etherdrv.c

这个是LINUX下的GDB调度工具的源码

/* 
 * Copyright (C) 1995 Advanced RISC Machines Limited. All rights reserved.
 * 
 * This software may be freely used, copied, modified, and distributed
 * provided that the above copyright notice is preserved in all copies of the
 * software.
 */

/* -*-C-*-
 *
 * $Revision: 1.9 $
 *     $Date: 2000/01/04 15:24:18 $
 *
 *
 * etherdrv.c - Ethernet Driver for Angel.
 */

#ifdef __hpux
# define _POSIX_SOURCE 1
# define _HPUX_SOURCE 1
# define _XOPEN_SOURCE 1
#endif

#include <stdio.h>
#ifdef __hpux
# define uint hide_HPs_uint
#endif
#ifdef STDC_HEADERS
# include <unistd.h>
# ifdef __hpux
#   undef uint
# endif
#endif
#include <stdlib.h>
#include <string.h>
#ifdef __hpux
# define uint hide_HPs_uint
#endif
#include <fcntl.h>
#ifdef __hpux
# undef uint
#endif
#include <errno.h>
#include <stdarg.h>
#include <ctype.h>
#include "host.h"

#ifdef COMPILING_ON_WINDOWS
  typedef char * caddr_t;
# undef IGNORE
# include <winsock.h>
# include "angeldll.h"
#else
# ifdef __hpux
#   define uint hide_HPs_uint
# endif
# include <sys/types.h>
# include <sys/socket.h>
# ifdef __hpux
#   undef uint
# endif
# include <netdb.h>
# include <sys/time.h>
# include <sys/ioctl.h>
# ifdef HAVE_SYS_FILIO_H
#   include <sys/filio.h>
# endif
# include <netinet/in.h>
# include <arpa/inet.h>
#endif

#include "hsys.h"
#include "devices.h"
#include "angel_endian.h"
#include "buffers.h"
#include "hostchan.h"
#include "params.h"
#include "logging.h"
#include "ethernet.h"


#if !defined(COMPILING_ON_WINDOWS) && !defined(STDC_HEADERS)
/* These two might not work for windows.  */
extern int sys_nerr;
extern char * sys_errlist[];
#endif

#ifndef UNUSED
# define UNUSED(x) (x = x)      /* Silence compiler warnings */
#endif

/*
 * forward declarations of static functions
 */
static int EthernetOpen(const char *name, const char *arg);
static int EthernetMatch(const char *name, const char *arg);
static void EthernetClose(void);
static int EthernetRead(DriverCall *dc, bool block);
static int EthernetWrite(DriverCall *dc);
static int EthernetIoctl(const int opcode, void *args);

/*
 * the device descriptor for Ethernet
 */
DeviceDescr angel_EthernetDevice =
{
    "Ethernet",
    EthernetOpen,
    EthernetMatch,
    EthernetClose,
    EthernetRead,
    EthernetWrite,
    EthernetIoctl
};

/*
 * descriptor for the socket that we talk down
 */
static int sock = -1;

/*
 * address of the remote target
 */
static struct sockaddr_in remote, *ia = &remote;

/*
 * array of dynamic port numbers on target
 */
static unsigned short int ports[2];

/*
 *  Function: set_address
 *   Purpose: Try to get an address into an understandable form
 *
 *    Params:
 *       Input: addr    The address to parse
 *
 *      Output: ia      Structure to hold the parsed address
 *
 *   Returns:
 *          OK:  0
 *       Error: -1
 */
static int set_address(const char *const addr, struct sockaddr_in *const ia)
{
    ia->sin_family = AF_INET;

    /*
     * Try address as a dotted decimal
     */
    ia->sin_addr.s_addr = inet_addr(addr);

    /*
     * If that failed, try it as a hostname
     */
    if (ia->sin_addr.s_addr == (u_int)-1)
    {
        struct hostent *hp = gethostbyname(addr);

        if (hp == NULL)
            return -1;

        (void)memcpy((caddr_t)&ia->sin_addr, hp->h_addr, hp->h_length);
    }

    return 0;
}

/*
 *  Function: open_socket
 *   Purpose: Open a non-blocking UDP socket, and bind it to a port
 *              assigned by the system.
 *
 *    Params: None
 *
 *   Returns:
 *          OK: socket descriptor
 *       Error: -1
 */
static int open_socket(void)
{
    int sfd;
#if 0                           /* see #if 0 just below -VVV- */
    int yesplease = 1;
#endif
    struct sockaddr_in local;

    /*
     * open the socket
     */
#ifdef COMPILING_ON_WINDOWS
    if ((sfd = socket(AF_INET, SOCK_DGRAM, 0)) == INVALID_SOCKET)
        return -1;
#else
    if ((sfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
    {
# ifdef DEBUG
        perror("socket");
# endif
        return -1;
    }
#endif

    /*
     * 960731 KWelton
     *
     * I don't believe that this should be necessary - if we
     * use select(), then non-blocking I/O is redundant.
     * Unfortunately, select() appears to be broken (under
     * Solaris, with a limited amount of time available for
     * debug), so this code stays in for the time being
     */
#if 0
    /*
     * enable non-blocking I/O
     */
    if (ioctlsocket(sfd, FIONBIO, &yesplease) < 0)
    {
# ifdef DEBUG
        perror("ioctl(FIONBIO)");
# endif
        closesocket(sfd);

        return -1;
    }
#endif /* 0/1 */

    /*
     * bind local address to a system-assigned port
     */
    memset((char *)&local, 0, sizeof(local));
    local.sin_family = AF_INET;
    local.sin_port = htons(0);
    local.sin_addr.s_addr = INADDR_ANY;
    if (bind(sfd, (struct sockaddr *)&local, sizeof(local)) < 0)
    {
#ifdef DEBUG
        perror("bind");
#endif
        closesocket(sfd);

        return -1;
    }

    /*
     * all done
     */
    return sfd;
}

/*
 *  Function: fetch_ports
 *   Purpose: Request assigned port numbers from remote target
 *
 *    Params: None
 *
 *   Returns: Nothing
 *
 * Post-conditions: This routine will *always* return something for the
 *                      port numbers.  If the remote target does not
 *                      respond, then it makes something up - this allows
 *                      the standard error message (from ardi.c) to be
 *                      generated when the target is dead for whatever
 *                      reason.
 */
static void fetch_ports(void)
{
    int i;
    char ctrlpacket[10];
    CtrlResponse response;

    memset (ctrlpacket, 0, 10);
    strcpy (ctrlpacket, CTRL_MAGIC);
    memset (response, 0, sizeof(CtrlResponse));
    /*
     * we will try 3 times to elicit a response from the target
     */
    for (i = 0; i < 3; ++i)
    {
        struct timeval tv;
        fd_set fdset;

        /*
         * send the magic string to the control
         * port on the remote target
         */
        ia->sin_port = htons(CTRL_PORT);
#ifdef DEBUG
	printf("CTLR_PORT=0x%04x  sin_port=0x%04x\n");
#endif

        if (sendto(sock, ctrlpacket, sizeof(ctrlpacket), 0,
                       (struct sockaddr *)ia, sizeof(*ia)) < 0)
        {
#ifdef DEBUG
            perror("fetch_ports: sendto");
#endif
            return;
        }

        FD_ZERO(&fdset);
        FD_SET(sock, &fdset);
        tv.tv_sec = 0;
        tv.tv_usec = 250000;

        if (select(sock + 1, &fdset, NULL, NULL, &tv) < 0)
        {
#ifdef DEBUG
            perror("fetch_ports: select");
#endif
            return;
        }

        if (FD_ISSET(sock, &fdset))
        {
            /*
             * there is something there - read it
             */
            if (recv(sock, (char *)&response, sizeof(response), 0) < 0)
            {
#ifdef COMPILING_ON_WINDOWS
                unsigned int werrno = WSAGetLastError();

                if (werrno == WSAEWOULDBLOCK || werrno == 0)
#else
                if (errno == EWOULDBLOCK)
#endif
                {
                    --i;
                    continue;
                }
                else
                {
#ifdef DEBUG
                    perror("fetch_ports: recv");
#endif
                    return;
                }
            }
            {
                /*
                 * XXX
                 *
                 * this is *very* unpleasant - try to match the structure
                 * layout
                 */
                unsigned short *sptr = (unsigned short *)(response + RESP_DBUG);

                if (strcmp(response, ctrlpacket) == 0)
                {
                    ports[DBUG_INDEX] = htons(*sptr);
                    sptr++;
                    ports[APPL_INDEX] = htons(*sptr);
                }

#ifdef DEBUG
                printf("fetch_ports: got response, DBUG=%d, APPL=%d\n",
                       ports[DBUG_INDEX], ports[APPL_INDEX]);
#endif
                return;
            }
        }
    }

    /*
     * we failed to get a response
     */
#ifdef DEBUG
    printf("fetch_ports: failed to get a real answer\n");