Adding upstream version 3.4.23.upstream/3.4.23upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 193 insertions, 0 deletions

diff --git a/src/util/unix_send_fd.c b/src/util/unix_send_fd.c
new file mode 100644
index 0000000..1998a7c
--- /dev/null
+++ b/src/util/unix_send_fd.c
@@ -0,0 +1,193 @@
+/*++
+/* NAME
+/*	unix_send_fd 3
+/* SUMMARY
+/*	send file descriptor
+/* SYNOPSIS
+/*	#include <iostuff.h>
+/*
+/*	int	unix_send_fd(fd, sendfd)
+/*	int	fd;
+/*	int	sendfd;
+/* DESCRIPTION
+/*	unix_send_fd() sends a file descriptor over the specified
+/*	UNIX-domain socket.
+/*
+/*	Arguments:
+/* .IP fd
+/*	File descriptor that connects the sending and receiving processes.
+/* .IP sendfd
+/*	The file descriptor to be sent.
+/* DIAGNOSTICS
+/*	unix_send_fd() returns -1 upon failure.
+/* 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>			/* includes <sys/types.h> */
+#include <sys/socket.h>
+#include <sys/uio.h>
+#include <string.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <iostuff.h>
+
+/* unix_send_fd - send file descriptor */
+
+int     unix_send_fd(int fd, int sendfd)
+{
+
+    /*
+     * This code does not work with version <2.2 Linux kernels, and it does
+     * not compile with version <2 Linux libraries.
+     */
+#ifdef CANT_USE_SEND_RECV_MSG
+    const char *myname = "unix_send_fd";
+
+    msg_warn("%s: your system has no support for file descriptor passing",
+	     myname);
+    return (-1);
+#else
+    struct msghdr msg;
+    struct iovec iov[1];
+
+    /*
+     * Adapted from: W. Richard Stevens, UNIX Network Programming, Volume 1,
+     * Second edition. Except that we use CMSG_LEN instead of CMSG_SPACE, for
+     * portability to some LP64 environments. See also unix_recv_fd.c.
+     */
+#if defined(CMSG_SPACE) && !defined(NO_MSGHDR_MSG_CONTROL)
+    union {
+	struct cmsghdr just_for_alignment;
+	char    control[CMSG_SPACE(sizeof(sendfd))];
+    }       control_un;
+    struct cmsghdr *cmptr;
+
+    memset((void *) &msg, 0, sizeof(msg));	/* Fix 200512 */
+    msg.msg_control = control_un.control;
+    if (unix_pass_fd_fix & UNIX_PASS_FD_FIX_CMSG_LEN) {
+	msg.msg_controllen = CMSG_LEN(sizeof(sendfd));	/* Fix 200506 */
+    } else {
+	msg.msg_controllen = sizeof(control_un.control);	/* normal */
+    }
+    cmptr = CMSG_FIRSTHDR(&msg);
+    cmptr->cmsg_len = CMSG_LEN(sizeof(sendfd));
+    cmptr->cmsg_level = SOL_SOCKET;
+    cmptr->cmsg_type = SCM_RIGHTS;
+    *(int *) CMSG_DATA(cmptr) = sendfd;
+#else
+    msg.msg_accrights = (char *) &sendfd;
+    msg.msg_accrightslen = sizeof(sendfd);
+#endif
+
+    msg.msg_name = 0;
+    msg.msg_namelen = 0;
+
+    /*
+     * XXX We don't want to pass any data, just a file descriptor. However,
+     * setting msg.msg_iov = 0 and msg.msg_iovlen = 0 causes trouble. See the
+     * comments in the unix_recv_fd() routine.
+     */
+    iov->iov_base = "";
+    iov->iov_len = 1;
+    msg.msg_iov = iov;
+    msg.msg_iovlen = 1;
+
+    /*
+     * The CMSG_LEN send/receive workaround was originally developed for
+     * OpenBSD 3.6 on SPARC64. After the workaround was verified to not break
+     * Solaris 8 on SPARC64, it was hard-coded with Postfix 2.3 for all
+     * platforms because of increasing pressure to work on other things. The
+     * workaround does nothing for 32-bit systems.
+     * 
+     * The investigation was reopened with Postfix 2.7 because the workaround
+     * broke with NetBSD 5.0 on 64-bit architectures. This time it was found
+     * that OpenBSD <= 4.3 on AMD64 and SPARC64 needed the workaround for
+     * sending only. The following platforms worked with and without the
+     * workaround: OpenBSD 4.5 on AMD64 and SPARC64, FreeBSD 7.2 on AMD64,
+     * Solaris 8 on SPARC64, and Linux 2.6-11 on x86_64.
+     * 
+     * As this appears to have been an OpenBSD-specific problem, we revert to
+     * the Postfix 2.2 behavior. Instead of hard-coding the workaround for
+     * all platforms, we now detect sendmsg() errors at run time and turn on
+     * the workaround dynamically.
+     * 
+     * The workaround was made run-time configurable to investigate the problem
+     * on multiple platforms. Though set_unix_pass_fd_fix() is over-kill for
+     * this specific problem, it is left in place so that it can serve as an
+     * example of how to add run-time configurable workarounds to Postfix.
+     */
+    if (sendmsg(fd, &msg, 0) >= 0)
+	return (0);
+    if (unix_pass_fd_fix == 0) {
+	if (msg_verbose)
+	    msg_info("sendmsg error (%m). Trying CMSG_LEN workaround.");
+	unix_pass_fd_fix = UNIX_PASS_FD_FIX_CMSG_LEN;
+	return (unix_send_fd(fd, sendfd));
+    } else {
+	return (-1);
+    }
+#endif
+}
+
+#ifdef TEST
+
+ /*
+  * Proof-of-concept program. Open a file and send the descriptor, presumably
+  * to the unix_recv_fd test program.
+  */
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <split_at.h>
+#include <connect.h>
+
+int     main(int argc, char **argv)
+{
+    char   *transport;
+    char   *endpoint;
+    char   *path;
+    int     server_sock;
+    int     client_fd;
+
+    msg_verbose = 1;
+
+    if (argc < 3
+	|| (endpoint = split_at(transport = argv[1], ':')) == 0
+	|| *endpoint == 0 || *transport == 0)
+	msg_fatal("usage: %s transport:endpoint file...", argv[0]);
+
+    if (strcmp(transport, "unix") == 0) {
+	server_sock = unix_connect(endpoint, BLOCKING, 0);
+    } else {
+	msg_fatal("invalid transport name: %s", transport);
+    }
+    if (server_sock < 0)
+	msg_fatal("connect %s:%s: %m", transport, endpoint);
+
+    argv += 2;
+    while ((path = *argv++) != 0) {
+	if ((client_fd = open(path, O_RDONLY, 0)) < 0)
+	    msg_fatal("open %s: %m", path);
+	msg_info("path=%s fd=%d", path, client_fd);
+	if (unix_send_fd(server_sock, client_fd) < 0)
+	    msg_fatal("send file descriptor: %m");
+	if (close(client_fd) != 0)
+	    msg_fatal("close(%d): %m", client_fd);
+    }
+    exit(0);
+}
+
+#endif