On 20/02/2023 09:58, Mathis Marion wrote:
From: Mathis Marion <mathis.mar...@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.mar...@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) {
After looking a bit more into it, linux/netlink.h defines: /* * nla_type (16 bits) * +---+---+-------------------------------+ * | N | O | Attribute Type | * +---+---+-------------------------------+ * N := Carries nested attributes * O := Payload stored in network byte order * * Note: The N and O flag are mutually exclusive. */ #define NLA_F_NESTED (1 << 15) #define NLA_F_NET_BYTEORDER (1 << 14) #define NLA_TYPE_MASK ~(NLA_F_NESTED | NLA_F_NET_BYTEORDER) So maybe I should use NLA_TYPE_MASK. However since NLA_F_NET_BYTEORDER is not supported it may make more sense to return an error.
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:
