serve: advertise session ID in v2 capabilities

When transfer.advertiseSID is true, advertise the server's session ID
for all protocol v2 connections via the new session-id capability.

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/serve.c b/serve.c
index f6341206c4e30122c3cb819ef8c01f6d2be06d22..8c0bb84f375985d0a1e2e462b154da6745dfbd23 100644 (file)
--- a/serve.c
+++ b/serve.c
@@ -8,6 +8,8 @@
 #include "serve.h"
 #include "upload-pack.h"
 
+static int advertise_sid;
+
 static int always_advertise(struct repository *r,
                            struct strbuf *value)
 {
@@ -30,6 +32,15 @@ static int object_format_advertise(struct repository *r,
        return 1;
 }
 
+static int session_id_advertise(struct repository *r, struct strbuf *value)
+{
+       if (!advertise_sid)
+               return 0;
+       if (value)
+               strbuf_addstr(value, trace2_session_id());
+       return 1;
+}
+
 struct protocol_capability {
        /*
         * The name of the capability.  The server uses this name when
@@ -66,6 +77,7 @@ static struct protocol_capability capabilities[] = {
        { "fetch", upload_pack_advertise, upload_pack_v2 },
        { "server-option", always_advertise, NULL },
        { "object-format", object_format_advertise, NULL },
+       { "session-id", session_id_advertise, NULL },
 };
 
 static void advertise_capabilities(void)
@@ -261,6 +273,8 @@ static int process_request(void)
 /* Main serve loop for protocol version 2 */
 void serve(struct serve_options *options)
 {
+       git_config_get_bool("transfer.advertisesid", &advertise_sid);
+
        if (options->advertise_capabilities || !options->stateless_rpc) {
                /* serve by default supports v2 */
                packet_write_fmt(1, "version 2\n");