void radixsort(int* nums, int count)
{
int digit, max;
Queue buckets[NDIGITS]; // One index per digit, including negatives
// Don't bother working on one-element and empty array
if (count < 2)
return;
for (int i = 0; i < NDIGITS; i++) { // Nullify each queue
buckets[i].head = NULL;
buckets[i].tail = NULL;
}
// Find the biggest number width
max = radix_len(nums[0]);
for (int i = 1; i < count; i++)
if (radix_len(nums[i]) > max)
max = radix_len(nums[i]);
// Go through each column
for (int i = 1; i <= max; i++) {
// of each element
for (int j = 0; j < count; j++) {
// to get the i-th digit from j-th nums[] element,
digit = radix_digit(nums[j], i) + BASE - 1; // compensate for negative digits
// and enqueue it to the corresponding digit-th bucket.
q_enq(buckets + digit, nums[j]);
}
// Take each element of nums[],
for (int j = 0; j < count; j++)
for (int k = 0; k < NDIGITS; k++) // and fill it with whatever
while (buckets[k].head != NULL) // we find in each non-empty bucket.
nums[j++] = q_deq(buckets + k);
}
}
void
pktdemux()
{
PACKET pkt;
NET ifc; /* interface packet came from */
IFMIB mib;
int pkts;
char * eth;
pkts = 0; /* packets per loop */
while (rcvdq.q_len)
{
/* If we are low on free packets, don't hog CPU cycles */
if (pkts++ > bigfreeq.q_len)
{
#ifdef SUPERLOOP
return; /* don't hog stack on superloop */
#else /* SUPERLOOP */
tk_yield(); /* let application tasks process received packets */
pkts = 0; /* reset counter */
#endif /* SUPERLOOP else */
}
/* If we get receive interupt from the net during this
lock, the MAC driver needs to wait or reschedule */
LOCK_NET_RESOURCE(RXQ_RESID);
pkt = (PACKET)q_deq(&rcvdq);
UNLOCK_NET_RESOURCE(RXQ_RESID);
if (!pkt) panic("pktdemux: got null pkt");
ifc = pkt->net;
mib = ifc->n_mib;
/* maintain mib stats for unicast and broadcast */
if (isbcast(ifc, (u_char*)pkt->nb_buff + ETHHDR_BIAS))
mib->ifInNUcastPkts++;
else
mib->ifInUcastPkts++;
if(mib->ifAdminStatus == NI_DOWN)
{
LOCK_NET_RESOURCE(FREEQ_RESID);
pk_free(pkt); /* dump packet from downed interface */
UNLOCK_NET_RESOURCE(FREEQ_RESID);
mib->ifInDiscards++;
continue; /* next packet */
}
#ifdef NPDEBUG
if (*(pkt->nb_buff - ALIGN_TYPE) != 'M' ||
*(pkt->nb_buff + pkt->nb_blen) != 'M')
{
dtrap();
panic("pktdemux: corrupt pkt");
}
#endif /* NPDEBUG */
#ifdef LOSSY_IO
if(NDEBUG & LOSSY_RX)
{
if(myloss())
{
LOCK_NET_RESOURCE(FREEQ_RESID);
pk_free(pkt); /* punt packet */
UNLOCK_NET_RESOURCE(FREEQ_RESID);
in_lastloss = (int)(cticks & 0x07) - 4; /* pseudo random reset */
continue; /* act as if we sent OK */
}
}
#endif /* LOSSY_IO */
/* see if driver set pkt->nb_prot and pkt->type */
if((ifc->n_flags & NF_NBPROT) == 0)
{
/* Set pkt->type and pkt->nb_prot based based on media type.
* Some device drivers pass nb_plen as the total length of the
* packet, while others subtract the MAC header. The latter is
* probably the right thing to do, but because of this historic
* inconsistency we don't try to fix it here - the longer size
* turns out to be harmless since the IP layer fixes the size
* based on the IP header length field.
*/
switch(ifc->n_mib->ifType)
{
case ETHERNET:
/* get pointer to ethernet header */
eth = (pkt->nb_buff + ETHHDR_BIAS);
#ifdef IEEE_802_3
/* see if it's got snap baggage */
if (ET_TYPE_GET(eth) <= 0x0600)
{
struct snap_hdr *snap;
snap = (struct snap_hdr *)(pkt->nb_buff + ETHHDR_SIZE);
pkt->type = (unshort)(snap->type);
pkt->nb_prot = pkt->nb_buff + pkt->net->n_lnh;
}
else
{
pkt->type = htons((unshort)ET_TYPE_GET(eth));
pkt->nb_prot = pkt->nb_buff + ETHHDR_SIZE;
}
#else
pkt->type = htons((unshort)ET_TYPE_GET(eth));
pkt->nb_prot = pkt->nb_buff + pkt->net->n_lnh;
#endif /* IEEE_802_3 */
break;
#if defined(USE_PPP) || defined(USE_SLIP) || defined(PROTOCOL_LIBS)
case PPP: /* PPP or SLIP over a UART */
case SLIP:
pkt->nb_prot = pkt->nb_buff + MaxLnh;
pkt->type = IPTP; /* only type our PPP supports */
break;
#endif /* USE_PPP || USE_SLIP */
#ifdef USE_PPPOE
case PPPOE:
/* do not change type yet, for PPPoE */
break;
#endif /* USE_PPPOE */
default: /* driver bug? */
dprintf("pktdemux: bad Iface type %ld\n",ifc->n_mib->ifType);
LOCK_NET_RESOURCE(FREEQ_RESID);
pk_free(pkt);
UNLOCK_NET_RESOURCE(FREEQ_RESID);
continue;
}
}
/* pkt->nb_prot and pkt->type are now set. pass pkt to upper layer */
switch(pkt->type)
{
case IPTP: /* IP type */
LOCK_NET_RESOURCE(NET_RESID);
#ifdef SHARED_IPADDRS
add_share_route(pkt);
#endif /* SHARED_IPADDRS */
#ifdef IP_V4
ip_rcv(pkt);
#else
/* don't care, it's IPv4 */
LOCK_NET_RESOURCE(FREEQ_RESID);
pk_free(pkt);
UNLOCK_NET_RESOURCE(FREEQ_RESID);
#endif
UNLOCK_NET_RESOURCE(NET_RESID);
break;
#ifdef INCLUDE_ARP
case ARPTP: /* ARP type */
LOCK_NET_RESOURCE(NET_RESID);
arprcv(pkt);
UNLOCK_NET_RESOURCE(NET_RESID);
break;
#endif /* INCLUDE_ARP */
#ifdef USE_PPPOE
case htons(0x8863):
case htons(0x8864):
LOCK_NET_RESOURCE(NET_RESID);
poe_rcv(pkt);
UNLOCK_NET_RESOURCE(NET_RESID);
break;
#endif /* USE_PPPOE */
#ifdef IP_V6
case htons(0x86DD):
/* Each received v6 pkt goes thru here exactly once, so set the
* outer (first, and usually only) ipv6 header pointer. Tunneled headers
* may exist further into the packet.
*/
pkt->ip6_hdr = (struct ipv6 *)pkt->nb_prot;
LOCK_NET_RESOURCE(NET_RESID);
ip6_rcv(pkt);
UNLOCK_NET_RESOURCE(NET_RESID);
break;
#endif
default:
#ifdef NPDEBUG
if (NDEBUG & UPCTRACE)
dprintf("pktdemux: bad pkt type 0x%04x\n", ntohs(pkt->type));
#endif /* NPDEBUG */
ifc->n_mib->ifInUnknownProtos++;
LOCK_NET_RESOURCE(FREEQ_RESID);
pk_free(pkt); /* return to free buffer */
UNLOCK_NET_RESOURCE(FREEQ_RESID);
break;
}
continue;
}
}
