/**
* Give up an echo reply queue, and flush any loitering packets.
*/
static int echoQueueDealloc(int echoent)
{
irqmask im;
struct packet *pkt = NULL;
struct icmpEchoQueue *eq = NULL;
if ((echoent < 0) || (echoent >= NPINGQUEUE))
{
return SYSERR;
}
eq = &echotab[echoent];
im = disable();
eq->tid = BADTID;
while (eq->tail != eq->head)
{
pkt = eq->pkts[eq->tail];
ICMP_TRACE("Discarding ping packet from closed queue %d",
echoent);
netFreebuf(pkt);
eq->tail = (eq->tail + 1) % NPINGHOLD;
}
restore(im);
return OK;
}
/**
* Send an ICMP Echo (Ping) Request.
* @param dst destination address
* @param id ping stream identifier
* @param seq sequence number
* @return OK if packet was sent, otherwise SYSERR
*/
syscall icmpEchoRequest(struct netaddr *dst, ushort id, ushort seq)
{
struct packet *pkt = NULL;
struct icmpEcho *echo = NULL;
int result = OK;
irqmask im;
ICMP_TRACE("echo request(%d, %d)", id, seq);
pkt = netGetbuf();
if (SYSERR == (int)pkt)
{
ICMP_TRACE("Failed to acquire packet buffer");
return SYSERR;
}
pkt->len = sizeof(struct icmpEcho);
pkt->curr -= pkt->len;
echo = (struct icmpEcho *)pkt->curr;
echo->id = hs2net(id);
echo->seq = hs2net(seq);
/* Our optional data payload includes room for the departure */
/* and arrival timestamps, in seconds, milliseconds, and */
/* clock cycles. */
im = disable();
echo->timecyc = hl2net(clkcount());
echo->timetic = hl2net(clkticks);
echo->timesec = hl2net(clktime);
restore(im);
echo->arrivcyc = 0;
echo->arrivtic = 0;
echo->arrivsec = 0;
ICMP_TRACE("Sending Echo Request id = %d, seq = %d, time = %d.%d",
net2hs(echo->id), net2hs(echo->seq),
net2hl(echo->timesec), net2hl(echo->timetic));
result = icmpSend(pkt, ICMP_ECHO, 0, sizeof(struct icmpEcho), dst);
netFreebuf(pkt);
return result;
}
/**
* @ingroup icmp
*
* Compose ICMP Time Exceeded message.
* @param unreached packet that could not be sent
* @param code ICMP destination unreachable code number
* @return OK if packet was sent, otherwise SYSERR
*/
syscall icmpTimeExceeded(struct packet *unreached, int code)
{
struct packet *pkt = NULL;
struct ipv4Pkt *ip = NULL;
struct netaddr dst;
int result = OK;
int ihl = 0;
ICMP_TRACE("Time exceeded (%d)", code);
pkt = netGetbuf();
if (SYSERR == (int)pkt)
{
ICMP_TRACE("Failed to acquire packet buffer");
return SYSERR;
}
ip = (struct ipv4Pkt *)unreached->nethdr;
dst.type = NETADDR_IPv4;
dst.len = IPv4_ADDR_LEN;
/* Send error message back to original source. */
memcpy(dst.addr, ip->src, dst.len);
ihl = (ip->ver_ihl & IPv4_IHL) * 4;
/* Message will contain at least ICMP_DEF_DATALEN */
/* of packet in question, as per RFC 792. */
pkt->len = ihl + ICMP_DEF_DATALEN;
pkt->curr -= pkt->len;
memcpy(pkt->curr, ip, ihl + ICMP_DEF_DATALEN);
/* First four octets of payload are unused. */
pkt->curr -= 4;
pkt->len += 4;
*((ulong *)pkt->curr) = 0;
result = icmpSend(pkt, ICMP_TIMEEXCD, code, pkt->len, &dst);
netFreebuf(pkt);
return result;
}
/**
* @ingroup icmp
*
* Processes an incoming ICMP packet.
* @param pkt pointer to the incoming packet
* return OK if packet was processed succesfully, otherwise SYSERR
*/
syscall icmpRecv(struct packet *pkt)
{
struct icmpPkt *icmp;
struct icmpEcho *echo;
int id;
/* Error check pointers */
if (NULL == pkt)
{
return SYSERR;
}
icmp = (struct icmpPkt *)pkt->curr;
switch (icmp->type)
{
case ICMP_ECHOREPLY:
ICMP_TRACE("Received Echo Reply");
echo = (struct icmpEcho *)icmp->data;
id = net2hs(echo->id);
if ((id >= 0) && (id < NTHREAD))
{
int i;
irqmask im;
im = disable();
echo->arrivcyc = clkcount();
echo->arrivtic = clkticks;
echo->arrivsec = clktime;
for (i = 0; i < NPINGQUEUE; i++)
{
struct icmpEchoQueue *eq;
eq = &echotab[i];
if (id == eq->tid)
{
ICMP_TRACE("Ping matches queue %d", i);
if (((eq->head + 1) % NPINGHOLD) == eq->tail)
{
ICMP_TRACE("Queue full, discarding");
restore(im);
netFreebuf(pkt);
return SYSERR;
}
eq->pkts[eq->head] = pkt;
eq->head = ((eq->head + 1) % NPINGHOLD);
send(id, (message)pkt);
restore(im);
return OK;
}
}
restore(im);
}
ICMP_TRACE("Reply id %d does not correspond to ping queue", id);
netFreebuf(pkt);
return SYSERR;
case ICMP_ECHO:
ICMP_TRACE("Enqueued Echo Request for daemon to reply");
mailboxSend(icmpqueue, (int)pkt);
return OK;
case ICMP_UNREACH:
case ICMP_SRCQNCH:
case ICMP_REDIRECT:
case ICMP_TIMEEXCD:
case ICMP_PARAMPROB:
case ICMP_TMSTMP:
case ICMP_TMSTMPREPLY:
case ICMP_INFORQST:
case ICMP_INFOREPLY:
case ICMP_TRACEROUTE:
ICMP_TRACE("ICMP message type %d not handled", icmp->type);
break;
default:
ICMP_TRACE("ICMP message type %d unknown", icmp->type);
break;
}
netFreebuf(pkt);
return OK;
}
