[RFC 6/7] transport: teach client to recognize v2 server response
Teach a client to recognize that a server understand protocol v2 by looking at the first pkt-line the server sends in response. This is done by looking for the response "version 2" sent by upload-pack.
Signed-off-by: Brandon Williams <bmwill@google.com>
---
builtin/fetch-pack.c | 4 +-
builtin/send-pack.c | 5 +-
connect.c | 165 ++++++++++++++++++++++++++++++---------------------
remote-curl.c | 7 ++-
remote.h | 22 ++++++-
transport.c | 60 ++++++++++++++++---
6 files changed, 178 insertions(+), 85 deletions(-)
diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index 366b9d13f..a2a5e1c73 100644
--- a/builtin/fetch-pack.c
+++ b/builtin/fetch-pack.c
@@ -52,6 +52,7 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
struct fetch_pack_args args;
struct oid_array shallow = OID_ARRAY_INIT;
struct string_list deepen_not = STRING_LIST_INIT_DUP;
+ struct remote_refs_scanner scanner;
packet_trace_identity("fetch-pack");
@@ -193,7 +194,8 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
if (!conn)
return args.diag_url ? 0 : 1;
}
- get_remote_heads(fd[0], NULL, 0, &ref, 0, NULL, &shallow);
+ remote_refs_scanner_init(&scanner, &ref, 0, NULL, &shallow);
+ get_remote_heads(fd[0], NULL, 0, &scanner);
ref = fetch_pack(&args, fd, conn, ref, dest, sought, nr_sought,
&shallow, pack_lockfile_ptr);
diff --git a/builtin/send-pack.c b/builtin/send-pack.c
index fc4f0bb5f..92ec1f871 100644
--- a/builtin/send-pack.c
+++ b/builtin/send-pack.c
@@ -154,6 +154,7 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
int progress = -1;
int from_stdin = 0;
struct push_cas_option cas = {0};
+ struct remote_refs_scanner scanner;
struct option options[] = {
OPT__VERBOSITY(&verbose),
@@ -256,8 +257,8 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
args.verbose ? CONNECT_VERBOSE : 0);
}
- get_remote_heads(fd[0], NULL, 0, &remote_refs, REF_NORMAL,
- &extra_have, &shallow);
+ remote_refs_scanner_init(&scanner, &remote_refs, REF_NORMAL, &extra_have, &shallow);
+ get_remote_heads(fd[0], NULL, 0, &scanner);
transport_verify_remote_names(nr_refspecs, refspecs);
diff --git a/connect.c b/connect.c
index d609267be..732b651d9 100644
--- a/connect.c
+++ b/connect.c
@@ -107,97 +107,124 @@ static void annotate_refs_with_symref_info(struct ref *ref)
string_list_clear(&symref, 0);
}
-/*
- * Read all the refs from the other end
- */
-struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
+void remote_refs_scanner_init(struct remote_refs_scanner *scanner,
struct ref **list, unsigned int flags,
struct oid_array *extra_have,
struct oid_array *shallow_points)
{
- struct ref **orig_list = list;
+ memset(scanner, 0, sizeof(*scanner));
+
+ scanner->orig_list = list;
+ *list = NULL;
+ scanner->list = list;
+ scanner->flags = flags;
+ scanner->extra_have = extra_have;
+ scanner->shallow_points = shallow_points;
+}
+
+int process_ref(struct remote_refs_scanner *scanner,
+ const char *buffer, int len)
+{
+ struct ref *ref;
+ struct object_id old_oid;
+ const char *name;
+ int name_len;
+ const char *arg;
+ int ret = 1;
+
+ if (len < 0)
+ die_initial_contact(scanner->seen_response);
+
+ if (!len) {
+ ret = 0;
+ goto out;
+ }
+
+ if (len > 4 && skip_prefix(buffer, "ERR ", &arg))
+ die("remote error: %s", arg);
+
+ if (len == GIT_SHA1_HEXSZ + strlen("shallow ") &&
+ skip_prefix(buffer, "shallow ", &arg)) {
+ if (get_oid_hex(arg, &old_oid))
+ die("protocol error: expected shallow sha-1, got '%s'", arg);
+ if (!scanner->shallow_points)
+ die("repository on the other end cannot be shallow");
+ oid_array_append(scanner->shallow_points, &old_oid);
+ goto out;
+ }
+
+ if (len < GIT_SHA1_HEXSZ + 2 || get_oid_hex(buffer, &old_oid) ||
+ buffer[GIT_SHA1_HEXSZ] != ' ')
+ die("protocol error: expected sha/ref, got '%s'", buffer);
+ name = buffer + GIT_SHA1_HEXSZ + 1;
+
+ name_len = strlen(name);
+ if (len != name_len + GIT_SHA1_HEXSZ + 1) {
+ free(server_capabilities);
+ server_capabilities = xstrdup(name + name_len + 1);
+ }
+
+ if (scanner->extra_have && !strcmp(name, ".have")) {
+ oid_array_append(scanner->extra_have, &old_oid);
+ goto out;
+ }
+
+ if (!strcmp(name, "capabilities^{}")) {
+ if (scanner->seen_response)
+ die("protocol error: unexpected capabilities^{}");
+ if (scanner->recieved_dummy_capabilities_ref)
+ die("protocol error: multiple capabilities^{}");
+ scanner->recieved_dummy_capabilities_ref = 1;
+ ret = 1;
+ goto out;
+ }
+
+ if (!check_ref(name, scanner->flags))
+ goto out;
+
+ if (scanner->recieved_dummy_capabilities_ref)
+ die("protocol error: unexpected ref after capabilities^{}");
+
+ ref = alloc_ref(buffer + GIT_SHA1_HEXSZ + 1);
+ oidcpy(&ref->old_oid, &old_oid);
+
+ *scanner->list = ref;
+ scanner->list = &ref->next;
+
+out:
+ scanner->seen_response = 1;
+ scanner->done = !ret;
+ return ret;
+}
+/*
+ * Read all the refs from the other end
+ */
+struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
+ struct remote_refs_scanner *scanner)
+{
/*
* A hang-up after seeing some response from the other end
* means that it is unexpected, as we know the other end is
* willing to talk to us. A hang-up before seeing any
* response does not necessarily mean an ACL problem, though.
*/
- int saw_response;
- int got_dummy_ref_with_capabilities_declaration = 0;
-
- *list = NULL;
- for (saw_response = 0; ; saw_response = 1) {
- struct ref *ref;
- struct object_id old_oid;
- char *name;
- int len, name_len;
+ while (!scanner->done) {
char *buffer = packet_buffer;
- const char *arg;
+ int len;
len = packet_read(in, &src_buf, &src_len,
packet_buffer, sizeof(packet_buffer),
PACKET_READ_GENTLE_ON_EOF |
PACKET_READ_CHOMP_NEWLINE);
- if (len < 0)
- die_initial_contact(saw_response);
- if (!len)
+ if (!process_ref(scanner, buffer, len))
break;
-
- if (len > 4 && skip_prefix(buffer, "ERR ", &arg))
- die("remote error: %s", arg);
-
- if (len == GIT_SHA1_HEXSZ + strlen("shallow ") &&
- skip_prefix(buffer, "shallow ", &arg)) {
- if (get_oid_hex(arg, &old_oid))
- die("protocol error: expected shallow sha-1, got '%s'", arg);
- if (!shallow_points)
- die("repository on the other end cannot be shallow");
- oid_array_append(shallow_points, &old_oid);
- continue;
- }
-
- if (len < GIT_SHA1_HEXSZ + 2 || get_oid_hex(buffer, &old_oid) ||
- buffer[GIT_SHA1_HEXSZ] != ' ')
- die("protocol error: expected sha/ref, got '%s'", buffer);
- name = buffer + GIT_SHA1_HEXSZ + 1;
-
- name_len = strlen(name);
- if (len != name_len + GIT_SHA1_HEXSZ + 1) {
- free(server_capabilities);
- server_capabilities = xstrdup(name + name_len + 1);
- }
-
- if (extra_have && !strcmp(name, ".have")) {
- oid_array_append(extra_have, &old_oid);
- continue;
- }
-
- if (!strcmp(name, "capabilities^{}")) {
- if (saw_response)
- die("protocol error: unexpected capabilities^{}");
- if (got_dummy_ref_with_capabilities_declaration)
- die("protocol error: multiple capabilities^{}");
- got_dummy_ref_with_capabilities_declaration = 1;
- continue;
- }
-
- if (!check_ref(name, flags))
- continue;
-
- if (got_dummy_ref_with_capabilities_declaration)
- die("protocol error: unexpected ref after capabilities^{}");
-
- ref = alloc_ref(buffer + GIT_SHA1_HEXSZ + 1);
- oidcpy(&ref->old_oid, &old_oid);
- *list = ref;
- list = &ref->next;
}
- annotate_refs_with_symref_info(*orig_list);
+ annotate_refs_with_symref_info(*scanner->orig_list);
- return list;
+ return scanner->list;
}
static const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
diff --git a/remote-curl.c b/remote-curl.c
index 0053b0954..04c191493 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -175,9 +175,12 @@ static struct discovery *last_discovery;
static struct ref *parse_git_refs(struct discovery *heads, int for_push)
{
+ struct remote_refs_scanner scanner;
struct ref *list = NULL;
- get_remote_heads(-1, heads->buf, heads->len, &list,
- for_push ? REF_NORMAL : 0, NULL, &heads->shallow);
+ remote_refs_scanner_init(&scanner, &list, for_push ? REF_NORMAL : 0,
+ NULL, &heads->shallow);
+ get_remote_heads(-1, heads->buf, heads->len, &scanner);
+
return list;
}
diff --git a/remote.h b/remote.h
index 2ecf4c8c7..3a60b8fc4 100644
--- a/remote.h
+++ b/remote.h
@@ -150,10 +150,26 @@ int check_ref_type(const struct ref *ref, int flags);
void free_refs(struct ref *ref);
struct oid_array;
+
+struct remote_refs_scanner {
+ struct ref **orig_list;
+ struct ref **list;
+ unsigned int flags;
+ struct oid_array *extra_have;
+ struct oid_array *shallow_points;
+ unsigned seen_response : 1;
+ unsigned recieved_dummy_capabilities_ref : 1;
+ unsigned done : 1;
+};
+void remote_refs_scanner_init(struct remote_refs_scanner *scanner,
+ struct ref **list, unsigned int flags,
+ struct oid_array *extra_have,
+ struct oid_array *shallow_points);
+int process_ref(struct remote_refs_scanner *scanner,
+ const char *buffer, int len);
+
extern struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
- struct ref **list, unsigned int flags,
- struct oid_array *extra_have,
- struct oid_array *shallow);
+ struct remote_refs_scanner *scanner);
int resolve_remote_symref(struct ref *ref, struct ref *list);
int ref_newer(const struct object_id *new_oid, const struct object_id *old_oid);
diff --git a/transport.c b/transport.c
index d75ff0514..c05e167d6 100644
--- a/transport.c
+++ b/transport.c
@@ -187,18 +187,59 @@ static int connect_setup(struct transport *transport, int for_push)
return 0;
}
+static int determine_version(int fd, struct strbuf *packet)
+{
+ const char *v;
+ int len;
+
+ len = strbuf_packet_read(fd, packet,
+ PACKET_READ_GENTLE_ON_EOF |
+ PACKET_READ_CHOMP_NEWLINE);
+ if (len < 0)
+ return -1;
+
+ if (skip_prefix(packet->buf, "version ", &v)) {
+ return 2;
+ }
+
+ return 1;
+}
+
static struct ref *get_refs_via_connect(struct transport *transport, int for_push)
{
struct git_transport_data *data = transport->data;
+ struct strbuf buf = STRBUF_INIT;
+ struct remote_refs_scanner scanner;
struct ref *refs;
+ remote_refs_scanner_init(&scanner, &refs, for_push ? REF_NORMAL : 0,
+ &data->extra_have, &data->shallow);
+
connect_setup(transport, for_push);
- get_remote_heads(data->fd[0], NULL, 0, &refs,
- for_push ? REF_NORMAL : 0,
- &data->extra_have,
- &data->shallow);
+
+ if (0)
+ determine_version(-1, NULL);
+ switch(determine_version(data->fd[0], &buf)) {
+ case 2:
+ /* The server understands Protocol v2 */
+ fprintf(stderr, "Server understands Protocol v2!\n");
+ break;
+ case 1:
+ /* Server is speaking Protocol v1 and sent a ref so process it */
+ process_ref(&scanner, buf.buf, buf.len);
+ break;
+ default:
+ process_ref(&scanner, NULL, -1);
+ break;
+
+ }
+
+ get_remote_heads(data->fd[0], NULL, 0, &scanner);
+
data->got_remote_heads = 1;
+ strbuf_release(&buf);
+
return refs;
}
@@ -231,9 +272,11 @@ static int fetch_refs_via_pack(struct transport *transport,
args.update_shallow = data->options.update_shallow;
if (!data->got_remote_heads) {
+ struct remote_refs_scanner scanner;
connect_setup(transport, 0);
- get_remote_heads(data->fd[0], NULL, 0, &refs_tmp, 0,
- NULL, &data->shallow);
+
+ remote_refs_scanner_init(&scanner, &refs_tmp, 0, NULL, &data->shallow);
+ get_remote_heads(data->fd[0], NULL, 0, &scanner);
data->got_remote_heads = 1;
}
@@ -544,10 +587,11 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
if (!data->got_remote_heads) {
struct ref *tmp_refs;
+ struct remote_refs_scanner scanner;
connect_setup(transport, 1);
- get_remote_heads(data->fd[0], NULL, 0, &tmp_refs, REF_NORMAL,
- NULL, &data->shallow);
+ remote_refs_scanner_init(&scanner, &tmp_refs, REF_NORMAL, NULL, &data->shallow);
+ get_remote_heads(data->fd[0], NULL, 0, &scanner);
data->got_remote_heads = 1;
}
--
2.14.1.342.g6490525c54-goog
