Commit | Line | Data |
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e576be50 | 1 | /* |
2 | * transmit.c | |
3 | * - construct queries | |
4 | * - send queries | |
5 | */ | |
6 | /* | |
ae8cc977 | 7 | * This file is part of adns, which is |
26e1c3d6 | 8 | * Copyright (C) 1997-2000,2003,2006,2014 Ian Jackson |
ae8cc977 | 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.) | |
e576be50 | 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 | |
7f8bbe29 | 15 | * the Free Software Foundation; either version 3, or (at your option) |
e576be50 | 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 | |
8c09a4c6 | 24 | * along with this program; if not, write to the Free Software Foundation. |
e576be50 | 25 | */ |
26 | ||
3955725c | 27 | #include <errno.h> |
3955725c | 28 | |
71a6ff46 | 29 | #include <sys/types.h> |
3955725c | 30 | #include <sys/uio.h> |
31 | ||
e576be50 | 32 | #include "internal.h" |
2953d358 | 33 | #include "tvarith.h" |
e576be50 | 34 | |
e062dcae | 35 | #define MKQUERY_START(vb) (rqp= (vb)->buf+(vb)->used) |
e576be50 | 36 | #define MKQUERY_ADDB(b) *rqp++= (b) |
37 | #define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff)) | |
e062dcae | 38 | #define MKQUERY_STOP(vb) ((vb)->used= rqp-(vb)->buf) |
e576be50 | 39 | |
609133ee | 40 | static adns_status mkquery_header(adns_state ads, vbuf *vb, |
41 | int *id_r, int qdlen) { | |
e062dcae | 42 | int id; |
43 | byte *rqp; | |
44 | ||
ea1e31e3 | 45 | if (!adns__vbuf_ensure(vb,DNS_HDRSIZE+qdlen+4)) return adns_s_nomemory; |
e576be50 | 46 | |
e062dcae | 47 | vb->used= 0; |
48 | MKQUERY_START(vb); | |
49 | ||
660d7d3b | 50 | *id_r= id= (ads->nextid++) & 0x0ffff; |
e576be50 | 51 | MKQUERY_ADDW(id); |
52 | MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */ | |
53 | MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */ | |
54 | MKQUERY_ADDW(1); /* QDCOUNT=1 */ | |
55 | MKQUERY_ADDW(0); /* ANCOUNT=0 */ | |
56 | MKQUERY_ADDW(0); /* NSCOUNT=0 */ | |
57 | MKQUERY_ADDW(0); /* ARCOUNT=0 */ | |
e062dcae | 58 | |
59 | MKQUERY_STOP(vb); | |
60 | ||
61 | return adns_s_ok; | |
62 | } | |
63 | ||
64 | static adns_status mkquery_footer(vbuf *vb, adns_rrtype type) { | |
65 | byte *rqp; | |
66 | ||
67 | MKQUERY_START(vb); | |
2c6eb096 | 68 | MKQUERY_ADDW(type & adns_rrt_typemask); /* QTYPE */ |
e062dcae | 69 | MKQUERY_ADDW(DNS_CLASS_IN); /* QCLASS=IN */ |
70 | MKQUERY_STOP(vb); | |
71 | assert(vb->used <= vb->avail); | |
72 | ||
73 | return adns_s_ok; | |
74 | } | |
75 | ||
e8e5aeac MW |
76 | static adns_status qdparselabel(adns_state ads, |
77 | const char **p_io, const char *pe, | |
78 | char label_r[], int *ll_io, | |
79 | adns_queryflags flags) { | |
d19b03d0 | 80 | int ll, c; |
81 | const char *p; | |
82 | ||
83 | ll= 0; | |
84 | p= *p_io; | |
85 | ||
86 | while (p!=pe && (c= *p++)!='.') { | |
87 | if (c=='\\') { | |
88 | if (!(flags & adns_qf_quoteok_query)) return adns_s_querydomaininvalid; | |
89 | if (ctype_digit(p[0])) { | |
90 | if (p+1==pe || p+2==pe) return adns_s_querydomaininvalid; | |
91 | if (ctype_digit(p[1]) && ctype_digit(p[2])) { | |
92 | c= (*p++ - '0')*100; | |
93 | c += (*p++ - '0')*10; | |
94 | c += (*p++ - '0'); | |
95 | if (c >= 256) return adns_s_querydomaininvalid; | |
96 | } else { | |
97 | return adns_s_querydomaininvalid; | |
98 | } | |
99 | } else if (!(c= *p++)) { | |
100 | return adns_s_querydomaininvalid; | |
101 | } | |
102 | } | |
d19b03d0 | 103 | if (ll == *ll_io) return adns_s_querydomaininvalid; |
104 | label_r[ll++]= c; | |
105 | } | |
106 | ||
107 | *p_io= p; | |
108 | *ll_io= ll; | |
109 | return adns_s_ok; | |
110 | } | |
111 | ||
e062dcae | 112 | adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r, |
113 | const char *owner, int ol, | |
2c6eb096 | 114 | const typeinfo *typei, adns_rrtype type, |
115 | adns_queryflags flags) { | |
e8e5aeac | 116 | int ll, nbytes; |
d19b03d0 | 117 | byte label[255]; |
118 | byte *rqp; | |
e062dcae | 119 | const char *p, *pe; |
120 | adns_status st; | |
121 | ||
914a5ff5 | 122 | st= mkquery_header(ads,vb,id_r,ol+2); if (st) return st; |
e062dcae | 123 | |
124 | MKQUERY_START(vb); | |
125 | ||
e576be50 | 126 | p= owner; pe= owner+ol; |
4b2c4f8a | 127 | nbytes= 0; |
e9e53c73 | 128 | while (p!=pe) { |
d19b03d0 | 129 | ll= sizeof(label); |
e8e5aeac | 130 | st= qdparselabel(ads, &p,pe, label, &ll, flags); |
d19b03d0 | 131 | if (st) return st; |
ea1e31e3 | 132 | if (!ll) return adns_s_querydomaininvalid; |
5b9dd636 | 133 | if (ll > DNS_MAXLABEL) return adns_s_querydomaintoolong; |
4b2c4f8a | 134 | nbytes+= ll+1; |
5b9dd636 | 135 | if (nbytes >= DNS_MAXDOMAIN) return adns_s_querydomaintoolong; |
e576be50 | 136 | MKQUERY_ADDB(ll); |
137 | memcpy(rqp,label,ll); rqp+= ll; | |
e9e53c73 | 138 | } |
e062dcae | 139 | MKQUERY_ADDB(0); |
140 | ||
141 | MKQUERY_STOP(vb); | |
142 | ||
2c6eb096 | 143 | st= mkquery_footer(vb,type); |
e062dcae | 144 | |
145 | return adns_s_ok; | |
146 | } | |
e576be50 | 147 | |
e062dcae | 148 | adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r, |
609133ee | 149 | const byte *qd_dgram, int qd_dglen, |
150 | int qd_begin, | |
e062dcae | 151 | adns_rrtype type, adns_queryflags flags) { |
152 | byte *rqp; | |
153 | findlabel_state fls; | |
154 | int lablen, labstart; | |
155 | adns_status st; | |
156 | ||
157 | st= mkquery_header(ads,vb,id_r,qd_dglen); if (st) return st; | |
158 | ||
159 | MKQUERY_START(vb); | |
160 | ||
161 | adns__findlabel_start(&fls,ads,-1,0,qd_dgram,qd_dglen,qd_dglen,qd_begin,0); | |
162 | for (;;) { | |
163 | st= adns__findlabel_next(&fls,&lablen,&labstart); assert(!st); | |
164 | if (!lablen) break; | |
165 | assert(lablen<255); | |
166 | MKQUERY_ADDB(lablen); | |
167 | memcpy(rqp,qd_dgram+labstart,lablen); | |
168 | rqp+= lablen; | |
169 | } | |
e576be50 | 170 | MKQUERY_ADDB(0); |
e576be50 | 171 | |
e062dcae | 172 | MKQUERY_STOP(vb); |
173 | ||
174 | st= mkquery_footer(vb,type); | |
e576be50 | 175 | |
176 | return adns_s_ok; | |
177 | } | |
178 | ||
f7f83b4a | 179 | void adns__querysend_tcp(adns_query qu, struct timeval now) { |
e576be50 | 180 | byte length[2]; |
181 | struct iovec iov[2]; | |
182 | int wr, r; | |
3955725c | 183 | adns_state ads; |
e576be50 | 184 | |
3955725c | 185 | if (qu->ads->tcpstate != server_ok) return; |
e576be50 | 186 | |
f7f83b4a | 187 | assert(qu->state == query_tcpw); |
188 | ||
e576be50 | 189 | length[0]= (qu->query_dglen&0x0ff00U) >>8; |
190 | length[1]= (qu->query_dglen&0x0ff); | |
3955725c | 191 | |
192 | ads= qu->ads; | |
609133ee | 193 | if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2)) |
194 | return; | |
e576be50 | 195 | |
f7f83b4a | 196 | qu->retries++; |
197 | ||
198 | /* Reset idle timeout. */ | |
199 | ads->tcptimeout.tv_sec= ads->tcptimeout.tv_usec= 0; | |
e576be50 | 200 | |
201 | if (ads->tcpsend.used) { | |
202 | wr= 0; | |
203 | } else { | |
204 | iov[0].iov_base= length; | |
205 | iov[0].iov_len= 2; | |
206 | iov[1].iov_base= qu->query_dgram; | |
207 | iov[1].iov_len= qu->query_dglen; | |
ac868fa8 | 208 | adns__sigpipe_protect(qu->ads); |
3955725c | 209 | wr= writev(qu->ads->tcpsocket,iov,2); |
ac868fa8 | 210 | adns__sigpipe_unprotect(qu->ads); |
e576be50 | 211 | if (wr < 0) { |
212 | if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC || | |
213 | errno == ENOBUFS || errno == ENOMEM)) { | |
214 | adns__tcp_broken(ads,"write",strerror(errno)); | |
215 | return; | |
216 | } | |
217 | wr= 0; | |
218 | } | |
219 | } | |
220 | ||
221 | if (wr<2) { | |
222 | r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r); | |
223 | wr= 0; | |
224 | } else { | |
225 | wr-= 2; | |
226 | } | |
227 | if (wr<qu->query_dglen) { | |
609133ee | 228 | r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr); |
229 | assert(r); | |
e576be50 | 230 | } |
231 | } | |
232 | ||
3955725c | 233 | static void query_usetcp(adns_query qu, struct timeval now) { |
f7f83b4a | 234 | qu->state= query_tcpw; |
e576be50 | 235 | qu->timeout= now; |
f7f83b4a | 236 | timevaladd(&qu->timeout,TCPWAITMS); |
237 | LIST_LINK_TAIL(qu->ads->tcpw,qu); | |
238 | adns__querysend_tcp(qu,now); | |
3955725c | 239 | adns__tcp_tryconnect(qu->ads,now); |
e576be50 | 240 | } |
241 | ||
3eb20edd MW |
242 | struct udpsocket *adns__udpsocket_by_af(adns_state ads, int af) { |
243 | int i; | |
97a937c8 IJ |
244 | for (i=0; i<ads->nudpsockets; i++) |
245 | if (ads->udpsockets[i].af == af) return &ads->udpsockets[i]; | |
3eb20edd MW |
246 | return 0; |
247 | } | |
248 | ||
d8c062fa | 249 | void adns__query_send(adns_query qu, struct timeval now) { |
e576be50 | 250 | int serv, r; |
3955725c | 251 | adns_state ads; |
3eb20edd | 252 | struct udpsocket *udp; |
f930c455 | 253 | adns_rr_addr *addr; |
e576be50 | 254 | |
d8c062fa | 255 | assert(qu->state == query_tosend); |
e576be50 | 256 | if ((qu->flags & adns_qf_usevc) || (qu->query_dglen > DNS_MAXUDP)) { |
3955725c | 257 | query_usetcp(qu,now); |
e576be50 | 258 | return; |
259 | } | |
260 | ||
f7f83b4a | 261 | if (qu->retries >= UDPMAXRETRIES) { |
3955725c | 262 | adns__query_fail(qu,adns_s_timeout); |
e576be50 | 263 | return; |
264 | } | |
265 | ||
3955725c | 266 | ads= qu->ads; |
f930c455 MW |
267 | serv= qu->udpnextserver; |
268 | addr= &ads->servers[serv]; | |
3eb20edd MW |
269 | udp= adns__udpsocket_by_af(ads, addr->addr.sa.sa_family); |
270 | assert(udp); | |
e576be50 | 271 | |
3eb20edd | 272 | r= sendto(udp->fd,qu->query_dgram,qu->query_dglen,0, |
f930c455 | 273 | &addr->addr.sa,addr->len); |
609133ee | 274 | if (r<0 && errno == EMSGSIZE) { |
275 | qu->retries= 0; | |
276 | query_usetcp(qu,now); | |
277 | return; | |
278 | } | |
279 | if (r<0 && errno != EAGAIN) | |
280 | adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno)); | |
e576be50 | 281 | |
e576be50 | 282 | qu->timeout= now; |
f7f83b4a | 283 | timevaladd(&qu->timeout,UDPRETRYMS); |
e576be50 | 284 | qu->udpsent |= (1<<serv); |
285 | qu->udpnextserver= (serv+1)%ads->nservers; | |
f7f83b4a | 286 | qu->retries++; |
287 | LIST_LINK_TAIL(ads->udpw,qu); | |
e576be50 | 288 | } |