fix position

backend/src/api/nft_manager.py

@@ -255,7 +255,7 @@ class CreateRuleRequest(BaseModel):
     table: str = Field(..., description="Table name (e.g. filter)", example="filter")
     chain: str = Field(..., description="Chain name (e.g. forward)", example="forward")
     expr: Any = Field(..., description="nft JSON expression (machine-readable). This field is required for JSON rule creation.")
-    position: Optional[int] = Field(None, description="Optional zero-based insertion position (0 = top). If omitted the rule is appended.")
+    position: Optional[int] = Field(None, description="Optional insertion position (zero-based). If provided endpoint will insert at that position.")
     comment: Optional[str] = Field(None, description="Optional comment")
 
     class Config:
@@ -264,42 +264,12 @@ class CreateRuleRequest(BaseModel):
                 "family": "bridge",
                 "table": "filter",
                 "chain": "forward",
-                "position": 1,
                 "expr": [{"match": {"left": {"payload": {"protocol": "ip", "field": "protocol"}}, "op": "==", "right": "icmp"}}, {"drop": None}],
+                "position": 0,
             }
         }
 
 
-# ---------- Move endpoints: request/response models ----------
-class MoveRequest(BaseModel):
-    """
-    Request body for moving a rule. Exactly one of these should typically be provided:
-      - position: numeric index to insert at (0 = first)
-      - before_handle: insert before an existing handle in the same chain
-      - to_top: boolean
-      - to_bottom: boolean
-    family/table/chain are required to identify the chain.
-    """
-    family: str = Field(..., example="bridge")
-    table: str = Field(..., example="filter")
-    chain: str = Field(..., example="forward")
-    position: Optional[int] = Field(None, description="Zero-based position to insert at (0 = top)")
-    before_handle: Optional[int] = Field(None, description="Insert before this handle (find its index and use that)")
-    to_top: Optional[bool] = Field(False, description="Move to top (equivalent to position=0)")
-    to_bottom: Optional[bool] = Field(False, description="Move to bottom (append)")
-
-
-class MoveSubResult(BaseModel):
-    cmd: str
-    out: Optional[ExecResult] = None
-    err: Optional[str] = None
-
-
-class MoveResult(BaseModel):
-    added: MoveSubResult
-    deleted: MoveSubResult
-
-
 # ruleset may be typed RulesetModel or raw textual string (fallback)
 RulesetValue = Optional[Union[RulesetModel, str]]
 
@@ -601,7 +571,6 @@ def expr_to_text(expr: Any) -> Optional[str]:
                 elif isinstance(q, (int, float)):
                     token += f" num {int(q)}"
                 elif isinstance(q, str):
-                    # preserve string but ensure spacing: client must supply numeric if nft expects it
                     token += f" num {q}"
                 parts.append(token)
                 continue
@@ -707,7 +676,8 @@ def list_rules():
 def create_rule_json(req: CreateRuleRequest):
     """
     Create a rule from JSON (expr required).
-    - Attempts to render expr -> textual fragment and execute: `add rule <family> <table> <chain> [position N] <fragment>`
+    - If req.position is provided, uses: insert rule <family> <table> <chain> position <n> <expr>
+    - Otherwise, uses: add rule <family> <table> <chain> <expr> (append)
     - If rendering fails: 400 instructing the client to use POST /firewall/raw
     - Returns ExecResult on success (201) or on error (400) with stdout/stderr in body.
     - If nft wrapper returns an invalid rc but the command produced no stderr, we double-check the chain
@@ -730,38 +700,20 @@ def create_rule_json(req: CreateRuleRequest):
 
         expr_text = rendered.strip()
 
-        # If a position is provided, try to determine chain length to clamp the position.
-        position_token = ""
+        # If a position is explicitly requested, use the 'insert rule ... position <n> ...' form.
+        # 'add rule ... position ...' is not supported by some nft versions / syntaxes.
         if req.position is not None:
-            # ensure numeric and non-negative
             try:
-                pos_candidate = int(req.position)
+                pos = int(req.position)
+                # clamp pos to >= 0
+                if pos < 0:
+                    pos = 0
             except Exception:
-                raise NftError("position must be an integer >= 0")
-            if pos_candidate < 0:
-                raise NftError("position must be >= 0")
+                pos = 0
+            cmd = f"insert rule {family} {table} {chain} position {pos} {expr_text}"
+        else:
+            cmd = f"add rule {family} {table} {chain} {expr_text}"
 
-            # attempt to read current ruleset to know chain length
-            try:
-                nft_json = mgr.list_rules_json()
-                custom = build_predictable_ruleset(nft_json)
-                chain_rules: List[Dict[str, Any]] = []
-                for t in custom.get("tables", []):
-                    if t.get("family") == family and t.get("name") == table:
-                        for ch in t.get("chains", []):
-                            if ch.get("name") == chain:
-                                chain_rules = ch.get("rules", [])
-                                break
-                chain_len = len(chain_rules)
-                # clamp position to [0, chain_len]
-                pos = max(0, min(chain_len, pos_candidate))
-            except Exception:
-                # if we cannot read ruleset, just use provided pos_candidate (server may still accept or fail)
-                pos = pos_candidate
-
-            position_token = f" position {pos}"
-
-        cmd = f"add rule {family} {table} {chain}{position_token} {expr_text}"
         logger.info("create_rule_json executing command: %s", cmd)
 
         res = mgr.cmd(cmd)