static int create_rx_ring(AFPacket_Context_t *afpc, AFPacketInstance *instance)
{
int rc, order;
/* Starting with page allocations of order 3, try to allocate an RX ring in the kernel. */
for (order = DEFAULT_ORDER; order >= 0; order--)
{
if (calculate_layout(afpc, instance, order))
return DAQ_ERROR;
/* Ask the kernel to create the ring. */
rc = setsockopt(instance->fd, SOL_PACKET, PACKET_RX_RING, (void*) &instance->layout, sizeof(struct tpacket_req));
if (rc)
{
if (errno == ENOMEM)
{
if (afpc->debug)
printf("%s: Allocation of kernel packet RX ring failed with order %d, retrying...\n", instance->name, order);
continue;
}
DPE(afpc->errbuf, "%s: Couldn't create kernel RX ring on packet socket: %s",
__FUNCTION__, strerror(errno));
return DAQ_ERROR;
}
return DAQ_SUCCESS;
}
/* If we got here, it means we failed allocation on order 0. */
DPE(afpc->errbuf, "%s: Couldn't allocate enough memory for the kernel RX ring!", instance->name);
return DAQ_ERROR;
}
static int create_ring(AFPacket_Context_t *afpc, AFPacketInstance *instance, AFPacketRing *ring, int optname)
{
int rc, order;
/* Starting with page allocations of order 3, try to allocate an RX ring in the kernel. */
for (order = DEFAULT_ORDER; order >= 0; order--)
{
if (calculate_layout(afpc, &ring->layout, instance->tp_hdrlen, order))
return DAQ_ERROR;
/* Ask the kernel to create the ring. */
rc = setsockopt(instance->fd, SOL_PACKET, optname, (void*) &ring->layout, sizeof(struct tpacket_req));
if (rc)
{
if (errno == ENOMEM)
{
if (afpc->debug)
printf("%s: Allocation of kernel packet ring failed with order %d, retrying...\n", instance->name, order);
continue;
}
DPE(afpc->errbuf, "%s: Couldn't create kernel ring on packet socket: %s",
__FUNCTION__, strerror(errno));
return DAQ_ERROR;
}
/* Store the total ring size for later. */
ring->size = ring->layout.tp_block_size * ring->layout.tp_block_nr;
if (afpc->debug)
printf("Created a ring of type %d with total size of %u\n", optname, ring->size);
return DAQ_SUCCESS;
}
/* If we got here, it means we failed allocation on order 0. */
DPE(afpc->errbuf, "%s: Couldn't allocate enough memory for the kernel packet ring!", instance->name);
return DAQ_ERROR;
}
