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-rw-r--r--net/dccp/feat.c1805
1 files changed, 461 insertions, 1344 deletions
diff --git a/net/dccp/feat.c b/net/dccp/feat.c
index f94c7c9d1a7..933a0ecf8d4 100644
--- a/net/dccp/feat.c
+++ b/net/dccp/feat.c
@@ -1,19 +1,11 @@
/*
* net/dccp/feat.c
*
- * Feature negotiation for the DCCP protocol (RFC 4340, section 6)
- *
- * Copyright (c) 2008 The University of Aberdeen, Scotland, UK
- * 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>
- *
+ * An implementation of the DCCP protocol
+ * 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 Changing NN values (Ack Ratio only) is supported in state OPEN/PARTOPEN.
* 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.
@@ -23,1510 +15,635 @@
* 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-specific sysctls - initialised to the defaults from RFC 4340, 6.4 */
-unsigned long sysctl_dccp_sequence_window __read_mostly = 100;
-int sysctl_dccp_rx_ccid __read_mostly = 2,
- sysctl_dccp_tx_ccid __read_mostly = 2;
+#define DCCP_FEAT_SP_NOAGREE (-123)
-/*
- * Feature activation handlers.
- *
- * These all use an u64 argument, to provide enough room for NN/SP features. At
- * this stage the negotiated values have been checked to be within their range.
- */
-static int dccp_hdlr_ccid(struct sock *sk, u64 ccid, bool rx)
+int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
+ u8 *val, u8 len, gfp_t gfp)
{
- struct dccp_sock *dp = dccp_sk(sk);
- struct ccid *new_ccid = ccid_new(ccid, sk, rx, gfp_any());
+ struct dccp_opt_pend *opt;
- if (new_ccid == NULL)
- return -ENOMEM;
+ dccp_feat_debug(type, feature, *val);
- 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;
+ if (len > 3) {
+ DCCP_WARN("invalid length %d\n", len);
+ return -EINVAL;
+ }
+ /* XXX add further sanity checks */
+
+ /* check if that feature is already being negotiated */
+ list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
+ /* ok we found a negotiation for this option already */
+ if (opt->dccpop_feat == feature && opt->dccpop_type == type) {
+ dccp_pr_debug("Replacing old\n");
+ /* replace */
+ BUG_ON(opt->dccpop_val == NULL);
+ kfree(opt->dccpop_val);
+ opt->dccpop_val = val;
+ opt->dccpop_len = len;
+ opt->dccpop_conf = 0;
+ return 0;
+ }
}
- return 0;
-}
-static int dccp_hdlr_seq_win(struct sock *sk, u64 seq_win, bool rx)
-{
- struct dccp_sock *dp = dccp_sk(sk);
+ /* negotiation for a new feature */
+ opt = kmalloc(sizeof(*opt), gfp);
+ if (opt == NULL)
+ return -ENOMEM;
- if (rx) {
- dp->dccps_r_seq_win = seq_win;
- /* propagate changes to update SWL/SWH */
- dccp_update_gsr(sk, dp->dccps_gsr);
- } else {
- dp->dccps_l_seq_win = seq_win;
- /* propagate changes to update AWL */
- dccp_update_gss(sk, dp->dccps_gss);
- }
- return 0;
-}
+ opt->dccpop_type = type;
+ opt->dccpop_feat = feature;
+ opt->dccpop_len = len;
+ opt->dccpop_val = val;
+ opt->dccpop_conf = 0;
+ opt->dccpop_sc = NULL;
-static int dccp_hdlr_ack_ratio(struct sock *sk, u64 ratio, bool rx)
-{
-#ifndef __CCID2_COPES_GRACEFULLY_WITH_DYNAMIC_ACK_RATIO_UPDATES__
- /*
- * FIXME: This is required until several problems in the CCID-2 code are
- * resolved. The CCID-2 code currently does not cope well; using dynamic
- * Ack Ratios greater than 1 caused instabilities. These were manifest
- * in hangups and long RTO timeouts (1...3 seconds). Until this has been
- * stabilised, it is safer not to activate dynamic Ack Ratio changes.
- */
- dccp_pr_debug("Not changing %s Ack Ratio from 1 to %u\n",
- rx ? "RX" : "TX", (u16)ratio);
- ratio = 1;
-#endif
- if (rx)
- dccp_sk(sk)->dccps_r_ack_ratio = ratio;
- else
- dccp_sk(sk)->dccps_l_ack_ratio = ratio;
+ BUG_ON(opt->dccpop_val == NULL);
+
+ list_add_tail(&opt->dccpop_node, &dmsk->dccpms_pending);
return 0;
}
-static int dccp_hdlr_ackvec(struct sock *sk, u64 enable, bool rx)
+EXPORT_SYMBOL_GPL(dccp_feat_change);
+
+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) {
- 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;
- }
+ 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_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)
+static int dccp_feat_update(struct sock *sk, u8 type, u8 feat, u8 val)
{
- struct dccp_sock *dp = dccp_sk(sk);
+ dccp_feat_debug(type, feat, val);
- 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);
+ 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 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)
+static int dccp_feat_reconcile(struct sock *sk, struct dccp_opt_pend *opt,
+ u8 *rpref, u8 rlen)
{
- /* 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;
+ 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;
+ }
/*
- * Other features: add cases for new feature types here after adding
- * them to the above table.
+ * Now we have server preference list in spref and client preference in
+ * rpref
*/
- 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;
-}
+ BUG_ON(spref == NULL);
+ BUG_ON(rpref == NULL);
-static int dccp_feat_default_value(u8 feat_num)
-{
- int idx = dccp_feat_index(feat_num);
+ /* FIXME sanity check vals */
- return idx < 0 ? : dccp_feat_table[idx].default_value;
-}
-
-/*
- * Debugging and verbose-printing section
- */
-static const char *dccp_feat_fname(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];
-}
-
-static const char *dccp_feat_sname[] = { "DEFAULT", "INITIALISING", "CHANGING",
- "UNSTABLE", "STABLE" };
-
-#ifdef CONFIG_IP_DCCP_DEBUG
-static const char *dccp_feat_oname(const u8 opt)
-{
- switch (opt) {
- case DCCPO_CHANGE_L: return "Change_L";
- case DCCPO_CONFIRM_L: return "Confirm_L";
- case DCCPO_CHANGE_R: return "Change_R";
- case DCCPO_CONFIRM_R: return "Confirm_R";
+ /* 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;
}
- return NULL;
-}
-static void dccp_feat_printval(u8 feat_num, dccp_feat_val const *val)
-{
- u8 i, type = dccp_feat_type(feat_num);
-
- if (val == NULL || (type == FEAT_SP && val->sp.vec == NULL))
- dccp_pr_debug_cat("(NULL)");
- else if (type == FEAT_SP)
- for (i = 0; i < val->sp.len; i++)
- dccp_pr_debug_cat("%s%u", i ? " " : "", val->sp.vec[i]);
- else if (type == FEAT_NN)
- dccp_pr_debug_cat("%llu", (unsigned long long)val->nn);
- else
- dccp_pr_debug_cat("unknown type %u", type);
-}
-
-static void dccp_feat_printvals(u8 feat_num, u8 *list, u8 len)
-{
- u8 type = dccp_feat_type(feat_num);
- dccp_feat_val fval = { .sp.vec = list, .sp.len = len };
-
- if (type == FEAT_NN)
- fval.nn = dccp_decode_value_var(list, len);
- dccp_feat_printval(feat_num, &fval);
-}
+ /* 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;
-static void dccp_feat_print_entry(struct dccp_feat_entry const *entry)
-{
- dccp_debug(" * %s %s = ", entry->is_local ? "local" : "remote",
- dccp_feat_fname(entry->feat_num));
- dccp_feat_printval(entry->feat_num, &entry->val);
- dccp_pr_debug_cat(", state=%s %s\n", dccp_feat_sname[entry->state],
- entry->needs_confirm ? "(Confirm pending)" : "");
-}
+ default:
+ DCCP_BUG("Fell through, feat=%d", opt->dccpop_feat);
+ /* XXX implement res */
+ return -EFAULT;
+ }
-#define dccp_feat_print_opt(opt, feat, val, len, mandatory) do { \
- dccp_pr_debug("%s(%s, ", dccp_feat_oname(opt), dccp_feat_fname(feat));\
- dccp_feat_printvals(feat, val, len); \
- dccp_pr_debug_cat(") %s\n", mandatory ? "!" : ""); } while (0)
-
-#define dccp_feat_print_fnlist(fn_list) { \
- const struct dccp_feat_entry *___entry; \
- \
- dccp_pr_debug("List Dump:\n"); \
- list_for_each_entry(___entry, fn_list, node) \
- dccp_feat_print_entry(___entry); \
-}
-#else /* ! CONFIG_IP_DCCP_DEBUG */
-#define dccp_feat_print_opt(opt, feat, val, len, mandatory)
-#define dccp_feat_print_fnlist(fn_list)
-#endif
+ dccp_pr_debug("Don't agree... reconfirming %d\n", *res);
+ agree = 0; /* this is used for mandatory options... */
+ }
-static int __dccp_feat_activate(struct sock *sk, const int idx,
- const bool is_local, dccp_feat_val const *fval)
-{
- bool rx;
- u64 val;
+ /* need to put result and our preference list */
+ rlen = 1 + opt->dccpop_len;
+ rpref = kmalloc(rlen, GFP_ATOMIC);
+ if (rpref == NULL)
+ return -ENOMEM;
- if (idx < 0 || idx >= DCCP_FEAT_SUPPORTED_MAX)
- return -1;
- if (dccp_feat_table[idx].activation_hdlr == NULL)
- return 0;
+ *rpref = *res;
+ memcpy(&rpref[1], opt->dccpop_val, opt->dccpop_len);
- 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];
+ /* 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 {
- val = fval->nn;
+ /* 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;
}
- /* Location is RX if this is a local-RX or remote-TX feature */
- rx = (is_local == (dccp_feat_table[idx].rxtx == FEAT_AT_RX));
-
- dccp_debug(" -> activating %s %s, %sval=%llu\n", rx ? "RX" : "TX",
- dccp_feat_fname(dccp_feat_table[idx].feat_num),
- fval ? "" : "default ", (unsigned long long)val);
-
- return dccp_feat_table[idx].activation_hdlr(sk, val, rx);
-}
-
-/**
- * dccp_feat_activate - Activate feature value on socket
- * @sk: fully connected DCCP socket (after handshake is complete)
- * @feat_num: feature to activate, one of %dccp_feature_numbers
- * @local: whether local (1) or remote (0) @feat_num is meant
- * @fval: the value (SP or NN) to activate, or NULL to use the default value
- * For general use this function is preferable over __dccp_feat_activate().
- */
-static int dccp_feat_activate(struct sock *sk, u8 feat_num, bool local,
- dccp_feat_val const *fval)
-{
- return __dccp_feat_activate(sk, dccp_feat_index(feat_num), local, fval);
-}
-
-/* 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;
-}
+ dccp_pr_debug("Will confirm %d\n", *rpref);
-/* 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;
- }
+ /* 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 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));
+ return agree ? 0 : DCCP_FEAT_SP_NOAGREE; /* used for mandatory opts */
}
-static struct dccp_feat_entry *
- dccp_feat_clone_entry(struct dccp_feat_entry const *original)
+static int dccp_feat_sp(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len)
{
- struct dccp_feat_entry *new;
- u8 type = dccp_feat_type(original->feat_num);
-
- if (type == FEAT_UNKNOWN)
- return NULL;
+ struct dccp_minisock *dmsk = dccp_msk(sk);
+ struct dccp_opt_pend *opt;
+ int rc = 1;
+ u8 t;
- new = kmemdup(original, sizeof(struct dccp_feat_entry), gfp_any());
- if (new == NULL)
- return NULL;
+ /*
+ * 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;
- 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;
-}
+ /* 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;
-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);
+ /* find the winner from the two preference lists */
+ rc = dccp_feat_reconcile(sk, opt, val, len);
+ break;
}
-}
-/*
- * 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;
+ /* 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);
- 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;
+ return rc;
}
-/**
- * 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)
+static int dccp_feat_nn(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len)
{
- 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;
- }
+ struct dccp_opt_pend *opt;
+ struct dccp_minisock *dmsk = dccp_msk(sk);
+ u8 *copy;
+ int rc;
- entry = kmalloc(sizeof(*entry), gfp_any());
- if (entry != NULL) {
- entry->feat_num = feat;
- entry->is_local = local;
- list_add_tail(&entry->node, head);
+ /* 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;
}
- 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);
+ /* XXX sanity check opt val */
- if (new == NULL)
+ /* copy option so we can confirm it */
+ opt = kzalloc(sizeof(*opt), GFP_ATOMIC);
+ if (opt == 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;
+ copy = kmemdup(val, len, GFP_ATOMIC);
+ if (copy == NULL) {
+ kfree(opt);
+ return -ENOMEM;
+ }
- return 0;
-}
+ opt->dccpop_type = DCCPO_CONFIRM_R; /* NN can only confirm R */
+ opt->dccpop_feat = feature;
+ opt->dccpop_val = copy;
+ opt->dccpop_len = len;
-/**
- * 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);
+ /* change feature */
+ rc = dccp_feat_update(sk, type, feature, *val);
+ if (rc) {
+ kfree(opt->dccpop_val);
+ kfree(opt);
+ return rc;
+ }
- if (new == NULL)
- return DCCP_RESET_CODE_TOO_BUSY;
+ dccp_feat_debug(type, feature, *copy);
- 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;
+ list_add_tail(&opt->dccpop_node, &dmsk->dccpms_conf);
return 0;
}
-static int dccp_push_empty_confirm(struct list_head *fn_list, u8 feat, u8 local)
+static void dccp_feat_empty_confirm(struct dccp_minisock *dmsk,
+ u8 type, u8 feature)
{
- return dccp_feat_push_confirm(fn_list, feat, local, NULL);
-}
+ /* XXX check if other confirms for that are queued and recycle slot */
+ struct dccp_opt_pend *opt = kzalloc(sizeof(*opt), GFP_ATOMIC);
-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);
+ if (opt == NULL) {
+ /* XXX what do we do? Ignoring should be fine. It's a change
+ * after all =P
+ */
+ return;
}
- return 0;
-cloning_failed:
- dccp_feat_list_purge(to);
- return -ENOMEM;
-}
+ 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;
-/**
- * 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;
-}
+ /* change feature */
+ dccp_pr_debug("Empty %s(%d)\n", dccp_feat_typename(type), feature);
-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 */
+ list_add_tail(&opt->dccpop_node, &dmsk->dccpms_conf);
}
-/* 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)
+static void dccp_feat_flush_confirm(struct sock *sk)
{
- 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 */
-}
+ 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);
-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;
-}
+ if (!yes) {
+ struct dccp_opt_pend *opt;
-/**
- * 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;
+ list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
+ if (opt->dccpop_conf) {
+ yes = 1;
+ break;
}
}
- dccp_feat_print_opt(opt, pos->feat_num, ptr, len, 0);
-
- 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;
+ if (!yes)
+ return;
- return dccp_feat_push_change(fn, feat, is_local, mandatory, &fval);
+ /* 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);
}
-/**
- * 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)
+int dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature, u8 *val, 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_NN)
- return -EINVAL;
- return __feat_register_nn(&dccp_sk(sk)->dccps_featneg, feat, 0, val);
-}
+ int rc;
-/**
- * dccp_feat_signal_nn_change - Update NN values for an established connection
- * @sk: DCCP socket of an established connection
- * @feat: NN feature number from %dccp_feature_numbers
- * @nn_val: the new value to use
- * This function is used to communicate NN updates out-of-band. The difference
- * to feature negotiation during connection setup is that values are activated
- * immediately after validation, i.e. we don't wait for the Confirm: either the
- * value is accepted by the peer (and then the waiting is futile), or it is not
- * (Reset or empty Confirm). We don't accept empty Confirms - transmitted values
- * are validated, and the peer "MUST accept any valid value" (RFC 4340, 6.3.2).
- */
-int dccp_feat_signal_nn_change(struct sock *sk, u8 feat, u64 nn_val)
-{
- struct list_head *fn = &dccp_sk(sk)->dccps_featneg;
- dccp_feat_val fval = { .nn = nn_val };
- struct dccp_feat_entry *entry;
+ dccp_feat_debug(type, feature, *val);
- if (sk->sk_state != DCCP_OPEN && sk->sk_state != DCCP_PARTOPEN)
- return 0;
+ /* 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;
- if (dccp_feat_type(feat) != FEAT_NN ||
- !dccp_feat_is_valid_nn_val(feat, nn_val))
- return -EINVAL;
+ /* deal with NN features */
+ case DCCPF_ACK_RATIO:
+ rc = dccp_feat_nn(sk, type, feature, val, len);
+ break;
- entry = dccp_feat_list_lookup(fn, feat, 1);
- if (entry != NULL) {
- dccp_pr_debug("Ignoring %llu, entry %llu exists in state %s\n",
- (unsigned long long)nn_val,
- (unsigned long long)entry->val.nn,
- dccp_feat_sname[entry->state]);
- return 0;
+ /* XXX implement other features */
+ default:
+ dccp_pr_debug("UNIMPLEMENTED: not handling %s(%d, ...)\n",
+ dccp_feat_typename(type), feature);
+ rc = -EFAULT;
+ break;
}
- if (dccp_feat_activate(sk, feat, 1, &fval))
- return -EADV;
-