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[PATCH v3 2/2] linux-user: handle netlink flag NLA_F_NESTED

Mathis Marion posted 2 patches 2 years, 3 months ago
[PATCH v3 2/2] linux-user: handle netlink flag NLA_F_NESTED
Posted by Mathis Marion 2 years, 3 months ago 
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]]
  ]

Masking the type is likely needed in other places. Only the above cases
are implemented in this patch.

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..c04a97c73a 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_TYPE_MASK) {
     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_TYPE_MASK) {
     /* uint32_t */
     case QEMU_IFLA_MTU:
     case QEMU_IFLA_TXQLEN:
-- 
2.39.2
Re: [PATCH v3 2/2] linux-user: handle netlink flag NLA_F_NESTED
Posted by Laurent Vivier 2 years, 3 months ago 
Le 07/03/2023 à 16:42, Mathis Marion a écrit :
> 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]]
>    ]
> 
> Masking the type is likely needed in other places. Only the above cases
> are implemented in this patch.
> 
> 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..c04a97c73a 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_TYPE_MASK) {
>       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_TYPE_MASK) {
>       /* uint32_t */
>       case QEMU_IFLA_MTU:
>       case QEMU_IFLA_TXQLEN:

Applied to my linux-user-for-8.0 branch.

Thanks,
Laurent
Re: [PATCH v3 2/2] linux-user: handle netlink flag NLA_F_NESTED
Posted by Laurent Vivier 2 years, 3 months ago 
Le 07/03/2023 à 16:42, Mathis Marion a écrit :
> 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]]
>    ]
> 
> Masking the type is likely needed in other places. Only the above cases
> are implemented in this patch.
> 
> 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..c04a97c73a 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_TYPE_MASK) {
>       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_TYPE_MASK) {
>       /* uint32_t */
>       case QEMU_IFLA_MTU:
>       case QEMU_IFLA_TXQLEN:

Reviewed-by: Laurent Vivier <laurent@vivier.eu>

Patchew 2.1-devel-8c64711

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