[dpdk-dev] [PATCH v4] 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.
If the number of multicast address in the list exceeds
the upper limit, it will cause failure, then need to
roll back previous addresses. 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>
Acked-by: Beilei Xing <beilei.x...@intel.com>
---
v4:
* modify commit message
* add Acked-by
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