns_pkt *p, uint16_t v)
Set the pr count.
Definition: update.c:310
void ldns_update_set_upcount(ldns_pkt *p, uint16_t v)
Set the up count.
Definition: update.c:316
ldns_status ldns_update_pkt_tsig_add(ldns_pkt *p, const ldns_resolver *r)
add tsig credentials to a packet from a resolver
Definition: update.c:70
ldns_status ldns_update_soa_mname(ldns_rdf *zone, ldns_resolver *r, ldns_rr_class c, ldns_rdf **mname)
Definition: update.c:90