From a8c5f90fb59a2d3bff0bd29adbb3e39fe0dd52f8 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Wed, 12 Nov 2014 11:54:09 -0800 Subject: [PATCH] ip_tunnel: Ops registration for secondary encap (fou, gue) Instead of calling fou and gue functions directly from ip_tunnel use ops for these that were previously registered. This patch adds the logic to add and remove encapsulation operations for ip_tunnel, and modified fou (and gue) to register with ip_tunnels. This patch also addresses a circular dependency between ip_tunnel and fou that was causing link errors when CONFIG_NET_IP_TUNNEL=y and CONFIG_NET_FOU=m. References to fou an gue have been removed from ip_tunnel.c Reported-by: Randy Dunlap Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- include/net/fou.h | 25 ++------------ include/net/ip_tunnels.h | 16 +++++++++ net/ipv4/fou.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++ net/ipv4/ip_tunnel.c | 78 ++++++++++++++++++++++++++++++-------------- 4 files changed, 157 insertions(+), 47 deletions(-) diff --git a/include/net/fou.h b/include/net/fou.h index 25b26ff..19b8a0c 100644 --- a/include/net/fou.h +++ b/include/net/fou.h @@ -8,31 +8,12 @@ #include #include +size_t fou_encap_hlen(struct ip_tunnel_encap *e); +static size_t gue_encap_hlen(struct ip_tunnel_encap *e); + int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, u8 *protocol, struct flowi4 *fl4); int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, u8 *protocol, struct flowi4 *fl4); -static size_t fou_encap_hlen(struct ip_tunnel_encap *e) -{ - return sizeof(struct udphdr); -} - -static size_t gue_encap_hlen(struct ip_tunnel_encap *e) -{ - size_t len; - bool need_priv = false; - - len = sizeof(struct udphdr) + sizeof(struct guehdr); - - if (e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) { - len += GUE_PLEN_REMCSUM; - need_priv = true; - } - - len += need_priv ? GUE_LEN_PRIV : 0; - - return len; -} - #endif diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h index 5bc6ede..25a59eb 100644 --- a/include/net/ip_tunnels.h +++ b/include/net/ip_tunnels.h @@ -117,6 +117,22 @@ struct ip_tunnel_net { struct hlist_head tunnels[IP_TNL_HASH_SIZE]; }; +struct ip_tunnel_encap_ops { + size_t (*encap_hlen)(struct ip_tunnel_encap *e); + int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e, + u8 *protocol, struct flowi4 *fl4); +}; + +#define MAX_IPTUN_ENCAP_OPS 8 + +extern const struct ip_tunnel_encap_ops __rcu * + iptun_encaps[MAX_IPTUN_ENCAP_OPS]; + +int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *op, + unsigned int num); +int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *op, + unsigned int num); + #ifdef CONFIG_INET int ip_tunnel_init(struct net_device *dev); diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c index 740ae09..fe09077 100644 --- a/net/ipv4/fou.c +++ b/net/ipv4/fou.c @@ -668,6 +668,30 @@ static const struct genl_ops fou_nl_ops[] = { }, }; +size_t fou_encap_hlen(struct ip_tunnel_encap *e) +{ + return sizeof(struct udphdr); +} +EXPORT_SYMBOL(fou_encap_hlen); + +size_t gue_encap_hlen(struct ip_tunnel_encap *e) +{ + size_t len; + bool need_priv = false; + + len = sizeof(struct udphdr) + sizeof(struct guehdr); + + if (e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) { + len += GUE_PLEN_REMCSUM; + need_priv = true; + } + + len += need_priv ? GUE_LEN_PRIV : 0; + + return len; +} +EXPORT_SYMBOL(gue_encap_hlen); + static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e, struct flowi4 *fl4, u8 *protocol, __be16 sport) { @@ -787,6 +811,57 @@ int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e, } EXPORT_SYMBOL(gue_build_header); +#ifdef CONFIG_NET_FOU_IP_TUNNELS + +static const struct ip_tunnel_encap_ops __read_mostly fou_iptun_ops = { + .encap_hlen = fou_encap_hlen, + .build_header = fou_build_header, +}; + +static const struct ip_tunnel_encap_ops __read_mostly gue_iptun_ops = { + .encap_hlen = gue_encap_hlen, + .build_header = gue_build_header, +}; + +static int ip_tunnel_encap_add_fou_ops(void) +{ + int ret; + + ret = ip_tunnel_encap_add_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU); + if (ret < 0) { + pr_err("can't add fou ops\n"); + return ret; + } + + ret = ip_tunnel_encap_add_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE); + if (ret < 0) { + pr_err("can't add gue ops\n"); + ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU); + return ret; + } + + return 0; +} + +static void ip_tunnel_encap_del_fou_ops(void) +{ + ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU); + ip_tunnel_encap_del_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE); +} + +#else + +static int ip_tunnel_encap_add_fou_ops(void) +{ + return 0; +} + +static int ip_tunnel_encap_del_fou_ops(void) +{ +} + +#endif + static int __init fou_init(void) { int ret; @@ -794,6 +869,14 @@ static int __init fou_init(void) ret = genl_register_family_with_ops(&fou_nl_family, fou_nl_ops); + if (ret < 0) + goto exit; + + ret = ip_tunnel_encap_add_fou_ops(); + if (ret < 0) + genl_unregister_family(&fou_nl_family); + +exit: return ret; } @@ -801,6 +884,8 @@ static void __exit fou_fini(void) { struct fou *fou, *next; + ip_tunnel_encap_del_fou_ops(); + genl_unregister_family(&fou_nl_family); /* Close all the FOU sockets */ diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index c3587e1..63e745a 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -57,10 +57,6 @@ #include #include -#if IS_ENABLED(CONFIG_NET_FOU) -#include -#endif - #if IS_ENABLED(CONFIG_IPV6) #include #include @@ -494,19 +490,50 @@ EXPORT_SYMBOL_GPL(ip_tunnel_rcv); static int ip_encap_hlen(struct ip_tunnel_encap *e) { - switch (e->type) { - case TUNNEL_ENCAP_NONE: + const struct ip_tunnel_encap_ops *ops; + int hlen = -EINVAL; + + if (e->type == TUNNEL_ENCAP_NONE) return 0; -#if IS_ENABLED(CONFIG_NET_FOU) - case TUNNEL_ENCAP_FOU: - return fou_encap_hlen(e); - case TUNNEL_ENCAP_GUE: - return gue_encap_hlen(e); -#endif - default: + + if (e->type >= MAX_IPTUN_ENCAP_OPS) return -EINVAL; - } + + rcu_read_lock(); + ops = rcu_dereference(iptun_encaps[e->type]); + if (likely(ops && ops->encap_hlen)) + hlen = ops->encap_hlen(e); + rcu_read_unlock(); + + return hlen; +} + +const struct ip_tunnel_encap_ops __rcu * + iptun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly; + +int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *ops, + unsigned int num) +{ + return !cmpxchg((const struct ip_tunnel_encap_ops **) + &iptun_encaps[num], + NULL, ops) ? 0 : -1; } +EXPORT_SYMBOL(ip_tunnel_encap_add_ops); + +int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *ops, + unsigned int num) +{ + int ret; + + ret = (cmpxchg((const struct ip_tunnel_encap_ops **) + &iptun_encaps[num], + ops, NULL) == ops) ? 0 : -1; + + synchronize_net(); + + return ret; +} +EXPORT_SYMBOL(ip_tunnel_encap_del_ops); int ip_tunnel_encap_setup(struct ip_tunnel *t, struct ip_tunnel_encap *ipencap) @@ -534,18 +561,19 @@ EXPORT_SYMBOL_GPL(ip_tunnel_encap_setup); int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t, u8 *protocol, struct flowi4 *fl4) { - switch (t->encap.type) { - case TUNNEL_ENCAP_NONE: + const struct ip_tunnel_encap_ops *ops; + int ret = -EINVAL; + + if (t->encap.type == TUNNEL_ENCAP_NONE) return 0; -#if IS_ENABLED(CONFIG_NET_FOU) - case TUNNEL_ENCAP_FOU: - return fou_build_header(skb, &t->encap, protocol, fl4); - case TUNNEL_ENCAP_GUE: - return gue_build_header(skb, &t->encap, protocol, fl4); -#endif - default: - return -EINVAL; - } + + rcu_read_lock(); + ops = rcu_dereference(iptun_encaps[t->encap.type]); + if (likely(ops && ops->build_header)) + ret = ops->build_header(skb, &t->encap, protocol, fl4); + rcu_read_unlock(); + + return ret; } EXPORT_SYMBOL(ip_tunnel_encap); -- 2.7.4