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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:46:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:46:30 +0000
commitb5896ba9f6047e7031e2bdee0622d543e11a6734 (patch)
treefd7b460593a2fee1be579bec5697e6d887ea3421 /src/master/master_proto.h
parentInitial commit. (diff)
downloadpostfix-b5896ba9f6047e7031e2bdee0622d543e11a6734.tar.xz
postfix-b5896ba9f6047e7031e2bdee0622d543e11a6734.zip
Adding upstream version 3.4.23.upstream/3.4.23upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/master/master_proto.h')
-rw-r--r--src/master/master_proto.h75
1 files changed, 75 insertions, 0 deletions
diff --git a/src/master/master_proto.h b/src/master/master_proto.h
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+/*++
+/* NAME
+/* master_proto 3h
+/* SUMMARY
+/* master process protocol
+/* SYNOPSIS
+/* #include <master_proto.h>
+/* DESCRIPTION
+/* .nf
+
+ /*
+ * Transport names. The master passes the transport name on the command
+ * line, and thus the name is part of the master to child protocol.
+ */
+#define MASTER_XPORT_NAME_UNIX "unix" /* local IPC */
+#define MASTER_XPORT_NAME_FIFO "fifo" /* local IPC */
+#define MASTER_XPORT_NAME_INET "inet" /* non-local IPC */
+#define MASTER_XPORT_NAME_PASS "pass" /* local IPC */
+#define MASTER_XPORT_NAME_UXDG "unix-dgram" /* local IPC */
+
+ /*
+ * Format of a status message sent by a child process to the process
+ * manager. Since this is between processes on the same machine we need not
+ * worry about byte order and word length.
+ */
+typedef struct MASTER_STATUS {
+ int pid; /* process ID */
+ unsigned gen; /* child generation number */
+ int avail; /* availability */
+} MASTER_STATUS;
+
+#define MASTER_GEN_NAME "GENERATION" /* passed via environment */
+
+#define MASTER_STAT_TAKEN 0 /* this one is occupied */
+#define MASTER_STAT_AVAIL 1 /* this process is idle */
+
+extern int master_notify(int, unsigned, int); /* encapsulate status msg */
+
+ /*
+ * File descriptors inherited from the master process. The flow control pipe
+ * is read by receive processes and is written to by send processes. If
+ * receive processes get too far ahead they will pause for a brief moment.
+ */
+#define MASTER_FLOW_READ 3
+#define MASTER_FLOW_WRITE 4
+
+ /*
+ * File descriptors inherited from the master process. All processes that
+ * provide a given service share the same status file descriptor, and listen
+ * on the same service socket(s). The kernel decides what process gets the
+ * next connection. Usually the number of listening processes is small, so
+ * one connection will not cause a "thundering herd" effect. When no process
+ * listens on a given socket, the master process will. MASTER_LISTEN_FD is
+ * actually the lowest-numbered descriptor of a sequence of descriptors to
+ * listen on.
+ */
+#define MASTER_STATUS_FD 5 /* shared channel to parent */
+#define MASTER_LISTEN_FD 6 /* accept connections here */
+
+/* LICENSE
+/* .ad
+/* .fi
+/* The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/* Wietse Venema
+/* IBM T.J. Watson Research
+/* P.O. Box 704
+/* Yorktown Heights, NY 10598, USA
+/*
+/* Wietse Venema
+/* Google, Inc.
+/* 111 8th Avenue
+/* New York, NY 10011, USA
+/*--*/
+