docs: sync reference doc with ipset-optional and ExecStartPre fixes

.opencode/01.wireguard-policy-firewall.md

@@ -153,8 +153,13 @@ validate_cidr() {
 # IPSET MANAGEMENT
 # ============================================================
 
+has_ipset() {
+    command -v ipset &>/dev/null
+}
+
 ensure_ipset() {
     local name="$1" family="$2"
+    has_ipset || return 0
     if ! ipset list "$name" &>/dev/null; then
         ipset create "$name" hash:net family "$family" hashsize 1024 maxelem 65536 timeout 0
         log_info "Created ipset: $name (family=$family)"
@@ -163,6 +168,7 @@ ensure_ipset() {
 
 flush_ipset() {
     local name="$1"
+    has_ipset || return 0
     if ipset list "$name" &>/dev/null; then
         ipset flush "$name"
     fi
@@ -170,6 +176,7 @@ flush_ipset() {
 
 destroy_ipset() {
     local name="$1"
+    has_ipset || return 0
     if ipset list "$name" &>/dev/null; then
         ipset destroy "$name"
     fi
@@ -640,6 +647,9 @@ main() {
     log_info "Chain $CHAIN created and linked to FORWARD"
 
     # === POPULATE IPSET (for large-scale whitelist) ===
+    local use_ipset=false
+    if has_ipset; then
+        use_ipset=true
         log_info "Populating ipsets..."
 
         ensure_ipset "$IPSET_V4" "inet"
@@ -663,7 +673,6 @@ main() {
         ' "$POLICY_FILE" 2>/dev/null | while read -r client_ip target; do
             [[ -z "$client_ip" || -z "$target" ]] && continue
 
-        # Determine if v4 or v6
             if [[ "$target" == *":"* ]]; then
                 if [[ "$use_ipv6" == true ]]; then
                     ipset add "$IPSET_V6" "$target" 2>/dev/null || \
@@ -679,12 +688,19 @@ main() {
         v4_count=$(ipset list "$IPSET_V4" 2>/dev/null | grep -c '^[0-9]' || echo 0)
         v6_count=$(ipset list "$IPSET_V6" 2>/dev/null | grep -c '^[0-9a-f:]' || echo 0)
         log_info "ipset $IPSET_V4: $v4_count entries, $IPSET_V6: $v6_count entries"
+    else
+        log_warn "ipset not installed, falling back to per-rule iptables whitelist"
+        local use_ipv6=false
+        if [[ -n "$WG_SUBNET_V6" ]] && command -v ip6tables &>/dev/null; then
+            use_ipv6=true
+        fi
+    fi
 
     # === RULE 1: ESTABLISHED,RELATED — allow return traffic ===
     iptables -A "$CHAIN" -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
 
-    # === RULE 2: WHITELIST via ipset (per-client source) ===
-    # For each client with access rules, allow only from that client's IP to ipset targets
+    # === RULE 2: WHITELIST (per-client source) ===
+    if [[ "$use_ipset" == true ]]; then
         jq -r '
             .clients // {} | to_entries[] |
             select(.value.access != null and (.value.access | length > 0)) |
@@ -693,15 +709,32 @@ main() {
             [[ -z "$client_ip" ]] && continue
 
             if [[ "$client_ip" == *":"* ]]; then
-            # IPv6 client
                 if [[ "$use_ipv6" == true ]]; then
                     ip6tables -A "$CHAIN" -s "$client_ip" -m set --match-set "$IPSET_V6" dst -j ACCEPT 2>/dev/null || true
                 fi
             else
-            # IPv4 client
                 iptables -A "$CHAIN" -s "$client_ip" -m set --match-set "$IPSET_V4" dst -j ACCEPT
             fi
         done
+    else
+        jq -r '
+            .clients // {} | to_entries[] |
+            select(.value.access != null and (.value.access | length > 0)) |
+            .key as $ip |
+            .value.access[] |
+            "\($ip) \(.)"
+        ' "$POLICY_FILE" 2>/dev/null | while read -r client_ip target; do
+            [[ -z "$client_ip" || -z "$target" ]] && continue
+
+            if [[ "$client_ip" == *":"* ]]; then
+                if [[ "$use_ipv6" == true ]]; then
+                    ip6tables -A "$CHAIN" -s "$client_ip" -d "$target" -j ACCEPT 2>/dev/null || true
+                fi
+            else
+                iptables -A "$CHAIN" -s "$client_ip" -d "$target" -j ACCEPT
+            fi
+        done
+    fi
 
     # === RULE 3: ISOLATION — drop NEW connections between WG clients ===
     if [[ -n "$WG_SUBNET" ]]; then
@@ -932,7 +965,7 @@ StartLimitBurst=5
 
 [Service]
 Type=simple
-ExecStartPre=/usr/local/bin/wg-policy-engine.sh --health-check
+ExecStartPre=/usr/local/bin/wg-sync-policy.sh
 ExecStart=/usr/local/bin/wg-sync-watch.sh
 ExecStopPost=/usr/local/bin/wg-policy-cleanup.sh
 Restart=always