xref: /freebsd/contrib/tcp_wrappers/scaffold.c (revision 05248206f720394d95c2a7475429311df670a2e9)
1  /*
2   * Routines for testing only. Not really industrial strength.
3   *
4   * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
5   *
6   * $FreeBSD$
7   */
8 
9 #ifndef lint
10 static char sccs_id[] = "@(#) scaffold.c 1.6 97/03/21 19:27:24";
11 #endif
12 
13 /* System libraries. */
14 
15 #include <sys/types.h>
16 #include <sys/stat.h>
17 #include <sys/socket.h>
18 #include <netinet/in.h>
19 #include <arpa/inet.h>
20 #include <netdb.h>
21 #include <stdio.h>
22 #include <syslog.h>
23 #include <setjmp.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <stdlib.h>
27 
28 #ifndef INADDR_NONE
29 #define	INADDR_NONE	(-1)		/* XXX should be 0xffffffff */
30 #endif
31 
32 /* Application-specific. */
33 
34 #include "tcpd.h"
35 #include "scaffold.h"
36 
37  /*
38   * These are referenced by the options module and by rfc931.c.
39   */
40 int     allow_severity = SEVERITY;
41 int     deny_severity = LOG_WARNING;
42 
43 #ifndef INET6
44 /* dup_hostent - create hostent in one memory block */
45 
46 static struct hostent *dup_hostent(struct hostent *hp)
47 {
48     struct hostent_block {
49 	struct hostent host;
50 	char   *addr_list[1];
51     };
52     struct hostent_block *hb;
53     int     count;
54     char   *data;
55     char   *addr;
56 
57     for (count = 0; hp->h_addr_list[count] != 0; count++)
58 	 /* void */ ;
59 
60     if ((hb = (struct hostent_block *) malloc(sizeof(struct hostent_block)
61 			 + (hp->h_length + sizeof(char *)) * count)) == 0) {
62 	fprintf(stderr, "Sorry, out of memory\n");
63 	exit(1);
64     }
65     memset((char *) &hb->host, 0, sizeof(hb->host));
66     hb->host.h_length = hp->h_length;
67     hb->host.h_addr_list = hb->addr_list;
68     hb->host.h_addr_list[count] = 0;
69     data = (char *) (hb->host.h_addr_list + count + 1);
70 
71     for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
72 	hb->host.h_addr_list[count] = data + hp->h_length * count;
73 	memcpy(hb->host.h_addr_list[count], addr, hp->h_length);
74     }
75     return (&hb->host);
76 }
77 #endif
78 
79 /* find_inet_addr - find all addresses for this host, result to free() */
80 
81 #ifdef INET6
82 struct addrinfo *find_inet_addr(char *host)
83 {
84     struct addrinfo hints, *res;
85 
86     memset(&hints, 0, sizeof(hints));
87     hints.ai_family = PF_UNSPEC;
88     hints.ai_socktype = SOCK_STREAM;
89     hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;
90     if (getaddrinfo(host, NULL, &hints, &res) == 0)
91 	return (res);
92 
93     memset(&hints, 0, sizeof(hints));
94     hints.ai_family = PF_UNSPEC;
95     hints.ai_socktype = SOCK_STREAM;
96     hints.ai_flags = AI_PASSIVE | AI_CANONNAME;
97     if (getaddrinfo(host, NULL, &hints, &res) != 0) {
98 	tcpd_warn("%s: host not found", host);
99 	return (0);
100     }
101     if (res->ai_family != AF_INET6 && res->ai_family != AF_INET) {
102 	tcpd_warn("%d: not an internet host", res->ai_family);
103 	freeaddrinfo(res);
104 	return (0);
105     }
106     if (!res->ai_canonname) {
107 	tcpd_warn("%s: hostname alias", host);
108 	tcpd_warn("(cannot obtain official name)", res->ai_canonname);
109     } else if (STR_NE(host, res->ai_canonname)) {
110 	tcpd_warn("%s: hostname alias", host);
111 	tcpd_warn("(official name: %.*s)", STRING_LENGTH, res->ai_canonname);
112     }
113     return (res);
114 }
115 #else
116 struct hostent *find_inet_addr(char *host)
117 {
118     struct in_addr addr;
119     struct hostent *hp;
120     static struct hostent h;
121     static char *addr_list[2];
122 
123     /*
124      * Host address: translate it to internal form.
125      */
126     if ((addr.s_addr = dot_quad_addr(host)) != INADDR_NONE) {
127 	h.h_addr_list = addr_list;
128 	h.h_addr_list[0] = (char *) &addr;
129 	h.h_length = sizeof(addr);
130 	return (dup_hostent(&h));
131     }
132 
133     /*
134      * Map host name to a series of addresses. Watch out for non-internet
135      * forms or aliases. The NOT_INADDR() is here in case gethostbyname() has
136      * been "enhanced" to accept numeric addresses. Make a copy of the
137      * address list so that later gethostbyXXX() calls will not clobber it.
138      */
139     if (NOT_INADDR(host) == 0) {
140 	tcpd_warn("%s: not an internet address", host);
141 	return (0);
142     }
143     if ((hp = gethostbyname(host)) == 0) {
144 	tcpd_warn("%s: host not found", host);
145 	return (0);
146     }
147     if (hp->h_addrtype != AF_INET) {
148 	tcpd_warn("%d: not an internet host", hp->h_addrtype);
149 	return (0);
150     }
151     if (STR_NE(host, hp->h_name)) {
152 	tcpd_warn("%s: hostname alias", host);
153 	tcpd_warn("(official name: %.*s)", STRING_LENGTH, hp->h_name);
154     }
155     return (dup_hostent(hp));
156 }
157 #endif
158 
159 /* check_dns - give each address thorough workout, return address count */
160 
161 int     check_dns(char *host)
162 {
163     struct request_info request;
164 #ifdef INET6
165     struct sockaddr_storage sin;
166     struct addrinfo *hp, *res;
167 #else
168     struct sockaddr_in sin;
169     struct hostent *hp;
170 #endif
171     int     count;
172     char   *addr;
173 
174     if ((hp = find_inet_addr(host)) == 0)
175 	return (0);
176     request_init(&request, RQ_CLIENT_SIN, &sin, 0);
177     sock_methods(&request);
178 #ifndef INET6
179     memset((char *) &sin, 0, sizeof(sin));
180     sin.sin_family = AF_INET;
181 #endif
182 
183 #ifdef INET6
184     for (res = hp, count = 0; res; res = res->ai_next, count++) {
185 	memcpy(&sin, res->ai_addr, res->ai_addrlen);
186 #else
187     for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
188 	memcpy((char *) &sin.sin_addr, addr, sizeof(sin.sin_addr));
189 #endif
190 
191 	/*
192 	 * Force host name and address conversions. Use the request structure
193 	 * as a cache. Detect hostname lookup problems. Any name/name or
194 	 * name/address conflicts will be reported while eval_hostname() does
195 	 * its job.
196 	 */
197 	request_set(&request, RQ_CLIENT_ADDR, "", RQ_CLIENT_NAME, "", 0);
198 	if (STR_EQ(eval_hostname(request.client), unknown))
199 	    tcpd_warn("host address %s->name lookup failed",
200 		      eval_hostaddr(request.client));
201     }
202 #ifdef INET6
203     freeaddrinfo(hp);
204 #else
205     free((char *) hp);
206 #endif
207     return (count);
208 }
209 
210 /* dummy function to intercept the real shell_cmd() */
211 
212 /* ARGSUSED */
213 
214 void    shell_cmd(char *command)
215 {
216     if (hosts_access_verbose)
217 	printf("command: %s", command);
218 }
219 
220 /* dummy function  to intercept the real clean_exit() */
221 
222 /* ARGSUSED */
223 
224 void    clean_exit(struct request_info *request)
225 {
226     exit(0);
227 }
228 
229 /* check_path - examine accessibility */
230 
231 int     check_path(char *path, struct stat *st)
232 {
233     struct stat stbuf;
234     char    buf[BUFSIZ];
235 
236     if (stat(path, st) < 0)
237 	return (-1);
238 #ifdef notdef
239     if (st->st_uid != 0)
240 	tcpd_warn("%s: not owned by root", path);
241     if (st->st_mode & 020)
242 	tcpd_warn("%s: group writable", path);
243 #endif
244     if (st->st_mode & 002)
245 	tcpd_warn("%s: world writable", path);
246     if (path[0] == '/' && path[1] != 0) {
247 	strrchr(strcpy(buf, path), '/')[0] = 0;
248 	(void) check_path(buf[0] ? buf : "/", &stbuf);
249     }
250     return (0);
251 }
252