| /* |
| * net/dccp/feat.c |
| * |
| * Feature negotiation for the DCCP protocol (RFC 4340, section 6) |
| * |
| * Copyright (c) 2008 Gerrit Renker <gerrit@erg.abdn.ac.uk> |
| * Rewrote from scratch, some bits from earlier code by |
| * Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk> |
| * |
| * |
| * 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. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| #include <linux/module.h> |
| #include "ccid.h" |
| #include "feat.h" |
| |
| /* |
| * 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_sk(sk)->dccps_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) |
| * +--------------------------+----+-----+----+----+---------+-----------+ |
| * | 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, 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) |
| |
| /** |
| * 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); |
| /* |
| * There are no default values for unknown features, so encountering a |
| * negative index here indicates a serious problem somewhere else. |
| */ |
| DCCP_BUG_ON(idx < 0); |
| |
| 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) |
| { |
| return feat_num == DCCPF_CCID || feat_num == DCCPF_SHORT_SEQNOS || |
| feat_num == DCCPF_SEQUENCE_WINDOW; |
| } |
| |
| /* 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; |
| } |
| |
| /** |
| * dccp_feat_valid_nn_length - Enforce length constraints on NN options |
| * Length is between 0 and %DCCP_OPTVAL_MAXLEN. Used for outgoing packets only, |
| * incoming options are accepted as long as their values are valid. |
| */ |
| static u8 dccp_feat_valid_nn_length(u8 feat_num) |
| { |
| if (feat_num == DCCPF_ACK_RATIO) /* RFC 4340, 11.3 and 6.6.8 */ |
| return 2; |
| if (feat_num == DCCPF_SEQUENCE_WINDOW) /* RFC 4340, 7.5.2 and 6.5 */ |
| return 6; |
| return 0; |
| } |
| |
| static u8 dccp_feat_is_valid_nn_val(u8 feat_num, u64 val) |
| { |
| switch (feat_num) { |
| case DCCPF_ACK_RATIO: |
| return val <= DCCPF_ACK_RATIO_MAX; |
| case DCCPF_SEQUENCE_WINDOW: |
| return val >= DCCPF_SEQ_WMIN && val <= DCCPF_SEQ_WMAX; |
| } |
| 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 == DCCPC_CCID2 || val == DCCPC_CCID3; |
| /* Type-check Boolean feature values: */ |
| case DCCPF_SHORT_SEQNOS: |
| case DCCPF_ECN_INCAPABLE: |
| case DCCPF_SEND_ACK_VECTOR: |
| case DCCPF_SEND_NDP_COUNT: |
| case DCCPF_DATA_CHECKSUM: |
| 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_insert_opts - Generate FN options from current list state |
| * @skb: next sk_buff to be sent to the peer |
| * @dp: for client during handshake and general negotiation |
| * @dreq: used by the server only (all Changes/Confirms in LISTEN/RESPOND) |
| */ |
| int dccp_feat_insert_opts(struct dccp_sock *dp, struct dccp_request_sock *dreq, |
| struct sk_buff *skb) |
| { |
| struct list_head *fn = dreq ? &dreq->dreq_featneg : &dp->dccps_featneg; |
| struct dccp_feat_entry *pos, *next; |
| u8 opt, type, len, *ptr, nn_in_nbo[DCCP_OPTVAL_MAXLEN]; |
| bool rpt; |
| |
| /* put entries into @skb in the order they appear in the list */ |
| list_for_each_entry_safe_reverse(pos, next, fn, node) { |
| opt = dccp_feat_genopt(pos); |
| type = dccp_feat_type(pos->feat_num); |
| rpt = false; |
| |
| if (pos->empty_confirm) { |
| len = 0; |
| ptr = NULL; |
| } else { |
| if (type == FEAT_SP) { |
| len = pos->val.sp.len; |
| ptr = pos->val.sp.vec; |
| rpt = pos->needs_confirm; |
| } else if (type == FEAT_NN) { |
| len = dccp_feat_valid_nn_length(pos->feat_num); |
| ptr = nn_in_nbo; |
| dccp_encode_value_var(pos->val.nn, ptr, len); |
| } else { |
| DCCP_BUG("unknown feature %u", pos->feat_num); |
| return -1; |
| } |
| } |
| |
| if (dccp_insert_fn_opt(skb, opt, pos->feat_num, ptr, len, rpt)) |
| return -1; |
| if (pos->needs_mandatory && dccp_insert_option_mandatory(skb)) |
| return -1; |
| /* |
| * Enter CHANGING after transmitting the Change option (6.6.2). |
| */ |
| if (pos->state == FEAT_INITIALISING) |
| pos->state = FEAT_CHANGING; |
| } |
| return 0; |
| } |
| |
| /** |
| * __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 __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); |
| } |
| |
| /** |
| * __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 __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; |
| |
| /* Avoid negotiating alien CCIDs by only advertising supported ones */ |
| if (feat == DCCPF_CCID && !ccid_support_check(sp_val, sp_len)) |
| return -EOPNOTSUPP; |
| |
| if (dccp_feat_clone_sp_val(&fval, sp_val, sp_len)) |
| return -ENOMEM; |
| |
| return dccp_feat_push_change(fn, feat, is_local, mandatory, &fval); |
| } |
| |
| /** |
| * dccp_feat_register_sp - Register requests to change SP feature values |
| * @sk: client or listening socket |
| * @feat: one of %dccp_feature_numbers |
| * @is_local: whether the local (1) or remote (0) @feat is meant |
| * @list: array of preferred values, in descending order of preference |
| * @len: length of @list in bytes |
| */ |
| int dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local, |
| u8 const *list, u8 len) |
| { /* any changes must be registered before establishing the connection */ |
| if (sk->sk_state != DCCP_CLOSED) |
| return -EISCONN; |
| if (dccp_feat_type(feat) != FEAT_SP) |
| return -EINVAL; |
| return __feat_register_sp(&dccp_sk(sk)->dccps_featneg, feat, is_local, |
| 0, list, len); |
| } |
| |
| /* Analogous to dccp_feat_register_sp(), but for non-negotiable values */ |
| int dccp_feat_register_nn(struct sock *sk, u8 feat, u64 val) |
| { |
| /* any changes must be registered before establishing the connection */ |
| if (sk->sk_state != DCCP_CLOSED) |
| return -EISCONN; |
| if (dccp_feat_type(feat) != FEAT_NN) |
| return -EINVAL; |
| return __feat_register_nn(&dccp_sk(sk)->dccps_featneg, feat, 0, val); |
| } |
| |
| /* |
| * Tracking features whose value depend on the choice of CCID |
| * |
| * This is designed with an extension in mind so that a list walk could be done |
| * before activating any features. However, the existing framework was found to |
| * work satisfactorily up until now, the automatic verification is left open. |
| * When adding new CCIDs, add a corresponding dependency table here. |
| */ |
| static const struct ccid_dependency *dccp_feat_ccid_deps(u8 ccid, bool is_local) |
| { |
| static const struct ccid_dependency ccid2_dependencies[2][2] = { |
| /* |
| * CCID2 mandates Ack Vectors (RFC 4341, 4.): as CCID is a TX |
| * feature and Send Ack Vector is an RX feature, `is_local' |
| * needs to be reversed. |
| */ |
| { /* Dependencies of the receiver-side (remote) CCID2 */ |
| { |
| .dependent_feat = DCCPF_SEND_ACK_VECTOR, |
| .is_local = true, |
| .is_mandatory = true, |
| .val = 1 |
| }, |
| { 0, 0, 0, 0 } |
| }, |
| { /* Dependencies of the sender-side (local) CCID2 */ |
| { |
| .dependent_feat = DCCPF_SEND_ACK_VECTOR, |
| .is_local = false, |
| .is_mandatory = true, |
| .val = 1 |
| }, |
| { 0, 0, 0, 0 } |
| } |
| }; |
| static const struct ccid_dependency ccid3_dependencies[2][5] = { |
| { /* |
| * Dependencies of the receiver-side CCID3 |
| */ |
| { /* locally disable Ack Vectors */ |
| .dependent_feat = DCCPF_SEND_ACK_VECTOR, |
| .is_local = true, |
| .is_mandatory = false, |
| .val = 0 |
| }, |
| { /* see below why Send Loss Event Rate is on */ |
| .dependent_feat = DCCPF_SEND_LEV_RATE, |
| .is_local = true, |
| .is_mandatory = true, |
| .val = 1 |
| }, |
| { /* NDP Count is needed as per RFC 4342, 6.1.1 */ |
| .dependent_feat = DCCPF_SEND_NDP_COUNT, |
| .is_local = false, |
| .is_mandatory = true, |
| .val = 1 |
| }, |
| { 0, 0, 0, 0 }, |
| }, |
| { /* |
| * CCID3 at the TX side: we request that the HC-receiver |
| * will not send Ack Vectors (they will be ignored, so |
| * Mandatory is not set); we enable Send Loss Event Rate |
| * (Mandatory since the implementation does not support |
| * the Loss Intervals option of RFC 4342, 8.6). |
| * The last two options are for peer's information only. |
| */ |
| { |
| .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; |
| } |
| |
| /** |
| * dccp_feat_server_ccid_dependencies - Resolve CCID-dependent features |
| * It is the server which resolves the dependencies once the CCID has been |
| * fully negotiated. If no CCID has been negotiated, it uses the default CCID. |
| */ |
| int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq) |
| { |
| struct list_head *fn = &dreq->dreq_featneg; |
| struct dccp_feat_entry *entry; |
| u8 is_local, ccid; |
| |
| for (is_local = 0; is_local <= 1; is_local++) { |
| entry = dccp_feat_list_lookup(fn, DCCPF_CCID, is_local); |
| |
| if (entry != NULL && !entry->empty_confirm) |
| ccid = entry->val.sp.vec[0]; |
| else |
| ccid = dccp_feat_default_value(DCCPF_CCID); |
| |
| if (dccp_feat_propagate_ccid(fn, ccid, is_local)) |
| return -1; |
| } |
| return 0; |
| } |
| |
| /* Select the first entry in @servlist that also occurs in @clilist (6.3.1) */ |
| static int dccp_feat_preflist_match(u8 *servlist, u8 slen, u8 *clilist, u8 clen) |
| { |
| u8 c, s; |
| |
| for (s = 0; s < slen; s++) |
| for (c = 0; c < clen; c++) |
| if (servlist[s] == clilist[c]) |
| return servlist[s]; |
| return -1; |
| } |
| |
| /** |
| * dccp_feat_prefer - Move preferred entry to the start of array |
| * Reorder the @array_len elements in @array so that @preferred_value comes |
| * first. Returns >0 to indicate that @preferred_value does occur in @array. |
| */ |
| static u8 dccp_feat_prefer(u8 preferred_value, u8 *array, u8 array_len) |
| { |
| u8 i, does_occur = 0; |
| |
| if (array != NULL) { |
| for (i = 0; i < array_len; i++) |
| if (array[i] == preferred_value) { |
| array[i] = array[0]; |
| does_occur++; |
| } |
| if (does_occur) |
| array[0] = preferred_value; |
| } |
| return does_occur; |
| } |
| |
| /** |
| * dccp_feat_reconcile - Reconcile SP preference lists |
| * @fval: SP list to reconcile into |
| * @arr: received SP preference list |
| * @len: length of @arr in bytes |
| * @is_server: whether this side is the server (and @fv is the server's list) |
| * @reorder: whether to reorder the list in @fv after reconciling with @arr |
| * When successful, > 0 is returned and the reconciled list is in @fval. |
| * A value of 0 means that negotiation failed (no shared entry). |
| */ |
| static int dccp_feat_reconcile(dccp_feat_val *fv, u8 *arr, u8 len, |
| bool is_server, bool reorder) |
| { |
| int rc; |
| |
| if (!fv->sp.vec || !arr) { |
| DCCP_CRIT("NULL feature value or array"); |
| return 0; |
| } |
| |
| if (is_server) |
| rc = dccp_feat_preflist_match(fv->sp.vec, fv->sp.len, arr, len); |
| else |
| rc = dccp_feat_preflist_match(arr, len, fv->sp.vec, fv->sp.len); |
| |
| if (!reorder) |
| return rc; |
| if (rc < 0) |
| return 0; |
| |
| /* |
| * Reorder list: used for activating features and in dccp_insert_fn_opt. |
| */ |
| return dccp_feat_prefer(rc, fv->sp.vec, fv->sp.len); |
| } |
| |
| /** |
| * dccp_feat_change_recv - Process incoming ChangeL/R options |
| * @fn: feature-negotiation list to update |
| * @is_mandatory: whether the Change was preceded by a Mandatory option |
| * @opt: %DCCPO_CHANGE_L or %DCCPO_CHANGE_R |
| * @feat: one of %dccp_feature_numbers |
| * @val: NN value or SP value/preference list |
| * @len: length of @val in bytes |
| * @server: whether this node is the server (1) or the client (0) |
| */ |
| static u8 dccp_feat_change_recv(struct list_head *fn, u8 is_mandatory, u8 opt, |
| u8 feat, u8 *val, u8 len, const bool server) |
| { |
| u8 defval, type = dccp_feat_type(feat); |
| const bool local = (opt == DCCPO_CHANGE_R); |
| struct dccp_feat_entry *entry; |
| dccp_feat_val fval; |
| |
| if (len == 0 || type == FEAT_UNKNOWN) /* 6.1 and 6.6.8 */ |
| goto unknown_feature_or_value; |
| |
| /* |
| * Negotiation of NN features: Change R is invalid, so there is no |
| * simultaneous negotiation; hence we do not look up in the list. |
| */ |
| if (type == FEAT_NN) { |
| if (local || len > sizeof(fval.nn)) |
| goto unknown_feature_or_value; |
| |
| /* 6.3.2: "The feature remote MUST accept any valid value..." */ |
| fval.nn = dccp_decode_value_var(val, len); |
| if (!dccp_feat_is_valid_nn_val(feat, fval.nn)) |
| goto unknown_feature_or_value; |
| |
| return dccp_feat_push_confirm(fn, feat, local, &fval); |
| } |
| |
| /* |
| * Unidirectional/simultaneous negotiation of SP features (6.3.1) |
| */ |
| entry = dccp_feat_list_lookup(fn, feat, local); |
| if (entry == NULL) { |
| /* |
| * No particular preferences have been registered. We deal with |
| * this situation by assuming that all valid values are equally |
| * acceptable, and apply the following checks: |
| * - if the peer's list is a singleton, we accept a valid value; |
| * - if we are the server, we first try to see if the peer (the |
| * client) advertises the default value. If yes, we use it, |
| * otherwise we accept the preferred value; |
| * - else if we are the client, we use the first list element. |
| */ |
| if (dccp_feat_clone_sp_val(&fval, val, 1)) |
| return DCCP_RESET_CODE_TOO_BUSY; |
| |
| if (len > 1 && server) { |
| defval = dccp_feat_default_value(feat); |
| if (dccp_feat_preflist_match(&defval, 1, val, len) > -1) |
| fval.sp.vec[0] = defval; |
| } else if (!dccp_feat_is_valid_sp_val(feat, fval.sp.vec[0])) { |
| kfree(fval.sp.vec); |
| goto unknown_feature_or_value; |
| } |
| |
| /* Treat unsupported CCIDs like invalid values */ |
| if (feat == DCCPF_CCID && !ccid_support_check(fval.sp.vec, 1)) { |
| kfree(fval.sp.vec); |
| goto not_valid_or_not_known; |
| } |
| |
| return dccp_feat_push_confirm(fn, feat, local, &fval); |
| |
| } else if (entry->state == FEAT_UNSTABLE) { /* 6.6.2 */ |
| return 0; |
| } |
| |
| if (dccp_feat_reconcile(&entry->val, val, len, server, true)) { |
| entry->empty_confirm = 0; |
| } else if (is_mandatory) { |
| return DCCP_RESET_CODE_MANDATORY_ERROR; |
| } else if (entry->state == FEAT_INITIALISING) { |
| /* |
| * Failed simultaneous negotiation (server only): try to `save' |
| * the connection by checking whether entry contains the default |
| * value for @feat. If yes, send an empty Confirm to signal that |
| * the received Change was not understood - which implies using |
| * the default value. |
| * If this also fails, we use Reset as the last resort. |
| */ |
| WARN_ON(!server); |
| defval = dccp_feat_default_value(feat); |
| if (!dccp_feat_reconcile(&entry->val, &defval, 1, server, true)) |
| return DCCP_RESET_CODE_OPTION_ERROR; |
| entry->empty_confirm = 1; |
| } |
| entry->needs_confirm = 1; |
| entry->needs_mandatory = 0; |
| entry->state = FEAT_STABLE; |
| return 0; |
| |
| unknown_feature_or_value: |
| if (!is_mandatory) |
| return dccp_push_empty_confirm(fn, feat, local); |
| |
| not_valid_or_not_known: |
| return is_mandatory ? DCCP_RESET_CODE_MANDATORY_ERROR |
| : DCCP_RESET_CODE_OPTION_ERROR; |
| } |
| |
| /** |
| * dccp_feat_confirm_recv - Process received Confirm options |
| * @fn: feature-negotiation list to update |
| * @is_mandatory: whether @opt was preceded by a Mandatory option |
| * @opt: %DCCPO_CONFIRM_L or %DCCPO_CONFIRM_R |
| * @feat: one of %dccp_feature_numbers |
| * @val: NN value or SP value/preference list |
| * @len: length of @val in bytes |
| * @server: whether this node is server (1) or client (0) |
| */ |
| static u8 dccp_feat_confirm_recv(struct list_head *fn, u8 is_mandatory, u8 opt, |
| u8 feat, u8 *val, u8 len, const bool server) |
| { |
| u8 *plist, plen, type = dccp_feat_type(feat); |
| const bool local = (opt == DCCPO_CONFIRM_R); |
| struct dccp_feat_entry *entry = dccp_feat_list_lookup(fn, feat, local); |
| |
| if (entry == NULL) { /* nothing queued: ignore or handle error */ |
| if (is_mandatory && type == FEAT_UNKNOWN) |
| return DCCP_RESET_CODE_MANDATORY_ERROR; |
| |
| if (!local && type == FEAT_NN) /* 6.3.2 */ |
| goto confirmation_failed; |
| return 0; |
| } |
| |
| if (entry->state != FEAT_CHANGING) /* 6.6.2 */ |
| return 0; |
| |
| if (len == 0) { |
| if (dccp_feat_must_be_understood(feat)) /* 6.6.7 */ |
| goto confirmation_failed; |
| /* |
| * Empty Confirm during connection setup: this means reverting |
| * to the `old' value, which in this case is the default. Since |
| * we handle default values automatically when no other values |
| * have been set, we revert to the old value by removing this |
| * entry from the list. |
| */ |
| dccp_feat_list_pop(entry); |
| return 0; |
| } |
| |
| if (type == FEAT_NN) { |
| if (len > sizeof(entry->val.nn)) |
| goto confirmation_failed; |
| |
| if (entry->val.nn == dccp_decode_value_var(val, len)) |
| goto confirmation_succeeded; |
| |
| DCCP_WARN("Bogus Confirm for non-existing value\n"); |
| goto confirmation_failed; |
| } |
| |
| /* |
| * Parsing SP Confirms: the first element of @val is the preferred |
| * SP value which the peer confirms, the remainder depends on @len. |
| * Note that only the confirmed value need to be a valid SP value. |
| */ |
| if (!dccp_feat_is_valid_sp_val(feat, *val)) |
| goto confirmation_failed; |
| |
| if (len == 1) { /* peer didn't supply a preference list */ |
| plist = val; |
| plen = len; |
| } else { /* preferred value + preference list */ |
| plist = val + 1; |
| plen = len - 1; |
| } |
| |
| /* Check whether the peer got the reconciliation right (6.6.8) */ |
| if (dccp_feat_reconcile(&entry->val, plist, plen, server, 0) != *val) { |
| DCCP_WARN("Confirm selected the wrong value %u\n", *val); |
| return DCCP_RESET_CODE_OPTION_ERROR; |
| } |
| entry->val.sp.vec[0] = *val; |
| |
| confirmation_succeeded: |
| entry->state = FEAT_STABLE; |
| return 0; |
| |
| confirmation_failed: |
| DCCP_WARN("Confirmation failed\n"); |
| return is_mandatory ? DCCP_RESET_CODE_MANDATORY_ERROR |
| : DCCP_RESET_CODE_OPTION_ERROR; |
| } |
| |
| /** |
| * dccp_feat_parse_options - Process Feature-Negotiation Options |
| * @sk: for general use and used by the client during connection setup |
| * @dreq: used by the server during connection setup |
| * @mandatory: whether @opt was preceded by a Mandatory option |
| * @opt: %DCCPO_CHANGE_L | %DCCPO_CHANGE_R | %DCCPO_CONFIRM_L | %DCCPO_CONFIRM_R |
| * @feat: one of %dccp_feature_numbers |
| * @val: value contents of @opt |
| * @len: length of @val in bytes |
| * Returns 0 on success, a Reset code for ending the connection otherwise. |
| */ |
| int dccp_feat_parse_options(struct sock *sk, struct dccp_request_sock *dreq, |
| u8 mandatory, u8 opt, u8 feat, u8 *val, u8 len) |
| { |
| struct dccp_sock *dp = dccp_sk(sk); |
| struct list_head *fn = dreq ? &dreq->dreq_featneg : &dp->dccps_featneg; |
| bool server = false; |
| |
| switch (sk->sk_state) { |
| /* |
| * Negotiation during connection setup |
| */ |
| case DCCP_LISTEN: |
| server = true; /* fall through */ |
| case DCCP_REQUESTING: |
| switch (opt) { |
| case DCCPO_CHANGE_L: |
| case DCCPO_CHANGE_R: |
| return dccp_feat_change_recv(fn, mandatory, opt, feat, |
| val, len, server); |
| case DCCPO_CONFIRM_R: |
| case DCCPO_CONFIRM_L: |
| return dccp_feat_confirm_recv(fn, mandatory, opt, feat, |
| val, len, server); |
| } |
| } |
| return 0; /* ignore FN options in all other states */ |
| } |
| |
| 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 */ |
| |
| /* Ack ratio */ |
| rc = __feat_register_nn(&dp->dccps_featneg, DCCPF_ACK_RATIO, 0, |
| dp->dccps_l_ack_ratio); |
| return rc; |
| } |
| |
| 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) |
| { |
| 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 */ |