System and method for intercepting data flow between computer process and system resource

1. A method for redirecting input/output, the method comprising:

on a CPU, interrupting an execution of a first process with a first object descriptor table associated with the first process, the first object descriptor table including a reference for the first process to a first system resource;

loading parasite code into memory, wherein the parasite code provides access to a second system resource under control of a second process;

the second process forcing a switch of execution from the first process to the parasite code, and replacing in the first object descriptor table the reference for the first process to the system resource by a reference to the second system resource, thereby causing the input/output to go through the second system resource instead of the first system resource; and

restoring the execution of the first process after the execution of the parasite code is complete.

2. The method according to claim 1 , wherein the second system resource is a communication channel.

3. The method according to claim 1 , wherein the second system resource is a socket.

4. The method according to claim 1 , wherein the second system resource is a file on a disk.

5. The method according to claim 1 , wherein the second system resource is a virtual file in the memory.

6. The method according to claim 1 , wherein the second system resource is a file system.

7. The method according to claim 1 , wherein the second system resource is a network card.

8. The method according to claim 1 , wherein the second system resource is a pipe.

9. The method according to claim 1 , wherein the second system resource is a timer.

10. The method according to claim 1 , wherein the second system resource is a disk or a partition.

11. The method according to claim 1 , wherein code of the first process is not modified by the loading of the parasite code into the memory.

12. The method according to claim 1 , wherein the first object descriptor table is a file descriptor table.

13. The method according to claim 1 , wherein the parasite code is inserted into an address space of the first process in the memory by the second process.

14. The method according to claim 1 , wherein the parasite code performs a logrotate on the fly.

15. The method according to claim 1 , wherein the parasite code performs checks on socket file descriptors to verify if a connection of the second process is frozen.

16. The method according to claim 1 , wherein the parasite code performs garbage collection.

17. The method according to claim 1 , wherein the parasite code intercepts SIGSEGV and acts upon an illegal memory access.

18. The method according to claim 1 , wherein the parasite code performs a remote swap for a task.

19. The method according to claim 1 , wherein the parasite code performs WSS (Working Set Size) detection.

20. The method according to claim 1 , wherein the parasite code performs death detection of a process that is unrelated to the first or second processes.

21. The method according to claim 1 , wherein the parasite code performs a binary update for live patching or libraries relink.

22. The method according to claim 1 , wherein the parasite code performs tunneling to replace an opened non-UNIX socket with a UNIX socket.

23. The method according to claim 1 , wherein the parasite code injects a socket spy.

24. The method according to claim 1 , wherein the parasite code performs a crypt and/or decrypt of an unsecured channel without restarting its original processes.

25. The method according to claim 1 , wherein the parasite code performs a traffic fanout (multiplex).

26. The method according to claim 1 , wherein the parasite code performs a filter and/or split log for a file on disks using a proxy via a pipe.

27. The method according to claim 1 , wherein the parasite code performs a nohup on the fly.

28. The method according to claim 1 , wherein the parasite code retrieves unread data for a frozen daemon.

29. The method according to claim 1 , wherein the parasite code performs a re-connect for sleeping sockets to other addresses.

30. The method according to claim 1 , wherein the parasite code performs “soft” restart of a service by calling execve( ) from a context of the service.

31. The method according to claim 1 , wherein the parasite code forces entry into a Container.

32. The method according to claim 1 , wherein the parasite code forces a reparent for a process.

33. The method according to claim 1 , further comprising updating a second object descriptor table for the second process so that the second object descriptor table includes a first reference to the first system resource and a second reference to the second system resource.

34. A system for redirecting input/output, the system comprising:

a CPU and a memory coupled to the CPU, the memory containing computer code implementing

a first process with a first object descriptor table associated with the first process, the first object descriptor table including a reference for the first process to a first system resource;

a second process that loads a parasite code into the memory, wherein the parasite code provides access to a second system resource under control of the second process;

the second process forcing a switch of execution from the first process to the parasite code, and replacing in the first object descriptor table the reference for the first process to the system resource by a reference to the second system resource, thereby causing the input/output to go through the second system resource instead of the first system resource; and

the second process restoring the execution of the first process after the execution of the parasite code is complete.