Reject AGC intervals that would wrap or silently disable resets

src/helpers/CommonCLI.cpp

@@ -4265,9 +4265,14 @@ void CommonCLI::handleSetCmd(uint32_t sender_timestamp, char* command, char* rep
       strcpy(reply, "OK");
     }
   } else if (memcmp(config, "agc.reset.interval ", 19) == 0) {
-    _prefs->agc_reset_interval = atoi(&config[19]) / 4;
-    savePrefs();
-    sprintf(reply, "OK - interval rounded to %d", ((uint32_t) _prefs->agc_reset_interval) * 4);
+    uint32_t seconds;
+    if (!mesh::cli::parseUnsignedIntegerStrict(&config[19], seconds) || seconds > 1020) {
+      strcpy(reply, "Error: AGC interval must be 0-1020 seconds");
+    } else {
+      _prefs->agc_reset_interval = seconds / 4;
+      savePrefs();
+      sprintf(reply, "OK - interval rounded to %d", ((uint32_t) _prefs->agc_reset_interval) * 4);
+    }
   } else if (memcmp(config, "multi.acks ", 11) == 0) {
     _prefs->multi_acks = atoi(&config[11]);
     savePrefs();

test/fixtures/cli_settings/main.cpp

@@ -134,6 +134,39 @@ int main() {
         assert(!strncmp(reply+2,state,strlen(state)));
       }
     }
+    // The saved byte represents four-second units. Reject malformed/out-of-
+    // range input before it can wrap (1024 used to silently disable AGC).
+    for (unsigned seconds=0; seconds<=1020; ++seconds) {
+      const unsigned saves=cli.callbacks.saves;
+      snprintf(text,sizeof(text),"set agc.reset.interval %u",seconds);
+      cli.call(sender,text,reply);
+      assert(!strncmp(reply,"OK",2) && cli.callbacks.saves==saves+1);
+      assert(cli.prefs.agc_reset_interval==seconds/4);
+      cli.call(sender,"get agc.reset.interval",reply);
+      unsigned actual=9999;
+      assert(sscanf(reply,"> %u",&actual)==1 && actual==(seconds/4)*4);
+      assert(cli.callbacks.saves==saves+1);
+    }
+    for (const char* value : {"1024", "1021", "1023", "-1", "-4", "",
+                              "garbage", "19tail", "1.5", "0x10", "+", "--4",
+                              "4294967295", "4294967296", "2147483648",
+                              "99999999999999999999999999999999999999"}) {
+      const unsigned saves=cli.callbacks.saves;
+      const uint8_t previous=cli.prefs.agc_reset_interval;
+      snprintf(text,sizeof(text),"set agc.reset.interval %s",value);
+      cli.call(sender,text,reply);
+      if (strncmp(reply,"Error",5))
+        fprintf(stderr,"invalid AGC interval %s accepted: %s\n",value,reply);
+      assert(!strncmp(reply,"Error",5));
+      assert(cli.prefs.agc_reset_interval==previous && cli.callbacks.saves==saves);
+    }
+    for (const char* value : {"+19", " 19 ", "\t19\t", "00019"}) {
+      const unsigned saves=cli.callbacks.saves;
+      snprintf(text,sizeof(text),"set agc.reset.interval %s",value);
+      cli.call(sender,text,reply);
+      assert(!strncmp(reply,"OK",2) && cli.callbacks.saves==saves+1);
+      assert(cli.prefs.agc_reset_interval==4);
+    }
     unsigned saves=cli.callbacks.saves;
     cli.call(sender,"set radio 916,125,8,6",reply);
     assert(!strncmp(reply,"OK",2) && cli.callbacks.saves==saves+1);

test/test_cli_settings_contract.py

@@ -8,6 +8,7 @@ from pathlib import Path
 import re
 import shutil
 import subprocess
+import sys
 import tempfile
 import unittest
 from test_replay_reset_integration import extract_braced
@@ -259,9 +260,12 @@ class CLISettingsContractTest(unittest.TestCase):
             cpp.write_text(fixture, encoding='utf-8')
             for macros in ([], ['-DUSE_LR2021=1']):
                 with self.subTest(macros=macros):
-                    subprocess.run([compiler, '-std=c++17', '-Wall', '-Wextra', '-Werror', *macros,
-                                    '-I', str(ROOT/'src'), str(cpp), '-o', str(exe)], check=True)
-                    subprocess.run([str(exe)], check=True)
+                    sanitizers = (['-fsanitize=address,undefined', '-fno-sanitize-recover=all',
+                                   '-fno-pie', '-no-pie'] if sys.platform.startswith('linux') else [])
+                    subprocess.run([compiler, '-std=c++17', '-Wall', '-Wextra', '-Werror',
+                                    *sanitizers, *macros, '-I', str(ROOT/'src'), str(cpp),
+                                    '-o', str(exe)], check=True, timeout=60)
+                    subprocess.run([str(exe)], check=True, timeout=15)
 
 
 if __name__ == '__main__':