cnc

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Introduction

cnc is a third-party campus network client for schools using Ruijie as the campus network provider. As a Python CLI tool, cnc is easy to install and lets you perform operations such as login, logout, status check, and keep-alive.

Plan

• :chart_with_upwards_trend: Add images
• :pencil2: Add flowchart（Using Mermaid）
• :iphone: Support iOS Shortcut
• :rocket: Support multiple ISP
• :school: Support multiple places(dormitory, classroom, etc.)
• :hammer: Upload to PyPI
• :beer: Upload to Homebrew
• :eyes: Add graphical user interface（maybe Next.js or Gradio）
• :file_folder: Package into a container

Install

• Pip

pip install cnc-cli

• Source Code

  1. Clone this repository

  git clone https://github.com/ermengchao/cnc . && cd cnc
  

  2. Install the cnc package

  pip install -e .
  

Usage

:exclamation::exclamation: Before first usage, please run

cnc login

to create the cache. Cache example:

portal_url: http://10.254.241.19
updated_at: 1766905991

• portal_url: Portal URL for authentication (varies by school)
• updated_at: Cache creation time

If the cache is not created properly, all commands except login may be limited.

After the cache is created, you can use cnc normally. Supported operations:

• login: Log in to campus network
• logout: Log out of campus network
• status: Check campus network status
• keep-alive: Keep login alive via a persistent script (recommended with systemd)
• help: Show usage help

login

Use:

cnc login --user-id 2023083061 --password ****** --service 电信

Input:

• user-id: Campus network account. You can also set CNC_USER_ID
• password: Campus network password. You can also set CNC_PASSWORD
• service: ISP. You can also set CNC_SERVICE

Output:

• Login successful: Login succeeded
• Already online. Login skipped.: Already online, login skipped
• You appear to be offline. Login skipped.: Not connected to campus network
• Login failed: <error>: Login failed with server error
• State is missing/expired but you appear to be already authenticated...: Cache missing

logout

Use:

cnc logout

Input:

• None (uses cached portal_url)

Output:

• Logged out successfully: Logout succeeded
• Already offline. Logout skipped.: Already offline, logout skipped
• Logout failed: <error>: Logout failed with server error
• No cached portal_url found. Please run cnc login once to initialize the cache before using other commands.: Cache missing

status

Use:

cnc status

Input:

• None (uses cached portal_url)

Output:

• Status: on_campus_unauth: On campus but unauthenticated
• Status: on_campus_auth: On campus and authenticated
• Status: off_campus: Off campus
• Status: unknown: Status unknown
• No cached portal_url found. Please run cnc login once to initialize the cache before using other commands.: Cache missing

keep-alive

Use (polling mode, default):

cnc keep-alive --polling --interval-seconds 300

Use (daily relogin mode):

cnc keep-alive --relogin --user-id 2023083061 --password ****** --service 电信 --run-at 05:00

Input:

• --polling or --relogin (choose one)
• --interval-seconds: Polling interval in seconds (polling mode only, default 300)
• --user-id, --password, --service: Relogin mode only (can also use CNC_USER_ID, CNC_PASSWORD, CNC_SERVICE)
• --run-at: Daily relogin time (relogin mode only, HH:MM, default 05:00)

Output:

• Choose only one mode: --polling or --relogin: Mode conflict
• relogin mode requires --user-id, --password, and --service: Missing relogin args
• Keep-alive failed: <error>: Keep-alive failed
• No cached portal_url found. Please run cnc login once to initialize the cache before using other commands.: Cache missing

help

Use:

cnc help
cnc help login

Input:

• Optional subcommand name

Output:

• Prints CLI help text

Process

flowchart TD
    A[CampusNetClient initialization] --> B[StateStore read/write state.yaml]

    A --> S["status()"]
    S --> S1{"Has cached portal_url?"}
    S1 -- No --> S2[StateError: login first to cache]
    S1 -- Yes --> S3["detect_network_status(redirect_url)"]
    S3 --> S4{Result UNKNOWN?}
    S4 -- No --> S5[Return NetworkState]
    S4 -- Yes --> S6["_status_from_portal_url(cached portal_url)"]

    A --> E["ensure_state()"]
    E --> E1["_state_has_fresh_portal_url?"]
    E1 -- Yes --> E2[Return cached]
    E1 -- No --> E3["status()"]
    E3 --> E4{ON_CAMPUS_AUTH?}
    E4 -- Yes --> E5[NeedUnauthed]
    E4 -- No --> E6["get_portal_info -> save state"]

    A --> L["login(user_id, password, service)"]
    L --> L1{"cached portal_url?"}
    L1 -- Yes --> L2["_status_from_portal_url"]
    L1 -- No --> L3["detect_network_status"]
    L2 --> L4{"ON_CAMPUS_AUTH?"}
    L3 --> L4
    L4 -- Yes --> L5[AlreadyOnline: Login skipped]
    L4 -- No --> L6{"OFF_CAMPUS?"}
    L6 -- Yes --> L7[AlreadyOffline: Login skipped]
    L6 -- No --> L8["get_portal_info -> portal_url/query -> save"]
    L8 --> L9["do_login(...)"]

    A --> O["logout()"]
    O --> O1{"cached portal_url?"}
    O1 -- No --> O2[StateError: no cache]
    O1 -- Yes --> O3["_status_from_portal_url"]
    O3 --> O4{"ON_CAMPUS_UNAUTH or OFF_CAMPUS?"}
    O4 -- Yes --> O5[AlreadyOffline: Logout skipped]
    O4 -- No --> O6{"UNKNOWN?"}
    O6 -- Yes --> O7[StateError: unknown]
    O6 -- No --> O8["get_portal_info -> save"]
    O8 --> O9{"portal_url exists?"}
    O9 -- No --> O10[StateError: no portal_url]
    O9 -- Yes --> O11["do_logout(...)"]

    subgraph Helper
        H1["_state_has_fresh_portal_url"]
        H2["_status_from_portal_url"]
    end

Principles

Optional. If you are interested, you can refer to the steps below. If you run into any issues, feel free to open an issue!

Login principle

Login is essentially a POST request to http://{portal_url}/eportal/Interface.do?method=login, with the following fields:

# Header
-H 'Content-Type: application/x-www-form-urlencoded; charset=UTF-8' \

# Body
# User info
--data-urlencode "userId=$userId" \
--data-urlencode "password=$password" \
--data-urlencode "service=$service" \
--data-urlencode "queryString=$queryString" \
# Placeholder fields
--data-urlencode 'operatorPwd=' \
--data-urlencode 'operatorUserId=' \
--data-urlencode 'validcode=' \
--data-urlencode 'passwordEncrypt=false'

Logout principle

Logout is essentially a POST request to http://{portal_url}/eportal/Interface.do?method=logout. Unlike login, logout does not require a request body.

Status principle

Status is essentially a GET request to http://{portal_url}/eportal/redirectortosuccess.jsp, and you can determine the state by checking the Location header:

• Authenticated: Location=http://{portal_url}/eportal/./success.jsp
• Unauthenticated: Location=http://123.123.123.123/
• Off campus: request timeout

LICENSE

MIT LICENSE