Import Dragonfly Mail Agent into base system

It is a small and lightweight Mail Transport Agent.
It accepts mails from locally installed Mail User Agents (MUA) and delivers the
mails either locally or to a remote destination. Remote delivery includes
several features like TLS/SSL support, SMTP authentication and NULLCLIENT.

Make dma conditional to new WITHOUT_DMA option and make it respect WITHOUT_MAIL

Reviewed by:	peter
Discussed with:	emaste, bz, peter

1 files changed, 160 insertions, 0 deletions

diff --git a/contrib/dma/dma-mbox-create.c b/contrib/dma/dma-mbox-create.c
new file mode 100644
index 0000000..c84652b
--- /dev/null
+++ b/contrib/dma/dma-mbox-create.c
@@ -0,0 +1,160 @@
+/*
+ * Copyright (c) 2010 Simon Schubert <2@0x2c.org>
+ * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
+ *
+ * This code is derived from software contributed to The DragonFly Project
+ * by Simon 'corecode' Schubert <corecode@fs.ei.tum.de>.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name of The DragonFly Project nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific, prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * This binary is setuid root.  Use extreme caution when touching
+ * user-supplied information.  Keep the root window as small as possible.
+ */
+
+#include <sys/param.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <paths.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <syslog.h>
+#include <unistd.h>
+
+#include "dma.h"
+
+
+static void
+logfail(const char *fmt, ...)
+{
+	int oerrno = errno;
+	va_list ap;
+	char outs[1024];
+
+	outs[0] = 0;
+	if (fmt != NULL) {
+		va_start(ap, fmt);
+		vsnprintf(outs, sizeof(outs), fmt, ap);
+		va_end(ap);
+	}
+
+	errno = oerrno;
+	if (*outs != 0)
+		syslog(LOG_ERR, errno ? "%s: %m" : "%s", outs);
+	else
+		syslog(LOG_ERR, errno ? "%m" : "unknown error");
+
+	exit(1);
+}
+
+/*
+ * Create a mbox in /var/mail for a given user, or make sure
+ * the permissions are correct for dma.
+ */
+
+int
+main(int argc, char **argv)
+{
+	const char *user;
+	struct passwd *pw;
+	struct group *gr;
+	uid_t user_uid;
+	gid_t mail_gid;
+	int error;
+	char fn[PATH_MAX+1];
+	int f;
+
+	openlog("dma-mbox-create", 0, LOG_MAIL);
+
+	errno = 0;
+	gr = getgrnam(DMA_GROUP);
+	if (!gr)
+		logfail("cannot find dma group `%s'", DMA_GROUP);
+
+	mail_gid = gr->gr_gid;
+
+	if (setgid(mail_gid) != 0)
+		logfail("cannot set gid to %d (%s)", mail_gid, DMA_GROUP);
+	if (getegid() != mail_gid)
+		logfail("cannot set gid to %d (%s), still at %d", mail_gid, DMA_GROUP, getegid());
+
+	/*
+	 * We take exactly one argument: the username.
+	 */
+	if (argc != 2) {
+		errno = 0;
+		logfail("no arguments");
+	}
+	user = argv[1];
+
+	syslog(LOG_NOTICE, "creating mbox for `%s'", user);
+
+	/* the username may not contain a pathname separator */
+	if (strchr(user, '/')) {
+		errno = 0;
+		logfail("path separator in username `%s'", user);
+		exit(1);
+	}
+
+	/* verify the user exists */
+	errno = 0;
+	pw = getpwnam(user);
+	if (!pw)
+		logfail("cannot find user `%s'", user);
+
+	user_uid = pw->pw_uid;
+
+	error = snprintf(fn, sizeof(fn), "%s/%s", _PATH_MAILDIR, user);
+	if (error < 0 || (size_t)error >= sizeof(fn)) {
+		if (error >= 0) {
+			errno = 0;
+			logfail("mbox path too long");
+		}
+		logfail("cannot build mbox path for `%s/%s'", _PATH_MAILDIR, user);
+	}
+
+	f = open(fn, O_RDONLY|O_CREAT, 0600);
+	if (f < 0)
+		logfail("cannot open mbox `%s'", fn);
+
+	if (fchown(f, user_uid, mail_gid))
+		logfail("cannot change owner of mbox `%s'", fn);
+
+	if (fchmod(f, 0620))
+		logfail("cannot change permissions of mbox `%s'", fn);
+
+	/* file should be present with the right owner and permissions */
+
+	syslog(LOG_NOTICE, "successfully created mbox for `%s'", user);
+
+	return (0);
+}