xref: /illumos-gate/usr/src/cmd/setuname/setuname.c (revision d1b7cae3)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
22 /*	  All Rights Reserved  	*/
23 
24 
25 /*
26  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 /*
31  * Copyright (c) 2018, Joyent, Inc.
32  */
33 
34 /*
35  *  setuname [-t] [-s name] [-n node]
36  */
37 
38 /*
39  *  Header files referenced:
40  *	<stdio.h>	Standard I/O
41  *	<unistd.h>	Standard UNIX definitions
42  *	<string.h>	String handling
43  *	<fmtmsg.h>	Standard message generation
44  *	<ctype.h>	Character types
45  *	<errno.h>	Error handling
46  *	<signal.h>	Signal handling
47  *	<sys/types.h>	Data types
48  *	<sys/fcntl.h>	File control
49  *	<sys/utsname.h>	System Name
50  *	<sys/sys3b.h>	sys3b() definitions
51  *	<nlist.h>	Definitions for Sun symbol table entries
52  */
53 
54 #include	<stdio.h>
55 #include	<unistd.h>
56 #include	<string.h>
57 #include	<fmtmsg.h>
58 #include	<ctype.h>
59 #include	<errno.h>
60 #include	<signal.h>
61 #include	<sys/types.h>
62 #include	<sys/uio.h>
63 #include	<sys/fcntl.h>
64 #include	<sys/psw.h>
65 #include	<sys/utsname.h>
66 
67 #if u3b || u3b15 || u3b2
68 #include	<sys/sys3b.h>
69 #endif
70 
71 #if sun
72 #include	<nlist.h>
73 #include	<kvm.h>
74 #endif
75 
76 /*
77  * Externals referenced (and not defined in a header)
78  *	optind		index to the next arg for getopt()
79  *	opterr		FLAG, TRUE tells getopt() to write messages
80  *	optarg		Ptr to an option's argument
81  *	getopt()	Gets an option from the command line
82  *	putenv()	Writes values into the environment
83  *	exit()		Exit the process
84  *	access()	Check accessibility of a file
85  *	malloc()	Allocate a block of main memory
86  *	free()		Free allocated space
87  *	lseek()		Seek within a file
88  *	open()		Open a file
89  *	close()		Close an open file
90  */
91 
92 extern	int		optind;		/* argv[] index of next arg */
93 extern	int		opterr;		/* TRUE if getopt() is to print msgs */
94 extern	char	       *optarg;		/* Argument to parsed option */
95 extern	int		getopt();	/* Get an option from the command line */
96 extern	int	       	putenv();	/* Put a value into the environment */
97 extern	void		exit();		/* Exit the process */
98 extern	int		access();	/* Check the accessibility of a file */
99 extern	void	       *malloc();	/* Get a chunk of main memory */
100 extern	void		free();		/* Free alloc'd space */
101 extern	long		lseek();	/* Seek within a file */
102 extern	int		open();		/* Open a file */
103 extern	int		close();	/* Close an open a file */
104 
105 /*
106  *  L O C A L   D E F I N I T I O N S
107  */
108 
109 /*
110  * Constants
111  */
112 
113 #ifndef	TRUE
114 #define	TRUE		(1)
115 #endif
116 
117 #ifndef	FALSE
118 #define	FALSE		(0)
119 #endif
120 
121 #ifndef	NULL
122 #define	NULL		(0)
123 #endif
124 
125 #define	OPTSTRING	"tn:s:"
126 
127 #define	EX_OK		0
128 #define	EX_ERROR	1
129 
130 #define	RC_FILENAME	"/etc/rc2.d/S18setuname"
131 #define RC_DIRNAME	"/etc/rc2.d"
132 
133 
134 /*
135  *  Messages
136  */
137 
138 #define	E_USAGE		"usage: setuname [-t] [-s name] [-n node]"
139 #define	E_MISSING	"Either -s name or -n node must be specified"
140 #define	E_UNAME		"Unable to get existing uname values"
141 #define E_INVNAME	"System-name invalid: %s"
142 #define E_LONGNAME	"System-name too long: %s"
143 #define E_INVNODE	"Network node-name invalid: %s"
144 #define E_LONGNODE	"Network node-name too long: %s"
145 #define E_NOPERMS	"No permissions, request denied"
146 #define E_NOSUCHDIR	"Directory doesn't exist: %s"
147 #define	E_INTERNAL	"Internal error: %d"
148 
149 /*
150  * Macros:
151  *	stdmsg(r,l,s,t)	    Write a standard message.
152  *				'r' is the recoverability flag
153  *				'l' is the label
154  *				's' is the severity
155  *				't' is the text.
156  *	strend(p)	    Return the address of the end of a string
157  *			    (This is supposed to be defined in <sys/inline.h>
158  *			    but that file has string-handing def'ns that
159  *			    conflict with <string.h>, so we can't use it!
160  *			    MR dn89-04701 requests this fix.
161  */
162 
163 #define	stdmsg(r,l,s,t)	(void) fmtmsg(MM_PRINT|MM_UTIL|r,l,s,t,MM_NULLACT,MM_NULLTAG)
164 #define strend(p)       strrchr(p,'\0')
165 
166 /*
167  * Local functions:
168  *	setuname	Changes the system name and the network node name
169  */
170 
171 static int	setuname();		/* This does the "real" work */
172 
173 
174 /*
175  * Local data
176  *	lbl		Buffer for the standard message label
177  *	txt		Buffer for the standard message text
178  */
179 
180 static	char		lbl[MM_MXLABELLN+1];	/* Space for std msg label */
181 static	char		msg[MM_MXTXTLN+1];	/* Space for std msg text  */
182 
183 /*
184  *  int main(argc, argv)
185  *	int	argc
186  *	char   *argv;
187  */
188 
189 int
main(argc,argv)190 main(argc, argv)
191 	int	argc;			/* Argument count  */
192 	char   *argv[];			/* Argument vector */
193 {
194 	/* Automatic data */
195 	char	       *n_arg;			/* Ptr to arg for -n */
196 	char	       *s_arg;			/* Ptr to arg for -s */
197 	int		t_seen;			/* FLAG, -t option seen */
198 	char	       *cmdname;		/* Ptr to the command's name */
199 	char	       *p;			/* Temp pointer */
200 	int		usageerr;		/* FLAG, TRUE if usage error */
201 	int		exitcode;		/* Value to exit with */
202 	int		c;			/* Temp character */
203 	int		ok;			/* Flag, everything okay? */
204 
205 	/* Build the standard-message label */
206 	if (p = strrchr(argv[0], '/')) cmdname = p+1;
207 	else cmdname = argv[0];
208 	(void) strcat(strcpy(lbl, "UX:"), cmdname);
209 
210 	/* Make only the text in standard messages appear (SVR4.0 only) */
211 	(void) putenv("MSGVERB=text");
212 
213 
214 	/* Initializations */
215 	n_arg = s_arg = (char *) NULL;
216 	t_seen = FALSE;
217 
218 
219 	/*
220 	 * Parse command
221 	 */
222 
223 	usageerr = FALSE;
224 	opterr = FALSE;
225 	while (!usageerr && (c = getopt(argc, argv, OPTSTRING)) != EOF) switch(c) {
226 
227 	case 'n':			/* -n node */
228 	    if (n_arg) usageerr = TRUE;
229 	    else n_arg = optarg;
230 	    break;
231 
232 	case 's':			/* -s name */
233 	    if (s_arg) usageerr = TRUE;
234 	    else s_arg = optarg;
235 	    break;
236 
237 	case 't':			/* -t */
238 	    if (t_seen) usageerr = TRUE;
239 	    else t_seen = TRUE;
240 	    break;
241 
242 	default:			/* Something that doesn't exist */
243 	    usageerr = TRUE;
244 	}   /* switch() */
245 
246 	/* If there was a usage error, report the error and exit */
247 	if ((argc >= (optind+1)) || usageerr) {
248 	    stdmsg(MM_NRECOV, lbl, MM_ERROR, E_USAGE);
249 	    exit(EX_ERROR);
250 	}
251 
252 	/* Either -n <node> or -s <name> has to be specified */
253 	if (!(n_arg || s_arg)) {
254 	    stdmsg(MM_NRECOV, lbl, MM_ERROR, E_MISSING);
255 	    exit(EX_ERROR);
256 	}
257 
258 
259 	/*
260 	 * Validate arguments:
261 	 *  - The length of the system name must be less than SYS_NMLN-1
262 	 *    characters,
263 	 *  - The length of the network node-name must be less than
264 	 *    SYS_NMLN-1 characters,
265 	 *  - The system name must equal [a-zA-Z0-9-_]+,
266 	 *  - The network node-name must equal [a-zA-Z0-9-_]+.
267 	 */
268 
269 	/* Check the length and the character-set of the system name */
270 	if (s_arg) {
271 
272 	    /* Check length of the system name */
273 	    if (strlen(s_arg) > (size_t)(SYS_NMLN-1)) {
274 		(void) sprintf(msg, E_LONGNAME, s_arg);
275 		stdmsg(MM_NRECOV, lbl, MM_ERROR, msg);
276 		exit(EX_ERROR);
277 	    }
278 
279 	    /* Check the character-set */
280 	    ok = TRUE;
281 	    for (p = s_arg ; ok && *p ; p++) {
282 		if (!isalnum(*p) && (*p != '-') && (*p != '_')) ok = FALSE;
283 	    }
284 	    if (!ok || (p == s_arg)) {
285 		(void) sprintf(msg, E_INVNAME, s_arg);
286 		stdmsg(MM_NRECOV, lbl, MM_ERROR, msg);
287 		exit(EX_ERROR);
288 	    }
289 	}
290 
291 	/* Check the length and the character-set of the network node-name */
292 
293 	if (n_arg) {
294 
295 	    /* Check length of the network node-name */
296 	    if (strlen(n_arg) > (size_t)(SYS_NMLN-1)) {
297 		(void) sprintf(msg, E_LONGNODE, n_arg);
298 		stdmsg(MM_NRECOV, lbl, MM_ERROR, msg);
299 		exit(EX_ERROR);
300 	    }
301 
302 	    /* Check the character-set */
303 	    ok = TRUE;
304 	    for (p = n_arg ; ok && *p ; p++) {
305 		if (!isalnum(*p) && (*p != '-') && (*p != '_')) ok = FALSE;
306 	    }
307 	    if (!ok || (p == n_arg)) {
308 		(void) sprintf(msg, E_INVNODE, n_arg);
309 		stdmsg(MM_NRECOV, lbl, MM_ERROR, msg);
310 		exit(EX_ERROR);
311 	    }
312 	}
313 
314 
315 	/*
316 	 * Make sure we have access to needed resources:
317 	 *   -  Read/write access to kernel memory (/dev/kmem)
318 	 *   -  If -t is not specified, read/write access to /etc/rc2.d
319 	 *   -  If -t is not specified, read access to /etc/rc2.d/S18setuname
320 	 */
321 
322 	if (access("/dev/kmem", R_OK|W_OK) == 0) {
323 	    if (access(RC_DIRNAME, R_OK|W_OK) == 0) {
324 		if ((access(RC_FILENAME, R_OK) != 0) &&
325 		    (access(RC_FILENAME, F_OK) == 0)) {
326 		    stdmsg(MM_NRECOV, lbl, MM_ERROR, E_NOPERMS);
327 		    exit(EX_ERROR);
328 		}
329 	    }
330 	    else {
331 		if (access(RC_DIRNAME, F_OK) == 0) {
332 		    stdmsg(MM_NRECOV, lbl, MM_ERROR, E_NOPERMS);
333 		    exit(EX_ERROR);
334 		}
335 		else {
336 		    (void) sprintf(msg, E_NOSUCHDIR, RC_DIRNAME);
337 		    stdmsg(MM_NRECOV, lbl, MM_ERROR, msg);
338 		    exit(EX_ERROR);
339 		}
340 	    }
341 	}
342 	else {
343 	    stdmsg(MM_NRECOV, lbl, MM_ERROR, E_NOPERMS);
344 	    exit(EX_ERROR);
345 	}
346 
347 
348 	/* Attempt the setuname */
349 	if (setuname(t_seen, s_arg, n_arg) == 0) exitcode = EX_OK;
350 	else {
351 	    (void) sprintf(msg, E_INTERNAL, errno);
352 	    stdmsg(MM_NRECOV, lbl, MM_ERROR, msg);
353 	    exitcode = EX_ERROR;
354 	}
355 
356 	/* Finished */
357 	return (exitcode);
358 }  /* main() */
359 
360 /*
361  * int setuname(temp, name, node)
362  *	int	temp
363  *	char   *name
364  *	char   *node
365  *
366  *	Set any or all of the following machine parameters, either
367  *	temporarily or permanently, depending on <temp>.
368  *	    - System name
369  *	    - Network Node-name
370  */
371 
372 static int
setuname(temp,sysname,nodename)373 setuname(temp, sysname, nodename)
374 	int	temp;		/* Set in kernel only flag */
375 	char   *sysname;	/* System name */
376 	char   *nodename;	/* Network node-name */
377 {
378 	/* Automatic Data */
379 	struct utsname	utsname;	/* Space for the kernel's utsname information */
380 #if u3b || u3b15 || u3b2
381 	struct s3bsym  *symbtbl;	/* The kernel's symbol table */
382 #endif
383 #if sun
384 	struct nlist nl[] = {
385 		{"utsname", 0, 0, 0, 0, 0},
386 		{NULL}
387 	};
388 	kvm_t *kd;
389 #endif
390 	uintptr_t	utsname_addr;	/* Addr of "utsname" in the kernel */
391 	char	       *sysnm = (char *)NULL;		/* System name to set (from file or arg) */
392 	char	       *nodenm = (char *)NULL;		/* Network node-name to set (from file or arg) */
393 	FILE	       *fd;		/* Std I/O File Descriptor for /etc/rc2.d/S18setuname */
394 	char	       *p;		/* Temp pointer */
395 	void	      (*oldsighup)();	/* Function to call for SIGHUP */
396 	void	      (*oldsigint)();	/* Function to call for SIGINT */
397 	int		rtncd;		/* Value to return to the caller */
398 	unsigned long	symbtblsz;	/* The size of the kernel's symbol table, in bytes */
399 	int		memfd;		/* File descriptor:  open kernel memory */
400 	int		i;		/* Temp counter */
401 
402 
403 	/* Nothing's gone wrong yet (but we've only just begun!) */
404 	rtncd = 0;
405 
406 
407 	/*
408 	 * Get the virtual address of the symbol "utsname" in the kernel
409 	 * so we can get set the system name and/or the network node-name
410 	 * directly in the kernel's memory space.
411 	 */
412 
413 #if u3b || u3b15 || u3b2
414 	if ((sys3b(S3BSYM, (struct s3bsym *) &symbtblsz, sizeof(symbtblsz)) == 0) &&
415 	    (symbtbl = (struct s3bsym *) malloc(symbtblsz))) {
416 
417 	    (void) sys3b(S3BSYM, symbtbl, symbtblsz);
418 	    p = (char *) symbtbl;
419 	    for (i = symbtbl->count; i-- && (strcmp(p, "utsname") != 0) ; p = S3BNXTSYM(p)) ;
420 	    if (i >= 0) utsname_addr = S3BSVAL(p);
421 	    else rtncd = -1;
422 	    free((void *) symbtbl);
423 
424 	} else rtncd = -1;
425 
426 #elif sun
427         /* Check out namelist and memory files. */
428 	if ((kd = kvm_open(NULL, NULL, NULL, O_RDWR, NULL)) == NULL)
429 		rtncd = -1;
430 	else if (kvm_nlist(kd, nl) != 0)
431 		rtncd = -1;
432 	else if (nl[0].n_value == 0)
433 		rtncd = -1;
434 	else
435 		utsname_addr = (uintptr_t)nl[0].n_value;
436 #else
437 	if (nlist("/unix", nl) != 0)
438 		rtncd = -1;
439 #endif
440 	if (rtncd != 0) return(rtncd);
441 
442 	/*
443 	 * Open the kernel's memory, get the existing "utsname" structure,
444 	 * change the system name and/or the network node-name in that struct,
445 	 * write it back out to kernel memory, then close kernel memory.
446 	 */
447 #ifdef sun
448 	if (kvm_kread(kd, utsname_addr, &utsname, sizeof (utsname)) ==
449 	    sizeof (utsname)) {
450 		if (sysname)
451 			(void) strncpy(utsname.sysname, sysname,
452 			    sizeof (utsname.sysname));
453 		if (nodename)
454 			(void) strncpy(utsname.nodename, nodename,
455 			    sizeof (utsname.nodename));
456 		(void) kvm_kwrite(kd, utsname_addr, &utsname, sizeof (utsname));
457 		(void) kvm_close(kd);
458 	} else
459 		return (-1);
460 #else /* sun */
461 	if ((memfd = open("/dev/kmem", O_RDWR, 0)) > 0) {
462 	    if ((lseek(memfd, (long) utsname_addr, SEEK_SET) != -1) &&
463 		(read(memfd, &utsname, sizeof(utsname)) == sizeof(utsname))) {
464 		if (sysname) (void) strncpy(utsname.sysname, sysname, sizeof(utsname.sysname));
465 		if (nodename) (void) strncpy(utsname.nodename, nodename, sizeof(utsname.nodename));
466 		(void) lseek(memfd, (long) utsname_addr, SEEK_SET);
467 		(void) write(memfd, &utsname, sizeof(utsname));
468 		(void) close(memfd);
469 	    } else rtncd = -1;
470 	} else rtncd = -1;
471 	if (rtncd != 0) return(rtncd);
472 #endif /* sun */
473 
474 
475 	/*
476 	 * If the "temp" flag is FALSE, we need to permanently set the
477 	 * system name in the file  /etc/rc2.d/S18setuname
478 	 */
479 
480 	if (!temp) {
481 	    /*
482 	     * If a name was specified by the caller, use that, otherwise, use
483 	     * whatever was in the "rc" file.
484 	     */
485 
486 		if (sysname) sysnm = sysname;
487 		if (nodename) nodenm = nodename;
488 
489 
490 	    /*
491 	     * Write the file /etc/rc2.d/S18setuname so that the system name is
492 	     * set on boots and state changes.
493 	     *
494 	     * DISABLED SIGNALS: SIGHUP, SIGINT
495 	     */
496 
497 	    /* Give us a reasonable chance to complete without interruptions */
498 		oldsighup = signal(SIGHUP, SIG_IGN);
499 		oldsigint = signal(SIGINT, SIG_IGN);
500 
501 	    /* Write the new setuname "rc" file */
502 		if (sysname != NULL) {
503 			if ((fd = fopen(RC_FILENAME, "w")) != (FILE *) NULL) {
504 				(void) fprintf(fd, "# %s\n", sysnm);
505 				(void) fprintf(fd, "#\n");
506 				(void) fprintf(fd, "# This script, generated by the setuname command,\n");
507 				(void) fprintf(fd, "# sets the system's system-name\n");
508 				(void) fprintf(fd, "#\n");
509 				if (sysnm && *sysnm)
510 					(void) fprintf(fd, "setuname -t -s %s\n", sysnm);
511 				(void) fclose(fd);
512 			} else return(rtncd = -1);
513 		}
514 
515 		if(nodename != NULL) {
516 			char curname[SYS_NMLN];
517 			int curlen;
518 			FILE *file;
519 
520 			if ((file = fopen("/etc/nodename", "r")) != NULL) {
521 				curlen = fread(curname, sizeof(char), SYS_NMLN, file);
522 				for (i = 0; i < curlen; i++) {
523 					if (curname[i] == '\n') {
524 						curname[i] = '\0';
525 						break;
526 					}
527 				}
528 				if (i == curlen) {
529 					curname[curlen] = '\0';
530 				}
531 				(void)fclose(file);
532 			} else {
533 				curname[0] = '\0';
534 			}
535 			if (strcmp(curname, nodenm) != 0) {
536 				if ((file = fopen("/etc/nodename", "w")) == NULL) {
537 					(void) fprintf(stderr, "setuname: error in writing name\n");
538 					exit(1);
539 				}
540 				if (fprintf(file, "%s\n", nodenm) < 0) {
541 					(void) fprintf(stderr, "setuname: error in writing name\n");
542 					exit(1);
543 				}
544 				(void)fclose(file);
545 			}
546 		}
547 	    /* Restore signal handling */
548 		(void) signal(SIGHUP, oldsighup);
549 		(void) signal(SIGINT, oldsigint);
550 	}	/* if (!temp) */
551 
552 	/* Fini */
553 	return(rtncd);
554 }
555