/*
* net/dccp/feat.c
*
- * An implementation of the DCCP protocol
- * Andrea Bittau <a.bittau@cs.ucl.ac.uk>
+ * 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
* -----------
* 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"
-#define DCCP_FEAT_SP_NOAGREE (-123)
+/* 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;
/*
* Feature activation handlers.
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());
+ struct ccid *new_ccid = ccid_new(ccid, sk, rx);
if (new_ccid == NULL)
return -ENOMEM;
static int dccp_hdlr_seq_win(struct sock *sk, u64 seq_win, bool rx)
{
- if (!rx)
- dccp_msk(sk)->dccpms_sequence_window = seq_win;
+ struct dccp_sock *dp = dccp_sk(sk);
+
+ 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;
}
static int dccp_hdlr_ndp(struct sock *sk, u64 enable, bool rx)
{
if (!rx)
- dccp_msk(sk)->dccpms_send_ndp_count = (enable > 0);
+ dccp_sk(sk)->dccps_send_ndp_count = (enable > 0);
return 0;
}
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;
+}
+
+/*
+ * 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];
- return idx < 0 ? : dccp_feat_table[idx].default_value;
+ 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";
+ }
+ 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);
+}
+
+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)" : "");
+}
+
+#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
+
static int __dccp_feat_activate(struct sock *sk, const int idx,
const bool is_local, dccp_feat_val const *fval)
{
/* 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);
}
{
struct dccp_feat_entry *entry;
- list_for_each_entry(entry, fn_list, node)
+ 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 -1;
}
}
+ 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;
while (i--)
if (ccids[i] > 0 && dccp_feat_propagate_ccid(fn, ccids[i], i))
return -1;
+ dccp_feat_print_fnlist(fn);
return 0;
}
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;
-}
-
/* 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)
{
return dccp_feat_prefer(rc, fv->sp.vec, fv->sp.len);
}
-#ifdef __this_is_the_old_framework_and_will_be_removed_later_in_a_subsequent_patch
-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:
- /* XXX Obsoleted by next patch
- rc = dccp_feat_sp(sk, type, feature, val, len); */
- break;
-
- /* deal with NN features */
- case DCCPF_ACK_RATIO:
- /* XXX Obsoleted by next patch
- 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);
-#endif /* (later) */
-
-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);
-
/**
* dccp_feat_change_recv - Process incoming ChangeL/R options
* @fn: feature-negotiation list to update
if (len == 0 || type == FEAT_UNKNOWN) /* 6.1 and 6.6.8 */
goto unknown_feature_or_value;
+ dccp_feat_print_opt(opt, feat, val, len, is_mandatory);
+
/*
* Negotiation of NN features: Change R is invalid, so there is no
* simultaneous negotiation; hence we do not look up in the list.
const bool local = (opt == DCCPO_CONFIRM_R);
struct dccp_feat_entry *entry = dccp_feat_list_lookup(fn, feat, local);
+ dccp_feat_print_opt(opt, feat, val, len, is_mandatory);
+
if (entry == NULL) { /* nothing queued: ignore or handle error */
if (is_mandatory && type == FEAT_UNKNOWN)
return DCCP_RESET_CODE_MANDATORY_ERROR;
return 0; /* ignore FN options in all other states */
}
+/**
+ * dccp_feat_init - Seed feature negotiation with host-specific defaults
+ * This initialises global defaults, depending on the value of the sysctls.
+ * These can later be overridden by registering changes via setsockopt calls.
+ * The last link in the chain is finalise_settings, to make sure that between
+ * here and the start of actual feature negotiation no inconsistencies enter.
+ *
+ * All features not appearing below use either defaults or are otherwise
+ * later adjusted through dccp_feat_finalise_settings().
+ */
int dccp_feat_init(struct sock *sk)
{
- struct dccp_sock *dp = dccp_sk(sk);
- struct dccp_minisock *dmsk = dccp_msk(sk);
+ struct list_head *fn = &dccp_sk(sk)->dccps_featneg;
+ u8 on = 1, off = 0;
int rc;
+ struct {
+ u8 *val;
+ u8 len;
+ } tx, rx;
+
+ /* Non-negotiable (NN) features */
+ rc = __feat_register_nn(fn, DCCPF_SEQUENCE_WINDOW, 0,
+ sysctl_dccp_sequence_window);
+ if (rc)
+ return rc;
- INIT_LIST_HEAD(&dmsk->dccpms_pending); /* XXX no longer used */
- INIT_LIST_HEAD(&dmsk->dccpms_conf); /* XXX no longer used */
+ /* Server-priority (SP) features */
- /* CCID L */
- rc = __feat_register_sp(&dp->dccps_featneg, DCCPF_CCID, 1, 0,
- &dmsk->dccpms_tx_ccid, 1);
+ /* Advertise that short seqnos are not supported (7.6.1) */
+ rc = __feat_register_sp(fn, DCCPF_SHORT_SEQNOS, true, true, &off, 1);
if (rc)
- goto out;
+ return rc;
+
+ /* RFC 4340 12.1: "If a DCCP is not ECN capable, ..." */
+ rc = __feat_register_sp(fn, DCCPF_ECN_INCAPABLE, true, true, &on, 1);
+ if (rc)
+ return rc;
+
+ /*
+ * We advertise the available list of CCIDs and reorder according to
+ * preferences, to avoid failure resulting from negotiating different
+ * singleton values (which always leads to failure).
+ * These settings can still (later) be overridden via sockopts.
+ */
+ if (ccid_get_builtin_ccids(&tx.val, &tx.len) ||
+ ccid_get_builtin_ccids(&rx.val, &rx.len))
+ return -ENOBUFS;
+
+ if (!dccp_feat_prefer(sysctl_dccp_tx_ccid, tx.val, tx.len) ||
+ !dccp_feat_prefer(sysctl_dccp_rx_ccid, rx.val, rx.len))
+ goto free_ccid_lists;
- /* CCID R */
- rc = __feat_register_sp(&dp->dccps_featneg, DCCPF_CCID, 0, 0,
- &dmsk->dccpms_rx_ccid, 1);
+ rc = __feat_register_sp(fn, DCCPF_CCID, true, false, tx.val, tx.len);
if (rc)
- goto out;
+ goto free_ccid_lists;
- /* Ack ratio */
- rc = __feat_register_nn(&dp->dccps_featneg, DCCPF_ACK_RATIO, 0,
- dp->dccps_l_ack_ratio);
-out:
+ rc = __feat_register_sp(fn, DCCPF_CCID, false, false, rx.val, rx.len);
+
+free_ccid_lists:
+ kfree(tx.val);
+ kfree(rx.val);
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);
goto activation_failed;
}
if (cur->state != FEAT_STABLE) {
- DCCP_CRIT("Negotiation of %s %u failed in state %u",
+ DCCP_CRIT("Negotiation of %s %s failed in state %s",
cur->is_local ? "local" : "remote",
- cur->feat_num, cur->state);
+ dccp_feat_fname(cur->feat_num),
+ dccp_feat_sname[cur->state]);
goto activation_failed;
}
fvals[idx][cur->is_local] = &cur->val;
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 */
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff