1124 lines
30 KiB
C
1124 lines
30 KiB
C
/*
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* net/dccp/feat.c
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*
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* An implementation of the DCCP protocol
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* Andrea Bittau <a.bittau@cs.ucl.ac.uk>
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*
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* ASSUMPTIONS
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* -----------
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* o Feature negotiation is coordinated with connection setup (as in TCP), wild
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* changes of parameters of an established connection are not supported.
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* o All currently known SP features have 1-byte quantities. If in the future
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* extensions of RFCs 4340..42 define features with item lengths larger than
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* one byte, a feature-specific extension of the code will be required.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/module.h>
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#include "ccid.h"
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#include "feat.h"
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#define DCCP_FEAT_SP_NOAGREE (-123)
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static const struct {
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u8 feat_num; /* DCCPF_xxx */
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enum dccp_feat_type rxtx; /* RX or TX */
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enum dccp_feat_type reconciliation; /* SP or NN */
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u8 default_value; /* as in 6.4 */
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/*
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* Lookup table for location and type of features (from RFC 4340/4342)
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* +--------------------------+----+-----+----+----+---------+-----------+
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* | Feature | Location | Reconc. | Initial | Section |
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* | | RX | TX | SP | NN | Value | Reference |
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* +--------------------------+----+-----+----+----+---------+-----------+
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* | DCCPF_CCID | | X | X | | 2 | 10 |
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* | DCCPF_SHORT_SEQNOS | | X | X | | 0 | 7.6.1 |
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* | DCCPF_SEQUENCE_WINDOW | | X | | X | 100 | 7.5.2 |
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* | DCCPF_ECN_INCAPABLE | X | | X | | 0 | 12.1 |
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* | DCCPF_ACK_RATIO | | X | | X | 2 | 11.3 |
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* | DCCPF_SEND_ACK_VECTOR | X | | X | | 0 | 11.5 |
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* | DCCPF_SEND_NDP_COUNT | | X | X | | 0 | 7.7.2 |
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* | DCCPF_MIN_CSUM_COVER | X | | X | | 0 | 9.2.1 |
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* | DCCPF_DATA_CHECKSUM | X | | X | | 0 | 9.3.1 |
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* | DCCPF_SEND_LEV_RATE | X | | X | | 0 | 4342/8.4 |
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* +--------------------------+----+-----+----+----+---------+-----------+
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*/
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} dccp_feat_table[] = {
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{ DCCPF_CCID, FEAT_AT_TX, FEAT_SP, 2 },
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{ DCCPF_SHORT_SEQNOS, FEAT_AT_TX, FEAT_SP, 0 },
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{ DCCPF_SEQUENCE_WINDOW, FEAT_AT_TX, FEAT_NN, 100 },
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{ DCCPF_ECN_INCAPABLE, FEAT_AT_RX, FEAT_SP, 0 },
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{ DCCPF_ACK_RATIO, FEAT_AT_TX, FEAT_NN, 2 },
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{ DCCPF_SEND_ACK_VECTOR, FEAT_AT_RX, FEAT_SP, 0 },
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{ DCCPF_SEND_NDP_COUNT, FEAT_AT_TX, FEAT_SP, 0 },
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{ DCCPF_MIN_CSUM_COVER, FEAT_AT_RX, FEAT_SP, 0 },
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{ DCCPF_DATA_CHECKSUM, FEAT_AT_RX, FEAT_SP, 0 },
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{ DCCPF_SEND_LEV_RATE, FEAT_AT_RX, FEAT_SP, 0 },
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};
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#define DCCP_FEAT_SUPPORTED_MAX ARRAY_SIZE(dccp_feat_table)
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/**
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* dccp_feat_index - Hash function to map feature number into array position
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* Returns consecutive array index or -1 if the feature is not understood.
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*/
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static int dccp_feat_index(u8 feat_num)
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{
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/* The first 9 entries are occupied by the types from RFC 4340, 6.4 */
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if (feat_num > DCCPF_RESERVED && feat_num <= DCCPF_DATA_CHECKSUM)
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return feat_num - 1;
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/*
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* Other features: add cases for new feature types here after adding
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* them to the above table.
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*/
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switch (feat_num) {
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case DCCPF_SEND_LEV_RATE:
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return DCCP_FEAT_SUPPORTED_MAX - 1;
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}
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return -1;
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}
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static u8 dccp_feat_type(u8 feat_num)
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{
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int idx = dccp_feat_index(feat_num);
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if (idx < 0)
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return FEAT_UNKNOWN;
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return dccp_feat_table[idx].reconciliation;
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}
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static int dccp_feat_default_value(u8 feat_num)
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{
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int idx = dccp_feat_index(feat_num);
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/*
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* There are no default values for unknown features, so encountering a
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* negative index here indicates a serious problem somewhere else.
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*/
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DCCP_BUG_ON(idx < 0);
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return idx < 0 ? 0 : dccp_feat_table[idx].default_value;
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}
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/* copy constructor, fval must not already contain allocated memory */
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static int dccp_feat_clone_sp_val(dccp_feat_val *fval, u8 const *val, u8 len)
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{
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fval->sp.len = len;
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if (fval->sp.len > 0) {
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fval->sp.vec = kmemdup(val, len, gfp_any());
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if (fval->sp.vec == NULL) {
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fval->sp.len = 0;
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return -ENOBUFS;
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}
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}
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return 0;
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}
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static void dccp_feat_val_destructor(u8 feat_num, dccp_feat_val *val)
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{
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if (unlikely(val == NULL))
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return;
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if (dccp_feat_type(feat_num) == FEAT_SP)
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kfree(val->sp.vec);
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memset(val, 0, sizeof(*val));
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}
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static struct dccp_feat_entry *
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dccp_feat_clone_entry(struct dccp_feat_entry const *original)
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{
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struct dccp_feat_entry *new;
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u8 type = dccp_feat_type(original->feat_num);
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if (type == FEAT_UNKNOWN)
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return NULL;
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new = kmemdup(original, sizeof(struct dccp_feat_entry), gfp_any());
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if (new == NULL)
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return NULL;
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if (type == FEAT_SP && dccp_feat_clone_sp_val(&new->val,
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original->val.sp.vec,
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original->val.sp.len)) {
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kfree(new);
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return NULL;
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}
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return new;
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}
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static void dccp_feat_entry_destructor(struct dccp_feat_entry *entry)
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{
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if (entry != NULL) {
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dccp_feat_val_destructor(entry->feat_num, &entry->val);
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kfree(entry);
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}
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}
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/*
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* List management functions
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*
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* Feature negotiation lists rely on and maintain the following invariants:
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* - each feat_num in the list is known, i.e. we know its type and default value
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* - each feat_num/is_local combination is unique (old entries are overwritten)
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* - SP values are always freshly allocated
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* - list is sorted in increasing order of feature number (faster lookup)
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*/
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/**
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* dccp_feat_entry_new - Central list update routine (called by all others)
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* @head: list to add to
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* @feat: feature number
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* @local: whether the local (1) or remote feature with number @feat is meant
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* This is the only constructor and serves to ensure the above invariants.
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*/
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static struct dccp_feat_entry *
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dccp_feat_entry_new(struct list_head *head, u8 feat, bool local)
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{
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struct dccp_feat_entry *entry;
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list_for_each_entry(entry, head, node)
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if (entry->feat_num == feat && entry->is_local == local) {
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dccp_feat_val_destructor(entry->feat_num, &entry->val);
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return entry;
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} else if (entry->feat_num > feat) {
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head = &entry->node;
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break;
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}
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entry = kmalloc(sizeof(*entry), gfp_any());
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if (entry != NULL) {
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entry->feat_num = feat;
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entry->is_local = local;
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list_add_tail(&entry->node, head);
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}
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return entry;
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}
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/**
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* dccp_feat_push_change - Add/overwrite a Change option in the list
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* @fn_list: feature-negotiation list to update
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* @feat: one of %dccp_feature_numbers
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* @local: whether local (1) or remote (0) @feat_num is meant
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* @needs_mandatory: whether to use Mandatory feature negotiation options
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* @fval: pointer to NN/SP value to be inserted (will be copied)
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*/
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static int dccp_feat_push_change(struct list_head *fn_list, u8 feat, u8 local,
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u8 mandatory, dccp_feat_val *fval)
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{
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struct dccp_feat_entry *new = dccp_feat_entry_new(fn_list, feat, local);
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if (new == NULL)
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return -ENOMEM;
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new->feat_num = feat;
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new->is_local = local;
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new->state = FEAT_INITIALISING;
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new->needs_confirm = 0;
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new->empty_confirm = 0;
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new->val = *fval;
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new->needs_mandatory = mandatory;
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return 0;
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}
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static inline void dccp_feat_list_pop(struct dccp_feat_entry *entry)
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{
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list_del(&entry->node);
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dccp_feat_entry_destructor(entry);
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}
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void dccp_feat_list_purge(struct list_head *fn_list)
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{
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struct dccp_feat_entry *entry, *next;
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list_for_each_entry_safe(entry, next, fn_list, node)
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dccp_feat_entry_destructor(entry);
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INIT_LIST_HEAD(fn_list);
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}
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EXPORT_SYMBOL_GPL(dccp_feat_list_purge);
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/* generate @to as full clone of @from - @to must not contain any nodes */
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int dccp_feat_clone_list(struct list_head const *from, struct list_head *to)
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{
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struct dccp_feat_entry *entry, *new;
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INIT_LIST_HEAD(to);
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list_for_each_entry(entry, from, node) {
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new = dccp_feat_clone_entry(entry);
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if (new == NULL)
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goto cloning_failed;
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list_add_tail(&new->node, to);
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}
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return 0;
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cloning_failed:
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dccp_feat_list_purge(to);
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return -ENOMEM;
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}
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static u8 dccp_feat_is_valid_nn_val(u8 feat_num, u64 val)
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{
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switch (feat_num) {
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case DCCPF_ACK_RATIO:
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return val <= DCCPF_ACK_RATIO_MAX;
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case DCCPF_SEQUENCE_WINDOW:
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return val >= DCCPF_SEQ_WMIN && val <= DCCPF_SEQ_WMAX;
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}
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return 0; /* feature unknown - so we can't tell */
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}
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/* check that SP values are within the ranges defined in RFC 4340 */
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static u8 dccp_feat_is_valid_sp_val(u8 feat_num, u8 val)
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{
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switch (feat_num) {
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case DCCPF_CCID:
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return val == DCCPC_CCID2 || val == DCCPC_CCID3;
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/* Type-check Boolean feature values: */
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case DCCPF_SHORT_SEQNOS:
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case DCCPF_ECN_INCAPABLE:
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case DCCPF_SEND_ACK_VECTOR:
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case DCCPF_SEND_NDP_COUNT:
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case DCCPF_DATA_CHECKSUM:
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case DCCPF_SEND_LEV_RATE:
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return val < 2;
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case DCCPF_MIN_CSUM_COVER:
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return val < 16;
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}
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return 0; /* feature unknown */
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}
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static u8 dccp_feat_sp_list_ok(u8 feat_num, u8 const *sp_list, u8 sp_len)
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{
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if (sp_list == NULL || sp_len < 1)
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return 0;
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while (sp_len--)
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if (!dccp_feat_is_valid_sp_val(feat_num, *sp_list++))
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return 0;
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return 1;
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}
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/**
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* __feat_register_nn - Register new NN value on socket
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* @fn: feature-negotiation list to register with
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* @feat: an NN feature from %dccp_feature_numbers
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* @mandatory: use Mandatory option if 1
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* @nn_val: value to register (restricted to 4 bytes)
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* Note that NN features are local by definition (RFC 4340, 6.3.2).
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*/
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static int __feat_register_nn(struct list_head *fn, u8 feat,
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u8 mandatory, u64 nn_val)
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{
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dccp_feat_val fval = { .nn = nn_val };
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if (dccp_feat_type(feat) != FEAT_NN ||
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!dccp_feat_is_valid_nn_val(feat, nn_val))
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return -EINVAL;
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/* Don't bother with default values, they will be activated anyway. */
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if (nn_val - (u64)dccp_feat_default_value(feat) == 0)
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return 0;
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return dccp_feat_push_change(fn, feat, 1, mandatory, &fval);
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}
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/**
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* __feat_register_sp - Register new SP value/list on socket
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* @fn: feature-negotiation list to register with
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* @feat: an SP feature from %dccp_feature_numbers
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* @is_local: whether the local (1) or the remote (0) @feat is meant
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* @mandatory: use Mandatory option if 1
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* @sp_val: SP value followed by optional preference list
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* @sp_len: length of @sp_val in bytes
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*/
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static int __feat_register_sp(struct list_head *fn, u8 feat, u8 is_local,
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u8 mandatory, u8 const *sp_val, u8 sp_len)
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{
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dccp_feat_val fval;
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if (dccp_feat_type(feat) != FEAT_SP ||
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!dccp_feat_sp_list_ok(feat, sp_val, sp_len))
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return -EINVAL;
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/* Avoid negotiating alien CCIDs by only advertising supported ones */
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if (feat == DCCPF_CCID && !ccid_support_check(sp_val, sp_len))
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return -EOPNOTSUPP;
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if (dccp_feat_clone_sp_val(&fval, sp_val, sp_len))
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return -ENOMEM;
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return dccp_feat_push_change(fn, feat, is_local, mandatory, &fval);
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}
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int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
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u8 *val, u8 len, gfp_t gfp)
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{
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struct dccp_opt_pend *opt;
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dccp_feat_debug(type, feature, *val);
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if (len > 3) {
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DCCP_WARN("invalid length %d\n", len);
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return -EINVAL;
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}
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/* XXX add further sanity checks */
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/* check if that feature is already being negotiated */
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list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
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/* ok we found a negotiation for this option already */
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if (opt->dccpop_feat == feature && opt->dccpop_type == type) {
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dccp_pr_debug("Replacing old\n");
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/* replace */
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BUG_ON(opt->dccpop_val == NULL);
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kfree(opt->dccpop_val);
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opt->dccpop_val = val;
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opt->dccpop_len = len;
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opt->dccpop_conf = 0;
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return 0;
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}
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}
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/* negotiation for a new feature */
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opt = kmalloc(sizeof(*opt), gfp);
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if (opt == NULL)
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return -ENOMEM;
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opt->dccpop_type = type;
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opt->dccpop_feat = feature;
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opt->dccpop_len = len;
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opt->dccpop_val = val;
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opt->dccpop_conf = 0;
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opt->dccpop_sc = NULL;
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BUG_ON(opt->dccpop_val == NULL);
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list_add_tail(&opt->dccpop_node, &dmsk->dccpms_pending);
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return 0;
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}
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EXPORT_SYMBOL_GPL(dccp_feat_change);
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/*
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* Tracking features whose value depend on the choice of CCID
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*
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* This is designed with an extension in mind so that a list walk could be done
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* before activating any features. However, the existing framework was found to
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* work satisfactorily up until now, the automatic verification is left open.
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* When adding new CCIDs, add a corresponding dependency table here.
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*/
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static const struct ccid_dependency *dccp_feat_ccid_deps(u8 ccid, bool is_local)
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{
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static const struct ccid_dependency ccid2_dependencies[2][2] = {
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/*
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* CCID2 mandates Ack Vectors (RFC 4341, 4.): as CCID is a TX
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* feature and Send Ack Vector is an RX feature, `is_local'
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* needs to be reversed.
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*/
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{ /* Dependencies of the receiver-side (remote) CCID2 */
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{
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.dependent_feat = DCCPF_SEND_ACK_VECTOR,
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.is_local = true,
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.is_mandatory = true,
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.val = 1
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},
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{ 0, 0, 0, 0 }
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},
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{ /* Dependencies of the sender-side (local) CCID2 */
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{
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.dependent_feat = DCCPF_SEND_ACK_VECTOR,
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.is_local = false,
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.is_mandatory = true,
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.val = 1
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},
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{ 0, 0, 0, 0 }
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}
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};
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static const struct ccid_dependency ccid3_dependencies[2][5] = {
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{ /*
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* Dependencies of the receiver-side CCID3
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*/
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{ /* locally disable Ack Vectors */
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.dependent_feat = DCCPF_SEND_ACK_VECTOR,
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.is_local = true,
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.is_mandatory = false,
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.val = 0
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},
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{ /* see below why Send Loss Event Rate is on */
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.dependent_feat = DCCPF_SEND_LEV_RATE,
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.is_local = true,
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.is_mandatory = true,
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.val = 1
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},
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{ /* NDP Count is needed as per RFC 4342, 6.1.1 */
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.dependent_feat = DCCPF_SEND_NDP_COUNT,
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.is_local = false,
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.is_mandatory = true,
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.val = 1
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},
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{ 0, 0, 0, 0 },
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},
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{ /*
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* CCID3 at the TX side: we request that the HC-receiver
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* will not send Ack Vectors (they will be ignored, so
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* Mandatory is not set); we enable Send Loss Event Rate
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* (Mandatory since the implementation does not support
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* the Loss Intervals option of RFC 4342, 8.6).
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|
* The last two options are for peer's information only.
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*/
|
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{
|
|
.dependent_feat = DCCPF_SEND_ACK_VECTOR,
|
|
.is_local = false,
|
|
.is_mandatory = false,
|
|
.val = 0
|
|
},
|
|
{
|
|
.dependent_feat = DCCPF_SEND_LEV_RATE,
|
|
.is_local = false,
|
|
.is_mandatory = true,
|
|
.val = 1
|
|
},
|
|
{ /* this CCID does not support Ack Ratio */
|
|
.dependent_feat = DCCPF_ACK_RATIO,
|
|
.is_local = true,
|
|
.is_mandatory = false,
|
|
.val = 0
|
|
},
|
|
{ /* tell receiver we are sending NDP counts */
|
|
.dependent_feat = DCCPF_SEND_NDP_COUNT,
|
|
.is_local = true,
|
|
.is_mandatory = false,
|
|
.val = 1
|
|
},
|
|
{ 0, 0, 0, 0 }
|
|
}
|
|
};
|
|
switch (ccid) {
|
|
case DCCPC_CCID2:
|
|
return ccid2_dependencies[is_local];
|
|
case DCCPC_CCID3:
|
|
return ccid3_dependencies[is_local];
|
|
default:
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* dccp_feat_propagate_ccid - Resolve dependencies of features on choice of CCID
|
|
* @fn: feature-negotiation list to update
|
|
* @id: CCID number to track
|
|
* @is_local: whether TX CCID (1) or RX CCID (0) is meant
|
|
* This function needs to be called after registering all other features.
|
|
*/
|
|
static int dccp_feat_propagate_ccid(struct list_head *fn, u8 id, bool is_local)
|
|
{
|
|
const struct ccid_dependency *table = dccp_feat_ccid_deps(id, is_local);
|
|
int i, rc = (table == NULL);
|
|
|
|
for (i = 0; rc == 0 && table[i].dependent_feat != DCCPF_RESERVED; i++)
|
|
if (dccp_feat_type(table[i].dependent_feat) == FEAT_SP)
|
|
rc = __feat_register_sp(fn, table[i].dependent_feat,
|
|
table[i].is_local,
|
|
table[i].is_mandatory,
|
|
&table[i].val, 1);
|
|
else
|
|
rc = __feat_register_nn(fn, table[i].dependent_feat,
|
|
table[i].is_mandatory,
|
|
table[i].val);
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* dccp_feat_finalise_settings - Finalise settings before starting negotiation
|
|
* @dp: client or listening socket (settings will be inherited)
|
|
* This is called after all registrations (socket initialisation, sysctls, and
|
|
* sockopt calls), and before sending the first packet containing Change options
|
|
* (ie. client-Request or server-Response), to ensure internal consistency.
|
|
*/
|
|
int dccp_feat_finalise_settings(struct dccp_sock *dp)
|
|
{
|
|
struct list_head *fn = &dp->dccps_featneg;
|
|
struct dccp_feat_entry *entry;
|
|
int i = 2, ccids[2] = { -1, -1 };
|
|
|
|
/*
|
|
* Propagating CCIDs:
|
|
* 1) not useful to propagate CCID settings if this host advertises more
|
|
* than one CCID: the choice of CCID may still change - if this is
|
|
* the client, or if this is the server and the client sends
|
|
* singleton CCID values.
|
|
* 2) since is that propagate_ccid changes the list, we defer changing
|
|
* the sorted list until after the traversal.
|
|
*/
|
|
list_for_each_entry(entry, fn, node)
|
|
if (entry->feat_num == DCCPF_CCID && entry->val.sp.len == 1)
|
|
ccids[entry->is_local] = entry->val.sp.vec[0];
|
|
while (i--)
|
|
if (ccids[i] > 0 && dccp_feat_propagate_ccid(fn, ccids[i], i))
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
static int dccp_feat_update_ccid(struct sock *sk, u8 type, u8 new_ccid_nr)
|
|
{
|
|
struct dccp_sock *dp = dccp_sk(sk);
|
|
struct dccp_minisock *dmsk = dccp_msk(sk);
|
|
/* figure out if we are changing our CCID or the peer's */
|
|
const int rx = type == DCCPO_CHANGE_R;
|
|
const u8 ccid_nr = rx ? dmsk->dccpms_rx_ccid : dmsk->dccpms_tx_ccid;
|
|
struct ccid *new_ccid;
|
|
|
|
/* Check if nothing is being changed. */
|
|
if (ccid_nr == new_ccid_nr)
|
|
return 0;
|
|
|
|
new_ccid = ccid_new(new_ccid_nr, sk, rx, GFP_ATOMIC);
|
|
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;
|
|
dmsk->dccpms_rx_ccid = new_ccid_nr;
|
|
} else {
|
|
ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
|
|
dp->dccps_hc_tx_ccid = new_ccid;
|
|
dmsk->dccpms_tx_ccid = new_ccid_nr;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int dccp_feat_update(struct sock *sk, u8 type, u8 feat, u8 val)
|
|
{
|
|
dccp_feat_debug(type, feat, val);
|
|
|
|
switch (feat) {
|
|
case DCCPF_CCID:
|
|
return dccp_feat_update_ccid(sk, type, val);
|
|
default:
|
|
dccp_pr_debug("UNIMPLEMENTED: %s(%d, ...)\n",
|
|
dccp_feat_typename(type), feat);
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int dccp_feat_reconcile(struct sock *sk, struct dccp_opt_pend *opt,
|
|
u8 *rpref, u8 rlen)
|
|
{
|
|
struct dccp_sock *dp = dccp_sk(sk);
|
|
u8 *spref, slen, *res = NULL;
|
|
int i, j, rc, agree = 1;
|
|
|
|
BUG_ON(rpref == NULL);
|
|
|
|
/* check if we are the black sheep */
|
|
if (dp->dccps_role == DCCP_ROLE_CLIENT) {
|
|
spref = rpref;
|
|
slen = rlen;
|
|
rpref = opt->dccpop_val;
|
|
rlen = opt->dccpop_len;
|
|
} else {
|
|
spref = opt->dccpop_val;
|
|
slen = opt->dccpop_len;
|
|
}
|
|
/*
|
|
* Now we have server preference list in spref and client preference in
|
|
* rpref
|
|
*/
|
|
BUG_ON(spref == NULL);
|
|
BUG_ON(rpref == NULL);
|
|
|
|
/* FIXME sanity check vals */
|
|
|
|
/* Are values in any order? XXX Lame "algorithm" here */
|
|
for (i = 0; i < slen; i++) {
|
|
for (j = 0; j < rlen; j++) {
|
|
if (spref[i] == rpref[j]) {
|
|
res = &spref[i];
|
|
break;
|
|
}
|
|
}
|
|
if (res)
|
|
break;
|
|
}
|
|
|
|
/* we didn't agree on anything */
|
|
if (res == NULL) {
|
|
/* confirm previous value */
|
|
switch (opt->dccpop_feat) {
|
|
case DCCPF_CCID:
|
|
/* XXX did i get this right? =P */
|
|
if (opt->dccpop_type == DCCPO_CHANGE_L)
|
|
res = &dccp_msk(sk)->dccpms_tx_ccid;
|
|
else
|
|
res = &dccp_msk(sk)->dccpms_rx_ccid;
|
|
break;
|
|
|
|
default:
|
|
DCCP_BUG("Fell through, feat=%d", opt->dccpop_feat);
|
|
/* XXX implement res */
|
|
return -EFAULT;
|
|
}
|
|
|
|
dccp_pr_debug("Don't agree... reconfirming %d\n", *res);
|
|
agree = 0; /* this is used for mandatory options... */
|
|
}
|
|
|
|
/* need to put result and our preference list */
|
|
rlen = 1 + opt->dccpop_len;
|
|
rpref = kmalloc(rlen, GFP_ATOMIC);
|
|
if (rpref == NULL)
|
|
return -ENOMEM;
|
|
|
|
*rpref = *res;
|
|
memcpy(&rpref[1], opt->dccpop_val, opt->dccpop_len);
|
|
|
|
/* put it in the "confirm queue" */
|
|
if (opt->dccpop_sc == NULL) {
|
|
opt->dccpop_sc = kmalloc(sizeof(*opt->dccpop_sc), GFP_ATOMIC);
|
|
if (opt->dccpop_sc == NULL) {
|
|
kfree(rpref);
|
|
return -ENOMEM;
|
|
}
|
|
} else {
|
|
/* recycle the confirm slot */
|
|
BUG_ON(opt->dccpop_sc->dccpoc_val == NULL);
|
|
kfree(opt->dccpop_sc->dccpoc_val);
|
|
dccp_pr_debug("recycling confirm slot\n");
|
|
}
|
|
memset(opt->dccpop_sc, 0, sizeof(*opt->dccpop_sc));
|
|
|
|
opt->dccpop_sc->dccpoc_val = rpref;
|
|
opt->dccpop_sc->dccpoc_len = rlen;
|
|
|
|
/* update the option on our side [we are about to send the confirm] */
|
|
rc = dccp_feat_update(sk, opt->dccpop_type, opt->dccpop_feat, *res);
|
|
if (rc) {
|
|
kfree(opt->dccpop_sc->dccpoc_val);
|
|
kfree(opt->dccpop_sc);
|
|
opt->dccpop_sc = NULL;
|
|
return rc;
|
|
}
|
|
|
|
dccp_pr_debug("Will confirm %d\n", *rpref);
|
|
|
|
/* say we want to change to X but we just got a confirm X, suppress our
|
|
* change
|
|
*/
|
|
if (!opt->dccpop_conf) {
|
|
if (*opt->dccpop_val == *res)
|
|
opt->dccpop_conf = 1;
|
|
dccp_pr_debug("won't ask for change of same feature\n");
|
|
}
|
|
|
|
return agree ? 0 : DCCP_FEAT_SP_NOAGREE; /* used for mandatory opts */
|
|
}
|
|
|
|
static int dccp_feat_sp(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len)
|
|
{
|
|
struct dccp_minisock *dmsk = dccp_msk(sk);
|
|
struct dccp_opt_pend *opt;
|
|
int rc = 1;
|
|
u8 t;
|
|
|
|
/*
|
|
* We received a CHANGE. We gotta match it against our own preference
|
|
* list. If we got a CHANGE_R it means it's a change for us, so we need
|
|
* to compare our CHANGE_L list.
|
|
*/
|
|
if (type == DCCPO_CHANGE_L)
|
|
t = DCCPO_CHANGE_R;
|
|
else
|
|
t = DCCPO_CHANGE_L;
|
|
|
|
/* find our preference list for this feature */
|
|
list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
|
|
if (opt->dccpop_type != t || opt->dccpop_feat != feature)
|
|
continue;
|
|
|
|
/* find the winner from the two preference lists */
|
|
rc = dccp_feat_reconcile(sk, opt, val, len);
|
|
break;
|
|
}
|
|
|
|
/* We didn't deal with the change. This can happen if we have no
|
|
* preference list for the feature. In fact, it just shouldn't
|
|
* happen---if we understand a feature, we should have a preference list
|
|
* with at least the default value.
|
|
*/
|
|
BUG_ON(rc == 1);
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int dccp_feat_nn(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len)
|
|
{
|
|
struct dccp_opt_pend *opt;
|
|
struct dccp_minisock *dmsk = dccp_msk(sk);
|
|
u8 *copy;
|
|
int rc;
|
|
|
|
/* NN features must be Change L (sec. 6.3.2) */
|
|
if (type != DCCPO_CHANGE_L) {
|
|
dccp_pr_debug("received %s for NN feature %d\n",
|
|
dccp_feat_typename(type), feature);
|
|
return -EFAULT;
|
|
}
|
|
|
|
/* XXX sanity check opt val */
|
|
|
|
/* copy option so we can confirm it */
|
|
opt = kzalloc(sizeof(*opt), GFP_ATOMIC);
|
|
if (opt == NULL)
|
|
return -ENOMEM;
|
|
|
|
copy = kmemdup(val, len, GFP_ATOMIC);
|
|
if (copy == NULL) {
|
|
kfree(opt);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
opt->dccpop_type = DCCPO_CONFIRM_R; /* NN can only confirm R */
|
|
opt->dccpop_feat = feature;
|
|
opt->dccpop_val = copy;
|
|
opt->dccpop_len = len;
|
|
|
|
/* change feature */
|
|
rc = dccp_feat_update(sk, type, feature, *val);
|
|
if (rc) {
|
|
kfree(opt->dccpop_val);
|
|
kfree(opt);
|
|
return rc;
|
|
}
|
|
|
|
dccp_feat_debug(type, feature, *copy);
|
|
|
|
list_add_tail(&opt->dccpop_node, &dmsk->dccpms_conf);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void dccp_feat_empty_confirm(struct dccp_minisock *dmsk,
|
|
u8 type, u8 feature)
|
|
{
|
|
/* XXX check if other confirms for that are queued and recycle slot */
|
|
struct dccp_opt_pend *opt = kzalloc(sizeof(*opt), GFP_ATOMIC);
|
|
|
|
if (opt == NULL) {
|
|
/* XXX what do we do? Ignoring should be fine. It's a change
|
|
* after all =P
|
|
*/
|
|
return;
|
|
}
|
|
|
|
switch (type) {
|
|
case DCCPO_CHANGE_L:
|
|
opt->dccpop_type = DCCPO_CONFIRM_R;
|
|
break;
|
|
case DCCPO_CHANGE_R:
|
|
opt->dccpop_type = DCCPO_CONFIRM_L;
|
|
break;
|
|
default:
|
|
DCCP_WARN("invalid type %d\n", type);
|
|
kfree(opt);
|
|
return;
|
|
}
|
|
opt->dccpop_feat = feature;
|
|
opt->dccpop_val = NULL;
|
|
opt->dccpop_len = 0;
|
|
|
|
/* change feature */
|
|
dccp_pr_debug("Empty %s(%d)\n", dccp_feat_typename(type), feature);
|
|
|
|
list_add_tail(&opt->dccpop_node, &dmsk->dccpms_conf);
|
|
}
|
|
|
|
static void dccp_feat_flush_confirm(struct sock *sk)
|
|
{
|
|
struct dccp_minisock *dmsk = dccp_msk(sk);
|
|
/* Check if there is anything to confirm in the first place */
|
|
int yes = !list_empty(&dmsk->dccpms_conf);
|
|
|
|
if (!yes) {
|
|
struct dccp_opt_pend *opt;
|
|
|
|
list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
|
|
if (opt->dccpop_conf) {
|
|
yes = 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!yes)
|
|
return;
|
|
|
|
/* OK there is something to confirm... */
|
|
/* XXX check if packet is in flight? Send delayed ack?? */
|
|
if (sk->sk_state == DCCP_OPEN)
|
|
dccp_send_ack(sk);
|
|
}
|
|
|
|
int dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len)
|
|
{
|
|
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 */
|
|
switch (feature) {
|
|
/* deal with SP features */
|
|
case DCCPF_CCID:
|
|
rc = dccp_feat_sp(sk, type, feature, val, len);
|
|
break;
|
|
|
|
/* deal with NN features */
|
|
case DCCPF_ACK_RATIO:
|
|
rc = dccp_feat_nn(sk, type, feature, val, len);
|
|
break;
|
|
|
|
/* XXX implement other features */
|
|
default:
|
|
dccp_pr_debug("UNIMPLEMENTED: not handling %s(%d, ...)\n",
|
|
dccp_feat_typename(type), feature);
|
|
rc = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
/* check if there were problems changing features */
|
|
if (rc) {
|
|
/* If we don't agree on SP, we sent a confirm for old value.
|
|
* However we propagate rc to caller in case option was
|
|
* mandatory
|
|
*/
|
|
if (rc != DCCP_FEAT_SP_NOAGREE)
|
|
dccp_feat_empty_confirm(dccp_msk(sk), type, feature);
|
|
}
|
|
|
|
/* generate the confirm [if required] */
|
|
dccp_feat_flush_confirm(sk);
|
|
|
|
return rc;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_feat_change_recv);
|
|
|
|
int dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
|
|
u8 *val, u8 len)
|
|
{
|
|
u8 t;
|
|
struct dccp_opt_pend *opt;
|
|
struct dccp_minisock *dmsk = dccp_msk(sk);
|
|
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 */
|
|
switch (type) {
|
|
case DCCPO_CONFIRM_L: t = DCCPO_CHANGE_R; break;
|
|
case DCCPO_CONFIRM_R: t = DCCPO_CHANGE_L; break;
|
|
default: DCCP_WARN("invalid type %d\n", type);
|
|
return 1;
|
|
|
|
}
|
|
/* XXX sanity check feature value */
|
|
|
|
list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
|
|
if (!opt->dccpop_conf && opt->dccpop_type == t &&
|
|
opt->dccpop_feat == feature) {
|
|
found = 1;
|
|
dccp_pr_debug("feature %d found\n", opt->dccpop_feat);
|
|
|
|
/* XXX do sanity check */
|
|
|
|
opt->dccpop_conf = 1;
|
|
|
|
/* We got a confirmation---change the option */
|
|
dccp_feat_update(sk, opt->dccpop_type,
|
|
opt->dccpop_feat, *val);
|
|
|
|
/* XXX check the return value of dccp_feat_update */
|
|
break;
|
|
}
|
|
|
|
if (!opt->dccpop_conf)
|
|
all_confirmed = 0;
|
|
}
|
|
|
|
if (!found)
|
|
dccp_pr_debug("%s(%d, ...) never requested\n",
|
|
dccp_feat_typename(type), feature);
|
|
return 0;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_feat_confirm_recv);
|
|
|
|
void dccp_feat_clean(struct dccp_minisock *dmsk)
|
|
{
|
|
struct dccp_opt_pend *opt, *next;
|
|
|
|
list_for_each_entry_safe(opt, next, &dmsk->dccpms_pending,
|
|
dccpop_node) {
|
|
BUG_ON(opt->dccpop_val == NULL);
|
|
kfree(opt->dccpop_val);
|
|
|
|
if (opt->dccpop_sc != NULL) {
|
|
BUG_ON(opt->dccpop_sc->dccpoc_val == NULL);
|
|
kfree(opt->dccpop_sc->dccpoc_val);
|
|
kfree(opt->dccpop_sc);
|
|
}
|
|
|
|
kfree(opt);
|
|
}
|
|
INIT_LIST_HEAD(&dmsk->dccpms_pending);
|
|
|
|
list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
|
|
BUG_ON(opt == NULL);
|
|
if (opt->dccpop_val != NULL)
|
|
kfree(opt->dccpop_val);
|
|
kfree(opt);
|
|
}
|
|
INIT_LIST_HEAD(&dmsk->dccpms_conf);
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_feat_clean);
|
|
|
|
/* this is to be called only when a listening sock creates its child. It is
|
|
* assumed by the function---the confirm is not duplicated, but rather it is
|
|
* "passed on".
|
|
*/
|
|
int dccp_feat_clone(struct sock *oldsk, struct sock *newsk)
|
|
{
|
|
struct dccp_minisock *olddmsk = dccp_msk(oldsk);
|
|
struct dccp_minisock *newdmsk = dccp_msk(newsk);
|
|
struct dccp_opt_pend *opt;
|
|
int rc = 0;
|
|
|
|
INIT_LIST_HEAD(&newdmsk->dccpms_pending);
|
|
INIT_LIST_HEAD(&newdmsk->dccpms_conf);
|
|
|
|
list_for_each_entry(opt, &olddmsk->dccpms_pending, dccpop_node) {
|
|
struct dccp_opt_pend *newopt;
|
|
/* copy the value of the option */
|
|
u8 *val = kmemdup(opt->dccpop_val, opt->dccpop_len, GFP_ATOMIC);
|
|
|
|
if (val == NULL)
|
|
goto out_clean;
|
|
|
|
newopt = kmemdup(opt, sizeof(*newopt), GFP_ATOMIC);
|
|
if (newopt == NULL) {
|
|
kfree(val);
|
|
goto out_clean;
|
|
}
|
|
|
|
/* insert the option */
|
|
newopt->dccpop_val = val;
|
|
list_add_tail(&newopt->dccpop_node, &newdmsk->dccpms_pending);
|
|
|
|
/* XXX what happens with backlogs and multiple connections at
|
|
* once...
|
|
*/
|
|
/* the master socket no longer needs to worry about confirms */
|
|
opt->dccpop_sc = NULL; /* it's not a memleak---new socket has it */
|
|
|
|
/* reset state for a new socket */
|
|
opt->dccpop_conf = 0;
|
|
}
|
|
|
|
/* XXX not doing anything about the conf queue */
|
|
|
|
out:
|
|
return rc;
|
|
|
|
out_clean:
|
|
dccp_feat_clean(newdmsk);
|
|
rc = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_feat_clone);
|
|
|
|
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); /* XXX no longer used */
|
|
INIT_LIST_HEAD(&dmsk->dccpms_conf); /* XXX no longer used */
|
|
|
|
/* CCID L */
|
|
rc = __feat_register_sp(&dp->dccps_featneg, DCCPF_CCID, 1, 0,
|
|
&dmsk->dccpms_tx_ccid, 1);
|
|
if (rc)
|
|
goto out;
|
|
|
|
/* CCID R */
|
|
rc = __feat_register_sp(&dp->dccps_featneg, DCCPF_CCID, 0, 0,
|
|
&dmsk->dccpms_rx_ccid, 1);
|
|
if (rc)
|
|
goto out;
|
|
|
|
/* Ack ratio */
|
|
rc = __feat_register_nn(&dp->dccps_featneg, DCCPF_ACK_RATIO, 0,
|
|
dmsk->dccpms_ack_ratio);
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_feat_init);
|
|
|
|
#ifdef CONFIG_IP_DCCP_DEBUG
|
|
const char *dccp_feat_typename(const u8 type)
|
|
{
|
|
switch(type) {
|
|
case DCCPO_CHANGE_L: return("ChangeL");
|
|
case DCCPO_CONFIRM_L: return("ConfirmL");
|
|
case DCCPO_CHANGE_R: return("ChangeR");
|
|
case DCCPO_CONFIRM_R: return("ConfirmR");
|
|
/* the following case must not appear in feature negotation */
|
|
default: dccp_pr_debug("unknown type %d [BUG!]\n", type);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_feat_typename);
|
|
|
|
const char *dccp_feat_name(const u8 feat)
|
|
{
|
|
static const char *feature_names[] = {
|
|
[DCCPF_RESERVED] = "Reserved",
|
|
[DCCPF_CCID] = "CCID",
|
|
[DCCPF_SHORT_SEQNOS] = "Allow Short Seqnos",
|
|
[DCCPF_SEQUENCE_WINDOW] = "Sequence Window",
|
|
[DCCPF_ECN_INCAPABLE] = "ECN Incapable",
|
|
[DCCPF_ACK_RATIO] = "Ack Ratio",
|
|
[DCCPF_SEND_ACK_VECTOR] = "Send ACK Vector",
|
|
[DCCPF_SEND_NDP_COUNT] = "Send NDP Count",
|
|
[DCCPF_MIN_CSUM_COVER] = "Min. Csum Coverage",
|
|
[DCCPF_DATA_CHECKSUM] = "Send Data Checksum",
|
|
};
|
|
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";
|
|
|
|
return feature_names[feat];
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_feat_name);
|
|
#endif /* CONFIG_IP_DCCP_DEBUG */
|