Commit | Line | Data |
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dc0d77d7 CE |
1 | #include "stralloc.h" |
2 | #include "uint16.h" | |
3 | #include "byte.h" | |
4 | #include "dns.h" | |
5 | ||
6 | int dns_txt_packet(stralloc *out,const char *buf,unsigned int len) | |
7 | { | |
8 | unsigned int pos; | |
9 | char header[12]; | |
10 | uint16 numanswers; | |
11 | uint16 datalen; | |
12 | char ch; | |
13 | unsigned int txtlen; | |
14 | int i; | |
15 | ||
16 | if (!stralloc_copys(out,"")) return -1; | |
17 | ||
18 | pos = dns_packet_copy(buf,len,0,header,12); if (!pos) return -1; | |
19 | uint16_unpack_big(header + 6,&numanswers); | |
20 | pos = dns_packet_skipname(buf,len,pos); if (!pos) return -1; | |
21 | pos += 4; | |
22 | ||
23 | while (numanswers--) { | |
24 | pos = dns_packet_skipname(buf,len,pos); if (!pos) return -1; | |
25 | pos = dns_packet_copy(buf,len,pos,header,10); if (!pos) return -1; | |
26 | uint16_unpack_big(header + 8,&datalen); | |
27 | if (byte_equal(header,2,DNS_T_TXT)) | |
28 | if (byte_equal(header + 2,2,DNS_C_IN)) { | |
29 | if (pos + datalen > len) return -1; | |
30 | txtlen = 0; | |
31 | for (i = 0;i < datalen;++i) { | |
32 | ch = buf[pos + i]; | |
33 | if (!txtlen) | |
34 | txtlen = (unsigned char) ch; | |
35 | else { | |
36 | --txtlen; | |
37 | if (ch < 32) ch = '?'; | |
38 | if (ch > 126) ch = '?'; | |
39 | if (!stralloc_append(out,&ch)) return -1; | |
40 | } | |
41 | } | |
42 | } | |
43 | pos += datalen; | |
44 | } | |
45 | ||
46 | return 0; | |
47 | } | |
48 | ||
49 | static char *q = 0; | |
50 | ||
51 | int dns_txt(stralloc *out,const stralloc *fqdn) | |
52 | { | |
53 | if (!dns_domain_fromdot(&q,fqdn->s,fqdn->len)) return -1; | |
54 | if (dns_resolve(q,DNS_T_TXT) == -1) return -1; | |
55 | if (dns_txt_packet(out,dns_resolve_tx.packet,dns_resolve_tx.packetlen) == -1) return -1; | |
56 | dns_transmit_free(&dns_resolve_tx); | |
57 | dns_domain_free(&q); | |
58 | return 0; | |
59 | } |