readdir: add dirent index array

This removes the risk of corrupted data being sent back to the kernel
should it use the offset from one opendir-readdir in another. In this case
it would at most skip dirents.

According to the standards the offset is only valid when used within
the opendir -> releasedir but NFS uses offsets across independent
calls.

libfuse/include/fuse_dirents.h

@@ -22,6 +22,7 @@
 extern "C" {
 #endif
 
+#include "kvec.h"
 #include "fuse_dirent.h"
 #include "fuse_direntplus.h"
 #include "fuse_entry.h"
@@ -48,6 +49,7 @@ struct fuse_dirents_s
   char                *buf;
   uint64_t             buf_len;
   uint64_t             data_len;
+  kvec_t(uint32_t)     offs;
   fuse_dirents_type_t  type;
 };
 

libfuse/include/kvec.h

@@ -0,0 +1,90 @@
+/* The MIT License
+
+   Copyright (c) 2008, by Attractive Chaos <attractor@live.co.uk>
+
+   Permission is hereby granted, free of charge, to any person obtaining
+   a copy of this software and associated documentation files (the
+   "Software"), to deal in the Software without restriction, including
+   without limitation the rights to use, copy, modify, merge, publish,
+   distribute, sublicense, and/or sell copies of the Software, and to
+   permit persons to whom the Software is furnished to do so, subject to
+   the following conditions:
+
+   The above copyright notice and this permission notice shall be
+   included in all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+   BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+   ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+   SOFTWARE.
+*/
+
+/*
+  An example:
+
+  #include "kvec.h"
+  int main() {
+  kvec_t(int) array;
+  kv_init(array);
+  kv_push(int, array, 10); // append
+  kv_a(int, array, 20) = 5; // dynamic
+  kv_A(array, 20) = 4; // static
+  kv_destroy(array);
+  return 0;
+  }
+*/
+
+/*
+  2008-09-22 (0.1.0):
+
+  * The initial version.
+
+  */
+
+#ifndef AC_KVEC_H
+#define AC_KVEC_H
+
+#include <stdlib.h>
+
+#define kv_roundup32(x) (--(x), (x)|=(x)>>1, (x)|=(x)>>2, (x)|=(x)>>4, (x)|=(x)>>8, (x)|=(x)>>16, ++(x))
+
+#define kvec_t(type) struct { size_t n, m; type *a; }
+#define kv_init(v) ((v).n = (v).m = 0, (v).a = 0)
+#define kv_destroy(v) free((v).a)
+#define kv_A(v, i) ((v).a[(i)])
+#define kv_pop(v) ((v).a[--(v).n])
+#define kv_size(v) ((v).n)
+#define kv_max(v) ((v).m)
+
+#define kv_resize(type, v, s)  ((v).m = (s), (v).a = (type*)realloc((v).a, sizeof(type) * (v).m))
+
+#define kv_copy(type, v1, v0) do {                      \
+    if ((v1).m < (v0).n) kv_resize(type, v1, (v0).n);	\
+    (v1).n = (v0).n;                                    \
+    memcpy((v1).a, (v0).a, sizeof(type) * (v0).n);      \
+  } while (0)                                           \
+
+#define kv_push(type, v, x) do {                                \
+    if ((v).n == (v).m) {                                       \
+      (v).m = (v).m? (v).m<<1 : 2;                              \
+      (v).a = (type*)realloc((v).a, sizeof(type) * (v).m);	\
+    }                                                           \
+    (v).a[(v).n++] = (x);                                       \
+  } while (0)
+
+#define kv_pushp(type, v) (((v).n == (v).m)?                            \
+                           ((v).m = ((v).m? (v).m<<1 : 2),              \
+                            (v).a = (type*)realloc((v).a, sizeof(type) * (v).m), 0) \
+                           : 0), ((v).a + ((v).n++))
+
+#define kv_a(type, v, i) (((v).m <= (size_t)(i)?                        \
+                           ((v).m = (v).n = (i) + 1, kv_roundup32((v).m), \
+                            (v).a = (type*)realloc((v).a, sizeof(type) * (v).m), 0) \
+                           : (v).n <= (size_t)(i)? (v).n = (i) + 1      \
+                           : 0), (v).a[(i)])
+
+#endif

libfuse/lib/fuse.c

@@ -3387,20 +3387,24 @@ readdir_plus_fill(struct fuse           *f_,
 }
 
 static
-uint64_t
-convert_plus2normal(fuse_dirents_t *d_,
-                    uint64_t        off_)
+size_t
+readdir_buf_size(fuse_dirents_t *d_,
+                 size_t          size_,
+                 off_t           off_)
 {
-  uint64_t ino;
-  fuse_dirent_t *d;
-  fuse_direntplus_t *dp;
-
-  dp  = (fuse_direntplus_t*)&d_->buf[off_];
-  ino = dp->dirent.ino;
-  fuse_dirents_convert_plus2normal(d_);
-  d   = fuse_dirents_find(d_,ino);
+  if(off_ >= kv_size(d_->offs))
+    return 0;
+  if((kv_A(d_->offs,off_) + size_) > d_->data_len)
+    return (d_->data_len - kv_A(d_->offs,off_));
+  return size_;
+}
 
-  return d->off;
+static
+char*
+readdir_buf(fuse_dirents_t *d_,
+            off_t           off_)
+{
+  return &d_->buf[kv_A(d_->offs,off_)];
 }
 
 static
@@ -3433,16 +3437,10 @@ fuse_lib_readdir(fuse_req_t             req_,
       goto out;
     }
 
-  if(off_ >= d->data_len)
-    size_ = 0;
-  else if((off_ + size_) > d->data_len)
-    size_ = (d->data_len - off_);
-
-  /* if((size_ > 0) && (d->type == PLUS)) */
-  /*   off_ = convert_plus2normal(d,off_); */
+  size_ = readdir_buf_size(d,size_,off_);
 
   fuse_reply_buf(req_,
-                 &d->buf[off_],
+                 readdir_buf(d,off_),
                  size_);
 
  out:
@@ -3479,13 +3477,10 @@ fuse_lib_readdir_plus(fuse_req_t             req_,
       goto out;
     }
 
-  if(off_ >= d->data_len)
-    size_ = 0;
-  else if((off_ + size_) > d->data_len)
-    size_ = (d->data_len - off_);
+  size_ = readdir_buf_size(d,size_,off_);
 
   fuse_reply_buf(req_,
-                 &d->buf[off_],
+                 readdir_buf(d,off_),
                  size_);
 
  out:

libfuse/lib/fuse_dirents.c

@@ -54,7 +54,7 @@ fuse_direntplus_size(const uint64_t namelen_)
 
 static
 int
-fuse_dirents_resize(fuse_dirents_t *d_,
+fuse_dirents_buf_resize(fuse_dirents_t *d_,
                         uint64_t        size_)
 {
   void *p;
@@ -74,19 +74,44 @@ fuse_dirents_resize(fuse_dirents_t *d_,
 
 static
 void*
-fuse_dirents_alloc(fuse_dirents_t *d_,
-                   uint64_t        size_)
+fuse_dirents_dirent_alloc(fuse_dirents_t *d_,
+                          uint64_t        namelen_)
+{
+  int rv;
+  uint64_t size;
+  fuse_dirent_t *d;
+
+  size = fuse_dirent_size(namelen_);
+
+  rv = fuse_dirents_buf_resize(d_,size);
+  if(rv)
+    return NULL;
+
+  d = (fuse_dirent_t*)&d_->buf[d_->data_len];
+
+  d_->data_len += size;
+
+  return d;
+}
+
+static
+void*
+fuse_dirents_direntplus_alloc(fuse_dirents_t *d_,
+                              uint64_t        namelen_)
 {
   int rv;
+  uint64_t size;
   fuse_dirent_t *d;
 
-  rv = fuse_dirents_resize(d_,size_);
+  size = fuse_direntplus_size(namelen_);
+
+  rv = fuse_dirents_buf_resize(d_,size);
   if(rv)
     return NULL;
 
   d = (fuse_dirent_t*)&d_->buf[d_->data_len];
 
-  d_->data_len += size_;
+  d_->data_len += size;
 
   return d;
 }
@@ -200,38 +225,7 @@ fuse_dirents_find(fuse_dirents_t *d_,
 int
 fuse_dirents_convert_plus2normal(fuse_dirents_t *d_)
 {
-  int rv;
-  uint64_t size;
-  fuse_dirent_t *d;
-  fuse_dirents_t normal;
-  fuse_direntplus_t *cur;
-  fuse_direntplus_t *end;
-
-  rv = fuse_dirents_init(&normal);
-  if(rv < 0)
-    return rv;
-
-  cur = (fuse_direntplus_t*)&d_->buf[0];
-  end = (fuse_direntplus_t*)&d_->buf[d_->data_len];
-  while(cur < end)
-    {
-      size = fuse_dirent_size(cur->dirent.namelen);
-      d = fuse_dirents_alloc(&normal,size);
-      if(d == NULL)
-        return -ENOMEM;
-
-      memcpy(d,&cur->dirent,size);
-      d->off = normal.data_len;;
-
-      cur = fuse_direntplus_next(cur);
-    }
-
-  fuse_dirents_free(d_);
-
-  normal.type = NORMAL;
-  *d_ = normal;
-
-  return 0;
+  return -ENOSYS;
 }
 
 int
@@ -239,7 +233,6 @@ fuse_dirents_add(fuse_dirents_t      *d_,
                  const struct dirent *dirent_,
                  const uint64_t       namelen_)
 {
-  uint64_t size;
   fuse_dirent_t *d;
 
   switch(d_->type)
@@ -253,14 +246,13 @@ fuse_dirents_add(fuse_dirents_t      *d_,
       return -EINVAL;
     }
 
-  size = fuse_dirent_size(namelen_);
-
-  d = fuse_dirents_alloc(d_,size);
+  d = fuse_dirents_dirent_alloc(d_,namelen_);
   if(d == NULL)
     return -ENOMEM;
 
+  d->off     = kv_size(d_->offs);
+  kv_push(uint32_t,d_->offs,d_->data_len);
   d->ino     = dirent_->d_ino;
-  d->off     = d_->data_len;
   d->namelen = namelen_;
   d->type    = dirent_->d_type;
   memcpy(d->name,dirent_->d_name,namelen_);
@@ -275,7 +267,6 @@ fuse_dirents_add_plus(fuse_dirents_t      *d_,
                       const fuse_entry_t  *entry_,
                       const struct stat   *st_)
 {
-  uint64_t size;
   fuse_direntplus_t *d;
 
   switch(d_->type)
@@ -289,14 +280,13 @@ fuse_dirents_add_plus(fuse_dirents_t      *d_,
       break;
     }
 
-  size = fuse_direntplus_size(namelen_);
-
-  d = fuse_dirents_alloc(d_,size);
+  d = fuse_dirents_direntplus_alloc(d_,namelen_);
   if(d == NULL)
     return -ENOMEM;
 
+  d->dirent.off     = kv_size(d_->offs);
+  kv_push(uint32_t,d_->offs,d_->data_len);
   d->dirent.ino     = dirent_->d_ino;
-  d->dirent.off     = d_->data_len;
   d->dirent.namelen = namelen_;
   d->dirent.type    = dirent_->d_type;
   memcpy(d->dirent.name,dirent_->d_name,namelen_);
@@ -313,7 +303,6 @@ fuse_dirents_add_linux(fuse_dirents_t            *d_,
                        const struct linux_dirent *dirent_,
                        const uint64_t             namelen_)
 {
-  uint64_t size;
   fuse_dirent_t *d;
 
   switch(d_->type)
@@ -327,14 +316,13 @@ fuse_dirents_add_linux(fuse_dirents_t            *d_,
       return -EINVAL;
     }
 
-  size = fuse_dirent_size(namelen_);
-
-  d = fuse_dirents_alloc(d_,size);
+  d = fuse_dirents_dirent_alloc(d_,namelen_);
   if(d == NULL)
     return -ENOMEM;
 
+  d->off     = kv_size(d_->offs);
+  kv_push(uint32_t,d_->offs,d_->data_len);
   d->ino     = dirent_->ino;
-  d->off     = d_->data_len;
   d->namelen = namelen_;
   d->type    = *((char*)dirent_ + dirent_->reclen - 1);
   memcpy(d->name,dirent_->name,namelen_);
@@ -349,7 +337,6 @@ fuse_dirents_add_linux_plus(fuse_dirents_t            *d_,
                             const fuse_entry_t        *entry_,
                             const struct stat         *st_)
 {
-  uint64_t size;
   fuse_direntplus_t *d;
 
   switch(d_->type)
@@ -363,14 +350,13 @@ fuse_dirents_add_linux_plus(fuse_dirents_t            *d_,
       break;
     }
 
-  size = fuse_direntplus_size(namelen_);
-
-  d = fuse_dirents_alloc(d_,size);
+  d = fuse_dirents_direntplus_alloc(d_,namelen_);
   if(d == NULL)
     return -ENOMEM;
 
+  d->dirent.off     = kv_size(d_->offs);
+  kv_push(uint32_t,d_->offs,d_->data_len);
   d->dirent.ino     = dirent_->ino;
-  d->dirent.off     = d_->data_len;
   d->dirent.namelen = namelen_;
   d->dirent.type    = *((char*)dirent_ + dirent_->reclen - 1);
   memcpy(d->dirent.name,dirent_->name,namelen_);
@@ -387,6 +373,7 @@ fuse_dirents_reset(fuse_dirents_t *d_)
 {
   d_->data_len      = 0;
   d_->type          = UNSET;
+  kv_size(d_->offs) = 1;
 }
 
 int
@@ -403,6 +390,10 @@ fuse_dirents_init(fuse_dirents_t *d_)
   d_->data_len = 0;
   d_->type     = UNSET;
 
+  kv_init(d_->offs);
+  kv_resize(uint32_t,d_->offs,64);
+  kv_push(uint32_t,d_->offs,0);
+
   return 0;
 }
 
@@ -412,5 +403,8 @@ fuse_dirents_free(fuse_dirents_t *d_)
   d_->buf_len  = 0;
   d_->data_len = 0;
   d_->type     = UNSET;
+
+  kv_destroy(d_->offs);
+
   free(d_->buf);
 }