1 #include <u.h>
2 #include <libc.h>
3 #include <bio.h>
4 #include <ndb.h>
5 #include <thread.h>
6 #include <9pclient.h>
7 #include "dns.h"
8 #include "ip.h"
9 
10 void
11 usage(void)
12 {
13 	fprint(2, "usage: dnsquery [-x service]\n");
14 	threadexitsall("usage");
15 }
16 
17 void
18 threadmain(int argc, char *argv[])
19 {
20 	CFid *fd;
21 	int n, len;
22 	Biobuf in;
23 	char line[1024], *lp, *p, *np, *dns;
24 	char buf[1024];
25 
26 	dns = "dns";
27 	ARGBEGIN{
28 	case 'x':
29 		dns = EARGF(usage());
30 		break;
31 	default:
32 		usage();
33 	}ARGEND;
34 
35 	if(argc)
36 		usage();
37 
38 	fd = nsopen(dns, nil, "dns", ORDWR);
39 	if(fd == nil)
40 		sysfatal("open %s!dns: %r", dns);
41 
42 	Binit(&in, 0, OREAD);
43 	for(print("> "); lp = Brdline(&in, '\n'); print("> ")){
44 		n = Blinelen(&in)-1;
45 		strncpy(line, lp, n);
46 		line[n] = 0;
47 		if (n<=1)
48 			continue;
49 		/* default to an "ip" request if alpha, "ptr" if numeric */
50 		if (strchr(line, ' ')==0) {
51 			if(strcmp(ipattr(line), "ip") == 0) {
52 				strcat(line, " ptr");
53 				n += 4;
54 			} else {
55 				strcat(line, " ip");
56 				n += 3;
57 			}
58 		}
59 
60 		/* inverse queries may need to be permuted */
61 		if(n > 4 && strcmp("ptr", &line[n-3]) == 0
62 		&& strstr(line, "IN-ADDR") == 0 && strstr(line, "in-addr") == 0){
63 			for(p = line; *p; p++)
64 				if(*p == ' '){
65 					*p = '.';
66 					break;
67 				}
68 			np = buf;
69 			len = 0;
70 			while(p >= line){
71 				len++;
72 				p--;
73 				if(*p == '.'){
74 					memmove(np, p+1, len);
75 					np += len;
76 					len = 0;
77 				}
78 			}
79 			memmove(np, p+1, len);
80 			np += len;
81 			strcpy(np, "in-addr.arpa ptr");
82 			strcpy(line, buf);
83 			n = strlen(line);
84 		}
85 
86 		fsseek(fd, 0, 0);
87 		if(fswrite(fd, line, n) < 0) {
88 			print("!%r\n");
89 			continue;
90 		}
91 		fsseek(fd, 0, 0);
92 		while((n = fsread(fd, buf, sizeof(buf))) > 0){
93 			buf[n] = 0;
94 			print("%s\n", buf);
95 		}
96 	}
97 	threadexitsall(0);
98 }