e576be50 |
1 | /* |
2 | * transmit.c |
3 | * - construct queries |
4 | * - send queries |
5 | */ |
6 | /* |
d942707d |
7 | * This file is |
8 | * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk> |
9 | * |
10 | * It is part of adns, which is |
11 | * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk> |
12 | * Copyright (C) 1999 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" |
35 | |
e062dcae |
36 | #define MKQUERY_START(vb) (rqp= (vb)->buf+(vb)->used) |
e576be50 |
37 | #define MKQUERY_ADDB(b) *rqp++= (b) |
38 | #define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff)) |
e062dcae |
39 | #define MKQUERY_STOP(vb) ((vb)->used= rqp-(vb)->buf) |
e576be50 |
40 | |
e062dcae |
41 | static adns_status mkquery_header(adns_state ads, vbuf *vb, int *id_r, int qdlen) { |
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); |
68 | MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */ |
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 | |
76 | adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r, |
77 | const char *owner, int ol, |
78 | const typeinfo *typei, adns_queryflags flags) { |
79 | int ll, c, nlabs; |
80 | byte label[255], *rqp; |
81 | const char *p, *pe; |
82 | adns_status st; |
83 | |
84 | st= mkquery_header(ads,vb,id_r,strlen(owner)+2); if (st) return st; |
85 | |
86 | MKQUERY_START(vb); |
87 | |
e576be50 |
88 | p= owner; pe= owner+ol; |
89 | nlabs= 0; |
e9e53c73 |
90 | while (p!=pe) { |
e576be50 |
91 | ll= 0; |
92 | while (p!=pe && (c= *p++)!='.') { |
93 | if (c=='\\') { |
ea1e31e3 |
94 | if (!(flags & adns_qf_quoteok_query)) return adns_s_querydomaininvalid; |
e576be50 |
95 | if (ctype_digit(p[0])) { |
96 | if (ctype_digit(p[1]) && ctype_digit(p[2])) { |
97 | c= (*p++ - '0')*100 + (*p++ - '0')*10 + (*p++ - '0'); |
ea1e31e3 |
98 | if (c >= 256) return adns_s_querydomaininvalid; |
e576be50 |
99 | } else { |
ea1e31e3 |
100 | return adns_s_querydomaininvalid; |
e576be50 |
101 | } |
102 | } else if (!(c= *p++)) { |
ea1e31e3 |
103 | return adns_s_querydomaininvalid; |
e576be50 |
104 | } |
105 | } |
828d89bd |
106 | if (!(flags & adns_qf_quoteok_query)) { |
ffbda80c |
107 | if (c == '-') { |
ea1e31e3 |
108 | if (!ll) return adns_s_querydomaininvalid; |
ffbda80c |
109 | } else if (!ctype_alpha(c) && !ctype_digit(c)) { |
ea1e31e3 |
110 | return adns_s_querydomaininvalid; |
e576be50 |
111 | } |
112 | } |
ea1e31e3 |
113 | if (ll == sizeof(label)) return adns_s_querydomaininvalid; |
e576be50 |
114 | label[ll++]= c; |
115 | } |
ea1e31e3 |
116 | if (!ll) return adns_s_querydomaininvalid; |
117 | if (nlabs++ > 63) return adns_s_querydomaintoolong; |
e576be50 |
118 | MKQUERY_ADDB(ll); |
119 | memcpy(rqp,label,ll); rqp+= ll; |
e9e53c73 |
120 | } |
e062dcae |
121 | MKQUERY_ADDB(0); |
122 | |
123 | MKQUERY_STOP(vb); |
124 | |
125 | st= mkquery_footer(vb,typei->type); |
126 | |
127 | return adns_s_ok; |
128 | } |
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129 | |
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130 | adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r, |
131 | const byte *qd_dgram, int qd_dglen, int qd_begin, |
132 | adns_rrtype type, adns_queryflags flags) { |
133 | byte *rqp; |
134 | findlabel_state fls; |
135 | int lablen, labstart; |
136 | adns_status st; |
137 | |
138 | st= mkquery_header(ads,vb,id_r,qd_dglen); if (st) return st; |
139 | |
140 | MKQUERY_START(vb); |
141 | |
142 | adns__findlabel_start(&fls,ads,-1,0,qd_dgram,qd_dglen,qd_dglen,qd_begin,0); |
143 | for (;;) { |
144 | st= adns__findlabel_next(&fls,&lablen,&labstart); assert(!st); |
145 | if (!lablen) break; |
146 | assert(lablen<255); |
147 | MKQUERY_ADDB(lablen); |
148 | memcpy(rqp,qd_dgram+labstart,lablen); |
149 | rqp+= lablen; |
150 | } |
e576be50 |
151 | MKQUERY_ADDB(0); |
e576be50 |
152 | |
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153 | MKQUERY_STOP(vb); |
154 | |
155 | st= mkquery_footer(vb,type); |
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156 | |
157 | return adns_s_ok; |
158 | } |
159 | |
3955725c |
160 | void adns__query_tcp(adns_query qu, struct timeval now) { |
e576be50 |
161 | byte length[2]; |
162 | struct iovec iov[2]; |
163 | int wr, r; |
3955725c |
164 | adns_state ads; |
e576be50 |
165 | |
3955725c |
166 | if (qu->ads->tcpstate != server_ok) return; |
e576be50 |
167 | |
168 | length[0]= (qu->query_dglen&0x0ff00U) >>8; |
169 | length[1]= (qu->query_dglen&0x0ff); |
3955725c |
170 | |
171 | ads= qu->ads; |
e576be50 |
172 | if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2)) return; |
173 | |
174 | timevaladd(&now,TCPMS); |
175 | qu->timeout= now; |
176 | qu->state= query_tcpsent; |
e576be50 |
177 | |
178 | if (ads->tcpsend.used) { |
179 | wr= 0; |
180 | } else { |
181 | iov[0].iov_base= length; |
182 | iov[0].iov_len= 2; |
183 | iov[1].iov_base= qu->query_dgram; |
184 | iov[1].iov_len= qu->query_dglen; |
ac868fa8 |
185 | adns__sigpipe_protect(qu->ads); |
3955725c |
186 | wr= writev(qu->ads->tcpsocket,iov,2); |
ac868fa8 |
187 | adns__sigpipe_unprotect(qu->ads); |
e576be50 |
188 | if (wr < 0) { |
189 | if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC || |
190 | errno == ENOBUFS || errno == ENOMEM)) { |
191 | adns__tcp_broken(ads,"write",strerror(errno)); |
192 | return; |
193 | } |
194 | wr= 0; |
195 | } |
196 | } |
197 | |
198 | if (wr<2) { |
199 | r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r); |
200 | wr= 0; |
201 | } else { |
202 | wr-= 2; |
203 | } |
204 | if (wr<qu->query_dglen) { |
205 | r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr); assert(r); |
206 | } |
207 | } |
208 | |
3955725c |
209 | static void query_usetcp(adns_query qu, struct timeval now) { |
e576be50 |
210 | timevaladd(&now,TCPMS); |
211 | qu->timeout= now; |
212 | qu->state= query_tcpwait; |
3955725c |
213 | LIST_LINK_TAIL(qu->ads->timew,qu); |
214 | adns__query_tcp(qu,now); |
215 | adns__tcp_tryconnect(qu->ads,now); |
e576be50 |
216 | } |
217 | |
d8c062fa |
218 | void adns__query_send(adns_query qu, struct timeval now) { |
e576be50 |
219 | struct sockaddr_in servaddr; |
220 | int serv, r; |
3955725c |
221 | adns_state ads; |
e576be50 |
222 | |
d8c062fa |
223 | assert(qu->state == query_tosend); |
e576be50 |
224 | if ((qu->flags & adns_qf_usevc) || (qu->query_dglen > DNS_MAXUDP)) { |
3955725c |
225 | query_usetcp(qu,now); |
e576be50 |
226 | return; |
227 | } |
228 | |
229 | if (qu->udpretries >= UDPMAXRETRIES) { |
3955725c |
230 | adns__query_fail(qu,adns_s_timeout); |
e576be50 |
231 | return; |
232 | } |
233 | |
234 | serv= qu->udpnextserver; |
235 | memset(&servaddr,0,sizeof(servaddr)); |
3955725c |
236 | |
237 | ads= qu->ads; |
e576be50 |
238 | servaddr.sin_family= AF_INET; |
239 | servaddr.sin_addr= ads->servers[serv].addr; |
240 | servaddr.sin_port= htons(DNS_PORT); |
241 | |
71a6ff46 |
242 | r= sendto(ads->udpsocket,qu->query_dgram,qu->query_dglen,0, |
243 | (const struct sockaddr*)&servaddr,sizeof(servaddr)); |
3955725c |
244 | if (r<0 && errno == EMSGSIZE) { query_usetcp(qu,now); return; } |
e576be50 |
245 | if (r<0) adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno)); |
246 | |
247 | timevaladd(&now,UDPRETRYMS); |
248 | qu->timeout= now; |
249 | qu->udpsent |= (1<<serv); |
250 | qu->udpnextserver= (serv+1)%ads->nservers; |
251 | qu->udpretries++; |
252 | LIST_LINK_TAIL(ads->timew,qu); |
253 | } |