1 /*
2 * pythonmod_utils.c: utilities used by wrapper
3 *
4 * Copyright (c) 2009, Zdenek Vasicek (vasicek AT fit.vutbr.cz)
5 * Marek Vavrusa (xvavru00 AT stud.fit.vutbr.cz)
6 *
7 * This software is open source.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * * Redistributions of source code must retain the above copyright notice,
14 * this list of conditions and the following disclaimer.
15 *
16 * * Redistributions in binary form must reproduce the above copyright notice,
17 * this list of conditions and the following disclaimer in the documentation
18 * and/or other materials provided with the distribution.
19 *
20 * * Neither the name of the organization nor the names of its
21 * contributors may be used to endorse or promote products derived from this
22 * software without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
26 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
27 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36 /**
37 * \file
38 * Utility functions for the python module that perform stores and loads and
39 * conversions.
40 */
41 #include "config.h"
42 #include "pythonmod/pythonmod_utils.h"
43 #include "util/module.h"
44 #include "util/netevent.h"
45 #include "util/net_help.h"
46 #include "services/cache/dns.h"
47 #include "services/cache/rrset.h"
48 #include "util/data/msgparse.h"
49 #include "util/data/msgreply.h"
50 #include "util/storage/slabhash.h"
51 #include "util/regional.h"
52 #include "iterator/iter_delegpt.h"
53 #include "sldns/sbuffer.h"
54
55 #undef _POSIX_C_SOURCE
56 #undef _XOPEN_SOURCE
57 #include <Python.h>
58
59 /* Store the reply_info and query_info pair in message cache
60 * (qstate->msg_cache) */
storeQueryInCache(struct module_qstate * qstate,struct query_info * qinfo,struct reply_info * msgrep,int is_referral)61 int storeQueryInCache(struct module_qstate* qstate, struct query_info* qinfo,
62 struct reply_info* msgrep, int is_referral)
63 {
64 if (!msgrep)
65 return 0;
66
67 /* authoritative answer can't be stored in cache */
68 if (msgrep->authoritative) {
69 PyErr_SetString(PyExc_ValueError,
70 "Authoritative answer can't be stored");
71 return 0;
72 }
73
74 return dns_cache_store(qstate->env, qinfo, msgrep, is_referral,
75 qstate->prefetch_leeway, 0, NULL, qstate->query_flags,
76 qstate->qstarttime);
77 }
78
79 /* Invalidate the message associated with query_info stored in message cache */
invalidateQueryInCache(struct module_qstate * qstate,struct query_info * qinfo)80 void invalidateQueryInCache(struct module_qstate* qstate,
81 struct query_info* qinfo)
82 {
83 hashvalue_type h;
84 struct lruhash_entry* e;
85 struct reply_info *r;
86 size_t i, j;
87
88 h = query_info_hash(qinfo, qstate->query_flags);
89 if ((e=slabhash_lookup(qstate->env->msg_cache, h, qinfo, 0))) {
90 r = (struct reply_info*)(e->data);
91 if (r) {
92 r->ttl = 0;
93 if(rrset_array_lock(r->ref, r->rrset_count, *qstate->env->now)) {
94 for(i=0; i< r->rrset_count; i++) {
95 struct packed_rrset_data* data =
96 (struct packed_rrset_data*) r->ref[i].key->entry.data;
97 if(i>0 && r->ref[i].key == r->ref[i-1].key)
98 continue;
99
100 data->ttl = r->ttl;
101 for(j=0; j<data->count + data->rrsig_count; j++)
102 data->rr_ttl[j] = r->ttl;
103 }
104 rrset_array_unlock(r->ref, r->rrset_count);
105 }
106 }
107 lock_rw_unlock(&e->lock);
108 } else {
109 log_info("invalidateQueryInCache: qinfo is not in cache");
110 }
111 }
112
113 /* Create response according to the ldns packet content */
createResponse(struct module_qstate * qstate,sldns_buffer * pkt)114 int createResponse(struct module_qstate* qstate, sldns_buffer* pkt)
115 {
116 struct msg_parse* prs;
117 struct edns_data edns;
118
119 /* parse message */
120 prs = (struct msg_parse*) regional_alloc(qstate->env->scratch,
121 sizeof(struct msg_parse));
122 if(!prs) {
123 log_err("createResponse: out of memory on incoming message");
124 return 0;
125 }
126
127 memset(prs, 0, sizeof(*prs));
128 memset(&edns, 0, sizeof(edns));
129
130 sldns_buffer_set_position(pkt, 0);
131 if(parse_packet(pkt, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) {
132 verbose(VERB_ALGO, "createResponse: parse error on reply packet");
133 return 0;
134 }
135 /* edns is not examined, but removed from message to help cache */
136 if(parse_extract_edns_from_response_msg(prs, &edns, qstate->env->scratch) !=
137 LDNS_RCODE_NOERROR)
138 return 0;
139
140 /* remove CD-bit, we asked for in case we handle validation ourself */
141 prs->flags &= ~BIT_CD;
142
143 /* allocate response dns_msg in region */
144 qstate->return_msg = (struct dns_msg*) regional_alloc(qstate->region,
145 sizeof(struct dns_msg));
146 if(!qstate->return_msg)
147 return 0;
148
149 memset(qstate->return_msg, 0, sizeof(*qstate->return_msg));
150 if(!parse_create_msg(pkt, prs, NULL, &(qstate->return_msg)->qinfo,
151 &(qstate->return_msg)->rep, qstate->region)) {
152 log_err("createResponse: malloc failure: allocating incoming dns_msg");
153 return 0;
154 }
155
156 /* Make sure that the RA flag is set (since the presence of
157 * this module means that recursion is available) */
158 /* qstate->return_msg->rep->flags |= BIT_RA; */
159
160 /* Clear the AA flag */
161 /* FIXME: does this action go here or in some other module? */
162 /*qstate->return_msg->rep->flags &= ~BIT_AA; */
163
164 /* make sure QR flag is on */
165 /*qstate->return_msg->rep->flags |= BIT_QR; */
166
167 if(verbosity >= VERB_ALGO)
168 log_dns_msg("createResponse: packet:", &qstate->return_msg->qinfo,
169 qstate->return_msg->rep);
170
171 return 1;
172 }
173
174
175 /* Convert reply->client_addr to string */
reply_addr2str(struct comm_reply * reply,char * dest,int maxlen)176 void reply_addr2str(struct comm_reply* reply, char* dest, int maxlen)
177 {
178 int af = (int)((struct sockaddr_in*) &(reply->client_addr))->sin_family;
179 void* sinaddr = &((struct sockaddr_in*) &(reply->client_addr))->sin_addr;
180
181 if(af == AF_INET6)
182 sinaddr = &((struct sockaddr_in6*)&(reply->client_addr))->sin6_addr;
183 dest[0] = 0;
184 if (inet_ntop(af, sinaddr, dest, (socklen_t)maxlen) == 0)
185 return;
186 dest[maxlen-1] = 0;
187 }
188
189 /* Convert target->addr to string */
delegpt_addr_addr2str(struct delegpt_addr * target,char * dest,int maxlen)190 void delegpt_addr_addr2str(struct delegpt_addr* target, char *dest, int maxlen)
191 {
192 int af = (int)((struct sockaddr_in*) &(target->addr))->sin_family;
193 void* sinaddr = &((struct sockaddr_in*) &(target->addr))->sin_addr;
194
195 if(af == AF_INET6)
196 sinaddr = &((struct sockaddr_in6*)&(target->addr))->sin6_addr;
197 dest[0] = 0;
198 if (inet_ntop(af, sinaddr, dest, (socklen_t)maxlen) == 0)
199 return;
200 dest[maxlen-1] = 0;
201 }
202