1 /* $NetBSD: refuse_opt.c,v 1.23 2022/01/22 07:58:32 pho Exp $ */
2
3 /*-
4 * Copyright (c) 2007 Juan Romero Pardines.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include <sys/types.h>
29
30 #include <err.h>
31 #include <fuse_internal.h>
32 #include <fuse_opt.h>
33 #include <stdbool.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37
38 #ifdef FUSE_OPT_DEBUG
39 #define DPRINTF(x) do { printf x; } while ( /* CONSTCOND */ 0)
40 #else
41 #define DPRINTF(x)
42 #endif
43
44 /*
45 * Public API.
46 */
47
48 /* ARGSUSED */
49 int
fuse_opt_add_arg(struct fuse_args * args,const char * arg)50 fuse_opt_add_arg(struct fuse_args *args, const char *arg)
51 {
52 struct fuse_args *ap;
53
54 if (args->allocated == 0) {
55 ap = fuse_opt_deep_copy_args(args->argc, args->argv);
56 args->argv = ap->argv;
57 args->argc = ap->argc;
58 args->allocated = ap->allocated;
59 (void) free(ap);
60 } else if (args->allocated == args->argc) {
61 int na = args->allocated + 10;
62
63 if (reallocarr(&args->argv, (size_t)na, sizeof(*args->argv)) != 0)
64 return -1;
65
66 args->allocated = na;
67 }
68 DPRINTF(("%s: arguments passed: [arg:%s]\n", __func__, arg));
69 if ((args->argv[args->argc++] = strdup(arg)) == NULL)
70 err(1, "fuse_opt_add_arg");
71 args->argv[args->argc] = NULL;
72 return 0;
73 }
74
75 struct fuse_args *
fuse_opt_deep_copy_args(int argc,char ** argv)76 fuse_opt_deep_copy_args(int argc, char **argv)
77 {
78 struct fuse_args *ap;
79 int i;
80
81 if ((ap = malloc(sizeof(*ap))) == NULL)
82 err(1, "_fuse_deep_copy_args");
83 /* deep copy args structure into channel args */
84 ap->allocated = ((argc / 10) + 1) * 10;
85
86 if ((ap->argv = calloc((size_t)ap->allocated,
87 sizeof(*ap->argv))) == NULL)
88 err(1, "_fuse_deep_copy_args");
89
90 for (i = 0; i < argc; i++) {
91 if ((ap->argv[i] = strdup(argv[i])) == NULL)
92 err(1, "_fuse_deep_copy_args");
93 }
94 ap->argv[ap->argc = i] = NULL;
95 return ap;
96 }
97
98 void
fuse_opt_free_args(struct fuse_args * ap)99 fuse_opt_free_args(struct fuse_args *ap)
100 {
101 if (ap) {
102 if (ap->allocated) {
103 int i;
104 for (i = 0; i < ap->argc; i++) {
105 free(ap->argv[i]);
106 }
107 free(ap->argv);
108 }
109 ap->argv = NULL;
110 ap->allocated = ap->argc = 0;
111 }
112 }
113
114 /* ARGSUSED */
115 int
fuse_opt_insert_arg(struct fuse_args * args,int pos,const char * arg)116 fuse_opt_insert_arg(struct fuse_args *args, int pos, const char *arg)
117 {
118 int i;
119 int na;
120
121 DPRINTF(("%s: arguments passed: [pos=%d] [arg=%s]\n",
122 __func__, pos, arg));
123 if (args->argv == NULL) {
124 na = 10;
125 } else {
126 na = args->allocated + 10;
127 }
128 if (reallocarr(&args->argv, (size_t)na, sizeof(*args->argv)) != 0) {
129 warn("fuse_opt_insert_arg");
130 return -1;
131 }
132 args->allocated = na;
133
134 for (i = args->argc++; i > pos; --i) {
135 args->argv[i] = args->argv[i - 1];
136 }
137 if ((args->argv[pos] = strdup(arg)) == NULL)
138 err(1, "fuse_opt_insert_arg");
139 args->argv[args->argc] = NULL;
140 return 0;
141 }
142
add_opt(char ** opts,const char * opt,bool escape)143 static int add_opt(char **opts, const char *opt, bool escape)
144 {
145 const size_t orig_len = *opts == NULL ? 0 : strlen(*opts);
146 char* buf = realloc(*opts, orig_len + 1 + strlen(opt) * 2 + 1);
147
148 if (buf == NULL) {
149 return -1;
150 }
151 *opts = buf;
152
153 if (orig_len > 0) {
154 buf += orig_len;
155 *buf++ = ',';
156 }
157
158 for (; *opt; opt++) {
159 if (escape && (*opt == ',' || *opt == '\\')) {
160 *buf++ = '\\';
161 }
162 *buf++ = *opt;
163 }
164 *buf = '\0';
165
166 return 0;
167 }
168
fuse_opt_add_opt(char ** opts,const char * opt)169 int fuse_opt_add_opt(char **opts, const char *opt)
170 {
171 DPRINTF(("%s: arguments passed: [opts=%s] [opt=%s]\n",
172 __func__, *opts, opt));
173 return add_opt(opts, opt, false);
174 }
175
fuse_opt_add_opt_escaped(char ** opts,const char * opt)176 int fuse_opt_add_opt_escaped(char **opts, const char *opt)
177 {
178 DPRINTF(("%s: arguments passed: [opts=%s] [opt=%s]\n",
179 __func__, *opts, opt));
180 return add_opt(opts, opt, true);
181 }
182
match_templ(const char * templ,const char * opt,ssize_t * sep_idx)183 static bool match_templ(const char *templ, const char *opt, ssize_t *sep_idx)
184 {
185 const char *sep = strpbrk(templ, "= ");
186
187 if (sep != NULL && (sep[1] == '\0' || sep[1] == '%')) {
188 const size_t cmp_len =
189 (size_t)(sep[0] == '=' ? sep - templ + 1 : sep - templ);
190
191 if (strlen(opt) >= cmp_len && strncmp(templ, opt, cmp_len) == 0) {
192 if (sep_idx != NULL)
193 *sep_idx = (ssize_t)(sep - templ);
194 return true;
195 }
196 else {
197 return false;
198 }
199 }
200 else {
201 if (strcmp(templ, opt) == 0) {
202 if (sep_idx != NULL)
203 *sep_idx = -1;
204 return true;
205 }
206 else {
207 return false;
208 }
209 }
210 }
211
212 static const struct fuse_opt *
find_opt(const struct fuse_opt * opts,const char * opt,ssize_t * sep_idx)213 find_opt(const struct fuse_opt *opts, const char *opt, ssize_t *sep_idx)
214 {
215 for (; opts != NULL && opts->templ != NULL; opts++) {
216 if (match_templ(opts->templ, opt, sep_idx))
217 return opts;
218 }
219 return NULL;
220 }
221
222 /*
223 * Returns 1 if opt was matched with any option from opts,
224 * otherwise returns 0.
225 */
226 int
fuse_opt_match(const struct fuse_opt * opts,const char * opt)227 fuse_opt_match(const struct fuse_opt *opts, const char *opt)
228 {
229 return find_opt(opts, opt, NULL) != NULL ? 1 : 0;
230 }
231
call_proc(fuse_opt_proc_t proc,void * data,const char * arg,int key,struct fuse_args * outargs,bool is_opt)232 static int call_proc(fuse_opt_proc_t proc, void* data,
233 const char* arg, int key, struct fuse_args *outargs, bool is_opt)
234 {
235 if (key == FUSE_OPT_KEY_DISCARD)
236 return 0;
237
238 if (key != FUSE_OPT_KEY_KEEP && proc != NULL) {
239 const int rv = proc(data, arg, key, outargs);
240
241 if (rv == -1 || /* error */
242 rv == 0 /* discard */)
243 return rv;
244 }
245
246 if (is_opt) {
247 /* Do we already have "-o" at the beginning of outargs? */
248 if (outargs->argc >= 3 && strcmp(outargs->argv[1], "-o") == 0) {
249 /* Append the option to the comma-separated list. */
250 if (fuse_opt_add_opt_escaped(&outargs->argv[2], arg) == -1)
251 return -1;
252 }
253 else {
254 /* Insert -o arg at the beginning. */
255 if (fuse_opt_insert_arg(outargs, 1, "-o") == -1)
256 return -1;
257 if (fuse_opt_insert_arg(outargs, 2, arg) == -1)
258 return -1;
259 }
260 }
261 else {
262 if (fuse_opt_add_arg(outargs, arg) == -1)
263 return -1;
264 }
265
266 return 0;
267 }
268
269 /* Skip the current argv if possible. */
next_arg(const struct fuse_args * args,int * i)270 static int next_arg(const struct fuse_args *args, int *i)
271 {
272 if (*i + 1 >= args->argc) {
273 (void)fprintf(stderr, "fuse: missing argument"
274 " after '%s'\n", args->argv[*i]);
275 return -1;
276 }
277 else {
278 *i += 1;
279 return 0;
280 }
281 }
282
283 /* Parse a single argument with a matched template. */
284 static int
parse_matched_arg(const char * arg,struct fuse_args * outargs,const struct fuse_opt * opt,ssize_t sep_idx,void * data,fuse_opt_proc_t proc,bool is_opt)285 parse_matched_arg(const char* arg, struct fuse_args *outargs,
286 const struct fuse_opt* opt, ssize_t sep_idx, void* data,
287 fuse_opt_proc_t proc, bool is_opt)
288 {
289 if (opt->offset == -1) {
290 /* The option description does not want any variables to be
291 * updated.*/
292 if (call_proc(proc, data, arg, opt->value, outargs, is_opt) == -1)
293 return -1;
294 }
295 else {
296 void *var = (char*)data + opt->offset;
297
298 if (sep_idx > 0 && opt->templ[sep_idx + 1] == '%') {
299 /* "foo=%y" or "-x %y" */
300 const char* param =
301 opt->templ[sep_idx] == '=' ? &arg[sep_idx + 1] : &arg[sep_idx];
302
303 if (opt->templ[sep_idx + 2] == 's') {
304 char* dup = strdup(param);
305 if (dup == NULL)
306 return -1;
307
308 *(char **)var = dup;
309 }
310 else {
311 /* The format string is not a literal. We all know
312 * this is a bad idea but it's exactly what fuse_opt
313 * wants to do... */
314 #pragma GCC diagnostic push
315 #pragma GCC diagnostic ignored "-Wformat-nonliteral"
316 if (sscanf(param, &opt->templ[sep_idx + 1], var) == -1) {
317 #pragma GCC diagnostic pop
318 (void)fprintf(stderr, "fuse: '%s' is not a "
319 "valid parameter for option '%.*s'\n",
320 param, (int)sep_idx, opt->templ);
321 return -1;
322 }
323 }
324 }
325 else {
326 /* No parameter format is given. */
327 *(int *)var = opt->value;
328 }
329 }
330 return 0;
331 }
332
333 /* Parse a single argument with matching templates. */
334 static int
parse_arg(struct fuse_args * args,int * argi,const char * arg,struct fuse_args * outargs,void * data,const struct fuse_opt * opts,fuse_opt_proc_t proc,bool is_opt)335 parse_arg(struct fuse_args* args, int *argi, const char* arg,
336 struct fuse_args *outargs, void *data,
337 const struct fuse_opt *opts, fuse_opt_proc_t proc, bool is_opt)
338 {
339 ssize_t sep_idx;
340 const struct fuse_opt *opt = find_opt(opts, arg, &sep_idx);
341
342 if (opt) {
343 /* An argument can match to multiple templates. Process them
344 * all. */
345 for (; opt != NULL && opt->templ != NULL;
346 opt = find_opt(++opt, arg, &sep_idx)) {
347
348 if (sep_idx > 0 && opt->templ[sep_idx] == ' ' &&
349 arg[sep_idx] == '\0') {
350 /* The template "-x %y" requests a separate
351 * parameter "%y". Try to find one. */
352 char *new_arg;
353 int rv;
354
355 if (next_arg(args, argi) == -1)
356 return -1;
357
358 /* ...but processor callbacks expect a concatenated
359 * argument "-xfoo". */
360 if ((new_arg = malloc((size_t)sep_idx +
361 strlen(args->argv[*argi]) + 1)) == NULL)
362 return -1;
363
364 strncpy(new_arg, arg, (size_t)sep_idx); /* -x */
365 strcpy(new_arg + sep_idx, args->argv[*argi]); /* foo */
366 rv = parse_matched_arg(new_arg, outargs, opt, sep_idx,
367 data, proc, is_opt);
368 free(new_arg);
369
370 if (rv == -1)
371 return -1;
372 }
373 else {
374 int rv;
375 rv = parse_matched_arg(arg, outargs, opt, sep_idx,
376 data, proc, is_opt);
377 if (rv == -1)
378 return -1;
379 }
380 }
381 return 0;
382 }
383 else {
384 /* No templates matched to it so just invoke the callback. */
385 return call_proc(proc, data, arg, FUSE_OPT_KEY_OPT, outargs, is_opt);
386 }
387 }
388
389 /* Parse a comma-separated list of options which possibly has escaped
390 * characters. */
391 static int
parse_opts(struct fuse_args * args,int * argi,const char * arg,struct fuse_args * outargs,void * data,const struct fuse_opt * opts,fuse_opt_proc_t proc)392 parse_opts(struct fuse_args *args, int *argi, const char* arg,
393 struct fuse_args *outargs, void *data,
394 const struct fuse_opt *opts, fuse_opt_proc_t proc)
395 {
396 char *opt;
397 size_t i, opt_len = 0;
398
399 /* An unescaped option can never be longer than the original
400 * list. */
401 if ((opt = malloc(strlen(arg) + 1)) == NULL)
402 return -1;
403
404 for (i = 0; i < strlen(arg); i++) {
405 if (arg[i] == ',') {
406 opt[opt_len] = '\0';
407 if (parse_arg(args, argi, opt, outargs,
408 data, opts, proc, true) == -1) {
409 free(opt);
410 return -1;
411 }
412 /* Start a new option. */
413 opt_len = 0;
414 }
415 else if (arg[i] == '\\' && arg[i+1] != '\0') {
416 /* Unescape it. */
417 opt[opt_len++] = arg[i+1];
418 i++;
419 }
420 else {
421 opt[opt_len++] = arg[i];
422 }
423 }
424
425 /* Parse the last option here. */
426 opt[opt_len] = '\0';
427 if (parse_arg(args, argi, opt, outargs, data, opts, proc, true) == -1) {
428 free(opt);
429 return -1;
430 }
431
432 free(opt);
433 return 0;
434 }
435
436 static int
parse_all(struct fuse_args * args,struct fuse_args * outargs,void * data,const struct fuse_opt * opts,fuse_opt_proc_t proc)437 parse_all(struct fuse_args *args, struct fuse_args *outargs, void *data,
438 const struct fuse_opt *opts, fuse_opt_proc_t proc)
439 {
440 bool nonopt = false; /* Have we seen the "--" marker? */
441 int i;
442
443 /* The first argument, the program name, is implicitly
444 * FUSE_OPT_KEY_KEEP. */
445 if (args->argc > 0) {
446 if (fuse_opt_add_arg(outargs, args->argv[0]) == -1)
447 return -1;
448 }
449
450 /* the real loop to process the arguments */
451 for (i = 1; i < args->argc; i++) {
452 const char *arg = args->argv[i];
453
454 /* argvn != -foo... */
455 if (nonopt || arg[0] != '-') {
456 if (call_proc(proc, data, arg, FUSE_OPT_KEY_NONOPT,
457 outargs, false) == -1)
458 return -1;
459 }
460 /* -o or -ofoo */
461 else if (arg[1] == 'o') {
462 /* -oblah,foo... */
463 if (arg[2] != '\0') {
464 /* skip -o */
465 if (parse_opts(args, &i, arg + 2, outargs,
466 data, opts, proc) == -1)
467 return -1;
468 }
469 /* -o blah,foo... */
470 else {
471 if (next_arg(args, &i) == -1)
472 return -1;
473 if (parse_opts(args, &i, args->argv[i], outargs,
474 data, opts, proc) == -1)
475 return -1;
476 }
477 }
478 /* -- */
479 else if (arg[1] == '-' && arg[2] == '\0') {
480 if (fuse_opt_add_arg(outargs, arg) == -1)
481 return -1;
482 nonopt = true;
483 }
484 /* -foo */
485 else {
486 if (parse_arg(args, &i, arg, outargs,
487 data, opts, proc, false) == -1)
488 return -1;
489 }
490 }
491
492 /* The "--" marker at the last of outargs should be removed */
493 if (nonopt && strcmp(outargs->argv[outargs->argc - 1], "--") == 0) {
494 free(outargs->argv[outargs->argc - 1]);
495 outargs->argv[--outargs->argc] = NULL;
496 }
497
498 return 0;
499 }
500
501 int
fuse_opt_parse(struct fuse_args * args,void * data,const struct fuse_opt * opts,fuse_opt_proc_t proc)502 fuse_opt_parse(struct fuse_args *args, void *data,
503 const struct fuse_opt *opts, fuse_opt_proc_t proc)
504 {
505 struct fuse_args outargs = FUSE_ARGS_INIT(0, NULL);
506 int rv;
507
508 if (!args || !args->argv || !args->argc)
509 return 0;
510
511 rv = parse_all(args, &outargs, data, opts, proc);
512 if (rv != -1) {
513 /* Succeeded. Swap the outargs and args. */
514 struct fuse_args tmp = *args;
515 *args = outargs;
516 outargs = tmp;
517 }
518
519 fuse_opt_free_args(&outargs);
520 return rv;
521 }
522