Added a netif encapsulating 6LowPAN in ZEP (ZigBee Enxapsulation Protocol)

This protocol is sent over a 2nd netif via UDP/IP and can used to analyze
6LoWPAN with a Wireshark dissector.

Signed-off-by: goldsimon <goldsimon@gmx.de>
This commit is contained in:
goldsimon 2018-02-28 22:58:48 +01:00
parent d9770d2c5f
commit 43a55003da
2 changed files with 347 additions and 0 deletions

77
src/include/netif/zepif.h Normal file
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/**
* @file
*
* A netif implementing the ZigBee Eencapsulation Protocol (ZEP).
* This is used to tunnel 6LowPAN over UDP.
*/
/*
* Copyright (c) 2018 Simon Goldschmidt
* 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: Simon Goldschmidt <goldsimon@gmx.de>
*
*/
#ifndef LWIP_HDR_ZEPIF_H
#define LWIP_HDR_ZEPIF_H
#include "lwip/opt.h"
#include "netif/lowpan6.h"
#if LWIP_IPV6 && LWIP_6LOWPAN /* don't build if not configured for use in lwipopts.h */
#include "lwip/netif.h"
#ifdef __cplusplus
extern "C" {
#endif
#define ZEPIF_DEFAULT_UDP_PORT 17754
/** Pass this struct as 'state' to netif_add to control the behaviour
* of this netif. If NULL is passed, default behaviour is chosen */
struct zepif_init {
/** The UDP port used for ZEP frames (0 = default) */
u16_t zep_udp_port;
/** The IP address to sed ZEP frames to */
const ip_addr_t *zep_ip_addr;
/** If != NULL, the udp pcb is bound to this netif */
const struct netif *zep_netif;
/** MAC address of the 6LowPAN device */
u8_t addr[6];
};
err_t zepif_init(struct netif *netif);
#ifdef __cplusplus
}
#endif
#endif /* LWIP_IPV6 && LWIP_6LOWPAN */
#endif /* LWIP_HDR_ZEPIF_H */

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src/netif/zepif.c Normal file
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/**
* @file
*
* A netif implementing the ZigBee Eencapsulation Protocol (ZEP).
* This is used to tunnel 6LowPAN over UDP.
*
* Usage (there must be a default netif before!):
* netif_add(&zep_netif, NULL, NULL, NULL, NULL, zepif_init, tcpip_6lowpan_input);
* netif_create_ip6_linklocal_address(&zep_netif, 1);
* netif_set_up(&zep_netif);
* netif_set_link_up(&zep_netif);
*/
/*
* Copyright (c) 2018 Simon Goldschmidt
* 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: Simon Goldschmidt <goldsimon@gmx.de>
*
*/
/**
* @defgroup sixlowpan 6LowPAN
* @ingroup netifs
* ZEP netif implementation
*/
#include "netif/zepif.h"
#if LWIP_IPV6 && LWIP_6LOWPAN
#include "netif/lowpan6.h"
#include "lwip/udp.h"
#include <string.h>
/** Define this to 1 to loop back TX packets for testing */
#ifndef ZEPIF_LOOPBACK
#define ZEPIF_LOOPBACK 1//0
#endif
#define ZEP_MAX_DATA_LEN 127
#ifdef PACK_STRUCT_USE_INCLUDES
# include "arch/bpstruct.h"
#endif
PACK_STRUCT_BEGIN
struct zep_hdr {
PACK_STRUCT_FLD_8(u8_t prot_id[2]);
PACK_STRUCT_FLD_8(u8_t prot_version);
PACK_STRUCT_FLD_8(u8_t type);
PACK_STRUCT_FLD_8(u8_t channel_id);
PACK_STRUCT_FIELD(u16_t device_id);
PACK_STRUCT_FLD_8(u8_t crc_mode);
PACK_STRUCT_FLD_8(u8_t unknown_1);
PACK_STRUCT_FIELD(u32_t timestamp[2]);
PACK_STRUCT_FIELD(u32_t seq_num);
PACK_STRUCT_FLD_8(u8_t unknown_2[10]);
PACK_STRUCT_FLD_8(u8_t len);
} PACK_STRUCT_STRUCT;
PACK_STRUCT_END
#ifdef PACK_STRUCT_USE_INCLUDES
# include "arch/epstruct.h"
#endif
struct zepif_state {
struct zepif_init init;
struct udp_pcb *pcb;
u32_t seqno;
};
/* Pass received pbufs into 6LowPAN netif */
static void
zepif_udp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p,
const ip_addr_t *addr, u16_t port)
{
err_t err;
struct netif *netif_lowpan6 = (struct netif *)arg;
struct zep_hdr *zep;
LWIP_ASSERT("arg != NULL", arg != NULL);
LWIP_ASSERT("pcb != NULL", pcb != NULL);
LWIP_UNUSED_ARG(addr);
LWIP_UNUSED_ARG(port);
if (p == NULL) {
return;
}
/* Parse and hide the ZEP header */
if (p->len < sizeof(struct zep_hdr)) {
/* need the zep_hdr in one piece */
goto err_return;
}
zep = (struct zep_hdr *)p->payload;
if (zep->prot_id[0] != 'E') {
goto err_return;
}
if (zep->prot_id[1] != 'X') {
goto err_return;
}
if (zep->prot_version != 2) {
/* we only support this version for now */
goto err_return;
}
if (zep->type != 1) {
goto err_return;
}
if (zep->crc_mode != 1) {
goto err_return;
}
if (zep->len != p->tot_len - sizeof(struct zep_hdr)) {
goto err_return;
}
/* everything seems to be OK, hide the ZEP header */
if (pbuf_remove_header(p, sizeof(struct zep_hdr))) {
goto err_return;
}
/* Call tcpip_6lowpan_input here, not netif->input as we know the direct call
* stack won't work as we could enter udp_input twice. */
err = tcpip_6lowpan_input(p, netif_lowpan6);
if (err == ERR_OK) {
return;
}
err_return:
pbuf_free(p);
}
/* Send 6LoWPAN TX packets as UDP broadcast */
static err_t
zepif_linkoutput(struct netif *netif, struct pbuf *p)
{
err_t err;
struct pbuf *q;
struct zep_hdr *zep;
struct zepif_state *state;
LWIP_ASSERT("invalid netif", netif != NULL);
LWIP_ASSERT("invalid pbuf", p != NULL);
if (p->tot_len > ZEP_MAX_DATA_LEN) {
return ERR_VAL;
}
LWIP_ASSERT("TODO: support chained pbufs", p->next == NULL);
state = (struct zepif_state *)netif->state;
LWIP_ASSERT("state->pcb != NULL", state->pcb != NULL);
q = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct zep_hdr) + p->tot_len, PBUF_RAM);
if (q == NULL) {
return ERR_MEM;
}
zep = (struct zep_hdr *)q->payload;
memset(zep, 0, sizeof(struct zep_hdr));
zep->prot_id[0] = 'E';
zep->prot_id[1] = 'X';
zep->prot_version = 2;
zep->type = 1; /* Data */
zep->channel_id = 0; /* whatever */
zep->device_id = lwip_htons(1); /* whatever */
zep->crc_mode = 1;
zep->unknown_1 = 0xff;
zep->seq_num = lwip_htonl(state->seqno);
state->seqno++;
zep->len = (u8_t)p->tot_len;
err = pbuf_take_at(q, p->payload, p->tot_len, sizeof(struct zep_hdr));
if (err == ERR_OK) {
#if ZEPIF_LOOPBACK
zepif_udp_recv(netif, state->pcb, pbuf_clone(PBUF_RAW, PBUF_RAM, q), NULL, 0);
#endif
err = udp_sendto(state->pcb, q, state->init.zep_ip_addr, state->init.zep_udp_port);
}
pbuf_free(q);
return err;
}
/** Set up a raw 6LowPAN netif and surround it with input- and output
* functions for ZEP
*/
err_t
zepif_init(struct netif *netif)
{
err_t err;
struct zepif_init *init_state = (struct zepif_init *)netif->state;
struct zepif_state *state = (struct zepif_state *)mem_malloc(sizeof(struct zepif_state));
if (state == NULL) {
return ERR_MEM;
}
memset(state, 0, sizeof(struct zepif_state));
if (init_state != NULL) {
state->init = *init_state;
}
if (state->init.zep_udp_port == 0) {
state->init.zep_udp_port = ZEPIF_DEFAULT_UDP_PORT;
}
if (state->init.zep_ip_addr == NULL) {
state->init.zep_ip_addr = IP_ADDR_ANY;
}
netif->state = NULL;
state->pcb = udp_new();
if (state->pcb == NULL) {
err = ERR_MEM;
goto err_ret;
}
err = udp_bind(state->pcb, state->init.zep_ip_addr, state->init.zep_udp_port);
if (err != ERR_OK) {
goto err_ret;
}
if (state->init.zep_netif != NULL) {
udp_bind_netif(state->pcb, state->init.zep_netif);
}
LWIP_ASSERT("udp_bind(lowpan6_broadcast_pcb) failed", err == ERR_OK);
ip_set_option(state->pcb, SOF_BROADCAST);
udp_recv(state->pcb, zepif_udp_recv, netif);
err = lowpan6_if_init(netif);
LWIP_ASSERT("lowpan6_if_init set a state", netif->state == NULL);
if (err == ERR_OK) {
netif->state = state;
netif->hwaddr_len = 6;
if (init_state != NULL) {
memcpy(netif->hwaddr, init_state->addr, 6);
} else {
u8_t i;
for (i = 0; i < 6; i++) {
netif->hwaddr[i] = i;
}
netif->hwaddr[0] &= 0xfc;
}
netif->linkoutput = zepif_linkoutput;
return ERR_OK;
}
err_ret:
if (state->pcb != NULL) {
udp_remove(state->pcb);
}
mem_free(state);
return err;
}
#endif /* LWIP_IPV6 && LWIP_6LOWPAN */