Re: [RFC 07/12] addrconf: put prefix address add in an own function

Stefan Schmidt <stefan@xxxxxxxxxxxxxxx> · Fri, 27 May 2016 15:17:31 +0200

Hello.

On 27/05/16 13:41, Alexander Aring wrote:
Hi,

On 05/27/2016 11:45 AM, Stefan Schmidt wrote:
Hello.

sorry, again I will change something on this patch which is buggy.

On 23/05/16 21:22, Alexander Aring wrote:
This patch moves the functionality to add a RA PIO prefix generated
address in an own function. This move prepares to add a hook for
adding a second address for a second link-layer address. E.g. short
address for 802.15.4 6LoWPAN.

Cc: David S. Miller<davem@xxxxxxxxxxxxx>
Cc: Alexey Kuznetsov<kuznet@xxxxxxxxxxxxx>
Cc: James Morris<jmorris@xxxxxxxxx>
Cc: Hideaki YOSHIFUJI<yoshfuji@xxxxxxxxxxxxxx>
Cc: Patrick McHardy<kaber@xxxxxxxxx>
Signed-off-by: Alexander Aring<aar@xxxxxxxxxxxxxx>
---
   net/ipv6/addrconf.c | 191 ++++++++++++++++++++++++++++------------------------
   1 file changed, 102 insertions(+), 89 deletions(-)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index beaad49..393cdbf 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2333,6 +2333,104 @@ static bool is_addr_mode_generate_stable(struct inet6_dev *idev)
              idev->addr_gen_mode == IN6_ADDR_GEN_MODE_RANDOM;
   }
   +static void addrconf_prefix_rcv_add_addr(struct net *net,
will change to return int here to indicates errors.

+                     struct net_device *dev,
+                     const struct prefix_info *pinfo,
+                     struct inet6_dev *in6_dev,
+                     const struct in6_addr *addr,
+                     int addr_type, u32 addr_flags,
+                     bool sllao, bool tokenized,
+                     __u32 valid_lft, u32 prefered_lft)
+{
+    struct inet6_ifaddr *ifp = ipv6_get_ifaddr(net, addr, dev, 1);
+    int create = 0, update_lft = 0;
+
+    if (!ifp && valid_lft) {
+        int max_addresses = in6_dev->cnf.max_addresses;
+
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+        if (in6_dev->cnf.optimistic_dad &&
+            !net->ipv6.devconf_all->forwarding && sllao)
+            addr_flags |= IFA_F_OPTIMISTIC;
+#endif
+
+        /* Do not allow to create too much of autoconfigured
+         * addresses; this would be too easy way to crash kernel.
+         */
+        if (!max_addresses ||
+            ipv6_count_addresses(in6_dev) < max_addresses)
+            ifp = ipv6_add_addr(in6_dev, addr, NULL,
+                        pinfo->prefix_len,
+                        addr_type&IPV6_ADDR_SCOPE_MASK,
+                        addr_flags, valid_lft,
+                        prefered_lft);
+
+        if (IS_ERR_OR_NULL(ifp)) {
+            in6_dev_put(in6_dev);
+            return;
return -1; and remove in6_dev_put stuff.

+        }
+
+        update_lft = 0;
+        create = 1;
+        spin_lock_bh(&ifp->lock);
+        ifp->flags |= IFA_F_MANAGETEMPADDR;
+        ifp->cstamp = jiffies;
+        ifp->tokenized = tokenized;
+        spin_unlock_bh(&ifp->lock);
+        addrconf_dad_start(ifp);
+    }
+
+    if (ifp) {
+        u32 flags;
+        unsigned long now;
+        u32 stored_lft;
+
+        /* update lifetime (RFC2462 5.5.3 e) */
+        spin_lock_bh(&ifp->lock);
+        now = jiffies;
+        if (ifp->valid_lft > (now - ifp->tstamp) / HZ)
+            stored_lft = ifp->valid_lft - (now - ifp->tstamp) / HZ;
+        else
+            stored_lft = 0;
+        if (!update_lft && !create && stored_lft) {
+            const u32 minimum_lft = min_t(u32,
+                stored_lft, MIN_VALID_LIFETIME);
+            valid_lft = max(valid_lft, minimum_lft);
+
+            /* RFC4862 Section 5.5.3e:
+             * "Note that the preferred lifetime of the
+             *  corresponding address is always reset to
+             *  the Preferred Lifetime in the received
+             *  Prefix Information option, regardless of
+             *  whether the valid lifetime is also reset or
+             *  ignored."
+             *
+             * So we should always update prefered_lft here.
+             */
+            update_lft = 1;
+        }
+
+        if (update_lft) {
+            ifp->valid_lft = valid_lft;
+            ifp->prefered_lft = prefered_lft;
+            ifp->tstamp = now;
+            flags = ifp->flags;
+            ifp->flags &= ~IFA_F_DEPRECATED;
+            spin_unlock_bh(&ifp->lock);
+
+            if (!(flags&IFA_F_TENTATIVE))
+                ipv6_ifa_notify(0, ifp);
+        } else
+            spin_unlock_bh(&ifp->lock);
+
+        manage_tempaddrs(in6_dev, ifp, valid_lft, prefered_lft,
+                 create, now);
+
+        in6_ifa_put(ifp);
+        addrconf_verify();
+    }
+}
+
   void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao)
   {
       struct prefix_info *pinfo;
@@ -2432,9 +2530,7 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao)
       /* Try to figure out our local address for this prefix */
         if (pinfo->autoconf && in6_dev->cnf.autoconf) {
-        struct inet6_ifaddr *ifp;
           struct in6_addr addr;
-        int create = 0, update_lft = 0;
           bool tokenized = false;
             if (pinfo->prefix_len == 64) {
@@ -2464,93 +2560,10 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao)
           return;
     ok:
-
-        ifp = ipv6_get_ifaddr(net, &addr, dev, 1);
-
-        if (!ifp && valid_lft) {
-            int max_addresses = in6_dev->cnf.max_addresses;
-
-#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
-            if (in6_dev->cnf.optimistic_dad &&
-                !net->ipv6.devconf_all->forwarding && sllao)
-                addr_flags |= IFA_F_OPTIMISTIC;
-#endif
-
-            /* Do not allow to create too much of autoconfigured
-             * addresses; this would be too easy way to crash kernel.
-             */
-            if (!max_addresses ||
-                ipv6_count_addresses(in6_dev) < max_addresses)
-                ifp = ipv6_add_addr(in6_dev, &addr, NULL,
-                            pinfo->prefix_len,
-                            addr_type&IPV6_ADDR_SCOPE_MASK,
-                            addr_flags, valid_lft,
-                            prefered_lft);
-
-            if (IS_ERR_OR_NULL(ifp)) {
-                in6_dev_put(in6_dev);
-                return;
-            }
-
-            update_lft = 0;
-            create = 1;
-            spin_lock_bh(&ifp->lock);
-            ifp->flags |= IFA_F_MANAGETEMPADDR;
-            ifp->cstamp = jiffies;
-            ifp->tokenized = tokenized;
-            spin_unlock_bh(&ifp->lock);
-            addrconf_dad_start(ifp);
-        }
-
-        if (ifp) {
-            u32 flags;
-            unsigned long now;
-            u32 stored_lft;
-
-            /* update lifetime (RFC2462 5.5.3 e) */
-            spin_lock_bh(&ifp->lock);
-            now = jiffies;
-            if (ifp->valid_lft > (now - ifp->tstamp) / HZ)
-                stored_lft = ifp->valid_lft - (now - ifp->tstamp) / HZ;
-            else
-                stored_lft = 0;
-            if (!update_lft && !create && stored_lft) {
-                const u32 minimum_lft = min_t(u32,
-                    stored_lft, MIN_VALID_LIFETIME);
-                valid_lft = max(valid_lft, minimum_lft);
-
-                /* RFC4862 Section 5.5.3e:
-                 * "Note that the preferred lifetime of the
-                 *  corresponding address is always reset to
-                 *  the Preferred Lifetime in the received
-                 *  Prefix Information option, regardless of
-                 *  whether the valid lifetime is also reset or
-                 *  ignored."
-                 *
-                 * So we should always update prefered_lft here.
-                 */
-                update_lft = 1;
-            }
-
-            if (update_lft) {
-                ifp->valid_lft = valid_lft;
-                ifp->prefered_lft = prefered_lft;
-                ifp->tstamp = now;
-                flags = ifp->flags;
-                ifp->flags &= ~IFA_F_DEPRECATED;
-                spin_unlock_bh(&ifp->lock);
-
-                if (!(flags&IFA_F_TENTATIVE))
-                    ipv6_ifa_notify(0, ifp);
-            } else
-                spin_unlock_bh(&ifp->lock);
-
-            manage_tempaddrs(in6_dev, ifp, valid_lft, prefered_lft,
-                     create, now);
-
-            in6_ifa_put(ifp);
-            addrconf_verify();
-        }
+        addrconf_prefix_rcv_add_addr(net, dev, pinfo, in6_dev, &addr,
+                         addr_type, addr_flags, sllao,
+                         tokenized, valid_lft,
+                         prefered_lft);
check error here and goto in6_dev_put stuff. Oderwise
inet6_prefix_notify will call on error.

       }
       inet6_prefix_notify(RTM_NEWPREFIX, in6_dev, pinfo);
       in6_dev_put(in6_dev);
Reviewed-by: Stefan Schmidt<stefan@xxxxxxxxxxxxxxx>

I hope this fits to your review by tag, I simple add it then in RFCv2.

You can do the change you described here and still keep my reviewed by.

regards
Stefan Schmidt
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