From c19e654ddbe3831252f61e76a74d661e1a755530 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 9 Oct 2008 11:59:55 -0700 Subject: gre: Add netlink interface This patch adds a netlink interface that will eventually displace the existing ioctl interface. It utilises the elegant rtnl_link_ops mechanism. This also means that user-space no longer needs to rely on the tunnel interface being of type GRE to identify GRE tunnels. The identification can now occur using rtnl_link_ops. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/ip_gre.c | 247 +++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 243 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index 80622dd6fb3f..25d2c77a7f38 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -41,6 +41,7 @@ #include #include #include +#include #ifdef CONFIG_IPV6 #include @@ -117,6 +118,7 @@ Alexey Kuznetsov. */ +static struct rtnl_link_ops ipgre_link_ops __read_mostly; static int ipgre_tunnel_init(struct net_device *dev); static void ipgre_tunnel_setup(struct net_device *dev); static int ipgre_tunnel_bind_dev(struct net_device *dev); @@ -286,9 +288,9 @@ static struct ip_tunnel * ipgre_tunnel_locate(struct net *net, goto failed_free; } - dev->init = ipgre_tunnel_init; nt = netdev_priv(dev); nt->parms = *parms; + dev->rtnl_link_ops = &ipgre_link_ops; dev->mtu = ipgre_tunnel_bind_dev(dev); @@ -1087,6 +1089,7 @@ static int ipgre_close(struct net_device *dev) static void ipgre_tunnel_setup(struct net_device *dev) { + dev->init = ipgre_tunnel_init; dev->uninit = ipgre_tunnel_uninit; dev->destructor = free_netdev; dev->hard_start_xmit = ipgre_tunnel_xmit; @@ -1196,6 +1199,7 @@ static int ipgre_init_net(struct net *net) ign->fb_tunnel_dev->init = ipgre_fb_tunnel_init; dev_net_set(ign->fb_tunnel_dev, net); + ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops; if ((err = register_netdev(ign->fb_tunnel_dev))) goto err_reg_dev; @@ -1228,6 +1232,229 @@ static struct pernet_operations ipgre_net_ops = { .exit = ipgre_exit_net, }; +static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[]) +{ + __be16 flags; + + if (!data) + return 0; + + flags = 0; + if (data[IFLA_GRE_IFLAGS]) + flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); + if (data[IFLA_GRE_OFLAGS]) + flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); + if (flags & (GRE_VERSION|GRE_ROUTING)) + return -EINVAL; + + return 0; +} + +static void ipgre_netlink_parms(struct nlattr *data[], + struct ip_tunnel_parm *parms) +{ + memset(parms, 0, sizeof(parms)); + + parms->iph.protocol = IPPROTO_GRE; + + if (!data) + return; + + if (data[IFLA_GRE_LINK]) + parms->link = nla_get_u32(data[IFLA_GRE_LINK]); + + if (data[IFLA_GRE_IFLAGS]) + parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]); + + if (data[IFLA_GRE_OFLAGS]) + parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]); + + if (data[IFLA_GRE_IKEY]) + parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); + + if (data[IFLA_GRE_OKEY]) + parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); + + if (data[IFLA_GRE_LOCAL]) + memcpy(&parms->iph.saddr, nla_data(data[IFLA_GRE_LOCAL]), 4); + + if (data[IFLA_GRE_REMOTE]) + memcpy(&parms->iph.daddr, nla_data(data[IFLA_GRE_REMOTE]), 4); + + if (data[IFLA_GRE_TTL]) + parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]); + + if (data[IFLA_GRE_TOS]) + parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]); + + if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) + parms->iph.frag_off = htons(IP_DF); +} + +static int ipgre_newlink(struct net_device *dev, struct nlattr *tb[], + struct nlattr *data[]) +{ + struct ip_tunnel *nt; + struct net *net = dev_net(dev); + struct ipgre_net *ign = net_generic(net, ipgre_net_id); + int mtu; + int err; + + nt = netdev_priv(dev); + ipgre_netlink_parms(data, &nt->parms); + + if (ipgre_tunnel_locate(net, &nt->parms, 0)) + return -EEXIST; + + mtu = ipgre_tunnel_bind_dev(dev); + if (!tb[IFLA_MTU]) + dev->mtu = mtu; + + err = register_netdevice(dev); + if (err) + goto out; + + dev_hold(dev); + ipgre_tunnel_link(ign, nt); + +out: + return err; +} + +static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], + struct nlattr *data[]) +{ + struct ip_tunnel *t, *nt; + struct net *net = dev_net(dev); + struct ipgre_net *ign = net_generic(net, ipgre_net_id); + struct ip_tunnel_parm p; + int mtu; + + if (dev == ign->fb_tunnel_dev) + return -EINVAL; + + nt = netdev_priv(dev); + ipgre_netlink_parms(data, &p); + + t = ipgre_tunnel_locate(net, &p, 0); + + if (t) { + if (t->dev != dev) + return -EEXIST; + } else { + unsigned nflags = 0; + + t = nt; + + if (ipv4_is_multicast(p.iph.daddr)) + nflags = IFF_BROADCAST; + else if (p.iph.daddr) + nflags = IFF_POINTOPOINT; + + if ((dev->flags ^ nflags) & + (IFF_POINTOPOINT | IFF_BROADCAST)) + return -EINVAL; + + ipgre_tunnel_unlink(ign, t); + t->parms.iph.saddr = p.iph.saddr; + t->parms.iph.daddr = p.iph.daddr; + t->parms.i_key = p.i_key; + memcpy(dev->dev_addr, &p.iph.saddr, 4); + memcpy(dev->broadcast, &p.iph.daddr, 4); + ipgre_tunnel_link(ign, t); + netdev_state_change(dev); + } + + t->parms.o_key = p.o_key; + t->parms.iph.ttl = p.iph.ttl; + t->parms.iph.tos = p.iph.tos; + t->parms.iph.frag_off = p.iph.frag_off; + + if (t->parms.link != p.link) { + t->parms.link = p.link; + mtu = ipgre_tunnel_bind_dev(dev); + if (!tb[IFLA_MTU]) + dev->mtu = mtu; + netdev_state_change(dev); + } + + return 0; +} + +static size_t ipgre_get_size(const struct net_device *dev) +{ + return + /* IFLA_GRE_LINK */ + nla_total_size(4) + + /* IFLA_GRE_IFLAGS */ + nla_total_size(2) + + /* IFLA_GRE_OFLAGS */ + nla_total_size(2) + + /* IFLA_GRE_IKEY */ + nla_total_size(4) + + /* IFLA_GRE_OKEY */ + nla_total_size(4) + + /* IFLA_GRE_LOCAL */ + nla_total_size(4) + + /* IFLA_GRE_REMOTE */ + nla_total_size(4) + + /* IFLA_GRE_TTL */ + nla_total_size(1) + + /* IFLA_GRE_TOS */ + nla_total_size(1) + + /* IFLA_GRE_PMTUDISC */ + nla_total_size(1) + + 0; +} + +static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) +{ + struct ip_tunnel *t = netdev_priv(dev); + struct ip_tunnel_parm *p = &t->parms; + + NLA_PUT_U32(skb, IFLA_GRE_LINK, p->link); + NLA_PUT_BE16(skb, IFLA_GRE_IFLAGS, p->i_flags); + NLA_PUT_BE16(skb, IFLA_GRE_OFLAGS, p->o_flags); + NLA_PUT_BE32(skb, IFLA_GRE_IFLAGS, p->i_flags); + NLA_PUT_BE32(skb, IFLA_GRE_OFLAGS, p->o_flags); + NLA_PUT(skb, IFLA_GRE_LOCAL, 4, &p->iph.saddr); + NLA_PUT(skb, IFLA_GRE_REMOTE, 4, &p->iph.daddr); + NLA_PUT_U8(skb, IFLA_GRE_TTL, p->iph.ttl); + NLA_PUT_U8(skb, IFLA_GRE_TOS, p->iph.tos); + NLA_PUT_U8(skb, IFLA_GRE_PMTUDISC, !!(p->iph.frag_off & htons(IP_DF))); + + return 0; + +nla_put_failure: + return -EMSGSIZE; +} + +static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { + [IFLA_GRE_LINK] = { .type = NLA_U32 }, + [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, + [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, + [IFLA_GRE_IKEY] = { .type = NLA_U32 }, + [IFLA_GRE_OKEY] = { .type = NLA_U32 }, + [IFLA_GRE_LOCAL] = { .len = 4 }, + [IFLA_GRE_REMOTE] = { .len = 4 }, + [IFLA_GRE_TTL] = { .type = NLA_U8 }, + [IFLA_GRE_TOS] = { .type = NLA_U8 }, + [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 }, +}; + +static struct rtnl_link_ops ipgre_link_ops __read_mostly = { + .kind = "gre", + .maxtype = IFLA_GRE_MAX, + .policy = ipgre_policy, + .priv_size = sizeof(struct ip_tunnel), + .setup = ipgre_tunnel_setup, + .validate = ipgre_tunnel_validate, + .newlink = ipgre_newlink, + .changelink = ipgre_changelink, + .get_size = ipgre_get_size, + .fill_info = ipgre_fill_info, +}; + /* * And now the modules code and kernel interface. */ @@ -1245,19 +1472,31 @@ static int __init ipgre_init(void) err = register_pernet_gen_device(&ipgre_net_id, &ipgre_net_ops); if (err < 0) - inet_del_protocol(&ipgre_protocol, IPPROTO_GRE); + goto gen_device_failed; + err = rtnl_link_register(&ipgre_link_ops); + if (err < 0) + goto rtnl_link_failed; + +out: return err; + +rtnl_link_failed: + unregister_pernet_gen_device(ipgre_net_id, &ipgre_net_ops); +gen_device_failed: + inet_del_protocol(&ipgre_protocol, IPPROTO_GRE); + goto out; } static void __exit ipgre_fini(void) { + rtnl_link_unregister(&ipgre_link_ops); + unregister_pernet_gen_device(ipgre_net_id, &ipgre_net_ops); if (inet_del_protocol(&ipgre_protocol, IPPROTO_GRE) < 0) printk(KERN_INFO "ipgre close: can't remove protocol\n"); - - unregister_pernet_gen_device(ipgre_net_id, &ipgre_net_ops); } module_init(ipgre_init); module_exit(ipgre_fini); MODULE_LICENSE("GPL"); +MODULE_ALIAS("rtnl-link-gre"); -- cgit v1.2.3