Teach the connection logic to tell a serve that it understands protocol v1. This is done in 2 different ways for the builtin transports. 1. git:// A normal request to git-daemon is structured as "command path/to/repo\0host=..\0" and due to a bug introduced in 49ba83fb6 (Add virtualization support to git-daemon, 2006-09-19) we aren't able to place any extra arguments (separated by NULs) besides the host otherwise the parsing of those arguments would enter an infinite loop. This bug was fixed in 73bb33a94 (daemon: Strictly parse the "extra arg" part of the command, 2009-06-04) but a check was put in place to disallow extra arguments so that new clients wouldn't trigger this bug in older servers. In order to get around this limitation git-daemon was taught to recognize additional request arguments hidden behind a second NUL byte. Requests can then be structured like: "command path/to/repo\0host=..\0\0version=1\0key=value\0". git-daemon can then parse out the extra arguments and set 'GIT_PROTOCOL' accordingly. By placing these extra arguments behind a second NUL byte we can skirt around both the infinite loop bug in 49ba83fb6 (Add virtualization support to git-daemon, 2006-09-19) as well as the explicit disallowing of extra arguments introduced in 73bb33a94 (daemon: Strictly parse the "extra arg" part of the command, 2009-06-04) because both of these versions of git-daemon check for a single NUL byte after the host argument before terminating the argument parsing. 2. ssh://, file:// Set 'GIT_PROTOCOL' environment variable with the desired protocol version. With the file:// transport, 'GIT_PROTOCOL' can be set explicitly in the locally running git-upload-pack or git-receive-pack processes. With the ssh:// transport and OpenSSH compliant ssh programs, 'GIT_PROTOCOL' can be sent across ssh by using '-o SendEnv=GIT_PROTOCOL' and having the server whitelist this environment variable. Signed-off-by: Brandon Williams <bmwill@xxxxxxxxxx> --- connect.c | 37 ++++++-- t/t5700-protocol-v1.sh | 223 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 255 insertions(+), 5 deletions(-) create mode 100755 t/t5700-protocol-v1.sh diff --git a/connect.c b/connect.c index a5e708a61..b8695a2fa 100644 --- a/connect.c +++ b/connect.c @@ -871,6 +871,7 @@ struct child_process *git_connect(int fd[2], const char *url, printf("Diag: path=%s\n", path ? path : "NULL"); conn = NULL; } else if (protocol == PROTO_GIT) { + struct strbuf request = STRBUF_INIT; /* * Set up virtual host information based on where we will * connect, unless the user has overridden us in @@ -898,13 +899,25 @@ struct child_process *git_connect(int fd[2], const char *url, * Note: Do not add any other headers here! Doing so * will cause older git-daemon servers to crash. */ - packet_write_fmt(fd[1], - "%s %s%chost=%s%c", - prog, path, 0, - target_host, 0); + strbuf_addf(&request, + "%s %s%chost=%s%c", + prog, path, 0, + target_host, 0); + + /* If using a new version put that stuff here after a second null byte */ + if (get_protocol_version_config() > 0) { + strbuf_addch(&request, '\0'); + strbuf_addf(&request, "version=%d%c", + get_protocol_version_config(), '\0'); + } + + packet_write(fd[1], request.buf, request.len); + free(target_host); + strbuf_release(&request); } else { struct strbuf cmd = STRBUF_INIT; + const char *const *var; conn = xmalloc(sizeof(*conn)); child_process_init(conn); @@ -917,7 +930,9 @@ struct child_process *git_connect(int fd[2], const char *url, sq_quote_buf(&cmd, path); /* remove repo-local variables from the environment */ - conn->env = local_repo_env; + for (var = local_repo_env; *var; var++) + argv_array_push(&conn->env_array, *var); + conn->use_shell = 1; conn->in = conn->out = -1; if (protocol == PROTO_SSH) { @@ -971,6 +986,14 @@ struct child_process *git_connect(int fd[2], const char *url, } argv_array_push(&conn->args, ssh); + + if (get_protocol_version_config() > 0) { + argv_array_push(&conn->args, "-o"); + argv_array_push(&conn->args, "SendEnv=" GIT_PROTOCOL_ENVIRONMENT); + argv_array_pushf(&conn->env_array, GIT_PROTOCOL_ENVIRONMENT "=version=%d", + get_protocol_version_config()); + } + if (flags & CONNECT_IPV4) argv_array_push(&conn->args, "-4"); else if (flags & CONNECT_IPV6) @@ -985,6 +1008,10 @@ struct child_process *git_connect(int fd[2], const char *url, argv_array_push(&conn->args, ssh_host); } else { transport_check_allowed("file"); + if (get_protocol_version_config() > 0) { + argv_array_pushf(&conn->env_array, GIT_PROTOCOL_ENVIRONMENT "=version=%d", + get_protocol_version_config()); + } } argv_array_push(&conn->args, cmd.buf); diff --git a/t/t5700-protocol-v1.sh b/t/t5700-protocol-v1.sh new file mode 100755 index 000000000..6551932da --- /dev/null +++ b/t/t5700-protocol-v1.sh @@ -0,0 +1,223 @@ +#!/bin/sh + +test_description='test git wire-protocol transition' + +TEST_NO_CREATE_REPO=1 + +. ./test-lib.sh + +# Test protocol v1 with 'git://' transport +# +. "$TEST_DIRECTORY"/lib-git-daemon.sh +start_git_daemon --export-all --enable=receive-pack +daemon_parent=$GIT_DAEMON_DOCUMENT_ROOT_PATH/parent + +test_expect_success 'create repo to be served by git-daemon' ' + git init "$daemon_parent" && + test_commit -C "$daemon_parent" one +' + +test_expect_success 'clone with git:// using protocol v1' ' + GIT_TRACE_PACKET=1 git -c protocol.version=1 \ + clone "$GIT_DAEMON_URL/parent" daemon_child 2>log && + + git -C daemon_child log -1 --format=%s >actual && + git -C "$daemon_parent" log -1 --format=%s >expect && + test_cmp expect actual && + + # Client requested to use protocol v1 + grep "clone> .*\\\0\\\0version=1\\\0$" log && + # Server responded using protocol v1 + grep "clone< version 1" log +' + +test_expect_success 'fetch with git:// using protocol v1' ' + test_commit -C "$daemon_parent" two && + + GIT_TRACE_PACKET=1 git -C daemon_child -c protocol.version=1 \ + fetch 2>log && + + git -C daemon_child log -1 --format=%s origin/master >actual && + git -C "$daemon_parent" log -1 --format=%s >expect && + test_cmp expect actual && + + # Client requested to use protocol v1 + grep "fetch> .*\\\0\\\0version=1\\\0$" log && + # Server responded using protocol v1 + grep "fetch< version 1" log +' + +test_expect_success 'pull with git:// using protocol v1' ' + GIT_TRACE_PACKET=1 git -C daemon_child -c protocol.version=1 \ + pull 2>log && + + git -C daemon_child log -1 --format=%s >actual && + git -C "$daemon_parent" log -1 --format=%s >expect && + test_cmp expect actual && + + # Client requested to use protocol v1 + grep "fetch> .*\\\0\\\0version=1\\\0$" log && + # Server responded using protocol v1 + grep "fetch< version 1" log +' + +test_expect_success 'push with git:// using protocol v1' ' + test_commit -C daemon_child three && + + # Push to another branch, as the target repository has the + # master branch checked out and we cannot push into it. + GIT_TRACE_PACKET=1 git -C daemon_child -c protocol.version=1 \ + push origin HEAD:client_branch 2>log && + + git -C daemon_child log -1 --format=%s >actual && + git -C "$daemon_parent" log -1 --format=%s client_branch >expect && + test_cmp expect actual && + + # Client requested to use protocol v1 + grep "push> .*\\\0\\\0version=1\\\0$" log && + # Server responded using protocol v1 + grep "push< version 1" log +' + +stop_git_daemon + +# Test protocol v1 with 'file://' transport +# +test_expect_success 'create repo to be served by file:// transport' ' + git init file_parent && + test_commit -C file_parent one +' + +test_expect_success 'clone with file:// using protocol v1' ' + GIT_TRACE_PACKET=1 git -c protocol.version=1 \ + clone "file://$(pwd)/file_parent" file_child 2>log && + + git -C file_child log -1 --format=%s >actual && + git -C file_parent log -1 --format=%s >expect && + test_cmp expect actual && + + # Server responded using protocol v1 + grep "clone< version 1" log +' + +test_expect_success 'fetch with file:// using protocol v1' ' + test_commit -C file_parent two && + + GIT_TRACE_PACKET=1 git -C file_child -c protocol.version=1 \ + fetch 2>log && + + git -C file_child log -1 --format=%s origin/master >actual && + git -C file_parent log -1 --format=%s >expect && + test_cmp expect actual && + + # Server responded using protocol v1 + grep "fetch< version 1" log +' + +test_expect_success 'pull with file:// using protocol v1' ' + GIT_TRACE_PACKET=1 git -C file_child -c protocol.version=1 \ + pull 2>log && + + git -C file_child log -1 --format=%s >actual && + git -C file_parent log -1 --format=%s >expect && + test_cmp expect actual && + + # Server responded using protocol v1 + grep "fetch< version 1" log +' + +test_expect_success 'push with file:// using protocol v1' ' + test_commit -C file_child three && + + # Push to another branch, as the target repository has the + # master branch checked out and we cannot push into it. + GIT_TRACE_PACKET=1 git -C file_child -c protocol.version=1 \ + push origin HEAD:client_branch 2>log && + + git -C file_child log -1 --format=%s >actual && + git -C file_parent log -1 --format=%s client_branch >expect && + test_cmp expect actual && + + # Server responded using protocol v1 + grep "push< version 1" log +' + +# Test protocol v1 with 'ssh://' transport +# +test_expect_success 'setup ssh wrapper' ' + GIT_SSH="$GIT_BUILD_DIR/t/helper/test-fake-ssh" && + export GIT_SSH && + export TRASH_DIRECTORY && + >"$TRASH_DIRECTORY"/ssh-output +' + +expect_ssh () { + test_when_finished '(cd "$TRASH_DIRECTORY" && rm -f ssh-expect && >ssh-output)' && + echo "ssh: -o SendEnv=GIT_PROTOCOL myhost $1 '$PWD/ssh_parent'" >"$TRASH_DIRECTORY/ssh-expect" && + (cd "$TRASH_DIRECTORY" && test_cmp ssh-expect ssh-output) +} + +test_expect_success 'create repo to be served by ssh:// transport' ' + git init ssh_parent && + test_commit -C ssh_parent one +' + +test_expect_success 'clone with ssh:// using protocol v1' ' + GIT_TRACE_PACKET=1 git -c protocol.version=1 \ + clone "ssh://myhost:$(pwd)/ssh_parent" ssh_child 2>log && + expect_ssh git-upload-pack && + + git -C ssh_child log -1 --format=%s >actual && + git -C ssh_parent log -1 --format=%s >expect && + test_cmp expect actual && + + # Server responded using protocol v1 + grep "clone< version 1" log +' + +test_expect_success 'fetch with ssh:// using protocol v1' ' + test_commit -C ssh_parent two && + + GIT_TRACE_PACKET=1 git -C ssh_child -c protocol.version=1 \ + fetch 2>log && + expect_ssh git-upload-pack && + + git -C ssh_child log -1 --format=%s origin/master >actual && + git -C ssh_parent log -1 --format=%s >expect && + test_cmp expect actual && + + # Server responded using protocol v1 + grep "fetch< version 1" log +' + +test_expect_success 'pull with ssh:// using protocol v1' ' + GIT_TRACE_PACKET=1 git -C ssh_child -c protocol.version=1 \ + pull 2>log && + expect_ssh git-upload-pack && + + git -C ssh_child log -1 --format=%s >actual && + git -C ssh_parent log -1 --format=%s >expect && + test_cmp expect actual && + + # Server responded using protocol v1 + grep "fetch< version 1" log +' + +test_expect_success 'push with ssh:// using protocol v1' ' + test_commit -C ssh_child three && + + # Push to another branch, as the target repository has the + # master branch checked out and we cannot push into it. + GIT_TRACE_PACKET=1 git -C ssh_child -c protocol.version=1 \ + push origin HEAD:client_branch 2>log && + expect_ssh git-receive-pack && + + git -C ssh_child log -1 --format=%s >actual && + git -C ssh_parent log -1 --format=%s client_branch >expect && + test_cmp expect actual && + + # Server responded using protocol v1 + grep "push< version 1" log +' + +test_done -- 2.14.2.920.gcf0c67979c-goog