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