HCoop / hcoop / zz_old / debian / djbdns.git / blame
| Commit | Line | Data |
|---|---|---|
| dc0d77d7 CE |
1 | #include "byte.h" |
| 2 | #include "case.h" | |
| 3 | #include "env.h" | |
| 4 | #include "buffer.h" | |
| 5 | #include "strerr.h" | |
| 6 | #include "ip4.h" | |
| 7 | #include "uint16.h" | |
| 8 | #include "ndelay.h" | |
| 9 | #include "socket.h" | |
| 10 | #include "droproot.h" | |
| 11 | #include "qlog.h" | |
| 12 | #include "response.h" | |
| 13 | #include "dns.h" | |
| 14 | ||
| 15 | extern char *fatal; | |
| 16 | extern char *starting; | |
| 17 | extern int respond(char *,char *,char *); | |
| 18 | extern void initialize(void); | |
| 19 | ||
| 20 | static char ip[4]; | |
| 21 | static uint16 port; | |
| 22 | ||
| 23 | static char buf[513]; | |
| 24 | static int len; | |
| 25 | ||
| 26 | static char *q; | |
| 27 | ||
| 28 | static int doit(void) | |
| 29 | { | |
| 30 | unsigned int pos; | |
| 31 | char header[12]; | |
| 32 | char qtype[2]; | |
| 33 | char qclass[2]; | |
| 34 | ||
| 35 | if (len >= sizeof buf) goto NOQ; | |
| 36 | pos = dns_packet_copy(buf,len,0,header,12); if (!pos) goto NOQ; | |
| 37 | if (header[2] & 128) goto NOQ; | |
| 38 | if (header[4]) goto NOQ; | |
| 39 | if (header[5] != 1) goto NOQ; | |
| 40 | ||
| 41 | pos = dns_packet_getname(buf,len,pos,&q); if (!pos) goto NOQ; | |
| 42 | pos = dns_packet_copy(buf,len,pos,qtype,2); if (!pos) goto NOQ; | |
| 43 | pos = dns_packet_copy(buf,len,pos,qclass,2); if (!pos) goto NOQ; | |
| 44 | ||
| 45 | if (!response_query(q,qtype,qclass)) goto NOQ; | |
| 46 | response_id(header); | |
| 47 | if (byte_equal(qclass,2,DNS_C_IN)) | |
| 48 | response[2] |= 4; | |
| 49 | else | |
| 50 | if (byte_diff(qclass,2,DNS_C_ANY)) goto WEIRDCLASS; | |
| 51 | response[3] &= ~128; | |
| 52 | if (!(header[2] & 1)) response[2] &= ~1; | |
| 53 | ||
| 54 | if (header[2] & 126) goto NOTIMP; | |
| 55 | if (byte_equal(qtype,2,DNS_T_AXFR)) goto NOTIMP; | |
| 56 | ||
| 57 | case_lowerb(q,dns_domain_length(q)); | |
| 58 | if (!respond(q,qtype,ip)) { | |
| 59 | qlog(ip,port,header,q,qtype," - "); | |
| 60 | return 0; | |
| 61 | } | |
| 62 | qlog(ip,port,header,q,qtype," + "); | |
| 63 | return 1; | |
| 64 | ||
| 65 | NOTIMP: | |
| 66 | response[3] &= ~15; | |
| 67 | response[3] |= 4; | |
| 68 | qlog(ip,port,header,q,qtype," I "); | |
| 69 | return 1; | |
| 70 | ||
| 71 | WEIRDCLASS: | |
| 72 | response[3] &= ~15; | |
| 73 | response[3] |= 1; | |
| 74 | qlog(ip,port,header,q,qtype," C "); | |
| 75 | return 1; | |
| 76 | ||
| 77 | NOQ: | |
| 78 | qlog(ip,port,"\0\0","","\0\0"," / "); | |
| 79 | return 0; | |
| 80 | } | |
| 81 | ||
| 82 | int main() | |
| 83 | { | |
| 84 | char *x; | |
| 85 | int udp53; | |
| 86 | ||
| 87 | x = env_get("IP"); | |
| 88 | if (!x) | |
| 89 | strerr_die2x(111,fatal,"$IP not set"); | |
| 90 | if (!ip4_scan(x,ip)) | |
| 91 | strerr_die3x(111,fatal,"unable to parse IP address ",x); | |
| 92 | ||
| 93 | udp53 = socket_udp(); | |
| 94 | if (udp53 == -1) | |
| 95 | strerr_die2sys(111,fatal,"unable to create UDP socket: "); | |
| 96 | if (socket_bind4_reuse(udp53,ip,53) == -1) | |
| 97 | strerr_die2sys(111,fatal,"unable to bind UDP socket: "); | |
| 98 | ||
| 99 | droproot(fatal); | |
| 100 | ||
| 101 | initialize(); | |
| 102 | ||
| 103 | ndelay_off(udp53); | |
| 104 | socket_tryreservein(udp53,65536); | |
| 105 | ||
| 106 | buffer_putsflush(buffer_2,starting); | |
| 107 | ||
| 108 | for (;;) { | |
| 109 | len = socket_recv4(udp53,buf,sizeof buf,ip,&port); | |
| 110 | if (len < 0) continue; | |
| 111 | if (!doit()) continue; | |
| 112 | if (response_len > 512) response_tc(); | |
| 113 | socket_send4(udp53,response,response_len,ip,port); | |
| 114 | /* may block for buffer space; if it fails, too bad */ | |
| 115 | } | |
| 116 | } |