sdcard.c revision 1bedb73f9fc239b69d958cbabc50c7ba382bacbc 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <stdio.h>
18#include <stdlib.h>
19#include <string.h>
20#include <unistd.h>
21#include <errno.h>
22#include <fcntl.h>
23#include <sys/mount.h>
24#include <sys/stat.h>
25#include <sys/statfs.h>
26#include <sys/uio.h>
27#include <dirent.h>
28#include <ctype.h>
29
30#include <private/android_filesystem_config.h>
31
32#include "fuse.h"
33
34/* README
35 *
36 * What is this?
37 *
38 * sdcard is a program that uses FUSE to emulate FAT-on-sdcard style
39 * directory permissions (all files are given fixed owner, group, and
40 * permissions at creation, owner, group, and permissions are not
41 * changeable, symlinks and hardlinks are not createable, etc.
42 *
43 * usage:  sdcard <path> <uid> <gid>
44 *
45 * It must be run as root, but will change to uid/gid as soon as it
46 * mounts a filesystem on /mnt/sdcard.  It will refuse to run if uid or
47 * gid are zero.
48 *
49 *
50 * Things I believe to be true:
51 *
52 * - ops that return a fuse_entry (LOOKUP, MKNOD, MKDIR, LINK, SYMLINK,
53 * CREAT) must bump that node's refcount
54 * - don't forget that FORGET can forget multiple references (req->nlookup)
55 * - if an op that returns a fuse_entry fails writing the reply to the
56 * kernel, you must rollback the refcount to reflect the reference the
57 * kernel did not actually acquire
58 *
59 */
60
61#define FUSE_TRACE 0
62
63#if FUSE_TRACE
64#define TRACE(x...) fprintf(stderr,x)
65#else
66#define TRACE(x...) do {} while (0)
67#endif
68
69#define ERROR(x...) fprintf(stderr,x)
70
71#define FUSE_UNKNOWN_INO 0xffffffff
72
73#define MOUNT_POINT "/mnt/sdcard"
74
75struct handle {
76    struct node *node;
77    int fd;
78};
79
80struct dirhandle {
81    struct node *node;
82    DIR *d;
83};
84
85struct node {
86    __u64 nid;
87    __u64 gen;
88
89    struct node *next;          /* per-dir sibling list */
90    struct node *child;         /* first contained file by this dir */
91    struct node *all;           /* global node list */
92    struct node *parent;        /* containing directory */
93
94    __u32 refcount;
95    __u32 namelen;
96
97    char *name;
98};
99
100struct fuse {
101    __u64 next_generation;
102    __u64 next_node_id;
103
104    int fd;
105
106    struct node *all;
107
108    struct node root;
109    char rootpath[1024];
110};
111
112/* true if file names should be squashed to lower case */
113static int force_lower_case = 0;
114static unsigned uid = -1;
115static unsigned gid = -1;
116
117#define PATH_BUFFER_SIZE 1024
118
119/*
120 * Get the real-life absolute path to a node.
121 *   node: start at this node
122 *   buf: storage for returned string
123 *   name: append this string to path if set
124 */
125char *node_get_path(struct node *node, char *buf, const char *name)
126{
127    char *out = buf + PATH_BUFFER_SIZE - 1;
128    int len;
129    out[0] = 0;
130
131    if (name) {
132        len = strlen(name);
133        goto start;
134    }
135
136    while (node) {
137        name = node->name;
138        len = node->namelen;
139        node = node->parent;
140    start:
141        if ((len + 1) > (out - buf))
142            return 0;
143        out -= len;
144        memcpy(out, name, len);
145        out --;
146        out[0] = '/';
147    }
148
149    return out;
150}
151
152void attr_from_stat(struct fuse_attr *attr, struct stat *s)
153{
154    attr->ino = s->st_ino;
155    attr->size = s->st_size;
156    attr->blocks = s->st_blocks;
157    attr->atime = s->st_atime;
158    attr->mtime = s->st_mtime;
159    attr->ctime = s->st_ctime;
160    attr->atimensec = s->st_atime_nsec;
161    attr->mtimensec = s->st_mtime_nsec;
162    attr->ctimensec = s->st_ctime_nsec;
163    attr->mode = s->st_mode;
164    attr->nlink = s->st_nlink;
165
166        /* force permissions to something reasonable:
167         * world readable
168         * writable by the sdcard group
169         */
170    if (attr->mode & 0100) {
171        attr->mode = (attr->mode & (~0777)) | 0775;
172    } else {
173        attr->mode = (attr->mode & (~0777)) | 0664;
174    }
175
176        /* all files owned by root.sdcard */
177    attr->uid = 0;
178    attr->gid = AID_SDCARD_RW;
179}
180
181int node_get_attr(struct node *node, struct fuse_attr *attr)
182{
183    int res;
184    struct stat s;
185    char *path, buffer[PATH_BUFFER_SIZE];
186
187    path = node_get_path(node, buffer, 0);
188    res = lstat(path, &s);
189    if (res < 0) {
190        ERROR("lstat('%s') errno %d\n", path, errno);
191        return -1;
192    }
193
194    attr_from_stat(attr, &s);
195    attr->ino = node->nid;
196
197    return 0;
198}
199
200static void add_node_to_parent(struct node *node, struct node *parent) {
201    node->parent = parent;
202    node->next = parent->child;
203    parent->child = node;
204    parent->refcount++;
205}
206
207struct node *node_create(struct node *parent, const char *name, __u64 nid, __u64 gen)
208{
209    struct node *node;
210    int namelen = strlen(name);
211
212    node = calloc(1, sizeof(struct node));
213    if (node == 0) {
214        return 0;
215    }
216    node->name = malloc(namelen + 1);
217    if (node->name == 0) {
218        free(node);
219        return 0;
220    }
221
222    node->nid = nid;
223    node->gen = gen;
224    add_node_to_parent(node, parent);
225    memcpy(node->name, name, namelen + 1);
226    node->namelen = namelen;
227
228    return node;
229}
230
231static char *rename_node(struct node *node, const char *name)
232{
233    node->namelen = strlen(name);
234    char *newname = realloc(node->name, node->namelen + 1);
235    if (newname == 0)
236        return 0;
237    node->name = newname;
238    memcpy(node->name, name, node->namelen + 1);
239    return node->name;
240}
241
242void fuse_init(struct fuse *fuse, int fd, const char *path)
243{
244    fuse->fd = fd;
245    fuse->next_node_id = 2;
246    fuse->next_generation = 0;
247
248    fuse->all = &fuse->root;
249
250    fuse->root.nid = FUSE_ROOT_ID; /* 1 */
251    fuse->root.next = 0;
252    fuse->root.child = 0;
253    fuse->root.parent = 0;
254
255    fuse->root.all = 0;
256    fuse->root.refcount = 2;
257
258    fuse->root.name = 0;
259    rename_node(&fuse->root, path);
260}
261
262static inline void *id_to_ptr(__u64 nid)
263{
264    return (void *) nid;
265}
266
267static inline __u64 ptr_to_id(void *ptr)
268{
269    return (__u64) ptr;
270}
271
272
273struct node *lookup_by_inode(struct fuse *fuse, __u64 nid)
274{
275    if (nid == FUSE_ROOT_ID) {
276        return &fuse->root;
277    } else {
278        return id_to_ptr(nid);
279    }
280}
281
282struct node *lookup_child_by_name(struct node *node, const char *name)
283{
284    for (node = node->child; node; node = node->next) {
285        if (!strcmp(name, node->name)) {
286            return node;
287        }
288    }
289    return 0;
290}
291
292struct node *lookup_child_by_inode(struct node *node, __u64 nid)
293{
294    for (node = node->child; node; node = node->next) {
295        if (node->nid == nid) {
296            return node;
297        }
298    }
299    return 0;
300}
301
302static void dec_refcount(struct node *node) {
303    if (node->refcount > 0) {
304        node->refcount--;
305        TRACE("dec_refcount %p(%s) -> %d\n", node, node->name, node->refcount);
306    } else {
307        ERROR("Zero refcnt %p\n", node);
308    }
309 }
310
311static struct node *remove_child(struct node *parent, __u64 nid)
312{
313    struct node *prev = 0;
314    struct node *node;
315
316    for (node = parent->child; node; node = node->next) {
317        if (node->nid == nid) {
318            if (prev) {
319                prev->next = node->next;
320            } else {
321                parent->child = node->next;
322            }
323            node->next = 0;
324            node->parent = 0;
325            dec_refcount(parent);
326            return node;
327        }
328        prev = node;
329    }
330    return 0;
331}
332
333struct node *node_lookup(struct fuse *fuse, struct node *parent, const char *name,
334                         struct fuse_attr *attr)
335{
336    int res;
337    struct stat s;
338    char *path, buffer[PATH_BUFFER_SIZE];
339    struct node *node;
340
341    path = node_get_path(parent, buffer, name);
342        /* XXX error? */
343
344    res = lstat(path, &s);
345    if (res < 0)
346        return 0;
347
348    node = lookup_child_by_name(parent, name);
349    if (!node) {
350        node = node_create(parent, name, fuse->next_node_id++, fuse->next_generation++);
351        if (!node)
352            return 0;
353        node->nid = ptr_to_id(node);
354        node->all = fuse->all;
355        fuse->all = node;
356    }
357
358    attr_from_stat(attr, &s);
359    attr->ino = node->nid;
360
361    return node;
362}
363
364void node_release(struct node *node)
365{
366    TRACE("RELEASE %p (%s) rc=%d\n", node, node->name, node->refcount);
367    dec_refcount(node);
368    if (node->refcount == 0) {
369        if (node->parent->child == node) {
370            node->parent->child = node->parent->child->next;
371        } else {
372            struct node *node2;
373
374            node2 = node->parent->child;
375            while (node2->next != node)
376                node2 = node2->next;
377            node2->next = node->next;
378        }
379
380        TRACE("DESTROY %p (%s)\n", node, node->name);
381
382        node_release(node->parent);
383
384        node->parent = 0;
385        node->next = 0;
386
387            /* TODO: remove debugging - poison memory */
388        memset(node->name, 0xef, node->namelen);
389        free(node->name);
390        memset(node, 0xfc, sizeof(*node));
391        free(node);
392    }
393}
394
395void fuse_status(struct fuse *fuse, __u64 unique, int err)
396{
397    struct fuse_out_header hdr;
398    hdr.len = sizeof(hdr);
399    hdr.error = err;
400    hdr.unique = unique;
401    if (err) {
402//        ERROR("*** %d ***\n", err);
403    }
404    write(fuse->fd, &hdr, sizeof(hdr));
405}
406
407void fuse_reply(struct fuse *fuse, __u64 unique, void *data, int len)
408{
409    struct fuse_out_header hdr;
410    struct iovec vec[2];
411    int res;
412
413    hdr.len = len + sizeof(hdr);
414    hdr.error = 0;
415    hdr.unique = unique;
416
417    vec[0].iov_base = &hdr;
418    vec[0].iov_len = sizeof(hdr);
419    vec[1].iov_base = data;
420    vec[1].iov_len = len;
421
422    res = writev(fuse->fd, vec, 2);
423    if (res < 0) {
424        ERROR("*** REPLY FAILED *** %d\n", errno);
425    }
426}
427
428void lookup_entry(struct fuse *fuse, struct node *node,
429                  const char *name, __u64 unique)
430{
431    struct fuse_entry_out out;
432
433    memset(&out, 0, sizeof(out));
434
435    node = node_lookup(fuse, node, name, &out.attr);
436    if (!node) {
437        fuse_status(fuse, unique, -ENOENT);
438        return;
439    }
440
441    node->refcount++;
442//    fprintf(stderr,"ACQUIRE %p (%s) rc=%d\n", node, node->name, node->refcount);
443    out.nodeid = node->nid;
444    out.generation = node->gen;
445    out.entry_valid = 10;
446    out.attr_valid = 10;
447
448    fuse_reply(fuse, unique, &out, sizeof(out));
449}
450
451static int name_needs_normalizing(const char* name) {
452    char ch;
453    while ((ch = *name++) != 0) {
454        if (ch != tolower(ch))
455            return 1;
456    }
457    return 0;
458}
459
460static void normalize_name(char *name)
461{
462    if (force_lower_case) {
463        char ch;
464        while ((ch = *name) != 0)
465            *name++ = tolower(ch);
466    }
467}
468
469static void recursive_fix_files(const char* path) {
470    DIR* dir;
471    struct dirent* entry;
472    char pathbuf[PATH_MAX];
473    char oldpath[PATH_MAX];
474    int pathLength = strlen(path);
475    int pathRemaining;
476    char* fileSpot;
477
478    if (pathLength >= sizeof(pathbuf) - 1) {
479        ERROR("path too long: %s\n", path);
480        return;
481    }
482    strcpy(pathbuf, path);
483    if (pathbuf[pathLength - 1] != '/') {
484        pathbuf[pathLength++] = '/';
485    }
486    fileSpot = pathbuf + pathLength;
487    pathRemaining = sizeof(pathbuf) - pathLength - 1;
488
489    dir = opendir(path);
490    if (!dir) {
491        ERROR("opendir %s failed: %s", path, strerror(errno));
492        return;
493    }
494
495    while ((entry = readdir(dir))) {
496        const char* name = entry->d_name;
497        int nameLength;
498
499        // ignore "." and ".."
500        if (name[0] == '.' && (name[1] == 0 || (name[1] == '.' && name[2] == 0))) {
501            continue;
502        }
503
504       nameLength = strlen(name);
505       if (nameLength > pathRemaining) {
506            ERROR("path %s/%s too long\n", path, name);
507            continue;
508        }
509        strcpy(fileSpot, name);
510
511        // make sure owner and group are correct
512        chown(pathbuf, uid, gid);
513
514        if (name_needs_normalizing(name)) {
515            /* rename file to lower case file name */
516            strlcpy(oldpath, pathbuf, sizeof(oldpath));
517            normalize_name(pathbuf);
518            rename(oldpath, pathbuf);
519        }
520
521        if (entry->d_type == DT_DIR) {
522            /* recurse to subdirectories */
523            recursive_fix_files(pathbuf);
524        }
525    }
526    closedir(dir);
527}
528
529void handle_fuse_request(struct fuse *fuse, struct fuse_in_header *hdr, void *data, unsigned len)
530{
531    struct node *node;
532
533    if ((len < sizeof(*hdr)) || (hdr->len != len)) {
534        ERROR("malformed header\n");
535        return;
536    }
537
538    len -= hdr->len;
539
540    if (hdr->nodeid) {
541        node = lookup_by_inode(fuse, hdr->nodeid);
542        if (!node) {
543            fuse_status(fuse, hdr->unique, -ENOENT);
544            return;
545        }
546    } else {
547        node = 0;
548    }
549
550    switch (hdr->opcode) {
551    case FUSE_LOOKUP: { /* bytez[] -> entry_out */
552        normalize_name((char*) data);
553        TRACE("LOOKUP %llx %s\n", hdr->nodeid, (char*) data);
554        lookup_entry(fuse, node, (char*) data, hdr->unique);
555        return;
556    }
557    case FUSE_FORGET: {
558        struct fuse_forget_in *req = data;
559        TRACE("FORGET %llx (%s) #%lld\n", hdr->nodeid, node->name, req->nlookup);
560            /* no reply */
561        while (req->nlookup--)
562            node_release(node);
563        return;
564    }
565    case FUSE_GETATTR: { /* getattr_in -> attr_out */
566        struct fuse_getattr_in *req = data;
567        struct fuse_attr_out out;
568
569        TRACE("GETATTR flags=%x fh=%llx\n", req->getattr_flags, req->fh);
570
571        memset(&out, 0, sizeof(out));
572        node_get_attr(node, &out.attr);
573        out.attr_valid = 10;
574
575        fuse_reply(fuse, hdr->unique, &out, sizeof(out));
576        return;
577    }
578    case FUSE_SETATTR: { /* setattr_in -> attr_out */
579        struct fuse_setattr_in *req = data;
580        struct fuse_attr_out out;
581        char *path, buffer[PATH_BUFFER_SIZE];
582        int res = 0;
583
584        TRACE("SETATTR fh=%llx id=%llx valid=%x\n",
585              req->fh, hdr->nodeid, req->valid);
586
587        /* XXX: incomplete implementation -- truncate only.  chmod/chown
588         * should NEVER be implemented. */
589
590        path = node_get_path(node, buffer, 0);
591        if (req->valid & FATTR_SIZE)
592            res = truncate(path, req->size);
593
594        memset(&out, 0, sizeof(out));
595        node_get_attr(node, &out.attr);
596        out.attr_valid = 10;
597
598        if (res)
599            fuse_status(fuse, hdr->unique, -errno);
600        else
601            fuse_reply(fuse, hdr->unique, &out, sizeof(out));
602        return;
603    }
604//    case FUSE_READLINK:
605//    case FUSE_SYMLINK:
606    case FUSE_MKNOD: { /* mknod_in, bytez[] -> entry_out */
607        struct fuse_mknod_in *req = data;
608        char *path, buffer[PATH_BUFFER_SIZE];
609        char *name = ((char*) data) + sizeof(*req);
610        int res;
611
612        normalize_name(name);
613
614        TRACE("MKNOD %s @ %llx\n", name, hdr->nodeid);
615        path = node_get_path(node, buffer, name);
616
617        req->mode = (req->mode & (~0777)) | 0664;
618        res = mknod(path, req->mode, req->rdev); /* XXX perm?*/
619        if (res < 0) {
620            fuse_status(fuse, hdr->unique, -errno);
621        } else {
622            lookup_entry(fuse, node, name, hdr->unique);
623        }
624        return;
625    }
626    case FUSE_MKDIR: { /* mkdir_in, bytez[] -> entry_out */
627        struct fuse_mkdir_in *req = data;
628        struct fuse_entry_out out;
629        char *path, buffer[PATH_BUFFER_SIZE];
630        char *name = ((char*) data) + sizeof(*req);
631        int res;
632
633        normalize_name(name);
634
635        TRACE("MKDIR %s @ %llx 0%o\n", name, hdr->nodeid, req->mode);
636        path = node_get_path(node, buffer, name);
637
638        req->mode = (req->mode & (~0777)) | 0775;
639        res = mkdir(path, req->mode);
640        if (res < 0) {
641            fuse_status(fuse, hdr->unique, -errno);
642        } else {
643            lookup_entry(fuse, node, name, hdr->unique);
644        }
645        return;
646    }
647    case FUSE_UNLINK: { /* bytez[] -> */
648        char *path, buffer[PATH_BUFFER_SIZE];
649        int res;
650        normalize_name((char*) data);
651        TRACE("UNLINK %s @ %llx\n", (char*) data, hdr->nodeid);
652        path = node_get_path(node, buffer, (char*) data);
653        res = unlink(path);
654        fuse_status(fuse, hdr->unique, res ? -errno : 0);
655        return;
656    }
657    case FUSE_RMDIR: { /* bytez[] -> */
658        char *path, buffer[PATH_BUFFER_SIZE];
659        int res;
660        normalize_name((char*) data);
661        TRACE("RMDIR %s @ %llx\n", (char*) data, hdr->nodeid);
662        path = node_get_path(node, buffer, (char*) data);
663        res = rmdir(path);
664        fuse_status(fuse, hdr->unique, res ? -errno : 0);
665        return;
666    }
667    case FUSE_RENAME: { /* rename_in, oldname, newname ->  */
668        struct fuse_rename_in *req = data;
669        char *oldname = ((char*) data) + sizeof(*req);
670        char *newname = oldname + strlen(oldname) + 1;
671        char *oldpath, oldbuffer[PATH_BUFFER_SIZE];
672        char *newpath, newbuffer[PATH_BUFFER_SIZE];
673        struct node *target;
674        struct node *newparent;
675        int res;
676
677        normalize_name(oldname);
678        normalize_name(newname);
679
680        TRACE("RENAME %s->%s @ %llx\n", oldname, newname, hdr->nodeid);
681
682        target = lookup_child_by_name(node, oldname);
683        if (!target) {
684            fuse_status(fuse, hdr->unique, -ENOENT);
685            return;
686        }
687        oldpath = node_get_path(node, oldbuffer, oldname);
688
689        newparent = lookup_by_inode(fuse, req->newdir);
690        if (!newparent) {
691            fuse_status(fuse, hdr->unique, -ENOENT);
692            return;
693        }
694        newpath = node_get_path(newparent, newbuffer, newname);
695
696        if (!remove_child(node, target->nid)) {
697            ERROR("RENAME remove_child not found");
698            fuse_status(fuse, hdr->unique, -ENOENT);
699            return;
700        }
701        if (!rename_node(target, newname)) {
702            fuse_status(fuse, hdr->unique, -ENOMEM);
703            return;
704        }
705        add_node_to_parent(target, newparent);
706
707        res = rename(oldpath, newpath);
708        TRACE("RENAME result %d\n", res);
709
710        fuse_status(fuse, hdr->unique, res ? -errno : 0);
711        return;
712    }
713//    case FUSE_LINK:
714    case FUSE_OPEN: { /* open_in -> open_out */
715        struct fuse_open_in *req = data;
716        struct fuse_open_out out;
717        char *path, buffer[PATH_BUFFER_SIZE];
718        struct handle *h;
719
720        h = malloc(sizeof(*h));
721        if (!h) {
722            fuse_status(fuse, hdr->unique, -ENOMEM);
723            return;
724        }
725
726        normalize_name(buffer);
727        path = node_get_path(node, buffer, 0);
728        TRACE("OPEN %llx '%s' 0%o fh=%p\n", hdr->nodeid, path, req->flags, h);
729        h->fd = open(path, req->flags);
730        if (h->fd < 0) {
731            ERROR("ERROR\n");
732            fuse_status(fuse, hdr->unique, errno);
733            free(h);
734            return;
735        }
736        out.fh = ptr_to_id(h);
737        out.open_flags = 0;
738        out.padding = 0;
739        fuse_reply(fuse, hdr->unique, &out, sizeof(out));
740        return;
741    }
742    case FUSE_READ: { /* read_in -> byte[] */
743        char buffer[128 * 1024];
744        struct fuse_read_in *req = data;
745        struct handle *h = id_to_ptr(req->fh);
746        int res;
747        TRACE("READ %p(%d) %u@%llu\n", h, h->fd, req->size, req->offset);
748        if (req->size > sizeof(buffer)) {
749            fuse_status(fuse, hdr->unique, -EINVAL);
750            return;
751        }
752        res = pread64(h->fd, buffer, req->size, req->offset);
753        if (res < 0) {
754            fuse_status(fuse, hdr->unique, errno);
755            return;
756        }
757        fuse_reply(fuse, hdr->unique, buffer, res);
758        return;
759    }
760    case FUSE_WRITE: { /* write_in, byte[write_in.size] -> write_out */
761        struct fuse_write_in *req = data;
762        struct fuse_write_out out;
763        struct handle *h = id_to_ptr(req->fh);
764        int res;
765        TRACE("WRITE %p(%d) %u@%llu\n", h, h->fd, req->size, req->offset);
766        res = pwrite64(h->fd, ((char*) data) + sizeof(*req), req->size, req->offset);
767        if (res < 0) {
768            fuse_status(fuse, hdr->unique, errno);
769            return;
770        }
771        out.size = res;
772        fuse_reply(fuse, hdr->unique, &out, sizeof(out));
773        goto oops;
774    }
775    case FUSE_STATFS: { /* getattr_in -> attr_out */
776        struct statfs stat;
777        struct fuse_statfs_out out;
778        int res;
779
780        TRACE("STATFS\n");
781
782        if (statfs(fuse->root.name, &stat)) {
783            fuse_status(fuse, hdr->unique, -errno);
784            return;
785        }
786
787        memset(&out, 0, sizeof(out));
788        out.st.blocks = stat.f_blocks;
789        out.st.bfree = stat.f_bfree;
790        out.st.bavail = stat.f_bavail;
791        out.st.files = stat.f_files;
792        out.st.ffree = stat.f_ffree;
793        out.st.bsize = stat.f_bsize;
794        out.st.namelen = stat.f_namelen;
795        out.st.frsize = stat.f_frsize;
796        fuse_reply(fuse, hdr->unique, &out, sizeof(out));
797        return;
798    }
799    case FUSE_RELEASE: { /* release_in -> */
800        struct fuse_release_in *req = data;
801        struct handle *h = id_to_ptr(req->fh);
802        TRACE("RELEASE %p(%d)\n", h, h->fd);
803        close(h->fd);
804        free(h);
805        fuse_status(fuse, hdr->unique, 0);
806        return;
807    }
808//    case FUSE_FSYNC:
809//    case FUSE_SETXATTR:
810//    case FUSE_GETXATTR:
811//    case FUSE_LISTXATTR:
812//    case FUSE_REMOVEXATTR:
813    case FUSE_FLUSH:
814        fuse_status(fuse, hdr->unique, 0);
815        return;
816    case FUSE_OPENDIR: { /* open_in -> open_out */
817        struct fuse_open_in *req = data;
818        struct fuse_open_out out;
819        char *path, buffer[PATH_BUFFER_SIZE];
820        struct dirhandle *h;
821
822        h = malloc(sizeof(*h));
823        if (!h) {
824            fuse_status(fuse, hdr->unique, -ENOMEM);
825            return;
826        }
827
828        normalize_name(buffer);
829        path = node_get_path(node, buffer, 0);
830        TRACE("OPENDIR %llx '%s'\n", hdr->nodeid, path);
831        h->d = opendir(path);
832        if (h->d == 0) {
833            ERROR("ERROR\n");
834            fuse_status(fuse, hdr->unique, -errno);
835            free(h);
836            return;
837        }
838        out.fh = ptr_to_id(h);
839        fuse_reply(fuse, hdr->unique, &out, sizeof(out));
840        return;
841    }
842    case FUSE_READDIR: {
843        struct fuse_read_in *req = data;
844        char buffer[8192];
845        struct fuse_dirent *fde = (struct fuse_dirent*) buffer;
846        struct dirent *de;
847        struct dirhandle *h = id_to_ptr(req->fh);
848        TRACE("READDIR %p\n", h);
849        de = readdir(h->d);
850        if (!de) {
851            fuse_status(fuse, hdr->unique, 0);
852            return;
853        }
854        fde->ino = FUSE_UNKNOWN_INO;
855        fde->off = 0;
856        fde->type = de->d_type;
857        fde->namelen = strlen(de->d_name);
858        memcpy(fde->name, de->d_name, fde->namelen + 1);
859        fuse_reply(fuse, hdr->unique, fde,
860                   FUSE_DIRENT_ALIGN(sizeof(struct fuse_dirent) + fde->namelen));
861        return;
862    }
863    case FUSE_RELEASEDIR: { /* release_in -> */
864        struct fuse_release_in *req = data;
865        struct dirhandle *h = id_to_ptr(req->fh);
866        TRACE("RELEASEDIR %p\n",h);
867        closedir(h->d);
868        free(h);
869        fuse_status(fuse, hdr->unique, 0);
870        return;
871    }
872//    case FUSE_FSYNCDIR:
873    case FUSE_INIT: { /* init_in -> init_out */
874        struct fuse_init_in *req = data;
875        struct fuse_init_out out;
876
877        TRACE("INIT ver=%d.%d maxread=%d flags=%x\n",
878                req->major, req->minor, req->max_readahead, req->flags);
879
880        out.major = FUSE_KERNEL_VERSION;
881        out.minor = FUSE_KERNEL_MINOR_VERSION;
882        out.max_readahead = req->max_readahead;
883        out.flags = FUSE_ATOMIC_O_TRUNC;
884        out.max_background = 32;
885        out.congestion_threshold = 32;
886        out.max_write = 256 * 1024;
887
888        fuse_reply(fuse, hdr->unique, &out, sizeof(out));
889        return;
890    }
891    default: {
892        struct fuse_out_header h;
893        ERROR("NOTIMPL op=%d uniq=%llx nid=%llx\n",
894                hdr->opcode, hdr->unique, hdr->nodeid);
895
896        oops:
897        h.len = sizeof(h);
898        h.error = -ENOSYS;
899        h.unique = hdr->unique;
900        write(fuse->fd, &h, sizeof(h));
901        break;
902    }
903    }
904}
905
906void handle_fuse_requests(struct fuse *fuse)
907{
908    unsigned char req[256 * 1024 + 128];
909    int len;
910
911    for (;;) {
912        len = read(fuse->fd, req, 8192);
913        if (len < 0) {
914            if (errno == EINTR)
915                continue;
916            ERROR("handle_fuse_requests: errno=%d\n", errno);
917            return;
918        }
919        handle_fuse_request(fuse, (void*) req, (void*) (req + sizeof(struct fuse_in_header)), len);
920    }
921}
922
923static int usage()
924{
925    ERROR("usage: sdcard [-l -f] <path> <uid> <gid>\n\n\t-l force file names to lower case when creating new files\n\t-f fix up file system before starting (repairs bad file name case and group ownership)\n");
926    return -1;
927}
928
929int main(int argc, char **argv)
930{
931    struct fuse fuse;
932    char opts[256];
933    int fd;
934    int res;
935    const char *path = NULL;
936    int fix_files = 0;
937    int i;
938
939    for (i = 1; i < argc; i++) {
940        char* arg = argv[i];
941        if (arg[0] == '-') {
942            if (!strcmp(arg, "-l")) {
943                force_lower_case = 1;
944            } else if (!strcmp(arg, "-f")) {
945                fix_files = 1;
946            } else {
947                return usage();
948            }
949        } else {
950            if (!path)
951                path = arg;
952            else if (uid == -1)
953                uid = strtoul(arg, 0, 10);
954            else if (gid == -1)
955                gid = strtoul(arg, 0, 10);
956            else {
957                ERROR("too many arguments\n");
958                return usage();
959            }
960        }
961    }
962
963    if (!path) {
964        ERROR("no path specified\n");
965        return usage();
966    }
967    if (uid <= 0 || gid <= 0) {
968        ERROR("uid and gid must be nonzero\n");
969        return usage();
970    }
971
972        /* cleanup from previous instance, if necessary */
973    umount2(MOUNT_POINT, 2);
974
975    fd = open("/dev/fuse", O_RDWR);
976    if (fd < 0){
977        ERROR("cannot open fuse device (%d)\n", errno);
978        return -1;
979    }
980
981    sprintf(opts, "fd=%i,rootmode=40000,default_permissions,allow_other,"
982            "user_id=%d,group_id=%d", fd, uid, gid);
983
984    res = mount("/dev/fuse", MOUNT_POINT, "fuse", MS_NOSUID | MS_NODEV, opts);
985    if (res < 0) {
986        ERROR("cannot mount fuse filesystem (%d)\n", errno);
987        return -1;
988    }
989
990    if (fix_files)
991        recursive_fix_files(path);
992
993    if (setgid(gid) < 0) {
994        ERROR("cannot setgid!\n");
995        return -1;
996    }
997    if (setuid(uid) < 0) {
998        ERROR("cannot setuid!\n");
999        return -1;
1000    }
1001
1002    fuse_init(&fuse, fd, path);
1003
1004    umask(0);
1005    handle_fuse_requests(&fuse);
1006
1007    return 0;
1008}
1009