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1 | /**/ |
2 | |
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3 | #include <errno.h> |
4 | #include <string.h> |
5 | |
6 | #include <sys/uio.h> |
7 | |
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8 | #include "internal.h" |
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9 | |
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10 | adns_status adns__mkquery(adns_state ads, const char *owner, int ol, int id, |
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11 | adns_rrtype type, adns_queryflags flags) { |
12 | /* Assembles a query packet in ads->rqbuf. */ |
13 | int ll, c, nlabs; |
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14 | byte label[255], *rqp; |
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15 | const char *p, *pe; |
16 | |
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17 | #define MKQUERY_ADDB(b) *rqp++= (b) |
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18 | #define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff)) |
19 | |
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20 | if (!adns__vbuf_ensure(&ads->rqbuf,12+strlen(owner)+1+5)) return adns_s_nolocalmem; |
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21 | rqp= ads->rqbuf.buf; |
22 | |
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23 | MKQUERY_ADDW(id); |
24 | MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */ |
25 | MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */ |
26 | MKQUERY_ADDW(1); /* QDCOUNT=1 */ |
27 | MKQUERY_ADDW(0); /* ANCOUNT=0 */ |
28 | MKQUERY_ADDW(0); /* NSCOUNT=0 */ |
29 | MKQUERY_ADDW(0); /* ARCOUNT=0 */ |
30 | p= owner; pe= owner+ol; |
31 | nlabs= 0; |
32 | if (!*p) return adns_s_invaliddomain; |
33 | do { |
34 | ll= 0; |
35 | while (p!=pe && (c= *p++)!='.') { |
36 | if (c=='\\') { |
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37 | if (!(flags & adns_qf_anyquote)) return adns_s_invaliddomain; |
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38 | if (ctype_digit(p[0])) { |
39 | if (ctype_digit(p[1]) && ctype_digit(p[2])) { |
40 | c= (*p++ - '0')*100 + (*p++ - '0')*10 + (*p++ - '0'); |
41 | if (c >= 256) return adns_s_invaliddomain; |
42 | } else { |
43 | return adns_s_invaliddomain; |
44 | } |
45 | } else if (!(c= *p++)) { |
46 | return adns_s_invaliddomain; |
47 | } |
48 | } |
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49 | if (!(flags & adns_qf_anyquote)) { |
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50 | if (ctype_digit(c) || c == '-') { |
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51 | if (!ll) return adns_s_invaliddomain; |
52 | } else if ((c < 'a' || c > 'z') && (c < 'A' && c > 'Z')) { |
53 | return adns_s_invaliddomain; |
54 | } |
55 | } |
56 | if (ll == sizeof(label)) return adns_s_invaliddomain; |
57 | label[ll++]= c; |
58 | } |
59 | if (!ll) return adns_s_invaliddomain; |
60 | if (nlabs++ > 63) return adns_s_invaliddomain; |
61 | MKQUERY_ADDB(ll); |
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62 | memcpy(rqp,label,ll); rqp+= ll; |
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63 | } while (p!=pe); |
64 | |
65 | MKQUERY_ADDB(0); |
66 | MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */ |
67 | MKQUERY_ADDW(1); /* QCLASS=IN */ |
68 | |
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69 | ads->rqbuf.used= rqp - ads->rqbuf.buf; |
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70 | assert(ads->rqbuf.used <= ads->rqbuf.avail); |
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71 | |
72 | return adns_s_ok; |
73 | } |
74 | |
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75 | void adns__query_tcp(adns_state ads, adns_query qu, struct timeval now) { |
ddfda861 |
76 | /* Query must be in state tcpwait/timew; it will be moved to a new state |
77 | * if possible and no further processing can be done on it for now. |
78 | * (Resulting state is one of tcpwait/timew (if server not connected), |
79 | * tcpsent/timew, child/childw or done/output.) |
80 | * |
81 | * adns__tcp_tryconnect should already have been called - _tcp |
82 | * will only use an existing connection (if there is one), which it |
83 | * may break. If the conn list lost then the caller is responsible for any |
84 | * reestablishment and retry. |
85 | */ |
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86 | byte length[2]; |
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87 | struct iovec iov[2]; |
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88 | int wr, r; |
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89 | |
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90 | if (ads->tcpstate != server_ok) return; |
91 | |
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92 | length[0]= (qu->querylen&0x0ff00U) >>8; |
93 | length[1]= (qu->querylen&0x0ff); |
94 | |
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95 | if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->querylen+2)) return; |
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96 | |
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97 | timevaladd(&now,TCPMS); |
98 | qu->timeout= now; |
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99 | qu->state= query_tcpsent; |
100 | LIST_LINK_TAIL(ads->timew,qu); |
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101 | |
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102 | if (ads->tcpsend.used) { |
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103 | wr= 0; |
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104 | } else { |
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105 | iov[0].iov_base= length; |
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106 | iov[0].iov_len= 2; |
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107 | iov[1].iov_base= qu->querymsg; |
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108 | iov[1].iov_len= qu->querylen; |
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109 | wr= writev(ads->tcpsocket,iov,2); |
110 | if (wr < 0) { |
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111 | if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC || |
112 | errno == ENOBUFS || errno == ENOMEM)) { |
113 | adns__tcp_broken(ads,"write",strerror(errno)); |
114 | return; |
115 | } |
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116 | wr= 0; |
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117 | } |
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118 | } |
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119 | |
120 | if (wr<2) { |
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121 | r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r); |
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122 | wr= 0; |
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123 | } else { |
ddfda861 |
124 | wr-= 2; |
125 | } |
126 | if (wr<qu->querylen) { |
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127 | r= adns__vbuf_append(&ads->tcpsend,qu->querymsg+wr,qu->querylen-wr); assert(r); |
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128 | } |
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129 | } |
130 | |
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131 | static void query_usetcp(adns_state ads, adns_query qu, struct timeval now) { |
132 | timevaladd(&now,TCPMS); |
133 | qu->timeout= now; |
134 | qu->state= query_tcpwait; |
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135 | LIST_LINK_TAIL(ads->timew,qu); |
136 | adns__query_tcp(ads,qu,now); |
137 | adns__tcp_tryconnect(ads,now); |
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138 | } |
139 | |
140 | void adns__query_udp(adns_state ads, adns_query qu, struct timeval now) { |
141 | /* Query must be in state udp/NONE; it will be moved to a new state, |
142 | * and no further processing can be done on it for now. |
143 | * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected), |
144 | * tcpsent/timew, child/childw or done/output.) |
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145 | */ |
146 | struct sockaddr_in servaddr; |
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147 | int serv, r; |
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148 | |
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149 | assert(qu->state == query_udp); |
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150 | if ((qu->flags & adns_qf_usevc) || (qu->querylen > MAXUDPDGRAM)) { |
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151 | query_usetcp(ads,qu,now); |
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152 | return; |
153 | } |
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154 | |
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155 | if (qu->udpretries >= MAXUDPRETRIES) { |
156 | adns__query_fail(ads,qu,adns_s_timeout); |
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157 | return; |
158 | } |
159 | |
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160 | serv= qu->udpnextserver; |
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161 | memset(&servaddr,0,sizeof(servaddr)); |
162 | servaddr.sin_family= AF_INET; |
163 | servaddr.sin_addr= ads->servers[serv].addr; |
164 | servaddr.sin_port= htons(NSPORT); |
165 | |
166 | r= sendto(ads->udpsocket,qu->querymsg,qu->querylen,0,&servaddr,sizeof(servaddr)); |
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167 | if (r<0 && errno == EMSGSIZE) { query_usetcp(ads,qu,now); return; } |
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168 | if (r<0) adns__warn(ads,serv,"sendto failed: %s",strerror(errno)); |
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169 | |
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170 | timevaladd(&now,UDPRETRYMS); |
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171 | qu->timeout= now; |
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172 | qu->udpsent |= (1<<serv); |
173 | qu->udpnextserver= (serv+1)%ads->nservers; |
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174 | qu->udpretries++; |
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175 | LIST_LINK_TAIL(ads->timew,qu); |
176 | } |
177 | |
178 | void adns__query_nomem(adns_state ads, adns_query qu) { |
179 | qu->answer.used= 0; |
180 | qu->id= -1; |
181 | LIST_LINK_TAIL(ads->output,qu); |
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182 | } |
183 | |
184 | void adns__query_fail(adns_state ads, adns_query qu, adns_status stat) { |
185 | adns_answer *ans; |
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186 | |
187 | if (!adns__vbuf_ensure(&qu->answer,sizeof(adns_answer))) { |
188 | adns__query_nomem(ads,qu); |
189 | return; |
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190 | } |
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191 | ans= (adns_answer*)qu->answer.buf; |
192 | ans->status= stat; |
193 | ans->cname= 0; |
194 | ans->type= qu->type; |
195 | ans->nrrs= 0; |
196 | qu->answer.used= sizeof(adns_answer); |
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197 | qu->id= -1; |
198 | LIST_LINK_TAIL(ads->output,qu); |
199 | } |