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- /****************************************************************************
- * net/devif/ipv6_input.c
- * Device driver IPv6 packet receipt interface
- *
- * Copyright (C) 2015, 2017 Gregory Nutt. All rights reserved.
- * Author: Gregory Nutt <gnutt@nuttx.org>
- *
- * Adapted for NuttX from logic in uIP which also has a BSD-like license:
- *
- * uIP is an implementation of the TCP/IP protocol stack intended for
- * small 8-bit and 16-bit microcontrollers.
- *
- * uIP provides the necessary protocols for Internet communication,
- * with a very small code footprint and RAM requirements - the uIP
- * code size is on the order of a few kilobytes and RAM usage is on
- * the order of a few hundred bytes.
- *
- * Original author Adam Dunkels <adam@dunkels.com>
- * Copyright () 2001-2003, Adam Dunkels.
- * All rights reserved.
- *
- * 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. The name of the author may not be used to endorse or promote
- * products derived from this software without specific prior
- * written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
- *
- ****************************************************************************/
- /****************************************************************************
- * uIP is a small implementation of the IP, UDP and TCP protocols (as
- * well as some basic ICMP stuff). The implementation couples the IP,
- * UDP, TCP and the application layers very tightly. To keep the size
- * of the compiled code down, this code frequently uses the goto
- * statement. While it would be possible to break the ipv6_input()
- * function into many smaller functions, this would increase the code
- * size because of the overhead of parameter passing and the fact that
- * the optimizer would not be as efficient.
- *
- * The principle is that we have a small buffer, called the d_buf,
- * in which the device driver puts an incoming packet. The TCP/IP
- * stack parses the headers in the packet, and calls the
- * application. If the remote host has sent data to the application,
- * this data is present in the d_buf and the application read the
- * data from there. It is up to the application to put this data into
- * a byte stream if needed. The application will not be fed with data
- * that is out of sequence.
- *
- * If the application wishes to send data to the peer, it should put
- * its data into the d_buf. The d_appdata pointer points to the
- * first available byte. The TCP/IP stack will calculate the
- * checksums, and fill in the necessary header fields and finally send
- * the packet back to the peer.
- *
- ****************************************************************************/
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #ifdef CONFIG_NET_IPv6
- #include <sys/ioctl.h>
- #include <stdint.h>
- #include <stdbool.h>
- #include <debug.h>
- #include <string.h>
- #include <net/if.h>
- #include <nuttx/net/netconfig.h>
- #include <nuttx/net/netdev.h>
- #include <nuttx/net/netstats.h>
- #include <nuttx/net/ip.h>
- #include <nuttx/net/ipv6ext.h>
- #include "neighbor/neighbor.h"
- #include "tcp/tcp.h"
- #include "udp/udp.h"
- #include "sixlowpan/sixlowpan.h"
- #include "pkt/pkt.h"
- #include "icmpv6/icmpv6.h"
- #include "netdev/netdev.h"
- #include "ipforward/ipforward.h"
- #include "inet/inet.h"
- #include "devif/devif.h"
- /****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
- /* Macros */
- #define IPv6BUF ((FAR struct ipv6_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
- #define PAYLOAD ((FAR uint8_t *)&dev->d_buf[NET_LL_HDRLEN(dev)] + IPv6_HDRLEN)
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: ipv6_exthdr
- *
- * Description:
- * Return true if the next header value is an IPv6 extension header.
- *
- ****************************************************************************/
- static bool ipv6_exthdr(uint8_t nxthdr)
- {
- switch (nxthdr)
- {
- case NEXT_HOPBYBOT_EH: /* Hop-by-Hop Options Header */
- case NEXT_ENCAP_EH: /* Encapsulated IPv6 Header */
- case NEXT_ROUTING_EH: /* Routing Header */
- case NEXT_FRAGMENT_EH: /* Fragment Header */
- case NEXT_RRSVP_EH: /* Resource ReSerVation Protocol */
- case NEXT_ENCAPSEC_EH: /* Encapsulating Security Payload */
- case NEXT_AUTH_EH: /* Authentication Header */
- case NEXT_DESTOPT_EH: /* Destination Options Header */
- case NEXT_MOBILITY_EH: /* Mobility */
- case NEXT_HOSTID_EH: /* Host Identity Protocol */
- case NEXT_SHIM6_EH: /* Shim6 Protocol */
- return true;
- case NEXT_NOHEADER: /* No next header */
- default:
- return false;
- }
- }
- /****************************************************************************
- * Name: check_dev_destipaddr
- *
- * Description:
- * Check if the destination address in the IPv6 is destined for the
- * provided network device.
- *
- * Returned Value:
- * 1 - This packet is destined for this network device
- * 0 - This packet is NOT destined for this network device
- *
- ****************************************************************************/
- static int check_dev_destipaddr(FAR struct net_driver_s *dev, FAR void *arg)
- {
- FAR struct ipv6_hdr_s *ipv6 = (FAR struct ipv6_hdr_s *)arg;
- /* Check if the IPv6 destination address matches the IPv6 address assigned
- * to this device.
- */
- if (net_ipv6addr_cmp(ipv6->destipaddr, dev->d_ipv6addr))
- {
- return 1;
- }
- /* No match, return 0 to keep searching */
- return 0;
- }
- /****************************************************************************
- * Name: check_destipaddr
- *
- * Description:
- * Check if the destination address in the IPv6 is destined for us. This
- * is typically just a comparison the of the IPv6 destination address in
- * the IPv6 packet with the IPv6 address assigned to the receiving device.
- *
- * Input Parameters:
- * dev - The device on which the packet was received and which contains
- * the IPv6 packet.
- * ipv6 - A convenience pointer to the IPv6 header in within the IPv6
- * packet
- *
- * Returned Value:
- * true - This packet is destined for us
- * false - This packet is NOT destined for us and may need to be forwarded.
- *
- ****************************************************************************/
- static bool check_destipaddr(FAR struct net_driver_s *dev,
- FAR struct ipv6_hdr_s *ipv6)
- {
- int ret;
- /* For IPv6, packet reception is a little trickier as we need to make sure
- * that we listen to certain multicast addresses (all hosts multicast
- * address, and the solicited-node multicast address) as well. However,
- * we will cheat here and accept all multicast packets that are sent to
- * the ff02::/16 addresses.
- */
- if (ipv6->destipaddr[0] == HTONS(0xff02))
- {
- #ifdef CONFIG_NET_IPFORWARD_BROADCAST
- /* Forward multicast packets */
- ipv6_forward_broadcast(dev, ipv6);
- #endif
- return true;
- }
- /* We will also allow for a perverse case where we receive a packet
- * addressed to us, but on a different device. Can that really happen?
- */
- ret = netdev_foreach(check_dev_destipaddr, ipv6);
- if (ret == 1)
- {
- /* The traversal of the network devices will return 0 if there is
- * no network device with that address or 1 if there is a network
- * device with such an address.
- */
- return true;
- }
- return false;
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: ipv6_input
- *
- * Description:
- * Receive an IPv6 packet from the network device. Verify and forward to
- * L3 packet handling logic if the packet is destined for us.
- *
- * Input Parameters:
- * dev - The device on which the packet was received and which contains
- * the IPv6 packet.
- * Returned Value:
- * OK - The packet was processed (or dropped) and can be discarded.
- * ERROR - Hold the packet and try again later. There is a listening
- * socket but no receive in place to catch the packet yet. The
- * device's d_len will be set to zero in this case as there is
- * no outgoing data.
- *
- * If this function returns to the network driver with dev->d_len > 0,
- * that is an indication to the driver that there is an outgoing response
- * to this input.
- *
- * Assumptions:
- * The network is locked.
- *
- ****************************************************************************/
- int ipv6_input(FAR struct net_driver_s *dev)
- {
- FAR struct ipv6_hdr_s *ipv6 = IPv6BUF;
- FAR uint8_t *payload;
- uint16_t llhdrlen;
- uint16_t iphdrlen;
- uint16_t paylen;
- uint8_t nxthdr;
- #ifdef CONFIG_NET_IPFORWARD
- int ret;
- #endif
- /* This is where the input processing starts. */
- #ifdef CONFIG_NET_STATISTICS
- g_netstats.ipv6.recv++;
- #endif
- /* Start of IP input header processing code.
- *
- * Check validity of the IP header.
- */
- if ((ipv6->vtc & 0xf0) != 0x60)
- {
- /* IP version and header length. */
- nwarn("WARNING: Invalid IPv6 version: %d\n", ipv6->vtc >> 4);
- #ifdef CONFIG_NET_STATISTICS
- g_netstats.ipv6.vhlerr++;
- #endif
- goto drop;
- }
- /* Get the size of the packet minus the size of link layer header */
- llhdrlen = NET_LL_HDRLEN(dev);
- if ((llhdrlen + IPv6_HDRLEN) > dev->d_len)
- {
- nwarn("WARNING: Packet shorter than IPv6 header\n");
- goto drop;
- }
- dev->d_len -= llhdrlen;
- /* Make sure that all packet processing logic knows that there is an IPv6
- * packet in the device buffer.
- */
- IFF_SET_IPv6(dev->d_flags);
- /* Check the size of the packet. If the size reported to us in d_len is
- * smaller the size reported in the IP header, we assume that the packet
- * has been corrupted in transit. If the size of d_len is larger than the
- * size reported in the IP packet header, the packet has been padded and
- * we set d_len to the correct value.
- *
- * The length reported in the IPv6 header is the length of the payload
- * that follows the header. The device interface uses the d_len variable
- * for holding the size of the entire packet, including the IP header but
- * without the link layer header (subtracted out above).
- *
- * NOTE: The payload length in the includes the size of the Ipv6 extension
- * options, but not the size of the IPv6 header.
- *
- * REVISIT: Length will be set to zero if the extension header carries
- * a Jumbo payload option.
- */
- paylen = ((uint16_t)ipv6->len[0] << 8) + (uint16_t)ipv6->len[1] +
- IPv6_HDRLEN;
- if (paylen <= dev->d_len)
- {
- dev->d_len = paylen;
- }
- else
- {
- nwarn("WARNING: IP packet shorter than length in IP header\n");
- goto drop;
- }
- /* Parse IPv6 extension headers (parsed but ignored) */
- payload = PAYLOAD; /* Assume payload starts right after IPv6 header */
- iphdrlen = IPv6_HDRLEN; /* Total length of the IPv6 header */
- nxthdr = ipv6->proto; /* Next header determined by IPv6 header prototype */
- while (ipv6_exthdr(nxthdr))
- {
- FAR struct ipv6_extension_s *exthdr;
- uint16_t extlen;
- /* Just skip over the extension header */
- exthdr = (FAR struct ipv6_extension_s *)payload;
- extlen = EXTHDR_LEN((unsigned int)exthdr->len);
- payload += extlen;
- iphdrlen += extlen;
- nxthdr = exthdr->nxthdr;
- }
- #ifdef CONFIG_NET_BROADCAST
- /* Check for a multicast packet, which may be destined to us (even if
- * there is no IP address yet assigned to the device). We only expect
- * multicast packets destined for sockets that have joined a multicast
- * group or for ICMPv6 Autoconfiguration and Neighbor discovery or ICMPv6
- * MLD packets.
- *
- * We should actually pick off certain multicast address (all hosts
- * multicast address, and the solicited-node multicast address). We
- * will cheat here and accept all multicast packets that are sent to the
- * ff00::/8 addresses (see net_is_addr_mcast).
- */
- if (net_is_addr_mcast(ipv6->destipaddr))
- {
- #ifdef CONFIG_NET_IPFORWARD_BROADCAST
- /* Packets sent to ffx0 are reserved, ffx1 are interface-local, and ffx2
- * are interface-local, and therefore, should not be forwarded
- */
- if ((ipv6->destipaddr[0] & HTONS(0xff0f) != HTONS(0xff00)) &&
- (ipv6->destipaddr[0] & HTONS(0xff0f) != HTONS(0xff01)) &&
- (ipv6->destipaddr[0] & HTONS(0xff0f) != HTONS(0xff02)))
- {
- /* Forward broadcast packets */
- ipv6_forward_broadcast(dev, ipv6);
- }
- #endif
- /* Fall through with no further address checks and handle the multicast
- * address by its IPv6 nexthdr field.
- */
- }
- /* In other cases, the device must be assigned a non-zero IP address
- * (the all zero address is the "unspecified" address.
- */
- else
- #endif
- #ifdef CONFIG_NET_ICMPv6
- if (net_ipv6addr_cmp(dev->d_ipv6addr, g_ipv6_unspecaddr))
- {
- nwarn("WARNING: No IP address assigned\n");
- goto drop;
- }
- /* Check if the packet is destined for out IP address */
- else
- #endif
- {
- /* Check if the packet is destined for us. */
- if (!check_destipaddr(dev, ipv6))
- {
- #ifdef CONFIG_NET_IPFORWARD
- /* Not destined for us, try to forward the packet */
- ret = ipv6_forward(dev, ipv6);
- if (ret >= 0)
- {
- /* The packet was forwarded. Return success; d_len will
- * be set appropriately by the forwarding logic: Cleared
- * if the packet is forward via another device or non-
- * zero if it will be forwarded by the same device that
- * it was received on.
- */
- return OK;
- }
- else
- #endif
- {
- /* Not destined for us and not forwardable... drop the packet. */
- nwarn("WARNING: Not destined for us; not forwardable... Dropping!\n");
- goto drop;
- }
- }
- }
- /* Now process the incoming packet according to the protocol specified in
- * the next header IPv6 field.
- */
- switch (nxthdr)
- {
- #ifdef NET_TCP_HAVE_STACK
- case IP_PROTO_TCP: /* TCP input */
- /* Forward the IPv6 TCP packet */
- tcp_ipv6_input(dev, iphdrlen);
- #ifdef CONFIG_NET_6LOWPAN
- /* TCP output comes through three different mechanisms. 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 6LoWPAN logic.
- * 2. TCP output from the TCP state machine. That will occur
- * during TCP packet processing by the TCP state machine.
- * 3. TCP output resulting from TX or timer polling
- *
- * Case 3 is handled here. Logic here detects 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, 6LoWPAN
- * logic will be called to create the IEEE80215.4 frames.
- */
- if (dev->d_len > 0 && dev->d_lltype == CONFIG_NET_6LOWPAN)
- {
- /* Let 6LoWPAN handle the TCP output */
- sixlowpan_tcp_send(dev, dev, ipv6);
- /* Drop the packet in the d_buf */
- goto drop;
- }
- #endif /* CONFIG_NET_6LOWPAN */
- break;
- #endif /* NET_TCP_HAVE_STACK */
- #ifdef NET_UDP_HAVE_STACK
- case IP_PROTO_UDP: /* UDP input */
- /* Forward the IPv6 UDP packet */
- udp_ipv6_input(dev, iphdrlen);
- break;
- #endif
- /* Check for ICMP input */
- #ifdef NET_ICMPv6_HAVE_STACK
- case IP_PROTO_ICMP6: /* ICMP6 input */
- /* Forward the ICMPv6 packet */
- icmpv6_input(dev, iphdrlen);
- #ifdef CONFIG_NET_6LOWPAN
- /* All outgoing ICMPv6 messages come through one of two mechanisms:
- *
- * 1. The output from internal ICMPv6 message passing. These
- * outgoing messages will use device polling and will be
- * handled elsewhere.
- * 2. ICMPv6 output resulting from TX or timer polling.
- *
- * Case 2 is handled here. Logic here detects 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, 6LoWPAN
- * logic will be called to create the IEEE80215.4 frames.
- */
- if (dev->d_len > 0 && dev->d_lltype == CONFIG_NET_6LOWPAN)
- {
- /* Let 6LoWPAN handle the ICMPv6 output */
- sixlowpan_icmpv6_send(dev, dev, ipv6);
- /* Drop the packet in the d_buf */
- goto drop;
- }
- #endif /* CONFIG_NET_6LOWPAN */
- break;
- #endif /* NET_ICMPv6_HAVE_STACK */
- default: /* Unrecognized/unsupported protocol */
- nwarn("WARNING: Unrecognized IP protocol: %04x\n", ipv6->proto);
- #ifdef CONFIG_NET_STATISTICS
- g_netstats.ipv6.protoerr++;
- #endif
- goto drop;
- }
- /* Return and let the caller do any pending transmission. */
- return OK;
- /* Drop the packet. NOTE that OK is returned meaning that the
- * packet has been processed (although processed unsuccessfully).
- */
- drop:
- #ifdef CONFIG_NET_STATISTICS
- g_netstats.ipv6.drop++;
- #endif
- dev->d_len = 0;
- return OK;
- }
- #endif /* CONFIG_NET_IPv6 */
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