libfuse: lib/fuse_opt.c Source File

libfuse

fuse_opt.c
1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu>
4
5 Implementation of option parsing routines (dealing with `struct
6 fuse_args`).
7
8 This program can be distributed under the terms of the GNU LGPLv2.
9 See the file COPYING.LIB
10 */
11
12 #include "config.h"
13 #include "fuse_i.h"
14 #include "fuse_opt.h"
15 #include "fuse_misc.h"
16
17 #include <stdio.h>
18 #include <stdlib.h>
19 #include <string.h>
20 #include <assert.h>
21
22 struct fuse_opt_context {
23 void *data;
24 const struct fuse_opt *opt;
25 fuse_opt_proc_t proc;
26 int argctr;
27 int argc;
28 char **argv;
29 struct fuse_args outargs;
30 char *opts;
31 int nonopt;
32 };
33
34 void fuse_opt_free_args(struct fuse_args *args)
35 {
36 if (args) {
37 if (args->argv && args->allocated) {
38 int i;
39 for (i = 0; i < args->argc; i++)
40 free(args->argv[i]);
41 free(args->argv);
42 }
43 args->argc = 0;
44 args->argv = NULL;
45 args->allocated = 0;
46 }
47 }
48
49 static int alloc_failed(void)
50 {
51 fuse_log(FUSE_LOG_ERR, "fuse: memory allocation failed\n");
52 return -1;
53 }
54
55 int fuse_opt_add_arg(struct fuse_args *args, const char *arg)
56 {
57 char **newargv;
58 char *newarg;
59
60 assert(!args->argv || args->allocated);
61
62 newarg = strdup(arg);
63 if (!newarg)
64 return alloc_failed();
65
66 newargv = realloc(args->argv, (args->argc + 2) * sizeof(char *));
67 if (!newargv) {
68 free(newarg);
69 return alloc_failed();
70 }
71
72 args->argv = newargv;
73 args->allocated = 1;
74 args->argv[args->argc++] = newarg;
75 args->argv[args->argc] = NULL;
76 return 0;
77 }
78
79 static int fuse_opt_insert_arg_common(struct fuse_args *args, int pos,
80 const char *arg)
81 {
82 assert(pos <= args->argc);
83 if (fuse_opt_add_arg(args, arg) == -1)
84 return -1;
85
86 if (pos != args->argc - 1) {
87 char *newarg = args->argv[args->argc - 1];
88 memmove(&args->argv[pos + 1], &args->argv[pos],
89 sizeof(char *) * (args->argc - pos - 1));
90 args->argv[pos] = newarg;
91 }
92 return 0;
93 }
94
95 int fuse_opt_insert_arg(struct fuse_args *args, int pos, const char *arg)
96 {
97 return fuse_opt_insert_arg_common(args, pos, arg);
98 }
99
100 static int next_arg(struct fuse_opt_context *ctx, const char *opt)
101 {
102 if (ctx->argctr + 1 >= ctx->argc) {
103 fuse_log(FUSE_LOG_ERR, "fuse: missing argument after `%s'\n", opt);
104 return -1;
105 }
106 ctx->argctr++;
107 return 0;
108 }
109
110 static int add_arg(struct fuse_opt_context *ctx, const char *arg)
111 {
112 return fuse_opt_add_arg(&ctx->outargs, arg);
113 }
114
115 static int add_opt_common(char **opts, const char *opt, int esc)
116 {
117 unsigned oldlen = *opts ? strlen(*opts) : 0;
118 char *d = realloc(*opts, oldlen + 1 + strlen(opt) * 2 + 1);
119
120 if (!d)
121 return alloc_failed();
122
123 *opts = d;
124 if (oldlen) {
125 d += oldlen;
126 *d++ = ',';
127 }
128
129 for (; *opt; opt++) {
130 if (esc && (*opt == ',' || *opt == '\\'))
131 *d++ = '\\';
132 *d++ = *opt;
133 }
134 *d = '\0';
135
136 return 0;
137 }
138
139 int fuse_opt_add_opt(char **opts, const char *opt)
140 {
141 return add_opt_common(opts, opt, 0);
142 }
143
144 int fuse_opt_add_opt_escaped(char **opts, const char *opt)
145 {
146 return add_opt_common(opts, opt, 1);
147 }
148
149 static int add_opt(struct fuse_opt_context *ctx, const char *opt)
150 {
151 return add_opt_common(&ctx->opts, opt, 1);
152 }
153
154 static int call_proc(struct fuse_opt_context *ctx, const char *arg, int key,
155 int iso)
156 {
157 if (key == FUSE_OPT_KEY_DISCARD)
158 return 0;
159
160 if (key != FUSE_OPT_KEY_KEEP && ctx->proc) {
161 int res = ctx->proc(ctx->data, arg, key, &ctx->outargs);
162 if (res == -1 || !res)
163 return res;
164 }
165 if (iso)
166 return add_opt(ctx, arg);
167 else
168 return add_arg(ctx, arg);
169 }
170
171 static int match_template(const char *t, const char *arg, unsigned *sepp)
172 {
173 int arglen = strlen(arg);
174 const char *sep = strchr(t, '=');
175 sep = sep ? sep : strchr(t, ' ');
176 if (sep && (!sep[1] || sep[1] == '%')) {
177 int tlen = sep - t;
178 if (sep[0] == '=')
179 tlen ++;
180 if (arglen >= tlen && strncmp(arg, t, tlen) == 0) {
181 *sepp = sep - t;
182 return 1;
183 }
184 }
185 if (strcmp(t, arg) == 0) {
186 *sepp = 0;
187 return 1;
188 }
189 return 0;
190 }
191
192 static const struct fuse_opt *find_opt(const struct fuse_opt *opt,
193 const char *arg, unsigned *sepp)
194 {
195 for (; opt && opt->templ; opt++)
196 if (match_template(opt->templ, arg, sepp))
197 return opt;
198 return NULL;
199 }
200
201 int fuse_opt_match(const struct fuse_opt *opts, const char *opt)
202 {
203 unsigned dummy;
204 return find_opt(opts, opt, &dummy) ? 1 : 0;
205 }
206
207 static int process_opt_param(void *var, const char *format, const char *param,
208 const char *arg)
209 {
210 assert(format[0] == '%');
211 if (format[1] == 's') {
212 char **s = var;
213 char *copy = strdup(param);
214 if (!copy)
215 return alloc_failed();
216
217 free(*s);
218 *s = copy;
219 } else {
220 if (sscanf(param, format, var) != 1) {
221 fuse_log(FUSE_LOG_ERR, "fuse: invalid parameter in option `%s'\n", arg);
222 return -1;
223 }
224 }
225 return 0;
226 }
227
228 static int process_opt(struct fuse_opt_context *ctx,
229 const struct fuse_opt *opt, unsigned sep,
230 const char *arg, int iso)
231 {
232 if (opt->offset == -1U) {
233 if (call_proc(ctx, arg, opt->value, iso) == -1)
234 return -1;
235 } else {
236 void *var = (char *)ctx->data + opt->offset;
237 if (sep && opt->templ[sep + 1]) {
238 const char *param = arg + sep;
239 if (opt->templ[sep] == '=')
240 param ++;
241 if (process_opt_param(var, opt->templ + sep + 1,
242 param, arg) == -1)
243 return -1;
244 } else
245 *(int *)var = opt->value;
246 }
247 return 0;
248 }
249
250 static int process_opt_sep_arg(struct fuse_opt_context *ctx,
251 const struct fuse_opt *opt, unsigned sep,
252 const char *arg, int iso)
253 {
254 int res;
255 char *newarg;
256 char *param;
257
258 if (next_arg(ctx, arg) == -1)
259 return -1;
260
261 param = ctx->argv[ctx->argctr];
262 newarg = malloc(sep + strlen(param) + 1);
263 if (!newarg)
264 return alloc_failed();
265
266 memcpy(newarg, arg, sep);
267 strcpy(newarg + sep, param);
268 res = process_opt(ctx, opt, sep, newarg, iso);
269 free(newarg);
270
271 return res;
272 }
273
274 static int process_gopt(struct fuse_opt_context *ctx, const char *arg, int iso)
275 {
276 unsigned sep;
277 const struct fuse_opt *opt = find_opt(ctx->opt, arg, &sep);
278 if (opt) {
279 for (; opt; opt = find_opt(opt + 1, arg, &sep)) {
280 int res;
281 if (sep && opt->templ[sep] == ' ' && !arg[sep])
282 res = process_opt_sep_arg(ctx, opt, sep, arg,
283 iso);
284 else
285 res = process_opt(ctx, opt, sep, arg, iso);
286 if (res == -1)
287 return -1;
288 }
289 return 0;
290 } else
291 return call_proc(ctx, arg, FUSE_OPT_KEY_OPT, iso);
292 }
293
294 static int process_real_option_group(struct fuse_opt_context *ctx, char *opts)
295 {
296 char *s = opts;
297 char *d = s;
298 int end = 0;
299
300 while (!end) {
301 if (*s == '\0')
302 end = 1;
303 if (*s == ',' || end) {
304 int res;
305
306 *d = '\0';
307 res = process_gopt(ctx, opts, 1);
308 if (res == -1)
309 return -1;
310 d = opts;
311 } else {
312 if (s[0] == '\\' && s[1] != '\0') {
313 s++;
314 if (s[0] >= '0' && s[0] <= '3' &&
315 s[1] >= '0' && s[1] <= '7' &&
316 s[2] >= '0' && s[2] <= '7') {
317 *d++ = (s[0] - '0') * 0100 +
318 (s[1] - '0') * 0010 +
319 (s[2] - '0');
320 s += 2;
321 } else {
322 *d++ = *s;
323 }
324 } else {
325 *d++ = *s;
326 }
327 }
328 s++;
329 }
330
331 return 0;
332 }
333
334 static int process_option_group(struct fuse_opt_context *ctx, const char *opts)
335 {
336 int res;
337 char *copy = strdup(opts);
338
339 if (!copy) {
340 fuse_log(FUSE_LOG_ERR, "fuse: memory allocation failed\n");
341 return -1;
342 }
343 res = process_real_option_group(ctx, copy);
344 free(copy);
345 return res;
346 }
347
348 static int process_one(struct fuse_opt_context *ctx, const char *arg)
349 {
350 if (ctx->nonopt || arg[0] != '-')
351 return call_proc(ctx, arg, FUSE_OPT_KEY_NONOPT, 0);
352 else if (arg[1] == 'o') {
353 if (arg[2])
354 return process_option_group(ctx, arg + 2);
355 else {
356 if (next_arg(ctx, arg) == -1)
357 return -1;
358
359 return process_option_group(ctx,
360 ctx->argv[ctx->argctr]);
361 }
362 } else if (arg[1] == '-' && !arg[2]) {
363 if (add_arg(ctx, arg) == -1)
364 return -1;
365 ctx->nonopt = ctx->outargs.argc;
366 return 0;
367 } else
368 return process_gopt(ctx, arg, 0);
369 }
370
371 static int opt_parse(struct fuse_opt_context *ctx)
372 {
373 if (ctx->argc) {
374 if (add_arg(ctx, ctx->argv[0]) == -1)
375 return -1;
376 }
377
378 for (ctx->argctr = 1; ctx->argctr < ctx->argc; ctx->argctr++)
379 if (process_one(ctx, ctx->argv[ctx->argctr]) == -1)
380 return -1;
381
382 if (ctx->opts) {
383 if (fuse_opt_insert_arg(&ctx->outargs, 1, "-o") == -1 ||
384 fuse_opt_insert_arg(&ctx->outargs, 2, ctx->opts) == -1)
385 return -1;
386 }
387
388 /* If option separator ("--") is the last argument, remove it */
389 if (ctx->nonopt && ctx->nonopt == ctx->outargs.argc &&
390 strcmp(ctx->outargs.argv[ctx->outargs.argc - 1], "--") == 0) {
391 free(ctx->outargs.argv[ctx->outargs.argc - 1]);
392 ctx->outargs.argv[--ctx->outargs.argc] = NULL;
393 }
394
395 return 0;
396 }
397
398 int fuse_opt_parse(struct fuse_args *args, void *data,
399 const struct fuse_opt opts[], fuse_opt_proc_t proc)
400 {
401 int res;
402 struct fuse_opt_context ctx = {
403 .data = data,
404 .opt = opts,
405 .proc = proc,
406 };
407
408 if (!args || !args->argv || !args->argc)
409 return 0;
410
411 ctx.argc = args->argc;
412 ctx.argv = args->argv;
413
414 res = opt_parse(&ctx);
415 if (res != -1) {
416 struct fuse_args tmp = *args;
417 *args = ctx.outargs;
418 ctx.outargs = tmp;
419 }
420 free(ctx.opts);
421 fuse_opt_free_args(&ctx.outargs);
422 return res;
423 }
fuse_log
void fuse_log(enum fuse_log_level level, const char *fmt,...)
Definition: fuse_log.c:33
fuse_opt_add_arg
int fuse_opt_add_arg(struct fuse_args *args, const char *arg)
Definition: fuse_opt.c:55
fuse_opt_free_args
void fuse_opt_free_args(struct fuse_args *args)
Definition: fuse_opt.c:34
fuse_opt_proc_t
int(* fuse_opt_proc_t)(void *data, const char *arg, int key, struct fuse_args *outargs)
Definition: fuse_opt.h:180
FUSE_OPT_KEY_OPT
#define FUSE_OPT_KEY_OPT
Definition: fuse_opt.h:129
fuse_opt_add_opt_escaped
int fuse_opt_add_opt_escaped(char **opts, const char *opt)
Definition: fuse_opt.c:144
fuse_opt_parse
int fuse_opt_parse(struct fuse_args *args, void *data, const struct fuse_opt opts[], fuse_opt_proc_t proc)
Definition: fuse_opt.c:398
FUSE_OPT_KEY_NONOPT
#define FUSE_OPT_KEY_NONOPT
Definition: fuse_opt.h:137
FUSE_OPT_KEY_DISCARD
#define FUSE_OPT_KEY_DISCARD
Definition: fuse_opt.h:153
FUSE_OPT_KEY_KEEP
#define FUSE_OPT_KEY_KEEP
Definition: fuse_opt.h:145
fuse_opt_add_opt
int fuse_opt_add_opt(char **opts, const char *opt)
Definition: fuse_opt.c:139
fuse_opt_insert_arg
int fuse_opt_insert_arg(struct fuse_args *args, int pos, const char *arg)
Definition: fuse_opt.c:95
fuse_opt_match
int fuse_opt_match(const struct fuse_opt opts[], const char *opt)
fuse_args
Definition: fuse_opt.h:109
fuse_args::allocated
int allocated
Definition: fuse_opt.h:117
fuse_args::argc
int argc
Definition: fuse_opt.h:111
fuse_args::argv
char ** argv
Definition: fuse_opt.h:114
fuse_opt
Definition: fuse_opt.h:77
fuse_opt::offset
unsigned long offset
Definition: fuse_opt.h:85
fuse_opt::templ
const char * templ
Definition: fuse_opt.h:79
fuse_opt::value
int value
Definition: fuse_opt.h:91