summaryrefslogtreecommitdiff
path: root/usr.bin/vi/ex/ex_init.c
blob: 6a78416a334413cd3e0cd3f9df8d864039bf50ce (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
/*-
 * Copyright (c) 1992, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1992, 1993, 1994, 1995, 1996
 *	Keith Bostic.  All rights reserved.
 *
 * See the LICENSE file for redistribution information.
 */

#include "config.h"

#ifndef lint
static const char sccsid[] = "@(#)ex_init.c	10.26 (Berkeley) 8/12/96";
#endif /* not lint */

#include <sys/param.h>
#include <sys/types.h>		/* XXX: param.h may not have included types.h */
#include <sys/queue.h>
#include <sys/stat.h>

#include <bitstring.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "../common/common.h"
#include "tag.h"
#include "pathnames.h"

enum rc { NOEXIST, NOPERM, RCOK };
static enum rc	exrc_isok __P((SCR *, struct stat *, char *, int, int));

static int ex_run_file __P((SCR *, char *));

/*
 * ex_screen_copy --
 *	Copy ex screen.
 *
 * PUBLIC: int ex_screen_copy __P((SCR *, SCR *));
 */
int
ex_screen_copy(orig, sp)
	SCR *orig, *sp;
{
	EX_PRIVATE *oexp, *nexp;

	/* Create the private ex structure. */
	CALLOC_RET(orig, nexp, EX_PRIVATE *, 1, sizeof(EX_PRIVATE));
	sp->ex_private = nexp;

	/* Initialize queues. */
	CIRCLEQ_INIT(&nexp->tq);
	TAILQ_INIT(&nexp->tagfq);
	LIST_INIT(&nexp->cscq);

	if (orig == NULL) {
	} else {
		oexp = EXP(orig);

		if (oexp->lastbcomm != NULL &&
		    (nexp->lastbcomm = strdup(oexp->lastbcomm)) == NULL) {
			msgq(sp, M_SYSERR, NULL);
			return(1);
		}
		if (ex_tag_copy(orig, sp))
			return (1);
	}
	return (0);
}

/*
 * ex_screen_end --
 *	End a vi screen.
 *
 * PUBLIC: int ex_screen_end __P((SCR *));
 */
int
ex_screen_end(sp)
	SCR *sp;
{
	EX_PRIVATE *exp;
	int rval;

	if ((exp = EXP(sp)) == NULL)
		return (0);

	rval = 0;

	/* Close down script connections. */
	if (F_ISSET(sp, SC_SCRIPT) && sscr_end(sp))
		rval = 1;

	if (argv_free(sp))
		rval = 1;

	if (exp->ibp != NULL)
		free(exp->ibp);

	if (exp->lastbcomm != NULL)
		free(exp->lastbcomm);

	if (ex_tag_free(sp))
		rval = 1;

	/* Free private memory. */
	free(exp);
	sp->ex_private = NULL;

	return (rval);
}

/*
 * ex_optchange --
 *	Handle change of options for ex.
 *
 * PUBLIC: int ex_optchange __P((SCR *, int, char *, u_long *));
 */
int
ex_optchange(sp, offset, str, valp)
	SCR *sp;
	int offset;
	char *str;
	u_long *valp;
{
	switch (offset) {
	case O_TAGS:
		return (ex_tagf_alloc(sp, str));
	}
	return (0);
}

/*
 * ex_exrc --
 *	Read the EXINIT environment variable and the startup exrc files,
 *	and execute their commands.
 *
 * PUBLIC: int ex_exrc __P((SCR *));
 */
int
ex_exrc(sp)
	SCR *sp;
{
	struct stat hsb, lsb;
	char *p, path[MAXPATHLEN];

	/*
	 * Source the system, environment, $HOME and local .exrc values.
	 * Vi historically didn't check $HOME/.exrc if the environment
	 * variable EXINIT was set.  This is all done before the file is
	 * read in, because things in the .exrc information can set, for
	 * example, the recovery directory.
	 *
	 * !!!
	 * While nvi can handle any of the options settings of historic vi,
	 * the converse is not true.  Since users are going to have to have
	 * files and environmental variables that work with both, we use nvi
	 * versions of both the $HOME and local startup files if they exist,
	 * otherwise the historic ones.
	 *
	 * !!!
	 * For a discussion of permissions and when what .exrc files are
	 * read, see the comment above the exrc_isok() function below.
	 *
	 * !!!
	 * If the user started the historic of vi in $HOME, vi read the user's
	 * .exrc file twice, as $HOME/.exrc and as ./.exrc.  We avoid this, as
	 * it's going to make some commands behave oddly, and I can't imagine
	 * anyone depending on it.
	 */
	switch (exrc_isok(sp, &hsb, _PATH_SYSEXRC, 1, 0)) {
	case NOEXIST:
	case NOPERM:
		break;
	case RCOK:
		if (ex_run_file(sp, _PATH_SYSEXRC))
			return (1);
		break;
	}

	/* Run the commands. */
	if (EXCMD_RUNNING(sp->gp))
		(void)ex_cmd(sp);
	if (F_ISSET(sp, SC_EXIT | SC_EXIT_FORCE))
		return (0);

	if ((p = getenv("NEXINIT")) != NULL) {
		if (ex_run_str(sp, "NEXINIT", p, strlen(p), 1, 0))
			return (1);
	} else if ((p = getenv("EXINIT")) != NULL) {
		if (ex_run_str(sp, "EXINIT", p, strlen(p), 1, 0))
			return (1);
	} else if ((p = getenv("HOME")) != NULL && *p) {
		(void)snprintf(path, sizeof(path), "%s/%s", p, _PATH_NEXRC);
		switch (exrc_isok(sp, &hsb, path, 0, 1)) {
		case NOEXIST:
			(void)snprintf(path,
			    sizeof(path), "%s/%s", p, _PATH_EXRC);
			if (exrc_isok(sp,
			    &hsb, path, 0, 1) == RCOK && ex_run_file(sp, path))
				return (1);
			break;
		case NOPERM:
			break;
		case RCOK:
			if (ex_run_file(sp, path))
				return (1);
			break;
		}
	}

	/* Run the commands. */
	if (EXCMD_RUNNING(sp->gp))
		(void)ex_cmd(sp);
	if (F_ISSET(sp, SC_EXIT | SC_EXIT_FORCE))
		return (0);

	/* Previous commands may have set the exrc option. */
	if (O_ISSET(sp, O_EXRC)) {
		switch (exrc_isok(sp, &lsb, _PATH_NEXRC, 0, 0)) {
		case NOEXIST:
			if (exrc_isok(sp, &lsb, _PATH_EXRC, 0, 0) == RCOK &&
			    (lsb.st_dev != hsb.st_dev ||
			    lsb.st_ino != hsb.st_ino) &&
			    ex_run_file(sp, _PATH_EXRC))
				return (1);
			break;
		case NOPERM:
			break;
		case RCOK:
			if ((lsb.st_dev != hsb.st_dev ||
			    lsb.st_ino != hsb.st_ino) &&
			    ex_run_file(sp, _PATH_NEXRC))
				return (1);
			break;
		}
		/* Run the commands. */
		if (EXCMD_RUNNING(sp->gp))
			(void)ex_cmd(sp);
		if (F_ISSET(sp, SC_EXIT | SC_EXIT_FORCE))
			return (0);
	}

	return (0);
}

/*
 * ex_run_file --
 *	Set up a file of ex commands to run.
 */
static int
ex_run_file(sp, name)
	SCR *sp;
	char *name;
{
	ARGS *ap[2], a;
	EXCMD cmd;

	ex_cinit(&cmd, C_SOURCE, 0, OOBLNO, OOBLNO, 0, ap);
	ex_cadd(&cmd, &a, name, strlen(name));
	return (ex_source(sp, &cmd));
}

/*
 * ex_run_str --
 *	Set up a string of ex commands to run.
 *
 * PUBLIC: int ex_run_str __P((SCR *, char *, char *, size_t, int, int));
 */
int
ex_run_str(sp, name, str, len, ex_flags, nocopy)
	SCR *sp;
	char *name, *str;
	size_t len;
	int ex_flags, nocopy;
{
	GS *gp;
	EXCMD *ecp;

	gp = sp->gp;
	if (EXCMD_RUNNING(gp)) {
		CALLOC_RET(sp, ecp, EXCMD *, 1, sizeof(EXCMD));
		LIST_INSERT_HEAD(&gp->ecq, ecp, q);
	} else
		ecp = &gp->excmd;

	F_INIT(ecp,
	    ex_flags ? E_BLIGNORE | E_NOAUTO | E_NOPRDEF | E_VLITONLY : 0);

	if (nocopy)
		ecp->cp = str;
	else
		if ((ecp->cp = v_strdup(sp, str, len)) == NULL)
			return (1);
	ecp->clen = len;

	if (name == NULL)
		ecp->if_name = NULL;
	else {
		if ((ecp->if_name = v_strdup(sp, name, strlen(name))) == NULL)
			return (1);
		ecp->if_lno = 1;
		F_SET(ecp, E_NAMEDISCARD);
	}

	return (0);
}

/*
 * exrc_isok --
 *	Check a .exrc file for source-ability.
 *
 * !!!
 * Historically, vi read the $HOME and local .exrc files if they were owned
 * by the user's real ID, or the "sourceany" option was set, regardless of
 * any other considerations.  We no longer support the sourceany option as
 * it's a security problem of mammoth proportions.  We require the system
 * .exrc file to be owned by root, the $HOME .exrc file to be owned by the
 * user's effective ID (or that the user's effective ID be root) and the
 * local .exrc files to be owned by the user's effective ID.  In all cases,
 * the file cannot be writeable by anyone other than its owner.
 *
 * In O'Reilly ("Learning the VI Editor", Fifth Ed., May 1992, page 106),
 * it notes that System V release 3.2 and later has an option "[no]exrc".
 * The behavior is that local .exrc files are read only if the exrc option
 * is set.  The default for the exrc option was off, so, by default, local
 * .exrc files were not read.  The problem this was intended to solve was
 * that System V permitted users to give away files, so there's no possible
 * ownership or writeability test to ensure that the file is safe.
 *
 * POSIX 1003.2-1992 standardized exrc as an option.  It required the exrc
 * option to be off by default, thus local .exrc files are not to be read
 * by default.  The Rationale noted (incorrectly) that this was a change
 * to historic practice, but correctly noted that a default of off improves
 * system security.  POSIX also required that vi check the effective user
 * ID instead of the real user ID, which is why we've switched from historic
 * practice.
 *
 * We initialize the exrc variable to off.  If it's turned on by the system
 * or $HOME .exrc files, and the local .exrc file passes the ownership and
 * writeability tests, then we read it.  This breaks historic 4BSD practice,
 * but it gives us a measure of security on systems where users can give away
 * files.
 */
static enum rc
exrc_isok(sp, sbp, path, rootown, rootid)
	SCR *sp;
	struct stat *sbp;
	char *path;
	int rootown, rootid;
{
	enum { ROOTOWN, OWN, WRITER } etype;
	uid_t euid;
	int nf1, nf2;
	char *a, *b, buf[MAXPATHLEN];

	/* Check for the file's existence. */
	if (stat(path, sbp))
		return (NOEXIST);

	/* Check ownership permissions. */
	euid = geteuid();
	if (!(rootown && sbp->st_uid == 0) &&
	    !(rootid && euid == 0) && sbp->st_uid != euid) {
		etype = rootown ? ROOTOWN : OWN;
		goto denied;
	}

	/* Check writeability. */
	if (sbp->st_mode & (S_IWGRP | S_IWOTH)) {
		etype = WRITER;
		goto denied;
	}
	return (RCOK);

denied:	a = msg_print(sp, path, &nf1);
	if (strchr(path, '/') == NULL && getcwd(buf, sizeof(buf)) != NULL) {
		b = msg_print(sp, buf, &nf2);
		switch (etype) {
		case ROOTOWN:
			msgq(sp, M_ERR,
			    "125|%s/%s: not sourced: not owned by you or root",
			    b, a);
			break;
		case OWN:
			msgq(sp, M_ERR,
			    "126|%s/%s: not sourced: not owned by you", b, a);
			break;
		case WRITER:
			msgq(sp, M_ERR,
    "127|%s/%s: not sourced: writeable by a user other than the owner", b, a);
			break;
		}
		if (nf2)
			FREE_SPACE(sp, b, 0);
	} else
		switch (etype) {
		case ROOTOWN:
			msgq(sp, M_ERR,
			    "128|%s: not sourced: not owned by you or root", a);
			break;
		case OWN:
			msgq(sp, M_ERR,
			    "129|%s: not sourced: not owned by you", a);
			break;
		case WRITER:
			msgq(sp, M_ERR,
	    "130|%s: not sourced: writeable by a user other than the owner", a);
			break;
		}

	if (nf1)
		FREE_SPACE(sp, a, 0);
	return (NOPERM);
}