diff options
Diffstat (limited to 'net/netfilter/nf_conntrack_proto_dccp.c')
| -rw-r--r-- | net/netfilter/nf_conntrack_proto_dccp.c | 826 |
1 files changed, 826 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_proto_dccp.c b/net/netfilter/nf_conntrack_proto_dccp.c new file mode 100644 index 000000000..e2db1f4ec --- /dev/null +++ b/net/netfilter/nf_conntrack_proto_dccp.c @@ -0,0 +1,826 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * DCCP connection tracking protocol helper + * + * Copyright (c) 2005, 2006, 2008 Patrick McHardy <kaber@trash.net> + */ +#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_DROP; + + 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_DROP; + + 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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