98db6da3 |
1 | /* |
2 | * transmit.c |
3 | * - construct queries |
4 | * - send queries |
5 | */ |
6 | /* |
a79ac5ba |
7 | * This file is |
89435c42 |
8 | * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk> |
a79ac5ba |
9 | * |
10 | * It is part of adns, which is |
89435c42 |
11 | * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk> |
c6826df6 |
12 | * Copyright (C) 1999-2000 Tony Finch <dot@dotat.at> |
98db6da3 |
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 | |
11c8bf9b |
29 | #include <errno.h> |
11c8bf9b |
30 | |
763d28b9 |
31 | #include <sys/types.h> |
11c8bf9b |
32 | #include <sys/uio.h> |
33 | |
98db6da3 |
34 | #include "internal.h" |
83e1be2f |
35 | #include "tvarith.h" |
98db6da3 |
36 | |
f2ad23ee |
37 | #define MKQUERY_START(vb) (rqp= (vb)->buf+(vb)->used) |
98db6da3 |
38 | #define MKQUERY_ADDB(b) *rqp++= (b) |
39 | #define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff)) |
f2ad23ee |
40 | #define MKQUERY_STOP(vb) ((vb)->used= rqp-(vb)->buf) |
98db6da3 |
41 | |
9c344a42 |
42 | static adns_status mkquery_header(adns_state ads, vbuf *vb, |
43 | int *id_r, int qdlen) { |
f2ad23ee |
44 | int id; |
45 | byte *rqp; |
46 | |
9b86645c |
47 | if (!adns__vbuf_ensure(vb,DNS_HDRSIZE+qdlen+4)) return adns_s_nomemory; |
98db6da3 |
48 | |
f2ad23ee |
49 | vb->used= 0; |
50 | MKQUERY_START(vb); |
51 | |
7e6a84a1 |
52 | *id_r= id= (ads->nextid++) & 0x0ffff; |
98db6da3 |
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 */ |
f2ad23ee |
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); |
7d0aaee4 |
70 | MKQUERY_ADDW(type & adns_rrt_typemask); /* QTYPE */ |
f2ad23ee |
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 | |
bddb4c18 |
78 | adns_status adns__qdpl_normal(adns_state ads, |
79 | const char **p_io, const char *pe, int labelnum, |
80 | char label_r[], int *ll_io, |
81 | adns_queryflags flags, |
82 | const typeinfo *typei) { |
83 | int ll, c; |
84 | const char *p; |
85 | |
86 | ll= 0; |
87 | p= *p_io; |
88 | |
89 | while (p!=pe && (c= *p++)!='.') { |
90 | if (c=='\\') { |
91 | if (!(flags & adns_qf_quoteok_query)) return adns_s_querydomaininvalid; |
92 | if (ctype_digit(p[0])) { |
93 | if (p+1==pe || p+2==pe) return adns_s_querydomaininvalid; |
94 | if (ctype_digit(p[1]) && ctype_digit(p[2])) { |
95 | c= (*p++ - '0')*100; |
96 | c += (*p++ - '0')*10; |
97 | c += (*p++ - '0'); |
98 | if (c >= 256) return adns_s_querydomaininvalid; |
99 | } else { |
100 | return adns_s_querydomaininvalid; |
101 | } |
102 | } else if (!(c= *p++)) { |
103 | return adns_s_querydomaininvalid; |
104 | } |
105 | } |
106 | if (!(flags & adns_qf_quoteok_query)) { |
107 | if (c == '-') { |
108 | if (!ll) return adns_s_querydomaininvalid; |
109 | } else if (!ctype_alpha(c) && !ctype_digit(c)) { |
110 | return adns_s_querydomaininvalid; |
111 | } |
112 | } |
113 | if (ll == *ll_io) return adns_s_querydomaininvalid; |
114 | label_r[ll++]= c; |
115 | } |
116 | |
117 | *p_io= p; |
118 | *ll_io= ll; |
119 | return adns_s_ok; |
120 | } |
121 | |
f2ad23ee |
122 | adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r, |
123 | const char *owner, int ol, |
7d0aaee4 |
124 | const typeinfo *typei, adns_rrtype type, |
125 | adns_queryflags flags) { |
bddb4c18 |
126 | int labelnum, ll, nbytes; |
127 | byte label[255]; |
128 | byte *rqp; |
f2ad23ee |
129 | const char *p, *pe; |
130 | adns_status st; |
131 | |
fc86e61f |
132 | st= mkquery_header(ads,vb,id_r,ol+2); if (st) return st; |
f2ad23ee |
133 | |
134 | MKQUERY_START(vb); |
135 | |
98db6da3 |
136 | p= owner; pe= owner+ol; |
f57665b9 |
137 | nbytes= 0; |
bddb4c18 |
138 | labelnum= 0; |
7683abe2 |
139 | while (p!=pe) { |
bddb4c18 |
140 | ll= sizeof(label); |
141 | st= typei->qdparselabel(ads, &p,pe, labelnum++, label, &ll, flags, typei); |
142 | if (st) return st; |
9b86645c |
143 | if (!ll) return adns_s_querydomaininvalid; |
3d75057b |
144 | if (ll > DNS_MAXLABEL) return adns_s_querydomaintoolong; |
f57665b9 |
145 | nbytes+= ll+1; |
3d75057b |
146 | if (nbytes >= DNS_MAXDOMAIN) return adns_s_querydomaintoolong; |
98db6da3 |
147 | MKQUERY_ADDB(ll); |
148 | memcpy(rqp,label,ll); rqp+= ll; |
7683abe2 |
149 | } |
f2ad23ee |
150 | MKQUERY_ADDB(0); |
151 | |
152 | MKQUERY_STOP(vb); |
153 | |
7d0aaee4 |
154 | st= mkquery_footer(vb,type); |
f2ad23ee |
155 | |
156 | return adns_s_ok; |
157 | } |
98db6da3 |
158 | |
f2ad23ee |
159 | adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r, |
9c344a42 |
160 | const byte *qd_dgram, int qd_dglen, |
161 | int qd_begin, |
f2ad23ee |
162 | adns_rrtype type, adns_queryflags flags) { |
163 | byte *rqp; |
164 | findlabel_state fls; |
165 | int lablen, labstart; |
166 | adns_status st; |
167 | |
168 | st= mkquery_header(ads,vb,id_r,qd_dglen); if (st) return st; |
169 | |
170 | MKQUERY_START(vb); |
171 | |
172 | adns__findlabel_start(&fls,ads,-1,0,qd_dgram,qd_dglen,qd_dglen,qd_begin,0); |
173 | for (;;) { |
174 | st= adns__findlabel_next(&fls,&lablen,&labstart); assert(!st); |
175 | if (!lablen) break; |
176 | assert(lablen<255); |
177 | MKQUERY_ADDB(lablen); |
178 | memcpy(rqp,qd_dgram+labstart,lablen); |
179 | rqp+= lablen; |
180 | } |
98db6da3 |
181 | MKQUERY_ADDB(0); |
98db6da3 |
182 | |
f2ad23ee |
183 | MKQUERY_STOP(vb); |
184 | |
185 | st= mkquery_footer(vb,type); |
98db6da3 |
186 | |
187 | return adns_s_ok; |
188 | } |
189 | |
d0a057ac |
190 | void adns__querysend_tcp(adns_query qu, struct timeval now) { |
98db6da3 |
191 | byte length[2]; |
192 | struct iovec iov[2]; |
193 | int wr, r; |
11c8bf9b |
194 | adns_state ads; |
98db6da3 |
195 | |
11c8bf9b |
196 | if (qu->ads->tcpstate != server_ok) return; |
98db6da3 |
197 | |
d0a057ac |
198 | assert(qu->state == query_tcpw); |
199 | |
98db6da3 |
200 | length[0]= (qu->query_dglen&0x0ff00U) >>8; |
201 | length[1]= (qu->query_dglen&0x0ff); |
11c8bf9b |
202 | |
203 | ads= qu->ads; |
9c344a42 |
204 | if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2)) |
205 | return; |
98db6da3 |
206 | |
d0a057ac |
207 | qu->retries++; |
208 | |
209 | /* Reset idle timeout. */ |
210 | ads->tcptimeout.tv_sec= ads->tcptimeout.tv_usec= 0; |
98db6da3 |
211 | |
212 | if (ads->tcpsend.used) { |
213 | wr= 0; |
214 | } else { |
215 | iov[0].iov_base= length; |
216 | iov[0].iov_len= 2; |
217 | iov[1].iov_base= qu->query_dgram; |
218 | iov[1].iov_len= qu->query_dglen; |
87e46054 |
219 | adns__sigpipe_protect(qu->ads); |
11c8bf9b |
220 | wr= writev(qu->ads->tcpsocket,iov,2); |
87e46054 |
221 | adns__sigpipe_unprotect(qu->ads); |
98db6da3 |
222 | if (wr < 0) { |
223 | if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC || |
224 | errno == ENOBUFS || errno == ENOMEM)) { |
225 | adns__tcp_broken(ads,"write",strerror(errno)); |
226 | return; |
227 | } |
228 | wr= 0; |
229 | } |
230 | } |
231 | |
232 | if (wr<2) { |
233 | r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r); |
234 | wr= 0; |
235 | } else { |
236 | wr-= 2; |
237 | } |
238 | if (wr<qu->query_dglen) { |
9c344a42 |
239 | r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr); |
240 | assert(r); |
98db6da3 |
241 | } |
242 | } |
243 | |
11c8bf9b |
244 | static void query_usetcp(adns_query qu, struct timeval now) { |
d0a057ac |
245 | qu->state= query_tcpw; |
98db6da3 |
246 | qu->timeout= now; |
d0a057ac |
247 | timevaladd(&qu->timeout,TCPWAITMS); |
248 | LIST_LINK_TAIL(qu->ads->tcpw,qu); |
249 | adns__querysend_tcp(qu,now); |
11c8bf9b |
250 | adns__tcp_tryconnect(qu->ads,now); |
98db6da3 |
251 | } |
252 | |
24d52b13 |
253 | void adns__query_send(adns_query qu, struct timeval now) { |
98db6da3 |
254 | struct sockaddr_in servaddr; |
255 | int serv, r; |
11c8bf9b |
256 | adns_state ads; |
98db6da3 |
257 | |
24d52b13 |
258 | assert(qu->state == query_tosend); |
98db6da3 |
259 | if ((qu->flags & adns_qf_usevc) || (qu->query_dglen > DNS_MAXUDP)) { |
11c8bf9b |
260 | query_usetcp(qu,now); |
98db6da3 |
261 | return; |
262 | } |
263 | |
d0a057ac |
264 | if (qu->retries >= UDPMAXRETRIES) { |
11c8bf9b |
265 | adns__query_fail(qu,adns_s_timeout); |
98db6da3 |
266 | return; |
267 | } |
268 | |
269 | serv= qu->udpnextserver; |
270 | memset(&servaddr,0,sizeof(servaddr)); |
11c8bf9b |
271 | |
272 | ads= qu->ads; |
98db6da3 |
273 | servaddr.sin_family= AF_INET; |
274 | servaddr.sin_addr= ads->servers[serv].addr; |
275 | servaddr.sin_port= htons(DNS_PORT); |
276 | |
763d28b9 |
277 | r= sendto(ads->udpsocket,qu->query_dgram,qu->query_dglen,0, |
278 | (const struct sockaddr*)&servaddr,sizeof(servaddr)); |
9c344a42 |
279 | if (r<0 && errno == EMSGSIZE) { |
280 | qu->retries= 0; |
281 | query_usetcp(qu,now); |
282 | return; |
283 | } |
284 | if (r<0 && errno != EAGAIN) |
285 | adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno)); |
98db6da3 |
286 | |
98db6da3 |
287 | qu->timeout= now; |
d0a057ac |
288 | timevaladd(&qu->timeout,UDPRETRYMS); |
98db6da3 |
289 | qu->udpsent |= (1<<serv); |
290 | qu->udpnextserver= (serv+1)%ads->nservers; |
d0a057ac |
291 | qu->retries++; |
292 | LIST_LINK_TAIL(ads->udpw,qu); |
98db6da3 |
293 | } |