Failed to upload large file

[fuzzbuster]

Prerequisite

• I have read the README
• I have searched the opened & closed issues
• I have searched the WIKI and its FAQ page

Environment Data

• Merlin Version: 2.1.4
• Operating System: All on Linux

Expected Behavior

Uploading large files via merlin-cli(version 1.15) should complete successfully without errors, and merlin-cli should remain running/responsive after the upload process.

Actual Behavior

When attempting to upload a large file (generated via dd), the upload fails midway, and merlin-cli crashes abruptly without providing a clear error message. The process exits completely, requiring a restart of merlin-cli to continue operations.

Steps to Reproduce Behavior

1. Generate a large test file using dd:
   dd if=/dev/zero of=large_test_file.bin bs=1G count=1 (adjust count to increase file size, e.g., count=2 for 2GB)
2. Start the Merlin server:
   ./merlin-server
3. Launch merlin-cli and establish a connection to the server:
   ./merlin-cli ....
4. In merlin-cli, navigate to the agent context and initiate the file upload:
   upload large_test_file.bin /remote/path/
5. Observe that the upload progresses partially but then fails, and merlin-cli crashes/quits unexpectedly.

Misc Information

• The issue is consistently reproducible with files larger than ~500MB (threshold may vary by environment).
• No obvious error logs are generated in merlin-server.log or the terminal where merlin-cli was running before the crash.
• Smaller files (e.g., 1MB) upload successfully without issues.
• System resources (RAM, disk space) are sufficient during the upload attempt.
• Upon reviewing the code, I noticed that chunked transfer is not implemented in the .proto definition for file transfers. I hypothesize that implementing chunked transfer (splitting files into smaller chunks for transmission) could resolve this large file upload failure and cli crash issue.