security_dac: Resolve virSecurityDACSetOwnershipInternal const correctness

The code at the very bottom of the DAC secdriver that calls
chown() should be fine with read-only data. If something needs to
be prepared it should have been done beforehand.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_driver.c

@@ -329,10 +329,11 @@ qemuAutostartDomains(virQEMUDriverPtr driver)
 
 
 static int
-qemuSecurityChownCallback(virStorageSourcePtr src,
+qemuSecurityChownCallback(const virStorageSource *src,
                           uid_t uid,
                           gid_t gid)
 {
+    virStorageSourcePtr cpy = NULL;
     struct stat sb;
     int save_errno = 0;
     int ret = -1;
@@ -354,22 +355,28 @@ qemuSecurityChownCallback(virStorageSourcePtr src,
             }
         }
 
-        return chown(src->path, uid, gid);
+        if (chown(src->path, uid, gid) < 0)
+            goto cleanup;
+    } else {
+        if (!(cpy = virStorageSourceCopy(src, false)))
+            goto cleanup;
+
+        /* src file init reports errors, return -2 on failure */
+        if (virStorageFileInit(cpy) < 0) {
+            ret = -2;
+            goto cleanup;
         }
 
-    /* storage file init reports errors, return -2 on failure */
-    if (virStorageFileInit(src) < 0)
-        return -2;
-
-    if (virStorageFileChown(src, uid, gid) < 0) {
-        save_errno = errno;
+        if (virStorageFileChown(cpy, uid, gid) < 0)
             goto cleanup;
     }
 
     ret = 0;
 
  cleanup:
-    virStorageFileDeinit(src);
+    save_errno = errno;
+    virStorageFileDeinit(cpy);
+    virStorageSourceFree(cpy);
     errno = save_errno;
 
     return ret;

src/security/security_dac.c

@@ -279,8 +279,8 @@ virSecurityDACPreFork(virSecurityManagerPtr mgr)
 }
 
 static int
-virSecurityDACSetOwnershipInternal(virSecurityDACDataPtr priv,
-                                   virStorageSourcePtr src,
+virSecurityDACSetOwnershipInternal(const virSecurityDACData *priv,
+                                   const virStorageSource *src,
                                    const char *path,
                                    uid_t uid,
                                    gid_t gid)

src/security/security_manager.h

@@ -62,7 +62,7 @@ int virSecurityManagerStackAddNested(virSecurityManagerPtr stack,
  * @src. The callback shall return 0 on success, -1 on error and errno set (no
  * libvirt error reported) OR -2 and a libvirt error reported. */
 typedef int
-(*virSecurityManagerDACChownCallback)(virStorageSourcePtr src,
+(*virSecurityManagerDACChownCallback)(const virStorageSource *src,
                                       uid_t uid,
                                       gid_t gid);
 

src/storage/storage_backend.h

@@ -285,7 +285,7 @@ typedef int
                                int mode);
 
 typedef int
-(*virStorageFileBackendChown)(virStorageSourcePtr src,
+(*virStorageFileBackendChown)(const virStorageSource *src,
                               uid_t uid,
                               gid_t gid);
 

src/storage/storage_backend_fs.c

@@ -1600,7 +1600,7 @@ virStorageFileBackendFileAccess(virStorageSourcePtr src,
 
 
 static int
-virStorageFileBackendFileChown(virStorageSourcePtr src,
+virStorageFileBackendFileChown(const virStorageSource *src,
                                uid_t uid,
                                gid_t gid)
 {

src/storage/storage_backend_gluster.c

@@ -809,7 +809,7 @@ virStorageFileBackendGlusterGetUniqueIdentifier(virStorageSourcePtr src)
 
 
 static int
-virStorageFileBackendGlusterChown(virStorageSourcePtr src,
+virStorageFileBackendGlusterChown(const virStorageSource *src,
                                   uid_t uid,
                                   gid_t gid)
 {

src/storage/storage_driver.c

@@ -2848,7 +2848,7 @@ int storageRegister(void)
 
 /* ----------- file handlers cooperating with storage driver --------------- */
 static bool
-virStorageFileIsInitialized(virStorageSourcePtr src)
+virStorageFileIsInitialized(const virStorageSource *src)
 {
     return src && src->drv;
 }
@@ -2888,7 +2888,7 @@ virStorageFileSupportsBackingChainTraversal(virStorageSourcePtr src)
  * driver to perform labelling
  */
 bool
-virStorageFileSupportsSecurityDriver(virStorageSourcePtr src)
+virStorageFileSupportsSecurityDriver(const virStorageSource *src)
 {
     int actualType;
     virStorageFileBackendPtr backend;
@@ -3179,7 +3179,7 @@ virStorageFileAccess(virStorageSourcePtr src,
  * by libvirt storage backend.
  */
 int
-virStorageFileChown(virStorageSourcePtr src,
+virStorageFileChown(const virStorageSource *src,
                     uid_t uid,
                     gid_t gid)
 {

src/storage/storage_driver.h

@@ -44,9 +44,9 @@ ssize_t virStorageFileReadHeader(virStorageSourcePtr src,
                                  char **buf);
 const char *virStorageFileGetUniqueIdentifier(virStorageSourcePtr src);
 int virStorageFileAccess(virStorageSourcePtr src, int mode);
-int virStorageFileChown(virStorageSourcePtr src, uid_t uid, gid_t gid);
+int virStorageFileChown(const virStorageSource *src, uid_t uid, gid_t gid);
 
-bool virStorageFileSupportsSecurityDriver(virStorageSourcePtr src);
+bool virStorageFileSupportsSecurityDriver(const virStorageSource *src);
 
 int virStorageFileGetMetadata(virStorageSourcePtr src,
                               uid_t uid, gid_t gid,

src/util/virstoragefile.c

@@ -2082,7 +2082,7 @@ virStorageSourceGetActualType(const virStorageSource *def)
 
 
 bool
-virStorageSourceIsLocalStorage(virStorageSourcePtr src)
+virStorageSourceIsLocalStorage(const virStorageSource *src)
 {
     virStorageType type = virStorageSourceGetActualType(src);
 

src/util/virstoragefile.h

@@ -349,7 +349,7 @@ int virStorageSourceInitChainElement(virStorageSourcePtr newelem,
 void virStorageSourcePoolDefFree(virStorageSourcePoolDefPtr def);
 void virStorageSourceClear(virStorageSourcePtr def);
 int virStorageSourceGetActualType(const virStorageSource *def);
-bool virStorageSourceIsLocalStorage(virStorageSourcePtr src);
+bool virStorageSourceIsLocalStorage(const virStorageSource *src);
 bool virStorageSourceIsEmpty(virStorageSourcePtr src);
 bool virStorageSourceIsBlockLocal(const virStorageSource *src);
 void virStorageSourceFree(virStorageSourcePtr def);