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nuttx/net/sixlowpan/sixlowpan_tcpsend.c

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/****************************************************************************
* net/sixlowpan/sixlowpan_tcpsend.c
*
* Copyright (C) 2017 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include "nuttx/net/netdev.h"
#include "nuttx/net/netstats.h"
#include "netdev/netdev.h"
#include "socket/socket.h"
#include "tcp/tcp.h"
#include "utils/utils.h"
#include "sixlowpan/sixlowpan_internal.h"
#if defined(CONFIG_NET_6LOWPAN) && defined(CONFIG_NET_TCP)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Buffer access helpers */
#define IPv6BUF(dev) ((FAR struct ipv6_hdr_s *)((dev)->d_buf))
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: sixlowpan_tcp_chksum
*
* Description:
* Perform the checksum calcaultion over the IPv6, protocol headers, and
* data payload as necessary.
*
* Input Parameters:
* ipv6tcp - A reference to a structure containing the IPv6 and TCP headers.
* buf - The beginning of the payload data
* buflen - The length of the payload data.
*
* Returned Value:
* The calculated checksum
*
****************************************************************************/
static uint16_t sixlowpan_tcp_chksum(FAR struct ipv6tcp_hdr_s *ipv6tcp,
FAR const uint8_t *buf, uint16_t buflen)
{
uint16_t upperlen;
uint16_t tcplen;
uint16_t sum;
/* The length reported in the IPv6 header is the length of the payload
* that follows the header.
*/
upperlen = ((uint16_t)ipv6tcp->ipv6.len[0] << 8) + ipv6tcp->ipv6.len[1];
/* Verify some minimal assumptions */
if (upperlen > CONFIG_NET_6LOWPAN_MTU)
{
return 0;
}
/* The checksum is calculated starting with a pseudo-header of IPv6 header
* fields according to the IPv6 standard, which consists of the source
* and destination addresses, the packet length and the next header field.
*/
sum = upperlen + ipv6tcp->ipv6.proto;
/* Sum IP source and destination addresses. */
sum = chksum(sum, (FAR uint8_t *)ipv6tcp->ipv6.srcipaddr,
2 * sizeof(net_ipv6addr_t));
/* Sum the TCP header
*
* The TCP header length is encoded in the top 4 bits of the tcpoffset
* field (in units of 32-bit words).
*/
tcplen = ((uint16_t)ipv6tcp->tcp.tcpoffset >> 4) << 2;
sum = chksum(sum, (FAR uint8_t *)&ipv6tcp->tcp, tcplen);
/* Sum payload data. */
sum = chksum(sum, buf, buflen);
return (sum == 0) ? 0xffff : htons(sum);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: psock_6lowpan_tcp_send
*
* Description:
* psock_6lowpan_tcp_send() call may be used only when the TCP socket is in a
* connected state (so that the intended recipient is known).
*
* Parameters:
* psock - An instance of the internal socket structure.
* buf - Data to send
* bulen - Length of data to send
*
* Returned Value:
* On success, returns the number of characters sent. On error,
* -1 is returned, and errno is set appropriately. Returned error numbers
* must be consistent with definition of errors reported by send() or
* sendto().
*
* Assumptions:
* Called with the network locked.
*
****************************************************************************/
ssize_t psock_6lowpan_tcp_send(FAR struct socket *psock, FAR const void *buf,
size_t buflen)
{
FAR struct tcp_conn_s *conn;
FAR struct net_driver_s *dev;
struct ipv6tcp_hdr_s ipv6tcp;
struct rimeaddr_s destmac;
uint16_t timeout;
uint16_t iplen;
int ret;
ninfo("buflen %lu\n", (unsigned long)buflen);
sixlowpan_dumpbuffer("Outgoing TCP payload", buf, buflen);
DEBUGASSERT(psock != NULL && psock->s_crefs > 0);
DEBUGASSERT(psock->s_type == SOCK_STREAM);
/* Make sure that this is a valid socket */
if (psock != NULL || psock->s_crefs <= 0)
{
nerr("ERROR: Invalid socket\n");
return (ssize_t)-EBADF;
}
/* Make sure that this is a connected TCP socket */
if (psock->s_type != SOCK_STREAM || !_SS_ISCONNECTED(psock->s_flags))
{
nerr("ERROR: Not connected\n");
return (ssize_t)-ENOTCONN;
}
/* Get the underlying TCP connection structure */
conn = (FAR struct tcp_conn_s *)psock->s_conn;
DEBUGASSERT(conn != NULL);
#ifdef CONFIG_NET_IPv4
/* Ignore if not IPv6 domain */
if (conn->domain != PF_INET6)
{
nwarn("WARNING: Not IPv6\n");
return (ssize_t)-EPROTOTYPE;
}
#endif
/* Route outgoing message to the correct device */
#ifdef CONFIG_NETDEV_MULTINIC
dev = netdev_findby_ipv6addr(conn->u.ipv6.laddr, conn->u.ipv6.raddr);
#ifdef CONFIG_NETDEV_MULTILINK
if (dev == NULL || dev->d_lltype != NET_LL_IEEE802154)
#else
if (dev == NULL)
#endif
{
nwarn("WARNING: Not routable or not IEEE802.15.4 MAC\n");
return (ssize_t)-ENETUNREACH;
}
#else
dev = netdev_findby_ipv6addr(conn->u.ipv6.raddr);
#ifdef CONFIG_NETDEV_MULTILINK
if (dev == NULL || dev->d_lltype != NET_LL_IEEE802154)
#else
if (dev == NULL)
#endif
{
nwarn("WARNING: Not routable\n");
return (ssize_t)-ENETUNREACH;
}
#endif
#ifdef CONFIG_NET_ICMPv6_NEIGHBOR
/* Make sure that the IP address mapping is in the Neighbor Table */
ret = icmpv6_neighbor(conn->u.ipv6.raddr);
if (ret < 0)
{
nerr("ERROR: Not reachable\n");
return (ssize_t)-ENETUNREACH;
}
#endif
/* Initialize the IPv6/TCP headers */
/* Initialize the IPv6/UDP headers */
ipv6tcp.ipv6.vtc = 0x60;
ipv6tcp.ipv6.tcf = 0x00;
ipv6tcp.ipv6.flow = 0x00;
ipv6tcp.ipv6.proto = IP_PROTO_TCP;
ipv6tcp.ipv6.ttl = IP_TTL;
/* The IPv6 header length field does not include the size of IPv6 IP
* header.
*/
iplen = buflen + TCP_HDRLEN;
ipv6tcp.ipv6.len[0] = (iplen >> 8);
ipv6tcp.ipv6.len[1] = (iplen & 0xff);
/* Copy the source and destination addresses */
net_ipv6addr_hdrcopy(ipv6tcp.ipv6.srcipaddr, conn->u.ipv6.laddr);
net_ipv6addr_hdrcopy(ipv6tcp.ipv6.destipaddr, conn->u.ipv6.raddr);
ninfo("IPv6 length: %d\n",
((int)ipv6tcp.ipv6.len[0] << 8) + ipv6tcp.ipv6.len[1]);
#ifdef CONFIG_NET_STATISTICS
g_netstats.ipv6.sent++;
#endif
/* Initialize the TCP header */
ipv6tcp.tcp.srcport = conn->lport; /* Local port */
ipv6tcp.tcp.destport = conn->rport; /* Connected remote port */
memcpy(ipv6tcp.tcp.ackno, conn->rcvseq, 4); /* ACK number */
memcpy(ipv6tcp.tcp.seqno, conn->sndseq, 4); /* Sequence number */
ipv6tcp.tcp.tcpoffset = (TCP_HDRLEN / 4) << 4; /* No optdata */
ipv6tcp.tcp.urgp[0] = 0; /* No urgent data */
ipv6tcp.tcp.urgp[1] = 0;
/* Set the TCP window */
if (conn->tcpstateflags & TCP_STOPPED)
{
/* If the connection has issued TCP_STOPPED, we advertise a zero
* window so that the remote host will stop sending data.
*/
ipv6tcp.tcp.wnd[0] = 0;
ipv6tcp.tcp.wnd[1] = 0;
}
else
{
ipv6tcp.tcp.wnd[0] = ((NET_DEV_RCVWNDO(dev)) >> 8);
ipv6tcp.tcp.wnd[1] = ((NET_DEV_RCVWNDO(dev)) & 0xff);
}
/* Calculate TCP checksum. */
ipv6tcp.tcp.tcpchksum = 0;
ipv6tcp.tcp.tcpchksum = ~sixlowpan_tcp_chksum(&ipv6tcp, buf, buflen);
ninfo("Outgoing TCP packet length: %d bytes\n", iplen + IPv6_HDRLEN);
#ifdef CONFIG_NET_STATISTICS
g_netstats.tcp.sent++;
#endif
/* Set the socket state to sending */
psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_SEND);
/* Get the Rime MAC address of the destination This assumes an encoding
* of the MAC address in the IPv6 address.
*/
sixlowpan_rimefromip(conn->u.ipv6.raddr, &destmac);
/* If routable, then call sixlowpan_send() to format and send the 6loWPAN
* packet.
*/
#ifdef CONFIG_NET_SOCKOPTS
timeout = psock->s_sndtimeo;
#else
timeout = 0;
#endif
ret = sixlowpan_send(dev, &conn->list,
(FAR const struct ipv6_hdr_s *)&ipv6tcp,
buf, buflen, &destmac, timeout);
if (ret < 0)
{
nerr("ERROR: sixlowpan_send() failed: %d\n", ret);
}
/* Set the socket state to idle */
psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_IDLE);
return ret;
}
/****************************************************************************
* Name: sixlowpan_tcp_send
*
* Description:
* TCP output comes through three different mechansims. Either from:
*
* 1. TCP socket output. For the case of TCP output to an
* IEEE802.15.4, the TCP output is caught in the socket
* send()/sendto() logic and and redirected to psock_6lowpan_tcp_send().
* 2. TCP output from the TCP state machine. That will occur
* during TCP packet processing by the TCP state meachine.
* 3. TCP output resulting from TX or timer polling
*
* Cases 2 and 3 will be handled here. Logic in ipv6_tcp_input(),
* devif_poll(), and devif_timer() detect if (1) an attempt to return with
* d_len > 0 and (2) that the device is an IEEE802.15.4 MAC network
* driver. Under those conditions, this function will be called to create
* the IEEE80215.4 frames.
*
* Parameters:
* dev - An instance of nework device state structure
*
* Returned Value:
* None
*
* Assumptions:
* Called with the network locked.
*
****************************************************************************/
void sixlowpan_tcp_send(FAR struct net_driver_s *dev)
{
DEBUGASSERT(dev != NULL && dev->d_len > 0);
/* Double check */
ninfo("d_len %u\n", dev->d_len);
sixlowpan_dumpbuffer("Outgoing TCP packet",
(FAR const uint8_t *)IPv6BUF(dev), dev->d_len);
if (dev != NULL && dev->d_len > 0)
{
FAR struct ipv6tcp_hdr_s *ipv6hdr;
/* The IPv6 header followed by a TCP headers should lie at the
* beginning of d_buf since there is no link layer protocol header
* and the TCP state machine should only response with TCP packets.
*/
ipv6hdr = (FAR struct ipv6tcp_hdr_s *)(dev->d_buf);
/* The TCP data payload should follow the IPv6 header plus the
* protocol header.
*/
if (ipv6hdr->ipv6.proto != IP_PROTO_TCP)
{
nwarn("WARNING: Expected TCP protoype: %u vs %s\n",
ipv6hdr->ipv6.proto, IP_PROTO_TCP);
}
else
{
struct rimeaddr_s destmac;
FAR uint8_t *buf;
uint16_t hdrlen;
uint16_t buflen;
/* Get the Rime MAC address of the destination. This assumes an
* encoding of the MAC address in the IPv6 address.
*/
sixlowpan_rimefromip(ipv6hdr->ipv6.destipaddr, &destmac);
/* Get the IPv6 + TCP combined header length. The size of the TCP
* header is encoded in the top 4 bits of the tcpoffset field (in
* units of 32-bit words).
*/
hdrlen = IPv6_HDRLEN + (((uint16_t)ipv6hdr->tcp.tcpoffset >> 4) << 2);
/* Drop the packet if the buffer length is less than this. */
if (hdrlen > dev->d_len)
{
nwarn("WARNING: Dropping small TCP packet: %u < %u\n",
buflen, hdrlen);
}
else
{
/* Convert the outgoing packet into a frame list. */
buf = dev->d_buf + hdrlen;
buflen = dev->d_len - hdrlen;
(void)sixlowpan_queue_frames(
(FAR struct ieee802154_driver_s *)dev, &ipv6hdr->ipv6,
buf, buflen, &destmac);
}
}
}
dev->d_len = 0;
}
#endif /* CONFIG_NET_6LOWPAN && CONFIG_NET_TCP */
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