xref: /freebsd/usr.sbin/nfscbd/nfscbd.c (revision 0bc7cf6fde4083c1a0cdf29b26075699028909e0)
1 /*-
2  * Copyright (c) 2009 Rick Macklem, University of Guelph
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/ioctl.h>
33 #include <sys/linker.h>
34 #include <sys/module.h>
35 #include <sys/mount.h>
36 #include <sys/socket.h>
37 #include <sys/socketvar.h>
38 #include <sys/stat.h>
39 #include <sys/ucred.h>
40 #include <sys/uio.h>
41 #include <sys/vnode.h>
42 #include <sys/wait.h>
43 
44 #include <nfs/nfssvc.h>
45 
46 #include <rpc/rpc.h>
47 
48 #include <fs/nfs/rpcv2.h>
49 #include <fs/nfs/nfsproto.h>
50 #include <fs/nfs/nfskpiport.h>
51 #include <fs/nfs/nfs.h>
52 
53 #include <err.h>
54 #include <errno.h>
55 #include <fcntl.h>
56 #include <grp.h>
57 #include <netdb.h>
58 #include <pwd.h>
59 #include <signal.h>
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <string.h>
63 #include <syslog.h>
64 #include <unistd.h>
65 
66 /* Global defs */
67 #ifdef DEBUG
68 #define	syslog(e, s)	fprintf(stderr,(s))
69 int	debug = 1;
70 #else
71 int	debug = 0;
72 #endif
73 
74 pid_t children;
75 
76 static void	nonfs(int);
77 static void	reapchild(int);
78 static void	usage(void);
79 static void	cleanup(int);
80 static void	child_cleanup(int);
81 static void	nfscbd_exit(int);
82 static void	killchildren(void);
83 
84 /*
85  * Nfs callback server daemon.
86  *
87  * 1 - do file descriptor and signal cleanup
88  * 2 - fork the nfscbd(s)
89  * 4 - create callback server socket(s)
90  * 5 - set up server socket for rpc
91  *
92  * For connectionless protocols, just pass the socket into the kernel via.
93  * nfssvc().
94  * For connection based sockets, loop doing accepts. When you get a new
95  * socket from accept, pass the msgsock into the kernel via. nfssvc().
96  */
97 int
98 main(int argc, char *argv[])
99 {
100 	struct nfscbd_args nfscbdargs;
101 	struct nfsd_nfscbd_args nfscbdargs2;
102 	struct sockaddr_in inetaddr, inetpeer;
103 	fd_set ready, sockbits;
104 	int ch, connect_type_cnt, len, maxsock, msgsock, error;
105 	int nfssvc_flag, on, sock, tcpsock, ret, mustfreeai = 0;
106 	char *cp, princname[128];
107 	char myname[MAXHOSTNAMELEN], *myfqdnname = NULL;
108 	struct addrinfo *aip, hints;
109 	pid_t pid;
110 	short myport = NFSV4_CBPORT;
111 
112 	if (modfind("nfscl") < 0) {
113 		/* Not present in kernel, try loading it */
114 		if (kldload("nfscl") < 0 ||
115 		    modfind("nfscl") < 0)
116 			errx(1, "nfscl is not available");
117 	}
118 	/*
119 	 * First, get our fully qualified host name, if possible.
120 	 */
121 	if (gethostname(myname, MAXHOSTNAMELEN) >= 0) {
122 		cp = strchr(myname, '.');
123 		if (cp != NULL && *(cp + 1) != '\0') {
124 			cp = myname;
125 		} else {
126 			/*
127 			 * No domain on myname, so try looking it up.
128 			 */
129 			cp = NULL;
130 			memset((void *)&hints, 0, sizeof (hints));
131 			hints.ai_flags = AI_CANONNAME;
132 			error = getaddrinfo(myname, NULL, &hints, &aip);
133 			if (error == 0) {
134 			    if (aip->ai_canonname != NULL &&
135 				(cp = strchr(aip->ai_canonname, '.')) != NULL
136 				&& *(cp + 1) != '\0') {
137 				    cp = aip->ai_canonname;
138 				    mustfreeai = 1;
139 			    } else {
140 				    freeaddrinfo(aip);
141 			    }
142 			}
143 		}
144 		if (cp == NULL)
145 			warnx("Can't get fully qualified host name");
146 		myfqdnname = cp;
147 	}
148 
149 	princname[0] = '\0';
150 #define	GETOPT	"p:P:"
151 #define	USAGE	"[ -p port_num ] [ -P client_principal ]"
152 	while ((ch = getopt(argc, argv, GETOPT)) != -1)
153 		switch (ch) {
154 		case 'p':
155 			myport = atoi(optarg);
156 			if (myport < 1) {
157 				warnx("port# non-positive, reset to %d",
158 				    NFSV4_CBPORT);
159 				myport = NFSV4_CBPORT;
160 			}
161 			break;
162 		case 'P':
163 			cp = optarg;
164 			if (cp != NULL && strlen(cp) > 0 &&
165 			    strlen(cp) < sizeof (princname)) {
166 				if (strchr(cp, '@') == NULL &&
167 				    myfqdnname != NULL)
168 					snprintf(princname, sizeof (princname),
169 					    "%s@%s", cp, myfqdnname);
170 				else
171 					strlcpy(princname, cp,
172 					    sizeof (princname));
173 			} else {
174 				warnx("client princ invalid. ignored\n");
175 			}
176 			break;
177 		default:
178 		case '?':
179 			usage();
180 		};
181 	argv += optind;
182 	argc -= optind;
183 
184 	if (argc > 0)
185 		usage();
186 
187 	if (mustfreeai)
188 		freeaddrinfo(aip);
189 	nfscbdargs2.principal = (const char *)princname;
190 	if (debug == 0) {
191 		daemon(0, 0);
192 		(void)signal(SIGTERM, SIG_IGN);
193 		(void)signal(SIGHUP, SIG_IGN);
194 		(void)signal(SIGINT, SIG_IGN);
195 		(void)signal(SIGQUIT, SIG_IGN);
196 	}
197 	(void)signal(SIGSYS, nonfs);
198 	(void)signal(SIGCHLD, reapchild);
199 
200 	openlog("nfscbd:", LOG_PID, LOG_DAEMON);
201 
202 	pid = fork();
203 	if (pid < 0) {
204 		syslog(LOG_ERR, "fork: %m");
205 		nfscbd_exit(1);
206 	} else if (pid > 0) {
207 		children = pid;
208 	} else {
209 		(void)signal(SIGUSR1, child_cleanup);
210 		setproctitle("server");
211 		nfssvc_flag = NFSSVC_NFSCBD;
212 		if (nfssvc(nfssvc_flag, &nfscbdargs2) < 0) {
213 			syslog(LOG_ERR, "nfssvc: %m");
214 			nfscbd_exit(1);
215 		}
216 		exit(0);
217 	}
218 	(void)signal(SIGUSR1, cleanup);
219 
220 	if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
221 		syslog(LOG_ERR, "can't create udp socket");
222 		nfscbd_exit(1);
223 	}
224 	memset(&inetaddr, 0, sizeof inetaddr);
225 	inetaddr.sin_family = AF_INET;
226 	inetaddr.sin_addr.s_addr = INADDR_ANY;
227 	inetaddr.sin_port = htons(myport);
228 	inetaddr.sin_len = sizeof(inetaddr);
229 	ret = bind(sock, (struct sockaddr *)&inetaddr, sizeof(inetaddr));
230 	/* If bind() fails, this is a restart, so just skip UDP. */
231 	if (ret == 0) {
232 		len = sizeof(inetaddr);
233 		if (getsockname(sock, (struct sockaddr *)&inetaddr, &len) < 0){
234 			syslog(LOG_ERR, "can't get bound addr");
235 			nfscbd_exit(1);
236 		}
237 		nfscbdargs.port = ntohs(inetaddr.sin_port);
238 		if (nfscbdargs.port != myport) {
239 			syslog(LOG_ERR, "BAD PORT#");
240 			nfscbd_exit(1);
241 		}
242 		nfscbdargs.sock = sock;
243 		nfscbdargs.name = NULL;
244 		nfscbdargs.namelen = 0;
245 		if (nfssvc(NFSSVC_CBADDSOCK, &nfscbdargs) < 0) {
246 			syslog(LOG_ERR, "can't Add UDP socket");
247 			nfscbd_exit(1);
248 		}
249 	}
250 	(void)close(sock);
251 
252 	/* Now set up the master server socket waiting for tcp connections. */
253 	on = 1;
254 	FD_ZERO(&sockbits);
255 	connect_type_cnt = 0;
256 	if ((tcpsock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
257 		syslog(LOG_ERR, "can't create tcp socket");
258 		nfscbd_exit(1);
259 	}
260 	if (setsockopt(tcpsock,
261 	    SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on)) < 0)
262 		syslog(LOG_ERR, "setsockopt SO_REUSEADDR: %m");
263 	/* sin_port is already set */
264 	inetaddr.sin_family = AF_INET;
265 	inetaddr.sin_addr.s_addr = INADDR_ANY;
266 	inetaddr.sin_port = htons(myport);
267 	inetaddr.sin_len = sizeof(inetaddr);
268 	if (bind(tcpsock,
269 	    (struct sockaddr *)&inetaddr, sizeof (inetaddr)) < 0) {
270 		syslog(LOG_ERR, "can't bind tcp addr");
271 		nfscbd_exit(1);
272 	}
273 	if (listen(tcpsock, 5) < 0) {
274 		syslog(LOG_ERR, "listen failed");
275 		nfscbd_exit(1);
276 	}
277 	FD_SET(tcpsock, &sockbits);
278 	maxsock = tcpsock;
279 	connect_type_cnt++;
280 
281 	setproctitle("master");
282 
283 	/*
284 	 * Loop forever accepting connections and passing the sockets
285 	 * into the kernel for the mounts.
286 	 */
287 	for (;;) {
288 		ready = sockbits;
289 		if (connect_type_cnt > 1) {
290 			if (select(maxsock + 1,
291 			    &ready, NULL, NULL, NULL) < 1) {
292 				syslog(LOG_ERR, "select failed: %m");
293 				nfscbd_exit(1);
294 			}
295 		}
296 		if (FD_ISSET(tcpsock, &ready)) {
297 			len = sizeof(inetpeer);
298 			if ((msgsock = accept(tcpsock,
299 			    (struct sockaddr *)&inetpeer, &len)) < 0) {
300 				syslog(LOG_ERR, "accept failed: %m");
301 				nfscbd_exit(1);
302 			}
303 			memset(inetpeer.sin_zero, 0,
304 			    sizeof (inetpeer.sin_zero));
305 			if (setsockopt(msgsock, SOL_SOCKET,
306 			    SO_KEEPALIVE, (char *)&on, sizeof(on)) < 0)
307 				syslog(LOG_ERR,
308 				    "setsockopt SO_KEEPALIVE: %m");
309 			nfscbdargs.sock = msgsock;
310 			nfscbdargs.name = (caddr_t)&inetpeer;
311 			nfscbdargs.namelen = sizeof(inetpeer);
312 			nfssvc(NFSSVC_CBADDSOCK, &nfscbdargs);
313 			(void)close(msgsock);
314 		}
315 	}
316 }
317 
318 static void
319 usage(void)
320 {
321 
322 	errx(1, "usage: nfscbd %s", USAGE);
323 }
324 
325 static void
326 nonfs(int signo __unused)
327 {
328 	syslog(LOG_ERR, "missing system call: NFS not available");
329 }
330 
331 static void
332 reapchild(int signo __unused)
333 {
334 	pid_t pid;
335 
336 	while ((pid = wait3(NULL, WNOHANG, NULL)) > 0) {
337 		if (pid == children)
338 			children = -1;
339 	}
340 }
341 
342 static void
343 killchildren(void)
344 {
345 
346 	if (children > 0)
347 		kill(children, SIGKILL);
348 }
349 
350 /*
351  * Cleanup master after SIGUSR1.
352  */
353 static void
354 cleanup(int signo __unused)
355 {
356 	nfscbd_exit(0);
357 }
358 
359 /*
360  * Cleanup child after SIGUSR1.
361  */
362 static void
363 child_cleanup(int signo __unused)
364 {
365 	exit(0);
366 }
367 
368 static void
369 nfscbd_exit(int status __unused)
370 {
371 	killchildren();
372 	exit(status);
373 }
374