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Diffstat (limited to 'spec/dos-spec.md')
| -rw-r--r-- | spec/dos-spec.md | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/spec/dos-spec.md b/spec/dos-spec.md index d0b8e89..d37649f 100644 --- a/spec/dos-spec.md +++ b/spec/dos-spec.md @@ -3,7 +3,7 @@ This document is incomplete; it describes some mechanisms that Tor uses to avoid different kinds of denial-of-service attacks. -## Handling low-memory conditions +## Handling low-memory conditions { #oom } (See also `tor-spec.txt`, section 8.1.) @@ -22,7 +22,7 @@ With this in mind, any Tor implementation—especially one that runs as a relay or onion service—must take steps to prevent memory-based denial-of-service attacks. -### Detecting low memory +### Detecting low memory { #oom-detection } The easiest way to notice you're out of memory would, in theory, be getting an error when you try to allocate more. Unfortunately, some @@ -52,7 +52,7 @@ kinds of allocation: Note that directory caches aren't counted, since those are stored on disk and accessed via mmap. -### Responding to low memory +### Responding to low memory { #oom-response } If our allocations exceed MaxMemInQueues, then we take the following steps to reduce our memory allocation. @@ -87,7 +87,7 @@ rule, according to the age of their oldest queued data. Upon freeing a circuit, a "DESTROY cell" must be sent in both directions. -### Reporting low memory +### Reporting low memory { #oom-reporting } We define a "low threshold" equal to 3/4 of MaxMemInQueues. Every time our memory usage is above the low threshold, we record |