uint16_t tcp_datahandler(FAR struct tcp_conn_s *conn, FAR uint8_t *buffer,
uint16_t buflen)
{
FAR struct iob_s *iob;
int ret;
/* Try to allocate on I/O buffer to start the chain without waiting (and
* throttling as necessary). If we would have to wait, then drop the
* packet.
*/
iob = iob_tryalloc(true);
if (iob == NULL)
{
nlldbg("ERROR: Failed to create new I/O buffer chain\n");
return 0;
}
/* Copy the new appdata into the I/O buffer chain (without waiting) */
ret = iob_trycopyin(iob, buffer, buflen, 0, true);
if (ret < 0)
{
/* On a failure, iob_copyin return a negated error value but does
* not free any I/O buffers.
*/
nlldbg("ERROR: Failed to add data to the I/O buffer chain: %d\n", ret);
(void)iob_free_chain(iob);
return 0;
}
/* Add the new I/O buffer chain to the tail of the read-ahead queue (again
* without waiting).
*/
ret = iob_tryadd_queue(iob, &conn->readahead);
if (ret < 0)
{
nlldbg("ERROR: Failed to queue the I/O buffer chain: %d\n", ret);
(void)iob_free_chain(iob);
return 0;
}
nllvdbg("Buffered %d bytes\n", buflen);
return buflen;
}
FAR struct iob_s *iob_alloc(bool throttled)
{
/* Were we called from the interrupt level? */
if (up_interrupt_context())
{
/* Yes, then try to allocate an I/O buffer without waiting */
return iob_tryalloc(throttled);
}
else
{
/* Then allocate an I/O buffer, waiting as necessary */
return iob_allocwait(throttled);
}
}
static int iob_copyin_internal(FAR struct iob_s *iob, FAR const uint8_t *src,
unsigned int len, unsigned int offset,
bool throttled, bool can_block)
{
FAR struct iob_s *head = iob;
FAR struct iob_s *next;
FAR uint8_t *dest;
unsigned int ncopy;
unsigned int avail;
unsigned int total = len;
ninfo("iob=%p len=%u offset=%u\n", iob, len, offset);
DEBUGASSERT(iob && src);
/* The offset must applied to data that is already in the I/O buffer chain */
if (offset > iob->io_pktlen)
{
nerr("ERROR: offset is past the end of data: %u > %u\n",
offset, iob->io_pktlen);
return -ESPIPE;
}
/* Skip to the I/O buffer containing the data offset */
while (offset > iob->io_len)
{
offset -= iob->io_len;
iob = iob->io_flink;
}
/* Then loop until all of the I/O data is copied from the user buffer */
while (len > 0)
{
next = iob->io_flink;
/* Get the destination I/O buffer address and the amount of data
* available from that address.
*/
dest = &iob->io_data[iob->io_offset + offset];
avail = iob->io_len - offset;
ninfo("iob=%p avail=%u len=%u next=%p\n", iob, avail, len, next);
/* Will the rest of the copy fit into this buffer, overwriting
* existing data.
*/
if (len > avail)
{
/* No.. Is this the last buffer in the chain? */
if (next)
{
/* No.. clip to size that will overwrite. We cannot
* extend the length of an I/O block in mid-chain.
*/
ncopy = avail;
}
else
{
unsigned int maxlen;
unsigned int newlen;
/* Yes.. We can extend this buffer to the up to the very end. */
maxlen = CONFIG_IOB_BUFSIZE - iob->io_offset;
/* This is the new buffer length that we need. Of course,
* clipped to the maximum possible size in this buffer.
*/
newlen = len + offset;
if (newlen > maxlen)
{
newlen = maxlen;
}
/* Set the new length and increment the packet length */
head->io_pktlen += (newlen - iob->io_len);
iob->io_len = newlen;
/* Set the new number of bytes to copy */
ncopy = newlen - offset;
}
}
else
{
/* Yes.. Copy all of the remaining bytes */
ncopy = len;
}
/* Copy from the user buffer to the I/O buffer. */
memcpy(dest, src, ncopy);
ninfo("iob=%p Copy %u bytes new len=%u\n",
iob, ncopy, iob->io_len);
/* Adjust the total length of the copy and the destination address in
* the user buffer.
*/
len -= ncopy;
src += ncopy;
/* Skip to the next I/O buffer in the chain. First, check if we
* are at the end of the buffer chain.
*/
if (len > 0 && !next)
{
/* Yes.. allocate a new buffer.
*
* Copy as many bytes as possible. If we have successfully copied
* any already don't block, otherwise block if we're allowed.
*/
if (!can_block || len < total)
{
next = iob_tryalloc(throttled);
}
else
{
next = iob_alloc(throttled);
}
if (next == NULL)
{
nerr("ERROR: Failed to allocate I/O buffer\n");
return len;
}
/* Add the new, empty I/O buffer to the end of the buffer chain. */
iob->io_flink = next;
ninfo("iob=%p added to the chain\n", iob);
}
iob = next;
offset = 0;
}
return 0;
}
static uint16_t udp_datahandler(FAR struct net_driver_s *dev, FAR struct udp_conn_s *conn,
FAR uint8_t *buffer, uint16_t buflen)
{
FAR struct iob_s *iob;
int ret;
#ifdef CONFIG_NET_IPv6
FAR struct sockaddr_in6 src_addr6;
#endif
#ifdef CONFIG_NET_IPv4
FAR struct sockaddr_in src_addr4;
#endif
FAR void *src_addr;
uint8_t src_addr_size;
/* Allocate on I/O buffer to start the chain (throttling as necessary).
* We will not wait for an I/O buffer to become available in this context.
*/
iob = iob_tryalloc(true);
if (iob == NULL)
{
nerr("ERROR: Failed to create new I/O buffer chain\n");
return 0;
}
#ifdef CONFIG_NET_IPv6
#ifdef CONFIG_NET_IPv4
if (IFF_IS_IPv6(dev->d_flags))
#endif
{
FAR struct udp_hdr_s *udp = UDPIPv6BUF;
FAR struct ipv6_hdr_s *ipv6 = IPv6BUF;
src_addr6.sin6_family = AF_INET6;
src_addr6.sin6_port = udp->srcport;
net_ipv6addr_copy(src_addr6.sin6_addr.s6_addr, ipv6->srcipaddr);
src_addr_size = sizeof(src_addr6);
src_addr = &src_addr6;
}
#endif /* CONFIG_NET_IPv6 */
#ifdef CONFIG_NET_IPv4
#ifdef CONFIG_NET_IPv6
else
#endif
{
#ifdef CONFIG_NET_IPv6
/* Hybrid dual-stack IPv6/IPv4 implementations recognize a special
* class of addresses, the IPv4-mapped IPv6 addresses.
*/
if (conn->domain == PF_INET6)
{
FAR struct udp_hdr_s *udp = UDPIPv6BUF;
FAR struct ipv6_hdr_s *ipv6 = IPv6BUF;
in_addr_t ipv4addr;
/* Encode the IPv4 address as an IPv-mapped IPv6 address */
src_addr6.sin6_family = AF_INET6;
src_addr6.sin6_port = udp->srcport;
ipv4addr = net_ip4addr_conv32(ipv6->srcipaddr);
ip6_map_ipv4addr(ipv4addr, src_addr6.sin6_addr.s6_addr16);
src_addr_size = sizeof(src_addr6);
src_addr = &src_addr6;
}
else
#endif
{
FAR struct udp_hdr_s *udp = UDPIPv4BUF;
FAR struct ipv4_hdr_s *ipv4 = IPv4BUF;
src_addr4.sin_family = AF_INET;
src_addr4.sin_port = udp->srcport;
net_ipv4addr_copy(src_addr4.sin_addr.s_addr,
net_ip4addr_conv32(ipv4->srcipaddr));
src_addr_size = sizeof(src_addr4);
src_addr = &src_addr4;
}
}
#endif /* CONFIG_NET_IPv4 */
/* Copy the src address info into the I/O buffer chain. We will not wait
* for an I/O buffer to become available in this context. It there is
* any failure to allocated, the entire I/O buffer chain will be discarded.
*/
ret = iob_trycopyin(iob, (FAR const uint8_t *)&src_addr_size,
sizeof(uint8_t), 0, true);
if (ret < 0)
{
/* On a failure, iob_trycopyin return a negated error value but does
* not free any I/O buffers.
*/
nerr("ERROR: Failed to add data to the I/O buffer chain: %d\n", ret);
(void)iob_free_chain(iob);
return 0;
}
ret = iob_trycopyin(iob, (FAR const uint8_t *)src_addr, src_addr_size,
sizeof(uint8_t), true);
if (ret < 0)
{
/* On a failure, iob_trycopyin return a negated error value but does
* not free any I/O buffers.
*/
nerr("ERROR: Failed to add data to the I/O buffer chain: %d\n", ret);
(void)iob_free_chain(iob);
return 0;
}
if (buflen > 0)
{
/* Copy the new appdata into the I/O buffer chain */
ret = iob_trycopyin(iob, buffer, buflen,
src_addr_size + sizeof(uint8_t), true);
if (ret < 0)
{
/* On a failure, iob_trycopyin return a negated error value but
* does not free any I/O buffers.
*/
nerr("ERROR: Failed to add data to the I/O buffer chain: %d\n",
ret);
(void)iob_free_chain(iob);
return 0;
}
}
/* Add the new I/O buffer chain to the tail of the read-ahead queue */
ret = iob_tryadd_queue(iob, &conn->readahead);
if (ret < 0)
{
nerr("ERROR: Failed to queue the I/O buffer chain: %d\n", ret);
(void)iob_free_chain(iob);
return 0;
}
#ifdef CONFIG_UDP_READAHEAD_NOTIFIER
/* Provided notification(s) that additional UDP read-ahead data is
* available.
*/
udp_notifier_signal(conn);
#endif
ninfo("Buffered %d bytes\n", buflen);
return buflen;
}
static FAR struct iob_s *iob_allocwait(bool throttled)
{
FAR struct iob_s *iob;
irqstate_t flags;
FAR sem_t *sem;
int ret = OK;
#if CONFIG_IOB_THROTTLE > 0
/* Select the semaphore count to check. */
sem = (throttled ? &g_throttle_sem : &g_iob_sem);
#else
sem = &g_iob_sem;
#endif
/* The following must be atomic; interrupt must be disabled so that there
* is no conflict with interrupt level I/O buffer allocations. This is
* not as bad as it sounds because interrupts will be re-enabled while
* we are waiting for I/O buffers to become free.
*/
flags = irqsave();
do
{
/* Try to get an I/O buffer. If successful, the semaphore count
* will be decremented atomically.
*/
iob = iob_tryalloc(throttled);
if (!iob)
{
/* If not successful, then the semaphore count was less than or
* equal to zero (meaning that there are no free buffers). We
* need to wait for an I/O buffer to be released when the semaphore
* count will be incremented.
*/
ret = sem_wait(sem);
if (ret < 0)
{
int errcode = get_errno();
/* EINTR is not an error! EINTR simply means that we were
* awakened by a signal and we should try again.
*
* REVISIT: Many end-user interfaces are required to return
* with an error if EINTR is set. Most uses of this function
* is in internal, non-user logic. But are there cases where
* the error should be returned.
*/
if (errcode == EINTR)
{
/* Force a success indication so that we will continue
* looping.
*/
ret = 0;
}
else
{
/* Stop the loop and return a error */
DEBUGASSERT(errcode > 0);
ret = -errcode;
}
}
else
{
/* When we wake up from wait successfully, an I/O buffer was
* returned to the free list. However, if there are concurrent
* allocations from interrupt handling, then I suspect that
* there is a race condition. But no harm, we will just wait
* again in that case.
*
* We need release our count so that it is available to
* iob_tryalloc(), perhaps allowing another thread to take our
* count. In that event, iob_tryalloc() will fail above and
* we will have to wait again.
*
* TODO: Consider a design modification to permit us to
* complete the allocation without losing our count.
*/
sem_post(sem);
}
}
}
while (ret == OK && iob == NULL);
irqrestore(flags);
return iob;
}
