/**************************************************************************** * net/sixlowpan/sixlowpan_tcpsend.c * * Copyright (C) 2017 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #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 ****************************************************************************/ /**************************************************************************** * Function: 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; } /**************************************************************************** * Function: 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 */