[dpdk-dev] [PATCH v3] net/iavf: fix adding multicast MAC address

[Guinan Sun]

When the multicast address list is added, it will flush
previous addresses first, and then add new ones.
So when the number of multicast addresses added to the list
exceeds the upper limit causes a failure, should add the
previous addresses back. This patch fixes the issue.

Fixes: 05e4c3aff35f ("net/iavf: support multicast configuration")

Signed-off-by: Guinan Sun <guinanx....@intel.com>
Tested-by: Peng Yuan <yuan.p...@intel.com>
---
v3:
* modify commit message
v2:
* modify the variable name
---
 drivers/net/iavf/iavf_ethdev.c | 30 ++++++++++++++++++++++--------
 drivers/net/iavf/iavf_vchnl.c  |  3 ---
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/drivers/net/iavf/iavf_ethdev.c b/drivers/net/iavf/iavf_ethdev.c
index e68e3bc71..8a7577230 100644
--- a/drivers/net/iavf/iavf_ethdev.c
+++ b/drivers/net/iavf/iavf_ethdev.c
@@ -164,7 +164,14 @@ iavf_set_mc_addr_list(struct rte_eth_dev *dev,
        struct iavf_info *vf = IAVF_DEV_PRIVATE_TO_VF(dev->data->dev_private);
        struct iavf_adapter *adapter =
                IAVF_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private);
-       int err;
+       int err, ret;
+
+       if (mc_addrs_num > IAVF_NUM_MACADDR_MAX) {
+               PMD_DRV_LOG(ERR,
+                           "can't add more than a limited number (%u) of 
addresses.",
+                           (uint32_t)IAVF_NUM_MACADDR_MAX);
+               return -EINVAL;
+       }
 
        /* flush previous addresses */
        err = iavf_add_del_mc_addr_list(adapter, vf->mc_addrs, vf->mc_addrs_num,
@@ -172,17 +179,24 @@ iavf_set_mc_addr_list(struct rte_eth_dev *dev,
        if (err)
                return err;
 
-       vf->mc_addrs_num = 0;
-
        /* add new ones */
        err = iavf_add_del_mc_addr_list(adapter, mc_addrs, mc_addrs_num, true);
-       if (err)
-               return err;
 
-       vf->mc_addrs_num = mc_addrs_num;
-       memcpy(vf->mc_addrs, mc_addrs, mc_addrs_num * sizeof(*mc_addrs));
+       if (err) {
+               /* if adding mac address list fails, should add the previous
+                * addresses back.
+                */
+               ret = iavf_add_del_mc_addr_list(adapter, vf->mc_addrs,
+                                               vf->mc_addrs_num, true);
+               if (ret)
+                       return ret;
+       } else {
+               vf->mc_addrs_num = mc_addrs_num;
+               memcpy(vf->mc_addrs,
+                      mc_addrs, mc_addrs_num * sizeof(*mc_addrs));
+       }
 
-       return 0;
+       return err;
 }
 
 static int
diff --git a/drivers/net/iavf/iavf_vchnl.c b/drivers/net/iavf/iavf_vchnl.c
index db0b76876..a2295f879 100644
--- a/drivers/net/iavf/iavf_vchnl.c
+++ b/drivers/net/iavf/iavf_vchnl.c
@@ -1107,9 +1107,6 @@ iavf_add_del_mc_addr_list(struct iavf_adapter *adapter,
        if (mc_addrs == NULL || mc_addrs_num == 0)
                return 0;
 
-       if (mc_addrs_num > IAVF_NUM_MACADDR_MAX)
-               return -EINVAL;
-
        list = (struct virtchnl_ether_addr_list *)cmd_buffer;
        list->vsi_id = vf->vsi_res->vsi_id;
        list->num_elements = mc_addrs_num;
-- 
2.17.1