int
jsonrpc_recv(struct jsonrpc *rpc, struct jsonrpc_msg **msgp)
{
*msgp = NULL;
if (rpc->status) {
return rpc->status;
}
while (!rpc->received) {
if (byteq_is_empty(&rpc->input)) {
size_t chunk;
int retval;
chunk = byteq_headroom(&rpc->input);
retval = stream_recv(rpc->stream, byteq_head(&rpc->input), chunk);
if (retval < 0) {
if (retval == -EAGAIN) {
return EAGAIN;
} else {
VLOG_WARN_RL(&rl, "%s: receive error: %s",
rpc->name, strerror(-retval));
jsonrpc_error(rpc, -retval);
return rpc->status;
}
} else if (retval == 0) {
jsonrpc_error(rpc, EOF);
return EOF;
}
byteq_advance_head(&rpc->input, retval);
} else {
size_t n, used;
if (!rpc->parser) {
rpc->parser = json_parser_create(0);
}
n = byteq_tailroom(&rpc->input);
used = json_parser_feed(rpc->parser,
(char *) byteq_tail(&rpc->input), n);
byteq_advance_tail(&rpc->input, used);
if (json_parser_is_done(rpc->parser)) {
jsonrpc_received(rpc);
if (rpc->status) {
const struct byteq *q = &rpc->input;
if (q->head <= BYTEQ_SIZE) {
stream_report_content(q->buffer, q->head,
STREAM_JSONRPC,
THIS_MODULE, rpc->name);
}
return rpc->status;
}
}
}
}
*msgp = rpc->received;
rpc->received = NULL;
return 0;
}
/* Removes a byte from the tail of 'q' and returns it. 'q' must not be
* empty. */
uint8_t
byteq_get(struct byteq *q)
{
uint8_t c;
ovs_assert(!byteq_is_empty(q));
c = *byteq_tail(q);
q->tail++;
return c;
}
/* Writes as much of 'q' as possible to 'fd'. Returns 0 if 'q' is fully
* drained by the write, otherwise a positive errno value (e.g. EAGAIN if a
* socket or tty buffer filled up). */
int
byteq_write(struct byteq *q, int fd)
{
while (!byteq_is_empty(q)) {
ssize_t n = write(fd, byteq_tail(q), byteq_tailroom(q));
if (n > 0) {
byteq_advance_tail(q, n);
} else {
ovs_assert(n < 0);
return errno;
}
}
return 0;
}
/* Attempts to receive a message from 'rpc'.
*
* If successful, stores the received message in '*msgp' and returns 0. The
* caller takes ownership of '*msgp' and must eventually destroy it with
* jsonrpc_msg_destroy().
*
* Otherwise, stores NULL in '*msgp' and returns one of the following:
*
* - EAGAIN: No message has been received.
*
* - EOF: The remote end closed the connection gracefully.
*
* - Otherwise an errno value that represents a JSON-RPC protocol violation
* or another error fatal to the connection. 'rpc' will not send or
* receive any more messages.
*/
int
jsonrpc_recv(struct jsonrpc *rpc, struct jsonrpc_msg **msgp)
{
int i;
*msgp = NULL;
if (rpc->status) {
return rpc->status;
}
for (i = 0; i < 50; i++) {
size_t n, used;
/* Fill our input buffer if it's empty. */
if (byteq_is_empty(&rpc->input)) {
size_t chunk;
int retval;
chunk = byteq_headroom(&rpc->input);
retval = stream_recv(rpc->stream, byteq_head(&rpc->input), chunk);
if (retval < 0) {
if (retval == -EAGAIN) {
return EAGAIN;
} else {
VLOG_WARN_RL(&rl, "%s: receive error: %s",
rpc->name, ovs_strerror(-retval));
jsonrpc_error(rpc, -retval);
return rpc->status;
}
} else if (retval == 0) {
jsonrpc_error(rpc, EOF);
return EOF;
}
byteq_advance_head(&rpc->input, retval);
}
/* We have some input. Feed it into the JSON parser. */
if (!rpc->parser) {
rpc->parser = json_parser_create(0);
}
n = byteq_tailroom(&rpc->input);
used = json_parser_feed(rpc->parser,
(char *) byteq_tail(&rpc->input), n);
byteq_advance_tail(&rpc->input, used);
/* If we have complete JSON, attempt to parse it as JSON-RPC. */
if (json_parser_is_done(rpc->parser)) {
*msgp = jsonrpc_parse_received_message(rpc);
if (*msgp) {
return 0;
}
if (rpc->status) {
const struct byteq *q = &rpc->input;
if (q->head <= q->size) {
stream_report_content(q->buffer, q->head, STREAM_JSONRPC,
THIS_MODULE, rpc->name);
}
return rpc->status;
}
}
}
return EAGAIN;
}