Commit | Line | Data |
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b423e985 | 1 | /* |
8ea4199d DF |
2 | * Copyright (c) 1985 Regents of the University of California. |
3 | * All rights reserved. The Berkeley software License Agreement | |
4 | * specifies the terms and conditions for redistribution. | |
b423e985 RC |
5 | */ |
6 | ||
8ea4199d | 7 | #ifndef lint |
27df2740 | 8 | static char sccsid[] = "@(#)res_send.c 5.4 (Berkeley) %G%"; |
8ea4199d DF |
9 | #endif not lint |
10 | ||
616a94ba RC |
11 | /* |
12 | * Send query to name server and wait for reply. | |
13 | */ | |
14 | ||
15 | #include <sys/types.h> | |
16 | #include <sys/time.h> | |
17 | #include <sys/socket.h> | |
18 | #include <netinet/in.h> | |
19 | #include <stdio.h> | |
20 | #include <errno.h> | |
27df2740 KD |
21 | #include <arpa/nameser.h> |
22 | #include <arpa/resolv.h> | |
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23 | |
24 | extern int errno; | |
25 | ||
31f0ead0 | 26 | res_send(buf, buflen, answer, anslen) |
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27 | char *buf; |
28 | int buflen; | |
29 | char *answer; | |
30 | int anslen; | |
31 | { | |
32 | register int n; | |
33 | int s, retry, v_circuit, resplen; | |
34 | u_short id, len; | |
35 | char *cp; | |
36 | int dsmask; | |
37 | struct timeval timeout; | |
38 | HEADER *hp = (HEADER *) buf; | |
39 | HEADER *anhp = (HEADER *) answer; | |
40 | ||
41 | if (_res.options & RES_DEBUG) { | |
31f0ead0 | 42 | printf("res_send()\n"); |
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43 | p_query(buf); |
44 | } | |
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45 | if (!(_res.options & RES_INIT)) |
46 | res_init(); | |
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47 | s = -1; |
48 | v_circuit = (_res.options & RES_USEVC) || buflen > PACKETSZ; | |
49 | id = hp->id; | |
50 | /* | |
51 | * Send request, RETRY times, or until successful | |
52 | */ | |
53 | for (retry = _res.retry; --retry >= 0; ) { | |
54 | if (v_circuit) { | |
55 | /* | |
56 | * Use virtual circuit. | |
57 | */ | |
58 | if (s < 0) | |
59 | s = socket(AF_INET, SOCK_STREAM, 0); | |
60 | if (connect(s, &_res.nsaddr, sizeof(_res.nsaddr)) < 0) { | |
61 | if (_res.options & RES_DEBUG) | |
62 | printf("connect failed %d\n", errno); | |
63 | (void) close(s); | |
64 | s = -1; | |
65 | continue; | |
66 | } | |
67 | /* | |
68 | * Send length & message | |
69 | */ | |
70 | len = htons(buflen); | |
71 | if (write(s, &len, sizeof(len)) != sizeof(len) || | |
72 | write(s, buf, buflen) != buflen) { | |
73 | if (_res.options & RES_DEBUG) | |
74 | printf("write failed %d\n", errno); | |
75 | (void) close(s); | |
76 | s = -1; | |
77 | continue; | |
78 | } | |
79 | /* | |
80 | * Receive length & response | |
81 | */ | |
82 | cp = answer; | |
83 | len = sizeof(short); | |
84 | while (len > 0 && (n = read(s, cp, len)) > 0) { | |
85 | cp += n; | |
86 | len -= n; | |
87 | } | |
88 | if (n <= 0) { | |
89 | if (_res.options & RES_DEBUG) | |
90 | printf("read failed %d\n", errno); | |
91 | (void) close(s); | |
92 | s = -1; | |
93 | continue; | |
94 | } | |
95 | cp = answer; | |
96 | resplen = len = ntohs(*(short *)cp); | |
97 | while (len > 0 && (n = read(s, cp, len)) > 0) { | |
98 | cp += n; | |
99 | len -= n; | |
100 | } | |
101 | if (n <= 0) { | |
102 | if (_res.options & RES_DEBUG) | |
103 | printf("read failed %d\n", errno); | |
104 | (void) close(s); | |
105 | s = -1; | |
106 | continue; | |
107 | } | |
108 | } else { | |
109 | /* | |
110 | * Use datagrams. | |
111 | */ | |
112 | if (s < 0) | |
113 | s = socket(AF_INET, SOCK_DGRAM, 0); | |
114 | if (sendto(s, buf, buflen, 0, &_res.nsaddr, | |
115 | sizeof(_res.nsaddr)) != buflen) { | |
116 | if (_res.options & RES_DEBUG) | |
117 | printf("sendto errno = %d\n", errno); | |
118 | } | |
119 | /* | |
120 | * Wait for reply | |
121 | */ | |
122 | timeout.tv_sec = _res.retrans; | |
123 | timeout.tv_usec = 0; | |
124 | dsmask = 1 << s; | |
125 | n = select(s+1, &dsmask, 0, 0, &timeout); | |
126 | if (n < 0) { | |
127 | if (_res.options & RES_DEBUG) | |
128 | printf("select errno = %d\n", errno); | |
129 | continue; | |
130 | } | |
131 | if (n == 0) { | |
132 | /* | |
133 | * timeout | |
134 | */ | |
135 | if (_res.options & RES_DEBUG) | |
136 | printf("timeout\n"); | |
137 | continue; | |
138 | } | |
139 | if ((resplen = recvfrom(s, answer, anslen, | |
140 | 0, 0, 0)) <= 0) { | |
141 | if (_res.options & RES_DEBUG) | |
142 | printf("recvfrom, errno=%d\n", errno); | |
143 | continue; | |
144 | } | |
145 | if (id != anhp->id) { | |
146 | /* | |
147 | * response from old query, ignore it | |
148 | */ | |
149 | if (_res.options & RES_DEBUG) { | |
616a94ba | 150 | printf("old answer:\n"); |
616a94ba RC |
151 | p_query(answer); |
152 | } | |
153 | continue; | |
154 | } | |
155 | if (!(_res.options & RES_IGNTC) && anhp->tc) { | |
156 | /* | |
157 | * get rest of answer | |
158 | */ | |
159 | if (_res.options & RES_DEBUG) | |
160 | printf("truncated answer\n"); | |
161 | (void) close(s); | |
162 | s = -1; | |
163 | retry = _res.retry; | |
164 | v_circuit = 1; | |
165 | continue; | |
166 | } | |
167 | } | |
168 | if (_res.options & RES_DEBUG) { | |
169 | printf("got answer:\n"); | |
170 | p_query(answer); | |
171 | } | |
e96fe2f7 | 172 | (void) close(s); |
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173 | return (resplen); |
174 | } | |
e96fe2f7 | 175 | (void) close(s); |
31b63904 | 176 | errno = ETIMEDOUT; |
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177 | return (-1); |
178 | } |