feat(modem): add ability to change ESP_MODEM_C_API_STR_MAX from Kconfig

Author: embedcat

components/esp_modem/Kconfig

@@ -63,4 +63,11 @@ menu "esp-modem"
             dce_factory::Factory::create_unique_dce_from<CustomModule, DCE*>(dce_config, std::move(dte), netif)
             Please refer to the pppos_client example for more details.
 
+    config ESP_MODEM_C_API_STR_MAX
+        int "Size in bytes for response from AT commands returning textual values (C-API)"
+        default 128
+        help
+            Some AT commands returns textrual values which C-API copy as c-string to user allocated space,
+            it also truncates the output data to this size. Increase this if some AT answers are truncated.
+
 endmenu

components/esp_modem/examples/pppos_client/main/custom_module.hpp

@@ -56,7 +56,7 @@ DCE *esp_modem_create_custom_dce(const esp_modem_dce_config_t *dce_config, std::
 /**
  * @brief This API is only needed for extending standard C-API, since we added get_time() method to our CustomModule
  *
- * @note This header is included from esp_modem_c_api.cpp, so it could use ESP_MODEM_C_API_STR_MAX macro
+ * @note This header is included from esp_modem_c_api.cpp, so it could use CONFIG_ESP_MODEM_C_API_STR_MAX macro
  * indicating maximum C-API string size
  *
  * @note In order to access the newly added API get_time(), we have to static_cast<> the GenericModule from DCE
@@ -70,10 +70,10 @@ extern "C" esp_err_t esp_modem_get_time(esp_modem_dce_t *dce_wrap, char *p_time)
     if (dce_wrap == nullptr || dce_wrap->dce == nullptr) {
         return ESP_ERR_INVALID_ARG;
     }
-    std::string time{ESP_MODEM_C_API_STR_MAX};
+    std::string time{CONFIG_ESP_MODEM_C_API_STR_MAX};
     auto ret = command_response_to_esp_err(static_cast<SIM7600_WITH_TIME *>(dce_wrap->dce->get_module())->get_time(time));
     if (ret == ESP_OK && !time.empty()) {
-        strlcpy(p_time, time.c_str(), ESP_MODEM_C_API_STR_MAX);
+        strlcpy(p_time, time.c_str(), CONFIG_ESP_MODEM_C_API_STR_MAX);
     }
     return ret;
 }

components/esp_modem/src/esp_modem_c_api.cpp

@@ -16,10 +16,6 @@
 #include "exception_stub.hpp"
 #include "esp_private/c_api_wrapper.hpp"
 
-#ifndef ESP_MODEM_C_API_STR_MAX
-#define ESP_MODEM_C_API_STR_MAX 128
-#endif
-
 #ifndef HAVE_STRLCPY
 size_t strlcpy(char *dest, const char *src, size_t len);
 #endif
@@ -180,7 +176,7 @@ extern "C" esp_err_t esp_modem_at(esp_modem_dce_t *dce_wrap, const char *at, cha
     std::string at_str(at);
     auto ret = command_response_to_esp_err(dce_wrap->dce->at(at_str, out, timeout));
     if ((p_out != NULL) && (!out.empty())) {
-        strlcpy(p_out, out.c_str(), ESP_MODEM_C_API_STR_MAX);
+        strlcpy(p_out, out.c_str(), CONFIG_ESP_MODEM_C_API_STR_MAX);
     }
     return ret;
 }
@@ -201,7 +197,7 @@ extern "C" esp_err_t esp_modem_get_imsi(esp_modem_dce_t *dce_wrap, char *p_imsi)
     std::string imsi;
     auto ret = command_response_to_esp_err(dce_wrap->dce->get_imsi(imsi));
     if (ret == ESP_OK && !imsi.empty()) {
-        strlcpy(p_imsi, imsi.c_str(), ESP_MODEM_C_API_STR_MAX);
+        strlcpy(p_imsi, imsi.c_str(), CONFIG_ESP_MODEM_C_API_STR_MAX);
     }
     return ret;
 }
@@ -214,7 +210,7 @@ extern "C" esp_err_t esp_modem_at_raw(esp_modem_dce_t *dce_wrap, const char *cmd
     std::string out;
     auto ret = command_response_to_esp_err(dce_wrap->dce->at_raw(cmd, out, pass, fail, timeout));
     if ((p_out != NULL) && (!out.empty())) {
-        strlcpy(p_out, out.c_str(), ESP_MODEM_C_API_STR_MAX);
+        strlcpy(p_out, out.c_str(), CONFIG_ESP_MODEM_C_API_STR_MAX);
     }
     return ret;
 }
@@ -244,7 +240,7 @@ extern "C" esp_err_t esp_modem_get_imei(esp_modem_dce_t *dce_wrap, char *p_imei)
     std::string imei;
     auto ret = command_response_to_esp_err(dce_wrap->dce->get_imei(imei));
     if (ret == ESP_OK && !imei.empty()) {
-        strlcpy(p_imei, imei.c_str(), ESP_MODEM_C_API_STR_MAX);
+        strlcpy(p_imei, imei.c_str(), CONFIG_ESP_MODEM_C_API_STR_MAX);
     }
     return ret;
 }
@@ -258,7 +254,7 @@ extern "C" esp_err_t esp_modem_get_operator_name(esp_modem_dce_t *dce_wrap, char
     int act;
     auto ret = command_response_to_esp_err(dce_wrap->dce->get_operator_name(name, act));
     if (ret == ESP_OK && !name.empty()) {
-        strlcpy(p_name, name.c_str(), ESP_MODEM_C_API_STR_MAX);
+        strlcpy(p_name, name.c_str(), CONFIG_ESP_MODEM_C_API_STR_MAX);
         *p_act = act;
     }
     return ret;
@@ -272,7 +268,7 @@ extern "C" esp_err_t esp_modem_get_module_name(esp_modem_dce_t *dce_wrap, char *
     std::string name;
     auto ret = command_response_to_esp_err(dce_wrap->dce->get_module_name(name));
     if (ret == ESP_OK && !name.empty()) {
-        strlcpy(p_name, name.c_str(), ESP_MODEM_C_API_STR_MAX);
+        strlcpy(p_name, name.c_str(), CONFIG_ESP_MODEM_C_API_STR_MAX);
     }
     return ret;
 }

docs/esp_modem/en/api_docs.rst

@@ -43,7 +43,7 @@ These functions are the actual commands to communicate with the modem using AT c
 
 Note that the functions which implement AT commands returning textual values use plain ``char *``
 pointer as the return value. The API expects the output data to point to user allocated space of at least
-``ESP_MODEM_C_API_STR_MAX`` (64 by default) bytes, it also truncates the output data to this size.
+``CONFIG_ESP_MODEM_C_API_STR_MAX`` (128 by default) bytes, it also truncates the output data to this size.
 
 .. doxygenfile:: esp_modem_api_commands.h