// SPDX-License-Identifier: GPL-2.0-only /* * net/dccp/proto.c * * An implementation of the DCCP protocol * Arnaldo Carvalho de Melo */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "ccid.h" #include "dccp.h" #include "feat.h" #define CREATE_TRACE_POINTS #include "trace.h" DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly; EXPORT_SYMBOL_GPL(dccp_statistics); DEFINE_PER_CPU(unsigned int, dccp_orphan_count); EXPORT_PER_CPU_SYMBOL_GPL(dccp_orphan_count); struct inet_hashinfo dccp_hashinfo; EXPORT_SYMBOL_GPL(dccp_hashinfo); /* the maximum queue length for tx in packets. 0 is no limit */ int sysctl_dccp_tx_qlen __read_mostly = 5; #ifdef CONFIG_IP_DCCP_DEBUG static const char *dccp_state_name(const int state) { static const char *const dccp_state_names[] = { [DCCP_OPEN] = "OPEN", [DCCP_REQUESTING] = "REQUESTING", [DCCP_PARTOPEN] = "PARTOPEN", [DCCP_LISTEN] = "LISTEN", [DCCP_RESPOND] = "RESPOND", [DCCP_CLOSING] = "CLOSING", [DCCP_ACTIVE_CLOSEREQ] = "CLOSEREQ", [DCCP_PASSIVE_CLOSE] = "PASSIVE_CLOSE", [DCCP_PASSIVE_CLOSEREQ] = "PASSIVE_CLOSEREQ", [DCCP_TIME_WAIT] = "TIME_WAIT", [DCCP_CLOSED] = "CLOSED", }; if (state >= DCCP_MAX_STATES) return "INVALID STATE!"; else return dccp_state_names[state]; } #endif void dccp_set_state(struct sock *sk, const int state) { const int oldstate = sk->sk_state; dccp_pr_debug("%s(%p) %s --> %s\n", dccp_role(sk), sk, dccp_state_name(oldstate), dccp_state_name(state)); WARN_ON(state == oldstate); switch (state) { case DCCP_OPEN: if (oldstate != DCCP_OPEN) DCCP_INC_STATS(DCCP_MIB_CURRESTAB); /* Client retransmits all Confirm options until entering OPEN */ if (oldstate == DCCP_PARTOPEN) dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg); break; case DCCP_CLOSED: if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ || oldstate == DCCP_CLOSING) DCCP_INC_STATS(DCCP_MIB_ESTABRESETS); sk->sk_prot->unhash(sk); if (inet_csk(sk)->icsk_bind_hash != NULL && !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) inet_put_port(sk); fallthrough; default: if (oldstate == DCCP_OPEN) DCCP_DEC_STATS(DCCP_MIB_CURRESTAB); } /* Change state AFTER socket is unhashed to avoid closed * socket sitting in hash tables. */ inet_sk_set_state(sk, state); } EXPORT_SYMBOL_GPL(dccp_set_state); static void dccp_finish_passive_close(struct sock *sk) { switch (sk->sk_state) { case DCCP_PASSIVE_CLOSE: /* Node (client or server) has received Close packet. */ dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED); dccp_set_state(sk, DCCP_CLOSED); break; case DCCP_PASSIVE_CLOSEREQ: /* * Client received CloseReq. We set the `active' flag so that * dccp_send_close() retransmits the Close as per RFC 4340, 8.3. */ dccp_send_close(sk, 1); dccp_set_state(sk, DCCP_CLOSING); } } void dccp_done(struct sock *sk) { dccp_set_state(sk, DCCP_CLOSED); dccp_clear_xmit_timers(sk); sk->sk_shutdown = SHUTDOWN_MASK; if (!sock_flag(sk, SOCK_DEAD)) sk->sk_state_change(sk); else inet_csk_destroy_sock(sk); } EXPORT_SYMBOL_GPL(dccp_done); const char *dccp_packet_name(const int type) { static const char *const dccp_packet_names[] = { [DCCP_PKT_REQUEST] = "REQUEST", [DCCP_PKT_RESPONSE] = "RESPONSE", [DCCP_PKT_DATA] = "DATA", [DCCP_PKT_ACK] = "ACK", [DCCP_PKT_DATAACK] = "DATAACK", [DCCP_PKT_CLOSEREQ] = "CLOSEREQ", [DCCP_PKT_CLOSE] = "CLOSE", [DCCP_PKT_RESET] = "RESET", [DCCP_PKT_SYNC] = "SYNC", [DCCP_PKT_SYNCACK] = "SYNCACK", }; if (type >= DCCP_NR_PKT_TYPES) return "INVALID"; else return dccp_packet_names[type]; } EXPORT_SYMBOL_GPL(dccp_packet_name); void dccp_destruct_common(struct sock *sk) { struct dccp_sock *dp = dccp_sk(sk); ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk); dp->dccps_hc_tx_ccid = NULL; } EXPORT_SYMBOL_GPL(dccp_destruct_common); static void dccp_sk_destruct(struct sock *sk) { dccp_destruct_common(sk); inet_sock_destruct(sk); } int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized) { struct dccp_sock *dp = dccp_sk(sk); struct inet_connection_sock *icsk = inet_csk(sk); icsk->icsk_rto = DCCP_TIMEOUT_INIT; icsk->icsk_syn_retries = sysctl_dccp_request_retries; sk->sk_state = DCCP_CLOSED; sk->sk_write_space = dccp_write_space; sk->sk_destruct = dccp_sk_destruct; icsk->icsk_sync_mss = dccp_sync_mss; dp->dccps_mss_cache = 536; dp->dccps_rate_last = jiffies; dp->dccps_role = DCCP_ROLE_UNDEFINED; dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT; dp->dccps_tx_qlen = sysctl_dccp_tx_qlen; dccp_init_xmit_timers(sk); INIT_LIST_HEAD(&dp->dccps_featneg); /* control socket doesn't need feat nego */ if (likely(ctl_sock_initialized)) return dccp_feat_init(sk); return 0; } EXPORT_SYMBOL_GPL(dccp_init_sock); void dccp_destroy_sock(struct sock *sk) { struct dccp_sock *dp = dccp_sk(sk); __skb_queue_purge(&sk->sk_write_queue); if (sk->sk_send_head != NULL) { kfree_skb(sk->sk_send_head); sk->sk_send_head = NULL; } /* Clean up a referenced DCCP bind bucket. */ if (inet_csk(sk)->icsk_bind_hash != NULL) inet_put_port(sk); kfree(dp->dccps_service_list); dp->dccps_service_list = NULL; if (dp->dccps_hc_rx_ackvec != NULL) { dccp_ackvec_free(dp->dccps_hc_rx_ackvec); dp->dccps_hc_rx_ackvec = NULL; } ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); dp->dccps_hc_rx_ccid = NULL; /* clean up feature negotiation state */ dccp_feat_list_purge(&dp->dccps_featneg); } EXPORT_SYMBOL_GPL(dccp_destroy_sock); static inline int dccp_listen_start(struct sock *sk, int backlog) { struct dccp_sock *dp = dccp_sk(sk); dp->dccps_role = DCCP_ROLE_LISTEN; /* do not start to listen if feature negotiation setup fails */ if (dccp_feat_finalise_settings(dp)) return -EPROTO; return inet_csk_listen_start(sk, backlog); } static inline int dccp_need_reset(int state) { return state != DCCP_CLOSED && state != DCCP_LISTEN && state != DCCP_REQUESTING; } int dccp_disconnect(struct sock *sk, int flags) { struct inet_connection_sock *icsk = inet_csk(sk); struct inet_sock *inet = inet_sk(sk); struct dccp_sock *dp = dccp_sk(sk); const int old_state = sk->sk_state; if (old_state != DCCP_CLOSED) dccp_set_state(sk, DCCP_CLOSED); /* * This corresponds to the ABORT function of RFC793, sec. 3.8 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted". */ if (old_state == DCCP_LISTEN) { inet_csk_listen_stop(sk); } else if (dccp_need_reset(old_state)) { dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED); sk->sk_err = ECONNRESET; } else if (old_state == DCCP_REQUESTING) sk->sk_err = ECONNRESET; dccp_clear_xmit_timers(sk); ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); dp->dccps_hc_rx_ccid = NULL; __skb_queue_purge(&sk->sk_receive_queue); __skb_queue_purge(&sk->sk_write_queue); if (sk->sk_send_head != NULL) { __kfree_skb(sk->sk_send_head); sk->sk_send_head = NULL; } inet->inet_dport = 0; if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) inet_reset_saddr(sk); sk->sk_shutdown = 0; sock_reset_flag(sk, SOCK_DONE); icsk->icsk_backoff = 0; inet_csk_delack_init(sk); __sk_dst_reset(sk); WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); sk_error_report(sk); return 0; } EXPORT_SYMBOL_GPL(dccp_disconnect); /* * Wait for a DCCP event. * * Note that we don't need to lock the socket, as the upper poll layers * take care of normal races (between the test and the event) and we don't * go look at any of the socket buffers directly. */ __poll_t dccp_poll(struct file *file, struct socket *sock, poll_table *wait) { struct sock *sk = sock->sk; __poll_t mask; u8 shutdown; int state; sock_poll_wait(file, sock, wait); state = inet_sk_state_load(sk); if (state == DCCP_LISTEN) return inet_csk_listen_poll(sk); /* Socket is not locked. We are protected from async events by poll logic and correct handling of state changes made by another threads is impossible in any case. */ mask = 0; if (READ_ONCE(sk->sk_err)) mask = EPOLLERR; shutdown = READ_ONCE(sk->sk_shutdown); if (shutdown == SHUTDOWN_MASK || state == DCCP_CLOSED) mask |= EPOLLHUP; if (shutdown & RCV_SHUTDOWN) mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP; /* Connected? */ if ((1 << state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) { if (atomic_read(&sk->sk_rmem_alloc) > 0) mask |= EPOLLIN | EPOLLRDNORM; if (!(shutdown & SEND_SHUTDOWN)) { if (sk_stream_is_writeable(sk)) { mask |= EPOLLOUT | EPOLLWRNORM; } else { /* send SIGIO later */ sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); /* Race breaker. If space is freed after * wspace test but before the flags are set, * IO signal will be lost. */ if (sk_stream_is_writeable(sk)) mask |= EPOLLOUT | EPOLLWRNORM; } } } return mask; } EXPORT_SYMBOL_GPL(dccp_poll); int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg) { int rc = -ENOTCONN; lock_sock(sk); if (sk->sk_state == DCCP_LISTEN) goto out; switch (cmd) { case SIOCOUTQ: { int amount = sk_wmem_alloc_get(sk); /* Using sk_wmem_alloc here because sk_wmem_queued is not used by DCCP and * always 0, comparably to UDP. */ rc = put_user(amount, (int __user *)arg); } break; case SIOCINQ: { struct sk_buff *skb; unsigned long amount = 0; skb = skb_peek(&sk->sk_receive_queue); if (skb != NULL) { /* * We will only return the amount of this packet since * that is all that will be read. */ amount = skb->len; } rc = put_user(amount, (int __user *)arg); } break; default: rc = -ENOIOCTLCMD; break; } out: release_sock(sk); return rc; } EXPORT_SYMBOL_GPL(dccp_ioctl); static int dccp_setsockopt_service(struct sock *sk, const __be32 service, sockptr_t optval, unsigned int optlen) { struct dccp_sock *dp = dccp_sk(sk); struct dccp_service_list *sl = NULL; if (service == DCCP_SERVICE_INVALID_VALUE || optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32)) return -EINVAL; if (optlen > sizeof(service)) { sl = kmalloc(optlen, GFP_KERNEL); if (sl == NULL) return -ENOMEM; sl->dccpsl_nr = optlen / sizeof(u32) - 1; if (copy_from_sockptr_offset(sl->dccpsl_list, optval, sizeof(service), optlen - sizeof(service)) || dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) { kfree(sl); return -EFAULT; } } lock_sock(sk); dp->dccps_service = service; kfree(dp->dccps_service_list); dp->dccps_service_list = sl; release_sock(sk); return 0; } static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx) { u8 *list, len; int i, rc; if (cscov < 0 || cscov > 15) return -EINVAL; /* * Populate a list of permissible values, in the range cscov...15. This * is necessary since feature negotiation of single values only works if * both sides incidentally choose the same value. Since the list starts * lowest-value first, negotiation will pick the smallest shared value. */ if (cscov == 0) return 0; len = 16 - cscov; list = kmalloc(len, GFP_KERNEL); if (list == NULL) return -ENOBUFS; for (i = 0; i < len; i++) list[i] = cscov++; rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len); if (rc == 0) { if (rx) dccp_sk(sk)->dccps_pcrlen = cscov; else dccp_sk(sk)->dccps_pcslen = cscov; } kfree(list); return rc; } static int dccp_setsockopt_ccid(struct sock *sk, int type, sockptr_t optval, unsigned int optlen) { u8 *val; int rc = 0; if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS) return -EINVAL; val = memdup_sockptr(optval, optlen); if (IS_ERR(val)) return PTR_ERR(val); lock_sock(sk); if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID) rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen); if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID)) rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen); release_sock(sk); kfree(val); return rc; } static int do_dccp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, unsigned int optlen) { struct dccp_sock *dp = dccp_sk(sk); int val, err = 0; switch (optname) { case DCCP_SOCKOPT_PACKET_SIZE: DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); return 0; case DCCP_SOCKOPT_CHANGE_L: case DCCP_SOCKOPT_CHANGE_R: DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n"); return 0; case DCCP_SOCKOPT_CCID: case DCCP_SOCKOPT_RX_CCID: case DCCP_SOCKOPT_TX_CCID: return dccp_setsockopt_ccid(sk, optname, optval, optlen); } if (optlen < (int)sizeof(int)) return -EINVAL; if (copy_from_sockptr(&val, optval, sizeof(int))) return -EFAULT; if (optname == DCCP_SOCKOPT_SERVICE) return dccp_setsockopt_service(sk, val, optval, optlen); lock_sock(sk); switch (optname) { case DCCP_SOCKOPT_SERVER_TIMEWAIT: if (dp->dccps_role != DCCP_ROLE_SERVER) err = -EOPNOTSUPP; else dp->dccps_server_timewait = (val != 0); break; case DCCP_SOCKOPT_SEND_CSCOV: err = dccp_setsockopt_cscov(sk, val, false); break; case DCCP_SOCKOPT_RECV_CSCOV: err = dccp_setsockopt_cscov(sk, val, true); break; case DCCP_SOCKOPT_QPOLICY_ID: if (sk->sk_state != DCCP_CLOSED) err = -EISCONN; else if (val < 0 || val >= DCCPQ_POLICY_MAX) err = -EINVAL; else dp->dccps_qpolicy = val; break; case DCCP_SOCKOPT_QPOLICY_TXQLEN: if (val < 0) err = -EINVAL; else dp->dccps_tx_qlen = val; break; default: err = -ENOPROTOOPT; break; } release_sock(sk); return err; } int dccp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, unsigned int optlen) { if (level != SOL_DCCP) return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level, optname, optval, optlen); return do_dccp_setsockopt(sk, level, optname, optval, optlen); } EXPORT_SYMBOL_GPL(dccp_setsockopt); static int dccp_getsockopt_service(struct sock *sk, int len, __be32 __user *optval, int __user *optlen) { const struct dccp_sock *dp = dccp_sk(sk); const struct dccp_service_list *sl; int err = -ENOENT, slen = 0, total_len = sizeof(u32); lock_sock(sk); if ((sl = dp->dccps_service_list) != NULL) { slen = sl->dccpsl_nr * sizeof(u32); total_len += slen; } err = -EINVAL; if (total_len > len) goto out; err = 0; if (put_user(total_len, optlen) || put_user(dp->dccps_service, optval) || (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen))) err = -EFAULT; out: release_sock(sk); return err; } static int do_dccp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen) { struct dccp_sock *dp; int val, len; if (get_user(len, optlen)) return -EFAULT; if (len < (int)sizeof(int)) return -EINVAL; dp = dccp_sk(sk); switch (optname) { case DCCP_SOCKOPT_PACKET_SIZE: DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); return 0; case DCCP_SOCKOPT_SERVICE: return dccp_getsockopt_service(sk, len, (__be32 __user *)optval, optlen); case DCCP_SOCKOPT_GET_CUR_MPS: val = READ_ONCE(dp->dccps_mss_cache); break; case DCCP_SOCKOPT_AVAILABLE_CCIDS: return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen); case DCCP_SOCKOPT_TX_CCID: val = ccid_get_current_tx_ccid(dp); if (val < 0) return -ENOPROTOOPT; break; case DCCP_SOCKOPT_RX_CCID: val = ccid_get_current_rx_ccid(dp); if (val < 0) return -ENOPROTOOPT; break; case DCCP_SOCKOPT_SERVER_TIMEWAIT: val = dp->dccps_server_timewait; break; case DCCP_SOCKOPT_SEND_CSCOV: val = dp->dccps_pcslen; break; case DCCP_SOCKOPT_RECV_CSCOV: val = dp->dccps_pcrlen; break; case DCCP_SOCKOPT_QPOLICY_ID: val = dp->dccps_qpolicy; break; case DCCP_SOCKOPT_QPOLICY_TXQLEN: val = dp->dccps_tx_qlen; break; case 128 ... 191: return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname, len, (u32 __user *)optval, optlen); case 192 ... 255: return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname, len, (u32 __user *)optval, optlen); default: return -ENOPROTOOPT; } len = sizeof(val); if (put_user(len, optlen) || copy_to_user(optval, &val, len)) return -EFAULT; return 0; } int dccp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen) { if (level != SOL_DCCP) return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level, optname, optval, optlen); return do_dccp_getsockopt(sk, level, optname, optval, optlen); } EXPORT_SYMBOL_GPL(dccp_getsockopt); static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb) { struct cmsghdr *cmsg; /* * Assign an (opaque) qpolicy priority value to skb->priority. * * We are overloading this skb field for use with the qpolicy subystem. * The skb->priority is normally used for the SO_PRIORITY option, which * is initialised from sk_priority. Since the assignment of sk_priority * to skb->priority happens later (on layer 3), we overload this field * for use with queueing priorities as long as the skb is on layer 4. * The default priority value (if nothing is set) is 0. */ skb->priority = 0; for_each_cmsghdr(cmsg, msg) { if (!CMSG_OK(msg, cmsg)) return -EINVAL; if (cmsg->cmsg_level != SOL_DCCP) continue; if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX && !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type)) return -EINVAL; switch (cmsg->cmsg_type) { case DCCP_SCM_PRIORITY: if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32))) return -EINVAL; skb->priority = *(__u32 *)CMSG_DATA(cmsg); break; default: return -EINVAL; } } return 0; } int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) { const struct dccp_sock *dp = dccp_sk(sk); const int flags = msg->msg_flags; const int noblock = flags & MSG_DONTWAIT; struct sk_buff *skb; int rc, size; long timeo; trace_dccp_probe(sk, len); if (len > READ_ONCE(dp->dccps_mss_cache)) return -EMSGSIZE; lock_sock(sk); timeo = sock_sndtimeo(sk, noblock); /* * We have to use sk_stream_wait_connect here to set sk_write_pending, * so that the trick in dccp_rcv_request_sent_state_process. */ /* Wait for a connection to finish. */ if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN)) if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0) goto out_release; size = sk->sk_prot->max_header + len; release_sock(sk); skb = sock_alloc_send_skb(sk, size, noblock, &rc); lock_sock(sk); if (skb == NULL) goto out_release; if (dccp_qpolicy_full(sk)) { rc = -EAGAIN; goto out_discard; } if (sk->sk_state == DCCP_CLOSED) { rc = -ENOTCONN; goto out_discard; } /* We need to check dccps_mss_cache after socket is locked. */ if (len > dp->dccps_mss_cache) { rc = -EMSGSIZE; goto out_discard; } skb_reserve(skb, sk->sk_prot->max_header); rc = memcpy_from_msg(skb_put(skb, len), msg, len); if (rc != 0) goto out_discard; rc = dccp_msghdr_parse(msg, skb); if (rc != 0) goto out_discard; dccp_qpolicy_push(sk, skb); /* * The xmit_timer is set if the TX CCID is rate-based and will expire * when congestion control permits to release further packets into the * network. Window-based CCIDs do not use this timer. */ if (!timer_pending(&dp->dccps_xmit_timer)) dccp_write_xmit(sk); out_release: release_sock(sk); return rc ? : len; out_discard: kfree_skb(skb); goto out_release; } EXPORT_SYMBOL_GPL(dccp_sendmsg); int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, int flags, int *addr_len) { const struct dccp_hdr *dh; long timeo; lock_sock(sk); if (sk->sk_state == DCCP_LISTEN) { len = -ENOTCONN; goto out; } timeo = sock_rcvtimeo(sk, nonblock); do { struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); if (skb == NULL) goto verify_sock_status; dh = dccp_hdr(skb); switch (dh->dccph_type) { case DCCP_PKT_DATA: case DCCP_PKT_DATAACK: goto found_ok_skb; case DCCP_PKT_CLOSE: case DCCP_PKT_CLOSEREQ: if (!(flags & MSG_PEEK)) dccp_finish_passive_close(sk); fallthrough; case DCCP_PKT_RESET: dccp_pr_debug("found fin (%s) ok!\n", dccp_packet_name(dh->dccph_type)); len = 0; goto found_fin_ok; default: dccp_pr_debug("packet_type=%s\n", dccp_packet_name(dh->dccph_type)); sk_eat_skb(sk, skb); } verify_sock_status: if (sock_flag(sk, SOCK_DONE)) { len = 0; break; } if (sk->sk_err) { len = sock_error(sk); break; } if (sk->sk_shutdown & RCV_SHUTDOWN) { len = 0; break; } if (sk->sk_state == DCCP_CLOSED) { if (!sock_flag(sk, SOCK_DONE)) { /* This occurs when user tries to read * from never connected socket. */ len = -ENOTCONN; break; } len = 0; break; } if (!timeo) { len = -EAGAIN; break; } if (signal_pending(current)) { len = sock_intr_errno(timeo); break; } sk_wait_data(sk, &timeo, NULL); continue; found_ok_skb: if (len > skb->len) len = skb->len; else if (len < skb->len) msg->msg_flags |= MSG_TRUNC; if (skb_copy_datagram_msg(skb, 0, msg, len)) { /* Exception. Bailout! */ len = -EFAULT; break; } if (flags & MSG_TRUNC) len = skb->len; found_fin_ok: if (!(flags & MSG_PEEK)) sk_eat_skb(sk, skb); break; } while (1); out: release_sock(sk); return len; } EXPORT_SYMBOL_GPL(dccp_recvmsg); int inet_dccp_listen(struct socket *sock, int backlog) { struct sock *sk = sock->sk; unsigned char old_state; int err; lock_sock(sk); err = -EINVAL; if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP) goto out; old_state = sk->sk_state; if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) goto out; WRITE_ONCE(sk->sk_max_ack_backlog, backlog); /* Really, if the socket is already in listen state * we can only allow the backlog to be adjusted. */ if (old_state != DCCP_LISTEN) { /* * FIXME: here it probably should be sk->sk_prot->listen_start * see tcp_listen_start */ err = dccp_listen_start(sk, backlog); if (err) goto out; } err = 0; out: release_sock(sk); return err; } EXPORT_SYMBOL_GPL(inet_dccp_listen); static void dccp_terminate_connection(struct sock *sk) { u8 next_state = DCCP_CLOSED; switch (sk->sk_state) { case DCCP_PASSIVE_CLOSE: case DCCP_PASSIVE_CLOSEREQ: dccp_finish_passive_close(sk); break; case DCCP_PARTOPEN: dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk); inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); fallthrough; case DCCP_OPEN: dccp_send_close(sk, 1); if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER && !dccp_sk(sk)->dccps_server_timewait) next_state = DCCP_ACTIVE_CLOSEREQ; else next_state = DCCP_CLOSING; fallthrough; default: dccp_set_state(sk, next_state); } } void dccp_close(struct sock *sk, long timeout) { struct dccp_sock *dp = dccp_sk(sk); struct sk_buff *skb; u32 data_was_unread = 0; int state; lock_sock(sk); sk->sk_shutdown = SHUTDOWN_MASK; if (sk->sk_state == DCCP_LISTEN) { dccp_set_state(sk, DCCP_CLOSED); /* Special case. */ inet_csk_listen_stop(sk); goto adjudge_to_death; } sk_stop_timer(sk, &dp->dccps_xmit_timer); /* * We need to flush the recv. buffs. We do this only on the * descriptor close, not protocol-sourced closes, because the *reader process may not have drained the data yet! */ while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { data_was_unread += skb->len; __kfree_skb(skb); } /* If socket has been already reset kill it. */ if (sk->sk_state == DCCP_CLOSED) goto adjudge_to_death; if (data_was_unread) { /* Unread data was tossed, send an appropriate Reset Code */ DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread); dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED); dccp_set_state(sk, DCCP_CLOSED); } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { /* Check zero linger _after_ checking for unread data. */ sk->sk_prot->disconnect(sk, 0); } else if (sk->sk_state != DCCP_CLOSED) { /* * Normal connection termination. May need to wait if there are * still packets in the TX queue that are delayed by the CCID. */ dccp_flush_write_queue(sk, &timeout); dccp_terminate_connection(sk); } /* * Flush write queue. This may be necessary in several cases: * - we have been closed by the peer but still have application data; * - abortive termination (unread data or zero linger time), * - normal termination but queue could not be flushed within time limit */ __skb_queue_purge(&sk->sk_write_queue); sk_stream_wait_close(sk, timeout); adjudge_to_death: state = sk->sk_state; sock_hold(sk); sock_orphan(sk); /* * It is the last release_sock in its life. It will remove backlog. */ release_sock(sk); /* * Now socket is owned by kernel and we acquire BH lock * to finish close. No need to check for user refs. */ local_bh_disable(); bh_lock_sock(sk); WARN_ON(sock_owned_by_user(sk)); this_cpu_inc(dccp_orphan_count); /* Have we already been destroyed by a softirq or backlog? */ if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED) goto out; if (sk->sk_state == DCCP_CLOSED) inet_csk_destroy_sock(sk); /* Otherwise, socket is reprieved until protocol close. */ out: bh_unlock_sock(sk); local_bh_enable(); sock_put(sk); } EXPORT_SYMBOL_GPL(dccp_close); void dccp_shutdown(struct sock *sk, int how) { dccp_pr_debug("called shutdown(%x)\n", how); } EXPORT_SYMBOL_GPL(dccp_shutdown); static inline int __init dccp_mib_init(void) { dccp_statistics = alloc_percpu(struct dccp_mib); if (!dccp_statistics) return -ENOMEM; return 0; } static inline void dccp_mib_exit(void) { free_percpu(dccp_statistics); } static int thash_entries; module_param(thash_entries, int, 0444); MODULE_PARM_DESC(thash_entries, "Number of ehash buckets"); #ifdef CONFIG_IP_DCCP_DEBUG bool dccp_debug; module_param(dccp_debug, bool, 0644); MODULE_PARM_DESC(dccp_debug, "Enable debug messages"); EXPORT_SYMBOL_GPL(dccp_debug); #endif static int __init dccp_init(void) { unsigned long goal; unsigned long nr_pages = totalram_pages(); int ehash_order, bhash_order, i; int rc; BUILD_BUG_ON(sizeof(struct dccp_skb_cb) > sizeof_field(struct sk_buff, cb)); rc = inet_hashinfo2_init_mod(&dccp_hashinfo); if (rc) goto out_fail; rc = -ENOBUFS; dccp_hashinfo.bind_bucket_cachep = kmem_cache_create("dccp_bind_bucket", sizeof(struct inet_bind_bucket), 0, SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL); if (!dccp_hashinfo.bind_bucket_cachep) goto out_free_hashinfo2; /* * Size and allocate the main established and bind bucket * hash tables. * * The methodology is similar to that of the buffer cache. */ if (nr_pages >= (128 * 1024)) goal = nr_pages >> (21 - PAGE_SHIFT); else goal = nr_pages >> (23 - PAGE_SHIFT); if (thash_entries) goal = (thash_entries * sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT; for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++) ; do { unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE / sizeof(struct inet_ehash_bucket); while (hash_size & (hash_size - 1)) hash_size--; dccp_hashinfo.ehash_mask = hash_size - 1; dccp_hashinfo.ehash = (struct inet_ehash_bucket *) __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order); } while (!dccp_hashinfo.ehash && --ehash_order > 0); if (!dccp_hashinfo.ehash) { DCCP_CRIT("Failed to allocate DCCP established hash table"); goto out_free_bind_bucket_cachep; } for (i = 0; i <= dccp_hashinfo.ehash_mask; i++) INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i); if (inet_ehash_locks_alloc(&dccp_hashinfo)) goto out_free_dccp_ehash; bhash_order = ehash_order; do { dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE / sizeof(struct inet_bind_hashbucket); if ((dccp_hashinfo.bhash_size > (64 * 1024)) && bhash_order > 0) continue; dccp_hashinfo.bhash = (struct inet_bind_hashbucket *) __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order); } while (!dccp_hashinfo.bhash && --bhash_order >= 0); if (!dccp_hashinfo.bhash) { DCCP_CRIT("Failed to allocate DCCP bind hash table"); goto out_free_dccp_locks; } for (i = 0; i < dccp_hashinfo.bhash_size; i++) { spin_lock_init(&dccp_hashinfo.bhash[i].lock); INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain); } rc = dccp_mib_init(); if (rc) goto out_free_dccp_bhash; rc = dccp_ackvec_init(); if (rc) goto out_free_dccp_mib; rc = dccp_sysctl_init(); if (rc) goto out_ackvec_exit; rc = ccid_initialize_builtins(); if (rc) goto out_sysctl_exit; dccp_timestamping_init(); return 0; out_sysctl_exit: dccp_sysctl_exit(); out_ackvec_exit: dccp_ackvec_exit(); out_free_dccp_mib: dccp_mib_exit(); out_free_dccp_bhash: free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order); out_free_dccp_locks: inet_ehash_locks_free(&dccp_hashinfo); out_free_dccp_ehash: free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order); out_free_bind_bucket_cachep: kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); out_free_hashinfo2: inet_hashinfo2_free_mod(&dccp_hashinfo); out_fail: dccp_hashinfo.bhash = NULL; dccp_hashinfo.ehash = NULL; dccp_hashinfo.bind_bucket_cachep = NULL; return rc; } static void __exit dccp_fini(void) { ccid_cleanup_builtins(); dccp_mib_exit(); free_pages((unsigned long)dccp_hashinfo.bhash, get_order(dccp_hashinfo.bhash_size * sizeof(struct inet_bind_hashbucket))); free_pages((unsigned long)dccp_hashinfo.ehash, get_order((dccp_hashinfo.ehash_mask + 1) * sizeof(struct inet_ehash_bucket))); inet_ehash_locks_free(&dccp_hashinfo); kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); dccp_ackvec_exit(); dccp_sysctl_exit(); inet_hashinfo2_free_mod(&dccp_hashinfo); } module_init(dccp_init); module_exit(dccp_fini); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Arnaldo Carvalho de Melo "); MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");