Return-Path: Subject: Re: [PATCHv2 bluetooth-next 07/10] ipv6: introduce neighbour discovery ops To: Alexander Aring , linux-wpan@vger.kernel.org References: <1461140382-4784-1-git-send-email-aar@pengutronix.de> <1461140382-4784-8-git-send-email-aar@pengutronix.de> Cc: kernel@pengutronix.de, marcel@holtmann.org, jukka.rissanen@linux.intel.com, stefan@osg.samsung.com, mcr@sandelman.ca, werner@almesberger.net, linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org, "David S . Miller" , Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Patrick McHardy From: Hannes Frederic Sowa Message-ID: Date: Mon, 2 May 2016 21:36:13 +0200 MIME-Version: 1.0 In-Reply-To: <1461140382-4784-8-git-send-email-aar@pengutronix.de> Content-Type: text/plain; charset=utf-8 List-ID: On 20.04.2016 10:19, Alexander Aring wrote: > This patch introduces neighbour discovery ops callback structure. The > structure contains at first receive and transmit handling for NS/NA and > userspace option field functionality. > > These callback offers 6lowpan different handling, such as 802.15.4 short > address handling or RFC6775 (Neighbor Discovery Optimization for IPv6 over > 6LoWPANs). > > Cc: David S. Miller > Cc: Alexey Kuznetsov > Cc: James Morris > Cc: Hideaki YOSHIFUJI > Cc: Patrick McHardy > Signed-off-by: Alexander Aring > --- > include/linux/netdevice.h | 3 ++ > include/net/ndisc.h | 96 +++++++++++++++++++++++++++++++++++++++++++---- > net/ipv6/addrconf.c | 1 + > net/ipv6/ndisc.c | 71 ++++++++++++++++++++++++----------- > net/ipv6/route.c | 2 +- > 5 files changed, 144 insertions(+), 29 deletions(-) > > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h > index 0052c42..bc60033 100644 > --- a/include/linux/netdevice.h > +++ b/include/linux/netdevice.h > @@ -1677,6 +1677,9 @@ struct net_device { > #ifdef CONFIG_NET_L3_MASTER_DEV > const struct l3mdev_ops *l3mdev_ops; > #endif > +#if IS_ENABLED(CONFIG_IPV6) > + const struct ndisc_ops *ndisc_ops; > +#endif > > const struct header_ops *header_ops; > > diff --git a/include/net/ndisc.h b/include/net/ndisc.h > index aac868e..14ed016 100644 > --- a/include/net/ndisc.h > +++ b/include/net/ndisc.h > @@ -110,7 +110,8 @@ struct ndisc_options { > > #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7) > > -struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len, > +struct ndisc_options *ndisc_parse_options(const struct net_device *dev, > + u8 *opt, int opt_len, > struct ndisc_options *ndopts); > > /* > @@ -173,6 +174,93 @@ static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, cons > return n; > } > > +static inline int __ip6_ndisc_is_useropt(struct nd_opt_hdr *opt) > +{ > + return opt->nd_opt_type == ND_OPT_RDNSS || > + opt->nd_opt_type == ND_OPT_DNSSL; > +} > + > +#if IS_ENABLED(CONFIG_IPV6) > +struct ndisc_ops { > + int (*is_useropt)(struct nd_opt_hdr *opt); > + void (*send_na)(struct net_device *dev, > + const struct in6_addr *daddr, > + const struct in6_addr *solicited_addr, > + bool router, bool solicited, > + bool override, bool inc_opt); > + void (*recv_na)(struct sk_buff *skb); > + void (*send_ns)(struct net_device *dev, > + const struct in6_addr *solicit, > + const struct in6_addr *daddr, > + const struct in6_addr *saddr); > + void (*recv_ns)(struct sk_buff *skb); > +}; > + > +static inline int ndisc_is_useropt(const struct net_device *dev, > + struct nd_opt_hdr *opt) > +{ > + if (likely(dev->ndisc_ops->is_useropt)) > + return dev->ndisc_ops->is_useropt(opt); > + else > + return 0; > +} > + > +static inline void ndisc_send_na(struct net_device *dev, > + const struct in6_addr *daddr, > + const struct in6_addr *solicited_addr, > + bool router, bool solicited, bool override, > + bool inc_opt) > +{ > + if (likely(dev->ndisc_ops->send_na)) > + dev->ndisc_ops->send_na(dev, daddr, solicited_addr, router, > + solicited, override, inc_opt); > +} > + > +static inline void ndisc_recv_na(struct sk_buff *skb) > +{ > + if (likely(skb->dev->ndisc_ops->recv_na)) > + skb->dev->ndisc_ops->recv_na(skb); > +} > + > +static inline void ndisc_send_ns(struct net_device *dev, > + const struct in6_addr *solicit, > + const struct in6_addr *daddr, > + const struct in6_addr *saddr) > +{ > + if (likely(dev->ndisc_ops->send_ns)) > + dev->ndisc_ops->send_ns(dev, solicit, daddr, saddr); > +} > + > +static inline void ndisc_recv_ns(struct sk_buff *skb) > +{ > + if (likely(skb->dev->ndisc_ops->recv_ns)) > + skb->dev->ndisc_ops->recv_ns(skb); > +} > +#else > +static inline int ndisc_is_useropt(const struct net_device *dev, > + struct nd_opt_hdr *opt) > +{ > + return 0; > +} > + > +static inline void ndisc_send_na(struct net_device *dev, > + const struct in6_addr *daddr, > + const struct in6_addr *solicited_addr, > + bool router, bool solicited, bool override, > + bool inc_opt) { } > + > +static inline void ndisc_recv_na(struct sk_buff *skb) { } > + > +static inline void ndisc_send_ns(struct net_device *dev, > + const struct in6_addr *solicit, > + const struct in6_addr *daddr, > + const struct in6_addr *saddr) { } > + > +static inline void ndisc_recv_ns(struct sk_buff *skb) { } > +#endif Do those empty functions actually make sense? I wonder a bit because 6lowpan strictly depends on ipv6 and they should never be called without IPv6, no? > + > +void ip6_register_ndisc_ops(struct net_device *dev); > + > int ndisc_init(void); > int ndisc_late_init(void); > > @@ -181,14 +269,8 @@ void ndisc_cleanup(void); > > int ndisc_rcv(struct sk_buff *skb); > > -void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit, > - const struct in6_addr *daddr, const struct in6_addr *saddr); > - > void ndisc_send_rs(struct net_device *dev, > const struct in6_addr *saddr, const struct in6_addr *daddr); > -void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr, > - const struct in6_addr *solicited_addr, > - bool router, bool solicited, bool override, bool inc_opt); > > void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target); > > diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c > index 54e18c2..a2ef04b 100644 > --- a/net/ipv6/addrconf.c > +++ b/net/ipv6/addrconf.c > @@ -3266,6 +3266,7 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, > idev = ipv6_add_dev(dev); > if (IS_ERR(idev)) > return notifier_from_errno(PTR_ERR(idev)); > + ip6_register_ndisc_ops(dev); Is it possible to register the ndisc options before we make the device visible to the stack? Maybe even as a pointer to ipv6_add_dev. > } > break; > > diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c > index 176c7c4..297080a 100644 > --- a/net/ipv6/ndisc.c > +++ b/net/ipv6/ndisc.c > @@ -185,24 +185,25 @@ static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur, > return cur <= end && cur->nd_opt_type == type ? cur : NULL; > } > > -static inline int ndisc_is_useropt(struct nd_opt_hdr *opt) > +static inline int ip6_ndisc_is_useropt(struct nd_opt_hdr *opt) > { > - return opt->nd_opt_type == ND_OPT_RDNSS || > - opt->nd_opt_type == ND_OPT_DNSSL; > + return __ip6_ndisc_is_useropt(opt); > } inline in C functions are not necessary. > > -static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur, > +static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev, > + struct nd_opt_hdr *cur, > struct nd_opt_hdr *end) > { > if (!cur || !end || cur >= end) > return NULL; > do { > cur = ((void *)cur) + (cur->nd_opt_len << 3); > - } while (cur < end && !ndisc_is_useropt(cur)); > - return cur <= end && ndisc_is_useropt(cur) ? cur : NULL; > + } while (cur < end && !ndisc_is_useropt(dev, cur)); > + return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL; > } > > -struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len, > +struct ndisc_options *ndisc_parse_options(const struct net_device *dev, > + u8 *opt, int opt_len, > struct ndisc_options *ndopts) > { > struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt; > @@ -243,7 +244,7 @@ struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len, > break; > #endif > default: > - if (ndisc_is_useropt(nd_opt)) { > + if (ndisc_is_useropt(dev, nd_opt)) { > ndopts->nd_useropts_end = nd_opt; > if (!ndopts->nd_useropts) > ndopts->nd_useropts = nd_opt; > @@ -479,9 +480,11 @@ static void ndisc_send_skb(struct sk_buff *skb, > rcu_read_unlock(); > } > > -void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr, > - const struct in6_addr *solicited_addr, > - bool router, bool solicited, bool override, bool inc_opt) > +static void ip6_ndisc_send_na(struct net_device *dev, > + const struct in6_addr *daddr, > + const struct in6_addr *solicited_addr, > + bool router, bool solicited, bool override, > + bool inc_opt) > { > struct sk_buff *skb; > struct in6_addr tmpaddr; > @@ -555,8 +558,10 @@ static void ndisc_send_unsol_na(struct net_device *dev) > in6_dev_put(idev); > } > > -void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit, > - const struct in6_addr *daddr, const struct in6_addr *saddr) > +static void ip6_ndisc_send_ns(struct net_device *dev, > + const struct in6_addr *solicit, > + const struct in6_addr *daddr, > + const struct in6_addr *saddr) > { > struct sk_buff *skb; > struct in6_addr addr_buf; > @@ -702,7 +707,7 @@ static int pndisc_is_router(const void *pkey, > return ret; > } > > -static void ndisc_recv_ns(struct sk_buff *skb) > +static void ip6_ndisc_recv_ns(struct sk_buff *skb) > { > struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); > const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; > @@ -738,7 +743,7 @@ static void ndisc_recv_ns(struct sk_buff *skb) > return; > } > > - if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { > + if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) { > ND_PRINTK(2, warn, "NS: invalid ND options\n"); > return; > } > @@ -874,7 +879,7 @@ out: > in6_dev_put(idev); > } > > -static void ndisc_recv_na(struct sk_buff *skb) > +static void ip6_ndisc_recv_na(struct sk_buff *skb) > { > struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); > struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; > @@ -912,7 +917,7 @@ static void ndisc_recv_na(struct sk_buff *skb) > idev->cnf.drop_unsolicited_na) > return; > > - if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { > + if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) { > ND_PRINTK(2, warn, "NS: invalid ND option\n"); > return; > } > @@ -1019,7 +1024,7 @@ static void ndisc_recv_rs(struct sk_buff *skb) > goto out; > > /* Parse ND options */ > - if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) { > + if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) { > ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n"); > goto out; > } > @@ -1137,7 +1142,7 @@ static void ndisc_router_discovery(struct sk_buff *skb) > return; > } > > - if (!ndisc_parse_options(opt, optlen, &ndopts)) { > + if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) { > ND_PRINTK(2, warn, "RA: invalid ND options\n"); > return; > } > @@ -1424,7 +1429,8 @@ skip_routeinfo: > struct nd_opt_hdr *p; > for (p = ndopts.nd_useropts; > p; > - p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) { > + p = ndisc_next_useropt(skb->dev, p, > + ndopts.nd_useropts_end)) { > ndisc_ra_useropt(skb, p); > } > } > @@ -1462,7 +1468,7 @@ static void ndisc_redirect_rcv(struct sk_buff *skb) > return; > } > > - if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) > + if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts)) > return; > > if (!ndopts.nd_opts_rh) { > @@ -1783,6 +1789,29 @@ int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *bu > > #endif > > +static const struct ndisc_ops ip6_ndisc_ops = { > + .is_useropt = ip6_ndisc_is_useropt, > + .send_na = ip6_ndisc_send_na, > + .recv_na = ip6_ndisc_recv_na, > + .send_ns = ip6_ndisc_send_ns, > + .recv_ns = ip6_ndisc_recv_ns, > +}; > + > +void ip6_register_ndisc_ops(struct net_device *dev) > +{ > + switch (dev->type) { > + default: > + if (dev->ndisc_ops) { > + ND_PRINTK(2, warn, > + "%s: ndisc_ops already defined for interface type=%d\n", > + __func__, dev->type); > + } else { > + dev->ndisc_ops = &ip6_ndisc_ops; > + } > + break; I would be more stricht with validation: if (!WARN_ON(dev->ndisc_ops)) dev->ndisc_ops = &ip6_ndisc_ops; > + } > +} > + > static int __net_init ndisc_net_init(struct net *net) > { > struct ipv6_pinfo *np; > diff --git a/net/ipv6/route.c b/net/ipv6/route.c > index cc180b3..5fa276d 100644 > --- a/net/ipv6/route.c > +++ b/net/ipv6/route.c > @@ -2149,7 +2149,7 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu > * first-hop router for the specified ICMP Destination Address. > */ > > - if (!ndisc_parse_options(msg->opt, optlen, &ndopts)) { > + if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) { > net_dbg_ratelimited("rt6_redirect: invalid ND options\n"); > return; > } >