On 10/23, Jonathan Nieder wrote: > Android's "repo" tool is a tool for managing a large codebase > consisting of multiple smaller repositories, similar to Git's > submodule feature. Starting with Git 94b8ae5a (ssh: introduce a > 'simple' ssh variant, 2017-10-16), users noticed that it stopped > handling the port in ssh:// URLs. > > The cause: when it encounters ssh:// URLs, repo pre-connects to the > server and sets GIT_SSH to a helper ".repo/repo/git_ssh" that reuses > that connection. Before 94b8ae5a, the helper was assumed to support > OpenSSH options for lack of a better guess and got passed a -p option > to set the port. After that patch, it uses the new default of a > simple helper that does not accept an option to set the port. > > The next release of "repo" will set GIT_SSH_VARIANT to "ssh" to avoid > that. But users of old versions and of other similar GIT_SSH > implementations would not get the benefit of that fix. > > So update the default to use OpenSSH options again, with a twist. As > observed in 94b8ae5a, we cannot assume that $GIT_SSH always handles > OpenSSH options: common helpers such as travis-ci's dpl[*] are > configured using GIT_SSH and do not accept OpenSSH options. So make > the default a new variant "auto", with the following behavior: > > 1. First, check for a recognized basename, like today. > > 2. If the basename is not recognized, check whether $GIT_SSH supports > OpenSSH options by running > > $GIT_SSH -G <options> <host> > > This returns status 0 and prints configuration in OpenSSH if it > recognizes all <options> and returns status 255 if it encounters > an unrecognized option. A wrapper script like > > exec ssh -- "$@" > > would fail with > > ssh: Could not resolve hostname -g: Name or service not known > > , correctly reflecting that it does not support OpenSSH options. > > 3. Based on the result from step (2), behave like "ssh" (if it > succeeded) or "simple" (if it failed). > > This way, the default ssh variant for unrecognized commands can handle > both the repo and dpl cases as intended. > > [*] https://github.com/travis-ci/dpl/blob/6c3fddfda1f2a85944c544446b068bac0a77c049/lib/dpl/provider.rb#L215 > > Reported-by: William Yan <wyan@xxxxxxxxxx> > Improved-by: Jonathan Tan <jonathantanmy@xxxxxxxxxx> > Signed-off-by: Jonathan Nieder <jrnieder@xxxxxxxxx> > --- > This is the main one. Simplified by making "auto" behave the same as > unset. I still don't see the benefit of allowing a user to explicitly set 'auto' then, if setting it to 'auto' is effectively a noop. But maybe there's something I'm not seeing. > > Documentation/config.txt | 24 ++++++++------ > connect.c | 82 +++++++++++++++++++++++++++++++----------------- > t/t5601-clone.sh | 20 ++++++++++++ > 3 files changed, 88 insertions(+), 38 deletions(-) > > diff --git a/Documentation/config.txt b/Documentation/config.txt > index 0460af37e2..6dffa4aa3d 100644 > --- a/Documentation/config.txt > +++ b/Documentation/config.txt > @@ -2081,16 +2081,22 @@ matched against are those given directly to Git commands. This means any URLs > visited as a result of a redirection do not participate in matching. > > ssh.variant:: > - Depending on the value of the environment variables `GIT_SSH` or > - `GIT_SSH_COMMAND`, or the config setting `core.sshCommand`, Git > - auto-detects whether to adjust its command-line parameters for use > - with ssh (OpenSSH), plink or tortoiseplink, as opposed to the default > - (simple). > + By default, Git determines the command line arguments to use > + based on the basename of the configured SSH command (configured > + using the environment variable `GIT_SSH` or `GIT_SSH_COMMAND` or > + the config setting `core.sshCommand`). If the basename is > + unrecognized, Git will attempt to detect support of OpenSSH > + options by first invoking the configured SSH command with the > + `-G` (print configuration) option and will subsequently use > + OpenSSH options (if that is successful) or no options besides > + the host and remote command (if it fails). > + > -The config variable `ssh.variant` can be set to override this auto-detection; > -valid values are `ssh`, `simple`, `plink`, `putty` or `tortoiseplink`. Any > -other value will be treated as normal ssh. This setting can be overridden via > -the environment variable `GIT_SSH_VARIANT`. > +The config variable `ssh.variant` can be set to override this detection: > +valid values are `ssh` (to use OpenSSH options), `plink`, `putty`, > +`tortoiseplink`, `simple` (no options except the host and remote command). > +The default auto-detection can be explicitly requested using the value > +`auto`. Any other value is treated as `ssh`. This setting can also be > +overridden via the environment variable `GIT_SSH_VARIANT`. > + > The current command-line parameters used for each variant are as > follows: > diff --git a/connect.c b/connect.c > index 77ab6db3bb..0441dcbacf 100644 > --- a/connect.c > +++ b/connect.c > @@ -777,6 +777,7 @@ static const char *get_ssh_command(void) > } > > enum ssh_variant { > + VARIANT_AUTO, > VARIANT_SIMPLE, > VARIANT_SSH, > VARIANT_PLINK, > @@ -784,14 +785,16 @@ enum ssh_variant { > VARIANT_TORTOISEPLINK, > }; > > -static int override_ssh_variant(enum ssh_variant *ssh_variant) > +static void override_ssh_variant(enum ssh_variant *ssh_variant) > { > const char *variant = getenv("GIT_SSH_VARIANT"); > > if (!variant && git_config_get_string_const("ssh.variant", &variant)) > - return 0; > + return; > > - if (!strcmp(variant, "plink")) > + if (!strcmp(variant, "auto")) > + *ssh_variant = VARIANT_AUTO; > + else if (!strcmp(variant, "plink")) > *ssh_variant = VARIANT_PLINK; > else if (!strcmp(variant, "putty")) > *ssh_variant = VARIANT_PUTTY; > @@ -801,18 +804,18 @@ static int override_ssh_variant(enum ssh_variant *ssh_variant) > *ssh_variant = VARIANT_SIMPLE; > else > *ssh_variant = VARIANT_SSH; > - > - return 1; > } > > static enum ssh_variant determine_ssh_variant(const char *ssh_command, > int is_cmdline) > { > - enum ssh_variant ssh_variant = VARIANT_SIMPLE; > + enum ssh_variant ssh_variant = VARIANT_AUTO; > const char *variant; > char *p = NULL; > > - if (override_ssh_variant(&ssh_variant)) > + override_ssh_variant(&ssh_variant); > + > + if (ssh_variant != VARIANT_AUTO) > return ssh_variant; > > if (!is_cmdline) { > @@ -908,6 +911,38 @@ static struct child_process *git_connect_git(int fd[2], char *hostandport, > return conn; > } > > +static void push_ssh_options(struct argv_array *args, struct argv_array *env, > + enum ssh_variant variant, const char *port, > + int flags) > +{ > + if (variant == VARIANT_SSH && > + get_protocol_version_config() > 0) { > + argv_array_push(args, "-o"); > + argv_array_push(args, "SendEnv=" GIT_PROTOCOL_ENVIRONMENT); > + argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=version=%d", > + get_protocol_version_config()); > + } > + > + if (variant != VARIANT_SIMPLE) { > + if (flags & CONNECT_IPV4) > + argv_array_push(args, "-4"); > + else if (flags & CONNECT_IPV6) > + argv_array_push(args, "-6"); > + } > + > + if (variant == VARIANT_TORTOISEPLINK) > + argv_array_push(args, "-batch"); > + > + if (port && variant != VARIANT_SIMPLE) { > + if (variant == VARIANT_SSH) > + argv_array_push(args, "-p"); > + else > + argv_array_push(args, "-P"); > + > + argv_array_push(args, port); > + } > +} > + > /* Prepare a child_process for use by Git's SSH-tunneled transport. */ > static void fill_ssh_args(struct child_process *conn, const char *ssh_host, > const char *port, int flags) > @@ -937,33 +972,22 @@ static void fill_ssh_args(struct child_process *conn, const char *ssh_host, > > argv_array_push(&conn->args, ssh); > > - if (variant == VARIANT_SSH && > - 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 (variant != VARIANT_SIMPLE) { > - if (flags & CONNECT_IPV4) > - argv_array_push(&conn->args, "-4"); > - else if (flags & CONNECT_IPV6) > - argv_array_push(&conn->args, "-6"); > - } > + if (variant == VARIANT_AUTO) { > + struct child_process detect = CHILD_PROCESS_INIT; > > - if (variant == VARIANT_TORTOISEPLINK) > - argv_array_push(&conn->args, "-batch"); > + detect.use_shell = conn->use_shell; > + detect.no_stdin = detect.no_stdout = detect.no_stderr = 1; > > - if (port && variant != VARIANT_SIMPLE) { > - if (variant == VARIANT_SSH) > - argv_array_push(&conn->args, "-p"); > - else > - argv_array_push(&conn->args, "-P"); > + argv_array_push(&detect.args, ssh); > + argv_array_push(&detect.args, "-G"); > + push_ssh_options(&detect.args, &detect.env_array, > + VARIANT_SSH, port, flags); > + argv_array_push(&detect.args, ssh_host); > > - argv_array_push(&conn->args, port); > + variant = run_command(&detect) ? VARIANT_SIMPLE : VARIANT_SSH; > } > > + push_ssh_options(&conn->args, &conn->env_array, variant, port, flags); > argv_array_push(&conn->args, ssh_host); > } > > diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh > index 86811a0c35..df9dfafdd8 100755 > --- a/t/t5601-clone.sh > +++ b/t/t5601-clone.sh > @@ -372,6 +372,12 @@ test_expect_success 'variant can be overriden' ' > expect_ssh myhost src > ' > > +test_expect_success 'variant=auto picks based on basename' ' > + copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink" && > + git -c ssh.variant=auto clone -4 "[myhost:123]:src" ssh-auto-clone && > + expect_ssh "-4 -P 123" myhost src > +' > + > test_expect_success 'simple is treated as simple' ' > copy_ssh_wrapper_as "$TRASH_DIRECTORY/simple" && > git clone -4 "[myhost:123]:src" ssh-bracket-clone-simple && > @@ -384,6 +390,20 @@ test_expect_success 'uplink is treated as simple' ' > expect_ssh myhost src > ' > > +test_expect_success 'OpenSSH-like uplink is treated as ssh' ' > + write_script "$TRASH_DIRECTORY/uplink" <<-EOF && > + if test "\$1" = "-G" > + then > + exit 0 > + fi && > + exec "\$TRASH_DIRECTORY/ssh$X" "\$@" > + EOF > + GIT_SSH="$TRASH_DIRECTORY/uplink" && > + export GIT_SSH && > + git clone "[myhost:123]:src" ssh-bracket-clone-sshlike-uplink && > + expect_ssh "-p 123" myhost src > +' > + > test_expect_success 'plink is treated specially (as putty)' ' > copy_ssh_wrapper_as "$TRASH_DIRECTORY/plink" && > git clone "[myhost:123]:src" ssh-bracket-clone-plink-0 && > -- > 2.15.0.rc1.287.g2b38de12cc > -- Brandon Williams
