diff options
| -rw-r--r-- | net/dccp/feat.c | 505 | ||||
| -rw-r--r-- | net/dccp/feat.h | 12 |
2 files changed, 12 insertions, 505 deletions
diff --git a/net/dccp/feat.c b/net/dccp/feat.c index f78bd357b5b..6c82dea409d 100644 --- a/net/dccp/feat.c +++ b/net/dccp/feat.c @@ -1,8 +1,13 @@ /* * 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 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> + * * * ASSUMPTIONS * ----------- @@ -17,14 +22,10 @@ * 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 activation handlers. * @@ -805,51 +806,6 @@ int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq) 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) { @@ -919,453 +875,6 @@ static int dccp_feat_reconcile(dccp_feat_val *fv, u8 *arr, u8 len, 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 diff --git a/net/dccp/feat.h b/net/dccp/feat.h index 618bed935b3..177e9c39ea9 100644 --- a/net/dccp/feat.h +++ b/net/dccp/feat.h @@ -3,14 +3,14 @@ /* * net/dccp/feat.h * - * An implementation of the DCCP protocol + * Feature negotiation for the DCCP protocol (RFC 4340, section 6) + * Copyright (c) 2008 Gerrit Renker <gerrit@erg.abdn.ac.uk> * Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk> * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. */ - #include <linux/types.h> #include "dccp.h" @@ -117,8 +117,6 @@ extern int dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local, extern int dccp_feat_register_nn(struct sock *sk, u8 feat, u64 val); extern int dccp_feat_parse_options(struct sock *, struct dccp_request_sock *, u8 mand, u8 opt, u8 feat, u8 *val, u8 len); -extern void dccp_feat_clean(struct dccp_minisock *dmsk); -extern int dccp_feat_clone(struct sock *oldsk, struct sock *newsk); extern int dccp_feat_clone_list(struct list_head const *, struct list_head *); extern int dccp_feat_init(struct sock *sk); |