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authorGravatar Denys Vlasenko <vda.linux@googlemail.com>2009-08-02 19:45:31 +0200
committerGravatar Denys Vlasenko <vda.linux@googlemail.com>2009-08-02 19:45:31 +0200
commitdc9495df03f411d67eb46002670ffea12bdd32ba (patch)
treec0d8f4c7a2482f6564252638d2d5f3b1f05aacb2 /miscutils/rx.c
parent80a3418b8c96300826842f109cd297280d3fbe05 (diff)
downloadbusybox-dc9495df03f411d67eb46002670ffea12bdd32ba.tar.gz
busybox-dc9495df03f411d67eb46002670ffea12bdd32ba.tar.bz2
rx: strip padding from last block. closes bug 501.
function old new delta rx_main 876 974 +98 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'miscutils/rx.c')
-rw-r--r--miscutils/rx.c102
1 files changed, 59 insertions, 43 deletions
diff --git a/miscutils/rx.c b/miscutils/rx.c
index 94eb4522d..3a8b6a8fe 100644
--- a/miscutils/rx.c
+++ b/miscutils/rx.c
@@ -1,15 +1,12 @@
/* vi: set sw=4 ts=4: */
-/*-------------------------------------------------------------------------
- * Filename: xmodem.c
+/*
* Copyright: Copyright (C) 2001, Hewlett-Packard Company
* Author: Christopher Hoover <ch@hpl.hp.com>
* Description: xmodem functionality for uploading of kernels
* and the like
* Created at: Thu Dec 20 01:58:08 PST 2001
- *-----------------------------------------------------------------------*/
-/*
- * xmodem.c: xmodem functionality for uploading of kernels and
- * the like
+ *
+ * xmodem functionality for uploading of kernels and the like
*
* Copyright (C) 2001 Hewlett-Packard Laboratories
*
@@ -26,6 +23,7 @@
#define ACK 0x06
#define NAK 0x15
#define BS 0x08
+#define PAD 0x1A
/*
Cf:
@@ -44,69 +42,93 @@ Cf:
static int read_byte(unsigned timeout)
{
- char buf[1];
+ unsigned char buf;
int n;
alarm(timeout);
/* NOT safe_read! We want ALRM to interrupt us */
- n = read(read_fd, buf, 1);
+ n = read(read_fd, &buf, 1);
alarm(0);
if (n == 1)
- return (unsigned char)buf[0];
+ return buf;
return -1;
}
static int receive(/*int read_fd, */int file_fd)
{
unsigned char blockBuf[1024];
+ unsigned blockLength = 0;
unsigned errors = 0;
unsigned wantBlockNo = 1;
unsigned length = 0;
int do_crc = 1;
- char nak = 'C';
+ char reply_char;
unsigned timeout = TIMEOUT_LONG;
/* Flush pending input */
tcflush(read_fd, TCIFLUSH);
/* Ask for CRC; if we get errors, we will go with checksum */
- full_write(write_fd, &nak, 1);
+ reply_char = 'C';
+ full_write(write_fd, &reply_char, 1);
for (;;) {
int blockBegin;
int blockNo, blockNoOnesCompl;
- int blockLength;
- int cksum_crc; /* cksum OR crc */
+ int cksum_or_crc;
int expected;
- int i,j;
+ int i, j;
blockBegin = read_byte(timeout);
if (blockBegin < 0)
goto timeout;
+ /* If last block, remove padding */
+ if (blockBegin == EOT) {
+ /* Data blocks can be padded with ^Z characters */
+ /* This code tries to detect and remove them */
+ if (blockLength >= 3
+ && blockBuf[blockLength - 1] == PAD
+ && blockBuf[blockLength - 2] == PAD
+ && blockBuf[blockLength - 3] == PAD
+ ) {
+ while (blockLength
+ && blockBuf[blockLength - 1] == PAD
+ ) {
+ blockLength--;
+ }
+ }
+ }
+ /* Write previously received block */
+ if (blockLength) {
+ errno = 0;
+ if (full_write(file_fd, blockBuf, blockLength) != blockLength) {
+ bb_perror_msg("can't write to file");
+ goto fatal;
+ }
+ }
+
timeout = TIMEOUT;
- nak = NAK;
+ reply_char = NAK;
switch (blockBegin) {
case SOH:
case STX:
break;
-
case EOT:
- nak = ACK;
- full_write(write_fd, &nak, 1);
+ reply_char = ACK;
+ full_write(write_fd, &reply_char, 1);
return length;
-
default:
goto error;
}
- /* block no */
+ /* Block no */
blockNo = read_byte(TIMEOUT);
if (blockNo < 0)
goto timeout;
- /* block no one's compliment */
+ /* Block no, in one's complement form */
blockNoOnesCompl = read_byte(TIMEOUT);
if (blockNoOnesCompl < 0)
goto timeout;
@@ -126,15 +148,15 @@ static int receive(/*int read_fd, */int file_fd)
}
if (do_crc) {
- cksum_crc = read_byte(TIMEOUT);
- if (cksum_crc < 0)
+ cksum_or_crc = read_byte(TIMEOUT);
+ if (cksum_or_crc < 0)
goto timeout;
- cksum_crc = (cksum_crc << 8) | read_byte(TIMEOUT);
- if (cksum_crc < 0)
+ cksum_or_crc = (cksum_or_crc << 8) | read_byte(TIMEOUT);
+ if (cksum_or_crc < 0)
goto timeout;
} else {
- cksum_crc = read_byte(TIMEOUT);
- if (cksum_crc < 0)
+ cksum_or_crc = read_byte(TIMEOUT);
+ if (cksum_or_crc < 0)
goto timeout;
}
@@ -155,9 +177,9 @@ static int receive(/*int read_fd, */int file_fd)
expected = expected ^ blockBuf[i] << 8;
for (j = 0; j < 8; j++) {
if (expected & 0x8000)
- expected = expected << 1 ^ 0x1021;
+ expected = (expected << 1) ^ 0x1021;
else
- expected = expected << 1;
+ expected = (expected << 1);
}
}
expected &= 0xffff;
@@ -166,25 +188,19 @@ static int receive(/*int read_fd, */int file_fd)
expected += blockBuf[i];
expected &= 0xff;
}
- if (cksum_crc != expected) {
+ if (cksum_or_crc != expected) {
bb_error_msg(do_crc ? "crc error, expected 0x%04x, got 0x%04x"
: "checksum error, expected 0x%02x, got 0x%02x",
- expected, cksum_crc);
+ expected, cksum_or_crc);
goto error;
}
wantBlockNo++;
length += blockLength;
-
- errno = 0;
- if (full_write(file_fd, blockBuf, blockLength) != blockLength) {
- bb_perror_msg("can't write to file");
- goto fatal;
- }
next:
errors = 0;
- nak = ACK;
- full_write(write_fd, &nak, 1);
+ reply_char = ACK;
+ full_write(write_fd, &reply_char, 1);
continue;
error:
timeout:
@@ -192,9 +208,9 @@ static int receive(/*int read_fd, */int file_fd)
if (errors == MAXERRORS) {
/* Abort */
- /* if were asking for crc, try again w/o crc */
- if (nak == 'C') {
- nak = NAK;
+ /* If were asking for crc, try again w/o crc */
+ if (reply_char == 'C') {
+ reply_char = NAK;
errors = 0;
do_crc = 0;
goto timeout;
@@ -209,7 +225,7 @@ static int receive(/*int read_fd, */int file_fd)
/* Flush pending input */
tcflush(read_fd, TCIFLUSH);
- full_write(write_fd, &nak, 1);
+ full_write(write_fd, &reply_char, 1);
} /* for (;;) */
}