lib/fuse_opt.c

   1 /*
   2   FUSE: Filesystem in Userspace
   3   Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>
   4
   5   This program can be distributed under the terms of the GNU LGPLv2.
   6   See the file COPYING.LIB
   7 */
   8
   9 #include "fuse_opt.h"
  10 #include "fuse_misc.h"
  11
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <assert.h>
  16
  17 struct fuse_opt_context {
  18         void *data;
  19         const struct fuse_opt *opt;
  20         fuse_opt_proc_t proc;
  21         int argctr;
  22         int argc;
  23         char **argv;
  24         struct fuse_args outargs;
  25         char *opts;
  26         int nonopt;
  27 };
  28
  29 void fuse_opt_free_args(struct fuse_args *args)
  30 {
  31         if (args) {
  32                 if (args->argv && args->allocated) {
  33                         int i;
  34                         for (i = 0; i < args->argc; i++)
  35                                 free(args->argv[i]);
  36                         free(args->argv);
  37                 }
  38                 args->argc = 0;
  39                 args->argv = NULL;
  40                 args->allocated = 0;
  41         }
  42 }
  43
  44 static int alloc_failed(void)
  45 {
  46         fprintf(stderr, "fuse: memory allocation failed\n");
  47         return -1;
  48 }
  49
  50 int fuse_opt_add_arg(struct fuse_args *args, const char *arg)
  51 {
  52         char **newargv;
  53         char *newarg;
  54
  55         assert(!args->argv || args->allocated);
  56
  57         newargv = realloc(args->argv, (args->argc + 2) * sizeof(char *));
  58         newarg = newargv ? strdup(arg) : NULL;
  59         if (!newargv || !newarg)
  60                 return alloc_failed();
  61
  62         args->argv = newargv;
  63         args->allocated = 1;
  64         args->argv[args->argc++] = newarg;
  65         args->argv[args->argc] = NULL;
  66         return 0;
  67 }
  68
  69 static int fuse_opt_insert_arg_common(struct fuse_args *args, int pos,
  70                                       const char *arg)
  71 {
  72         assert(pos <= args->argc);
  73         if (fuse_opt_add_arg(args, arg) == -1)
  74                 return -1;
  75
  76         if (pos != args->argc - 1) {
  77                 char *newarg = args->argv[args->argc - 1];
  78                 memmove(&args->argv[pos + 1], &args->argv[pos],
  79                         sizeof(char *) * (args->argc - pos - 1));
  80                 args->argv[pos] = newarg;
  81         }
  82         return 0;
  83 }
  84
  85 int fuse_opt_insert_arg(struct fuse_args *args, int pos, const char *arg)
  86 {
  87         return fuse_opt_insert_arg_common(args, pos, arg);
  88 }
  89
  90 int fuse_opt_insert_arg_compat(struct fuse_args *args, int pos,
  91                                const char *arg);
  92 int fuse_opt_insert_arg_compat(struct fuse_args *args, int pos, const char *arg)
  93 {
  94         return fuse_opt_insert_arg_common(args, pos, arg);
  95 }
  96
  97 static int next_arg(struct fuse_opt_context *ctx, const char *opt)
  98 {
  99         if (ctx->argctr + 1 >= ctx->argc) {
 100                 fprintf(stderr, "fuse: missing argument after `%s'\n", opt);
 101                 return -1;
 102         }
 103         ctx->argctr++;
 104         return 0;
 105 }
 106
 107 static int add_arg(struct fuse_opt_context *ctx, const char *arg)
 108 {
 109         return fuse_opt_add_arg(&ctx->outargs, arg);
 110 }
 111
 112 static int add_opt_common(char **opts, const char *opt, int esc)
 113 {
 114         unsigned oldlen = *opts ? strlen(*opts) : 0;
 115         char *d = realloc(*opts, oldlen + 1 + strlen(opt) * 2 + 1);
 116
 117         if (!d)
 118                 return alloc_failed();
 119
 120         *opts = d;
 121         if (oldlen) {
 122                 d += oldlen;
 123                 *d++ = ',';
 124         }
 125
 126         for (; *opt; opt++) {
 127                 if (esc && (*opt == ',' || *opt == '\\'))
 128                         *d++ = '\\';
 129                 *d++ = *opt;
 130         }
 131         *d = '\0';
 132
 133         return 0;
 134 }
 135
 136 int fuse_opt_add_opt(char **opts, const char *opt)
 137 {
 138         return add_opt_common(opts, opt, 0);
 139 }
 140
 141 int fuse_opt_add_opt_escaped(char **opts, const char *opt)
 142 {
 143         return add_opt_common(opts, opt, 1);
 144 }
 145
 146 static int add_opt(struct fuse_opt_context *ctx, const char *opt)
 147 {
 148         return add_opt_common(&ctx->opts, opt, 1);
 149 }
 150
 151 static int call_proc(struct fuse_opt_context *ctx, const char *arg, int key,
 152                      int iso)
 153 {
 154         if (key == FUSE_OPT_KEY_DISCARD)
 155                 return 0;
 156
 157         if (key != FUSE_OPT_KEY_KEEP && ctx->proc) {
 158                 int res = ctx->proc(ctx->data, arg, key, &ctx->outargs);
 159                 if (res == -1 || !res)
 160                         return res;
 161         }
 162         if (iso)
 163                 return add_opt(ctx, arg);
 164         else
 165                 return add_arg(ctx, arg);
 166 }
 167
 168 static int match_template(const char *t, const char *arg, unsigned *sepp)
 169 {
 170         int arglen = strlen(arg);
 171         const char *sep = strchr(t, '=');
 172         sep = sep ? sep : strchr(t, ' ');
 173         if (sep && (!sep[1] || sep[1] == '%')) {
 174                 int tlen = sep - t;
 175                 if (sep[0] == '=')
 176                         tlen ++;
 177                 if (arglen >= tlen && strncmp(arg, t, tlen) == 0) {
 178                         *sepp = sep - t;
 179                         return 1;
 180                 }
 181         }
 182         if (strcmp(t, arg) == 0) {
 183                 *sepp = 0;
 184                 return 1;
 185         }
 186         return 0;
 187 }
 188
 189 static const struct fuse_opt *find_opt(const struct fuse_opt *opt,
 190                                        const char *arg, unsigned *sepp)
 191 {
 192         for (; opt && opt->templ; opt++)
 193                 if (match_template(opt->templ, arg, sepp))
 194                         return opt;
 195         return NULL;
 196 }
 197
 198 int fuse_opt_match(const struct fuse_opt *opts, const char *opt)
 199 {
 200         unsigned dummy;
 201         return find_opt(opts, opt, &dummy) ? 1 : 0;
 202 }
 203
 204 static int process_opt_param(void *var, const char *format, const char *param,
 205                              const char *arg)
 206 {
 207         assert(format[0] == '%');
 208         if (format[1] == 's') {
 209                 char *copy = strdup(param);
 210                 if (!copy)
 211                         return alloc_failed();
 212
 213                 *(char **) var = copy;
 214         } else {
 215                 if (sscanf(param, format, var) != 1) {
 216                         fprintf(stderr, "fuse: invalid parameter in option `%s'\n", arg);
 217                         return -1;
 218                 }
 219         }
 220         return 0;
 221 }
 222
 223 static int process_opt(struct fuse_opt_context *ctx,
 224                        const struct fuse_opt *opt, unsigned sep,
 225                        const char *arg, int iso)
 226 {
 227         if (opt->offset == -1U) {
 228                 if (call_proc(ctx, arg, opt->value, iso) == -1)
 229                         return -1;
 230         } else {
 231                 void *var = ctx->data + opt->offset;
 232                 if (sep && opt->templ[sep + 1]) {
 233                         const char *param = arg + sep;
 234                         if (opt->templ[sep] == '=')
 235                                 param ++;
 236                         if (process_opt_param(var, opt->templ + sep + 1,
 237                                               param, arg) == -1)
 238                                 return -1;
 239                 } else
 240                         *(int *)var = opt->value;
 241         }
 242         return 0;
 243 }
 244
 245 static int process_opt_sep_arg(struct fuse_opt_context *ctx,
 246                                const struct fuse_opt *opt, unsigned sep,
 247                                const char *arg, int iso)
 248 {
 249         int res;
 250         char *newarg;
 251         char *param;
 252
 253         if (next_arg(ctx, arg) == -1)
 254                 return -1;
 255
 256         param = ctx->argv[ctx->argctr];
 257         newarg = malloc(sep + strlen(param) + 1);
 258         if (!newarg)
 259                 return alloc_failed();
 260
 261         memcpy(newarg, arg, sep);
 262         strcpy(newarg + sep, param);
 263         res = process_opt(ctx, opt, sep, newarg, iso);
 264         free(newarg);
 265
 266         return res;
 267 }
 268
 269 static int process_gopt(struct fuse_opt_context *ctx, const char *arg, int iso)
 270 {
 271         unsigned sep;
 272         const struct fuse_opt *opt = find_opt(ctx->opt, arg, &sep);
 273         if (opt) {
 274                 for (; opt; opt = find_opt(opt + 1, arg, &sep)) {
 275                         int res;
 276                         if (sep && opt->templ[sep] == ' ' && !arg[sep])
 277                                 res = process_opt_sep_arg(ctx, opt, sep, arg,
 278                                                           iso);
 279                         else
 280                                 res = process_opt(ctx, opt, sep, arg, iso);
 281                         if (res == -1)
 282                                 return -1;
 283                 }
 284                 return 0;
 285         } else
 286                 return call_proc(ctx, arg, FUSE_OPT_KEY_OPT, iso);
 287 }
 288
 289 static int process_real_option_group(struct fuse_opt_context *ctx, char *opts)
 290 {
 291         char *s = opts;
 292         char *d = s;
 293         int end = 0;
 294
 295         while (!end) {
 296                 if (*s == '\0')
 297                         end = 1;
 298                 if (*s == ',' || end) {
 299                         int res;
 300
 301                         *d = '\0';
 302                         res = process_gopt(ctx, opts, 1);
 303                         if (res == -1)
 304                                 return -1;
 305                         d = opts;
 306                 } else {
 307                         if (s[0] == '\\' && s[1] != '\0')
 308                                 s++;
 309                         *d++ = *s;
 310                 }
 311                 s++;
 312         }
 313
 314         return 0;
 315 }
 316
 317 static int process_option_group(struct fuse_opt_context *ctx, const char *opts)
 318 {
 319         int res;
 320         char *copy = strdup(opts);
 321
 322         if (!copy) {
 323                 fprintf(stderr, "fuse: memory allocation failed\n");
 324                 return -1;
 325         }
 326         res = process_real_option_group(ctx, copy);
 327         free(copy);
 328         return res;
 329 }
 330
 331 static int process_one(struct fuse_opt_context *ctx, const char *arg)
 332 {
 333         if (ctx->nonopt || arg[0] != '-')
 334                 return call_proc(ctx, arg, FUSE_OPT_KEY_NONOPT, 0);
 335         else if (arg[1] == 'o') {
 336                 if (arg[2])
 337                         return process_option_group(ctx, arg + 2);
 338                 else {
 339                         if (next_arg(ctx, arg) == -1)
 340                                 return -1;
 341
 342                         return process_option_group(ctx,
 343                                                     ctx->argv[ctx->argctr]);
 344                 }
 345         } else if (arg[1] == '-' && !arg[2]) {
 346                 if (add_arg(ctx, arg) == -1)
 347                         return -1;
 348                 ctx->nonopt = ctx->outargs.argc;
 349                 return 0;
 350         } else
 351                 return process_gopt(ctx, arg, 0);
 352 }
 353
 354 static int opt_parse(struct fuse_opt_context *ctx)
 355 {
 356         if (ctx->argc) {
 357                 if (add_arg(ctx, ctx->argv[0]) == -1)
 358                         return -1;
 359         }
 360
 361         for (ctx->argctr = 1; ctx->argctr < ctx->argc; ctx->argctr++)
 362                 if (process_one(ctx, ctx->argv[ctx->argctr]) == -1)
 363                         return -1;
 364
 365         if (ctx->opts) {
 366                 if (fuse_opt_insert_arg(&ctx->outargs, 1, "-o") == -1 ||
 367                     fuse_opt_insert_arg(&ctx->outargs, 2, ctx->opts) == -1)
 368                         return -1;
 369         }
 370
 371         /* If option separator ("--") is the last argument, remove it */
 372         if (ctx->nonopt && ctx->nonopt == ctx->outargs.argc &&
 373             strcmp(ctx->outargs.argv[ctx->outargs.argc - 1], "--") == 0) {
 374                 free(ctx->outargs.argv[ctx->outargs.argc - 1]);
 375                 ctx->outargs.argv[--ctx->outargs.argc] = NULL;
 376         }
 377
 378         return 0;
 379 }
 380
 381 int fuse_opt_parse(struct fuse_args *args, void *data,
 382                    const struct fuse_opt opts[], fuse_opt_proc_t proc)
 383 {
 384         int res;
 385         struct fuse_opt_context ctx = {
 386                 .data = data,
 387                 .opt = opts,
 388                 .proc = proc,
 389         };
 390
 391         if (!args || !args->argv || !args->argc)
 392                 return 0;
 393
 394         ctx.argc = args->argc;
 395         ctx.argv = args->argv;
 396
 397         res = opt_parse(&ctx);
 398         if (res != -1) {
 399                 struct fuse_args tmp = *args;
 400                 *args = ctx.outargs;
 401                 ctx.outargs = tmp;
 402         }
 403         free(ctx.opts);
 404         fuse_opt_free_args(&ctx.outargs);
 405         return res;
 406 }
 407
 408 /* This symbol version was mistakenly added to the version script */
 409 FUSE_SYMVER(".symver fuse_opt_insert_arg_compat,fuse_opt_insert_arg@FUSE_2.5");