lib: pdn: use heap for AT response buffer and make size configurable

Add CONFIG_PDN_DYNAMIC_INFO_AT_BUF_SIZE to make the AT response buffer
size for AT+CGCONTRDP configurable, as it depends on the APN.
Use k_malloc for AT buffer to avoid increasing system workqueue stack
size requirement.

Signed-off-by: Eivind Jølsgard <[email protected]>

Author: eivindj-nordic

doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst

@@ -531,6 +531,7 @@ Modem libraries
 
 * :ref:`pdn_readme` library:
 
+  * Added the :kconfig:option:`CONFIG_PDN_DYNAMIC_INFO_AT_BUF_SIZE ` Kconfig option to set the response buffer size for the ``AT+CGCONTRDP`` AT command.
   * Deprecated the :c:func:`pdn_dynamic_params_get` function.
     Use the new function :c:func:`pdn_dynamic_info_get` instead.
 

lib/pdn/Kconfig

@@ -27,6 +27,13 @@ config PDN_INIT_PRIORITY
 	int "Initialization priority"
 	default APPLICATION_INIT_PRIORITY
 
+config PDN_DYNAMIC_INFO_AT_BUF_SIZE
+	int "Dynamic info AT buffer size"
+	default 512
+	help
+	   Buffer size for storing the response of the AT+CGCONTRDP AT command used in the
+	   pdn_dynamic_info_get() function.
+
 config PDN_DEFAULTS_OVERRIDE
 	bool "Override defaults for PDP context 0"
 	help

lib/pdn/pdn.c

@@ -688,7 +688,7 @@ int pdn_dynamic_info_get(uint32_t cid, struct pdn_dynamic_info *pdn_info)
 	struct at_parser parser;
 	size_t param_str_len;
 
-	char cgcontrdp_at_rsp_buf[512];
+	char *cgcontrdp_at_rsp_buf;
 
 	char *at_ptr;
 	char *tmp_ptr;
@@ -706,18 +706,24 @@ int pdn_dynamic_info_get(uint32_t cid, struct pdn_dynamic_info *pdn_info)
 		return -EINVAL;
 	}
 
+	cgcontrdp_at_rsp_buf = k_malloc(CONFIG_PDN_DYNAMIC_INFO_AT_BUF_SIZE);
+	if (!cgcontrdp_at_rsp_buf) {
+		LOG_ERR("k_malloc failed for CGDCONTRDP response buffer");
+		return -ENOMEM;
+	}
+
 	at_ptr = cgcontrdp_at_rsp_buf;
 	tmp_ptr = cgcontrdp_at_rsp_buf;
 
 	sprintf(at_cmd_pdn_context_read_info_cmd_str, AT_CMD_PDN_CONTEXT_READ_INFO, cid);
-	ret = nrf_modem_at_cmd(cgcontrdp_at_rsp_buf, sizeof(cgcontrdp_at_rsp_buf), "%s",
+	ret = nrf_modem_at_cmd(cgcontrdp_at_rsp_buf, CONFIG_PDN_DYNAMIC_INFO_AT_BUF_SIZE, "%s",
 			       at_cmd_pdn_context_read_info_cmd_str);
 	if (ret) {
 		LOG_ERR(
 			"nrf_modem_at_cmd returned err: %d for %s",
 			ret,
 			at_cmd_pdn_context_read_info_cmd_str);
-		return ret;
+		goto clean_exit;
 	}
 
 	/* Check how many rows of info do we have */
@@ -732,7 +738,7 @@ int pdn_dynamic_info_get(uint32_t cid, struct pdn_dynamic_info *pdn_info)
 	if (ret) {
 		LOG_ERR("Could not init AT parser for %s, error: %d\n",
 			   at_cmd_pdn_context_read_info_cmd_str, ret);
-		return ret;
+		goto clean_exit;
 	}
 
 parse:
@@ -813,6 +819,7 @@ int pdn_dynamic_info_get(uint32_t cid, struct pdn_dynamic_info *pdn_info)
 	}
 
 clean_exit:
+	k_free(cgcontrdp_at_rsp_buf);
 	return ret;
 }
 

tests/lib/pdn/CMakeLists.txt

@@ -28,3 +28,4 @@ add_compile_definitions(CONFIG_PDN_ESM_TIMEOUT=1000)
 add_compile_definitions(CONFIG_PDN_DEFAULTS_OVERRIDE)
 add_compile_definitions(CONFIG_PDN_DEFAULT_APN="apn0")
 add_compile_definitions(CONFIG_PDN_DEFAULT_FAM=2)
+add_compile_definitions(CONFIG_PDN_DYNAMIC_INFO_AT_BUF_SIZE=512)