[DCCP]: Registration routines for changing feature values

Two registration routines, for SP and NN features, are provided by this patch,
replacing a previous routine which was used for both feature types.

Signed-off-by: Gerrit Renker <[EMAIL PROTECTED]>
---
 net/dccp/feat.c  |  120 ++++++++++++++++++++++++++++++++++++++++++++-----------
 net/dccp/feat.h  |    2 
 net/dccp/proto.c |    2 
 3 files changed, 99 insertions(+), 25 deletions(-)

--- a/net/dccp/feat.c
+++ b/net/dccp/feat.c
@@ -294,6 +294,92 @@ cloning_failed:
        return -ENOMEM;
 }
 
+static u8 dccp_feat_is_valid_nn_val(u8 feat_num, u64 val)
+{
+       switch (feat_num) {
+               /* Ack Ratio takes 2-byte integer values (11.3) */
+               case DCCPF_ACK_RATIO:       return (val <= 0xFFFF);
+               /* Must be between Wmin=32 and Wmax=2^46-1 (7.5.2) */
+               case DCCPF_SEQUENCE_WINDOW: return (val >= 32 &&
+                                                   val <= 0x3FFFFFFFFFFFull);
+       }
+       return 0;       /* feature unknown - so we can't tell */
+}
+
+/* check that SP values are within the ranges defined in RFC 4340 */
+static u8 dccp_feat_is_valid_sp_val(u8 feat_num, u8 val)
+{
+       switch (feat_num) {
+       case DCCPF_CCID:                return val == 2 || val == 3;
+       case DCCPF_SHORT_SEQNOS:        /* fall through */
+       case DCCPF_ECN_INCAPABLE:       /* fall through */
+       case DCCPF_SEND_ACK_VECTOR:     /* fall through */
+       case DCCPF_SEND_NDP_COUNT:      /* fall through */
+       case DCCPF_DATA_CHECKSUM:       /* fall through */
+       case DCCPF_SEND_LEV_RATE:       return val < 2;
+       case DCCPF_MIN_CSUM_COVER:      return val < 16;
+       }
+       return 0;                       /* feature unknown */
+}
+
+static u8 dccp_feat_sp_list_ok(u8 feat_num, u8 const *sp_list, u8 sp_len)
+{
+       if (sp_list == NULL || sp_len < 1)
+               return 0;
+       while (sp_len--)
+               if (!dccp_feat_is_valid_sp_val(feat_num, *sp_list++))
+                       return 0;
+       return 1;
+}
+
+/**
+ * dccp_feat_register_nn  -  Register new NN value on socket
+ * @fn: feature-negotiation list to register with
+ * @feat: an NN feature from %dccp_feature_numbers
+ * @mandatory: use Mandatory option if 1
+ * @nn_val: value to register (restricted to 4 bytes)
+ * Note that NN features are local by definition (RFC 4340, 6.3.2).
+ */
+static int dccp_feat_register_nn(struct list_head *fn, u8 feat,
+                                u8 mandatory, u64 nn_val)
+{
+       dccp_feat_val fval = { .nn = nn_val };
+
+       if (dccp_feat_type(feat) != FEAT_NN ||
+           !dccp_feat_is_valid_nn_val(feat, nn_val))
+               return -EINVAL;
+
+       /* Don't bother with default values, they will be activated anyway. */
+       if (nn_val - (u64)dccp_feat_default_value(feat) == 0)
+               return 0;
+
+       return dccp_feat_push_change(fn, feat, 1, mandatory, &fval);
+}
+
+/**
+ * dccp_feat_register_sp  -  Register new SP value/list on socket
+ * @fn: feature-negotiation list to register with
+ * @feat: an SP feature from %dccp_feature_numbers
+ * @is_local: whether the local (1) or the remote (0) @feat is meant
+ * @mandatory: use Mandatory option if 1
+ * @sp_val: SP value followed by optional preference list
+ * @sp_len: length of @sp_val in bytes
+ */
+static int dccp_feat_register_sp(struct list_head *fn, u8 feat, u8 is_local,
+                                u8 mandatory, u8 const *sp_val, u8 sp_len)
+{
+       dccp_feat_val fval;
+
+       if (dccp_feat_type(feat) != FEAT_SP ||
+           !dccp_feat_sp_list_ok(feat, sp_val, sp_len))
+               return -EINVAL;
+
+       if (dccp_feat_clone_sp_val(&fval, sp_val, sp_len))
+               return -ENOMEM;
+
+       return dccp_feat_push_change(fn, feat, is_local, mandatory, &fval);
+}
+
 int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
                     u8 *val, u8 len, gfp_t gfp)
 {
@@ -830,42 +916,30 @@ out_clean:
 
 EXPORT_SYMBOL_GPL(dccp_feat_clone);
 
-static int __dccp_feat_init(struct dccp_minisock *dmsk, u8 type, u8 feat,
-                           u8 *val, u8 len)
-{
-       int rc = -ENOMEM;
-       u8 *copy = kmemdup(val, len, GFP_KERNEL);
-
-       if (copy != NULL) {
-               rc = dccp_feat_change(dmsk, type, feat, copy, len, GFP_KERNEL);
-               if (rc)
-                       kfree(copy);
-       }
-       return rc;
-}
-
-int dccp_feat_init(struct dccp_minisock *dmsk)
+int dccp_feat_init(struct sock *sk)
 {
+       struct dccp_sock *dp = dccp_sk(sk);
+       struct dccp_minisock *dmsk = dccp_msk(sk);
        int rc;
 
-       INIT_LIST_HEAD(&dmsk->dccpms_pending);
-       INIT_LIST_HEAD(&dmsk->dccpms_conf);
+       INIT_LIST_HEAD(&dmsk->dccpms_pending);  /* XXX no longer used */
+       INIT_LIST_HEAD(&dmsk->dccpms_conf);     /* XXX no longer used */
 
        /* CCID L */
-       rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_L, DCCPF_CCID,
-                             &dmsk->dccpms_tx_ccid, 1);
+       rc = dccp_feat_register_sp(&dp->dccps_featneg, DCCPF_CCID, 1, 0,
+                                  &dmsk->dccpms_tx_ccid, 1);
        if (rc)
                goto out;
 
        /* CCID R */
-       rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_R, DCCPF_CCID,
-                             &dmsk->dccpms_rx_ccid, 1);
+       rc = dccp_feat_register_sp(&dp->dccps_featneg, DCCPF_CCID, 0, 0,
+                                  &dmsk->dccpms_rx_ccid, 1);
        if (rc)
                goto out;
 
        /* Ack ratio */
-       rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_L, DCCPF_ACK_RATIO,
-                             &dmsk->dccpms_ack_ratio, 1);
+       rc = dccp_feat_register_nn(&dp->dccps_featneg, DCCPF_ACK_RATIO, 0,
+                                  dmsk->dccpms_ack_ratio);
 out:
        return rc;
 }
--- a/net/dccp/feat.h
+++ b/net/dccp/feat.h
@@ -96,6 +96,6 @@ extern int  dccp_feat_confirm_recv(struc
 extern void dccp_feat_clean(struct dccp_minisock *dmsk);
 extern int  dccp_feat_clone(struct sock *oldsk, struct sock *newsk);
 extern int  dccp_feat_clone_list(struct list_head const *, struct list_head *);
-extern int  dccp_feat_init(struct dccp_minisock *dmsk);
+extern int  dccp_feat_init(struct sock *sk);
 
 #endif /* _DCCP_FEAT_H */
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -186,7 +186,7 @@ int dccp_init_sock(struct sock *sk, cons
         * 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;
-
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