The fetch-pack/upload-pack protocol currently uses the side-band-64k
protocol extension to pass the stderr output from the upload-pack
side of the connection down to the fetch-pack side. This lets the
remote send progress messages from pack-objects down to the user,
so they know the server is working on their behalf and don't just
break a connection off.
In the past we haven't needed this secondary channel during push,
as most users only push over SSH and there is already a multiplexed
stdout and stderr available as part of the native SSH protocol and
client/server implementations. All output from hooks executed
by receive-pack on the remote side is sent to stderr, which is
automatically routed back to the user's terminal by SSH, completely
bypassing fetch-pack.
In Git 1.5.0 Linus allowed users to enable receive-pack as a service
in git-daemon, which is useful in friendly office LAN situations
where all of the users can be implicitly trusted. However as
git-daemon runs on a straight TCP/IP channel there is no automated
multiplexing to bring the stderr output from any hooks back to the
push client.
This change adds the sideband multiplexer/demultiplexer and uses
it to wrap the status response from receive-pack into band #1,
which is the standard payload band. To keep this change smaller
we do not wrap the hook output yet, which should be on band #2,
the standard "stderr/verbose/progress" band.
One of the complexities of arranging the status response data into
band #1 is the use of pkt-line for both the status reponse and for
the sideband multiplexing. We have to wrap the pkt-lines inside of
another set of pkt-lines (but with the additional band field) to get
the data correctly sent over the wire. Further when we do actually
flush we now have two flushes; one to end the status and another to
end the multiplexing. The first flush is actually still part of band
The side-band-64k extension is only enabled if both sides have the
capability, and only if send-pack sent commands to receive-pack
for processing. This allows both sides to transparently work with
older clients or servers.
Signed-off-by: Shawn O. Pearce <spearce@xxxxxxxxxxx>
---
builtin-send-pack.c | 37 +++++++++++++++++++++++++++++++------
pkt-line.c | 28 +++++++++++++++++++++++++---
pkt-line.h | 2 ++
receive-pack.c | 17 ++++++++++++-----
4 files changed, 70 insertions(+), 14 deletions(-)
diff --git a/builtin-send-pack.c b/builtin-send-pack.c
index 63fbcd2..5c4844c 100644
--- a/builtin-send-pack.c
+++ b/builtin-send-pack.c
@@ -3,6 +3,7 @@
#include "tag.h"
#include "refs.h"
#include "pkt-line.h"
+#include "sideband.h"
#include "run-command.h"
#include "remote.h"
#include "send-pack.h"
@@ -374,12 +375,18 @@ static int refs_pushed(struct ref *ref)
return 0;
}
+static int sideband_demux(int fd, void *data)
+{
+ return recv_sideband("send-pack", *((int*)data), fd, 2);
+}
+
static int do_send_pack(int in, int out, struct remote *remote, const char *dest, int nr_refspec, const char **refspec)
{
struct ref *ref;
int new_refs;
int allow_deleting_refs = 0;
int expect_status_report = 0;
+ int use_sideband = 0;
int flags = MATCH_REFS_NONE;
int pushing = 0;
int ret;
@@ -398,6 +405,8 @@ static int do_send_pack(int in, int out, struct remote *remote, const char *dest
expect_status_report = 1;
if (server_supports("delete-refs"))
allow_deleting_refs = 1;
+ if (server_supports("side-band-64k"))
+ use_sideband = 1;
/* match them up */
if (!remote_tail)
@@ -478,9 +487,10 @@ static int do_send_pack(int in, int out, struct remote *remote, const char *dest
char *new_hex = sha1_to_hex(ref->new_sha1);
if (!pushing)
- packet_write(out, "%s %s %s%c%s",
+ packet_write(out, "%s %s %s%c%s%s",
old_hex, new_hex, ref->name, 0,
- (expect_status_report ? " report-status" : "")
+ (expect_status_report ? " report-status" : ""),
+ (use_sideband ? " side-band-64k" : "")
);
else
packet_write(out, "%s %s %s",
@@ -501,11 +511,26 @@ static int do_send_pack(int in, int out, struct remote *remote, const char *dest
}
close(out);
- if (pushing && expect_status_report)
- ret = receive_status(in, remote_refs);
- else
- ret = 0;
+ ret = 0;
+ if (pushing) {
+ struct async demux;
+ int demux_in = in;
+
+ if (use_sideband) {
+ memset(&demux, 0, sizeof(demux));
+ demux.proc = sideband_demux;
+ demux.data = &demux_in;
+ if (start_async(&demux))
+ die("send-pack: unable to start sideband demultiplexer");
+ in = demux.out;
+ }
+
+ if (expect_status_report)
+ ret = receive_status(in, remote_refs);
+ if (use_sideband && (finish_async(&demux) || close(demux.out)))
+ die("error in sideband demultiplexer");
+ }
print_push_status(dest, remote_refs);
if (!args.dry_run && remote) {
diff --git a/pkt-line.c b/pkt-line.c
index 5917e1d..0b5f422 100644
--- a/pkt-line.c
+++ b/pkt-line.c
@@ -1,5 +1,6 @@
#include "cache.h"
#include "pkt-line.h"
+#include "sideband.h"
/*
* Write a packetized stream, where each line is preceded by
@@ -37,14 +38,23 @@ ssize_t safe_write(int fd, const void *buf, ssize_t n)
* If we buffered things up above (we don't, but we should),
* we'd flush it here
*/
+void packet_sideband_flush(int fd, int band)
+{
+ if (band >= 0)
+ send_sideband(fd, band, "0000", 4, LARGE_PACKET_MAX);
+ else
+ safe_write(fd, "0000", 4);
+}
+
void packet_flush(int fd)
{
- safe_write(fd, "0000", 4);
+ packet_sideband_flush(fd, -1);
}
#define hex(a) (hexchar[(a) & 15])
static void packet_vwrite(
int fd,
+ int band,
const char *fmt,
va_list args)
{
@@ -60,7 +70,10 @@ static void packet_vwrite(
buffer[1] = hex(n >> 8);
buffer[2] = hex(n >> 4);
buffer[3] = hex(n);
- safe_write(fd, buffer, n);
+ if (band >= 0)
+ send_sideband(fd, band, buffer, n, LARGE_PACKET_MAX);
+ else
+ safe_write(fd, buffer, n);
}
void packet_write(int fd, const char *fmt, ...)
@@ -68,7 +81,16 @@ void packet_write(int fd, const char *fmt, ...)
va_list args;
va_start(args, fmt);
- packet_vwrite(fd, fmt, args);
+ packet_vwrite(fd, -1, fmt, args);
+ va_end(args);
+}
+
+void packet_sideband_write(int fd, int band, const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ packet_vwrite(fd, band, fmt, args);
va_end(args);
}
diff --git a/pkt-line.h b/pkt-line.h
index 9df653f..0b7ded1 100644
--- a/pkt-line.h
+++ b/pkt-line.h
@@ -7,7 +7,9 @@
* Silly packetized line writing interface
*/
void packet_flush(int fd);
+void packet_sideband_flush(int fd, int band);
void packet_write(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
+void packet_sideband_write(int fd, int band, const char *fmt, ...) __attribute__((format (printf, 3, 4)));
int packet_read_line(int fd, char *buffer, unsigned size);
ssize_t safe_write(int, const void *, ssize_t);
diff --git a/receive-pack.c b/receive-pack.c
index 7380395..8962c4c 100644
--- a/receive-pack.c
+++ b/receive-pack.c
@@ -2,6 +2,7 @@
#include "pack.h"
#include "refs.h"
#include "pkt-line.h"
+#include "sideband.h"
#include "run-command.h"
#include "exec_cmd.h"
#include "commit.h"
@@ -14,8 +15,9 @@ static int receive_unpack_limit = -1;
static int transfer_unpack_limit = -1;
static int unpack_limit = 100;
static int report_status;
+static int use_sideband;
-static char capabilities[] = " report-status delete-refs ";
+static char capabilities[] = " report-status delete-refs side-band-64k ";
static int capabilities_sent;
static int receive_pack_config(const char *var, const char *value)
@@ -321,6 +323,8 @@ static void read_head_info(void)
const char *reqcap = refname + reflen + 1;
if (strstr(reqcap, "report-status"))
report_status = 1;
+ if (strstr(reqcap, "side-band-64k"))
+ use_sideband = LARGE_PACKET_MAX;
}
cmd = xmalloc(sizeof(struct command) + len - 80);
hashcpy(cmd->old_sha1, old_sha1);
@@ -426,18 +430,19 @@ static const char *unpack(void)
static void report(const char *unpack_status)
{
+ int band = use_sideband ? 1 : -1;
struct command *cmd;
- packet_write(1, "unpack %s\n",
+ packet_sideband_write(1, band, "unpack %s\n",
unpack_status ? unpack_status : "ok");
for (cmd = commands; cmd; cmd = cmd->next) {
if (!cmd->error_string)
- packet_write(1, "ok %s\n",
+ packet_sideband_write(1, band, "ok %s\n",
cmd->ref_name);
else
- packet_write(1, "ng %s %s\n",
+ packet_sideband_write(1, band, "ng %s %s\n",
cmd->ref_name, cmd->error_string);
}
- packet_flush(1);
+ packet_sideband_flush(1, band);
}
static int delete_only(struct command *cmd)
@@ -501,6 +506,8 @@ int main(int argc, char **argv)
report(unpack_status);
run_hook(post_receive_hook);
run_update_post_hook(commands);
+ if (use_sideband)
+ packet_flush(1);
}
return 0;
}
--
1.5.4.1.1309.g833c2
-
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