transport: log received server session ID

When a client receives a session-id capability from a protocol v0, v1,
or v2 server, log the received session ID via a trace2 data event.

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

diff --git a/t/t5705-session-id-in-capabilities.sh b/t/t5705-session-id-in-capabilities.sh
new file mode 100755 (executable)
index 0000000..9e782f4
--- /dev/null
+++ b/t/t5705-session-id-in-capabilities.sh
@@ -0,0 +1,64 @@
+#!/bin/sh
+
+test_description='session ID in capabilities'
+
+. ./test-lib.sh
+
+REPO="$(pwd)/repo"
+LOCAL_PRISTINE="$(pwd)/local_pristine"
+
+test_expect_success 'setup repos for session ID capability tests' '
+       git init "$REPO" &&
+       test_commit -C "$REPO" a &&
+       git clone "file://$REPO" "$LOCAL_PRISTINE" &&
+       test_commit -C "$REPO" b
+'
+
+for PROTO in 0 1 2
+do
+       test_expect_success "session IDs not advertised by default (fetch v${PROTO})" '
+               test_when_finished "rm -rf local tr2-client-events" &&
+               cp -r "$LOCAL_PRISTINE" local &&
+               GIT_TRACE2_EVENT="$(pwd)/tr2-client-events" \
+               git -c protocol.version=$PROTO -C local fetch origin &&
+               test -z "$(grep \"key\":\"server-sid\" tr2-client-events)"
+       '
+
+       test_expect_success "session IDs not advertised by default (push v${PROTO})" '
+               test_when_finished "rm -rf local tr2-client-events" &&
+               cp -r "$LOCAL_PRISTINE" local &&
+               git -C local pull --no-rebase origin &&
+               GIT_TRACE2_EVENT_NESTING=5 \
+               GIT_TRACE2_EVENT="$(pwd)/tr2-client-events" \
+               git -c protocol.version=$PROTO -C local push origin &&
+               test -z "$(grep \"key\":\"server-sid\" tr2-client-events)"
+       '
+done
+
+test_expect_success 'enable SID advertisement' '
+       git -C "$REPO" config transfer.advertiseSID true &&
+       git -C "$LOCAL_PRISTINE" config transfer.advertiseSID true
+'
+
+for PROTO in 0 1 2
+do
+       test_expect_success "session IDs advertised (fetch v${PROTO})" '
+               test_when_finished "rm -rf local tr2-client-events" &&
+               cp -r "$LOCAL_PRISTINE" local &&
+               GIT_TRACE2_EVENT="$(pwd)/tr2-client-events" \
+               git -c protocol.version=$PROTO -C local fetch origin &&
+               grep \"key\":\"server-sid\" tr2-client-events
+       '
+
+       test_expect_success "session IDs advertised (push v${PROTO})" '
+               test_when_finished "rm -rf local tr2-client-events" &&
+               cp -r "$LOCAL_PRISTINE" local &&
+               git -C local pull --no-rebase origin &&
+               GIT_TRACE2_EVENT_NESTING=5 \
+               GIT_TRACE2_EVENT="$(pwd)/tr2-client-events" \
+               git -c protocol.version=$PROTO -C local push origin &&
+               grep \"key\":\"server-sid\" tr2-client-events
+       '
+done
+
+test_done

diff --git a/transport.c b/transport.c
index 47da955e4fe4548199c28365d3f894bd0b1a81b7..679a35e7c1b6168d3b8fc93f72ec9a50178d894c 100644 (file)
--- a/transport.c
+++ b/transport.c
@@ -286,6 +286,8 @@ static struct ref *handshake(struct transport *transport, int for_push,
        struct git_transport_data *data = transport->data;
        struct ref *refs = NULL;
        struct packet_reader reader;
+       int sid_len;
+       const char *server_sid;
 
        connect_setup(transport, for_push);
 
@@ -297,6 +299,8 @@ static struct ref *handshake(struct transport *transport, int for_push,
        data->version = discover_version(&reader);
        switch (data->version) {
        case protocol_v2:
+               if (server_feature_v2("session-id", &server_sid))
+                       trace2_data_string("transfer", NULL, "server-sid", server_sid);
                if (must_list_refs)
                        get_remote_refs(data->fd[1], &reader, &refs, for_push,
                                        ref_prefixes,
@@ -310,6 +314,12 @@ static struct ref *handshake(struct transport *transport, int for_push,
                                 for_push ? REF_NORMAL : 0,
                                 &data->extra_have,
                                 &data->shallow);
+               server_sid = server_feature_value("session-id", &sid_len);
+               if (server_sid) {
+                       char *sid = xstrndup(server_sid, sid_len);
+                       trace2_data_string("transfer", NULL, "server-sid", sid);
+                       free(sid);
+               }
                break;
        case protocol_unknown_version:
                BUG("unknown protocol version");