Least privilege support for Solaris

This commit is contained in:
John Levon 2009-01-22 17:49:41 +00:00
parent e52d74e536
commit 2b29698352
8 changed files with 188 additions and 27 deletions

View File

@ -1,3 +1,15 @@
Thu Jan 22 09:23:53 PST 2009 John Levon <john.levon@sun.com>
Least privilege support for Solaris
* qemud/qemud.c: init privs and refuse non-privileged
connections
* src/remote_internal.c: don't attempt user daemon instance on
Solaris
* src/xen_internal.c, src/xen_internal.h, src/xen_unified.c,
src/xend_internal.c, src/xs_internal.c: replace UID checks
with privilege checks. Refuse to load the Xen driver unless
we're libvirtd
Wed Jan 21 18:10:12 GMT 2009 Daniel P. Berrange <berrange@redhat.com>
Make Xen driver threadsafe

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@ -84,6 +84,39 @@
#endif
#ifdef __sun
#include <ucred.h>
#include <priv.h>
#ifndef PRIV_VIRT_MANAGE
#define PRIV_VIRT_MANAGE ((const char *)"virt_manage")
#endif
#ifndef PRIV_XVM_CONTROL
#define PRIV_XVM_CONTROL ((const char *)"xvm_control")
#endif
#define PU_RESETGROUPS 0x0001 /* Remove supplemental groups */
#define PU_CLEARLIMITSET 0x0008 /* L=0 */
extern int __init_daemon_priv(int, uid_t, gid_t, ...);
#define SYSTEM_UID 60
static gid_t unix_sock_gid = 60; /* Not used */
static int unix_sock_rw_mask = 0666;
static int unix_sock_ro_mask = 0666;
#else
#define SYSTEM_UID 0
static gid_t unix_sock_gid = 0; /* Only root by default */
static int unix_sock_rw_mask = 0700; /* Allow user only */
static int unix_sock_ro_mask = 0777; /* Allow world */
#endif /* __sun */
static int godaemon = 0; /* -d: Be a daemon */
static int verbose = 0; /* -v: Verbose mode */
static int timeout = -1; /* -t: Shutdown timeout */
@ -102,10 +135,6 @@ static char *listen_addr = (char *) LIBVIRTD_LISTEN_ADDR;
static char *tls_port = (char *) LIBVIRTD_TLS_PORT;
static char *tcp_port = (char *) LIBVIRTD_TCP_PORT;
static gid_t unix_sock_gid = 0; /* Only root by default */
static int unix_sock_rw_mask = 0700; /* Allow user only */
static int unix_sock_ro_mask = 0777; /* Allow world */
#if HAVE_POLKIT
static int auth_unix_rw = REMOTE_AUTH_POLKIT;
static int auth_unix_ro = REMOTE_AUTH_POLKIT;
@ -669,10 +698,11 @@ cleanup:
static int qemudInitPaths(struct qemud_server *server,
char *sockname,
char *roSockname,
int maxlen) {
int maxlen)
{
uid_t uid = geteuid();
if (!uid) {
if (uid == SYSTEM_UID) {
if (snprintf (sockname, maxlen, "%s/run/libvirt/libvirt-sock",
LOCAL_STATE_DIR) >= maxlen)
goto snprintf_error;
@ -1155,6 +1185,29 @@ static int qemudDispatchServer(struct qemud_server *server, struct qemud_socket
return -1;
}
#ifdef __sun
{
ucred_t *ucred = NULL;
const priv_set_t *privs;
if (getpeerucred (fd, &ucred) == -1 ||
(privs = ucred_getprivset (ucred, PRIV_EFFECTIVE)) == NULL) {
if (ucred != NULL)
ucred_free (ucred);
close (fd);
return -1;
}
if (!priv_ismember (privs, PRIV_VIRT_MANAGE)) {
ucred_free (ucred);
close (fd);
return -1;
}
ucred_free (ucred);
}
#endif /* __sun */
/* Disable Nagle. Unix sockets will ignore this. */
setsockopt (fd, IPPROTO_TCP, TCP_NODELAY, (void *)&no_slow_start,
sizeof no_slow_start);
@ -2524,6 +2577,30 @@ version (const char *argv0)
printf ("%s (%s) %s\n", argv0, PACKAGE_NAME, PACKAGE_VERSION);
}
#ifdef __sun
static int
qemudSetupPrivs (void)
{
chown ("/var/run/libvirt", SYSTEM_UID, SYSTEM_UID);
if (__init_daemon_priv (PU_RESETGROUPS | PU_CLEARLIMITSET,
SYSTEM_UID, SYSTEM_UID, PRIV_XVM_CONTROL, NULL)) {
fprintf (stderr, "additional privileges are required\n");
return -1;
}
if (priv_set (PRIV_OFF, PRIV_ALLSETS, PRIV_FILE_LINK_ANY, PRIV_PROC_INFO,
PRIV_PROC_SESSION, PRIV_PROC_EXEC, PRIV_PROC_FORK, NULL)) {
fprintf (stderr, "failed to set reduced privileges\n");
return -1;
}
return 0;
}
#else
#define qemudSetupPrivs() 0
#endif
/* Print command-line usage. */
static void
usage (const char *argv0)
@ -2701,6 +2778,21 @@ int main(int argc, char **argv) {
sig_action.sa_handler = SIG_IGN;
sigaction(SIGPIPE, &sig_action, NULL);
/* Ensure the rundir exists (on tmpfs on some systems) */
if (geteuid () == 0) {
const char *rundir = LOCAL_STATE_DIR "/run/libvirt";
if (mkdir (rundir, 0755)) {
if (errno != EEXIST) {
VIR_ERROR0 (_("unable to create rundir"));
return -1;
}
}
}
if (qemudSetupPrivs() < 0)
goto error2;
if (!(server = qemudInitialize(sigpipe[0]))) {
ret = 2;
goto error2;

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@ -957,18 +957,21 @@ remoteOpen (virConnectPtr conn,
}
/*
* If URI is NULL, then do a UNIX connection
* possibly auto-spawning unprivileged server
* and probe remote server for URI
* If URI is NULL, then do a UNIX connection possibly auto-spawning
* unprivileged server and probe remote server for URI. On Solaris,
* this isn't supported, but we may be privileged enough to connect
* to the UNIX socket anyway.
*/
if (!conn->uri) {
DEBUG0("Auto-probe remote URI");
rflags |= VIR_DRV_OPEN_REMOTE_UNIX;
#ifndef __sun
if (getuid() > 0) {
DEBUG0("Auto-spawn user daemon instance");
rflags |= VIR_DRV_OPEN_REMOTE_USER;
rflags |= VIR_DRV_OPEN_REMOTE_AUTOSTART;
}
#endif
}
priv->sock = -1;

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@ -26,6 +26,17 @@
#include <errno.h>
#include <sys/utsname.h>
#ifdef __sun
#include <sys/systeminfo.h>
#include <priv.h>
#ifndef PRIV_XVM_CONTROL
#define PRIV_XVM_CONTROL ((const char *)"xvm_control")
#endif
#endif /* __sun */
/* required for dom0_getdomaininfo_t */
#include <xen/dom0_ops.h>
#include <xen/version.h>
@ -37,10 +48,6 @@
#endif
#endif
#ifdef __sun
#include <sys/systeminfo.h>
#endif
/* required for shutdown flags */
#include <xen/sched.h>
@ -3405,3 +3412,17 @@ xenHypervisorGetVcpuMax(virDomainPtr domain)
return maxcpu;
}
/**
* xenHavePrivilege()
*
* Return true if the current process should be able to connect to Xen.
*/
int
xenHavePrivilege()
{
#ifdef __sun
return priv_ineffect (PRIV_XVM_CONTROL);
#else
return getuid () == 0;
#endif
}

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@ -104,4 +104,6 @@ int xenHypervisorNodeGetCellsFreeMemory(virConnectPtr conn,
int startCell,
int maxCells);
int xenHavePrivilege(void);
#endif /* __VIR_XEN_INTERNAL_H__ */

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@ -67,6 +67,8 @@ static struct xenUnifiedDriver const * const drivers[XEN_UNIFIED_NR_DRIVERS] = {
#endif
};
static int inside_daemon;
#define xenUnifiedError(conn, code, fmt...) \
virReportErrorHelper(conn, VIR_FROM_XEN, code, __FILE__, \
__FUNCTION__, __LINE__, fmt)
@ -168,6 +170,21 @@ done:
return(res);
}
#ifdef WITH_LIBVIRTD
static int
xenInitialize (void)
{
inside_daemon = 1;
return 0;
}
static virStateDriver state_driver = {
.initialize = xenInitialize,
};
#endif
/*----- Dispatch functions. -----*/
/* These dispatch functions follow the model used historically
@ -204,6 +221,15 @@ xenUnifiedOpen (virConnectPtr conn, virConnectAuthPtr auth, int flags)
xenUnifiedPrivatePtr priv;
virDomainEventCallbackListPtr cbList;
#ifdef __sun
/*
* Only the libvirtd instance can open this driver.
* Everything else falls back to the remote driver.
*/
if (!inside_daemon)
return VIR_DRV_OPEN_DECLINED;
#endif
if (conn->uri == NULL) {
if (!xenUnifiedProbe())
return VIR_DRV_OPEN_DECLINED;
@ -265,8 +291,8 @@ xenUnifiedOpen (virConnectPtr conn, virConnectAuthPtr auth, int flags)
priv->proxy = -1;
/* Hypervisor is only run as root & required to succeed */
if (getuid() == 0) {
/* Hypervisor is only run with privilege & required to succeed */
if (xenHavePrivilege()) {
DEBUG0("Trying hypervisor sub-driver");
if (drivers[XEN_UNIFIED_HYPERVISOR_OFFSET]->open(conn, auth, flags) ==
VIR_DRV_OPEN_SUCCESS) {
@ -275,7 +301,7 @@ xenUnifiedOpen (virConnectPtr conn, virConnectAuthPtr auth, int flags)
}
}
/* XenD is required to suceed if root.
/* XenD is required to succeed if privileged.
* If it fails as non-root, then the proxy driver may take over
*/
DEBUG0("Trying XenD sub-driver");
@ -300,12 +326,12 @@ xenUnifiedOpen (virConnectPtr conn, virConnectAuthPtr auth, int flags)
DEBUG0("Activated XS sub-driver");
priv->opened[XEN_UNIFIED_XS_OFFSET] = 1;
} else {
if (getuid() == 0)
goto fail; /* XS is mandatory as root */
if (xenHavePrivilege())
goto fail; /* XS is mandatory when privileged */
}
} else {
if (getuid() == 0) {
goto fail; /* XenD is mandatory as root */
if (xenHavePrivilege()) {
goto fail; /* XenD is mandatory when privileged */
} else {
#if WITH_PROXY
DEBUG0("Trying proxy sub-driver");
@ -1472,6 +1498,10 @@ xenRegister (void)
/* Ignore failures here. */
(void) xenHypervisorInit ();
#ifdef WITH_LIBVIRTD
if (virRegisterStateDriver (&state_driver) == -1) return -1;
#endif
return virRegisterDriver (&xenUnifiedDriver);
}

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@ -42,7 +42,7 @@
#include "buf.h"
#include "uuid.h"
#include "xen_unified.h"
#include "xen_internal.h" /* for DOM0_INTERFACE_VERSION */
#include "xen_internal.h"
#include "xs_internal.h" /* To extract VNC port & Serial console TTY */
#include "memory.h"
@ -161,9 +161,10 @@ do_connect(virConnectPtr xend)
s = -1;
/*
* Connecting to XenD as root is mandatory, so log this error
* Connecting to XenD when privileged is mandatory, so log this
* error
*/
if (getuid() == 0) {
if (xenHavePrivilege()) {
virXendError(xend, VIR_ERR_INTERNAL_ERROR,
"%s", _("failed to connect to xend"));
}

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@ -35,7 +35,7 @@
#include "uuid.h"
#include "xen_unified.h"
#include "xs_internal.h"
#include "xen_internal.h" /* for xenHypervisorCheckID */
#include "xen_internal.h"
#ifndef PROXY
static char *xenStoreDomainGetOSType(virDomainPtr domain);
@ -290,11 +290,11 @@ xenStoreOpen(virConnectPtr conn,
if (priv->xshandle == NULL) {
/*
* not being able to connect via the socket as a normal user
* is rather normal, this should fallback to the proxy (or
* not being able to connect via the socket as an unprivileged
* user is rather normal, this should fallback to the proxy (or
* remote) mechanism.
*/
if (getuid() == 0) {
if (xenHavePrivilege()) {
virXenStoreError(NULL, VIR_ERR_NO_XEN,
"%s", _("failed to connect to Xen Store"));
}