fix(iis): strip IPv6 zone/scope id from client IP string

[A13501350]

Summary

Windows GetNameInfo() appends the zone/scope identifier (e.g. "%6") to
link-local IPv6 addresses (fe80::/10) in their string form, because
sin6_scope_id is the interface index for link-local addresses.

ModSecurity's IP-match parser rejects addresses containing a zone suffix,
causing "IPmatch: bad IPv6 specification" and rule processing failures
(e.g. id=905110) for clients connecting from link-local IPv6.

Root cause

iis/mymodule.cpp — GetIpAddr() builds the client IP string consumed as
REMOTE_ADDR / client_ip. The "%" suffix makes the address
unparseable by ModSecurity's IP matcher.

Fix

Strip the "%" suffix from the textual IP in GetIpAddr() for
AF_INET6. The binary address (sin6_addr) carried by CopySockAddr() is
unaffected, and the zone id is irrelevant for IP matching. Added
#include <string.h> for strchr().

Fixes #3630

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[Copilot]

🟢 Approval recommended

The reviewed change addresses the stated parsing issue without unresolved blocking concerns.

Pull request overview

Fixes IIS IPv6 link-local client IP parsing by removing Windows zone identifiers before ModSecurity matching.

Changes:

• Adds string.h for strchr.
• Strips %zone suffixes from IPv6 address strings.

File summaries

File	Description
iis/mymodule.cpp	Normalizes IPv6 client IP strings before ModSecurity processing.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 0
• Review effort level: Lite

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