diff options
Diffstat (limited to 'net/dccp/proto.c')
| -rw-r--r-- | net/dccp/proto.c | 1271 |
1 files changed, 1271 insertions, 0 deletions
diff --git a/net/dccp/proto.c b/net/dccp/proto.c new file mode 100644 index 000000000..c647035a3 --- /dev/null +++ b/net/dccp/proto.c @@ -0,0 +1,1271 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * net/dccp/proto.c + * + * An implementation of the DCCP protocol + * Arnaldo Carvalho de Melo <acme@conectiva.com.br> + */ + +#include <linux/dccp.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/skbuff.h> +#include <linux/netdevice.h> +#include <linux/in.h> +#include <linux/if_arp.h> +#include <linux/init.h> +#include <linux/random.h> +#include <linux/slab.h> +#include <net/checksum.h> + +#include <net/inet_sock.h> +#include <net/inet_common.h> +#include <net/sock.h> +#include <net/xfrm.h> + +#include <asm/ioctls.h> +#include <linux/spinlock.h> +#include <linux/timer.h> +#include <linux/delay.h> +#include <linux/poll.h> + +#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->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)); + inet_hashinfo_init(&dccp_hashinfo); + 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, 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 <acme@conectiva.com.br>"); +MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol"); |