/** | |
* @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/inet.h" | |
#include "lwip/ip_addr.h" | |
#include "lwip/netif.h" | |
#include "lwip/raw.h" | |
#include "lwip/stats.h" | |
#include "lwip/snmp.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 = 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) { | |
/* 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, &(iphdr->src)) != 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, struct ip_addr *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, struct ip_addr *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, | |
u8_t (* recv)(void *arg, struct raw_pcb *upcb, struct pbuf *p, | |
struct ip_addr *addr), | |
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, struct ip_addr *ipaddr) | |
{ | |
err_t err; | |
struct netif *netif; | |
struct ip_addr *src_ip; | |
struct pbuf *q; /* q will be sent down the stack */ | |
LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | 3, ("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 | 2, ("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 | 1, ("raw_sendto: No route to 0x%"X32_F"\n", ipaddr->addr)); | |
/* free any temporary header pbuf allocated by pbuf_header() */ | |
if (q != p) { | |
pbuf_free(q); | |
} | |
return ERR_RTE; | |
} | |
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 | 3, ("raw_new\n")); | |
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 */ |