src/Unix/ether_unix.cpp

/*
 *  ether_unix.cpp - Ethernet device driver, Unix specific stuff (Linux and FreeBSD)
 *
 *  Basilisk II (C) 1997-2005 Christian Bauer
 *
 *  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 2 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, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "sysdeps.h"

/*
 *  NOTES concerning MacOS X issues:
 *  - poll() does not exist in 10.2.8, but is available in 10.4.4
 *  - select(), and very likely poll(), are not cancellation points. So
 *    the ethernet thread doesn't stop on exit. An explicit check is
 *    performed to workaround this problem.
 */
#if (defined __APPLE__ && defined __MACH__) || ! defined HAVE_POLL
#define USE_POLL 0
#else
#define USE_POLL 1
#endif

#ifdef HAVE_SYS_POLL_H
#include <sys/poll.h>
#endif
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <pthread.h>
#include <semaphore.h>
#include <errno.h>
#include <stdio.h>
#include <map>

#if defined(__FreeBSD__) || defined(sgi) || (defined(__APPLE__) && defined(__MACH__))
#include <net/if.h>
#endif

#if defined(HAVE_LINUX_IF_H) && defined(HAVE_LINUX_IF_TUN_H)
#include <linux/if.h>
#include <linux/if_tun.h>
#endif

#if defined(HAVE_NET_IF_H) && defined(HAVE_NET_IF_TUN_H)
#include <net/if.h>
#include <net/if_tun.h>
#endif

#ifdef HAVE_SLIRP
#include "libslirp.h"
#endif

#include "cpu_emulation.h"
#include "main.h"
#include "macos_util.h"
#include "prefs.h"
#include "user_strings.h"
#include "ether.h"
#include "ether_defs.h"

#ifndef NO_STD_NAMESPACE
using std::map;
#endif

#define DEBUG 0
#include "debug.h"

#define STATISTICS 0
#define MONITOR 0


// Ethernet device types
enum {
        NET_IF_SHEEPNET,
        NET_IF_ETHERTAP,
        NET_IF_TUNTAP,
        NET_IF_SLIRP
};

// Constants
static const char ETHERCONFIG_FILE_NAME[] = DATADIR "/tunconfig";

// Global variables
static int fd = -1;                                                     // fd of sheep_net device
static pthread_t ether_thread;                          // Packet reception thread
static pthread_attr_t ether_thread_attr;        // Packet reception thread attributes
static bool thread_active = false;                      // Flag: Packet reception thread installed
static sem_t int_ack;                                           // Interrupt acknowledge semaphore
static bool udp_tunnel;                                         // Flag: UDP tunnelling active, fd is the socket descriptor
static int net_if_type = -1;                            // Ethernet device type
static char *net_if_name = NULL;                        // TUN/TAP device name
static const char *net_if_script = NULL;        // Network config script
static pthread_t slirp_thread;                          // Slirp reception thread
static bool slirp_thread_active = false;        // Flag: Slirp reception threadinstalled
static int slirp_output_fd = -1;                        // fd of slirp output pipe
static int slirp_input_fds[2] = { -1, -1 };     // fds of slirp input pipe
#ifdef SHEEPSHAVER
static bool net_open = false;                           // Flag: initialization succeeded, network device open
static uint8 ether_addr[6];                                     // Our Ethernet address
#else
const bool ether_driver_opened = true;          // Flag: is the MacOS driver opened?
#endif

// Attached network protocols, maps protocol type to MacOS handler address
static map<uint16, uint32> net_protocols;

// Prototypes
static void *receive_func(void *arg);
static void *slirp_receive_func(void *arg);
static int poll_fd(int fd);
static int16 ether_do_add_multicast(uint8 *addr);
static int16 ether_do_del_multicast(uint8 *addr);
static int16 ether_do_write(uint32 arg);
static void ether_do_interrupt(void);


/*
 *  Start packet reception thread
 */

static bool start_thread(void)
{
        if (sem_init(&int_ack, 0, 0) < 0) {
                printf("WARNING: Cannot init semaphore");
                return false;
        }

        Set_pthread_attr(&ether_thread_attr, 1);
        thread_active = (pthread_create(&ether_thread, &ether_thread_attr, receive_func, NULL) == 0);
        if (!thread_active) {
                printf("WARNING: Cannot start Ethernet thread");
                return false;
        }

#ifdef HAVE_SLIRP
        if (net_if_type == NET_IF_SLIRP) {
                slirp_thread_active = (pthread_create(&slirp_thread, NULL, slirp_receive_func, NULL) == 0);
                if (!slirp_thread_active) {
                        printf("WARNING: Cannot start slirp reception thread\n");
                        return false;
                }
        }
#endif

        return true;
}


/*
 *  Stop packet reception thread
 */

static void stop_thread(void)
{
#ifdef HAVE_SLIRP
        if (slirp_thread_active) {
#ifdef HAVE_PTHREAD_CANCEL
                pthread_cancel(slirp_thread);
#endif
                pthread_join(slirp_thread, NULL);
                slirp_thread_active = false;
        }
#endif

        if (thread_active) {
#ifdef HAVE_PTHREAD_CANCEL
                pthread_cancel(ether_thread);
#endif
#ifdef AQUA
                // This call, which waits for ether_thread to terminate,
                // never returns when used in Nigel's OS X port.
#else
                pthread_join(ether_thread, NULL);
#endif
                sem_destroy(&int_ack);
                thread_active = false;
        }
}


/*
 *  Execute network script up|down
 */

static bool execute_network_script(const char *action)
{
        if (net_if_script == NULL || net_if_name == NULL)
                return false;

        int pid = fork();
        if (pid >= 0) {
                if (pid == 0) {
                        char *args[4];
                        args[0] = (char *)net_if_script;
                        args[1] = net_if_name;
                        args[2] = (char *)action;
                        args[3] = NULL;
                        execv(net_if_script, args);
                        exit(1);
                }
                int status;
                while (waitpid(pid, &status, 0) != pid);
                return WIFEXITED(status) && WEXITSTATUS(status) == 0;
        }

        return false;
}


/*
 *  Initialization
 */

bool ether_init(void)
{
        int nonblock = 1;
        char str[256];

        // Do nothing if no Ethernet device specified
        const char *name = PrefsFindString("ether");
        if (name == NULL)
                return false;

        // Determine Ethernet device type
        net_if_type = -1;
        if (strncmp(name, "tap", 3) == 0)
                net_if_type = NET_IF_ETHERTAP;
#if ENABLE_TUNTAP
        else if (strcmp(name, "tun") == 0)
                net_if_type = NET_IF_TUNTAP;
#endif
#ifdef HAVE_SLIRP
        else if (strcmp(name, "slirp") == 0)
                net_if_type = NET_IF_SLIRP;
#endif
        else
                net_if_type = NET_IF_SHEEPNET;

#ifdef HAVE_SLIRP
        // Initialize slirp library
        if (net_if_type == NET_IF_SLIRP) {
                if (slirp_init() < 0) {
                        sprintf(str, GetString(STR_SLIRP_NO_DNS_FOUND_WARN));
                        WarningAlert(str);
                        return false;
                }

                // Open slirp output pipe
                int fds[2];
                if (pipe(fds) < 0)
                        return false;
                fd = fds[0];
                slirp_output_fd = fds[1];

                // Open slirp input pipe
                if (pipe(slirp_input_fds) < 0)
                        return false;
        }
#endif

        // Open sheep_net or ethertap or TUN/TAP device
        char dev_name[16];
        switch (net_if_type) {
        case NET_IF_ETHERTAP:
                sprintf(dev_name, "/dev/%s", name);
                break;
        case NET_IF_TUNTAP:
                strcpy(dev_name, "/dev/net/tun");
                break;
        case NET_IF_SHEEPNET:
                strcpy(dev_name, "/dev/sheep_net");
                break;
        }
        if (net_if_type != NET_IF_SLIRP) {
                fd = open(dev_name, O_RDWR);
                if (fd < 0) {
                        sprintf(str, GetString(STR_NO_SHEEP_NET_DRIVER_WARN), dev_name, strerror(errno));
                        WarningAlert(str);
                        goto open_error;
                }
        }

#if ENABLE_TUNTAP
        // Open TUN/TAP interface
        if (net_if_type == NET_IF_TUNTAP) {
                struct ifreq ifr;
                memset(&ifr, 0, sizeof(ifr));
                ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
                strcpy(ifr.ifr_name, "tun%d");
                if (ioctl(fd, TUNSETIFF, (void *) &ifr) != 0) {
                        sprintf(str, GetString(STR_SHEEP_NET_ATTACH_WARN), strerror(errno));
                        WarningAlert(str);
                        goto open_error;
                }

                // Get network config script file path
                net_if_script = PrefsFindString("etherconfig");
                if (net_if_script == NULL)
                        net_if_script = ETHERCONFIG_FILE_NAME;

                // Start network script up
                if (net_if_script == NULL) {
                        sprintf(str, GetString(STR_TUN_TAP_CONFIG_WARN), "script not found");
                        WarningAlert(str);
                        goto open_error;
                }
                net_if_name = strdup(ifr.ifr_name);
                if (!execute_network_script("up")) {
                        sprintf(str, GetString(STR_TUN_TAP_CONFIG_WARN), "script execute error");
                        WarningAlert(str);
                        goto open_error;
                }
                D(bug("Connected to host network interface: %s\n", net_if_name));
        }
#endif

#if defined(__linux__)
        // Attach sheep_net to selected Ethernet card
        if (net_if_type == NET_IF_SHEEPNET && ioctl(fd, SIOCSIFLINK, name) < 0) {
                sprintf(str, GetString(STR_SHEEP_NET_ATTACH_WARN), strerror(errno));
                WarningAlert(str);
                goto open_error;
        }
#endif

        // Set nonblocking I/O
        ioctl(fd, FIONBIO, &nonblock);

        // Get Ethernet address
        if (net_if_type == NET_IF_ETHERTAP) {
                pid_t p = getpid();     // If configured for multicast, ethertap requires that the lower 32 bit of the Ethernet address are our PID
                ether_addr[0] = 0xfe;
                ether_addr[1] = 0xfd;
                ether_addr[2] = p >> 24;
                ether_addr[3] = p >> 16;
                ether_addr[4] = p >> 8;
                ether_addr[5] = p;
#ifdef HAVE_SLIRP
        } else if (net_if_type == NET_IF_SLIRP) {
                ether_addr[0] = 0x52;
                ether_addr[1] = 0x54;
                ether_addr[2] = 0x00;
                ether_addr[3] = 0x12;
                ether_addr[4] = 0x34;
                ether_addr[5] = 0x56;
#endif
        } else
                ioctl(fd, SIOCGIFADDR, ether_addr);
        D(bug("Ethernet address %02x %02x %02x %02x %02x %02x\n", ether_addr[0], ether_addr[1], ether_addr[2], ether_addr[3], ether_addr[4], ether_addr[5]));

        // Start packet reception thread
        if (!start_thread())
                goto open_error;

        // Everything OK
        return true;

open_error:
        stop_thread();

        if (fd > 0) {
                close(fd);
                fd = -1;
        }
        if (slirp_input_fds[0] >= 0) {
                close(slirp_input_fds[0]);
                slirp_input_fds[0] = -1;
        }
        if (slirp_input_fds[1] >= 0) {
                close(slirp_input_fds[1]);
                slirp_input_fds[1] = -1;
        }
        if (slirp_output_fd >= 0) {
                close(slirp_output_fd);
                slirp_output_fd = -1;
        }
        return false;
}


/*
 *  Deinitialization
 */

void ether_exit(void)
{
        // Stop reception threads
        stop_thread();

        // Shut down TUN/TAP interface
        if (net_if_type == NET_IF_TUNTAP)
                execute_network_script("down");

        // Free TUN/TAP device name
        if (net_if_name)
                free(net_if_name);

        // Close sheep_net device
        if (fd > 0)
                close(fd);

        // Close slirp input buffer
        if (slirp_input_fds[0] >= 0)
                close(slirp_input_fds[0]);
        if (slirp_input_fds[1] >= 0)
                close(slirp_input_fds[1]);

        // Close slirp output buffer
        if (slirp_output_fd > 0)
                close(slirp_output_fd);

#if STATISTICS
        // Show statistics
        printf("%ld messages put on write queue\n", num_wput);
        printf("%ld error acks\n", num_error_acks);
        printf("%ld packets transmitted (%ld raw, %ld normal)\n", num_tx_packets, num_tx_raw_packets, num_tx_normal_packets);
        printf("%ld tx packets dropped because buffer full\n", num_tx_buffer_full);
        printf("%ld packets received\n", num_rx_packets);
        printf("%ld packets passed upstream (%ld Fast Path, %ld normal)\n", num_rx_fastpath + num_unitdata_ind, num_rx_fastpath, num_unitdata_ind);
        printf("EtherIRQ called %ld times\n", num_ether_irq);
        printf("%ld rx packets dropped due to low memory\n", num_rx_no_mem);
        printf("%ld rx packets dropped because no stream found\n", num_rx_dropped);
        printf("%ld rx packets dropped because stream not ready\n", num_rx_stream_not_ready);
        printf("%ld rx packets dropped because no memory for unitdata_ind\n", num_rx_no_unitdata_mem);
#endif
}


/*
 *  Glue around low-level implementation
 */

#ifdef SHEEPSHAVER
// Error codes
enum {
        eMultiErr               = -91,
        eLenErr                 = -92,
        lapProtErr              = -94,
        excessCollsns   = -95
};

// Initialize ethernet
void EtherInit(void)
{
        net_open = false;

        // Do nothing if the user disabled the network
        if (PrefsFindBool("nonet"))
                return;

        net_open = ether_init();
}

// Exit ethernet
void EtherExit(void)
{
        ether_exit();
        net_open = false;
}

// Get ethernet hardware address
void AO_get_ethernet_address(uint32 arg)
{
        uint8 *addr = Mac2HostAddr(arg);
        if (net_open)
                OTCopy48BitAddress(ether_addr, addr);
        else {
                addr[0] = 0x12;
                addr[1] = 0x34;
                addr[2] = 0x56;
                addr[3] = 0x78;
                addr[4] = 0x9a;
                addr[5] = 0xbc;
        }
        D(bug("AO_get_ethernet_address: got address %02x%02x%02x%02x%02x%02x\n", addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]));
}

// Add multicast address
void AO_enable_multicast(uint32 addr)
{
        if (net_open)
                ether_do_add_multicast(Mac2HostAddr(addr));
}

// Disable multicast address
void AO_disable_multicast(uint32 addr)
{
        if (net_open)
                ether_do_del_multicast(Mac2HostAddr(addr));
}

// Transmit one packet
void AO_transmit_packet(uint32 mp)
{
        if (net_open) {
                switch (ether_do_write(mp)) {
                case noErr:
                        num_tx_packets++;
                        break;
                case excessCollsns:
                        num_tx_buffer_full++;
                        break;
                }
        }
}

// Copy packet data from message block to linear buffer
static inline int ether_arg_to_buffer(uint32 mp, uint8 *p)
{
        return ether_msgb_to_buffer(mp, p);
}

// Ethernet interrupt
void EtherIRQ(void)
{
        D(bug("EtherIRQ\n"));
        num_ether_irq++;

        OTEnterInterrupt();
        ether_do_interrupt();
        OTLeaveInterrupt();

        // Acknowledge interrupt to reception thread
        D(bug(" EtherIRQ done\n"));
        sem_post(&int_ack);
}
#else
// Add multicast address
int16 ether_add_multicast(uint32 pb)
{
        return ether_do_add_multicast(Mac2HostAddr(pb + eMultiAddr));
}

// Disable multicast address
int16 ether_del_multicast(uint32 pb)
{
        return ether_do_del_multicast(Mac2HostAddr(pb + eMultiAddr));
}

// Transmit one packet
int16 ether_write(uint32 wds)
{
        return ether_do_write(wds);
}

// Copy packet data from WDS to linear buffer
static inline int ether_arg_to_buffer(uint32 wds, uint8 *p)
{
        return ether_wds_to_buffer(wds, p);
}

// Dispatch packet to protocol handler
static void ether_dispatch_packet(uint32 p, uint32 length)
{
        // Get packet type
        uint16 type = ReadMacInt16(p + 12);

        // Look for protocol
        uint16 search_type = (type <= 1500 ? 0 : type);
        if (net_protocols.find(search_type) == net_protocols.end())
                return;
        uint32 handler = net_protocols[search_type];

        // No default handler
        if (handler == 0)
                return;

        // Copy header to RHA
        Mac2Mac_memcpy(ether_data + ed_RHA, p, 14);
        D(bug(" header %08x%04x %08x%04x %04x\n", ReadMacInt32(ether_data + ed_RHA), ReadMacInt16(ether_data + ed_RHA + 4), ReadMacInt32(ether_data + ed_RHA + 6), ReadMacInt16(ether_data + ed_RHA + 10), ReadMacInt16(ether_data + ed_RHA + 12)));

        // Call protocol handler
        M68kRegisters r;
        r.d[0] = type;                                                                  // Packet type
        r.d[1] = length - 14;                                                   // Remaining packet length (without header, for ReadPacket)
        r.a[0] = p + 14;                                                                // Pointer to packet (Mac address, for ReadPacket)
        r.a[3] = ether_data + ed_RHA + 14;                              // Pointer behind header in RHA
        r.a[4] = ether_data + ed_ReadPacket;                    // Pointer to ReadPacket/ReadRest routines
        D(bug(" calling protocol handler %08x, type %08x, length %08x, data %08x, rha %08x, read_packet %08x\n", handler, r.d[0], r.d[1], r.a[0], r.a[3], r.a[4]));
        Execute68k(handler, &r);
}

// Ethernet interrupt
void EtherInterrupt(void)
{
        D(bug("EtherIRQ\n"));
        ether_do_interrupt();

        // Acknowledge interrupt to reception thread
        D(bug(" EtherIRQ done\n"));
        sem_post(&int_ack);
}
#endif


/*
 *  Reset
 */

void ether_reset(void)
{
        net_protocols.clear();
}


/*
 *  Add multicast address
 */

static int16 ether_do_add_multicast(uint8 *addr)
{
        switch (net_if_type) {
        case NET_IF_ETHERTAP:
        case NET_IF_SHEEPNET:
                if (ioctl(fd, SIOCADDMULTI, addr) < 0) {
                        D(bug("WARNING: Couldn't enable multicast address\n"));
                        if (net_if_type == NET_IF_ETHERTAP)
                                return noErr;
                        else
                                return eMultiErr;
                }
        default:
                return noErr;
        }
}


/*
 *  Delete multicast address
 */

static int16 ether_do_del_multicast(uint8 *addr)
{
        switch (net_if_type) {
        case NET_IF_ETHERTAP:
        case NET_IF_SHEEPNET:
                if (ioctl(fd, SIOCDELMULTI, addr) < 0) {
                        D(bug("WARNING: Couldn't disable multicast address\n"));
                        return eMultiErr;
                }
        default:
                return noErr;
        }
}


/*
 *  Attach protocol handler
 */

int16 ether_attach_ph(uint16 type, uint32 handler)
{
        if (net_protocols.find(type) != net_protocols.end())
                return lapProtErr;
        net_protocols[type] = handler;
        return noErr;
}


/*
 *  Detach protocol handler
 */

int16 ether_detach_ph(uint16 type)
{
        if (net_protocols.erase(type) == 0)
                return lapProtErr;
        return noErr;
}


/*
 *  Transmit raw ethernet packet
 */

static int16 ether_do_write(uint32 arg)
{
        // Copy packet to buffer
        uint8 packet[1516], *p = packet;
        int len = 0;
#if defined(__linux__)
        if (net_if_type == NET_IF_ETHERTAP) {
                *p++ = 0;       // Linux ethertap discards the first 2 bytes
                *p++ = 0;
                len += 2;
        }
#endif
        len += ether_arg_to_buffer(arg, p);

#if MONITOR
        bug("Sending Ethernet packet:\n");
        for (int i=0; i<len; i++) {
                bug("%02x ", packet[i]);
        }
        bug("\n");
#endif

        // Transmit packet
#ifdef HAVE_SLIRP
        if (net_if_type == NET_IF_SLIRP) {
                const int slirp_input_fd = slirp_input_fds[1];
                write(slirp_input_fd, &len, sizeof(len));
                write(slirp_input_fd, packet, len);
                return noErr;
        } else
#endif
        if (write(fd, packet, len) < 0) {
                D(bug("WARNING: Couldn't transmit packet\n"));
                return excessCollsns;
        } else
                return noErr;
}


/*
 *  Start UDP packet reception thread
 */

bool ether_start_udp_thread(int socket_fd)
{
        fd = socket_fd;
        udp_tunnel = true;
        return start_thread();
}


/*
 *  Stop UDP packet reception thread
 */

void ether_stop_udp_thread(void)
{
        stop_thread();
        fd = -1;
}


/*
 *  SLIRP output buffer glue
 */

#ifdef HAVE_SLIRP
int slirp_can_output(void)
{
        return 1;
}

void slirp_output(const uint8 *packet, int len)
{
        write(slirp_output_fd, packet, len);
}

void *slirp_receive_func(void *arg)
{
        const int slirp_input_fd = slirp_input_fds[0];

        for (;;) {
                // Wait for packets to arrive
                fd_set rfds, wfds, xfds;
                int nfds;
                struct timeval tv;

                // ... in the input queue
                FD_ZERO(&rfds);
                FD_SET(slirp_input_fd, &rfds);
                tv.tv_sec = 0;
                tv.tv_usec = 0;
                if (select(slirp_input_fd + 1, &rfds, NULL, NULL, &tv) > 0) {
                        int len;
                        read(slirp_input_fd, &len, sizeof(len));
                        uint8 packet[1516];
                        assert(len <= sizeof(packet));
                        read(slirp_input_fd, packet, len);
                        slirp_input(packet, len);
                }

                // ... in the output queue
                nfds = -1;
                FD_ZERO(&rfds);
                FD_ZERO(&wfds);
                FD_ZERO(&xfds);
                slirp_select_fill(&nfds, &rfds, &wfds, &xfds);
                tv.tv_sec = 0;
                tv.tv_usec = 10000;
                if (select(nfds + 1, &rfds, &wfds, &xfds, &tv) >= 0)
                        slirp_select_poll(&rfds, &wfds, &xfds);

#ifdef HAVE_PTHREAD_TESTCANCEL
                // Explicit cancellation point if select() was not covered
                // This seems to be the case on MacOS X 10.2
                pthread_testcancel();
#endif
        }
        return NULL;
}
#else
int slirp_can_output(void)
{
        return 0;
}

void slirp_output(const uint8 *packet, int len)
{
}
#endif


/*
 *  Packet reception thread
 */

static void *receive_func(void *arg)
{
        for (;;) {

                // Wait for packets to arrive
#if USE_POLL
                struct pollfd pf = {fd, POLLIN, 0};
                int res = poll(&pf, 1, -1);
#else
                fd_set rfds;
                FD_ZERO(&rfds);
                FD_SET(fd, &rfds);
                // A NULL timeout could cause select() to block indefinitely,
                // even if it is supposed to be a cancellation point [MacOS X]
                struct timeval tv = { 0, 20000 };
                int res = select(fd + 1, &rfds, NULL, NULL, &tv);
#ifdef HAVE_PTHREAD_TESTCANCEL
                pthread_testcancel();
#endif
                if (res == 0 || (res == -1 && errno == EINTR))
                        continue;
#endif
                if (res <= 0)
                        break;

                if (ether_driver_opened) {
                        // Trigger Ethernet interrupt
                        D(bug(" packet received, triggering Ethernet interrupt\n"));
                        SetInterruptFlag(INTFLAG_ETHER);
                        TriggerInterrupt();

                        // Wait for interrupt acknowledge by EtherInterrupt()
                        sem_wait(&int_ack);
                } else
                        usleep(20000);
        }
        return NULL;
}


/*
 *  Ethernet interrupt - activate deferred tasks to call IODone or protocol handlers
 */

void ether_do_interrupt(void)
{
        // Call protocol handler for received packets
        EthernetPacket ether_packet;
        uint32 packet = ether_packet.addr();
        ssize_t length;
        for (;;) {

#ifndef SHEEPSHAVER
                if (udp_tunnel) {

                        // Read packet from socket
                        struct sockaddr_in from;
                        socklen_t from_len = sizeof(from);
                        length = recvfrom(fd, Mac2HostAddr(packet), 1514, 0, (struct sockaddr *)&from, &from_len);
                        if (length < 14)
                                break;
                        ether_udp_read(packet, length, &from);

                } else
#endif
                {

                        // Read packet from sheep_net device
#if defined(__linux__)
                        length = read(fd, Mac2HostAddr(packet), net_if_type == NET_IF_ETHERTAP ? 1516 : 1514);
#else
                        length = read(fd, Mac2HostAddr(packet), 1514);
#endif
                        if (length < 14)
                                break;

#if MONITOR
                        bug("Receiving Ethernet packet:\n");
                        for (int i=0; i<length; i++) {
                                bug("%02x ", ReadMacInt8(packet + i));
                        }
                        bug("\n");
#endif

                        // Pointer to packet data (Ethernet header)
                        uint32 p = packet;
#if defined(__linux__)
                        if (net_if_type == NET_IF_ETHERTAP) {
                                p += 2;                 // Linux ethertap has two random bytes before the packet
                                length -= 2;
                        }
#endif

                        // Dispatch packet
                        ether_dispatch_packet(p, length);
                }
        }
}
Revision:	1.25
Committed:	2006-01-21T16:19:47Z (18 years, 7 months ago) by gbeauche
Branch:	MAIN
Changes since 1.24:	+14 -1 lines
Log Message:	poll() and select() are still not cancellation points in MacOS X 10.4.4...