nss-ecm: switch to using named sections in uci

The way ECM uci config is handled is pretty ugly due to it not specifying a
named section for 'general'.

Current:
```
➤ uci show ecm
ecm.global=ecm
ecm.global.acceleration_engine='nss'
ecm.@general[0]=general
ecm.@general[0].enable_bridge_filtering='0'
ecm.@general[0].disable_offloads='0'
ecm.@general[0].disable_flow_control='0'
ecm.@general[0].disable_interrupt_moderation='0'
ecm.@general[0].disable_gro='0'
```

None of the options require the use of unnamed sections
(like /etc/config/dhcp does when defining configs for multiple hosts)

With this change the config would produce:
```
ecm.global=ecm
ecm.global.acceleration_engine='nss'
ecm.general=ecm
ecm.general.enable_bridge_filtering='0'
ecm.general.disable_offloads='0'
ecm.general.disable_flow_control='0'
ecm.general.disable_interrupt_moderation='0'
ecm.general.disable_gro='0'
```

Which is a lot easier to read, and access programmatically.

We can also merge `global` and `general` into a single section as it
doesn't really make sense why we need global/general when it's
technically "ALL" globally applied.

For now, to ease users on the change, let's just stick to 2 sections.

**PLEASE NOTE: For users building their own images, and storing their**
**configs in 'files/etc/config/ecm' you will need to manually update the**
**config before compiling.**

For users using **sysupgrade** or installing without custom config at build
time 'files/etc/config/ecm' should be OK.

The following can be run manually on the config file 'ecm'

```sh
conf=/etc/config/ecm
uci -q show ecm.general || {
  echo "Converting 'ECM' config to new format."
  sed -i "s/config.*general.*/config ecm 'general'/g" "$conf"
}
```

Signed-off-by: Sean Khan <datapronix@protonmail.com>

qca-nss-ecm/Makefile

@@ -1,7 +1,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=qca-nss-ecm
-PKG_RELEASE:=4
+PKG_RELEASE:=5
 
 PKG_SOURCE_URL:=https://git.codelinaro.org/clo/qsdk/oss/lklm/qca-nss-ecm.git
 PKG_SOURCE_PROTO:=git

qca-nss-ecm/files/disable_offloads.sh

@@ -1,5 +1,5 @@
 #!/bin/sh
-# shellcheck disable=3014
+# shellcheck disable=3014,3043,2086,1091,2154
 #
 # Helper script which uses ethtool to disable (most)
 # interface offloads, if possible.
@@ -172,19 +172,14 @@ disable_interrupt_moderation() {
   fi
 }
 
-parse_opt() {
-  local cfg="$1"
-
-  config_get_bool enable_bridge_filtering "$cfg" enable_bridge_filtering 0
-  config_get_bool disable_offloads "$cfg" disable_offloads 0
-  config_get_bool disable_flow_control "$cfg" disable_flow_control 0
-  config_get_bool disable_interrupt_moderation "$cfg" disable_interrupt_moderation 0
-  config_get_bool disable_gro "$cfg" disable_gro 0
-}
-
 disable_offload() {
   config_load ecm
-  config_foreach parse_opt general
+
+  config_get_bool enable_bridge_filtering      ecm enable_bridge_filtering 0
+  config_get_bool disable_offloads             ecm disable_offloads 0
+  config_get_bool disable_flow_control         ecm disable_flow_control 0
+  config_get_bool disable_interrupt_moderation ecm disable_interrupt_moderation 0
+  config_get_bool disable_gro                  ecm disable_gro 0
 
   [ -z $1 ] && interface=$(echo /sys/class/net/*) || interface=$*
 

qca-nss-ecm/files/qca-nss-ecm.defaults

@@ -1,19 +1,10 @@
 #!/bin/sh
-#
-# Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
-#
-# Permission to use, copy, modify, and/or distribute this software for any
-# purpose with or without fee is hereby granted, provided that the above
-# copyright notice and this permission notice appear in all copies.
-#
-# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
-# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
-# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-#
+
+# convert old ecm config to new format
+uci -q show ecm.general || {
+  echo "Converting 'ECM' config to new format."
+  sed -i "s/config.*general.*/config ecm 'general'/g" /etc/config/ecm
+}
 
 uci -q batch << EOF
     delete firewall.qcanssecm

qca-nss-ecm/files/qca-nss-ecm.init

@@ -1,4 +1,5 @@
 #!/bin/sh  /etc/rc.common
+# shellcheck disable=3043,3060,2086,2034
 #
 # Copyright (c) 2014, 2019-2020 The Linux Foundation. All rights reserved.
 #
@@ -22,9 +23,11 @@ START=26
 
 sysctl_update() {
   local name value file
+
   name=${1//\//\\/}
   value=${2//\//\\/}
   file=${3:-/etc/sysctl.d/qca-nss-ecm.conf}
+
   sed -i -e '/^#\?\(\s*'"${name}"'\s*=\s*\).*/{s//\1'"${value}"'/;:a;n;ba;q}' \
     -e '$a'"${name}"'='"${value}" "${file}"
   sysctl -w ${name}=${value}
@@ -32,8 +35,10 @@ sysctl_update() {
 
 get_front_end_mode() {
   config_load "ecm"
+
   config_get front_end global acceleration_engine "auto"
 
+  # shellcheck disable=2154
   case $front_end in
     auto)
       echo '0'
@@ -75,6 +80,7 @@ load_ecm() {
     echo 1 > /sys/kernel/debug/ecm/ecm_classifier_default/accel_delay_pkts
   }
 
+  # shellcheck disable=1091
   . /lib/netifd/offload/disable_offloads.sh
 
   disable_offload
@@ -119,12 +125,6 @@ unload_ecm() {
   fi
 }
 
-parse_opt() {
-  local cfg="$1"
-
-  config_get_bool enable_bridge_filtering "$cfg" enable_bridge_filtering 0
-}
-
 start() {
   load_ecm
 
@@ -133,8 +133,9 @@ start() {
 
   # If bridge filtering is enabled, apply and persist the sysctl flags
   config_load ecm
-  config_foreach parse_opt general
+  config_get enable_bridge_filtering general enable_bridge_filtering "0"
 
+  # shellcheck disable=2154
   if [ "$enable_bridge_filtering" -eq 1 ]; then
     echo "Bridge filtering is enabled in the ECM config, this will cause issues with NAT loopback!"
     enable_bridge_filtering

qca-nss-ecm/files/qca-nss-ecm.uci

@@ -1,7 +1,7 @@
 config ecm 'global'
 	option acceleration_engine 'auto'
 
-config general
+config ecm 'general'
 	option enable_bridge_filtering	'0'
 	option disable_offloads '0'
 	option disable_flow_control '0'