diff options
Diffstat (limited to 'net/dccp/ipv6.c')
| -rw-r--r-- | net/dccp/ipv6.c | 1181 |
1 files changed, 1181 insertions, 0 deletions
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c new file mode 100644 index 000000000..e0b0bf75a --- /dev/null +++ b/net/dccp/ipv6.c @@ -0,0 +1,1181 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * DCCP over IPv6 + * Linux INET6 implementation + * + * Based on net/dccp6/ipv6.c + * + * Arnaldo Carvalho de Melo <acme@ghostprotocols.net> + */ + +#include <linux/module.h> +#include <linux/random.h> +#include <linux/slab.h> +#include <linux/xfrm.h> +#include <linux/string.h> + +#include <net/addrconf.h> +#include <net/inet_common.h> +#include <net/inet_hashtables.h> +#include <net/inet_sock.h> +#include <net/inet6_connection_sock.h> +#include <net/inet6_hashtables.h> +#include <net/ip6_route.h> +#include <net/ipv6.h> +#include <net/protocol.h> +#include <net/transp_v6.h> +#include <net/ip6_checksum.h> +#include <net/xfrm.h> +#include <net/secure_seq.h> +#include <net/netns/generic.h> +#include <net/sock.h> + +#include "dccp.h" +#include "ipv6.h" +#include "feat.h" + +struct dccp_v6_pernet { + struct sock *v6_ctl_sk; +}; + +static unsigned int dccp_v6_pernet_id __read_mostly; + +/* The per-net v6_ctl_sk is used for sending RSTs and ACKs */ + +static const struct inet_connection_sock_af_ops dccp_ipv6_mapped; +static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops; + +/* add pseudo-header to DCCP checksum stored in skb->csum */ +static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb, + const struct in6_addr *saddr, + const struct in6_addr *daddr) +{ + return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum); +} + +static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb) +{ + struct ipv6_pinfo *np = inet6_sk(sk); + struct dccp_hdr *dh = dccp_hdr(skb); + + dccp_csum_outgoing(skb); + dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &sk->sk_v6_daddr); +} + +static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb) +{ + return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32, + ipv6_hdr(skb)->saddr.s6_addr32, + dccp_hdr(skb)->dccph_dport, + dccp_hdr(skb)->dccph_sport ); + +} + +static int dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, + u8 type, u8 code, int offset, __be32 info) +{ + const struct ipv6hdr *hdr; + const struct dccp_hdr *dh; + struct dccp_sock *dp; + struct ipv6_pinfo *np; + struct sock *sk; + int err; + __u64 seq; + struct net *net = dev_net(skb->dev); + + if (!pskb_may_pull(skb, offset + sizeof(*dh))) + return -EINVAL; + dh = (struct dccp_hdr *)(skb->data + offset); + if (!pskb_may_pull(skb, offset + __dccp_basic_hdr_len(dh))) + return -EINVAL; + hdr = (const struct ipv6hdr *)skb->data; + dh = (struct dccp_hdr *)(skb->data + offset); + + sk = __inet6_lookup_established(net, &dccp_hashinfo, + &hdr->daddr, dh->dccph_dport, + &hdr->saddr, ntohs(dh->dccph_sport), + inet6_iif(skb), 0); + + if (!sk) { + __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), + ICMP6_MIB_INERRORS); + return -ENOENT; + } + + if (sk->sk_state == DCCP_TIME_WAIT) { + inet_twsk_put(inet_twsk(sk)); + return 0; + } + seq = dccp_hdr_seq(dh); + if (sk->sk_state == DCCP_NEW_SYN_RECV) { + dccp_req_err(sk, seq); + return 0; + } + + bh_lock_sock(sk); + if (sock_owned_by_user(sk)) + __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); + + if (sk->sk_state == DCCP_CLOSED) + goto out; + + dp = dccp_sk(sk); + if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) && + !between48(seq, dp->dccps_awl, dp->dccps_awh)) { + __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); + goto out; + } + + np = inet6_sk(sk); + + if (type == NDISC_REDIRECT) { + if (!sock_owned_by_user(sk)) { + struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie); + + if (dst) + dst->ops->redirect(dst, sk, skb); + } + goto out; + } + + if (type == ICMPV6_PKT_TOOBIG) { + struct dst_entry *dst = NULL; + + if (!ip6_sk_accept_pmtu(sk)) + goto out; + + if (sock_owned_by_user(sk)) + goto out; + if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED)) + goto out; + + dst = inet6_csk_update_pmtu(sk, ntohl(info)); + if (!dst) + goto out; + + if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) + dccp_sync_mss(sk, dst_mtu(dst)); + goto out; + } + + icmpv6_err_convert(type, code, &err); + + /* Might be for an request_sock */ + switch (sk->sk_state) { + case DCCP_REQUESTING: + case DCCP_RESPOND: /* Cannot happen. + It can, it SYNs are crossed. --ANK */ + if (!sock_owned_by_user(sk)) { + __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS); + sk->sk_err = err; + /* + * Wake people up to see the error + * (see connect in sock.c) + */ + sk_error_report(sk); + dccp_done(sk); + } else + sk->sk_err_soft = err; + goto out; + } + + if (!sock_owned_by_user(sk) && np->recverr) { + sk->sk_err = err; + sk_error_report(sk); + } else + sk->sk_err_soft = err; + +out: + bh_unlock_sock(sk); + sock_put(sk); + return 0; +} + + +static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req) +{ + struct inet_request_sock *ireq = inet_rsk(req); + struct ipv6_pinfo *np = inet6_sk(sk); + struct sk_buff *skb; + struct in6_addr *final_p, final; + struct flowi6 fl6; + int err = -1; + struct dst_entry *dst; + + memset(&fl6, 0, sizeof(fl6)); + fl6.flowi6_proto = IPPROTO_DCCP; + fl6.daddr = ireq->ir_v6_rmt_addr; + fl6.saddr = ireq->ir_v6_loc_addr; + fl6.flowlabel = 0; + fl6.flowi6_oif = ireq->ir_iif; + fl6.fl6_dport = ireq->ir_rmt_port; + fl6.fl6_sport = htons(ireq->ir_num); + security_req_classify_flow(req, flowi6_to_flowi_common(&fl6)); + + + rcu_read_lock(); + final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final); + rcu_read_unlock(); + + dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p); + if (IS_ERR(dst)) { + err = PTR_ERR(dst); + dst = NULL; + goto done; + } + + skb = dccp_make_response(sk, dst, req); + if (skb != NULL) { + struct dccp_hdr *dh = dccp_hdr(skb); + struct ipv6_txoptions *opt; + + dh->dccph_checksum = dccp_v6_csum_finish(skb, + &ireq->ir_v6_loc_addr, + &ireq->ir_v6_rmt_addr); + fl6.daddr = ireq->ir_v6_rmt_addr; + rcu_read_lock(); + opt = ireq->ipv6_opt; + if (!opt) + opt = rcu_dereference(np->opt); + err = ip6_xmit(sk, skb, &fl6, READ_ONCE(sk->sk_mark), opt, + np->tclass, sk->sk_priority); + rcu_read_unlock(); + err = net_xmit_eval(err); + } + +done: + dst_release(dst); + return err; +} + +static void dccp_v6_reqsk_destructor(struct request_sock *req) +{ + dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg); + kfree(inet_rsk(req)->ipv6_opt); + kfree_skb(inet_rsk(req)->pktopts); +} + +static void dccp_v6_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb) +{ + const struct ipv6hdr *rxip6h; + struct sk_buff *skb; + struct flowi6 fl6; + struct net *net = dev_net(skb_dst(rxskb)->dev); + struct dccp_v6_pernet *pn; + struct sock *ctl_sk; + struct dst_entry *dst; + + if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET) + return; + + if (!ipv6_unicast_destination(rxskb)) + return; + + pn = net_generic(net, dccp_v6_pernet_id); + ctl_sk = pn->v6_ctl_sk; + skb = dccp_ctl_make_reset(ctl_sk, rxskb); + if (skb == NULL) + return; + + rxip6h = ipv6_hdr(rxskb); + dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr, + &rxip6h->daddr); + + memset(&fl6, 0, sizeof(fl6)); + fl6.daddr = rxip6h->saddr; + fl6.saddr = rxip6h->daddr; + + fl6.flowi6_proto = IPPROTO_DCCP; + fl6.flowi6_oif = inet6_iif(rxskb); + fl6.fl6_dport = dccp_hdr(skb)->dccph_dport; + fl6.fl6_sport = dccp_hdr(skb)->dccph_sport; + security_skb_classify_flow(rxskb, flowi6_to_flowi_common(&fl6)); + + /* sk = NULL, but it is safe for now. RST socket required. */ + dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL); + if (!IS_ERR(dst)) { + skb_dst_set(skb, dst); + ip6_xmit(ctl_sk, skb, &fl6, 0, NULL, 0, 0); + DCCP_INC_STATS(DCCP_MIB_OUTSEGS); + DCCP_INC_STATS(DCCP_MIB_OUTRSTS); + return; + } + + kfree_skb(skb); +} + +static struct request_sock_ops dccp6_request_sock_ops = { + .family = AF_INET6, + .obj_size = sizeof(struct dccp6_request_sock), + .rtx_syn_ack = dccp_v6_send_response, + .send_ack = dccp_reqsk_send_ack, + .destructor = dccp_v6_reqsk_destructor, + .send_reset = dccp_v6_ctl_send_reset, + .syn_ack_timeout = dccp_syn_ack_timeout, +}; + +static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb) +{ + struct request_sock *req; + struct dccp_request_sock *dreq; + struct inet_request_sock *ireq; + struct ipv6_pinfo *np = inet6_sk(sk); + const __be32 service = dccp_hdr_request(skb)->dccph_req_service; + struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); + + if (skb->protocol == htons(ETH_P_IP)) + return dccp_v4_conn_request(sk, skb); + + if (!ipv6_unicast_destination(skb)) + return 0; /* discard, don't send a reset here */ + + if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) { + __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS); + return 0; + } + + if (dccp_bad_service_code(sk, service)) { + dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE; + goto drop; + } + /* + * There are no SYN attacks on IPv6, yet... + */ + dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY; + if (inet_csk_reqsk_queue_is_full(sk)) + goto drop; + + if (sk_acceptq_is_full(sk)) + goto drop; + + req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk, true); + if (req == NULL) + goto drop; + + if (dccp_reqsk_init(req, dccp_sk(sk), skb)) + goto drop_and_free; + + dreq = dccp_rsk(req); + if (dccp_parse_options(sk, dreq, skb)) + goto drop_and_free; + + ireq = inet_rsk(req); + ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr; + ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr; + ireq->ireq_family = AF_INET6; + ireq->ir_mark = inet_request_mark(sk, skb); + + if (security_inet_conn_request(sk, skb, req)) + goto drop_and_free; + + if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) || + np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo || + np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) { + refcount_inc(&skb->users); + ireq->pktopts = skb; + } + ireq->ir_iif = READ_ONCE(sk->sk_bound_dev_if); + + /* So that link locals have meaning */ + if (!ireq->ir_iif && + ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) + ireq->ir_iif = inet6_iif(skb); + + /* + * Step 3: Process LISTEN state + * + * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie + * + * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child(). + */ + dreq->dreq_isr = dcb->dccpd_seq; + dreq->dreq_gsr = dreq->dreq_isr; + dreq->dreq_iss = dccp_v6_init_sequence(skb); + dreq->dreq_gss = dreq->dreq_iss; + dreq->dreq_service = service; + + if (dccp_v6_send_response(sk, req)) + goto drop_and_free; + + inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT); + reqsk_put(req); + return 0; + +drop_and_free: + reqsk_free(req); +drop: + __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS); + return -1; +} + +static struct sock *dccp_v6_request_recv_sock(const struct sock *sk, + struct sk_buff *skb, + struct request_sock *req, + struct dst_entry *dst, + struct request_sock *req_unhash, + bool *own_req) +{ + struct inet_request_sock *ireq = inet_rsk(req); + struct ipv6_pinfo *newnp; + const struct ipv6_pinfo *np = inet6_sk(sk); + struct ipv6_txoptions *opt; + struct inet_sock *newinet; + struct dccp6_sock *newdp6; + struct sock *newsk; + + if (skb->protocol == htons(ETH_P_IP)) { + /* + * v6 mapped + */ + newsk = dccp_v4_request_recv_sock(sk, skb, req, dst, + req_unhash, own_req); + if (newsk == NULL) + return NULL; + + newdp6 = (struct dccp6_sock *)newsk; + newinet = inet_sk(newsk); + newinet->pinet6 = &newdp6->inet6; + newnp = inet6_sk(newsk); + + memcpy(newnp, np, sizeof(struct ipv6_pinfo)); + + newnp->saddr = newsk->sk_v6_rcv_saddr; + + inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped; + newsk->sk_backlog_rcv = dccp_v4_do_rcv; + newnp->pktoptions = NULL; + newnp->opt = NULL; + newnp->ipv6_mc_list = NULL; + newnp->ipv6_ac_list = NULL; + newnp->ipv6_fl_list = NULL; + newnp->mcast_oif = inet_iif(skb); + newnp->mcast_hops = ip_hdr(skb)->ttl; + + /* + * No need to charge this sock to the relevant IPv6 refcnt debug socks count + * here, dccp_create_openreq_child now does this for us, see the comment in + * that function for the gory details. -acme + */ + + /* It is tricky place. Until this moment IPv4 tcp + worked with IPv6 icsk.icsk_af_ops. + Sync it now. + */ + dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie); + + return newsk; + } + + + if (sk_acceptq_is_full(sk)) + goto out_overflow; + + if (!dst) { + struct flowi6 fl6; + + dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_DCCP); + if (!dst) + goto out; + } + + newsk = dccp_create_openreq_child(sk, req, skb); + if (newsk == NULL) + goto out_nonewsk; + + /* + * No need to charge this sock to the relevant IPv6 refcnt debug socks + * count here, dccp_create_openreq_child now does this for us, see the + * comment in that function for the gory details. -acme + */ + + ip6_dst_store(newsk, dst, NULL, NULL); + newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM | + NETIF_F_TSO); + newdp6 = (struct dccp6_sock *)newsk; + newinet = inet_sk(newsk); + newinet->pinet6 = &newdp6->inet6; + newnp = inet6_sk(newsk); + + memcpy(newnp, np, sizeof(struct ipv6_pinfo)); + + newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr; + newnp->saddr = ireq->ir_v6_loc_addr; + newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr; + newsk->sk_bound_dev_if = ireq->ir_iif; + + /* Now IPv6 options... + + First: no IPv4 options. + */ + newinet->inet_opt = NULL; + + /* Clone RX bits */ + newnp->rxopt.all = np->rxopt.all; + + newnp->ipv6_mc_list = NULL; + newnp->ipv6_ac_list = NULL; + newnp->ipv6_fl_list = NULL; + newnp->pktoptions = NULL; + newnp->opt = NULL; + newnp->mcast_oif = inet6_iif(skb); + newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; + + /* + * Clone native IPv6 options from listening socket (if any) + * + * Yes, keeping reference count would be much more clever, but we make + * one more one thing there: reattach optmem to newsk. + */ + opt = ireq->ipv6_opt; + if (!opt) + opt = rcu_dereference(np->opt); + if (opt) { + opt = ipv6_dup_options(newsk, opt); + RCU_INIT_POINTER(newnp->opt, opt); + } + inet_csk(newsk)->icsk_ext_hdr_len = 0; + if (opt) + inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen + + opt->opt_flen; + + dccp_sync_mss(newsk, dst_mtu(dst)); + + newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6; + newinet->inet_rcv_saddr = LOOPBACK4_IPV6; + + if (__inet_inherit_port(sk, newsk) < 0) { + inet_csk_prepare_forced_close(newsk); + dccp_done(newsk); + goto out; + } + *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), NULL); + /* Clone pktoptions received with SYN, if we own the req */ + if (*own_req && ireq->pktopts) { + newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk); + consume_skb(ireq->pktopts); + ireq->pktopts = NULL; + } + + return newsk; + +out_overflow: + __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); +out_nonewsk: + dst_release(dst); +out: + __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); + return NULL; +} + +/* The socket must have it's spinlock held when we get + * here. + * + * We have a potential double-lock case here, so even when + * doing backlog processing we use the BH locking scheme. + * This is because we cannot sleep with the original spinlock + * held. + */ +static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) +{ + struct ipv6_pinfo *np = inet6_sk(sk); + struct sk_buff *opt_skb = NULL; + + /* Imagine: socket is IPv6. IPv4 packet arrives, + goes to IPv4 receive handler and backlogged. + From backlog it always goes here. Kerboom... + Fortunately, dccp_rcv_established and rcv_established + handle them correctly, but it is not case with + dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK + */ + + if (skb->protocol == htons(ETH_P_IP)) + return dccp_v4_do_rcv(sk, skb); + + if (sk_filter(sk, skb)) + goto discard; + + /* + * socket locking is here for SMP purposes as backlog rcv is currently + * called with bh processing disabled. + */ + + /* Do Stevens' IPV6_PKTOPTIONS. + + Yes, guys, it is the only place in our code, where we + may make it not affecting IPv4. + The rest of code is protocol independent, + and I do not like idea to uglify IPv4. + + Actually, all the idea behind IPV6_PKTOPTIONS + looks not very well thought. For now we latch + options, received in the last packet, enqueued + by tcp. Feel free to propose better solution. + --ANK (980728) + */ + if (np->rxopt.all) + opt_skb = skb_clone_and_charge_r(skb, sk); + + if (sk->sk_state == DCCP_OPEN) { /* Fast path */ + if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len)) + goto reset; + if (opt_skb) + goto ipv6_pktoptions; + return 0; + } + + /* + * Step 3: Process LISTEN state + * If S.state == LISTEN, + * If P.type == Request or P contains a valid Init Cookie option, + * (* Must scan the packet's options to check for Init + * Cookies. Only Init Cookies are processed here, + * however; other options are processed in Step 8. This + * scan need only be performed if the endpoint uses Init + * Cookies *) + * (* Generate a new socket and switch to that socket *) + * Set S := new socket for this port pair + * S.state = RESPOND + * Choose S.ISS (initial seqno) or set from Init Cookies + * Initialize S.GAR := S.ISS + * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies + * Continue with S.state == RESPOND + * (* A Response packet will be generated in Step 11 *) + * Otherwise, + * Generate Reset(No Connection) unless P.type == Reset + * Drop packet and return + * + * NOTE: the check for the packet types is done in + * dccp_rcv_state_process + */ + + if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len)) + goto reset; + if (opt_skb) + goto ipv6_pktoptions; + return 0; + +reset: + dccp_v6_ctl_send_reset(sk, skb); +discard: + if (opt_skb != NULL) + __kfree_skb(opt_skb); + kfree_skb(skb); + return 0; + +/* Handling IPV6_PKTOPTIONS skb the similar + * way it's done for net/ipv6/tcp_ipv6.c + */ +ipv6_pktoptions: + if (!((1 << sk->sk_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) { + if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo) + np->mcast_oif = inet6_iif(opt_skb); + if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) + np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit; + if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass) + np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb)); + if (np->repflow) + np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb)); + if (ipv6_opt_accepted(sk, opt_skb, + &DCCP_SKB_CB(opt_skb)->header.h6)) { + memmove(IP6CB(opt_skb), + &DCCP_SKB_CB(opt_skb)->header.h6, + sizeof(struct inet6_skb_parm)); + opt_skb = xchg(&np->pktoptions, opt_skb); + } else { + __kfree_skb(opt_skb); + opt_skb = xchg(&np->pktoptions, NULL); + } + } + + kfree_skb(opt_skb); + return 0; +} + +static int dccp_v6_rcv(struct sk_buff *skb) +{ + const struct dccp_hdr *dh; + bool refcounted; + struct sock *sk; + int min_cov; + + /* Step 1: Check header basics */ + + if (dccp_invalid_packet(skb)) + goto discard_it; + + /* Step 1: If header checksum is incorrect, drop packet and return. */ + if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr, + &ipv6_hdr(skb)->daddr)) { + DCCP_WARN("dropped packet with invalid checksum\n"); + goto discard_it; + } + + dh = dccp_hdr(skb); + + DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh); + DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type; + + if (dccp_packet_without_ack(skb)) + DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ; + else + DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb); + +lookup: + sk = __inet6_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh), + dh->dccph_sport, dh->dccph_dport, + inet6_iif(skb), 0, &refcounted); + if (!sk) { + dccp_pr_debug("failed to look up flow ID in table and " + "get corresponding socket\n"); + goto no_dccp_socket; + } + + /* + * Step 2: + * ... or S.state == TIMEWAIT, + * Generate Reset(No Connection) unless P.type == Reset + * Drop packet and return + */ + if (sk->sk_state == DCCP_TIME_WAIT) { + dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n"); + inet_twsk_put(inet_twsk(sk)); + goto no_dccp_socket; + } + + if (sk->sk_state == DCCP_NEW_SYN_RECV) { + struct request_sock *req = inet_reqsk(sk); + struct sock *nsk; + + sk = req->rsk_listener; + if (unlikely(sk->sk_state != DCCP_LISTEN)) { + inet_csk_reqsk_queue_drop_and_put(sk, req); + goto lookup; + } + sock_hold(sk); + refcounted = true; + nsk = dccp_check_req(sk, skb, req); + if (!nsk) { + reqsk_put(req); + goto discard_and_relse; + } + if (nsk == sk) { + reqsk_put(req); + } else if (dccp_child_process(sk, nsk, skb)) { + dccp_v6_ctl_send_reset(sk, skb); + goto discard_and_relse; + } else { + sock_put(sk); + return 0; + } + } + /* + * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage + * o if MinCsCov = 0, only packets with CsCov = 0 are accepted + * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov + */ + min_cov = dccp_sk(sk)->dccps_pcrlen; + if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) { + dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n", + dh->dccph_cscov, min_cov); + /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */ + goto discard_and_relse; + } + + if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) + goto discard_and_relse; + nf_reset_ct(skb); + + return __sk_receive_skb(sk, skb, 1, dh->dccph_doff * 4, + refcounted) ? -1 : 0; + +no_dccp_socket: + if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) + goto discard_it; + /* + * Step 2: + * If no socket ... + * Generate Reset(No Connection) unless P.type == Reset + * Drop packet and return + */ + if (dh->dccph_type != DCCP_PKT_RESET) { + DCCP_SKB_CB(skb)->dccpd_reset_code = + DCCP_RESET_CODE_NO_CONNECTION; + dccp_v6_ctl_send_reset(sk, skb); + } + +discard_it: + kfree_skb(skb); + return 0; + +discard_and_relse: + if (refcounted) + sock_put(sk); + goto discard_it; +} + +static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr, + int addr_len) +{ + struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr; + struct inet_connection_sock *icsk = inet_csk(sk); + struct inet_sock *inet = inet_sk(sk); + struct ipv6_pinfo *np = inet6_sk(sk); + struct dccp_sock *dp = dccp_sk(sk); + struct in6_addr *saddr = NULL, *final_p, final; + struct ipv6_txoptions *opt; + struct flowi6 fl6; + struct dst_entry *dst; + int addr_type; + int err; + + dp->dccps_role = DCCP_ROLE_CLIENT; + + if (addr_len < SIN6_LEN_RFC2133) + return -EINVAL; + + if (usin->sin6_family != AF_INET6) + return -EAFNOSUPPORT; + + memset(&fl6, 0, sizeof(fl6)); + + if (np->sndflow) { + fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK; + IP6_ECN_flow_init(fl6.flowlabel); + if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) { + struct ip6_flowlabel *flowlabel; + flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); + if (IS_ERR(flowlabel)) + return -EINVAL; + fl6_sock_release(flowlabel); + } + } + /* + * connect() to INADDR_ANY means loopback (BSD'ism). + */ + if (ipv6_addr_any(&usin->sin6_addr)) + usin->sin6_addr.s6_addr[15] = 1; + + addr_type = ipv6_addr_type(&usin->sin6_addr); + + if (addr_type & IPV6_ADDR_MULTICAST) + return -ENETUNREACH; + + if (addr_type & IPV6_ADDR_LINKLOCAL) { + if (addr_len >= sizeof(struct sockaddr_in6) && + usin->sin6_scope_id) { + /* If interface is set while binding, indices + * must coincide. + */ + if (sk->sk_bound_dev_if && + sk->sk_bound_dev_if != usin->sin6_scope_id) + return -EINVAL; + + sk->sk_bound_dev_if = usin->sin6_scope_id; + } + + /* Connect to link-local address requires an interface */ + if (!sk->sk_bound_dev_if) + return -EINVAL; + } + + sk->sk_v6_daddr = usin->sin6_addr; + np->flow_label = fl6.flowlabel; + + /* + * DCCP over IPv4 + */ + if (addr_type == IPV6_ADDR_MAPPED) { + u32 exthdrlen = icsk->icsk_ext_hdr_len; + struct sockaddr_in sin; + + SOCK_DEBUG(sk, "connect: ipv4 mapped\n"); + + if (ipv6_only_sock(sk)) + return -ENETUNREACH; + + sin.sin_family = AF_INET; + sin.sin_port = usin->sin6_port; + sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3]; + + icsk->icsk_af_ops = &dccp_ipv6_mapped; + sk->sk_backlog_rcv = dccp_v4_do_rcv; + + err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin)); + if (err) { + icsk->icsk_ext_hdr_len = exthdrlen; + icsk->icsk_af_ops = &dccp_ipv6_af_ops; + sk->sk_backlog_rcv = dccp_v6_do_rcv; + goto failure; + } + np->saddr = sk->sk_v6_rcv_saddr; + return err; + } + + if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) + saddr = &sk->sk_v6_rcv_saddr; + + fl6.flowi6_proto = IPPROTO_DCCP; + fl6.daddr = sk->sk_v6_daddr; + fl6.saddr = saddr ? *saddr : np->saddr; + fl6.flowi6_oif = sk->sk_bound_dev_if; + fl6.fl6_dport = usin->sin6_port; + fl6.fl6_sport = inet->inet_sport; + security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6)); + + opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk)); + final_p = fl6_update_dst(&fl6, opt, &final); + + dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p); + if (IS_ERR(dst)) { + err = PTR_ERR(dst); + goto failure; + } + + if (saddr == NULL) { + saddr = &fl6.saddr; + + err = inet_bhash2_update_saddr(sk, saddr, AF_INET6); + if (err) + goto failure; + } + + /* set the source address */ + np->saddr = *saddr; + inet->inet_rcv_saddr = LOOPBACK4_IPV6; + + ip6_dst_store(sk, dst, NULL, NULL); + + icsk->icsk_ext_hdr_len = 0; + if (opt) + icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen; + + inet->inet_dport = usin->sin6_port; + + dccp_set_state(sk, DCCP_REQUESTING); + err = inet6_hash_connect(&dccp_death_row, sk); + if (err) + goto late_failure; + + dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32, + sk->sk_v6_daddr.s6_addr32, + inet->inet_sport, + inet->inet_dport); + err = dccp_connect(sk); + if (err) + goto late_failure; + + return 0; + +late_failure: + dccp_set_state(sk, DCCP_CLOSED); + inet_bhash2_reset_saddr(sk); + __sk_dst_reset(sk); +failure: + inet->inet_dport = 0; + sk->sk_route_caps = 0; + return err; +} + +static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = { + .queue_xmit = inet6_csk_xmit, + .send_check = dccp_v6_send_check, + .rebuild_header = inet6_sk_rebuild_header, + .conn_request = dccp_v6_conn_request, + .syn_recv_sock = dccp_v6_request_recv_sock, + .net_header_len = sizeof(struct ipv6hdr), + .setsockopt = ipv6_setsockopt, + .getsockopt = ipv6_getsockopt, + .addr2sockaddr = inet6_csk_addr2sockaddr, + .sockaddr_len = sizeof(struct sockaddr_in6), +}; + +/* + * DCCP over IPv4 via INET6 API + */ +static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = { + .queue_xmit = ip_queue_xmit, + .send_check = dccp_v4_send_check, + .rebuild_header = inet_sk_rebuild_header, + .conn_request = dccp_v6_conn_request, + .syn_recv_sock = dccp_v6_request_recv_sock, + .net_header_len = sizeof(struct iphdr), + .setsockopt = ipv6_setsockopt, + .getsockopt = ipv6_getsockopt, + .addr2sockaddr = inet6_csk_addr2sockaddr, + .sockaddr_len = sizeof(struct sockaddr_in6), +}; + +static void dccp_v6_sk_destruct(struct sock *sk) +{ + dccp_destruct_common(sk); + inet6_sock_destruct(sk); +} + +/* NOTE: A lot of things set to zero explicitly by call to + * sk_alloc() so need not be done here. + */ +static int dccp_v6_init_sock(struct sock *sk) +{ + static __u8 dccp_v6_ctl_sock_initialized; + int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized); + + if (err == 0) { + if (unlikely(!dccp_v6_ctl_sock_initialized)) + dccp_v6_ctl_sock_initialized = 1; + inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops; + sk->sk_destruct = dccp_v6_sk_destruct; + } + + return err; +} + +static struct timewait_sock_ops dccp6_timewait_sock_ops = { + .twsk_obj_size = sizeof(struct dccp6_timewait_sock), +}; + +static struct proto dccp_v6_prot = { + .name = "DCCPv6", + .owner = THIS_MODULE, + .close = dccp_close, + .connect = dccp_v6_connect, + .disconnect = dccp_disconnect, + .ioctl = dccp_ioctl, + .init = dccp_v6_init_sock, + .setsockopt = dccp_setsockopt, + .getsockopt = dccp_getsockopt, + .sendmsg = dccp_sendmsg, + .recvmsg = dccp_recvmsg, + .backlog_rcv = dccp_v6_do_rcv, + .hash = inet6_hash, + .unhash = inet_unhash, + .accept = inet_csk_accept, + .get_port = inet_csk_get_port, + .shutdown = dccp_shutdown, + .destroy = dccp_destroy_sock, + .orphan_count = &dccp_orphan_count, + .max_header = MAX_DCCP_HEADER, + .obj_size = sizeof(struct dccp6_sock), + .slab_flags = SLAB_TYPESAFE_BY_RCU, + .rsk_prot = &dccp6_request_sock_ops, + .twsk_prot = &dccp6_timewait_sock_ops, + .h.hashinfo = &dccp_hashinfo, +}; + +static const struct inet6_protocol dccp_v6_protocol = { + .handler = dccp_v6_rcv, + .err_handler = dccp_v6_err, + .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, +}; + +static const struct proto_ops inet6_dccp_ops = { + .family = PF_INET6, + .owner = THIS_MODULE, + .release = inet6_release, + .bind = inet6_bind, + .connect = inet_stream_connect, + .socketpair = sock_no_socketpair, + .accept = inet_accept, + .getname = inet6_getname, + .poll = dccp_poll, + .ioctl = inet6_ioctl, + .gettstamp = sock_gettstamp, + .listen = inet_dccp_listen, + .shutdown = inet_shutdown, + .setsockopt = sock_common_setsockopt, + .getsockopt = sock_common_getsockopt, + .sendmsg = inet_sendmsg, + .recvmsg = sock_common_recvmsg, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, +#ifdef CONFIG_COMPAT + .compat_ioctl = inet6_compat_ioctl, +#endif +}; + +static struct inet_protosw dccp_v6_protosw = { + .type = SOCK_DCCP, + .protocol = IPPROTO_DCCP, + .prot = &dccp_v6_prot, + .ops = &inet6_dccp_ops, + .flags = INET_PROTOSW_ICSK, +}; + +static int __net_init dccp_v6_init_net(struct net *net) +{ + struct dccp_v6_pernet *pn = net_generic(net, dccp_v6_pernet_id); + + if (dccp_hashinfo.bhash == NULL) + return -ESOCKTNOSUPPORT; + + return inet_ctl_sock_create(&pn->v6_ctl_sk, PF_INET6, + SOCK_DCCP, IPPROTO_DCCP, net); +} + +static void __net_exit dccp_v6_exit_net(struct net *net) +{ + struct dccp_v6_pernet *pn = net_generic(net, dccp_v6_pernet_id); + + inet_ctl_sock_destroy(pn->v6_ctl_sk); +} + +static void __net_exit dccp_v6_exit_batch(struct list_head *net_exit_list) +{ + inet_twsk_purge(&dccp_hashinfo, AF_INET6); +} + +static struct pernet_operations dccp_v6_ops = { + .init = dccp_v6_init_net, + .exit = dccp_v6_exit_net, + .exit_batch = dccp_v6_exit_batch, + .id = &dccp_v6_pernet_id, + .size = sizeof(struct dccp_v6_pernet), +}; + +static int __init dccp_v6_init(void) +{ + int err = proto_register(&dccp_v6_prot, 1); + + if (err) + goto out; + + inet6_register_protosw(&dccp_v6_protosw); + + err = register_pernet_subsys(&dccp_v6_ops); + if (err) + goto out_destroy_ctl_sock; + + err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP); + if (err) + goto out_unregister_proto; + +out: + return err; +out_unregister_proto: + unregister_pernet_subsys(&dccp_v6_ops); +out_destroy_ctl_sock: + inet6_unregister_protosw(&dccp_v6_protosw); + proto_unregister(&dccp_v6_prot); + goto out; +} + +static void __exit dccp_v6_exit(void) +{ + inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP); + unregister_pernet_subsys(&dccp_v6_ops); + inet6_unregister_protosw(&dccp_v6_protosw); + proto_unregister(&dccp_v6_prot); +} + +module_init(dccp_v6_init); +module_exit(dccp_v6_exit); + +/* + * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33) + * values directly, Also cover the case where the protocol is not specified, + * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP + */ +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6); +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>"); +MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol"); |