#define DCCP_FEAT_SP_NOAGREE (-123)
+/*
+ * Feature activation handlers.
+ *
+ * These all use an u64 argument, to provide enough room for NN/SP features. At
+ * this stage the negotiated values have been checked to be within their range.
+ */
+static int dccp_hdlr_ccid(struct sock *sk, u64 ccid, bool rx)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid *new_ccid = ccid_new(ccid, sk, rx, gfp_any());
+
+ if (new_ccid == NULL)
+ return -ENOMEM;
+
+ if (rx) {
+ ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
+ dp->dccps_hc_rx_ccid = new_ccid;
+ } else {
+ ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
+ dp->dccps_hc_tx_ccid = new_ccid;
+ }
+ return 0;
+}
+
+static int dccp_hdlr_seq_win(struct sock *sk, u64 seq_win, bool rx)
+{
+ if (!rx)
+ dccp_msk(sk)->dccpms_sequence_window = seq_win;
+ return 0;
+}
+
+static int dccp_hdlr_ack_ratio(struct sock *sk, u64 ratio, bool rx)
+{
+ if (rx)
+ dccp_sk(sk)->dccps_r_ack_ratio = ratio;
+ else
+ dccp_sk(sk)->dccps_l_ack_ratio = ratio;
+ return 0;
+}
+
+static int dccp_hdlr_ackvec(struct sock *sk, u64 enable, bool rx)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+
+ if (rx) {
+ if (enable && dp->dccps_hc_rx_ackvec == NULL) {
+ dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(gfp_any());
+ if (dp->dccps_hc_rx_ackvec == NULL)
+ return -ENOMEM;
+ } else if (!enable) {
+ dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
+ dp->dccps_hc_rx_ackvec = NULL;
+ }
+ }
+ return 0;
+}
+
+static int dccp_hdlr_ndp(struct sock *sk, u64 enable, bool rx)
+{
+ if (!rx)
+ dccp_msk(sk)->dccpms_send_ndp_count = (enable > 0);
+ return 0;
+}
+
+/*
+ * Minimum Checksum Coverage is located at the RX side (9.2.1). This means that
+ * `rx' holds when the sending peer informs about his partial coverage via a
+ * ChangeR() option. In the other case, we are the sender and the receiver
+ * announces its coverage via ChangeL() options. The policy here is to honour
+ * such communication by enabling the corresponding partial coverage - but only
+ * if it has not been set manually before; the warning here means that all
+ * packets will be dropped.
+ */
+static int dccp_hdlr_min_cscov(struct sock *sk, u64 cscov, bool rx)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+
+ if (rx)
+ dp->dccps_pcrlen = cscov;
+ else {
+ if (dp->dccps_pcslen == 0)
+ dp->dccps_pcslen = cscov;
+ else if (cscov > dp->dccps_pcslen)
+ DCCP_WARN("CsCov %u too small, peer requires >= %u\n",
+ dp->dccps_pcslen, (u8)cscov);
+ }
+ return 0;
+}
+
static const struct {
u8 feat_num; /* DCCPF_xxx */
enum dccp_feat_type rxtx; /* RX or TX */
enum dccp_feat_type reconciliation; /* SP or NN */
u8 default_value; /* as in 6.4 */
+ int (*activation_hdlr)(struct sock *sk, u64 val, bool rx);
/*
* Lookup table for location and type of features (from RFC 4340/4342)
* +--------------------------+----+-----+----+----+---------+-----------+
* +--------------------------+----+-----+----+----+---------+-----------+
*/
} dccp_feat_table[] = {
- { DCCPF_CCID, FEAT_AT_TX, FEAT_SP, 2 },
- { DCCPF_SHORT_SEQNOS, FEAT_AT_TX, FEAT_SP, 0 },
- { DCCPF_SEQUENCE_WINDOW, FEAT_AT_TX, FEAT_NN, 100 },
- { DCCPF_ECN_INCAPABLE, FEAT_AT_RX, FEAT_SP, 0 },
- { DCCPF_ACK_RATIO, FEAT_AT_TX, FEAT_NN, 2 },
- { DCCPF_SEND_ACK_VECTOR, FEAT_AT_RX, FEAT_SP, 0 },
- { DCCPF_SEND_NDP_COUNT, FEAT_AT_TX, FEAT_SP, 0 },
- { DCCPF_MIN_CSUM_COVER, FEAT_AT_RX, FEAT_SP, 0 },
- { DCCPF_DATA_CHECKSUM, FEAT_AT_RX, FEAT_SP, 0 },
- { DCCPF_SEND_LEV_RATE, FEAT_AT_RX, FEAT_SP, 0 },
+ { DCCPF_CCID, FEAT_AT_TX, FEAT_SP, 2, dccp_hdlr_ccid },
+ { DCCPF_SHORT_SEQNOS, FEAT_AT_TX, FEAT_SP, 0, NULL },
+ { DCCPF_SEQUENCE_WINDOW, FEAT_AT_TX, FEAT_NN, 100, dccp_hdlr_seq_win },
+ { DCCPF_ECN_INCAPABLE, FEAT_AT_RX, FEAT_SP, 0, NULL },
+ { DCCPF_ACK_RATIO, FEAT_AT_TX, FEAT_NN, 2, dccp_hdlr_ack_ratio},
+ { DCCPF_SEND_ACK_VECTOR, FEAT_AT_RX, FEAT_SP, 0, dccp_hdlr_ackvec },
+ { DCCPF_SEND_NDP_COUNT, FEAT_AT_TX, FEAT_SP, 0, dccp_hdlr_ndp },
+ { DCCPF_MIN_CSUM_COVER, FEAT_AT_RX, FEAT_SP, 0, dccp_hdlr_min_cscov},
+ { DCCPF_DATA_CHECKSUM, FEAT_AT_RX, FEAT_SP, 0, NULL },
+ { DCCPF_SEND_LEV_RATE, FEAT_AT_RX, FEAT_SP, 0, NULL },
};
#define DCCP_FEAT_SUPPORTED_MAX ARRAY_SIZE(dccp_feat_table)
return idx < 0 ? 0 : dccp_feat_table[idx].default_value;
}
+static int __dccp_feat_activate(struct sock *sk, const int idx,
+ const bool is_local, dccp_feat_val const *fval)
+{
+ bool rx;
+ u64 val;
+
+ if (idx < 0 || idx >= DCCP_FEAT_SUPPORTED_MAX)
+ return -1;
+ if (dccp_feat_table[idx].activation_hdlr == NULL)
+ return 0;
+
+ if (fval == NULL) {
+ val = dccp_feat_table[idx].default_value;
+ } else if (dccp_feat_table[idx].reconciliation == FEAT_SP) {
+ if (fval->sp.vec == NULL) {
+ /*
+ * This can happen when an empty Confirm is sent
+ * for an SP (i.e. known) feature. In this case
+ * we would be using the default anyway.
+ */
+ DCCP_CRIT("Feature #%d undefined: using default", idx);
+ val = dccp_feat_table[idx].default_value;
+ } else {
+ val = fval->sp.vec[0];
+ }
+ } else {
+ val = fval->nn;
+ }
+
+ /* Location is RX if this is a local-RX or remote-TX feature */
+ rx = (is_local == (dccp_feat_table[idx].rxtx == FEAT_AT_RX));
+
+ return dccp_feat_table[idx].activation_hdlr(sk, val, rx);
+}
+
/* Test for "Req'd" feature (RFC 4340, 6.4) */
static inline int dccp_feat_must_be_understood(u8 feat_num)
{
EXPORT_SYMBOL_GPL(dccp_feat_init);
+int dccp_feat_activate_values(struct sock *sk, struct list_head *fn_list)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct dccp_feat_entry *cur, *next;
+ int idx;
+ dccp_feat_val *fvals[DCCP_FEAT_SUPPORTED_MAX][2] = {
+ [0 ... DCCP_FEAT_SUPPORTED_MAX-1] = { NULL, NULL }
+ };
+
+ list_for_each_entry(cur, fn_list, node) {
+ /*
+ * An empty Confirm means that either an unknown feature type
+ * or an invalid value was present. In the first case there is
+ * nothing to activate, in the other the default value is used.
+ */
+ if (cur->empty_confirm)
+ continue;
+
+ idx = dccp_feat_index(cur->feat_num);
+ if (idx < 0) {
+ DCCP_BUG("Unknown feature %u", cur->feat_num);
+ goto activation_failed;
+ }
+ if (cur->state != FEAT_STABLE) {
+ DCCP_CRIT("Negotiation of %s %u failed in state %u",
+ cur->is_local ? "local" : "remote",
+ cur->feat_num, cur->state);
+ goto activation_failed;
+ }
+ fvals[idx][cur->is_local] = &cur->val;
+ }
+
+ /*
+ * Activate in decreasing order of index, so that the CCIDs are always
+ * activated as the last feature. This avoids the case where a CCID
+ * relies on the initialisation of one or more features that it depends
+ * on (e.g. Send NDP Count, Send Ack Vector, and Ack Ratio features).
+ */
+ for (idx = DCCP_FEAT_SUPPORTED_MAX; --idx >= 0;)
+ if (__dccp_feat_activate(sk, idx, 0, fvals[idx][0]) ||
+ __dccp_feat_activate(sk, idx, 1, fvals[idx][1])) {
+ DCCP_CRIT("Could not activate %d", idx);
+ goto activation_failed;
+ }
+
+ /* Clean up Change options which have been confirmed already */
+ list_for_each_entry_safe(cur, next, fn_list, node)
+ if (!cur->needs_confirm)
+ dccp_feat_list_pop(cur);
+
+ dccp_pr_debug("Activation OK\n");
+ return 0;
+
+activation_failed:
+ /*
+ * We clean up everything that may have been allocated, since
+ * it is difficult to track at which stage negotiation failed.
+ * This is ok, since all allocation functions below are robust
+ * against NULL arguments.
+ */
+ ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
+ ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
+ dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
+ dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
+ dp->dccps_hc_rx_ackvec = NULL;
+ return -1;
+}
+
#ifdef CONFIG_IP_DCCP_DEBUG
const char *dccp_feat_typename(const u8 type)
{
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff