dccp: Feature negotiation for minimum-checksum-coverage
[safe/jmp/linux-2.6] / net / dccp / proto.c
index a4c1b36..47b137a 100644 (file)
@@ -27,7 +27,6 @@
 #include <net/xfrm.h>
 
 #include <asm/ioctls.h>
-#include <asm/semaphore.h>
 #include <linux/spinlock.h>
 #include <linux/timer.h>
 #include <linux/delay.h>
@@ -194,6 +193,7 @@ int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
 
        dccp_init_xmit_timers(sk);
 
+       INIT_LIST_HEAD(&dp->dccps_featneg);
        /*
         * FIXME: We're hardcoding the CCID, and doing this at this point makes
         * the listening (master) sock get CCID control blocks, which is not
@@ -202,7 +202,7 @@ int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
         * setsockopt(CCIDs-I-want/accept). -acme
         */
        if (likely(ctl_sock_initialized)) {
-               int rc = dccp_feat_init(dmsk);
+               int rc = dccp_feat_init(sk);
 
                if (rc)
                        return rc;
@@ -238,7 +238,7 @@ int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
 
 EXPORT_SYMBOL_GPL(dccp_init_sock);
 
-int dccp_destroy_sock(struct sock *sk)
+void dccp_destroy_sock(struct sock *sk)
 {
        struct dccp_sock *dp = dccp_sk(sk);
        struct dccp_minisock *dmsk = dccp_msk(sk);
@@ -268,9 +268,7 @@ int dccp_destroy_sock(struct sock *sk)
        dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
 
        /* clean up feature negotiation state */
-       dccp_feat_clean(dmsk);
-
-       return 0;
+       dccp_feat_list_purge(&dp->dccps_featneg);
 }
 
 EXPORT_SYMBOL_GPL(dccp_destroy_sock);
@@ -280,6 +278,9 @@ static inline int dccp_listen_start(struct sock *sk, int backlog)
        struct dccp_sock *dp = dccp_sk(sk);
 
        dp->dccps_role = DCCP_ROLE_LISTEN;
+       /* do not start to listen if feature negotiation setup fails */
+       if (dccp_feat_finalise_settings(dp))
+               return -EPROTO;
        return inet_csk_listen_start(sk, backlog);
 }
 
@@ -312,7 +313,9 @@ int dccp_disconnect(struct sock *sk, int flags)
                sk->sk_err = ECONNRESET;
 
        dccp_clear_xmit_timers(sk);
+
        __skb_queue_purge(&sk->sk_receive_queue);
+       __skb_queue_purge(&sk->sk_write_queue);
        if (sk->sk_send_head != NULL) {
                __kfree_skb(sk->sk_send_head);
                sk->sk_send_head = NULL;
@@ -330,7 +333,7 @@ int dccp_disconnect(struct sock *sk, int flags)
        inet_csk_delack_init(sk);
        __sk_dst_reset(sk);
 
-       BUG_TRAP(!inet->num || icsk->icsk_bind_hash);
+       WARN_ON(inet->num && !icsk->icsk_bind_hash);
 
        sk->sk_error_report(sk);
        return err;
@@ -467,37 +470,40 @@ static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
        return 0;
 }
 
-/* byte 1 is feature.  the rest is the preference list */
-static int dccp_setsockopt_change(struct sock *sk, int type,
-                                 struct dccp_so_feat __user *optval)
+static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
 {
-       struct dccp_so_feat opt;
-       u8 *val;
-       int rc;
+       u8 *list, len;
+       int i, rc;
 
-       if (copy_from_user(&opt, optval, sizeof(opt)))
-               return -EFAULT;
+       if (cscov < 0 || cscov > 15)
+               return -EINVAL;
+       /*
+        * Populate a list of permissible values, in the range cscov...15. This
+        * is necessary since feature negotiation of single values only works if
+        * both sides incidentally choose the same value. Since the list starts
+        * lowest-value first, negotiation will pick the smallest shared value.
+        */
+       if (cscov == 0)
+               return 0;
+       len = 16 - cscov;
 
-       val = kmalloc(opt.dccpsf_len, GFP_KERNEL);
-       if (!val)
-               return -ENOMEM;
+       list = kmalloc(len, GFP_KERNEL);
+       if (list == NULL)
+               return -ENOBUFS;
 
-       if (copy_from_user(val, opt.dccpsf_val, opt.dccpsf_len)) {
-               rc = -EFAULT;
-               goto out_free_val;
-       }
+       for (i = 0; i < len; i++)
+               list[i] = cscov++;
 
-       rc = dccp_feat_change(dccp_msk(sk), type, opt.dccpsf_feat,
-                             val, opt.dccpsf_len, GFP_KERNEL);
-       if (rc)
-               goto out_free_val;
+       rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
 
-out:
+       if (rc == 0) {
+               if (rx)
+                       dccp_sk(sk)->dccps_pcrlen = cscov;
+               else
+                       dccp_sk(sk)->dccps_pcslen = cscov;
+       }
+       kfree(list);
        return rc;
-
-out_free_val:
-       kfree(val);
-       goto out;
 }
 
 static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
@@ -522,20 +528,9 @@ static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
                err = 0;
                break;
        case DCCP_SOCKOPT_CHANGE_L:
-               if (optlen != sizeof(struct dccp_so_feat))
-                       err = -EINVAL;
-               else
-                       err = dccp_setsockopt_change(sk, DCCPO_CHANGE_L,
-                                                    (struct dccp_so_feat __user *)
-                                                    optval);
-               break;
        case DCCP_SOCKOPT_CHANGE_R:
-               if (optlen != sizeof(struct dccp_so_feat))
-                       err = -EINVAL;
-               else
-                       err = dccp_setsockopt_change(sk, DCCPO_CHANGE_R,
-                                                    (struct dccp_so_feat __user *)
-                                                    optval);
+               DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
+               err = 0;
                break;
        case DCCP_SOCKOPT_SERVER_TIMEWAIT:
                if (dp->dccps_role != DCCP_ROLE_SERVER)
@@ -543,20 +538,11 @@ static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
                else
                        dp->dccps_server_timewait = (val != 0);
                break;
-       case DCCP_SOCKOPT_SEND_CSCOV:   /* sender side, RFC 4340, sec. 9.2 */
-               if (val < 0 || val > 15)
-                       err = -EINVAL;
-               else
-                       dp->dccps_pcslen = val;
+       case DCCP_SOCKOPT_SEND_CSCOV:
+               err = dccp_setsockopt_cscov(sk, val, false);
                break;
-       case DCCP_SOCKOPT_RECV_CSCOV:   /* receiver side, RFC 4340 sec. 9.2.1 */
-               if (val < 0 || val > 15)
-                       err = -EINVAL;
-               else {
-                       dp->dccps_pcrlen = val;
-                       /* FIXME: add feature negotiation,
-                        * ChangeL(MinimumChecksumCoverage, val) */
-               }
+       case DCCP_SOCKOPT_RECV_CSCOV:
+               err = dccp_setsockopt_cscov(sk, val, true);
                break;
        default:
                err = -ENOPROTOOPT;
@@ -644,6 +630,8 @@ static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
        case DCCP_SOCKOPT_GET_CUR_MPS:
                val = dp->dccps_mss_cache;
                break;
+       case DCCP_SOCKOPT_AVAILABLE_CCIDS:
+               return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
        case DCCP_SOCKOPT_SERVER_TIMEWAIT:
                val = dp->dccps_server_timewait;
                break;
@@ -984,7 +972,7 @@ adjudge_to_death:
         */
        local_bh_disable();
        bh_lock_sock(sk);
-       BUG_TRAP(!sock_owned_by_user(sk));
+       WARN_ON(sock_owned_by_user(sk));
 
        /* Have we already been destroyed by a softirq or backlog? */
        if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
@@ -1026,7 +1014,7 @@ MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");
 
 #ifdef CONFIG_IP_DCCP_DEBUG
 int dccp_debug;
-module_param(dccp_debug, bool, 0444);
+module_param(dccp_debug, bool, 0644);
 MODULE_PARM_DESC(dccp_debug, "Enable debug messages");
 
 EXPORT_SYMBOL_GPL(dccp_debug);