/**
* Copyright (C) 2001-2018 Artifex Software, Inc.
*
* 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.
**/
#include <string.h>
#include "unistd_.h"
#include "ijs.h"
static void
ijs_put_int (char *p, int val)
{
p[0] = (val >> 24) & 0xff;
p[1] = (val >> 16) & 0xff;
p[2] = (val >> 8) & 0xff;
p[3] = val & 0xff;
}
void
ijs_send_init (IjsSendChan *ch, int fd)
{
ch->fd = fd;
ch->buf_size = 0;
}
int
ijs_send_int (IjsSendChan *ch, int val)
{
if ((ch->buf_size + 4) > (int)sizeof(ch->buf))
return IJS_ERANGE;
ijs_put_int (ch->buf + ch->buf_size, val);
ch->buf_size += 4;
return 0;
}
int
ijs_send_begin (IjsSendChan *ch, IjsCommand cmd)
{
if (ch->buf_size != 0)
return IJS_EINTERNAL;
ijs_send_int (ch, cmd);
ch->buf_size += 4; /* leave room for size field */
return 0;
}
int
ijs_send_block (IjsSendChan *ch, const char *buf, int len)
{
if ((ch->buf_size + len) > (int)sizeof(ch->buf))
return IJS_ERANGE;
memcpy (ch->buf + ch->buf_size, buf, len);
ch->buf_size += len;
return 0;
}
int
ijs_send_buf (IjsSendChan *ch)
{
int status;
ijs_put_int (ch->buf + 4, ch->buf_size);
status = write (ch->fd, ch->buf, ch->buf_size);
status = (status == ch->buf_size) ? 0 : IJS_EIO;
ch->buf_size = 0;
return status;
}
void
ijs_recv_init (IjsRecvChan *ch, int fd)
{
ch->fd = fd;
ch->buf_size = 0;
}
int
ijs_get_int (const char *p)
{
const unsigned char *up = (const unsigned char *)p;
return (up[0] << 24) | (up[1] << 16) | (up[2] << 8) | up[3];
}
/* This is a drop-in replacement for read(), but handles partial reads. */
int
ijs_recv_read (IjsRecvChan *ch, char *buf, int size)
{
int ix = 0;
int nbytes;
do
{
nbytes = read (ch->fd, buf + ix, size - ix);
if (nbytes < 0)
return nbytes;
else if (nbytes == 0)
return ix;
else
ix += nbytes;
}
while (ix < size);
return ix;
}
int
ijs_recv_buf (IjsRecvChan *ch)
{
int nbytes;
int data_size;
nbytes = ijs_recv_read (ch, ch->buf, 8);
if (nbytes != 8)
return IJS_EIO;
ch->buf_size = ijs_get_int (ch->buf + 4);
if (ch->buf_size < 8 || ch->buf_size > (int)sizeof(ch->buf))
return IJS_ERANGE;
data_size = ch->buf_size - 8;
if (data_size > 0)
{
nbytes = ijs_recv_read (ch, ch->buf + 8, data_size);
if (nbytes != data_size)
return IJS_EIO;
}
ch->buf_idx = 8;
return 0;
}
/**
* ijs_recv_ack: Receive an acknowledgement.
* @ch: Channel.
*
* Receives an acknowledgement code (generally from server to client).
* Note that the distinction between local error and error generated
* by the remote peer is lost in this routine. If it is important to
* preserve this distinction, use ijs_recv_buf directly instead.
*
* Return value: 0 on success, negative on error.
**/
int
ijs_recv_ack (IjsRecvChan *ch)
{
int status;
status = ijs_recv_buf (ch);
if (status == 0)
{
int cmd = ijs_get_int (ch->buf);
if (cmd == IJS_CMD_NAK)
{
if (ch->buf_size != 12)
status = IJS_EPROTO;
else
status = ijs_get_int (ch->buf + 8);
}
}
return status;
}
int
ijs_recv_int (IjsRecvChan *ch, int *val)
{
if (ch->buf_idx + 4 > ch->buf_size)
return IJS_EPROTO;
*val = ijs_get_int (ch->buf + ch->buf_idx);
ch->buf_idx += 4;
return 0;
}
/**
* Return value: data block size if nonnegative, or error code if
* negative.
**/
int
ijs_recv_block (IjsRecvChan *ch, char *buf, int buf_size)
{
int size = ch->buf_size - ch->buf_idx;
if (size > buf_size)
return IJS_ERANGE;
memcpy (buf, ch->buf + ch->buf_idx, size);
ch->buf_idx = ch->buf_size;
return size;
}