NetBSD/usr.bin/tftp/tftpsubs.c
briggs 4441128638 Support negotiation and use of TFTP Option Extension (rfc 2347) for the
'blksize' option (rfc 2348) and the 'timeout' and 'tsize' options (rfc 2349).

Contributed by Wasabi Systems, Inc.
2003-06-11 01:43:52 +00:00

290 lines
8.4 KiB
C

/* $NetBSD: tftpsubs.c,v 1.7 2003/06/11 01:44:32 briggs 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.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)tftpsubs.c 8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: tftpsubs.c,v 1.7 2003/06/11 01:44:32 briggs Exp $");
#endif
#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 <stdio.h>
#include <unistd.h>
#include "tftpsubs.h"
struct bf {
int counter; /* size of data in buffer, or flag */
char buf[MAXPKTSIZE]; /* 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 */
/* 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 __P((int));
struct tftphdr *
w_init() /* write-behind */
{
return rw_init(0);
}
struct tftphdr *
r_init() /* read-ahead */
{
return rw_init(1);
}
static struct tftphdr *
rw_init(x) /* init for either read-ahead or write-behind */
int x; /* zero for write-behind, one for read-head */
{
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? */
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, dpp, amt, convert)
FILE *file; /* file opened for read */
struct tftphdr **dpp;
int amt;
int convert; /* if true, convert to ascii */
{
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, amt, 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, amt, convert)
FILE *file; /* file opened for read */
int amt; /* number of bytes to read */
int convert; /* if true, convert to ascii */
{
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, amt);
return;
}
p = dp->th_data;
for (i = 0 ; i < amt; 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, dpp, ct, convert)
FILE *file;
struct tftphdr **dpp;
int ct, convert;
{
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 */
(void)write_behind(file, convert); /* flush it */
bfs[current].counter = BF_ALLOC; /* mark as alloc'd */
*dpp = (struct tftphdr *)bfs[current].buf;
return ct; /* this is a lie of course */
}
/*
* 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, convert)
FILE *file;
int convert;
{
char *buf;
int count;
int ct;
char *p;
int c; /* current character */
struct bf *b;
struct tftphdr *dp;
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)
return write(fileno(file), buf, count);
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(f, bsize)
int f; /* socket to flush */
int bsize; /* size of buffer to sync */
{
int i, j = 0;
char rbuf[PKTSIZE];
struct sockaddr_storage 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);
}
}
}