fix: fixup gRPC buffer overflow bug with unit test. #3376
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aaron-kasten
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aaron-kasten
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Feb 21, 2025
| @@ -35,7 +35,7 @@ func tmpDir(c *C) string { | |||
| // limit the size of the address while retaining some of the properties | |||
| // of the original directory name | |||
| hs := adler32.Checksum([]byte(c.TestName())) | |||
| d, err := os.MkdirTemp("", fmt.Sprintf("%08x%.20s", hs, c.TestName())) | |||
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Change to make these temp files easier to find. Having the filename hash first can be really confusing when using ls and an alphabetical sort.
aaron-kasten
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Feb 21, 2025
| t := time.NewTicker(s.tailTickDuration) | ||
| for { | ||
| n, err := buf.ReadFrom(fh) |
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Fixup misuse of bytes.Buffer: bytes.Buffer will grow to size of write regardless of backing buffer capacity.
aaron-kasten
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Feb 21, 2025
| @@ -219,7 +218,7 @@ func (s *processServiceServer) streamOutput(ss sender, p *process, fh *os.File) | |||
| <-t.C | |||
| continue | |||
| } | |||
| o := &Output{Output: buf.String()} | |||
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Performs an extra allocation for the string object which may add measurable overhead considering how large the buffer is (2MB). May want to convert this code to a 2 thread bucket brigade at some point.
aaron-kasten
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Feb 21, 2025
| @@ -449,3 +449,37 @@ func (s *KanXSuite) TestCreateProcess_Exit2(c *C) { | |||
| c.Assert(p0.GetExitErr(), Equals, "signal: killed") | |||
| c.Assert(p0.GetExitCode(), Equals, int64(-1)) | |||
| } | |||
|
|
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| func (s *KanXSuite) TestCreateProcess_BufferOverflow_1(c *C) { | |||
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Test that buffer does not overflow.
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hairyhum
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Signed-off-by: Aaron Alpar <[email protected]>
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Signed-off-by: Aaron Alpar <[email protected]>
Signed-off-by: Aaron Alpar <[email protected]>
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Signed-off-by: Aaron Alpar <[email protected]>
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Change Overview
gRPC has a over-the-wire buffer limit of 4MB. gRPC buffer overflow errors can occur if this figure is use as a before the wire buffer measure as gRPC adds overhead (JSON overhead) when sending messages from gRPC API clients.
This fix just divides the gRPC buffer limit in half (2MB) which is much smaller than the theoretical max (theoretical_max = 4MB - protocol overhead) but intuitively large enough to hold enough data.
This also includes a fix for using
bytes.Bufferas a circular buffer, which its not very good at. Instead a[]bytebuffer is used. If performance is a concern then the buffer copy should be split across 2 threads in a bucket brigade.Pull request type
Please check the type of change your PR introduces:
Issues
There is no github issue for this fix.
Test Plan