From 296b847c0d6de63353e236cfbf94163d24155529 Mon Sep 17 00:00:00 2001 From: David Turner Date: Fri, 18 Nov 2016 15:30:49 -0500 Subject: remote-curl: don't hang when a server dies before any output In the event that a HTTP server closes the connection after giving a 200 but before giving any packets, we don't want to hang forever waiting for a response that will never come. Instead, we should die immediately. One case where this happens is when attempting to fetch a dangling object by its object name. In this case, the server dies before sending any data. Prior to this patch, fetch-pack would wait for data from the server, and remote-curl would wait for fetch-pack, causing a deadlock. Despite this patch, there is other possible malformed input that could cause the same deadlock (e.g. a half-finished pktline, or a pktline but no trailing flush). There are a few possible solutions to this: 1. Allowing remote-curl to tell fetch-pack about the EOF (so that fetch-pack could know that no more data is coming until it says something else). This is tricky because an out-of-band signal would be required, or the http response would have to be re-framed inside another layer of pkt-line or something. 2. Make remote-curl understand some of the protocol. It turns out that in addition to understanding pkt-line, it would need to watch for ack/nak. This is somewhat fragile, as information about the protocol would end up in two places. Also, pkt-lines which are already at the length limit would need special handling. Both of these solutions would require a fair amount of work, whereas this hack is easy and solves at least some of the problem. Still to do: it would be good to give a better error message than "fatal: The remote end hung up unexpectedly". Signed-off-by: David Turner Signed-off-by: Junio C Hamano --- t/t5551-http-fetch-smart.sh | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 't') diff --git a/t/t5551-http-fetch-smart.sh b/t/t5551-http-fetch-smart.sh index 1ec5b2747a..43665ab4a8 100755 --- a/t/t5551-http-fetch-smart.sh +++ b/t/t5551-http-fetch-smart.sh @@ -276,6 +276,36 @@ test_expect_success 'large fetch-pack requests can be split across POSTs' ' test_line_count = 2 posts ' +test_expect_success 'test allowreachablesha1inwant' ' + test_when_finished "rm -rf test_reachable.git" && + server="$HTTPD_DOCUMENT_ROOT_PATH/repo.git" && + master_sha=$(git -C "$server" rev-parse refs/heads/master) && + git -C "$server" config uploadpack.allowreachablesha1inwant 1 && + + git init --bare test_reachable.git && + git -C test_reachable.git remote add origin "$HTTPD_URL/smart/repo.git" && + git -C test_reachable.git fetch origin "$master_sha" +' + +test_expect_success 'test allowreachablesha1inwant with unreachable' ' + test_when_finished "rm -rf test_reachable.git; git reset --hard $(git rev-parse HEAD)" && + + #create unreachable sha + echo content >file2 && + git add file2 && + git commit -m two && + git push public HEAD:refs/heads/doomed && + git push public :refs/heads/doomed && + + server="$HTTPD_DOCUMENT_ROOT_PATH/repo.git" && + master_sha=$(git -C "$server" rev-parse refs/heads/master) && + git -C "$server" config uploadpack.allowreachablesha1inwant 1 && + + git init --bare test_reachable.git && + git -C test_reachable.git remote add origin "$HTTPD_URL/smart/repo.git" && + test_must_fail git -C test_reachable.git fetch origin "$(git rev-parse HEAD)" +' + test_expect_success EXPENSIVE 'http can handle enormous ref negotiation' ' ( cd "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" && -- cgit v1.2.1 From f8edeaa05d8623a9f6dad408237496c51101aad8 Mon Sep 17 00:00:00 2001 From: David Turner Date: Fri, 11 Nov 2016 12:23:48 -0500 Subject: upload-pack: optionally allow fetching any sha1 It seems a little silly to do a reachabilty check in the case where we trust the user to access absolutely everything in the repository. Also, it's racy in a distributed system -- perhaps one server advertises a ref, but another has since had a force-push to that ref, and perhaps the two HTTP requests end up directed to these different servers. Signed-off-by: David Turner Signed-off-by: Junio C Hamano --- t/t5551-http-fetch-smart.sh | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 't') diff --git a/t/t5551-http-fetch-smart.sh b/t/t5551-http-fetch-smart.sh index 43665ab4a8..8d3db405c0 100755 --- a/t/t5551-http-fetch-smart.sh +++ b/t/t5551-http-fetch-smart.sh @@ -306,6 +306,28 @@ test_expect_success 'test allowreachablesha1inwant with unreachable' ' test_must_fail git -C test_reachable.git fetch origin "$(git rev-parse HEAD)" ' +test_expect_success 'test allowanysha1inwant with unreachable' ' + test_when_finished "rm -rf test_reachable.git; git reset --hard $(git rev-parse HEAD)" && + + #create unreachable sha + echo content >file2 && + git add file2 && + git commit -m two && + git push public HEAD:refs/heads/doomed && + git push public :refs/heads/doomed && + + server="$HTTPD_DOCUMENT_ROOT_PATH/repo.git" && + master_sha=$(git -C "$server" rev-parse refs/heads/master) && + git -C "$server" config uploadpack.allowreachablesha1inwant 1 && + + git init --bare test_reachable.git && + git -C test_reachable.git remote add origin "$HTTPD_URL/smart/repo.git" && + test_must_fail git -C test_reachable.git fetch origin "$(git rev-parse HEAD)" && + + git -C "$server" config uploadpack.allowanysha1inwant 1 && + git -C test_reachable.git fetch origin "$(git rev-parse HEAD)" +' + test_expect_success EXPENSIVE 'http can handle enormous ref negotiation' ' ( cd "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" && -- cgit v1.2.1