From c80f70390c3763d5d7248979db9542cd05b7cb44 Mon Sep 17 00:00:00 2001 From: Michael Adam Date: Thu, 15 Mar 2012 16:29:27 +0100 Subject: s3:smbd: let smbd/nmbd/winbindd child processes terminate if the parent process died. This applies to all child processes making use of reinit_after_fork(). It is implemented by establishing a pipe between parent and child. The child watches for EOF on the read end of the pipe, indidcating an exited parent. Pair-Programmed-With: Stefan Metzmacher --- source3/lib/util.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) (limited to 'source3/lib') diff --git a/source3/lib/util.c b/source3/lib/util.c index 822db43fef..fa2cc9fd83 100644 --- a/source3/lib/util.c +++ b/source3/lib/util.c @@ -356,6 +356,46 @@ ssize_t write_data_at_offset(int fd, const char *buffer, size_t N, SMB_OFF_T pos #endif } +static int reinit_after_fork_pipe[2] = { -1, -1 }; + +NTSTATUS init_before_fork(void) +{ + int ret; + + ret = pipe(reinit_after_fork_pipe); + if (ret == -1) { + NTSTATUS status; + + status = map_nt_error_from_unix_common(errno); + + DEBUG(0, ("Error creating child_pipe: %s\n", + nt_errstr(status))); + + return status; + } + + return NT_STATUS_OK; +} + +/** + * Detect died parent by detecting EOF on the pipe + */ +static void reinit_after_fork_pipe_handler(struct tevent_context *ev, + struct tevent_fd *fde, + uint16_t flags, + void *private_data) +{ + char c; + + if (read(reinit_after_fork_pipe[0], &c, 1) != 1) { + /* + * we have reached EOF on stdin, which means the + * parent has exited. Shutdown the server + */ + (void)kill(getpid(), SIGTERM); + } +} + NTSTATUS reinit_after_fork(struct messaging_context *msg_ctx, struct event_context *ev_ctx, @@ -363,6 +403,11 @@ NTSTATUS reinit_after_fork(struct messaging_context *msg_ctx, { NTSTATUS status = NT_STATUS_OK; + if (reinit_after_fork_pipe[1] != -1) { + close(reinit_after_fork_pipe[1]); + reinit_after_fork_pipe[1] = -1; + } + /* Reset the state of the random * number generation system, so * children do not get the same random @@ -380,6 +425,17 @@ NTSTATUS reinit_after_fork(struct messaging_context *msg_ctx, smb_panic(__location__ ": Failed to re-initialise event context"); } + if (reinit_after_fork_pipe[0] != -1) { + struct tevent_fd *fde; + + fde = tevent_add_fd(ev_ctx, ev_ctx /* TALLOC_CTX */, + reinit_after_fork_pipe[0], TEVENT_FD_READ, + reinit_after_fork_pipe_handler, NULL); + if (fde == NULL) { + smb_panic(__location__ ": Failed to add reinit_after_fork pipe event"); + } + } + if (msg_ctx) { /* * For clustering, we need to re-init our ctdbd connection after the -- cgit