xref: /titanic_41/usr/src/cmd/krb5/kadmin/kdcmgr/klookup.c (revision f94098a9c7a9cee33e29ec877a160392bbc010f9)
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, priority, weight, 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 	if (argc > 3)
64 		exit(1);
65 
66 	if (argc == 1) {
67 		if (gethostname(name, MAXHOSTNAMELEN) != 0)
68 			exit(1);
69 	} else {
70 		(void) strncpy(name, (char *)argv[1], NS_MAXDNAME);
71 		if (argc == 3) {
72 			typestr = argv[2];
73 
74 			switch (*typestr) {
75 			case 'A':
76 				rr_type = T_A;
77 				break;
78 			case 'C':
79 				rr_type = T_CNAME;
80 				break;
81 			case 'I':
82 				rr_type = T_A;
83 				break;
84 			case 'P':
85 				rr_type = T_PTR;
86 				(void) sscanf(name, "%hhd.%hhd.%hhd.%hhd",
87 				    &a, &b, &c, &d);
88 				(void) sprintf(name, "%d.%d.%d.%d.in-addr.arpa",
89 				    d, c, b, a);
90 				break;
91 			case 'S':
92 				rr_type = T_SRV;
93 				break;
94 			default:
95 				exit(1);
96 			}
97 		}
98 	}
99 
100 	(void) memset(&stat, 0, sizeof (stat));
101 
102 	if (res_ninit(&stat) == -1)
103 		exit(1);
104 
105 	anslen = sizeof (answer);
106 	len = res_nsearch(&stat, name, C_IN, rr_type, answer, anslen);
107 
108 	if (len < sizeof (HEADER)) {
109 		res_ndestroy(&stat);
110 		exit(1);
111 	}
112 
113 	ansp = answer;
114 	end = ansp + anslen;
115 
116 	/* LINTED */
117 	h = (HEADER *)answer;
118 	nq = ntohs(h->qdcount);
119 	na = ntohs(h->ancount);
120 	ansp += HFIXEDSZ;
121 
122 	if (nq != 1 || na < 1) {
123 		res_ndestroy(&stat);
124 		exit(1);
125 	}
126 
127 	hostlen = sizeof (name);
128 	len = dn_expand(answer, end, ansp, name, hostlen);
129 	if (len < 0) {
130 		res_ndestroy(&stat);
131 		exit(1);
132 	}
133 
134 	ansp += len + QFIXEDSZ;
135 
136 	if (ansp > end) {
137 		res_ndestroy(&stat);
138 		exit(1);
139 	}
140 
141 	while (na-- > 0 && ansp < end) {
142 
143 		len = dn_expand(answer, end, ansp, name, hostlen);
144 
145 		if (len < 0)
146 			continue;
147 		ansp += len;			/* name */
148 		NS_GET16(type, ansp);		/* type */
149 		NS_GET16(class, ansp);		/* class */
150 		NS_GET32(ttl, ansp);		/* ttl */
151 		NS_GET16(size, ansp);		/* size */
152 
153 		if ((ansp + size) > end) {
154 			res_ndestroy(&stat);
155 			exit(1);
156 		}
157 		if (type == T_SRV) {
158 			NS_GET16(priority, ansp);
159 			NS_GET16(weight, ansp);
160 			NS_GET16(port, ansp);
161 			len = dn_expand(answer, end, ansp, name, hostlen);
162 			if (len < 0) {
163 				res_ndestroy(&stat);
164 				exit(1);
165 			}
166 			for (cp = name; *cp; cp++) {
167 				*cp = tolower(*cp);
168 			}
169 			(void) printf("%s %d\n", name, port);
170 		} else if (typestr && *typestr == 'I') {
171 			(void) inet_ntop(AF_INET, (void *)ansp, nbuf,
172 			    INET6_ADDRSTRLEN);
173 			len = size;
174 			(void) printf("%s\n", nbuf);
175 		} else if (type == T_PTR) {
176 			len = dn_expand(answer, end, ansp, name, hostlen);
177 			if (len < 0) {
178 				res_ndestroy(&stat);
179 				exit(1);
180 			}
181 		}
182 		ansp += len;
183 		if (type == rr_type && class == C_IN) {
184 			found = 1;
185 			if (type != T_SRV && !(typestr && *typestr == 'I'))
186 				break;
187 		}
188 	}
189 
190 	if (found != 1) {
191 		res_ndestroy(&stat);
192 		exit(1);
193 	}
194 
195 	for (cp = name; *cp; cp++) {
196 		*cp = tolower(*cp);
197 	}
198 
199 	if (type != T_SRV && !(typestr && *typestr == 'I'))
200 		(void) printf("%s\n", name);
201 
202 	res_ndestroy(&stat);
203 
204 	return (0);
205 }
206