Fix SOCK_CLOEXEC handling to maintain socktype equality checks

[bagder]

socket_open unconditionally ORs SOCK_CLOEXEC into addr->socktype. The same addr structure is later reused in cf_socket_open, which checks ctx->addr.socktype == SOCK_STREAM to decide whether to enable TCP_NODELAY and TCP keepalive. With SOCK_CLOEXEC set, the equality check fails, so TCP-specific options are skipped and ctx->sock_connected is also computed against SOCK_DGRAM with a mismatching value.

Follow-up to 0536769

Found by Codex Security

/cc @ibookstein

[nextsilicon-itay-bookstein]

Nice catch. Note that the proposed change will stop affecting the fopensocket != NULL case, which then makes the unconditional fcntl exemption wrong... Maybe it is better to mask out that flag in the equality comparisons when it is defined?

[bagder]

@aisle-analyzer augment review

[aisle-research-bot]

🔒 Aisle Security Analysis

✅ We scanned this PR and did not find any security vulnerabilities.

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Analyzed PR: #20808 at commit af2dea5

_{Last updated on: 2026-03-07T10:34:27Z}

[augmentcode]

🤖 Augment PR Summary

Summary: Prevents TCP-specific socket options from being skipped when addr->socktype has extra bits (e.g., SOCK_CLOEXEC) ORed in.
Changes: Introduces a SOCKTYPE() masking macro and uses it for SOCK_STREAM / SOCK_DGRAM comparisons in cf_socket_open().

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[augmentcode]

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[Copilot]

Pull request overview

This PR fixes a regression in cf_socket_open() where SOCK_CLOEXEC (and potentially SOCK_NONBLOCK) being ORed into addr->socktype caused direct equality checks against SOCK_STREAM/SOCK_DGRAM to fail, skipping TCP-specific socket options and miscomputing connection state.

Changes:

• Introduce a SOCKTYPE() helper macro to strip SOCK_CLOEXEC/SOCK_NONBLOCK bits before comparing socket types.
• Use SOCKTYPE(ctx->addr.socktype) for TCP detection (SOCK_STREAM) and for sock_connected determination (SOCK_DGRAM).

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