feat(userspace/libsinsp): improve recvmsg SCM_RIGHTS cmsg handling

[ekoops]

What type of PR is this?

Uncomment one (or more) /kind <> lines:

/kind bug

/kind cleanup

/kind design

/kind documentation

/kind failing-test

/kind feature

Any specific area of the project related to this PR?

Uncomment one (or more) /area <> lines:

/area API-version

/area build

/area CI

/area driver-kmod

/area driver-bpf

/area driver-modern-bpf

/area libscap-engine-bpf

/area libscap-engine-gvisor

/area libscap-engine-kmod

/area libscap-engine-modern-bpf

/area libscap-engine-nodriver

/area libscap-engine-noop

/area libscap-engine-source-plugin

/area libscap-engine-savefile

/area libscap

/area libpman

/area libsinsp

/area tests

/area proposals

Does this PR require a change in the driver versions?

/version driver-API-version-major

/version driver-API-version-minor

/version driver-API-version-patch

/version driver-SCHEMA-version-major

/version driver-SCHEMA-version-minor

/version driver-SCHEMA-version-patch

What this PR does / why we need it:

This enhances file descriptor handling in the context of SCM_RIGHTS control message processing for recvmsg events. Specifically:

• it introduces a new API in libscap for getting single fd info
• it handles all cmsghdr and all file descriptors contained in SCM_RIGHTS control messages, by selectively call the new API on them, instead of entirely scanning the entire procfs fd directory each time.
• it replaces readlink + sscanf calls with a single call to stat for retrieving the inode number of a network namespace in scap_fd_scan_fd_dir and scap_fd_get_fdinfo

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

NONE

[poiana]

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[FedeDP]

/milestone 0.21.0

[github-actions]

Perf diff from master - unit tests

    10.01%     +0.62%  [.] sinsp_parser::reset
     1.19%     +0.40%  [.] libsinsp::sinsp_suppress::process_event
     1.04%     -0.36%  [.] std::vector<sinsp_evt_param, std::allocator<sinsp_evt_param> >::emplace_back<sinsp_evt*, unsigned int&, char const*, unsigned long&>
     1.70%     -0.36%  [.] sinsp::fetch_next_event
     2.75%     +0.32%  [.] sinsp_thread_manager::find_thread
     2.34%     -0.31%  [.] is_conversion_needed
     0.59%     -0.29%  [.] sinsp_evt::is_filtered_out
     5.22%     +0.27%  [.] next_event_from_file
     2.03%     -0.26%  [.] std::_Hashtable<long, std::pair<long const, std::shared_ptr<sinsp_threadinfo> >, std::allocator<std::pair<long const, std::shared_ptr<sinsp_threadinfo> > >, std::__detail::_Select1st, std::equal_to<long>, std::hash<long>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::_M_find_before_node
     3.02%     -0.24%  [.] sinsp_thread_manager::get_thread_ref

Heap diff from master - unit tests

peak heap memory consumption: 0B
peak RSS (including heaptrack overhead): 0B
total memory leaked: 0B

Heap diff from master - scap file

peak heap memory consumption: 0B
peak RSS (including heaptrack overhead): 0B
total memory leaked: 0B

Benchmarks diff from master

Comparing gbench_data.json to /root/actions-runner/_work/libs/libs/build/gbench_data.json
Benchmark                                                         Time             CPU      Time Old      Time New       CPU Old       CPU New
----------------------------------------------------------------------------------------------------------------------------------------------
BM_sinsp_split_mean                                            +0.0177         +0.0178           144           146           144           146
BM_sinsp_split_median                                          +0.0188         +0.0189           144           146           144           146
BM_sinsp_split_stddev                                          +0.0293         +0.0276             1             1             1             1
BM_sinsp_split_cv                                              +0.0114         +0.0096             0             0             0             0
BM_sinsp_concatenate_paths_relative_path_mean                  +0.0131         +0.0132            57            58            57            58
BM_sinsp_concatenate_paths_relative_path_median                +0.0057         +0.0058            57            57            57            57
BM_sinsp_concatenate_paths_relative_path_stddev                +1.1598         +1.1599             0             1             0             1
BM_sinsp_concatenate_paths_relative_path_cv                    +1.1320         +1.1319             0             0             0             0
BM_sinsp_concatenate_paths_empty_path_mean                     +0.0058         +0.0059            25            25            25            25
BM_sinsp_concatenate_paths_empty_path_median                   +0.0019         +0.0020            25            25            25            25
BM_sinsp_concatenate_paths_empty_path_stddev                   +0.6378         +0.6390             0             0             0             0
BM_sinsp_concatenate_paths_empty_path_cv                       +0.6283         +0.6294             0             0             0             0
BM_sinsp_concatenate_paths_absolute_path_mean                  +0.1241         +0.1242            57            64            57            64
BM_sinsp_concatenate_paths_absolute_path_median                +0.1197         +0.1198            57            64            57            64
BM_sinsp_concatenate_paths_absolute_path_stddev                +0.4103         +0.4106             0             1             0             1
BM_sinsp_concatenate_paths_absolute_path_cv                    +0.2546         +0.2547             0             0             0             0
BM_sinsp_split_container_image_mean                            -0.0189         -0.0188           392           385           392           385
BM_sinsp_split_container_image_median                          -0.0184         -0.0183           392           385           392           385
BM_sinsp_split_container_image_stddev                          -0.1252         -0.1267             3             2             3             2
BM_sinsp_split_container_image_cv                              -0.1083         -0.1100             0             0             0             0

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 35 lines in your changes missing coverage. Please review.

Project coverage is 75.29%. Comparing base (3476089) to head (7c9c7e7).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
userspace/libsinsp/parsers.cpp	0.00%	35 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2262      +/-   ##
==========================================
- Coverage   75.34%   75.29%   -0.05%     
==========================================
  Files         279      279              
  Lines       34368    34389      +21     
  Branches     5872     5878       +6     
==========================================
- Hits        25894    25893       -1     
- Misses       8474     8496      +22     

Flag	Coverage Δ
libsinsp	75.29% <0.00%> (-0.05%)	⬇️

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[ekoops]

/hold

[ekoops]

/unhold