diff --git a/src/shared/varlink.c b/src/shared/varlink.c index 99343167f6..7a566762fa 100644 --- a/src/shared/varlink.c +++ b/src/shared/varlink.c @@ -29,6 +29,7 @@ typedef enum VarlinkState { /* Client side states */ VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY, + VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_CALLED, VARLINK_PROCESSING_REPLY, @@ -39,7 +40,6 @@ typedef enum VarlinkState { VARLINK_PROCESSING_METHOD_MORE, VARLINK_PROCESSING_METHOD_ONEWAY, VARLINK_PROCESSED_METHOD, - VARLINK_PROCESSED_METHOD_MORE, VARLINK_PENDING_METHOD, VARLINK_PENDING_METHOD_MORE, @@ -63,6 +63,7 @@ typedef enum VarlinkState { IN_SET(state, \ VARLINK_IDLE_CLIENT, \ VARLINK_AWAITING_REPLY, \ + VARLINK_AWAITING_REPLY_MORE, \ VARLINK_CALLING, \ VARLINK_CALLED, \ VARLINK_PROCESSING_REPLY, \ @@ -71,7 +72,6 @@ typedef enum VarlinkState { VARLINK_PROCESSING_METHOD_MORE, \ VARLINK_PROCESSING_METHOD_ONEWAY, \ VARLINK_PROCESSED_METHOD, \ - VARLINK_PROCESSED_METHOD_MORE, \ VARLINK_PENDING_METHOD, \ VARLINK_PENDING_METHOD_MORE) @@ -185,6 +185,7 @@ struct VarlinkServer { static const char* const varlink_state_table[_VARLINK_STATE_MAX] = { [VARLINK_IDLE_CLIENT] = "idle-client", [VARLINK_AWAITING_REPLY] = "awaiting-reply", + [VARLINK_AWAITING_REPLY_MORE] = "awaiting-reply-more", [VARLINK_CALLING] = "calling", [VARLINK_CALLED] = "called", [VARLINK_PROCESSING_REPLY] = "processing-reply", @@ -193,7 +194,6 @@ static const char* const varlink_state_table[_VARLINK_STATE_MAX] = { [VARLINK_PROCESSING_METHOD_MORE] = "processing-method-more", [VARLINK_PROCESSING_METHOD_ONEWAY] = "processing-method-oneway", [VARLINK_PROCESSED_METHOD] = "processed-method", - [VARLINK_PROCESSED_METHOD_MORE] = "processed-method-more", [VARLINK_PENDING_METHOD] = "pending-method", [VARLINK_PENDING_METHOD_MORE] = "pending-method-more", [VARLINK_PENDING_DISCONNECT] = "pending-disconnect", @@ -405,7 +405,7 @@ static int varlink_test_disconnect(Varlink *v) { goto disconnect; /* If we are waiting for incoming data but the read side is shut down, disconnect. */ - if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING, VARLINK_IDLE_SERVER) && v->read_disconnected) + if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER) && v->read_disconnected) goto disconnect; /* Similar, if are a client that hasn't written anything yet but the write side is dead, also @@ -478,7 +478,7 @@ static int varlink_read(Varlink *v) { assert(v); - if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING, VARLINK_IDLE_SERVER)) + if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER)) return 0; if (v->connecting) /* read() on a socket while we are in connect() will fail with EINVAL, hence exit early here */ return 0; @@ -596,7 +596,7 @@ static int varlink_parse_message(Varlink *v) { static int varlink_test_timeout(Varlink *v) { assert(v); - if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING)) + if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING)) return 0; if (v->timeout == USEC_INFINITY) return 0; @@ -673,7 +673,7 @@ static int varlink_dispatch_reply(Varlink *v) { assert(v); - if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING)) + if (!IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING)) return 0; if (!v->current) return 0; @@ -715,6 +715,11 @@ static int varlink_dispatch_reply(Varlink *v) { goto invalid; } + /* Replies with 'continue' set are only OK if we set 'more' when the method call was initiated */ + if (v->state != VARLINK_AWAITING_REPLY_MORE && FLAGS_SET(flags, VARLINK_REPLY_CONTINUES)) + goto invalid; + + /* An error is final */ if (error && FLAGS_SET(flags, VARLINK_REPLY_CONTINUES)) goto invalid; @@ -722,7 +727,7 @@ static int varlink_dispatch_reply(Varlink *v) { if (r < 0) goto invalid; - if (v->state == VARLINK_AWAITING_REPLY) { + if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE)) { varlink_set_state(v, VARLINK_PROCESSING_REPLY); if (v->reply_callback) { @@ -734,17 +739,18 @@ static int varlink_dispatch_reply(Varlink *v) { v->current = json_variant_unref(v->current); if (v->state == VARLINK_PROCESSING_REPLY) { - assert(v->n_pending > 0); - v->n_pending--; - varlink_set_state(v, v->n_pending == 0 ? VARLINK_IDLE_CLIENT : VARLINK_AWAITING_REPLY); + assert(v->n_pending > 0); + + if (!FLAGS_SET(flags, VARLINK_REPLY_CONTINUES)) + v->n_pending--; + + varlink_set_state(v, + FLAGS_SET(flags, VARLINK_REPLY_CONTINUES) ? VARLINK_AWAITING_REPLY_MORE : + v->n_pending == 0 ? VARLINK_IDLE_CLIENT : VARLINK_AWAITING_REPLY); } } else { assert(v->state == VARLINK_CALLING); - - if (FLAGS_SET(flags, VARLINK_REPLY_CONTINUES)) - goto invalid; - varlink_set_state(v, VARLINK_CALLED); } @@ -878,7 +884,6 @@ static int varlink_dispatch_method(Varlink *v) { varlink_set_state(v, VARLINK_PENDING_METHOD); break; - case VARLINK_PROCESSED_METHOD_MORE: /* One reply for a "more" message was sent, more to come */ case VARLINK_PROCESSING_METHOD_MORE: /* No reply for a "more" message was sent, more to come */ varlink_set_state(v, VARLINK_PENDING_METHOD_MORE); break; @@ -1073,7 +1078,7 @@ int varlink_get_events(Varlink *v) { return EPOLLOUT; if (!v->read_disconnected && - IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING, VARLINK_IDLE_SERVER) && + IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING, VARLINK_IDLE_SERVER) && !v->current && v->input_buffer_unscanned <= 0) ret |= EPOLLIN; @@ -1091,7 +1096,7 @@ int varlink_get_timeout(Varlink *v, usec_t *ret) { if (v->state == VARLINK_DISCONNECTED) return -ENOTCONN; - if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_CALLING) && + if (IN_SET(v->state, VARLINK_AWAITING_REPLY, VARLINK_AWAITING_REPLY_MORE, VARLINK_CALLING) && v->timeout != USEC_INFINITY) { if (ret) *ret = usec_add(v->timestamp, v->timeout); @@ -1259,6 +1264,8 @@ int varlink_send(Varlink *v, const char *method, JsonVariant *parameters) { if (v->state == VARLINK_DISCONNECTED) return -ENOTCONN; + + /* We allow enqueuing multiple method calls at once! */ if (!IN_SET(v->state, VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY)) return -EBUSY; @@ -1308,6 +1315,8 @@ int varlink_invoke(Varlink *v, const char *method, JsonVariant *parameters) { if (v->state == VARLINK_DISCONNECTED) return -ENOTCONN; + + /* We allow enqueing multiple method calls at once! */ if (!IN_SET(v->state, VARLINK_IDLE_CLIENT, VARLINK_AWAITING_REPLY)) return -EBUSY; @@ -1349,6 +1358,60 @@ int varlink_invokeb(Varlink *v, const char *method, ...) { return varlink_invoke(v, method, parameters); } +int varlink_observe(Varlink *v, const char *method, JsonVariant *parameters) { + _cleanup_(json_variant_unrefp) JsonVariant *m = NULL; + int r; + + assert_return(v, -EINVAL); + assert_return(method, -EINVAL); + + if (v->state == VARLINK_DISCONNECTED) + return -ENOTCONN; + /* Note that we don't allow enqueuing multiple method calls when we are in more/continues mode! We + * thus insist on an idle client here. */ + if (v->state != VARLINK_IDLE_CLIENT) + return -EBUSY; + + r = varlink_sanitize_parameters(¶meters); + if (r < 0) + return r; + + r = json_build(&m, JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("method", JSON_BUILD_STRING(method)), + JSON_BUILD_PAIR("parameters", JSON_BUILD_VARIANT(parameters)), + JSON_BUILD_PAIR("more", JSON_BUILD_BOOLEAN(true)))); + if (r < 0) + return r; + + r = varlink_enqueue_json(v, m); + if (r < 0) + return r; + + + varlink_set_state(v, VARLINK_AWAITING_REPLY_MORE); + v->n_pending++; + v->timestamp = now(CLOCK_MONOTONIC); + + return 0; +} + +int varlink_observeb(Varlink *v, const char *method, ...) { + _cleanup_(json_variant_unrefp) JsonVariant *parameters = NULL; + va_list ap; + int r; + + assert_return(v, -EINVAL); + + va_start(ap, method); + r = json_buildv(¶meters, ap); + va_end(ap); + + if (r < 0) + return r; + + return varlink_observe(v, method, parameters); +} + int varlink_call( Varlink *v, const char *method, diff --git a/src/shared/varlink.h b/src/shared/varlink.h index d96fa93619..0208802010 100644 --- a/src/shared/varlink.h +++ b/src/shared/varlink.h @@ -86,6 +86,10 @@ int varlink_callb(Varlink *v, const char *method, JsonVariant **ret_parameters, int varlink_invoke(Varlink *v, const char *method, JsonVariant *parameters); int varlink_invokeb(Varlink *v, const char *method, ...); +/* Enqueue method call, expect a reply now, and possibly more later, which are all delivered to the reply callback */ +int varlink_observe(Varlink *v, const char *method, JsonVariant *parameters); +int varlink_observeb(Varlink *v, const char *method, ...); + /* Enqueue a final reply */ int varlink_reply(Varlink *v, JsonVariant *parameters); int varlink_replyb(Varlink *v, ...);