lib: pdn: decrease stack and heap for pdn_dynamic_info_get()

Decrease stack requirements for pdn_dynamic_info_get(). Remove use
of k_malloc(). Add use of pdn_dynamic_info_get() to PDN sample and
add tests.

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

Author: eivindj-nordic

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

@@ -346,6 +346,10 @@ Cellular samples
 
    * Fixed an issue with devicetree configuration after HCI updates in `sdk-zephyr`_.
 
+* :ref:`pdn_sample` sample:
+
+  * Added dynamic PDN information.
+
 Cryptography samples
 --------------------
 
@@ -559,7 +563,6 @@ 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.
 

include/modem/pdn.h

@@ -243,7 +243,7 @@ __deprecated int pdn_dynamic_params_get(uint8_t cid, struct in_addr *dns4_pri,
  *
  * @return Zero on success or an error code on failure.
  */
-int pdn_dynamic_info_get(uint32_t cid, struct pdn_dynamic_info *pdn_info);
+int pdn_dynamic_info_get(uint8_t cid, struct pdn_dynamic_info *pdn_info);
 
 /**
  * @brief Retrieve the default Access Point Name (APN).

lib/pdn/Kconfig

@@ -27,13 +27,6 @@ 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

@@ -15,7 +15,6 @@
 #include <zephyr/net/socket.h>
 #include <zephyr/sys/slist.h>
 #include <zephyr/logging/log.h>
-#include <zephyr/posix/arpa/inet.h>
 #include <nrf_modem_at.h>
 #include <modem/pdn.h>
 #include <modem/at_monitor.h>
@@ -36,15 +35,22 @@ LOG_MODULE_REGISTER(pdn, CONFIG_PDN_LOG_LEVEL);
 #define MODEM_CFUN_NORMAL 1
 #define MODEM_CFUN_ACTIVATE_LTE 21
 
-#define AT_CMD_PDN_CONTEXT_READ_IP_ADDR_STR_MAX_LEN (255)
-
-#define AT_CMD_PDN_CONTEXT_READ_INFO  "AT+CGCONTRDP=%d"
+#define AT_CMD_PDN_CONTEXT_READ_INFO  "AT+CGCONTRDP=%u"
 #define AT_CMD_PDN_CONTEXT_READ_INFO_DNS_ADDR_PRIMARY_INDEX 6
 #define AT_CMD_PDN_CONTEXT_READ_INFO_DNS_ADDR_SECONDARY_INDEX 7
 #define AT_CMD_PDN_CONTEXT_READ_INFO_MTU_INDEX 12
 
 #define AT_CMD_PDN_CONTEXT_READ_RSP_DELIM "\r\n"
 
+     /* "+CGCONTRDP: 0,,"example.com","","","198.276.154.230","12.34.56.78",,,,,1464\r\n
+      *  +CGCONTRDP: 0,,"example.com","","","1111:2222:3:FFF::55","1111:2222:3:FFF::55",,,,,1464"
+      */
+#define AT_CMD_PDN_CONTEXT_READ_INFO_PARSE_LINE1 \
+	"+CGCONTRDP: %*u,,\"%*[^\"]\",\"\",\"\",\"%15[0-9.]\",\"%15[0-9.]\",,,,,%u"
+#define AT_CMD_PDN_CONTEXT_READ_INFO_PARSE_LINE2 \
+	"+%*[^+]"\
+	"+CGCONTRDP: %*u,,\"%*[^\"]\",\"\",\"\",\"%39[0-9A-Fa-f:]\",\"%39[0-9A-Fa-f:]\",,,,,%u"
+
 static K_MUTEX_DEFINE(list_mutex);
 
 static sys_slist_t pdn_contexts = SYS_SLIST_STATIC_INIT(&pdn_context);
@@ -633,13 +639,13 @@ int pdn_dynamic_params_get(uint8_t cid, struct in_addr *dns4_pri,
 	unsigned int mtu;
 	char dns4_pri_str[INET_ADDRSTRLEN];
 	char dns4_sec_str[INET_ADDRSTRLEN];
-	char at_cmd[sizeof("AT+CGCONTRDP=10")];
+	char at_cmd[sizeof("AT+CGCONTRDP=###")];
 
-	if (snprintf(at_cmd, sizeof(at_cmd), "AT+CGCONTRDP=%u", cid) >= sizeof(at_cmd)) {
+	if (snprintf(at_cmd, sizeof(at_cmd), AT_CMD_PDN_CONTEXT_READ_INFO, cid) >= sizeof(at_cmd)) {
 		return -E2BIG;
 	}
-	   /* "+CGCONTRDP: 0,,"example.com","","","198.276.154.230","12.34.56.78",,,,,1464" */
-	fmt = "+CGCONTRDP: %*u,,\"%*[^\"]\",\"\",\"\",\"%15[0-9.]\",\"%15[0-9.]\",,,,,%u";
+
+	fmt = AT_CMD_PDN_CONTEXT_READ_INFO_PARSE_LINE1;
 
 	/* If IPv4 is enabled, it will be the first response line. */
 	matched = nrf_modem_at_scanf(at_cmd, fmt, &dns4_pri_str, &dns4_sec_str, &mtu);
@@ -674,153 +680,79 @@ static int pdn_sa_family_from_ip_string(const char *src)
 {
 	char buf[INET6_ADDRSTRLEN];
 
-	if (inet_pton(AF_INET, src, buf)) {
+	if (zsock_inet_pton(AF_INET, src, buf)) {
 		return AF_INET;
-	} else if (inet_pton(AF_INET6, src, buf)) {
+	} else if (zsock_inet_pton(AF_INET6, src, buf)) {
 		return AF_INET6;
 	}
 	return -1;
 }
 
-int pdn_dynamic_info_get(uint32_t cid, struct pdn_dynamic_info *pdn_info)
+/** @brief Fill PDN dynamic info with DNS addresses adnd mtu. */
+static void pdn_dynamic_info_dns_addr_fill(struct pdn_dynamic_info *pdn_info, uint32_t mtu,
+					   const char *dns_addr_str_primary,
+					   const char *dns_addr_str_secondary)
 {
-	int ret = 0;
-	struct at_parser parser;
-	size_t param_str_len;
-
-	char *cgcontrdp_at_rsp_buf;
-
-	char *at_ptr;
-	char *tmp_ptr;
-	int lines = 0;
-	int iterator = 0;
-	char dns_addr_str[AT_CMD_PDN_CONTEXT_READ_IP_ADDR_STR_MAX_LEN];
+	const int family = pdn_sa_family_from_ip_string(dns_addr_str_primary);
 
-	char at_cmd_pdn_context_read_info_cmd_str[15];
+	if (family == AF_INET) {
+		(void)zsock_inet_pton(AF_INET, dns_addr_str_primary,
+				      &(pdn_info->dns_addr4_primary));
+		(void)zsock_inet_pton(AF_INET, dns_addr_str_secondary,
+				      &(pdn_info->dns_addr4_secondary));
+		pdn_info->ipv4_mtu = mtu;
+	} else if (family == AF_INET6) {
+		(void)zsock_inet_pton(AF_INET6, dns_addr_str_primary,
+				      &(pdn_info->dns_addr6_primary));
+		(void)zsock_inet_pton(AF_INET6, dns_addr_str_secondary,
+				      &(pdn_info->dns_addr6_secondary));
+		pdn_info->ipv6_mtu = mtu;
+	}
+}
 
-	int family;
-	struct in_addr *addr;
-	struct in6_addr *addr6;
+int pdn_dynamic_info_get(uint8_t cid, struct pdn_dynamic_info *pdn_info)
+{
+	int ret;
+	char at_cmd_buf[sizeof("AT+CGCONTRDP=###")];
+	char dns_addr_str_primary[INET6_ADDRSTRLEN];
+	char dns_addr_str_secondary[INET6_ADDRSTRLEN];
+	uint32_t mtu = 0;
 
 	if (!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;
-	}
+	/* Reset PDN dynamic info. */
+	memset(pdn_info, 0, sizeof(struct pdn_dynamic_info));
 
-	at_ptr = cgcontrdp_at_rsp_buf;
-	tmp_ptr = cgcontrdp_at_rsp_buf;
+	/* Clear secondary DNS address buffer. */
+	memset(dns_addr_str_secondary, 0, sizeof(dns_addr_str_secondary));
 
-	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, 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);
-		goto clean_exit;
+	(void)snprintf(at_cmd_buf, sizeof(at_cmd_buf), AT_CMD_PDN_CONTEXT_READ_INFO, cid);
+	ret = nrf_modem_at_scanf(at_cmd_buf, AT_CMD_PDN_CONTEXT_READ_INFO_PARSE_LINE1,
+				 dns_addr_str_primary, dns_addr_str_secondary, &mtu);
+	if (ret < 1) {
+		LOG_ERR("nrf_modem_at_scanf failed, ret: %d", ret);
+		return ret;
 	}
 
-	/* Check how many rows of info do we have */
-	while (strncmp(tmp_ptr, "OK", 2) &&
-	       (tmp_ptr = strstr(tmp_ptr, AT_CMD_PDN_CONTEXT_READ_RSP_DELIM)) != NULL) {
-		tmp_ptr += 2;
-		lines++;
-	}
+	pdn_dynamic_info_dns_addr_fill(pdn_info, mtu, dns_addr_str_primary, dns_addr_str_secondary);
 
-	/* Parse the response */
-	ret = at_parser_init(&parser, at_ptr);
-	if (ret) {
-		LOG_ERR("Could not init AT parser for %s, error: %d\n",
-			   at_cmd_pdn_context_read_info_cmd_str, ret);
-		goto clean_exit;
-	}
+	/* Reset secondary DNS address buffer and mtu. */
+	memset(dns_addr_str_secondary, 0, sizeof(dns_addr_str_secondary));
+	mtu = 0;
 
-parse:
-	/* Read primary DNS address */
-	param_str_len = sizeof(dns_addr_str);
-	ret = at_parser_string_get(
-		&parser,
-		AT_CMD_PDN_CONTEXT_READ_INFO_DNS_ADDR_PRIMARY_INDEX,
-		dns_addr_str, &param_str_len);
-	if (ret) {
-		LOG_ERR("Could not parse dns str for cid %d, err: %d", cid, ret);
-		goto clean_exit;
+	/* Scan second line if PDN has dual stack capabilities. */
+	ret = nrf_modem_at_scanf(at_cmd_buf, AT_CMD_PDN_CONTEXT_READ_INFO_PARSE_LINE2,
+				 dns_addr_str_primary, dns_addr_str_secondary, &mtu);
+	if (ret < 1) {
+		/* We only got one entry, but that is ok. */
+		return 0;
 	}
-	dns_addr_str[param_str_len] = '\0';
 
-	family = pdn_sa_family_from_ip_string(dns_addr_str);
+	pdn_dynamic_info_dns_addr_fill(pdn_info, mtu, dns_addr_str_primary, dns_addr_str_secondary);
 
-	if (family == AF_INET) {
-		addr = &(pdn_info->dns_addr4_primary);
-		(void)inet_pton(AF_INET, dns_addr_str, addr);
-	} else if (family == AF_INET6) {
-		addr6 = &(pdn_info->dns_addr6_primary);
-		(void)inet_pton(AF_INET6, dns_addr_str, addr6);
-	}
-
-	/* Read secondary DNS address */
-	param_str_len = sizeof(dns_addr_str);
-
-	ret = at_parser_string_get(
-		&parser,
-		AT_CMD_PDN_CONTEXT_READ_INFO_DNS_ADDR_SECONDARY_INDEX,
-		dns_addr_str, &param_str_len);
-	if (ret) {
-		LOG_ERR("Could not parse dns str, err: %d", ret);
-		goto clean_exit;
-	}
-	dns_addr_str[param_str_len] = '\0';
-
-	family = pdn_sa_family_from_ip_string(dns_addr_str);
-
-	if (family == AF_INET) {
-		addr = &(pdn_info->dns_addr4_secondary);
-		(void)inet_pton(AF_INET, dns_addr_str, addr);
-	} else if (family == AF_INET6) {
-		addr6 = &(pdn_info->dns_addr6_secondary);
-		(void)inet_pton(AF_INET6, dns_addr_str, addr6);
-	}
-
-	/* Read link MTU if exists:
-	 * AT command spec:
-	 * Note: If the PDN connection has dual stack capabilities, at least one pair of
-	 * lines with information is returned per <cid>: First one line with the IPv4
-	 * parameters followed by one line with the IPv6 parameters.
-	 */
-	if (iterator == 1) {
-		ret = at_parser_num_get(&parser, AT_CMD_PDN_CONTEXT_READ_INFO_MTU_INDEX,
-					&(pdn_info->ipv6_mtu));
-		if (ret) {
-			/* Don't care if it fails */
-			ret = 0;
-			pdn_info->ipv6_mtu = 0;
-		}
-	} else {
-		ret = at_parser_num_get(&parser, AT_CMD_PDN_CONTEXT_READ_INFO_MTU_INDEX,
-					&(pdn_info->ipv4_mtu));
-		if (ret) {
-			/* Don't care if it fails */
-			ret = 0;
-			pdn_info->ipv4_mtu = 0;
-		}
-	}
-
-	if (at_parser_cmd_next(&parser) == 0) {
-		iterator++;
-		if (iterator < lines) {
-			goto parse;
-		}
-	}
-
-clean_exit:
-	k_free(cgcontrdp_at_rsp_buf);
-	return ret;
+	return 0;
 }
 
 int pdn_default_apn_get(char *buf, size_t len)

samples/cellular/pdn/README.rst

@@ -62,26 +62,39 @@ The sample shows the following output, which may vary based on the network provi
 
 .. code-block:: console
 
+   *** Booting nRF Connect SDK v2.9.99-0f7da9c375d1 ***
+   *** Using Zephyr OS v3.7.99-2d1e173dfed0 ***
    PDN sample started
    Event: PDP context 0 activated
-   Default APN is telenor.iot
+   Default APN is telenor.smart
    Created new PDP context 1
-   PDP contEvent: PDP context 0 IPv6 up
-   ext 1 configured: APN telenor.iot, Family IPV4V6
+   PDP context 1 configured: APN telenor.smart, Family IPV4V6
    Event: PDP context 1 activated
+   Event: PDP context 0 IPv6 up
    Event: PDP context 1 IPv6 up
    PDP Context 0, PDN ID 0
    PDP Context 1, PDN ID 0
+   Dynamic info for cid 0:
+   Primary IPv4 DNS address: 111.222.233.4
+   Secondary IPv4 DNS address: 111.222.233.4
+   Primary IPv6 DNS address: 1111:2222:3:fff::55
+   Secondary IPv6 DNS address: 1111:2222:3:fff::55
+   IPv4 MTU: 1500, IPv6 MTU: 1500
+   Dynamic info for cid 1:
+   Primary IPv4 DNS address: 111.222.233.4
+   Secondary IPv4 DNS address: 111.222.233.4
+   Primary IPv6 DNS address: 1111:2222:3:fff::55
+   Secondary IPv6 DNS address: 1111:2222:3:fff::55
+   IPv4 MTU: 1500, IPv6 MTU: 1500
 
    Interface addresses:
-   l0: (AF_INET) 10.243.140.208
-   l0: (AF_INET6) fe80::63:b639:ab01
-   l0: (AF_INET6) 2a02:2121:20d:175d:0:63:b639:ab01
+   l0: (AF_INET) 10.22.233.44
+   l0: (AF_INET6) aaaa::bbbb:cccc
+   l0: (AF_INET6) aaa:bbbbb:cccc:dddd::eeee:2cd2
 
-   Event: PDP context 0 deactivated
-   Event: PDP context 1 deactivated
    Event: PDP context 0 network detach
    Event: PDP context 1 network detach
+   Event: PDP context 1 context destroyed
    Bye
 
 Dependencies