/**************************************************************************** * net/devif/ipv6_input.c * Device driver IPv6 packet receipt interface * * Copyright (C) 2015 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 * 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 #ifdef CONFIG_NET_IPv6 #include #include #include #include #include #include #include #include #include "ipv6/ipv6.h" #include "tcp/tcp.h" #include "udp/udp.h" #include "pkt/pkt.h" #include "icmpv6/icmpv6.h" #include "devif/devif.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* Macros */ #define BUF ((FAR struct net_ipv6hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)]) /**************************************************************************** * Public Data ****************************************************************************/ /**************************************************************************** * Private Data ****************************************************************************/ /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Function: ipv6_input * * Description: * * Returned Value: * OK The packet was processed (or dropped) and can be discarded. * ERROR There is a matching connection, but could not dispatch the packet * yet. Currently useful for UDP when a packet arrives before a recv * call is in place. * * Assumptions: * ****************************************************************************/ int ipv6_input(FAR struct net_driver_s *dev) { FAR struct net_ipv6hdr_s *pbuf = BUF; uint16_t iplen; /* This is where the input processing starts. */ #ifdef CONFIG_NET_STATISTICS g_netstats.ip.recv++; #endif /* Start of IP input header processing code. */ /* Check validity of the IP header. */ if ((pbuf->vtc & 0xf0) != 0x60) { /* IP version and header length. */ #ifdef CONFIG_NET_STATISTICS g_netstats.ip.drop++; g_netstats.ip.vhlerr++; #endif nlldbg("Invalid IPv6 version: %d\n", pbuf->vtc >> 4); goto drop; } /* 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. However, uIP uses the d_len variable for * holding the size of the entire packet, including the IP header. For * IPv4 this is not a problem as the length field in the IPv4 header * contains the length of the entire packet. But for IPv6 we need to add * the size of the IPv6 header (40 bytes). */ iplen = (pbuf->len[0] << 8) + pbuf->len[1] + IPv6_HDRLEN; if (iplen <= dev->d_len) { dev->d_len = iplen; } else { nlldbg("IP packet shorter than length in IP header\n"); goto drop; } /* If IP broadcast support is configured, we check for a broadcast * UDP packet, which may be destined to us (even if there is no IP * address yet assigned to the device as is the case when we are * negotiating over DHCP for an address). */ #if defined(CONFIG_NET_BROADCAST) && defined(CONFIG_NET_UDP) if (pbuf->proto == IP_PROTO_UDP && net_ipv6addr_cmp(pbuf->destipaddr, g_ipv6_alloneaddr)) { return udp_ipv6_input(dev); } /* In most other cases, the device must be assigned a non-zero IP * address. Another exception is when CONFIG_NET_PINGADDRCONF is * enabled... */ else #endif #ifdef CONFIG_NET_ICMPv6 if (net_ipv6addr_cmp(dev->d_ipv6addr, g_ipv6_allzeroaddr)) { /* If we are configured to use ping IP address configuration and * hasn't been assigned an IP address yet, we accept all ICMP * packets. */ nlldbg("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 our IP address. * * 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 (!net_ipv6addr_cmp(pbuf->destipaddr, dev->d_ipv6addr) && pbuf->destipaddr[0] != 0xff02) { #ifdef CONFIG_NET_STATISTICS g_netstats.ip.drop++; #endif goto drop; } } /* Everything looks good so far. Now process the incoming packet * according to the protocol. */ switch (pbuf->proto) { #ifdef CONFIG_NET_TCP case IP_PROTO_TCP: /* TCP input */ tcp_ipv6_input(dev); break; #endif #ifdef CONFIG_NET_UDP case IP_PROTO_UDP: /* UDP input */ udp_ipv6_input(dev); break; #endif /* Check for ICMP input */ #ifdef CONFIG_NET_ICMPv6 case IP_PROTO_ICMP6: /* ICMP6 input */ icmpv6_input(dev); break; #endif default: /* Unrecognized/unsupported protocol */ #ifdef CONFIG_NET_STATISTICS g_netstats.ip.drop++; g_netstats.ip.protoerr++; #endif nlldbg("Unrecognized IP protocol\n"); 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: dev->d_len = 0; return OK; } #endif /* CONFIG_NET_IPv6 */