microsoft / microsoft/ebpf-for-windows
Support for libbpf_probe_bpf_prog_type / libbpf_probe_bpf_map_type / libbpf_probe_bpf_helper
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- Dominant language
- C
- Stars
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- Forks
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- Avg merge
- 6d 10h
- Merged PRs (30d)
- 21
Description
### Describe the feature you'd like supported
This issue is track adding support for the following libbpf functions:
- [ ] libbpf_probe_bpf_helper
- [ ] libbpf_probe_bpf_prog_type
- [ ] libbpf_probe_bpf_map_type
These helper functions will be useful for any user mode application to determine which program types, maps and helper functions are supported by a specific version of eBPF running on a system.
```
/**
* @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports
* BPF programs of a given type.
* @param prog_type BPF program type to detect kernel support for
* @param opts reserved for future extensibility, should be NULL
* @return 1, if given program type is supported; 0, if given program type is
* not supported; negative error code if feature detection failed or can't be
* performed
*
* Make sure the process has required set of CAP_* permissions (or runs as
* root) when performing feature checking.
*/
LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts);
/**
* @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports
* BPF maps of a given type.
* @param map_type BPF map type to detect kernel support for
* @param opts reserved for future extensibility, should be NULL
* @return 1, if given map type is supported; 0, if given map type is
* not supported; negative error code if feature detection failed or can't be
* performed
*
* Make sure the process has required set of CAP_* permissions (or runs as
* root) when performing feature checking.
*/
LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts);
/**
* @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the
* use of a given BPF helper from specified BPF program type.
* @param prog_type BPF program type used to check the support of BPF helper
* @param helper_id BPF helper ID (enum bpf_func_id) to check support for
* @param opts reserved for future extensibility, should be NULL
* @return 1, if given combination of program type and helper is supported; 0,
* if the combination is not supported; negative error code if feature
* detection for provided input arguments failed or can't be performed
*
* Make sure the process has required set of CAP_* permissions (or runs as
* root) when performing feature checking.
*/
LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type,
enum bpf_func_id helper_id, const void *opts);
```
### Proposed solution
Implement these libbpf APIs
### Additional context
_No response_
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the three proposed entry points: libbpf_probe_bpf_helper, libbpf_probe_bpf_prog_type, and libbpf_probe_bpf_map_type. Review the existing libbpf-facing API structure and determine how support detection is tested; done means all three APIs are implemented with the documented return behavior for supported, unsupported, and failed checks.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- c
- Domain
- api, operating-systems
- Issue type
- Feature
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 28/100