Commit | Line | Data |
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616a94ba | 1 | #ifndef lint |
31f0ead0 | 2 | static char sccsid[] = "@(#)res_send.c 4.3 (Berkeley) %G%"; |
616a94ba RC |
3 | #endif |
4 | ||
5 | /* | |
6 | * Send query to name server and wait for reply. | |
7 | */ | |
8 | ||
9 | #include <sys/types.h> | |
10 | #include <sys/time.h> | |
11 | #include <sys/socket.h> | |
12 | #include <netinet/in.h> | |
13 | #include <stdio.h> | |
14 | #include <errno.h> | |
15 | #include <nameser.h> | |
16 | #include <resolv.h> | |
17 | ||
18 | extern int errno; | |
19 | ||
31f0ead0 | 20 | res_send(buf, buflen, answer, anslen) |
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21 | char *buf; |
22 | int buflen; | |
23 | char *answer; | |
24 | int anslen; | |
25 | { | |
26 | register int n; | |
27 | int s, retry, v_circuit, resplen; | |
28 | u_short id, len; | |
29 | char *cp; | |
30 | int dsmask; | |
31 | struct timeval timeout; | |
32 | HEADER *hp = (HEADER *) buf; | |
33 | HEADER *anhp = (HEADER *) answer; | |
34 | ||
35 | if (_res.options & RES_DEBUG) { | |
31f0ead0 | 36 | printf("res_send()\n"); |
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37 | p_query(buf); |
38 | } | |
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39 | if (!(_res.options & RES_INIT)) |
40 | res_init(); | |
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41 | s = -1; |
42 | v_circuit = (_res.options & RES_USEVC) || buflen > PACKETSZ; | |
43 | id = hp->id; | |
44 | /* | |
45 | * Send request, RETRY times, or until successful | |
46 | */ | |
47 | for (retry = _res.retry; --retry >= 0; ) { | |
48 | if (v_circuit) { | |
49 | /* | |
50 | * Use virtual circuit. | |
51 | */ | |
52 | if (s < 0) | |
53 | s = socket(AF_INET, SOCK_STREAM, 0); | |
54 | if (connect(s, &_res.nsaddr, sizeof(_res.nsaddr)) < 0) { | |
55 | if (_res.options & RES_DEBUG) | |
56 | printf("connect failed %d\n", errno); | |
57 | (void) close(s); | |
58 | s = -1; | |
59 | continue; | |
60 | } | |
61 | /* | |
62 | * Send length & message | |
63 | */ | |
64 | len = htons(buflen); | |
65 | if (write(s, &len, sizeof(len)) != sizeof(len) || | |
66 | write(s, buf, buflen) != buflen) { | |
67 | if (_res.options & RES_DEBUG) | |
68 | printf("write failed %d\n", errno); | |
69 | (void) close(s); | |
70 | s = -1; | |
71 | continue; | |
72 | } | |
73 | /* | |
74 | * Receive length & response | |
75 | */ | |
76 | cp = answer; | |
77 | len = sizeof(short); | |
78 | while (len > 0 && (n = read(s, cp, len)) > 0) { | |
79 | cp += n; | |
80 | len -= n; | |
81 | } | |
82 | if (n <= 0) { | |
83 | if (_res.options & RES_DEBUG) | |
84 | printf("read failed %d\n", errno); | |
85 | (void) close(s); | |
86 | s = -1; | |
87 | continue; | |
88 | } | |
89 | cp = answer; | |
90 | resplen = len = ntohs(*(short *)cp); | |
91 | while (len > 0 && (n = read(s, cp, len)) > 0) { | |
92 | cp += n; | |
93 | len -= n; | |
94 | } | |
95 | if (n <= 0) { | |
96 | if (_res.options & RES_DEBUG) | |
97 | printf("read failed %d\n", errno); | |
98 | (void) close(s); | |
99 | s = -1; | |
100 | continue; | |
101 | } | |
102 | } else { | |
103 | /* | |
104 | * Use datagrams. | |
105 | */ | |
106 | if (s < 0) | |
107 | s = socket(AF_INET, SOCK_DGRAM, 0); | |
108 | if (sendto(s, buf, buflen, 0, &_res.nsaddr, | |
109 | sizeof(_res.nsaddr)) != buflen) { | |
110 | if (_res.options & RES_DEBUG) | |
111 | printf("sendto errno = %d\n", errno); | |
112 | } | |
113 | /* | |
114 | * Wait for reply | |
115 | */ | |
116 | timeout.tv_sec = _res.retrans; | |
117 | timeout.tv_usec = 0; | |
118 | dsmask = 1 << s; | |
119 | n = select(s+1, &dsmask, 0, 0, &timeout); | |
120 | if (n < 0) { | |
121 | if (_res.options & RES_DEBUG) | |
122 | printf("select errno = %d\n", errno); | |
123 | continue; | |
124 | } | |
125 | if (n == 0) { | |
126 | /* | |
127 | * timeout | |
128 | */ | |
129 | if (_res.options & RES_DEBUG) | |
130 | printf("timeout\n"); | |
131 | continue; | |
132 | } | |
133 | if ((resplen = recvfrom(s, answer, anslen, | |
134 | 0, 0, 0)) <= 0) { | |
135 | if (_res.options & RES_DEBUG) | |
136 | printf("recvfrom, errno=%d\n", errno); | |
137 | continue; | |
138 | } | |
139 | if (id != anhp->id) { | |
140 | /* | |
141 | * response from old query, ignore it | |
142 | */ | |
143 | if (_res.options & RES_DEBUG) { | |
616a94ba | 144 | printf("old answer:\n"); |
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145 | p_query(answer); |
146 | } | |
147 | continue; | |
148 | } | |
149 | if (!(_res.options & RES_IGNTC) && anhp->tc) { | |
150 | /* | |
151 | * get rest of answer | |
152 | */ | |
153 | if (_res.options & RES_DEBUG) | |
154 | printf("truncated answer\n"); | |
155 | (void) close(s); | |
156 | s = -1; | |
157 | retry = _res.retry; | |
158 | v_circuit = 1; | |
159 | continue; | |
160 | } | |
161 | } | |
162 | if (_res.options & RES_DEBUG) { | |
163 | printf("got answer:\n"); | |
164 | p_query(answer); | |
165 | } | |
166 | return (resplen); | |
167 | } | |
168 | return (-1); | |
169 | } |