dccp: Clean up old feature-negotiation infrastructure (23479cbf) · Commits · e / devices / android_kernel_fairphone_FP3

net/dccp/feat.c

+7 −498

Original line number	Diff line number	Diff line
		/*
		* 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

net/dccp/feat.h

+5 −7

Original line number	Diff line number	Diff line
		@@ -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.
		*/

		#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);