Adding upstream version 3.5.24.upstream/3.5.24

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

1 files changed, 619 insertions, 0 deletions

diff --git a/src/global/mail_stream.c b/src/global/mail_stream.c
new file mode 100644
index 0000000..a98d3ad
--- /dev/null
+++ b/src/global/mail_stream.c
@@ -0,0 +1,619 @@
+/*++
+/* NAME
+/*	mail_stream 3
+/* SUMMARY
+/*	mail stream management
+/* SYNOPSIS
+/*	#include <mail_stream.h>
+/*
+/*	typedef struct {
+/* .in +4
+/*		VSTREAM	*stream;	/* read/write stream */
+/*		char	*id;		/* queue ID */
+/*		struct timeval ctime;	/* create time */
+/*		private members...
+/* .in -4
+/*	} MAIL_STREAM;
+/*
+/*	MAIL_STREAM *mail_stream_file(queue, class, service, mode)
+/*	const char *queue;
+/*	const char *class;
+/*	const char *service;
+/*	int	mode;
+/*
+/*	MAIL_STREAM *mail_stream_service(class, service)
+/*	const char *class;
+/*	const char *service;
+/*
+/*	MAIL_STREAM *mail_stream_command(command)
+/*	const char *command;
+/*
+/*	void	mail_stream_cleanup(info)
+/*	MAIL_STREAM *info;
+/*
+/*	int	mail_stream_finish(info, why)
+/*	MAIL_STREAM *info;
+/*	VSTRING	*why;
+/*
+/*	void	mail_stream_ctl(info, op, ...)
+/*	MAIL_STREAM *info;
+/*	int	op;
+/* DESCRIPTION
+/*	This module provides a generic interface to Postfix queue file
+/*	format messages to file, to Postfix server, or to external command.
+/*	The routines that open a stream return a handle with an initialized
+/*	stream and queue id member. The handle is either given to a cleanup
+/*	routine, to dispose of a failed request, or to a finish routine, to
+/*	complete the request.
+/*
+/*	mail_stream_file() opens a mail stream to a newly-created file and
+/*	arranges for trigger delivery at finish time. This call never fails.
+/*	But it may take forever. The mode argument specifies additional
+/*	file permissions that will be OR-ed in when the file is finished.
+/*	While embryonic files have mode 0600, finished files have mode 0700.
+/*
+/*	mail_stream_command() opens a mail stream to external command,
+/*	and receives queue ID information from the command. The result
+/*	is a null pointer when the initial handshake fails. The command
+/*	is given to the shell only when necessary. At finish time, the
+/*	command is expected to send a completion status.
+/*
+/*	mail_stream_service() opens a mail stream to Postfix service,
+/*	and receives queue ID information from the command. The result
+/*	is a null pointer when the initial handshake fails. At finish
+/*	time, the daemon is expected to send a completion status.
+/*
+/*	mail_stream_cleanup() cancels the operation that was started with
+/*	any of the mail_stream_xxx() routines, and destroys the argument.
+/*	It is up to the caller to remove incomplete file objects.
+/*
+/*	mail_stream_finish() completes the operation that was started with
+/*	any of the mail_stream_xxx() routines, and destroys the argument.
+/*	The result is any of the status codes defined in <cleanup_user.h>.
+/*	It is up to the caller to remove incomplete file objects.
+/*	The why argument can be a null pointer.
+/*
+/*	mail_stream_ctl() selectively overrides information that
+/*	was specified with mail_stream_file(); none of the attributes
+/*	are applicable for other mail stream types.  The arguments
+/*	are a list macros with arguments, terminated with
+/*	CA_MAIL_STREAM_CTL_END which has none.  The following lists
+/*	the macros and the types of the corresponding arguments.
+/* .IP "CA_MAIL_STREAM_CTL_QUEUE(const char *)"
+/*	The argument specifies an alternate destination queue. The
+/*	queue file is moved to the specified queue before the call
+/*	returns. Failure to rename the queue file results in a fatal
+/*	error.
+/* .IP "CA_MAIL_STREAM_CTL_CLASS(const char *)"
+/*	The argument specifies an alternate trigger class.
+/* .IP "CA_MAIL_STREAM_CTL_SERVICE(const char *)"
+/*	The argument specifies an alternate trigger service.
+/* .IP "CA_MAIL_STREAM_CTL_MODE(int)"
+/*	The argument specifies alternate permissions that override
+/*	the permissions specified with mail_stream_file().
+/* .IP "CA_MAIL_STREAM_CTL_DELAY(int)"
+/*	Attempt to postpone initial delivery by advancing the queue
+/*	file modification time stamp by this amount.  This has
+/*	effect only within the deferred mail queue.
+/*	This feature may have no effect with remote file systems.
+/* 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 <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+#include <utime.h>
+#include <string.h>
+#include <stdarg.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+#include <vstring.h>
+#include <vstream.h>
+#include <stringops.h>
+#include <argv.h>
+#include <sane_fsops.h>
+#include <warn_stat.h>
+
+/* Global library. */
+
+#include <cleanup_user.h>
+#include <mail_proto.h>
+#include <mail_queue.h>
+#include <opened.h>
+#include <mail_params.h>
+#include <mail_stream.h>
+#include <mail_parm_split.h>
+
+/* Application-specific. */
+
+static VSTRING *id_buf;
+
+#define FREE_AND_WIPE(free, arg) do { if (arg) free(arg); arg = 0; } while (0)
+
+#define STR(x)	vstring_str(x)
+
+/* mail_stream_cleanup - clean up after success or failure */
+
+void    mail_stream_cleanup(MAIL_STREAM *info)
+{
+    FREE_AND_WIPE(info->close, info->stream);
+    FREE_AND_WIPE(myfree, info->queue);
+    FREE_AND_WIPE(myfree, info->id);
+    FREE_AND_WIPE(myfree, info->class);
+    FREE_AND_WIPE(myfree, info->service);
+    myfree((void *) info);
+}
+
+#if defined(HAS_FUTIMES_AT)
+#define CAN_STAMP_BY_STREAM
+
+/* stamp_stream - update open file [am]time stamp */
+
+static int stamp_stream(VSTREAM *fp, time_t when)
+{
+    struct timeval tv[2];
+
+    if (when != 0) {
+	tv[0].tv_sec = tv[1].tv_sec = when;
+	tv[0].tv_usec = tv[1].tv_usec = 0;
+	return (futimesat(vstream_fileno(fp), (char *) 0, tv));
+    } else {
+	return (futimesat(vstream_fileno(fp), (char *) 0, (struct timeval *) 0));
+    }
+}
+
+#elif defined(HAS_FUTIMES)
+#define CAN_STAMP_BY_STREAM
+
+/* stamp_stream - update open file [am]time stamp */
+
+static int stamp_stream(VSTREAM *fp, time_t when)
+{
+    struct timeval tv[2];
+
+    if (when != 0) {
+	tv[0].tv_sec = tv[1].tv_sec = when;
+	tv[0].tv_usec = tv[1].tv_usec = 0;
+	return (futimes(vstream_fileno(fp), tv));
+    } else {
+	return (futimes(vstream_fileno(fp), (struct timeval *) 0));
+    }
+}
+
+#endif
+
+/* stamp_path - update file [am]time stamp by pathname */
+
+static int stamp_path(const char *path, time_t when)
+{
+    struct utimbuf tbuf;
+
+    if (when != 0) {
+	tbuf.actime = tbuf.modtime = when;
+	return (utime(path, &tbuf));
+    } else {
+	return (utime(path, (struct utimbuf *) 0));
+    }
+}
+
+/* mail_stream_finish_file - finish file mail stream */
+
+static int mail_stream_finish_file(MAIL_STREAM *info, VSTRING *unused_why)
+{
+    int     status = CLEANUP_STAT_OK;
+    static char wakeup[] = {TRIGGER_REQ_WAKEUP};
+    struct stat st;
+    char   *path_to_reset = 0;
+    static int incoming_fs_clock_ok = 0;
+    static int incoming_clock_warned = 0;
+    int     check_incoming_fs_clock;
+    int     err;
+    time_t  want_stamp;
+    time_t  expect_stamp;
+
+    /*
+     * Make sure the message makes it to file. Set the execute bit when no
+     * write error was detected. Some people believe that this code has a
+     * problem if the system crashes before fsync() returns; fchmod() could
+     * take effect before all the data blocks are written. Wietse claims that
+     * this is not a problem. Postfix rejects incomplete queue files, even
+     * when the +x attribute is set. Every Postfix queue file record has a
+     * type code and a length field. Files with missing records are rejected,
+     * as are files with unknown record type codes. Every Postfix queue file
+     * must end with an explicit END record. Postfix queue files without END
+     * record are discarded.
+     * 
+     * Attempt to detect file system clocks that are ahead of local time, but
+     * don't check the file system clock all the time. The effect of file
+     * system clock drift can be difficult to understand (Postfix ignores new
+     * mail until the local clock catches up with the file mtime stamp).
+     * 
+     * This clock drift detection code may not work with file systems that work
+     * on a local copy of the file and that update the server only after the
+     * file is closed.
+     * 
+     * Optionally set a cooldown time.
+     * 
+     * XXX: We assume that utime() does control the file modification time even
+     * when followed by an fchmod(), fsync(), close() sequence. This may fail
+     * with remote file systems when fsync() actually updates the file. Even
+     * then, we still delay the average message by 1/2 of the
+     * queue_run_delay.
+     * 
+     * XXX: Victor does not like running utime() after the close(), since this
+     * creates a race even with local filesystems. But Wietse is not
+     * confident that utime() before fsync() and close() will work reliably
+     * with remote file systems.
+     * 
+     * XXX Don't run the clock skew tests with Postfix sendmail submissions.
+     * Don't whine against unsuspecting users or applications.
+     */
+    check_incoming_fs_clock =
+	(!incoming_fs_clock_ok && !strcmp(info->queue, MAIL_QUEUE_INCOMING));
+
+#ifdef DELAY_ACTION
+    if (strcmp(info->queue, MAIL_QUEUE_DEFERRED) != 0)
+	info->delay = 0;
+    if (info->delay > 0)
+	want_stamp = time((time_t *) 0) + info->delay;
+    else
+#endif
+	want_stamp = 0;
+
+    /*
+     * If we can cheaply set the file time stamp (no pathname lookup) do it
+     * anyway, so that we can avoid whining later about file server/client
+     * clock skew.
+     * 
+     * Otherwise, if we must set the file time stamp for delayed delivery, use
+     * whatever means we have to get the job done, no matter if it is
+     * expensive.
+     * 
+     * XXX Unfortunately, Linux futimes() is not usable because it uses /proc.
+     * This may not be available because of chroot, or because of access
+     * restrictions after a process changes privileges.
+     */
+    if (vstream_fflush(info->stream)
+#ifdef CAN_STAMP_BY_STREAM
+	|| stamp_stream(info->stream, want_stamp)
+#else
+	|| (want_stamp && stamp_path(VSTREAM_PATH(info->stream), want_stamp))
+#endif
+	|| fchmod(vstream_fileno(info->stream), 0700 | info->mode)
+#ifdef HAS_FSYNC
+	|| fsync(vstream_fileno(info->stream))
+#endif
+	|| (check_incoming_fs_clock
+	    && fstat(vstream_fileno(info->stream), &st) < 0)
+	)
+	status = (errno == EFBIG ? CLEANUP_STAT_SIZE : CLEANUP_STAT_WRITE);
+#ifdef TEST
+    st.st_mtime += 10;
+#endif
+
+    /*
+     * Work around file system clock skew. If the file system clock is ahead
+     * of the local clock, Postfix won't deliver mail immediately, which is
+     * bad for performance. If the file system clock falls behind the local
+     * clock, it just looks silly in mail headers.
+     */
+    if (status == CLEANUP_STAT_OK && check_incoming_fs_clock) {
+	/* Do NOT use time() result from before fsync(). */
+	expect_stamp = want_stamp ? want_stamp : time((time_t *) 0);
+	if (st.st_mtime > expect_stamp) {
+	    path_to_reset = mystrdup(VSTREAM_PATH(info->stream));
+	    if (incoming_clock_warned == 0) {
+		msg_warn("file system clock is %d seconds ahead of local clock",
+			 (int) (st.st_mtime - expect_stamp));
+		msg_warn("resetting file time stamps - this hurts performance");
+		incoming_clock_warned = 1;
+	    }
+	} else {
+	    if (st.st_mtime < expect_stamp - 100)
+		msg_warn("file system clock is %d seconds behind local clock",
+			 (int) (expect_stamp - st.st_mtime));
+	    incoming_fs_clock_ok = 1;
+	}
+    }
+
+    /*
+     * Close the queue file and mark it as closed. Be prepared for
+     * vstream_fclose() to fail even after vstream_fflush() and fsync()
+     * reported no error. Reason: after a file is closed, some networked file
+     * systems copy the file out to another machine. Running the queue on a
+     * remote file system is not recommended, if only for performance
+     * reasons.
+     */
+    err = info->close(info->stream);
+    info->stream = 0;
+    if (status == CLEANUP_STAT_OK && err != 0)
+	status = (errno == EFBIG ? CLEANUP_STAT_SIZE : CLEANUP_STAT_WRITE);
+
+    /*
+     * Work around file system clocks that are ahead of local time.
+     */
+    if (path_to_reset != 0) {
+	if (status == CLEANUP_STAT_OK) {
+	    if (stamp_path(path_to_reset, expect_stamp) < 0 && errno != ENOENT)
+		msg_fatal("%s: update file time stamps: %m", info->id);
+	}
+	myfree(path_to_reset);
+    }
+
+    /*
+     * When all is well, notify the next service that a new message has been
+     * queued.
+     */
+    if (status == CLEANUP_STAT_OK && info->class && info->service)
+	mail_trigger(info->class, info->service, wakeup, sizeof(wakeup));
+
+    /*
+     * Cleanup.
+     */
+    mail_stream_cleanup(info);
+    return (status);
+}
+
+/* mail_stream_finish_ipc - finish IPC mail stream */
+
+static int mail_stream_finish_ipc(MAIL_STREAM *info, VSTRING *why)
+{
+    int     status = CLEANUP_STAT_WRITE;
+
+    /*
+     * Receive the peer's completion status.
+     */
+    if ((why && attr_scan(info->stream, ATTR_FLAG_STRICT,
+			  RECV_ATTR_INT(MAIL_ATTR_STATUS, &status),
+			  RECV_ATTR_STR(MAIL_ATTR_WHY, why),
+			  ATTR_TYPE_END) != 2)
+	|| (!why && attr_scan(info->stream, ATTR_FLAG_MISSING,
+			      RECV_ATTR_INT(MAIL_ATTR_STATUS, &status),
+			      ATTR_TYPE_END) != 1))
+	status = CLEANUP_STAT_WRITE;
+
+    /*
+     * Cleanup.
+     */
+    mail_stream_cleanup(info);
+    return (status);
+}
+
+/* mail_stream_finish - finish action */
+
+int     mail_stream_finish(MAIL_STREAM *info, VSTRING *why)
+{
+    return (info->finish(info, why));
+}
+
+/* mail_stream_file - destination is file */
+
+MAIL_STREAM *mail_stream_file(const char *queue, const char *class,
+			              const char *service, int mode)
+{
+    struct timeval tv;
+    MAIL_STREAM *info;
+    VSTREAM *stream;
+
+    stream = mail_queue_enter(queue, 0600 | mode, &tv);
+    if (msg_verbose)
+	msg_info("open %s", VSTREAM_PATH(stream));
+
+    info = (MAIL_STREAM *) mymalloc(sizeof(*info));
+    info->stream = stream;
+    info->finish = mail_stream_finish_file;
+    info->close = vstream_fclose;
+    info->queue = mystrdup(queue);
+    info->id = mystrdup(basename(VSTREAM_PATH(stream)));
+    info->class = mystrdup(class);
+    info->service = mystrdup(service);
+    info->mode = mode;
+#ifdef DELAY_ACTION
+    info->delay = 0;
+#endif
+    info->ctime = tv;
+    return (info);
+}
+
+/* mail_stream_service - destination is service */
+
+MAIL_STREAM *mail_stream_service(const char *class, const char *name)
+{
+    VSTREAM *stream;
+    MAIL_STREAM *info;
+
+    if (id_buf == 0)
+	id_buf = vstring_alloc(10);
+
+    stream = mail_connect_wait(class, name);
+    if (attr_scan(stream, ATTR_FLAG_MISSING,
+		  RECV_ATTR_STR(MAIL_ATTR_QUEUEID, id_buf), 0) != 1) {
+	vstream_fclose(stream);
+	return (0);
+    } else {
+	info = (MAIL_STREAM *) mymalloc(sizeof(*info));
+	info->stream = stream;
+	info->finish = mail_stream_finish_ipc;
+	info->close = vstream_fclose;
+	info->queue = 0;
+	info->id = mystrdup(vstring_str(id_buf));
+	info->class = 0;
+	info->service = 0;
+	return (info);
+    }
+}
+
+/* mail_stream_command - destination is command */
+
+MAIL_STREAM *mail_stream_command(const char *command)
+{
+    VSTREAM *stream;
+    MAIL_STREAM *info;
+    ARGV   *export_env;
+    int     status;
+
+    if (id_buf == 0)
+	id_buf = vstring_alloc(10);
+
+    /*
+     * Treat fork() failure as a transient problem. Treat bad handshake as a
+     * permanent error.
+     * 
+     * XXX Are we invoking a Postfix process or a non-Postfix process? In the
+     * former case we can share the full environment; in the latter case only
+     * a restricted environment should be propagated. Even though we are
+     * talking a Postfix-internal protocol there is no way we can tell what
+     * is being executed except by duplicating a lot of existing code.
+     */
+    export_env = mail_parm_split(VAR_EXPORT_ENVIRON, var_export_environ);
+    while ((stream = vstream_popen(O_RDWR,
+				   CA_VSTREAM_POPEN_COMMAND(command),
+				   CA_VSTREAM_POPEN_EXPORT(export_env->argv),
+				   CA_VSTREAM_POPEN_END)) == 0) {
+	msg_warn("fork: %m");
+	sleep(10);
+    }
+    argv_free(export_env);
+    vstream_control(stream,
+		    CA_VSTREAM_CTL_PATH(command),
+		    CA_VSTREAM_CTL_END);
+
+    if (attr_scan(stream, ATTR_FLAG_MISSING,
+		  RECV_ATTR_STR(MAIL_ATTR_QUEUEID, id_buf), 0) != 1) {
+	if ((status = vstream_pclose(stream)) != 0)
+	    msg_warn("command \"%s\" exited with status %d", command, status);
+	return (0);
+    } else {
+	info = (MAIL_STREAM *) mymalloc(sizeof(*info));
+	info->stream = stream;
+	info->finish = mail_stream_finish_ipc;
+	info->close = vstream_pclose;
+	info->queue = 0;
+	info->id = mystrdup(vstring_str(id_buf));
+	info->class = 0;
+	info->service = 0;
+	return (info);
+    }
+}
+
+/* mail_stream_ctl - update file-based mail stream properties */
+
+void    mail_stream_ctl(MAIL_STREAM *info, int op,...)
+{
+    const char *myname = "mail_stream_ctl";
+    va_list ap;
+    char   *new_queue = 0;
+    char   *string_value;
+
+    /*
+     * Sanity check. None of the attributes below are applicable unless the
+     * target is a file-based stream.
+     */
+    if (info->finish != mail_stream_finish_file)
+	msg_panic("%s: attempt to update non-file stream %s",
+		  myname, info->id);
+
+    for (va_start(ap, op); op != MAIL_STREAM_CTL_END; op = va_arg(ap, int)) {
+
+	switch (op) {
+
+	    /*
+	     * Change the queue directory. We do this at the end of this
+	     * call.
+	     */
+	case MAIL_STREAM_CTL_QUEUE:
+	    if ((new_queue = va_arg(ap, char *)) == 0)
+		msg_panic("%s: NULL queue",
+			  myname);
+	    break;
+
+	    /*
+	     * Change the service that needs to be notified.
+	     */
+	case MAIL_STREAM_CTL_CLASS:
+	    FREE_AND_WIPE(myfree, info->class);
+	    if ((string_value = va_arg(ap, char *)) != 0)
+		info->class = mystrdup(string_value);
+	    break;
+
+	case MAIL_STREAM_CTL_SERVICE:
+	    FREE_AND_WIPE(myfree, info->service);
+	    if ((string_value = va_arg(ap, char *)) != 0)
+		info->service = mystrdup(string_value);
+	    break;
+
+	    /*
+	     * Change the (finished) file access mode.
+	     */
+	case MAIL_STREAM_CTL_MODE:
+	    info->mode = va_arg(ap, int);
+	    break;
+
+	    /*
+	     * Advance the (finished) file modification time.
+	     */
+#ifdef DELAY_ACTION
+	case MAIL_STREAM_CTL_DELAY:
+	    if ((info->delay = va_arg(ap, int)) < 0)
+		msg_panic("%s: bad delay time %d", myname, info->delay);
+	    break;
+#endif
+
+	default:
+	    msg_panic("%s: bad op code %d", myname, op);
+	}
+    }
+    va_end(ap);
+
+    /*
+     * Rename the queue file after allocating memory for new information, so
+     * that the caller can still remove an embryonic file when memory
+     * allocation fails (there is no risk of deleting the wrong file).
+     * 
+     * Wietse opposed the idea to update run-time error handler information
+     * here, because this module wasn't designed to defend against internal
+     * concurrency issues with error handlers that attempt to follow dangling
+     * pointers.
+     * 
+     * This code duplicates mail_queue_rename(), except that we need the new
+     * path to update the stream pathname.
+     */
+    if (new_queue != 0 && strcmp(info->queue, new_queue) != 0) {
+	char   *saved_queue = info->queue;
+	char   *saved_path = mystrdup(VSTREAM_PATH(info->stream));
+	VSTRING *new_path = vstring_alloc(100);
+
+	(void) mail_queue_path(new_path, new_queue, info->id);
+	info->queue = mystrdup(new_queue);
+	vstream_control(info->stream, CA_VSTREAM_CTL_PATH(STR(new_path)),
+			CA_VSTREAM_CTL_END);
+
+	if (sane_rename(saved_path, STR(new_path)) == 0
+	    || (mail_queue_mkdirs(STR(new_path)) == 0
+		&& sane_rename(saved_path, STR(new_path)) == 0)) {
+	    if (msg_verbose)
+		msg_info("%s: placed in %s queue", info->id, info->queue);
+	} else {
+	    msg_fatal("%s: move to %s queue failed: %m", info->id,
+		      info->queue);
+	}
+
+	myfree(saved_path);
+	myfree(saved_queue);
+	vstring_free(new_path);
+    }
+}