Merge pull request #14 from morehouse/contributing_guide

README.md: add contributing guide

README.md

@@ -2,3 +2,46 @@
 
 Fuzzing seeds for the [Lightning Network
 Daemon](https://github.com/lightningnetwork/lnd).
+
+## Contributing
+
+If you find coverage-increasing inputs while fuzzing LND, please create a pull
+request adding them to this repository. Use the `corpus_merge.sh` script to only
+add inputs that increase coverage.
+
+### Example
+
+Here's an example workflow to contribute new inputs for the lnwire
+`FuzzAcceptChannel` target. We'll assume the `lnd` and `lnd-fuzz` repositories
+are checked out in the current directory.
+
+First create a directory for corpus inputs to be saved in. Use the `lnd-fuzz`
+corpus to seed the new corpus, and begin fuzzing:
+
+```shell
+export ROOT=$(pwd)
+mkdir lnwire_corpus
+cp -r lnd-fuzz/lnwire/testdata/fuzz/FuzzAcceptChannel lnwire_corpus/
+cd lnd/lnwire
+go test -fuzz=FuzzAcceptChannel -parallel=4 -test.fuzzcachedir="$ROOT/lnwire_corpus"
+```
+
+After some time, the fuzzer may find some potential coverage-increasing inputs
+and save them to `lnwire_corpus/FuzzAcceptChannel/`. We can then merge them into
+the `lnd-fuzz` corpus:
+
+```shell
+cd $ROOT
+lnd-fuzz/corpus_merge.sh lnd-fuzz/lnwire/testdata/fuzz/FuzzAcceptChannel \
+    lnwire_corpus/FuzzAcceptChannel lnd/lnwire FuzzAcceptChannel
+```
+
+Any inputs in `lnwire_corpus/FuzzAcceptChannel` that increase coverage over the
+existing `lnd-fuzz` corpus will be copied over. If new inputs were added, create
+a pull request to improve the upstream seed corpus:
+
+```shell
+cd lnd-fuzz
+git add lnwire/testdata/fuzz/FuzzAcceptChannel/*
+git commit
+```