// SPDX-License-Identifier: GPL-2.0-only
/*
* DCCP connection tracking protocol helper
*
* Copyright (c) 2005, 2006, 2008 Patrick McHardy <[email protected]>
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/spinlock.h>
#include <linux/skbuff.h>
#include <linux/dccp.h>
#include <linux/slab.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <linux/netfilter/nfnetlink_conntrack.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_ecache.h>
#include <net/netfilter/nf_conntrack_timeout.h>
#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).
*
* - 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)
#ifdef CONFIG_NF_CONNTRACK_PROCFS
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",
[CT_DCCP_CLOSEREQ] = "CLOSEREQ",
[CT_DCCP_CLOSING] = "CLOSING",
[CT_DCCP_TIMEWAIT] = "TIMEWAIT",
[CT_DCCP_IGNORE] = "IGNORE",
[CT_DCCP_INVALID] = "INVALID",
};
#endif
#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
#define sCG CT_DCCP_CLOSING
#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,
const struct nf_hook_state *hook_state)
{
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, hook_state, "%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)
{
static const unsigned long require_seq48 = 1 << DCCP_PKT_REQUEST |
1 << DCCP_PKT_RESPONSE |
1 << DCCP_PKT_CLOSEREQ |
1 << DCCP_PKT_CLOSE |
1 << DCCP_PKT_RESET |
1 << DCCP_PKT_SYNC |
1 << DCCP_PKT_SYNCACK;
unsigned int dccp_len = skb->len - dataoff;
unsigned int cscov;
const char *msg;
u8 type;
BUILD_BUG_ON(DCCP_PKT_INVALID >= BITS_PER_LONG);
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;
}
type = dh->dccph_type;
if (type >= DCCP_PKT_INVALID) {
msg = "nf_ct_dccp: reserved packet type ";
goto out_invalid;
}
if (test_bit(type, &require_seq48) && !dh->dccph_x) {
msg = "nf_ct_dccp: type lacks 48bit sequence numbers";
goto out_invalid;
}
return false;
out_invalid:
nf_l4proto_log_invalid(skb, state, IPPROTO_DCCP, "%s", msg);
return true;
}
struct nf_conntrack_dccp_buf {
struct dccp_hdr dh; /* generic header part */
struct dccp_hdr_ext ext; /* optional depending dh->dccph_x */
union { /* depends on header type */
struct dccp_hdr_ack_bits ack;
struct dccp_hdr_request req;
struct dccp_hdr_response response;
struct dccp_hdr_reset rst;
} u;
};
static struct dccp_hdr *
dccp_header_pointer(const struct sk_buff *skb, int offset, const struct dccp_hdr *dh,
struct nf_conntrack_dccp_buf *buf)
{
unsigned int hdrlen = __dccp_hdr_len(dh);
if (hdrlen > sizeof(*buf))
return NULL;
return skb_header_pointer(skb, offset, hdrlen, buf);
}
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 nf_conntrack_dccp_buf _dh;
u_int8_t type, old_state, new_state;
enum ct_dccp_roles role;
unsigned int *timeouts;
struct dccp_hdr *dh;
dh = skb_header_pointer(skb, dataoff, sizeof(*dh), &_dh.dh);
if (!dh)
return -NF_ACCEPT;
if (dccp_error(dh, skb, dataoff, state))
return -NF_ACCEPT;
/* pull again, including possible 48 bit sequences and subtype header */
dh = dccp_header_pointer(skb, dataoff, dh, &_dh);
if (!dh)
return -NF_ACCEPT;
type = dh->dccph_type;
if (!nf_ct_is_confirmed(ct) && !dccp_new(ct, skb, dh, state))
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, state, "%s", "invalid packet");
return NF_ACCEPT;
case CT_DCCP_INVALID:
spin_unlock_bh(&ct->lock);
nf_ct_l4proto_log_invalid(skb, ct, state, "%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, bool destroy)
{
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))
goto nla_put_failure;
if (destroy)
goto skip_state;
if (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;
skip_state:
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 */
};
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