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• Configuring the DHCP Server

• L2 on board switches

• Setting up the iptables

• Process Monitors

• Configuring MultiLan interfaces and creating bridges

• Creating multiple VLans for isolating/securing the traffic across interfaces

High Level Architecture

Figure 1 - High level architecture of Utopia module

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As described in the previous section Utopia is launched and initialised through a set of shell scripts. This section details the scripts and the initialisation sequence.

Figure 2 - Utopia Initialization Sequence Diagram

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Syscfg_create executable creates shared memory with user configuration data (/nvram/syscfg.db). This is present in the code base at the location /ccsp/utopia/source/syscfg

Apply_system_defaults executable reads the data from system_defaults file (path: /etc/utopia/system_defaults) and compares with syscfg.db, in case of any data is missing in syscfg, those defaults are written in to shared memory. On start of any module, data is read from the shared memory during initialization.

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Gw_prov_utopia exe calls Init script. Init script executes all executables present in /etc/utopia/registration.d/ directory. 10_firewall exe is responsible for firewall events and it registers for sysevent callback with service name as firewall. Handler script is firewall_log_handle.sh. If any firewall event occurs sysevent is triggered with firewall-restart event name.

Firewall Initialization Process

On firewall-restart event service_start() method gets called. Ip4table and Ip6table rules are prepared by reading data from shared memory, written into /tmp/.ipt and /tmp/.ipt_v6 files respectively. Iptable rules are restored using these files.

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• syscfg_set() checks if the syscfg value exists, if not allocates memory and add it to the end of the linked list and sets the value.
• SysCfg_Commit() – calls syscfg_commit().
• syscfg_commit API updates the persistent memory with the shared memory details.

Example set flow for PC URL