afs: Sanity-check some AFSFetchStatus structures

We currently do not do any sanity checking on the AFSFetchStatus
structures returned from fileservers. Add some sanity checking for
BulkStatus and FetchStatus calls, so we do not screw up our cache if a
fileserver gives us bogus data.

If we do get an invalid AFSFetchStatus structure, act as if the server
gave us a VBUSY error code, so we will retry the request. For OpenAFS
fileservers prior to 1.6.1 that yield this situation, VBUSY is likely
the error code the fileserver should have responded anyway.

Change-Id: Ie16a5210149b21dd5945380f5d7b6a4d9ee01a72
Reviewed-on: http://gerrit.openafs.org/6880
Reviewed-by: Alistair Ferguson <alistair.ferguson@mac.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>

diff --git a/src/afs/VNOPS/afs_vnop_lookup.c b/src/afs/VNOPS/afs_vnop_lookup.c
index 1a15f49..c14b4a5 100644 (file)
--- a/src/afs/VNOPS/afs_vnop_lookup.c
+++ b/src/afs/VNOPS/afs_vnop_lookup.c
@@ -622,6 +622,29 @@ Next_AtSys(struct vcache *avc, struct vrequest *areq,
     return 1;
 }
 
+static int
+afs_CheckBulkStatus(struct afs_conn *tc, int nFids, AFSBulkStats *statParm,
+                    AFSCBs *cbParm)
+{
+    int i;
+    int code;
+
+    if (statParm->AFSBulkStats_len != nFids || cbParm->AFSCBs_len != nFids) {
+       return VBUSY;
+    }
+    for (i = 0; i < nFids; i++) {
+       if (statParm->AFSBulkStats_val[i].errorCode) {
+           continue;
+       }
+       code = afs_CheckFetchStatus(tc, &statParm->AFSBulkStats_val[i]);
+       if (code) {
+           return code;
+       }
+    }
+
+    return 0;
+}
+
 extern int BlobScan(struct dcache * afile, afs_int32 ablob);
 
 /* called with an unlocked directory and directory cookie.  Areqp
@@ -1002,6 +1025,10 @@ afs_DoBulkStat(struct vcache *adp, long dirCookie, struct vrequest *areqp)
                RX_AFS_GLOCK();
            }
            XSTATS_END_TIME;
+
+           if (code == 0) {
+               code = afs_CheckBulkStatus(tcp, fidIndex, &statParm, &cbParm);
+           }
        } else
            code = -1;
     } while (afs_Analyze

diff --git a/src/afs/afs_prototypes.h b/src/afs/afs_prototypes.h
index 71ef0a6..2633528 100644 (file)
--- a/src/afs/afs_prototypes.h
+++ b/src/afs/afs_prototypes.h
@@ -1071,6 +1071,8 @@ extern void afs_FlushReclaimedVcaches(void);
 void afs_vcacheInit(int astatSize);
 extern struct vcache *afs_FindVCache(struct VenusFid *afid, afs_int32 * retry,
                                     afs_int32 flag);
+extern int afs_CheckFetchStatus(struct afs_conn *tc,
+                                struct AFSFetchStatus *status);
 extern afs_int32 afs_FetchStatus(struct vcache *avc, struct VenusFid *afid,
                                 struct vrequest *areq,
                                 struct AFSFetchStatus *Outsp);

diff --git a/src/afs/afs_vcache.c b/src/afs/afs_vcache.c
index 7428c94..4f1372b 100644 (file)
--- a/src/afs/afs_vcache.c
+++ b/src/afs/afs_vcache.c
@@ -2346,6 +2346,30 @@ afs_UpdateStatus(struct vcache *avc, struct VenusFid *afid,
        afs_PutVolume(volp, READ_LOCK);
 }
 
+/**
+ * Check if a given AFSFetchStatus structure is sane.
+ *
+ * @param[in] tc The server from which we received the status
+ * @param[in] status The status we received
+ *
+ * @return whether the given structure is valid or not
+ *  @retval 0 the structure is fine
+ *  @retval nonzero the structure looks like garbage; act as if we received
+ *                  the returned error code from the server
+ */
+int
+afs_CheckFetchStatus(struct afs_conn *tc, struct AFSFetchStatus *status)
+{
+    if (status->errorCode ||
+        status->InterfaceVersion != 1 ||
+        !(status->FileType > Invalid && status->FileType <= SymbolicLink) ||
+        status->ParentVnode == 0 || status->ParentUnique == 0) {
+
+       return VBUSY;
+    }
+    return 0;
+}
+
 /*!
  * Must be called with avc write-locked
  * don't absolutely have to invalidate the hint unless the dv has
@@ -2377,6 +2401,10 @@ afs_FetchStatus(struct vcache * avc, struct VenusFid * afid,
 
            XSTATS_END_TIME;
 
+           if (code == 0) {
+               code = afs_CheckFetchStatus(tc, Outsp);
+           }
+
        } else
            code = -1;
     } while (afs_Analyze