[LibOS] Updates to encrypted files

* make corruption status for encrypted files sticky
* update filemap state for any corruption also encountered
  during operations other than open, close, unlink and rename

Author: g2flyer

common/src/protected_files/protected_files.c

@@ -791,6 +791,9 @@ static bool ipf_init_existing_file(pf_context_t* pf, const char* path) {
     if (PF_FAILURE(status)) {
         pf->last_error = status;
         DEBUG_PF("failed to decrypt metadata: %d", status);
+        if (status == PF_STATUS_MAC_MISMATCH)
+            // MAC could also mismatch if wrong key was provided but we err on side of safety ...
+            pf->file_status = PF_STATUS_CORRUPTED;
         return false;
     }
 
@@ -818,6 +821,8 @@ static bool ipf_init_existing_file(pf_context_t* pf, const char* path) {
                                       &pf->metadata_decrypted.root_mht_node_mac);
         if (PF_FAILURE(status)) {
             pf->last_error = status;
+            if (status == PF_STATUS_MAC_MISMATCH)
+                pf->file_status = PF_STATUS_CORRUPTED;
             return false;
         }
     }
@@ -1162,6 +1167,9 @@ pf_status_t pf_get_size(pf_context_t* pf, uint64_t* size) {
     if (!g_initialized)
         return PF_STATUS_UNINITIALIZED;
 
+    if (pf->file_status == PF_STATUS_CORRUPTED)
+        return pf->file_status;  // Make corruption "sticky"
+
     *size = pf->metadata_decrypted.file_size;
     return PF_STATUS_SUCCESS;
 }
@@ -1173,6 +1181,9 @@ pf_status_t pf_set_size(pf_context_t* pf, uint64_t size) {
     if (!(pf->mode & PF_FILE_MODE_WRITE))
         return PF_STATUS_INVALID_MODE;
 
+    if (pf->file_status == PF_STATUS_CORRUPTED)
+        return pf->file_status;  // Make corruption "sticky"
+
     if (size == pf->metadata_decrypted.file_size)
         return PF_STATUS_SUCCESS;
 
@@ -1221,6 +1232,9 @@ pf_status_t pf_rename(pf_context_t* pf, const char* new_path, pf_mac_t* new_root
     if (!g_initialized)
         return PF_STATUS_UNINITIALIZED;
 
+    if (pf->file_status == PF_STATUS_CORRUPTED)
+        return pf->file_status;  // Make corruption "sticky"
+
     if (!(pf->mode & PF_FILE_MODE_WRITE))
         return PF_STATUS_INVALID_MODE;
 
@@ -1293,6 +1307,9 @@ pf_status_t pf_flush(pf_context_t* pf) {
     if (!g_initialized)
         return PF_STATUS_UNINITIALIZED;
 
+    if (pf->file_status == PF_STATUS_CORRUPTED)
+        return pf->file_status;  // Make corruption "sticky"
+
     if (!ipf_internal_flush(pf))
         return pf->last_error;
 

libos/include/libos_fs_encrypted.h

@@ -41,14 +41,19 @@ typedef enum {
     PF_FILE_STATE_DELETED = 2,  // file was previously seen but then either unlinked or renamed
 } libos_encrypted_file_state_t;
 
+inline static const char* file_state_to_string(libos_encrypted_file_state_t state) {
+    return (state == PF_FILE_STATE_ERROR ? "error"
+                                         : (state == PF_FILE_STATE_ACTIVE ? "active" : "deleted"));
+}
+
 /*
  * Map mapping file URIs to state providing information on files, in particular whether we have seen
  * them before and what the last seen root-hash is.  This is necessary to provide rollback
  */
 struct libos_encrypted_volume_state_map {
     char* norm_path;  // assumptions: all paths canonicalized, symlinks are resolved & no hard links
     libos_encrypted_file_state_t state;
-    pf_mac_t last_seen_root_mac;
+    pf_mac_t last_seen_root_mac;  // valid only if state == PF_FILE_STATE_ACTIVE
     UT_hash_handle hh;
 };
 
@@ -224,16 +229,17 @@ void encrypted_file_put(struct libos_encrypted_file* enc, bool fs_reachable);
 /*
  * \brief Flush pending writes to an encrypted file.
  */
-int encrypted_file_flush(struct libos_encrypted_file* enc);
+int encrypted_file_flush(struct libos_encrypted_file* enc, bool fs_reachable);
 
 int encrypted_file_read(struct libos_encrypted_file* enc, void* buf, size_t buf_size,
-                        file_off_t offset, size_t* out_count);
+                        file_off_t offset, size_t* out_count, bool fs_reachable);
 int encrypted_file_write(struct libos_encrypted_file* enc, const void* buf, size_t buf_size,
-                         file_off_t offset, size_t* out_count);
+                         file_off_t offset, size_t* out_count, bool fs_reachable);
 int encrypted_file_rename(struct libos_encrypted_file* enc, const char* new_uri);
 int encrypted_file_unlink(struct libos_encrypted_file* enc);
 
-int encrypted_file_get_size(struct libos_encrypted_file* enc, file_off_t* out_size);
-int encrypted_file_set_size(struct libos_encrypted_file* enc, file_off_t size);
+int encrypted_file_get_size(struct libos_encrypted_file* enc, file_off_t* out_size,
+                            bool fs_reachable);
+int encrypted_file_set_size(struct libos_encrypted_file* enc, file_off_t size, bool fs_reachable);
 
 int parse_pf_key(const char* key_str, pf_key_t* pf_key);

libos/src/fs/chroot/encrypted.c

@@ -207,7 +207,7 @@ static int chroot_encrypted_lookup(struct libos_dentry* dent) {
                 goto out;
             }
         } else {
-            ret = encrypted_file_get_size(enc, &size);
+            ret = encrypted_file_get_size(enc, &size, true);
             encrypted_file_put(enc, true);
 
             if (ret < 0) {
@@ -468,7 +468,7 @@ static int chroot_encrypted_flush(struct libos_handle* hdl) {
 
     /* This will write changes from `enc` to host file */
     lock(&hdl->inode->lock);
-    ret = encrypted_file_flush(enc);
+    ret = encrypted_file_flush(enc, hdl->inode == hdl->dentry->inode);
     unlock(&hdl->inode->lock);
     return ret;
 }
@@ -502,7 +502,8 @@ static ssize_t chroot_encrypted_read(struct libos_handle* hdl, void* buf, size_t
     size_t actual_count;
 
     lock(&hdl->inode->lock);
-    int ret = encrypted_file_read(enc, buf, count, *pos, &actual_count);
+    int ret =
+        encrypted_file_read(enc, buf, count, *pos, &actual_count, hdl->inode == hdl->dentry->inode);
     unlock(&hdl->inode->lock);
 
     if (ret < 0)
@@ -527,7 +528,8 @@ static ssize_t chroot_encrypted_write(struct libos_handle* hdl, const void* buf,
 
     lock(&hdl->inode->lock);
 
-    int ret = encrypted_file_write(enc, buf, count, *pos, &actual_count);
+    int ret = encrypted_file_write(enc, buf, count, *pos, &actual_count,
+                                   hdl->inode == hdl->dentry->inode);
     if (ret < 0) {
         unlock(&hdl->inode->lock);
         return ret;
@@ -557,7 +559,7 @@ static int chroot_encrypted_truncate(struct libos_handle* hdl, file_off_t size)
     assert(enc);
 
     lock(&hdl->inode->lock);
-    ret = encrypted_file_set_size(enc, size);
+    ret = encrypted_file_set_size(enc, size, hdl->inode == hdl->dentry->inode);
     if (ret < 0) {
         unlock(&hdl->inode->lock);
         return ret;