[PR #1851] fix(rust): Handle NULL file pointer in ccxr_demuxer_open for UDP/TCP input #2615

New Issue

claunia · 2026-01-29T17:23:06Z

claunia commented

2026-01-29 17:23:06 +00:00

Original Pull Request: https://github.com/CCExtractor/ccextractor/pull/1851

State: closed
Merged: Yes

Summary

Fixes #1846

When using --udp or --tcp options, ccxr_demuxer_open() was called with a NULL file pointer, causing a crash in CStr::from_ptr().

Root Cause

The Rust FFI function ccxr_demuxer_open assumed the file parameter was always a valid C string pointer:

let c_str = CStr::from_ptr(file);  // Crashes if file is NULL

For network input modes (UDP/TCP), the C code passes NULL since there's no file to open.

Fix

Check if the file pointer is NULL before dereferencing:

let file_str = if !file.is_null() {
    match CStr::from_ptr(file).to_str() {
        Ok(s) => s,
        Err(_) => return -1,
    }
} else {
    ""
};

Testing

Verified both UDP and TCP modes work:

# UDP - confirmed listening with ss
$ timeout 10 ./ccextractor --udp 54321 &
$ ss -ulnp | grep 54321
UNCONN 0 0 0.0.0.0:54321 0.0.0.0:* users:(("ccextractor",pid=99942,fd=4))

# TCP - confirmed listening
$ timeout 10 ./ccextractor --tcp 54322 &
$ ss -tlnp | grep 54322
LISTEN 0 128 *:54322 *:* users:(("ccextractor",pid=98972,fd=4))

Test Plan

Build succeeds
UDP mode starts and listens on specified port
TCP mode starts and listens on specified port
No crash on startup

🤖 Generated with Claude Code

**Original Pull Request:** https://github.com/CCExtractor/ccextractor/pull/1851 **State:** closed **Merged:** Yes --- ## Summary Fixes #1846 When using `--udp` or `--tcp` options, `ccxr_demuxer_open()` was called with a NULL file pointer, causing a crash in `CStr::from_ptr()`. ### Root Cause The Rust FFI function `ccxr_demuxer_open` assumed the `file` parameter was always a valid C string pointer: ```rust let c_str = CStr::from_ptr(file); // Crashes if file is NULL ``` For network input modes (UDP/TCP), the C code passes NULL since there's no file to open. ### Fix Check if the file pointer is NULL before dereferencing: ```rust let file_str = if !file.is_null() { match CStr::from_ptr(file).to_str() { Ok(s) => s, Err(_) => return -1, } } else { "" }; ``` ## Testing Verified both UDP and TCP modes work: ```bash # UDP - confirmed listening with ss $ timeout 10 ./ccextractor --udp 54321 & $ ss -ulnp | grep 54321 UNCONN 0 0 0.0.0.0:54321 0.0.0.0:* users:(("ccextractor",pid=99942,fd=4)) # TCP - confirmed listening $ timeout 10 ./ccextractor --tcp 54322 & $ ss -tlnp | grep 54322 LISTEN 0 128 *:54322 *:* users:(("ccextractor",pid=98972,fd=4)) ``` ## Test Plan - [x] Build succeeds - [x] UDP mode starts and listens on specified port - [x] TCP mode starts and listens on specified port - [x] No crash on startup 🤖 Generated with [Claude Code](https://claude.com/claude-code)

claunia added the pull-request label 2026-01-29 17:23:06 +00:00

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Reference: starred/ccextractor#2615