/**
* 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)
{
if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, ipaddr)) {
return ERR_VAL;
}
ip_addr_set_ipaddr(&pcb->remote_ip, ipaddr);
return ERR_OK;
}
/**
* 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, const ip_addr_t *ipaddr)
{
err_t err;
struct netif *netif;
const ip_addr_t *src_ip;
struct pbuf *q; /* q will be sent down the stack */
s16_t header_size;
const ip_addr_t *dst_ip = ipaddr;
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"));
header_size = (
#if LWIP_IPV4 && LWIP_IPV6
IP_IS_V6(ipaddr) ? IP6_HLEN : IP_HLEN);
#elif LWIP_IPV4
IP_HLEN);
#else
IP6_HLEN);
#endif
/* not enough space to add an IP header to first pbuf in given p chain? */
if (pbuf_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_header(q, -header_size)) {
LWIP_ASSERT("Can't restore header we just removed!", 0);
return ERR_MEM;
}
}
netif = ip_route(&pcb->local_ip, dst_ip);
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, dst_ip);
/* free any temporary header pbuf allocated by pbuf_header() */
if (q != p) {
pbuf_free(q);
}
return ERR_RTE;
}
#if IP_SOF_BROADCAST
if (IP_IS_V4(ipaddr))
{
/* broadcast filter? */
if (!ip_get_option(pcb, SOF_BROADCAST) && 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 = ip_netif_get_local_ip(netif, dst_ip);
#if LWIP_IPV6
if (src_ip == NULL) {
if (q != p) {
pbuf_free(q);
}
return ERR_RTE;
}
#endif /* LWIP_IPV6 */
} else {
/* use RAW PCB local IP address as source address */
src_ip = &pcb->local_ip;
}
#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
NETIF_SET_HWADDRHINT(netif, &pcb->addr_hint);
err = ip_output_if(q, src_ip, dst_ip, pcb->ttl, pcb->tos, pcb->protocol, netif);
NETIF_SET_HWADDRHINT(netif, NULL);
/* did we chain a header earlier? */
if (q != p) {
/* free the header */
pbuf_free(q);
}
return err;
}
