IPv6: data structure changes for new socket options

Add underlying data structure changes and basic setsockopt()
and getsockopt() support for IPV6_RECVPATHMTU, IPV6_PATHMTU,
and IPV6_DONTFRAG.  IPV6_PATHMTU is actually fully functional
at this point.

Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 57 insertions, 4 deletions

diff --git a/include/linux/in6.h b/include/linux/in6.h
index 9b90cb296eb1..c4bf46f764bf 100644
--- a/include/linux/in6.h
+++ b/include/linux/in6.h
@@ -221,10 +221,10 @@ struct in6_flowlabel_req {
 #define IPV6_RTHDR              57
 #define IPV6_RECVDSTOPTS        58
 #define IPV6_DSTOPTS            59
-#if 0   /* not yet */
 #define IPV6_RECVPATHMTU        60
 #define IPV6_PATHMTU            61
 #define IPV6_DONTFRAG           62
+#if 0   /* not yet */
 #define IPV6_USE_MIN_MTU        63
 #endif
 
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 1bdbebf08d16..1976942cf6f9 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -21,6 +21,10 @@ struct in6_pktinfo {
         int             ipi6_ifindex;
 };
 
+struct ip6_mtuinfo {
+        struct sockaddr_in6     ip6m_addr;
+        __u32                   ip6m_mtu;
+};
 
 struct in6_ifreq {
         struct in6_addr ifr6_addr;
@@ -334,22 +338,25 @@ struct ipv6_pinfo {
                                 dstopts:1,
                                 odstopts:1,
                                 rxflow:1,
-                                rxtclass:1;
+                                rxtclass:1,
+                                rxpmtu:1;
                 } bits;
                 __u16           all;
         } rxopt;
 
         /* sockopt flags */
-        __u8                    recverr:1,
+        __u16                   recverr:1,
                                 sndflow:1,
                                 pmtudisc:2,
                                 ipv6only:1,
-                                srcprefs:3;     /* 001: prefer temporary address
+                                srcprefs:3,     /* 001: prefer temporary address
                                                  * 010: prefer public address
                                                  * 100: prefer care-of address
                                                  */
+                                dontfrag:1;
         __u8                    min_hopcount;
         __u8                    tclass;
+        __u8                    padding;
 
         __u32                   dst_cookie;
 
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 92295ad3487a..2bf9eda72788 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -337,6 +337,13 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
                 retv = 0;
                 break;
 
+        case IPV6_RECVPATHMTU:
+                if (optlen < sizeof(int))
+                        goto e_inval;
+                np->rxopt.bits.rxpmtu = valbool;
+                retv = 0;
+                break;
+
         case IPV6_HOPOPTS:
         case IPV6_RTHDRDSTOPTS:
         case IPV6_RTHDR:
@@ -773,6 +780,9 @@ pref_skip_coa:
                 if (val < 0 || val > 255)
                         goto e_inval;
                 np->min_hopcount = val;
+                break;
+        case IPV6_DONTFRAG:
+                np->dontfrag = valbool;
                 retv = 0;
                 break;
         }
@@ -1063,6 +1073,38 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
                 val = np->rxopt.bits.rxflow;
                 break;
 
+        case IPV6_RECVPATHMTU:
+                val = np->rxopt.bits.rxpmtu;
+                break;
+
+        case IPV6_PATHMTU:
+        {
+                struct dst_entry *dst;
+                struct ip6_mtuinfo mtuinfo;
+
+                if (len < sizeof(mtuinfo))
+                        return -EINVAL;
+
+                len = sizeof(mtuinfo);
+                memset(&mtuinfo, 0, sizeof(mtuinfo));
+
+                rcu_read_lock();
+                dst = __sk_dst_get(sk);
+                if (dst)
+                        mtuinfo.ip6m_mtu = dst_mtu(dst);
+                rcu_read_unlock();
+                if (!mtuinfo.ip6m_mtu)
+                        return -ENOTCONN;
+
+                if (put_user(len, optlen))
+                        return -EFAULT;
+                if (copy_to_user(optval, &mtuinfo, len))
+                        return -EFAULT;
+
+                return 0;
+                break;
+        }
+
         case IPV6_UNICAST_HOPS:
         case IPV6_MULTICAST_HOPS:
         {
@@ -1128,6 +1170,10 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
                 val = np->min_hopcount;
                 break;
 
+        case IPV6_DONTFRAG:
+                val = np->dontfrag;
+                break;
+
         default:
                 return -ENOPROTOOPT;
         }