| /* |
| * 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 <net/tcp.h> |
| |
| #include "rds.h" |
| #include "tcp.h" |
| |
| static struct kmem_cache *rds_tcp_incoming_slab; |
| |
| void rds_tcp_inc_purge(struct rds_incoming *inc) |
| { |
| struct rds_tcp_incoming *tinc; |
| tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); |
| rdsdebug("purging tinc %p inc %p\n", tinc, inc); |
| skb_queue_purge(&tinc->ti_skb_list); |
| } |
| |
| void rds_tcp_inc_free(struct rds_incoming *inc) |
| { |
| struct rds_tcp_incoming *tinc; |
| tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); |
| rds_tcp_inc_purge(inc); |
| rdsdebug("freeing tinc %p inc %p\n", tinc, inc); |
| kmem_cache_free(rds_tcp_incoming_slab, tinc); |
| } |
| |
| /* |
| * this is pretty lame, but, whatever. |
| */ |
| int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov, |
| size_t size) |
| { |
| struct rds_tcp_incoming *tinc; |
| struct iovec *iov, tmp; |
| struct sk_buff *skb; |
| unsigned long to_copy, skb_off; |
| int ret = 0; |
| |
| if (size == 0) |
| goto out; |
| |
| tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); |
| iov = first_iov; |
| tmp = *iov; |
| |
| skb_queue_walk(&tinc->ti_skb_list, skb) { |
| skb_off = 0; |
| while (skb_off < skb->len) { |
| while (tmp.iov_len == 0) { |
| iov++; |
| tmp = *iov; |
| } |
| |
| to_copy = min(tmp.iov_len, size); |
| to_copy = min(to_copy, skb->len - skb_off); |
| |
| rdsdebug("ret %d size %zu skb %p skb_off %lu " |
| "skblen %d iov_base %p iov_len %zu cpy %lu\n", |
| ret, size, skb, skb_off, skb->len, |
| tmp.iov_base, tmp.iov_len, to_copy); |
| |
| /* modifies tmp as it copies */ |
| if (skb_copy_datagram_iovec(skb, skb_off, &tmp, |
| to_copy)) { |
| ret = -EFAULT; |
| goto out; |
| } |
| |
| rds_stats_add(s_copy_to_user, to_copy); |
| size -= to_copy; |
| ret += to_copy; |
| skb_off += to_copy; |
| if (size == 0) |
| goto out; |
| } |
| } |
| out: |
| return ret; |
| } |
| |
| /* |
| * We have a series of skbs that have fragmented pieces of the congestion |
| * bitmap. They must add up to the exact size of the congestion bitmap. We |
| * use the skb helpers to copy those into the pages that make up the in-memory |
| * congestion bitmap for the remote address of this connection. We then tell |
| * the congestion core that the bitmap has been changed so that it can wake up |
| * sleepers. |
| * |
| * This is racing with sending paths which are using test_bit to see if the |
| * bitmap indicates that their recipient is congested. |
| */ |
| |
| static void rds_tcp_cong_recv(struct rds_connection *conn, |
| struct rds_tcp_incoming *tinc) |
| { |
| struct sk_buff *skb; |
| unsigned int to_copy, skb_off; |
| unsigned int map_off; |
| unsigned int map_page; |
| struct rds_cong_map *map; |
| int ret; |
| |
| /* catch completely corrupt packets */ |
| if (be32_to_cpu(tinc->ti_inc.i_hdr.h_len) != RDS_CONG_MAP_BYTES) |
| return; |
| |
| map_page = 0; |
| map_off = 0; |
| map = conn->c_fcong; |
| |
| skb_queue_walk(&tinc->ti_skb_list, skb) { |
| skb_off = 0; |
| while (skb_off < skb->len) { |
| to_copy = min_t(unsigned int, PAGE_SIZE - map_off, |
| skb->len - skb_off); |
| |
| BUG_ON(map_page >= RDS_CONG_MAP_PAGES); |
| |
| /* only returns 0 or -error */ |
| ret = skb_copy_bits(skb, skb_off, |
| (void *)map->m_page_addrs[map_page] + map_off, |
| to_copy); |
| BUG_ON(ret != 0); |
| |
| skb_off += to_copy; |
| map_off += to_copy; |
| if (map_off == PAGE_SIZE) { |
| map_off = 0; |
| map_page++; |
| } |
| } |
| } |
| |
| rds_cong_map_updated(map, ~(u64) 0); |
| } |
| |
| struct rds_tcp_desc_arg { |
| struct rds_connection *conn; |
| gfp_t gfp; |
| enum km_type km; |
| }; |
| |
| static int rds_tcp_data_recv(read_descriptor_t *desc, struct sk_buff *skb, |
| unsigned int offset, size_t len) |
| { |
| struct rds_tcp_desc_arg *arg = desc->arg.data; |
| struct rds_connection *conn = arg->conn; |
| struct rds_tcp_connection *tc = conn->c_transport_data; |
| struct rds_tcp_incoming *tinc = tc->t_tinc; |
| struct sk_buff *clone; |
| size_t left = len, to_copy; |
| |
| rdsdebug("tcp data tc %p skb %p offset %u len %zu\n", tc, skb, offset, |
| len); |
| |
| /* |
| * tcp_read_sock() interprets partial progress as an indication to stop |
| * processing. |
| */ |
| while (left) { |
| if (tinc == NULL) { |
| tinc = kmem_cache_alloc(rds_tcp_incoming_slab, |
| arg->gfp); |
| if (tinc == NULL) { |
| desc->error = -ENOMEM; |
| goto out; |
| } |
| tc->t_tinc = tinc; |
| rdsdebug("alloced tinc %p\n", tinc); |
| rds_inc_init(&tinc->ti_inc, conn, conn->c_faddr); |
| /* |
| * XXX * we might be able to use the __ variants when |
| * we've already serialized at a higher level. |
| */ |
| skb_queue_head_init(&tinc->ti_skb_list); |
| } |
| |
| if (left && tc->t_tinc_hdr_rem) { |
| to_copy = min(tc->t_tinc_hdr_rem, left); |
| rdsdebug("copying %zu header from skb %p\n", to_copy, |
| skb); |
| skb_copy_bits(skb, offset, |
| (char *)&tinc->ti_inc.i_hdr + |
| sizeof(struct rds_header) - |
| tc->t_tinc_hdr_rem, |
| to_copy); |
| tc->t_tinc_hdr_rem -= to_copy; |
| left -= to_copy; |
| offset += to_copy; |
| |
| if (tc->t_tinc_hdr_rem == 0) { |
| /* could be 0 for a 0 len message */ |
| tc->t_tinc_data_rem = |
| be32_to_cpu(tinc->ti_inc.i_hdr.h_len); |
| } |
| } |
| |
| if (left && tc->t_tinc_data_rem) { |
| clone = skb_clone(skb, arg->gfp); |
| if (clone == NULL) { |
| desc->error = -ENOMEM; |
| goto out; |
| } |
| |
| to_copy = min(tc->t_tinc_data_rem, left); |
| pskb_pull(clone, offset); |
| pskb_trim(clone, to_copy); |
| skb_queue_tail(&tinc->ti_skb_list, clone); |
| |
| rdsdebug("skb %p data %p len %d off %u to_copy %zu -> " |
| "clone %p data %p len %d\n", |
| skb, skb->data, skb->len, offset, to_copy, |
| clone, clone->data, clone->len); |
| |
| tc->t_tinc_data_rem -= to_copy; |
| left -= to_copy; |
| offset += to_copy; |
| } |
| |
| if (tc->t_tinc_hdr_rem == 0 && tc->t_tinc_data_rem == 0) { |
| if (tinc->ti_inc.i_hdr.h_flags == RDS_FLAG_CONG_BITMAP) |
| rds_tcp_cong_recv(conn, tinc); |
| else |
| rds_recv_incoming(conn, conn->c_faddr, |
| conn->c_laddr, &tinc->ti_inc, |
| arg->gfp, arg->km); |
| |
| tc->t_tinc_hdr_rem = sizeof(struct rds_header); |
| tc->t_tinc_data_rem = 0; |
| tc->t_tinc = NULL; |
| rds_inc_put(&tinc->ti_inc); |
| tinc = NULL; |
| } |
| } |
| out: |
| rdsdebug("returning len %zu left %zu skb len %d rx queue depth %d\n", |
| len, left, skb->len, |
| skb_queue_len(&tc->t_sock->sk->sk_receive_queue)); |
| return len - left; |
| } |
| |
| /* the caller has to hold the sock lock */ |
| int rds_tcp_read_sock(struct rds_connection *conn, gfp_t gfp, enum km_type km) |
| { |
| struct rds_tcp_connection *tc = conn->c_transport_data; |
| struct socket *sock = tc->t_sock; |
| read_descriptor_t desc; |
| struct rds_tcp_desc_arg arg; |
| |
| /* It's like glib in the kernel! */ |
| arg.conn = conn; |
| arg.gfp = gfp; |
| arg.km = km; |
| desc.arg.data = &arg; |
| desc.error = 0; |
| desc.count = 1; /* give more than one skb per call */ |
| |
| tcp_read_sock(sock->sk, &desc, rds_tcp_data_recv); |
| rdsdebug("tcp_read_sock for tc %p gfp 0x%x returned %d\n", tc, gfp, |
| desc.error); |
| |
| return desc.error; |
| } |
| |
| /* |
| * We hold the sock lock to serialize our rds_tcp_recv->tcp_read_sock from |
| * data_ready. |
| * |
| * if we fail to allocate we're in trouble.. blindly wait some time before |
| * trying again to see if the VM can free up something for us. |
| */ |
| int rds_tcp_recv(struct rds_connection *conn) |
| { |
| struct rds_tcp_connection *tc = conn->c_transport_data; |
| struct socket *sock = tc->t_sock; |
| int ret = 0; |
| |
| rdsdebug("recv worker conn %p tc %p sock %p\n", conn, tc, sock); |
| |
| lock_sock(sock->sk); |
| ret = rds_tcp_read_sock(conn, GFP_KERNEL, KM_USER0); |
| release_sock(sock->sk); |
| |
| return ret; |
| } |
| |
| void rds_tcp_data_ready(struct sock *sk, int bytes) |
| { |
| void (*ready)(struct sock *sk, int bytes); |
| struct rds_connection *conn; |
| struct rds_tcp_connection *tc; |
| |
| rdsdebug("data ready sk %p bytes %d\n", sk, bytes); |
| |
| read_lock(&sk->sk_callback_lock); |
| conn = sk->sk_user_data; |
| if (conn == NULL) { /* check for teardown race */ |
| ready = sk->sk_data_ready; |
| goto out; |
| } |
| |
| tc = conn->c_transport_data; |
| ready = tc->t_orig_data_ready; |
| rds_tcp_stats_inc(s_tcp_data_ready_calls); |
| |
| if (rds_tcp_read_sock(conn, GFP_ATOMIC, KM_SOFTIRQ0) == -ENOMEM) |
| queue_delayed_work(rds_wq, &conn->c_recv_w, 0); |
| out: |
| read_unlock(&sk->sk_callback_lock); |
| ready(sk, bytes); |
| } |
| |
| int __init rds_tcp_recv_init(void) |
| { |
| rds_tcp_incoming_slab = kmem_cache_create("rds_tcp_incoming", |
| sizeof(struct rds_tcp_incoming), |
| 0, 0, NULL); |
| if (rds_tcp_incoming_slab == NULL) |
| return -ENOMEM; |
| return 0; |
| } |
| |
| void rds_tcp_recv_exit(void) |
| { |
| kmem_cache_destroy(rds_tcp_incoming_slab); |
| } |