944 lines
		
	
	
		
			30 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			944 lines
		
	
	
		
			30 KiB
		
	
	
	
		
			C
		
	
	
	
| /************************************************************
 | |
| 
 | |
| Author: Eamon Walsh <ewalsh@tycho.nsa.gov>
 | |
| 
 | |
| Permission to use, copy, modify, distribute, and sell this software and its
 | |
| documentation for any purpose is hereby granted without fee, provided that
 | |
| this permission notice appear in supporting documentation.  This permission
 | |
| notice shall be included in all copies or substantial portions of the
 | |
| Software.
 | |
| 
 | |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 | |
| IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 | |
| FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
 | |
| AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 | |
| AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 | |
| CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 | |
| 
 | |
| ********************************************************/
 | |
| 
 | |
| /*
 | |
|  * Portions of this code copyright (c) 2005 by Trusted Computer Solutions, Inc.
 | |
|  * All rights reserved.
 | |
|  */
 | |
| 
 | |
| #ifdef HAVE_DIX_CONFIG_H
 | |
| #include <dix-config.h>
 | |
| #endif
 | |
| 
 | |
| #include <sys/socket.h>
 | |
| #include <stdio.h>
 | |
| #include <stdarg.h>
 | |
| 
 | |
| #include <libaudit.h>
 | |
| 
 | |
| #include <X11/Xatom.h>
 | |
| #include "selection.h"
 | |
| #include "inputstr.h"
 | |
| #include "scrnintstr.h"
 | |
| #include "windowstr.h"
 | |
| #include "propertyst.h"
 | |
| #include "extnsionst.h"
 | |
| #include "xacestr.h"
 | |
| #include "client.h"
 | |
| #include "../os/osdep.h"
 | |
| #define _XSELINUX_NEED_FLASK_MAP
 | |
| #include "xselinuxint.h"
 | |
| 
 | |
| /* structure passed to auditing callback */
 | |
| typedef struct {
 | |
|     ClientPtr client;           /* client */
 | |
|     DeviceIntPtr dev;           /* device */
 | |
|     char *command;              /* client's executable path */
 | |
|     unsigned id;                /* resource id, if any */
 | |
|     int restype;                /* resource type, if any */
 | |
|     int event;                  /* event type, if any */
 | |
|     Atom property;              /* property name, if any */
 | |
|     Atom selection;             /* selection name, if any */
 | |
|     char *extension;            /* extension name, if any */
 | |
| } SELinuxAuditRec;
 | |
| 
 | |
| /* private state keys */
 | |
| DevPrivateKeyRec subjectKeyRec;
 | |
| DevPrivateKeyRec objectKeyRec;
 | |
| DevPrivateKeyRec dataKeyRec;
 | |
| 
 | |
| /* audit file descriptor */
 | |
| static int audit_fd;
 | |
| 
 | |
| /* atoms for window label properties */
 | |
| static Atom atom_ctx;
 | |
| static Atom atom_client_ctx;
 | |
| 
 | |
| /* The unlabeled SID */
 | |
| static security_id_t unlabeled_sid;
 | |
| 
 | |
| /* forward declarations */
 | |
| static void SELinuxScreen(CallbackListPtr *, pointer, pointer);
 | |
| 
 | |
| /* "true" pointer value for use as callback data */
 | |
| static pointer truep = (pointer) 1;
 | |
| 
 | |
| /*
 | |
|  * Performs an SELinux permission check.
 | |
|  */
 | |
| static int
 | |
| SELinuxDoCheck(SELinuxSubjectRec * subj, SELinuxObjectRec * obj,
 | |
|                security_class_t class, Mask mode, SELinuxAuditRec * auditdata)
 | |
| {
 | |
|     /* serverClient requests OK */
 | |
|     if (subj->privileged)
 | |
|         return Success;
 | |
| 
 | |
|     auditdata->command = subj->command;
 | |
|     errno = 0;
 | |
| 
 | |
|     if (avc_has_perm(subj->sid, obj->sid, class, mode, &subj->aeref,
 | |
|                      auditdata) < 0) {
 | |
|         if (mode == DixUnknownAccess)
 | |
|             return Success;     /* DixUnknownAccess requests OK ... for now */
 | |
|         if (errno == EACCES)
 | |
|             return BadAccess;
 | |
|         ErrorF("SELinux: avc_has_perm: unexpected error %d\n", errno);
 | |
|         return BadValue;
 | |
|     }
 | |
| 
 | |
|     return Success;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Labels a newly connected client.
 | |
|  */
 | |
| static void
 | |
| SELinuxLabelClient(ClientPtr client)
 | |
| {
 | |
|     int fd = XaceGetConnectionNumber(client);
 | |
|     SELinuxSubjectRec *subj;
 | |
|     SELinuxObjectRec *obj;
 | |
|     security_context_t ctx;
 | |
| 
 | |
|     subj = dixLookupPrivate(&client->devPrivates, subjectKey);
 | |
|     obj = dixLookupPrivate(&client->devPrivates, objectKey);
 | |
| 
 | |
|     /* Try to get a context from the socket */
 | |
|     if (fd < 0 || getpeercon_raw(fd, &ctx) < 0) {
 | |
|         /* Otherwise, fall back to a default context */
 | |
|         ctx = SELinuxDefaultClientLabel();
 | |
|     }
 | |
| 
 | |
|     /* For local clients, try and determine the executable name */
 | |
|     if (XaceIsLocal(client)) {
 | |
|         /* Get cached command name if CLIENTIDS is enabled. */
 | |
|         const char *cmdname = GetClientCmdName(client);
 | |
|         Bool cached = (cmdname != NULL);
 | |
| 
 | |
|         /* If CLIENTIDS is disabled, figure out the command name from
 | |
|          * scratch. */
 | |
|         if (!cmdname) {
 | |
|             pid_t pid = DetermineClientPid(client);
 | |
| 
 | |
|             if (pid != -1)
 | |
|                 DetermineClientCmd(pid, &cmdname, NULL);
 | |
|         }
 | |
| 
 | |
|         if (!cmdname)
 | |
|             goto finish;
 | |
| 
 | |
|         strncpy(subj->command, cmdname, COMMAND_LEN - 1);
 | |
| 
 | |
|         if (!cached)
 | |
|             free((void *) cmdname);     /* const char * */
 | |
|     }
 | |
| 
 | |
|  finish:
 | |
|     /* Get a SID from the context */
 | |
|     if (avc_context_to_sid_raw(ctx, &subj->sid) < 0)
 | |
|         FatalError("SELinux: client %d: context_to_sid_raw(%s) failed\n",
 | |
|                    client->index, ctx);
 | |
| 
 | |
|     obj->sid = subj->sid;
 | |
|     freecon(ctx);
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Labels initial server objects.
 | |
|  */
 | |
| static void
 | |
| SELinuxLabelInitial(void)
 | |
| {
 | |
|     int i;
 | |
|     XaceScreenAccessRec srec;
 | |
|     SELinuxSubjectRec *subj;
 | |
|     SELinuxObjectRec *obj;
 | |
|     security_context_t ctx;
 | |
|     pointer unused;
 | |
| 
 | |
|     /* Do the serverClient */
 | |
|     subj = dixLookupPrivate(&serverClient->devPrivates, subjectKey);
 | |
|     obj = dixLookupPrivate(&serverClient->devPrivates, objectKey);
 | |
|     subj->privileged = 1;
 | |
| 
 | |
|     /* Use the context of the X server process for the serverClient */
 | |
|     if (getcon_raw(&ctx) < 0)
 | |
|         FatalError("SELinux: couldn't get context of X server process\n");
 | |
| 
 | |
|     /* Get a SID from the context */
 | |
|     if (avc_context_to_sid_raw(ctx, &subj->sid) < 0)
 | |
|         FatalError("SELinux: serverClient: context_to_sid(%s) failed\n", ctx);
 | |
| 
 | |
|     obj->sid = subj->sid;
 | |
|     freecon(ctx);
 | |
| 
 | |
|     srec.client = serverClient;
 | |
|     srec.access_mode = DixCreateAccess;
 | |
|     srec.status = Success;
 | |
| 
 | |
|     for (i = 0; i < screenInfo.numScreens; i++) {
 | |
|         /* Do the screen object */
 | |
|         srec.screen = screenInfo.screens[i];
 | |
|         SELinuxScreen(NULL, NULL, &srec);
 | |
| 
 | |
|         /* Do the default colormap */
 | |
|         dixLookupResourceByType(&unused, screenInfo.screens[i]->defColormap,
 | |
|                                 RT_COLORMAP, serverClient, DixCreateAccess);
 | |
|     }
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Labels new resource objects.
 | |
|  */
 | |
| static int
 | |
| SELinuxLabelResource(XaceResourceAccessRec * rec, SELinuxSubjectRec * subj,
 | |
|                      SELinuxObjectRec * obj, security_class_t class)
 | |
| {
 | |
|     int offset;
 | |
|     security_id_t tsid;
 | |
| 
 | |
|     /* Check for a create context */
 | |
|     if (rec->rtype & RC_DRAWABLE && subj->win_create_sid) {
 | |
|         obj->sid = subj->win_create_sid;
 | |
|         return Success;
 | |
|     }
 | |
| 
 | |
|     if (rec->parent)
 | |
|         offset = dixLookupPrivateOffset(rec->ptype);
 | |
| 
 | |
|     if (rec->parent && offset >= 0) {
 | |
|         /* Use the SID of the parent object in the labeling operation */
 | |
|         PrivateRec **privatePtr = DEVPRIV_AT(rec->parent, offset);
 | |
|         SELinuxObjectRec *pobj = dixLookupPrivate(privatePtr, objectKey);
 | |
| 
 | |
|         tsid = pobj->sid;
 | |
|     }
 | |
|     else {
 | |
|         /* Use the SID of the subject */
 | |
|         tsid = subj->sid;
 | |
|     }
 | |
| 
 | |
|     /* Perform a transition to obtain the final SID */
 | |
|     if (avc_compute_create(subj->sid, tsid, class, &obj->sid) < 0) {
 | |
|         ErrorF("SELinux: a compute_create call failed!\n");
 | |
|         return BadValue;
 | |
|     }
 | |
| 
 | |
|     return Success;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Libselinux Callbacks
 | |
|  */
 | |
| 
 | |
| static int
 | |
| SELinuxAudit(void *auditdata,
 | |
|              security_class_t class, char *msgbuf, size_t msgbufsize)
 | |
| {
 | |
|     SELinuxAuditRec *audit = auditdata;
 | |
|     ClientPtr client = audit->client;
 | |
|     char idNum[16];
 | |
|     const char *propertyName, *selectionName;
 | |
|     int major = -1, minor = -1;
 | |
| 
 | |
|     if (client) {
 | |
|         REQUEST(xReq);
 | |
|         if (stuff) {
 | |
|             major = client->majorOp;
 | |
|             minor = client->minorOp;
 | |
|         }
 | |
|     }
 | |
|     if (audit->id)
 | |
|         snprintf(idNum, 16, "%x", audit->id);
 | |
| 
 | |
|     propertyName = audit->property ? NameForAtom(audit->property) : NULL;
 | |
|     selectionName = audit->selection ? NameForAtom(audit->selection) : NULL;
 | |
| 
 | |
|     return snprintf(msgbuf, msgbufsize,
 | |
|                     "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
 | |
|                     (major >= 0) ? "request=" : "",
 | |
|                     (major >= 0) ? LookupRequestName(major, minor) : "",
 | |
|                     audit->command ? " comm=" : "",
 | |
|                     audit->command ? audit->command : "",
 | |
|                     audit->dev ? " xdevice=\"" : "",
 | |
|                     audit->dev ? audit->dev->name : "",
 | |
|                     audit->dev ? "\"" : "",
 | |
|                     audit->id ? " resid=" : "",
 | |
|                     audit->id ? idNum : "",
 | |
|                     audit->restype ? " restype=" : "",
 | |
|                     audit->restype ? LookupResourceName(audit->restype) : "",
 | |
|                     audit->event ? " event=" : "",
 | |
|                     audit->event ? LookupEventName(audit->event & 127) : "",
 | |
|                     audit->property ? " property=" : "",
 | |
|                     audit->property ? propertyName : "",
 | |
|                     audit->selection ? " selection=" : "",
 | |
|                     audit->selection ? selectionName : "",
 | |
|                     audit->extension ? " extension=" : "",
 | |
|                     audit->extension ? audit->extension : "");
 | |
| }
 | |
| 
 | |
| static int
 | |
| SELinuxLog(int type, const char *fmt, ...)
 | |
| {
 | |
|     va_list ap;
 | |
|     char buf[MAX_AUDIT_MESSAGE_LENGTH];
 | |
|     int rc, aut;
 | |
| 
 | |
|     switch (type) {
 | |
|     case SELINUX_INFO:
 | |
|         aut = AUDIT_USER_MAC_POLICY_LOAD;
 | |
|         break;
 | |
|     case SELINUX_AVC:
 | |
|         aut = AUDIT_USER_AVC;
 | |
|         break;
 | |
|     default:
 | |
|         aut = AUDIT_USER_SELINUX_ERR;
 | |
|         break;
 | |
|     }
 | |
| 
 | |
|     va_start(ap, fmt);
 | |
|     vsnprintf(buf, MAX_AUDIT_MESSAGE_LENGTH, fmt, ap);
 | |
|     rc = audit_log_user_avc_message(audit_fd, aut, buf, NULL, NULL, NULL, 0);
 | |
|     va_end(ap);
 | |
|     LogMessageVerb(X_WARNING, 0, "%s", buf);
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * XACE Callbacks
 | |
|  */
 | |
| 
 | |
| static void
 | |
| SELinuxDevice(CallbackListPtr *pcbl, pointer unused, pointer calldata)
 | |
| {
 | |
|     XaceDeviceAccessRec *rec = calldata;
 | |
|     SELinuxSubjectRec *subj;
 | |
|     SELinuxObjectRec *obj;
 | |
|     SELinuxAuditRec auditdata = {.client = rec->client,.dev = rec->dev };
 | |
|     security_class_t cls;
 | |
|     int rc;
 | |
| 
 | |
|     subj = dixLookupPrivate(&rec->client->devPrivates, subjectKey);
 | |
|     obj = dixLookupPrivate(&rec->dev->devPrivates, objectKey);
 | |
| 
 | |
|     /* If this is a new object that needs labeling, do it now */
 | |
|     if (rec->access_mode & DixCreateAccess) {
 | |
|         SELinuxSubjectRec *dsubj;
 | |
| 
 | |
|         dsubj = dixLookupPrivate(&rec->dev->devPrivates, subjectKey);
 | |
| 
 | |
|         if (subj->dev_create_sid) {
 | |
|             /* Label the device with the create context */
 | |
|             obj->sid = subj->dev_create_sid;
 | |
|             dsubj->sid = subj->dev_create_sid;
 | |
|         }
 | |
|         else {
 | |
|             /* Label the device directly with the process SID */
 | |
|             obj->sid = subj->sid;
 | |
|             dsubj->sid = subj->sid;
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     cls = IsPointerDevice(rec->dev) ? SECCLASS_X_POINTER : SECCLASS_X_KEYBOARD;
 | |
|     rc = SELinuxDoCheck(subj, obj, cls, rec->access_mode, &auditdata);
 | |
|     if (rc != Success)
 | |
|         rec->status = rc;
 | |
| }
 | |
| 
 | |
| static void
 | |
| SELinuxSend(CallbackListPtr *pcbl, pointer unused, pointer calldata)
 | |
| {
 | |
|     XaceSendAccessRec *rec = calldata;
 | |
|     SELinuxSubjectRec *subj;
 | |
|     SELinuxObjectRec *obj, ev_sid;
 | |
|     SELinuxAuditRec auditdata = {.client = rec->client,.dev = rec->dev };
 | |
|     security_class_t class;
 | |
|     int rc, i, type;
 | |
| 
 | |
|     if (rec->dev)
 | |
|         subj = dixLookupPrivate(&rec->dev->devPrivates, subjectKey);
 | |
|     else
 | |
|         subj = dixLookupPrivate(&rec->client->devPrivates, subjectKey);
 | |
| 
 | |
|     obj = dixLookupPrivate(&rec->pWin->devPrivates, objectKey);
 | |
| 
 | |
|     /* Check send permission on window */
 | |
|     rc = SELinuxDoCheck(subj, obj, SECCLASS_X_DRAWABLE, DixSendAccess,
 | |
|                         &auditdata);
 | |
|     if (rc != Success)
 | |
|         goto err;
 | |
| 
 | |
|     /* Check send permission on specific event types */
 | |
|     for (i = 0; i < rec->count; i++) {
 | |
|         type = rec->events[i].u.u.type;
 | |
|         class = (type & 128) ? SECCLASS_X_FAKEEVENT : SECCLASS_X_EVENT;
 | |
| 
 | |
|         rc = SELinuxEventToSID(type, obj->sid, &ev_sid);
 | |
|         if (rc != Success)
 | |
|             goto err;
 | |
| 
 | |
|         auditdata.event = type;
 | |
|         rc = SELinuxDoCheck(subj, &ev_sid, class, DixSendAccess, &auditdata);
 | |
|         if (rc != Success)
 | |
|             goto err;
 | |
|     }
 | |
|     return;
 | |
|  err:
 | |
|     rec->status = rc;
 | |
| }
 | |
| 
 | |
| static void
 | |
| SELinuxReceive(CallbackListPtr *pcbl, pointer unused, pointer calldata)
 | |
| {
 | |
|     XaceReceiveAccessRec *rec = calldata;
 | |
|     SELinuxSubjectRec *subj;
 | |
|     SELinuxObjectRec *obj, ev_sid;
 | |
|     SELinuxAuditRec auditdata = {.client = NULL };
 | |
|     security_class_t class;
 | |
|     int rc, i, type;
 | |
| 
 | |
|     subj = dixLookupPrivate(&rec->client->devPrivates, subjectKey);
 | |
|     obj = dixLookupPrivate(&rec->pWin->devPrivates, objectKey);
 | |
| 
 | |
|     /* Check receive permission on window */
 | |
|     rc = SELinuxDoCheck(subj, obj, SECCLASS_X_DRAWABLE, DixReceiveAccess,
 | |
|                         &auditdata);
 | |
|     if (rc != Success)
 | |
|         goto err;
 | |
| 
 | |
|     /* Check receive permission on specific event types */
 | |
|     for (i = 0; i < rec->count; i++) {
 | |
|         type = rec->events[i].u.u.type;
 | |
|         class = (type & 128) ? SECCLASS_X_FAKEEVENT : SECCLASS_X_EVENT;
 | |
| 
 | |
|         rc = SELinuxEventToSID(type, obj->sid, &ev_sid);
 | |
|         if (rc != Success)
 | |
|             goto err;
 | |
| 
 | |
|         auditdata.event = type;
 | |
|         rc = SELinuxDoCheck(subj, &ev_sid, class, DixReceiveAccess, &auditdata);
 | |
|         if (rc != Success)
 | |
|             goto err;
 | |
|     }
 | |
|     return;
 | |
|  err:
 | |
|     rec->status = rc;
 | |
| }
 | |
| 
 | |
| static void
 | |
| SELinuxExtension(CallbackListPtr *pcbl, pointer unused, pointer calldata)
 | |
| {
 | |
|     XaceExtAccessRec *rec = calldata;
 | |
|     SELinuxSubjectRec *subj, *serv;
 | |
|     SELinuxObjectRec *obj;
 | |
|     SELinuxAuditRec auditdata = {.client = rec->client };
 | |
|     int rc;
 | |
| 
 | |
|     subj = dixLookupPrivate(&rec->client->devPrivates, subjectKey);
 | |
|     obj = dixLookupPrivate(&rec->ext->devPrivates, objectKey);
 | |
| 
 | |
|     /* If this is a new object that needs labeling, do it now */
 | |
|     /* XXX there should be a separate callback for this */
 | |
|     if (obj->sid == NULL) {
 | |
|         security_id_t sid;
 | |
| 
 | |
|         serv = dixLookupPrivate(&serverClient->devPrivates, subjectKey);
 | |
|         rc = SELinuxExtensionToSID(rec->ext->name, &sid);
 | |
|         if (rc != Success) {
 | |
|             rec->status = rc;
 | |
|             return;
 | |
|         }
 | |
| 
 | |
|         /* Perform a transition to obtain the final SID */
 | |
|         if (avc_compute_create(serv->sid, sid, SECCLASS_X_EXTENSION,
 | |
|                                &obj->sid) < 0) {
 | |
|             ErrorF("SELinux: a SID transition call failed!\n");
 | |
|             rec->status = BadValue;
 | |
|             return;
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     /* Perform the security check */
 | |
|     auditdata.extension = rec->ext->name;
 | |
|     rc = SELinuxDoCheck(subj, obj, SECCLASS_X_EXTENSION, rec->access_mode,
 | |
|                         &auditdata);
 | |
|     if (rc != Success)
 | |
|         rec->status = rc;
 | |
| }
 | |
| 
 | |
| static void
 | |
| SELinuxSelection(CallbackListPtr *pcbl, pointer unused, pointer calldata)
 | |
| {
 | |
|     XaceSelectionAccessRec *rec = calldata;
 | |
|     SELinuxSubjectRec *subj;
 | |
|     SELinuxObjectRec *obj, *data;
 | |
|     Selection *pSel = *rec->ppSel;
 | |
|     Atom name = pSel->selection;
 | |
|     Mask access_mode = rec->access_mode;
 | |
|     SELinuxAuditRec auditdata = {.client = rec->client,.selection = name };
 | |
|     security_id_t tsid;
 | |
|     int rc;
 | |
| 
 | |
|     subj = dixLookupPrivate(&rec->client->devPrivates, subjectKey);
 | |
|     obj = dixLookupPrivate(&pSel->devPrivates, objectKey);
 | |
| 
 | |
|     /* If this is a new object that needs labeling, do it now */
 | |
|     if (access_mode & DixCreateAccess) {
 | |
|         rc = SELinuxSelectionToSID(name, subj, &obj->sid, &obj->poly);
 | |
|         if (rc != Success)
 | |
|             obj->sid = unlabeled_sid;
 | |
|         access_mode = DixSetAttrAccess;
 | |
|     }
 | |
|     /* If this is a polyinstantiated object, find the right instance */
 | |
|     else if (obj->poly) {
 | |
|         rc = SELinuxSelectionToSID(name, subj, &tsid, NULL);
 | |
|         if (rc != Success) {
 | |
|             rec->status = rc;
 | |
|             return;
 | |
|         }
 | |
|         while (pSel->selection != name || obj->sid != tsid) {
 | |
|             if ((pSel = pSel->next) == NULL)
 | |
|                 break;
 | |
|             obj = dixLookupPrivate(&pSel->devPrivates, objectKey);
 | |
|         }
 | |
| 
 | |
|         if (pSel)
 | |
|             *rec->ppSel = pSel;
 | |
|         else {
 | |
|             rec->status = BadMatch;
 | |
|             return;
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     /* Perform the security check */
 | |
|     rc = SELinuxDoCheck(subj, obj, SECCLASS_X_SELECTION, access_mode,
 | |
|                         &auditdata);
 | |
|     if (rc != Success)
 | |
|         rec->status = rc;
 | |
| 
 | |
|     /* Label the content (advisory only) */
 | |
|     if (access_mode & DixSetAttrAccess) {
 | |
|         data = dixLookupPrivate(&pSel->devPrivates, dataKey);
 | |
|         if (subj->sel_create_sid)
 | |
|             data->sid = subj->sel_create_sid;
 | |
|         else
 | |
|             data->sid = obj->sid;
 | |
|     }
 | |
| }
 | |
| 
 | |
| static void
 | |
| SELinuxProperty(CallbackListPtr *pcbl, pointer unused, pointer calldata)
 | |
| {
 | |
|     XacePropertyAccessRec *rec = calldata;
 | |
|     SELinuxSubjectRec *subj;
 | |
|     SELinuxObjectRec *obj, *data;
 | |
|     PropertyPtr pProp = *rec->ppProp;
 | |
|     Atom name = pProp->propertyName;
 | |
|     SELinuxAuditRec auditdata = {.client = rec->client,.property = name };
 | |
|     security_id_t tsid;
 | |
|     int rc;
 | |
| 
 | |
|     /* Don't care about the new content check */
 | |
|     if (rec->access_mode & DixPostAccess)
 | |
|         return;
 | |
| 
 | |
|     subj = dixLookupPrivate(&rec->client->devPrivates, subjectKey);
 | |
|     obj = dixLookupPrivate(&pProp->devPrivates, objectKey);
 | |
| 
 | |
|     /* If this is a new object that needs labeling, do it now */
 | |
|     if (rec->access_mode & DixCreateAccess) {
 | |
|         rc = SELinuxPropertyToSID(name, subj, &obj->sid, &obj->poly);
 | |
|         if (rc != Success) {
 | |
|             rec->status = rc;
 | |
|             return;
 | |
|         }
 | |
|     }
 | |
|     /* If this is a polyinstantiated object, find the right instance */
 | |
|     else if (obj->poly) {
 | |
|         rc = SELinuxPropertyToSID(name, subj, &tsid, NULL);
 | |
|         if (rc != Success) {
 | |
|             rec->status = rc;
 | |
|             return;
 | |
|         }
 | |
|         while (pProp->propertyName != name || obj->sid != tsid) {
 | |
|             if ((pProp = pProp->next) == NULL)
 | |
|                 break;
 | |
|             obj = dixLookupPrivate(&pProp->devPrivates, objectKey);
 | |
|         }
 | |
| 
 | |
|         if (pProp)
 | |
|             *rec->ppProp = pProp;
 | |
|         else {
 | |
|             rec->status = BadMatch;
 | |
|             return;
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     /* Perform the security check */
 | |
|     rc = SELinuxDoCheck(subj, obj, SECCLASS_X_PROPERTY, rec->access_mode,
 | |
|                         &auditdata);
 | |
|     if (rc != Success)
 | |
|         rec->status = rc;
 | |
| 
 | |
|     /* Label the content (advisory only) */
 | |
|     if (rec->access_mode & DixWriteAccess) {
 | |
|         data = dixLookupPrivate(&pProp->devPrivates, dataKey);
 | |
|         if (subj->prp_create_sid)
 | |
|             data->sid = subj->prp_create_sid;
 | |
|         else
 | |
|             data->sid = obj->sid;
 | |
|     }
 | |
| }
 | |
| 
 | |
| static void
 | |
| SELinuxResource(CallbackListPtr *pcbl, pointer unused, pointer calldata)
 | |
| {
 | |
|     XaceResourceAccessRec *rec = calldata;
 | |
|     SELinuxSubjectRec *subj;
 | |
|     SELinuxObjectRec *obj;
 | |
|     SELinuxAuditRec auditdata = {.client = rec->client };
 | |
|     Mask access_mode = rec->access_mode;
 | |
|     PrivateRec **privatePtr;
 | |
|     security_class_t class;
 | |
|     int rc, offset;
 | |
| 
 | |
|     subj = dixLookupPrivate(&rec->client->devPrivates, subjectKey);
 | |
| 
 | |
|     /* Determine if the resource object has a devPrivates field */
 | |
|     offset = dixLookupPrivateOffset(rec->rtype);
 | |
|     if (offset < 0) {
 | |
|         /* No: use the SID of the owning client */
 | |
|         class = SECCLASS_X_RESOURCE;
 | |
|         privatePtr = &clients[CLIENT_ID(rec->id)]->devPrivates;
 | |
|         obj = dixLookupPrivate(privatePtr, objectKey);
 | |
|     }
 | |
|     else {
 | |
|         /* Yes: use the SID from the resource object itself */
 | |
|         class = SELinuxTypeToClass(rec->rtype);
 | |
|         privatePtr = DEVPRIV_AT(rec->res, offset);
 | |
|         obj = dixLookupPrivate(privatePtr, objectKey);
 | |
|     }
 | |
| 
 | |
|     /* If this is a new object that needs labeling, do it now */
 | |
|     if (access_mode & DixCreateAccess && offset >= 0) {
 | |
|         rc = SELinuxLabelResource(rec, subj, obj, class);
 | |
|         if (rc != Success) {
 | |
|             rec->status = rc;
 | |
|             return;
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     /* Collapse generic resource permissions down to read/write */
 | |
|     if (class == SECCLASS_X_RESOURCE) {
 | |
|         access_mode = ! !(rec->access_mode & SELinuxReadMask);  /* rd */
 | |
|         access_mode |= ! !(rec->access_mode & ~SELinuxReadMask) << 1;   /* wr */
 | |
|     }
 | |
| 
 | |
|     /* Perform the security check */
 | |
|     auditdata.restype = rec->rtype;
 | |
|     auditdata.id = rec->id;
 | |
|     rc = SELinuxDoCheck(subj, obj, class, access_mode, &auditdata);
 | |
|     if (rc != Success)
 | |
|         rec->status = rc;
 | |
| 
 | |
|     /* Perform the background none check on windows */
 | |
|     if (access_mode & DixCreateAccess && rec->rtype == RT_WINDOW) {
 | |
|         rc = SELinuxDoCheck(subj, obj, class, DixBlendAccess, &auditdata);
 | |
|         if (rc != Success)
 | |
|             ((WindowPtr) rec->res)->forcedBG = TRUE;
 | |
|     }
 | |
| }
 | |
| 
 | |
| static void
 | |
| SELinuxScreen(CallbackListPtr *pcbl, pointer is_saver, pointer calldata)
 | |
| {
 | |
|     XaceScreenAccessRec *rec = calldata;
 | |
|     SELinuxSubjectRec *subj;
 | |
|     SELinuxObjectRec *obj;
 | |
|     SELinuxAuditRec auditdata = {.client = rec->client };
 | |
|     Mask access_mode = rec->access_mode;
 | |
|     int rc;
 | |
| 
 | |
|     subj = dixLookupPrivate(&rec->client->devPrivates, subjectKey);
 | |
|     obj = dixLookupPrivate(&rec->screen->devPrivates, objectKey);
 | |
| 
 | |
|     /* If this is a new object that needs labeling, do it now */
 | |
|     if (access_mode & DixCreateAccess) {
 | |
|         /* Perform a transition to obtain the final SID */
 | |
|         if (avc_compute_create(subj->sid, subj->sid, SECCLASS_X_SCREEN,
 | |
|                                &obj->sid) < 0) {
 | |
|             ErrorF("SELinux: a compute_create call failed!\n");
 | |
|             rec->status = BadValue;
 | |
|             return;
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     if (is_saver)
 | |
|         access_mode <<= 2;
 | |
| 
 | |
|     rc = SELinuxDoCheck(subj, obj, SECCLASS_X_SCREEN, access_mode, &auditdata);
 | |
|     if (rc != Success)
 | |
|         rec->status = rc;
 | |
| }
 | |
| 
 | |
| static void
 | |
| SELinuxClient(CallbackListPtr *pcbl, pointer unused, pointer calldata)
 | |
| {
 | |
|     XaceClientAccessRec *rec = calldata;
 | |
|     SELinuxSubjectRec *subj;
 | |
|     SELinuxObjectRec *obj;
 | |
|     SELinuxAuditRec auditdata = {.client = rec->client };
 | |
|     int rc;
 | |
| 
 | |
|     subj = dixLookupPrivate(&rec->client->devPrivates, subjectKey);
 | |
|     obj = dixLookupPrivate(&rec->target->devPrivates, objectKey);
 | |
| 
 | |
|     rc = SELinuxDoCheck(subj, obj, SECCLASS_X_CLIENT, rec->access_mode,
 | |
|                         &auditdata);
 | |
|     if (rc != Success)
 | |
|         rec->status = rc;
 | |
| }
 | |
| 
 | |
| static void
 | |
| SELinuxServer(CallbackListPtr *pcbl, pointer unused, pointer calldata)
 | |
| {
 | |
|     XaceServerAccessRec *rec = calldata;
 | |
|     SELinuxSubjectRec *subj;
 | |
|     SELinuxObjectRec *obj;
 | |
|     SELinuxAuditRec auditdata = {.client = rec->client };
 | |
|     int rc;
 | |
| 
 | |
|     subj = dixLookupPrivate(&rec->client->devPrivates, subjectKey);
 | |
|     obj = dixLookupPrivate(&serverClient->devPrivates, objectKey);
 | |
| 
 | |
|     rc = SELinuxDoCheck(subj, obj, SECCLASS_X_SERVER, rec->access_mode,
 | |
|                         &auditdata);
 | |
|     if (rc != Success)
 | |
|         rec->status = rc;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * DIX Callbacks
 | |
|  */
 | |
| 
 | |
| static void
 | |
| SELinuxClientState(CallbackListPtr *pcbl, pointer unused, pointer calldata)
 | |
| {
 | |
|     NewClientInfoRec *pci = calldata;
 | |
| 
 | |
|     switch (pci->client->clientState) {
 | |
|     case ClientStateInitial:
 | |
|         SELinuxLabelClient(pci->client);
 | |
|         break;
 | |
| 
 | |
|     default:
 | |
|         break;
 | |
|     }
 | |
| }
 | |
| 
 | |
| static void
 | |
| SELinuxResourceState(CallbackListPtr *pcbl, pointer unused, pointer calldata)
 | |
| {
 | |
|     ResourceStateInfoRec *rec = calldata;
 | |
|     SELinuxSubjectRec *subj;
 | |
|     SELinuxObjectRec *obj;
 | |
|     WindowPtr pWin;
 | |
| 
 | |
|     if (rec->type != RT_WINDOW)
 | |
|         return;
 | |
|     if (rec->state != ResourceStateAdding)
 | |
|         return;
 | |
| 
 | |
|     pWin = (WindowPtr) rec->value;
 | |
|     subj = dixLookupPrivate(&wClient(pWin)->devPrivates, subjectKey);
 | |
| 
 | |
|     if (subj->sid) {
 | |
|         security_context_t ctx;
 | |
|         int rc = avc_sid_to_context_raw(subj->sid, &ctx);
 | |
| 
 | |
|         if (rc < 0)
 | |
|             FatalError("SELinux: Failed to get security context!\n");
 | |
|         rc = dixChangeWindowProperty(serverClient,
 | |
|                                      pWin, atom_client_ctx, XA_STRING, 8,
 | |
|                                      PropModeReplace, strlen(ctx), ctx, FALSE);
 | |
|         if (rc != Success)
 | |
|             FatalError("SELinux: Failed to set label property on window!\n");
 | |
|         freecon(ctx);
 | |
|     }
 | |
|     else
 | |
|         FatalError("SELinux: Unexpected unlabeled client found\n");
 | |
| 
 | |
|     obj = dixLookupPrivate(&pWin->devPrivates, objectKey);
 | |
| 
 | |
|     if (obj->sid) {
 | |
|         security_context_t ctx;
 | |
|         int rc = avc_sid_to_context_raw(obj->sid, &ctx);
 | |
| 
 | |
|         if (rc < 0)
 | |
|             FatalError("SELinux: Failed to get security context!\n");
 | |
|         rc = dixChangeWindowProperty(serverClient,
 | |
|                                      pWin, atom_ctx, XA_STRING, 8,
 | |
|                                      PropModeReplace, strlen(ctx), ctx, FALSE);
 | |
|         if (rc != Success)
 | |
|             FatalError("SELinux: Failed to set label property on window!\n");
 | |
|         freecon(ctx);
 | |
|     }
 | |
|     else
 | |
|         FatalError("SELinux: Unexpected unlabeled window found\n");
 | |
| }
 | |
| 
 | |
| static int netlink_fd;
 | |
| 
 | |
| static void
 | |
| SELinuxBlockHandler(void *data, struct timeval **tv, void *read_mask)
 | |
| {
 | |
| }
 | |
| 
 | |
| static void
 | |
| SELinuxWakeupHandler(void *data, int err, void *read_mask)
 | |
| {
 | |
|     if (FD_ISSET(netlink_fd, (fd_set *) read_mask))
 | |
|         avc_netlink_check_nb();
 | |
| }
 | |
| 
 | |
| void
 | |
| SELinuxFlaskReset(void)
 | |
| {
 | |
|     /* Unregister callbacks */
 | |
|     DeleteCallback(&ClientStateCallback, SELinuxClientState, NULL);
 | |
|     DeleteCallback(&ResourceStateCallback, SELinuxResourceState, NULL);
 | |
| 
 | |
|     XaceDeleteCallback(XACE_EXT_DISPATCH, SELinuxExtension, NULL);
 | |
|     XaceDeleteCallback(XACE_RESOURCE_ACCESS, SELinuxResource, NULL);
 | |
|     XaceDeleteCallback(XACE_DEVICE_ACCESS, SELinuxDevice, NULL);
 | |
|     XaceDeleteCallback(XACE_PROPERTY_ACCESS, SELinuxProperty, NULL);
 | |
|     XaceDeleteCallback(XACE_SEND_ACCESS, SELinuxSend, NULL);
 | |
|     XaceDeleteCallback(XACE_RECEIVE_ACCESS, SELinuxReceive, NULL);
 | |
|     XaceDeleteCallback(XACE_CLIENT_ACCESS, SELinuxClient, NULL);
 | |
|     XaceDeleteCallback(XACE_EXT_ACCESS, SELinuxExtension, NULL);
 | |
|     XaceDeleteCallback(XACE_SERVER_ACCESS, SELinuxServer, NULL);
 | |
|     XaceDeleteCallback(XACE_SELECTION_ACCESS, SELinuxSelection, NULL);
 | |
|     XaceDeleteCallback(XACE_SCREEN_ACCESS, SELinuxScreen, NULL);
 | |
|     XaceDeleteCallback(XACE_SCREENSAVER_ACCESS, SELinuxScreen, truep);
 | |
| 
 | |
|     /* Tear down SELinux stuff */
 | |
|     audit_close(audit_fd);
 | |
|     avc_netlink_release_fd();
 | |
|     RemoveBlockAndWakeupHandlers(SELinuxBlockHandler, SELinuxWakeupHandler,
 | |
|                                  NULL);
 | |
|     RemoveGeneralSocket(netlink_fd);
 | |
| 
 | |
|     avc_destroy();
 | |
| }
 | |
| 
 | |
| void
 | |
| SELinuxFlaskInit(void)
 | |
| {
 | |
|     struct selinux_opt avc_option = { AVC_OPT_SETENFORCE, (char *) 0 };
 | |
|     security_context_t ctx;
 | |
|     int ret = TRUE;
 | |
| 
 | |
|     switch (selinuxEnforcingState) {
 | |
|     case SELINUX_MODE_ENFORCING:
 | |
|         LogMessage(X_INFO, "SELinux: Configured in enforcing mode\n");
 | |
|         avc_option.value = (char *) 1;
 | |
|         break;
 | |
|     case SELINUX_MODE_PERMISSIVE:
 | |
|         LogMessage(X_INFO, "SELinux: Configured in permissive mode\n");
 | |
|         avc_option.value = (char *) 0;
 | |
|         break;
 | |
|     default:
 | |
|         avc_option.type = AVC_OPT_UNUSED;
 | |
|         break;
 | |
|     }
 | |
| 
 | |
|     /* Set up SELinux stuff */
 | |
|     selinux_set_callback(SELINUX_CB_LOG, (union selinux_callback) SELinuxLog);
 | |
|     selinux_set_callback(SELINUX_CB_AUDIT,
 | |
|                          (union selinux_callback) SELinuxAudit);
 | |
| 
 | |
|     if (selinux_set_mapping(map) < 0) {
 | |
|         if (errno == EINVAL) {
 | |
|             ErrorF
 | |
|                 ("SELinux: Invalid object class mapping, disabling SELinux support.\n");
 | |
|             return;
 | |
|         }
 | |
|         FatalError("SELinux: Failed to set up security class mapping\n");
 | |
|     }
 | |
| 
 | |
|     if (avc_open(&avc_option, 1) < 0)
 | |
|         FatalError("SELinux: Couldn't initialize SELinux userspace AVC\n");
 | |
| 
 | |
|     if (security_get_initial_context_raw("unlabeled", &ctx) < 0)
 | |
|         FatalError("SELinux: Failed to look up unlabeled context\n");
 | |
|     if (avc_context_to_sid_raw(ctx, &unlabeled_sid) < 0)
 | |
|         FatalError("SELinux: a context_to_SID call failed!\n");
 | |
|     freecon(ctx);
 | |
| 
 | |
|     /* Prepare for auditing */
 | |
|     audit_fd = audit_open();
 | |
|     if (audit_fd < 0)
 | |
|         FatalError("SELinux: Failed to open the system audit log\n");
 | |
| 
 | |
|     /* Allocate private storage */
 | |
|     if (!dixRegisterPrivateKey
 | |
|         (subjectKey, PRIVATE_XSELINUX, sizeof(SELinuxSubjectRec)) ||
 | |
|         !dixRegisterPrivateKey(objectKey, PRIVATE_XSELINUX,
 | |
|                                sizeof(SELinuxObjectRec)) ||
 | |
|         !dixRegisterPrivateKey(dataKey, PRIVATE_XSELINUX,
 | |
|                                sizeof(SELinuxObjectRec)))
 | |
|         FatalError("SELinux: Failed to allocate private storage.\n");
 | |
| 
 | |
|     /* Create atoms for doing window labeling */
 | |
|     atom_ctx = MakeAtom("_SELINUX_CONTEXT", 16, TRUE);
 | |
|     if (atom_ctx == BAD_RESOURCE)
 | |
|         FatalError("SELinux: Failed to create atom\n");
 | |
|     atom_client_ctx = MakeAtom("_SELINUX_CLIENT_CONTEXT", 23, TRUE);
 | |
|     if (atom_client_ctx == BAD_RESOURCE)
 | |
|         FatalError("SELinux: Failed to create atom\n");
 | |
| 
 | |
|     netlink_fd = avc_netlink_acquire_fd();
 | |
|     AddGeneralSocket(netlink_fd);
 | |
|     RegisterBlockAndWakeupHandlers(SELinuxBlockHandler, SELinuxWakeupHandler,
 | |
|                                    NULL);
 | |
| 
 | |
|     /* Register callbacks */
 | |
|     ret &= AddCallback(&ClientStateCallback, SELinuxClientState, NULL);
 | |
|     ret &= AddCallback(&ResourceStateCallback, SELinuxResourceState, NULL);
 | |
| 
 | |
|     ret &= XaceRegisterCallback(XACE_EXT_DISPATCH, SELinuxExtension, NULL);
 | |
|     ret &= XaceRegisterCallback(XACE_RESOURCE_ACCESS, SELinuxResource, NULL);
 | |
|     ret &= XaceRegisterCallback(XACE_DEVICE_ACCESS, SELinuxDevice, NULL);
 | |
|     ret &= XaceRegisterCallback(XACE_PROPERTY_ACCESS, SELinuxProperty, NULL);
 | |
|     ret &= XaceRegisterCallback(XACE_SEND_ACCESS, SELinuxSend, NULL);
 | |
|     ret &= XaceRegisterCallback(XACE_RECEIVE_ACCESS, SELinuxReceive, NULL);
 | |
|     ret &= XaceRegisterCallback(XACE_CLIENT_ACCESS, SELinuxClient, NULL);
 | |
|     ret &= XaceRegisterCallback(XACE_EXT_ACCESS, SELinuxExtension, NULL);
 | |
|     ret &= XaceRegisterCallback(XACE_SERVER_ACCESS, SELinuxServer, NULL);
 | |
|     ret &= XaceRegisterCallback(XACE_SELECTION_ACCESS, SELinuxSelection, NULL);
 | |
|     ret &= XaceRegisterCallback(XACE_SCREEN_ACCESS, SELinuxScreen, NULL);
 | |
|     ret &= XaceRegisterCallback(XACE_SCREENSAVER_ACCESS, SELinuxScreen, truep);
 | |
|     if (!ret)
 | |
|         FatalError("SELinux: Failed to register one or more callbacks\n");
 | |
| 
 | |
|     /* Label objects that were created before we could register ourself */
 | |
|     SELinuxLabelInitial();
 | |
| }
 |