*
* ASSUMPTIONS
* -----------
- * o Feature negotiation is coordinated with connection setup (as in TCP), wild
- * changes of parameters of an established connection are not supported.
* o All currently known SP features have 1-byte quantities. If in the future
* extensions of RFCs 4340..42 define features with item lengths larger than
* one byte, a feature-specific extension of the code will be required.
#define DCCP_FEAT_SP_NOAGREE (-123)
-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 */
-/*
- * Lookup table for location and type of features (from RFC 4340/4342)
- * +--------------------------+----+-----+----+----+---------+-----------+
- * | Feature | Location | Reconc. | Initial | Section |
- * | | RX | TX | SP | NN | Value | Reference |
- * +--------------------------+----+-----+----+----+---------+-----------+
- * | DCCPF_CCID | | X | X | | 2 | 10 |
- * | DCCPF_SHORT_SEQNOS | | X | X | | 0 | 7.6.1 |
- * | DCCPF_SEQUENCE_WINDOW | | X | | X | 100 | 7.5.2 |
- * | DCCPF_ECN_INCAPABLE | X | | X | | 0 | 12.1 |
- * | DCCPF_ACK_RATIO | | X | | X | 2 | 11.3 |
- * | DCCPF_SEND_ACK_VECTOR | X | | X | | 0 | 11.5 |
- * | DCCPF_SEND_NDP_COUNT | | X | X | | 0 | 7.7.2 |
- * | DCCPF_MIN_CSUM_COVER | X | | X | | 0 | 9.2.1 |
- * | DCCPF_DATA_CHECKSUM | X | | X | | 0 | 9.3.1 |
- * | DCCPF_SEND_LEV_RATE | X | | X | | 0 | 4342/8.4 |
- * +--------------------------+----+-----+----+----+---------+-----------+
- */
-} 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 },
-};
-#define DCCP_FEAT_SUPPORTED_MAX ARRAY_SIZE(dccp_feat_table)
-
-/**
- * dccp_feat_index - Hash function to map feature number into array position
- * Returns consecutive array index or -1 if the feature is not understood.
- */
-static int dccp_feat_index(u8 feat_num)
-{
- /* The first 9 entries are occupied by the types from RFC 4340, 6.4 */
- if (feat_num > DCCPF_RESERVED && feat_num <= DCCPF_DATA_CHECKSUM)
- return feat_num - 1;
-
- /*
- * Other features: add cases for new feature types here after adding
- * them to the above table.
- */
- switch (feat_num) {
- case DCCPF_SEND_LEV_RATE:
- return DCCP_FEAT_SUPPORTED_MAX - 1;
- }
- return -1;
-}
-
-static u8 dccp_feat_type(u8 feat_num)
-{
- int idx = dccp_feat_index(feat_num);
-
- if (idx < 0)
- return FEAT_UNKNOWN;
- return dccp_feat_table[idx].reconciliation;
-}
-
-static int dccp_feat_default_value(u8 feat_num)
-{
- int idx = dccp_feat_index(feat_num);
-
- return idx < 0 ? : dccp_feat_table[idx].default_value;
-}
-
-/* copy constructor, fval must not already contain allocated memory */
-static int dccp_feat_clone_sp_val(dccp_feat_val *fval, u8 const *val, u8 len)
-{
- fval->sp.len = len;
- if (fval->sp.len > 0) {
- fval->sp.vec = kmemdup(val, len, gfp_any());
- if (fval->sp.vec == NULL) {
- fval->sp.len = 0;
- return -ENOBUFS;
- }
- }
- return 0;
-}
-
-static void dccp_feat_val_destructor(u8 feat_num, dccp_feat_val *val)
-{
- if (unlikely(val == NULL))
- return;
- if (dccp_feat_type(feat_num) == FEAT_SP)
- kfree(val->sp.vec);
- memset(val, 0, sizeof(*val));
-}
-
-static struct dccp_feat_entry *
- dccp_feat_clone_entry(struct dccp_feat_entry const *original)
-{
- struct dccp_feat_entry *new;
- u8 type = dccp_feat_type(original->feat_num);
-
- if (type == FEAT_UNKNOWN)
- return NULL;
-
- new = kmemdup(original, sizeof(struct dccp_feat_entry), gfp_any());
- if (new == NULL)
- return NULL;
-
- if (type == FEAT_SP && dccp_feat_clone_sp_val(&new->val,
- original->val.sp.vec,
- original->val.sp.len)) {
- kfree(new);
- return NULL;
- }
- return new;
-}
-
-static void dccp_feat_entry_destructor(struct dccp_feat_entry *entry)
-{
- if (entry != NULL) {
- dccp_feat_val_destructor(entry->feat_num, &entry->val);
- kfree(entry);
- }
-}
-
-/*
- * List management functions
- *
- * Feature negotiation lists rely on and maintain the following invariants:
- * - each feat_num in the list is known, i.e. we know its type and default value
- * - each feat_num/is_local combination is unique (old entries are overwritten)
- * - SP values are always freshly allocated
- * - list is sorted in increasing order of feature number (faster lookup)
- */
-static struct dccp_feat_entry *dccp_feat_list_lookup(struct list_head *fn_list,
- u8 feat_num, bool is_local)
-{
- struct dccp_feat_entry *entry;
-
- list_for_each_entry(entry, fn_list, node)
- if (entry->feat_num == feat_num && entry->is_local == is_local)
- return entry;
- else if (entry->feat_num > feat_num)
- break;
- return NULL;
-}
-
-/**
- * dccp_feat_entry_new - Central list update routine (called by all others)
- * @head: list to add to
- * @feat: feature number
- * @local: whether the local (1) or remote feature with number @feat is meant
- * This is the only constructor and serves to ensure the above invariants.
- */
-static struct dccp_feat_entry *
- dccp_feat_entry_new(struct list_head *head, u8 feat, bool local)
-{
- struct dccp_feat_entry *entry;
-
- list_for_each_entry(entry, head, node)
- if (entry->feat_num == feat && entry->is_local == local) {
- dccp_feat_val_destructor(entry->feat_num, &entry->val);
- return entry;
- } else if (entry->feat_num > feat) {
- head = &entry->node;
- break;
- }
-
- entry = kmalloc(sizeof(*entry), gfp_any());
- if (entry != NULL) {
- entry->feat_num = feat;
- entry->is_local = local;
- list_add_tail(&entry->node, head);
- }
- return entry;
-}
-
-/**
- * dccp_feat_push_change - Add/overwrite a Change option in the list
- * @fn_list: feature-negotiation list to update
- * @feat: one of %dccp_feature_numbers
- * @local: whether local (1) or remote (0) @feat_num is meant
- * @needs_mandatory: whether to use Mandatory feature negotiation options
- * @fval: pointer to NN/SP value to be inserted (will be copied)
- */
-static int dccp_feat_push_change(struct list_head *fn_list, u8 feat, u8 local,
- u8 mandatory, dccp_feat_val *fval)
-{
- struct dccp_feat_entry *new = dccp_feat_entry_new(fn_list, feat, local);
-
- if (new == NULL)
- return -ENOMEM;
-
- new->feat_num = feat;
- new->is_local = local;
- new->state = FEAT_INITIALISING;
- new->needs_confirm = 0;
- new->empty_confirm = 0;
- new->val = *fval;
- new->needs_mandatory = mandatory;
-
- return 0;
-}
-
-/**
- * dccp_feat_push_confirm - Add a Confirm entry to the FN list
- * @fn_list: feature-negotiation list to add to
- * @feat: one of %dccp_feature_numbers
- * @local: whether local (1) or remote (0) @feat_num is being confirmed
- * @fval: pointer to NN/SP value to be inserted or NULL
- * Returns 0 on success, a Reset code for further processing otherwise.
- */
-static int dccp_feat_push_confirm(struct list_head *fn_list, u8 feat, u8 local,
- dccp_feat_val *fval)
-{
- struct dccp_feat_entry *new = dccp_feat_entry_new(fn_list, feat, local);
-
- if (new == NULL)
- return DCCP_RESET_CODE_TOO_BUSY;
-
- new->feat_num = feat;
- new->is_local = local;
- new->state = FEAT_STABLE; /* transition in 6.6.2 */
- new->needs_confirm = 1;
- new->empty_confirm = (fval == NULL);
- new->val.nn = 0; /* zeroes the whole structure */
- if (!new->empty_confirm)
- new->val = *fval;
- new->needs_mandatory = 0;
-
- return 0;
-}
-
-static int dccp_push_empty_confirm(struct list_head *fn_list, u8 feat, u8 local)
-{
- return dccp_feat_push_confirm(fn_list, feat, local, NULL);
-}
-
-static inline void dccp_feat_list_pop(struct dccp_feat_entry *entry)
-{
- list_del(&entry->node);
- dccp_feat_entry_destructor(entry);
-}
-
-void dccp_feat_list_purge(struct list_head *fn_list)
-{
- struct dccp_feat_entry *entry, *next;
-
- list_for_each_entry_safe(entry, next, fn_list, node)
- dccp_feat_entry_destructor(entry);
- INIT_LIST_HEAD(fn_list);
-}
-EXPORT_SYMBOL_GPL(dccp_feat_list_purge);
-
-/* generate @to as full clone of @from - @to must not contain any nodes */
-int dccp_feat_clone_list(struct list_head const *from, struct list_head *to)
-{
- struct dccp_feat_entry *entry, *new;
-
- INIT_LIST_HEAD(to);
- list_for_each_entry(entry, from, node) {
- new = dccp_feat_clone_entry(entry);
- if (new == NULL)
- goto cloning_failed;
- list_add_tail(&new->node, to);
- }
- return 0;
-
-cloning_failed:
- dccp_feat_list_purge(to);
- return -ENOMEM;
-}
-
int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
u8 *val, u8 len, gfp_t gfp)
{
{
int rc;
- /* Ignore Change requests other than during connection setup */
- if (sk->sk_state != DCCP_LISTEN && sk->sk_state != DCCP_REQUESTING)
- return 0;
dccp_feat_debug(type, feature, *val);
/* figure out if it's SP or NN feature */
int found = 0;
int all_confirmed = 1;
- /* Ignore Confirm options other than during connection setup */
- if (sk->sk_state != DCCP_LISTEN && sk->sk_state != DCCP_REQUESTING)
- return 0;
dccp_feat_debug(type, feature, *val);
/* locate our change request */
all_confirmed = 0;
}
+ /* fix re-transmit timer */
+ /* XXX gotta make sure that no option negotiation occurs during
+ * connection shutdown. Consider that the CLOSEREQ is sent and timer is
+ * on. if all options are confirmed it might kill timer which should
+ * remain alive until close is received.
+ */
+ if (all_confirmed) {
+ dccp_pr_debug("clear feat negotiation timer %p\n", sk);
+ inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
+ }
+
if (!found)
dccp_pr_debug("%s(%d, ...) never requested\n",
dccp_feat_typename(type), feature);
if (feat > DCCPF_DATA_CHECKSUM && feat < DCCPF_MIN_CCID_SPECIFIC)
return feature_names[DCCPF_RESERVED];
- if (feat == DCCPF_SEND_LEV_RATE)
- return "Send Loss Event Rate";
if (feat >= DCCPF_MIN_CCID_SPECIFIC)
return "CCID-specific";
projects / linux-2.6-omap-h63xx.git / blobdiff