[IP_SOCKGLUE]: Remove most of the tcp specific calls

As DCCP needs to be called in the same spots.

Now we have a member in inet_sock (is_icsk), set at sock creation time from
struct inet_protosw->flags (if INET_PROTOSW_ICSK is set, like for TCP and
DCCP) to see if a struct sock instance is a inet_connection_sock for places
like the ones in ip_sockglue.c (v4 and v6) where we previously were looking if
sk_type was SOCK_STREAM, that is insufficient because we now use the same code
for DCCP, that has sk_type SOCK_DCCP.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

20 files changed, 97 insertions, 83 deletions

diff --git a/include/linux/dccp.h b/include/linux/dccp.h
index 71fab4311e92..d0bdb499cf8d 100644
--- a/include/linux/dccp.h
+++ b/include/linux/dccp.h
@@ -408,8 +408,6 @@ struct dccp_ackvec;
  * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
  * @dccps_timestamp_time - time of latest TIMESTAMP option
  * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
- * @dccps_ext_header_len - network protocol overhead (IP/IPv6 options)
- * @dccps_pmtu_cookie - Last pmtu seen by socket
  * @dccps_packet_size - Set thru setsockopt
  * @dccps_role - Role of this sock, one of %dccp_role
  * @dccps_ndp_count - number of Non Data Packets since last data packet
@@ -434,8 +432,6 @@ struct dccp_sock {
         __u32                           dccps_timestamp_echo;
         __u32                           dccps_packet_size;
         unsigned long                   dccps_ndp_count;
-        __u16                           dccps_ext_header_len;
-        __u32                           dccps_pmtu_cookie;
         __u32                           dccps_mss_cache;
         struct dccp_options             dccps_options;
         struct dccp_ackvec              *dccps_hc_rx_ackvec;
diff --git a/include/linux/ip.h b/include/linux/ip.h
index 5a560daeade5..6ccc596c19c8 100644
--- a/include/linux/ip.h
+++ b/include/linux/ip.h
@@ -155,6 +155,7 @@ struct inet_sock {
         __u8                    mc_ttl;         /* Multicasting TTL */
         __u8                    pmtudisc;
         unsigned                recverr : 1,
+                                is_icsk : 1,    /* inet_connection_sock? */
                                 freebind : 1,
                                 hdrincl : 1,
                                 mc_loop : 1;
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index da38eea1994b..f2bb2396853f 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -238,10 +238,9 @@ struct tcp_sock {
         __u32   snd_wl1;        /* Sequence for window update           */
         __u32   snd_wnd;        /* The window we expect to receive      */
         __u32   max_window;     /* Maximal window ever seen from peer   */
-        __u32   pmtu_cookie;    /* Last pmtu seen by socket             */
         __u32   mss_cache;      /* Cached effective mss, not including SACKS */
         __u16   xmit_size_goal; /* Goal for segmenting output packets   */
-        __u16   ext_header_len; /* Network protocol overhead (IP/IPv6 options) */
+        /* XXX Two bytes hole, try to pack */
 
         __u32   window_clamp;   /* Maximal window to advertise          */
         __u32   rcv_ssthresh;   /* Current window clamp                 */
diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
index e50e2b890c6d..91888967d3e3 100644
--- a/include/net/inet_connection_sock.h
+++ b/include/net/inet_connection_sock.h
@@ -60,6 +60,7 @@ struct inet_connection_sock_af_ops {
  * @icsk_timeout:          Timeout
  * @icsk_retransmit_timer: Resend (no ack)
  * @icsk_rto:              Retransmit timeout
+ * @icsk_pmtu_cookie       Last pmtu seen by socket
  * @icsk_ca_ops            Pluggable congestion control hook
  * @icsk_af_ops            Operations which are AF_INET{4,6} specific
  * @icsk_ca_state:         Congestion control state
@@ -68,6 +69,7 @@ struct inet_connection_sock_af_ops {
  * @icsk_backoff:          Backoff
  * @icsk_syn_retries:      Number of allowed SYN (or equivalent) retries
  * @icsk_probes_out:       unanswered 0 window probes
+ * @icsk_ext_hdr_len:      Network protocol overhead (IP/IPv6 options)
  * @icsk_ack:              Delayed ACK control data
  */
 struct inet_connection_sock {
@@ -79,15 +81,17 @@ struct inet_connection_sock {
         struct timer_list         icsk_retransmit_timer;
         struct timer_list         icsk_delack_timer;
         __u32                     icsk_rto;
+        __u32                     icsk_pmtu_cookie;
         struct tcp_congestion_ops *icsk_ca_ops;
         struct inet_connection_sock_af_ops *icsk_af_ops;
+        unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
         __u8                      icsk_ca_state;
         __u8                      icsk_retransmits;
         __u8                      icsk_pending;
         __u8                      icsk_backoff;
         __u8                      icsk_syn_retries;
         __u8                      icsk_probes_out;
-        /* 2 BYTES HOLE, TRY TO PACK! */
+        __u16                     icsk_ext_hdr_len;
         struct {
                 __u8              pending;       /* ACK is pending                         */
                 __u8              quick;         /* Scheduled number of quick acks         */
diff --git a/include/net/protocol.h b/include/net/protocol.h
index 357691f6a45f..a29cb29647d0 100644
--- a/include/net/protocol.h
+++ b/include/net/protocol.h
@@ -76,6 +76,7 @@ struct inet_protosw {
 };
 #define INET_PROTOSW_REUSE 0x01      /* Are ports automatically reusable? */
 #define INET_PROTOSW_PERMANENT 0x02  /* Permanent protocols are unremovable. */
+#define INET_PROTOSW_ICSK      0x04  /* Is this an inet_connection_sock? */
 
 extern struct net_protocol *inet_protocol_base;
 extern struct net_protocol *inet_protos[MAX_INET_PROTOS];
diff --git a/net/dccp/diag.c b/net/dccp/diag.c
index f675d8e642d3..3f78c00e3822 100644
--- a/net/dccp/diag.c
+++ b/net/dccp/diag.c
@@ -28,7 +28,7 @@ static void dccp_get_info(struct sock *sk, struct tcp_info *info)
         info->tcpi_retransmits  = icsk->icsk_retransmits;
         info->tcpi_probes       = icsk->icsk_probes_out;
         info->tcpi_backoff      = icsk->icsk_backoff;
-        info->tcpi_pmtu         = dp->dccps_pmtu_cookie;
+        info->tcpi_pmtu         = icsk->icsk_pmtu_cookie;
 
         if (dp->dccps_options.dccpo_send_ack_vector)
                 info->tcpi_options |= TCPI_OPT_SACK;
diff --git a/net/dccp/input.c b/net/dccp/input.c
index 9a724ff2a622..55e921bdd131 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -311,7 +311,7 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
                         goto out_invalid_packet;
                 }
 
-                dccp_sync_mss(sk, dp->dccps_pmtu_cookie);
+                dccp_sync_mss(sk, icsk->icsk_pmtu_cookie);
 
                 /*
                  *    Step 10: Process REQUEST state (second part)
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 671fbf3b2379..c363051a7f16 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -104,9 +104,9 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
         inet->dport = usin->sin_port;
         inet->daddr = daddr;
 
-        dp->dccps_ext_header_len = 0;
+        inet_csk(sk)->icsk_ext_hdr_len = 0;
         if (inet->opt != NULL)
-                dp->dccps_ext_header_len = inet->opt->optlen;
+                inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
         /*
          * Socket identity is still unknown (sport may be zero).
          * However we set state to DCCP_REQUESTING and not releasing socket
@@ -191,7 +191,7 @@ static inline void dccp_do_pmtu_discovery(struct sock *sk,
         mtu = dst_mtu(dst);
 
         if (inet->pmtudisc != IP_PMTUDISC_DONT &&
-            dp->dccps_pmtu_cookie > mtu) {
+            inet_csk(sk)->icsk_pmtu_cookie > mtu) {
                 dccp_sync_mss(sk, mtu);
 
                 /*
@@ -1051,6 +1051,7 @@ struct inet_connection_sock_af_ops dccp_ipv4_af_ops = {
 int dccp_v4_init_sock(struct sock *sk)
 {
         struct dccp_sock *dp = dccp_sk(sk);
+        struct inet_connection_sock *icsk = inet_csk(sk);
         static int dccp_ctl_socket_init = 1;
 
         dccp_options_init(&dp->dccps_options);
@@ -1090,10 +1091,11 @@ int dccp_v4_init_sock(struct sock *sk)
                 dccp_ctl_socket_init = 0;
 
         dccp_init_xmit_timers(sk);
-        inet_csk(sk)->icsk_rto = DCCP_TIMEOUT_INIT;
+        icsk->icsk_rto = DCCP_TIMEOUT_INIT;
         sk->sk_state = DCCP_CLOSED;
         sk->sk_write_space = dccp_write_space;
-        inet_csk(sk)->icsk_af_ops = &dccp_ipv4_af_ops;
+        icsk->icsk_af_ops = &dccp_ipv4_af_ops;
+        icsk->icsk_sync_mss = dccp_sync_mss;
         dp->dccps_mss_cache = 536;
         dp->dccps_role = DCCP_ROLE_UNDEFINED;
         dp->dccps_service = DCCP_SERVICE_INVALID_VALUE;
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 71bf04eb21e1..599b0be21515 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -88,6 +88,7 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
                            int addr_len)
 {
         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
+        struct inet_connection_sock *icsk = inet_csk(sk);
         struct inet_sock *inet = inet_sk(sk);
         struct ipv6_pinfo *np = inet6_sk(sk);
         struct dccp_sock *dp = dccp_sk(sk);
@@ -158,7 +159,7 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
          */
 
         if (addr_type == IPV6_ADDR_MAPPED) {
-                u32 exthdrlen = dp->dccps_ext_header_len;
+                u32 exthdrlen = icsk->icsk_ext_hdr_len;
                 struct sockaddr_in sin;
 
                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
@@ -170,14 +171,14 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
                 sin.sin_port = usin->sin6_port;
                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 
-                inet_csk(sk)->icsk_af_ops = &dccp_ipv6_mapped;
+                icsk->icsk_af_ops = &dccp_ipv6_mapped;
                 sk->sk_backlog_rcv = dccp_v4_do_rcv;
 
                 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 
                 if (err) {
-                        dp->dccps_ext_header_len = exthdrlen;
-                        inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
+                        icsk->icsk_ext_hdr_len = exthdrlen;
+                        icsk->icsk_af_ops = &dccp_ipv6_af_ops;
                         sk->sk_backlog_rcv = dccp_v6_do_rcv;
                         goto failure;
                 } else {
@@ -227,9 +228,10 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 
         ip6_dst_store(sk, dst, NULL);
 
-        dp->dccps_ext_header_len = 0;
+        icsk->icsk_ext_hdr_len = 0;
         if (np->opt)
-                dp->dccps_ext_header_len = np->opt->opt_flen + np->opt->opt_nflen;
+                icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
+                                          np->opt->opt_nflen);
 
         inet->dport = usin->sin6_port;
 
@@ -292,7 +294,6 @@ static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
         np = inet6_sk(sk);
 
         if (type == ICMPV6_PKT_TOOBIG) {
-                struct dccp_sock *dp = dccp_sk(sk);
                 struct dst_entry *dst = NULL;
 
                 if (sock_owned_by_user(sk))
@@ -332,7 +333,7 @@ static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
                 } else
                         dst_hold(dst);
 
-                if (dp->dccps_pmtu_cookie > dst_mtu(dst)) {
+                if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
                         dccp_sync_mss(sk, dst_mtu(dst));
                 } /* else let the usual retransmit timer handle it */
                 dst_release(dst);
@@ -808,7 +809,7 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
                    worked with IPv6 icsk.icsk_af_ops.
                    Sync it now.
                  */
-                dccp_sync_mss(newsk, newdp->dccps_pmtu_cookie);
+                dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
 
                 return newsk;
         }
@@ -916,10 +917,10 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
                         sock_kfree_s(sk, opt, opt->tot_len);
         }
 
-        newdp->dccps_ext_header_len = 0;
+        inet_csk(newsk)->icsk_ext_hdr_len = 0;
         if (newnp->opt)
-                newdp->dccps_ext_header_len = newnp->opt->opt_nflen +
-                                              newnp->opt->opt_flen;
+                inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
+                                                     newnp->opt->opt_flen);
 
         dccp_sync_mss(newsk, dst_mtu(dst));
 
@@ -1230,6 +1231,7 @@ static struct inet_protosw dccp_v6_protosw = {
         .prot           = &dccp_v6_prot,
         .ops            = &inet6_dccp_ops,
         .capability     = -1,
+        .flags          = INET_PROTOSW_ICSK,
 };
 
 static int __init dccp_v6_init(void)
diff --git a/net/dccp/output.c b/net/dccp/output.c
index c40f7f8a328b..95a3c2c6a3ce 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -134,12 +134,13 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
 
 unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu)
 {
+        struct inet_connection_sock *icsk = inet_csk(sk);
         struct dccp_sock *dp = dccp_sk(sk);
-        int mss_now = (pmtu - inet_csk(sk)->icsk_af_ops->net_header_len -
+        int mss_now = (pmtu - icsk->icsk_af_ops->net_header_len -
                        sizeof(struct dccp_hdr) - sizeof(struct dccp_hdr_ext));
 
         /* Now subtract optional transport overhead */
-        mss_now -= dp->dccps_ext_header_len;
+        mss_now -= icsk->icsk_ext_hdr_len;
 
         /*
          * FIXME: this should come from the CCID infrastructure, where, say,
@@ -152,7 +153,7 @@ unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu)
         mss_now -= ((5 + 6 + 10 + 6 + 6 + 6 + 3) / 4) * 4;
 
         /* And store cached results */
-        dp->dccps_pmtu_cookie = pmtu;
+        icsk->icsk_pmtu_cookie = pmtu;
         dp->dccps_mss_cache = mss_now;
 
         return mss_now;
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 51dfacd22a6e..40a4c6899051 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -712,7 +712,7 @@ static struct inet_protosw dccp_v4_protosw = {
         .ops            = &inet_dccp_ops,
         .capability     = -1,
         .no_check       = 0,
-        .flags          = 0,
+        .flags          = INET_PROTOSW_ICSK,
 };
 
 /*
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index d368cf249000..617e858beff1 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -302,6 +302,7 @@ lookup_protocol:
                 sk->sk_reuse = 1;
 
         inet = inet_sk(sk);
+        inet->is_icsk = INET_PROTOSW_ICSK & answer_flags;
 
         if (SOCK_RAW == sock->type) {
                 inet->num = protocol;
@@ -869,7 +870,8 @@ static struct inet_protosw inetsw_array[] =
                 .ops =        &inet_stream_ops,
                 .capability = -1,
                 .no_check =   0,
-                .flags =      INET_PROTOSW_PERMANENT,
+                .flags =      INET_PROTOSW_PERMANENT |
+                              INET_PROTOSW_ICSK,
         },
 
         {
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 4f2d87257309..add019c746f8 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -29,8 +29,7 @@
 #include <net/sock.h>
 #include <net/ip.h>
 #include <net/icmp.h>
-#include <net/tcp.h>
-#include <linux/tcp.h>
+#include <net/tcp_states.h>
 #include <linux/udp.h>
 #include <linux/igmp.h>
 #include <linux/netfilter.h>
@@ -427,8 +426,8 @@ int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
                         err = ip_options_get_from_user(&opt, optval, optlen);
                         if (err)
                                 break;
-                        if (sk->sk_type == SOCK_STREAM) {
-                                struct tcp_sock *tp = tcp_sk(sk);
+                        if (inet->is_icsk) {
+                                struct inet_connection_sock *icsk = inet_csk(sk);
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
                                 if (sk->sk_family == PF_INET ||
                                     (!((1 << sk->sk_state) &
@@ -436,10 +435,10 @@ int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
                                      inet->daddr != LOOPBACK4_IPV6)) {
 #endif
                                         if (inet->opt)
-                                                tp->ext_header_len -= inet->opt->optlen;
+                                                icsk->icsk_ext_hdr_len -= inet->opt->optlen;
                                         if (opt)
-                                                tp->ext_header_len += opt->optlen;
-                                        tcp_sync_mss(sk, tp->pmtu_cookie);
+                                                icsk->icsk_ext_hdr_len += opt->optlen;
+                                        icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
                                 }
 #endif
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index eacfe6a3442c..00aa80e93243 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1914,7 +1914,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
         info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
         info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
 
-        info->tcpi_pmtu = tp->pmtu_cookie;
+        info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
         info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
         info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
         info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 7de6184d4bd8..981d1203b152 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2342,7 +2342,7 @@ static int tcp_ack_update_window(struct sock *sk, struct tcp_sock *tp,
 
                         if (nwin > tp->max_window) {
                                 tp->max_window = nwin;
-                                tcp_sync_mss(sk, tp->pmtu_cookie);
+                                tcp_sync_mss(sk, inet_csk(sk)->icsk_pmtu_cookie);
                         }
                 }
         }
@@ -3967,12 +3967,12 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
                                          struct tcphdr *th, unsigned len)
 {
         struct tcp_sock *tp = tcp_sk(sk);
+        struct inet_connection_sock *icsk = inet_csk(sk);
         int saved_clamp = tp->rx_opt.mss_clamp;
 
         tcp_parse_options(skb, &tp->rx_opt, 0);
 
         if (th->ack) {
-                struct inet_connection_sock *icsk;
                 /* rfc793:
                  * "If the state is SYN-SENT then
                  *    first check the ACK bit
@@ -4061,7 +4061,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
                 if (tp->rx_opt.sack_ok && sysctl_tcp_fack)
                         tp->rx_opt.sack_ok |= 2;
 
-                tcp_sync_mss(sk, tp->pmtu_cookie);
+                tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
                 tcp_initialize_rcv_mss(sk);
 
                 /* Remember, tcp_poll() does not lock socket!
@@ -4071,8 +4071,6 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
                 mb();
                 tcp_set_state(sk, TCP_ESTABLISHED);
 
-                icsk = inet_csk(sk);
-
                 /* Make sure socket is routed, for correct metrics.  */
                 icsk->icsk_af_ops->rebuild_header(sk);
 
@@ -4173,7 +4171,7 @@ discard:
                 if (tp->ecn_flags&TCP_ECN_OK)
                         sock_set_flag(sk, SOCK_NO_LARGESEND);
 
-                tcp_sync_mss(sk, tp->pmtu_cookie);
+                tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
                 tcp_initialize_rcv_mss(sk);
 
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index c2fe61becd61..9b62d80bb20f 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -220,9 +220,9 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
         inet->dport = usin->sin_port;
         inet->daddr = daddr;
 
-        tp->ext_header_len = 0;
+        inet_csk(sk)->icsk_ext_hdr_len = 0;
         if (inet->opt)
-                tp->ext_header_len = inet->opt->optlen;
+                inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
 
         tp->rx_opt.mss_clamp = 536;
 
@@ -275,7 +275,6 @@ static inline void do_pmtu_discovery(struct sock *sk, struct iphdr *iph,
 {
         struct dst_entry *dst;
         struct inet_sock *inet = inet_sk(sk);
-        struct tcp_sock *tp = tcp_sk(sk);
 
         /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs
          * send out by Linux are always <576bytes so they should go through
@@ -304,7 +303,7 @@ static inline void do_pmtu_discovery(struct sock *sk, struct iphdr *iph,
         mtu = dst_mtu(dst);
 
         if (inet->pmtudisc != IP_PMTUDISC_DONT &&
-            tp->pmtu_cookie > mtu) {
+            inet_csk(sk)->icsk_pmtu_cookie > mtu) {
                 tcp_sync_mss(sk, mtu);
 
                 /* Resend the TCP packet because it's
@@ -895,9 +894,9 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
         ireq->opt             = NULL;
         newinet->mc_index     = inet_iif(skb);
         newinet->mc_ttl       = skb->nh.iph->ttl;
-        newtp->ext_header_len = 0;
+        inet_csk(newsk)->icsk_ext_hdr_len = 0;
         if (newinet->opt)
-                newtp->ext_header_len = newinet->opt->optlen;
+                inet_csk(newsk)->icsk_ext_hdr_len = newinet->opt->optlen;
         newinet->id = newtp->write_seq ^ jiffies;
 
         tcp_sync_mss(newsk, dst_mtu(dst));
@@ -1266,6 +1265,7 @@ static int tcp_v4_init_sock(struct sock *sk)
         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
 
         icsk->icsk_af_ops = &ipv4_specific;
+        icsk->icsk_sync_mss = tcp_sync_mss;
 
         sk->sk_sndbuf = sysctl_tcp_wmem[1];
         sk->sk_rcvbuf = sysctl_tcp_rmem[1];
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index af1946c52c37..3a0a914de917 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -621,7 +621,7 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
    It is minimum of user_mss and mss received with SYN.
    It also does not include TCP options.
 
-   tp->pmtu_cookie is last pmtu, seen by this function.
+   inet_csk(sk)->icsk_pmtu_cookie is last pmtu, seen by this function.
 
    tp->mss_cache is current effective sending mss, including
    all tcp options except for SACKs. It is evaluated,
@@ -631,17 +631,18 @@ int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
    NOTE1. rfc1122 clearly states that advertised MSS
    DOES NOT include either tcp or ip options.
 
-   NOTE2. tp->pmtu_cookie and tp->mss_cache are READ ONLY outside
-   this function.                       --ANK (980731)
+   NOTE2. inet_csk(sk)->icsk_pmtu_cookie and tp->mss_cache
+   are READ ONLY outside this function.         --ANK (980731)
  */
 
 unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu)
 {
         struct tcp_sock *tp = tcp_sk(sk);
+        struct inet_connection_sock *icsk = inet_csk(sk);
         /* Calculate base mss without TCP options:
            It is MMS_S - sizeof(tcphdr) of rfc1122
          */
-        int mss_now = (pmtu - inet_csk(sk)->icsk_af_ops->net_header_len -
+        int mss_now = (pmtu - icsk->icsk_af_ops->net_header_len -
                        sizeof(struct tcphdr));
 
         /* Clamp it (mss_clamp does not include tcp options) */
@@ -649,7 +650,7 @@ unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu)
                 mss_now = tp->rx_opt.mss_clamp;
 
         /* Now subtract optional transport overhead */
-        mss_now -= tp->ext_header_len;
+        mss_now -= icsk->icsk_ext_hdr_len;
 
         /* Then reserve room for full set of TCP options and 8 bytes of data */
         if (mss_now < 48)
@@ -663,7 +664,7 @@ unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu)
                 mss_now = max((tp->max_window>>1), 68U - tp->tcp_header_len);
 
         /* And store cached results */
-        tp->pmtu_cookie = pmtu;
+        icsk->icsk_pmtu_cookie = pmtu;
         tp->mss_cache = mss_now;
 
         return mss_now;
@@ -693,7 +694,7 @@ unsigned int tcp_current_mss(struct sock *sk, int large_allowed)
 
         if (dst) {
                 u32 mtu = dst_mtu(dst);
-                if (mtu != tp->pmtu_cookie)
+                if (mtu != inet_csk(sk)->icsk_pmtu_cookie)
                         mss_now = tcp_sync_mss(sk, mtu);
         }
 
@@ -706,7 +707,8 @@ unsigned int tcp_current_mss(struct sock *sk, int large_allowed)
         if (doing_tso) {
                 xmit_size_goal = (65535 -
                                   inet_csk(sk)->icsk_af_ops->net_header_len -
-                                  tp->ext_header_len - tp->tcp_header_len);
+                                  inet_csk(sk)->icsk_ext_hdr_len -
+                                  tp->tcp_header_len);
 
                 if (tp->max_window &&
                     (xmit_size_goal > (tp->max_window >> 1)))
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index bf17aab9b776..70a510ff31ee 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -167,6 +167,7 @@ lookup_protocol:
                 sk->sk_reuse = 1;
 
         inet = inet_sk(sk);
+        inet->is_icsk = INET_PROTOSW_ICSK & answer_flags;
 
         if (SOCK_RAW == sock->type) {
                 inet->num = protocol;
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index b6b63fa8454c..c63868dd2ca2 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -163,17 +163,17 @@ int ipv6_setsockopt(struct sock *sk, int level, int optname,
                         sk_refcnt_debug_dec(sk);
 
                         if (sk->sk_protocol == IPPROTO_TCP) {
-                                struct tcp_sock *tp = tcp_sk(sk);
+                                struct inet_connection_sock *icsk = inet_csk(sk);
 
                                 local_bh_disable();
                                 sock_prot_dec_use(sk->sk_prot);
                                 sock_prot_inc_use(&tcp_prot);
                                 local_bh_enable();
                                 sk->sk_prot = &tcp_prot;
-                                inet_csk(sk)->icsk_af_ops = &ipv4_specific;
+                                icsk->icsk_af_ops = &ipv4_specific;
                                 sk->sk_socket->ops = &inet_stream_ops;
                                 sk->sk_family = PF_INET;
-                                tcp_sync_mss(sk, tp->pmtu_cookie);
+                                tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
                         } else {
                                 local_bh_disable();
                                 sock_prot_dec_use(sk->sk_prot);
@@ -317,14 +317,15 @@ int ipv6_setsockopt(struct sock *sk, int level, int optname,
                 }
 
                 retv = 0;
-                if (sk->sk_type == SOCK_STREAM) {
+                if (inet_sk(sk)->is_icsk) {
                         if (opt) {
-                                struct tcp_sock *tp = tcp_sk(sk);
+                                struct inet_connection_sock *icsk = inet_csk(sk);
                                 if (!((1 << sk->sk_state) &
                                       (TCPF_LISTEN | TCPF_CLOSE))
                                     && inet_sk(sk)->daddr != LOOPBACK4_IPV6) {
-                                        tp->ext_header_len = opt->opt_flen + opt->opt_nflen;
-                                        tcp_sync_mss(sk, tp->pmtu_cookie);
+                                        icsk->icsk_ext_hdr_len =
+                                                opt->opt_flen + opt->opt_nflen;
+                                        icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
                                 }
                         }
                         opt = xchg(&np->opt, opt);
@@ -380,14 +381,15 @@ sticky_done:
                         goto done;
 update:
                 retv = 0;
-                if (sk->sk_type == SOCK_STREAM) {
+                if (inet_sk(sk)->is_icsk) {
                         if (opt) {
-                                struct tcp_sock *tp = tcp_sk(sk);
+                                struct inet_connection_sock *icsk = inet_csk(sk);
                                 if (!((1 << sk->sk_state) &
                                       (TCPF_LISTEN | TCPF_CLOSE))
                                     && inet_sk(sk)->daddr != LOOPBACK4_IPV6) {
-                                        tp->ext_header_len = opt->opt_flen + opt->opt_nflen;
-                                        tcp_sync_mss(sk, tp->pmtu_cookie);
+                                        icsk->icsk_ext_hdr_len =
+                                                opt->opt_flen + opt->opt_nflen;
+                                        icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
                                 }
                         }
                         opt = xchg(&np->opt, opt);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index a682eb9093e1..2947bc56d8a0 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -123,7 +123,8 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
                           int addr_len)
 {
         struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
-        struct inet_sock *inet = inet_sk(sk);
+        struct inet_sock *inet = inet_sk(sk);
+        struct inet_connection_sock *icsk = inet_csk(sk);
         struct ipv6_pinfo *np = inet6_sk(sk);
         struct tcp_sock *tp = tcp_sk(sk);
         struct in6_addr *saddr = NULL, *final_p = NULL, final;
@@ -198,7 +199,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
          */
 
         if (addr_type == IPV6_ADDR_MAPPED) {
-                u32 exthdrlen = tp->ext_header_len;
+                u32 exthdrlen = icsk->icsk_ext_hdr_len;
                 struct sockaddr_in sin;
 
                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
@@ -210,14 +211,14 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
                 sin.sin_port = usin->sin6_port;
                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 
-                inet_csk(sk)->icsk_af_ops = &ipv6_mapped;
+                icsk->icsk_af_ops = &ipv6_mapped;
                 sk->sk_backlog_rcv = tcp_v4_do_rcv;
 
                 err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 
                 if (err) {
-                        tp->ext_header_len = exthdrlen;
-                        inet_csk(sk)->icsk_af_ops = &ipv6_specific;
+                        icsk->icsk_ext_hdr_len = exthdrlen;
+                        icsk->icsk_af_ops = &ipv6_specific;
                         sk->sk_backlog_rcv = tcp_v6_do_rcv;
                         goto failure;
                 } else {
@@ -270,9 +271,10 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
         sk->sk_route_caps = dst->dev->features &
                 ~(NETIF_F_IP_CSUM | NETIF_F_TSO);
 
-        tp->ext_header_len = 0;
+        icsk->icsk_ext_hdr_len = 0;
         if (np->opt)
-                tp->ext_header_len = np->opt->opt_flen + np->opt->opt_nflen;
+                icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
+                                          np->opt->opt_nflen);
 
         tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 
@@ -385,7 +387,7 @@ static void tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
                 } else
                         dst_hold(dst);
 
-                if (tp->pmtu_cookie > dst_mtu(dst)) {
+                if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
                         tcp_sync_mss(sk, dst_mtu(dst));
                         tcp_simple_retransmit(sk);
                 } /* else let the usual retransmit timer handle it */
@@ -869,7 +871,7 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
                    worked with IPv6 icsk.icsk_af_ops.
                    Sync it now.
                  */
-                tcp_sync_mss(newsk, newtp->pmtu_cookie);
+                tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
 
                 return newsk;
         }
@@ -976,10 +978,10 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
                         sock_kfree_s(sk, opt, opt->tot_len);
         }
 
-        newtp->ext_header_len = 0;
+        inet_csk(newsk)->icsk_ext_hdr_len = 0;
         if (newnp->opt)
-                newtp->ext_header_len = newnp->opt->opt_nflen +
-                                        newnp->opt->opt_flen;
+                inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
+                                                     newnp->opt->opt_flen);
 
         tcp_sync_mss(newsk, dst_mtu(dst));
         newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
@@ -1361,6 +1363,7 @@ static int tcp_v6_init_sock(struct sock *sk)
 
         icsk->icsk_af_ops = &ipv6_specific;
         icsk->icsk_ca_ops = &tcp_init_congestion_ops;
+        icsk->icsk_sync_mss = tcp_sync_mss;
         sk->sk_write_space = sk_stream_write_space;
         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
 
@@ -1591,7 +1594,8 @@ static struct inet_protosw tcpv6_protosw = {
         .ops            =       &inet6_stream_ops,
         .capability     =       -1,
         .no_check       =       0,
-        .flags          =       INET_PROTOSW_PERMANENT,
+        .flags          =       INET_PROTOSW_PERMANENT |
+                                INET_PROTOSW_ICSK,
 };
 
 void __init tcpv6_init(void)