/**
* Call netif_poll() in the main loop of your application. This is to prevent
* reentering non-reentrant functions like tcp_input(). Packets passed to
* netif_loop_output() are put on a list that is passed to netif->input() by
* netif_poll().
*/
void
netif_poll(struct netif *netif)
{
struct pbuf *in;
/* If we have a loopif, SNMP counters are adjusted for it,
* if not they are adjusted for 'netif'. */
#if LWIP_SNMP
#if LWIP_HAVE_LOOPIF
struct netif *stats_if = &loop_netif;
#else /* LWIP_HAVE_LOOPIF */
struct netif *stats_if = netif;
#endif /* LWIP_HAVE_LOOPIF */
#endif /* LWIP_SNMP */
SYS_ARCH_DECL_PROTECT(lev);
do {
/* Get a packet from the list. With SYS_LIGHTWEIGHT_PROT=1, this is protected */
SYS_ARCH_PROTECT(lev);
in = netif->loop_first;
if (in != NULL) {
struct pbuf *in_end = in;
#if LWIP_LOOPBACK_MAX_PBUFS
u8_t clen = pbuf_clen(in);
/* adjust the number of pbufs on queue */
LWIP_ASSERT("netif->loop_cnt_current underflow",
((netif->loop_cnt_current - clen) < netif->loop_cnt_current));
netif->loop_cnt_current -= clen;
#endif /* LWIP_LOOPBACK_MAX_PBUFS */
while (in_end->len != in_end->tot_len) {
LWIP_ASSERT("bogus pbuf: len != tot_len but next == NULL!", in_end->next != NULL);
in_end = in_end->next;
}
/* 'in_end' now points to the last pbuf from 'in' */
if (in_end == netif->loop_last) {
/* this was the last pbuf in the list */
netif->loop_first = netif->loop_last = NULL;
} else {
/* pop the pbuf off the list */
netif->loop_first = in_end->next;
LWIP_ASSERT("should not be null since first != last!", netif->loop_first != NULL);
}
/* De-queue the pbuf from its successors on the 'loop_' list. */
in_end->next = NULL;
}
SYS_ARCH_UNPROTECT(lev);
if (in != NULL) {
LINK_STATS_INC(link.recv);
snmp_add_ifinoctets(stats_if, in->tot_len);
snmp_inc_ifinucastpkts(stats_if);
/* loopback packets are always IP packets! */
if (ip_input(in, netif) != ERR_OK) {
pbuf_free(in);
}
/* Don't reference the packet any more! */
in = NULL;
}
/* go on while there is a packet on the list */
} while (netif->loop_first != NULL);
}
/*-----------------------------------------------------------------------------------*/
static struct pbuf *
low_level_input(struct netif *netif)
{
struct pbuf *p, *q;
u16_t len;
char buf[1514];
char *bufptr;
struct mintapif *mintapif;
mintapif = netif->state;
/* Obtain the size of the packet and put it into the "len"
variable. */
len = read(mintapif->fd, buf, sizeof(buf));
snmp_add_ifinoctets(netif,len);
/* if (((double)rand()/(double)RAND_MAX) < 0.1) {
printf("drop\n");
return NULL;
}*/
/* We allocate a pbuf chain of pbufs from the pool. */
p = pbuf_alloc(PBUF_LINK, len, PBUF_POOL);
if (p != NULL) {
/* We iterate over the pbuf chain until we have read the entire
packet into the pbuf. */
bufptr = &buf[0];
for(q = p; q != NULL; q = q->next) {
/* Read enough bytes to fill this pbuf in the chain. The
available data in the pbuf is given by the q->len
variable. */
/* read data into(q->payload, q->len); */
memcpy(q->payload, bufptr, q->len);
bufptr += q->len;
}
/* acknowledge that packet has been read(); */
} else {
/* drop packet(); */
snmp_inc_ifindiscards(netif);
printf("Could not allocate pbufs\n");
}
return p;
}
/** low_level_input(): Allocate a pbuf and transfer the bytes of the incoming
* packet from the interface into the pbuf.
*/
static struct pbuf *
pcapif_low_level_input(struct netif *netif, const void *packet, int packet_len)
{
struct pbuf *p, *q;
int start;
int length = packet_len;
struct eth_addr *dest = (struct eth_addr*)packet;
struct eth_addr *src = dest + 1;
int unicast;
const u8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
const u8_t mcast[] = {0x01, 0x00, 0x5e};
/* MAC filter: only let my MAC or non-unicast through (pcap receives loopback traffic, too) */
unicast = ((dest->addr[0] & 0x01) == 0);
if ((memcmp(dest, &netif->hwaddr, ETHARP_HWADDR_LEN) &&
memcmp(dest, mcast, 3) && memcmp(dest, bcast, 6)) ||
/* and don't let feedback packets through (limitation in winpcap?) */
(!memcmp(src, netif->hwaddr, ETHARP_HWADDR_LEN))) {
/* don't update counters here! */
return NULL;
}
/* We allocate a pbuf chain of pbufs from the pool. */
p = pbuf_alloc(PBUF_RAW, (u16_t)length + ETH_PAD_SIZE, PBUF_POOL);
LWIP_DEBUGF(NETIF_DEBUG, ("netif: recv length %i p->tot_len %i\n", length, (int)p->tot_len));
if (p != NULL) {
/* We iterate over the pbuf chain until we have read the entire
packet into the pbuf. */
start=0;
for (q = p; q != NULL; q = q->next) {
u16_t copy_len = q->len;
/* Read enough bytes to fill this pbuf in the chain. The
available data in the pbuf is given by the q->len
variable. */
/* read data into(q->payload, q->len); */
LWIP_DEBUGF(NETIF_DEBUG, ("netif: recv start %i length %i q->payload %p q->len %i q->next %p\n", start, length, q->payload, (int)q->len, (void*)q->next));
if (q == p) {
#if ETH_PAD_SIZE
LWIP_ASSERT("q->len >= ETH_PAD_SIZE", q->len >= ETH_PAD_SIZE);
copy_len -= ETH_PAD_SIZE;
#endif /* ETH_PAD_SIZE*/
memcpy(&((char*)q->payload)[ETH_PAD_SIZE], &((char*)packet)[start], copy_len);
} else {
memcpy(q->payload, &((char*)packet)[start], copy_len);
}
start += copy_len;
length -= copy_len;
if (length <= 0) {
break;
}
}
LINK_STATS_INC(link.recv);
snmp_add_ifinoctets(netif, p->tot_len);
if (unicast) {
snmp_inc_ifinucastpkts(netif);
} else {
snmp_inc_ifinnucastpkts(netif);
}
} else {
/* drop packet(); */
LINK_STATS_INC(link.memerr);
LINK_STATS_INC(link.drop);
}
return p;
}
/**
* Move a received packet from the cs8900 into a new pbuf.
*
* Must be called after reading an ISQ event containing the
* "Receiver Event" register, before reading new ISQ events.
*
* This function copies a frame from the CS8900A.
* It is designed failsafe:
* - It does not assume a frame is actually present.
* - It checks for non-zero length
* - It does not overflow the frame buffer
*/
static struct pbuf *cs8900_input(struct netif *netif)
{
volatile u16_t* rxtx_reg;
volatile u32_t rxtx_num = (MEM_BASE + IO_BASE);
u16_t* ptr = NULL;
struct pbuf *p = NULL, *q = NULL;
u16_t len = 0;
u16_t event_type;
u16_t i;
/* optimized register mapping for Tasking c166 7.5 (default optimalisation setting)
Using RXTXREG directly produces inefficient code with many const address loads. */
rxtx_reg = ((volatile u16_t *)(rxtx_num));
// read RxStatus
event_type = *rxtx_reg;
// correctly received frame, either broadcast or individual address?
// TODO: maybe defer these conditions to cs8900_input()
if ((event_type & 0x0100U/*RxOK*/) && (event_type & 0x0c00U/*Broadcast | Individual*/))
{
#if LWIP_SNMP > 0
// update number of received MAC-unicast and non-MAC-unicast packets
if (event_type & 0x0400U/*Individual*/)
{
snmp_inc_ifinucastpkts(netif);
}
else
{
snmp_inc_ifinnucastpkts(netif);
}
#endif
event_type = 0;
// read RxLength
len = *rxtx_reg;
LWIP_DEBUGF(NETIF_DEBUG, ("cs8900_input: packet len %"U16_F"\n", len));
snmp_add_ifinoctets(netif,len);
// positive length?
if (len > 0)
{
// allocate a pbuf chain with total length 'len + ETH_PAD_SIZE'
p = pbuf_alloc(PBUF_RAW, len + ETH_PAD_SIZE, PBUF_POOL);
if (p != NULL)
{
#if ETH_PAD_SIZE
/* drop the padding word */
pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
#endif
for (q = p; q != 0; q = q->next)
{
LWIP_DEBUGF(NETIF_DEBUG, ("cs8900_input: pbuf @%p tot_len %"U16_F" len %"U16_F"\n", q, q->tot_len, q->len));
/* read 8 bytes per iteration */
ptr = q->payload;
i = q->len / 8;
while(i > 0)
{
*ptr = *rxtx_reg;
ptr++;
*ptr = *rxtx_reg;
ptr++;
*ptr = *rxtx_reg;
ptr++;
*ptr = *rxtx_reg;
ptr++;
i--;
}
/* read remainder */
i = ((q->len % 8) + 1) / 2;
while(i > 0)
{
*ptr = *rxtx_reg;
ptr++;
i--;
}
}
#if ETH_PAD_SIZE
/* reclaim the padding word */
pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
#endif
}
// could not allocate a pbuf
else
{
// skip received frame
// TODO: maybe do not skip the frame at this point in time?
PACKETPP = CS_PP_RXCFG;
PPDATA = (0x0003U | 0x0100U/*RxOKiE*/ | 0x0040U/*Skip_1*/);
#if (CS8900_STATS > 0)
((struct cs8900if *)netif->state)->dropped++;
#endif
snmp_inc_ifindiscards(netif);
len = 0;
}
}
// length was zero
else
{
}
}
return p;
}