1 /*
2 * Copyright (c) 1997-2014 Erez Zadok
3 * Copyright (c) 1990 Jan-Simon Pendry
4 * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
5 * Copyright (c) 1990 The Regents of the University of California.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Jan-Simon Pendry at Imperial College, London.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 *
36 * File: am-utils/conf/transp/transp_sockets.c
37 *
38 * Socket specific utilities.
39 * -Erez Zadok <ezk@cs.columbia.edu>
40 */
41
42 #ifdef HAVE_CONFIG_H
43 # include <config.h>
44 #endif /* HAVE_CONFIG_H */
45 #include <am_defs.h>
46 #include <amu.h>
47
48
49 /*
50 * find the IP address that can be used to connect to the local host
51 */
52 void
amu_get_myaddress(struct in_addr * iap,const char * preferred_localhost)53 amu_get_myaddress(struct in_addr *iap, const char *preferred_localhost)
54 {
55 struct hostent *hp;
56 char dq[20];
57
58 #ifdef DEBUG_off
59 #error this code is old and probably not useful any longer.
60 #error Erez, Jan 21, 2004.
61 struct sockaddr_in sin;
62
63 /*
64 * Most modern systems should use 127.0.0.1 as the localhost address over
65 * which you can do NFS mounts. In the past we found that some NFS
66 * clients may not allow mounts from localhost. So we used
67 * get_myaddress() and that seemed to work. Alas, on some other systems,
68 * get_myaddress() may return one of the interface addresses at random,
69 * and thus use a less efficient IP address than 127.0.0.1. The solution
70 * is to hard-code 127.0.0.1, but still check if get_myaddress() returns a
71 * different value and warn about it.
72 */
73 memset((char *) &sin, 0, sizeof(sin));
74 get_myaddress(&sin);
75 if (sin.sin_addr.s_addr != htonl(INADDR_LOOPBACK))
76 dlog("amu_get_myaddress: myaddress conflict (0x%x vs. 0x%lx)",
77 sin.sin_addr.s_addr, (u_long) htonl(INADDR_LOOPBACK));
78 #endif /* DEBUG_off */
79
80 if (preferred_localhost == NULL)
81 goto out;
82
83 /* if specified preferred locahost, then try to use it */
84 hp = gethostbyname(preferred_localhost);
85 if (hp == NULL) {
86 /* XXX: if hstrerror()/h_errno aren't portable, then need to port the next statement */
87 plog(XLOG_ERROR, "Unable to resolve localhost_address \"%s\" (%s): using default",
88 preferred_localhost, hstrerror(h_errno));
89 goto out;
90 }
91 if (hp->h_addr_list == NULL) {
92 plog(XLOG_ERROR, "localhost_address \"%s\" has no IP addresses: using default",
93 preferred_localhost);
94 goto out;
95 }
96 if (hp->h_addr_list[1] != NULL) {
97 plog(XLOG_ERROR, "localhost_address \"%s\" has more than one IP addresses: using first",
98 preferred_localhost);
99 goto out;
100 }
101 memmove((voidp) &iap->s_addr, (voidp) hp->h_addr_list[0], sizeof(iap->s_addr));
102 plog(XLOG_INFO, "localhost_address \"%s\" requested, using %s",
103 preferred_localhost, inet_dquad(dq, sizeof(dq), iap->s_addr));
104 return;
105
106 out:
107 iap->s_addr = htonl(INADDR_LOOPBACK);
108 }
109
110
111 /*
112 * How to bind to reserved ports.
113 * Note: if *pp is non-null and is greater than 0, then *pp will not be modified.
114 */
115 int
bind_resv_port(int so,u_short * pp)116 bind_resv_port(int so, u_short *pp)
117 {
118 struct sockaddr_in sin;
119 int rc;
120 u_short port;
121
122 memset((voidp) &sin, 0, sizeof(sin));
123 sin.sin_family = AF_INET;
124
125 if (pp && *pp > 0) {
126 sin.sin_port = htons(*pp);
127 rc = bind(so, (struct sockaddr *) &sin, sizeof(sin));
128 } else {
129 port = IPPORT_RESERVED;
130
131 do {
132 --port;
133 sin.sin_port = htons(port);
134 rc = bind(so, (struct sockaddr *) &sin, sizeof(sin));
135 } while (rc < 0 && (int) port > IPPORT_RESERVED / 2);
136
137 if (pp && rc == 0)
138 *pp = port;
139 }
140
141 return rc;
142 }
143
144
145 /*
146 * close a descriptor, Sockets style
147 */
148 int
amu_close(int fd)149 amu_close(int fd)
150 {
151 return close(fd);
152 }
153
154
155 /*
156 * Create an rpc client attached to the mount daemon.
157 */
158 CLIENT *
get_mount_client(char * unused_host,struct sockaddr_in * sin,struct timeval * tv,int * sock,u_long mnt_version)159 get_mount_client(char *unused_host, struct sockaddr_in *sin, struct timeval *tv, int *sock, u_long mnt_version)
160 {
161 CLIENT *client;
162
163 /*
164 * First try a TCP socket
165 */
166 if ((*sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) > 0) {
167 /*
168 * Bind to a privileged port
169 */
170 if (bind_resv_port(*sock, (u_short *) NULL) < 0)
171 plog(XLOG_ERROR, "can't bind privileged port (socket)");
172
173 /*
174 * Find mountd port to connect to.
175 * Connect to mountd.
176 * Create a tcp client.
177 */
178 if ((sin->sin_port = htons(pmap_getport(sin, MOUNTPROG, mnt_version, IPPROTO_TCP))) != 0) {
179 if (connect(*sock, (struct sockaddr *) sin, sizeof(*sin)) >= 0
180 && ((client = clnttcp_create(sin, MOUNTPROG, mnt_version, sock, 0, 0)) != NULL))
181 return client;
182 }
183 /*
184 * Failed so close socket
185 */
186 (void) close(*sock);
187 } /* tcp socket opened */
188 /* TCP failed so try UDP */
189 if ((*sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
190 plog(XLOG_ERROR, "Can't create socket to connect to mountd: %m");
191 *sock = RPC_ANYSOCK;
192 return NULL;
193 }
194 /*
195 * Bind to a privileged port
196 */
197 if (bind_resv_port(*sock, (u_short *) NULL) < 0)
198 plog(XLOG_ERROR, "can't bind privileged port");
199
200 /*
201 * Zero out the port - make sure we recompute
202 */
203 sin->sin_port = 0;
204
205 /*
206 * Make a UDP client
207 */
208 if ((client = clntudp_create(sin, MOUNTPROG, mnt_version, *tv, sock)) == NULL) {
209 (void) close(*sock);
210 *sock = RPC_ANYSOCK;
211 return NULL;
212 }
213 dlog("get_mount_client: Using udp, port %d", sin->sin_port);
214 return client;
215 }
216
217
218 /*
219 * find the address of the caller of an RPC procedure.
220 */
221 struct sockaddr_in *
amu_svc_getcaller(SVCXPRT * xprt)222 amu_svc_getcaller(SVCXPRT *xprt)
223 {
224 /* glibc 2.2 returns a sockaddr_storage ??? */
225 return (struct sockaddr_in *) svc_getcaller(xprt);
226 }
227
228
229 /*
230 * Register an RPC server:
231 * return 1 on success, 0 otherwise.
232 */
233 int
amu_svc_register(SVCXPRT * xprt,u_long prognum,u_long versnum,void (* dispatch)(struct svc_req * rqstp,SVCXPRT * transp),u_long protocol,struct netconfig * dummy)234 amu_svc_register(SVCXPRT *xprt, u_long prognum, u_long versnum,
235 void (*dispatch)(struct svc_req *rqstp, SVCXPRT *transp),
236 u_long protocol, struct netconfig *dummy)
237 {
238 /* on Sockets: svc_register returns 1 on success, 0 otherwise */
239 return svc_register(xprt, prognum, versnum, dispatch, protocol);
240 }
241
242
243 /*
244 * Create the nfs service for amd
245 */
246 int
create_nfs_service(int * soNFSp,u_short * nfs_portp,SVCXPRT ** nfs_xprtp,void (* dispatch_fxn)(struct svc_req * rqstp,SVCXPRT * transp),u_long nfs_version)247 create_nfs_service(int *soNFSp, u_short *nfs_portp, SVCXPRT **nfs_xprtp, void (*dispatch_fxn)(struct svc_req *rqstp, SVCXPRT *transp), u_long nfs_version)
248 {
249 *soNFSp = socket(AF_INET, SOCK_DGRAM, 0);
250
251 if (*soNFSp < 0 || bind_resv_port(*soNFSp, nfs_portp) < 0) {
252 plog(XLOG_FATAL, "Can't create privileged nfs port (socket)");
253 if (*soNFSp >= 0)
254 close(*soNFSp);
255 return 1;
256 }
257 if ((*nfs_xprtp = svcudp_create(*soNFSp)) == NULL) {
258 plog(XLOG_FATAL, "cannot create rpc/udp service");
259 close(*soNFSp);
260 return 2;
261 }
262 if ((*nfs_portp = (*nfs_xprtp)->xp_port) >= IPPORT_RESERVED) {
263 plog(XLOG_FATAL, "Can't create privileged nfs port");
264 svc_destroy(*nfs_xprtp);
265 close(*soNFSp);
266 return 1;
267 }
268 if (!svc_register(*nfs_xprtp, NFS_PROGRAM, nfs_version, dispatch_fxn, 0)) {
269 plog(XLOG_FATAL, "unable to register (%lu, %lu, 0)",
270 (u_long) NFS_PROGRAM, nfs_version);
271 svc_destroy(*nfs_xprtp);
272 close(*soNFSp);
273 return 3;
274 }
275
276 return 0; /* all is well */
277 }
278
279
280 /*
281 * Create the amq service for amd (both TCP and UDP)
282 */
283 int
create_amq_service(int * udp_soAMQp,SVCXPRT ** udp_amqpp,struct netconfig ** dummy1,int * tcp_soAMQp,SVCXPRT ** tcp_amqpp,struct netconfig ** dummy2,u_short preferred_amq_port)284 create_amq_service(int *udp_soAMQp,
285 SVCXPRT **udp_amqpp,
286 struct netconfig **dummy1,
287 int *tcp_soAMQp,
288 SVCXPRT **tcp_amqpp,
289 struct netconfig **dummy2,
290 u_short preferred_amq_port)
291 {
292 /* first create TCP service */
293 if (tcp_soAMQp) {
294 *tcp_soAMQp = socket(AF_INET, SOCK_STREAM, 0);
295 if (*tcp_soAMQp < 0) {
296 plog(XLOG_FATAL, "cannot create tcp socket for amq service: %m");
297 return 1;
298 }
299
300 /* next, bind to a specific (TCP) port if asked for */
301 if (preferred_amq_port > 0) {
302 /*
303 * Note: if &preferred_amq_port is non-null and is greater than 0,
304 * then the pointer will not be modified. We don't want it to be
305 * modified because it was passed down to create_amq_service as a
306 * non-pointer (a variable on the stack, not to be modified!)
307 */
308 if (bind_resv_port(*tcp_soAMQp, &preferred_amq_port) < 0) {
309 plog(XLOG_FATAL, "can't bind amq service to requested TCP port %d: %m)", preferred_amq_port);
310 return 1;
311 }
312 }
313
314 /* now create RPC service handle for amq */
315 if (tcp_amqpp &&
316 (*tcp_amqpp = svctcp_create(*tcp_soAMQp, AMQ_SIZE, AMQ_SIZE)) == NULL) {
317 plog(XLOG_FATAL, "cannot create tcp service for amq: soAMQp=%d", *tcp_soAMQp);
318 return 1;
319 }
320
321 #ifdef SVCSET_CONNMAXREC
322 /*
323 * This is *BSD at its best.
324 * They just had to do things differently than everyone else
325 * so they fixed a library DoS issue by forcing client-side changes...
326 */
327 # ifndef RPC_MAXDATASIZE
328 # define RPC_MAXDATASIZE 9000
329 # endif /* not RPC_MAXDATASIZE */
330 if (tcp_amqpp) {
331 int maxrec = RPC_MAXDATASIZE;
332 SVC_CONTROL(*tcp_amqpp, SVCSET_CONNMAXREC, &maxrec);
333 }
334 #endif /* not SVCSET_CONNMAXREC */
335 }
336
337 /* next create UDP service */
338 if (udp_soAMQp) {
339 *udp_soAMQp = socket(AF_INET, SOCK_DGRAM, 0);
340 if (*udp_soAMQp < 0) {
341 plog(XLOG_FATAL, "cannot create udp socket for amq service: %m");
342 return 1;
343 }
344
345 /* next, bind to a specific (UDP) port if asked for */
346 if (preferred_amq_port > 0) {
347 /*
348 * Note: see comment about using &preferred_amq_port above in this
349 * function.
350 */
351 if (bind_resv_port(*udp_soAMQp, &preferred_amq_port) < 0) {
352 plog(XLOG_FATAL, "can't bind amq service to requested UDP port %d: %m)", preferred_amq_port);
353 return 1;
354 }
355 }
356
357 /* now create RPC service handle for amq */
358 if (udp_amqpp &&
359 (*udp_amqpp = svcudp_bufcreate(*udp_soAMQp, AMQ_SIZE, AMQ_SIZE)) == NULL) {
360 plog(XLOG_FATAL, "cannot create udp service for amq: soAMQp=%d", *udp_soAMQp);
361 return 1;
362 }
363 }
364
365 return 0; /* all is well */
366 }
367
368
369 /*
370 * Check if the portmapper is running and reachable: 0==down, 1==up
371 */
check_pmap_up(char * host,struct sockaddr_in * sin)372 int check_pmap_up(char *host, struct sockaddr_in* sin)
373 {
374 CLIENT *client;
375 enum clnt_stat clnt_stat = RPC_TIMEDOUT; /* assume failure */
376 int socket = RPC_ANYSOCK;
377 struct timeval timeout;
378
379 timeout.tv_sec = 2;
380 timeout.tv_usec = 0;
381 sin->sin_port = htons(PMAPPORT);
382 client = clntudp_create(sin, PMAPPROG, PMAPVERS, timeout, &socket);
383
384 if (client == (CLIENT *) NULL) {
385 plog(XLOG_ERROR,
386 "%s: cannot create connection to contact portmapper on host \"%s\"%s",
387 __func__, host, clnt_spcreateerror(""));
388 return 0;
389 }
390
391 timeout.tv_sec = 6;
392 /* Ping the portmapper on a remote system by calling the nullproc */
393 clnt_stat = clnt_call(client,
394 PMAPPROC_NULL,
395 (XDRPROC_T_TYPE) xdr_void,
396 NULL,
397 (XDRPROC_T_TYPE) xdr_void,
398 NULL,
399 timeout);
400 clnt_destroy(client);
401 close(socket);
402 sin->sin_port = 0;
403
404 if (clnt_stat == RPC_TIMEDOUT) {
405 plog(XLOG_ERROR,
406 "%s: failed to contact portmapper on host \"%s\": %s",
407 __func__, host, clnt_sperrno(clnt_stat));
408 return 0;
409 }
410 return 1;
411 }
412
413
414 /*
415 * Find the best NFS version for a host and protocol.
416 */
417 u_long
get_nfs_version(char * host,struct sockaddr_in * sin,u_long nfs_version,const char * proto,u_long def)418 get_nfs_version(char *host, struct sockaddr_in *sin, u_long nfs_version, const char *proto, u_long def)
419 {
420 CLIENT *clnt;
421 int again = 0;
422 enum clnt_stat clnt_stat;
423 struct timeval tv;
424 int sock;
425 char *errstr;
426
427 /*
428 * If not set or set wrong, then try from NFS_VERS_MAX on down. If
429 * set, then try from nfs_version on down.
430 */
431 if (!nfs_valid_version(nfs_version)) {
432 if (nfs_valid_version(def))
433 nfs_version = def;
434 else
435 nfs_version = NFS_VERS_MAX;
436 again = 1;
437 }
438 tv.tv_sec = 2; /* retry every 2 seconds, but also timeout */
439 tv.tv_usec = 0;
440
441 for (; nfs_version >= NFS_VERS_MIN; nfs_version--) {
442
443 sock = RPC_ANYSOCK;
444 errstr = NULL;
445 if (STREQ(proto, "tcp"))
446 clnt = clnttcp_create(sin, NFS_PROGRAM, nfs_version, &sock, 0, 0);
447 else if (STREQ(proto, "udp"))
448 clnt = clntudp_create(sin, NFS_PROGRAM, nfs_version, tv, &sock);
449 else
450 clnt = NULL;
451
452 if (clnt != NULL) {
453 /* Try three times (6/2=3) to verify the CLIENT handle. */
454 tv.tv_sec = 6;
455 clnt_stat = clnt_call(clnt,
456 NFSPROC_NULL,
457 (XDRPROC_T_TYPE) xdr_void,
458 0,
459 (XDRPROC_T_TYPE) xdr_void,
460 0,
461 tv);
462
463 if (clnt_stat != RPC_SUCCESS)
464 errstr = clnt_sperrno(clnt_stat);
465
466 close(sock);
467 clnt_destroy(clnt);
468 if (clnt_stat == RPC_SUCCESS)
469 break;
470 } else {
471 #ifdef HAVE_CLNT_SPCREATEERROR
472 errstr = clnt_spcreateerror("");
473 #else /* not HAVE_CLNT_SPCREATEERROR */
474 errstr = "";
475 #endif /* not HAVE_CLNT_SPCREATEERROR */
476 }
477
478 if (errstr) {
479 plog(XLOG_INFO, "%s: NFS(%lu,%s) failed for %s: %s", __func__,
480 nfs_version, proto, host, errstr);
481 }
482 }
483
484 if (nfs_version < NFS_VERS_MIN)
485 nfs_version = 0;
486
487 plog(XLOG_INFO, "%s: returning NFS(%lu,%s) on host %s", __func__,
488 nfs_version, proto, host);
489 return nfs_version;
490 }
491
492
493 #if defined(HAVE_FS_AUTOFS) && defined(AUTOFS_PROG)
494 /*
495 * Register the autofs service for amd
496 */
497 int
register_autofs_service(char * autofs_conftype,void (* autofs_dispatch)(struct svc_req * rqstp,SVCXPRT * transp))498 register_autofs_service(char *autofs_conftype, void (*autofs_dispatch)(struct svc_req *rqstp, SVCXPRT *transp))
499 {
500 int autofs_socket;
501 SVCXPRT *autofs_xprt = NULL;
502
503 autofs_socket = socket(AF_INET, SOCK_DGRAM, 0);
504
505 if (autofs_socket < 0 || bind_resv_port(autofs_socket, NULL) < 0) {
506 plog(XLOG_FATAL, "Can't create privileged autofs port (socket)");
507 return 1;
508 }
509 if ((autofs_xprt = svcudp_create(autofs_socket)) == NULL) {
510 plog(XLOG_FATAL, "Can't create autofs rpc/udp service");
511 return 2;
512 }
513 if (autofs_xprt->xp_port >= IPPORT_RESERVED) {
514 plog(XLOG_FATAL, "Can't create privileged autofs port");
515 return 1;
516 }
517 if (!svc_register(autofs_xprt, AUTOFS_PROG, AUTOFS_VERS, autofs_dispatch, 0)) {
518 plog(XLOG_FATAL, "unable to register (%ld, %ld, 0)",
519 (u_long) AUTOFS_PROG, (u_long) AUTOFS_VERS);
520 return 3;
521 }
522
523 return 0; /* all is well */
524 }
525
526
527 int
unregister_autofs_service(char * autofs_conftype)528 unregister_autofs_service(char *autofs_conftype)
529 {
530 svc_unregister(AUTOFS_PROG, AUTOFS_VERS);
531 return 0;
532 }
533 #endif /* HAVE_FS_AUTOFS && AUTOFS_PROG */
534