*/
/**
- @defgroups messages Internal messaging framework
- @{
- @file messages.c
-
- This module is used for internal messaging between Samba daemons.
+ @defgroup messages Internal messaging framework
+ @{
+ @file messages.c
+
+ @brief Module for internal messaging between Samba daemons.
The idea is that if a part of Samba wants to do communication with
another Samba process then it will do a message_register() of a
use that to reply by message_send_pid(). See ping_message() for a
simple example.
- *NOTE*: Dispatch functions must be able to cope with incoming
+ @caution Dispatch functions must be able to cope with incoming
messages on an *odd* byte boundary.
This system doesn't have any inherent size limitations but is not
struct message_rec {
int msg_version;
int msg_type;
- pid_t dest;
- pid_t src;
+ struct server_id dest;
+ struct server_id src;
size_t len;
};
static struct dispatch_fns {
struct dispatch_fns *next, *prev;
int msg_type;
- void (*fn)(int msg_type, pid_t pid, void *buf, size_t len);
+ void (*fn)(int msg_type, struct server_id pid, void *buf, size_t len,
+ void *private_data);
+ void *private_data;
} *dispatch_fns;
+/****************************************************************************
+ Free global objects.
+****************************************************************************/
+
+void gfree_messages(void)
+{
+ struct dispatch_fns *dfn, *next;
+
+ /* delete the dispatch_fns list */
+ dfn = dispatch_fns;
+ while( dfn ) {
+ next = dfn->next;
+ DLIST_REMOVE(dispatch_fns, dfn);
+ SAFE_FREE(dfn);
+ dfn = next;
+ }
+}
+
/****************************************************************************
Notifications come in as signals.
****************************************************************************/
static void sig_usr1(void)
{
received_signal = 1;
- sys_select_signal();
+ sys_select_signal(SIGUSR1);
}
/****************************************************************************
A useful function for testing the message system.
****************************************************************************/
-static void ping_message(int msg_type, pid_t src, void *buf, size_t len)
+static void ping_message(int msg_type, struct server_id src,
+ void *buf, size_t len, void *private_data)
{
- const char *msg = buf ? buf : "none";
- DEBUG(1,("INFO: Received PING message from PID %u [%s]\n",(unsigned int)src, msg));
+ const char *msg = buf ? (const char *)buf : "none";
+
+ DEBUG(1,("INFO: Received PING message from PID %s [%s]\n",
+ procid_str_static(&src), msg));
message_send_pid(src, MSG_PONG, buf, len, True);
}
BOOL message_init(void)
{
- if (tdb) return True;
+ sec_init();
+
+ if (tdb)
+ return True;
tdb = tdb_open_log(lock_path("messages.tdb"),
0, TDB_CLEAR_IF_FIRST|TDB_DEFAULT,
return False;
}
+ /* Activate the per-hashchain freelist */
+ tdb_set_max_dead(tdb, 5);
+
CatchSignal(SIGUSR1, SIGNAL_CAST sig_usr1);
- message_register(MSG_PING, ping_message);
+ message_register(MSG_PING, ping_message, NULL);
+
+ /* Register some debugging related messages */
+
+ register_msg_pool_usage();
+ register_dmalloc_msgs();
return True;
}
Form a static tdb key from a pid.
******************************************************************/
-static TDB_DATA message_key_pid(pid_t pid)
+static TDB_DATA message_key_pid(struct server_id pid)
{
static char key[20];
TDB_DATA kbuf;
- slprintf(key, sizeof(key)-1, "PID/%d", (int)pid);
+ slprintf(key, sizeof(key)-1, "PID/%s", procid_str_static(&pid));
- kbuf.dptr = (char *)key;
+ kbuf.dptr = (uint8 *)key;
kbuf.dsize = strlen(key)+1;
return kbuf;
}
then delete its record in the database.
****************************************************************************/
-static BOOL message_notify(pid_t pid)
+static NTSTATUS message_notify(struct server_id procid)
{
+ pid_t pid = procid.pid;
+ int ret;
+ uid_t euid = geteuid();
+
/*
* Doing kill with a non-positive pid causes messages to be
* sent to places we don't want.
SMB_ASSERT(pid > 0);
- if (kill(pid, SIGUSR1) == -1) {
+ if (euid != 0) {
+ /* If we're not root become so to send the message. */
+ save_re_uid();
+ set_effective_uid(0);
+ }
+
+ ret = kill(pid, SIGUSR1);
+
+ if (euid != 0) {
+ /* Go back to who we were. */
+ int saved_errno = errno;
+ restore_re_uid_fromroot();
+ errno = saved_errno;
+ }
+
+ if (ret == -1) {
if (errno == ESRCH) {
- DEBUG(2,("pid %d doesn't exist - deleting messages record\n", (int)pid));
- tdb_delete(tdb, message_key_pid(pid));
- } else {
- DEBUG(2,("message to process %d failed - %s\n", (int)pid, strerror(errno)));
+ DEBUG(2,("pid %d doesn't exist - deleting messages record\n",
+ (int)pid));
+ tdb_delete(tdb, message_key_pid(procid));
+
+ /*
+ * INVALID_HANDLE is the closest I can think of -- vl
+ */
+ return NT_STATUS_INVALID_HANDLE;
}
- return False;
+
+ DEBUG(2,("message to process %d failed - %s\n", (int)pid,
+ strerror(errno)));
+
+ /*
+ * No call to map_nt_error_from_unix -- don't want to link in
+ * errormap.o into lots of utils.
+ */
+
+ if (errno == EINVAL) return NT_STATUS_INVALID_PARAMETER;
+ if (errno == EPERM) return NT_STATUS_ACCESS_DENIED;
+ return NT_STATUS_UNSUCCESSFUL;
}
- return True;
+
+ return NT_STATUS_OK;
}
/****************************************************************************
Send a message to a particular pid.
****************************************************************************/
-static BOOL message_send_pid_internal(pid_t pid, int msg_type, const void *buf, size_t len,
- BOOL duplicates_allowed, unsigned int timeout)
+static NTSTATUS message_send_pid_internal(struct server_id pid, int msg_type,
+ const void *buf, size_t len,
+ BOOL duplicates_allowed,
+ unsigned int timeout)
{
TDB_DATA kbuf;
TDB_DATA dbuf;
TDB_DATA old_dbuf;
struct message_rec rec;
- char *ptr;
+ uint8 *ptr;
struct message_rec prec;
+ /* NULL pointer means implicit length zero. */
+ if (!buf) {
+ SMB_ASSERT(len == 0);
+ }
+
/*
* Doing kill with a non-positive pid causes messages to be
* sent to places we don't want.
*/
- SMB_ASSERT(pid > 0);
+ SMB_ASSERT(procid_to_pid(&pid) > 0);
rec.msg_version = MESSAGE_VERSION;
rec.msg_type = msg_type;
rec.dest = pid;
- rec.src = sys_getpid();
- rec.len = len;
+ rec.src = procid_self();
+ rec.len = buf ? len : 0;
kbuf = message_key_pid(pid);
- dbuf.dptr = (void *)malloc(len + sizeof(rec));
- if (!dbuf.dptr)
- return False;
+ dbuf.dptr = (uint8 *)SMB_MALLOC(len + sizeof(rec));
+ if (!dbuf.dptr) {
+ return NT_STATUS_NO_MEMORY;
+ }
memcpy(dbuf.dptr, &rec, sizeof(rec));
- if (len > 0)
+ if (len > 0 && buf)
memcpy((void *)((char*)dbuf.dptr+sizeof(rec)), buf, len);
dbuf.dsize = len + sizeof(rec);
/* lock the record for the destination */
if (timeout) {
if (tdb_chainlock_with_timeout(tdb, kbuf, timeout) == -1) {
- DEBUG(0,("message_send_pid_internal: failed to get chainlock with timeout %ul.\n", timeout));
- return False;
+ DEBUG(0,("message_send_pid_internal: failed to get "
+ "chainlock with timeout %ul.\n", timeout));
+ return NT_STATUS_IO_TIMEOUT;
}
} else {
if (tdb_chainlock(tdb, kbuf) == -1) {
- DEBUG(0,("message_send_pid_internal: failed to get chainlock.\n"));
- return False;
+ DEBUG(0,("message_send_pid_internal: failed to get "
+ "chainlock.\n"));
+ return NT_STATUS_LOCK_NOT_GRANTED;
}
}
tdb_append(tdb, kbuf, dbuf);
/* lock the record for the destination */
if (timeout) {
if (tdb_chainlock_with_timeout(tdb, kbuf, timeout) == -1) {
- DEBUG(0,("message_send_pid_internal: failed to get chainlock with timeout %ul.\n", timeout));
- return False;
+ DEBUG(0,("message_send_pid_internal: failed to get chainlock "
+ "with timeout %ul.\n", timeout));
+ return NT_STATUS_IO_TIMEOUT;
}
} else {
if (tdb_chainlock(tdb, kbuf) == -1) {
- DEBUG(0,("message_send_pid_internal: failed to get chainlock.\n"));
- return False;
+ DEBUG(0,("message_send_pid_internal: failed to get "
+ "chainlock.\n"));
+ return NT_STATUS_LOCK_NOT_GRANTED;
}
}
/* Not a new record. Check for duplicates. */
- for(ptr = (char *)old_dbuf.dptr; ptr < old_dbuf.dptr + old_dbuf.dsize; ) {
+ for(ptr = old_dbuf.dptr; ptr < old_dbuf.dptr + old_dbuf.dsize; ) {
/*
* First check if the message header matches, then, if it's a non-zero
* sized message, check if the data matches. If so it's a duplicate and
if (!memcmp(ptr, &rec, sizeof(rec))) {
if (!len || (len && !memcmp( ptr + sizeof(rec), buf, len))) {
tdb_chainunlock(tdb, kbuf);
- DEBUG(10,("message_send_pid_internal: discarding duplicate message.\n"));
+ DEBUG(10,("message_send_pid_internal: discarding "
+ "duplicate message.\n"));
SAFE_FREE(dbuf.dptr);
SAFE_FREE(old_dbuf.dptr);
- return True;
+ return NT_STATUS_OK;
}
}
memcpy(&prec, ptr, sizeof(prec));
Send a message to a particular pid - no timeout.
****************************************************************************/
-BOOL message_send_pid(pid_t pid, int msg_type, const void *buf, size_t len, BOOL duplicates_allowed)
+NTSTATUS message_send_pid(struct server_id pid, int msg_type, const void *buf,
+ size_t len, BOOL duplicates_allowed)
{
- return message_send_pid_internal(pid, msg_type, buf, len, duplicates_allowed, 0);
+ return message_send_pid_internal(pid, msg_type, buf, len,
+ duplicates_allowed, 0);
}
/****************************************************************************
Send a message to a particular pid, with timeout in seconds.
****************************************************************************/
-BOOL message_send_pid_with_timeout(pid_t pid, int msg_type, const void *buf, size_t len,
- BOOL duplicates_allowed, unsigned int timeout)
+NTSTATUS message_send_pid_with_timeout(struct server_id pid, int msg_type,
+ const void *buf, size_t len,
+ BOOL duplicates_allowed, unsigned int timeout)
{
- return message_send_pid_internal(pid, msg_type, buf, len, duplicates_allowed, timeout);
+ return message_send_pid_internal(pid, msg_type, buf, len, duplicates_allowed,
+ timeout);
+}
+
+/****************************************************************************
+ Count the messages pending for a particular pid. Expensive....
+****************************************************************************/
+
+unsigned int messages_pending_for_pid(struct server_id pid)
+{
+ TDB_DATA kbuf;
+ TDB_DATA dbuf;
+ uint8 *buf;
+ unsigned int message_count = 0;
+
+ kbuf = message_key_pid(pid);
+
+ dbuf = tdb_fetch(tdb, kbuf);
+ if (dbuf.dptr == NULL || dbuf.dsize == 0) {
+ SAFE_FREE(dbuf.dptr);
+ return 0;
+ }
+
+ for (buf = dbuf.dptr; dbuf.dsize > sizeof(struct message_rec);) {
+ struct message_rec rec;
+ memcpy(&rec, buf, sizeof(rec));
+ buf += (sizeof(rec) + rec.len);
+ dbuf.dsize -= (sizeof(rec) + rec.len);
+ message_count++;
+ }
+
+ SAFE_FREE(dbuf.dptr);
+ return message_count;
}
/****************************************************************************
*msgs_buf = NULL;
*total_len = 0;
- kbuf = message_key_pid(sys_getpid());
+ kbuf = message_key_pid(pid_to_procid(sys_getpid()));
+
+ if (tdb_chainlock(tdb, kbuf) == -1)
+ return False;
- tdb_chainlock(tdb, kbuf);
dbuf = tdb_fetch(tdb, kbuf);
/*
* Replace with an empty record to keep the allocated
return False;
}
- *msgs_buf = dbuf.dptr;
+ *msgs_buf = (char *)dbuf.dptr;
*total_len = dbuf.dsize;
return True;
Parse out the next message for the current process.
****************************************************************************/
-static BOOL message_recv(char *msgs_buf, size_t total_len, int *msg_type, pid_t *src, char **buf, size_t *len)
+static BOOL message_recv(char *msgs_buf, size_t total_len, int *msg_type,
+ struct server_id *src, char **buf, size_t *len)
{
struct message_rec rec;
char *ret_buf = *buf;
/****************************************************************************
Receive and dispatch any messages pending for this process.
- Notice that all dispatch handlers for a particular msg_type get called,
- so you can register multiple handlers for a message.
+ JRA changed Dec 13 2006. Only one message handler now permitted per type.
*NOTE*: Dispatch functions must be able to cope with incoming
messages on an *odd* byte boundary.
****************************************************************************/
void message_dispatch(void)
{
int msg_type;
- pid_t src;
+ struct server_id src;
char *buf;
char *msgs_buf;
size_t len, total_len;
- struct dispatch_fns *dfn;
int n_handled;
if (!received_signal)
return;
for (buf = msgs_buf; message_recv(msgs_buf, total_len, &msg_type, &src, &buf, &len); buf += len) {
- DEBUG(10,("message_dispatch: received msg_type=%d src_pid=%u\n",
- msg_type, (unsigned int) src));
+ struct dispatch_fns *dfn;
+
+ DEBUG(10,("message_dispatch: received msg_type=%d "
+ "src_pid=%u\n", msg_type,
+ (unsigned int) procid_to_pid(&src)));
+
n_handled = 0;
for (dfn = dispatch_fns; dfn; dfn = dfn->next) {
if (dfn->msg_type == msg_type) {
DEBUG(10,("message_dispatch: processing message of type %d.\n", msg_type));
- dfn->fn(msg_type, src, len ? (void *)buf : NULL, len);
+ dfn->fn(msg_type, src,
+ len ? (void *)buf : NULL, len,
+ dfn->private_data);
n_handled++;
+ break;
}
}
if (!n_handled) {
- DEBUG(5,("message_dispatch: warning: no handlers registed for "
+ DEBUG(5,("message_dispatch: warning: no handler registed for "
"msg_type %d in pid %u\n",
msg_type, (unsigned int)sys_getpid()));
}
}
/****************************************************************************
- Register a dispatch function for a particular message type.
+ Register/replace a dispatch function for a particular message type.
+ JRA changed Dec 13 2006. Only one message handler now permitted per type.
*NOTE*: Dispatch functions must be able to cope with incoming
messages on an *odd* byte boundary.
****************************************************************************/
void message_register(int msg_type,
- void (*fn)(int msg_type, pid_t pid, void *buf, size_t len))
+ void (*fn)(int msg_type, struct server_id pid,
+ void *buf, size_t len,
+ void *private_data),
+ void *private_data)
{
struct dispatch_fns *dfn;
- dfn = (struct dispatch_fns *)malloc(sizeof(*dfn));
+ for (dfn = dispatch_fns; dfn; dfn = dfn->next) {
+ if (dfn->msg_type == msg_type) {
+ dfn->fn = fn;
+ return;
+ }
+ }
+
+ dfn = SMB_MALLOC_P(struct dispatch_fns);
if (dfn != NULL) {
dfn->msg_type = msg_type;
dfn->fn = fn;
+ dfn->private_data = private_data;
DLIST_ADD(dispatch_fns, dfn);
}
if (dfn->msg_type == msg_type) {
DLIST_REMOVE(dispatch_fns, dfn);
SAFE_FREE(dfn);
+ return;
}
}
}
{
struct connections_data crec;
struct msg_all *msg_all = (struct msg_all *)state;
+ NTSTATUS status;
if (dbuf.dsize != sizeof(crec))
return 0;
/* If the msg send fails because the pid was not found (i.e. smbd died),
* the msg has already been deleted from the messages.tdb.*/
- if (!message_send_pid(crec.pid, msg_all->msg_type,
- msg_all->buf, msg_all->len,
- msg_all->duplicates)) {
+ status = message_send_pid(crec.pid, msg_all->msg_type,
+ msg_all->buf, msg_all->len,
+ msg_all->duplicates);
+
+ if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_HANDLE)) {
/* If the pid was not found delete the entry from connections.tdb */
- if (errno == ESRCH) {
- DEBUG(2,("pid %u doesn't exist - deleting connections %d [%s]\n",
- (unsigned int)crec.pid, crec.cnum, crec.name));
- tdb_delete(the_tdb, kbuf);
- }
+ DEBUG(2,("pid %s doesn't exist - deleting connections %d [%s]\n",
+ procid_str_static(&crec.pid), crec.cnum, crec.servicename));
+ tdb_delete(the_tdb, kbuf);
}
msg_all->n_sent++;
return 0;
* @param n_sent Set to the number of messages sent. This should be
* equal to the number of processes, but be careful for races.
*
- * @return True for success.
+ * @retval True for success.
**/
-BOOL message_send_all(TDB_CONTEXT *conn_tdb, int msg_type,
+BOOL message_send_all(int msg_type,
const void *buf, size_t len,
BOOL duplicates_allowed,
int *n_sent)
msg_all.msg_flag = FLAG_MSG_GENERAL;
else if (msg_type > 1000 && msg_type < 2000)
msg_all.msg_flag = FLAG_MSG_NMBD;
- else if (msg_type > 2000 && msg_type < 3000)
- msg_all.msg_flag = FLAG_MSG_PRINTING;
+ else if (msg_type > 2000 && msg_type < 2100)
+ msg_all.msg_flag = FLAG_MSG_PRINT_NOTIFY;
+ else if (msg_type > 2100 && msg_type < 3000)
+ msg_all.msg_flag = FLAG_MSG_PRINT_GENERAL;
else if (msg_type > 3000 && msg_type < 4000)
msg_all.msg_flag = FLAG_MSG_SMBD;
else
msg_all.duplicates = duplicates_allowed;
msg_all.n_sent = 0;
- tdb_traverse(conn_tdb, traverse_fn, &msg_all);
+ connections_traverse(traverse_fn, &msg_all);
if (n_sent)
*n_sent = msg_all.n_sent;
return True;
}
+
+/*
+ * Block and unblock receiving of messages. Allows removal of race conditions
+ * when doing a fork and changing message disposition.
+ */
+
+void message_block(void)
+{
+ BlockSignals(True, SIGUSR1);
+}
+
+void message_unblock(void)
+{
+ BlockSignals(False, SIGUSR1);
+}
+
+/*
+ * Samba4 API wrapper around the Samba3 implementation. Yes, I know, we could
+ * import the whole Samba4 thing, but I want notify.c from Samba4 in first.
+ */
+
+struct messaging_callback {
+ struct messaging_callback *prev, *next;
+ uint32 msg_type;
+ void (*fn)(struct messaging_context *msg, void *private_data,
+ uint32_t msg_type,
+ struct server_id server_id, DATA_BLOB *data);
+ void *private_data;
+};
+
+struct messaging_context {
+ struct server_id id;
+ struct messaging_callback *callbacks;
+};
+
+static int messaging_context_destructor(struct messaging_context *ctx)
+{
+ struct messaging_callback *cb;
+
+ for (cb = ctx->callbacks; cb; cb = cb->next) {
+ /*
+ * We unconditionally remove all instances of our callback
+ * from the tdb basis.
+ */
+ message_deregister(cb->msg_type);
+ }
+ return 0;
+}
+
+struct messaging_context *messaging_init(TALLOC_CTX *mem_ctx,
+ struct server_id server_id,
+ struct event_context *ev)
+{
+ struct messaging_context *ctx;
+
+ if (!(ctx = TALLOC_ZERO_P(mem_ctx, struct messaging_context))) {
+ return NULL;
+ }
+
+ ctx->id = server_id;
+ talloc_set_destructor(ctx, messaging_context_destructor);
+ return ctx;
+}
+
+static void messaging_callback(int msg_type, struct server_id pid,
+ void *buf, size_t len, void *private_data)
+{
+ struct messaging_context *ctx = talloc_get_type_abort(
+ private_data, struct messaging_context);
+ struct messaging_callback *cb, *next;
+
+ for (cb = ctx->callbacks; cb; cb = next) {
+ /*
+ * Allow a callback to remove itself
+ */
+ next = cb->next;
+
+ if (msg_type == cb->msg_type) {
+ DATA_BLOB blob;
+
+ blob.data = (uint8 *)buf;
+ blob.length = len;
+
+ cb->fn(ctx, cb->private_data, msg_type, pid, &blob);
+ }
+ }
+}
+
+/*
+ * Register a dispatch function for a particular message type. Allow multiple
+ * registrants
+*/
+NTSTATUS messaging_register(struct messaging_context *ctx, void *private_data,
+ uint32_t msg_type,
+ void (*fn)(struct messaging_context *msg,
+ void *private_data,
+ uint32_t msg_type,
+ struct server_id server_id,
+ DATA_BLOB *data))
+{
+ struct messaging_callback *cb;
+
+ if (!(cb = talloc(ctx, struct messaging_callback))) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ cb->msg_type = msg_type;
+ cb->fn = fn;
+ cb->private_data = private_data;
+
+ DLIST_ADD(ctx->callbacks, cb);
+ message_register(msg_type, messaging_callback, ctx);
+ return NT_STATUS_OK;
+}
+
+/*
+ De-register the function for a particular message type.
+*/
+void messaging_deregister(struct messaging_context *ctx, uint32_t msg_type,
+ void *private_data)
+{
+ struct messaging_callback *cb, *next;
+
+ for (cb = ctx->callbacks; cb; cb = next) {
+ next = cb->next;
+ if ((cb->msg_type == msg_type)
+ && (cb->private_data == private_data)) {
+ DLIST_REMOVE(ctx->callbacks, cb);
+ TALLOC_FREE(cb);
+ }
+ }
+}
+
+/*
+ Send a message to a particular server
+*/
+NTSTATUS messaging_send(struct messaging_context *msg,
+ struct server_id server,
+ uint32_t msg_type, const DATA_BLOB *data)
+{
+ return message_send_pid_internal(server, msg_type, data->data,
+ data->length, True, 0);
+}
+
/** @} **/
git.samba.org / sfrench / samba-autobuild / .git / blobdiff