NetBSD-5.0.2/sys/lib/libsa/tftp.c
/* $NetBSD: tftp.c,v 1.26 2008/05/11 11:29:12 chris Exp $ */
/*
* Copyright (c) 1996
* Matthias Drochner. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
*/
/*
* Simple TFTP implementation for libsa.
* Assumes:
* - socket descriptor (int) at open_file->f_devdata
* - server host IP in global servip
* Restrictions:
* - read only
* - lseek only with SEEK_SET or SEEK_CUR
* - no big time differences between transfers (<tftp timeout)
*/
/*
* XXX Does not currently implement:
* XXX
* XXX LIBSA_NO_FS_CLOSE
* XXX LIBSA_NO_FS_SEEK
* XXX LIBSA_NO_FS_WRITE
* XXX LIBSA_NO_FS_SYMLINK (does this even make sense?)
* XXX LIBSA_FS_SINGLECOMPONENT (does this even make sense?)
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <netinet/udp.h>
#include <netinet/in_systm.h>
#include <lib/libkern/libkern.h>
#include "stand.h"
#include "net.h"
#include "tftp.h"
extern struct in_addr servip;
static int tftpport = 2000;
#define RSPACE 520 /* max data packet, rounded up */
struct tftp_handle {
struct iodesc *iodesc;
int currblock; /* contents of lastdata */
int islastblock; /* flag */
int validsize;
int off;
const char *path; /* saved for re-requests */
struct {
u_char header[HEADER_SIZE];
struct tftphdr t;
u_char space[RSPACE];
} lastdata;
};
static const int tftperrors[8] = {
0, /* ??? */
ENOENT,
EPERM,
ENOSPC,
EINVAL, /* ??? */
EINVAL, /* ??? */
EEXIST,
EINVAL, /* ??? */
};
static ssize_t recvtftp __P((struct iodesc *, void *, size_t, time_t));
static int tftp_makereq __P((struct tftp_handle *));
static int tftp_getnextblock __P((struct tftp_handle *));
#ifndef TFTP_NOTERMINATE
static void tftp_terminate __P((struct tftp_handle *));
#endif
static ssize_t tftp_size_of_file __P((struct tftp_handle *tftpfile));
static ssize_t
recvtftp(struct iodesc *d, void *pkt, size_t len, time_t tleft)
{
ssize_t n;
struct tftphdr *t;
errno = 0;
n = readudp(d, pkt, len, tleft);
if (n < 4)
return -1;
t = (struct tftphdr *)pkt;
switch (ntohs(t->th_opcode)) {
case DATA:
if (htons(t->th_block) != d->xid) {
/*
* Expected block?
*/
return -1;
}
if (d->xid == 1) {
/*
* First data packet from new port.
*/
struct udphdr *uh;
uh = (struct udphdr *)pkt - 1;
d->destport = uh->uh_sport;
} /* else check uh_sport has not changed??? */
return (n - (t->th_data - (char *)t));
case ERROR:
if ((unsigned int)ntohs(t->th_code) >= 8) {
printf("illegal tftp error %d\n", ntohs(t->th_code));
errno = EIO;
} else {
#ifdef DEBUG
printf("tftp-error %d\n", ntohs(t->th_code));
#endif
errno = tftperrors[ntohs(t->th_code)];
}
return -1;
default:
#ifdef DEBUG
printf("tftp type %d not handled\n", ntohs(t->th_opcode));
#endif
return -1;
}
}
/* send request, expect first block (or error) */
static int
tftp_makereq(struct tftp_handle *h)
{
struct {
u_char header[HEADER_SIZE];
struct tftphdr t;
u_char space[FNAME_SIZE + 6];
} wbuf;
char *wtail;
int l;
ssize_t res;
struct tftphdr *t;
wbuf.t.th_opcode = htons((u_short)RRQ);
wtail = wbuf.t.th_stuff;
l = strlen(h->path);
(void)memcpy(wtail, h->path, l + 1);
wtail += l + 1;
(void)memcpy(wtail, "octet", 6);
wtail += 6;
t = &h->lastdata.t;
/* h->iodesc->myport = htons(--tftpport); */
h->iodesc->myport = htons(tftpport + (getsecs() & 0x3ff));
h->iodesc->destport = htons(IPPORT_TFTP);
h->iodesc->xid = 1; /* expected block */
res = sendrecv(h->iodesc, sendudp, &wbuf.t, wtail - (char *)&wbuf.t,
recvtftp, t, sizeof(*t) + RSPACE);
if (res == -1)
return errno;
h->currblock = 1;
h->validsize = res;
h->islastblock = 0;
if (res < SEGSIZE)
h->islastblock = 1; /* very short file */
return 0;
}
/* ack block, expect next */
static int
tftp_getnextblock(struct tftp_handle *h)
{
struct {
u_char header[HEADER_SIZE];
struct tftphdr t;
} wbuf;
char *wtail;
int res;
struct tftphdr *t;
wbuf.t.th_opcode = htons((u_short)ACK);
wbuf.t.th_block = htons((u_short)h->currblock);
wtail = (char *)&wbuf.t.th_data;
t = &h->lastdata.t;
h->iodesc->xid = h->currblock + 1; /* expected block */
res = sendrecv(h->iodesc, sendudp, &wbuf.t, wtail - (char *)&wbuf.t,
recvtftp, t, sizeof(*t) + RSPACE);
if (res == -1) /* 0 is OK! */
return errno;
h->currblock++;
h->validsize = res;
if (res < SEGSIZE)
h->islastblock = 1; /* EOF */
return 0;
}
#ifndef TFTP_NOTERMINATE
static void
tftp_terminate(struct tftp_handle *h)
{
struct {
u_char header[HEADER_SIZE];
struct tftphdr t;
} wbuf;
char *wtail;
if (h->islastblock) {
wbuf.t.th_opcode = htons((u_short)ACK);
wbuf.t.th_block = htons((u_short)h->currblock);
} else {
wbuf.t.th_opcode = htons((u_short)ERROR);
wbuf.t.th_code = htons((u_short)ENOSPACE); /* ??? */
}
wtail = (char *)&wbuf.t.th_data;
(void)sendudp(h->iodesc, &wbuf.t, wtail - (char *)&wbuf.t);
}
#endif
int
tftp_open(const char *path, struct open_file *f)
{
struct tftp_handle *tftpfile;
struct iodesc *io;
int res;
tftpfile = (struct tftp_handle *)alloc(sizeof(*tftpfile));
if (!tftpfile)
return ENOMEM;
tftpfile->iodesc = io = socktodesc(*(int *)(f->f_devdata));
io->destip = servip;
tftpfile->off = 0;
tftpfile->path = path; /* XXXXXXX we hope it's static */
res = tftp_makereq(tftpfile);
if (res) {
dealloc(tftpfile, sizeof(*tftpfile));
return res;
}
f->f_fsdata = (void *)tftpfile;
return 0;
}
int
tftp_read(struct open_file *f, void *addr, size_t size, size_t *resid)
{
struct tftp_handle *tftpfile;
#if !defined(LIBSA_NO_TWIDDLE)
static int tc = 0;
#endif
tftpfile = (struct tftp_handle *)f->f_fsdata;
while (size > 0) {
int needblock;
size_t count;
#if !defined(LIBSA_NO_TWIDDLE)
if (!(tc++ % 16))
twiddle();
#endif
needblock = tftpfile->off / SEGSIZE + 1;
if (tftpfile->currblock > needblock) { /* seek backwards */
#ifndef TFTP_NOTERMINATE
tftp_terminate(tftpfile);
#endif
tftp_makereq(tftpfile); /* no error check, it worked
* for open */
}
while (tftpfile->currblock < needblock) {
int res;
res = tftp_getnextblock(tftpfile);
if (res) { /* no answer */
#ifdef DEBUG
printf("tftp: read error (block %d->%d)\n",
tftpfile->currblock, needblock);
#endif
return res;
}
if (tftpfile->islastblock)
break;
}
if (tftpfile->currblock == needblock) {
size_t offinblock, inbuffer;
offinblock = tftpfile->off % SEGSIZE;
inbuffer = tftpfile->validsize - offinblock;
if (inbuffer < 0) {
#ifdef DEBUG
printf("tftp: invalid offset %d\n",
tftpfile->off);
#endif
return EINVAL;
}
count = (size < inbuffer ? size : inbuffer);
(void)memcpy(addr,
tftpfile->lastdata.t.th_data + offinblock,
count);
addr = (char *)addr + count;
tftpfile->off += count;
size -= count;
if ((tftpfile->islastblock) && (count == inbuffer))
break; /* EOF */
} else {
#ifdef DEBUG
printf("tftp: block %d not found\n", needblock);
#endif
return EINVAL;
}
}
if (resid)
*resid = size;
return 0;
}
int
tftp_close(struct open_file *f)
{
struct tftp_handle *tftpfile;
tftpfile = (struct tftp_handle *)f->f_fsdata;
#ifdef TFTP_NOTERMINATE
/* let it time out ... */
#else
tftp_terminate(tftpfile);
#endif
dealloc(tftpfile, sizeof(*tftpfile));
return 0;
}
int
tftp_write(struct open_file *f, void *start, size_t size, size_t *resid)
{
return EROFS;
}
static ssize_t
tftp_size_of_file(struct tftp_handle *tftpfile)
{
ssize_t filesize;
if (tftpfile->currblock > 1) { /* move to start of file */
#ifndef TFTP_NOTERMINATE
tftp_terminate(tftpfile);
#endif
tftp_makereq(tftpfile); /* no error check, it worked
* for open */
}
/* start with the size of block 1 */
filesize = tftpfile->validsize;
/* and keep adding the sizes till we hit the last block */
while (!tftpfile->islastblock) {
int res;
res = tftp_getnextblock(tftpfile);
if (res) { /* no answer */
#ifdef DEBUG
printf("tftp: read error (block %d)\n",
tftpfile->currblock);
#endif
return -1;
}
filesize += tftpfile->validsize;
}
#ifdef DEBUG
printf("tftp_size_of_file: file is %d bytes\n", filesize);
#endif
return filesize;
}
int
tftp_stat(struct open_file *f, struct stat *sb)
{
struct tftp_handle *tftpfile;
tftpfile = (struct tftp_handle *)f->f_fsdata;
sb->st_mode = 0444;
sb->st_nlink = 1;
sb->st_uid = 0;
sb->st_gid = 0;
sb->st_size = tftp_size_of_file(tftpfile);
return 0;
}
off_t
tftp_seek(struct open_file *f, off_t offset, int where)
{
struct tftp_handle *tftpfile;
tftpfile = (struct tftp_handle *)f->f_fsdata;
switch (where) {
case SEEK_SET:
tftpfile->off = offset;
break;
case SEEK_CUR:
tftpfile->off += offset;
break;
default:
errno = EOFFSET;
return -1;
}
return tftpfile->off;
}