mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 14:56:39 +07:00
0b53d4604a
This fixes a problem and a potential loophole with regard to seqno/ackno validity: currently the initial adjustments to AWL/SWL are only performed once at the begin of the connection, during the handshake. Since the Sequence Window feature is always greater than Wmin=32 (7.5.2), it is however necessary to perform these adjustments at least for the first W/W' (variables as per 7.5.1) packets in the lifetime of a connection. This requirement is complicated by the fact that W/W' can change at any time during the lifetime of a connection. Therefore it is better to perform that safety check each time SWL/AWL are updated, as implemented by the patch. A second problem solved by this patch is that the remote/local Sequence Window feature values (which set the bounds for AWL/SWL/SWH) are undefined until the feature negotiation has completed. During the initial handshake we have more stringent sequence number protection; the changes added by this patch effect that {A,S}W{L,H} are within the correct bounds at the instant that feature negotiation completes (since the SeqWin feature activation handlers call dccp_update_gsr/gss()). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
279 lines
7.9 KiB
C
279 lines
7.9 KiB
C
/*
|
|
* net/dccp/minisocks.c
|
|
*
|
|
* An implementation of the DCCP protocol
|
|
* Arnaldo Carvalho de Melo <acme@conectiva.com.br>
|
|
*
|
|
* 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/dccp.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/timer.h>
|
|
|
|
#include <net/sock.h>
|
|
#include <net/xfrm.h>
|
|
#include <net/inet_timewait_sock.h>
|
|
|
|
#include "ackvec.h"
|
|
#include "ccid.h"
|
|
#include "dccp.h"
|
|
#include "feat.h"
|
|
|
|
struct inet_timewait_death_row dccp_death_row = {
|
|
.sysctl_max_tw_buckets = NR_FILE * 2,
|
|
.period = DCCP_TIMEWAIT_LEN / INET_TWDR_TWKILL_SLOTS,
|
|
.death_lock = __SPIN_LOCK_UNLOCKED(dccp_death_row.death_lock),
|
|
.hashinfo = &dccp_hashinfo,
|
|
.tw_timer = TIMER_INITIALIZER(inet_twdr_hangman, 0,
|
|
(unsigned long)&dccp_death_row),
|
|
.twkill_work = __WORK_INITIALIZER(dccp_death_row.twkill_work,
|
|
inet_twdr_twkill_work),
|
|
/* Short-time timewait calendar */
|
|
|
|
.twcal_hand = -1,
|
|
.twcal_timer = TIMER_INITIALIZER(inet_twdr_twcal_tick, 0,
|
|
(unsigned long)&dccp_death_row),
|
|
};
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_death_row);
|
|
|
|
void dccp_time_wait(struct sock *sk, int state, int timeo)
|
|
{
|
|
struct inet_timewait_sock *tw = NULL;
|
|
|
|
if (dccp_death_row.tw_count < dccp_death_row.sysctl_max_tw_buckets)
|
|
tw = inet_twsk_alloc(sk, state);
|
|
|
|
if (tw != NULL) {
|
|
const struct inet_connection_sock *icsk = inet_csk(sk);
|
|
const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1);
|
|
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
|
|
if (tw->tw_family == PF_INET6) {
|
|
const struct ipv6_pinfo *np = inet6_sk(sk);
|
|
struct inet6_timewait_sock *tw6;
|
|
|
|
tw->tw_ipv6_offset = inet6_tw_offset(sk->sk_prot);
|
|
tw6 = inet6_twsk((struct sock *)tw);
|
|
ipv6_addr_copy(&tw6->tw_v6_daddr, &np->daddr);
|
|
ipv6_addr_copy(&tw6->tw_v6_rcv_saddr, &np->rcv_saddr);
|
|
tw->tw_ipv6only = np->ipv6only;
|
|
}
|
|
#endif
|
|
/* Linkage updates. */
|
|
__inet_twsk_hashdance(tw, sk, &dccp_hashinfo);
|
|
|
|
/* Get the TIME_WAIT timeout firing. */
|
|
if (timeo < rto)
|
|
timeo = rto;
|
|
|
|
tw->tw_timeout = DCCP_TIMEWAIT_LEN;
|
|
if (state == DCCP_TIME_WAIT)
|
|
timeo = DCCP_TIMEWAIT_LEN;
|
|
|
|
inet_twsk_schedule(tw, &dccp_death_row, timeo,
|
|
DCCP_TIMEWAIT_LEN);
|
|
inet_twsk_put(tw);
|
|
} else {
|
|
/* Sorry, if we're out of memory, just CLOSE this
|
|
* socket up. We've got bigger problems than
|
|
* non-graceful socket closings.
|
|
*/
|
|
DCCP_WARN("time wait bucket table overflow\n");
|
|
}
|
|
|
|
dccp_done(sk);
|
|
}
|
|
|
|
struct sock *dccp_create_openreq_child(struct sock *sk,
|
|
const struct request_sock *req,
|
|
const struct sk_buff *skb)
|
|
{
|
|
/*
|
|
* Step 3: Process LISTEN state
|
|
*
|
|
* (* Generate a new socket and switch to that socket *)
|
|
* Set S := new socket for this port pair
|
|
*/
|
|
struct sock *newsk = inet_csk_clone(sk, req, GFP_ATOMIC);
|
|
|
|
if (newsk != NULL) {
|
|
struct dccp_request_sock *dreq = dccp_rsk(req);
|
|
struct inet_connection_sock *newicsk = inet_csk(newsk);
|
|
struct dccp_sock *newdp = dccp_sk(newsk);
|
|
|
|
newdp->dccps_role = DCCP_ROLE_SERVER;
|
|
newdp->dccps_hc_rx_ackvec = NULL;
|
|
newdp->dccps_service_list = NULL;
|
|
newdp->dccps_service = dreq->dreq_service;
|
|
newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
|
|
newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
|
|
newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
|
|
|
|
INIT_LIST_HEAD(&newdp->dccps_featneg);
|
|
/*
|
|
* Step 3: Process LISTEN state
|
|
*
|
|
* Choose S.ISS (initial seqno) or set from Init Cookies
|
|
* Initialize S.GAR := S.ISS
|
|
* Set S.ISR, S.GSR from packet (or Init Cookies)
|
|
*
|
|
* Setting AWL/AWH and SWL/SWH happens as part of the feature
|
|
* activation below, as these windows all depend on the local
|
|
* and remote Sequence Window feature values (7.5.2).
|
|
*/
|
|
newdp->dccps_gss = newdp->dccps_iss = dreq->dreq_iss;
|
|
newdp->dccps_gar = newdp->dccps_iss;
|
|
newdp->dccps_gsr = newdp->dccps_isr = dreq->dreq_isr;
|
|
|
|
/*
|
|
* Activate features: initialise CCIDs, sequence windows etc.
|
|
*/
|
|
if (dccp_feat_activate_values(newsk, &dreq->dreq_featneg)) {
|
|
/* It is still raw copy of parent, so invalidate
|
|
* destructor and make plain sk_free() */
|
|
newsk->sk_destruct = NULL;
|
|
sk_free(newsk);
|
|
return NULL;
|
|
}
|
|
dccp_init_xmit_timers(newsk);
|
|
|
|
DCCP_INC_STATS_BH(DCCP_MIB_PASSIVEOPENS);
|
|
}
|
|
return newsk;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_create_openreq_child);
|
|
|
|
/*
|
|
* Process an incoming packet for RESPOND sockets represented
|
|
* as an request_sock.
|
|
*/
|
|
struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
|
|
struct request_sock *req,
|
|
struct request_sock **prev)
|
|
{
|
|
struct sock *child = NULL;
|
|
struct dccp_request_sock *dreq = dccp_rsk(req);
|
|
|
|
/* Check for retransmitted REQUEST */
|
|
if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {
|
|
|
|
if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dreq->dreq_isr)) {
|
|
dccp_pr_debug("Retransmitted REQUEST\n");
|
|
dreq->dreq_isr = DCCP_SKB_CB(skb)->dccpd_seq;
|
|
/*
|
|
* Send another RESPONSE packet
|
|
* To protect against Request floods, increment retrans
|
|
* counter (backoff, monitored by dccp_response_timer).
|
|
*/
|
|
req->retrans++;
|
|
req->rsk_ops->rtx_syn_ack(sk, req, NULL);
|
|
}
|
|
/* Network Duplicate, discard packet */
|
|
return NULL;
|
|
}
|
|
|
|
DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
|
|
|
|
if (dccp_hdr(skb)->dccph_type != DCCP_PKT_ACK &&
|
|
dccp_hdr(skb)->dccph_type != DCCP_PKT_DATAACK)
|
|
goto drop;
|
|
|
|
/* Invalid ACK */
|
|
if (DCCP_SKB_CB(skb)->dccpd_ack_seq != dreq->dreq_iss) {
|
|
dccp_pr_debug("Invalid ACK number: ack_seq=%llu, "
|
|
"dreq_iss=%llu\n",
|
|
(unsigned long long)
|
|
DCCP_SKB_CB(skb)->dccpd_ack_seq,
|
|
(unsigned long long) dreq->dreq_iss);
|
|
goto drop;
|
|
}
|
|
|
|
if (dccp_parse_options(sk, dreq, skb))
|
|
goto drop;
|
|
|
|
child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL);
|
|
if (child == NULL)
|
|
goto listen_overflow;
|
|
|
|
inet_csk_reqsk_queue_unlink(sk, req, prev);
|
|
inet_csk_reqsk_queue_removed(sk, req);
|
|
inet_csk_reqsk_queue_add(sk, req, child);
|
|
out:
|
|
return child;
|
|
listen_overflow:
|
|
dccp_pr_debug("listen_overflow!\n");
|
|
DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
|
|
drop:
|
|
if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET)
|
|
req->rsk_ops->send_reset(sk, skb);
|
|
|
|
inet_csk_reqsk_queue_drop(sk, req, prev);
|
|
goto out;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_check_req);
|
|
|
|
/*
|
|
* Queue segment on the new socket if the new socket is active,
|
|
* otherwise we just shortcircuit this and continue with
|
|
* the new socket.
|
|
*/
|
|
int dccp_child_process(struct sock *parent, struct sock *child,
|
|
struct sk_buff *skb)
|
|
{
|
|
int ret = 0;
|
|
const int state = child->sk_state;
|
|
|
|
if (!sock_owned_by_user(child)) {
|
|
ret = dccp_rcv_state_process(child, skb, dccp_hdr(skb),
|
|
skb->len);
|
|
|
|
/* Wakeup parent, send SIGIO */
|
|
if (state == DCCP_RESPOND && child->sk_state != state)
|
|
parent->sk_data_ready(parent, 0);
|
|
} else {
|
|
/* Alas, it is possible again, because we do lookup
|
|
* in main socket hash table and lock on listening
|
|
* socket does not protect us more.
|
|
*/
|
|
__sk_add_backlog(child, skb);
|
|
}
|
|
|
|
bh_unlock_sock(child);
|
|
sock_put(child);
|
|
return ret;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_child_process);
|
|
|
|
void dccp_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
|
|
struct request_sock *rsk)
|
|
{
|
|
DCCP_BUG("DCCP-ACK packets are never sent in LISTEN/RESPOND state");
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack);
|
|
|
|
int dccp_reqsk_init(struct request_sock *req,
|
|
struct dccp_sock const *dp, struct sk_buff const *skb)
|
|
{
|
|
struct dccp_request_sock *dreq = dccp_rsk(req);
|
|
|
|
inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
|
|
inet_rsk(req)->loc_port = dccp_hdr(skb)->dccph_dport;
|
|
inet_rsk(req)->acked = 0;
|
|
dreq->dreq_timestamp_echo = 0;
|
|
|
|
/* inherit feature negotiation options from listening socket */
|
|
return dccp_feat_clone_list(&dp->dccps_featneg, &dreq->dreq_featneg);
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dccp_reqsk_init);
|