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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 12:06:34 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 12:06:34 +0000
commit5e61585d76ae77fd5e9e96ebabb57afa4d74880d (patch)
tree2b467823aaeebc7ef8bc9e3cabe8074eaef1666d /src/util/fifo_trigger.c
parentInitial commit. (diff)
downloadpostfix-5b7b6342ca8708be5ee306c089f8c5b3d3d122d8.tar.xz
postfix-5b7b6342ca8708be5ee306c089f8c5b3d3d122d8.zip
Adding upstream version 3.5.24.upstream/3.5.24upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/util/fifo_trigger.c')
-rw-r--r--src/util/fifo_trigger.c168
1 files changed, 168 insertions, 0 deletions
diff --git a/src/util/fifo_trigger.c b/src/util/fifo_trigger.c
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+/*++
+/* NAME
+/* fifo_trigger 3
+/* SUMMARY
+/* wakeup fifo server
+/* SYNOPSIS
+/* #include <trigger.h>
+/*
+/* int fifo_trigger(service, buf, len, timeout)
+/* const char *service;
+/* const char *buf;
+/* ssize_t len;
+/* int timeout;
+/* DESCRIPTION
+/* fifo_trigger() wakes up the named fifo server by writing
+/* the contents of the specified buffer to the fifo. There is
+/* no guarantee that the written data will actually be received.
+/*
+/* Arguments:
+/* .IP service
+/* Name of the communication endpoint.
+/* .IP buf
+/* Address of data to be written.
+/* .IP len
+/* Amount of data to be written.
+/* .IP timeout
+/* Deadline in seconds. Specify a value <= 0 to disable
+/* the time limit.
+/* DIAGNOSTICS
+/* The result is zero when the fifo could be opened, -1 otherwise.
+/* BUGS
+/* 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
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <iostuff.h>
+#include <safe_open.h>
+#include <trigger.h>
+
+/* fifo_trigger - wakeup fifo server */
+
+int fifo_trigger(const char *service, const char *buf, ssize_t len, int timeout)
+{
+ static VSTRING *why;
+ const char *myname = "fifo_trigger";
+ VSTREAM *fp;
+ int fd;
+
+ if (why == 0)
+ why = vstring_alloc(1);
+
+ /*
+ * Write the request to the service fifo. According to POSIX, the open
+ * shall always return immediately, and shall return an error when no
+ * process is reading from the FIFO.
+ *
+ * Use safe_open() so that we don't follow symlinks, and so that we don't
+ * open files with multiple hard links. We're not (yet) going to bother
+ * the caller with safe_open() specific quirks such as the why argument.
+ */
+ if ((fp = safe_open(service, O_WRONLY | O_NONBLOCK, 0,
+ (struct stat *) 0, -1, -1, why)) == 0) {
+ if (msg_verbose)
+ msg_info("%s: open %s: %s", myname, service, vstring_str(why));
+ return (-1);
+ }
+ fd = vstream_fileno(fp);
+
+ /*
+ * Write the request...
+ */
+ non_blocking(fd, timeout > 0 ? NON_BLOCKING : BLOCKING);
+ if (write_buf(fd, buf, len, timeout) < 0)
+ if (msg_verbose)
+ msg_warn("%s: write %s: %m", myname, service);
+
+ /*
+ * Disconnect.
+ */
+ if (vstream_fclose(fp))
+ if (msg_verbose)
+ msg_warn("%s: close %s: %m", myname, service);
+ return (0);
+}
+
+#ifdef TEST
+
+ /*
+ * Set up a FIFO listener, and keep triggering until the listener becomes
+ * idle, which should never happen.
+ */
+#include <signal.h>
+#include <stdlib.h>
+
+#include "events.h"
+#include "listen.h"
+
+#define TEST_FIFO "test-fifo"
+
+int trig_count;
+int wakeup_count;
+
+static void cleanup(void)
+{
+ unlink(TEST_FIFO);
+ exit(1);
+}
+
+static void handler(int sig)
+{
+ msg_fatal("got signal %d after %d triggers %d wakeups",
+ sig, trig_count, wakeup_count);
+}
+
+static void read_event(int unused_event, char *context)
+{
+ int fd = CAST_ANY_PTR_TO_INT(context);
+ char ch;
+
+ wakeup_count++;
+
+ if (read(fd, &ch, 1) != 1)
+ msg_fatal("read %s: %m", TEST_FIFO);
+}
+
+int main(int unused_argc, char **unused_argv)
+{
+ int listen_fd;
+
+ listen_fd = fifo_listen(TEST_FIFO, 0600, NON_BLOCKING);
+ msg_cleanup(cleanup);
+ event_enable_read(listen_fd, read_event, CAST_INT_TO_VOID_PTR(listen_fd));
+ signal(SIGINT, handler);
+ signal(SIGALRM, handler);
+ for (;;) {
+ alarm(10);
+ if (fifo_trigger(TEST_FIFO, "", 1, 0) < 0)
+ msg_fatal("trigger %s: %m", TEST_FIFO);
+ trig_count++;
+ if (fifo_trigger(TEST_FIFO, "", 1, 0) < 0)
+ msg_fatal("trigger %s: %m", TEST_FIFO);
+ trig_count++;
+ if (fifo_trigger(TEST_FIFO, "", 1, 0) < 0)
+ msg_fatal("trigger %s: %m", TEST_FIFO);
+ trig_count++;
+ event_loop(-1);
+ event_loop(-1);
+ event_loop(-1);
+ }
+}
+
+#endif