/*!
* \brief Allocate an ARP network buffer structure.
*
* \param type Type of ARP packet.
* \param ip Target IP address.
* \param mac Target MAC address, null pointer for broadcast.
*
* \return Pointer to the allocated network buffer structure
* or 0 on failure.
*/
NETBUF *NutArpAllocNetBuf(uint16_t type, uint32_t ip, uint8_t * mac)
{
NETBUF *nb;
ETHERARP *ea;
ARPHDR *ah;
if ((nb = NutNetBufAlloc(0, NBAF_NETWORK, sizeof(ETHERARP))) == 0)
return 0;
ea = nb->nb_nw.vp;
ah = (ARPHDR *) & ea->ea_hdr;
/*
* Set ARP header.
*/
ah->ar_hrd = htons(ARPHRD_ETHER);
ah->ar_pro = htons(ETHERTYPE_IP);
ah->ar_hln = 6;
ah->ar_pln = 4;
ah->ar_op = htons(type);
/*
* Set ARP destination data.
*/
if (mac)
memcpy(ea->arp_tha, mac, 6);
else
memset(ea->arp_tha, 0xff, 6);
ea->arp_tpa = ip;
return nb;
}
/*
* Send a Configure-Request.
*/
void PapTxAuthReq(NUTDEVICE *dev, uint8_t id)
{
PPPDCB *dcb = dev->dev_dcb;
NETBUF *nb;
char *cp;
int len;
/*
* Create the request.
*/
len = 2;
if(dcb->dcb_user)
len += strlen((char*)dcb->dcb_user);
if(dcb->dcb_pass)
len += strlen((char*)dcb->dcb_pass);
if ((nb = NutNetBufAlloc(0, NBAF_APPLICATION, len)) != 0) {
cp = nb->nb_ap.vp;
*cp = dcb->dcb_user ? (char)strlen((char*)dcb->dcb_user) : 0;
if(*cp)
memcpy(cp + 1, dcb->dcb_user, *cp);
cp += *cp + 1;
*cp = dcb->dcb_pass ? (char)strlen((char*)dcb->dcb_pass) : 0;
if(*cp)
memcpy(cp + 1, dcb->dcb_pass, *cp);
dcb->dcb_auth_state = PAPCS_AUTHREQ;
NutPapOutput(dev, XCP_CONFREQ, ++dcb->dcb_reqid, nb);
}
}
/*
* This function will send an ICMP echo request to the specified destionation.
*/
static int IcmpSendPing(uint32_t dest, uint16_t id, uint16_t seq, int len)
{
NETBUF *nb;
int i;
uint8_t *dp;
uint32_t spec;
/* Create a new NETBUF. */
nb = NutNetBufAlloc(NULL, NBAF_APPLICATION, len);
if (nb) {
/* Fill the data area with sample characters. */
dp = (uint8_t *) nb->nb_ap.vp;
for (i = 0; i < len; i++) {
*dp++ = 'a' + (i & 15);
}
/* Set up the echo request ID and sequence number. */
spec = id;
spec <<= 16;
spec |= seq;
/* Send out the packet. The name of this function is misleading. */
if (NutIcmpReply(ICMP_ECHO, 0, htonl(spec), dest, nb) == 0) {
/* Funny Nut/Net expects us to release the packet only if
it has been successfully processed. */
NutNetBufFree(nb);
return 0;
}
}
/* Return an error. */
return -1;
}
/*!
* \brief Send a UDP packet.
*
* \param sock Socket descriptor. This pointer must have been
* retrieved by calling NutUdpCreateSocket().
* \param daddr IP address of the remote host in network byte order.
* \param port Remote port number in host byte order.
* \param nb Network buffer structure containing the datagram.
* This buffer will be released if the function returns
* an error.
*
* \note Applications typically do not call this function but
* use the UDP socket interface.
*
* \return 0 on success, -1 otherwise.
*/
int NutUdpOutput(UDPSOCKET * sock, uint32_t daddr, uint16_t port, NETBUF * nb)
{
uint32_t saddr;
uint32_t csum;
UDPHDR *uh;
NUTDEVICE *dev;
IFNET *nif;
if ((nb = NutNetBufAlloc(nb, NBAF_TRANSPORT, sizeof(UDPHDR))) == 0)
return -1;
uh = nb->nb_tp.vp;
uh->uh_sport = sock->so_local_port;
uh->uh_dport = htons(port);
uh->uh_ulen = htons((uint16_t)(nb->nb_tp.sz + nb->nb_ap.sz));
/*
* Get local address for this destination.
*/
if ((dev = NutIpRouteQuery(daddr, &saddr)) != 0) {
nif = dev->dev_icb;
saddr = nif->if_local_ip;
} else
saddr = 0;
uh->uh_sum = 0;
csum = NutIpPseudoChkSumPartial(saddr, daddr, IPPROTO_UDP, uh->uh_ulen);
csum = NutIpChkSumPartial(csum, uh, sizeof(UDPHDR));
uh->uh_sum = NutIpChkSum(csum, nb->nb_ap.vp, nb->nb_ap.sz);
return NutIpOutput(IPPROTO_UDP, daddr, nb);
}
/*!
* \brief Release a network buffer structure.
*
* Returns all memory previously allocated by a
* network buffer to the available heap space.
*
* \param nb Points to an existing network buffer
* structure, previously allocated by
* NutNetBufAlloc().
*
* \return 0 if successfull or -1 if the structure
* contains previously released memory space.
*/
int NutNetBufFree(NETBUF * nb)
{
if(nb) {
NutNetBufAlloc(nb, nb->nb_flags, 0);
if (NutHeapFree(nb)) {
return -1;
}
}
return 0;
}
/*!
* \brief Send an ICMP message to a given destination.
*
* \param type Type of the ICMP message. See NutIcmpOutput() for
* a list of valid types.
* \param code Type subcode.
* \param spec Type specific data item.
* \param dest IP address of the target.
* \param nb Network buffer structure containing the message to be sent.
* The structure must have been allocated by a previous
* call NutNetBufAlloc() and will be freed if this function
* returns with an error.
*
* \return 0 on success, -1 otherwise.
*/
int NutIcmpReply(uint8_t type, uint8_t code, uint32_t spec, uint32_t dest, NETBUF * nb)
{
ICMPHDR *icp;
if ((nb = NutNetBufAlloc(nb, NBAF_TRANSPORT, sizeof(ICMPHDR))) == 0)
return -1;
icp = (ICMPHDR *) nb->nb_tp.vp;
icp->icmp_code = code;
icp->icmp_spec = spec;
return NutIcmpOutput(type, dest, nb);
}
/*
* Send a Protocol-Reject for some protocol.
*/
void LcpTxProtRej(NUTDEVICE * dev, uint16_t protocol, NETBUF * nb)
{
PPPDCB *dcb = dev->dev_dcb;
NETBUF *nbr;
uint16_t *sp;
if ((nbr = NutNetBufAlloc(0, NBAF_APPLICATION, nb->nb_nw.sz)) != 0) {
sp = nbr->nb_ap.vp;
*sp++ = htons(protocol);
memcpy(sp, nb->nb_nw.vp, nb->nb_nw.sz - 2);
NutNetBufFree(nb);
NutLcpOutput(dev, LCP_PROTREJ, ++dcb->dcb_rejid, nbr);
} else {
NutNetBufFree(nb);
}
}
/*!
* \brief Send an ICMP message as a response to a given destination.
*
* \param type Type of the ICMP message. See NutIcmpOutput() for
* a list of valid types.
* \param code Type subcode.
* \param spec Type specific data item.
* \param nb Network buffer structure containing the previously recevied
* network packet. According to RFC792 the complete ip header
* and the first 8 bytes of the transport netbuf is used as the
* application data for the response. If this function returns
* with an error, the buffer is freed. The destination addess is
* taken from the ip header.
*
* \return 0 on success, -1 otherwise.
*/
int NutIcmpResponse(uint8_t type, uint8_t code, uint32_t spec, NETBUF * nb)
{
IPHDR *ip;
uint32_t dest;
ip = nb->nb_nw.vp;
dest = ip->ip_src;
if ((nb = NutNetBufAlloc(nb, NBAF_APPLICATION, sizeof(IPHDR) + 8)) == 0)
return -1;
memcpy(nb->nb_ap.vp, nb->nb_nw.vp, sizeof(IPHDR));
memcpy((char *)nb->nb_ap.vp + sizeof(IPHDR), nb->nb_tp.vp, 8);
return NutIcmpReply(type, code, spec, dest, nb);
}
/*!
* \brief Send a PAP packet.
*
* \note Applications typically do not call this function.
*
* \param dev Identifies the device to use.
* \param code Type subcode.
* \param id Exchange identifier.
* \param nb Network buffer structure containing the packet to send
* or null if the packet contains no information.
* The structure must have been allocated by a previous
* call NutNetBufAlloc() and will be freed when this function
* returns.
*
* \return 0 on success, -1 in case of any errors.
*/
int NutPapOutput(NUTDEVICE * dev, uint8_t code, uint8_t id, NETBUF * nb)
{
XCPHDR *xch;
if ((nb = NutNetBufAlloc(nb, NBAF_NETWORK, sizeof(XCPHDR))) == 0)
return -1;
xch = nb->nb_nw.vp;
xch->xch_code = code;
xch->xch_id = id;
xch->xch_len = htons(nb->nb_nw.sz + nb->nb_tp.sz + nb->nb_ap.sz);
if (NutPppOutput(dev, PPP_PAP, 0, nb) == 0)
NutNetBufFree(nb);
return 0;
}
/*
* Send a Configure-Request.
*/
void LcpTxConfReq(NUTDEVICE * dev, uint8_t id, uint8_t rejected)
{
PPPDCB *dcb = dev->dev_dcb;
XCPOPT *xcpo;
NETBUF *nb;
/*
* Not currently negotiating, reset options.
*/
if (dcb->dcb_lcp_state != PPPS_REQSENT && dcb->dcb_lcp_state != PPPS_ACKRCVD && dcb->dcb_lcp_state != PPPS_ACKSENT) {
LcpResetOptions(dev);
dcb->dcb_lcp_naks = 0;
}
dcb->dcb_acked = 0;
dcb->dcb_retries = 0;
/*
* Create the request.
*/
if ((nb = NutNetBufAlloc(0, NBAF_APPLICATION, rejected ? 6 : 12)) != 0) {
xcpo = nb->nb_ap.vp;
xcpo->xcpo_type = LCP_ASYNCMAP;
xcpo->xcpo_len = 6;
xcpo->xcpo_.ul = htonl(LCP_DEFOPT_ASYNCMAP); /* Should this be "= 0;" instead? */
/*
* This is a temporary hack. In the initial version
* we sent the ASYNCMAP only and never expected any
* rejects. The MAGICNUMBER had been added later
* to support echo requests, but some servers reject
* this option. Now we still do not provide full
* reject processing but blindly assume, that the
* MAGICNUMBER is the rejected option.
*/
if (!rejected) {
xcpo = (XCPOPT *) ((char *) xcpo + xcpo->xcpo_len);
xcpo->xcpo_type = LCP_MAGICNUMBER;
xcpo->xcpo_len = 6;
xcpo->xcpo_.ul = dcb->dcb_neg_magic;
}
NutLcpOutput(dev, XCP_CONFREQ, id, nb);
}
}
/*!
* \brief Initiate TCP segment transmission.
*
* Check the TCP socket status and send any segment waiting
* for transmission.
*
* The function will not return until the data has been stored in the
* network device hardware for transmission. If the device is not ready
* for transmitting a new packet, the calling thread will be suspended
* until the device becomes ready again.
*
* If the target host is connected through an Ethernet network and if
* the hardware address of that host is currently unknown, an ARP
* request is sent out and the function will block until a response
* is received or an ARP timeout occurs.
*
* Segments containing data or SYN and FIN flags are added to a special
* queue for unacknowledged segments and will be retransmitted by the
* TCP timer thread, if not acknowledged by the remote within a specific
* time. The state machine will remove these segments from the queue
* as soon as they are acknowledged.
*
* \note This function is mainly used by the TCP state machine.
* Applications typically do not call this function but
* use NutTcpSend(), which is part of the TCP socket interface.
*
* \param sock Socket descriptor. This pointer must have been retrieved
* by calling NutTcpCreateSocket().
* \param data Pointer to TCP segment contents.
* \param size TCP segment length.
*
* \return 0 on success, -1 otherwise. Returning 0 does not imply that
* the data has been successfully delivered, because flow control
* and retransmission is still handled in the background.
*/
int NutTcpOutput(TCPSOCKET * sock, CONST u_char * data, u_short size)
{
NETBUF *nb;
NETBUF *nb_clone = 0;
TCPHDR *th;
u_short csum;
u_char hlen;
/*
* Check if anything to send at all.
*/
if (size == 0
&& (sock->so_tx_flags & (SO_SYN | SO_FIN | SO_FORCE)) == 0)
return 0;
/*
* Build TCP header. Add room for MAXSEG option if this is a
* SYN segment.
*/
hlen = sizeof(TCPHDR);
if (sock->so_tx_flags & SO_SYN)
hlen += 4;
if ((nb = NutNetBufAlloc(0, NBAF_TRANSPORT, hlen)) == 0) {
sock->so_last_error = ENOBUFS;
return -1;
}
th = (TCPHDR *) nb->nb_tp.vp;
th->th_sport = sock->so_local_port;
th->th_dport = sock->so_remote_port;
th->th_x2 = 0;
th->th_off = hlen >> 2;
sock->so_tx_flags &= ~SO_FORCE;
/*
* Process ACK flag.
*/
th->th_seq = htonl(sock->so_tx_nxt);
if (sock->so_tx_flags & SO_ACK) {
th->th_flags = TH_ACK;
sock->so_tx_flags &= ~SO_ACK;
th->th_ack = htonl(sock->so_rx_nxt);
} else {
th->th_flags = 0;
th->th_ack = 0;
}
/*
* Any SYN is sent first. Add options too. We rely on the caller
* not to send a SYN segment with data, because this may break
* some old stacks.
*/
if (sock->so_tx_flags & SO_SYN) {
u_char *cp;
u_short n_mss = htons(sock->so_mss);
th->th_flags |= TH_SYN;
sock->so_tx_flags &= ~SO_SYN;
sock->so_tx_nxt++;
cp = (u_char *) (th + 1);
*cp++ = TCPOPT_MAXSEG;
*cp++ = TCPOLEN_MAXSEG;
*cp++ = *(u_char *)&n_mss;
*cp = *((u_char *)(&n_mss) + 1);
}
/*
* Next preference is sending data. Set PUSH flag.
*/
else if (size) {
if ((nb = NutNetBufAlloc(nb, NBAF_APPLICATION, size)) == 0) {
sock->so_last_error = ENOBUFS;
return -1;
}
memcpy(nb->nb_ap.vp, (void *)data, size);
sock->so_tx_nxt += size;
th->th_flags |= TH_PUSH;
}
/*
* If all data sent, transmit any waiting FIN.
*/
else if (sock->so_tx_flags & SO_FIN) {
th->th_flags |= TH_FIN;
sock->so_tx_flags &= ~SO_FIN;
sock->so_tx_nxt++;
//@@@printf ("[%04X]TcpOutput: sending FIN\n", (u_short) sock);
}
/*
* We close our receiver window, if it is
* below the maximum segment size.
*/
if (sock->so_rx_win < sock->so_mss)
th->th_win = 0;
else
th->th_win = htons(sock->so_rx_win);
th->th_sum = 0;
th->th_urp = 0;
/*
* Calculate TCP checksum.
*/
csum =
NutIpPseudoChkSumPartial(sock->so_local_addr, sock->so_remote_addr,
IPPROTO_TCP,
htons(nb->nb_tp.sz + nb->nb_ap.sz));
csum = NutIpChkSumPartial(csum, th, nb->nb_tp.sz);
th->th_sum = NutIpChkSum(csum, nb->nb_ap.vp, nb->nb_ap.sz);
#ifdef NUTDEBUG
if (__tcp_trf)
NutDumpTcpHeader(__tcp_trs, "OUT", sock, nb);
#endif
/*
* To avoid a race condition in tcp state machine, the segment is first
* appended to the transmission que, and then sent to the network.
*/
/*
* Append the segment to our transmission queue.
*/
//@@@printf ("[%04X]TcpOutput: size: %u, flags: %u\n", (u_short) sock, size, th->th_flags);
if (size || ((th->th_flags & (TH_FIN | TH_SYN)))) {
//@@@printf ("[%04X]TcpOutput: appending nb to queue\n", (u_short) sock);
NETBUF *nbp;
nb->nb_next = 0;
if ((nbp = sock->so_tx_nbq) == 0) {
sock->so_tx_nbq = nb;
/*
* First entry, so initialize our retransmission timer.
* It is also set at various places in the state machine,
* but here is the best central point to do it. We may
* carefully check later, if we can remove some in the
* state machine.
*/
sock->so_retran_time = (u_short) NutGetMillis() | 1;
}
else {
while (nbp->nb_next)
nbp = nbp->nb_next;
nbp->nb_next = nb;
}
if (sock->so_rtt_seq == 0)
sock->so_rtt_seq = ntohl (th->th_seq);
nb_clone = NutNetBufClone (nb);
}
else
nb_clone = nb;
/*
* IP output might fail because of routing, ARP or network device
* problems or because the system ran out of memory.
*/
if (NutIpOutput(IPPROTO_TCP, sock->so_remote_addr, nb_clone))
return -1;
NutNetBufFree (nb_clone);
return 0;
}
/*! \fn AhdlcRx(void *arg)
* \brief Asynchronous HDLC receiver thread.
*
*
* Running at high priority.
*/
THREAD(AhdlcRx, arg)
{
NUTDEVICE *dev = arg;
NUTDEVICE *netdev;
AHDLCDCB *dcb = dev->dev_dcb;
IFNET *ifn;
NETBUF *nb;
uint8_t *rxbuf;
uint8_t *rxptr;
uint16_t rxcnt;
uint8_t ch;
uint16_t tbx;
uint8_t inframe;
uint8_t escaped;
uint16_t rxfcs;
NutThreadSetPriority(9);
for (;;) {
/*
* Reset variables to their initial state
*/
rxptr = 0;
rxcnt = 0;
escaped = 0;
rxfcs = AHDLC_INITFCS;
inframe = 0;
for (;;) {
/*
* Wait until the network interface has been attached.
* This will be initiated by the application calling
* NutNetIfConfig(), which in turn calls a HDLC_SETIFNET
* ioctl() to store the NUTDEVICE pointer of the network
* device in dev_icb and trigger an event on dcb_mf_evt.
*/
while ((netdev = dev->dev_icb) == 0) {
if (NutEventWait(&dcb->dcb_mf_evt, 1000) == 0) {
NutSleep(100);
}
}
ifn = netdev->dev_icb;
dcb->dcb_rtimeout = 1000;
inframe = 0;
/*
* Allocate the receive buffer, if this fails, we are in a
* low memory situation. Take a nap and see, if the
* situation improved.
*/
if ((rxbuf = NutHeapAlloc(dcb->dcb_rx_mru)) != 0) {
break;
}
NutSleep(1000);
}
/*
* Signal the link driver that we are up.
*/
ifn->if_send = AhdlcOutput;
netdev->dev_ioctl(netdev, LCP_LOWERUP, 0);
for (;;) {
/*
* If we are still connected to a network, fetch the next
* character from the buffer.
*/
while (dcb->dcb_rd_idx == dcb->dcb_rx_idx) {
if (dev->dev_icb == 0)
break;
// TODO: Check for idle timeout.
if (NutEventWait(&dcb->dcb_rx_rdy, dcb->dcb_rtimeout)) {
continue;
}
}
/*
* Leave loop if network interface is detached
*/
if (dev->dev_icb == 0)
break;
/*
* If RAW mode is active, we are not allowing any data encapsulation
* processing. So we just sleep for a while.
*/
if (dcb->dcb_modeflags & UART_MF_RAWMODE) {
/*
* It is a must to sleep here, because if we just yield it could create
* too much processing in here and stall processing elsewhere. This gives
* opportunity to other threads to process incoming data from USART.
*/
NutSleep(100);
continue;
}
/*
* Read next character from input buffer
*/
ch = dcb->dcb_rx_buf[dcb->dcb_rd_idx++];
if (inframe) {
if (ch != AHDLC_FLAG) {
if (ch == AHDLC_ESCAPE) {
escaped = 1;
continue;
}
if (escaped) {
ch ^= AHDLC_TRANS;
escaped = 0;
}
/*
* Unless the peer lied to us about the negotiated MRU,
* we should never get a frame which is too long. If it
* happens, toss it away and grab the next incoming one.
*/
if (rxcnt++ < dcb->dcb_rx_mru) {
/* Update calculated checksum and store character in buffer. */
tbx = (uint16_t) ((uint8_t) rxfcs ^ ch) << 1;
rxfcs >>= 8;
rxfcs ^= ((uint16_t) PRG_RDB(fcstab + tbx) << 8) | PRG_RDB(fcstab + tbx + 1);
*rxptr++ = ch;
} else
inframe = 0;
continue;
}
if (rxcnt > 6 && rxfcs == AHDLC_GOODFCS) {
/*
* If the frame checksum is valid, create a NETBUF
* and pass it to the network specific receive handler.
*/
rxcnt -= 2;
if ((nb = NutNetBufAlloc(0, NBAF_DATALINK, rxcnt)) != 0) {
memcpy(nb->nb_dl.vp, rxbuf, rxcnt);
(*ifn->if_recv) (netdev, nb);
}
}
}
/*
* If frame flag is received, resync frame processing
*/
if (ch == AHDLC_FLAG) {
inframe = 1;
escaped = 0;
rxptr = rxbuf;
rxcnt = 0;
rxfcs = AHDLC_INITFCS;
}
}
