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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/util/fifo_rdonly_bug.c
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/util/fifo_rdonly_bug.c')
-rw-r--r--src/util/fifo_rdonly_bug.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/src/util/fifo_rdonly_bug.c b/src/util/fifo_rdonly_bug.c
new file mode 100644
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--- /dev/null
+++ b/src/util/fifo_rdonly_bug.c
@@ -0,0 +1,127 @@
+/*++
+/* NAME
+/* fifo_rdonly_bug 1
+/* SUMMARY
+/* fifo server test program
+/* SYNOPSIS
+/* fifo_rdonly_bug
+/* DESCRIPTION
+/* fifo_rdonly_bug creates a FIFO and opens it read only. It
+/* then opens the FIFO for writing, writes one byte, and closes
+/* the writing end. On Linux Redhat 4.2 and 5.0, and HP-UX 9.05
+/* and 10.20, select() will report that the FIFO remains readable
+/* even after multiple read operations.
+/* DIAGNOSTICS
+/* Problems are reported to the standard error stream.
+/* 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
+/*--*/
+
+#include <sys_defs.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <string.h>
+
+#define FIFO_PATH "test-fifo"
+#define TRIGGER_DELAY 5
+
+#define perrorexit(s) { perror(s); exit(1); }
+
+static void cleanup(void)
+{
+ printf("Removing fifo %s...\n", FIFO_PATH);
+ if (unlink(FIFO_PATH))
+ perrorexit("unlink");
+ printf("Done.\n");
+}
+
+static void perrorcleanup(char *str)
+{
+ perror(str);
+ cleanup();
+ exit(0);
+}
+
+static void readable_event(int fd)
+{
+ char ch;
+ static int count = 0;
+
+ if (read(fd, &ch, 1) < 0) {
+ perror("read");
+ sleep(1);
+ }
+ if (count++ > 5) {
+ printf("FIFO remains readable after multiple reads.\n");
+ cleanup();
+ exit(1);
+ }
+}
+
+int main(int unused_argc, char **unused_argv)
+{
+ struct timeval tv;
+ fd_set read_fds;
+ fd_set except_fds;
+ int fd;
+ int fd2;
+
+ (void) unlink(FIFO_PATH);
+
+ printf("Create fifo %s...\n", FIFO_PATH);
+ if (mkfifo(FIFO_PATH, 0600) < 0)
+ perrorexit("mkfifo");
+
+ printf("Open fifo %s, read-only mode...\n", FIFO_PATH);
+ if ((fd = open(FIFO_PATH, O_RDONLY | O_NONBLOCK, 0)) < 0)
+ perrorcleanup("open");
+
+ printf("Write one byte to the fifo, then close it...\n");
+ if ((fd2 = open(FIFO_PATH, O_WRONLY, 0)) < 0)
+ perrorcleanup("open fifo O_WRONLY");
+ if (write(fd2, "", 1) < 1)
+ perrorcleanup("write one byte to fifo");
+ if (close(fd2) < 0)
+ perrorcleanup("close fifo");
+
+ printf("Selecting the fifo for readability...\n");
+
+ for (;;) {
+ FD_ZERO(&read_fds);
+ FD_SET(fd, &read_fds);
+ FD_ZERO(&except_fds);
+ FD_SET(fd, &except_fds);
+ tv.tv_sec = 1;
+ tv.tv_usec = 0;
+
+ switch (select(fd + 1, &read_fds, (fd_set *) 0, &except_fds, &tv)) {
+ case -1:
+ perrorexit("select");
+ default:
+ if (FD_ISSET(fd, &except_fds)) {
+ printf("Exceptional fifo condition! You are not normal!\n");
+ readable_event(fd);
+ } else if (FD_ISSET(fd, &read_fds)) {
+ printf("Readable fifo condition\n");
+ readable_event(fd);
+ }
+ break;
+ case 0:
+ printf("The fifo is not readable. You're normal.\n");
+ cleanup();
+ exit(0);
+ break;
+ }
+ }
+}