[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, 83 insertions, 2 deletions

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 18a0e69c9dc7..9bda2868eba6 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -94,7 +94,15 @@ EXPORT_SYMBOL_GPL(dccp_state_name);
 
 static inline int dccp_listen_start(struct sock *sk)
 {
-        dccp_sk(sk)->dccps_role = DCCP_ROLE_LISTEN;
+        struct dccp_sock *dp = dccp_sk(sk);
+
+        dp->dccps_role = DCCP_ROLE_LISTEN;
+        /*
+         * Apps need to use setsockopt(DCCP_SOCKOPT_SERVICE)
+         * before calling listen()
+         */
+        if (dccp_service_not_initialized(sk))
+                return -EPROTO;
         return inet_csk_listen_start(sk, TCP_SYNQ_HSIZE);
 }
 
@@ -202,6 +210,42 @@ int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
         return -ENOIOCTLCMD;
 }
 
+static int dccp_setsockopt_service(struct sock *sk, const u32 service,
+                                   char __user *optval, int optlen)
+{
+        struct dccp_sock *dp = dccp_sk(sk);
+        struct dccp_service_list *sl = NULL;
+
+        if (service == DCCP_SERVICE_INVALID_VALUE || 
+            optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
+                return -EINVAL;
+
+        if (optlen > sizeof(service)) {
+                sl = kmalloc(optlen, GFP_KERNEL);
+                if (sl == NULL)
+                        return -ENOMEM;
+
+                sl->dccpsl_nr = optlen / sizeof(u32) - 1;
+                if (copy_from_user(sl->dccpsl_list,
+                                   optval + sizeof(service),
+                                   optlen - sizeof(service)) ||
+                    dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
+                        kfree(sl);
+                        return -EFAULT;
+                }
+        }
+
+        lock_sock(sk);
+        dp->dccps_service = service;
+
+        if (dp->dccps_service_list != NULL)
+                kfree(dp->dccps_service_list);
+
+        dp->dccps_service_list = sl;
+        release_sock(sk);
+        return 0;
+}
+
 int dccp_setsockopt(struct sock *sk, int level, int optname,
                     char __user *optval, int optlen)
 {
@@ -218,8 +262,10 @@ int dccp_setsockopt(struct sock *sk, int level, int optname,
         if (get_user(val, (int __user *)optval))
                 return -EFAULT;
 
-        lock_sock(sk);
+        if (optname == DCCP_SOCKOPT_SERVICE)
+                return dccp_setsockopt_service(sk, val, optval, optlen);
 
+        lock_sock(sk);
         dp = dccp_sk(sk);
         err = 0;
 
@@ -236,6 +282,37 @@ int dccp_setsockopt(struct sock *sk, int level, int optname,
         return err;
 }
 
+static int dccp_getsockopt_service(struct sock *sk, int len,
+                                   u32 __user *optval,
+                                   int __user *optlen)
+{
+        const struct dccp_sock *dp = dccp_sk(sk);
+        const struct dccp_service_list *sl;
+        int err = -ENOENT, slen = 0, total_len = sizeof(u32);
+
+        lock_sock(sk);
+        if (dccp_service_not_initialized(sk))
+                goto out;
+
+        if ((sl = dp->dccps_service_list) != NULL) {
+                slen = sl->dccpsl_nr * sizeof(u32);
+                total_len += slen;
+        }
+
+        err = -EINVAL;
+        if (total_len > len)
+                goto out;
+
+        err = 0;
+        if (put_user(total_len, optlen) ||
+            put_user(dp->dccps_service, optval) ||
+            (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
+                err = -EFAULT;
+out:
+        release_sock(sk);
+        return err;
+}
+
 int dccp_getsockopt(struct sock *sk, int level, int optname,
                     char __user *optval, int __user *optlen)
 {
@@ -248,6 +325,10 @@ int dccp_getsockopt(struct sock *sk, int level, int optname,
         if (get_user(len, optlen))
                 return -EFAULT;
 
+        if (optname == DCCP_SOCKOPT_SERVICE)
+                return dccp_getsockopt_service(sk, len,
+                                               (u32 __user *)optval, optlen);
+
         len = min_t(unsigned int, len, sizeof(int));
         if (len < 0)
                 return -EINVAL;