0.6.2

support short gateway ip expression
fix dnsmasq pid not get watchdog zombie judgement iptables nft and comment judgement use fifo for dnsmasq log
2025-12-30 10:48:28 +01:00 · 2021-08-22 09:27:49 +08:00 · 2021-04-17 12:29:53 +08:00 · 2021-02-22 09:20:41 +08:00
2 changed files with 130 additions and 49 deletions
--- a/README.md
+++ b/README.md
@@ -4,7 +4,8 @@ Set Linux as router in one command. Able to Provide Internet, or create Wifi hot

 It wraps `iptables`, `dnsmasq` etc. stuff. Use in one command, restore in one command or by `control-c` (or even by closing terminal window).

-[Buy me a coffee](https://github.com/garywill/receiving/blob/master/receiving_methods.md) :)
+[Buy me a coffee](https://github.com/garywill/receiving/blob/master/receiving_methods.md)
+

 ## Features

@@ -110,7 +111,9 @@ lxc.network.hwaddr = xx:xx:xx:xx:xx:xx
 sudo lnxrouter -i lxcbr5
 ```

-### Transparent proxy with Tor
+### Transparent proxy 
+
+For example through Tor

 ```
 sudo lnxrouter -i eth1 --tp 9040 --dns 9053 -g 192.168.55.1 --p6 fd00:5:6:7::
@@ -127,7 +130,7 @@ DNSPort [fd00:5:6:7::1]:9053

 ### Clients-in-sandbox network

-To not give our infomation to clients:
+To not give our infomation to clients. Clients can still access Internet.

 ```
 sudo lnxrouter -i eth1 \
@@ -232,12 +235,14 @@ Options:
    --ban-priv              Disallow clients to access my private network
    
    -g <ip>                 This host's IPv4 address in subnet (mask is /24)
+                            (example: '192.168.5.1' or '5' shortly)
    -6                      Enable IPv6 (NAT)
    --no4                   Disable IPv4 Internet (not forwarding IPv4)
                            (See Notice 1). Usually used with '-6'
                            
    --p6 <prefix>           Set IPv6 LAN address prefix (length 64) 
-                            (example: fd00:1:2:3::) Using this enables '-6'
+                            (example: 'fd00:0:0:5::' or '5' shortly) 
+                            Using this enables '-6'
                            
    --dns <ip>|<port>|<ip:port>
                            DNS server's upstream DNS.
@@ -303,10 +308,11 @@ Options:

  Instance managing:
    --daemon                Run in background
-    --list-running          Show running instances
-    --lc, --list-clients <id>     
+    -l, --list-running      Show running instances
+    --lc, --list-clients <id|interface>     
                            List clients of an instance. Or list neighbors of
-                            any interface, even if it isn't handled by us
+                            an interface, even if it isn't handled by us.
+                            (passive mode)
    --stop <id>             Stop a running instance
        For <id> you can use PID or subnet interface name.
        You can get them with '--list-running'
@@ -332,13 +338,13 @@ Options:
 - procps or procps-ng
 - iproute2
 - dnsmasq
- iptables
+- iptables (legacy. nft not tested)
 - WiFi hotspot dependencies
   - hostapd
   - iw
   - iwconfig (you only need this if 'iw' can not recognize your adapter)
   - haveged (optional)
-   - qrencode (opional)
+   - qrencode (optional)

 ## TODO

@@ -351,12 +357,18 @@ Options:

 [Buy me a coffee](https://github.com/garywill/receiving/blob/master/receiving_methods.md) , this project took me lots of time!

-（ ^\_^）o自自o（^_^ ）

-No? Okay, or just give me a star!
+[打赏一个](https://github.com/garywill/receiving/blob/master/receiving_methods.md) 

 ## For developers

 **Many thanks to project [create_ap](https://github.com/oblique/create_ap)**.

 This script was forked from create\_ap. Now it's quite different from it. (See `history` branch for how I modified create_ap)
+
+There're some TO-DOs listed, at both above and in the code file. We'll appreciate your help.
+
+------------------
+
+More of my projects: https://garywill.github.io
+
--- a/143
+++ b/143
@@ -1,6 +1,7 @@
 #!/bin/bash

-VERSION=0.6.0
+# TODO: showing version (or git commit) on running
+VERSION=0.6.2
 PROGNAME="$(basename $0)"

 export LC_ALL=C
@@ -29,12 +30,14 @@ Options:
    --ban-priv              Disallow clients to access my private network
    
    -g <ip>                 This host's IPv4 address in subnet (mask is /24)
+                            (example: '192.168.5.1' or '5' shortly)
    -6                      Enable IPv6 (NAT)
    --no4                   Disable IPv4 Internet (not forwarding IPv4)
                            (See Notice 1). Usually used with '-6'
                            
    --p6 <prefix>           Set IPv6 LAN address prefix (length 64) 
-                            (example: fd00:1:2:3::) Using this enables '-6'
+                            (example: 'fd00:0:0:5::' or '5' shortly) 
+                            Using this enables '-6'
                            
    --dns <ip>|<port>|<ip:port>
                            DNS server's upstream DNS.
@@ -100,10 +103,11 @@ Options:

  Instance managing:
    --daemon                Run in background
-    --list-running          Show running instances
-    --lc, --list-clients <id>     
+    -l, --list-running      Show running instances
+    --lc, --list-clients <id|interface>     
                            List clients of an instance. Or list neighbors of
-                            any interface, even if it isn't handled by us
+                            an interface, even if it isn't handled by us.
+                            (passive mode)
    --stop <id>             Stop a running instance
        For <id> you can use PID or subnet interface name.
        You can get them with '--list-running'
@@ -118,7 +122,6 @@ Examples:
    $PROGNAME -i eth1
    $PROGNAME --ap wlan0 MyAccessPoint
    $PROGNAME --ap wlan0 MyAccessPoint -p MyPassPhrase
-    $PROGNAME -n --ap wlan0 MyAccessPoint -p MyPassPhrase
    $PROGNAME -i eth1 --tp <transparent-proxy> --dns <dns-proxy>
 EOF
 }
@@ -200,6 +203,7 @@ define_global_variables(){
    CONFDIR=
    NM_RUNNING=0
    NM_UNM_LIST=  # it's called "list" but for now one interface
+    XT_COMMENT=1
 }

 parse_user_options(){
@@ -440,7 +444,7 @@ parse_user_options(){
                STOP_ID="$1"
                shift
                ;;
-            --list-running)
+            -l|--list-running)
                shift
                LIST_RUNNING=1
                ;;
@@ -735,7 +739,7 @@ haveged_watchdog() {
                    echo "WARN: Low entropy detected. We recommend you to install \`haveged'" 1>&2
                    show_warn=0
                fi
-            elif ! pidof haveged > /dev/null 2>&1; then
+            elif ! pidof haveged > /dev/null 2>&1; then # TODO judge zombie ?
                echo "Low entropy detected, starting haveged" 1>&2
                # boost low-entropy
                haveged -w 1024 -p $COMMON_CONFDIR/haveged.pid
@@ -744,7 +748,24 @@ haveged_watchdog() {
        sleep 2
    done
 }
+pid_watchdog() {
+    local PID="$1"
+    local SLEEP="$2"
+    local ERR_MSG="$3"
+    local ST
+    while true
+    do 
+        if [[ -e "/proc/$PID" ]]; then
+            ST="$(cat "/proc/$PID/status" | grep "^State:" | awk '{print $2}')"
+            if [[ "$ST" != 'Z' ]]; then
+                sleep $SLEEP
+                continue
+            fi
+        fi
+        die "$ERR_MSG"
+    done
    
+}
 #========


@@ -791,15 +812,22 @@ nm_restore_manage() {
    fi
 }
 #=========
-
 iptables_()
 {
-    iptables -w $@ -m comment --comment "lnxrouter-$$-$SUBNET_IFACE"
+    if [[ $XT_COMMENT -eq 1 ]]; then
+        iptables -w $@ -m comment --comment "lnxrouter-$$-$SUBNET_IFACE"
+    else
+        iptables -w $@ 
+    fi
    return $?
 }
 ip6tables_()
 {
-    ip6tables -w $@ -m comment --comment "lnxrouter-$$-$SUBNET_IFACE"
+    if [[ $XT_COMMENT -eq 1 ]]; then
+        ip6tables -w $@ -m comment --comment "lnxrouter-$$-$SUBNET_IFACE"
+    else
+        ip6tables -w $@
+    fi
    return $?
 }

@@ -842,7 +870,7 @@ start_ban_lan() {
    echo
    echo "iptables: Disallow clients to access LAN"
    iptables_ -N BANLAN-f-${SUBNET_IFACE}  || die
-    iptables_ -v -I BANLAN-f-${SUBNET_IFACE} -d 0.0.0.0/8 -j REJECT || die
+    iptables_ -v -I BANLAN-f-${SUBNET_IFACE} -d 0.0.0.0/8 -j REJECT || die # TODO: use array
    iptables_ -v -I BANLAN-f-${SUBNET_IFACE} -d 10.0.0.0/8 -j REJECT || die
    iptables_ -v -I BANLAN-f-${SUBNET_IFACE} -d 100.64.0.0/10 -j REJECT || die
    iptables_ -v -I BANLAN-f-${SUBNET_IFACE} -d 127.0.0.0/8 -j REJECT || die
@@ -857,6 +885,7 @@ start_ban_lan() {
    iptables_ -N BANLAN-i-${SUBNET_IFACE}
    #iptables_ -v -I BANLAN-i-${SUBNET_IFACE} -i ${SUBNET_IFACE} -j REJECT || die
    iptables_ -v -I BANLAN-i-${SUBNET_IFACE} -i ${SUBNET_IFACE} ! -p icmp -j REJECT || die
+    # TODO: ipv6 need icmp to function. maybe we can block some unneeded icmp to improve security
    
    iptables_ -I INPUT -i ${SUBNET_IFACE} -j BANLAN-i-${SUBNET_IFACE} || die
    
@@ -960,6 +989,7 @@ unallow_dhcp() {
    fi
 }

+# TODO: use 'DNAT' instead of '--to-ports' to support other IP
 start_redsocks() {
    echo
    echo "iptables: transparent proxy non-LAN TCP/UDP traffic to port ${TP_PORT}"
@@ -1026,7 +1056,7 @@ backup_ipv6_bits() {
        "/proc/sys/net/ipv6/conf/$SUBNET_IFACE/accept_ra"     \
        "/proc/sys/net/ipv6/conf/$SUBNET_IFACE/use_tempaddr"  \
        "/proc/sys/net/ipv6/conf/$SUBNET_IFACE/addr_gen_mode" \
-            "$CONFDIR/sys_6_conf_iface/" || die "Failed backking up interface ipv6 bits"
+            "$CONFDIR/sys_6_conf_iface/" || die "Failed backing up interface ipv6 bits"
            
    if [[ "$SHARE_METHOD" == 'redsocks' ]] ; then
        cp "/proc/sys/net/ipv6/conf/$SUBNET_IFACE/forwarding" \
@@ -1066,10 +1096,10 @@ backup_interface_status() {
    (ip link show ${SUBNET_IFACE} |grep -q "state UP") && SUBNET_IFACE_ORIGINAL_UP_STATUS=1
    
    # save interface old mac 
-    if [[ -n "$NEW_MACADDR" ]]; then 
+    #if [[ -n "$NEW_MACADDR" ]]; then 
        OLD_MACADDR=$(get_interface_mac $SUBNET_IFACE)
-        echo "Saved ${SUBNET_IFACE} old MAC address ${OLD_MACADDR} into RAM"
-    fi
+        #echo "Saved ${SUBNET_IFACE} old MAC address ${OLD_MACADDR} into RAM"
+    #fi
    
    backup_ipv6_bits
    
@@ -1084,9 +1114,9 @@ restore_interface_status() {
    
    restore_ipv6_bits

-    if [[ -n "$OLD_MACADDR" ]] ; then
+    if [[ -n "$OLD_MACADDR" && "$(get_interface_mac $SUBNET_IFACE)" != "$OLD_MACADDR" ]] ; then
        echo "Restoring ${SUBNET_IFACE} to old MAC address ${OLD_MACADDR} ..."
-        set_interface_mac ${SUBNET_IFACE} ${OLD_MACADDR} && echo "Successfully restored ${SUBNET_IFACE} to old MAC address ${OLD_MACADDR}"
+        set_interface_mac ${SUBNET_IFACE} ${OLD_MACADDR} || echo "Failed restoring ${SUBNET_IFACE} to old MAC address ${OLD_MACADDR}" >&2
    fi
    
    nm_restore_manage
@@ -1180,6 +1210,7 @@ cleanup() {
    #kill -9 -$pgid
 }

+# NOTE function die() is designed not to be used before init_trap() executed
 die() { # SIGUSR2
    echo "Error occured"
    [[ -n "$1" ]] && echo -e "\nERROR: $1\n" >&2
@@ -1204,7 +1235,7 @@ init_conf_dirs() {
    chmod 755 "$TMPDIR" 2>/dev/null
    cd "$TMPDIR" || die "Couldn't change directory to linux-router's temporary path"

-    CONFDIR="$(mktemp -d $TMPDIR/lnxrouter.${TARGET_IFACE}.conf.XXX)" || die "Instance couldn't make config dir" # config dir for one instance
+    CONFDIR="$(mktemp -d $TMPDIR/lnxrouter.${TARGET_IFACE}.conf.XXXXXX)" || die "Instance couldn't make config dir" # config dir for one instance
    chmod 755 "$CONFDIR"
    #echo "Config dir: $CONFDIR"
    echo $$ > "$CONFDIR/pid"
@@ -1267,18 +1298,19 @@ print_clients_from_leases() {  # MAC|IP|HOST|lease
    
    FILEC="$(cat "$LEASE_FILE" | grep -v -E "^duid\b" | sed -r '/^\s*$/d' )"

+    # TODO: duid is somewhat related to ipv6. I don't know about it. Not sure excluding it miss some info or not
    echo "$FILEC" | while read line
    do
        #echo aa$line
        LEASEstamp="$(echo "$line" | awk '{print $1}')"
        MAC="$(echo "$line" | awk '{print $2}')"
        IP="$(echo "$line" | awk '{print $3}'  | sed 's/\[//g' | sed 's/\]//g')"
-        HOST="$(echo "$line" | awk '{print $4}' | sed 's/*/?/g')"
+        HOST="$(echo "$line" | awk '{print $4}' | sed 's/*/?/g' | sed 's/|/_/g' | sed 's/ /_/g' )"
        
        if [[ -n "$MAC" ]]; then
            LEASEstr="$(date -d @${LEASEstamp} +%m-%d_%X)"
            
-            echo "$MAC|$IP|$HOST|$LEASEstr"
+            echo "$MAC|$IP|$HOST|lease_$LEASEstr"
        fi
    done
    
@@ -1303,7 +1335,7 @@ print_interface_neighbors_via_iproute() {  # MAC|IP|_|STATUS
            MAC="?"
            STATUS="$(echo $line | awk -F'|' '$1="";$2="";$3="";$4="";{print}' | awk '{$1=$1;print}' | sed 's/ /,/g')"
        fi
-        if [[ -n "$IP" ]]; then
+        if [[ -n "$IP" && ( "$MAC" != "?" || "$STATUS" != "FAILED" ) ]]; then
            echo "$MAC|$IP|?|$STATUS"
        fi
    done
@@ -1315,12 +1347,12 @@ print_interface_neighbors_via_iw() {  # MAC|_|_|signal
    do
        if [[ -n "$MAC" ]]; then
            SIGNAL="$(iw dev $IFACE station get $MAC | grep "signal:" | awk '{print $2}')"
-            echo "${MAC}|?|?|${SIGNAL} dBm"
+            echo "${MAC}|?|?|${SIGNAL}_dBm"
        fi
    done
 }

-list_clients() {
+list_clients() { # passive mode. (use 'arp-scan' or 'netdiscover' if want active mode)
    local IFACE pid
    local CONFDIR
    
@@ -1336,7 +1368,7 @@ list_clients() {
    else # non-number given
        IFACE="$1"
        if ( ! is_interface $IFACE ) ; then
-            echo "'$IFACE' is not an interface" >&2
+            echo "'$IFACE' is not an interface or PID" >&2
            exit 1
        fi
        pid=$(get_pid_from_subn_iface "$IFACE")
@@ -1459,6 +1491,19 @@ daemonizing_check(){

 #============================
 check_wifi_settings() {
+
+    if ! ( which iw > /dev/null 2>&1 && iw dev $WIFI_IFACE info > /dev/null 2>&1 ); then
+        echo "WARN: Can't use 'iw' to operate interfce '$WIFI_IFACE', trying 'iwconfig' (not as good as 'iw') ..." >&2
+        USE_IWCONFIG=1
+    fi
+    
+    if [[ $USE_IWCONFIG -eq 1 ]]; then
+        if ! (which iwconfig > /dev/null 2>&1 && iwconfig $WIFI_IFACE > /dev/null 2>&1); then
+            echo "ERROR: Can't use 'iwconfig' to operate interfce '$WIFI_IFACE'" >&2
+            exit 1
+        fi
+    fi
+    
    if [[ $FREQ_BAND != 2.4 && $FREQ_BAND != 5 ]]; then
        echo "ERROR: Invalid frequency band" >&2
        exit 1
@@ -1547,8 +1592,8 @@ decide_target_interface() {
    elif [[ "$WIFI_IFACE" ]]; then
        echo "$WIFI_IFACE"
    else
-        die "No target interface specified" 
-        exit 1
+        echo "No target interface specified"  >&2
+        return 1
    fi
 }

@@ -1556,11 +1601,15 @@ decide_ip_addresses() {
    if [[ ! -n $GATEWAY ]]; then
        GATEWAY="$(generate_random_ip4)"
        echo "Use random LAN IPv4 address $GATEWAY"
+    elif [[ ! "$GATEWAY" =~ "." ]]; then
+        GATEWAY="192.168.${GATEWAY}.1"
    fi

    if [[ $IPV6 -eq 1 && ! -n $PREFIX6 ]]; then
        PREFIX6="$(generate_random_lan_ip6_prefix)"
        echo "Use random LAN IPv6 address ${PREFIX6}${IID6}"
+    elif [[ ! "$PREFIX6" =~ ":" ]]; then
+        PREFIX6="fd00:0:0:${PREFIX6}::"
    fi
    if [[ $IPV6 -eq 1 ]]; then
        GATEWAY6="${PREFIX6}${IID6}"
@@ -1595,8 +1644,9 @@ prepare_wifi_interface() {
        VWIFI_IFACE=$(alloc_new_vface_name)
        if iw dev ${WIFI_IFACE} interface add ${VWIFI_IFACE} type __ap; then
            # Successfully created virtual wifi interface
-            sleep 2  # wait for virtual interface MAC may change by system (but could be changed back by other programs)
-            echo "${VWIFI_IFACE} created)"
+            # if NM running, it will give the new virtual interface a random MAC. MAC will go back after setting NM unmanaged
+            sleep 2  
+            echo "${VWIFI_IFACE} created"
        else
            VWIFI_IFACE=
            die "Failed creating virtual WiFi interface. Maybe your WiFi adapter does not fully support virtual interfaces. Try again with '--no-virt'"
@@ -1712,6 +1762,11 @@ write_dnsmasq_conf() {
    else
        NOBODY_GROUP="nogroup"
    fi
+    
+    mkfifo "$CONFDIR/dnsmasq.log" || die "Failed creating pipe file for dnsmasq"
+    chown nobody "$CONFDIR/dnsmasq.log" || die "Failed changing dnsmasq log file owner"
+    cat "$CONFDIR/dnsmasq.log" & 
+    
    cat <<- EOF > "$CONFDIR/dnsmasq.conf"
 		user=nobody
 		group=$NOBODY_GROUP
@@ -1723,7 +1778,7 @@ write_dnsmasq_conf() {
 		dhcp-range=${GATEWAY%.*}.10,${GATEWAY%.*}.250,255.255.255.0
 		dhcp-option-force=option:router,${GATEWAY}
 		#log-dhcp
-		log-facility=/dev/stdout
+		log-facility=$CONFDIR/dnsmasq.log
 		bogus-priv
 		domain-needed
 	EOF
@@ -1814,8 +1869,7 @@ run_wifi_ap_processes() {
    #    sleep 1
    #done
    #echo -n "hostapd PID: " ; cat $CONFDIR/hostapd.pid
-    ( while [ -e /proc/$HOSTAPD_PID ]; do sleep 10; done ; die "hostapd exited" ) &
-
+    pid_watchdog $HOSTAPD_PID 10 "hostapd failed" &
    sleep 3
 }

@@ -1838,9 +1892,10 @@ start_dnsmasq() {
        i=$((i + 1))
        if [[ $i -gt 10 ]]; then die "Couldn't get dnsmasq PID" ; fi
    done
-    echo -n "dnsmasq PID: " ; cat "$CONFDIR/dnsmasq.pid"
+    DNSMASQ_PID="$(cat "$CONFDIR/dnsmasq.pid" )"
+    echo  "dnsmasq PID: $DNSMASQ_PID" 
    ######(wait $DNSMASQ_PID ; die "dnsmasq failed") &  # wait can't deal with non-child
-    ( while [ -e "/proc/$DNSMASQ_PID" ]; do sleep 10; done ; die "dnsmasq exited" ) &
+    pid_watchdog $DNSMASQ_PID 9 "dnsmasq failed" &
    sleep 2
 }

@@ -1890,8 +1945,9 @@ daemonizing_check
 ## ========================================================
 echo "PID: $$"

-TARGET_IFACE="$(decide_target_interface)"  # judge wired (-i CONN_IFACE) or wireless hotspot (--ap $WIFI_IFACE)
-echo "Target interface is ${TARGET_IFACE}"
+TARGET_IFACE="$(decide_target_interface)" || exit 1 # judge wired (-i CONN_IFACE) or wireless hotspot (--ap $WIFI_IFACE)
+echo "Target interface is ${TARGET_IFACE} ($(get_interface_mac $TARGET_IFACE))"
+# TODO: show interface type, device model and pci/usb id (hwdata  pci.ids), current driver

 if [[ "$MAC_USE_RANDOM" -eq 1 ]] ; then
    NEW_MACADDR="$(generate_random_mac)"
@@ -1907,6 +1963,7 @@ decide_ip_addresses # ip 4 & 6 lan addresses
 #==== begin to do some change on config files and system===

 init_trap
+# NOTE function die() is designed not to be used before init_trap() executed

 init_conf_dirs #   CONFDIR  , COMMON_CONFDIR  . make dir

@@ -1947,7 +2004,7 @@ ip link set down dev ${SUBNET_IFACE} || die "Failed setting ${SUBNET_IFACE} down
 # flush old IPs of subnet interface
 ip addr flush ${SUBNET_IFACE} || die "Failed flush ${SUBNET_IFACE} IP"

-dealwith_mac
+dealwith_mac # setting MAC should be after setting NM unmanaged

 [[ $WIFI_IFACE ]] && check_rfkill_unblock_wifi

@@ -1967,6 +2024,18 @@ if [[ $IPV6 -eq 1 ]] ; then
    ip -6 addr add ${GATEWAY6}/64  dev ${SUBNET_IFACE} || die "Failed setting ${SUBNET_IFACE} IPv6 address"
 fi

+function check_iptables() {
+    if iptables --version | grep "nf_tables" >/dev/null 2>&1 ; then
+        echo -e "\nWARN: Your system is using nftables. This script is tested with iptables legacy only. If you encounter problems, visit following URL for infomation:\n  https://github.com/oblique/create_ap/issues/373\n  https://github.com/oblique/create_ap/issues/433\n  https://github.com/garywill/linux-router/issues/18\n" >&2
+    fi
+    
+    if ! lsmod | grep -E "\bxt_comment\b" >/dev/null 2>&1 ; then
+        XT_COMMENT=0
+    fi
+}
+
+check_iptables
+
 # enable Internet sharing
 if [[ "$SHARE_METHOD" == "none" ]]; then