1 /* $NetBSD: security.c,v 1.5 2000/06/08 09:01:05 fvdl Exp $ */
2 /* $FreeBSD: src/usr.sbin/rpcbind/security.c,v 1.6 2002/12/16 22:24:26 mbr Exp $ */
3
4 #include <sys/types.h>
5 #include <sys/time.h>
6 #include <sys/socket.h>
7 #include <netinet/in.h>
8 #include <arpa/inet.h>
9 #include <rpc/rpc.h>
10 #include <rpc/rpcb_prot.h>
11 #include <rpc/pmap_prot.h>
12 #include <err.h>
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <string.h>
16 #include <unistd.h>
17 #include <libutil.h>
18 #include <syslog.h>
19 #include <netdb.h>
20
21 /*
22 * XXX for special case checks in check_callit.
23 */
24 #include <rpcsvc/mount.h>
25 #include <rpcsvc/rquota.h>
26 #include <rpcsvc/nfs_prot.h>
27 #include <rpcsvc/yp.h>
28 #include <rpcsvc/ypclnt.h>
29 #include <rpcsvc/yppasswd.h>
30
31 #include "rpcbind.h"
32
33 #ifdef LIBWRAP
34 # include <tcpd.h>
35 #ifndef LIBWRAP_ALLOW_FACILITY
36 # define LIBWRAP_ALLOW_FACILITY LOG_AUTH
37 #endif
38 #ifndef LIBWRAP_ALLOW_SEVERITY
39 # define LIBWRAP_ALLOW_SEVERITY LOG_INFO
40 #endif
41 #ifndef LIBWRAP_DENY_FACILITY
42 # define LIBWRAP_DENY_FACILITY LOG_AUTH
43 #endif
44 #ifndef LIBWRAP_DENY_SEVERITY
45 # define LIBWRAP_DENY_SEVERITY LOG_WARNING
46 #endif
47 int allow_severity = LIBWRAP_ALLOW_FACILITY|LIBWRAP_ALLOW_SEVERITY;
48 int deny_severity = LIBWRAP_DENY_FACILITY|LIBWRAP_DENY_SEVERITY;
49 #endif
50
51 #ifndef PORTMAP_LOG_FACILITY
52 # define PORTMAP_LOG_FACILITY LOG_AUTH
53 #endif
54 #ifndef PORTMAP_LOG_SEVERITY
55 # define PORTMAP_LOG_SEVERITY LOG_INFO
56 #endif
57 int log_severity = PORTMAP_LOG_FACILITY|PORTMAP_LOG_SEVERITY;
58
59 extern int verboselog;
60
61 int
check_access(SVCXPRT * xprt,rpcproc_t proc,void * args,unsigned int rpcbvers)62 check_access(SVCXPRT *xprt, rpcproc_t proc, void *args, unsigned int rpcbvers)
63 {
64 struct netbuf *caller = svc_getrpccaller(xprt);
65 struct sockaddr *addr = (struct sockaddr *)caller->buf;
66 #ifdef LIBWRAP
67 struct request_info req;
68 #endif
69 rpcprog_t prog = 0;
70 rpcb *rpcbp;
71 struct pmap *pmap;
72
73 /*
74 * The older PMAP_* equivalents have the same numbers, so
75 * they are accounted for here as well.
76 */
77 switch (proc) {
78 case RPCBPROC_GETADDR:
79 case RPCBPROC_SET:
80 case RPCBPROC_UNSET:
81 if (rpcbvers > PMAPVERS) {
82 rpcbp = (rpcb *)args;
83 prog = rpcbp->r_prog;
84 } else {
85 pmap = (struct pmap *)args;
86 prog = pmap->pm_prog;
87 }
88 if (proc == RPCBPROC_GETADDR)
89 break;
90 if (!insecure && !is_loopback(caller)) {
91 if (verboselog)
92 logit(log_severity, addr, proc, prog,
93 " declined (non-loopback sender)");
94 return 0;
95 }
96 break;
97 case RPCBPROC_CALLIT:
98 case RPCBPROC_INDIRECT:
99 case RPCBPROC_DUMP:
100 case RPCBPROC_GETTIME:
101 case RPCBPROC_UADDR2TADDR:
102 case RPCBPROC_TADDR2UADDR:
103 case RPCBPROC_GETVERSADDR:
104 case RPCBPROC_GETADDRLIST:
105 case RPCBPROC_GETSTAT:
106 default:
107 break;
108 }
109
110 #ifdef LIBWRAP
111 if (addr->sa_family == AF_LOCAL)
112 return 1;
113 request_init(&req, RQ_DAEMON, "rpcbind", RQ_CLIENT_SIN, addr, 0);
114 sock_methods(&req);
115 if(!hosts_access(&req)) {
116 logit(deny_severity, addr, proc, prog, ": request from unauthorized host");
117 return 0;
118 }
119 #endif
120 if (verboselog)
121 logit(log_severity, addr, proc, prog, "");
122 return 1;
123 }
124
125 int
is_loopback(struct netbuf * nbuf)126 is_loopback(struct netbuf *nbuf)
127 {
128 struct sockaddr *addr = (struct sockaddr *)nbuf->buf;
129 struct sockaddr_in *sin;
130 #ifdef INET6
131 struct sockaddr_in6 *sin6;
132 #endif
133
134 switch (addr->sa_family) {
135 case AF_INET:
136 if (!oldstyle_local)
137 return 0;
138 sin = (struct sockaddr_in *)addr;
139 return ((sin->sin_addr.s_addr == htonl(INADDR_LOOPBACK)) &&
140 (ntohs(sin->sin_port) < IPPORT_RESERVED));
141 #ifdef INET6
142 case AF_INET6:
143 if (!oldstyle_local)
144 return 0;
145 sin6 = (struct sockaddr_in6 *)addr;
146 return (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr) &&
147 (ntohs(sin6->sin6_port) < IPV6PORT_RESERVED));
148 #endif
149 case AF_LOCAL:
150 return 1;
151 default:
152 break;
153 }
154
155 return 0;
156 }
157
158
159 /* logit - report events of interest via the syslog daemon */
160 void
logit(int severity,struct sockaddr * addr,rpcproc_t procnum,rpcprog_t prognum,const char * text)161 logit(int severity, struct sockaddr *addr, rpcproc_t procnum, rpcprog_t prognum,
162 const char *text)
163 {
164 const char *procname;
165 char procbuf[32];
166 char *progname;
167 char progbuf[32];
168 char fromname[NI_MAXHOST];
169 struct rpcent *rpc;
170 static const char *procmap[] = {
171 /* RPCBPROC_NULL */ "null",
172 /* RPCBPROC_SET */ "set",
173 /* RPCBPROC_UNSET */ "unset",
174 /* RPCBPROC_GETADDR */ "getport/addr",
175 /* RPCBPROC_DUMP */ "dump",
176 /* RPCBPROC_CALLIT */ "callit",
177 /* RPCBPROC_GETTIME */ "gettime",
178 /* RPCBPROC_UADDR2TADDR */ "uaddr2taddr",
179 /* RPCBPROC_TADDR2UADDR */ "taddr2uaddr",
180 /* RPCBPROC_GETVERSADDR */ "getversaddr",
181 /* RPCBPROC_INDIRECT */ "indirect",
182 /* RPCBPROC_GETADDRLIST */ "getaddrlist",
183 /* RPCBPROC_GETSTAT */ "getstat"
184 };
185
186 /*
187 * Fork off a process or the portmap daemon might hang while
188 * getrpcbynumber() or syslog() does its thing.
189 */
190
191 if (fork() == 0) {
192 setproctitle("logit");
193
194 /* Try to map program number to name. */
195
196 if (prognum == 0) {
197 progname = "";
198 } else if ((rpc = getrpcbynumber((int) prognum))) {
199 progname = rpc->r_name;
200 } else {
201 snprintf(progname = progbuf, sizeof(progbuf), "%u",
202 (unsigned)prognum);
203 }
204
205 /* Try to map procedure number to name. */
206
207 if (procnum >= (sizeof procmap / sizeof (char *))) {
208 snprintf(procbuf, sizeof procbuf, "%u",
209 (unsigned)procnum);
210 procname = procbuf;
211 } else
212 procname = procmap[procnum];
213
214 /* Write syslog record. */
215
216 if (addr->sa_family == AF_LOCAL)
217 strcpy(fromname, "local");
218 else
219 getnameinfo(addr, addr->sa_len, fromname,
220 sizeof fromname, NULL, 0, NI_NUMERICHOST);
221
222 syslog(severity, "connect from %s to %s(%s)%s",
223 fromname, procname, progname, text);
224 _exit(0);
225 }
226 }
227
228 int
check_callit(SVCXPRT * xprt,struct r_rmtcall_args * args,int versnum __unused)229 check_callit(SVCXPRT *xprt, struct r_rmtcall_args *args, int versnum __unused)
230 {
231 struct sockaddr *sa = (struct sockaddr *)svc_getrpccaller(xprt)->buf;
232
233 /*
234 * Always allow calling NULLPROC
235 */
236 if (args->rmt_proc == 0)
237 return 1;
238
239 /*
240 * XXX - this special casing sucks.
241 */
242 switch (args->rmt_prog) {
243 case RPCBPROG:
244 /*
245 * Allow indirect calls to ourselves in insecure mode.
246 * The is_loopback checks aren't useful then anyway.
247 */
248 if (!insecure)
249 goto deny;
250 break;
251 case MOUNTPROG:
252 if (args->rmt_proc != MOUNTPROC_MNT &&
253 args->rmt_proc != MOUNTPROC_UMNT)
254 break;
255 goto deny;
256 case YPBINDPROG:
257 if (args->rmt_proc != YPBINDPROC_SETDOM)
258 break;
259 /* FALLTHROUGH */
260 case YPPASSWDPROG:
261 case NFS_PROGRAM:
262 case RQUOTAPROG:
263 goto deny;
264 case YPPROG:
265 switch (args->rmt_proc) {
266 case YPPROC_ALL:
267 case YPPROC_MATCH:
268 case YPPROC_FIRST:
269 case YPPROC_NEXT:
270 goto deny;
271 default:
272 break;
273 }
274 default:
275 break;
276 }
277
278 return 1;
279 deny:
280 #ifdef LIBWRAP
281 logit(deny_severity, sa, args->rmt_proc, args->rmt_prog,
282 ": indirect call not allowed");
283 #else
284 logit(0, sa, args->rmt_proc, args->rmt_prog,
285 ": indirect call not allowed");
286 #endif
287 return 0;
288 }
289