[DCCP]: Prepare the AF agnostic core for the introduction of DCCPv6

Basically exports a similar set of functions as the one exported by
the non-AF specific TCP code.

In the process moved some non-AF specific code from dccp_v4_connect to
dccp_connect_init and moved the checksum verification from
dccp_invalid_packet to dccp_v4_rcv, so as to use it in dccp_v6_rcv
too.

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

6 files changed, 114 insertions, 52 deletions

diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index e711f850053b..93f26dd6e6cb 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -228,6 +228,9 @@ extern int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
                                 const struct dccp_hdr *dh, const unsigned len);
 
+extern int dccp_v4_init_sock(struct sock *sk);
+extern int dccp_v4_destroy_sock(struct sock *sk);
+
 extern void             dccp_close(struct sock *sk, long timeout);
 extern struct sk_buff   *dccp_make_response(struct sock *sk,
                                             struct dst_entry *dst,
@@ -238,6 +241,7 @@ extern struct sk_buff	*dccp_make_reset(struct sock *sk,
 
 extern int         dccp_connect(struct sock *sk);
 extern int         dccp_disconnect(struct sock *sk, int flags);
+extern void        dccp_unhash(struct sock *sk);
 extern int         dccp_getsockopt(struct sock *sk, int level, int optname,
                                    char __user *optval, int __user *optlen);
 extern int         dccp_setsockopt(struct sock *sk, int level, int optname,
@@ -249,6 +253,13 @@ extern int	   dccp_recvmsg(struct kiocb *iocb, struct sock *sk,
                                 struct msghdr *msg, size_t len, int nonblock,
                                 int flags, int *addr_len);
 extern void        dccp_shutdown(struct sock *sk, int how);
+extern int         inet_dccp_listen(struct socket *sock, int backlog);
+extern unsigned int dccp_poll(struct file *file, struct socket *sock,
+                             poll_table *wait);
+extern void        dccp_v4_send_check(struct sock *sk, int len,
+                                      struct sk_buff *skb);
+extern int         dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
+                                   int addr_len);
 
 extern int         dccp_v4_checksum(const struct sk_buff *skb,
                                     const u32 saddr, const u32 daddr);
@@ -256,6 +267,17 @@ extern int	   dccp_v4_checksum(const struct sk_buff *skb,
 extern int         dccp_v4_send_reset(struct sock *sk,
                                       enum dccp_reset_codes code);
 extern void        dccp_send_close(struct sock *sk, const int active);
+extern int         dccp_invalid_packet(struct sk_buff *skb);
+
+static inline int dccp_bad_service_code(const struct sock *sk,
+                                        const __u32 service)
+{
+        const struct dccp_sock *dp = dccp_sk(sk);
+
+        if (dp->dccps_service == service)
+                return 0;
+        return !dccp_list_has_service(dp->dccps_service_list, service);
+}
 
 struct dccp_skb_cb {
         __u8  dccpd_type:4;
diff --git a/net/dccp/input.c b/net/dccp/input.c
index c81488fa293e..9a724ff2a622 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -250,6 +250,8 @@ discard:
         return 0;
 }
 
+EXPORT_SYMBOL_GPL(dccp_rcv_established);
+
 static int dccp_rcv_request_sent_state_process(struct sock *sk,
                                                struct sk_buff *skb,
                                                const struct dccp_hdr *dh,
@@ -567,3 +569,5 @@ discard:
         }
         return 0;
 }
+
+EXPORT_SYMBOL_GPL(dccp_rcv_state_process);
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 9f69a67a4b01..3108c9d464f7 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -46,11 +46,13 @@ static void dccp_v4_hash(struct sock *sk)
         inet_hash(&dccp_hashinfo, sk);
 }
 
-static void dccp_v4_unhash(struct sock *sk)
+void dccp_unhash(struct sock *sk)
 {
         inet_unhash(&dccp_hashinfo, sk);
 }
 
+EXPORT_SYMBOL_GPL(dccp_unhash);
+
 /* called with local bh disabled */
 static int __dccp_v4_check_established(struct sock *sk, const __u16 lport,
                                       struct inet_timewait_sock **twp)
@@ -209,8 +211,7 @@ out:
         }
 }
 
-static int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
-                           int addr_len)
+int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 {
         struct inet_sock *inet = inet_sk(sk);
         struct dccp_sock *dp = dccp_sk(sk);
@@ -288,16 +289,6 @@ static int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
                                                             usin->sin_port);
         dccp_update_gss(sk, dp->dccps_iss);
 
-        /*
-         * SWL and AWL are initially adjusted so that they are not less than
-         * the initial Sequence Numbers received and sent, respectively:
-         *      SWL := max(GSR + 1 - floor(W/4), ISR),
-         *      AWL := max(GSS - W' + 1, ISS).
-         * These adjustments MUST be applied only at the beginning of the
-         * connection.
-         */
-        dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss));
-
         inet->id = dp->dccps_iss ^ jiffies;
 
         err = dccp_connect(sk);
@@ -317,6 +308,8 @@ failure:
         goto out;
 }
 
+EXPORT_SYMBOL_GPL(dccp_v4_connect);
+
 /*
  * This routine does path mtu discovery as defined in RFC1191.
  */
@@ -608,7 +601,7 @@ out:
 }
 
 /* This routine computes an IPv4 DCCP checksum. */
-static void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
+void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
 {
         const struct inet_sock *inet = inet_sk(sk);
         struct dccp_hdr *dh = dccp_hdr(skb);
@@ -616,6 +609,8 @@ static void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
         dh->dccph_checksum = dccp_v4_checksum(skb, inet->saddr, inet->daddr);
 }
 
+EXPORT_SYMBOL_GPL(dccp_v4_send_check);
+
 int dccp_v4_send_reset(struct sock *sk, enum dccp_reset_codes code)
 {
         struct sk_buff *skb;
@@ -651,16 +646,6 @@ static inline u64 dccp_v4_init_sequence(const struct sock *sk,
                                            dccp_hdr(skb)->dccph_sport);
 }
 
-static inline int dccp_bad_service_code(const struct sock *sk,
-                                        const __u32 service)
-{
-        const struct dccp_sock *dp = dccp_sk(sk);
-
-        if (dp->dccps_service == service)
-                return 0;
-        return !dccp_list_has_service(dp->dccps_service_list, service);
-}
-
 int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 {
         struct inet_request_sock *ireq;
@@ -672,7 +657,6 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
         const __u32 service = dccp_hdr_request(skb)->dccph_req_service;
         struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
         __u8 reset_code = DCCP_RESET_CODE_TOO_BUSY;
-        struct dst_entry *dst = NULL;
 
         /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
         if (((struct rtable *)skb->dst)->rt_flags &
@@ -713,7 +697,6 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
         ireq = inet_rsk(req);
         ireq->loc_addr = daddr;
         ireq->rmt_addr = saddr;
-        /* FIXME: Merge Aristeu's option parsing code when ready */
         req->rcv_wnd    = 100; /* Fake, option parsing will get the
                                   right value */
         ireq->opt       = NULL;
@@ -731,7 +714,7 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
         dreq->dreq_iss     = dccp_v4_init_sequence(sk, skb);
         dreq->dreq_service = service;
 
-        if (dccp_v4_send_response(sk, req, dst))
+        if (dccp_v4_send_response(sk, req, NULL))
                 goto drop_and_free;
 
         inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
@@ -748,6 +731,8 @@ drop:
         return -1;
 }
 
+EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
+
 /*
  * The three way handshake has completed - we got a valid ACK or DATAACK -
  * now create the new socket.
@@ -802,6 +787,8 @@ exit:
         return NULL;
 }
 
+EXPORT_SYMBOL_GPL(dccp_v4_request_recv_sock);
+
 static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
 {
         const struct dccp_hdr *dh = dccp_hdr(skb);
@@ -1021,7 +1008,9 @@ discard:
         return 0;
 }
 
-static inline int dccp_invalid_packet(struct sk_buff *skb)
+EXPORT_SYMBOL_GPL(dccp_v4_do_rcv);
+
+int dccp_invalid_packet(struct sk_buff *skb)
 {
         const struct dccp_hdr *dh;
 
@@ -1075,17 +1064,11 @@ static inline int dccp_invalid_packet(struct sk_buff *skb)
                 return 1;
         }
 
-        /* If the header checksum is incorrect, drop packet and return */
-        if (dccp_v4_verify_checksum(skb, skb->nh.iph->saddr,
-                                    skb->nh.iph->daddr) < 0) {
-                LIMIT_NETDEBUG(KERN_WARNING "DCCP: header checksum is "
-                                            "incorrect\n");
-                return 1;
-        }
-
         return 0;
 }
 
+EXPORT_SYMBOL_GPL(dccp_invalid_packet);
+
 /* this is called when real data arrives */
 int dccp_v4_rcv(struct sk_buff *skb)
 {
@@ -1098,6 +1081,14 @@ int dccp_v4_rcv(struct sk_buff *skb)
         if (dccp_invalid_packet(skb))
                 goto discard_it;
 
+        /* If the header checksum is incorrect, drop packet and return */
+        if (dccp_v4_verify_checksum(skb, skb->nh.iph->saddr,
+                                    skb->nh.iph->daddr) < 0) {
+                LIMIT_NETDEBUG(KERN_WARNING "%s: incorrect header checksum\n",
+                               __FUNCTION__);
+                goto discard_it;
+        }
+
         dh = dccp_hdr(skb);
 
         DCCP_SKB_CB(skb)->dccpd_seq  = dccp_hdr_seq(skb);
@@ -1217,7 +1208,7 @@ struct inet_connection_sock_af_ops dccp_ipv4_af_ops = {
         .sockaddr_len   = sizeof(struct sockaddr_in),
 };
 
-static int dccp_v4_init_sock(struct sock *sk)
+int dccp_v4_init_sock(struct sock *sk)
 {
         struct dccp_sock *dp = dccp_sk(sk);
         static int dccp_ctl_socket_init = 1;
@@ -1270,7 +1261,9 @@ static int dccp_v4_init_sock(struct sock *sk)
         return 0;
 }
 
-static int dccp_v4_destroy_sock(struct sock *sk)
+EXPORT_SYMBOL_GPL(dccp_v4_init_sock);
+
+int dccp_v4_destroy_sock(struct sock *sk)
 {
         struct dccp_sock *dp = dccp_sk(sk);
 
@@ -1303,6 +1296,8 @@ static int dccp_v4_destroy_sock(struct sock *sk)
         return 0;
 }
 
+EXPORT_SYMBOL_GPL(dccp_v4_destroy_sock);
+
 static void dccp_v4_reqsk_destructor(struct request_sock *req)
 {
         kfree(inet_rsk(req)->opt);
@@ -1331,7 +1326,7 @@ struct proto dccp_prot = {
         .recvmsg                = dccp_recvmsg,
         .backlog_rcv            = dccp_v4_do_rcv,
         .hash                   = dccp_v4_hash,
-        .unhash                 = dccp_v4_unhash,
+        .unhash                 = dccp_unhash,
         .accept                 = inet_csk_accept,
         .get_port               = dccp_v4_get_port,
         .shutdown               = dccp_shutdown,
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index c7ff80cf53a0..5c767b5e9a52 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -40,6 +40,8 @@ struct inet_timewait_death_row dccp_death_row = {
                                             (unsigned long)&dccp_death_row),
 };
 
+EXPORT_SYMBOL_GPL(dccp_death_row);
+
 void dccp_time_wait(struct sock *sk, int state, int timeo)
 {
         struct inet_timewait_sock *tw = NULL;
@@ -170,6 +172,8 @@ out_free:
         return newsk;
 }
 
+EXPORT_SYMBOL_GPL(dccp_create_openreq_child);
+
 /* 
  * Process an incoming packet for RESPOND sockets represented
  * as an request_sock.
@@ -236,6 +240,8 @@ drop:
         goto out;
 }
 
+EXPORT_SYMBOL_GPL(dccp_check_req);
+
 /*
  *  Queue segment on the new socket if the new socket is active,
  *  otherwise we just shortcircuit this and continue with
@@ -266,3 +272,5 @@ int dccp_child_process(struct sock *parent, struct sock *child,
         sock_put(child);
         return ret;
 }
+
+EXPORT_SYMBOL_GPL(dccp_child_process);
diff --git a/net/dccp/output.c b/net/dccp/output.c
index f35880503bb8..c40f7f8a328b 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -135,12 +135,6 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
 unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu)
 {
         struct dccp_sock *dp = dccp_sk(sk);
-        /*
-         * FIXME: we really should be using the af_specific thing to support
-         *        IPv6.
-         * mss_now = pmtu - tp->af_specific->net_header_len -
-         *           sizeof(struct dccp_hdr) - sizeof(struct dccp_hdr_ext);
-         */
         int mss_now = (pmtu - inet_csk(sk)->icsk_af_ops->net_header_len -
                        sizeof(struct dccp_hdr) - sizeof(struct dccp_hdr_ext));
 
@@ -164,6 +158,8 @@ unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu)
         return mss_now;
 }
 
+EXPORT_SYMBOL_GPL(dccp_sync_mss);
+
 void dccp_write_space(struct sock *sk)
 {
         read_lock(&sk->sk_callback_lock);
@@ -319,6 +315,8 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
         return skb;
 }
 
+EXPORT_SYMBOL_GPL(dccp_make_response);
+
 struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst,
                                 const enum dccp_reset_codes code)
                                    
@@ -375,6 +373,7 @@ struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst,
  */
 static inline void dccp_connect_init(struct sock *sk)
 {
+        struct dccp_sock *dp = dccp_sk(sk);
         struct dst_entry *dst = __sk_dst_get(sk);
         struct inet_connection_sock *icsk = inet_csk(sk);
 
@@ -383,10 +382,16 @@ static inline void dccp_connect_init(struct sock *sk)
         
         dccp_sync_mss(sk, dst_mtu(dst));
 
-        /*
-         * FIXME: set dp->{dccps_swh,dccps_swl}, with
-         * something like dccp_inc_seq
-         */
+        dccp_update_gss(sk, dp->dccps_iss);
+        /*
+         * SWL and AWL are initially adjusted so that they are not less than
+         * the initial Sequence Numbers received and sent, respectively:
+         *      SWL := max(GSR + 1 - floor(W/4), ISR),
+         *      AWL := max(GSS - W' + 1, ISS).
+         * These adjustments MUST be applied only at the beginning of the
+         * connection.
+         */
+        dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss));
 
         icsk->icsk_retransmits = 0;
 }
@@ -418,6 +423,8 @@ int dccp_connect(struct sock *sk)
         return 0;
 }
 
+EXPORT_SYMBOL_GPL(dccp_connect);
+
 void dccp_send_ack(struct sock *sk)
 {
         /* If we have been reset, we may not send again. */
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 9cb2989f93b2..51dfacd22a6e 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -41,8 +41,12 @@
 
 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
 
+EXPORT_SYMBOL_GPL(dccp_statistics);
+
 atomic_t dccp_orphan_count = ATOMIC_INIT(0);
 
+EXPORT_SYMBOL_GPL(dccp_orphan_count);
+
 static struct net_protocol dccp_protocol = {
         .handler        = dccp_v4_rcv,
         .err_handler    = dccp_v4_err,
@@ -149,6 +153,8 @@ int dccp_disconnect(struct sock *sk, int flags)
         return err;
 }
 
+EXPORT_SYMBOL_GPL(dccp_disconnect);
+
 /*
  *      Wait for a DCCP event.
  *
@@ -156,8 +162,8 @@ int dccp_disconnect(struct sock *sk, int flags)
  *      take care of normal races (between the test and the event) and we don't
  *      go look at any of the socket buffers directly.
  */
-static unsigned int dccp_poll(struct file *file, struct socket *sock,
-                              poll_table *wait)
+unsigned int dccp_poll(struct file *file, struct socket *sock,
+                       poll_table *wait)
 {
         unsigned int mask;
         struct sock *sk = sock->sk;
@@ -205,12 +211,16 @@ static unsigned int dccp_poll(struct file *file, struct socket *sock,
         return mask;
 }
 
+EXPORT_SYMBOL_GPL(dccp_poll);
+
 int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 {
         dccp_pr_debug("entry\n");
         return -ENOIOCTLCMD;
 }
 
+EXPORT_SYMBOL_GPL(dccp_ioctl);
+
 static int dccp_setsockopt_service(struct sock *sk, const u32 service,
                                    char __user *optval, int optlen)
 {
@@ -284,6 +294,8 @@ int dccp_setsockopt(struct sock *sk, int level, int optname,
         return err;
 }
 
+EXPORT_SYMBOL_GPL(dccp_setsockopt);
+
 static int dccp_getsockopt_service(struct sock *sk, int len,
                                    u32 __user *optval,
                                    int __user *optlen)
@@ -357,6 +369,8 @@ int dccp_getsockopt(struct sock *sk, int level, int optname,
         return 0;
 }
 
+EXPORT_SYMBOL_GPL(dccp_getsockopt);
+
 int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                  size_t len)
 {
@@ -413,6 +427,8 @@ out_discard:
         goto out_release;
 }
 
+EXPORT_SYMBOL_GPL(dccp_sendmsg);
+
 int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                  size_t len, int nonblock, int flags, int *addr_len)
 {
@@ -510,7 +526,9 @@ out:
         return len;
 }
 
-static int inet_dccp_listen(struct socket *sock, int backlog)
+EXPORT_SYMBOL_GPL(dccp_recvmsg);
+
+int inet_dccp_listen(struct socket *sock, int backlog)
 {
         struct sock *sk = sock->sk;
         unsigned char old_state;
@@ -546,6 +564,8 @@ out:
         return err;
 }
 
+EXPORT_SYMBOL_GPL(inet_dccp_listen);
+
 static const unsigned char dccp_new_state[] = {
         /* current state:   new state:      action:     */
         [0]               = DCCP_CLOSED,
@@ -651,11 +671,15 @@ adjudge_to_death:
         sock_put(sk);
 }
 
+EXPORT_SYMBOL_GPL(dccp_close);
+
 void dccp_shutdown(struct sock *sk, int how)
 {
         dccp_pr_debug("entry\n");
 }
 
+EXPORT_SYMBOL_GPL(dccp_shutdown);
+
 static struct proto_ops inet_dccp_ops = {
         .family         = PF_INET,
         .owner          = THIS_MODULE,
@@ -763,6 +787,8 @@ MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
 int dccp_debug;
 module_param(dccp_debug, int, 0444);
 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
+
+EXPORT_SYMBOL_GPL(dccp_debug);
 #endif
 
 static int __init dccp_init(void)