diff options
Diffstat (limited to 'lwip/src/core/ipv6/icmp6.c')
-rw-r--r-- | lwip/src/core/ipv6/icmp6.c | 425 |
1 files changed, 425 insertions, 0 deletions
diff --git a/lwip/src/core/ipv6/icmp6.c b/lwip/src/core/ipv6/icmp6.c new file mode 100644 index 0000000..167738a --- /dev/null +++ b/lwip/src/core/ipv6/icmp6.c @@ -0,0 +1,425 @@ +/** + * @file + * + * IPv6 version of ICMP, as per RFC 4443. + */ + +/* + * Copyright (c) 2010 Inico Technologies Ltd. + * 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. + * + * This file is part of the lwIP TCP/IP stack. + * + * Author: Ivan Delamer <delamer@inicotech.com> + * + * + * Please coordinate changes and requests with Ivan Delamer + * <delamer@inicotech.com> + */ + +#include "lwip/opt.h" + +#if LWIP_ICMP6 && LWIP_IPV6 /* don't build if not configured for use in lwipopts.h */ + +#include "lwip/icmp6.h" +#include "lwip/prot/icmp6.h" +#include "lwip/ip6.h" +#include "lwip/ip6_addr.h" +#include "lwip/inet_chksum.h" +#include "lwip/pbuf.h" +#include "lwip/netif.h" +#include "lwip/nd6.h" +#include "lwip/mld6.h" +#include "lwip/ip.h" +#include "lwip/stats.h" + +#include <string.h> + +#if LWIP_ICMP6_DATASIZE == 0 +#undef LWIP_ICMP6_DATASIZE +#define LWIP_ICMP6_DATASIZE 8 +#endif + +/* Forward declarations */ +static void icmp6_send_response(struct pbuf *p, u8_t code, u32_t data, u8_t type); +static void icmp6_send_response_with_addrs(struct pbuf *p, u8_t code, u32_t data, + u8_t type, const ip6_addr_t *src_addr, const ip6_addr_t *dest_addr); +static void icmp6_send_response_with_addrs_and_netif(struct pbuf *p, u8_t code, u32_t data, + u8_t type, const ip6_addr_t *src_addr, const ip6_addr_t *dest_addr, struct netif *netif); + + +/** + * Process an input ICMPv6 message. Called by ip6_input. + * + * Will generate a reply for echo requests. Other messages are forwarded + * to nd6_input, or mld6_input. + * + * @param p the mld packet, p->payload pointing to the icmpv6 header + * @param inp the netif on which this packet was received + */ +void +icmp6_input(struct pbuf *p, struct netif *inp) +{ + struct icmp6_hdr *icmp6hdr; + struct pbuf *r; + const ip6_addr_t *reply_src; + + ICMP6_STATS_INC(icmp6.recv); + + /* Check that ICMPv6 header fits in payload */ + if (p->len < sizeof(struct icmp6_hdr)) { + /* drop short packets */ + pbuf_free(p); + ICMP6_STATS_INC(icmp6.lenerr); + ICMP6_STATS_INC(icmp6.drop); + return; + } + + icmp6hdr = (struct icmp6_hdr *)p->payload; + +#if CHECKSUM_CHECK_ICMP6 + IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_ICMP6) { + if (ip6_chksum_pseudo(p, IP6_NEXTH_ICMP6, p->tot_len, ip6_current_src_addr(), + ip6_current_dest_addr()) != 0) { + /* Checksum failed */ + pbuf_free(p); + ICMP6_STATS_INC(icmp6.chkerr); + ICMP6_STATS_INC(icmp6.drop); + return; + } + } +#endif /* CHECKSUM_CHECK_ICMP6 */ + + switch (icmp6hdr->type) { + case ICMP6_TYPE_NA: /* Neighbor advertisement */ + case ICMP6_TYPE_NS: /* Neighbor solicitation */ + case ICMP6_TYPE_RA: /* Router advertisement */ + case ICMP6_TYPE_RD: /* Redirect */ + case ICMP6_TYPE_PTB: /* Packet too big */ + nd6_input(p, inp); + return; + case ICMP6_TYPE_RS: +#if LWIP_IPV6_FORWARD + /* @todo implement router functionality */ +#endif + break; +#if LWIP_IPV6_MLD + case ICMP6_TYPE_MLQ: + case ICMP6_TYPE_MLR: + case ICMP6_TYPE_MLD: + mld6_input(p, inp); + return; +#endif + case ICMP6_TYPE_EREQ: +#if !LWIP_MULTICAST_PING + /* multicast destination address? */ + if (ip6_addr_ismulticast(ip6_current_dest_addr())) { + /* drop */ + pbuf_free(p); + ICMP6_STATS_INC(icmp6.drop); + return; + } +#endif /* LWIP_MULTICAST_PING */ + + /* Allocate reply. */ + r = pbuf_alloc(PBUF_IP, p->tot_len, PBUF_RAM); + if (r == NULL) { + /* drop */ + pbuf_free(p); + ICMP6_STATS_INC(icmp6.memerr); + return; + } + + /* Copy echo request. */ + if (pbuf_copy(r, p) != ERR_OK) { + /* drop */ + pbuf_free(p); + pbuf_free(r); + ICMP6_STATS_INC(icmp6.err); + return; + } + + /* Determine reply source IPv6 address. */ +#if LWIP_MULTICAST_PING + if (ip6_addr_ismulticast(ip6_current_dest_addr())) { + reply_src = ip_2_ip6(ip6_select_source_address(inp, ip6_current_src_addr())); + if (reply_src == NULL) { + /* drop */ + pbuf_free(p); + pbuf_free(r); + ICMP6_STATS_INC(icmp6.rterr); + return; + } + } + else +#endif /* LWIP_MULTICAST_PING */ + { + reply_src = ip6_current_dest_addr(); + } + + /* Set fields in reply. */ + ((struct icmp6_echo_hdr *)(r->payload))->type = ICMP6_TYPE_EREP; + ((struct icmp6_echo_hdr *)(r->payload))->chksum = 0; +#if CHECKSUM_GEN_ICMP6 + IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_ICMP6) { + ((struct icmp6_echo_hdr *)(r->payload))->chksum = ip6_chksum_pseudo(r, + IP6_NEXTH_ICMP6, r->tot_len, reply_src, ip6_current_src_addr()); + } +#endif /* CHECKSUM_GEN_ICMP6 */ + + /* Send reply. */ + ICMP6_STATS_INC(icmp6.xmit); + ip6_output_if(r, reply_src, ip6_current_src_addr(), + LWIP_ICMP6_HL, 0, IP6_NEXTH_ICMP6, inp); + pbuf_free(r); + + break; + default: + ICMP6_STATS_INC(icmp6.proterr); + ICMP6_STATS_INC(icmp6.drop); + break; + } + + pbuf_free(p); +} + + +/** + * Send an icmpv6 'destination unreachable' packet. + * + * This function must be used only in direct response to a packet that is being + * received right now. Otherwise, address zones would be lost. + * + * @param p the input packet for which the 'unreachable' should be sent, + * p->payload pointing to the IPv6 header + * @param c ICMPv6 code for the unreachable type + */ +void +icmp6_dest_unreach(struct pbuf *p, enum icmp6_dur_code c) +{ + icmp6_send_response(p, c, 0, ICMP6_TYPE_DUR); +} + +/** + * Send an icmpv6 'packet too big' packet. + * + * This function must be used only in direct response to a packet that is being + * received right now. Otherwise, address zones would be lost. + * + * @param p the input packet for which the 'packet too big' should be sent, + * p->payload pointing to the IPv6 header + * @param mtu the maximum mtu that we can accept + */ +void +icmp6_packet_too_big(struct pbuf *p, u32_t mtu) +{ + icmp6_send_response(p, 0, mtu, ICMP6_TYPE_PTB); +} + +/** + * Send an icmpv6 'time exceeded' packet. + * + * This function must be used only in direct response to a packet that is being + * received right now. Otherwise, address zones would be lost. + * + * @param p the input packet for which the 'time exceeded' should be sent, + * p->payload pointing to the IPv6 header + * @param c ICMPv6 code for the time exceeded type + */ +void +icmp6_time_exceeded(struct pbuf *p, enum icmp6_te_code c) +{ + icmp6_send_response(p, c, 0, ICMP6_TYPE_TE); +} + +/** + * Send an icmpv6 'time exceeded' packet, with explicit source and destination + * addresses. + * + * This function may be used to send a response sometime after receiving the + * packet for which this response is meant. The provided source and destination + * addresses are used primarily to retain their zone information. + * + * @param p the input packet for which the 'time exceeded' should be sent, + * p->payload pointing to the IPv6 header + * @param c ICMPv6 code for the time exceeded type + * @param src_addr source address of the original packet, with zone information + * @param dest_addr destination address of the original packet, with zone + * information + */ +void +icmp6_time_exceeded_with_addrs(struct pbuf *p, enum icmp6_te_code c, + const ip6_addr_t *src_addr, const ip6_addr_t *dest_addr) +{ + icmp6_send_response_with_addrs(p, c, 0, ICMP6_TYPE_TE, src_addr, dest_addr); +} + +/** + * Send an icmpv6 'parameter problem' packet. + * + * This function must be used only in direct response to a packet that is being + * received right now. Otherwise, address zones would be lost and the calculated + * offset would be wrong (calculated against ip6_current_header()). + * + * @param p the input packet for which the 'param problem' should be sent, + * p->payload pointing to the IP header + * @param c ICMPv6 code for the param problem type + * @param pointer the pointer to the byte where the parameter is found + */ +void +icmp6_param_problem(struct pbuf *p, enum icmp6_pp_code c, const void *pointer) +{ + u32_t pointer_u32 = (u32_t)((const u8_t *)pointer - (const u8_t *)ip6_current_header()); + icmp6_send_response(p, c, pointer_u32, ICMP6_TYPE_PP); +} + +/** + * Send an ICMPv6 packet in response to an incoming packet. + * The packet is sent *to* ip_current_src_addr() on ip_current_netif(). + * + * @param p the input packet for which the response should be sent, + * p->payload pointing to the IPv6 header + * @param code Code of the ICMPv6 header + * @param data Additional 32-bit parameter in the ICMPv6 header + * @param type Type of the ICMPv6 header + */ +static void +icmp6_send_response(struct pbuf *p, u8_t code, u32_t data, u8_t type) +{ + const struct ip6_addr *reply_src, *reply_dest; + struct netif *netif = ip_current_netif(); + + LWIP_ASSERT("icmpv6 packet not a direct response", netif != NULL); + reply_dest = ip6_current_src_addr(); + + /* Select an address to use as source. */ + reply_src = ip_2_ip6(ip6_select_source_address(netif, reply_dest)); + if (reply_src == NULL) { + ICMP6_STATS_INC(icmp6.rterr); + return; + } + icmp6_send_response_with_addrs_and_netif(p, code, data, type, reply_src, reply_dest, netif); +} + +/** + * Send an ICMPv6 packet in response to an incoming packet. + * + * Call this function if the packet is NOT sent as a direct response to an + * incoming packet, but rather sometime later (e.g. for a fragment reassembly + * timeout). The caller must provide the zoned source and destination addresses + * from the original packet with the src_addr and dest_addr parameters. The + * reason for this approach is that while the addresses themselves are part of + * the original packet, their zone information is not, thus possibly resulting + * in a link-local response being sent over the wrong link. + * + * @param p the input packet for which the response should be sent, + * p->payload pointing to the IPv6 header + * @param code Code of the ICMPv6 header + * @param data Additional 32-bit parameter in the ICMPv6 header + * @param type Type of the ICMPv6 header + * @param src_addr original source address + * @param dest_addr original destination address + */ +static void +icmp6_send_response_with_addrs(struct pbuf *p, u8_t code, u32_t data, u8_t type, + const ip6_addr_t *src_addr, const ip6_addr_t *dest_addr) +{ + const struct ip6_addr *reply_src, *reply_dest; + struct netif *netif; + + /* Get the destination address and netif for this ICMP message. */ + LWIP_ASSERT("must provide both source and destination", src_addr != NULL); + LWIP_ASSERT("must provide both source and destination", dest_addr != NULL); + + /* Special case, as ip6_current_xxx is either NULL, or points + to a different packet than the one that expired. */ + IP6_ADDR_ZONECHECK(src_addr); + IP6_ADDR_ZONECHECK(dest_addr); + /* Swap source and destination for the reply. */ + reply_dest = src_addr; + reply_src = dest_addr; + netif = ip6_route(reply_src, reply_dest); + if (netif == NULL) { + ICMP6_STATS_INC(icmp6.rterr); + return; + } + icmp6_send_response_with_addrs_and_netif(p, code, data, type, reply_src, + reply_dest, netif); +} + +/** + * Send an ICMPv6 packet (with srd/dst address and netif given). + * + * @param p the input packet for which the response should be sent, + * p->payload pointing to the IPv6 header + * @param code Code of the ICMPv6 header + * @param data Additional 32-bit parameter in the ICMPv6 header + * @param type Type of the ICMPv6 header + * @param reply_src source address of the packet to send + * @param reply_dest destination address of the packet to send + * @param netif netif to send the packet + */ +static void +icmp6_send_response_with_addrs_and_netif(struct pbuf *p, u8_t code, u32_t data, u8_t type, + const ip6_addr_t *reply_src, const ip6_addr_t *reply_dest, struct netif *netif) +{ + struct pbuf *q; + struct icmp6_hdr *icmp6hdr; + + /* ICMPv6 header + IPv6 header + data */ + q = pbuf_alloc(PBUF_IP, sizeof(struct icmp6_hdr) + IP6_HLEN + LWIP_ICMP6_DATASIZE, + PBUF_RAM); + if (q == NULL) { + LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded: failed to allocate pbuf for ICMPv6 packet.\n")); + ICMP6_STATS_INC(icmp6.memerr); + return; + } + LWIP_ASSERT("check that first pbuf can hold icmp 6message", + (q->len >= (sizeof(struct icmp6_hdr) + IP6_HLEN + LWIP_ICMP6_DATASIZE))); + + icmp6hdr = (struct icmp6_hdr *)q->payload; + icmp6hdr->type = type; + icmp6hdr->code = code; + icmp6hdr->data = lwip_htonl(data); + + /* copy fields from original packet */ + SMEMCPY((u8_t *)q->payload + sizeof(struct icmp6_hdr), (u8_t *)p->payload, + IP6_HLEN + LWIP_ICMP6_DATASIZE); + + /* calculate checksum */ + icmp6hdr->chksum = 0; +#if CHECKSUM_GEN_ICMP6 + IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_ICMP6) { + icmp6hdr->chksum = ip6_chksum_pseudo(q, IP6_NEXTH_ICMP6, q->tot_len, + reply_src, reply_dest); + } +#endif /* CHECKSUM_GEN_ICMP6 */ + + ICMP6_STATS_INC(icmp6.xmit); + ip6_output_if(q, reply_src, reply_dest, LWIP_ICMP6_HL, 0, IP6_NEXTH_ICMP6, netif); + pbuf_free(q); +} + +#endif /* LWIP_ICMP6 && LWIP_IPV6 */ |