// SPDX-License-Identifier: GPL-2.0-only
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/*
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* DCCP connection tracking protocol helper
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*
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* Copyright (c) 2005, 2006, 2008 Patrick McHardy <kaber@trash.net>
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/sysctl.h>
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#include <linux/spinlock.h>
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#include <linux/skbuff.h>
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#include <linux/dccp.h>
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#include <linux/slab.h>
|
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#include <net/net_namespace.h>
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#include <net/netns/generic.h>
|
|
#include <linux/netfilter/nfnetlink_conntrack.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_l4proto.h>
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#include <net/netfilter/nf_conntrack_ecache.h>
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#include <net/netfilter/nf_conntrack_timeout.h>
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#include <net/netfilter/nf_log.h>
|
|
/* Timeouts are based on values from RFC4340:
|
*
|
* - REQUEST:
|
*
|
* 8.1.2. Client Request
|
*
|
* A client MAY give up on its DCCP-Requests after some time
|
* (3 minutes, for example).
|
*
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* - RESPOND:
|
*
|
* 8.1.3. Server Response
|
*
|
* It MAY also leave the RESPOND state for CLOSED after a timeout of
|
* not less than 4MSL (8 minutes);
|
*
|
* - PARTOPEN:
|
*
|
* 8.1.5. Handshake Completion
|
*
|
* If the client remains in PARTOPEN for more than 4MSL (8 minutes),
|
* it SHOULD reset the connection with Reset Code 2, "Aborted".
|
*
|
* - OPEN:
|
*
|
* The DCCP timestamp overflows after 11.9 hours. If the connection
|
* stays idle this long the sequence number won't be recognized
|
* as valid anymore.
|
*
|
* - CLOSEREQ/CLOSING:
|
*
|
* 8.3. Termination
|
*
|
* The retransmission timer should initially be set to go off in two
|
* round-trip times and should back off to not less than once every
|
* 64 seconds ...
|
*
|
* - TIMEWAIT:
|
*
|
* 4.3. States
|
*
|
* A server or client socket remains in this state for 2MSL (4 minutes)
|
* after the connection has been town down, ...
|
*/
|
|
#define DCCP_MSL (2 * 60 * HZ)
|
|
static const char * const dccp_state_names[] = {
|
[CT_DCCP_NONE] = "NONE",
|
[CT_DCCP_REQUEST] = "REQUEST",
|
[CT_DCCP_RESPOND] = "RESPOND",
|
[CT_DCCP_PARTOPEN] = "PARTOPEN",
|
[CT_DCCP_OPEN] = "OPEN",
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[CT_DCCP_CLOSEREQ] = "CLOSEREQ",
|
[CT_DCCP_CLOSING] = "CLOSING",
|
[CT_DCCP_TIMEWAIT] = "TIMEWAIT",
|
[CT_DCCP_IGNORE] = "IGNORE",
|
[CT_DCCP_INVALID] = "INVALID",
|
};
|
|
#define sNO CT_DCCP_NONE
|
#define sRQ CT_DCCP_REQUEST
|
#define sRS CT_DCCP_RESPOND
|
#define sPO CT_DCCP_PARTOPEN
|
#define sOP CT_DCCP_OPEN
|
#define sCR CT_DCCP_CLOSEREQ
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#define sCG CT_DCCP_CLOSING
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#define sTW CT_DCCP_TIMEWAIT
|
#define sIG CT_DCCP_IGNORE
|
#define sIV CT_DCCP_INVALID
|
|
/*
|
* DCCP state transition table
|
*
|
* The assumption is the same as for TCP tracking:
|
*
|
* We are the man in the middle. All the packets go through us but might
|
* get lost in transit to the destination. It is assumed that the destination
|
* can't receive segments we haven't seen.
|
*
|
* The following states exist:
|
*
|
* NONE: Initial state, expecting Request
|
* REQUEST: Request seen, waiting for Response from server
|
* RESPOND: Response from server seen, waiting for Ack from client
|
* PARTOPEN: Ack after Response seen, waiting for packet other than Response,
|
* Reset or Sync from server
|
* OPEN: Packet other than Response, Reset or Sync seen
|
* CLOSEREQ: CloseReq from server seen, expecting Close from client
|
* CLOSING: Close seen, expecting Reset
|
* TIMEWAIT: Reset seen
|
* IGNORE: Not determinable whether packet is valid
|
*
|
* Some states exist only on one side of the connection: REQUEST, RESPOND,
|
* PARTOPEN, CLOSEREQ. For the other side these states are equivalent to
|
* the one it was in before.
|
*
|
* Packets are marked as ignored (sIG) if we don't know if they're valid
|
* (for example a reincarnation of a connection we didn't notice is dead
|
* already) and the server may send back a connection closing Reset or a
|
* Response. They're also used for Sync/SyncAck packets, which we don't
|
* care about.
|
*/
|
static const u_int8_t
|
dccp_state_table[CT_DCCP_ROLE_MAX + 1][DCCP_PKT_SYNCACK + 1][CT_DCCP_MAX + 1] = {
|
[CT_DCCP_ROLE_CLIENT] = {
|
[DCCP_PKT_REQUEST] = {
|
/*
|
* sNO -> sRQ Regular Request
|
* sRQ -> sRQ Retransmitted Request or reincarnation
|
* sRS -> sRS Retransmitted Request (apparently Response
|
* got lost after we saw it) or reincarnation
|
* sPO -> sIG Ignore, conntrack might be out of sync
|
* sOP -> sIG Ignore, conntrack might be out of sync
|
* sCR -> sIG Ignore, conntrack might be out of sync
|
* sCG -> sIG Ignore, conntrack might be out of sync
|
* sTW -> sRQ Reincarnation
|
*
|
* sNO, sRQ, sRS, sPO. sOP, sCR, sCG, sTW, */
|
sRQ, sRQ, sRS, sIG, sIG, sIG, sIG, sRQ,
|
},
|
[DCCP_PKT_RESPONSE] = {
|
/*
|
* sNO -> sIV Invalid
|
* sRQ -> sIG Ignore, might be response to ignored Request
|
* sRS -> sIG Ignore, might be response to ignored Request
|
* sPO -> sIG Ignore, might be response to ignored Request
|
* sOP -> sIG Ignore, might be response to ignored Request
|
* sCR -> sIG Ignore, might be response to ignored Request
|
* sCG -> sIG Ignore, might be response to ignored Request
|
* sTW -> sIV Invalid, reincarnation in reverse direction
|
* goes through sRQ
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIV,
|
},
|
[DCCP_PKT_ACK] = {
|
/*
|
* sNO -> sIV No connection
|
* sRQ -> sIV No connection
|
* sRS -> sPO Ack for Response, move to PARTOPEN (8.1.5.)
|
* sPO -> sPO Retransmitted Ack for Response, remain in PARTOPEN
|
* sOP -> sOP Regular ACK, remain in OPEN
|
* sCR -> sCR Ack in CLOSEREQ MAY be processed (8.3.)
|
* sCG -> sCG Ack in CLOSING MAY be processed (8.3.)
|
* sTW -> sIV
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIV, sPO, sPO, sOP, sCR, sCG, sIV
|
},
|
[DCCP_PKT_DATA] = {
|
/*
|
* sNO -> sIV No connection
|
* sRQ -> sIV No connection
|
* sRS -> sIV No connection
|
* sPO -> sIV MUST use DataAck in PARTOPEN state (8.1.5.)
|
* sOP -> sOP Regular Data packet
|
* sCR -> sCR Data in CLOSEREQ MAY be processed (8.3.)
|
* sCG -> sCG Data in CLOSING MAY be processed (8.3.)
|
* sTW -> sIV
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIV, sIV, sIV, sOP, sCR, sCG, sIV,
|
},
|
[DCCP_PKT_DATAACK] = {
|
/*
|
* sNO -> sIV No connection
|
* sRQ -> sIV No connection
|
* sRS -> sPO Ack for Response, move to PARTOPEN (8.1.5.)
|
* sPO -> sPO Remain in PARTOPEN state
|
* sOP -> sOP Regular DataAck packet in OPEN state
|
* sCR -> sCR DataAck in CLOSEREQ MAY be processed (8.3.)
|
* sCG -> sCG DataAck in CLOSING MAY be processed (8.3.)
|
* sTW -> sIV
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIV, sPO, sPO, sOP, sCR, sCG, sIV
|
},
|
[DCCP_PKT_CLOSEREQ] = {
|
/*
|
* CLOSEREQ may only be sent by the server.
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV
|
},
|
[DCCP_PKT_CLOSE] = {
|
/*
|
* sNO -> sIV No connection
|
* sRQ -> sIV No connection
|
* sRS -> sIV No connection
|
* sPO -> sCG Client-initiated close
|
* sOP -> sCG Client-initiated close
|
* sCR -> sCG Close in response to CloseReq (8.3.)
|
* sCG -> sCG Retransmit
|
* sTW -> sIV Late retransmit, already in TIME_WAIT
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIV, sIV, sCG, sCG, sCG, sIV, sIV
|
},
|
[DCCP_PKT_RESET] = {
|
/*
|
* sNO -> sIV No connection
|
* sRQ -> sTW Sync received or timeout, SHOULD send Reset (8.1.1.)
|
* sRS -> sTW Response received without Request
|
* sPO -> sTW Timeout, SHOULD send Reset (8.1.5.)
|
* sOP -> sTW Connection reset
|
* sCR -> sTW Connection reset
|
* sCG -> sTW Connection reset
|
* sTW -> sIG Ignore (don't refresh timer)
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sTW, sTW, sTW, sTW, sTW, sTW, sIG
|
},
|
[DCCP_PKT_SYNC] = {
|
/*
|
* We currently ignore Sync packets
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
|
},
|
[DCCP_PKT_SYNCACK] = {
|
/*
|
* We currently ignore SyncAck packets
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
|
},
|
},
|
[CT_DCCP_ROLE_SERVER] = {
|
[DCCP_PKT_REQUEST] = {
|
/*
|
* sNO -> sIV Invalid
|
* sRQ -> sIG Ignore, conntrack might be out of sync
|
* sRS -> sIG Ignore, conntrack might be out of sync
|
* sPO -> sIG Ignore, conntrack might be out of sync
|
* sOP -> sIG Ignore, conntrack might be out of sync
|
* sCR -> sIG Ignore, conntrack might be out of sync
|
* sCG -> sIG Ignore, conntrack might be out of sync
|
* sTW -> sRQ Reincarnation, must reverse roles
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIG, sIG, sIG, sIG, sIG, sIG, sRQ
|
},
|
[DCCP_PKT_RESPONSE] = {
|
/*
|
* sNO -> sIV Response without Request
|
* sRQ -> sRS Response to clients Request
|
* sRS -> sRS Retransmitted Response (8.1.3. SHOULD NOT)
|
* sPO -> sIG Response to an ignored Request or late retransmit
|
* sOP -> sIG Ignore, might be response to ignored Request
|
* sCR -> sIG Ignore, might be response to ignored Request
|
* sCG -> sIG Ignore, might be response to ignored Request
|
* sTW -> sIV Invalid, Request from client in sTW moves to sRQ
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sRS, sRS, sIG, sIG, sIG, sIG, sIV
|
},
|
[DCCP_PKT_ACK] = {
|
/*
|
* sNO -> sIV No connection
|
* sRQ -> sIV No connection
|
* sRS -> sIV No connection
|
* sPO -> sOP Enter OPEN state (8.1.5.)
|
* sOP -> sOP Regular Ack in OPEN state
|
* sCR -> sIV Waiting for Close from client
|
* sCG -> sCG Ack in CLOSING MAY be processed (8.3.)
|
* sTW -> sIV
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV
|
},
|
[DCCP_PKT_DATA] = {
|
/*
|
* sNO -> sIV No connection
|
* sRQ -> sIV No connection
|
* sRS -> sIV No connection
|
* sPO -> sOP Enter OPEN state (8.1.5.)
|
* sOP -> sOP Regular Data packet in OPEN state
|
* sCR -> sIV Waiting for Close from client
|
* sCG -> sCG Data in CLOSING MAY be processed (8.3.)
|
* sTW -> sIV
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV
|
},
|
[DCCP_PKT_DATAACK] = {
|
/*
|
* sNO -> sIV No connection
|
* sRQ -> sIV No connection
|
* sRS -> sIV No connection
|
* sPO -> sOP Enter OPEN state (8.1.5.)
|
* sOP -> sOP Regular DataAck in OPEN state
|
* sCR -> sIV Waiting for Close from client
|
* sCG -> sCG Data in CLOSING MAY be processed (8.3.)
|
* sTW -> sIV
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIV, sIV, sOP, sOP, sIV, sCG, sIV
|
},
|
[DCCP_PKT_CLOSEREQ] = {
|
/*
|
* sNO -> sIV No connection
|
* sRQ -> sIV No connection
|
* sRS -> sIV No connection
|
* sPO -> sOP -> sCR Move directly to CLOSEREQ (8.1.5.)
|
* sOP -> sCR CloseReq in OPEN state
|
* sCR -> sCR Retransmit
|
* sCG -> sCR Simultaneous close, client sends another Close
|
* sTW -> sIV Already closed
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIV, sIV, sCR, sCR, sCR, sCR, sIV
|
},
|
[DCCP_PKT_CLOSE] = {
|
/*
|
* sNO -> sIV No connection
|
* sRQ -> sIV No connection
|
* sRS -> sIV No connection
|
* sPO -> sOP -> sCG Move direcly to CLOSING
|
* sOP -> sCG Move to CLOSING
|
* sCR -> sIV Close after CloseReq is invalid
|
* sCG -> sCG Retransmit
|
* sTW -> sIV Already closed
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIV, sIV, sCG, sCG, sIV, sCG, sIV
|
},
|
[DCCP_PKT_RESET] = {
|
/*
|
* sNO -> sIV No connection
|
* sRQ -> sTW Reset in response to Request
|
* sRS -> sTW Timeout, SHOULD send Reset (8.1.3.)
|
* sPO -> sTW Timeout, SHOULD send Reset (8.1.3.)
|
* sOP -> sTW
|
* sCR -> sTW
|
* sCG -> sTW
|
* sTW -> sIG Ignore (don't refresh timer)
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW, sTW */
|
sIV, sTW, sTW, sTW, sTW, sTW, sTW, sTW, sIG
|
},
|
[DCCP_PKT_SYNC] = {
|
/*
|
* We currently ignore Sync packets
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
|
},
|
[DCCP_PKT_SYNCACK] = {
|
/*
|
* We currently ignore SyncAck packets
|
*
|
* sNO, sRQ, sRS, sPO, sOP, sCR, sCG, sTW */
|
sIV, sIG, sIG, sIG, sIG, sIG, sIG, sIG,
|
},
|
},
|
};
|
|
static noinline bool
|
dccp_new(struct nf_conn *ct, const struct sk_buff *skb,
|
const struct dccp_hdr *dh)
|
{
|
struct net *net = nf_ct_net(ct);
|
struct nf_dccp_net *dn;
|
const char *msg;
|
u_int8_t state;
|
|
state = dccp_state_table[CT_DCCP_ROLE_CLIENT][dh->dccph_type][CT_DCCP_NONE];
|
switch (state) {
|
default:
|
dn = nf_dccp_pernet(net);
|
if (dn->dccp_loose == 0) {
|
msg = "not picking up existing connection ";
|
goto out_invalid;
|
}
|
break;
|
case CT_DCCP_REQUEST:
|
break;
|
case CT_DCCP_INVALID:
|
msg = "invalid state transition ";
|
goto out_invalid;
|
}
|
|
ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT;
|
ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER;
|
ct->proto.dccp.state = CT_DCCP_NONE;
|
ct->proto.dccp.last_pkt = DCCP_PKT_REQUEST;
|
ct->proto.dccp.last_dir = IP_CT_DIR_ORIGINAL;
|
ct->proto.dccp.handshake_seq = 0;
|
return true;
|
|
out_invalid:
|
nf_ct_l4proto_log_invalid(skb, ct, "%s", msg);
|
return false;
|
}
|
|
static u64 dccp_ack_seq(const struct dccp_hdr *dh)
|
{
|
const struct dccp_hdr_ack_bits *dhack;
|
|
dhack = (void *)dh + __dccp_basic_hdr_len(dh);
|
return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) +
|
ntohl(dhack->dccph_ack_nr_low);
|
}
|
|
static bool dccp_error(const struct dccp_hdr *dh,
|
struct sk_buff *skb, unsigned int dataoff,
|
const struct nf_hook_state *state)
|
{
|
unsigned int dccp_len = skb->len - dataoff;
|
unsigned int cscov;
|
const char *msg;
|
|
if (dh->dccph_doff * 4 < sizeof(struct dccp_hdr) ||
|
dh->dccph_doff * 4 > dccp_len) {
|
msg = "nf_ct_dccp: truncated/malformed packet ";
|
goto out_invalid;
|
}
|
|
cscov = dccp_len;
|
if (dh->dccph_cscov) {
|
cscov = (dh->dccph_cscov - 1) * 4;
|
if (cscov > dccp_len) {
|
msg = "nf_ct_dccp: bad checksum coverage ";
|
goto out_invalid;
|
}
|
}
|
|
if (state->hook == NF_INET_PRE_ROUTING &&
|
state->net->ct.sysctl_checksum &&
|
nf_checksum_partial(skb, state->hook, dataoff, cscov,
|
IPPROTO_DCCP, state->pf)) {
|
msg = "nf_ct_dccp: bad checksum ";
|
goto out_invalid;
|
}
|
|
if (dh->dccph_type >= DCCP_PKT_INVALID) {
|
msg = "nf_ct_dccp: reserved packet type ";
|
goto out_invalid;
|
}
|
return false;
|
out_invalid:
|
nf_l4proto_log_invalid(skb, state->net, state->pf,
|
IPPROTO_DCCP, "%s", msg);
|
return true;
|
}
|
|
int nf_conntrack_dccp_packet(struct nf_conn *ct, struct sk_buff *skb,
|
unsigned int dataoff,
|
enum ip_conntrack_info ctinfo,
|
const struct nf_hook_state *state)
|
{
|
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
|
struct dccp_hdr _dh, *dh;
|
u_int8_t type, old_state, new_state;
|
enum ct_dccp_roles role;
|
unsigned int *timeouts;
|
|
dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh);
|
if (!dh)
|
return NF_DROP;
|
|
if (dccp_error(dh, skb, dataoff, state))
|
return -NF_ACCEPT;
|
|
type = dh->dccph_type;
|
if (!nf_ct_is_confirmed(ct) && !dccp_new(ct, skb, dh))
|
return -NF_ACCEPT;
|
|
if (type == DCCP_PKT_RESET &&
|
!test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
|
/* Tear down connection immediately if only reply is a RESET */
|
nf_ct_kill_acct(ct, ctinfo, skb);
|
return NF_ACCEPT;
|
}
|
|
spin_lock_bh(&ct->lock);
|
|
role = ct->proto.dccp.role[dir];
|
old_state = ct->proto.dccp.state;
|
new_state = dccp_state_table[role][type][old_state];
|
|
switch (new_state) {
|
case CT_DCCP_REQUEST:
|
if (old_state == CT_DCCP_TIMEWAIT &&
|
role == CT_DCCP_ROLE_SERVER) {
|
/* Reincarnation in the reverse direction: reopen and
|
* reverse client/server roles. */
|
ct->proto.dccp.role[dir] = CT_DCCP_ROLE_CLIENT;
|
ct->proto.dccp.role[!dir] = CT_DCCP_ROLE_SERVER;
|
}
|
break;
|
case CT_DCCP_RESPOND:
|
if (old_state == CT_DCCP_REQUEST)
|
ct->proto.dccp.handshake_seq = dccp_hdr_seq(dh);
|
break;
|
case CT_DCCP_PARTOPEN:
|
if (old_state == CT_DCCP_RESPOND &&
|
type == DCCP_PKT_ACK &&
|
dccp_ack_seq(dh) == ct->proto.dccp.handshake_seq)
|
set_bit(IPS_ASSURED_BIT, &ct->status);
|
break;
|
case CT_DCCP_IGNORE:
|
/*
|
* Connection tracking might be out of sync, so we ignore
|
* packets that might establish a new connection and resync
|
* if the server responds with a valid Response.
|
*/
|
if (ct->proto.dccp.last_dir == !dir &&
|
ct->proto.dccp.last_pkt == DCCP_PKT_REQUEST &&
|
type == DCCP_PKT_RESPONSE) {
|
ct->proto.dccp.role[!dir] = CT_DCCP_ROLE_CLIENT;
|
ct->proto.dccp.role[dir] = CT_DCCP_ROLE_SERVER;
|
ct->proto.dccp.handshake_seq = dccp_hdr_seq(dh);
|
new_state = CT_DCCP_RESPOND;
|
break;
|
}
|
ct->proto.dccp.last_dir = dir;
|
ct->proto.dccp.last_pkt = type;
|
|
spin_unlock_bh(&ct->lock);
|
nf_ct_l4proto_log_invalid(skb, ct, "%s", "invalid packet");
|
return NF_ACCEPT;
|
case CT_DCCP_INVALID:
|
spin_unlock_bh(&ct->lock);
|
nf_ct_l4proto_log_invalid(skb, ct, "%s", "invalid state transition");
|
return -NF_ACCEPT;
|
}
|
|
ct->proto.dccp.last_dir = dir;
|
ct->proto.dccp.last_pkt = type;
|
ct->proto.dccp.state = new_state;
|
spin_unlock_bh(&ct->lock);
|
|
if (new_state != old_state)
|
nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
|
|
timeouts = nf_ct_timeout_lookup(ct);
|
if (!timeouts)
|
timeouts = nf_dccp_pernet(nf_ct_net(ct))->dccp_timeout;
|
nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]);
|
|
return NF_ACCEPT;
|
}
|
|
static bool dccp_can_early_drop(const struct nf_conn *ct)
|
{
|
switch (ct->proto.dccp.state) {
|
case CT_DCCP_CLOSEREQ:
|
case CT_DCCP_CLOSING:
|
case CT_DCCP_TIMEWAIT:
|
return true;
|
default:
|
break;
|
}
|
|
return false;
|
}
|
|
#ifdef CONFIG_NF_CONNTRACK_PROCFS
|
static void dccp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
|
{
|
seq_printf(s, "%s ", dccp_state_names[ct->proto.dccp.state]);
|
}
|
#endif
|
|
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
|
static int dccp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
|
struct nf_conn *ct)
|
{
|
struct nlattr *nest_parms;
|
|
spin_lock_bh(&ct->lock);
|
nest_parms = nla_nest_start(skb, CTA_PROTOINFO_DCCP);
|
if (!nest_parms)
|
goto nla_put_failure;
|
if (nla_put_u8(skb, CTA_PROTOINFO_DCCP_STATE, ct->proto.dccp.state) ||
|
nla_put_u8(skb, CTA_PROTOINFO_DCCP_ROLE,
|
ct->proto.dccp.role[IP_CT_DIR_ORIGINAL]) ||
|
nla_put_be64(skb, CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ,
|
cpu_to_be64(ct->proto.dccp.handshake_seq),
|
CTA_PROTOINFO_DCCP_PAD))
|
goto nla_put_failure;
|
nla_nest_end(skb, nest_parms);
|
spin_unlock_bh(&ct->lock);
|
return 0;
|
|
nla_put_failure:
|
spin_unlock_bh(&ct->lock);
|
return -1;
|
}
|
|
static const struct nla_policy dccp_nla_policy[CTA_PROTOINFO_DCCP_MAX + 1] = {
|
[CTA_PROTOINFO_DCCP_STATE] = { .type = NLA_U8 },
|
[CTA_PROTOINFO_DCCP_ROLE] = { .type = NLA_U8 },
|
[CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ] = { .type = NLA_U64 },
|
[CTA_PROTOINFO_DCCP_PAD] = { .type = NLA_UNSPEC },
|
};
|
|
#define DCCP_NLATTR_SIZE ( \
|
NLA_ALIGN(NLA_HDRLEN + 1) + \
|
NLA_ALIGN(NLA_HDRLEN + 1) + \
|
NLA_ALIGN(NLA_HDRLEN + sizeof(u64)) + \
|
NLA_ALIGN(NLA_HDRLEN + 0))
|
|
static int nlattr_to_dccp(struct nlattr *cda[], struct nf_conn *ct)
|
{
|
struct nlattr *attr = cda[CTA_PROTOINFO_DCCP];
|
struct nlattr *tb[CTA_PROTOINFO_DCCP_MAX + 1];
|
int err;
|
|
if (!attr)
|
return 0;
|
|
err = nla_parse_nested_deprecated(tb, CTA_PROTOINFO_DCCP_MAX, attr,
|
dccp_nla_policy, NULL);
|
if (err < 0)
|
return err;
|
|
if (!tb[CTA_PROTOINFO_DCCP_STATE] ||
|
!tb[CTA_PROTOINFO_DCCP_ROLE] ||
|
nla_get_u8(tb[CTA_PROTOINFO_DCCP_ROLE]) > CT_DCCP_ROLE_MAX ||
|
nla_get_u8(tb[CTA_PROTOINFO_DCCP_STATE]) >= CT_DCCP_IGNORE) {
|
return -EINVAL;
|
}
|
|
spin_lock_bh(&ct->lock);
|
ct->proto.dccp.state = nla_get_u8(tb[CTA_PROTOINFO_DCCP_STATE]);
|
if (nla_get_u8(tb[CTA_PROTOINFO_DCCP_ROLE]) == CT_DCCP_ROLE_CLIENT) {
|
ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT;
|
ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER;
|
} else {
|
ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_SERVER;
|
ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_CLIENT;
|
}
|
if (tb[CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ]) {
|
ct->proto.dccp.handshake_seq =
|
be64_to_cpu(nla_get_be64(tb[CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ]));
|
}
|
spin_unlock_bh(&ct->lock);
|
return 0;
|
}
|
#endif
|
|
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
|
|
#include <linux/netfilter/nfnetlink.h>
|
#include <linux/netfilter/nfnetlink_cttimeout.h>
|
|
static int dccp_timeout_nlattr_to_obj(struct nlattr *tb[],
|
struct net *net, void *data)
|
{
|
struct nf_dccp_net *dn = nf_dccp_pernet(net);
|
unsigned int *timeouts = data;
|
int i;
|
|
if (!timeouts)
|
timeouts = dn->dccp_timeout;
|
|
/* set default DCCP timeouts. */
|
for (i=0; i<CT_DCCP_MAX; i++)
|
timeouts[i] = dn->dccp_timeout[i];
|
|
/* there's a 1:1 mapping between attributes and protocol states. */
|
for (i=CTA_TIMEOUT_DCCP_UNSPEC+1; i<CTA_TIMEOUT_DCCP_MAX+1; i++) {
|
if (tb[i]) {
|
timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ;
|
}
|
}
|
|
timeouts[CTA_TIMEOUT_DCCP_UNSPEC] = timeouts[CTA_TIMEOUT_DCCP_REQUEST];
|
return 0;
|
}
|
|
static int
|
dccp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
|
{
|
const unsigned int *timeouts = data;
|
int i;
|
|
for (i=CTA_TIMEOUT_DCCP_UNSPEC+1; i<CTA_TIMEOUT_DCCP_MAX+1; i++) {
|
if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ)))
|
goto nla_put_failure;
|
}
|
return 0;
|
|
nla_put_failure:
|
return -ENOSPC;
|
}
|
|
static const struct nla_policy
|
dccp_timeout_nla_policy[CTA_TIMEOUT_DCCP_MAX+1] = {
|
[CTA_TIMEOUT_DCCP_REQUEST] = { .type = NLA_U32 },
|
[CTA_TIMEOUT_DCCP_RESPOND] = { .type = NLA_U32 },
|
[CTA_TIMEOUT_DCCP_PARTOPEN] = { .type = NLA_U32 },
|
[CTA_TIMEOUT_DCCP_OPEN] = { .type = NLA_U32 },
|
[CTA_TIMEOUT_DCCP_CLOSEREQ] = { .type = NLA_U32 },
|
[CTA_TIMEOUT_DCCP_CLOSING] = { .type = NLA_U32 },
|
[CTA_TIMEOUT_DCCP_TIMEWAIT] = { .type = NLA_U32 },
|
};
|
#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
|
|
void nf_conntrack_dccp_init_net(struct net *net)
|
{
|
struct nf_dccp_net *dn = nf_dccp_pernet(net);
|
|
/* default values */
|
dn->dccp_loose = 1;
|
dn->dccp_timeout[CT_DCCP_REQUEST] = 2 * DCCP_MSL;
|
dn->dccp_timeout[CT_DCCP_RESPOND] = 4 * DCCP_MSL;
|
dn->dccp_timeout[CT_DCCP_PARTOPEN] = 4 * DCCP_MSL;
|
dn->dccp_timeout[CT_DCCP_OPEN] = 12 * 3600 * HZ;
|
dn->dccp_timeout[CT_DCCP_CLOSEREQ] = 64 * HZ;
|
dn->dccp_timeout[CT_DCCP_CLOSING] = 64 * HZ;
|
dn->dccp_timeout[CT_DCCP_TIMEWAIT] = 2 * DCCP_MSL;
|
|
/* timeouts[0] is unused, make it same as SYN_SENT so
|
* ->timeouts[0] contains 'new' timeout, like udp or icmp.
|
*/
|
dn->dccp_timeout[CT_DCCP_NONE] = dn->dccp_timeout[CT_DCCP_REQUEST];
|
}
|
|
const struct nf_conntrack_l4proto nf_conntrack_l4proto_dccp = {
|
.l4proto = IPPROTO_DCCP,
|
.can_early_drop = dccp_can_early_drop,
|
#ifdef CONFIG_NF_CONNTRACK_PROCFS
|
.print_conntrack = dccp_print_conntrack,
|
#endif
|
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
|
.nlattr_size = DCCP_NLATTR_SIZE,
|
.to_nlattr = dccp_to_nlattr,
|
.from_nlattr = nlattr_to_dccp,
|
.tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
|
.nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
|
.nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
|
.nla_policy = nf_ct_port_nla_policy,
|
#endif
|
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
|
.ctnl_timeout = {
|
.nlattr_to_obj = dccp_timeout_nlattr_to_obj,
|
.obj_to_nlattr = dccp_timeout_obj_to_nlattr,
|
.nlattr_max = CTA_TIMEOUT_DCCP_MAX,
|
.obj_size = sizeof(unsigned int) * CT_DCCP_MAX,
|
.nla_policy = dccp_timeout_nla_policy,
|
},
|
#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
|
};
|
