feat: state the device's own address in origin.ip

[DavidCozens]

Pull request

What this stage adds

The ip PARAM, sourced from the same interface address HOSTNAME reports. A relay or
NAT between device and collector rewrites what the collector observes; ip is what
the device says about itself, which survives the hop.

Flash +12,388 B (+408 on the previous stage)
RAM +7,384 B (unchanged)
Log stack +712 B (+8)
Service +992 B (unchanged)

ip is repeatable per RFC 5424 section 7.2, so the library asks for a count and then
one value per index rather than taking a string. This device has one address and
returns one, and none before the interface has an address.

SyslogFields_IpAddress is now the single place that reads the address; HOSTNAME
formats the same string through it.

The record is 260 bytes, inside the 512-byte cap with room for both counters at
full width.

Files

 README.md                  | 14 ++++++--------
 app/syslog/Syslog.c        | 29 +++++++++++++++++++++++++++--
 app/syslog/SyslogFields.c  | 19 +++++++++++++------
 app/syslog/SyslogFields.h  |  5 +++++
 measurements/origin-ip.csv | 13 +++++++++++++
 measurements/stages.tsv    |  1 +
 run-report.md              | 26 +++++++++++++-------------
 7 files changed, 78 insertions(+), 29 deletions(-)

Checklist

• The diff is application-only — no change to board bring-up, config headers, or build infra.
• measurements/origin-ip.csv committed.
• Row added to measurements/stages.tsv.
• README regenerated: python3 scripts/gen-cost-table.py.
• ./run.sh green (build + QEMU + baseline self-check) — run-report.md committed.

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Context for review: 15 of 21 sequential single-commit PRs replaying the integration on top of the Baseline root. Each lands green and reviewed before the next is built on it, because a change to an early commit would force every commit above it to be re-run and re-measured.

Summary by CodeRabbit

• New Features

  • Syslog messages now include the device’s own IPv4 address in the origin information.
  • The origin address remains available when messages pass through relays or NAT.

• Documentation

  • Updated usage documentation, cost estimates, and performance reports to reflect origin address support.
  • Added updated validation examples showing the origin IP in generated logs.

[coderabbitai]

📝 Walkthrough

Walkthrough

The syslog implementation now derives the default interface IPv4 address through a shared helper and emits it as the origin.ip structured-data value. README cost data and run-report measurements were updated for the new origin-address stage.

Changes

Origin IP emission

Layer / File(s)	Summary
IPv4 address helper app/syslog/SyslogFields.{c,h}	Adds SyslogFields_IpAddress, which formats a valid default-interface IPv4 address under the lwIP core lock; hostname generation reuses it.
Origin structured-data wiring app/syslog/Syslog.c	Adds callbacks and configures the origin structured-data element to emit the address when available.
Documentation and measurements README.md, run-report.md	Updates the origin-address stage, cost tables, run descriptor, size cross-check, and self-check output.

Estimated code review effort: 2 (Simple) | ~15 minutes

Possibly related PRs

• cososo-ltd/solid-syslog-example#19: Directly overlaps origin IP structured-data callbacks and shared field-helper changes.
• cososo-ltd/solid-syslog-example#18: Introduces the origin structured-data element extended here with an IP value.
• cososo-ltd/solid-syslog-example#32: Adds the IPv4-based hostname field logic refactored here into the shared helper.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the new origin.ip feature and matches the main change set.
Description check	✅ Passed	The description follows the template and includes the feature summary plus all checklist items.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch stage/origin-ip

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_{Comment @coderabbitai help to get the list of available commands.}

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@app/syslog/SyslogFields.c`:
- Around line 42-44: Update SyslogFields_IpAddress to return immediately when
out is NULL or size is zero, before accessing out[0]; preserve the existing
empty-string initialization for valid buffers.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: e84b1287-159a-40e6-9044-72ab40bfab06

📥 Commits

Reviewing files that changed from the base of the PR and between cc775f5 and f97a252.

⛔ Files ignored due to path filters (2)

• measurements/origin-ip.csv is excluded by !**/*.csv
• measurements/stages.tsv is excluded by !**/*.tsv

📒 Files selected for processing (5)

• README.md
• app/syslog/Syslog.c
• app/syslog/SyslogFields.c
• app/syslog/SyslogFields.h
• run-report.md