/* * Copyright (c) 2006 Oracle. All rights reserved. * * This software is available to you under a choice of one of two * licenses. You may choose to be licensed under the terms of the GNU * General Public License (GPL) Version 2, available from the file * COPYING in the main directory of this source tree, or the * OpenIB.org BSD license below: * * Redistribution and use in source and binary forms, with or * without modification, are permitted provided that the following * conditions are met: * * - Redistributions of source code must retain the above * copyright notice, this list of conditions and the following * disclaimer. * * - Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials * provided with the distribution. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. * */ #include <linux/kernel.h> #include <linux/slab.h> #include <net/sock.h> #include <linux/in.h> #include <linux/export.h> #include <linux/time.h> #include <linux/rds.h> #include "rds.h" void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn, __be32 saddr) { int i; atomic_set(&inc->i_refcount, 1); INIT_LIST_HEAD(&inc->i_item); inc->i_conn = conn; inc->i_saddr = saddr; inc->i_rdma_cookie = 0; inc->i_rx_tstamp.tv_sec = 0; inc->i_rx_tstamp.tv_usec = 0; for (i = 0; i < RDS_RX_MAX_TRACES; i++) inc->i_rx_lat_trace[i] = 0; } EXPORT_SYMBOL_GPL(rds_inc_init); void rds_inc_path_init(struct rds_incoming *inc, struct rds_conn_path *cp, __be32 saddr) { atomic_set(&inc->i_refcount, 1); INIT_LIST_HEAD(&inc->i_item); inc->i_conn = cp->cp_conn; inc->i_conn_path = cp; inc->i_saddr = saddr; inc->i_rdma_cookie = 0; inc->i_rx_tstamp.tv_sec = 0; inc->i_rx_tstamp.tv_usec = 0; } EXPORT_SYMBOL_GPL(rds_inc_path_init); static void rds_inc_addref(struct rds_incoming *inc) { rdsdebug("addref inc %p ref %d\n", inc, atomic_read(&inc->i_refcount)); atomic_inc(&inc->i_refcount); } void rds_inc_put(struct rds_incoming *inc) { rdsdebug("put inc %p ref %d\n", inc, atomic_read(&inc->i_refcount)); if (atomic_dec_and_test(&inc->i_refcount)) { BUG_ON(!list_empty(&inc->i_item)); inc->i_conn->c_trans->inc_free(inc); } } EXPORT_SYMBOL_GPL(rds_inc_put); static void rds_recv_rcvbuf_delta(struct rds_sock *rs, struct sock *sk, struct rds_cong_map *map, int delta, __be16 port) { int now_congested; if (delta == 0) return; rs->rs_rcv_bytes += delta; if (delta > 0) rds_stats_add(s_recv_bytes_added_to_socket, delta); else rds_stats_add(s_recv_bytes_removed_from_socket, -delta); now_congested = rs->rs_rcv_bytes > rds_sk_rcvbuf(rs); rdsdebug("rs %p (%pI4:%u) recv bytes %d buf %d " "now_cong %d delta %d\n", rs, &rs->rs_bound_addr, ntohs(rs->rs_bound_port), rs->rs_rcv_bytes, rds_sk_rcvbuf(rs), now_congested, delta); /* wasn't -> am congested */ if (!rs->rs_congested && now_congested) { rs->rs_congested = 1; rds_cong_set_bit(map, port); rds_cong_queue_updates(map); } /* was -> aren't congested */ /* Require more free space before reporting uncongested to prevent bouncing cong/uncong state too often */ else if (rs->rs_congested && (rs->rs_rcv_bytes < (rds_sk_rcvbuf(rs)/2))) { rs->rs_congested = 0; rds_cong_clear_bit(map, port); rds_cong_queue_updates(map); } /* do nothing if no change in cong state */ } static void rds_conn_peer_gen_update(struct rds_connection *conn, u32 peer_gen_num) { int i; struct rds_message *rm, *tmp; unsigned long flags; WARN_ON(conn->c_trans->t_type != RDS_TRANS_TCP); if (peer_gen_num != 0) { if (conn->c_peer_gen_num != 0 && peer_gen_num != conn->c_peer_gen_num) { for (i = 0; i < RDS_MPATH_WORKERS; i++) { struct rds_conn_path *cp; cp = &conn->c_path[i]; spin_lock_irqsave(&cp->cp_lock, flags); cp->cp_next_tx_seq = 1; cp->cp_next_rx_seq = 0; list_for_each_entry_safe(rm, tmp, &cp->cp_retrans, m_conn_item) { set_bit(RDS_MSG_FLUSH, &rm->m_flags); } spin_unlock_irqrestore(&cp->cp_lock, flags); } } conn->c_peer_gen_num = peer_gen_num; } } /* * Process all extension headers that come with this message. */ static void rds_recv_incoming_exthdrs(struct rds_incoming *inc, struct rds_sock *rs) { struct rds_header *hdr = &inc->i_hdr; unsigned int pos = 0, type, len; union { struct rds_ext_header_version version; struct rds_ext_header_rdma rdma; struct rds_ext_header_rdma_dest rdma_dest; } buffer; while (1) { len = sizeof(buffer); type = rds_message_next_extension(hdr, &pos, &buffer, &len); if (type == RDS_EXTHDR_NONE) break; /* Process extension header here */ switch (type) { case RDS_EXTHDR_RDMA: rds_rdma_unuse(rs, be32_to_cpu(buffer.rdma.h_rdma_rkey), 0); break; case RDS_EXTHDR_RDMA_DEST: /* We ignore the size for now. We could stash it * somewhere and use it for error checking. */ inc->i_rdma_cookie = rds_rdma_make_cookie( be32_to_cpu(buffer.rdma_dest.h_rdma_rkey), be32_to_cpu(buffer.rdma_dest.h_rdma_offset)); break; } } } static void rds_recv_hs_exthdrs(struct rds_header *hdr, struct rds_connection *conn) { unsigned int pos = 0, type, len; union { struct rds_ext_header_version version; u16 rds_npaths; u32 rds_gen_num; } buffer; u32 new_peer_gen_num = 0; while (1) { len = sizeof(buffer); type = rds_message_next_extension(hdr, &pos, &buffer, &len); if (type == RDS_EXTHDR_NONE) break; /* Process extension header here */ switch (type) { case RDS_EXTHDR_NPATHS: conn->c_npaths = min_t(int, RDS_MPATH_WORKERS, buffer.rds_npaths); break; case RDS_EXTHDR_GEN_NUM: new_peer_gen_num = buffer.rds_gen_num; break; default: pr_warn_ratelimited("ignoring unknown exthdr type " "0x%x\n", type); } } /* if RDS_EXTHDR_NPATHS was not found, default to a single-path */ conn->c_npaths = max_t(int, conn->c_npaths, 1); rds_conn_peer_gen_update(conn, new_peer_gen_num); } /* rds_start_mprds() will synchronously start multiple paths when appropriate. * The scheme is based on the following rules: * * 1. rds_sendmsg on first connect attempt sends the probe ping, with the * sender's npaths (s_npaths) * 2. rcvr of probe-ping knows the mprds_paths = min(s_npaths, r_npaths). It * sends back a probe-pong with r_npaths. After that, if rcvr is the * smaller ip addr, it starts rds_conn_path_connect_if_down on all * mprds_paths. * 3. sender gets woken up, and can move to rds_conn_path_connect_if_down. * If it is the smaller ipaddr, rds_conn_path_connect_if_down can be * called after reception of the probe-pong on all mprds_paths. * Otherwise (sender of probe-ping is not the smaller ip addr): just call * rds_conn_path_connect_if_down on the hashed path. (see rule 4) * 4. when cp_index > 0, rds_connect_worker must only trigger * a connection if laddr < faddr. * 5. sender may end up queuing the packet on the cp. will get sent out later. * when connection is completed. */ static void rds_start_mprds(struct rds_connection *conn) { int i; struct rds_conn_path *cp; if (conn->c_npaths > 1 && conn->c_laddr < conn->c_faddr) { for (i = 1; i < conn->c_npaths; i++) { cp = &conn->c_path[i]; rds_conn_path_connect_if_down(cp); } } } /* * The transport must make sure that this is serialized against other * rx and conn reset on this specific conn. * * We currently assert that only one fragmented message will be sent * down a connection at a time. This lets us reassemble in the conn * instead of per-flow which means that we don't have to go digging through * flows to tear down partial reassembly progress on conn failure and * we save flow lookup and locking for each frag arrival. It does mean * that small messages will wait behind large ones. Fragmenting at all * is only to reduce the memory consumption of pre-posted buffers. * * The caller passes in saddr and daddr instead of us getting it from the * conn. This lets loopback, who only has one conn for both directions, * tell us which roles the addrs in the conn are playing for this message. */ void rds_recv_incoming(struct rds_connection *conn, __be32 saddr, __be32 daddr, struct rds_incoming *inc, gfp_t gfp) { struct rds_sock *rs = NULL; struct sock *sk; unsigned long flags; struct rds_conn_path *cp; inc->i_conn = conn; inc->i_rx_jiffies = jiffies; if (conn->c_trans->t_mp_capable) cp = inc->i_conn_path; else cp = &conn->c_path[0]; rdsdebug("conn %p next %llu inc %p seq %llu len %u sport %u dport %u " "flags 0x%x rx_jiffies %lu\n", conn, (unsigned long long)cp->cp_next_rx_seq, inc, (unsigned long long)be64_to_cpu(inc->i_hdr.h_sequence), be32_to_cpu(inc->i_hdr.h_len), be16_to_cpu(inc->i_hdr.h_sport), be16_to_cpu(inc->i_hdr.h_dport), inc->i_hdr.h_flags, inc->i_rx_jiffies); /* * Sequence numbers should only increase. Messages get their * sequence number as they're queued in a sending conn. They * can be dropped, though, if the sending socket is closed before * they hit the wire. So sequence numbers can skip forward * under normal operation. They can also drop back in the conn * failover case as previously sent messages are resent down the * new instance of a conn. We drop those, otherwise we have * to assume that the next valid seq does not come after a * hole in the fragment stream. * * The headers don't give us a way to realize if fragments of * a message have been dropped. We assume that frags that arrive * to a flow are part of the current message on the flow that is * being reassembled. This means that senders can't drop messages * from the sending conn until all their frags are sent. * * XXX we could spend more on the wire to get more robust failure * detection, arguably worth it to avoid data corruption. */ if (be64_to_cpu(inc->i_hdr.h_sequence) < cp->cp_next_rx_seq && (inc->i_hdr.h_flags & RDS_FLAG_RETRANSMITTED)) { rds_stats_inc(s_recv_drop_old_seq); goto out; } cp->cp_next_rx_seq = be64_to_cpu(inc->i_hdr.h_sequence) + 1; if (rds_sysctl_ping_enable && inc->i_hdr.h_dport == 0) { if (inc->i_hdr.h_sport == 0) { rdsdebug("ignore ping with 0 sport from 0x%x\n", saddr); goto out; } rds_stats_inc(s_recv_ping); rds_send_pong(cp, inc->i_hdr.h_sport); /* if this is a handshake ping, start multipath if necessary */ if (RDS_HS_PROBE(inc->i_hdr.h_sport, inc->i_hdr.h_dport)) { rds_recv_hs_exthdrs(&inc->i_hdr, cp->cp_conn); rds_start_mprds(cp->cp_conn); } goto out; } if (inc->i_hdr.h_dport == RDS_FLAG_PROBE_PORT && inc->i_hdr.h_sport == 0) { rds_recv_hs_exthdrs(&inc->i_hdr, cp->cp_conn); /* if this is a handshake pong, start multipath if necessary */ rds_start_mprds(cp->cp_conn); wake_up(&cp->cp_conn->c_hs_waitq); goto out; } rs = rds_find_bound(daddr, inc->i_hdr.h_dport); if (!rs) { rds_stats_inc(s_recv_drop_no_sock); goto out; } /* Process extension headers */ rds_recv_incoming_exthdrs(inc, rs); /* We can be racing with rds_release() which marks the socket dead. */ sk = rds_rs_to_sk(rs); /* serialize with rds_release -> sock_orphan */ write_lock_irqsave(&rs->rs_recv_lock, flags); if (!sock_flag(sk, SOCK_DEAD)) { rdsdebug("adding inc %p to rs %p's recv queue\n", inc, rs); rds_stats_inc(s_recv_queued); rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong, be32_to_cpu(inc->i_hdr.h_len), inc->i_hdr.h_dport); if (sock_flag(sk, SOCK_RCVTSTAMP)) do_gettimeofday(&inc->i_rx_tstamp); rds_inc_addref(inc); inc->i_rx_lat_trace[RDS_MSG_RX_END] = local_clock(); list_add_tail(&inc->i_item, &rs->rs_recv_queue); __rds_wake_sk_sleep(sk); } else { rds_stats_inc(s_recv_drop_dead_sock); } write_unlock_irqrestore(&rs->rs_recv_lock, flags); out: if (rs) rds_sock_put(rs); } EXPORT_SYMBOL_GPL(rds_recv_incoming); /* * be very careful here. This is being called as the condition in * wait_event_*() needs to cope with being called many times. */ static int rds_next_incoming(struct rds_sock *rs, struct rds_incoming **inc) { unsigned long flags; if (!*inc) { read_lock_irqsave(&rs->rs_recv_lock, flags); if (!list_empty(&rs->rs_recv_queue)) { *inc = list_entry(rs->rs_recv_queue.next, struct rds_incoming, i_item); rds_inc_addref(*inc); } read_unlock_irqrestore(&rs->rs_recv_lock, flags); } return *inc != NULL; } static int rds_still_queued(struct rds_sock *rs, struct rds_incoming *inc, int drop) { struct sock *sk = rds_rs_to_sk(rs); int ret = 0; unsigned long flags; write_lock_irqsave(&rs->rs_recv_lock, flags); if (!list_empty(&inc->i_item)) { ret = 1; if (drop) { /* XXX make sure this i_conn is reliable */ rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong, -be32_to_cpu(inc->i_hdr.h_len), inc->i_hdr.h_dport); list_del_init(&inc->i_item); rds_inc_put(inc); } } write_unlock_irqrestore(&rs->rs_recv_lock, flags); rdsdebug("inc %p rs %p still %d dropped %d\n", inc, rs, ret, drop); return ret; } /* * Pull errors off the error queue. * If msghdr is NULL, we will just purge the error queue. */ int rds_notify_queue_get(struct rds_sock *rs, struct msghdr *msghdr) { struct rds_notifier *notifier; struct rds_rdma_notify cmsg = { 0 }; /* fill holes with zero */ unsigned int count = 0, max_messages = ~0U; unsigned long flags; LIST_HEAD(copy); int err = 0; /* put_cmsg copies to user space and thus may sleep. We can't do this * with rs_lock held, so first grab as many notifications as we can stuff * in the user provided cmsg buffer. We don't try to copy more, to avoid * losing notifications - except when the buffer is so small that it wouldn't * even hold a single notification. Then we give him as much of this single * msg as we can squeeze in, and set MSG_CTRUNC. */ if (msghdr) { max_messages = msghdr->msg_controllen / CMSG_SPACE(sizeof(cmsg)); if (!max_messages) max_messages = 1; } spin_lock_irqsave(&rs->rs_lock, flags); while (!list_empty(&rs->rs_notify_queue) && count < max_messages) { notifier = list_entry(rs->rs_notify_queue.next, struct rds_notifier, n_list); list_move(¬ifier->n_list, ©); count++; } spin_unlock_irqrestore(&rs->rs_lock, flags); if (!count) return 0; while (!list_empty(©)) { notifier = list_entry(copy.next, struct rds_notifier, n_list); if (msghdr) { cmsg.user_token = notifier->n_user_token; cmsg.status = notifier->n_status; err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_RDMA_STATUS, sizeof(cmsg), &cmsg); if (err) break; } list_del_init(¬ifier->n_list); kfree(notifier); } /* If we bailed out because of an error in put_cmsg, * we may be left with one or more notifications that we * didn't process. Return them to the head of the list. */ if (!list_empty(©)) { spin_lock_irqsave(&rs->rs_lock, flags); list_splice(©, &rs->rs_notify_queue); spin_unlock_irqrestore(&rs->rs_lock, flags); } return err; } /* * Queue a congestion notification */ static int rds_notify_cong(struct rds_sock *rs, struct msghdr *msghdr) { uint64_t notify = rs->rs_cong_notify; unsigned long flags; int err; err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_CONG_UPDATE, sizeof(notify), ¬ify); if (err) return err; spin_lock_irqsave(&rs->rs_lock, flags); rs->rs_cong_notify &= ~notify; spin_unlock_irqrestore(&rs->rs_lock, flags); return 0; } /* * Receive any control messages. */ static int rds_cmsg_recv(struct rds_incoming *inc, struct msghdr *msg, struct rds_sock *rs) { int ret = 0; if (inc->i_rdma_cookie) { ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RDMA_DEST, sizeof(inc->i_rdma_cookie), &inc->i_rdma_cookie); if (ret) goto out; } if ((inc->i_rx_tstamp.tv_sec != 0) && sock_flag(rds_rs_to_sk(rs), SOCK_RCVTSTAMP)) { ret = put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP, sizeof(struct timeval), &inc->i_rx_tstamp); if (ret) goto out; } if (rs->rs_rx_traces) { struct rds_cmsg_rx_trace t; int i, j; inc->i_rx_lat_trace[RDS_MSG_RX_CMSG] = local_clock(); t.rx_traces = rs->rs_rx_traces; for (i = 0; i < rs->rs_rx_traces; i++) { j = rs->rs_rx_trace[i]; t.rx_trace_pos[i] = j; t.rx_trace[i] = inc->i_rx_lat_trace[j + 1] - inc->i_rx_lat_trace[j]; } ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RXPATH_LATENCY, sizeof(t), &t); if (ret) goto out; } out: return ret; } int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, int msg_flags) { struct sock *sk = sock->sk; struct rds_sock *rs = rds_sk_to_rs(sk); long timeo; int ret = 0, nonblock = msg_flags & MSG_DONTWAIT; DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); struct rds_incoming *inc = NULL; /* udp_recvmsg()->sock_recvtimeo() gets away without locking too.. */ timeo = sock_rcvtimeo(sk, nonblock); rdsdebug("size %zu flags 0x%x timeo %ld\n", size, msg_flags, timeo); if (msg_flags & MSG_OOB) goto out; while (1) { struct iov_iter save; /* If there are pending notifications, do those - and nothing else */ if (!list_empty(&rs->rs_notify_queue)) { ret = rds_notify_queue_get(rs, msg); break; } if (rs->rs_cong_notify) { ret = rds_notify_cong(rs, msg); break; } if (!rds_next_incoming(rs, &inc)) { if (nonblock) { ret = -EAGAIN; break; } timeo = wait_event_interruptible_timeout(*sk_sleep(sk), (!list_empty(&rs->rs_notify_queue) || rs->rs_cong_notify || rds_next_incoming(rs, &inc)), timeo); rdsdebug("recvmsg woke inc %p timeo %ld\n", inc, timeo); if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT) continue; ret = timeo; if (ret == 0) ret = -ETIMEDOUT; break; } rdsdebug("copying inc %p from %pI4:%u to user\n", inc, &inc->i_conn->c_faddr, ntohs(inc->i_hdr.h_sport)); save = msg->msg_iter; ret = inc->i_conn->c_trans->inc_copy_to_user(inc, &msg->msg_iter); if (ret < 0) break; /* * if the message we just copied isn't at the head of the * recv queue then someone else raced us to return it, try * to get the next message. */ if (!rds_still_queued(rs, inc, !(msg_flags & MSG_PEEK))) { rds_inc_put(inc); inc = NULL; rds_stats_inc(s_recv_deliver_raced); msg->msg_iter = save; continue; } if (ret < be32_to_cpu(inc->i_hdr.h_len)) { if (msg_flags & MSG_TRUNC) ret = be32_to_cpu(inc->i_hdr.h_len); msg->msg_flags |= MSG_TRUNC; } if (rds_cmsg_recv(inc, msg, rs)) { ret = -EFAULT; goto out; } rds_stats_inc(s_recv_delivered); if (sin) { sin->sin_family = AF_INET; sin->sin_port = inc->i_hdr.h_sport; sin->sin_addr.s_addr = inc->i_saddr; memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); msg->msg_namelen = sizeof(*sin); } break; } if (inc) rds_inc_put(inc); out: return ret; } /* * The socket is being shut down and we're asked to drop messages that were * queued for recvmsg. The caller has unbound the socket so the receive path * won't queue any more incoming fragments or messages on the socket. */ void rds_clear_recv_queue(struct rds_sock *rs) { struct sock *sk = rds_rs_to_sk(rs); struct rds_incoming *inc, *tmp; unsigned long flags; write_lock_irqsave(&rs->rs_recv_lock, flags); list_for_each_entry_safe(inc, tmp, &rs->rs_recv_queue, i_item) { rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong, -be32_to_cpu(inc->i_hdr.h_len), inc->i_hdr.h_dport); list_del_init(&inc->i_item); rds_inc_put(inc); } write_unlock_irqrestore(&rs->rs_recv_lock, flags); } /* * inc->i_saddr isn't used here because it is only set in the receive * path. */ void rds_inc_info_copy(struct rds_incoming *inc, struct rds_info_iterator *iter, __be32 saddr, __be32 daddr, int flip) { struct rds_info_message minfo; minfo.seq = be64_to_cpu(inc->i_hdr.h_sequence); minfo.len = be32_to_cpu(inc->i_hdr.h_len); if (flip) { minfo.laddr = daddr; minfo.faddr = saddr; minfo.lport = inc->i_hdr.h_dport; minfo.fport = inc->i_hdr.h_sport; } else { minfo.laddr = saddr; minfo.faddr = daddr; minfo.lport = inc->i_hdr.h_sport; minfo.fport = inc->i_hdr.h_dport; } minfo.flags = 0; rds_info_copy(iter, &minfo, sizeof(minfo)); }