xref: /illumos-gate/usr/src/cmd/mdb/common/mdb/mdb_tab.c (revision d75f3745)
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 /*
22  * Copyright (c) 2013 by Delphix. All rights reserved.
23  * Copyright (c) 2018, Joyent, Inc.
24  * Copyright (c) 2013 Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
25  */
26 /*
27  * This file contains all of the interfaces for mdb's tab completion engine.
28  * Currently some interfaces are private to mdb and its internal implementation,
29  * those are in mdb_tab.h. Other pieces are public interfaces. Those are in
30  * mdb_modapi.h.
31  *
32  * Memory allocations in tab completion context have to be done very carefully.
33  * We need to think of ourselves as the same as any other command that is being
34  * executed by the user, which means we must use UM_GC to handle being
35  * interrupted.
36  */
37 
38 #include <mdb/mdb_modapi.h>
39 #include <mdb/mdb_ctf.h>
40 #include <mdb/mdb_ctf_impl.h>
41 #include <mdb/mdb_string.h>
42 #include <mdb/mdb_module.h>
43 #include <mdb/mdb_debug.h>
44 #include <mdb/mdb_print.h>
45 #include <mdb/mdb_nv.h>
46 #include <mdb/mdb_tab.h>
47 #include <mdb/mdb_target.h>
48 #include <mdb/mdb.h>
49 
50 #include <ctype.h>
51 
52 /*
53  * There may be another way to do this, but this works well enough.
54  */
55 #define	COMMAND_SEPARATOR "::"
56 
57 /*
58  * find_command_start --
59  *
60  *	Given a buffer find the start of the last command.
61  */
62 static char *
tab_find_command_start(char * buf)63 tab_find_command_start(char *buf)
64 {
65 	char *offset = strstr(buf, COMMAND_SEPARATOR);
66 
67 	if (offset == NULL)
68 		return (NULL);
69 
70 	for (;;) {
71 		char *next = strstr(offset + strlen(COMMAND_SEPARATOR),
72 		    COMMAND_SEPARATOR);
73 
74 		if (next == NULL) {
75 			return (offset);
76 		}
77 
78 		offset = next;
79 	}
80 }
81 
82 /*
83  * get_dcmd --
84  *
85  *	Given a buffer containing a command and its argument return
86  *	the name of the command and the offset in the buffer where
87  *	the command arguments start.
88  *
89  *	Note: This will modify the buffer.
90  */
91 char *
tab_get_dcmd(char * buf,char ** args,uint_t * flags)92 tab_get_dcmd(char *buf, char **args, uint_t *flags)
93 {
94 	char *start = buf + strlen(COMMAND_SEPARATOR);
95 	char *separator = start;
96 	const char *end = buf + strlen(buf);
97 	uint_t space = 0;
98 
99 	while (separator < end && !isspace(*separator))
100 		separator++;
101 
102 	if (separator == end) {
103 		*args = NULL;
104 	} else {
105 		if (isspace(*separator))
106 			space = 1;
107 
108 		*separator++ = '\0';
109 		*args = separator;
110 	}
111 
112 	if (space)
113 		*flags |= DCMD_TAB_SPACE;
114 
115 	return (start);
116 }
117 
118 /*
119  * count_args --
120  *
121  *	Given a buffer containing dmcd arguments return the total number
122  *	of arguments.
123  *
124  *	While parsing arguments we need to keep track of whether or not the last
125  *	arguments ends with a trailing space.
126  */
127 static int
tab_count_args(const char * input,uint_t * flags)128 tab_count_args(const char *input, uint_t *flags)
129 {
130 	const char *index;
131 	int argc = 0;
132 	uint_t space = *flags & DCMD_TAB_SPACE;
133 	index = input;
134 
135 	while (*index != '\0') {
136 		while (*index != '\0' && isspace(*index)) {
137 			index++;
138 			space = 1;
139 		}
140 
141 		if (*index != '\0' && !isspace(*index)) {
142 			argc++;
143 			space = 0;
144 			while (*index != '\0' && !isspace (*index)) {
145 				index++;
146 			}
147 		}
148 	}
149 
150 	if (space)
151 		*flags |= DCMD_TAB_SPACE;
152 	else
153 		*flags &= ~DCMD_TAB_SPACE;
154 
155 	return (argc);
156 }
157 
158 /*
159  * copy_args --
160  *
161  *	Given a buffer containing dcmd arguments and an array of mdb_arg_t's
162  *	initialize the string value of each mdb_arg_t.
163  *
164  *	Note: This will modify the buffer.
165  */
166 static int
tab_copy_args(char * input,int argc,mdb_arg_t * argv)167 tab_copy_args(char *input, int argc, mdb_arg_t *argv)
168 {
169 	int i = 0;
170 	char *index;
171 
172 	index = input;
173 
174 	while (*index) {
175 		while (*index && isspace(*index)) {
176 			index++;
177 		}
178 
179 		if (*index && !isspace(*index)) {
180 			char *end = index;
181 
182 			while (*end && !isspace(*end)) {
183 				end++;
184 			}
185 
186 			if (*end) {
187 				*end++ = '\0';
188 			}
189 
190 			argv[i].a_type = MDB_TYPE_STRING;
191 			argv[i].a_un.a_str = index;
192 
193 			index = end;
194 			i++;
195 		}
196 	}
197 
198 	if (i != argc)
199 		return (-1);
200 
201 	return (0);
202 }
203 
204 /*
205  * parse-buf --
206  *
207  *	Parse the given buffer and return the specified dcmd, the number
208  *	of arguments, and array of mdb_arg_t containing the argument
209  *	values.
210  *
211  *	Note: this will modify the specified buffer. Caller is responisble
212  *	for freeing argvp.
213  */
214 static int
tab_parse_buf(char * buf,char ** dcmdp,int * argcp,mdb_arg_t ** argvp,uint_t * flags)215 tab_parse_buf(char *buf, char **dcmdp, int *argcp, mdb_arg_t **argvp,
216     uint_t *flags)
217 {
218 	char *data = tab_find_command_start(buf);
219 	char *args_data = NULL;
220 	char *dcmd = NULL;
221 	int argc = 0;
222 	mdb_arg_t *argv = NULL;
223 
224 	if (data == NULL) {
225 		return (-1);
226 	}
227 
228 	dcmd = tab_get_dcmd(data, &args_data, flags);
229 
230 	if (dcmd == NULL) {
231 		return (-1);
232 	}
233 
234 	if (args_data != NULL) {
235 		argc = tab_count_args(args_data, flags);
236 
237 		if (argc != 0) {
238 			argv = mdb_alloc(sizeof (mdb_arg_t) * argc,
239 			    UM_SLEEP | UM_GC);
240 
241 			if (tab_copy_args(args_data, argc, argv) == -1)
242 				return (-1);
243 		}
244 	}
245 
246 	*dcmdp = dcmd;
247 	*argcp = argc;
248 	*argvp = argv;
249 
250 	return (0);
251 }
252 
253 /*
254  * tab_command --
255  *
256  *	This function is executed anytime a tab is entered. It checks
257  *	the current buffer to determine if there is a valid dmcd,
258  *	if that dcmd has a tab completion handler it will invoke it.
259  *
260  *	This function returns the string (if any) that should be added to the
261  *	existing buffer to complete it.
262  */
263 int
mdb_tab_command(mdb_tab_cookie_t * mcp,const char * buf)264 mdb_tab_command(mdb_tab_cookie_t *mcp, const char *buf)
265 {
266 	char *data;
267 	char *dcmd = NULL;
268 	int argc = 0;
269 	mdb_arg_t *argv = NULL;
270 	int ret = 0;
271 	mdb_idcmd_t *cp;
272 	uint_t flags = 0;
273 
274 	/*
275 	 * Parsing the command and arguments will modify the buffer
276 	 * (replacing spaces with \0), so make a copy of the specified
277 	 * buffer first.
278 	 */
279 	data = mdb_alloc(strlen(buf) + 1, UM_SLEEP | UM_GC);
280 	(void) strcpy(data, buf);
281 
282 	/*
283 	 * Get the specified dcmd and arguments from the buffer.
284 	 */
285 	ret = tab_parse_buf(data, &dcmd, &argc, &argv, &flags);
286 
287 	/*
288 	 * Match against global symbols if the input is not a dcmd
289 	 */
290 	if (ret != 0) {
291 		(void) mdb_tab_complete_global(mcp, buf);
292 		goto out;
293 	}
294 
295 	/*
296 	 * Check to see if the buffer contains a valid dcmd
297 	 */
298 	cp = mdb_dcmd_lookup(dcmd);
299 
300 	/*
301 	 * When argc is zero it indicates that we are trying to tab complete
302 	 * a dcmd or a global symbol. Note, that if there isn't the start of
303 	 * a dcmd, i.e. ::, then we will have already bailed in the call to
304 	 * tab_parse_buf.
305 	 */
306 	if (cp == NULL && argc != 0) {
307 		goto out;
308 	}
309 
310 	/*
311 	 * Invoke the command specific tab completion handler or the built in
312 	 * dcmd one if there is no dcmd.
313 	 */
314 	if (cp == NULL)
315 		(void) mdb_tab_complete_dcmd(mcp, dcmd);
316 	else
317 		mdb_call_tab(cp, mcp, flags, argc, argv);
318 
319 out:
320 	return (mdb_tab_size(mcp));
321 }
322 
323 static int
tab_complete_dcmd(mdb_var_t * v,void * arg)324 tab_complete_dcmd(mdb_var_t *v, void *arg)
325 {
326 	mdb_idcmd_t *idcp = mdb_nv_get_cookie(mdb_nv_get_cookie(v));
327 	mdb_tab_cookie_t *mcp = (mdb_tab_cookie_t *)arg;
328 
329 	/*
330 	 * The way that mdb is implemented, even commands like $C will show up
331 	 * here. As such, we don't want to match anything that doesn't start
332 	 * with an alpha or number. While nothing currently appears (via a
333 	 * cursory search with mdb -k) to start with a capital letter or a
334 	 * number, we'll support them anyways.
335 	 */
336 	if (!isalnum(idcp->idc_name[0]))
337 		return (0);
338 
339 	mdb_tab_insert(mcp, idcp->idc_name);
340 	return (0);
341 }
342 
343 int
mdb_tab_complete_dcmd(mdb_tab_cookie_t * mcp,const char * dcmd)344 mdb_tab_complete_dcmd(mdb_tab_cookie_t *mcp, const char *dcmd)
345 {
346 	if (dcmd != NULL)
347 		mdb_tab_setmbase(mcp, dcmd);
348 	mdb_nv_sort_iter(&mdb.m_dcmds, tab_complete_dcmd, mcp,
349 	    UM_GC | UM_SLEEP);
350 	return (0);
351 }
352 
353 static int
tab_complete_walker(mdb_var_t * v,void * arg)354 tab_complete_walker(mdb_var_t *v, void *arg)
355 {
356 	mdb_iwalker_t *iwp = mdb_nv_get_cookie(mdb_nv_get_cookie(v));
357 	mdb_tab_cookie_t *mcp = arg;
358 
359 	mdb_tab_insert(mcp, iwp->iwlk_name);
360 	return (0);
361 }
362 
363 int
mdb_tab_complete_walker(mdb_tab_cookie_t * mcp,const char * walker)364 mdb_tab_complete_walker(mdb_tab_cookie_t *mcp, const char *walker)
365 {
366 	if (walker != NULL)
367 		mdb_tab_setmbase(mcp, walker);
368 	mdb_nv_sort_iter(&mdb.m_walkers, tab_complete_walker, mcp,
369 	    UM_GC | UM_SLEEP);
370 
371 	return (0);
372 }
373 
374 mdb_tab_cookie_t *
mdb_tab_init(void)375 mdb_tab_init(void)
376 {
377 	mdb_tab_cookie_t *mcp;
378 
379 	mcp = mdb_zalloc(sizeof (mdb_tab_cookie_t), UM_SLEEP | UM_GC);
380 	(void) mdb_nv_create(&mcp->mtc_nv, UM_SLEEP | UM_GC);
381 
382 	return (mcp);
383 }
384 
385 size_t
mdb_tab_size(mdb_tab_cookie_t * mcp)386 mdb_tab_size(mdb_tab_cookie_t *mcp)
387 {
388 	return (mdb_nv_size(&mcp->mtc_nv));
389 }
390 
391 /*
392  * Determine whether the specified name is a valid tab completion for
393  * the given command. If the name is a valid tab completion then
394  * it will be saved in the mdb_tab_cookie_t.
395  */
396 void
mdb_tab_insert(mdb_tab_cookie_t * mcp,const char * name)397 mdb_tab_insert(mdb_tab_cookie_t *mcp, const char *name)
398 {
399 	size_t matches, index;
400 	mdb_var_t *v;
401 
402 	/*
403 	 * If we have a match set, then we want to verify that we actually match
404 	 * it.
405 	 */
406 	if (strncmp(name, mcp->mtc_base, strlen(mcp->mtc_base)) != 0)
407 		return;
408 
409 	v = mdb_nv_lookup(&mcp->mtc_nv, name);
410 	if (v != NULL)
411 		return;
412 
413 	(void) mdb_nv_insert(&mcp->mtc_nv, name, NULL, 0, MDB_NV_RDONLY);
414 
415 	matches = mdb_tab_size(mcp);
416 	if (matches == 1) {
417 		(void) strlcpy(mcp->mtc_match, name, MDB_SYM_NAMLEN);
418 	} else {
419 		index = 0;
420 		while (mcp->mtc_match[index] &&
421 		    mcp->mtc_match[index] == name[index])
422 			index++;
423 
424 		mcp->mtc_match[index] = '\0';
425 	}
426 }
427 
428 /*ARGSUSED*/
429 static int
tab_print_cb(mdb_var_t * v,void * ignored)430 tab_print_cb(mdb_var_t *v, void *ignored)
431 {
432 	mdb_printf("%s\n", mdb_nv_get_name(v));
433 	return (0);
434 }
435 
436 void
mdb_tab_print(mdb_tab_cookie_t * mcp)437 mdb_tab_print(mdb_tab_cookie_t *mcp)
438 {
439 	mdb_nv_sort_iter(&mcp->mtc_nv, tab_print_cb, NULL, UM_SLEEP | UM_GC);
440 }
441 
442 const char *
mdb_tab_match(mdb_tab_cookie_t * mcp)443 mdb_tab_match(mdb_tab_cookie_t *mcp)
444 {
445 	return (mcp->mtc_match + strlen(mcp->mtc_base));
446 }
447 
448 void
mdb_tab_setmbase(mdb_tab_cookie_t * mcp,const char * base)449 mdb_tab_setmbase(mdb_tab_cookie_t *mcp, const char *base)
450 {
451 	(void) strlcpy(mcp->mtc_base, base, MDB_SYM_NAMLEN);
452 }
453 
454 /*
455  * This function is currently a no-op due to the fact that we have to GC because
456  * we're in command context.
457  */
458 /*ARGSUSED*/
459 void
mdb_tab_fini(mdb_tab_cookie_t * mcp)460 mdb_tab_fini(mdb_tab_cookie_t *mcp)
461 {
462 }
463 
464 /*ARGSUSED*/
465 static int
tab_complete_global(void * arg,const GElf_Sym * sym,const char * name,const mdb_syminfo_t * sip,const char * obj)466 tab_complete_global(void *arg, const GElf_Sym *sym, const char *name,
467     const mdb_syminfo_t *sip, const char *obj)
468 {
469 	mdb_tab_cookie_t *mcp = arg;
470 	mdb_tab_insert(mcp, name);
471 	return (0);
472 }
473 
474 /*
475  * This function tab completes against all loaded global symbols.
476  */
477 int
mdb_tab_complete_global(mdb_tab_cookie_t * mcp,const char * name)478 mdb_tab_complete_global(mdb_tab_cookie_t *mcp, const char *name)
479 {
480 	mdb_tab_setmbase(mcp, name);
481 	(void) mdb_tgt_symbol_iter(mdb.m_target, MDB_TGT_OBJ_EVERY,
482 	    MDB_TGT_SYMTAB, MDB_TGT_BIND_ANY | MDB_TGT_TYPE_OBJECT |
483 	    MDB_TGT_TYPE_FUNC, tab_complete_global, mcp);
484 	return (0);
485 }
486 
487 /*
488  * This function takes a ctf id and determines whether or not the associated
489  * type should be considered as a potential match for the given tab
490  * completion command. We verify that the type itself is valid
491  * for completion given the current context of the command, resolve
492  * its actual name, and then pass it off to mdb_tab_insert to determine
493  * if it's an actual match.
494  */
495 static int
tab_complete_type(mdb_ctf_id_t id,void * arg)496 tab_complete_type(mdb_ctf_id_t id, void *arg)
497 {
498 	int rkind;
499 	char buf[MDB_SYM_NAMLEN];
500 	mdb_ctf_id_t rid;
501 	mdb_tab_cookie_t *mcp = arg;
502 	uint_t flags = (uint_t)(uintptr_t)mcp->mtc_cba;
503 
504 	/*
505 	 * CTF data includes types that mdb commands don't understand. Before
506 	 * we resolve the actual type prune any entry that is a type we
507 	 * don't care about.
508 	 */
509 	switch (mdb_ctf_type_kind(id)) {
510 	case CTF_K_CONST:
511 	case CTF_K_RESTRICT:
512 	case CTF_K_VOLATILE:
513 		return (0);
514 	}
515 
516 	if (mdb_ctf_type_resolve(id, &rid) != 0)
517 		return (1);
518 
519 	rkind = mdb_ctf_type_kind(rid);
520 
521 	if ((flags & MDB_TABC_MEMBERS) && rkind != CTF_K_STRUCT &&
522 	    rkind != CTF_K_UNION)
523 		return (0);
524 
525 	if ((flags & MDB_TABC_NOPOINT) && rkind == CTF_K_POINTER)
526 		return (0);
527 
528 	if ((flags & MDB_TABC_NOARRAY) && rkind == CTF_K_ARRAY)
529 		return (0);
530 
531 	(void) mdb_ctf_type_name(id, buf, sizeof (buf));
532 
533 	mdb_tab_insert(mcp, buf);
534 	return (0);
535 }
536 
537 /*ARGSUSED*/
538 static int
mdb_tab_complete_module(void * data,const mdb_map_t * mp,const char * name)539 mdb_tab_complete_module(void *data, const mdb_map_t *mp, const char *name)
540 {
541 	(void) mdb_ctf_type_iter(name, tab_complete_type, data);
542 	return (0);
543 }
544 
545 int
mdb_tab_complete_type(mdb_tab_cookie_t * mcp,const char * name,uint_t flags)546 mdb_tab_complete_type(mdb_tab_cookie_t *mcp, const char *name, uint_t flags)
547 {
548 	mdb_tgt_t *t = mdb.m_target;
549 
550 	mcp->mtc_cba = (void *)(uintptr_t)flags;
551 	if (name != NULL)
552 		mdb_tab_setmbase(mcp, name);
553 
554 	(void) mdb_tgt_object_iter(t, mdb_tab_complete_module, mcp);
555 	(void) mdb_ctf_type_iter(MDB_CTF_SYNTHETIC_ITER, tab_complete_type,
556 	    mcp);
557 	return (0);
558 }
559 
560 /*ARGSUSED*/
561 static int
tab_complete_member(const char * name,mdb_ctf_id_t id,ulong_t off,void * arg)562 tab_complete_member(const char *name, mdb_ctf_id_t id, ulong_t off, void *arg)
563 {
564 	mdb_tab_cookie_t *mcp = arg;
565 	mdb_tab_insert(mcp, name);
566 	return (0);
567 }
568 
569 int
mdb_tab_complete_member_by_id(mdb_tab_cookie_t * mcp,mdb_ctf_id_t id,const char * member)570 mdb_tab_complete_member_by_id(mdb_tab_cookie_t *mcp, mdb_ctf_id_t id,
571     const char *member)
572 {
573 	if (member != NULL)
574 		mdb_tab_setmbase(mcp, member);
575 	(void) mdb_ctf_member_iter(id, tab_complete_member, mcp);
576 	return (0);
577 }
578 
579 int
mdb_tab_complete_member(mdb_tab_cookie_t * mcp,const char * type,const char * member)580 mdb_tab_complete_member(mdb_tab_cookie_t *mcp, const char *type,
581     const char *member)
582 {
583 	mdb_ctf_id_t id;
584 
585 	if (mdb_ctf_lookup_by_name(type, &id) != 0)
586 		return (-1);
587 
588 	return (mdb_tab_complete_member_by_id(mcp, id, member));
589 }
590 
591 int
mdb_tab_complete_mt(mdb_tab_cookie_t * mcp,uint_t flags,int argc,const mdb_arg_t * argv)592 mdb_tab_complete_mt(mdb_tab_cookie_t *mcp, uint_t flags, int argc,
593     const mdb_arg_t *argv)
594 {
595 	char tn[MDB_SYM_NAMLEN];
596 	int ret;
597 
598 	if (argc == 0 && !(flags & DCMD_TAB_SPACE))
599 		return (0);
600 
601 	if (argc == 0)
602 		return (mdb_tab_complete_type(mcp, NULL, MDB_TABC_MEMBERS));
603 
604 	if ((ret = mdb_tab_typename(&argc, &argv, tn, sizeof (tn))) < 0)
605 		return (ret);
606 
607 	if (argc == 1 && (!(flags & DCMD_TAB_SPACE) || ret == 1))
608 		return (mdb_tab_complete_type(mcp, tn, MDB_TABC_MEMBERS));
609 
610 	if (argc == 1 && (flags & DCMD_TAB_SPACE))
611 		return (mdb_tab_complete_member(mcp, tn, NULL));
612 
613 	if (argc == 2)
614 		return (mdb_tab_complete_member(mcp, tn, argv[1].a_un.a_str));
615 
616 	return (0);
617 }
618 
619 /*
620  * This is similar to mdb_print.c's args_to_typename, but it has subtle
621  * differences surrounding how the strings of one element are handled that have
622  * 'struct', 'enum', or 'union' in them and instead works with them for tab
623  * completion purposes.
624  */
625 int
mdb_tab_typename(int * argcp,const mdb_arg_t ** argvp,char * buf,size_t len)626 mdb_tab_typename(int *argcp, const mdb_arg_t **argvp, char *buf, size_t len)
627 {
628 	int argc = *argcp;
629 	const mdb_arg_t *argv = *argvp;
630 
631 	if (argc < 1 || argv->a_type != MDB_TYPE_STRING)
632 		return (DCMD_USAGE);
633 
634 	if (strcmp(argv->a_un.a_str, "struct") == 0 ||
635 	    strcmp(argv->a_un.a_str, "enum") == 0 ||
636 	    strcmp(argv->a_un.a_str, "union") == 0) {
637 		if (argc == 1) {
638 			(void) mdb_snprintf(buf, len, "%s ",
639 			    argv[0].a_un.a_str);
640 			return (1);
641 		}
642 
643 		if (argv[1].a_type != MDB_TYPE_STRING)
644 			return (DCMD_USAGE);
645 
646 		(void) mdb_snprintf(buf, len, "%s %s",
647 		    argv[0].a_un.a_str, argv[1].a_un.a_str);
648 
649 		*argcp = argc - 1;
650 		*argvp = argv + 1;
651 	} else {
652 		(void) mdb_snprintf(buf, len, "%s", argv[0].a_un.a_str);
653 	}
654 
655 	return (0);
656 }
657