e576be50 |
1 | /* |
2 | * transmit.c |
3 | * - construct queries |
4 | * - send queries |
5 | */ |
6 | /* |
d942707d |
7 | * This file is |
3d5cde09 |
8 | * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk> |
d942707d |
9 | * |
10 | * It is part of adns, which is |
3d5cde09 |
11 | * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk> |
bef232ae |
12 | * Copyright (C) 1999-2000 Tony Finch <dot@dotat.at> |
e576be50 |
13 | * |
14 | * This program is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2, or (at your option) |
17 | * any later version. |
18 | * |
19 | * This program is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU General Public License |
25 | * along with this program; if not, write to the Free Software Foundation, |
26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
27 | */ |
28 | |
3955725c |
29 | #include <errno.h> |
3955725c |
30 | |
71a6ff46 |
31 | #include <sys/types.h> |
3955725c |
32 | #include <sys/uio.h> |
33 | |
e576be50 |
34 | #include "internal.h" |
2953d358 |
35 | #include "tvarith.h" |
e576be50 |
36 | |
e062dcae |
37 | #define MKQUERY_START(vb) (rqp= (vb)->buf+(vb)->used) |
e576be50 |
38 | #define MKQUERY_ADDB(b) *rqp++= (b) |
39 | #define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff)) |
e062dcae |
40 | #define MKQUERY_STOP(vb) ((vb)->used= rqp-(vb)->buf) |
e576be50 |
41 | |
609133ee |
42 | static adns_status mkquery_header(adns_state ads, vbuf *vb, |
43 | int *id_r, int qdlen) { |
e062dcae |
44 | int id; |
45 | byte *rqp; |
46 | |
ea1e31e3 |
47 | if (!adns__vbuf_ensure(vb,DNS_HDRSIZE+qdlen+4)) return adns_s_nomemory; |
e576be50 |
48 | |
e062dcae |
49 | vb->used= 0; |
50 | MKQUERY_START(vb); |
51 | |
660d7d3b |
52 | *id_r= id= (ads->nextid++) & 0x0ffff; |
e576be50 |
53 | MKQUERY_ADDW(id); |
54 | MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */ |
55 | MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */ |
56 | MKQUERY_ADDW(1); /* QDCOUNT=1 */ |
57 | MKQUERY_ADDW(0); /* ANCOUNT=0 */ |
58 | MKQUERY_ADDW(0); /* NSCOUNT=0 */ |
59 | MKQUERY_ADDW(0); /* ARCOUNT=0 */ |
e062dcae |
60 | |
61 | MKQUERY_STOP(vb); |
62 | |
63 | return adns_s_ok; |
64 | } |
65 | |
66 | static adns_status mkquery_footer(vbuf *vb, adns_rrtype type) { |
67 | byte *rqp; |
68 | |
69 | MKQUERY_START(vb); |
70 | MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */ |
71 | MKQUERY_ADDW(DNS_CLASS_IN); /* QCLASS=IN */ |
72 | MKQUERY_STOP(vb); |
73 | assert(vb->used <= vb->avail); |
74 | |
75 | return adns_s_ok; |
76 | } |
77 | |
78 | adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r, |
79 | const char *owner, int ol, |
80 | const typeinfo *typei, adns_queryflags flags) { |
4b2c4f8a |
81 | int ll, c, nbytes; |
e062dcae |
82 | byte label[255], *rqp; |
83 | const char *p, *pe; |
84 | adns_status st; |
85 | |
914a5ff5 |
86 | st= mkquery_header(ads,vb,id_r,ol+2); if (st) return st; |
e062dcae |
87 | |
88 | MKQUERY_START(vb); |
89 | |
e576be50 |
90 | p= owner; pe= owner+ol; |
4b2c4f8a |
91 | nbytes= 0; |
e9e53c73 |
92 | while (p!=pe) { |
e576be50 |
93 | ll= 0; |
94 | while (p!=pe && (c= *p++)!='.') { |
95 | if (c=='\\') { |
ea1e31e3 |
96 | if (!(flags & adns_qf_quoteok_query)) return adns_s_querydomaininvalid; |
e576be50 |
97 | if (ctype_digit(p[0])) { |
98 | if (ctype_digit(p[1]) && ctype_digit(p[2])) { |
0d66e373 |
99 | c= (*p++ - '0')*100; |
100 | c += (*p++ - '0')*10; |
101 | c += (*p++ - '0'); |
ea1e31e3 |
102 | if (c >= 256) return adns_s_querydomaininvalid; |
e576be50 |
103 | } else { |
ea1e31e3 |
104 | return adns_s_querydomaininvalid; |
e576be50 |
105 | } |
106 | } else if (!(c= *p++)) { |
ea1e31e3 |
107 | return adns_s_querydomaininvalid; |
e576be50 |
108 | } |
109 | } |
828d89bd |
110 | if (!(flags & adns_qf_quoteok_query)) { |
ffbda80c |
111 | if (c == '-') { |
ea1e31e3 |
112 | if (!ll) return adns_s_querydomaininvalid; |
ffbda80c |
113 | } else if (!ctype_alpha(c) && !ctype_digit(c)) { |
ea1e31e3 |
114 | return adns_s_querydomaininvalid; |
e576be50 |
115 | } |
116 | } |
ea1e31e3 |
117 | if (ll == sizeof(label)) return adns_s_querydomaininvalid; |
e576be50 |
118 | label[ll++]= c; |
119 | } |
ea1e31e3 |
120 | if (!ll) return adns_s_querydomaininvalid; |
5b9dd636 |
121 | if (ll > DNS_MAXLABEL) return adns_s_querydomaintoolong; |
4b2c4f8a |
122 | nbytes+= ll+1; |
5b9dd636 |
123 | if (nbytes >= DNS_MAXDOMAIN) return adns_s_querydomaintoolong; |
e576be50 |
124 | MKQUERY_ADDB(ll); |
125 | memcpy(rqp,label,ll); rqp+= ll; |
e9e53c73 |
126 | } |
e062dcae |
127 | MKQUERY_ADDB(0); |
128 | |
129 | MKQUERY_STOP(vb); |
130 | |
131 | st= mkquery_footer(vb,typei->type); |
132 | |
133 | return adns_s_ok; |
134 | } |
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135 | |
e062dcae |
136 | adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r, |
609133ee |
137 | const byte *qd_dgram, int qd_dglen, |
138 | int qd_begin, |
e062dcae |
139 | adns_rrtype type, adns_queryflags flags) { |
140 | byte *rqp; |
141 | findlabel_state fls; |
142 | int lablen, labstart; |
143 | adns_status st; |
144 | |
145 | st= mkquery_header(ads,vb,id_r,qd_dglen); if (st) return st; |
146 | |
147 | MKQUERY_START(vb); |
148 | |
149 | adns__findlabel_start(&fls,ads,-1,0,qd_dgram,qd_dglen,qd_dglen,qd_begin,0); |
150 | for (;;) { |
151 | st= adns__findlabel_next(&fls,&lablen,&labstart); assert(!st); |
152 | if (!lablen) break; |
153 | assert(lablen<255); |
154 | MKQUERY_ADDB(lablen); |
155 | memcpy(rqp,qd_dgram+labstart,lablen); |
156 | rqp+= lablen; |
157 | } |
e576be50 |
158 | MKQUERY_ADDB(0); |
e576be50 |
159 | |
e062dcae |
160 | MKQUERY_STOP(vb); |
161 | |
162 | st= mkquery_footer(vb,type); |
e576be50 |
163 | |
164 | return adns_s_ok; |
165 | } |
166 | |
f7f83b4a |
167 | void adns__querysend_tcp(adns_query qu, struct timeval now) { |
e576be50 |
168 | byte length[2]; |
169 | struct iovec iov[2]; |
170 | int wr, r; |
3955725c |
171 | adns_state ads; |
e576be50 |
172 | |
3955725c |
173 | if (qu->ads->tcpstate != server_ok) return; |
e576be50 |
174 | |
f7f83b4a |
175 | assert(qu->state == query_tcpw); |
176 | |
e576be50 |
177 | length[0]= (qu->query_dglen&0x0ff00U) >>8; |
178 | length[1]= (qu->query_dglen&0x0ff); |
3955725c |
179 | |
180 | ads= qu->ads; |
609133ee |
181 | if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2)) |
182 | return; |
e576be50 |
183 | |
f7f83b4a |
184 | qu->retries++; |
185 | |
186 | /* Reset idle timeout. */ |
187 | ads->tcptimeout.tv_sec= ads->tcptimeout.tv_usec= 0; |
e576be50 |
188 | |
189 | if (ads->tcpsend.used) { |
190 | wr= 0; |
191 | } else { |
192 | iov[0].iov_base= length; |
193 | iov[0].iov_len= 2; |
194 | iov[1].iov_base= qu->query_dgram; |
195 | iov[1].iov_len= qu->query_dglen; |
ac868fa8 |
196 | adns__sigpipe_protect(qu->ads); |
3955725c |
197 | wr= writev(qu->ads->tcpsocket,iov,2); |
ac868fa8 |
198 | adns__sigpipe_unprotect(qu->ads); |
e576be50 |
199 | if (wr < 0) { |
200 | if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC || |
201 | errno == ENOBUFS || errno == ENOMEM)) { |
202 | adns__tcp_broken(ads,"write",strerror(errno)); |
203 | return; |
204 | } |
205 | wr= 0; |
206 | } |
207 | } |
208 | |
209 | if (wr<2) { |
210 | r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r); |
211 | wr= 0; |
212 | } else { |
213 | wr-= 2; |
214 | } |
215 | if (wr<qu->query_dglen) { |
609133ee |
216 | r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr); |
217 | assert(r); |
e576be50 |
218 | } |
219 | } |
220 | |
3955725c |
221 | static void query_usetcp(adns_query qu, struct timeval now) { |
f7f83b4a |
222 | qu->state= query_tcpw; |
e576be50 |
223 | qu->timeout= now; |
f7f83b4a |
224 | timevaladd(&qu->timeout,TCPWAITMS); |
225 | LIST_LINK_TAIL(qu->ads->tcpw,qu); |
226 | adns__querysend_tcp(qu,now); |
3955725c |
227 | adns__tcp_tryconnect(qu->ads,now); |
e576be50 |
228 | } |
229 | |
d8c062fa |
230 | void adns__query_send(adns_query qu, struct timeval now) { |
e576be50 |
231 | struct sockaddr_in servaddr; |
232 | int serv, r; |
3955725c |
233 | adns_state ads; |
e576be50 |
234 | |
d8c062fa |
235 | assert(qu->state == query_tosend); |
e576be50 |
236 | if ((qu->flags & adns_qf_usevc) || (qu->query_dglen > DNS_MAXUDP)) { |
3955725c |
237 | query_usetcp(qu,now); |
e576be50 |
238 | return; |
239 | } |
240 | |
f7f83b4a |
241 | if (qu->retries >= UDPMAXRETRIES) { |
3955725c |
242 | adns__query_fail(qu,adns_s_timeout); |
e576be50 |
243 | return; |
244 | } |
245 | |
246 | serv= qu->udpnextserver; |
247 | memset(&servaddr,0,sizeof(servaddr)); |
3955725c |
248 | |
249 | ads= qu->ads; |
e576be50 |
250 | servaddr.sin_family= AF_INET; |
251 | servaddr.sin_addr= ads->servers[serv].addr; |
252 | servaddr.sin_port= htons(DNS_PORT); |
253 | |
71a6ff46 |
254 | r= sendto(ads->udpsocket,qu->query_dgram,qu->query_dglen,0, |
255 | (const struct sockaddr*)&servaddr,sizeof(servaddr)); |
609133ee |
256 | if (r<0 && errno == EMSGSIZE) { |
257 | qu->retries= 0; |
258 | query_usetcp(qu,now); |
259 | return; |
260 | } |
261 | if (r<0 && errno != EAGAIN) |
262 | adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno)); |
e576be50 |
263 | |
e576be50 |
264 | qu->timeout= now; |
f7f83b4a |
265 | timevaladd(&qu->timeout,UDPRETRYMS); |
e576be50 |
266 | qu->udpsent |= (1<<serv); |
267 | qu->udpnextserver= (serv+1)%ads->nservers; |
f7f83b4a |
268 | qu->retries++; |
269 | LIST_LINK_TAIL(ads->udpw,qu); |
e576be50 |
270 | } |