haproxy/dev/h2/mkhdr.sh
Willy Tarreau e8ae99b111 DEV: h2: support reading frame payload from a file
Now we can build a series of data frames by reading from a file and
chunking it into frames of requested length. It's mostly useful for
data frames (e.g. post). One way to announce these upfront is to
capture the output of curl use without content-length:

  $ nc -lp4446 > post-h2-nocl.bin
  $ curl -v --http2-prior-knowledge http://127.0.0.1:4446/url -H "content-length:" -d @/dev/null

Then just change the 5th byte from the end from 1 to 0 to remove the
end-of-stream bit, it will allow to chain a file, then to send an
empty DATA frame with ES set :

  $ (dev/h2/mkhdr.sh -i 1 -t data -d CHANGELOG;
     dev/h2/mkhdr.sh -i 1 -t data -l 0 -f es) > h2-data-changelog.bin

Then post that to the server:
  $ cat post-h2-nocl.bin h2-data-changelog.bin | nc 0 4446
2023-04-26 11:36:02 +02:00

152 lines
3.4 KiB
Bash
Executable File

#!/usr/bin/env bash
# Usage: mkhdr -l <len> -t <type> -f <flags> -sid <sid> > hdr.bin
# All fields are optional. 0 assumed when absent.
USAGE=\
"Usage: %s [-l <len> ] [-t <type>] [-f <flags>] [-i <sid>] [ -d <data> ] > hdr.bin
Numbers are decimal or 0xhex. Not set=0. If <data> is passed, it points
to a file that is read and chunked into frames of <len> bytes.
Supported symbolic types (case insensitive prefix match):
DATA (0x00) PUSH_PROMISE (0x05)
HEADERS (0x01) PING (0x06)
PRIORITY (0x02) GOAWAY (0x07)
RST_STREAM (0x03) WINDOW_UPDATE (0x08)
SETTINGS (0x04) CONTINUATION (0x09)
Supported symbolic flags (case insensitive prefix match):
ES (0x01) PAD (0x08)
EH (0x04) PRIO (0x20)
"
LEN=
TYPE=
FLAGS=
ID=
die() {
[ "$#" -eq 0 ] || echo "$*" >&2
exit 1
}
quit() {
[ "$#" -eq 0 ] || echo "$*"
exit 0
}
# print usage with $1 as the cmd name
usage() {
printf "$USAGE" "$1";
}
# Send frame made of $1 $2 $3 $4 to stdout.
# Usage: mkframe <len> <type> <flags> <id>
mkframe() {
local L="${1:-0}"
local T="${2:-0}"
local F="${3:-0}"
local I="${4:-0}"
local t f
# get the first match in this order
for t in DATA:0x00 HEADERS:0x01 RST_STREAM:0x03 SETTINGS:0x04 PING:0x06 \
GOAWAY:0x07 WINDOW_UPDATE:0x08 CONTINUATION:0x09 PRIORITY:0x02 \
PUSH_PROMISE:0x05; do
if [ -z "${t##${T^^*}*}" ]; then
T="${t##*:}"
break
fi
done
if [ -n "${T##[0-9]*}" ]; then
echo "Unknown type '$T'" >&2
usage "${0##*}"
die
fi
# get the first match in this order
for f in ES:0x01 EH:0x04 PAD:0x08 PRIO:0x20; do
if [ -z "${f##${F^^*}*}" ]; then
F="${f##*:}"
fi
done
if [ -n "${F##[0-9]*}" ]; then
echo "Unknown type '$T'" >&2
usage "${0##*}"
die
fi
L=$(( L )); T=$(( T )); F=$(( F )); I=$(( I ))
L0=$(( (L >> 16) & 255 )); L0=$(printf "%02x" $L0)
L1=$(( (L >> 8) & 255 )); L1=$(printf "%02x" $L1)
L2=$(( (L >> 0) & 255 )); L2=$(printf "%02x" $L2)
T0=$(( (T >> 0) & 255 )); T0=$(printf "%02x" $T0)
F0=$(( (F >> 0) & 255 )); F0=$(printf "%02x" $F0)
I0=$(( (I >> 24) & 127 )); I0=$(printf "%02x" $I0)
I1=$(( (I >> 16) & 255 )); I1=$(printf "%02x" $I1)
I2=$(( (I >> 8) & 255 )); I2=$(printf "%02x" $I2)
I3=$(( (I >> 0) & 255 )); I3=$(printf "%02x" $I3)
printf "\x$L0\x$L1\x$L2\x$T0\x$F0\x$I0\x$I1\x$I2\x$I3"
}
## main
if [ $# -le 1 ]; then
usage "${0##*}"
die
fi
while [ -n "$1" -a -z "${1##-*}" ]; do
case "$1" in
-l) LEN="$2" ; shift 2 ;;
-t) TYPE="$2" ; shift 2 ;;
-f) FLAGS="$2" ; shift 2 ;;
-i) ID="$2" ; shift 2 ;;
-d) DATA="$2" ; shift 2 ;;
-h|--help) usage "${0##*}"; quit;;
*) usage "${0##*}"; die ;;
esac
done
if [ $# -gt 0 ]; then
usage "${0##*}"
die
fi
# default values for LEN and ID
LEN=${LEN:-0};
if [ -n "${LEN##[0-9]*}" ]; then
echo "Unparsable length '$LEN'" >&2
usage "${0##*}"
die
fi
ID=${ID:-0};
if [ -n "${ID##[0-9]*}" ]; then
echo "Unparsable stream ID '$ID'" >&2
usage "${0##*}"
die
fi
if [ -z "$DATA" ]; then
mkframe "$LEN" "$TYPE" "$FLAGS" "$ID"
else
# read file $DATA in <LEN> chunks and send it in multiple frames
# advertising their respective lengths.
[ $LEN -gt 0 ] || LEN=16384
while read -rN "$LEN" payload || [ ${#payload} -gt 0 ]; do
mkframe "${#payload}" "$TYPE" "$FLAGS" "$ID"
echo -n "$payload"
done < "$DATA"
fi
exit 0