/* * 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)); }