Commit afe00251 authored by Andrea Bittau's avatar Andrea Bittau Committed by David S. Miller
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[DCCP]: Initial feature negotiation implementation



Still needs more work, but boots and doesn't crashes, even
does some negotiation!

18:38:52.174934  127.0.0.1.43458 > 127.0.0.1.5001: request <change_l ack_ratio 2, change_r ccid 2, change_l ccid 2>
18:38:52.218526  127.0.0.1.5001 > 127.0.0.1.43458: response <nop, nop, change_l ack_ratio 2, confirm_r ccid 2 2, confirm_l ccid 2 2, confirm_r ack_ratio 2>
18:38:52.185398  127.0.0.1.43458 > 127.0.0.1.5001: <nop, confirm_r ack_ratio 2, ack_vector0 0x00, elapsed_time 212>

:-)
Signed-off-by: default avatarAndrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2a91aa39
......@@ -154,6 +154,10 @@ enum {
DCCPO_MANDATORY = 1,
DCCPO_MIN_RESERVED = 3,
DCCPO_MAX_RESERVED = 31,
DCCPO_CHANGE_L = 32,
DCCPO_CONFIRM_L = 33,
DCCPO_CHANGE_R = 34,
DCCPO_CONFIRM_R = 35,
DCCPO_NDP_COUNT = 37,
DCCPO_ACK_VECTOR_0 = 38,
DCCPO_ACK_VECTOR_1 = 39,
......@@ -168,7 +172,9 @@ enum {
/* DCCP features */
enum {
DCCPF_RESERVED = 0,
DCCPF_CCID = 1,
DCCPF_SEQUENCE_WINDOW = 3,
DCCPF_ACK_RATIO = 5,
DCCPF_SEND_ACK_VECTOR = 6,
DCCPF_SEND_NDP_COUNT = 7,
/* 10-127 reserved */
......@@ -176,9 +182,18 @@ enum {
DCCPF_MAX_CCID_SPECIFIC = 255,
};
/* this structure is argument to DCCP_SOCKOPT_CHANGE_X */
struct dccp_so_feat {
__u8 dccpsf_feat;
__u8 *dccpsf_val;
__u8 dccpsf_len;
};
/* DCCP socket options */
#define DCCP_SOCKOPT_PACKET_SIZE 1
#define DCCP_SOCKOPT_SERVICE 2
#define DCCP_SOCKOPT_CHANGE_L 3
#define DCCP_SOCKOPT_CHANGE_R 4
#define DCCP_SOCKOPT_CCID_RX_INFO 128
#define DCCP_SOCKOPT_CCID_TX_INFO 192
......@@ -314,8 +329,8 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
/* initial values for each feature */
#define DCCPF_INITIAL_SEQUENCE_WINDOW 100
/* FIXME: for now we're using CCID 2 (TCP-Like) */
#define DCCPF_INITIAL_CCID 2
#define DCCPF_INITIAL_ACK_RATIO 2
#define DCCPF_INITIAL_SEND_ACK_VECTOR 1
/* FIXME: for now we're default to 1 but it should really be 0 */
#define DCCPF_INITIAL_SEND_NDP_COUNT 1
......@@ -335,6 +350,24 @@ struct dccp_options {
__u8 dccpo_tx_ccid;
__u8 dccpo_send_ack_vector;
__u8 dccpo_send_ndp_count;
__u8 dccpo_ack_ratio;
struct list_head dccpo_pending;
struct list_head dccpo_conf;
};
struct dccp_opt_conf {
__u8 *dccpoc_val;
__u8 dccpoc_len;
};
struct dccp_opt_pend {
struct list_head dccpop_node;
__u8 dccpop_type;
__u8 dccpop_feat;
__u8 *dccpop_val;
__u8 dccpop_len;
int dccpop_conf;
struct dccp_opt_conf *dccpop_sc;
};
extern void __dccp_options_init(struct dccp_options *dccpo);
......
......@@ -4,7 +4,7 @@ dccp_ipv6-y := ipv6.o
obj-$(CONFIG_IP_DCCP) += dccp.o
dccp-y := ccid.o input.o ipv4.o minisocks.o options.o output.o proto.o \
dccp-y := ccid.o feat.o input.o ipv4.o minisocks.o options.o output.o proto.o \
timer.o
dccp-$(CONFIG_IP_DCCP_ACKVEC) += ackvec.o
......
/*
* net/dccp/feat.c
*
* An implementation of the DCCP protocol
* 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
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/config.h>
#include <linux/module.h>
#include "dccp.h"
#include "feat.h"
#define DCCP_FEAT_SP_NOAGREE (-123)
int dccp_feat_change(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len,
gfp_t gfp)
{
struct dccp_sock *dp = dccp_sk(sk);
struct dccp_opt_pend *opt;
dccp_pr_debug("feat change type=%d feat=%d\n", type, feature);
/* check if that feature is already being negotiated */
list_for_each_entry(opt, &dp->dccps_options.dccpo_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;
}
}
/* negotiation for a new feature */
opt = kmalloc(sizeof(*opt), gfp);
if (opt == NULL)
return -ENOMEM;
opt->dccpop_type = type;
opt->dccpop_feat = feature;
opt->dccpop_len = len;
opt->dccpop_val = val;
opt->dccpop_conf = 0;
opt->dccpop_sc = NULL;
BUG_ON(opt->dccpop_val == NULL);
list_add_tail(&opt->dccpop_node, &dp->dccps_options.dccpo_pending);
return 0;
}
EXPORT_SYMBOL_GPL(dccp_feat_change);
/* XXX taking only u8 vals */
static int dccp_feat_update(struct sock *sk, u8 type, u8 feat, u8 val)
{
/* FIXME implement */
dccp_pr_debug("changing [%d] feat %d to %d\n", type, feat, val);
return 0;
}
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 */
/* XXX assume values are 1 byte */
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 = &dp->dccps_options.dccpo_tx_ccid;
else
res = &dp->dccps_options.dccpo_rx_ccid;
break;
default:
WARN_ON(1); /* 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 */
/* XXX assume 1 byte vals */
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 = 0;
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_sock *dp = dccp_sk(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, &dp->dccps_options.dccpo_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_sock *dp = dccp_sk(sk);
u8 *copy;
int rc;
/* NN features must be change L */
if (type == DCCPO_CHANGE_R) {
dccp_pr_debug("received CHANGE_R %d for NN feat %d\n",
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 = kmalloc(len, GFP_ATOMIC);
if (copy == NULL) {
kfree(opt);
return -ENOMEM;
}
memcpy(copy, val, len);
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_pr_debug("Confirming NN feature %d (val=%d)\n", feature, *copy);
list_add_tail(&opt->dccpop_node, &dp->dccps_options.dccpo_conf);
return 0;
}
static void dccp_feat_empty_confirm(struct sock *sk, u8 type, u8 feature)
{
struct dccp_sock *dp = dccp_sk(sk);
/* 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;
}
opt->dccpop_type = type == DCCPO_CHANGE_L ? DCCPO_CONFIRM_R :
DCCPO_CONFIRM_L;
opt->dccpop_feat = feature;
opt->dccpop_val = 0;
opt->dccpop_len = 0;
/* change feature */
dccp_pr_debug("Empty confirm feature %d type %d\n", feature, type);
list_add_tail(&opt->dccpop_node, &dp->dccps_options.dccpo_conf);
}
static void dccp_feat_flush_confirm(struct sock *sk)
{
struct dccp_sock *dp = dccp_sk(sk);
/* Check if there is anything to confirm in the first place */
int yes = !list_empty(&dp->dccps_options.dccpo_conf);
if (!yes) {
struct dccp_opt_pend *opt;
list_for_each_entry(opt, &dp->dccps_options.dccpo_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;
dccp_pr_debug("got feat change type=%d feat=%d\n", type, feature);
/* 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;
/* deal with NN features */
case DCCPF_ACK_RATIO:
rc = dccp_feat_nn(sk, type, feature, val, len);
break;
/* XXX implement other features */
default:
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(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_sock *dp = dccp_sk(sk);
int rc = 1;
int all_confirmed = 1;
dccp_pr_debug("got feat confirm type=%d feat=%d\n", type, feature);
/* XXX sanity check type & feat */
/* locate our change request */
t = type == DCCPO_CONFIRM_L ? DCCPO_CHANGE_R : DCCPO_CHANGE_L;
list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
dccpop_node) {
if (!opt->dccpop_conf && opt->dccpop_type == t &&
opt->dccpop_feat == feature) {
/* we found it */
/* 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);
dccp_pr_debug("feat %d type %d confirmed %d\n",
feature, type, *val);
rc = 0;
break;
}
if (!opt->dccpop_conf)
all_confirmed = 0;
}
/* fix re-transmit timer */
/* XXX gotta make sure that no option negotiation occurs during
* connection shutdown. Consider that the CLOSEREQ is sent and timer is
* on. if all options are confirmed it might kill timer which should
* remain alive until close is received.
*/
if (all_confirmed) {
dccp_pr_debug("clear feat negotiation timer %p\n", sk);
inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
}
if (rc)
dccp_pr_debug("feat %d type %d never requested\n",
feature, type);
return 0;
}
EXPORT_SYMBOL_GPL(dccp_feat_confirm_recv);
void dccp_feat_clean(struct sock *sk)
{
struct dccp_sock *dp = dccp_sk(sk);
struct dccp_opt_pend *opt, *next;
list_for_each_entry_safe(opt, next, &dp->dccps_options.dccpo_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(&dp->dccps_options.dccpo_pending);
list_for_each_entry_safe(opt, next, &dp->dccps_options.dccpo_conf,
dccpop_node) {
BUG_ON(opt == NULL);
if (opt->dccpop_val != NULL)
kfree(opt->dccpop_val);
kfree(opt);
}
INIT_LIST_HEAD(&dp->dccps_options.dccpo_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_sock *olddp = dccp_sk(oldsk);
struct dccp_sock *newdp = dccp_sk(newsk);
struct dccp_opt_pend *opt;
int rc = 0;
INIT_LIST_HEAD(&newdp->dccps_options.dccpo_pending);
INIT_LIST_HEAD(&newdp->dccps_options.dccpo_conf);
list_for_each_entry(opt, &olddp->dccps_options.dccpo_pending,
dccpop_node) {
struct dccp_opt_pend *newopt;
/* copy the value of the option */
u8 *val = kmalloc(opt->dccpop_len, GFP_ATOMIC);
if (val == NULL)
goto out_clean;
memcpy(val, opt->dccpop_val, opt->dccpop_len);
newopt = kmalloc(sizeof(*newopt), GFP_ATOMIC);
if (newopt == NULL) {
kfree(val);
goto out_clean;
}
/* insert the option */
memcpy(newopt, opt, sizeof(*newopt));
newopt->dccpop_val = val;
list_add_tail(&newopt->dccpop_node,
&newdp->dccps_options.dccpo_pending);
/* XXX what happens with backlogs and multiple connections at
* once...
*/
/* the master socket no longer needs to worry about confirms */
opt->dccpop_sc = 0; /* 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(newsk);
rc = -ENOMEM;
goto out;
}
EXPORT_SYMBOL_GPL(dccp_feat_clone);
static int __dccp_feat_init(struct sock *sk, u8 type, u8 feat, u8 *val, u8 len)
{
int rc = -ENOMEM;
u8 *copy = kmalloc(len, GFP_KERNEL);
if (copy != NULL) {
memcpy(copy, val, len);
rc = dccp_feat_change(sk, type, feat, copy, len, GFP_KERNEL);
if (rc)
kfree(copy);
}
return rc;
}
int dccp_feat_init(struct sock *sk)
{
struct dccp_sock *dp = dccp_sk(sk);
int rc;
INIT_LIST_HEAD(&dp->dccps_options.dccpo_pending);
INIT_LIST_HEAD(&dp->dccps_options.dccpo_conf);
/* CCID L */
rc = __dccp_feat_init(sk, DCCPO_CHANGE_L, DCCPF_CCID,
&dp->dccps_options.dccpo_tx_ccid, 1);
if (rc)
goto out;
/* CCID R */
rc = __dccp_feat_init(sk, DCCPO_CHANGE_R, DCCPF_CCID,
&dp->dccps_options.dccpo_rx_ccid, 1);
if (rc)
goto out;
/* Ack ratio */