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Diff: lwip/core/raw.c
- Revision:
- 0:ac1725ba162c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lwip/core/raw.c Tue Nov 09 20:54:15 2010 +0000 @@ -0,0 +1,352 @@ +/** + * @file + * Implementation of raw protocol PCBs for low-level handling of + * different types of protocols besides (or overriding) those + * already available in lwIP. + * + */ + +/* + * 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 <adam@sics.se> + * + */ + +#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/stats.h" +#include "arch/perf.h" + +#include <string.h> + +/** The list of RAW PCBs */ +static struct raw_pcb *raw_pcbs; + +/** + * 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). + * + */ +u8_t +raw_input(struct pbuf *p, struct netif *inp) +{ + struct raw_pcb *pcb, *prev; + struct ip_hdr *iphdr; + s16_t proto; + u8_t eaten = 0; + + LWIP_UNUSED_ARG(inp); + + iphdr = (struct ip_hdr *)p->payload; + proto = IPH_PROTO(iphdr); + + 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 ((eaten == 0) && (pcb != NULL)) { + if ((pcb->protocol == proto) && + (ip_addr_isany(&pcb->local_ip) || + ip_addr_cmp(&(pcb->local_ip), ¤t_iphdr_dest))) { +#if IP_SOF_BROADCAST_RECV + /* broadcast filter? */ + if ((pcb->so_options & SOF_BROADCAST) || !ip_addr_isbroadcast(¤t_iphdr_dest, inp)) +#endif /* IP_SOF_BROADCAST_RECV */ + { + /* receive callback function available? */ + if (pcb->recv != NULL) { + /* the receive callback function did not eat the packet? */ + if (pcb->recv(pcb->recv_arg, pcb, p, ip_current_src_addr()) != 0) { + /* receive function ate the packet */ + p = NULL; + eaten = 1; + 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; + } + } + } + /* no receive callback function was set for this raw PCB */ + } + /* drop the packet */ + } + prev = pcb; + pcb = pcb->next; + } + return eaten; +} + +/** + * 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 IP_ADDR_ANY to + * bind to all local interfaces. + * + * @return lwIP error code. + * - ERR_OK. Successful. No error occured. + * - 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, ip_addr_t *ipaddr) +{ + ip_addr_set(&pcb->local_ip, ipaddr); + return ERR_OK; +} + +/** + * 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, ip_addr_t *ipaddr) +{ + ip_addr_set(&pcb->remote_ip, ipaddr); + return ERR_OK; +} + + +/** + * 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. + * + * @return non-zero if the packet was free()d, zero if the packet remains + * available for others. + */ +void +raw_recv(struct raw_pcb *pcb, raw_recv_fn recv, void *recv_arg) +{ + /* remember recv() callback and user data */ + pcb->recv = recv; + pcb->recv_arg = recv_arg; +} + +/** + * Send the raw IP packet to the given address. Note that actually you cannot + * modify the IP headers (this is inconsistent with the receive callback where + * you actually get the IP headers), you can only specify the IP payload here. + * It requires some more changes in lwIP. (there will be a raw_send() function + * then.) + * + * @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, ip_addr_t *ipaddr) +{ + err_t err; + struct netif *netif; + ip_addr_t *src_ip; + struct pbuf *q; /* q will be sent down the stack */ + + LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_sendto\n")); + + /* not enough space to add an IP header to first pbuf in given p chain? */ + if (pbuf_header(p, IP_HLEN)) { + /* 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; + } + /* 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_header(q, -IP_HLEN)) { + LWIP_ASSERT("Can't restore header we just removed!", 0); + return ERR_MEM; + } + } + + if ((netif = ip_route(ipaddr)) == NULL) { + LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, ("raw_sendto: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", + ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr))); + /* free any temporary header pbuf allocated by pbuf_header() */ + if (q != p) { + pbuf_free(q); + } + return ERR_RTE; + } + +#if IP_SOF_BROADCAST + /* broadcast filter? */ + if (((pcb->so_options & SOF_BROADCAST) == 0) && ip_addr_isbroadcast(ipaddr, 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 */ + + if (ip_addr_isany(&pcb->local_ip)) { + /* use outgoing network interface IP address as source address */ + src_ip = &(netif->ip_addr); + } else { + /* use RAW PCB local IP address as source address */ + src_ip = &(pcb->local_ip); + } + +#if LWIP_NETIF_HWADDRHINT + netif->addr_hint = &(pcb->addr_hint); +#endif /* LWIP_NETIF_HWADDRHINT*/ + err = ip_output_if (q, src_ip, ipaddr, pcb->ttl, pcb->tos, pcb->protocol, netif); +#if LWIP_NETIF_HWADDRHINT + netif->addr_hint = NULL; +#endif /* LWIP_NETIF_HWADDRHINT*/ + + /* did we chain a header earlier? */ + if (q != p) { + /* free the header */ + pbuf_free(q); + } + return err; +} + +/** + * 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); +} + +/** + * 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; + /* 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; + } + } + } + memp_free(MEMP_RAW_PCB, pcb); +} + +/** + * 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")); + + 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; + pcb->next = raw_pcbs; + raw_pcbs = pcb; + } + return pcb; +} + +#endif /* LWIP_RAW */