refactor: extract SSRF-safe dial logic into core/network package and replace duplicate implementations in fetch.go and skills_serving.go

[Pratham-Mishra04]

Summary

The SSRF protection logic (IP classification and safe dial context) was duplicated across core/providers/utils/fetch.go and transports/bifrost-http/handlers/skills_serving.go, with the skills handler using a weaker isPrivateIP check that missed CGNAT, IPv6 transition addresses, site-local IPv6, broadcast, and interface-local multicast. This PR extracts a single, hardened implementation into core/network and replaces both call sites with it.

Changes

• Added core/network/ssrf.go with IsPublicIP and SSRFSafeDialContext as the canonical SSRF-safe dialing primitives. IsPublicIP blocks loopback, RFC 1918, CGNAT (RFC 6598), link-local, site-local (RFC 3879), multicast, broadcast, unspecified, and IPv4 addresses smuggled inside IPv6 transition representations (6to4 2002::/16, NAT64 64:ff9b::/96, NAT64 local-use 64:ff9b:1::/48). SSRFSafeDialContext resolves the host, validates every returned IP against IsPublicIP, and dials the first validated IP directly — eliminating the DNS-rebinding TOCTOU window.
• Removed the private isPublicIP/embeddedIPv4 functions from fetch.go and the weaker ssrfSafeDialContext/isPrivateIP functions from skills_serving.go; both now call network.SSRFSafeDialContext.
• Moved tests from core/providers/utils/fetch_test.go into core/network/ssrf_test.go, expanded them to cover the additional blocked ranges (CGNAT, broadcast, interface-local multicast, IPv6 site-local), and added dial-path tests for DNS error propagation, empty resolution, missing port, re-resolution per dial, and the DNS-rebinding TOCTOU guard.

Type of change

• Bug fix
• Feature
• Refactor
• Documentation
• Chore/CI

Affected areas

• Core (Go)
• Transports (HTTP)
• Providers/Integrations
• Plugins
• UI (React)
• Docs

How to test

go test ./core/network/... ./core/providers/utils/... ./transports/bifrost-http/...

The TestSSRFSafeDialContextBlocksLoopbackLiteral test exercises the exported constructor end-to-end against the real resolver and will fail if the dial gate is not applied. All other tests use a fakeResolver and require no network access.

Screenshots/Recordings

N/A

Breaking changes

• Yes
• No

Related issues

N/A

Security considerations

The skills handler previously used isPrivateIP, which did not block CGNAT addresses (used as pod IPs on EKS), IPv6 site-local (fec0::/10), broadcast (255.255.255.255), interface-local multicast, or IPv4 addresses wrapped in 6to4/NAT64 IPv6 representations. An admin-controlled source_url or a user-controlled fetch URL could have reached internal infrastructure through any of those gaps. The consolidated IsPublicIP closes all of them. The DNS-rebinding TOCTOU fix (dial the already-resolved IP directly) was present in fetch.go but absent in the skills handler; it is now enforced in both paths via the shared implementation.

Checklist

• I read docs/contributing/README.md and followed the guidelines
• I added/updated tests where appropriate
• I updated documentation where needed
• I verified builds succeed (Go and UI)
• I verified the CI pipeline passes locally if applicable

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[Pratham-Mishra04]

• docs: add Webhooks management API paths, schemas, and x-bf-async-webhook header parameter to async job endpoints #5270
• docs: add webhooks feature page and link it from async inference #5269
• feat: add dependency-free Go webhook receiver example with Standard Webhooks signature verification #5268
• test: add Postman e2e collection, Newman runner, and webhook-receiver sidecar for async webhook delivery #5267
• feat: add server-side pagination, search, and filtering to webhook endpoints list #5266
• feat: propagate inference request_id through async jobs and webhook deliveries for LLM log reconciliation #5265
• feat: add webhooks management UI with endpoint CRUD, delivery history, secret reveal, and sidebar entry #5264
• refactor: resolve async webhook endpoint by name at submit time via WebhookManager instead of pre-normalizing to ID in context #5252
• feat: add webhook endpoint admin API, in-memory store, config.json sync, and per-endpoint delivery tuning #5251
• feat: add WebhookDispatcher interface and wire async job terminal-state webhook notifications via BifrostContextKeyAsyncWebhook #5250
• feat: add webhook delivery dispatcher with SSRF-safe HTTP client, Standard Webhooks signing, and per-endpoint retry/concurrency tuning #5249
• feat: add webhook jobs work-queue and delivery history tables with store methods and tests #5248
• feat: add config_webhook_endpoints table, store CRUD methods, and secret rotation with Standard Webhooks signing #5247
• refactor: extract SSRF-safe dial logic into core/network package and replace duplicate implementations in fetch.go and skills_serving.go #5246 👈 (View in Graphite)
• dev

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[coderabbitai]

📝 Walkthrough

Summary by CodeRabbit

• Security Enhancements
  • Strengthened protection against server-side request forgery (SSRF) when fetching remote URLs.
  • Blocks connections to private, loopback, link-local, multicast, reserved, and other non-public IP addresses.
  • Validates DNS results before connecting and prevents DNS rebinding during requests.
  • Applied consistent SSRF protection across URL fetching and skills-related HTTP requests.
• Tests
  • Added coverage for public IP validation, DNS resolution failures, malformed addresses, and blocked connection scenarios.

Walkthrough

Changes

SSRF protection

Layer / File(s)	Summary
IP safety validation core/network/ssrf.go	Adds public-IP classification and unwraps supported IPv6 transition addresses before applying unsafe-range checks.
Validated DNS dialing core/network/ssrf.go, core/network/ssrf_test.go	Adds resolver-injected safe dialing that validates every DNS result, dials the validated IP directly, and tests blocking, rebinding protection, and error paths.
HTTP client integration core/providers/utils/fetch.go, transports/bifrost-http/handlers/skills_serving.go	Replaces duplicated local SSRF dialers with network.SSRFSafeDialContext.

Estimated code review effort: 3 (Moderate) | ~25 minutes

Sequence Diagram(s)

sequenceDiagram
  participant Caller
  participant SSRFSafeDialContext
  participant Resolver
  participant netDialer
  Caller->>SSRFSafeDialContext: dial host and port
  SSRFSafeDialContext->>Resolver: resolve hostname
  Resolver-->>SSRFSafeDialContext: resolved IP addresses
  SSRFSafeDialContext->>SSRFSafeDialContext: validate every IP with IsPublicIP
  SSRFSafeDialContext->>netDialer: dial first validated IP and port
  netDialer-->>Caller: connection or dial error

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Suggested reviewers: akshaydeo, danpiths

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main refactor: centralizing SSRF-safe dial logic and replacing duplicate implementations.
Description check	✅ Passed	The description matches the template closely and covers summary, changes, testing, security, and 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 07-14-refactor_share_ssrf-safe_outbound_dialer_via_core_network

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 golangci-lint (2.12.2)

level=error msg="[linters_context] typechecking error: pattern ./...: directory prefix . does not contain main module or its selected dependencies"

---

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[greptile-apps]

Confidence Score: 4/5

The standalone transport build needs dependency alignment before merging.

• The shared SSRF logic preserves the existing provider fetch behavior.
• The skills path gains stricter address checks and direct validated-IP dialing.
• The transport module's pinned core version does not provide the new dialer API.

transports/go.mod must reference a core release containing SSRFSafeDialContext.

Important Files Changed

Filename	Overview
core/network/ssrf.go	Adds the shared IP classifier and DNS-rebinding-safe dial function.
core/network/ssrf_test.go	Covers restricted address ranges, resolver failures, repeated resolution, and direct IP dialing.
core/providers/utils/fetch.go	Replaces equivalent local SSRF logic with the shared core implementation.
transports/bifrost-http/handlers/skills_serving.go	Uses the stronger shared dialer, but the transport module remains pinned to a core release without the new symbol.

_{Reviews (1): Last reviewed commit: "refactor: share SSRF-safe outbound diale..." | Re-trigger Greptile}

[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 `@core/network/ssrf.go`:
- Around line 62-68: Update embeddedIPv4 and its callers to accept the active
operator-configured NAT64/Pref64 prefixes, extract the embedded IPv4 address for
those prefixes, and apply the existing SSRF validation to that address before
allowing the request. Preserve handling for 6to4 and the standard NAT64
prefixes, and add a regression test proving a custom prefix targeting a
private/IMDS IPv4 address is rejected.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

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

---

ℹ️ Review info

⚙️ Run configuration

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Run ID: a0a9eef1-bf00-4ab9-80c8-08e6dc53d4a4

📥 Commits

Reviewing files that changed from the base of the PR and between c0909f9 and 968d6bf.

📒 Files selected for processing (5)

• core/network/ssrf.go
• core/network/ssrf_test.go
• core/providers/utils/fetch.go
• core/providers/utils/fetch_test.go
• transports/bifrost-http/handlers/skills_serving.go

💤 Files with no reviewable changes (1)

• core/providers/utils/fetch_test.go

[Pratham-Mishra04]

Merge activity

• Jul 17, 8:36 AM UTC: A user started a stack merge that includes this pull request via Graphite.
• Jul 17, 8:37 AM UTC: @Pratham-Mishra04 merged this pull request with Graphite.