/*
* Interface to file system close.
*
* *pipep points to pipe control structure. When the last user releases pipe,
* it will be set to NULL.
*/
int pipe_release(
pipe_control_t **pipep,
rtems_libio_t *iop
)
{
pipe_control_t *pipe = *pipep;
uint32_t mode;
rtems_status_code sc;
sc = rtems_semaphore_obtain(pipe->Semaphore,
RTEMS_WAIT, RTEMS_NO_TIMEOUT);
/* WARN pipe not released! */
if(sc != RTEMS_SUCCESSFUL)
rtems_fatal_error_occurred(sc);
mode = LIBIO_ACCMODE(iop);
if (mode & LIBIO_FLAGS_READ)
pipe->Readers --;
if (mode & LIBIO_FLAGS_WRITE)
pipe->Writers --;
sc = rtems_semaphore_obtain(rtems_pipe_semaphore,
RTEMS_WAIT, RTEMS_NO_TIMEOUT);
/* WARN pipe not freed and pipep not set to NULL! */
if(sc != RTEMS_SUCCESSFUL)
rtems_fatal_error_occurred(sc);
PIPE_UNLOCK(pipe);
if (pipe->Readers == 0 && pipe->Writers == 0) {
#if 0
/* To delete an anonymous pipe file when all users closed it */
if (pipe->Anonymous)
delfile = TRUE;
#endif
pipe_free(pipe);
*pipep = NULL;
}
else if (pipe->Readers == 0 && mode != LIBIO_FLAGS_WRITE)
/* Notify waiting Writers that all their partners left */
PIPE_WAKEUPWRITERS(pipe);
else if (pipe->Writers == 0 && mode != LIBIO_FLAGS_READ)
PIPE_WAKEUPREADERS(pipe);
rtems_semaphore_release(rtems_pipe_semaphore);
#if 0
if (! delfile)
return 0;
if (iop->pathinfo.ops->unlink_h == NULL)
return 0;
/* This is safe for IMFS, but how about other FSes? */
iop->flags &= ~LIBIO_FLAGS_OPEN;
if(iop->pathinfo.ops->unlink_h(&iop->pathinfo))
return -errno;
#endif
return 0;
}
/*
* Interface to file system close.
*
* *pipep points to pipe control structure. When the last user releases pipe,
* it will be set to NULL.
*/
void pipe_release(
pipe_control_t **pipep,
rtems_libio_t *iop
)
{
pipe_control_t *pipe = *pipep;
uint32_t mode;
#if defined(RTEMS_DEBUG)
/* WARN pipe not freed and pipep not set to NULL! */
if (pipe_lock())
rtems_fatal_error_occurred(0xdeadbeef);
/* WARN pipe not released! */
if (!PIPE_LOCK(pipe))
rtems_fatal_error_occurred(0xdeadbeef);
#endif
mode = LIBIO_ACCMODE(iop);
if (mode & LIBIO_FLAGS_READ)
pipe->Readers --;
if (mode & LIBIO_FLAGS_WRITE)
pipe->Writers --;
PIPE_UNLOCK(pipe);
if (pipe->Readers == 0 && pipe->Writers == 0) {
#if 0
/* To delete an anonymous pipe file when all users closed it */
if (pipe->Anonymous)
delfile = TRUE;
#endif
pipe_free(pipe);
*pipep = NULL;
}
else if (pipe->Readers == 0 && mode != LIBIO_FLAGS_WRITE)
/* Notify waiting Writers that all their partners left */
PIPE_WAKEUPWRITERS(pipe);
else if (pipe->Writers == 0 && mode != LIBIO_FLAGS_READ)
PIPE_WAKEUPREADERS(pipe);
pipe_unlock();
#if 0
if (! delfile)
return;
if (iop->pathinfo.ops->unlink_h == NULL)
return;
/* This is safe for IMFS, but how about other FSes? */
iop->flags &= ~LIBIO_FLAGS_OPEN;
if(iop->pathinfo.ops->unlink_h(&iop->pathinfo))
return;
#endif
}
/*
* Interface to file system ioctl.
*/
int pipe_ioctl(
pipe_control_t *pipe,
uint32_t cmd,
void *buffer,
rtems_libio_t *iop
)
{
if (cmd == FIONREAD) {
if (buffer == NULL)
return -EFAULT;
if (! PIPE_LOCK(pipe))
return -EINTR;
/* Return length of pipe */
*(unsigned int *)buffer = pipe->Length;
PIPE_UNLOCK(pipe);
return 0;
}
return -EINVAL;
}
/*
* Interface to file system write.
*/
ssize_t pipe_write(
pipe_control_t *pipe,
const void *buffer,
size_t count,
rtems_libio_t *iop
)
{
int chunk, chunk1, written = 0, ret = 0;
/* Write nothing */
if (count == 0)
return 0;
if (! PIPE_LOCK(pipe))
return -EINTR;
if (pipe->Readers == 0) {
ret = -EPIPE;
goto out_locked;
}
/* Write of PIPE_BUF bytes or less shall not be interleaved */
chunk = count <= pipe->Size ? count : 1;
while (written < count) {
while (PIPE_SPACE(pipe) < chunk) {
if (LIBIO_NODELAY(iop)) {
ret = -EAGAIN;
goto out_locked;
}
/* Wait until there is chunk bytes space or no reader exists */
pipe->waitingWriters ++;
PIPE_UNLOCK(pipe);
if (! PIPE_WRITEWAIT(pipe))
ret = -EINTR;
if (! PIPE_LOCK(pipe)) {
/* WARN waitingWriters not restored! */
ret = -EINTR;
goto out_nolock;
}
pipe->waitingWriters --;
if (ret != 0)
goto out_locked;
if (pipe->Readers == 0) {
ret = -EPIPE;
goto out_locked;
}
}
chunk = MIN(count - written, PIPE_SPACE(pipe));
chunk1 = pipe->Size - PIPE_WSTART(pipe);
if (chunk > chunk1) {
memcpy(pipe->Buffer + PIPE_WSTART(pipe), buffer + written, chunk1);
memcpy(pipe->Buffer, buffer + written + chunk1, chunk - chunk1);
}
else
memcpy(pipe->Buffer + PIPE_WSTART(pipe), buffer + written, chunk);
pipe->Length += chunk;
if (pipe->waitingReaders > 0)
PIPE_WAKEUPREADERS(pipe);
written += chunk;
/* Write of more than PIPE_BUF bytes can be interleaved */
chunk = 1;
}
out_locked:
PIPE_UNLOCK(pipe);
out_nolock:
#ifdef RTEMS_POSIX_API
/* Signal SIGPIPE */
if (ret == -EPIPE)
kill(getpid(), SIGPIPE);
#endif
if (written > 0)
return written;
return ret;
}
/*
* Interface to file system read.
*/
ssize_t pipe_read(
pipe_control_t *pipe,
void *buffer,
size_t count,
rtems_libio_t *iop
)
{
int chunk, chunk1, read = 0, ret = 0;
if (! PIPE_LOCK(pipe))
return -EINTR;
while (read < count) {
while (PIPE_EMPTY(pipe)) {
/* Not an error */
if (pipe->Writers == 0)
goto out_locked;
if (LIBIO_NODELAY(iop)) {
ret = -EAGAIN;
goto out_locked;
}
/* Wait until pipe is no more empty or no writer exists */
pipe->waitingReaders ++;
PIPE_UNLOCK(pipe);
if (! PIPE_READWAIT(pipe))
ret = -EINTR;
if (! PIPE_LOCK(pipe)) {
/* WARN waitingReaders not restored! */
ret = -EINTR;
goto out_nolock;
}
pipe->waitingReaders --;
if (ret != 0)
goto out_locked;
}
/* Read chunk bytes */
chunk = MIN(count - read, pipe->Length);
chunk1 = pipe->Size - pipe->Start;
if (chunk > chunk1) {
memcpy(buffer + read, pipe->Buffer + pipe->Start, chunk1);
memcpy(buffer + read + chunk1, pipe->Buffer, chunk - chunk1);
}
else
memcpy(buffer + read, pipe->Buffer + pipe->Start, chunk);
pipe->Start += chunk;
pipe->Start %= pipe->Size;
pipe->Length -= chunk;
/* For buffering optimization */
if (PIPE_EMPTY(pipe))
pipe->Start = 0;
if (pipe->waitingWriters > 0)
PIPE_WAKEUPWRITERS(pipe);
read += chunk;
}
out_locked:
PIPE_UNLOCK(pipe);
out_nolock:
if (read > 0)
return read;
return ret;
}
/*
* Interface to file system open.
*
* *pipep points to pipe control structure. If called with *pipep = NULL,
* fifo_open will try allocating and initializing a control structure. If the
* call succeeds, *pipep will be set to address of new control structure.
*/
int fifo_open(
pipe_control_t **pipep,
rtems_libio_t *iop
)
{
pipe_control_t *pipe;
unsigned int prevCounter;
int err;
err = pipe_new(pipep);
if (err)
return err;
pipe = *pipep;
switch (LIBIO_ACCMODE(iop)) {
case LIBIO_FLAGS_READ:
pipe->readerCounter ++;
if (pipe->Readers ++ == 0)
PIPE_WAKEUPWRITERS(pipe);
if (pipe->Writers == 0) {
/* Not an error */
if (LIBIO_NODELAY(iop))
break;
prevCounter = pipe->writerCounter;
err = -EINTR;
/* Wait until a writer opens the pipe */
do {
PIPE_UNLOCK(pipe);
if (! PIPE_READWAIT(pipe))
goto out_error;
if (! PIPE_LOCK(pipe))
goto out_error;
} while (prevCounter == pipe->writerCounter);
}
break;
case LIBIO_FLAGS_WRITE:
pipe->writerCounter ++;
if (pipe->Writers ++ == 0)
PIPE_WAKEUPREADERS(pipe);
if (pipe->Readers == 0 && LIBIO_NODELAY(iop)) {
PIPE_UNLOCK(pipe);
err = -ENXIO;
goto out_error;
}
if (pipe->Readers == 0) {
prevCounter = pipe->readerCounter;
err = -EINTR;
do {
PIPE_UNLOCK(pipe);
if (! PIPE_WRITEWAIT(pipe))
goto out_error;
if (! PIPE_LOCK(pipe))
goto out_error;
} while (prevCounter == pipe->readerCounter);
}
break;
case LIBIO_FLAGS_READ_WRITE:
pipe->readerCounter ++;
if (pipe->Readers ++ == 0)
PIPE_WAKEUPWRITERS(pipe);
pipe->writerCounter ++;
if (pipe->Writers ++ == 0)
PIPE_WAKEUPREADERS(pipe);
break;
}
PIPE_UNLOCK(pipe);
return 0;
out_error:
pipe_release(pipep, iop);
return err;
}
int
pipe_stat(struct pipe *cpipe, void *ub, int isstat64)
{
#if CONFIG_MACF
int error;
#endif
int pipe_size = 0;
int pipe_count;
struct stat *sb = (struct stat *)0; /* warning avoidance ; protected by isstat64 */
struct stat64 * sb64 = (struct stat64 *)0; /* warning avoidance ; protected by isstat64 */
if (cpipe == NULL)
return (EBADF);
PIPE_LOCK(cpipe);
#if CONFIG_MACF
error = mac_pipe_check_stat(kauth_cred_get(), cpipe);
if (error) {
PIPE_UNLOCK(cpipe);
return (error);
}
#endif
if (cpipe->pipe_buffer.buffer == 0) {
/* must be stat'ing the write fd */
if (cpipe->pipe_peer) {
/* the peer still exists, use it's info */
pipe_size = MAX_PIPESIZE(cpipe->pipe_peer);
pipe_count = cpipe->pipe_peer->pipe_buffer.cnt;
} else {
pipe_count = 0;
}
} else {
pipe_size = MAX_PIPESIZE(cpipe);
pipe_count = cpipe->pipe_buffer.cnt;
}
/*
* since peer's buffer is setup ouside of lock
* we might catch it in transient state
*/
if (pipe_size == 0)
pipe_size = MAX(PIPE_SIZE, pipesize_blocks[0]);
if (isstat64 != 0) {
sb64 = (struct stat64 *)ub;
bzero(sb64, sizeof(*sb64));
sb64->st_mode = S_IFIFO | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
sb64->st_blksize = pipe_size;
sb64->st_size = pipe_count;
sb64->st_blocks = (sb64->st_size + sb64->st_blksize - 1) / sb64->st_blksize;
sb64->st_uid = kauth_getuid();
sb64->st_gid = kauth_getgid();
sb64->st_atimespec.tv_sec = cpipe->st_atimespec.tv_sec;
sb64->st_atimespec.tv_nsec = cpipe->st_atimespec.tv_nsec;
sb64->st_mtimespec.tv_sec = cpipe->st_mtimespec.tv_sec;
sb64->st_mtimespec.tv_nsec = cpipe->st_mtimespec.tv_nsec;
sb64->st_ctimespec.tv_sec = cpipe->st_ctimespec.tv_sec;
sb64->st_ctimespec.tv_nsec = cpipe->st_ctimespec.tv_nsec;
/*
* Return a relatively unique inode number based on the current
* address of this pipe's struct pipe. This number may be recycled
* relatively quickly.
*/
sb64->st_ino = (ino64_t)VM_KERNEL_ADDRPERM((uintptr_t)cpipe);
} else {
sb = (struct stat *)ub;
bzero(sb, sizeof(*sb));
sb->st_mode = S_IFIFO | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
sb->st_blksize = pipe_size;
sb->st_size = pipe_count;
sb->st_blocks = (sb->st_size + sb->st_blksize - 1) / sb->st_blksize;
sb->st_uid = kauth_getuid();
sb->st_gid = kauth_getgid();
sb->st_atimespec.tv_sec = cpipe->st_atimespec.tv_sec;
sb->st_atimespec.tv_nsec = cpipe->st_atimespec.tv_nsec;
sb->st_mtimespec.tv_sec = cpipe->st_mtimespec.tv_sec;
sb->st_mtimespec.tv_nsec = cpipe->st_mtimespec.tv_nsec;
sb->st_ctimespec.tv_sec = cpipe->st_ctimespec.tv_sec;
sb->st_ctimespec.tv_nsec = cpipe->st_ctimespec.tv_nsec;
/*
* Return a relatively unique inode number based on the current
* address of this pipe's struct pipe. This number may be recycled
* relatively quickly.
*/
sb->st_ino = (ino_t)VM_KERNEL_ADDRPERM((uintptr_t)cpipe);
}
PIPE_UNLOCK(cpipe);
/*
* POSIX: Left as 0: st_dev, st_nlink, st_rdev, st_flags, st_gen,
* st_uid, st_gid.
*
* XXX (st_dev) should be unique, but there is no device driver that
* XXX is associated with pipes, since they are implemented via a
* XXX struct fileops indirection rather than as FS objects.
*/
return (0);
}
