Allow users to name and reuse sets

[qdeslandes]

Currently, users can use sets to efficiently filter packets against a large pool of similarly formatted data. Sets are defined as part of a rule, and can't be reused for other rules. If a user wants to filter on the same 10k elements sets in 2 different rules, bpfilter will create the set twice.

This change adds a new syntax to allow users to create named sets at the beginning of a chain, then filter on it in a rule using its name:

chain mychain BF_HOOK_XDP{ifindex=2} ACCEPT
    set myset (ip4.saddr, ip4.proto) in {
        192.168.1.1, udp;
        192.168.1.1, tcp
    }

    rule
        (ip4.saddr, ip4.proto) in myset
        tcp.flags any syn
        counter
        ACCEPT
      
    rule
        (ip4.saddr, ip4.proto) in myset
        counter
        ACCEPT

[Copilot]

Pull Request Overview

This PR adds support for named sets in bpfilter, allowing users to define reusable sets at the chain level and reference them in multiple rules. Previously, sets were anonymous and defined inline within individual rules, leading to duplication when the same set was needed across multiple rules.

Key changes include:

• Adding a name field to the bf_set structure to support named sets
• Updating set creation functions to accept an optional name parameter
• Extending the parser to handle named set declarations and references
• Adding comprehensive test coverage for the new named set functionality

Reviewed Changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/core/set.h	Adds name field to bf_set structure and updates function signatures
src/core/set.c	Implements named set functionality with memory management for set names
src/bfcli/parser.y	Adds grammar rules for named set declarations and references
src/bfcli/lexer.l	Updates lexer to handle 'set' keyword and improved whitespace handling
src/bfcli/print.c	Adds printing support for named sets in ruleset output
tests/unit/core/set.c	Updates all test calls to use new function signatures
tests/harness/filters.c	Updates test helper to use new bf_set_new signature
tests/e2e/cli.sh	Adds comprehensive end-to-end tests for named set functionality
tests/rules.bpfilter	Adds example usage of named sets in test ruleset
doc/usage/bfcli.rst	Documents the new named set syntax and usage

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