Introduced in v3.8.0-rc1~96, the virNetDevGetFamilyId() gets
netlink family ID for passed family name (even though it's used
only for getting "devlink" ID). Nevertheless, the function
returns 0 on an error or if no family ID was found. This makes it
harder for a caller to distinguish these two. Change the retval
so that a negative value is returned upon error, zero is no ID
found (but no error encountered) and a positive value is returned
on successful translation.
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/util/virnetdev.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)
diff --git a/src/util/virnetdev.c b/src/util/virnetdev.c
index b465bdac2e..8c149c5fc5 100644
--- a/src/util/virnetdev.c
+++ b/src/util/virnetdev.c
@@ -3057,11 +3057,15 @@ virNetDevGetEthtoolFeatures(virBitmapPtr bitmap,
* This function supplies the devlink family id
*
* @family_name: the name of the family to query
+ * @family_id: family ID
*
- * Returns family id or 0 on failure.
+ * Returns: 0 if no family was found,
+ * 1 if family was found (@family_id is set),
+ * -1 othewise.
*/
-static uint32_t
-virNetDevGetFamilyId(const char *family_name)
+static int
+virNetDevGetFamilyId(const char *family_name,
+ uint32_t *family_id)
{
struct nl_msg *nl_msg = NULL;
struct nlmsghdr *resp = NULL;
@@ -3072,7 +3076,7 @@ virNetDevGetFamilyId(const char *family_name)
};
struct nlattr *tb[CTRL_ATTR_MAX + 1] = {NULL, };
unsigned int recvbuflen;
- uint32_t family_id = 0;
+ int ret = -1;
if (!(nl_msg = nlmsg_alloc_simple(GENL_ID_CTRL,
NLM_F_REQUEST | NLM_F_ACK))) {
@@ -3098,15 +3102,18 @@ virNetDevGetFamilyId(const char *family_name)
goto cleanup;
}
- if (tb[CTRL_ATTR_FAMILY_ID] == NULL)
+ if (tb[CTRL_ATTR_FAMILY_ID] == NULL) {
+ ret = 0;
goto cleanup;
+ }
- family_id = *(uint32_t *)RTA_DATA(tb[CTRL_ATTR_FAMILY_ID]);
+ *family_id = *(uint32_t *)RTA_DATA(tb[CTRL_ATTR_FAMILY_ID]);
+ ret = 1;
cleanup:
nlmsg_free(nl_msg);
VIR_FREE(resp);
- return family_id;
+ return ret;
}
@@ -3140,7 +3147,7 @@ virNetDevSwitchdevFeature(const char *ifname,
int ret = -1;
uint32_t family_id;
- if ((family_id = virNetDevGetFamilyId(DEVLINK_GENL_NAME)) <= 0)
+ if (virNetDevGetFamilyId(DEVLINK_GENL_NAME, &family_id) <= 0)
return ret;
if ((is_vf = virNetDevIsVirtualFunction(ifname)) < 0)
--
2.25.3