3c43f71084
This change refactors the Unix socket / pipe backend to have a ring buffer containing segments, where each segment has an optional leading ancillary buffer containing control messages followed by a normal data buffer. The SCM_RIGHTS control message has been implemented which transfers file descriptors to the receiving process. File descriptors are reference counted and cycles are prevented using the following restrictions: 1) Unix sockets cannot be sent on themselves (on either end). 2) Unix sockets themselves being sent cannot be sent on. 3) Unix sockets cannot send a Unix socket being sent on. This is a compatible ABI change.
129 lines
3.4 KiB
C++
129 lines
3.4 KiB
C++
/*
|
|
* Copyright (c) 2013, 2015, 2017 Jonas 'Sortie' Termansen.
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*
|
|
* partition.cpp
|
|
* Block device representing a partition of another block device.
|
|
*/
|
|
|
|
#include <sys/types.h>
|
|
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
|
|
#include <sortix/seek.h>
|
|
#include <sortix/stat.h>
|
|
|
|
#include <sortix/kernel/inode.h>
|
|
#include <sortix/kernel/ioctx.h>
|
|
#include <sortix/kernel/kernel.h>
|
|
#include <sortix/kernel/refcount.h>
|
|
|
|
#include "partition.h"
|
|
|
|
namespace Sortix {
|
|
|
|
Partition::Partition(Ref<Inode> inner_inode, off_t start, off_t length)
|
|
{
|
|
assert(0 <= start);
|
|
assert(0 <= length);
|
|
assert(length <= OFF_MAX - start);
|
|
assert(!(inner_inode->type & S_IFNEVERWRAP));
|
|
assert(S_ISBLK(inner_inode->type) || S_ISREG(inner_inode->type));
|
|
this->dev = (dev_t) this;
|
|
this->ino = (ino_t) this;
|
|
this->type = inner_inode->type;
|
|
this->inode_type = INODE_TYPE_FILE;
|
|
this->inner_inode = inner_inode;
|
|
this->start = start;
|
|
this->length = length;
|
|
}
|
|
|
|
Partition::~Partition()
|
|
{
|
|
}
|
|
|
|
int Partition::sync(ioctx_t* ctx)
|
|
{
|
|
return inner_inode->sync(ctx);
|
|
}
|
|
|
|
int Partition::truncate(ioctx_t* /*ctx*/, off_t new_length)
|
|
{
|
|
if ( new_length != length )
|
|
return errno = EPERM, -1;
|
|
return 0;
|
|
}
|
|
|
|
off_t Partition::lseek(ioctx_t* /*ctx*/, off_t offset, int whence)
|
|
{
|
|
if ( whence == SEEK_END && offset == 0 )
|
|
return length;
|
|
return errno = EINVAL, -1;
|
|
}
|
|
|
|
ssize_t Partition::pread(ioctx_t* ctx, uint8_t* buf, size_t count, off_t off)
|
|
{
|
|
if ( off < 0 )
|
|
return errno = EINVAL, -1;
|
|
if ( length <= off )
|
|
return 0;
|
|
off_t available = length - off;
|
|
if ( (uintmax_t) available < (uintmax_t) count )
|
|
count = available;
|
|
if ( count == 0 )
|
|
return 0;
|
|
off_t final_offset;
|
|
if ( __builtin_add_overflow(start, off, &final_offset) )
|
|
return errno = EOVERFLOW, -1;
|
|
assert(start <= final_offset);
|
|
assert(final_offset < start + length);
|
|
return inner_inode->pread(ctx, buf, count, final_offset);
|
|
}
|
|
|
|
ssize_t Partition::pwrite(ioctx_t* ctx, const uint8_t* buf, size_t count,
|
|
off_t off)
|
|
{
|
|
if ( off < 0 )
|
|
return errno = EINVAL, -1;
|
|
if ( length <= off )
|
|
return count ? (errno = EFBIG, -1) : 0;
|
|
off_t available = length - off;
|
|
if ( (uintmax_t) available < (uintmax_t) count )
|
|
count = available;
|
|
if ( count == 0 )
|
|
return 0;
|
|
off_t final_offset;
|
|
if ( __builtin_add_overflow(start, off, &final_offset) )
|
|
return errno = EOVERFLOW, -1;
|
|
assert(start <= final_offset);
|
|
assert(final_offset < start + length);
|
|
return inner_inode->pwrite(ctx, buf, count, final_offset);
|
|
}
|
|
|
|
int Partition::stat(ioctx_t* ctx, struct stat* st)
|
|
{
|
|
if ( inner_inode->stat(ctx, st) < 0 )
|
|
return -1;
|
|
struct stat myst;
|
|
if ( !ctx->copy_from_src(&myst, st, sizeof(myst)) )
|
|
return -1;
|
|
myst.st_size = length;
|
|
myst.st_blocks = length / 512;
|
|
if ( !ctx->copy_to_dest(st, &myst, sizeof(myst)) )
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
}
|