sbuf.c revision caff8bc1842e1ba69d4115103177264909cbb97b
/*
* Copyright (c) 1995 Danny Gasparovski.
*
* Please read the file COPYRIGHT for the
* terms and conditions of the copyright.
*/
#include <slirp.h>
/* Done as a macro in socket.h */
/* int
* sbspace(struct sockbuff *sb)
* {
* return SB_DATALEN - sb->sb_cc;
* }
*/
void
sbfree(struct sbuf *sb)
{
RTMemFree(sb->sb_data);
}
void
sbdrop(struct sbuf *sb, int num)
{
/*
* We can only drop how much we have
* This should never succeed
*/
if (num > sb->sb_cc)
num = sb->sb_cc;
sb->sb_cc -= num;
sb->sb_rptr += num;
if (sb->sb_rptr >= sb->sb_data + sb->sb_datalen)
sb->sb_rptr -= sb->sb_datalen;
}
void
sbreserve(PNATState pData, struct sbuf *sb, int size)
{
if (sb->sb_data)
{
/* Already alloced, realloc if necessary */
if (sb->sb_datalen != size)
{
sb->sb_wptr =
sb->sb_rptr =
sb->sb_data = (char *)RTMemRealloc(sb->sb_data, size);
sb->sb_cc = 0;
if (sb->sb_wptr)
sb->sb_datalen = size;
else
sb->sb_datalen = 0;
}
}
else
{
sb->sb_wptr = sb->sb_rptr = sb->sb_data = (char *)RTMemAlloc(size);
sb->sb_cc = 0;
if (sb->sb_wptr)
sb->sb_datalen = size;
else
sb->sb_datalen = 0;
}
}
/*
* Try and write() to the socket, whatever doesn't get written
* append to the buffer... for a host with a fast net connection,
* this prevents an unnecessary copy of the data
* (the socket is non-blocking, so we won't hang)
*/
void
sbappend(PNATState pData, struct socket *so, struct mbuf *m)
{
int ret = 0;
STAM_PROFILE_START(&pData->StatIOSBAppend_pf, a);
DEBUG_CALL("sbappend");
DEBUG_ARG("so = %lx", (long)so);
DEBUG_ARG("m = %lx", (long)m);
DEBUG_ARG("m->m_len = %d", m->m_len);
STAM_COUNTER_INC(&pData->StatIOSBAppend);
/* Shouldn't happen, but... e.g. foreign host closes connection */
if (m->m_len <= 0)
{
STAM_COUNTER_INC(&pData->StatIOSBAppend_zm);
goto done;
}
/*
* If there is urgent data, call sosendoob
* if not all was sent, sowrite will take care of the rest
* (The rest of this function is just an optimisation)
*/
if (so->so_urgc)
{
sbappendsb(pData, &so->so_rcv, m);
m_free(pData, m);
sosendoob(so);
return;
}
/*
* We only write if there's nothing in the buffer,
* ottherwise it'll arrive out of order, and hence corrupt
*/
if (!so->so_rcv.sb_cc)
ret = send(so->s, m->m_data, m->m_len, 0);
if (ret <= 0)
{
STAM_COUNTER_INC(&pData->StatIOSBAppend_wf);
/*
* Nothing was written
* It's possible that the socket has closed, but
* we don't need to check because if it has closed,
* it will be detected in the normal way by soread()
*/
sbappendsb(pData, &so->so_rcv, m);
STAM_PROFILE_STOP(&pData->StatIOSBAppend_pf_wf, a);
goto done;
}
else if (ret != m->m_len)
{
STAM_COUNTER_INC(&pData->StatIOSBAppend_wp);
/*
* Something was written, but not everything..
* sbappendsb the rest
*/
m->m_len -= ret;
m->m_data += ret;
sbappendsb(pData, &so->so_rcv, m);
STAM_PROFILE_STOP(&pData->StatIOSBAppend_pf_wp, a);
goto done;
} /* else */
/* Whatever happened, we free the mbuf */
STAM_COUNTER_INC(&pData->StatIOSBAppend_wa);
STAM_PROFILE_STOP(&pData->StatIOSBAppend_pf_wa, a);
done:
m_free(pData, m);
}
/*
* Copy the data from m into sb
* The caller is responsible to make sure there's enough room
*/
void
sbappendsb(PNATState pData, struct sbuf *sb, struct mbuf *m)
{
int len, n, nn;
len = m->m_len;
STAM_COUNTER_INC(&pData->StatIOSBAppendSB);
if (sb->sb_wptr < sb->sb_rptr)
{
STAM_COUNTER_INC(&pData->StatIOSBAppendSB_w_l_r);
n = sb->sb_rptr - sb->sb_wptr;
if (n > len)
n = len;
memcpy(sb->sb_wptr, m->m_data, n);
}
else
{
STAM_COUNTER_INC(&pData->StatIOSBAppendSB_w_ge_r);
/* Do the right edge first */
n = sb->sb_data + sb->sb_datalen - sb->sb_wptr;
if (n > len)
n = len;
memcpy(sb->sb_wptr, m->m_data, n);
len -= n;
if (len)
{
/* Now the left edge */
nn = sb->sb_rptr - sb->sb_data;
if (nn > len)
nn = len;
memcpy(sb->sb_data, m->m_data+n, nn);
n += nn;
}
}
sb->sb_cc += n;
sb->sb_wptr += n;
if (sb->sb_wptr >= sb->sb_data + sb->sb_datalen)
{
STAM_COUNTER_INC(&pData->StatIOSBAppendSB_w_alter);
sb->sb_wptr -= sb->sb_datalen;
}
}
/*
* Copy data from sbuf to a normal, straight buffer
* Don't update the sbuf rptr, this will be
* done in sbdrop when the data is acked
*/
void
sbcopy(struct sbuf *sb, int off, int len, char *to)
{
char *from;
from = sb->sb_rptr + off;
if (from >= sb->sb_data + sb->sb_datalen)
from -= sb->sb_datalen;
if (from < sb->sb_wptr)
{
if (len > sb->sb_cc)
len = sb->sb_cc;
memcpy(to, from, len);
}
else
{
/* re-use off */
off = (sb->sb_data + sb->sb_datalen) - from;
if (off > len)
off = len;
memcpy(to, from, off);
len -= off;
if (len)
memcpy(to+off, sb->sb_data, len);
}
}