/* 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];
} __packed __aligned(4) wbuf;
char *wtail;
int l;
ssize_t res;
struct tftphdr *t;
char *tftp_blksize = NULL;
int blksize_l;
unsigned short rtype = 0;
/*
* Allow overriding default TFTP block size by setting
* a tftp.blksize environment variable.
*/
if ((tftp_blksize = getenv("tftp.blksize")) != NULL) {
tftp_set_blksize(h, tftp_blksize);
}
wbuf.t.th_opcode = htons((u_short) RRQ);
wtail = wbuf.t.th_stuff;
l = strlen(h->path);
#ifdef TFTP_PREPEND_PATH
if (l > FNAME_SIZE - (sizeof(TFTP_PREPEND_PATH) - 1))
return (ENAMETOOLONG);
bcopy(TFTP_PREPEND_PATH, wtail, sizeof(TFTP_PREPEND_PATH) - 1);
wtail += sizeof(TFTP_PREPEND_PATH) - 1;
#else
if (l > FNAME_SIZE)
return (ENAMETOOLONG);
#endif
bcopy(h->path, wtail, l + 1);
wtail += l + 1;
bcopy("octet", wtail, 6);
wtail += 6;
bcopy("blksize", wtail, 8);
wtail += 8;
blksize_l = sprintf(wtail, "%d", h->tftp_blksize);
wtail += blksize_l + 1;
bcopy("tsize", wtail, 6);
wtail += 6;
bcopy("0", wtail, 2);
wtail += 2;
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 */
h->currblock = 0;
h->islastblock = 0;
h->validsize = 0;
res = sendrecv_tftp(h, &sendudp, &wbuf.t, wtail - (char *) &wbuf.t,
&recvtftp, t, sizeof(*t) + h->tftp_blksize, &rtype);
if (rtype == OACK)
return (tftp_getnextblock(h));
/* Server ignored our blksize request, revert to TFTP default. */
h->tftp_blksize = SEGSIZE;
switch (rtype) {
case DATA: {
h->currblock = 1;
h->validsize = res;
h->islastblock = 0;
if (res < h->tftp_blksize) {
h->islastblock = 1; /* very short file */
tftp_sendack(h);
}
return (0);
}
case ERROR:
default:
return (errno);
}
}
static int
tftp_read(struct open_file *f, void *addr, size_t size,
size_t *resid /* out */)
{
struct tftp_handle *tftpfile;
static int tc = 0;
tftpfile = (struct tftp_handle *) f->f_fsdata;
while (size > 0) {
int needblock, count;
if (!(tc++ % 16))
twiddle();
needblock = tftpfile->off / tftpfile->tftp_blksize + 1;
if (tftpfile->currblock > needblock) { /* seek backwards */
tftp_senderr(tftpfile, 0, "No error: read aborted");
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 TFTP_DEBUG
printf("tftp: read error\n");
#endif
return (res);
}
if (tftpfile->islastblock)
break;
}
if (tftpfile->currblock == needblock) {
int offinblock, inbuffer;
offinblock = tftpfile->off % tftpfile->tftp_blksize;
inbuffer = tftpfile->validsize - offinblock;
if (inbuffer < 0) {
#ifdef TFTP_DEBUG
printf("tftp: invalid offset %d\n",
tftpfile->off);
#endif
return (EINVAL);
}
count = (size < inbuffer ? size : inbuffer);
bcopy(tftpfile->lastdata.t.th_data + offinblock,
addr, count);
addr = (char *)addr + count;
tftpfile->off += count;
size -= count;
if ((tftpfile->islastblock) && (count == inbuffer))
break; /* EOF */
} else {
#ifdef TFTP_DEBUG
printf("tftp: block %d not found\n", needblock);
#endif
return (EINVAL);
}
}
if (resid)
*resid = size;
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;
needblock = tftpfile->off / SEGSIZE + 1;
if (tftpfile->currblock > needblock) { /* seek backwards */
#ifndef TFTP_NOTERMINATE
tftp_terminate(tftpfile);
#endif
/* Don't bother to check retval: it worked for open() */
tftp_makereq(tftpfile);
}
while (tftpfile->currblock < needblock) {
int res;
#if !defined(LIBSA_NO_TWIDDLE)
if ((tc++ % 16) == 0)
twiddle();
#endif
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);
bcopy(tftpfile->lastdata.t.th_data + offinblock,
addr, count);
addr = (caddr_t)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 != NULL)
*resid = size;
return 0;
}
