[PATCH v2 4/4] linux-user: handle netlink flag NLA_F_NESTED

[Mathis Marion <Mathis.Marion@silabs.com>]

From: Mathis Marion <mathis.marion@silabs.com>

Newer kernel versions require this flag to be present contrary to older
ones. Depending on the libnl version it is added or not.

Typically when using rtnl_link_inet6_set_addr_gen_mode, the netlink
packet generated may contain the following attribute:

with libnl 3.4

  {nla_len=16, nla_type=IFLA_AF_SPEC},
  [
    {nla_len=12, nla_type=AF_INET6},
    [{nla_len=5, nla_type=IFLA_INET6_ADDR_GEN_MODE}, IN6_ADDR_GEN_MODE_NONE]
  ]

with libnl 3.7

  {nla_len=16, nla_type=NLA_F_NESTED|IFLA_AF_SPEC},
  [
    {nla_len=12, nla_type=NLA_F_NESTED|AF_INET6},
    [{nla_len=5, nla_type=IFLA_INET6_ADDR_GEN_MODE}, IN6_ADDR_GEN_MODE_NONE]]
  ]

Signed-off-by: Mathis Marion <mathis.marion@silabs.com>
---
 linux-user/fd-trans.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/linux-user/fd-trans.c b/linux-user/fd-trans.c
index 4852a75d9d..1fb8ef9d4e 100644
--- a/linux-user/fd-trans.c
+++ b/linux-user/fd-trans.c
@@ -1359,7 +1359,7 @@ static abi_long target_to_host_for_each_rtattr(struct rtattr *rtattr,
 
 static abi_long target_to_host_data_spec_nlattr(struct nlattr *nlattr)
 {
-    switch (nlattr->nla_type) {
+    switch (nlattr->nla_type & ~NLA_F_NESTED) {
     case AF_INET6:
         return target_to_host_for_each_nlattr(NLA_DATA(nlattr), nlattr->nla_len,
                                               target_to_host_data_inet6_nlattr);
@@ -1375,7 +1375,7 @@ static abi_long target_to_host_data_link_rtattr(struct rtattr *rtattr)
 {
     uint32_t *u32;
 
-    switch (rtattr->rta_type) {
+    switch (rtattr->rta_type & ~NLA_F_NESTED) {
     /* uint32_t */
     case QEMU_IFLA_MTU:
     case QEMU_IFLA_TXQLEN:
-- 
2.39.1