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Date: Tue, 06 Feb 2007 16:13:25 -0500
From: Vlad Yasevich <vladislav.yasevich@...com>
To: Neil Horman <nhorman@...driver.com>
Cc: YOSHIFUJI Hideaki / 吉藤英明
<yoshfuji@...ux-ipv6.org>, sri@...ibm.com, davem@...emloft.net,
kuznet@....inr.ac.ru, pekkas@...core.fi, jmorris@...ei.org,
kaber@...eworks.de, netdev@...r.kernel.org
Subject: Re: [PATCH] IPv6: Implement RFC 4429 Optimistic Duplicate Address
Detection
Hi Neil
a few comments. sorry, just can't resist... :)
> @@ -2627,6 +2673,9 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp)
> * Configure the address for reception. Now it is valid.
> */
>
> + if (ifp->flags & IFA_F_OPTIMISTIC)
> + addrconf_leave_anycast(ifp);
> +
> ipv6_ifa_notify(RTM_NEWADDR, ifp);
Since we are no longer doing anycast, remove the above.
> diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
> index 7b7bd44..b8a5261 100644
> --- a/net/ipv6/ip6_output.c
> +++ b/net/ipv6/ip6_output.c
> @@ -857,6 +857,34 @@ static int ip6_dst_lookup_tail(struct sock *sk,
>
> if (ipv6_addr_any(&fl->fl6_src)) {
> err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src);
> +#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
> + /*
> + * Here if the dst entry we've looked up
> + * has a neighbour entry that is in the INCOMPLETE
> + * state and the src address from the flow is
> + * marked as OPTIMISTIC, we release the found
> + * dst entry and replace it instead with the
> + * dst entry of the nexthop router
> + */
> + if (!((*dst)->neighbour->nud_state & NUD_VALID)) {
> + struct inet6_ifaddr *ifp;
> + struct flowi fl_gw;
> + ifp = ipv6_get_ifaddr(&fl->fl6_src, (*dst)->dev, 1);
> +
> + if (ifp && ifp->flags & IFA_F_OPTIMISTIC) {
> + /*
> + * We need to get the dst entry for the
> + * default router instead
> + */
> + dst_release(*dst);
> + memcpy(&fl_gw, fl, sizeof(struct flowi));
> + memset(&fl_gw.fl6_dst, 0, sizeof(struct in6_addr));
> + *dst = ip6_route_output(sk, &fl_gw);
> + if ((err = (*dst)->error))
> + goto out_err_release;
> + }
> + }
> +#endif
> if (err)
> goto out_err_release;
This actually doesn't look right.... What if ipv6_get_saddr returned an error?
I think the new code should go after the 'goto out_err_release;'...
That way, we do optimistic checks if we have a valid source address.
> }
> diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
> index 882cde4..9c5273c 100644
> --- a/net/ipv6/mcast.c
> +++ b/net/ipv6/mcast.c
> @@ -1411,7 +1411,7 @@ static struct sk_buff *mld_newpack(struct net_device *dev, int size)
>
> skb_reserve(skb, LL_RESERVED_SPACE(dev));
>
> - if (ipv6_get_lladdr(dev, &addr_buf)) {
> + if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) {
> /* <draft-ietf-magma-mld-source-05.txt>:
> * use unspecified address as the source address
> * when a valid link-local address is not available.
> @@ -1789,7 +1789,7 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
>
> skb_reserve(skb, LL_RESERVED_SPACE(dev));
>
> - if (ipv6_get_lladdr(dev, &addr_buf)) {
> + if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) {
> /* <draft-ietf-magma-mld-source-05.txt>:
> * use unspecified address as the source address
> * when a valid link-local address is not available.
> diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
> index 39bb658..7400805 100644
> --- a/net/ipv6/ndisc.c
> +++ b/net/ipv6/ndisc.c
> @@ -447,6 +447,8 @@ static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
> ifp = ipv6_get_ifaddr(solicited_addr, dev, 1);
> if (ifp) {
> src_addr = solicited_addr;
> + if (ifp->flags & IFA_F_OPTIMISTIC)
> + override = 0;
> in6_ifa_put(ifp);
> } else {
> if (ipv6_dev_get_saddr(dev, daddr, &tmpaddr))
> @@ -500,6 +502,7 @@ static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
> msg->icmph.icmp6_solicited = solicited;
> msg->icmph.icmp6_override = override;
>
> +
Empty line...
> /* Set the target address. */
> ipv6_addr_copy(&msg->target, solicited_addr);
>
> @@ -542,7 +545,8 @@ void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
> int send_llinfo;
>
> if (saddr == NULL) {
> - if (ipv6_get_lladdr(dev, &addr_buf))
> + if (ipv6_get_lladdr(dev, &addr_buf,
> + (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)))
> return;
> saddr = &addr_buf;
> }
> @@ -559,7 +563,7 @@ void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
> return;
>
> len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
> - send_llinfo = dev->addr_len && !ipv6_addr_any(saddr);
> + send_llinfo = dev->addr_len && !ipv6_addr_any(saddr);
space to tab conversion???
> if (send_llinfo)
> len += ndisc_opt_addr_space(dev);
>
> @@ -622,9 +626,29 @@ void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
> struct sk_buff *skb;
> struct icmp6hdr *hdr;
> __u8 * opt;
> + struct inet6_ifaddr *ifp;
> + int send_sllao = 1;
> int len;
> int err;
>
> + /*
> + * Check the source address. If its OPTIMISTIC
> + * and addr_len is non-zero (implying the sllao option)
> + * then don't send the RS (RFC 4429, section 2.2)
> + */
> + ifp = ipv6_get_ifaddr(saddr, dev, 1);
> +
> + /*
> + * According to section 2.2 of RFC 4429, we must not
> + * send router solicitations with a sllao from
> + * optimistic addresses, but we may send the solicitation
> + * if we don't include the sallo. So here we check
> + * if our address is optimistic, and if so, we
> + * supress the inclusion of the sllao.
> + */
> + if (!dev->addr_len || !ifp || (ifp->flags & IFA_F_OPTIMISTIC))
> + send_sllao=0;
> +
> ndisc_flow_init(&fl, NDISC_ROUTER_SOLICITATION, saddr, daddr,
> dev->ifindex);
>
> @@ -637,7 +661,7 @@ void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
> return;
>
> len = sizeof(struct icmp6hdr);
> - if (dev->addr_len)
> + if (dev->addr_len && send_sllao)
> len += ndisc_opt_addr_space(dev);
>
> skb = sock_alloc_send_skb(sk,
> @@ -664,7 +688,7 @@ void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
>
> opt = (u8*) (hdr + 1);
>
> - if (dev->addr_len)
> + if (dev->addr_len && send_sllao)
> ndisc_fill_addr_option(opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr,
> dev->addr_len, dev->type);
>
> @@ -746,6 +770,7 @@ static void ndisc_recv_ns(struct sk_buff *skb)
> int dad = ipv6_addr_any(saddr);
> int inc;
> int is_router;
> + int type;
'type' is unused.
>
> if (ipv6_addr_is_multicast(&msg->target)) {
> ND_PRINTK2(KERN_WARNING
> @@ -796,28 +821,39 @@ static void ndisc_recv_ns(struct sk_buff *skb)
> inc = ipv6_addr_is_multicast(daddr);
>
> if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1)) != NULL) {
> - if (ifp->flags & IFA_F_TENTATIVE) {
> - /* Address is tentative. If the source
> - is unspecified address, it is someone
> - does DAD, otherwise we ignore solicitations
> - until DAD timer expires.
> - */
> - if (!dad)
> +
> + if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) {
> + if (dad) {
> + if (dev->type == ARPHRD_IEEE802_TR) {
> + unsigned char *sadr = skb->mac.raw;
> + if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
> + sadr[9] == dev->dev_addr[1] &&
> + sadr[10] == dev->dev_addr[2] &&
> + sadr[11] == dev->dev_addr[3] &&
> + sadr[12] == dev->dev_addr[4] &&
> + sadr[13] == dev->dev_addr[5]) {
> + /* looped-back to us */
> + goto out;
> + }
> + }
> +
> + /*
> + * We are colliding with another node
> + * who is doing DAD
> + * so fail our DAD process
> + */
> + addrconf_dad_failure(ifp);
> goto out;
> - if (dev->type == ARPHRD_IEEE802_TR) {
> - unsigned char *sadr = skb->mac.raw;
> - if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 &&
> - sadr[9] == dev->dev_addr[1] &&
> - sadr[10] == dev->dev_addr[2] &&
> - sadr[11] == dev->dev_addr[3] &&
> - sadr[12] == dev->dev_addr[4] &&
> - sadr[13] == dev->dev_addr[5]) {
> - /* looped-back to us */
> + } else {
> + /*
> + * This is not a dad solicitation.
> + * If we are an optimistic node,
> + * we should respond.
> + * Otherwise, we should ignore it.
> + */
> + if (!(ifp->flags & IFA_F_OPTIMISTIC))
> goto out;
> - }
> }
> - addrconf_dad_failure(ifp);
> - return;
> }
>
> idev = ifp->idev;
> @@ -1406,7 +1442,7 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
>
> dev = skb->dev;
>
> - if (ipv6_get_lladdr(dev, &saddr_buf)) {
> + if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
> ND_PRINTK2(KERN_WARNING
> "ICMPv6 Redirect: no link-local address on %s\n",
> dev->name);
>
Regards
-vlad
-
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