/**
* Checks if the head of the receive ring is a UDP packet matching the given
* criteria.
*
* @returns Pointer to the data if it matches.
* @param pBuf The IntNet buffers.
* @param uDstPort The destination port to match.
* @param pDstMac The destination address to match if
* VBOXNETUDP_MATCH_UNICAST is specied.
* @param fFlags Flags indicating what to match and some debug stuff.
* See VBOXNETUDP_MATCH_*.
* @param pHdrs Where to return the pointers to the headers.
* Optional.
* @param pcb Where to return the size of the data on success.
*/
void *VBoxNetUDPMatch(PINTNETBUF pBuf, unsigned uDstPort, PCRTMAC pDstMac, uint32_t fFlags, PVBOXNETUDPHDRS pHdrs, size_t *pcb)
{
/*
* Clear return values so we can return easier on mismatch.
*/
*pcb = 0;
if (pHdrs)
{
pHdrs->pEth = NULL;
pHdrs->pIpv4 = NULL;
pHdrs->pUdp = NULL;
}
/*
* Valid IntNet Ethernet frame?
*/
PCINTNETHDR pHdr = IntNetRingGetNextFrameToRead(&pBuf->Recv);
if ( !pHdr
|| ( pHdr->u16Type != INTNETHDR_TYPE_FRAME
&& pHdr->u16Type != INTNETHDR_TYPE_GSO))
return NULL;
size_t cbFrame = pHdr->cbFrame;
const void *pvFrame = IntNetHdrGetFramePtr(pHdr, pBuf);
PCPDMNETWORKGSO pGso = NULL;
if (pHdr->u16Type == INTNETHDR_TYPE_GSO)
{
pGso = (PCPDMNETWORKGSO)pvFrame;
if (!PDMNetGsoIsValid(pGso, cbFrame, cbFrame - sizeof(*pGso)))
return NULL;
/** @todo IPv6 UDP support, goes for this entire function really. Not really
* important yet since this is currently only used by the DHCP server. */
if (pGso->u8Type != PDMNETWORKGSOTYPE_IPV4_UDP)
return NULL;
pvFrame = pGso + 1;
cbFrame -= sizeof(*pGso);
}
PCRTNETETHERHDR pEthHdr = (PCRTNETETHERHDR)pvFrame;
if (pHdrs)
pHdrs->pEth = pEthHdr;
#ifdef IN_RING3
/* Dump if to stderr/log if that's wanted. */
if (fFlags & VBOXNETUDP_MATCH_PRINT_STDERR)
{
RTStrmPrintf(g_pStdErr, "frame: cb=%04x dst=%.6Rhxs src=%.6Rhxs type=%04x%s\n",
cbFrame, &pEthHdr->DstMac, &pEthHdr->SrcMac, RT_BE2H_U16(pEthHdr->EtherType),
!memcmp(&pEthHdr->DstMac, pDstMac, sizeof(*pDstMac)) ? " Mine!" : "");
}
#endif
/*
* Ethernet matching.
*/
/* Ethernet min frame size. */
if (cbFrame < 64)
return NULL;
/* Match Ethertype: IPV4? */
/** @todo VLAN tagging? */
if (pEthHdr->EtherType != RT_H2BE_U16_C(RTNET_ETHERTYPE_IPV4))
return NULL;
/* Match destination address (ethernet) */
if ( ( !(fFlags & VBOXNETUDP_MATCH_UNICAST)
|| memcmp(&pEthHdr->DstMac, pDstMac, sizeof(pEthHdr->DstMac)))
&& ( !(fFlags & VBOXNETUDP_MATCH_BROADCAST)
|| pEthHdr->DstMac.au16[0] != 0xffff
|| pEthHdr->DstMac.au16[1] != 0xffff
|| pEthHdr->DstMac.au16[2] != 0xffff))
return NULL;
/*
* If we're working on a GSO frame, we need to make sure the length fields
* are set correctly (they are usually set to 0).
*/
if (pGso)
PDMNetGsoPrepForDirectUse(pGso, (void *)pvFrame, cbFrame, PDMNETCSUMTYPE_NONE);
/*
* IP validation and matching.
*/
PCRTNETIPV4 pIpHdr = (PCRTNETIPV4)(pEthHdr + 1);
if (pHdrs)
pHdrs->pIpv4 = pIpHdr;
/* Protocol: UDP */
if (pIpHdr->ip_p != RTNETIPV4_PROT_UDP)
return NULL;
/* Valid IPv4 header? */
size_t const offIpHdr = (uintptr_t)pIpHdr - (uintptr_t)pEthHdr;
if (!RTNetIPv4IsHdrValid(pIpHdr, cbFrame - offIpHdr, cbFrame - offIpHdr, !pGso /*fChecksum*/))
return NULL;
/*
* UDP matching and validation.
*/
PCRTNETUDP pUdpHdr = (PCRTNETUDP)((uint32_t *)pIpHdr + pIpHdr->ip_hl);
if (pHdrs)
pHdrs->pUdp = pUdpHdr;
/* Destination port */
if (RT_BE2H_U16(pUdpHdr->uh_dport) != uDstPort)
return NULL;
if (!pGso)
{
/* Validate the UDP header according to flags. */
size_t offUdpHdr = (uintptr_t)pUdpHdr - (uintptr_t)pEthHdr;
if (fFlags & (VBOXNETUDP_MATCH_CHECKSUM | VBOXNETUDP_MATCH_REQUIRE_CHECKSUM))
{
if (!RTNetIPv4IsUDPValid(pIpHdr, pUdpHdr, pUdpHdr + 1, cbFrame - offUdpHdr, true /*fChecksum*/))
return NULL;
if ( (fFlags & VBOXNETUDP_MATCH_REQUIRE_CHECKSUM)
&& !pUdpHdr->uh_sum)
return NULL;
}
else
{
if (!RTNetIPv4IsUDPSizeValid(pIpHdr, pUdpHdr, cbFrame - offUdpHdr))
return NULL;
}
}
/*
* We've got a match!
*/
*pcb = pUdpHdr->uh_ulen - sizeof(*pUdpHdr);
return (void *)(pUdpHdr + 1);
}
/**
* Internal worker for vboxNetFltDarwinIffInput and vboxNetFltDarwinIffOutput,
*
* @returns 0 or EJUSTRETURN.
* @param pThis The instance.
* @param pMBuf The mbuf.
* @param pvFrame The start of the frame, optional.
* @param fSrc Where the packet (allegedly) comes from, one INTNETTRUNKDIR_* value.
* @param eProtocol The protocol.
*/
static errno_t vboxNetFltDarwinIffInputOutputWorker(PVBOXNETFLTINS pThis, mbuf_t pMBuf, void *pvFrame,
uint32_t fSrc, protocol_family_t eProtocol)
{
/*
* Drop it immediately?
*/
Log2(("vboxNetFltDarwinIffInputOutputWorker: pThis=%p pMBuf=%p pvFrame=%p fSrc=%#x cbPkt=%x\n",
pThis, pMBuf, pvFrame, fSrc, pMBuf ? mbuf_pkthdr_len(pMBuf) : -1));
if (!pMBuf)
return 0;
#if 0 /* debugging lost icmp packets */
if (mbuf_pkthdr_len(pMBuf) > 0x300)
{
uint8_t *pb = (uint8_t *)(pvFrame ? pvFrame : mbuf_data(pMBuf));
Log3(("D=%.6Rhxs S=%.6Rhxs T=%04x IFF\n", pb, pb + 6, RT_BE2H_U16(*(uint16_t *)(pb + 12))));
}
#endif
if (vboxNetFltDarwinMBufIsOur(pThis, pMBuf, pvFrame))
return 0;
/*
* Active? Retain the instance and increment the busy counter.
*/
if (!vboxNetFltTryRetainBusyActive(pThis))
return 0;
/*
* Finalize out-bound packets since the stack puts off finalizing
* TCP/IP checksums as long as possible.
* ASSUMES this only applies to outbound IP packets.
*/
if ( (fSrc & INTNETTRUNKDIR_HOST)
&& eProtocol == PF_INET)
{
Assert(!pvFrame);
mbuf_outbound_finalize(pMBuf, eProtocol, sizeof(RTNETETHERHDR));
}
/*
* Create a (scatter/)gather list for the mbuf and feed it to the internal network.
*/
bool fDropIt = false;
unsigned cSegs = vboxNetFltDarwinMBufCalcSGSegs(pThis, pMBuf, pvFrame);
if (cSegs < VBOXNETFLT_DARWIN_MAX_SEGS)
{
PINTNETSG pSG = (PINTNETSG)alloca(RT_OFFSETOF(INTNETSG, aSegs[cSegs]));
vboxNetFltDarwinMBufToSG(pThis, pMBuf, pvFrame, pSG, cSegs, fSrc);
fDropIt = pThis->pSwitchPort->pfnRecv(pThis->pSwitchPort, NULL /* pvIf */, pSG, fSrc);
if (fDropIt)
{
/*
* Check if this interface is in promiscuous mode. We should not drop
* any packets before they get to the driver as it passes them to tap
* callbacks in order for BPF to work properly.
*/
if (vboxNetFltDarwinIsPromiscuous(pThis))
fDropIt = false;
else
mbuf_freem(pMBuf);
}
}
vboxNetFltRelease(pThis, true /* fBusy */);
return fDropIt ? EJUSTRETURN : 0;
}
