tftpsubs.c

ks8695的SOHO应用中的tftp部分

/* tftp-hpa: $Id: tftpsubs.c,v 1.1.1.1 2004/05/06 19:43:41 hjia Exp $ */

/* $OpenBSD: tftpsubs.c,v 1.2 1996/06/26 05:40:36 deraadt Exp $	*/
/* $NetBSD: tftpsubs.c,v 1.3 1994/12/08 09:51:31 jtc Exp $	*/

/*
 * Copyright (c) 1983, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*#ifndef lint*/
/* static char sccsid[] = "@(#)tftpsubs.c	8.1 (Berkeley) 6/6/93"; */
/* static char rcsid[] = "$OpenBSD: tftpsubs.c,v 1.2 1996/06/26 05:40:36 deraadt Exp $"; */
/*static const char *rcsid = "tftp-hpa: $Id: tftpsubs.c,v 1.1.1.1 2004/05/06 19:43:41 hjia Exp $";*/
/*#endif*/ /* not lint */

/* Simple minded read-ahead/write-behind subroutines for tftp user and
   server.  Written originally with multiple buffers in mind, but current
   implementation has two buffer logic wired in.

   Todo:  add some sort of final error check so when the write-buffer
   is finally flushed, the caller can detect if the disk filled up
   (or had an i/o error) and return a nak to the other side.

			Jim Guyton 10/85
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <arpa/tftp.h>
#include <errno.h>

#include <stdio.h>
#include <unistd.h>

#include "tftpsubs.h"
/*#include "../web/webconfig/util.h"*/

#define PKTSIZE MAX_SEGSIZE+4       /* should be moved to tftp.h */

int segsize = SEGSIZE;		/* Default segsize */

struct bf {
	int counter;            /* size of data in buffer, or flag */
	char buf[PKTSIZE];      /* room for data packet */
} bfs[2];

				/* Values for bf.counter  */
#define BF_ALLOC -3             /* alloc'd but not yet filled */
#define BF_FREE  -2             /* free */
/* [-1 .. segsize] = size of data in the data buffer */

static int nextone;		/* index of next buffer to use */
static int current;		/* index of buffer in use */
static int total_written;

				/* control flags for crlf conversions */
int newline = 0;		/* fillbuf: in middle of newline expansion */
int prevchar = -1;		/* putbuf: previous char (cr check) */

static struct tftphdr *rw_init(int);

struct tftphdr *w_init() { return rw_init(0); }         /* write-behind */
struct tftphdr *r_init() { return rw_init(1); }         /* read-ahead */

/* init for either read-ahead or write-behind */
/* x == zero for write-behind, one for read-head */
static struct tftphdr *
rw_init(int x)
{
	newline = 0;		/* init crlf flag */
	prevchar = -1;
	bfs[0].counter =  BF_ALLOC;     /* pass out the first buffer */
	current = 0;
	bfs[1].counter = BF_FREE;
	nextone = x;           /* ahead or behind? */
	total_written = 0;
	return (struct tftphdr *)bfs[0].buf;
}


/* Have emptied current buffer by sending to net and getting ack.
   Free it and return next buffer filled with data.
 */
int
readit(FILE *file, struct tftphdr **dpp, int convert)
{
	struct bf *b;

	bfs[current].counter = BF_FREE; /* free old one */
	current = !current;             /* "incr" current */

	b = &bfs[current];              /* look at new buffer */
	if (b->counter == BF_FREE)      /* if it's empty */
		read_ahead(file, convert);      /* fill it */
/*      assert(b->counter != BF_FREE);*//* check */
	*dpp = (struct tftphdr *)b->buf;        /* set caller's ptr */
	return b->counter;
}

/*
 * fill the input buffer, doing ascii conversions if requested
 * conversions are  lf -> cr,lf  and cr -> cr, nul
 */
void
read_ahead(FILE *file, int convert)
{
	int i;
	char *p;
	int c;
	struct bf *b;
	struct tftphdr *dp;

	b = &bfs[nextone];              /* look at "next" buffer */
	if (b->counter != BF_FREE)      /* nop if not free */
		return;
	nextone = !nextone;             /* "incr" next buffer ptr */

	dp = (struct tftphdr *)b->buf;

	if (convert == 0) {
		b->counter = read(fileno(file), dp->th_data, segsize);
		return;
	}

	p = dp->th_data;
	for (i = 0 ; i < segsize; i++) {
		if (newline) {
			if (prevchar == '\n')
				c = '\n';       /* lf to cr,lf */
			else    c = '\0';       /* cr to cr,nul */
			newline = 0;
		}
		else {
			c = getc(file);
			if (c == EOF) break;
			if (c == '\n' || c == '\r') {
				prevchar = c;
				c = '\r';
				newline = 1;
			}
		}
	       *p++ = c;
	}
	b->counter = (int)(p - dp->th_data);
}

/* Update count associated with the buffer, get new buffer
   from the queue.  Calls write_behind only if next buffer not
   available.
 */
int
writeit(FILE *file, struct tftphdr **dpp, int ct, int convert)
{
  int written=0;

	bfs[current].counter = ct;      /* set size of data to write */
	current = !current;             /* switch to other buffer */
	if (bfs[current].counter != BF_FREE) {    /* if not free */
	  // never get into here, 
		written = write_behind(file, convert); /* flush it */
		//kd_Log("written1 %d",written);
	}
	//		(void)write_behind(file, convert); /* flush it */
	bfs[current].counter = BF_ALLOC;        /* mark as alloc'd */
	*dpp =  (struct tftphdr *)bfs[current].buf;
	//kd_Log("written2 %d",written);
	return ct;                      /* this is a lie of course */
	//	return written;
}

/*
 * Output a buffer to a file, converting from netascii if requested.
 * CR,NUL -> CR  and CR,LF => LF.
 * Note spec is undefined if we get CR as last byte of file or a
 * CR followed by anything else.  In this case we leave it alone.
 */
int
write_behind(FILE *file, int convert)
{
	char *buf;
	int count;
	int ct;
	char *p;
	int c;                 /* current character */
	struct bf *b;
	struct tftphdr *dp;
	int written;

	b = &bfs[nextone];
	if (b->counter < -1)            /* anything to flush? */
		return 0;               /* just nop if nothing to do */

	count = b->counter;             /* remember byte count */
	b->counter = BF_FREE;           /* reset flag */
	dp = (struct tftphdr *)b->buf;
	nextone = !nextone;             /* incr for next time */
	buf = dp->th_data;

	if (count <= 0) return -1;      /* nak logic? */

	if (convert == 0) {
	  written = write(fileno(file), buf, count);
		// printf("written0 %d",written);		
		//		total_written += written;
		//		kd_Log("tftp accumulated %d",total_written);
		if (written != count) {
		  //kd_Log("tftp: write err errno=0x%x %d @ %d bytes",
		  //  errno,written,count);
		  if (written == -1)
		    return -1;         // use errno      
		  return -2;           // not enough disk space
		}
		return written;
	}

	p = buf;
	ct = count;
	while (ct--) {                  /* loop over the buffer */
	    c = *p++;                   /* pick up a character */
	    if (prevchar == '\r') {     /* if prev char was cr */
		if (c == '\n')          /* if have cr,lf then just */
		   fseek(file, -1, 1);  /* smash lf on top of the cr */
		else
		   if (c == '\0')       /* if have cr,nul then */
			goto skipit;    /* just skip over the putc */
		/* else just fall through and allow it */
	    }
	    putc(c, file);
skipit:
	    prevchar = c;
	}
	return count;
}


/* When an error has occurred, it is possible that the two sides
 * are out of synch.  Ie: that what I think is the other side's
 * response to packet N is really their response to packet N-1.
 *
 * So, to try to prevent that, we flush all the input queued up
 * for us on the network connection on our host.
 *
 * We return the number of packets we flushed (mostly for reporting
 * when trace is active).
 */

int
synchnet(int f)		/* socket to flush */
{
	int i, j = 0;
	char rbuf[PKTSIZE];
	struct sockaddr_in from;
	int fromlen;

	while (1) {
		(void) ioctl(f, FIONREAD, &i);
		if (i) {
			j++;
			fromlen = sizeof from;
			(void) recvfrom(f, rbuf, sizeof (rbuf), 0,
				(struct sockaddr *)&from, &fromlen);
		} else {
			return(j);
		}
	}
}