+static int add_haves(struct fetch_negotiator *negotiator,
+ int seen_ack,
+ struct strbuf *req_buf,
+ int *haves_to_send, int *in_vain)
+{
+ int ret = 0;
+ int haves_added = 0;
+ const struct object_id *oid;
+
+ while ((oid = negotiator->next(negotiator))) {
+ packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
+ if (++haves_added >= *haves_to_send)
+ break;
+ }
+
+ *in_vain += haves_added;
+ if (!haves_added || (seen_ack && *in_vain >= MAX_IN_VAIN)) {
+ /* Send Done */
+ packet_buf_write(req_buf, "done\n");
+ ret = 1;
+ }
+
+ /* Increase haves to send on next round */
+ *haves_to_send = next_flush(1, *haves_to_send);
+
+ return ret;
+}
+
+static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
+ struct fetch_pack_args *args,
+ const struct ref *wants, struct oidset *common,
+ int *haves_to_send, int *in_vain,
+ int sideband_all, int seen_ack)
+{
+ int ret = 0;
+ const char *hash_name;
+ struct strbuf req_buf = STRBUF_INIT;
+
+ if (server_supports_v2("fetch", 1))
+ packet_buf_write(&req_buf, "command=fetch");
+ if (server_supports_v2("agent", 0))
+ packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
+ if (advertise_sid && server_supports_v2("session-id", 0))
+ packet_buf_write(&req_buf, "session-id=%s", trace2_session_id());
+ if (args->server_options && args->server_options->nr &&
+ server_supports_v2("server-option", 1)) {
+ int i;
+ for (i = 0; i < args->server_options->nr; i++)
+ packet_buf_write(&req_buf, "server-option=%s",
+ args->server_options->items[i].string);
+ }
+
+ if (server_feature_v2("object-format", &hash_name)) {
+ int hash_algo = hash_algo_by_name(hash_name);
+ if (hash_algo_by_ptr(the_hash_algo) != hash_algo)
+ die(_("mismatched algorithms: client %s; server %s"),
+ the_hash_algo->name, hash_name);
+ packet_write_fmt(fd_out, "object-format=%s", the_hash_algo->name);
+ } else if (hash_algo_by_ptr(the_hash_algo) != GIT_HASH_SHA1) {
+ die(_("the server does not support algorithm '%s'"),
+ the_hash_algo->name);
+ }
+
+ packet_buf_delim(&req_buf);
+ if (args->use_thin_pack)
+ packet_buf_write(&req_buf, "thin-pack");
+ if (args->no_progress)
+ packet_buf_write(&req_buf, "no-progress");
+ if (args->include_tag)
+ packet_buf_write(&req_buf, "include-tag");
+ if (prefer_ofs_delta)
+ packet_buf_write(&req_buf, "ofs-delta");
+ if (sideband_all)
+ packet_buf_write(&req_buf, "sideband-all");
+
+ /* Add shallow-info and deepen request */
+ if (server_supports_feature("fetch", "shallow", 0))
+ add_shallow_requests(&req_buf, args);
+ else if (is_repository_shallow(the_repository) || args->deepen)
+ die(_("Server does not support shallow requests"));
+
+ /* Add filter */
+ if (server_supports_feature("fetch", "filter", 0) &&
+ args->filter_options.choice) {
+ const char *spec =
+ expand_list_objects_filter_spec(&args->filter_options);
+ print_verbose(args, _("Server supports filter"));
+ packet_buf_write(&req_buf, "filter %s", spec);
+ } else if (args->filter_options.choice) {
+ warning("filtering not recognized by server, ignoring");
+ }
+
+ if (server_supports_feature("fetch", "packfile-uris", 0)) {
+ int i;
+ struct strbuf to_send = STRBUF_INIT;
+
+ for (i = 0; i < uri_protocols.nr; i++) {
+ const char *s = uri_protocols.items[i].string;
+
+ if (!strcmp(s, "https") || !strcmp(s, "http")) {
+ if (to_send.len)
+ strbuf_addch(&to_send, ',');
+ strbuf_addstr(&to_send, s);
+ }
+ }
+ if (to_send.len) {
+ packet_buf_write(&req_buf, "packfile-uris %s",
+ to_send.buf);
+ strbuf_release(&to_send);
+ }
+ }
+
+ /* add wants */
+ add_wants(wants, &req_buf);
+
+ /* Add all of the common commits we've found in previous rounds */
+ add_common(&req_buf, common);
+
+ /* Add initial haves */
+ ret = add_haves(negotiator, seen_ack, &req_buf,
+ haves_to_send, in_vain);
+
+ /* Send request */
+ packet_buf_flush(&req_buf);
+ if (write_in_full(fd_out, req_buf.buf, req_buf.len) < 0)
+ die_errno(_("unable to write request to remote"));
+
+ strbuf_release(&req_buf);
+ return ret;
+}
+
+/*
+ * Processes a section header in a server's response and checks if it matches
+ * `section`. If the value of `peek` is 1, the header line will be peeked (and
+ * not consumed); if 0, the line will be consumed and the function will die if
+ * the section header doesn't match what was expected.
+ */
+static int process_section_header(struct packet_reader *reader,
+ const char *section, int peek)
+{
+ int ret;
+
+ if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
+ die(_("error reading section header '%s'"), section);
+
+ ret = !strcmp(reader->line, section);
+
+ if (!peek) {
+ if (!ret)
+ die(_("expected '%s', received '%s'"),
+ section, reader->line);
+ packet_reader_read(reader);
+ }
+
+ return ret;
+}
+
+enum common_found {
+ /*
+ * No commit was found to be possessed by both the client and the
+ * server, and "ready" was not received.
+ */
+ NO_COMMON_FOUND,
+
+ /*
+ * At least one commit was found to be possessed by both the client and
+ * the server, and "ready" was not received.
+ */
+ COMMON_FOUND,
+
+ /*
+ * "ready" was received, indicating that the server is ready to send
+ * the packfile without any further negotiation.
+ */
+ READY
+};
+
+static enum common_found process_acks(struct fetch_negotiator *negotiator,
+ struct packet_reader *reader,
+ struct oidset *common)
+{
+ /* received */
+ int received_ready = 0;
+ int received_ack = 0;
+
+ process_section_header(reader, "acknowledgments", 0);
+ while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+ const char *arg;
+
+ if (!strcmp(reader->line, "NAK"))
+ continue;
+
+ if (skip_prefix(reader->line, "ACK ", &arg)) {
+ struct object_id oid;
+ received_ack = 1;
+ if (!get_oid_hex(arg, &oid)) {
+ struct commit *commit;
+ oidset_insert(common, &oid);
+ commit = lookup_commit(the_repository, &oid);
+ if (negotiator)
+ negotiator->ack(negotiator, commit);
+ }
+ continue;
+ }
+
+ if (!strcmp(reader->line, "ready")) {
+ received_ready = 1;
+ continue;
+ }
+
+ die(_("unexpected acknowledgment line: '%s'"), reader->line);
+ }
+
+ if (reader->status != PACKET_READ_FLUSH &&
+ reader->status != PACKET_READ_DELIM)
+ die(_("error processing acks: %d"), reader->status);
+
+ /*
+ * If an "acknowledgments" section is sent, a packfile is sent if and
+ * only if "ready" was sent in this section. The other sections
+ * ("shallow-info" and "wanted-refs") are sent only if a packfile is
+ * sent. Therefore, a DELIM is expected if "ready" is sent, and a FLUSH
+ * otherwise.
+ */
+ if (received_ready && reader->status != PACKET_READ_DELIM)
+ die(_("expected packfile to be sent after 'ready'"));
+ if (!received_ready && reader->status != PACKET_READ_FLUSH)
+ die(_("expected no other sections to be sent after no 'ready'"));
+
+ return received_ready ? READY :
+ (received_ack ? COMMON_FOUND : NO_COMMON_FOUND);
+}
+
+static void receive_shallow_info(struct fetch_pack_args *args,
+ struct packet_reader *reader,
+ struct oid_array *shallows,
+ struct shallow_info *si)
+{
+ int unshallow_received = 0;
+
+ process_section_header(reader, "shallow-info", 0);
+ while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+ const char *arg;
+ struct object_id oid;
+
+ if (skip_prefix(reader->line, "shallow ", &arg)) {
+ if (get_oid_hex(arg, &oid))
+ die(_("invalid shallow line: %s"), reader->line);
+ oid_array_append(shallows, &oid);
+ continue;
+ }
+ if (skip_prefix(reader->line, "unshallow ", &arg)) {
+ if (get_oid_hex(arg, &oid))
+ die(_("invalid unshallow line: %s"), reader->line);
+ if (!lookup_object(the_repository, &oid))
+ die(_("object not found: %s"), reader->line);
+ /* make sure that it is parsed as shallow */
+ if (!parse_object(the_repository, &oid))
+ die(_("error in object: %s"), reader->line);
+ if (unregister_shallow(&oid))
+ die(_("no shallow found: %s"), reader->line);
+ unshallow_received = 1;
+ continue;
+ }
+ die(_("expected shallow/unshallow, got %s"), reader->line);
+ }
+
+ if (reader->status != PACKET_READ_FLUSH &&
+ reader->status != PACKET_READ_DELIM)
+ die(_("error processing shallow info: %d"), reader->status);
+
+ if (args->deepen || unshallow_received) {
+ /*
+ * Treat these as shallow lines caused by our depth settings.
+ * In v0, these lines cannot cause refs to be rejected; do the
+ * same.
+ */
+ int i;
+
+ for (i = 0; i < shallows->nr; i++)
+ register_shallow(the_repository, &shallows->oid[i]);
+ setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
+ NULL);
+ args->deepen = 1;
+ } else if (shallows->nr) {
+ /*
+ * Treat these as shallow lines caused by the remote being
+ * shallow. In v0, remote refs that reach these objects are
+ * rejected (unless --update-shallow is set); do the same.
+ */
+ prepare_shallow_info(si, shallows);
+ if (si->nr_ours || si->nr_theirs)
+ alternate_shallow_file =
+ setup_temporary_shallow(si->shallow);
+ else
+ alternate_shallow_file = NULL;
+ } else {
+ alternate_shallow_file = NULL;
+ }
+}
+
+static int cmp_name_ref(const void *name, const void *ref)
+{
+ return strcmp(name, (*(struct ref **)ref)->name);
+}
+
+static void receive_wanted_refs(struct packet_reader *reader,
+ struct ref **sought, int nr_sought)
+{
+ process_section_header(reader, "wanted-refs", 0);
+ while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+ struct object_id oid;
+ const char *end;
+ struct ref **found;
+
+ if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
+ die(_("expected wanted-ref, got '%s'"), reader->line);
+
+ found = bsearch(end, sought, nr_sought, sizeof(*sought),
+ cmp_name_ref);
+ if (!found)
+ die(_("unexpected wanted-ref: '%s'"), reader->line);
+ oidcpy(&(*found)->old_oid, &oid);
+ }
+
+ if (reader->status != PACKET_READ_DELIM)
+ die(_("error processing wanted refs: %d"), reader->status);
+}
+
+static void receive_packfile_uris(struct packet_reader *reader,
+ struct string_list *uris)
+{
+ process_section_header(reader, "packfile-uris", 0);
+ while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+ if (reader->pktlen < the_hash_algo->hexsz ||
+ reader->line[the_hash_algo->hexsz] != ' ')
+ die("expected '<hash> <uri>', got: %s\n", reader->line);
+
+ string_list_append(uris, reader->line);
+ }
+ if (reader->status != PACKET_READ_DELIM)
+ die("expected DELIM");
+}
+
+enum fetch_state {
+ FETCH_CHECK_LOCAL = 0,
+ FETCH_SEND_REQUEST,
+ FETCH_PROCESS_ACKS,
+ FETCH_GET_PACK,
+ FETCH_DONE,
+};
+
+static void do_check_stateless_delimiter(const struct fetch_pack_args *args,
+ struct packet_reader *reader)
+{
+ check_stateless_delimiter(args->stateless_rpc, reader,
+ _("git fetch-pack: expected response end packet"));
+}
+
+static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
+ int fd[2],
+ const struct ref *orig_ref,
+ struct ref **sought, int nr_sought,
+ struct oid_array *shallows,
+ struct shallow_info *si,
+ struct string_list *pack_lockfiles)
+{
+ struct repository *r = the_repository;
+ struct ref *ref = copy_ref_list(orig_ref);
+ enum fetch_state state = FETCH_CHECK_LOCAL;
+ struct oidset common = OIDSET_INIT;
+ struct packet_reader reader;
+ int in_vain = 0, negotiation_started = 0;
+ int haves_to_send = INITIAL_FLUSH;
+ struct fetch_negotiator negotiator_alloc;
+ struct fetch_negotiator *negotiator;
+ int seen_ack = 0;
+ struct string_list packfile_uris = STRING_LIST_INIT_DUP;
+ int i;
+
+ negotiator = &negotiator_alloc;
+ fetch_negotiator_init(r, negotiator);
+
+ packet_reader_init(&reader, fd[0], NULL, 0,
+ PACKET_READ_CHOMP_NEWLINE |
+ PACKET_READ_DIE_ON_ERR_PACKET);
+ if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 1) &&
+ server_supports_feature("fetch", "sideband-all", 0)) {
+ reader.use_sideband = 1;
+ reader.me = "fetch-pack";