xref: /illumos-gate/usr/src/cmd/krb5/kadmin/kdcmgr/klookup.c (revision 66597161e2ba69a84fa138bce7ac02a1e6b9746c)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 /*
27  * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
28  */
29 
30 #include <sys/types.h>
31 #include <netinet/in.h>
32 #include <arpa/nameser.h>
33 #include <resolv.h>
34 #include <netdb.h>
35 #include <limits.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <unistd.h>
39 #include <ctype.h>
40 
41 /*
42  * Private resolver of target and type with arguments:
43  * klooukp [ target [ RR_type ] ]
44  *
45  * Utitilizes DNS lookups to discover domain and realm information.  This CLI
46  * is used primarily by kdcmgr(1M) and kclient(1M).
47  */
48 
49 int
50 /* ARGSUSED */
51 main(int argc, char **argv)
52 {
53 	unsigned char answer[NS_MAXMSG], *ansp = NULL, *end, a, b, c, d;
54 	int len = 0, anslen, hostlen, nq, na, type, class;
55 	int ttl __unused, priority __unused, weight __unused, port, size;
56 	char name[NS_MAXDNAME], *cp, *typestr = NULL;
57 	char nbuf[INET6_ADDRSTRLEN];
58 	struct __res_state stat;
59 	int found = 0;
60 	int rr_type = T_A;
61 	HEADER *h;
62 
63 	type = T_A;
64 
65 	if (argc > 3)
66 		exit(1);
67 
68 	if (argc == 1) {
69 		if (gethostname(name, MAXHOSTNAMELEN) != 0)
70 			exit(1);
71 	} else {
72 		(void) strncpy(name, (char *)argv[1], NS_MAXDNAME);
73 		if (argc == 3) {
74 			typestr = argv[2];
75 
76 			switch (*typestr) {
77 			case 'A':
78 				rr_type = T_A;
79 				break;
80 			case 'C':
81 				rr_type = T_CNAME;
82 				break;
83 			case 'I':
84 				rr_type = T_A;
85 				break;
86 			case 'P':
87 				rr_type = T_PTR;
88 				(void) sscanf(name, "%hhd.%hhd.%hhd.%hhd",
89 				    &a, &b, &c, &d);
90 				(void) sprintf(name, "%d.%d.%d.%d.in-addr.arpa",
91 				    d, c, b, a);
92 				break;
93 			case 'S':
94 				rr_type = T_SRV;
95 				break;
96 			default:
97 				exit(1);
98 			}
99 		}
100 	}
101 
102 	(void) memset(&stat, 0, sizeof (stat));
103 
104 	if (res_ninit(&stat) == -1)
105 		exit(1);
106 
107 	anslen = sizeof (answer);
108 	len = res_nsearch(&stat, name, C_IN, rr_type, answer, anslen);
109 
110 	if (len < sizeof (HEADER)) {
111 		res_ndestroy(&stat);
112 		exit(1);
113 	}
114 
115 	ansp = answer;
116 	end = ansp + anslen;
117 
118 	/* LINTED */
119 	h = (HEADER *)answer;
120 	nq = ntohs(h->qdcount);
121 	na = ntohs(h->ancount);
122 	ansp += HFIXEDSZ;
123 
124 	if (nq != 1 || na < 1) {
125 		res_ndestroy(&stat);
126 		exit(1);
127 	}
128 
129 	hostlen = sizeof (name);
130 	len = dn_expand(answer, end, ansp, name, hostlen);
131 	if (len < 0) {
132 		res_ndestroy(&stat);
133 		exit(1);
134 	}
135 
136 	ansp += len + QFIXEDSZ;
137 
138 	if (ansp > end) {
139 		res_ndestroy(&stat);
140 		exit(1);
141 	}
142 
143 	while (na-- > 0 && ansp < end) {
144 
145 		len = dn_expand(answer, end, ansp, name, hostlen);
146 
147 		if (len < 0)
148 			continue;
149 		ansp += len;			/* name */
150 		NS_GET16(type, ansp);		/* type */
151 		NS_GET16(class, ansp);		/* class */
152 		NS_GET32(ttl, ansp);		/* ttl */
153 		NS_GET16(size, ansp);		/* size */
154 
155 		if ((ansp + size) > end) {
156 			res_ndestroy(&stat);
157 			exit(1);
158 		}
159 		if (type == T_SRV) {
160 			NS_GET16(priority, ansp);
161 			NS_GET16(weight, ansp);
162 			NS_GET16(port, ansp);
163 			len = dn_expand(answer, end, ansp, name, hostlen);
164 			if (len < 0) {
165 				res_ndestroy(&stat);
166 				exit(1);
167 			}
168 			for (cp = name; *cp; cp++) {
169 				*cp = tolower(*cp);
170 			}
171 			(void) printf("%s %d\n", name, port);
172 		} else if (typestr && *typestr == 'I') {
173 			(void) inet_ntop(AF_INET, (void *)ansp, nbuf,
174 			    INET6_ADDRSTRLEN);
175 			len = size;
176 			(void) printf("%s\n", nbuf);
177 		} else if (type == T_PTR) {
178 			len = dn_expand(answer, end, ansp, name, hostlen);
179 			if (len < 0) {
180 				res_ndestroy(&stat);
181 				exit(1);
182 			}
183 		}
184 		ansp += len;
185 		if (type == rr_type && class == C_IN) {
186 			found = 1;
187 			if (type != T_SRV && !(typestr && *typestr == 'I'))
188 				break;
189 		}
190 	}
191 
192 	if (found != 1) {
193 		res_ndestroy(&stat);
194 		exit(1);
195 	}
196 
197 	for (cp = name; *cp; cp++) {
198 		*cp = tolower(*cp);
199 	}
200 
201 	if (type != T_SRV && !(typestr && *typestr == 'I'))
202 		(void) printf("%s\n", name);
203 
204 	res_ndestroy(&stat);
205 
206 	return (0);
207 }
208