[IPV6] SIT: Add SIOCGETPRL ioctl to get/dump PRL.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

3 files changed, 95 insertions, 10 deletions

diff --git a/include/linux/if_tunnel.h b/include/linux/if_tunnel.h
index f20c224d544c..f1fbe9c930d7 100644
--- a/include/linux/if_tunnel.h
+++ b/include/linux/if_tunnel.h
@@ -7,6 +7,7 @@
 #define SIOCADDTUNNEL   (SIOCDEVPRIVATE + 1)
 #define SIOCDELTUNNEL   (SIOCDEVPRIVATE + 2)
 #define SIOCCHGTUNNEL   (SIOCDEVPRIVATE + 3)
+#define SIOCGETPRL      (SIOCDEVPRIVATE + 4)
 #define SIOCADDPRL      (SIOCDEVPRIVATE + 5)
 #define SIOCDELPRL      (SIOCDEVPRIVATE + 6)
 #define SIOCCHGPRL      (SIOCDEVPRIVATE + 7)
@@ -38,6 +39,9 @@ struct ip_tunnel_prl {
         __be32                  addr;
         __u16                   flags;
         __u16                   __reserved;
+        __u32                   datalen;
+        __u32                   __reserved2;
+        void __user             *data;
 };
 
 /* PRL flags */
diff --git a/include/net/ipip.h b/include/net/ipip.h
index 205536a014e8..633ed4def8e3 100644
--- a/include/net/ipip.h
+++ b/include/net/ipip.h
@@ -24,13 +24,16 @@ struct ip_tunnel
         int                     mlink;
 
         struct ip_tunnel_parm   parms;
+
         struct ip_tunnel_prl_entry      *prl;           /* potential router list */
+        unsigned int                    prl_count;      /* # of entries in PRL */
 };
 
 struct ip_tunnel_prl_entry
 {
         struct ip_tunnel_prl_entry      *next;
-        struct ip_tunnel_prl            entry;
+        __be32                          addr;
+        u16                             flags;
 };
 
 #define IPTUNNEL_XMIT() do {                                            \
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 84c1ed246afb..08a483a8de50 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -203,12 +203,73 @@ __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
         struct ip_tunnel_prl_entry *p = (struct ip_tunnel_prl_entry *)NULL;
 
         for (p = t->prl; p; p = p->next)
-                if (p->entry.addr == addr)
+                if (p->addr == addr)
                         break;
         return p;
 
 }
 
+static int ipip6_tunnel_get_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
+{
+        struct ip_tunnel_prl *kp;
+        struct ip_tunnel_prl_entry *prl;
+        unsigned int cmax, c = 0, ca, len;
+        int ret = 0;
+
+        cmax = a->datalen / sizeof(*a);
+        if (cmax > 1 && a->addr != htonl(INADDR_ANY))
+                cmax = 1;
+
+        /* For simple GET or for root users,
+         * we try harder to allocate.
+         */
+        kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
+                kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
+                NULL;
+
+        read_lock(&ipip6_lock);
+
+        ca = t->prl_count < cmax ? t->prl_count : cmax;
+
+        if (!kp) {
+                /* We don't try hard to allocate much memory for
+                 * non-root users.
+                 * For root users, retry allocating enough memory for
+                 * the answer.
+                 */
+                kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
+                if (!kp) {
+                        ret = -ENOMEM;
+                        goto out;
+                }
+        }
+
+        c = 0;
+        for (prl = t->prl; prl; prl = prl->next) {
+                if (c > cmax)
+                        break;
+                if (a->addr != htonl(INADDR_ANY) && prl->addr != a->addr)
+                        continue;
+                kp[c].addr = prl->addr;
+                kp[c].flags = prl->flags;
+                c++;
+                if (a->addr != htonl(INADDR_ANY))
+                        break;
+        }
+out:
+        read_unlock(&ipip6_lock);
+
+        len = sizeof(*kp) * c;
+        ret = len ? copy_to_user(a->data, kp, len) : 0;
+
+        kfree(kp);
+        if (ret)
+                return -EFAULT;
+
+        a->datalen = len;
+        return 0;
+}
+
 static int
 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
 {
@@ -221,7 +282,7 @@ ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
         write_lock(&ipip6_lock);
 
         for (p = t->prl; p; p = p->next) {
-                if (p->entry.addr == a->addr) {
+                if (p->addr == a->addr) {
                         if (chg)
                                 goto update;
                         err = -EEXIST;
@@ -242,8 +303,10 @@ ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
 
         p->next = t->prl;
         t->prl = p;
+        t->prl_count++;
 update:
-        p->entry = *a;
+        p->addr = a->addr;
+        p->flags = a->flags;
 out:
         write_unlock(&ipip6_lock);
         return err;
@@ -259,10 +322,11 @@ ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
 
         if (a && a->addr != htonl(INADDR_ANY)) {
                 for (p = &t->prl; *p; p = &(*p)->next) {
-                        if ((*p)->entry.addr == a->addr) {
+                        if ((*p)->addr == a->addr) {
                                 x = *p;
                                 *p = x->next;
                                 kfree(x);
+                                t->prl_count--;
                                 goto out;
                         }
                 }
@@ -272,6 +336,7 @@ ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
                         x = t->prl;
                         t->prl = t->prl->next;
                         kfree(x);
+                        t->prl_count--;
                 }
         }
 out:
@@ -313,7 +378,7 @@ isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t)
         read_lock(&ipip6_lock);
         p = __ipip6_tunnel_locate_prl(t, iph->saddr);
         if (p) {
-                if (p->entry.flags & PRL_DEFAULT)
+                if (p->flags & PRL_DEFAULT)
                         skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
                 else
                         skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
@@ -899,11 +964,12 @@ ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
                 err = 0;
                 break;
 
+        case SIOCGETPRL:
         case SIOCADDPRL:
         case SIOCDELPRL:
         case SIOCCHGPRL:
                 err = -EPERM;
-                if (!capable(CAP_NET_ADMIN))
+                if (cmd != SIOCGETPRL && !capable(CAP_NET_ADMIN))
                         goto done;
                 err = -EINVAL;
                 if (dev == ipip6_fb_tunnel_dev)
@@ -915,11 +981,23 @@ ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
                 if (!(t = netdev_priv(dev)))
                         goto done;
 
-                if (cmd == SIOCDELPRL)
+                switch (cmd) {
+                case SIOCGETPRL:
+                        err = ipip6_tunnel_get_prl(t, &prl);
+                        if (!err && copy_to_user(ifr->ifr_ifru.ifru_data,
+                                                 &prl, sizeof(prl)))
+                                err = -EFAULT;
+                        break;
+                case SIOCDELPRL:
                         err = ipip6_tunnel_del_prl(t, &prl);
-                else
+                        break;
+                case SIOCADDPRL:
+                case SIOCCHGPRL:
                         err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
-                netdev_state_change(dev);
+                        break;
+                }
+                if (cmd != SIOCGETPRL)
+                        netdev_state_change(dev);
                 break;
 
         default: