From 901271e0403af638c224987c2a4e55cebade7e91 Mon Sep 17 00:00:00 2001 From: GhantaKrishnamurthy MohanKrishna Date: Thu, 19 Apr 2018 11:06:19 +0200 Subject: [PATCH] tipc: implement configuration of UDP media MTU In previous commit, we changed the default emulated MTU for UDP bearers to 14k. This commit adds the functionality to set/change the default value by configuring new MTU for UDP media. UDP bearer(s) have to be disabled and enabled back for the new MTU to take effect. Acked-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: GhantaKrishnamurthy MohanKrishna Signed-off-by: David S. Miller --- include/uapi/linux/tipc_netlink.h | 1 + net/tipc/bearer.c | 13 +++++++++++++ net/tipc/bearer.h | 3 +++ net/tipc/udp_media.h | 14 ++++++++++++++ 4 files changed, 31 insertions(+) diff --git a/include/uapi/linux/tipc_netlink.h b/include/uapi/linux/tipc_netlink.h index 0affb682e5e3..85c11982c89b 100644 --- a/include/uapi/linux/tipc_netlink.h +++ b/include/uapi/linux/tipc_netlink.h @@ -266,6 +266,7 @@ enum { TIPC_NLA_PROP_PRIO, /* u32 */ TIPC_NLA_PROP_TOL, /* u32 */ TIPC_NLA_PROP_WIN, /* u32 */ + TIPC_NLA_PROP_MTU, /* u32 */ __TIPC_NLA_PROP_MAX, TIPC_NLA_PROP_MAX = __TIPC_NLA_PROP_MAX - 1 diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c index f7d47c89d658..a22caf9e5a18 100644 --- a/net/tipc/bearer.c +++ b/net/tipc/bearer.c @@ -1029,6 +1029,9 @@ static int __tipc_nl_add_media(struct tipc_nl_msg *msg, goto prop_msg_full; if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, media->window)) goto prop_msg_full; + if (media->type_id == TIPC_MEDIA_TYPE_UDP) + if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, media->mtu)) + goto prop_msg_full; nla_nest_end(msg->skb, prop); nla_nest_end(msg->skb, attrs); @@ -1158,6 +1161,16 @@ int __tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info) m->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]); if (props[TIPC_NLA_PROP_WIN]) m->window = nla_get_u32(props[TIPC_NLA_PROP_WIN]); + if (props[TIPC_NLA_PROP_MTU]) { + if (m->type_id != TIPC_MEDIA_TYPE_UDP) + return -EINVAL; +#ifdef CONFIG_TIPC_MEDIA_UDP + if (tipc_udp_mtu_bad(nla_get_u32 + (props[TIPC_NLA_PROP_MTU]))) + return -EINVAL; + m->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]); +#endif + } } return 0; diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h index 6efcee63a381..394290cbbb1d 100644 --- a/net/tipc/bearer.h +++ b/net/tipc/bearer.h @@ -94,6 +94,8 @@ struct tipc_bearer; * @priority: default link (and bearer) priority * @tolerance: default time (in ms) before declaring link failure * @window: default window (in packets) before declaring link congestion + * @mtu: max packet size bearer can support for media type not dependent on + * underlying device MTU * @type_id: TIPC media identifier * @hwaddr_len: TIPC media address len * @name: media name @@ -118,6 +120,7 @@ struct tipc_media { u32 priority; u32 tolerance; u32 window; + u32 mtu; u32 type_id; u32 hwaddr_len; char name[TIPC_MAX_MEDIA_NAME]; diff --git a/net/tipc/udp_media.h b/net/tipc/udp_media.h index 281bbae87726..e7455cc73e16 100644 --- a/net/tipc/udp_media.h +++ b/net/tipc/udp_media.h @@ -38,9 +38,23 @@ #ifndef _TIPC_UDP_MEDIA_H #define _TIPC_UDP_MEDIA_H +#include +#include + int tipc_udp_nl_bearer_add(struct tipc_bearer *b, struct nlattr *attr); int tipc_udp_nl_add_bearer_data(struct tipc_nl_msg *msg, struct tipc_bearer *b); int tipc_udp_nl_dump_remoteip(struct sk_buff *skb, struct netlink_callback *cb); +/* check if configured MTU is too low for tipc headers */ +static inline bool tipc_udp_mtu_bad(u32 mtu) +{ + if (mtu >= (TIPC_MIN_BEARER_MTU + sizeof(struct iphdr) + + sizeof(struct udphdr))) + return false; + + pr_warn("MTU too low for tipc bearer\n"); + return true; +} + #endif #endif -- 2.30.2