@@ -527,8 +527,8 @@ struct dccp_sock {
__u32 dccps_timestamp_time;
__u16 dccps_l_ack_ratio;
__u16 dccps_r_ack_ratio;
- __u16 dccps_pcslen;
- __u16 dccps_pcrlen;
+ __u8 dccps_pcslen:4;
+ __u8 dccps_pcrlen:4;
__u64 dccps_ndp_count:48;
unsigned long dccps_rate_last;
struct dccp_minisock dccps_minisock;
@@ -470,6 +470,42 @@ static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
return 0;
}
+static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
+{
+ u8 *list, len;
+ int i, rc;
+
+ 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;
+
+ list = kmalloc(len, GFP_KERNEL);
+ if (list == NULL)
+ return -ENOBUFS;
+
+ for (i = 0; i < len; i++)
+ list[i] = cscov++;
+
+ rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);
+
+ if (rc == 0) {
+ if (rx)
+ dccp_sk(sk)->dccps_pcrlen = cscov;
+ else
+ dccp_sk(sk)->dccps_pcslen = cscov;
+ }
+ kfree(list);
+ return rc;
+}
+
static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, int optlen)
{
@@ -502,20 +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;