/*
The following code does:
* receive address (2 bytes), add them to CRC
* transmit anything from this address onwards until
0x8F is reached
* send the 2 crc bytes.
This is all very straightforward, except that the CRC calculation
for the first byte to transmit is delayed somewhat:
the time between recv_byte_in() and xmit_byte() is only a bit wide,
which may not be enough time to add a CRC byte.
*/
void do_read_pio(void)
{
u_short crc = 0;
u_short adr;
u_char bcrc = 1;
u_char b;
recv_byte();
crc = crc16(crc,0xF0);
b = recv_byte_in(); // address low byte
recv_byte();
crc = crc16(crc, b);
adr = b;
b = recv_byte_in(); // address high byte
adr |= b<<8;
/* note: bcrc is only true for the first byte to transmit */
#define XMIT(val) do { \
xmit_byte(val); \
if(bcrc) { crc = crc16(crc, b); bcrc = 0; } \
crc = crc16(crc,val); \
} while(0)
while(adr < 0x88) { XMIT(0); adr++; }
switch(adr) {
case 0x88: XMIT(pio_logic);
case 0x89: XMIT(pio_output_latch);
case 0x8A: XMIT(pio_activity_latch);
case 0x8B: XMIT(cond_search_mask);
case 0x8C: XMIT(cond_polarity_mask);
case 0x8D: XMIT(control_status);
case 0x8E: XMIT(0xFF);
case 0x8F: XMIT(0xFF);
crc = ~crc;
xmit_byte(crc);
xmit_byte(crc >> 8);
default:
while(1)
XMIT(0xFF);
}
}
int NSCLASS dsr_ack_req_send(struct in_addr neigh_addr, unsigned short id)
{
struct dsr_pkt *dp;
struct dsr_ack_req_opt *ack_req;
int len = DSR_OPT_HDR_LEN + DSR_ACK_REQ_HDR_LEN;
char *buf;
dp = dsr_pkt_alloc(NULL);
dp->dst = neigh_addr;
dp->nxt_hop = neigh_addr;
dp->src = my_addr();
buf = dsr_pkt_alloc_opts(dp, len);
if (!buf)
goto out_err;
dp->nh.iph = dsr_build_ip(dp, dp->src, dp->dst, IP_HDR_LEN,
IP_HDR_LEN + len, IPPROTO_DSR, 1);
if (!dp->nh.iph) {
LOG_DBG("Could not create IP header\n");
goto out_err;
}
dp->dh.opth = dsr_opt_hdr_add(buf, len, DSR_NO_NEXT_HDR_TYPE);
if (!dp->dh.opth) {
LOG_DBG("Could not create DSR opt header\n");
goto out_err;
}
buf += DSR_OPT_HDR_LEN;
len -= DSR_OPT_HDR_LEN;
ack_req = dsr_ack_req_opt_create(buf, len, id);
if (!ack_req) {
LOG_DBG("Could not create ACK REQ opt\n");
goto out_err;
}
LOG_DBG("Sending ACK REQ for %s id=%u\n", print_ip(neigh_addr), id);
XMIT(dp);
return 1;
out_err:
dsr_pkt_free(dp);
return -1;
}
void NSCLASS dsr_start_xmit(struct dsr_pkt *dp)
{
int res;
if (!dp) {
DEBUG("Could not allocate DSR packet\n");
return;
}
dp->srt = dsr_rtc_find(dp->src, dp->dst);
if (dp->srt) {
if (dsr_srt_add(dp) < 0) {
DEBUG("Could not add source route\n");
goto out;
}
/* Send packet */
XMIT(dp);
return;
} else {
res = send_buf_enqueue_packet(dp, &dsr_dev_xmit);
if (res < 0) {
DEBUG("Queueing failed!\n");
goto out;
}
res = dsr_rreq_route_discovery(dp->dst);
if (res < 0)
DEBUG("RREQ Transmission failed...");
return;
}
out:
dsr_pkt_free(dp);
}
int NSCLASS dsr_ack_send(struct in_addr dst, unsigned short id)
{
struct dsr_pkt *dp;
struct dsr_ack_opt *ack_opt;
int len;
char *buf;
/* srt = dsr_rtc_find(my_addr(), dst); */
/* if (!srt) { */
/* LOG_DBG("No source route to %s\n", print_ip(dst.s_addr)); */
/* return -1; */
/* } */
len = DSR_OPT_HDR_LEN + /* DSR_SRT_OPT_LEN(srt) + */ DSR_ACK_HDR_LEN;
dp = dsr_pkt_alloc(NULL);
dp->dst = dst;
/* dp->srt = srt; */
dp->nxt_hop = dst; //dsr_srt_next_hop(dp->srt, 0);
dp->src = my_addr();
buf = dsr_pkt_alloc_opts(dp, len);
if (!buf)
goto out_err;
dp->nh.iph = dsr_build_ip(dp, dp->src, dp->dst, IP_HDR_LEN,
IP_HDR_LEN + len, IPPROTO_DSR, IPDEFTTL);
if (!dp->nh.iph) {
LOG_DBG("Could not create IP header\n");
goto out_err;
}
dp->dh.opth = dsr_opt_hdr_add(buf, len, DSR_NO_NEXT_HDR_TYPE);
if (!dp->dh.opth) {
LOG_DBG("Could not create DSR opt header\n");
goto out_err;
}
buf += DSR_OPT_HDR_LEN;
len -= DSR_OPT_HDR_LEN;
/* dp->srt_opt = dsr_srt_opt_add(buf, len, dp->srt); */
/* if (!dp->srt_opt) { */
/* LOG_DBG("Could not create Source Route option header\n"); */
/* goto out_err; */
/* } */
/* buf += DSR_SRT_OPT_LEN(dp->srt); */
/* len -= DSR_SRT_OPT_LEN(dp->srt); */
ack_opt = dsr_ack_opt_add(buf, len, dp->src, dp->dst, id);
if (!ack_opt) {
LOG_DBG("Could not create DSR ACK opt header\n");
goto out_err;
}
LOG_DBG("Sending ACK to %s id=%u\n", print_ip(dst), id);
dp->flags |= PKT_XMIT_JITTER;
XMIT(dp);
return 1;
out_err:
dsr_pkt_free(dp);
return -1;
}
int NSCLASS dsr_recv(struct dsr_pkt *dp)
{
int i = 0, action;
int mask = DSR_PKT_NONE;
/* Process DSR Options */
action = dsr_opt_recv(dp);
/* Add mac address of previous hop to the neighbor table */
if (dp->flags & PKT_PROMISC_RECV) {
dsr_pkt_free(dp);
return 0;
}
for (i = 0; i < DSR_PKT_ACTION_LAST; i++) {
switch (action & mask) {
case DSR_PKT_NONE:
break;
case DSR_PKT_DROP:
case DSR_PKT_ERROR:
DEBUG("DSR_PKT_DROP or DSR_PKT_ERROR\n");
dsr_pkt_free(dp);
return 0;
case DSR_PKT_SEND_ACK:
/* Moved to dsr-ack.c */
break;
case DSR_PKT_SRT_REMOVE:
//DEBUG("Remove source route\n");
// Hmm, we remove the DSR options when we deliver a
//packet
//dsr_opt_remove(dp);
break;
case DSR_PKT_FORWARD:
if (dp->nh.iph->ttl < 1)
{
DEBUG("ttl=0, dropping!\n");
dsr_pkt_free(dp);
return 0;
} else {
DEBUG("Forwarding %s %s nh %s\n",
print_ip(dp->src),
print_ip(dp->dst), print_ip(dp->nxt_hop));
XMIT(dp);
return 0;
}
break;
case DSR_PKT_FORWARD_RREQ:
XMIT(dp);
return 0;
case DSR_PKT_SEND_RREP:
/* In dsr-rrep.c */
break;
case DSR_PKT_SEND_ICMP:
DEBUG("Send ICMP\n");
break;
case DSR_PKT_SEND_BUFFERED:
if (dp->rrep_opt) {
struct in_addr rrep_srt_dst;
int i;
for (i = 0; i < dp->num_rrep_opts; i++) {
rrep_srt_dst.s_addr = dp->rrep_opt[i]->addrs[DSR_RREP_ADDRS_LEN(dp->rrep_opt[i]) / sizeof(struct in_addr)];
send_buf_set_verdict(SEND_BUF_SEND, rrep_srt_dst);
}
}
break;
case DSR_PKT_DELIVER:
DEBUG("Deliver to DSR device\n");
DELIVER(dp);
return 0;
case 0:
break;
default:
DEBUG("Unknown pkt action\n");
}
mask = (mask << 1);
}
dsr_pkt_free(dp);
return 0;
}
