diff options
Diffstat (limited to 'contrib/dma/dma-mbox-create.c')
-rw-r--r-- | contrib/dma/dma-mbox-create.c | 160 |
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); +} |