diff options
Diffstat (limited to 'net/dccp/ipv4.c')
| -rw-r--r-- | net/dccp/ipv4.c | 1106 |
1 files changed, 0 insertions, 1106 deletions
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c deleted file mode 100644 index be515ba821e2..000000000000 --- a/net/dccp/ipv4.c +++ /dev/null @@ -1,1106 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * net/dccp/ipv4.c - * - * An implementation of the DCCP protocol - * Arnaldo Carvalho de Melo <acme@conectiva.com.br> - */ - -#include <linux/dccp.h> -#include <linux/icmp.h> -#include <linux/slab.h> -#include <linux/module.h> -#include <linux/skbuff.h> -#include <linux/random.h> - -#include <net/icmp.h> -#include <net/inet_common.h> -#include <net/inet_dscp.h> -#include <net/inet_hashtables.h> -#include <net/inet_sock.h> -#include <net/protocol.h> -#include <net/sock.h> -#include <net/timewait_sock.h> -#include <net/tcp_states.h> -#include <net/xfrm.h> -#include <net/secure_seq.h> -#include <net/netns/generic.h> -#include <net/rstreason.h> - -#include "ackvec.h" -#include "ccid.h" -#include "dccp.h" -#include "feat.h" - -struct dccp_v4_pernet { - struct sock *v4_ctl_sk; -}; - -static unsigned int dccp_v4_pernet_id __read_mostly; - -/* - * The per-net v4_ctl_sk socket is used for responding to - * the Out-of-the-blue (OOTB) packets. A control sock will be created - * for this socket at the initialization time. - */ - -int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) -{ - const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr; - struct inet_sock *inet = inet_sk(sk); - struct dccp_sock *dp = dccp_sk(sk); - __be16 orig_sport, orig_dport; - __be32 daddr, nexthop; - struct flowi4 *fl4; - struct rtable *rt; - int err; - struct ip_options_rcu *inet_opt; - - dp->dccps_role = DCCP_ROLE_CLIENT; - - if (addr_len < sizeof(struct sockaddr_in)) - return -EINVAL; - - if (usin->sin_family != AF_INET) - return -EAFNOSUPPORT; - - nexthop = daddr = usin->sin_addr.s_addr; - - inet_opt = rcu_dereference_protected(inet->inet_opt, - lockdep_sock_is_held(sk)); - if (inet_opt != NULL && inet_opt->opt.srr) { - if (daddr == 0) - return -EINVAL; - nexthop = inet_opt->opt.faddr; - } - - orig_sport = inet->inet_sport; - orig_dport = usin->sin_port; - fl4 = &inet->cork.fl.u.ip4; - rt = ip_route_connect(fl4, nexthop, inet->inet_saddr, - sk->sk_bound_dev_if, IPPROTO_DCCP, orig_sport, - orig_dport, sk); - if (IS_ERR(rt)) - return PTR_ERR(rt); - - if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) { - ip_rt_put(rt); - return -ENETUNREACH; - } - - if (inet_opt == NULL || !inet_opt->opt.srr) - daddr = fl4->daddr; - - if (inet->inet_saddr == 0) { - err = inet_bhash2_update_saddr(sk, &fl4->saddr, AF_INET); - if (err) { - ip_rt_put(rt); - return err; - } - } else { - sk_rcv_saddr_set(sk, inet->inet_saddr); - } - - inet->inet_dport = usin->sin_port; - sk_daddr_set(sk, daddr); - - inet_csk(sk)->icsk_ext_hdr_len = 0; - if (inet_opt) - inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen; - /* - * Socket identity is still unknown (sport may be zero). - * However we set state to DCCP_REQUESTING and not releasing socket - * lock select source port, enter ourselves into the hash tables and - * complete initialization after this. - */ - dccp_set_state(sk, DCCP_REQUESTING); - err = inet_hash_connect(&dccp_death_row, sk); - if (err != 0) - goto failure; - - rt = ip_route_newports(fl4, rt, orig_sport, orig_dport, - inet->inet_sport, inet->inet_dport, sk); - if (IS_ERR(rt)) { - err = PTR_ERR(rt); - rt = NULL; - goto failure; - } - /* OK, now commit destination to socket. */ - sk_setup_caps(sk, &rt->dst); - - dp->dccps_iss = secure_dccp_sequence_number(inet->inet_saddr, - inet->inet_daddr, - inet->inet_sport, - inet->inet_dport); - atomic_set(&inet->inet_id, get_random_u16()); - - err = dccp_connect(sk); - rt = NULL; - if (err != 0) - goto failure; -out: - return err; -failure: - /* - * This unhashes the socket and releases the local port, if necessary. - */ - dccp_set_state(sk, DCCP_CLOSED); - inet_bhash2_reset_saddr(sk); - ip_rt_put(rt); - sk->sk_route_caps = 0; - inet->inet_dport = 0; - goto out; -} -EXPORT_SYMBOL_GPL(dccp_v4_connect); - -/* - * This routine does path mtu discovery as defined in RFC1191. - */ -static inline void dccp_do_pmtu_discovery(struct sock *sk, - const struct iphdr *iph, - u32 mtu) -{ - struct dst_entry *dst; - const struct inet_sock *inet = inet_sk(sk); - const struct dccp_sock *dp = dccp_sk(sk); - - /* We are not interested in DCCP_LISTEN and request_socks (RESPONSEs - * send out by Linux are always < 576bytes so they should go through - * unfragmented). - */ - if (sk->sk_state == DCCP_LISTEN) - return; - - dst = inet_csk_update_pmtu(sk, mtu); - if (!dst) - return; - - /* Something is about to be wrong... Remember soft error - * for the case, if this connection will not able to recover. - */ - if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst)) - WRITE_ONCE(sk->sk_err_soft, EMSGSIZE); - - mtu = dst_mtu(dst); - - if (inet->pmtudisc != IP_PMTUDISC_DONT && - ip_sk_accept_pmtu(sk) && - inet_csk(sk)->icsk_pmtu_cookie > mtu) { - dccp_sync_mss(sk, mtu); - - /* - * From RFC 4340, sec. 14.1: - * - * DCCP-Sync packets are the best choice for upward - * probing, since DCCP-Sync probes do not risk application - * data loss. - */ - dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC); - } /* else let the usual retransmit timer handle it */ -} - -static void dccp_do_redirect(struct sk_buff *skb, struct sock *sk) -{ - struct dst_entry *dst = __sk_dst_check(sk, 0); - - if (dst) - dst->ops->redirect(dst, sk, skb); -} - -void dccp_req_err(struct sock *sk, u64 seq) - { - struct request_sock *req = inet_reqsk(sk); - struct net *net = sock_net(sk); - - /* - * ICMPs are not backlogged, hence we cannot get an established - * socket here. - */ - if (!between48(seq, dccp_rsk(req)->dreq_iss, dccp_rsk(req)->dreq_gss)) { - __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); - } else { - /* - * Still in RESPOND, just remove it silently. - * There is no good way to pass the error to the newly - * created socket, and POSIX does not want network - * errors returned from accept(). - */ - inet_csk_reqsk_queue_drop(req->rsk_listener, req); - } - reqsk_put(req); -} -EXPORT_SYMBOL(dccp_req_err); - -/* - * This routine is called by the ICMP module when it gets some sort of error - * condition. If err < 0 then the socket should be closed and the error - * returned to the user. If err > 0 it's just the icmp type << 8 | icmp code. - * After adjustment header points to the first 8 bytes of the tcp header. We - * need to find the appropriate port. - * - * The locking strategy used here is very "optimistic". When someone else - * accesses the socket the ICMP is just dropped and for some paths there is no - * check at all. A more general error queue to queue errors for later handling - * is probably better. - */ -static int dccp_v4_err(struct sk_buff *skb, u32 info) -{ - const struct iphdr *iph = (struct iphdr *)skb->data; - const u8 offset = iph->ihl << 2; - const struct dccp_hdr *dh; - struct dccp_sock *dp; - const int type = icmp_hdr(skb)->type; - const int code = icmp_hdr(skb)->code; - struct sock *sk; - __u64 seq; - int err; - 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; - iph = (struct iphdr *)skb->data; - dh = (struct dccp_hdr *)(skb->data + offset); - - sk = __inet_lookup_established(net, &dccp_hashinfo, - iph->daddr, dh->dccph_dport, - iph->saddr, ntohs(dh->dccph_sport), - inet_iif(skb), 0); - if (!sk) { - __ICMP_INC_STATS(net, ICMP_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 too many ICMPs get dropped on busy - * servers this needs to be solved differently. - */ - 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; - } - - switch (type) { - case ICMP_REDIRECT: - if (!sock_owned_by_user(sk)) - dccp_do_redirect(skb, sk); - goto out; - case ICMP_SOURCE_QUENCH: - /* Just silently ignore these. */ - goto out; - case ICMP_PARAMETERPROB: - err = EPROTO; - break; - case ICMP_DEST_UNREACH: - if (code > NR_ICMP_UNREACH) - goto out; - - if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ - if (!sock_owned_by_user(sk)) - dccp_do_pmtu_discovery(sk, iph, info); - goto out; - } - - err = icmp_err_convert[code].errno; - break; - case ICMP_TIME_EXCEEDED: - err = EHOSTUNREACH; - break; - default: - goto out; - } - - switch (sk->sk_state) { - case DCCP_REQUESTING: - case DCCP_RESPOND: - if (!sock_owned_by_user(sk)) { - __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS); - sk->sk_err = err; - - sk_error_report(sk); - - dccp_done(sk); - } else { - WRITE_ONCE(sk->sk_err_soft, err); - } - goto out; - } - - /* If we've already connected we will keep trying - * until we time out, or the user gives up. - * - * rfc1122 4.2.3.9 allows to consider as hard errors - * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too, - * but it is obsoleted by pmtu discovery). - * - * Note, that in modern internet, where routing is unreliable - * and in each dark corner broken firewalls sit, sending random - * errors ordered by their masters even this two messages finally lose - * their original sense (even Linux sends invalid PORT_UNREACHs) - * - * Now we are in compliance with RFCs. - * --ANK (980905) - */ - - if (!sock_owned_by_user(sk) && inet_test_bit(RECVERR, sk)) { - sk->sk_err = err; - sk_error_report(sk); - } else { /* Only an error on timeout */ - WRITE_ONCE(sk->sk_err_soft, err); - } -out: - bh_unlock_sock(sk); - sock_put(sk); - return 0; -} - -static inline __sum16 dccp_v4_csum_finish(struct sk_buff *skb, - __be32 src, __be32 dst) -{ - return csum_tcpudp_magic(src, dst, skb->len, IPPROTO_DCCP, skb->csum); -} - -void dccp_v4_send_check(struct sock *sk, struct sk_buff *skb) -{ - const struct inet_sock *inet = inet_sk(sk); - struct dccp_hdr *dh = dccp_hdr(skb); - - dccp_csum_outgoing(skb); - dh->dccph_checksum = dccp_v4_csum_finish(skb, - inet->inet_saddr, - inet->inet_daddr); -} -EXPORT_SYMBOL_GPL(dccp_v4_send_check); - -static inline u64 dccp_v4_init_sequence(const struct sk_buff *skb) -{ - return secure_dccp_sequence_number(ip_hdr(skb)->daddr, - ip_hdr(skb)->saddr, - dccp_hdr(skb)->dccph_dport, - dccp_hdr(skb)->dccph_sport); -} - -/* - * The three way handshake has completed - we got a valid ACK or DATAACK - - * now create the new socket. - * - * This is the equivalent of TCP's tcp_v4_syn_recv_sock - */ -struct sock *dccp_v4_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; - struct inet_sock *newinet; - struct sock *newsk; - - if (sk_acceptq_is_full(sk)) - goto exit_overflow; - - newsk = dccp_create_openreq_child(sk, req, skb); - if (newsk == NULL) - goto exit_nonewsk; - - newinet = inet_sk(newsk); - ireq = inet_rsk(req); - sk_daddr_set(newsk, ireq->ir_rmt_addr); - sk_rcv_saddr_set(newsk, ireq->ir_loc_addr); - newinet->inet_saddr = ireq->ir_loc_addr; - RCU_INIT_POINTER(newinet->inet_opt, rcu_dereference(ireq->ireq_opt)); - newinet->mc_index = inet_iif(skb); - newinet->mc_ttl = ip_hdr(skb)->ttl; - atomic_set(&newinet->inet_id, get_random_u16()); - - if (dst == NULL && (dst = inet_csk_route_child_sock(sk, newsk, req)) == NULL) - goto put_and_exit; - - sk_setup_caps(newsk, dst); - - dccp_sync_mss(newsk, dst_mtu(dst)); - - if (__inet_inherit_port(sk, newsk) < 0) - goto put_and_exit; - *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), NULL); - if (*own_req) - ireq->ireq_opt = NULL; - else - newinet->inet_opt = NULL; - return newsk; - -exit_overflow: - __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); -exit_nonewsk: - dst_release(dst); -exit: - __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); - return NULL; -put_and_exit: - newinet->inet_opt = NULL; - inet_csk_prepare_forced_close(newsk); - dccp_done(newsk); - goto exit; -} -EXPORT_SYMBOL_GPL(dccp_v4_request_recv_sock); - -static struct dst_entry* dccp_v4_route_skb(struct net *net, struct sock *sk, - struct sk_buff *skb) -{ - struct rtable *rt; - const struct iphdr *iph = ip_hdr(skb); - struct flowi4 fl4 = { - .flowi4_oif = inet_iif(skb), - .daddr = iph->saddr, - .saddr = iph->daddr, - .flowi4_tos = inet_dscp_to_dsfield(inet_sk_dscp(inet_sk(sk))), - .flowi4_scope = ip_sock_rt_scope(sk), - .flowi4_proto = sk->sk_protocol, - .fl4_sport = dccp_hdr(skb)->dccph_dport, - .fl4_dport = dccp_hdr(skb)->dccph_sport, - }; - - security_skb_classify_flow(skb, flowi4_to_flowi_common(&fl4)); - rt = ip_route_output_flow(net, &fl4, sk); - if (IS_ERR(rt)) { - IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); - return NULL; - } - - return &rt->dst; -} - -static int dccp_v4_send_response(const struct sock *sk, struct request_sock *req) -{ - int err = -1; - struct sk_buff *skb; - struct dst_entry *dst; - struct flowi4 fl4; - - dst = inet_csk_route_req(sk, &fl4, req); - if (dst == NULL) - goto out; - - skb = dccp_make_response(sk, dst, req); - if (skb != NULL) { - const struct inet_request_sock *ireq = inet_rsk(req); - struct dccp_hdr *dh = dccp_hdr(skb); - - dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->ir_loc_addr, - ireq->ir_rmt_addr); - rcu_read_lock(); - err = ip_build_and_send_pkt(skb, sk, ireq->ir_loc_addr, - ireq->ir_rmt_addr, - rcu_dereference(ireq->ireq_opt), - READ_ONCE(inet_sk(sk)->tos)); - rcu_read_unlock(); - err = net_xmit_eval(err); - } - -out: - dst_release(dst); - return err; -} - -static void dccp_v4_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb, - enum sk_rst_reason reason) -{ - int err; - const struct iphdr *rxiph; - struct sk_buff *skb; - struct dst_entry *dst; - struct net *net = dev_net(skb_dst(rxskb)->dev); - struct dccp_v4_pernet *pn; - struct sock *ctl_sk; - - /* Never send a reset in response to a reset. */ - if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET) - return; - - if (skb_rtable(rxskb)->rt_type != RTN_LOCAL) - return; - - pn = net_generic(net, dccp_v4_pernet_id); - ctl_sk = pn->v4_ctl_sk; - dst = dccp_v4_route_skb(net, ctl_sk, rxskb); - if (dst == NULL) - return; - - skb = dccp_ctl_make_reset(ctl_sk, rxskb); - if (skb == NULL) - goto out; - - rxiph = ip_hdr(rxskb); - dccp_hdr(skb)->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr, - rxiph->daddr); - skb_dst_set(skb, dst_clone(dst)); - - local_bh_disable(); - bh_lock_sock(ctl_sk); - err = ip_build_and_send_pkt(skb, ctl_sk, - rxiph->daddr, rxiph->saddr, NULL, - inet_sk(ctl_sk)->tos); - bh_unlock_sock(ctl_sk); - - if (net_xmit_eval(err) == 0) { - __DCCP_INC_STATS(DCCP_MIB_OUTSEGS); - __DCCP_INC_STATS(DCCP_MIB_OUTRSTS); - } - local_bh_enable(); -out: - dst_release(dst); -} - -static void dccp_v4_reqsk_destructor(struct request_sock *req) -{ - dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg); - kfree(rcu_dereference_protected(inet_rsk(req)->ireq_opt, 1)); -} - -void dccp_syn_ack_timeout(const struct request_sock *req) -{ -} -EXPORT_SYMBOL(dccp_syn_ack_timeout); - -static struct request_sock_ops dccp_request_sock_ops __read_mostly = { - .family = PF_INET, - .obj_size = sizeof(struct dccp_request_sock), - .rtx_syn_ack = dccp_v4_send_response, - .send_ack = dccp_reqsk_send_ack, - .destructor = dccp_v4_reqsk_destructor, - .send_reset = dccp_v4_ctl_send_reset, - .syn_ack_timeout = dccp_syn_ack_timeout, -}; - -int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb) -{ - struct inet_request_sock *ireq; - struct request_sock *req; - struct dccp_request_sock *dreq; - const __be32 service = dccp_hdr_request(skb)->dccph_req_service; - struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); - - /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */ - if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) - return 0; /* discard, don't send a reset here */ - - if (dccp_bad_service_code(sk, service)) { - dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE; - goto drop; - } - /* - * TW buckets are converted to open requests without - * limitations, they conserve resources and peer is - * evidently real one. - */ - 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(&dccp_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); - sk_rcv_saddr_set(req_to_sk(req), ip_hdr(skb)->daddr); - sk_daddr_set(req_to_sk(req), ip_hdr(skb)->saddr); - ireq->ir_mark = inet_request_mark(sk, skb); - ireq->ireq_family = AF_INET; - ireq->ir_iif = READ_ONCE(sk->sk_bound_dev_if); - - if (security_inet_conn_request(sk, skb, req)) - goto drop_and_free; - - /* - * 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_v4_init_sequence(skb); - dreq->dreq_gss = dreq->dreq_iss; - dreq->dreq_service = service; - - if (dccp_v4_send_response(sk, req)) - goto drop_and_free; - - if (unlikely(!inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT))) - reqsk_free(req); - else - reqsk_put(req); - - return 0; - -drop_and_free: - reqsk_free(req); -drop: - __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS); - return -1; -} -EXPORT_SYMBOL_GPL(dccp_v4_conn_request); - -int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) -{ - struct dccp_hdr *dh = dccp_hdr(skb); - - if (sk->sk_state == DCCP_OPEN) { /* Fast path */ - if (dccp_rcv_established(sk, skb, dh, skb->len)) - goto reset; - return 0; - } - - /* - * Step 3: Process LISTEN state - * 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, dh, skb->len)) - goto reset; - return 0; - -reset: - dccp_v4_ctl_send_reset(sk, skb, SK_RST_REASON_NOT_SPECIFIED); - kfree_skb(skb); - return 0; -} -EXPORT_SYMBOL_GPL(dccp_v4_do_rcv); - -/** - * dccp_invalid_packet - check for malformed packets - * @skb: Packet to validate - * - * Implements RFC 4340, 8.5: Step 1: Check header basics - * Packets that fail these checks are ignored and do not receive Resets. - */ -int dccp_invalid_packet(struct sk_buff *skb) -{ - const struct dccp_hdr *dh; - unsigned int cscov; - u8 dccph_doff; - - if (skb->pkt_type != PACKET_HOST) - return 1; - - /* If the packet is shorter than 12 bytes, drop packet and return */ - if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) { - DCCP_WARN("pskb_may_pull failed\n"); - return 1; - } - - dh = dccp_hdr(skb); - - /* If P.type is not understood, drop packet and return */ - if (dh->dccph_type >= DCCP_PKT_INVALID) { - DCCP_WARN("invalid packet type\n"); - return 1; - } - - /* - * If P.Data Offset is too small for packet type, drop packet and return - */ - dccph_doff = dh->dccph_doff; - if (dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) { - DCCP_WARN("P.Data Offset(%u) too small\n", dccph_doff); - return 1; - } - /* - * If P.Data Offset is too large for packet, drop packet and return - */ - if (!pskb_may_pull(skb, dccph_doff * sizeof(u32))) { - DCCP_WARN("P.Data Offset(%u) too large\n", dccph_doff); - return 1; - } - dh = dccp_hdr(skb); - /* - * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet - * has short sequence numbers), drop packet and return - */ - if ((dh->dccph_type < DCCP_PKT_DATA || - dh->dccph_type > DCCP_PKT_DATAACK) && dh->dccph_x == 0) { - DCCP_WARN("P.type (%s) not Data || [Data]Ack, while P.X == 0\n", - dccp_packet_name(dh->dccph_type)); - return 1; - } - - /* - * If P.CsCov is too large for the packet size, drop packet and return. - * This must come _before_ checksumming (not as RFC 4340 suggests). - */ - cscov = dccp_csum_coverage(skb); - if (cscov > skb->len) { - DCCP_WARN("P.CsCov %u exceeds packet length %d\n", - dh->dccph_cscov, skb->len); - return 1; - } - - /* If header checksum is incorrect, drop packet and return. - * (This step is completed in the AF-dependent functions.) */ - skb->csum = skb_checksum(skb, 0, cscov, 0); - - return 0; -} -EXPORT_SYMBOL_GPL(dccp_invalid_packet); - -/* this is called when real data arrives */ -static int dccp_v4_rcv(struct sk_buff *skb) -{ - const struct dccp_hdr *dh; - const struct iphdr *iph; - bool refcounted; - struct sock *sk; - int min_cov; - - /* Step 1: Check header basics */ - - if (dccp_invalid_packet(skb)) - goto discard_it; - - iph = ip_hdr(skb); - /* Step 1: If header checksum is incorrect, drop packet and return */ - if (dccp_v4_csum_finish(skb, iph->saddr, iph->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; - - dccp_pr_debug("%8.8s src=%pI4@%-5d dst=%pI4@%-5d seq=%llu", - dccp_packet_name(dh->dccph_type), - &iph->saddr, ntohs(dh->dccph_sport), - &iph->daddr, ntohs(dh->dccph_dport), - (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq); - - if (dccp_packet_without_ack(skb)) { - DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ; - dccp_pr_debug_cat("\n"); - } else { - DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb); - dccp_pr_debug_cat(", ack=%llu\n", (unsigned long long) - DCCP_SKB_CB(skb)->dccpd_ack_seq); - } - -lookup: - sk = __inet_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh), - dh->dccph_sport, dh->dccph_dport, 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_v4_ctl_send_reset(sk, skb, SK_RST_REASON_NOT_SPECIFIED); - 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: "Such packets SHOULD be reported using Data Dropped - * options (Section 11.7) with Drop Code 0, Protocol - * Constraints." */ - goto discard_and_relse; - } - - if (!xfrm4_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); - -no_dccp_socket: - if (!xfrm4_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_v4_ctl_send_reset(sk, skb, SK_RST_REASON_NOT_SPECIFIED); - } - -discard_it: - kfree_skb(skb); - return 0; - -discard_and_relse: - if (refcounted) - sock_put(sk); - goto discard_it; -} - -static const struct inet_connection_sock_af_ops dccp_ipv4_af_ops = { - .queue_xmit = ip_queue_xmit, - .send_check = dccp_v4_send_check, - .rebuild_header = inet_sk_rebuild_header, - .conn_request = dccp_v4_conn_request, - .syn_recv_sock = dccp_v4_request_recv_sock, - .net_header_len = sizeof(struct iphdr), - .setsockopt = ip_setsockopt, - .getsockopt = ip_getsockopt, - .addr2sockaddr = inet_csk_addr2sockaddr, - .sockaddr_len = sizeof(struct sockaddr_in), -}; - -static int dccp_v4_init_sock(struct sock *sk) -{ - static __u8 dccp_v4_ctl_sock_initialized; - int err = dccp_init_sock(sk, dccp_v4_ctl_sock_initialized); - - if (err == 0) { - if (unlikely(!dccp_v4_ctl_sock_initialized)) - dccp_v4_ctl_sock_initialized = 1; - inet_csk(sk)->icsk_af_ops = &dccp_ipv4_af_ops; - } - - return err; -} - -static struct timewait_sock_ops dccp_timewait_sock_ops = { - .twsk_obj_size = sizeof(struct inet_timewait_sock), -}; - -static struct proto dccp_v4_prot = { - .name = "DCCP", - .owner = THIS_MODULE, - .close = dccp_close, - .connect = dccp_v4_connect, - .disconnect = dccp_disconnect, - .ioctl = dccp_ioctl, - .init = dccp_v4_init_sock, - .setsockopt = dccp_setsockopt, - .getsockopt = dccp_getsockopt, - .sendmsg = dccp_sendmsg, - .recvmsg = dccp_recvmsg, - .backlog_rcv = dccp_v4_do_rcv, - .hash = inet_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 dccp_sock), - .slab_flags = SLAB_TYPESAFE_BY_RCU, - .rsk_prot = &dccp_request_sock_ops, - .twsk_prot = &dccp_timewait_sock_ops, - .h.hashinfo = &dccp_hashinfo, -}; - -static const struct net_protocol dccp_v4_protocol = { - .handler = dccp_v4_rcv, - .err_handler = dccp_v4_err, - .no_policy = 1, - .icmp_strict_tag_validation = 1, -}; - -static const struct proto_ops inet_dccp_ops = { - .family = PF_INET, - .owner = THIS_MODULE, - .release = inet_release, - .bind = inet_bind, - .connect = inet_stream_connect, - .socketpair = sock_no_socketpair, - .accept = inet_accept, - .getname = inet_getname, - /* FIXME: work on tcp_poll to rename it to inet_csk_poll */ - .poll = dccp_poll, - .ioctl = inet_ioctl, - .gettstamp = sock_gettstamp, - /* FIXME: work on inet_listen to rename it to sock_common_listen */ - .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, -}; - -static struct inet_protosw dccp_v4_protosw = { - .type = SOCK_DCCP, - .protocol = IPPROTO_DCCP, - .prot = &dccp_v4_prot, - .ops = &inet_dccp_ops, - .flags = INET_PROTOSW_ICSK, -}; - -static int __net_init dccp_v4_init_net(struct net *net) -{ - struct dccp_v4_pernet *pn = net_generic(net, dccp_v4_pernet_id); - - if (dccp_hashinfo.bhash == NULL) - return -ESOCKTNOSUPPORT; - - return inet_ctl_sock_create(&pn->v4_ctl_sk, PF_INET, - SOCK_DCCP, IPPROTO_DCCP, net); -} - -static void __net_exit dccp_v4_exit_net(struct net *net) -{ - struct dccp_v4_pernet *pn = net_generic(net, dccp_v4_pernet_id); - - inet_ctl_sock_destroy(pn->v4_ctl_sk); -} - -static void __net_exit dccp_v4_exit_batch(struct list_head *net_exit_list) -{ - inet_twsk_purge(&dccp_hashinfo); -} - -static struct pernet_operations dccp_v4_ops = { - .init = dccp_v4_init_net, - .exit = dccp_v4_exit_net, - .exit_batch = dccp_v4_exit_batch, - .id = &dccp_v4_pernet_id, - .size = sizeof(struct dccp_v4_pernet), -}; - -static int __init dccp_v4_init(void) -{ - int err = proto_register(&dccp_v4_prot, 1); - - if (err) - goto out; - - inet_register_protosw(&dccp_v4_protosw); - - err = register_pernet_subsys(&dccp_v4_ops); - if (err) - goto out_destroy_ctl_sock; - - err = inet_add_protocol(&dccp_v4_protocol, IPPROTO_DCCP); - if (err) - goto out_proto_unregister; - -out: - return err; -out_proto_unregister: - unregister_pernet_subsys(&dccp_v4_ops); -out_destroy_ctl_sock: - inet_unregister_protosw(&dccp_v4_protosw); - proto_unregister(&dccp_v4_prot); - goto out; -} - -static void __exit dccp_v4_exit(void) -{ - inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP); - unregister_pernet_subsys(&dccp_v4_ops); - inet_unregister_protosw(&dccp_v4_protosw); - proto_unregister(&dccp_v4_prot); -} - -module_init(dccp_v4_init); -module_exit(dccp_v4_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_INET-proto-0-type-SOCK_DCCP - */ -MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 33, 6); -MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 0, 6); -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>"); -MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol"); |