From 95bd11720c8e88a1f65b9d600f50d71662241ba9 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Thu, 24 Aug 2023 13:53:33 +0300 Subject: [PATCH v2 1/1] Use FD_CLOEXEC on ListenSockets It's good hygiene if e.g. an extension launches a subprogram when being loaded. And we went through some effort to close them in the child process in EXEC_BACKEND mode; better to not hand them down to the child process in the first place. We still need to close them after fork when !EXEC_BACKEND, but it's a little simpler. In the passing, LOG a message if closing the client connection or listen socket fails. Shouldn't happen, but if it does, would be nice to know. Reviewed-by: Tristan Partin, Andres Freund Discussion: https://www.postgresql.org/message-id/7a59b073-5b5b-151e-7ed3-8b01ff7ce9ef@iki.fi --- src/backend/libpq/pqcomm.c | 6 +++++- src/backend/postmaster/postmaster.c | 14 ++++++-------- 2 files changed, 11 insertions(+), 9 deletions(-) diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c index 1bdcbe4f636..8d217b06455 100644 --- a/src/backend/libpq/pqcomm.c +++ b/src/backend/libpq/pqcomm.c @@ -458,6 +458,9 @@ StreamServerPort(int family, const char *hostName, unsigned short portNumber, } #ifndef WIN32 + /* Don't give the listen socket to any subprograms we execute. */ + if (fcntl(fd, F_SETFD, FD_CLOEXEC) < 0) + elog(FATAL, "fcntl(F_SETFD) failed on socket: %m"); /* * Without the SO_REUSEADDR flag, a new postmaster can't be started @@ -831,7 +834,8 @@ StreamConnection(pgsocket server_fd, Port *port) void StreamClose(pgsocket sock) { - closesocket(sock); + if (closesocket(sock) != 0) + elog(LOG, "could not close client or listen socket: %m"); } /* diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 07d376d77ec..41bccb46a87 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -496,7 +496,6 @@ typedef struct Port port; InheritableSocket portsocket; char DataDir[MAXPGPATH]; - pgsocket ListenSocket[MAXLISTEN]; int32 MyCancelKey; int MyPMChildSlot; #ifndef WIN32 @@ -2545,8 +2544,6 @@ ConnFree(Port *port) void ClosePostmasterPorts(bool am_syslogger) { - int i; - /* Release resources held by the postmaster's WaitEventSet. */ if (pm_wait_set) { @@ -2573,8 +2570,12 @@ ClosePostmasterPorts(bool am_syslogger) /* * Close the postmaster's listen sockets. These aren't tracked by fd.c, * so we don't call ReleaseExternalFD() here. + * + * The listen sockets are marked as FD_CLOEXEC, so this isn't needed in + * EXEC_BACKEND mode. */ - for (i = 0; i < MAXLISTEN; i++) +#ifndef EXEC_BACKEND + for (int i = 0; i < MAXLISTEN; i++) { if (ListenSocket[i] != PGINVALID_SOCKET) { @@ -2582,6 +2583,7 @@ ClosePostmasterPorts(bool am_syslogger) ListenSocket[i] = PGINVALID_SOCKET; } } +#endif /* * If using syslogger, close the read side of the pipe. We don't bother @@ -6038,8 +6040,6 @@ save_backend_variables(BackendParameters *param, Port *port, strlcpy(param->DataDir, DataDir, MAXPGPATH); - memcpy(¶m->ListenSocket, &ListenSocket, sizeof(ListenSocket)); - param->MyCancelKey = MyCancelKey; param->MyPMChildSlot = MyPMChildSlot; @@ -6271,8 +6271,6 @@ restore_backend_variables(BackendParameters *param, Port *port) SetDataDir(param->DataDir); - memcpy(&ListenSocket, ¶m->ListenSocket, sizeof(ListenSocket)); - MyCancelKey = param->MyCancelKey; MyPMChildSlot = param->MyPMChildSlot; -- 2.39.2