/*
* Convert from mbufs to vbox scatter-gather data structure
*/
static void vboxNetFltFreeBSDMBufToSG(PVBOXNETFLTINS pThis, struct mbuf *m, PINTNETSG pSG,
unsigned int cSegs, unsigned int segOffset)
{
static uint8_t const s_abZero[128] = {0};
unsigned int i;
struct mbuf *m0;
IntNetSgInitTempSegs(pSG, m_length(m, NULL), cSegs, 0 /*cSegsUsed*/);
for (m0 = m, i = segOffset; m0; m0 = m0->m_next)
{
if (m0->m_len == 0)
continue;
pSG->aSegs[i].cb = m0->m_len;
pSG->aSegs[i].pv = mtod(m0, uint8_t *);
pSG->aSegs[i].Phys = NIL_RTHCPHYS;
i++;
}
#ifdef PADD_RUNT_FRAMES_FROM_HOST
if (pSG->cbTotal < 60)
{
pSG->aSegs[i].Phys = NIL_RTHCPHYS;
pSG->aSegs[i].pv = (void *)&s_abZero[0];
pSG->aSegs[i].cb = 60 - pSG->cbTotal;
pSG->cbTotal = 60;
i++;
}
#endif
pSG->cSegsUsed = i;
}
/**
* Initializes a SG list from an mbuf.
*
* @returns Number of segments.
* @param pThis The instance.
* @param pMBuf The mbuf.
* @param pSG The SG.
* @param pvFrame The frame pointer, optional.
* @param cSegs The number of segments allocated for the SG.
* This should match the number in the mbuf exactly!
* @param fSrc The source of the frame.
*/
DECLINLINE(void) vboxNetFltDarwinMBufToSG(PVBOXNETFLTINS pThis, mbuf_t pMBuf, void *pvFrame, PINTNETSG pSG, unsigned cSegs, uint32_t fSrc)
{
NOREF(pThis);
/*
* Walk the chain and convert the buffers to segments. Works INTNETSG::cbTotal.
*/
unsigned iSeg = 0;
IntNetSgInitTempSegs(pSG, 0 /*cbTotal*/, cSegs, 0 /*cSegsUsed*/);
for (mbuf_t pCur = pMBuf; pCur; pCur = mbuf_next(pCur))
{
size_t cbSeg = mbuf_len(pCur);
if (cbSeg)
{
void *pvSeg = mbuf_data(pCur);
/* deal with pvFrame */
if (!iSeg && pvFrame && pvFrame != pvSeg)
{
void *pvStart = mbuf_datastart(pMBuf);
uintptr_t offSeg = (uintptr_t)pvSeg - (uintptr_t)pvStart;
uintptr_t offSegEnd = offSeg + cbSeg;
Assert(pvStart && pvSeg && offSeg < mbuf_maxlen(pMBuf) && offSegEnd <= mbuf_maxlen(pMBuf)); NOREF(offSegEnd);
uintptr_t offFrame = (uintptr_t)pvFrame - (uintptr_t)pvStart;
if (RT_LIKELY(offFrame < offSeg))
{
pvSeg = pvFrame;
cbSeg += offSeg - offFrame;
}
else
AssertMsgFailed(("pvFrame=%p pvStart=%p pvSeg=%p offSeg=%p cbSeg=%#zx offSegEnd=%p offFrame=%p maxlen=%#zx\n",
pvFrame, pvStart, pvSeg, offSeg, cbSeg, offSegEnd, offFrame, mbuf_maxlen(pMBuf)));
pvFrame = NULL;
}
AssertBreak(iSeg < cSegs);
pSG->cbTotal += cbSeg;
pSG->aSegs[iSeg].cb = cbSeg;
pSG->aSegs[iSeg].pv = pvSeg;
pSG->aSegs[iSeg].Phys = NIL_RTHCPHYS;
iSeg++;
}
/* The pvFrame might be in a now empty buffer. */
else if ( !iSeg
&& pvFrame
&& (uintptr_t)pvFrame - (uintptr_t)mbuf_datastart(pMBuf) < mbuf_maxlen(pMBuf))
{
cbSeg = (uintptr_t)mbuf_datastart(pMBuf) + mbuf_maxlen(pMBuf) - (uintptr_t)pvFrame;
pSG->cbTotal += cbSeg;
pSG->aSegs[iSeg].cb = cbSeg;
pSG->aSegs[iSeg].pv = pvFrame;
pSG->aSegs[iSeg].Phys = NIL_RTHCPHYS;
iSeg++;
pvFrame = NULL;
}
}
Assert(iSeg && iSeg <= cSegs);
pSG->cSegsUsed = iSeg;
#ifdef PADD_RUNT_FRAMES_FROM_HOST
/*
* Add a trailer if the frame is too small.
*
* Since we're getting to the packet before it is framed, it has not
* yet been padded. The current solution is to add a segment pointing
* to a buffer containing all zeros and pray that works for all frames...
*/
if (pSG->cbTotal < 60 && (fSrc & INTNETTRUNKDIR_HOST))
{
AssertReturnVoid(iSeg < cSegs);
static uint8_t const s_abZero[128] = {0};
pSG->aSegs[iSeg].Phys = NIL_RTHCPHYS;
pSG->aSegs[iSeg].pv = (void *)&s_abZero[0];
pSG->aSegs[iSeg].cb = 60 - pSG->cbTotal;
pSG->cbTotal = 60;
pSG->cSegsUsed++;
}
#endif
#ifdef VBOXNETFLT_DARWIN_TEST_SEG_SIZE
/*
* Redistribute the segments.
*/
if (pSG->cSegsUsed < pSG->cSegsAlloc)
{
/* copy the segments to the end. */
int iSrc = pSG->cSegsUsed;
int iDst = pSG->cSegsAlloc;
while (iSrc > 0)
{
iDst--;
iSrc--;
pSG->aSegs[iDst] = pSG->aSegs[iSrc];
}
/* create small segments from the start. */
pSG->cSegsUsed = pSG->cSegsAlloc;
iSrc = iDst;
iDst = 0;
while ( iDst < iSrc
&& iDst < pSG->cSegsAlloc)
{
pSG->aSegs[iDst].Phys = NIL_RTHCPHYS;
pSG->aSegs[iDst].pv = pSG->aSegs[iSrc].pv;
pSG->aSegs[iDst].cb = RT_MIN(pSG->aSegs[iSrc].cb, VBOXNETFLT_DARWIN_TEST_SEG_SIZE);
if (pSG->aSegs[iDst].cb != pSG->aSegs[iSrc].cb)
{
pSG->aSegs[iSrc].cb -= pSG->aSegs[iDst].cb;
pSG->aSegs[iSrc].pv = (uint8_t *)pSG->aSegs[iSrc].pv + pSG->aSegs[iDst].cb;
}
else if (++iSrc >= pSG->cSegsAlloc)
{
pSG->cSegsUsed = iDst + 1;
break;
}
iDst++;
}
}
#endif
AssertMsg(!pvFrame, ("pvFrame=%p pMBuf=%p iSeg=%d\n", pvFrame, pMBuf, iSeg));
}