| Message ID | b73c0deb97ca299207d2197db28f78d3992fbdbf.1682807958.git.lucien.xin@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | tipc: fix the mtu update in link mtu negotiation | expand |
>-----Original Message----- >From: Xin Long <lucien.xin@gmail.com> >Sent: Sunday, April 30, 2023 5:41 AM >To: network dev <netdev@vger.kernel.org>; tipc-discussion@lists.sourceforge.net >Cc: kuba@kernel.org; Eric Dumazet <edumazet@google.com>; Paolo Abeni <pabeni@redhat.com>; davem@davemloft.net >Subject: [tipc-discussion] [PATCH net 1/2] tipc: add tipc_bearer_min_mtu to calculate min mtu > >As different media may requires different min mtu, and even the >same media with different net family requires different min mtu, >add tipc_bearer_min_mtu() to calculate min mtu accordingly. > >This API will be used to check the new mtu when doing the link >mtu negotiation in the next patch. > >Signed-off-by: Xin Long <lucien.xin@gmail.com> >--- > net/tipc/bearer.c | 13 +++++++++++++ > net/tipc/bearer.h | 3 +++ > net/tipc/udp_media.c | 5 +++-- > 3 files changed, 19 insertions(+), 2 deletions(-) > >diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c >index 35cac7733fd3..c5d2e8c45f88 100644 >--- a/net/tipc/bearer.c >+++ b/net/tipc/bearer.c >@@ -541,6 +541,19 @@ int tipc_bearer_mtu(struct net *net, u32 bearer_id) > return mtu; > } > >+int tipc_bearer_min_mtu(struct net *net, u32 bearer_id) >+{ >+ int mtu = TIPC_MIN_BEARER_MTU; >+ struct tipc_bearer *b; >+ >+ rcu_read_lock(); >+ b = rcu_dereference(tipc_net(net)->bearer_list[bearer_id]); >+ if (b) >+ mtu += b->encap_hlen; >+ rcu_read_unlock(); >+ return mtu; >+} >+ > /* tipc_bearer_xmit_skb - sends buffer to destination over bearer > */ > void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id, >diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h >index 490ad6e5f7a3..bd0cc5c287ef 100644 >--- a/net/tipc/bearer.h >+++ b/net/tipc/bearer.h >@@ -146,6 +146,7 @@ struct tipc_media { > * @identity: array index of this bearer within TIPC bearer array > * @disc: ptr to link setup request > * @net_plane: network plane ('A' through 'H') currently associated with bearer >+ * @encap_hlen: encap headers length > * @up: bearer up flag (bit 0) > * @refcnt: tipc_bearer reference counter > * >@@ -170,6 +171,7 @@ struct tipc_bearer { > u32 identity; > struct tipc_discoverer *disc; > char net_plane; >+ u16 encap_hlen; > unsigned long up; > refcount_t refcnt; > }; >@@ -232,6 +234,7 @@ int tipc_bearer_setup(void); > void tipc_bearer_cleanup(void); > void tipc_bearer_stop(struct net *net); > int tipc_bearer_mtu(struct net *net, u32 bearer_id); >+int tipc_bearer_min_mtu(struct net *net, u32 bearer_id); > bool tipc_bearer_bcast_support(struct net *net, u32 bearer_id); > void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id, > struct sk_buff *skb, >diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c >index c2bb818704c8..0a85244fd618 100644 >--- a/net/tipc/udp_media.c >+++ b/net/tipc/udp_media.c >@@ -738,8 +738,8 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, > udp_conf.local_ip.s_addr = local.ipv4.s_addr; > udp_conf.use_udp_checksums = false; > ub->ifindex = dev->ifindex; >- if (tipc_mtu_bad(dev, sizeof(struct iphdr) + >- sizeof(struct udphdr))) { >+ b->encap_hlen = sizeof(struct iphdr) + sizeof(struct udphdr); >+ if (tipc_mtu_bad(dev, b->encap_hlen)) { > err = -EINVAL; > goto err; > } >@@ -760,6 +760,7 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, > else > udp_conf.local_ip6 = local.ipv6; > ub->ifindex = dev->ifindex; >+ b->encap_hlen = sizeof(struct ipv6hdr) + sizeof(struct udphdr); tipc_mtu_bad() needs to be called here to check for the minimum required MTU like the way ipv4 UDP bearer does. > b->mtu = 1280; > #endif > } else { >-- >2.39.1 > > > >_______________________________________________ >tipc-discussion mailing list >tipc-discussion@lists.sourceforge.net >https://lists.sourceforge.net/lists/listinfo/tipc-discussion
On Mon, May 1, 2023 at 11:35 AM Xin Long <lucien.xin@gmail.com> wrote: > On Mon, May 1, 2023 at 1:21 AM Tung Quang Nguyen <tung.q.nguyen@dektech.com.au> wrote: >> >@@ -760,6 +760,7 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, >> > else >> > udp_conf.local_ip6 = local.ipv6; >> > ub->ifindex = dev->ifindex; >> >+ b->encap_hlen = sizeof(struct ipv6hdr) + sizeof(struct udphdr); >> tipc_mtu_bad() needs to be called here to check for the minimum required MTU like the way ipv4 UDP bearer does. > > Agree, especially after commit 5a6f6f579178 ("tipc: set ub->ifindex for local ipv6 address"), we have the dev there. After taking a second look, I think we should delete the tipc_mtu_bad() call for ipv4 UDP bearer, as b->mtu is no longer using dev->mtu since: commit a4dfa72d0acd ("tipc: set default MTU for UDP media") The issue described in commit 3de81b758853 ("tipc: check minimum bearer MTU") no longer exists in UDP bearer. Besides, dev->mtu can still be changed to a too small mtu after the UDP bearer is created even with the tipc_mtu_bad() check in tipc_udp_enable(). Note that NETDEV_CHANGEMTU event processing in tipc_l2_device_event() doesn't really work for UDP bearer. I will leave this patch as it is in my v2 post, and create another patch for net-next to delete the unnecessary tipc_mtu_bad() check in UDP bearer. Agree? Thanks.
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c index 35cac7733fd3..c5d2e8c45f88 100644 --- a/net/tipc/bearer.c +++ b/net/tipc/bearer.c @@ -541,6 +541,19 @@ int tipc_bearer_mtu(struct net *net, u32 bearer_id) return mtu; } +int tipc_bearer_min_mtu(struct net *net, u32 bearer_id) +{ + int mtu = TIPC_MIN_BEARER_MTU; + struct tipc_bearer *b; + + rcu_read_lock(); + b = rcu_dereference(tipc_net(net)->bearer_list[bearer_id]); + if (b) + mtu += b->encap_hlen; + rcu_read_unlock(); + return mtu; +} + /* tipc_bearer_xmit_skb - sends buffer to destination over bearer */ void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id, diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h index 490ad6e5f7a3..bd0cc5c287ef 100644 --- a/net/tipc/bearer.h +++ b/net/tipc/bearer.h @@ -146,6 +146,7 @@ struct tipc_media { * @identity: array index of this bearer within TIPC bearer array * @disc: ptr to link setup request * @net_plane: network plane ('A' through 'H') currently associated with bearer + * @encap_hlen: encap headers length * @up: bearer up flag (bit 0) * @refcnt: tipc_bearer reference counter * @@ -170,6 +171,7 @@ struct tipc_bearer { u32 identity; struct tipc_discoverer *disc; char net_plane; + u16 encap_hlen; unsigned long up; refcount_t refcnt; }; @@ -232,6 +234,7 @@ int tipc_bearer_setup(void); void tipc_bearer_cleanup(void); void tipc_bearer_stop(struct net *net); int tipc_bearer_mtu(struct net *net, u32 bearer_id); +int tipc_bearer_min_mtu(struct net *net, u32 bearer_id); bool tipc_bearer_bcast_support(struct net *net, u32 bearer_id); void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id, struct sk_buff *skb, diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c index c2bb818704c8..0a85244fd618 100644 --- a/net/tipc/udp_media.c +++ b/net/tipc/udp_media.c @@ -738,8 +738,8 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, udp_conf.local_ip.s_addr = local.ipv4.s_addr; udp_conf.use_udp_checksums = false; ub->ifindex = dev->ifindex; - if (tipc_mtu_bad(dev, sizeof(struct iphdr) + - sizeof(struct udphdr))) { + b->encap_hlen = sizeof(struct iphdr) + sizeof(struct udphdr); + if (tipc_mtu_bad(dev, b->encap_hlen)) { err = -EINVAL; goto err; } @@ -760,6 +760,7 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, else udp_conf.local_ip6 = local.ipv6; ub->ifindex = dev->ifindex; + b->encap_hlen = sizeof(struct ipv6hdr) + sizeof(struct udphdr); b->mtu = 1280; #endif } else {
As different media may requires different min mtu, and even the same media with different net family requires different min mtu, add tipc_bearer_min_mtu() to calculate min mtu accordingly. This API will be used to check the new mtu when doing the link mtu negotiation in the next patch. Signed-off-by: Xin Long <lucien.xin@gmail.com> --- net/tipc/bearer.c | 13 +++++++++++++ net/tipc/bearer.h | 3 +++ net/tipc/udp_media.c | 5 +++-- 3 files changed, 19 insertions(+), 2 deletions(-)