mirror of
https://github.com/samba-team/samba.git
synced 2024-12-27 03:21:53 +03:00
r7206: changed the messaging library to use sendto instead of a connected
send on the unix domain datagram socket. This gains us about 50% in speed, and also means that we don't run the risk of running out of file descriptors due to heavy messaging traffic. We now use a single file descriptor no matter how many messages are pending to any number of servers.
This commit is contained in:
Andrew Tridgell
Gerald (Jerry) Carter
parent
35ef6e3b15
commit
2369170fc1
@ -31,9 +31,6 @@
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/* change the message version with any incompatible changes in the protocol */
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#define MESSAGING_VERSION 1
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/* the number of microseconds to backoff in retrying to send a message */
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#define MESSAGING_BACKOFF 250000
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/* maximum message size */
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#define MESSAGING_MAX_SIZE 512
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@ -42,6 +39,7 @@ struct messaging_context {
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struct socket_context *sock;
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const char *path;
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struct dispatch_fn *dispatch;
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struct messaging_rec *pending;
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struct {
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struct event_context *ev;
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@ -61,8 +59,8 @@ struct dispatch_fn {
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/* an individual message */
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struct messaging_rec {
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struct messaging_rec *next, *prev;
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struct messaging_context *msg;
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struct socket_context *sock;
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const char *path;
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struct {
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@ -76,6 +74,7 @@ struct messaging_rec {
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DATA_BLOB data;
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};
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/*
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A useful function for testing the message system.
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*/
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@ -111,19 +110,67 @@ static void messaging_dispatch(struct messaging_context *msg, struct messaging_r
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d->fn(msg, d->private, d->msg_type, rec->header.from, &rec->data);
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}
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}
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rec->header.length = 0;
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}
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/*
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handle a new incoming connection
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try to send the message
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*/
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static void messaging_recv_handler(struct event_context *ev, struct fd_event *fde,
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uint16_t flags, void *private)
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static NTSTATUS try_send(struct messaging_rec *rec)
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{
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struct messaging_context *msg = rec->msg;
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DATA_BLOB blob;
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size_t nsent;
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void *priv;
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NTSTATUS status;
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blob = data_blob_talloc(rec, NULL, sizeof(rec->header) + rec->data.length);
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NT_STATUS_HAVE_NO_MEMORY(blob.data);
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memcpy(blob.data, &rec->header, sizeof(rec->header));
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memcpy(blob.data + sizeof(rec->header), rec->data.data, rec->data.length);
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/* we send with privileges so messages work from any context */
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priv = root_privileges();
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status = socket_sendto(msg->sock, &blob, &nsent, 0, rec->path, 0);
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talloc_free(priv);
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data_blob_free(&blob);
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return status;
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}
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/*
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handle a socket write event
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*/
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static void messaging_send_handler(struct messaging_context *msg)
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{
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while (msg->pending) {
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struct messaging_rec *rec = msg->pending;
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NTSTATUS status;
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status = try_send(rec);
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if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
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break;
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}
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if (!NT_STATUS_IS_OK(status)) {
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DEBUG(1,("messaging: Lost message from %u to %u of type %u - %s\n",
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rec->header.from, rec->header.to, rec->header.msg_type,
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nt_errstr(status)));
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}
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DLIST_REMOVE(msg->pending, rec);
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talloc_free(rec);
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}
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if (msg->pending == NULL) {
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EVENT_FD_NOT_WRITEABLE(msg->event.fde);
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}
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}
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/*
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handle a new incoming packet
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*/
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static void messaging_recv_handler(struct messaging_context *msg)
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{
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struct messaging_context *msg = talloc_get_type(private,
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struct messaging_context);
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struct messaging_rec *rec;
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NTSTATUS status;
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uint8_t data[MESSAGING_MAX_SIZE];
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@ -146,7 +193,6 @@ static void messaging_recv_handler(struct event_context *ev, struct fd_event *fd
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rec->msg = msg;
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rec->path = msg->path;
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rec->sock = NULL;
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memcpy(&rec->header, data, sizeof(rec->header));
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if (msize != sizeof(rec->header) + rec->header.length) {
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@ -166,6 +212,24 @@ static void messaging_recv_handler(struct event_context *ev, struct fd_event *fd
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talloc_free(rec);
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}
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/*
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handle a socket event
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*/
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static void messaging_handler(struct event_context *ev, struct fd_event *fde,
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uint16_t flags, void *private)
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{
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struct messaging_context *msg = talloc_get_type(private,
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struct messaging_context);
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if (flags & EVENT_FD_WRITE) {
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messaging_send_handler(msg);
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}
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if (flags & EVENT_FD_READ) {
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messaging_recv_handler(msg);
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}
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}
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/*
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Register a dispatch function for a particular message type.
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*/
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@ -200,89 +264,11 @@ void messaging_deregister(struct messaging_context *msg, uint32_t msg_type, void
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}
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/*
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handle IO for sending a message
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*/
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static void messaging_send_handler(struct event_context *ev, struct fd_event *fde,
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uint16_t flags, void *private)
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{
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struct messaging_rec *rec = talloc_get_type(private, struct messaging_rec);
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uint8_t data[MESSAGING_MAX_SIZE];
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DATA_BLOB blob;
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size_t nsent;
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NTSTATUS status;
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memcpy(data, &rec->header, sizeof(rec->header));
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memcpy(data + sizeof(rec->header), rec->data.data, rec->data.length);
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blob.data = data;
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blob.length = sizeof(rec->header) + rec->header.length;
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status = socket_send(rec->sock, &blob, &nsent, 0);
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if (NT_STATUS_IS_ERR(status)) {
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DEBUG(3,("Unable to send message of type %d length %d - %s\n",
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rec->header.msg_type,
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rec->header.length,
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nt_errstr(status)));
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talloc_free(rec);
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return;
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}
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if (NT_STATUS_IS_OK(status)) {
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talloc_free(rec);
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}
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}
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/*
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wrapper around socket_connect with raised privileges
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*/
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static NTSTATUS try_connect(struct messaging_rec *rec)
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{
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NTSTATUS status;
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void *priv = root_privileges();
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status = socket_connect(rec->sock, NULL, 0, rec->path, 0, 0);
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talloc_free(priv);
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return status;
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}
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/*
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when the servers listen queue is full we use this to backoff the message
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*/
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static void messaging_backoff_handler(struct event_context *ev, struct timed_event *te,
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struct timeval t, void *private)
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{
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struct messaging_rec *rec = talloc_get_type(private, struct messaging_rec);
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struct messaging_context *msg = rec->msg;
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NTSTATUS status;
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status = try_connect(rec);
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if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
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/* backoff again */
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event_add_timed(msg->event.ev, rec,
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timeval_add(&t, 0, MESSAGING_BACKOFF),
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messaging_backoff_handler, rec);
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return;
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}
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if (!NT_STATUS_IS_OK(status)) {
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DEBUG(1,("messaging: Lost message from %u to %u of type %u after backoff - %s\n",
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rec->header.from, rec->header.to, rec->header.msg_type, nt_errstr(status)));
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talloc_free(rec);
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return;
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}
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event_add_fd(msg->event.ev, rec, socket_get_fd(rec->sock),
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EVENT_FD_WRITE, messaging_send_handler, rec);
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}
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/*
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Send a message to a particular server
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*/
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NTSTATUS messaging_send(struct messaging_context *msg, uint32_t server, uint32_t msg_type, DATA_BLOB *data)
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NTSTATUS messaging_send(struct messaging_context *msg, uint32_t server,
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uint32_t msg_type, DATA_BLOB *data)
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{
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struct messaging_rec *rec;
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NTSTATUS status;
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@ -292,45 +278,32 @@ NTSTATUS messaging_send(struct messaging_context *msg, uint32_t server, uint32_t
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return NT_STATUS_NO_MEMORY;
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}
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rec->msg = msg;
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rec->header.version = MESSAGING_VERSION;
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rec->msg = msg;
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rec->header.version = MESSAGING_VERSION;
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rec->header.msg_type = msg_type;
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rec->header.from = msg->server_id;
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rec->header.to = server;
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rec->header.length = data?data->length:0;
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rec->header.from = msg->server_id;
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rec->header.to = server;
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rec->header.length = data?data->length:0;
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if (rec->header.length != 0) {
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rec->data = data_blob_talloc(rec, data->data, data->length);
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} else {
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rec->data = data_blob(NULL, 0);
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}
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status = socket_create("unix", SOCKET_TYPE_DGRAM, &rec->sock, 0);
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if (!NT_STATUS_IS_OK(status)) {
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talloc_free(rec);
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return status;
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}
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talloc_steal(rec, rec->sock);
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rec->path = messaging_path(rec, server);
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status = try_connect(rec);
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status = try_send(rec);
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if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
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/* backoff on this message - the servers listen queue is full */
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event_add_timed(msg->event.ev, rec,
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timeval_current_ofs(0, MESSAGING_BACKOFF),
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messaging_backoff_handler, rec);
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if (msg->pending == NULL) {
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EVENT_FD_WRITEABLE(msg->event.fde);
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}
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DLIST_ADD(msg->pending, rec);
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return NT_STATUS_OK;
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}
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if (!NT_STATUS_IS_OK(status)) {
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talloc_free(rec);
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return status;
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}
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talloc_free(rec);
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event_add_fd(msg->event.ev, rec, socket_get_fd(rec->sock),
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EVENT_FD_WRITE, messaging_send_handler, rec);
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return NT_STATUS_OK;
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return status;
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}
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/*
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@ -381,6 +354,7 @@ struct messaging_context *messaging_init(TALLOC_CTX *mem_ctx, uint32_t server_id
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msg->path = messaging_path(msg, server_id);
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msg->server_id = server_id;
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msg->dispatch = NULL;
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msg->pending = NULL;
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status = socket_create("unix", SOCKET_TYPE_DGRAM, &msg->sock, 0);
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if (!NT_STATUS_IS_OK(status)) {
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@ -399,9 +373,12 @@ struct messaging_context *messaging_init(TALLOC_CTX *mem_ctx, uint32_t server_id
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return NULL;
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}
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/* it needs to be non blocking for sends */
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set_blocking(socket_get_fd(msg->sock), False);
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msg->event.ev = talloc_reference(msg, ev);
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msg->event.fde = event_add_fd(ev, msg, socket_get_fd(msg->sock),
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EVENT_FD_READ, messaging_recv_handler, msg);
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EVENT_FD_READ, messaging_handler, msg);
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talloc_set_destructor(msg, messaging_destructor);
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@ -409,5 +386,3 @@ struct messaging_context *messaging_init(TALLOC_CTX *mem_ctx, uint32_t server_id
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return msg;
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}
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