]> bbs.cooldavid.org Git - net-next-2.6.git/blobdiff - net/dccp/options.c
dccp: Integrate feature-negotiation insertion code
[net-next-2.6.git] / net / dccp / options.c
index 9cb0ff8940521aae59921704a56077cc614c2f10..86c7a20d39b2ed65e76ae07ae394d236ae73be03 100644 (file)
@@ -67,7 +67,7 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
                                        (dh->dccph_doff * 4);
        struct dccp_options_received *opt_recv = &dp->dccps_options_received;
        unsigned char opt, len;
-       unsigned char *value;
+       unsigned char *uninitialized_var(value);
        u32 elapsed_time;
        __be32 opt_val;
        int rc;
@@ -467,23 +467,61 @@ static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
        return 0;
 }
 
-static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
-                               u8 *val, u8 len)
+/**
+ * dccp_insert_option_mandatory  -  Mandatory option (5.8.2)
+ * Note that since we are using skb_push, this function needs to be called
+ * _after_ inserting the option it is supposed to influence (stack order).
+ */
+int dccp_insert_option_mandatory(struct sk_buff *skb)
 {
-       u8 *to;
+       if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN)
+               return -1;
 
-       if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
-               DCCP_WARN("packet too small for feature %d option!\n", feat);
+       DCCP_SKB_CB(skb)->dccpd_opt_len++;
+       *skb_push(skb, 1) = DCCPO_MANDATORY;
+       return 0;
+}
+
+/**
+ * dccp_insert_fn_opt  -  Insert single Feature-Negotiation option into @skb
+ * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R
+ * @feat: one out of %dccp_feature_numbers
+ * @val: NN value or SP array (preferred element first) to copy
+ * @len: true length of @val in bytes (excluding first element repetition)
+ * @repeat_first: whether to copy the first element of @val twice
+ * The last argument is used to construct Confirm options, where the preferred
+ * value and the preference list appear separately (RFC 4340, 6.3.1). Preference
+ * lists are kept such that the preferred entry is always first, so we only need
+ * to copy twice, and avoid the overhead of cloning into a bigger array.
+ */
+int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat,
+                      u8 *val, u8 len, bool repeat_first)
+{
+       u8 tot_len, *to;
+
+       /* take the `Feature' field and possible repetition into account */
+       if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) {
+               DCCP_WARN("length %u for feature %u too large\n", len, feat);
                return -1;
        }
 
-       DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
+       if (unlikely(val == NULL || len == 0))
+               len = repeat_first = 0;
+       tot_len = 3 + repeat_first + len;
+
+       if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) {
+               DCCP_WARN("packet too small for feature %d option!\n", feat);
+               return -1;
+       }
+       DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len;
 
-       to    = skb_push(skb, len + 3);
+       to    = skb_push(skb, tot_len);
        *to++ = type;
-       *to++ = len + 3;
+       *to++ = tot_len;
        *to++ = feat;
 
+       if (repeat_first)
+               *to++ = *val;
        if (len)
                memcpy(to, val, len);
 
@@ -493,51 +531,6 @@ static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
        return 0;
 }
 
-static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb)
-{
-       struct dccp_minisock *dmsk = dccp_msk(sk);
-       struct dccp_opt_pend *opt, *next;
-       int change = 0;
-
-       /* confirm any options [NN opts] */
-       list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
-               dccp_insert_feat_opt(skb, opt->dccpop_type,
-                                    opt->dccpop_feat, opt->dccpop_val,
-                                    opt->dccpop_len);
-               /* fear empty confirms */
-               if (opt->dccpop_val)
-                       kfree(opt->dccpop_val);
-               kfree(opt);
-       }
-       INIT_LIST_HEAD(&dmsk->dccpms_conf);
-
-       /* see which features we need to send */
-       list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
-               /* see if we need to send any confirm */
-               if (opt->dccpop_sc) {
-                       dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
-                                            opt->dccpop_feat,
-                                            opt->dccpop_sc->dccpoc_val,
-                                            opt->dccpop_sc->dccpoc_len);
-
-                       BUG_ON(!opt->dccpop_sc->dccpoc_val);
-                       kfree(opt->dccpop_sc->dccpoc_val);
-                       kfree(opt->dccpop_sc);
-                       opt->dccpop_sc = NULL;
-               }
-
-               /* any option not confirmed, re-send it */
-               if (!opt->dccpop_conf) {
-                       dccp_insert_feat_opt(skb, opt->dccpop_type,
-                                            opt->dccpop_feat, opt->dccpop_val,
-                                            opt->dccpop_len);
-                       change++;
-               }
-       }
-
-       return 0;
-}
-
 /* The length of all options needs to be a multiple of 4 (5.8) */
 static void dccp_insert_option_padding(struct sk_buff *skb)
 {
@@ -561,11 +554,25 @@ int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
            dccp_insert_option_ndp(sk, skb))
                return -1;
 
-       if (!dccp_packet_without_ack(skb)) {
-               if (dmsk->dccpms_send_ack_vector &&
-                   dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
-                   dccp_insert_option_ackvec(sk, skb))
+       if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) {
+
+               /* Feature Negotiation */
+               if (dccp_feat_insert_opts(dp, NULL, skb))
                        return -1;
+
+               if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) {
+                       /*
+                        * Obtain RTT sample from Request/Response exchange.
+                        * This is currently used in CCID 3 initialisation.
+                        */
+                       if (dccp_insert_option_timestamp(sk, skb))
+                               return -1;
+
+               } else if (dmsk->dccpms_send_ack_vector &&
+                          dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
+                          dccp_insert_option_ackvec(sk, skb)) {
+                               return -1;
+               }
        }
 
        if (dp->dccps_hc_rx_insert_options) {
@@ -574,21 +581,6 @@ int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
                dp->dccps_hc_rx_insert_options = 0;
        }
 
-       /* Feature negotiation */
-       /* Data packets can't do feat negotiation */
-       if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA &&
-           DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK &&
-           dccp_insert_options_feat(sk, skb))
-               return -1;
-
-       /*
-        * Obtain RTT sample from Request/Response exchange.
-        * This is currently used in CCID 3 initialisation.
-        */
-       if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST &&
-           dccp_insert_option_timestamp(sk, skb))
-               return -1;
-
        if (dp->dccps_timestamp_echo != 0 &&
            dccp_insert_option_timestamp_echo(dp, NULL, skb))
                return -1;
@@ -601,6 +593,9 @@ int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb)
 {
        DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
 
+       if (dccp_feat_insert_opts(NULL, dreq, skb))
+               return -1;
+
        if (dreq->dreq_timestamp_echo != 0 &&
            dccp_insert_option_timestamp_echo(NULL, dreq, skb))
                return -1;