yanger: Allow to read back SSIDs encoded with utf-8

Author: mattiaswal

board/common/rootfs/usr/libexec/infix/iw.py

@@ -13,6 +13,13 @@
 import json
 import subprocess
 import re
+def decode_iw_ssid(ssid):
+    """Decode iw escaped SSID (\\xHH) to UTF-8, stripping non-printable chars."""
+    try:
+        ssid = ssid.encode().decode('unicode_escape').encode('latin-1').decode('utf-8')
+    except (UnicodeDecodeError, UnicodeEncodeError):
+        return ssid
+    return ''.join(c for c in ssid if c.isprintable())
 
 
 def run_iw(*args):
@@ -260,7 +267,7 @@ def parse_interface_info(ifname):
 
         # SSID
         elif stripped.startswith('ssid '):
-            result['ssid'] = ' '.join(stripped.split()[1:])
+            result['ssid'] = decode_iw_ssid(' '.join(stripped.split()[1:]))
 
         # Channel/frequency
         elif stripped.startswith('channel '):
@@ -488,7 +495,7 @@ def parse_link(ifname):
 
         # SSID: NetworkName
         elif stripped.startswith('SSID: '):
-            result['ssid'] = stripped[6:]
+            result['ssid'] = decode_iw_ssid(stripped[6:])
 
         # freq: 5180
         elif stripped.startswith('freq: '):
@@ -582,7 +589,7 @@ def main():
         else:
             data = {'error': f'Unknown command: {command}'}
 
-        print(json.dumps(data, indent=2))
+        print(json.dumps(data, indent=2, ensure_ascii=False))
 
     except Exception as e:
         print(json.dumps({'error': str(e)}))

src/confd/yang/confd/infix-if-wifi.yang

@@ -151,6 +151,9 @@ submodule infix-if-wifi {
             leaf ssid {
               type string {
                 length "1..32";
+                pattern '[^\x00-\x1f\x22\x5c\x7f]*' {
+                  error-message "SSID must not contain control characters, double quotes, or backslashes.";
+                }
               }
               mandatory true;
               description
@@ -322,6 +325,9 @@ submodule infix-if-wifi {
             leaf ssid {
               type string {
                 length "1..32";
+                pattern '[^\x00-\x1f\x22\x5c\x7f]*' {
+                  error-message "SSID must not contain control characters, double quotes, or backslashes.";
+                }
               }
               mandatory true;
               description

src/statd/python/yanger/__main__.py

@@ -97,7 +97,7 @@ def dirpath(path):
         common.LOG.warning("Unsupported model %s", args.model)
         sys.exit(1)
 
-    print(json.dumps(yang_data, indent=2))
+    print(json.dumps(yang_data, indent=2, ensure_ascii=False))
 
 
 if __name__ == "__main__":

src/statd/python/yanger/ietf_interfaces/wifi.py

@@ -122,9 +122,15 @@ def parse_wpa_scan_result(scan_output):
 
                 flags = parts[3].strip()
                 ssid = parts[4].strip() if len(parts) > 4 else ""
+                try:
+                    ssid = ssid.encode().decode('unicode_escape').encode('latin-1').decode('utf-8')
+                except (UnicodeDecodeError, UnicodeEncodeError):
+                    pass
+                # Strip control chars (terminal injection risk from rogue APs)
+                ssid = ''.join(c for c in ssid if c.isprintable())
 
                 # Skip hidden SSIDs (empty or null-filled)
-                if not ssid or ssid.isspace() or '\\x00' in ssid:
+                if not ssid or ssid.isspace():
                     continue
 
                 encryption = extract_encryption(flags)