/** * @file * Implementation of raw protocol PCBs for low-level handling of * different types of protocols besides (or overriding) those * already available in lwIP.
* See also @ref raw_raw * * @defgroup raw_raw RAW * @ingroup callbackstyle_api * Implementation of raw protocol PCBs for low-level handling of * different types of protocols besides (or overriding) those * already available in lwIP.
* @see @ref api */ /* * Copyright (c) 2001-2004 Swedish Institute of Computer Science. * 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: Adam Dunkels * */ #include "lwip/opt.h" #if LWIP_RAW /* don't build if not configured for use in lwipopts.h */ #include "lwip/def.h" #include "lwip/memp.h" #include "lwip/ip_addr.h" #include "lwip/netif.h" #include "lwip/raw.h" #include "lwip/priv/raw_priv.h" #include "lwip/stats.h" #include "lwip/ip6.h" #include "lwip/ip6_addr.h" #include "lwip/inet_chksum.h" #include /** The list of RAW PCBs */ static struct raw_pcb *raw_pcbs; static u8_t raw_input_local_match(struct raw_pcb *pcb, u8_t broadcast) { LWIP_UNUSED_ARG(broadcast); /* in IPv6 only case */ /* check if PCB is bound to specific netif */ if ((pcb->netif_idx != NETIF_NO_INDEX) && (pcb->netif_idx != netif_get_index(ip_data.current_input_netif))) { return 0; } #if LWIP_IPV4 && LWIP_IPV6 /* Dual-stack: PCBs listening to any IP type also listen to any IP address */ if (IP_IS_ANY_TYPE_VAL(pcb->local_ip)) { #if IP_SOF_BROADCAST_RECV if ((broadcast != 0) && !ip_get_option(pcb, SOF_BROADCAST)) { return 0; } #endif /* IP_SOF_BROADCAST_RECV */ return 1; } #endif /* LWIP_IPV4 && LWIP_IPV6 */ /* Only need to check PCB if incoming IP version matches PCB IP version */ if (IP_ADDR_PCB_VERSION_MATCH_EXACT(pcb, ip_current_dest_addr())) { #if LWIP_IPV4 /* Special case: IPv4 broadcast: receive all broadcasts * Note: broadcast variable can only be 1 if it is an IPv4 broadcast */ if (broadcast != 0) { #if IP_SOF_BROADCAST_RECV if (ip_get_option(pcb, SOF_BROADCAST)) #endif /* IP_SOF_BROADCAST_RECV */ { if (ip4_addr_isany(ip_2_ip4(&pcb->local_ip))) { return 1; } } } else #endif /* LWIP_IPV4 */ /* Handle IPv4 and IPv6: catch all or exact match */ if (ip_addr_isany(&pcb->local_ip) || ip_addr_eq(&pcb->local_ip, ip_current_dest_addr())) { return 1; } } return 0; } /** * Determine if in incoming IP packet is covered by a RAW PCB * and if so, pass it to a user-provided receive callback function. * * Given an incoming IP datagram (as a chain of pbufs) this function * finds a corresponding RAW PCB and calls the corresponding receive * callback function. * * @param p pbuf to be demultiplexed to a RAW PCB. * @param inp network interface on which the datagram was received. * @return - 1 if the packet has been eaten by a RAW PCB receive * callback function. The caller MAY NOT not reference the * packet any longer, and MAY NOT call pbuf_free(). * @return - 0 if packet is not eaten (pbuf is still referenced by the * caller). * */ raw_input_state_t raw_input(struct pbuf *p, struct netif *inp) { struct raw_pcb *pcb, *prev; s16_t proto; raw_input_state_t ret = RAW_INPUT_NONE; u8_t broadcast = ip_addr_isbroadcast(ip_current_dest_addr(), ip_current_netif()); LWIP_UNUSED_ARG(inp); #if LWIP_IPV6 #if LWIP_IPV4 if (IP_HDR_GET_VERSION(p->payload) == 6) #endif /* LWIP_IPV4 */ { struct ip6_hdr *ip6hdr = (struct ip6_hdr *)p->payload; proto = IP6H_NEXTH(ip6hdr); } #if LWIP_IPV4 else #endif /* LWIP_IPV4 */ #endif /* LWIP_IPV6 */ #if LWIP_IPV4 { proto = IPH_PROTO((struct ip_hdr *)p->payload); } #endif /* LWIP_IPV4 */ prev = NULL; pcb = raw_pcbs; /* loop through all raw pcbs until the packet is eaten by one */ /* this allows multiple pcbs to match against the packet by design */ while (pcb != NULL) { if ((pcb->protocol == proto) && raw_input_local_match(pcb, broadcast) && (((pcb->flags & RAW_FLAGS_CONNECTED) == 0) || ip_addr_eq(&pcb->remote_ip, ip_current_src_addr()))) { /* receive callback function available? */ if (pcb->recv != NULL) { u8_t eaten; #ifndef LWIP_NOASSERT void *old_payload = p->payload; #endif ret = RAW_INPUT_DELIVERED; /* the receive callback function did not eat the packet? */ eaten = pcb->recv(pcb->recv_arg, pcb, p, ip_current_src_addr()); if (eaten != 0) { /* receive function ate the packet */ p = NULL; if (prev != NULL) { /* move the pcb to the front of raw_pcbs so that is found faster next time */ prev->next = pcb->next; pcb->next = raw_pcbs; raw_pcbs = pcb; } return RAW_INPUT_EATEN; } else { /* sanity-check that the receive callback did not alter the pbuf */ LWIP_ASSERT("raw pcb recv callback altered pbuf payload pointer without eating packet", p->payload == old_payload); } } /* no receive callback function was set for this raw PCB */ } /* drop the packet */ prev = pcb; pcb = pcb->next; } return ret; } /** * @ingroup raw_raw * Bind a RAW PCB. * * @param pcb RAW PCB to be bound with a local address ipaddr. * @param ipaddr local IP address to bind with. Use IP4_ADDR_ANY to * bind to all local interfaces. * * @return lwIP error code. * - ERR_OK. Successful. No error occurred. * - ERR_USE. The specified IP address is already bound to by * another RAW PCB. * * @see raw_disconnect() */ err_t raw_bind(struct raw_pcb *pcb, const ip_addr_t *ipaddr) { LWIP_ASSERT_CORE_LOCKED(); if ((pcb == NULL) || (ipaddr == NULL)) { return ERR_VAL; } ip_addr_set_ipaddr(&pcb->local_ip, ipaddr); #if LWIP_IPV6 && LWIP_IPV6_SCOPES /* If the given IP address should have a zone but doesn't, assign one now. * This is legacy support: scope-aware callers should always provide properly * zoned source addresses. */ if (IP_IS_V6(&pcb->local_ip) && ip6_addr_lacks_zone(ip_2_ip6(&pcb->local_ip), IP6_UNKNOWN)) { ip6_addr_select_zone(ip_2_ip6(&pcb->local_ip), ip_2_ip6(&pcb->local_ip)); } #endif /* LWIP_IPV6 && LWIP_IPV6_SCOPES */ return ERR_OK; } /** * @ingroup raw_raw * Bind an RAW PCB to a specific netif. * After calling this function, all packets received via this PCB * are guaranteed to have come in via the specified netif, and all * outgoing packets will go out via the specified netif. * * @param pcb RAW PCB to be bound with netif. * @param netif netif to bind to. Can be NULL. * * @see raw_disconnect() */ void raw_bind_netif(struct raw_pcb *pcb, const struct netif *netif) { LWIP_ASSERT_CORE_LOCKED(); if (netif != NULL) { pcb->netif_idx = netif_get_index(netif); } else { pcb->netif_idx = NETIF_NO_INDEX; } } /** * @ingroup raw_raw * Connect an RAW PCB. This function is required by upper layers * of lwip. Using the raw api you could use raw_sendto() instead * * This will associate the RAW PCB with the remote address. * * @param pcb RAW PCB to be connected with remote address ipaddr and port. * @param ipaddr remote IP address to connect with. * * @return lwIP error code * * @see raw_disconnect() and raw_sendto() */ err_t raw_connect(struct raw_pcb *pcb, const ip_addr_t *ipaddr) { LWIP_ASSERT_CORE_LOCKED(); if ((pcb == NULL) || (ipaddr == NULL)) { return ERR_VAL; } ip_addr_set_ipaddr(&pcb->remote_ip, ipaddr); #if LWIP_IPV6 && LWIP_IPV6_SCOPES /* If the given IP address should have a zone but doesn't, assign one now, * using the bound address to make a more informed decision when possible. */ if (IP_IS_V6(&pcb->remote_ip) && ip6_addr_lacks_zone(ip_2_ip6(&pcb->remote_ip), IP6_UNKNOWN)) { ip6_addr_select_zone(ip_2_ip6(&pcb->remote_ip), ip_2_ip6(&pcb->local_ip)); } #endif /* LWIP_IPV6 && LWIP_IPV6_SCOPES */ raw_set_flags(pcb, RAW_FLAGS_CONNECTED); return ERR_OK; } /** * @ingroup raw_raw * Disconnect a RAW PCB. * * @param pcb the raw pcb to disconnect. */ void raw_disconnect(struct raw_pcb *pcb) { LWIP_ASSERT_CORE_LOCKED(); /* reset remote address association */ #if LWIP_IPV4 && LWIP_IPV6 if (IP_IS_ANY_TYPE_VAL(pcb->local_ip)) { ip_addr_copy(pcb->remote_ip, *IP_ANY_TYPE); } else { #endif ip_addr_set_any(IP_IS_V6_VAL(pcb->remote_ip), &pcb->remote_ip); #if LWIP_IPV4 && LWIP_IPV6 } #endif pcb->netif_idx = NETIF_NO_INDEX; /* mark PCB as unconnected */ raw_clear_flags(pcb, RAW_FLAGS_CONNECTED); } /** * @ingroup raw_raw * Set the callback function for received packets that match the * raw PCB's protocol and binding. * * The callback function MUST either * - eat the packet by calling pbuf_free() and returning non-zero. The * packet will not be passed to other raw PCBs or other protocol layers. * - not free the packet, and return zero. The packet will be matched * against further PCBs and/or forwarded to another protocol layers. */ void raw_recv(struct raw_pcb *pcb, raw_recv_fn recv, void *recv_arg) { LWIP_ASSERT_CORE_LOCKED(); /* remember recv() callback and user data */ pcb->recv = recv; pcb->recv_arg = recv_arg; } /** * @ingroup raw_raw * Send the raw IP packet to the given address. An IP header will be prepended * to the packet, unless the RAW_FLAGS_HDRINCL flag is set on the PCB. In that * case, the packet must include an IP header, which will then be sent as is. * * @param pcb the raw pcb which to send * @param p the IP payload to send * @param ipaddr the destination address of the IP packet * */ err_t raw_sendto(struct raw_pcb *pcb, struct pbuf *p, const ip_addr_t *ipaddr) { struct netif *netif; const ip_addr_t *src_ip; if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, ipaddr)) { return ERR_VAL; } LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_sendto\n")); if (pcb->netif_idx != NETIF_NO_INDEX) { netif = netif_get_by_index(pcb->netif_idx); } else { #if LWIP_MULTICAST_TX_OPTIONS netif = NULL; if (ip_addr_ismulticast(ipaddr)) { /* For multicast-destined packets, use the user-provided interface index to * determine the outgoing interface, if an interface index is set and a * matching netif can be found. Otherwise, fall back to regular routing. */ netif = netif_get_by_index(pcb->mcast_ifindex); } if (netif == NULL) #endif /* LWIP_MULTICAST_TX_OPTIONS */ { netif = ip_route(&pcb->local_ip, ipaddr); } } if (netif == NULL) { LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, ("raw_sendto: No route to ")); ip_addr_debug_print(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, ipaddr); return ERR_RTE; } if (ip_addr_isany(&pcb->local_ip) || ip_addr_ismulticast(&pcb->local_ip)) { /* use outgoing network interface IP address as source address */ src_ip = ip_netif_get_local_ip(netif, ipaddr); #if LWIP_IPV6 if (src_ip == NULL) { return ERR_RTE; } #endif /* LWIP_IPV6 */ } else { /* use RAW PCB local IP address as source address */ src_ip = &pcb->local_ip; } return raw_sendto_if_src(pcb, p, ipaddr, netif, src_ip); } /** * @ingroup raw_raw * Send the raw IP packet to the given address, using a particular outgoing * netif and source IP address. An IP header will be prepended to the packet, * unless the RAW_FLAGS_HDRINCL flag is set on the PCB. In that case, the * packet must include an IP header, which will then be sent as is. * * @param pcb RAW PCB used to send the data * @param p chain of pbufs to be sent * @param dst_ip destination IP address * @param netif the netif used for sending * @param src_ip source IP address */ err_t raw_sendto_if_src(struct raw_pcb *pcb, struct pbuf *p, const ip_addr_t *dst_ip, struct netif *netif, const ip_addr_t *src_ip) { err_t err; struct pbuf *q; /* q will be sent down the stack */ u16_t header_size; u8_t ttl; LWIP_ASSERT_CORE_LOCKED(); if ((pcb == NULL) || (dst_ip == NULL) || (netif == NULL) || (src_ip == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, src_ip) || !IP_ADDR_PCB_VERSION_MATCH(pcb, dst_ip)) { return ERR_VAL; } header_size = ( #if LWIP_IPV4 && LWIP_IPV6 IP_IS_V6(dst_ip) ? IP6_HLEN : IP_HLEN); #elif LWIP_IPV4 IP_HLEN); #else IP6_HLEN); #endif /* Handle the HDRINCL option as an exception: none of the code below applies * to this case, and sending the packet needs to be done differently too. */ if (pcb->flags & RAW_FLAGS_HDRINCL) { /* A full header *must* be present in the first pbuf of the chain, as the * output routines may access its fields directly. */ if (p->len < header_size) { return ERR_VAL; } /* @todo multicast loop support, if at all desired for this scenario.. */ NETIF_SET_HINTS(netif, &pcb->netif_hints); err = ip_output_if_hdrincl(p, src_ip, dst_ip, netif); NETIF_RESET_HINTS(netif); return err; } /* packet too large to add an IP header without causing an overflow? */ if ((u16_t)(p->tot_len + header_size) < p->tot_len) { return ERR_MEM; } /* not enough space to add an IP header to first pbuf in given p chain? */ if (pbuf_add_header(p, header_size)) { /* allocate header in new pbuf */ q = pbuf_alloc(PBUF_IP, 0, PBUF_RAM); /* new header pbuf could not be allocated? */ if (q == NULL) { LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("raw_sendto: could not allocate header\n")); return ERR_MEM; } if (p->tot_len != 0) { /* chain header q in front of given pbuf p */ pbuf_chain(q, p); } /* { first pbuf q points to header pbuf } */ LWIP_DEBUGF(RAW_DEBUG, ("raw_sendto: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p)); } else { /* first pbuf q equals given pbuf */ q = p; if (pbuf_remove_header(q, header_size)) { LWIP_ASSERT("Can't restore header we just removed!", 0); return ERR_MEM; } } #if IP_SOF_BROADCAST if (IP_IS_V4(dst_ip)) { /* broadcast filter? */ if (!ip_get_option(pcb, SOF_BROADCAST) && ip_addr_isbroadcast(dst_ip, netif)) { LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, ("raw_sendto: SOF_BROADCAST not enabled on pcb %p\n", (void *)pcb)); /* free any temporary header pbuf allocated by pbuf_header() */ if (q != p) { pbuf_free(q); } return ERR_VAL; } } #endif /* IP_SOF_BROADCAST */ /* Multicast Loop? */ #if LWIP_MULTICAST_TX_OPTIONS if (((pcb->flags & RAW_FLAGS_MULTICAST_LOOP) != 0) && ip_addr_ismulticast(dst_ip)) { q->flags |= PBUF_FLAG_MCASTLOOP; } #endif /* LWIP_MULTICAST_TX_OPTIONS */ #if LWIP_IPV6 /* If requested, based on the IPV6_CHECKSUM socket option per RFC3542, compute the checksum and update the checksum in the payload. */ if (IP_IS_V6(dst_ip) && pcb->chksum_reqd) { u16_t chksum = ip6_chksum_pseudo(p, pcb->protocol, p->tot_len, ip_2_ip6(src_ip), ip_2_ip6(dst_ip)); LWIP_ASSERT("Checksum must fit into first pbuf", p->len >= (pcb->chksum_offset + 2)); SMEMCPY(((u8_t *)p->payload) + pcb->chksum_offset, &chksum, sizeof(u16_t)); } #endif /* Determine TTL to use */ #if LWIP_MULTICAST_TX_OPTIONS ttl = (ip_addr_ismulticast(dst_ip) ? raw_get_multicast_ttl(pcb) : pcb->ttl); #else /* LWIP_MULTICAST_TX_OPTIONS */ ttl = pcb->ttl; #endif /* LWIP_MULTICAST_TX_OPTIONS */ NETIF_SET_HINTS(netif, &pcb->netif_hints); err = ip_output_if(q, src_ip, dst_ip, ttl, pcb->tos, pcb->protocol, netif); NETIF_RESET_HINTS(netif); /* did we chain a header earlier? */ if (q != p) { /* free the header */ pbuf_free(q); } return err; } /** * @ingroup raw_raw * Send the raw IP packet to the address given by raw_connect() * * @param pcb the raw pcb which to send * @param p the IP payload to send * */ err_t raw_send(struct raw_pcb *pcb, struct pbuf *p) { return raw_sendto(pcb, p, &pcb->remote_ip); } /** * @ingroup raw_raw * Remove an RAW PCB. * * @param pcb RAW PCB to be removed. The PCB is removed from the list of * RAW PCB's and the data structure is freed from memory. * * @see raw_new() */ void raw_remove(struct raw_pcb *pcb) { struct raw_pcb *pcb2; LWIP_ASSERT_CORE_LOCKED(); /* pcb to be removed is first in list? */ if (raw_pcbs == pcb) { /* make list start at 2nd pcb */ raw_pcbs = raw_pcbs->next; /* pcb not 1st in list */ } else { for (pcb2 = raw_pcbs; pcb2 != NULL; pcb2 = pcb2->next) { /* find pcb in raw_pcbs list */ if (pcb2->next != NULL && pcb2->next == pcb) { /* remove pcb from list */ pcb2->next = pcb->next; break; } } } memp_free(MEMP_RAW_PCB, pcb); } /** * @ingroup raw_raw * Create a RAW PCB. * * @return The RAW PCB which was created. NULL if the PCB data structure * could not be allocated. * * @param proto the protocol number of the IPs payload (e.g. IP_PROTO_ICMP) * * @see raw_remove() */ struct raw_pcb * raw_new(u8_t proto) { struct raw_pcb *pcb; LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_new\n")); LWIP_ASSERT_CORE_LOCKED(); pcb = (struct raw_pcb *)memp_malloc(MEMP_RAW_PCB); /* could allocate RAW PCB? */ if (pcb != NULL) { /* initialize PCB to all zeroes */ memset(pcb, 0, sizeof(struct raw_pcb)); pcb->protocol = proto; pcb->ttl = RAW_TTL; #if LWIP_MULTICAST_TX_OPTIONS raw_set_multicast_ttl(pcb, RAW_TTL); #endif /* LWIP_MULTICAST_TX_OPTIONS */ pcb->next = raw_pcbs; raw_pcbs = pcb; } return pcb; } /** * @ingroup raw_raw * Create a RAW PCB for specific IP type. * * @return The RAW PCB which was created. NULL if the PCB data structure * could not be allocated. * * @param type IP address type, see @ref lwip_ip_addr_type definitions. * If you want to listen to IPv4 and IPv6 (dual-stack) packets, * supply @ref IPADDR_TYPE_ANY as argument and bind to @ref IP_ANY_TYPE. * @param proto the protocol number (next header) of the IPv6 packet payload * (e.g. IP6_NEXTH_ICMP6) * * @see raw_remove() */ struct raw_pcb * raw_new_ip_type(u8_t type, u8_t proto) { struct raw_pcb *pcb; LWIP_ASSERT_CORE_LOCKED(); pcb = raw_new(proto); #if LWIP_IPV4 && LWIP_IPV6 if (pcb != NULL) { IP_SET_TYPE_VAL(pcb->local_ip, type); IP_SET_TYPE_VAL(pcb->remote_ip, type); } #else /* LWIP_IPV4 && LWIP_IPV6 */ LWIP_UNUSED_ARG(type); #endif /* LWIP_IPV4 && LWIP_IPV6 */ return pcb; } /** This function is called from netif.c when address is changed * * @param old_addr IP address of the netif before change * @param new_addr IP address of the netif after change */ void raw_netif_ip_addr_changed(const ip_addr_t *old_addr, const ip_addr_t *new_addr) { struct raw_pcb *rpcb; if (!ip_addr_isany(old_addr) && !ip_addr_isany(new_addr)) { for (rpcb = raw_pcbs; rpcb != NULL; rpcb = rpcb->next) { /* PCB bound to current local interface address? */ if (ip_addr_eq(&rpcb->local_ip, old_addr)) { /* The PCB is bound to the old ipaddr and * is set to bound to the new one instead */ ip_addr_copy(rpcb->local_ip, *new_addr); } } } } #endif /* LWIP_RAW */