subsystem: fota_download: correcting URI check

- HASH checksums are used to validate changed URI Signed-off-by: Veli-Tapani Peltoketo <veli-tapani.peltoketo@nordicsemi.no>
nrfconnect · Aug 4, 2023 · d3bcf52 · d3bcf52
1 parent 5f1a49a
commit d3bcf52
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Showing 4 changed files with 21 additions and 1 deletion.
diff --git a/doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst b/doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst
@@ -595,6 +595,12 @@ Libraries for networking
     * The :kconfig:option:`CONFIG_DOWNLOAD_CLIENT_MAX_HOSTNAME_SIZE` Kconfig option's default value to ``255``.
     * The :kconfig:option:`CONFIG_DOWNLOAD_CLIENT_MAX_FILENAME_SIZE` Kconfig option's default value to ``255``.
 
+* :ref:`lib_fota_download` library:
+
+  * Updated:
+
+    * The library now verifies whether the download started with the same URI and resumes the interrupted download.
+
 Libraries for NFC
 -----------------
 

diff --git a/subsys/net/lib/fota_download/Kconfig b/subsys/net/lib/fota_download/Kconfig
@@ -8,6 +8,7 @@ menuconfig FOTA_DOWNLOAD
 	bool "FOTA Download"
 	depends on DOWNLOAD_CLIENT
 	depends on DFU_TARGET
+	select SYS_HASH_FUNC32
 	imply FW_INFO
 
 if (FOTA_DOWNLOAD)

diff --git a/subsys/net/lib/fota_download/src/fota_download.c b/subsys/net/lib/fota_download/src/fota_download.c
@@ -6,6 +6,7 @@
 
 #include <zephyr/kernel.h>
 #include <zephyr/logging/log.h>
+#include <zephyr/sys/hash_function.h>
 #include <net/fota_download.h>
 #include <net/download_client.h>
 #include <pm_config.h>
@@ -29,6 +30,8 @@ LOG_MODULE_REGISTER(fota_download, CONFIG_FOTA_DOWNLOAD_LOG_LEVEL);
 static fota_download_callback_t callback;
 static const char *dl_host;
 static const char *dl_file;
+static uint32_t dl_host_hash;
+static uint32_t dl_file_hash;
 static struct download_client dlc;
 static struct k_work_delayable  dlc_with_offset_work;
 static int socket_retries_left;
@@ -415,6 +418,8 @@ int fota_download_start_with_image_type(const char *host, const char *file,
 	const enum dfu_target_image_type expected_type)
 {
 	static int sec_tag_list[1];
+	uint32_t host_hash = 0;
+	uint32_t file_hash = 0;
 	int err = -1;
 
 	struct download_client_cfg config = {
@@ -434,12 +439,19 @@ int fota_download_start_with_image_type(const char *host, const char *file,
 	atomic_clear_bit(&flags, FLAG_RESUME);
 	set_error_state(FOTA_DOWNLOAD_ERROR_CAUSE_NO_ERROR);
 
+	host_hash = sys_hash32(host, strlen(host));
+	file_hash = sys_hash32(file, strlen(file));
+	LOG_DBG("URI checksums %d,%d,%d,%d\r\n", host_hash, file_hash,
+						 dl_host_hash, dl_file_hash);
+
 	/* Verify if the URI is same as last time, if not, prevent resuming. */
-	if ((!dl_host || strcmp(dl_host, host) != 0) || (!dl_file || strcmp(dl_file, file) != 0)) {
+	if (dl_host_hash != host_hash || dl_file_hash != file_hash) {
 		atomic_set_bit(&flags, FLAG_NEW_URI);
 	} else {
 		atomic_clear_bit(&flags, FLAG_NEW_URI);
 	}
+	dl_host_hash = host_hash;
+	dl_file_hash = file_hash;
 	dl_host = host;
 	dl_file = file;
 

diff --git a/tests/subsys/net/lib/fota_download/prj.conf b/tests/subsys/net/lib/fota_download/prj.conf
@@ -8,3 +8,4 @@ CONFIG_ZTEST_NEW_API=y
 CONFIG_FLASH=y
 CONFIG_FW_INFO=y
 CONFIG_TFM_BUILD_NS=y # In order to mock tfm_platform_s0_active
+CONFIG_SYS_HASH_FUNC32=y