98db6da3 |
1 | /* |
2 | * transmit.c |
3 | * - construct queries |
4 | * - send queries |
5 | */ |
6 | /* |
39f45e7e |
7 | * This file is part of adns, which is |
8 | * Copyright (C) 1997-2000,2003,2006 Ian Jackson |
9 | * Copyright (C) 1999-2000,2003,2006 Tony Finch |
10 | * Copyright (C) 1991 Massachusetts Institute of Technology |
11 | * (See the file INSTALL for full details.) |
98db6da3 |
12 | * |
13 | * This program is free software; you can redistribute it and/or modify |
14 | * it under the terms of the GNU General Public License as published by |
15 | * the Free Software Foundation; either version 2, or (at your option) |
16 | * any later version. |
17 | * |
18 | * This program is distributed in the hope that it will be useful, |
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
21 | * GNU General Public License for more details. |
22 | * |
23 | * You should have received a copy of the GNU General Public License |
24 | * along with this program; if not, write to the Free Software Foundation, |
25 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
26 | */ |
27 | |
11c8bf9b |
28 | #include <errno.h> |
11c8bf9b |
29 | |
763d28b9 |
30 | #include <sys/types.h> |
11c8bf9b |
31 | #include <sys/uio.h> |
32 | |
98db6da3 |
33 | #include "internal.h" |
83e1be2f |
34 | #include "tvarith.h" |
98db6da3 |
35 | |
f2ad23ee |
36 | #define MKQUERY_START(vb) (rqp= (vb)->buf+(vb)->used) |
98db6da3 |
37 | #define MKQUERY_ADDB(b) *rqp++= (b) |
38 | #define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff)) |
f2ad23ee |
39 | #define MKQUERY_STOP(vb) ((vb)->used= rqp-(vb)->buf) |
98db6da3 |
40 | |
9c344a42 |
41 | static adns_status mkquery_header(adns_state ads, vbuf *vb, |
42 | int *id_r, int qdlen) { |
f2ad23ee |
43 | int id; |
44 | byte *rqp; |
45 | |
9b86645c |
46 | if (!adns__vbuf_ensure(vb,DNS_HDRSIZE+qdlen+4)) return adns_s_nomemory; |
98db6da3 |
47 | |
f2ad23ee |
48 | vb->used= 0; |
49 | MKQUERY_START(vb); |
50 | |
7e6a84a1 |
51 | *id_r= id= (ads->nextid++) & 0x0ffff; |
98db6da3 |
52 | MKQUERY_ADDW(id); |
53 | MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */ |
54 | MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */ |
55 | MKQUERY_ADDW(1); /* QDCOUNT=1 */ |
56 | MKQUERY_ADDW(0); /* ANCOUNT=0 */ |
57 | MKQUERY_ADDW(0); /* NSCOUNT=0 */ |
58 | MKQUERY_ADDW(0); /* ARCOUNT=0 */ |
f2ad23ee |
59 | |
60 | MKQUERY_STOP(vb); |
61 | |
62 | return adns_s_ok; |
63 | } |
64 | |
65 | static adns_status mkquery_footer(vbuf *vb, adns_rrtype type) { |
66 | byte *rqp; |
67 | |
68 | MKQUERY_START(vb); |
7d0aaee4 |
69 | MKQUERY_ADDW(type & adns_rrt_typemask); /* QTYPE */ |
f2ad23ee |
70 | MKQUERY_ADDW(DNS_CLASS_IN); /* QCLASS=IN */ |
71 | MKQUERY_STOP(vb); |
72 | assert(vb->used <= vb->avail); |
73 | |
74 | return adns_s_ok; |
75 | } |
76 | |
bddb4c18 |
77 | adns_status adns__qdpl_normal(adns_state ads, |
78 | const char **p_io, const char *pe, int labelnum, |
79 | char label_r[], int *ll_io, |
80 | adns_queryflags flags, |
81 | const typeinfo *typei) { |
82 | int ll, c; |
83 | const char *p; |
84 | |
85 | ll= 0; |
86 | p= *p_io; |
87 | |
88 | while (p!=pe && (c= *p++)!='.') { |
89 | if (c=='\\') { |
90 | if (!(flags & adns_qf_quoteok_query)) return adns_s_querydomaininvalid; |
91 | if (ctype_digit(p[0])) { |
92 | if (p+1==pe || p+2==pe) return adns_s_querydomaininvalid; |
93 | if (ctype_digit(p[1]) && ctype_digit(p[2])) { |
94 | c= (*p++ - '0')*100; |
95 | c += (*p++ - '0')*10; |
96 | c += (*p++ - '0'); |
97 | if (c >= 256) return adns_s_querydomaininvalid; |
98 | } else { |
99 | return adns_s_querydomaininvalid; |
100 | } |
101 | } else if (!(c= *p++)) { |
102 | return adns_s_querydomaininvalid; |
103 | } |
104 | } |
105 | if (!(flags & adns_qf_quoteok_query)) { |
106 | if (c == '-') { |
107 | if (!ll) return adns_s_querydomaininvalid; |
108 | } else if (!ctype_alpha(c) && !ctype_digit(c)) { |
109 | return adns_s_querydomaininvalid; |
110 | } |
111 | } |
112 | if (ll == *ll_io) return adns_s_querydomaininvalid; |
113 | label_r[ll++]= c; |
114 | } |
115 | |
116 | *p_io= p; |
117 | *ll_io= ll; |
118 | return adns_s_ok; |
119 | } |
120 | |
f2ad23ee |
121 | adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r, |
122 | const char *owner, int ol, |
7d0aaee4 |
123 | const typeinfo *typei, adns_rrtype type, |
124 | adns_queryflags flags) { |
bddb4c18 |
125 | int labelnum, ll, nbytes; |
126 | byte label[255]; |
127 | byte *rqp; |
f2ad23ee |
128 | const char *p, *pe; |
129 | adns_status st; |
130 | |
fc86e61f |
131 | st= mkquery_header(ads,vb,id_r,ol+2); if (st) return st; |
f2ad23ee |
132 | |
133 | MKQUERY_START(vb); |
134 | |
98db6da3 |
135 | p= owner; pe= owner+ol; |
f57665b9 |
136 | nbytes= 0; |
bddb4c18 |
137 | labelnum= 0; |
7683abe2 |
138 | while (p!=pe) { |
bddb4c18 |
139 | ll= sizeof(label); |
140 | st= typei->qdparselabel(ads, &p,pe, labelnum++, label, &ll, flags, typei); |
141 | if (st) return st; |
9b86645c |
142 | if (!ll) return adns_s_querydomaininvalid; |
3d75057b |
143 | if (ll > DNS_MAXLABEL) return adns_s_querydomaintoolong; |
f57665b9 |
144 | nbytes+= ll+1; |
3d75057b |
145 | if (nbytes >= DNS_MAXDOMAIN) return adns_s_querydomaintoolong; |
98db6da3 |
146 | MKQUERY_ADDB(ll); |
147 | memcpy(rqp,label,ll); rqp+= ll; |
7683abe2 |
148 | } |
f2ad23ee |
149 | MKQUERY_ADDB(0); |
150 | |
151 | MKQUERY_STOP(vb); |
152 | |
7d0aaee4 |
153 | st= mkquery_footer(vb,type); |
f2ad23ee |
154 | |
155 | return adns_s_ok; |
156 | } |
98db6da3 |
157 | |
f2ad23ee |
158 | adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r, |
9c344a42 |
159 | const byte *qd_dgram, int qd_dglen, |
160 | int qd_begin, |
f2ad23ee |
161 | adns_rrtype type, adns_queryflags flags) { |
162 | byte *rqp; |
163 | findlabel_state fls; |
164 | int lablen, labstart; |
165 | adns_status st; |
166 | |
167 | st= mkquery_header(ads,vb,id_r,qd_dglen); if (st) return st; |
168 | |
169 | MKQUERY_START(vb); |
170 | |
171 | adns__findlabel_start(&fls,ads,-1,0,qd_dgram,qd_dglen,qd_dglen,qd_begin,0); |
172 | for (;;) { |
173 | st= adns__findlabel_next(&fls,&lablen,&labstart); assert(!st); |
174 | if (!lablen) break; |
175 | assert(lablen<255); |
176 | MKQUERY_ADDB(lablen); |
177 | memcpy(rqp,qd_dgram+labstart,lablen); |
178 | rqp+= lablen; |
179 | } |
98db6da3 |
180 | MKQUERY_ADDB(0); |
98db6da3 |
181 | |
f2ad23ee |
182 | MKQUERY_STOP(vb); |
183 | |
184 | st= mkquery_footer(vb,type); |
98db6da3 |
185 | |
186 | return adns_s_ok; |
187 | } |
188 | |
d0a057ac |
189 | void adns__querysend_tcp(adns_query qu, struct timeval now) { |
98db6da3 |
190 | byte length[2]; |
191 | struct iovec iov[2]; |
192 | int wr, r; |
11c8bf9b |
193 | adns_state ads; |
98db6da3 |
194 | |
11c8bf9b |
195 | if (qu->ads->tcpstate != server_ok) return; |
98db6da3 |
196 | |
d0a057ac |
197 | assert(qu->state == query_tcpw); |
198 | |
98db6da3 |
199 | length[0]= (qu->query_dglen&0x0ff00U) >>8; |
200 | length[1]= (qu->query_dglen&0x0ff); |
11c8bf9b |
201 | |
202 | ads= qu->ads; |
9c344a42 |
203 | if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2)) |
204 | return; |
98db6da3 |
205 | |
d0a057ac |
206 | qu->retries++; |
207 | |
208 | /* Reset idle timeout. */ |
209 | ads->tcptimeout.tv_sec= ads->tcptimeout.tv_usec= 0; |
98db6da3 |
210 | |
211 | if (ads->tcpsend.used) { |
212 | wr= 0; |
213 | } else { |
214 | iov[0].iov_base= length; |
215 | iov[0].iov_len= 2; |
216 | iov[1].iov_base= qu->query_dgram; |
217 | iov[1].iov_len= qu->query_dglen; |
87e46054 |
218 | adns__sigpipe_protect(qu->ads); |
11c8bf9b |
219 | wr= writev(qu->ads->tcpsocket,iov,2); |
87e46054 |
220 | adns__sigpipe_unprotect(qu->ads); |
98db6da3 |
221 | if (wr < 0) { |
222 | if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC || |
223 | errno == ENOBUFS || errno == ENOMEM)) { |
224 | adns__tcp_broken(ads,"write",strerror(errno)); |
225 | return; |
226 | } |
227 | wr= 0; |
228 | } |
229 | } |
230 | |
231 | if (wr<2) { |
232 | r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r); |
233 | wr= 0; |
234 | } else { |
235 | wr-= 2; |
236 | } |
237 | if (wr<qu->query_dglen) { |
9c344a42 |
238 | r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr); |
239 | assert(r); |
98db6da3 |
240 | } |
241 | } |
242 | |
11c8bf9b |
243 | static void query_usetcp(adns_query qu, struct timeval now) { |
d0a057ac |
244 | qu->state= query_tcpw; |
98db6da3 |
245 | qu->timeout= now; |
d0a057ac |
246 | timevaladd(&qu->timeout,TCPWAITMS); |
247 | LIST_LINK_TAIL(qu->ads->tcpw,qu); |
248 | adns__querysend_tcp(qu,now); |
11c8bf9b |
249 | adns__tcp_tryconnect(qu->ads,now); |
98db6da3 |
250 | } |
251 | |
24d52b13 |
252 | void adns__query_send(adns_query qu, struct timeval now) { |
98db6da3 |
253 | struct sockaddr_in servaddr; |
254 | int serv, r; |
11c8bf9b |
255 | adns_state ads; |
98db6da3 |
256 | |
24d52b13 |
257 | assert(qu->state == query_tosend); |
98db6da3 |
258 | if ((qu->flags & adns_qf_usevc) || (qu->query_dglen > DNS_MAXUDP)) { |
11c8bf9b |
259 | query_usetcp(qu,now); |
98db6da3 |
260 | return; |
261 | } |
262 | |
d0a057ac |
263 | if (qu->retries >= UDPMAXRETRIES) { |
11c8bf9b |
264 | adns__query_fail(qu,adns_s_timeout); |
98db6da3 |
265 | return; |
266 | } |
267 | |
268 | serv= qu->udpnextserver; |
269 | memset(&servaddr,0,sizeof(servaddr)); |
11c8bf9b |
270 | |
271 | ads= qu->ads; |
98db6da3 |
272 | servaddr.sin_family= AF_INET; |
273 | servaddr.sin_addr= ads->servers[serv].addr; |
274 | servaddr.sin_port= htons(DNS_PORT); |
275 | |
763d28b9 |
276 | r= sendto(ads->udpsocket,qu->query_dgram,qu->query_dglen,0, |
277 | (const struct sockaddr*)&servaddr,sizeof(servaddr)); |
9c344a42 |
278 | if (r<0 && errno == EMSGSIZE) { |
279 | qu->retries= 0; |
280 | query_usetcp(qu,now); |
281 | return; |
282 | } |
283 | if (r<0 && errno != EAGAIN) |
284 | adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno)); |
98db6da3 |
285 | |
98db6da3 |
286 | qu->timeout= now; |
d0a057ac |
287 | timevaladd(&qu->timeout,UDPRETRYMS); |
98db6da3 |
288 | qu->udpsent |= (1<<serv); |
289 | qu->udpnextserver= (serv+1)%ads->nservers; |
d0a057ac |
290 | qu->retries++; |
291 | LIST_LINK_TAIL(ads->udpw,qu); |
98db6da3 |
292 | } |