[scarthgap][PATCH v2] cve-update-nvd2-native: allow setting resultsPerPage

[Awais B <awais.belal@gmail.com>]

It is seen that during bulk updates on the NVD side the server
struggles to keep up with the default/max of 2000 entries per
page and we see a lot of incomplete read errors resulting in
proper db sync failures most of the times. Lowering the per
page value noticably increases the reliability of the process
and hence should ideally be configurable.

Signed-off-by: Awais B <awais.belal@gmail.com>
---
 meta/recipes-core/meta/cve-update-nvd2-native.bb | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/meta/recipes-core/meta/cve-update-nvd2-native.bb b/meta/recipes-core/meta/cve-update-nvd2-native.bb
index 945bd1d927..731cbb5d88 100644
--- a/meta/recipes-core/meta/cve-update-nvd2-native.bb
+++ b/meta/recipes-core/meta/cve-update-nvd2-native.bb
@@ -34,6 +34,10 @@ CVE_DB_INCR_UPDATE_AGE_THRES ?= "10368000"
 # Number of attempts for each http query to nvd server before giving up
 CVE_DB_UPDATE_ATTEMPTS ?= "5"
 
+# Maximum number of CVE records per API response.
+# Lowering this value can help avoid incomplete read errors during bulk NVD updates.
+CVE_DB_RESULTS_PER_PAGE ?= ""
+
 CVE_CHECK_DB_DLDIR_FILE ?= "${DL_DIR}/CVE_CHECK/${CVE_CHECK_DB_FILENAME}"
 CVE_CHECK_DB_DLDIR_LOCK ?= "${CVE_CHECK_DB_DLDIR_FILE}.lock"
 CVE_CHECK_DB_TEMP_FILE ?= "${CVE_CHECK_DB_FILE}.tmp"
@@ -217,6 +221,15 @@ def update_db_file(db_tmp_file, d, database_time):
         api_key = d.getVar("NVDCVE_API_KEY") or None
         attempts = int(d.getVar("CVE_DB_UPDATE_ATTEMPTS"))
 
+        results_per_page = d.getVar("CVE_DB_RESULTS_PER_PAGE")
+        RESULTS_PER_PAGE_MAX = 2000 # imposed by NVD
+        if results_per_page:
+            results_per_page = int(results_per_page)
+            if results_per_page > RESULTS_PER_PAGE_MAX:
+                bb.warn("CVE_DB_RESULTS_PER_PAGE exceeds maximum of %d, capping" % RESULTS_PER_PAGE_MAX)
+                results_per_page = RESULTS_PER_PAGE_MAX
+            req_args['resultsPerPage'] = results_per_page
+
         # Recommended by NVD
         wait_time = 6
         if api_key:
-- 
2.34.1