static int icmp_proc(struct netbuf *buf)
{
int ret = 0;
switch (buf->cmd) {
case ICMP_CMD_RECV:
ret = icmp_recv(buf);
break;
case ICMP_CMD_SEND:
ret = icmp_send(buf);
break;
default:
break;
}
return ret;
}
/*------------------------------------------------------------------------
* xsh_ping - shell command to ping a remote host
*------------------------------------------------------------------------
*/
shellcmd xsh_ping(int nargs, char *args[])
{
uint32 ipaddr; /* IP address in binary */
int32 retval; /* return value */
int32 icmpid; /* ICMP ID to use */
static int32 seq = 0; /* sequence number */
char buf[56]; /* buffer of chars */
int32 i; /* index into buffer */
int32 nextval; /* next value to use */
/* For argument '--help', emit help about the 'ping' command */
if (nargs == 2 && strncmp(args[1], "--help", 7) == 0) {
printf("Use: %s address\n\n", args[0]);
printf("Description:\n");
printf("\tUse ICMP Echo to ping a remote host\n");
printf("Options:\n");
printf("\t--help\t display this help and exit\n");
printf("\taddress\t an IP address in dotted decimal\n");
return 0;
}
/* Check for valid number of arguments */
if (nargs != 2) {
fprintf(stderr, "%s: invalid arguments\n", args[0]);
fprintf(stderr, "Try '%s --help' for more information\n",
args[0]);
return 1;
}
/* convert argument to binary */
retval = dot2ip(args[1], &ipaddr);
if ((int32)retval == SYSERR) {
fprintf(stderr, "%s: invalid IP address\n", args[0]);
return 1;
}
/* Register to receive an ICMP Echo Reply */
icmpid = icmp_register(ipaddr);
if (icmpid == SYSERR) {
fprintf(stderr, "%s: ICMP registration fails\n", args[0]);
return 1;
}
/* Fill the buffer with values - start with low-order byte of */
/* the sequence number and increment */
nextval = seq;
for (i = 0; i<sizeof(buf); i++) {
buf[i] = 0xff & nextval++;
}
/* Send an ICMP Echo Request */
retval = icmp_send(ipaddr, ICMP_ECHOREQST, icmpid, seq++, buf,
sizeof(buf));
if (retval == SYSERR) {
fprintf(stderr, "%s: cannot send a ping\n", args[0]);
icmp_release(icmpid);
return 1;
}
/* Read a reply */
retval = icmp_recv(icmpid, buf, sizeof(buf), 3000);
icmp_release(icmpid);
if (retval == TIMEOUT) {
fprintf(stderr, "%s: no response from %s\n\n", args[0],
args[1]);
return 1;
}
fprintf(stderr, "host %s is alive\n", args[1]);
return 0;
}
static void *recv_loop(void *data)
{
session_t *session = net_init(ifname, src_ip_addr, 0, 0, 0, ICMP, -1);
icmp_packet_t packet;
ndp_neighbor_discover_t n_discvr;
while(is_initialized)
{
size_t recv = icmp_recv(session, &packet);
if(!recv)
continue;
switch(packet.type)
{
case ICMP_TYPE_NEIGHBOR_SOLICITATION:
memcpy(n_discvr.buffer, packet.body, recv);
if(memcmp(n_discvr.target_addr, session->src_ip,
IP_ADDR_LEN) != 0)
continue;
ndp_option_t opt;
memcpy(opt.buffer, n_discvr.options, recv + NDP_ND_HEADER_LEN);
if(opt.type != NDP_SOURCE_LINK_ADDR_OPT || opt.len != 1)
{
fprintf(stderr, "Error: Invalid NDP option type: %d. "
"Expected: %d (NDP_SOURCE_LINK_ADDR_OPT)"
"\n.", opt.type, NDP_SOURCE_LINK_ADDR_OPT);
continue;
}
ndp_table_insert(session->last_sender_ip, opt.body);
ndp_neighbor_discover_t ndp_resp;
ndp_option_t opt_resp;
memcpy(ndp_resp.target_addr, n_discvr.target_addr, IP_ADDR_LEN);
// sol & override flag
ndp_resp.reserved = netb_l( 1 << 30 | 1 << 29 );
opt_resp.type = NDP_TARGET_LINK_ADDR_OPT;
opt_resp.len = 1;
memcpy(opt_resp.body, session->src_addr, ETH_ADDR_LEN);
size_t opts_len = NDP_OPT_HEADER_LEN + ETH_ADDR_LEN;
memcpy(ndp_resp.options, opt_resp.buffer, opts_len);
size_t resp = icmp_send(session, session->last_sender_ip,
ICMP_TYPE_NEIGHBOR_ADVERTISEMENT, 0,
ndp_resp.buffer,
NDP_ND_HEADER_LEN + opts_len);
if(resp <= 0)
{
fprintf(stderr, "Error: Cannot respond with "
"ICMP_TYPE_NEIGHBOR_ADVERTISEMENT!\n.");
continue;
}
break;
case ICMP_TYPE_NEIGHBOR_ADVERTISEMENT:
memcpy(n_discvr.buffer, packet.body, recv);
uint8_t zeros[IP_ADDR_LEN] = { 0x0 };
if(memcmp(zeros, n_discvr.target_addr, IP_ADDR_LEN) == 0)
continue; // not sure why it's even possible...
if(recv <= offsetof(ndp_neighbor_discover_t, options))
continue; // If there's no option, ignore
memcpy(opt.buffer, n_discvr.options, recv + NDP_ND_HEADER_LEN);
if(opt.type != NDP_TARGET_LINK_ADDR_OPT || opt.len != 1)
{
fprintf(stderr, "Error: Invalid NDP option type: %d. "
"Expected: %d (NDP_TARGET_LINK_ADDR_OPT)"
"\n.", opt.type, NDP_TARGET_LINK_ADDR_OPT);
continue;
}
ndp_table_insert(n_discvr.target_addr, opt.body);
break;
default:
break; // unsupported ICMP type
}
}
net_free(session);
return 0;
}
