124 lines
4.2 KiB
Bash
Executable file
124 lines
4.2 KiB
Bash
Executable file
#!/usr/bin/env bash
|
|
set -Eeuo pipefail
|
|
IFS=$'\n\t'
|
|
|
|
readonly TABLE_FAMILY="inet"
|
|
readonly TABLE_NAME="ochenstarik_smm"
|
|
readonly CHAIN_NAME="links"
|
|
|
|
fail() { printf '%s\n' "policy helper: $*" >&2; exit 78; }
|
|
|
|
testing="${SMM_POLICY_TESTING:-0}"
|
|
if [[ "$testing" != "1" ]]; then
|
|
[[ ${EUID:-$(id -u)} -eq 0 ]] || fail "root is required"
|
|
readonly STATE_FILE="/var/lib/ochenstarik-server-monitor-manager/mesh/nodes.tsv"
|
|
else
|
|
readonly STATE_FILE="${SMM_POLICY_STATE_FILE:?SMM_POLICY_STATE_FILE is required in testing mode}"
|
|
fi
|
|
|
|
node_pattern='^[a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?$'
|
|
ipv4_pattern='^([0-9]{1,3}\.){3}[0-9]{1,3}$'
|
|
|
|
validate_node_id() {
|
|
[[ "$1" =~ $node_pattern ]] || fail "invalid node id"
|
|
}
|
|
|
|
lookup_node_ip() {
|
|
local node_id="$1" ip
|
|
[[ -r "$STATE_FILE" ]] || fail "mesh node state is unavailable"
|
|
ip="$(awk -F '\t' -v node="$node_id" '$1 == node { print $2; exit }' "$STATE_FILE")"
|
|
[[ "$ip" =~ $ipv4_pattern ]] || fail "node has no valid mesh address: $node_id"
|
|
printf '%s\n' "$ip"
|
|
}
|
|
|
|
validate_rule() {
|
|
local action="$1"
|
|
case "$action" in
|
|
link-connect) [[ $# -eq 6 ]] || fail "invalid link-connect argument count" ;;
|
|
link-disconnect) [[ $# -eq 5 ]] || fail "invalid link-disconnect argument count" ;;
|
|
link-status) [[ $# -eq 5 ]] || fail "invalid link-status argument count" ;;
|
|
*) fail "unsupported action" ;;
|
|
esac
|
|
validate_node_id "$2"
|
|
validate_node_id "$3"
|
|
[[ "$2" != "$3" ]] || fail "source and destination must differ"
|
|
[[ "$4" == "tcp" || "$4" == "udp" ]] || fail "invalid protocol"
|
|
[[ "$5" =~ ^[0-9]+$ ]] && (( 10#$5 >= 1 && 10#$5 <= 65535 )) || fail "invalid port"
|
|
if [[ "$action" == "link-connect" ]]; then
|
|
[[ "$6" =~ ^[0-9]+$ ]] && (( 10#$6 >= 0 && 10#$6 <= 525600 )) || fail "invalid TTL"
|
|
fi
|
|
}
|
|
|
|
run_nft() {
|
|
if [[ "$testing" == "1" ]]; then
|
|
printf 'nft'
|
|
printf ' %q' "$@"
|
|
printf '\n'
|
|
else
|
|
/usr/sbin/nft "$@"
|
|
fi
|
|
}
|
|
|
|
rule_exists() {
|
|
local comment="$1" listing
|
|
if [[ "$testing" == "1" ]]; then
|
|
return 1
|
|
fi
|
|
if ! listing="$(/usr/sbin/nft -a list chain "$TABLE_FAMILY" "$TABLE_NAME" "$CHAIN_NAME")"; then
|
|
fail "could not inspect nftables Link policy"
|
|
fi
|
|
grep -Fq "comment \"$comment\"" <<<"$listing"
|
|
}
|
|
|
|
connect_rule() {
|
|
local source_id="$1" target_id="$2" protocol="$3" port="$4"
|
|
local source_ip target_ip comment
|
|
source_ip="$(lookup_node_ip "$source_id")"
|
|
target_ip="$(lookup_node_ip "$target_id")"
|
|
comment="smm:${source_id}:${target_id}:${protocol}:${port}"
|
|
rule_exists "$comment" && return 0
|
|
run_nft add rule "$TABLE_FAMILY" "$TABLE_NAME" "$CHAIN_NAME" \
|
|
ip saddr "$source_ip" ip daddr "$target_ip" "$protocol" dport "$port" \
|
|
counter accept comment "$comment"
|
|
}
|
|
|
|
disconnect_rule() {
|
|
local source_id="$1" target_id="$2" protocol="$3" port="$4" comment handle
|
|
# Resolve both identities before touching firewall state.
|
|
lookup_node_ip "$source_id" >/dev/null
|
|
lookup_node_ip "$target_id" >/dev/null
|
|
comment="smm:${source_id}:${target_id}:${protocol}:${port}"
|
|
if [[ "$testing" == "1" ]]; then
|
|
printf 'nft-delete-comment %q\n' "$comment"
|
|
return
|
|
fi
|
|
while IFS= read -r handle; do
|
|
[[ "$handle" =~ ^[0-9]+$ ]] || continue
|
|
run_nft delete rule "$TABLE_FAMILY" "$TABLE_NAME" "$CHAIN_NAME" handle "$handle"
|
|
done < <(
|
|
/usr/sbin/nft -a list chain "$TABLE_FAMILY" "$TABLE_NAME" "$CHAIN_NAME" \
|
|
| grep -F "comment \"$comment\"" \
|
|
| sed -n 's/.* # handle \([0-9][0-9]*\)$/\1/p'
|
|
)
|
|
}
|
|
|
|
status_rule() {
|
|
local source_id="$1" target_id="$2" protocol="$3" port="$4" comment
|
|
# A status is meaningful only for identities currently known to the mesh.
|
|
lookup_node_ip "$source_id" >/dev/null
|
|
lookup_node_ip "$target_id" >/dev/null
|
|
comment="smm:${source_id}:${target_id}:${protocol}:${port}"
|
|
if rule_exists "$comment"; then
|
|
printf '%s\n' active
|
|
else
|
|
printf '%s\n' disabled
|
|
fi
|
|
}
|
|
|
|
action="${1:-}"
|
|
validate_rule "$@"
|
|
case "$action" in
|
|
link-connect) connect_rule "$2" "$3" "$4" "$5" ;;
|
|
link-disconnect) disconnect_rule "$2" "$3" "$4" "$5" ;;
|
|
link-status) status_rule "$2" "$3" "$4" "$5" ;;
|
|
esac
|