1#!/bin/sh
2
3# post_upload.htm example:
4# <html>
5# <body>
6# <form action=/cgi-bin/httpd_post_upload.cgi method=post enctype=multipart/form-data>
7# File to upload: <input type=file name=file1> <input type=submit>
8# </form>
9
10# POST upload format:
11# -----------------------------29995809218093749221856446032^M
12# Content-Disposition: form-data; name="file1"; filename="..."^M
13# Content-Type: application/octet-stream^M
14# ^M    <--------- headers end with empty line
15# file contents
16# file contents
17# file contents
18# ^M    <--------- extra empty line
19# -----------------------------29995809218093749221856446032--^M
20
21file=$(mktemp)
22
23CR=`printf '\r'`
24
25# CGI output must start with at least empty line (or headers)
26printf '\r\n'
27
28IFS="$CR"
29read -r delim_line
30IFS=""
31
32while read -r line; do
33    test x"$line" = x"" && break
34    test x"$line" = x"$CR" && break
35done
36
37cat >"$file"
38
39# We need to delete the tail of "\r\ndelim_line--\r\n"
40tail_len=$((${#delim_line} + 6))
41
42# Get and check file size
43filesize=`stat -c"%s" "$file"`
44test "$filesize" -lt "$tail_len" && exit 1
45
46# Check that tail is correct
47dd if="$file" skip=$((filesize - tail_len)) bs=1 count=1000 >"$file.tail" 2>/dev/null
48printf "\r\n%s--\r\n" "$delim_line" >"$file.tail.expected"
49if ! diff -q "$file.tail" "$file.tail.expected" >/dev/null; then
50    printf "<html>\n<body>\nMalformed file upload"
51    exit 1
52fi
53rm "$file.tail"
54rm "$file.tail.expected"
55
56# Truncate the file
57dd of="$file" seek=$((filesize - tail_len)) bs=1 count=0 >/dev/null 2>/dev/null
58
59printf "<html>\n<body>\nFile upload has been accepted"
60