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authorGary Lockyer <gary@catalyst.net.nz>2017-08-22 07:58:14 +1200
committerRalph Boehme <slow@samba.org>2017-09-28 02:08:34 +0200
commit099df25f567a34bf0c159e18b62cd67b073c3002 (patch)
treeb3b259d68abbafbf3099283a7261fa2caef6998e /source4/smbd/server.c
parent575f1e2bf51131709f55d565568198f56a0cbdda (diff)
downloadsamba-099df25f567a34bf0c159e18b62cd67b073c3002.tar.gz
source4 smbd: remove global control pipe from process_standard.
The standard model uses a pipe to signal the worker processes spawned on accept that the controlling process has terminated and that they should shut down. This pipe is currently a static global variable in process_standard.c. This patch replaces that global pipe with a file descriptor passed into the process model init functions, giving a single mechanism across all process models. This paves the way for the addition of a pre-fork process model. Ensuring that the correct file descriptors are closed, is difficult so it is best do this only once rather than require the process models to do this individually. Notes on debugging pipe ownership: Add code to log the process id and the file descriptor of the writeable pipe. run: lsof | grep FIFO | grep samba | grep <process id> this will produce lines like: samba 25624 him 4w FIFO 0,10 0t0 472206 pipe where: 4w is the file descriptor and mode and the number to the left of "pipe" is the pipe id. then: lsof | grep FIFO | grep samba | grep <pipe id> This will display all the processes with the pipe open and the mode only the smbd master process should have it open in write mode. Signed-off-by: Gary Lockyer <gary@catalyst.net.nz> Reviewed-by: Andrew Bartlett <abartlet@samba.org> Reviewed-by: Ralph Boehme <slow@samba.org> Autobuild-User(master): Ralph Böhme <slow@samba.org> Autobuild-Date(master): Thu Sep 28 02:08:34 CEST 2017 on sn-devel-144
Diffstat (limited to 'source4/smbd/server.c')
-rw-r--r--source4/smbd/server.c73
1 files changed, 67 insertions, 6 deletions
diff --git a/source4/smbd/server.c b/source4/smbd/server.c
index 249391c0dff..66f2794a38a 100644
--- a/source4/smbd/server.c
+++ b/source4/smbd/server.c
@@ -43,6 +43,11 @@
#include "lib/util/samba_modules.h"
#include "nsswitch/winbind_client.h"
#include "libds/common/roles.h"
+#include "lib/util/tfork.h"
+
+#ifdef HAVE_PTHREAD
+#include <pthread.h>
+#endif
struct server_state {
struct tevent_context *event_ctx;
@@ -332,6 +337,20 @@ static int event_ctx_destructor(struct tevent_context *event_ctx)
return 0;
}
+#ifdef HAVE_PTHREAD
+static int to_children_fd = -1;
+static void atfork_prepare(void) {
+}
+static void atfork_parent(void) {
+}
+static void atfork_child(void) {
+ if (to_children_fd != -1) {
+ close(to_children_fd);
+ to_children_fd = -1;
+ }
+}
+#endif
+
/*
main server.
*/
@@ -608,12 +627,54 @@ static int binary_smbd_main(const char *binary_name,
DEBUG(0,("%s: using '%s' process model\n", binary_name, model));
- status = server_service_startup(state->event_ctx, cmdline_lp_ctx, model,
- lpcfg_server_services(cmdline_lp_ctx));
- if (!NT_STATUS_IS_OK(status)) {
- TALLOC_FREE(state);
- exit_daemon("Samba failed to start services",
- NT_STATUS_V(status));
+ {
+ int child_pipe[2];
+ int rc;
+ bool start_services = false;
+
+ rc = pipe(child_pipe);
+ if (rc < 0) {
+ TALLOC_FREE(state);
+ exit_daemon("Samba failed to open process control pipe",
+ errno);
+ }
+ smb_set_close_on_exec(child_pipe[0]);
+ smb_set_close_on_exec(child_pipe[1]);
+
+#ifdef HAVE_PTHREAD
+ to_children_fd = child_pipe[1];
+ pthread_atfork(atfork_prepare, atfork_parent,
+ atfork_child);
+ start_services = true;
+#else
+ pid_t pid;
+ struct tfork *t = NULL;
+ t = tfork_create();
+ if (t == NULL) {
+ exit_daemon(
+ "Samba unable to fork master process",
+ 0);
+ }
+ pid = tfork_child_pid(t);
+ if (pid == 0) {
+ start_services = false;
+ } else {
+ /* In the child process */
+ start_services = true;
+ close(child_pipe[1]);
+ }
+#endif
+ if (start_services) {
+ status = server_service_startup(
+ state->event_ctx, cmdline_lp_ctx, model,
+ lpcfg_server_services(cmdline_lp_ctx),
+ child_pipe[0]);
+ if (!NT_STATUS_IS_OK(status)) {
+ TALLOC_FREE(state);
+ exit_daemon("Samba failed to start services",
+ NT_STATUS_V(status));
+ }
+ }
}
if (opt_daemon) {