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varlink: fix support for more/continues method calls

This commit is contained in:
Lennart Poettering 2019-08-07 12:44:13 +02:00
parent bdf2357c12
commit 45a6c96598
2 changed files with 85 additions and 18 deletions
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99
src/shared/varlink.c
View File

@ -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(&parameters);
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(&parameters, ap);
va_end(ap);
if (r < 0)
return r;
return varlink_observe(v, method, parameters);
}
int varlink_call(
Varlink *v,
const char *method,

4
src/shared/varlink.h
View File

@ -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, ...);