kmed.c - devel/kme - Rivoreo Source Code Repositories

 /*
  * This is a sample kme UDP server for implementing
  * remote kme.  In this case, we interface to the
  * linux device driver for HLC by default.
  *
  * 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, 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 "config.h"

 #if !defined(HAVE_SOCKET)
 #error kmed requires the system socket() call.
 #endif

 #if HAVE_UNISTD_H
 #  include <unistd.h>
 #endif

 #if HAVE_STDLIB_H
 #  include <stdlib.h>
 #endif

 #if HAVE_STRING_H
 #  include <string.h>
 #endif

 #if HAVE_STRINGS_H
 #  include <strings.h>
 #endif

 #if HAVE_GETOPT_H
 #  include <getopt.h>
 #endif

 #include <stdio.h>
 #include <fcntl.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <netdb.h>
 #if HAVE_MMAP
 #  include <sys/mman.h>
 #endif

 #include "kme.h"

 char kmed_c_version[] = "@Id$";

 /*
  *  Unsigned variables.  This form makes them impervious
  *  to similar defs in sys/types.h.
  */

 #define uchar unsigned char
 #define ushort unsigned short
 #define ulong unsigned long

 /*
  *	The name of the memory device(s) to use by default
  *
  *	May consist of several device/file names separated by colons.
  *	This allows you to select one of several different memory
  *	spaces remotely.
  *
  *	In addition, the device name may be suffixed by ",offset,size",
  *	which causes the device to be mmap'ed into this process.
  */

 char	*MemName = "/dev/kmem";		/* Kernel memory */

 typedef struct
 {
     char	name[256];
     ulong	mmap_addr;
     ulong	mmap_size;

     int		fd;
     int		warned;
     ulong	mmap_curaddr;
     void	*mmap_vaddr;
 } COREINFO;

 #define	NUMCORE	16
 COREINFO	CoreInfo[NUMCORE];
 int		NumCore = 0;

 /*
  *	The current rw_t struct leaves the endianness of rw_size and
  *	rw_addr undefined.  This is not good.  We can run this server
  *	in three modes to try to deal with this.
  */

 #define	RW_ASIS			0	/* Pray its right already */
 #define	RW_IN_NETWORK_ORDER	1	/* Assume its in network order */
 #define	RW_DETECT		2	/* Guess, based on rw_size */

 int	RwEndianness = RW_DETECT;

 int	ReadOnly = 0;

 int	Debug = 0;

 /*
  *	Create coreinfo data
  */
 void
 coreinfo(char *str)
 {
     int i;
     int len;
     char *start = str;
     char *end;

     for (NumCore = 0; NumCore < NUMCORE; )
     {
 	end = strchr(start, ':');
 	if (!end) end = strchr(start, 0);

 	if (end - start == 2 && start[2] == '\\') {
 	    end = index(start+3, ':');
 	    if (!end) end = strchr(start+3, 0);
 	}

 	len = end - start;
 	if (len >= sizeof(CoreInfo[NumCore].name))
 	    len = sizeof(CoreInfo[NumCore].name) - 1;

 	strncpy(CoreInfo[NumCore].name, start, len);
 	CoreInfo[NumCore].name[len] = 0;

 	start = strchr(CoreInfo[NumCore].name, ',');
 	if (start)
 	{
 	    #if !HAVE_MMAP
 		fprintf(stderr, "Sorry, no mmap support on this target\n");
 		exit(1);
 	    #endif
 	    *start++ = 0;
 	    CoreInfo[NumCore].mmap_addr = strtoul(start, 0, 0);
 	    start = strchr(start, ',');
 	    if (start)
 		CoreInfo[NumCore].mmap_size = strtoul(start+1, 0, 0);
 	}

 	CoreInfo[NumCore].fd = -1;
 	CoreInfo[NumCore].mmap_curaddr = 0;
 	CoreInfo[NumCore].mmap_vaddr = (void *) -1;
 	++NumCore;

 	if (*end == 0)
 	    break;
 	else
 	    start = end+1;
     }
     if (Debug > 1)
 	for (i = 0; i < NumCore; ++i)
 	{
 	    fprintf(stderr, "%d	'%s'	%lu	%lu\n",
 		i, CoreInfo[i].name,
 		CoreInfo[i].mmap_addr,
 		CoreInfo[i].mmap_size);
 	}
 }

 void *
 map_range(COREINFO *cp, ulong addr, ulong size)
 {
     /*
      * Open the memory device if it isn't already open
      */
     if (cp->fd < 0)
     {
 	cp->fd = open(cp->name, ReadOnly ? O_RDONLY : O_RDWR);
 	if (cp->fd < 0)
 	{
 	    if (!cp->warned)
 	    {
 		perror("corefile open");
 		cp->warned = 1;
 	    }
 	    return (void *) -1;
 	}
     }

     /*
      * Check to see if mmap() is desired,
      */
     if (cp->mmap_size == 0)
 	return (void *) -1;

     #if HAVE_MMAP
 	if (cp->mmap_addr == 1)
 	{
 	    /*
 	     * Floating mmap requested
 	     *
 	     * This is a simplistic implementation
 	     */
 	    ulong baseaddr;
 	    ulong offset;

 	    baseaddr = addr & ~4095;
 	    offset = addr - baseaddr;
 	    if ((offset+size) > cp->mmap_size)
 		    return (void *) -1;
 	    if (cp->mmap_vaddr == (void *) -1 || baseaddr != cp->mmap_curaddr)
 	    {
 		if (cp->mmap_vaddr != (void *) -1)
 		{
 		    if (Debug)
 			fprintf(stderr, "unmap vaddr=%lx size=%lx\n",
 			    (long) cp->mmap_vaddr, cp->mmap_size);
 		    munmap(cp->mmap_vaddr, cp->mmap_size);
 		    cp->mmap_vaddr = (void *) -1;
 		}

 		cp->mmap_curaddr = baseaddr;
 		cp->mmap_vaddr = mmap(NULL, cp->mmap_size,
 				ReadOnly ? PROT_READ : (PROT_READ|PROT_WRITE),
 				MAP_SHARED, cp->fd, cp->mmap_curaddr);
 		if (Debug)
 		    fprintf(stderr, "new mmap vaddr=%lx addr=%lx size=%lx\n",
 			    (long) cp->mmap_vaddr, cp->mmap_curaddr,
 			    cp->mmap_size);
 		if (cp->mmap_vaddr == ((void *) -1))
 		{
 		    perror("floating mmap");
 		    return (void *) -1;
 		}
 	    }
 	    if (Debug)
 		fprintf(stderr, "cur=%lx size=%lx vaddr=%lx offset=%lx\n",
 			(long) cp->mmap_curaddr, cp->mmap_size,
 			(long) cp->mmap_vaddr, offset);
 	    return cp->mmap_vaddr + offset;
 	}
 	else
 	{
 	    /*
 	     * Fixed mmap requested
 	     */
 	    if (addr < cp->mmap_addr)
 		return (void *) -1;
 	    if ((addr+size) >= (cp->mmap_addr+cp->mmap_size))
 		return (void *) -1;

 	    if (cp->mmap_vaddr == (void *) -1)
 	    {
 		cp->mmap_curaddr = cp->mmap_addr;
 		cp->mmap_vaddr = mmap(NULL, cp->mmap_size,
 				ReadOnly ? PROT_READ : (PROT_READ|PROT_WRITE),
 				MAP_SHARED, cp->fd, cp->mmap_addr);
 		if (cp->mmap_vaddr == ((void *) -1))
 		{
 		    perror("fixed mmap");
 		    return (void *) -1;
 		}
 	    }
 	    return (cp->mmap_vaddr + addr);
 	}
     #else
 	return (void *) -1;
     #endif
 }

 /*
  *	Read memory.
  */
 int
 read_mem(rw_t* rw)
 {
     void		*vaddr;
     COREINFO		*cp;
     unsigned int	boardnum = rw->rw_module;

     if (boardnum >= NumCore)
 	return 0;
     cp = &CoreInfo[boardnum];
     vaddr = map_range(cp, rw->rw_addr, rw->rw_size);
     if (vaddr == (void *) -1)
     {
 	/* Not an mmap device, or need to fallback to lseek/read */
 	if (cp->fd == -1)
 	    return 0;
 	lseek(cp->fd, (off_t) rw->rw_addr + cp->mmap_addr, 0);
 	return read(cp->fd, rw->rw_data, rw->rw_size);
     }
     else
     {
 	memcpy(rw->rw_data, vaddr, rw->rw_size);
 	return rw->rw_size;
     }
 }

 /*
  *	Write memory.
  */
 int
 write_mem(rw_t* rw)
 {
     void		*vaddr;
     COREINFO		*cp;
     unsigned int	boardnum = rw->rw_module;

     if (boardnum >= NumCore)
 	return 0;
     cp = &CoreInfo[boardnum];
     vaddr = map_range(cp, rw->rw_addr, rw->rw_size);
     if (vaddr == (void *) -1)
     {
 	/* Not an mmap device, or need to fallback to lseek/write */
 	if (cp->fd == -1)
 	    return 0;
 	lseek(cp->fd, (off_t) rw->rw_addr + cp->mmap_addr, 0);
 	return write(cp->fd, rw->rw_data, rw->rw_size);
     }
     else
     {
 	memcpy(vaddr, rw->rw_data, rw->rw_size);
 	return rw->rw_size;
     }
 }

 /*
  *	swap routines
  */

 static ushort
 swapshort(ushort value)
 {
     value &= 0xffff;
     return ((value << 8) | (value >> 8));
 }

 static ulong
 swaplong (ulong val)
 {
     const ulong mask = 0x00ff00ff;

     ulong d = (val << 16) | (val >> 16);
     return ((d >> 8) & mask) | ((d & mask) << 8);
 }


 /*
  *	This is the request/response processing loop
  */

 void
 process(int fd)
 {
     int len;
     int rc;
     rw_t rw;
     struct sockaddr client_addr;
     int swap;

     for (;;)
     {
 	/*
 	 *	Get the next request from the client
 	 */

 	socklen_t client_len = sizeof(client_addr);
 	len = recvfrom(fd, (void*) &rw, sizeof(rw), 0,
 		       (struct sockaddr *) &client_addr, &client_len);
 	if (len < 0)
 	{
 	    perror("recvfrom");
 	    exit(5);
 	}

 	if (Debug)
 	    fprintf(stderr, "%s %d bytes at %lx from board=%d module=%d\n",
 		   rw.rw_req == RW_READ ? "Read" : "Write",
 		   rw.rw_size, rw.rw_addr, rw.rw_board, rw.rw_module);

 	/*
 	 * 	Convert request to host byte order (hopefully)
 	 */

 	switch (RwEndianness)
 	{
 	case RW_ASIS:
 	    break;
 	case RW_IN_NETWORK_ORDER:
 	    rw.rw_addr = ntohl(rw.rw_addr);
 	    rw.rw_size = ntohs(rw.rw_size);
 	    break;
 	default:
 	case RW_DETECT:
 	    if (rw.rw_size & 0xff00)
 	    {
 		rw.rw_size = swapshort(rw.rw_size);
 		rw.rw_addr = swaplong(rw.rw_addr);
 		swap = 1;
 	    }
 	    else
 	    {
 		swap = 0;
 	    }
 	    break;
 	}

 	/*
 	 *	Process the request
 	 */

 	if (rw.rw_size > sizeof(rw.rw_data))
 	    rw.rw_size = sizeof(rw.rw_data);

 	switch (rw.rw_req)
 	{
 	case RW_READ:
 	    rw.rw_size = read_mem(&rw);
 	    break;

 	case RW_WRITE:
 	    rw.rw_size = write_mem(&rw);
 	    break;
 	default:
 	    continue;
 	}

 	if (rw.rw_size > sizeof(rw.rw_data))
 	    rw.rw_size = 0;

 	/*
 	 * 	Convert request back to proper byte order (hopefully)
 	 */

 	switch (RwEndianness)
 	{
 	case RW_ASIS:
 	    break;
 	case RW_IN_NETWORK_ORDER:
 	    rw.rw_addr = ntohl(rw.rw_addr);
 	    rw.rw_size = ntohs(rw.rw_size);
 	    break;
 	default:
 	case RW_DETECT:
 	    if (swap)
 	    {
 		rw.rw_size = swapshort(rw.rw_size);
 		rw.rw_addr = swaplong(rw.rw_addr);
 	    }
 	    break;
 	}

 	/*
 	 *	Send the reply
 	 */

 	rc = sendto(fd, &rw, len, 0,
 		    (struct sockaddr *) &client_addr, client_len);
 	if (rc != len)
 	{
 	    perror("sendto");
 	    exit(6);
 	}
     }
 }

 /*
  *	The usual usage message
  */

 void
 usage(void)
 {
     fprintf(stderr,
     "Usage:	kmed [options]\n"
     "\n"
     "	A server to enable KME access over the network.\n"
     "\n"
     "Options:\n"
     "	-c corefile    Colon-separated list of filename(s) [%s]\n"
     "	                 normal access is via lseek() and read()/write()\n"
     "	                 to use a fixed mmap say: device,offset,size\n"
     "	                 to use a floating mmap say: device,1,size\n"
     "	-e endian      Endianness of RW protocol\n"
     "	                 (0=as-is, 1=network, 2==autodetect) [%d]\n"
     "	-r             Open corefile(s) read-only\n"
     "	-U port        KME access port number. [%d]\n"
     "	-D debug       Debug level. [%d]\n"
     "\n"
     "Standard /etc/services entry:\n"
     "	kme             %d/udp        kme            # kme server\n"
     "\n"
     "Example using two corefiles (2nd uses floating mmap):\n"
     "	kmed -c /dev/kmem:/dev/mem,1,4096\n"
 	    , MemName, RwEndianness, UDP_PORT, Debug, UDP_PORT
     );
     exit(1);
 }

 /*
  *	The main program
  */

 int
 main(int argc, char *argv[])
 {
     struct sockaddr_in serv_addr;
     char ch;
     int sockfd;
     int rc;
     int c;
     extern char *optarg;
     int port = 0;

     /*
      *	Process options
      */
     while ((c = getopt(argc, argv, "c:d:e:p:rU:D:")) != EOF)
     {
 	switch (c)
 	{
 	case 'c':
 	case 'd':
 	    MemName = optarg; break;
 	    break;

 	case 'e':
 	    RwEndianness = atoi(optarg);
 	    break;

 	case 'r':
 	    ReadOnly = 1;
 	    break;

 	case 'p':
 	case 'U':
 	    if (sscanf(optarg, "%d%c", &port, &ch) != 1 || port < 10)
 		usage();
 	    break;

 	case 'D':
 	    Debug = atoi(optarg);
 	    break;

 	default:
 	    usage();
 	    break;
 	}
     }

     coreinfo(MemName);

     /*
      *	Get a socket
      */
     sockfd = socket(AF_INET, SOCK_DGRAM, 0);
     if (sockfd < 0)
     {
 	perror("Can't open socket");
 	exit(2);
     }

     /*
      *	Figure out port number we want to use
      */
     if (port == 0)
     {
 	/*
 	 *	Get port number from /etc/services entry:
 	 *
 	 *	kme             2773/udp        kme             # kme
 	 */
 	struct servent *sep;

 	sep = getservbyname("kme", "udp");

 	if (sep != 0)
 	    port = sep->s_port;
 	else
 	    port = htons(UDP_PORT);
     }
     else
     {
 	port = htons(port) ;
     }

     /*
      *	Fill in INET address structure
      */
     memset(&serv_addr, 0, sizeof(serv_addr));
     serv_addr.sin_family = AF_INET;
     serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
     serv_addr.sin_port = port;

     /*
      *	Bind to the socket
      */
     rc = bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
     if (rc < 0)
     {
 	perror("bind failed");
 	exit(4);
     }

     /*
      *	Now run the actual server
      */
     process(sockfd);

     exit(0);
 }
	/*
	* This is a sample kme UDP server for implementing
	* remote kme. In this case, we interface to the
	* linux device driver for HLC by default.
	*
	* 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, 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 "config.h"

	#if !defined(HAVE_SOCKET)
	#error kmed requires the system socket() call.
	#endif

	#if HAVE_UNISTD_H
	# include <unistd.h>
	#endif

	#if HAVE_STDLIB_H
	# include <stdlib.h>
	#endif

	#if HAVE_STRING_H
	# include <string.h>
	#endif

	#if HAVE_STRINGS_H
	# include <strings.h>
	#endif

	#if HAVE_GETOPT_H
	# include <getopt.h>
	#endif

	#include <stdio.h>
	#include <fcntl.h>
	#include <sys/types.h>
	#include <sys/socket.h>
	#include <netinet/in.h>
	#include <netdb.h>
	#if HAVE_MMAP
	# include <sys/mman.h>
	#endif

	#include "kme.h"

	char kmed_c_version[] = "@Id$";

	/*
	* Unsigned variables. This form makes them impervious
	* to similar defs in sys/types.h.
	*/

	#define uchar unsigned char
	#define ushort unsigned short
	#define ulong unsigned long

	/*
	* The name of the memory device(s) to use by default
	*
	* May consist of several device/file names separated by colons.
	* This allows you to select one of several different memory
	* spaces remotely.
	*
	* In addition, the device name may be suffixed by ",offset,size",
	* which causes the device to be mmap'ed into this process.
	*/

	char MemName = "/dev/kmem"; / Kernel memory */

	typedef struct
	{
	char name[256];
	ulong mmap_addr;
	ulong mmap_size;

	int fd;
	int warned;
	ulong mmap_curaddr;
	void *mmap_vaddr;
	} COREINFO;

	#define NUMCORE 16
	COREINFO CoreInfo[NUMCORE];
	int NumCore = 0;

	/*
	* The current rw_t struct leaves the endianness of rw_size and
	* rw_addr undefined. This is not good. We can run this server
	* in three modes to try to deal with this.
	*/

	#define RW_ASIS 0 /* Pray its right already */
	#define RW_IN_NETWORK_ORDER 1 /* Assume its in network order */
	#define RW_DETECT 2 /* Guess, based on rw_size */

	int RwEndianness = RW_DETECT;

	int ReadOnly = 0;

	int Debug = 0;

	/*
	* Create coreinfo data
	*/
	void
	coreinfo(char *str)
	{
	int i;
	int len;
	char *start = str;
	char *end;

	for (NumCore = 0; NumCore < NUMCORE; )
	{
	end = strchr(start, ':');
	if (!end) end = strchr(start, 0);

	if (end - start == 2 && start[2] == '\\') {
	end = index(start+3, ':');
	if (!end) end = strchr(start+3, 0);
	}

	len = end - start;
	if (len >= sizeof(CoreInfo[NumCore].name))
	len = sizeof(CoreInfo[NumCore].name) - 1;

	strncpy(CoreInfo[NumCore].name, start, len);
	CoreInfo[NumCore].name[len] = 0;

	start = strchr(CoreInfo[NumCore].name, ',');
	if (start)
	{
	#if !HAVE_MMAP
	fprintf(stderr, "Sorry, no mmap support on this target\n");
	exit(1);
	#endif
	*start++ = 0;
	CoreInfo[NumCore].mmap_addr = strtoul(start, 0, 0);
	start = strchr(start, ',');
	if (start)
	CoreInfo[NumCore].mmap_size = strtoul(start+1, 0, 0);
	}

	CoreInfo[NumCore].fd = -1;
	CoreInfo[NumCore].mmap_curaddr = 0;
	CoreInfo[NumCore].mmap_vaddr = (void *) -1;
	++NumCore;

	if (*end == 0)
	break;
	else
	start = end+1;
	}
	if (Debug > 1)
	for (i = 0; i < NumCore; ++i)
	{
	fprintf(stderr, "%d '%s' %lu %lu\n",
	i, CoreInfo[i].name,
	CoreInfo[i].mmap_addr,
	CoreInfo[i].mmap_size);
	}
	}

	void *
	map_range(COREINFO *cp, ulong addr, ulong size)
	{
	/*
	* Open the memory device if it isn't already open
	*/
	if (cp->fd < 0)
	{
	cp->fd = open(cp->name, ReadOnly ? O_RDONLY : O_RDWR);
	if (cp->fd < 0)
	{
	if (!cp->warned)
	{
	perror("corefile open");
	cp->warned = 1;
	}
	return (void *) -1;
	}
	}

	/*
	* Check to see if mmap() is desired,
	*/
	if (cp->mmap_size == 0)
	return (void *) -1;

	#if HAVE_MMAP
	if (cp->mmap_addr == 1)
	{
	/*
	* Floating mmap requested
	*
	* This is a simplistic implementation
	*/
	ulong baseaddr;
	ulong offset;

	baseaddr = addr & ~4095;
	offset = addr - baseaddr;
	if ((offset+size) > cp->mmap_size)
	return (void *) -1;
	if (cp->mmap_vaddr == (void *) -1 \|\| baseaddr != cp->mmap_curaddr)
	{
	if (cp->mmap_vaddr != (void *) -1)
	{
	if (Debug)
	fprintf(stderr, "unmap vaddr=%lx size=%lx\n",
	(long) cp->mmap_vaddr, cp->mmap_size);
	munmap(cp->mmap_vaddr, cp->mmap_size);
	cp->mmap_vaddr = (void *) -1;
	}

	cp->mmap_curaddr = baseaddr;
	cp->mmap_vaddr = mmap(NULL, cp->mmap_size,
	ReadOnly ? PROT_READ : (PROT_READ\|PROT_WRITE),
	MAP_SHARED, cp->fd, cp->mmap_curaddr);
	if (Debug)
	fprintf(stderr, "new mmap vaddr=%lx addr=%lx size=%lx\n",
	(long) cp->mmap_vaddr, cp->mmap_curaddr,
	cp->mmap_size);
	if (cp->mmap_vaddr == ((void *) -1))
	{
	perror("floating mmap");
	return (void *) -1;
	}
	}
	if (Debug)
	fprintf(stderr, "cur=%lx size=%lx vaddr=%lx offset=%lx\n",
	(long) cp->mmap_curaddr, cp->mmap_size,
	(long) cp->mmap_vaddr, offset);
	return cp->mmap_vaddr + offset;
	}
	else
	{
	/*
	* Fixed mmap requested
	*/
	if (addr < cp->mmap_addr)
	return (void *) -1;
	if ((addr+size) >= (cp->mmap_addr+cp->mmap_size))
	return (void *) -1;

	if (cp->mmap_vaddr == (void *) -1)
	{
	cp->mmap_curaddr = cp->mmap_addr;
	cp->mmap_vaddr = mmap(NULL, cp->mmap_size,
	ReadOnly ? PROT_READ : (PROT_READ\|PROT_WRITE),
	MAP_SHARED, cp->fd, cp->mmap_addr);
	if (cp->mmap_vaddr == ((void *) -1))
	{
	perror("fixed mmap");
	return (void *) -1;
	}
	}
	return (cp->mmap_vaddr + addr);
	}
	#else
	return (void *) -1;
	#endif
	}

	/*
	* Read memory.
	*/
	int
	read_mem(rw_t* rw)
	{
	void *vaddr;
	COREINFO *cp;
	unsigned int boardnum = rw->rw_module;

	if (boardnum >= NumCore)
	return 0;
	cp = &CoreInfo[boardnum];
	vaddr = map_range(cp, rw->rw_addr, rw->rw_size);
	if (vaddr == (void *) -1)
	{
	/* Not an mmap device, or need to fallback to lseek/read */
	if (cp->fd == -1)
	return 0;
	lseek(cp->fd, (off_t) rw->rw_addr + cp->mmap_addr, 0);
	return read(cp->fd, rw->rw_data, rw->rw_size);
	}
	else
	{
	memcpy(rw->rw_data, vaddr, rw->rw_size);
	return rw->rw_size;
	}
	}

	/*
	* Write memory.
	*/
	int
	write_mem(rw_t* rw)
	{
	void *vaddr;
	COREINFO *cp;
	unsigned int boardnum = rw->rw_module;

	if (boardnum >= NumCore)
	return 0;
	cp = &CoreInfo[boardnum];
	vaddr = map_range(cp, rw->rw_addr, rw->rw_size);
	if (vaddr == (void *) -1)
	{
	/* Not an mmap device, or need to fallback to lseek/write */
	if (cp->fd == -1)
	return 0;
	lseek(cp->fd, (off_t) rw->rw_addr + cp->mmap_addr, 0);
	return write(cp->fd, rw->rw_data, rw->rw_size);
	}
	else
	{
	memcpy(vaddr, rw->rw_data, rw->rw_size);
	return rw->rw_size;
	}
	}

	/*
	* swap routines
	*/

	static ushort
	swapshort(ushort value)
	{
	value &= 0xffff;
	return ((value << 8) \| (value >> 8));
	}

	static ulong
	swaplong (ulong val)
	{
	const ulong mask = 0x00ff00ff;

	ulong d = (val << 16) \| (val >> 16);
	return ((d >> 8) & mask) \| ((d & mask) << 8);
	}


	/*
	* This is the request/response processing loop
	*/

	void
	process(int fd)
	{
	int len;
	int rc;
	rw_t rw;
	struct sockaddr client_addr;
	int swap;

	for (;;)
	{
	/*
	* Get the next request from the client
	*/

	socklen_t client_len = sizeof(client_addr);
	len = recvfrom(fd, (void*) &rw, sizeof(rw), 0,
	(struct sockaddr *) &client_addr, &client_len);
	if (len < 0)
	{
	perror("recvfrom");
	exit(5);
	}

	if (Debug)
	fprintf(stderr, "%s %d bytes at %lx from board=%d module=%d\n",
	rw.rw_req == RW_READ ? "Read" : "Write",
	rw.rw_size, rw.rw_addr, rw.rw_board, rw.rw_module);

	/*
	* Convert request to host byte order (hopefully)
	*/

	switch (RwEndianness)
	{
	case RW_ASIS:
	break;
	case RW_IN_NETWORK_ORDER:
	rw.rw_addr = ntohl(rw.rw_addr);
	rw.rw_size = ntohs(rw.rw_size);
	break;
	default:
	case RW_DETECT:
	if (rw.rw_size & 0xff00)
	{
	rw.rw_size = swapshort(rw.rw_size);
	rw.rw_addr = swaplong(rw.rw_addr);
	swap = 1;
	}
	else
	{
	swap = 0;
	}
	break;
	}

	/*
	* Process the request
	*/

	if (rw.rw_size > sizeof(rw.rw_data))
	rw.rw_size = sizeof(rw.rw_data);

	switch (rw.rw_req)
	{
	case RW_READ:
	rw.rw_size = read_mem(&rw);
	break;

	case RW_WRITE:
	rw.rw_size = write_mem(&rw);
	break;
	default:
	continue;
	}

	if (rw.rw_size > sizeof(rw.rw_data))
	rw.rw_size = 0;

	/*
	* Convert request back to proper byte order (hopefully)
	*/

	switch (RwEndianness)
	{
	case RW_ASIS:
	break;
	case RW_IN_NETWORK_ORDER:
	rw.rw_addr = ntohl(rw.rw_addr);
	rw.rw_size = ntohs(rw.rw_size);
	break;
	default:
	case RW_DETECT:
	if (swap)
	{
	rw.rw_size = swapshort(rw.rw_size);
	rw.rw_addr = swaplong(rw.rw_addr);
	}
	break;
	}

	/*
	* Send the reply
	*/

	rc = sendto(fd, &rw, len, 0,
	(struct sockaddr *) &client_addr, client_len);
	if (rc != len)
	{
	perror("sendto");
	exit(6);
	}
	}
	}

	/*
	* The usual usage message
	*/

	void
	usage(void)
	{
	fprintf(stderr,
	"Usage: kmed [options]\n"
	"\n"
	" A server to enable KME access over the network.\n"
	"\n"
	"Options:\n"
	" -c corefile Colon-separated list of filename(s) [%s]\n"
	" normal access is via lseek() and read()/write()\n"
	" to use a fixed mmap say: device,offset,size\n"
	" to use a floating mmap say: device,1,size\n"
	" -e endian Endianness of RW protocol\n"
	" (0=as-is, 1=network, 2==autodetect) [%d]\n"
	" -r Open corefile(s) read-only\n"
	" -U port KME access port number. [%d]\n"
	" -D debug Debug level. [%d]\n"
	"\n"
	"Standard /etc/services entry:\n"
	" kme %d/udp kme # kme server\n"
	"\n"
	"Example using two corefiles (2nd uses floating mmap):\n"
	" kmed -c /dev/kmem:/dev/mem,1,4096\n"
	, MemName, RwEndianness, UDP_PORT, Debug, UDP_PORT
	);
	exit(1);
	}

	/*
	* The main program
	*/

	int
	main(int argc, char *argv[])
	{
	struct sockaddr_in serv_addr;
	char ch;
	int sockfd;
	int rc;
	int c;
	extern char *optarg;
	int port = 0;

	/*
	* Process options
	*/
	while ((c = getopt(argc, argv, "c:d:e:p:rU:D:")) != EOF)
	{
	switch (c)
	{
	case 'c':
	case 'd':
	MemName = optarg; break;
	break;

	case 'e':
	RwEndianness = atoi(optarg);
	break;

	case 'r':
	ReadOnly = 1;
	break;

	case 'p':
	case 'U':
	if (sscanf(optarg, "%d%c", &port, &ch) != 1 \|\| port < 10)
	usage();
	break;

	case 'D':
	Debug = atoi(optarg);
	break;

	default:
	usage();
	break;
	}
	}

	coreinfo(MemName);

	/*
	* Get a socket
	*/
	sockfd = socket(AF_INET, SOCK_DGRAM, 0);
	if (sockfd < 0)
	{
	perror("Can't open socket");
	exit(2);
	}

	/*
	* Figure out port number we want to use
	*/
	if (port == 0)
	{
	/*
	* Get port number from /etc/services entry:
	*
	* kme 2773/udp kme # kme
	*/
	struct servent *sep;

	sep = getservbyname("kme", "udp");

	if (sep != 0)
	port = sep->s_port;
	else
	port = htons(UDP_PORT);
	}
	else
	{
	port = htons(port) ;
	}

	/*
	* Fill in INET address structure
	*/
	memset(&serv_addr, 0, sizeof(serv_addr));
	serv_addr.sin_family = AF_INET;
	serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
	serv_addr.sin_port = port;

	/*
	* Bind to the socket
	*/
	rc = bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
	if (rc < 0)
	{
	perror("bind failed");
	exit(4);
	}

	/*
	* Now run the actual server
	*/
	process(sockfd);

	exit(0);
	}