File content as of revision 9:e55652bed36c:

/*
 UIPUdp.cpp - Arduino implementation of a UIP wrapper class.
 Copyright (c) 2013 Norbert Truchsess <norbert.truchsess@t-online.de>
 All rights reserved.

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include "UIPEthernet.h"
#include "UIPUdp.h"
#include "Dns.h"

extern "C"
{
#include "utility/uip-conf.h"
#include "utility/uip.h"
#include "utility/uip_arp.h"
}
#if UIP_UDP
#define UIP_ARPHDRSIZE  42
#define UDPBUF          ((struct uip_udpip_hdr*) &uip_buf[UIP_LLH_LEN])

// Constructor
UIPUDP::UIPUDP(void) :
    _uip_udp_conn(NULL) {
    memset(&appdata, 0, sizeof(appdata));
}

// initialize, start listening on specified port. Returns 1 if successful, 0 if there are no sockets available to use
uint8_t UIPUDP::begin(uint16_t port) {
    if (!_uip_udp_conn) {
        _uip_udp_conn = uip_udp_new(NULL, 0);
    }

    if (_uip_udp_conn) {
        uip_udp_bind(_uip_udp_conn, htons(port));
        _uip_udp_conn->appstate = &appdata;
        return 1;
    }

    return 0;
}

// Finish with the UDP socket
void UIPUDP::stop(void) {
    if (_uip_udp_conn) {
        uip_udp_remove(_uip_udp_conn);
        _uip_udp_conn->appstate = NULL;
        _uip_udp_conn = NULL;
        uIPEthernet.network.freeBlock(appdata.packet_in);
        uIPEthernet.network.freeBlock(appdata.packet_next);
        uIPEthernet.network.freeBlock(appdata.packet_out);
        memset(&appdata, 0, sizeof(appdata));
    }
}

// Sending UDP packets
// Start building up a packet to send to the remote host specific in ip and port

// Returns 1 if successful, 0 if there was a problem with the supplied IP address or port
int UIPUDP::beginPacket(IPAddress ip, uint16_t port) {
    uIPEthernet.tick();
    if (ip && port) {
        uip_ipaddr_t    ripaddr;
        uip_ip_addr(&ripaddr, ip);
#ifdef UIPETHERNET_DEBUG_UDP
        printf("udp beginPacket, ");
#endif
        if (_uip_udp_conn) {
            _uip_udp_conn->rport = htons(port);
            uip_ipaddr_copy(_uip_udp_conn->ripaddr, &ripaddr);
        }
        else {
            _uip_udp_conn = uip_udp_new(&ripaddr, htons(port));
            if (_uip_udp_conn)
            {
#ifdef UIPETHERNET_DEBUG_UDP
                printf("new connection, ");
#endif
                _uip_udp_conn->appstate = &appdata;
            }
            else
            {
#ifdef UIPETHERNET_DEBUG_UDP
                printf("failed to allocate new connection\r\n");
#endif
                return 0;
            }
        }

#ifdef UIPETHERNET_DEBUG_UDP
        printf("rip: %s, port: %d\r\n", ip.asString(), port);
#endif
    }

    if (_uip_udp_conn) {
        if (appdata.packet_out == NOBLOCK) {
            appdata.packet_out = uIPEthernet.network.allocBlock(UIP_UDP_MAXPACKETSIZE);
            appdata.out_pos = UIP_UDP_PHYH_LEN;
            if (appdata.packet_out != NOBLOCK)
                return 1;
#ifdef UIPETHERNET_DEBUG_UDP
            else
                printf("failed to allocate memory for packet\r\n");
#endif
        }

#ifdef UIPETHERNET_DEBUG_UDP
        else
            printf("previous packet on that connection not sent yet\r\n");
#endif
    }

    return 0;
}

// Start building up a packet to send to the remote host specific in host and port

// Returns 1 if successful, 0 if there was a problem resolving the hostname or port
int UIPUDP::beginPacket(const char* host, uint16_t port) {

    // Look up the host first
    int         ret = 0;
    DNSClient   dns;
    IPAddress   remote_addr;

    dns.begin(uIPEthernet.dnsServerIP());
    ret = dns.getHostByName(host, remote_addr);
    if (ret == 1) {
        return beginPacket(remote_addr, port);
    }
    else {
        return ret;
    }
}

// Finish off this packet and send it

// Returns 1 if the packet was sent successfully, 0 if there was an error
int UIPUDP::endPacket(void) {
    if (_uip_udp_conn && appdata.packet_out != NOBLOCK) {
        appdata.send = true;
        uIPEthernet.network.resizeBlock(appdata.packet_out, 0, appdata.out_pos);
        uip_udp_periodic_conn(_uip_udp_conn);
        if (uip_len > 0) {
            _send(&appdata);
            return 1;
        }
    }

    return 0;
}

// Write a single byte into the packet
size_t UIPUDP::write(uint8_t c) {
    return write(&c, 1);
}

// Write size bytes from buffer into the packet
size_t UIPUDP::write(const uint8_t* buffer, size_t size) {
    if (appdata.packet_out != NOBLOCK) {
        size_t  ret = uIPEthernet.network.writePacket(appdata.packet_out, appdata.out_pos, (uint8_t*)buffer, size);
        appdata.out_pos += ret;
        return ret;
    }

    return 0;
}

// Start processing the next available incoming packet

// Returns the size of the packet in bytes, or 0 if no packets are available
int UIPUDP::parsePacket(void) {
    uIPEthernet.tick();
#ifdef UIPETHERNET_DEBUG_UDP
    if (appdata.packet_in != NOBLOCK) {
        printf("udp parsePacket freeing previous packet: %d\r\n", appdata.packet_in);
    }
#endif
    uIPEthernet.network.freeBlock(appdata.packet_in);

    appdata.packet_in = appdata.packet_next;
    appdata.packet_next = NOBLOCK;

#ifdef UIPETHERNET_DEBUG_UDP
    if (appdata.packet_in != NOBLOCK) {
        printf("udp parsePacket received packet: %d", appdata.packet_in);
    }
#endif

    int size = uIPEthernet.network.blockSize(appdata.packet_in);
#ifdef UIPETHERNET_DEBUG_UDP
    if (appdata.packet_in != NOBLOCK) {
        printf(", size: %d\r\n", size);
    }
#endif
    return size;
}

// Number of bytes remaining in the current packet
int UIPUDP::available(void) {
    uIPEthernet.tick();
    return uIPEthernet.network.blockSize(appdata.packet_in);
}

// Read a single byte from the current packet
int UIPUDP::read(void) {
    static unsigned char    c;
    if (read(&c, 1) > 0) {
        return c;
    }

    return -1;
}

// Read up to len bytes from the current packet and place them into buffer

// Returns the number of bytes read, or 0 if none are available
int UIPUDP::read(unsigned char* buffer, size_t len) {
    uIPEthernet.tick();
    if (appdata.packet_in != NOBLOCK) {
        memaddress  read = uIPEthernet.network.readPacket(appdata.packet_in, 0, buffer, len);
        if (read == uIPEthernet.network.blockSize(appdata.packet_in)) {
            uIPEthernet.network.freeBlock(appdata.packet_in);
            appdata.packet_in = NOBLOCK;
        }
        else
            uIPEthernet.network.resizeBlock(appdata.packet_in, read);
        return read;
    }

    return 0;
}

// Return the next byte from the current packet without moving on to the next byte
int UIPUDP::peek(void) {
    uIPEthernet.tick();
    if (appdata.packet_in != NOBLOCK) {
        unsigned char   c;
        if (uIPEthernet.network.readPacket(appdata.packet_in, 0, &c, 1) == 1)
            return c;
    }

    return -1;
}

// Finish reading the current packet
void UIPUDP::flush(void) {
    uIPEthernet.tick();
    uIPEthernet.network.freeBlock(appdata.packet_in);
    appdata.packet_in = NOBLOCK;
}

// Return the IP address of the host who sent the current incoming packet
IPAddress UIPUDP::remoteIP(void) {
    return _uip_udp_conn ? ip_addr_uip(_uip_udp_conn->ripaddr) : IPAddress();
}

// Return the port of the host who sent the current incoming packet
uint16_t UIPUDP::remotePort(void) {
    return _uip_udp_conn ? ntohs(_uip_udp_conn->rport) : 0;
}

// UIP callback function
void uipudp_appcall(void) {
    if (uip_udp_userdata_t * data = (uip_udp_userdata_t *) (uip_udp_conn->appstate)) {
        if (uip_newdata()) {
            if (data->packet_next == NOBLOCK) {
                uip_udp_conn->rport = UDPBUF->srcport;
                uip_ipaddr_copy(uip_udp_conn->ripaddr, UDPBUF->srcipaddr);
                data->packet_next = uIPEthernet.network.allocBlock(ntohs(UDPBUF->udplen) - UIP_UDPH_LEN);

                //if we are unable to allocate memory the packet is dropped. udp doesn't guarantee packet delivery
                if (data->packet_next != NOBLOCK) {

                    //discard Linklevel and IP and udp-header and any trailing bytes:
                    uIPEthernet.network.copyPacket
                        (
                            data->packet_next,
                            0,
                            UIPEthernet::in_packet,
                            UIP_UDP_PHYH_LEN,
                            uIPEthernet.network.blockSize(data->packet_next)
                        );
#ifdef UIPETHERNET_DEBUG_UDP
                    printf
                    (
                        "udp, uip_newdata received packet: %d, size: %d\r\n",
                        data->packet_next,
                        UIPEthernet.network.blockSize(data->packet_next)
                    );
#endif
                }
            }
        }

        if (uip_poll() && data->send)
        {
            //set uip_slen (uip private) by calling uip_udp_send
#ifdef UIPETHERNET_DEBUG_UDP
            printf
            (
                "udp, uip_poll preparing packet to send: %d, size: %d\r\n",
                data->packet_out,
                UIPEthernet.network.blockSize(data->packet_out)
            );
#endif
            UIPEthernet::uip_packet = data->packet_out;
            UIPEthernet::uip_hdrlen = UIP_UDP_PHYH_LEN;
            uip_udp_send(data->out_pos - (UIP_UDP_PHYH_LEN));
        }
    }
}

/**
 * @brief
 * @note
 * @param
 * @retval
 */
void UIPUDP::_send(uip_udp_userdata_t* data) {
    uip_arp_out();  //add arp
    if (uip_len == UIP_ARPHDRSIZE) {
        UIPEthernet::uip_packet = NOBLOCK;
        UIPEthernet::packetstate &= ~UIPETHERNET_SENDPACKET;
#ifdef UIPETHERNET_DEBUG_UDP
        printf("udp, uip_poll results in ARP-packet\r\n");
#endif
    }
    else {

        //arp found ethaddr for ip (otherwise packet is replaced by arp-request)
        data->send = false;
        data->packet_out = NOBLOCK;
        UIPEthernet::packetstate |= UIPETHERNET_SENDPACKET;
#ifdef UIPETHERNET_DEBUG_UDP
        printf("udp, uip_packet to send: %d\r\n", UIPEthernet::uip_packet);
#endif
    }

    uIPEthernet.network_send();
}
#endif