| Message ID | c77bb9511c1c10193cc05651ed785506d6aee3e8.1616345643.git.pabeni@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | udp: GRO L4 improvements | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for net-next |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | warning | 2 maintainers not CCed: yoshfuji@linux-ipv6.org dsahern@kernel.org |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 3308 this patch: 3308 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | warning | WARNING: line length of 84 exceeds 80 columns WARNING: line length of 89 exceeds 80 columns |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 3539 this patch: 3539 |
| netdev/header_inline | success | Link |
On Sun, Mar 21, 2021 at 1:01 PM Paolo Abeni <pabeni@redhat.com> wrote: > > Currently the UDP protocol delivers GSO_FRAGLIST packets to > the sockets without the expected segmentation. > > This change addresses the issue introducing and maintaining > a per socket bitmask of GSO types requiring segmentation. > Enabling GSO removes SKB_GSO_UDP_L4 from such mask, while > GSO_FRAGLIST packets are never accepted > > Note: this also updates the 'unused' field size to really > fit the otherwise existing hole. It's size become incorrect > after commit bec1f6f69736 ("udp: generate gso with UDP_SEGMENT"). > > Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > --- > include/linux/udp.h | 10 ++++++---- > net/ipv4/udp.c | 12 +++++++++++- > 2 files changed, 17 insertions(+), 5 deletions(-) > > diff --git a/include/linux/udp.h b/include/linux/udp.h > index aa84597bdc33c..6da342f15f351 100644 > --- a/include/linux/udp.h > +++ b/include/linux/udp.h > @@ -51,7 +51,7 @@ struct udp_sock { > * different encapsulation layer set > * this > */ > - gro_enabled:1; /* Can accept GRO packets */ > + gro_enabled:1; /* Request GRO aggregation */ unnecessary comment change? > /* > * Following member retains the information to create a UDP header > * when the socket is uncorked. > @@ -68,7 +68,10 @@ struct udp_sock { > #define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */ > #define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */ > __u8 pcflag; /* marks socket as UDP-Lite if > 0 */ > - __u8 unused[3]; > + __u8 unused[1]; > + unsigned int unexpected_gso;/* GSO types this socket can't accept, > + * any of SKB_GSO_UDP_L4 or SKB_GSO_FRAGLIST > + */ An extra unsigned int for this seems overkill. Current sockets that support SKB_GSO_UDP_L4 implicitly also support SKB_GSO_FRAGLIST. This patch makes explicit that the second is not supported.. > /* > * For encapsulation sockets. > */ > @@ -131,8 +134,7 @@ static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk, > > static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) > { > - return !udp_sk(sk)->gro_enabled && skb_is_gso(skb) && > - skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4; > + return skb_is_gso(skb) && skb_shinfo(skb)->gso_type & udp_sk(sk)->unexpected_gso; .. just update this function as follows ? - return !udp_sk(sk)->gro_enabled && skb_is_gso(skb) && - skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4; + return skb_is_gso(skb) && + (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST || !udp_sk(sk)->gro_enabled) where the latter is shorthand for (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !udp_sk(sk)->gro_enabled) but the are the only two GSO types that could arrive here.
On Mon, 2021-03-22 at 09:42 -0400, Willem de Bruijn wrote: > On Sun, Mar 21, 2021 at 1:01 PM Paolo Abeni <pabeni@redhat.com> wrote: > > Currently the UDP protocol delivers GSO_FRAGLIST packets to > > the sockets without the expected segmentation. > > > > This change addresses the issue introducing and maintaining > > a per socket bitmask of GSO types requiring segmentation. > > Enabling GSO removes SKB_GSO_UDP_L4 from such mask, while > > GSO_FRAGLIST packets are never accepted > > > > Note: this also updates the 'unused' field size to really > > fit the otherwise existing hole. It's size become incorrect > > after commit bec1f6f69736 ("udp: generate gso with UDP_SEGMENT"). > > > > Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") > > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > > --- > > include/linux/udp.h | 10 ++++++---- > > net/ipv4/udp.c | 12 +++++++++++- > > 2 files changed, 17 insertions(+), 5 deletions(-) > > > > diff --git a/include/linux/udp.h b/include/linux/udp.h > > index aa84597bdc33c..6da342f15f351 100644 > > --- a/include/linux/udp.h > > +++ b/include/linux/udp.h > > @@ -51,7 +51,7 @@ struct udp_sock { > > * different encapsulation layer set > > * this > > */ > > - gro_enabled:1; /* Can accept GRO packets */ > > + gro_enabled:1; /* Request GRO aggregation */ > > unnecessary comment change? Before this patch 'gro_enabled' was used in udp_unexpected_gso() to check for GSO packets acceptance, after this patch such field is not used there anymore, so does not carry explicilty the 'accept GRO packets' semantic. Anyway I don't have strong feeling regarding changing or not this comment > > /* > > * Following member retains the information to create a UDP header > > * when the socket is uncorked. > > @@ -68,7 +68,10 @@ struct udp_sock { > > #define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */ > > #define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */ > > __u8 pcflag; /* marks socket as UDP-Lite if > 0 */ > > - __u8 unused[3]; > > + __u8 unused[1]; > > + unsigned int unexpected_gso;/* GSO types this socket can't accept, > > + * any of SKB_GSO_UDP_L4 or SKB_GSO_FRAGLIST > > + */ > > An extra unsigned int for this seems overkill. Should be more clear after the next patch. Using an explicit 'acceptable GSO types' field makes the patch 5/8 quite simple. After this patch the 'udp_sock' struct size remains unchanged and even the number of 'udp_sock' cachelines touched for every packet is unchanged. I opted for an 'unsigned int' so that I could simply copy a gso_type there. > Current sockets that support SKB_GSO_UDP_L4 implicitly also support > SKB_GSO_FRAGLIST. This patch makes explicit that the second is not > supported.. > > > /* > > * For encapsulation sockets. > > */ > > @@ -131,8 +134,7 @@ static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk, > > > > static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) > > { > > - return !udp_sk(sk)->gro_enabled && skb_is_gso(skb) && > > - skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4; > > + return skb_is_gso(skb) && skb_shinfo(skb)->gso_type & udp_sk(sk)->unexpected_gso; > > .. just update this function as follows ? > > - return !udp_sk(sk)->gro_enabled && skb_is_gso(skb) && > - skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4; > + return skb_is_gso(skb) && > + (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST || > !udp_sk(sk)->gro_enabled) > > where the latter is shorthand for > > (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !udp_sk(sk)->gro_enabled) > > but the are the only two GSO types that could arrive here. With the above patch 5/8 becomes messy ?!? Thanks! Paolo
On Mon, Mar 22, 2021 at 1:12 PM Paolo Abeni <pabeni@redhat.com> wrote: > > On Mon, 2021-03-22 at 09:42 -0400, Willem de Bruijn wrote: > > On Sun, Mar 21, 2021 at 1:01 PM Paolo Abeni <pabeni@redhat.com> wrote: > > > Currently the UDP protocol delivers GSO_FRAGLIST packets to > > > the sockets without the expected segmentation. > > > > > > This change addresses the issue introducing and maintaining > > > a per socket bitmask of GSO types requiring segmentation. > > > Enabling GSO removes SKB_GSO_UDP_L4 from such mask, while > > > GSO_FRAGLIST packets are never accepted > > > > > > Note: this also updates the 'unused' field size to really > > > fit the otherwise existing hole. It's size become incorrect > > > after commit bec1f6f69736 ("udp: generate gso with UDP_SEGMENT"). > > > > > > Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") > > > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > > > --- > > > include/linux/udp.h | 10 ++++++---- > > > net/ipv4/udp.c | 12 +++++++++++- > > > 2 files changed, 17 insertions(+), 5 deletions(-) > > > > > > /* > > > * Following member retains the information to create a UDP header > > > * when the socket is uncorked. > > > @@ -68,7 +68,10 @@ struct udp_sock { > > > #define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */ > > > #define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */ > > > __u8 pcflag; /* marks socket as UDP-Lite if > 0 */ > > > - __u8 unused[3]; > > > + __u8 unused[1]; > > > + unsigned int unexpected_gso;/* GSO types this socket can't accept, > > > + * any of SKB_GSO_UDP_L4 or SKB_GSO_FRAGLIST > > > + */ > > > > An extra unsigned int for this seems overkill. > > Should be more clear after the next patch. > > Using an explicit 'acceptable GSO types' field makes the patch 5/8 > quite simple. > > After this patch the 'udp_sock' struct size remains unchanged and even > the number of 'udp_sock' cachelines touched for every packet is > unchanged. But there is opportunity cost, of course. Next time we need to add something to the struct, we will add a new cacheline. A 32-bit field for just 2 bits, where 1 already exists does seem like overkill. More importantly, I just think it's less obvious code than a pair of fields accepts_udp_l4:1, accepts_udp_fraglist:1, Local sockets can only accept the first, as there does not exist an interface to pass along the multiple frag sizes that a frag_list based approach might have. Sockets with encap_rcv != NULL may opt-in to being able to handle either. I think explicit code will be more maintainable. At the cost of perhaps two branches instead of one, admittedly. But that seems premature optimization.
On Tue, 2021-03-23 at 22:21 -0400, Willem de Bruijn wrote: > On Mon, Mar 22, 2021 at 1:12 PM Paolo Abeni <pabeni@redhat.com> wrote: > > On Mon, 2021-03-22 at 09:42 -0400, Willem de Bruijn wrote: > > > On Sun, Mar 21, 2021 at 1:01 PM Paolo Abeni <pabeni@redhat.com> wrote: > > > > Currently the UDP protocol delivers GSO_FRAGLIST packets to > > > > the sockets without the expected segmentation. > > > > > > > > This change addresses the issue introducing and maintaining > > > > a per socket bitmask of GSO types requiring segmentation. > > > > Enabling GSO removes SKB_GSO_UDP_L4 from such mask, while > > > > GSO_FRAGLIST packets are never accepted > > > > > > > > Note: this also updates the 'unused' field size to really > > > > fit the otherwise existing hole. It's size become incorrect > > > > after commit bec1f6f69736 ("udp: generate gso with UDP_SEGMENT"). > > > > > > > > Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") > > > > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > > > > --- > > > > include/linux/udp.h | 10 ++++++---- > > > > net/ipv4/udp.c | 12 +++++++++++- > > > > 2 files changed, 17 insertions(+), 5 deletions(-) > > > > > > > > /* > > > > * Following member retains the information to create a UDP header > > > > * when the socket is uncorked. > > > > @@ -68,7 +68,10 @@ struct udp_sock { > > > > #define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */ > > > > #define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */ > > > > __u8 pcflag; /* marks socket as UDP-Lite if > 0 */ > > > > - __u8 unused[3]; > > > > + __u8 unused[1]; > > > > + unsigned int unexpected_gso;/* GSO types this socket can't accept, > > > > + * any of SKB_GSO_UDP_L4 or SKB_GSO_FRAGLIST > > > > + */ > > > > > > An extra unsigned int for this seems overkill. > > > > Should be more clear after the next patch. > > > > Using an explicit 'acceptable GSO types' field makes the patch 5/8 > > quite simple. > > > > After this patch the 'udp_sock' struct size remains unchanged and even > > the number of 'udp_sock' cachelines touched for every packet is > > unchanged. > > But there is opportunity cost, of course. Next time we need to add > something to the struct, we will add a new cacheline. > > A 32-bit field for just 2 bits, where 1 already exists does seem like overkill. > > More importantly, I just think it's less obvious code than a pair of fields > > accepts_udp_l4:1, > accepts_udp_fraglist:1, > > Local sockets can only accept the first, as there does not exist an > interface to pass along the multiple frag sizes that a frag_list based > approach might have. > > Sockets with encap_rcv != NULL may opt-in to being able to handle either. > > I think explicit code will be more maintainable. ok > At the cost of > perhaps two branches instead of one, admittedly. But that seems > premature optimization. well, if it don't hurt too much your eyes, something along the following could save udp_sock space and code branches: rejects_udp_l4_fraglist:2; #define SKB_GSO_UDP_L4_SHIFT (NETIF_F_GSO_UDP_L4_BIT - NETIF_F_GSO_SHIFT) static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) { BUILD_BUG_ON(1 << SKB_GSO_UDP_L4_SHIFT != SKB_GSO_UDP_L4); BUILD_BUG_ON(1 << (SKB_GSO_UDP_L4_SHIFT + 1) != SKB_GSO_FRAGLIST); return skb_is_gso(skb) && skb_shinfo(skb)->gso_type & (udp_sk(sk)->rejects_udp_l4_fraglist << SKB_GSO_UDP_L4_SHIFT); } (not sure if /me runs/hides ;) /P
On Wed, Mar 24, 2021 at 3:00 PM Paolo Abeni <pabeni@redhat.com> wrote: > > On Tue, 2021-03-23 at 22:21 -0400, Willem de Bruijn wrote: > > On Mon, Mar 22, 2021 at 1:12 PM Paolo Abeni <pabeni@redhat.com> wrote: > > > On Mon, 2021-03-22 at 09:42 -0400, Willem de Bruijn wrote: > > > > On Sun, Mar 21, 2021 at 1:01 PM Paolo Abeni <pabeni@redhat.com> wrote: > > > > > Currently the UDP protocol delivers GSO_FRAGLIST packets to > > > > > the sockets without the expected segmentation. > > > > > > > > > > This change addresses the issue introducing and maintaining > > > > > a per socket bitmask of GSO types requiring segmentation. > > > > > Enabling GSO removes SKB_GSO_UDP_L4 from such mask, while > > > > > GSO_FRAGLIST packets are never accepted > > > > > > > > > > Note: this also updates the 'unused' field size to really > > > > > fit the otherwise existing hole. It's size become incorrect > > > > > after commit bec1f6f69736 ("udp: generate gso with UDP_SEGMENT"). > > > > > > > > > > Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") > > > > > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > > > > > --- > > > > > include/linux/udp.h | 10 ++++++---- > > > > > net/ipv4/udp.c | 12 +++++++++++- > > > > > 2 files changed, 17 insertions(+), 5 deletions(-) > > > > > > > > > > /* > > > > > * Following member retains the information to create a UDP header > > > > > * when the socket is uncorked. > > > > > @@ -68,7 +68,10 @@ struct udp_sock { > > > > > #define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */ > > > > > #define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */ > > > > > __u8 pcflag; /* marks socket as UDP-Lite if > 0 */ > > > > > - __u8 unused[3]; > > > > > + __u8 unused[1]; > > > > > + unsigned int unexpected_gso;/* GSO types this socket can't accept, > > > > > + * any of SKB_GSO_UDP_L4 or SKB_GSO_FRAGLIST > > > > > + */ > > > > > > > > An extra unsigned int for this seems overkill. > > > > > > Should be more clear after the next patch. > > > > > > Using an explicit 'acceptable GSO types' field makes the patch 5/8 > > > quite simple. > > > > > > After this patch the 'udp_sock' struct size remains unchanged and even > > > the number of 'udp_sock' cachelines touched for every packet is > > > unchanged. > > > > But there is opportunity cost, of course. Next time we need to add > > something to the struct, we will add a new cacheline. > > > > A 32-bit field for just 2 bits, where 1 already exists does seem like overkill. > > > > More importantly, I just think it's less obvious code than a pair of fields > > > > accepts_udp_l4:1, > > accepts_udp_fraglist:1, > > > > Local sockets can only accept the first, as there does not exist an > > interface to pass along the multiple frag sizes that a frag_list based > > approach might have. > > > > Sockets with encap_rcv != NULL may opt-in to being able to handle either. > > > > I think explicit code will be more maintainable. > > ok > > > At the cost of > > perhaps two branches instead of one, admittedly. But that seems > > premature optimization. > > well, if it don't hurt too much your eyes, something along the > following could save udp_sock space and code branches: > > rejects_udp_l4_fraglist:2; > > #define SKB_GSO_UDP_L4_SHIFT (NETIF_F_GSO_UDP_L4_BIT - NETIF_F_GSO_SHIFT) > static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) > { > BUILD_BUG_ON(1 << SKB_GSO_UDP_L4_SHIFT != SKB_GSO_UDP_L4); > BUILD_BUG_ON(1 << (SKB_GSO_UDP_L4_SHIFT + 1) != SKB_GSO_FRAGLIST); > return skb_is_gso(skb) && skb_shinfo(skb)->gso_type & > (udp_sk(sk)->rejects_udp_l4_fraglist << SKB_GSO_UDP_L4_SHIFT); > } > > (not sure if /me runs/hides ;) :) My opinion is just one, but I do find this a lot less readable and hence maintainable than if (likely(!skb_is_gso(skb))) return true; if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !udp_sk(sk)->accept_udp_l4) return false; if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST && !udp_sk(sk)->accept_udp_fraglist) return false; return true; at no obvious benefit. The tunnel gso code is hard enough to fathom as it is. > /P > > >
On Wed, 2021-03-24 at 18:12 -0400, Willem de Bruijn wrote: > On Wed, Mar 24, 2021 at 3:00 PM Paolo Abeni <pabeni@redhat.com> wrote: > > On Tue, 2021-03-23 at 22:21 -0400, Willem de Bruijn wrote: > > > On Mon, Mar 22, 2021 at 1:12 PM Paolo Abeni <pabeni@redhat.com> wrote: > > > > On Mon, 2021-03-22 at 09:42 -0400, Willem de Bruijn wrote: > > > > > On Sun, Mar 21, 2021 at 1:01 PM Paolo Abeni <pabeni@redhat.com> wrote: > > > > > > Currently the UDP protocol delivers GSO_FRAGLIST packets to > > > > > > the sockets without the expected segmentation. > > > > > > > > > > > > This change addresses the issue introducing and maintaining > > > > > > a per socket bitmask of GSO types requiring segmentation. > > > > > > Enabling GSO removes SKB_GSO_UDP_L4 from such mask, while > > > > > > GSO_FRAGLIST packets are never accepted > > > > > > > > > > > > Note: this also updates the 'unused' field size to really > > > > > > fit the otherwise existing hole. It's size become incorrect > > > > > > after commit bec1f6f69736 ("udp: generate gso with UDP_SEGMENT"). > > > > > > > > > > > > Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") > > > > > > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > > > > > > --- > > > > > > include/linux/udp.h | 10 ++++++---- > > > > > > net/ipv4/udp.c | 12 +++++++++++- > > > > > > 2 files changed, 17 insertions(+), 5 deletions(-) > > > > > > > > > > > > /* > > > > > > * Following member retains the information to create a UDP header > > > > > > * when the socket is uncorked. > > > > > > @@ -68,7 +68,10 @@ struct udp_sock { > > > > > > #define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */ > > > > > > #define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */ > > > > > > __u8 pcflag; /* marks socket as UDP-Lite if > 0 */ > > > > > > - __u8 unused[3]; > > > > > > + __u8 unused[1]; > > > > > > + unsigned int unexpected_gso;/* GSO types this socket can't accept, > > > > > > + * any of SKB_GSO_UDP_L4 or SKB_GSO_FRAGLIST > > > > > > + */ > > > > > > > > > > An extra unsigned int for this seems overkill. > > > > > > > > Should be more clear after the next patch. > > > > > > > > Using an explicit 'acceptable GSO types' field makes the patch 5/8 > > > > quite simple. > > > > > > > > After this patch the 'udp_sock' struct size remains unchanged and even > > > > the number of 'udp_sock' cachelines touched for every packet is > > > > unchanged. > > > > > > But there is opportunity cost, of course. Next time we need to add > > > something to the struct, we will add a new cacheline. > > > > > > A 32-bit field for just 2 bits, where 1 already exists does seem like overkill. > > > > > > More importantly, I just think it's less obvious code than a pair of fields > > > > > > accepts_udp_l4:1, > > > accepts_udp_fraglist:1, > > > > > > Local sockets can only accept the first, as there does not exist an > > > interface to pass along the multiple frag sizes that a frag_list based > > > approach might have. > > > > > > Sockets with encap_rcv != NULL may opt-in to being able to handle either. > > > > > > I think explicit code will be more maintainable. > > > > ok > > > > > At the cost of > > > perhaps two branches instead of one, admittedly. But that seems > > > premature optimization. > > > > well, if it don't hurt too much your eyes, something along the > > following could save udp_sock space and code branches: > > > > rejects_udp_l4_fraglist:2; > > > > #define SKB_GSO_UDP_L4_SHIFT (NETIF_F_GSO_UDP_L4_BIT - NETIF_F_GSO_SHIFT) > > static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) > > { > > BUILD_BUG_ON(1 << SKB_GSO_UDP_L4_SHIFT != SKB_GSO_UDP_L4); > > BUILD_BUG_ON(1 << (SKB_GSO_UDP_L4_SHIFT + 1) != SKB_GSO_FRAGLIST); > > return skb_is_gso(skb) && skb_shinfo(skb)->gso_type & > > (udp_sk(sk)->rejects_udp_l4_fraglist << SKB_GSO_UDP_L4_SHIFT); > > } > > > > (not sure if /me runs/hides ;) > > :) > > My opinion is just one, but I do find this a lot less readable and > hence maintainable than > > if (likely(!skb_is_gso(skb))) > return true; > > if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !udp_sk(sk)->accept_udp_l4) > return false; > > if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST && > !udp_sk(sk)->accept_udp_fraglist) > return false; > > return true; > > at no obvious benefit. The tunnel gso code is hard enough to fathom as it is. ok. I'm only doubtful about the likely() annotation: systems with UDP tunnels likely expect receiving a majority of UDP-encaped traffic, which in turn will likely be GRO (e.g. TCP over UDP-tunnel). In my next iteration I'll use the above, dropping the annotation. Cheers, Paolo
diff --git a/include/linux/udp.h b/include/linux/udp.h index aa84597bdc33c..6da342f15f351 100644 --- a/include/linux/udp.h +++ b/include/linux/udp.h @@ -51,7 +51,7 @@ struct udp_sock { * different encapsulation layer set * this */ - gro_enabled:1; /* Can accept GRO packets */ + gro_enabled:1; /* Request GRO aggregation */ /* * Following member retains the information to create a UDP header * when the socket is uncorked. @@ -68,7 +68,10 @@ struct udp_sock { #define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */ #define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */ __u8 pcflag; /* marks socket as UDP-Lite if > 0 */ - __u8 unused[3]; + __u8 unused[1]; + unsigned int unexpected_gso;/* GSO types this socket can't accept, + * any of SKB_GSO_UDP_L4 or SKB_GSO_FRAGLIST + */ /* * For encapsulation sockets. */ @@ -131,8 +134,7 @@ static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk, static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb) { - return !udp_sk(sk)->gro_enabled && skb_is_gso(skb) && - skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4; + return skb_is_gso(skb) && skb_shinfo(skb)->gso_type & udp_sk(sk)->unexpected_gso; } #define udp_portaddr_for_each_entry(__sk, list) \ diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index ff54135c51ffa..1ba6d153c2f0a 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1600,8 +1600,13 @@ EXPORT_SYMBOL_GPL(udp_destruct_sock); int udp_init_sock(struct sock *sk) { - skb_queue_head_init(&udp_sk(sk)->reader_queue); + struct udp_sock *up = udp_sk(sk); + + skb_queue_head_init(&up->reader_queue); sk->sk_destruct = udp_destruct_sock; + + /* do not accept any GSO packet by default */ + up->unexpected_gso = SKB_GSO_FRAGLIST | SKB_GSO_UDP_L4; return 0; } EXPORT_SYMBOL_GPL(udp_init_sock); @@ -2674,8 +2679,13 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname, case UDP_GRO: lock_sock(sk); + + /* when enabling GRO, accept the related GSO packet type */ + up->unexpected_gso = SKB_GSO_FRAGLIST; if (valbool) udp_tunnel_encap_enable(sk->sk_socket); + else + up->unexpected_gso |= SKB_GSO_UDP_L4; up->gro_enabled = valbool; release_sock(sk); break;
Currently the UDP protocol delivers GSO_FRAGLIST packets to the sockets without the expected segmentation. This change addresses the issue introducing and maintaining a per socket bitmask of GSO types requiring segmentation. Enabling GSO removes SKB_GSO_UDP_L4 from such mask, while GSO_FRAGLIST packets are never accepted Note: this also updates the 'unused' field size to really fit the otherwise existing hole. It's size become incorrect after commit bec1f6f69736 ("udp: generate gso with UDP_SEGMENT"). Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- include/linux/udp.h | 10 ++++++---- net/ipv4/udp.c | 12 +++++++++++- 2 files changed, 17 insertions(+), 5 deletions(-)