/*-
* Copyright (c) 2010 The FreeBSD Foundation
* Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>
* All rights reserved.
*
* This software was developed by Pawel Jakub Dawidek under sponsorship from
* the FreeBSD Foundation.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/disk.h>
#include <sys/ioctl.h>
#include <sys/jail.h>
#include <sys/stat.h>
#ifdef HAVE_CAPSICUM
#include <sys/capsicum.h>
#include <geom/gate/g_gate.h>
#endif
#include <errno.h>
#include <fcntl.h>
#include <pwd.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <pjdlog.h>
#include "hast.h"
#include "subr.h"
int
vsnprlcat(char *str, size_t size, const char *fmt, va_list ap)
{
size_t len;
len = strlen(str);
return (vsnprintf(str + len, size - len, fmt, ap));
}
int
snprlcat(char *str, size_t size, const char *fmt, ...)
{
va_list ap;
int result;
va_start(ap, fmt);
result = vsnprlcat(str, size, fmt, ap);
va_end(ap);
return (result);
}
int
provinfo(struct hast_resource *res, bool dowrite)
{
struct stat sb;
PJDLOG_ASSERT(res->hr_localpath != NULL &&
res->hr_localpath[0] != '\0');
if (res->hr_localfd == -1) {
res->hr_localfd = open(res->hr_localpath,
dowrite ? O_RDWR : O_RDONLY);
if (res->hr_localfd == -1) {
pjdlog_errno(LOG_ERR, "Unable to open %s",
res->hr_localpath);
return (-1);
}
}
if (fstat(res->hr_localfd, &sb) == -1) {
pjdlog_errno(LOG_ERR, "Unable to stat %s", res->hr_localpath);
return (-1);
}
if (S_ISCHR(sb.st_mode)) {
/*
* If this is character device, it is most likely GEOM provider.
*/
if (ioctl(res->hr_localfd, DIOCGMEDIASIZE,
&res->hr_local_mediasize) == -1) {
pjdlog_errno(LOG_ERR,
"Unable obtain provider %s mediasize",
res->hr_localpath);
return (-1);
}
if (ioctl(res->hr_localfd, DIOCGSECTORSIZE,
&res->hr_local_sectorsize) == -1) {
pjdlog_errno(LOG_ERR,
"Unable obtain provider %s sectorsize",
res->hr_localpath);
return (-1);
}
} else if (S_ISREG(sb.st_mode)) {
/*
* We also support regular files for which we hardcode
* sector size of 512 bytes.
*/
res->hr_local_mediasize = sb.st_size;
res->hr_local_sectorsize = 512;
} else {
/*
* We support no other file types.
*/
pjdlog_error("%s is neither GEOM provider nor regular file.",
res->hr_localpath);
errno = EFTYPE;
return (-1);
}
return (0);
}
const char *
role2str(int role)
{
switch (role) {
case HAST_ROLE_INIT:
return ("init");
case HAST_ROLE_PRIMARY:
return ("primary");
case HAST_ROLE_SECONDARY:
return ("secondary");
}
return ("unknown");
}
int
drop_privs(const struct hast_resource *res)
{
char jailhost[sizeof(res->hr_name) * 2];
struct jail jailst;
struct passwd *pw;
uid_t ruid, euid, suid;
gid_t rgid, egid, sgid;
gid_t gidset[1];
bool capsicum, jailed;
/*
* According to getpwnam(3) we have to clear errno before calling the
* function to be able to distinguish between an error and missing
* entry (with is not treated as error by getpwnam(3)).
*/
errno = 0;
pw = getpwnam(HAST_USER);
if (pw == NULL) {
if (errno != 0) {
pjdlog_errno(LOG_ERR,
"Unable to find info about '%s' user", HAST_USER);
return (-1);
} else {
pjdlog_error("'%s' user doesn't exist.", HAST_USER);
errno = ENOENT;
return (-1);
}
}
bzero(&jailst, sizeof(jailst));
jailst.version = JAIL_API_VERSION;
jailst.path = pw->pw_dir;
if (res == NULL) {
(void)snprintf(jailhost, sizeof(jailhost), "hastctl");
} else {
(void)snprintf(jailhost, sizeof(jailhost), "hastd: %s (%s)",
res->hr_name, role2str(res->hr_role));
}
jailst.hostname = jailhost;
jailst.jailname = NULL;
jailst.ip4s = 0;
jailst.ip4 = NULL;
jailst.ip6s = 0;
jailst.ip6 = NULL;
if (jail(&jailst) >= 0) {
jailed = true;
} else {
jailed = false;
pjdlog_errno(LOG_WARNING,
"Unable to jail to directory to %s", pw->pw_dir);
if (chroot(pw->pw_dir) == -1) {
pjdlog_errno(LOG_ERR,
"Unable to change root directory to %s",
pw->pw_dir);
return (-1);
}
}
PJDLOG_VERIFY(chdir("/") == 0);
gidset[0] = pw->pw_gid;
if (setgroups(1, gidset) == -1) {
pjdlog_errno(LOG_ERR, "Unable to set groups to gid %u",
(unsigned int)pw->pw_gid);
return (-1);
}
if (setgid(pw->pw_gid) == -1) {
pjdlog_errno(LOG_ERR, "Unable to set gid to %u",
(unsigned int)pw->pw_gid);
return (-1);
}
if (setuid(pw->pw_uid) == -1) {
pjdlog_errno(LOG_ERR, "Unable to set uid to %u",
(unsigned int)pw->pw_uid);
return (-1);
}
#ifdef HAVE_CAPSICUM
capsicum = (cap_enter() == 0);
if (!capsicum) {
pjdlog_common(LOG_DEBUG, 1, errno,
"Unable to sandbox using capsicum");
} else if (res != NULL) {
cap_rights_t rights;
static const unsigned long geomcmds[] = {
DIOCGDELETE,
DIOCGFLUSH
};
PJDLOG_ASSERT(res->hr_role == HAST_ROLE_PRIMARY ||
res->hr_role == HAST_ROLE_SECONDARY);
cap_rights_init(&rights, CAP_FLOCK, CAP_IOCTL, CAP_PREAD,
CAP_PWRITE);
if (cap_rights_limit(res->hr_localfd, &rights) == -1) {
pjdlog_errno(LOG_ERR,
"Unable to limit capability rights on local descriptor");
}
if (cap_ioctls_limit(res->hr_localfd, geomcmds,
sizeof(geomcmds) / sizeof(geomcmds[0])) == -1) {
pjdlog_errno(LOG_ERR,
"Unable to limit allowed GEOM ioctls");
}
if (res->hr_role == HAST_ROLE_PRIMARY) {
static const unsigned long ggatecmds[] = {
G_GATE_CMD_MODIFY,
G_GATE_CMD_START,
G_GATE_CMD_DONE,
G_GATE_CMD_DESTROY
};
cap_rights_init(&rights, CAP_IOCTL);
if (cap_rights_limit(res->hr_ggatefd, &rights) == -1) {
pjdlog_errno(LOG_ERR,
"Unable to limit capability rights to CAP_IOCTL on ggate descriptor");
}
if (cap_ioctls_limit(res->hr_ggatefd, ggatecmds,
sizeof(ggatecmds) / sizeof(ggatecmds[0])) == -1) {
pjdlog_errno(LOG_ERR,
"Unable to limit allowed ggate ioctls");
}
}
}
#else
capsicum = false;
#endif
/*
* Better be sure that everything succeeded.
*/
PJDLOG_VERIFY(getresuid(&ruid, &euid, &suid) == 0);
PJDLOG_VERIFY(ruid == pw->pw_uid);
PJDLOG_VERIFY(euid == pw->pw_uid);
PJDLOG_VERIFY(suid == pw->pw_uid);
PJDLOG_VERIFY(getresgid(&rgid, &egid, &sgid) == 0);
PJDLOG_VERIFY(rgid == pw->pw_gid);
PJDLOG_VERIFY(egid == pw->pw_gid);
PJDLOG_VERIFY(sgid == pw->pw_gid);
PJDLOG_VERIFY(getgroups(0, NULL) == 1);
PJDLOG_VERIFY(getgroups(1, gidset) == 1);
PJDLOG_VERIFY(gidset[0] == pw->pw_gid);
pjdlog_debug(1,
"Privileges successfully dropped using %s%s+setgid+setuid.",
capsicum ? "capsicum+" : "", jailed ? "jail" : "chroot");
return (0);
}
