On Wed, Sep 16, 2015 at 01:18:03PM -0700, Junio C Hamano wrote:
> > + /* Now go back and fill in the size */
> > + if (buffer.len > 0xFFFF)
> > die("Request too large to send");
> > + xsnprintf(buffer.buf, buffer.alloc, "%04x", (unsigned)buffer.len);
>
> So we now write "0000something something\0host=something" into the buffer
> and then try to overwrite the first four bytes? Does this xsnprintf()
> stop after writing the four hexadecimal, or does it clobber the first
> byte of the payload (i.e. copy of serv[0]) by a NUL termination?
Argh, you're right, this is totally broken. We obviously have zero test
coverage of this feature. :(
This strategy cannot work at all without a way to format without adding
the NUL (or hackily saving and restoring the overwritten character).
The pkt-line code does its own hex formatting to get around this.
In fact...I think this whole patch can basically be replaced with a call
to packet_write().
Like this:
-- >8 --
Subject: [PATCH] remote-ext: simplify git pkt-line generation
We format a pkt-line into a heap buffer, which requires
manual computation of the required size, and uses some bare
sprintf calls. We could use a strbuf instead, which would
take care of the computation for us. But it's even easier
still to use packet_write(). Besides handling the formatting
and writing for us, it fixes two things:
1. Our manual max-size check used 0xFFFF, while technically
LARGE_PACKET_MAX is slightly smaller than this.
2. Our packet will now be output as part of
GIT_TRACE_PACKET debugging.
Unfortunately packet_write() does not let us build up the
buffer progressively, so we do have to repeat ourselves a
little depending on the "vhost" setting, but the end result
is still far more readable than the original.
Since there were no tests covering this feature at all,
we'll add a few into t5802.
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
builtin/remote-ext.c | 34 +++++-----------------------------
t/t5802-connect-helper.sh | 28 ++++++++++++++++++++++++++++
2 files changed, 33 insertions(+), 29 deletions(-)
diff --git a/builtin/remote-ext.c b/builtin/remote-ext.c
index 3b8c22c..e3cd25d 100644
--- a/builtin/remote-ext.c
+++ b/builtin/remote-ext.c
@@ -1,6 +1,7 @@
#include "builtin.h"
#include "transport.h"
#include "run-command.h"
+#include "pkt-line.h"
/*
* URL syntax:
@@ -142,36 +143,11 @@ static const char **parse_argv(const char *arg, const char *service)
static void send_git_request(int stdin_fd, const char *serv, const char *repo,
const char *vhost)
{
- size_t bufferspace;
- size_t wpos = 0;
- char *buffer;
-
- /*
- * Request needs 12 bytes extra if there is vhost (xxxx \0host=\0) and
- * 6 bytes extra (xxxx \0) if there is no vhost.
- */
- if (vhost)
- bufferspace = strlen(serv) + strlen(repo) + strlen(vhost) + 12;
+ if (!vhost)
+ packet_write(stdin_fd, "%s %s%c", serv, repo, 0);
else
- bufferspace = strlen(serv) + strlen(repo) + 6;
-
- if (bufferspace > 0xFFFF)
- die("Request too large to send");
- buffer = xmalloc(bufferspace);
-
- /* Make the packet. */
- wpos = sprintf(buffer, "%04x%s %s%c", (unsigned)bufferspace,
- serv, repo, 0);
-
- /* Add vhost if any. */
- if (vhost)
- sprintf(buffer + wpos, "host=%s%c", vhost, 0);
-
- /* Send the request */
- if (write_in_full(stdin_fd, buffer, bufferspace) < 0)
- die_errno("Failed to send request");
-
- free(buffer);
+ packet_write(stdin_fd, "%s %s%chost=%s%c", serv, repo, 0,
+ vhost, 0);
}
static int run_child(const char *arg, const char *service)
diff --git a/t/t5802-connect-helper.sh b/t/t5802-connect-helper.sh
index 878faf2..b7a7f9d 100755
--- a/t/t5802-connect-helper.sh
+++ b/t/t5802-connect-helper.sh
@@ -69,4 +69,32 @@ test_expect_success 'update backfilled tag without primary transfer' '
test_cmp expect actual
'
+
+test_expect_success 'set up fake git-daemon' '
+ mkdir remote &&
+ git init --bare remote/one.git &&
+ mkdir remote/host &&
+ git init --bare remote/host/two.git &&
+ write_script fake-daemon <<-\EOF &&
+ git daemon --inetd \
+ --informative-errors \
+ --export-all \
+ --base-path="$TRASH_DIRECTORY/remote" \
+ --interpolated-path="$TRASH_DIRECTORY/remote/%H%D" \
+ "$TRASH_DIRECTORY/remote"
+ EOF
+ export TRASH_DIRECTORY &&
+ PATH=$TRASH_DIRECTORY:$PATH
+'
+
+test_expect_success 'ext command can connect to git daemon (no vhost)' '
+ rm -rf dst &&
+ git clone "ext::fake-daemon %G/one.git" dst
+'
+
+test_expect_success 'ext command can connect to git daemon (vhost)' '
+ rm -rf dst &&
+ git clone "ext::fake-daemon %G/two.git %Vhost" dst
+'
+
test_done
--
2.6.0.rc2.408.ga2926b9
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