xref: /freebsd/contrib/tcp_wrappers/scaffold.c (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
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(hp)
47 struct hostent *hp;
48 {
49     struct hostent_block {
50 	struct hostent host;
51 	char   *addr_list[1];
52     };
53     struct hostent_block *hb;
54     int     count;
55     char   *data;
56     char   *addr;
57 
58     for (count = 0; hp->h_addr_list[count] != 0; count++)
59 	 /* void */ ;
60 
61     if ((hb = (struct hostent_block *) malloc(sizeof(struct hostent_block)
62 			 + (hp->h_length + sizeof(char *)) * count)) == 0) {
63 	fprintf(stderr, "Sorry, out of memory\n");
64 	exit(1);
65     }
66     memset((char *) &hb->host, 0, sizeof(hb->host));
67     hb->host.h_length = hp->h_length;
68     hb->host.h_addr_list = hb->addr_list;
69     hb->host.h_addr_list[count] = 0;
70     data = (char *) (hb->host.h_addr_list + count + 1);
71 
72     for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
73 	hb->host.h_addr_list[count] = data + hp->h_length * count;
74 	memcpy(hb->host.h_addr_list[count], addr, hp->h_length);
75     }
76     return (&hb->host);
77 }
78 #endif
79 
80 /* find_inet_addr - find all addresses for this host, result to free() */
81 
82 #ifdef INET6
83 struct addrinfo *find_inet_addr(host)
84 char   *host;
85 {
86     struct addrinfo hints, *res;
87 
88     memset(&hints, 0, sizeof(hints));
89     hints.ai_family = PF_UNSPEC;
90     hints.ai_socktype = SOCK_STREAM;
91     hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;
92     if (getaddrinfo(host, NULL, &hints, &res) == 0)
93 	return (res);
94 
95     memset(&hints, 0, sizeof(hints));
96     hints.ai_family = PF_UNSPEC;
97     hints.ai_socktype = SOCK_STREAM;
98     hints.ai_flags = AI_PASSIVE | AI_CANONNAME;
99     if (getaddrinfo(host, NULL, &hints, &res) != 0) {
100 	tcpd_warn("%s: host not found", host);
101 	return (0);
102     }
103     if (res->ai_family != AF_INET6 && res->ai_family != AF_INET) {
104 	tcpd_warn("%d: not an internet host", res->ai_family);
105 	freeaddrinfo(res);
106 	return (0);
107     }
108     if (!res->ai_canonname) {
109 	tcpd_warn("%s: hostname alias", host);
110 	tcpd_warn("(cannot obtain official name)", res->ai_canonname);
111     } else if (STR_NE(host, res->ai_canonname)) {
112 	tcpd_warn("%s: hostname alias", host);
113 	tcpd_warn("(official name: %.*s)", STRING_LENGTH, res->ai_canonname);
114     }
115     return (res);
116 }
117 #else
118 struct hostent *find_inet_addr(host)
119 char   *host;
120 {
121     struct in_addr addr;
122     struct hostent *hp;
123     static struct hostent h;
124     static char *addr_list[2];
125 
126     /*
127      * Host address: translate it to internal form.
128      */
129     if ((addr.s_addr = dot_quad_addr(host)) != INADDR_NONE) {
130 	h.h_addr_list = addr_list;
131 	h.h_addr_list[0] = (char *) &addr;
132 	h.h_length = sizeof(addr);
133 	return (dup_hostent(&h));
134     }
135 
136     /*
137      * Map host name to a series of addresses. Watch out for non-internet
138      * forms or aliases. The NOT_INADDR() is here in case gethostbyname() has
139      * been "enhanced" to accept numeric addresses. Make a copy of the
140      * address list so that later gethostbyXXX() calls will not clobber it.
141      */
142     if (NOT_INADDR(host) == 0) {
143 	tcpd_warn("%s: not an internet address", host);
144 	return (0);
145     }
146     if ((hp = gethostbyname(host)) == 0) {
147 	tcpd_warn("%s: host not found", host);
148 	return (0);
149     }
150     if (hp->h_addrtype != AF_INET) {
151 	tcpd_warn("%d: not an internet host", hp->h_addrtype);
152 	return (0);
153     }
154     if (STR_NE(host, hp->h_name)) {
155 	tcpd_warn("%s: hostname alias", host);
156 	tcpd_warn("(official name: %.*s)", STRING_LENGTH, hp->h_name);
157     }
158     return (dup_hostent(hp));
159 }
160 #endif
161 
162 /* check_dns - give each address thorough workout, return address count */
163 
164 int     check_dns(host)
165 char   *host;
166 {
167     struct request_info request;
168 #ifdef INET6
169     struct sockaddr_storage sin;
170     struct addrinfo *hp, *res;
171 #else
172     struct sockaddr_in sin;
173     struct hostent *hp;
174 #endif
175     int     count;
176     char   *addr;
177 
178     if ((hp = find_inet_addr(host)) == 0)
179 	return (0);
180     request_init(&request, RQ_CLIENT_SIN, &sin, 0);
181     sock_methods(&request);
182 #ifndef INET6
183     memset((char *) &sin, 0, sizeof(sin));
184     sin.sin_family = AF_INET;
185 #endif
186 
187 #ifdef INET6
188     for (res = hp, count = 0; res; res = res->ai_next, count++) {
189 	memcpy(&sin, res->ai_addr, res->ai_addrlen);
190 #else
191     for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
192 	memcpy((char *) &sin.sin_addr, addr, sizeof(sin.sin_addr));
193 #endif
194 
195 	/*
196 	 * Force host name and address conversions. Use the request structure
197 	 * as a cache. Detect hostname lookup problems. Any name/name or
198 	 * name/address conflicts will be reported while eval_hostname() does
199 	 * its job.
200 	 */
201 	request_set(&request, RQ_CLIENT_ADDR, "", RQ_CLIENT_NAME, "", 0);
202 	if (STR_EQ(eval_hostname(request.client), unknown))
203 	    tcpd_warn("host address %s->name lookup failed",
204 		      eval_hostaddr(request.client));
205     }
206 #ifdef INET6
207     freeaddrinfo(hp);
208 #else
209     free((char *) hp);
210 #endif
211     return (count);
212 }
213 
214 /* dummy function to intercept the real shell_cmd() */
215 
216 /* ARGSUSED */
217 
218 void    shell_cmd(command)
219 char   *command;
220 {
221     if (hosts_access_verbose)
222 	printf("command: %s", command);
223 }
224 
225 /* dummy function  to intercept the real clean_exit() */
226 
227 /* ARGSUSED */
228 
229 void    clean_exit(request)
230 struct request_info *request;
231 {
232     exit(0);
233 }
234 
235 /* check_path - examine accessibility */
236 
237 int     check_path(path, st)
238 char   *path;
239 struct stat *st;
240 {
241     struct stat stbuf;
242     char    buf[BUFSIZ];
243 
244     if (stat(path, st) < 0)
245 	return (-1);
246 #ifdef notdef
247     if (st->st_uid != 0)
248 	tcpd_warn("%s: not owned by root", path);
249     if (st->st_mode & 020)
250 	tcpd_warn("%s: group writable", path);
251 #endif
252     if (st->st_mode & 002)
253 	tcpd_warn("%s: world writable", path);
254     if (path[0] == '/' && path[1] != 0) {
255 	strrchr(strcpy(buf, path), '/')[0] = 0;
256 	(void) check_path(buf[0] ? buf : "/", &stbuf);
257     }
258     return (0);
259 }
260