[DCCP]: Introduce DCCP_SOCKOPT_SERVICE

As discussed in the dccp@vger mailing list:

Now applications have to use setsockopt(DCCP_SOCKOPT_SERVICE, service[s]),
prior to calling listen() and connect().

An array of unsigned ints can be passed meaning that the listening sock accepts
connection requests for several services.

With this we can ditch struct sockaddr_dccp and use only sockaddr_in (and
sockaddr_in6 in the future).

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

1 files changed, 27 insertions, 3 deletions

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index e09907d8b7da..94a440b2685b 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -246,6 +246,9 @@ static int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
 
         dp->dccps_role = DCCP_ROLE_CLIENT;
 
+        if (dccp_service_not_initialized(sk))
+                return -EPROTO;
+
         if (addr_len < sizeof(struct sockaddr_in))
                 return -EINVAL;
 
@@ -661,6 +664,16 @@ 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;
@@ -669,6 +682,7 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
         struct dccp_request_sock *dreq;
         const __u32 saddr = skb->nh.iph->saddr;
         const __u32 daddr = skb->nh.iph->daddr;
+        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;
@@ -680,6 +694,10 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
                 goto drop;
         }
 
+        if (dccp_bad_service_code(sk, service)) {
+                reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
+                goto drop;
+        }
         /*
          * TW buckets are converted to open requests without
          * limitations, they conserve resources and peer is
@@ -722,9 +740,9 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
          * dccp_create_openreq_child.
          */
         dreq = dccp_rsk(req);
-        dreq->dreq_isr = dcb->dccpd_seq;
-        dreq->dreq_iss = dccp_v4_init_sequence(sk, skb);
-        dreq->dreq_service = dccp_hdr_request(skb)->dccph_req_service;
+        dreq->dreq_isr     = dcb->dccpd_seq;
+        dreq->dreq_iss     = dccp_v4_init_sequence(sk, skb);
+        dreq->dreq_service = service;
 
         if (dccp_v4_send_response(sk, req, dst))
                 goto drop_and_free;
@@ -1284,6 +1302,7 @@ static int dccp_v4_init_sock(struct sock *sk)
         sk->sk_write_space = dccp_write_space;
         dp->dccps_mss_cache = 536;
         dp->dccps_role = DCCP_ROLE_UNDEFINED;
+        dp->dccps_service = DCCP_SERVICE_INVALID_VALUE;
 
         return 0;
 }
@@ -1305,6 +1324,11 @@ static int dccp_v4_destroy_sock(struct sock *sk)
         if (inet_csk(sk)->icsk_bind_hash != NULL)
                 inet_put_port(&dccp_hashinfo, sk);
 
+        if (dp->dccps_service_list != NULL) {
+                kfree(dp->dccps_service_list);
+                dp->dccps_service_list = NULL;
+        }
+
         ccid_hc_rx_exit(dp->dccps_hc_rx_ccid, sk);
         ccid_hc_tx_exit(dp->dccps_hc_tx_ccid, sk);
         dccp_ackpkts_free(dp->dccps_hc_rx_ackpkts);