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Use irtt streaming mode (-s) for unbounded pinger sessions #395

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133 changes: 64 additions & 69 deletions cake-autorate.sh
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Original file line number Diff line number Diff line change
Expand Up @@ -514,60 +514,40 @@ start_pinger()
irtt)
sleep_until_next_pinger_time_slot "${pinger}"

# The raw stream (-r) carries neither the reflector nor a wall-clock
# timestamp, and every pinger shares the one response fd, so a
# plain-bash helper prefixes both onto each line; the parsing itself
# lives with the other pinger methods in the main loop. A server-side
# max duration clamps the negotiated session and the client just
# exits, so the helper also respawns the client, rate-limited when
# the stream dies quickly (unreachable reflector, refused dial).
# --loose accepts server-restricted test parameters (e.g. a public
# server's min send interval): without it the client exits pre-test
# on any restriction and the respawn loop would spin forever
# producing zero samples.
local irtt_target=${reflectors[$pinger]}
[[ ${irtt_target} == *:* ]] && irtt_target="[${irtt_target}]"

# shellcheck disable=SC2155 # the subshell status (echo $!) is intentionally unused
local pinger_pid=$( (
set -m
${ping_prefix_string} gawk -v extra_args="${ping_extra_args}" -v interval_s="${reflector_ping_interval_s}" -v duration_m="${irtt_session_duration_m}" -v reflector="${reflectors[$pinger]}" -f <(cat <<-'EOT'
@load "time"

function to_us(val, mult)
{
# Test bare /s$/ LAST: "5µs" and "5ns" also end in "s", so an
# earlier /s$/ branch would swallow them (mult=1000000) and the
# µs/ns branches would be unreachable -> sub-ms OWDs inflated 10^6x.
mult = (val ~ /ms$/) ? 1000 : \
(val ~ /µs$/) ? 1 : \
(val ~ /ns$/) ? 0.001 : \
(val ~ /s$/) ? 1000000 : -1

if (val ~ /^-/ || mult < 0) return -1
return sprintf("%.0f", val * mult)
}

BEGIN {
FS = "[= ]+"

irtt_cmd = sprintf("stdbuf -oL irtt client %s -i '%ss' -d '%sm' '%s'", extra_args, interval_s, duration_m, (reflector ~ /:/ ? "[" reflector "]" : reflector))

while (1)
{
start_time = systime()

while ((irtt_cmd | getline) > 0)
{
if (/seq=/ && /rd=/ && /sd=/)
{
ts = gensub(/\./, "", 1, sprintf("%.6f", gettimeofday()))
seq = $2; dl_owd = to_us($6); ul_owd = to_us($8)

if (dl_owd >= 0 && ul_owd >= 0)
{
printf("%s %s %d %d %d\n", ts, reflector, seq, dl_owd, ul_owd)
fflush("")
}
}
else if (/WaitForPackets/)
{
break
}
}

close(irtt_cmd)
if (systime() - start_time < 3) system("sleep 1")
}
}
EOT
) 2> /dev/null >&"${main_fd}" &
while :
do
session_start_s=${SECONDS}

${ping_prefix_string} irtt client -s -r --loose ${ping_extra_args} -i "${reflector_ping_interval_s}s" "${irtt_target}" |
while read -r irtt_line
do
printf '%s %s %s\n' "${EPOCHREALTIME/.}" "${reflectors[$pinger]}" "${irtt_line}"
done

if (( SECONDS - session_start_s < 3 ))
then
sleep 1
fi
done
} 2> /dev/null >&"${main_fd}" &
echo $!
) )

Expand Down Expand Up @@ -1064,14 +1044,12 @@ then
log_msg "DEBUG" "Local list of reflectors now contains ${#reflectors[*]} entries."
fi

# Validate every reflector before use. For pinger_method=irtt a reflector is
# interpolated into a shell command (gawk builds "irtt client ... '<reflector>'"
# and runs it via | getline), so a reflector containing shell metacharacters is
# command injection -- and reflectors can come unvalidated from the remote
# reflectors_url (fetched over the network above, possibly without TLS) or from
# a hand-edited config. Allow only IP-/hostname-shaped strings (no quotes, ';',
# spaces, '$', etc.); the first char excludes '-' (blocks option injection) but
# admits ':' for compressed IPv6 (e.g. ::1, ::ffff:1.2.3.4).
# Validate every reflector before use. Reflectors can come unvalidated from the
# remote reflectors_url (fetched over the network above, possibly without TLS)
# or from a hand-edited config, and every pinger method hands them to its ping
# binary as command-line arguments. Allow only IP-/hostname-shaped strings (no
# quotes, ';', spaces, '$', etc.); the first char excludes '-' (blocks option
# injection) but admits ':' for compressed IPv6 (e.g. ::1, ::ffff:1.2.3.4).
for reflector in "${reflectors[@]}"
do
[[ ${reflector} =~ ^[0-9A-Za-z:][0-9A-Za-z.:_-]*$ ]] || { log_msg "ERROR" "Invalid reflector '${reflector}': must be an IP address or hostname. Exiting script."; exit 1; }
Expand All @@ -1086,15 +1064,18 @@ case ${pinger_method} in
command -v "fping" &> /dev/null || { log_msg "ERROR" "ping binary fping does not exist. Exiting script."; exit 1; }
;;
irtt)
# The irtt path hard-requires gawk (gawk -f), the gawk-only 'time'
# extension (systime/gettimeofday) and stdbuf -- none of which are the
# 'irtt' binary. Without them the gawk pinger dies, but its stderr is
# /dev/null so the daemon is NOT killed: it silently produces no data and
# pins CAKE at the min rates. Name the missing dependency up front.
command -v "irtt" &> /dev/null || { log_msg "ERROR" "ping binary irtt does not exist. Exiting script."; exit 1; }
command -v "gawk" &> /dev/null || { log_msg "ERROR" "pinger_method=irtt requires gawk. Exiting script."; exit 1; }
command -v "stdbuf" &> /dev/null || { log_msg "ERROR" "pinger_method=irtt requires stdbuf (coreutils). Exiting script."; exit 1; }
gawk '@load "time"; BEGIN{exit}' < /dev/null &> /dev/null || { log_msg "ERROR" "pinger_method=irtt requires the gawk 'time' extension (gawk-gawkextra). Exiting script."; exit 1; }
# An irtt too old for streaming mode (< 0.9.2) rejects -s at every
# respawn, but the helper's stderr is /dev/null so the daemon is NOT
# killed: it silently produces no data and pins CAKE at the min rates.
# Probe the client help text for the capability up front instead. The
# help goes to stderr and 'irtt client -h' exits 2, so no pipe to grep
# (pipefail would poison the status even on a match); read -t bounds
# the probe so a non-conforming irtt that never exits on -h fails the
# check instead of hanging startup with no ERROR ever logged.
command -v "irtt" &> /dev/null || { log_msg "ERROR" "ping binary irtt does not exist. Exiting script."; exit 1; }
irtt_help=""
read -r -t 5 -d '' irtt_help < <(irtt client -h 2>&1)
[[ ${irtt_help} == *"streaming mode"* ]] || { log_msg "ERROR" "pinger_method=irtt requires irtt >= 0.9.2 (streaming mode). Exiting script."; exit 1; }
;;
*)
command -v "${pinger_method}" &> /dev/null || { log_msg "ERROR" "ping binary ${pinger_method} does not exist. Exiting script."; exit 1; }
Expand Down Expand Up @@ -1452,9 +1433,17 @@ do
case "${pinger_method}" in

irtt)
if ((${#command[@]} == 5))
# helper-prefixed raw stream line:
# ts reflector seqno rtt rd sd ipdv dup late
# rd/sd are the DL/UL OWDs in fixed-unit ms; ipdv is NaN on
# the first reply of a session, so it never gates a sample.
# The glob checks (patterns, not regexes: [[ =~ ]] recompiles
# the ERE every sample) drop NaN OWDs (no server timestamps),
# negative OWDs (client and server clocks out of step) and
# duplicates (dup=1 lines carry NaN OWDs by construction).
if ((${#command[@]} == 9)) && [[ ${command[4]} != *[!0-9.]* && ${command[5]} != *[!0-9.]* ]]
then
timestamp=${command[0]} reflector=${command[1]} seq=${command[2]} dl_owd_us=${command[3]} ul_owd_us=${command[4]} reflector_response=1
timestamp=${command[0]} reflector=${command[1]} seq=${command[2]} dl_owd_ms=${command[4]} ul_owd_ms=${command[5]} reflector_response=1
fi
;;
tsping)
Expand Down Expand Up @@ -1520,7 +1509,13 @@ do
case ${pinger_method} in

irtt)
printf -v dl_owd_us %.3f "${dl_owd_ms}"
printf -v ul_owd_us %.3f "${ul_owd_ms}"

((
dl_owd_us=10#${dl_owd_us//.},
ul_owd_us=10#${ul_owd_us//.},

dl_alpha = dl_owd_us >= dl_owd_baselines_us[${reflector}] ? alpha_baseline_increase : alpha_baseline_decrease,
ul_alpha = ul_owd_us >= ul_owd_baselines_us[${reflector}] ? alpha_baseline_increase : alpha_baseline_decrease,

Expand Down
8 changes: 4 additions & 4 deletions defaults.sh
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Original file line number Diff line number Diff line change
Expand Up @@ -169,10 +169,10 @@ ping_extra_args=""
# WARNING: no error checking - so use at own risk!
ping_prefix_string=""

# duration in minutes for each irtt session
# irtt stores all results in-memory during a session
# longer durations increase memory usage
# lower values reduce memory but can cause gaps in data during session restarts
# DEPRECATED and ignored: irtt sessions are now unbounded (streaming mode -s),
# so there is no per-session in-memory result set left to cap and no periodic
# session restart. The key is retained so existing config files that set it
# remain valid.
irtt_session_duration_m=10 # (minutes)

# interval in ms for monitoring achieved rx/tx rates
Expand Down