1/* 2 * Copyright (c) 2006 Oracle. All rights reserved. 3 * 4 * This software is available to you under a choice of one of two 5 * licenses. You may choose to be licensed under the terms of the GNU 6 * General Public License (GPL) Version 2, available from the file 7 * COPYING in the main directory of this source tree, or the 8 * OpenIB.org BSD license below: 9 * 10 * Redistribution and use in source and binary forms, with or 11 * without modification, are permitted provided that the following 12 * conditions are met: 13 * 14 * - Redistributions of source code must retain the above 15 * copyright notice, this list of conditions and the following 16 * disclaimer. 17 * 18 * - Redistributions in binary form must reproduce the above 19 * copyright notice, this list of conditions and the following 20 * disclaimer in the documentation and/or other materials 21 * provided with the distribution. 22 * 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 30 * SOFTWARE. 31 * 32 */ 33#include <linux/kernel.h> 34#include <linux/slab.h> 35#include <net/tcp.h> 36 37#include "rds.h" 38#include "tcp.h" 39 40static struct kmem_cache *rds_tcp_incoming_slab; 41 42void rds_tcp_inc_purge(struct rds_incoming *inc) 43{ 44 struct rds_tcp_incoming *tinc; 45 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); 46 rdsdebug("purging tinc %p inc %p\n", tinc, inc); 47 skb_queue_purge(&tinc->ti_skb_list); 48} 49 50void rds_tcp_inc_free(struct rds_incoming *inc) 51{ 52 struct rds_tcp_incoming *tinc; 53 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); 54 rds_tcp_inc_purge(inc); 55 rdsdebug("freeing tinc %p inc %p\n", tinc, inc); 56 kmem_cache_free(rds_tcp_incoming_slab, tinc); 57} 58 59/* 60 * this is pretty lame, but, whatever. 61 */ 62int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov, 63 size_t size) 64{ 65 struct rds_tcp_incoming *tinc; 66 struct iovec *iov, tmp; 67 struct sk_buff *skb; 68 unsigned long to_copy, skb_off; 69 int ret = 0; 70 71 if (size == 0) 72 goto out; 73 74 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); 75 iov = first_iov; 76 tmp = *iov; 77 78 skb_queue_walk(&tinc->ti_skb_list, skb) { 79 skb_off = 0; 80 while (skb_off < skb->len) { 81 while (tmp.iov_len == 0) { 82 iov++; 83 tmp = *iov; 84 } 85 86 to_copy = min(tmp.iov_len, size); 87 to_copy = min(to_copy, skb->len - skb_off); 88 89 rdsdebug("ret %d size %zu skb %p skb_off %lu " 90 "skblen %d iov_base %p iov_len %zu cpy %lu\n", 91 ret, size, skb, skb_off, skb->len, 92 tmp.iov_base, tmp.iov_len, to_copy); 93 94 /* modifies tmp as it copies */ 95 if (skb_copy_datagram_iovec(skb, skb_off, &tmp, 96 to_copy)) { 97 ret = -EFAULT; 98 goto out; 99 } 100 101 rds_stats_add(s_copy_to_user, to_copy); 102 size -= to_copy; 103 ret += to_copy; 104 skb_off += to_copy; 105 if (size == 0) 106 goto out; 107 } 108 } 109out: 110 return ret; 111} 112 113/* 114 * We have a series of skbs that have fragmented pieces of the congestion 115 * bitmap. They must add up to the exact size of the congestion bitmap. We 116 * use the skb helpers to copy those into the pages that make up the in-memory 117 * congestion bitmap for the remote address of this connection. We then tell 118 * the congestion core that the bitmap has been changed so that it can wake up 119 * sleepers. 120 * 121 * This is racing with sending paths which are using test_bit to see if the 122 * bitmap indicates that their recipient is congested. 123 */ 124 125static void rds_tcp_cong_recv(struct rds_connection *conn, 126 struct rds_tcp_incoming *tinc) 127{ 128 struct sk_buff *skb; 129 unsigned int to_copy, skb_off; 130 unsigned int map_off; 131 unsigned int map_page; 132 struct rds_cong_map *map; 133 int ret; 134 135 /* catch completely corrupt packets */ 136 if (be32_to_cpu(tinc->ti_inc.i_hdr.h_len) != RDS_CONG_MAP_BYTES) 137 return; 138 139 map_page = 0; 140 map_off = 0; 141 map = conn->c_fcong; 142 143 skb_queue_walk(&tinc->ti_skb_list, skb) { 144 skb_off = 0; 145 while (skb_off < skb->len) { 146 to_copy = min_t(unsigned int, PAGE_SIZE - map_off, 147 skb->len - skb_off); 148 149 BUG_ON(map_page >= RDS_CONG_MAP_PAGES); 150 151 /* only returns 0 or -error */ 152 ret = skb_copy_bits(skb, skb_off, 153 (void *)map->m_page_addrs[map_page] + map_off, 154 to_copy); 155 BUG_ON(ret != 0); 156 157 skb_off += to_copy; 158 map_off += to_copy; 159 if (map_off == PAGE_SIZE) { 160 map_off = 0; 161 map_page++; 162 } 163 } 164 } 165 166 rds_cong_map_updated(map, ~(u64) 0); 167} 168 169struct rds_tcp_desc_arg { 170 struct rds_connection *conn; 171 gfp_t gfp; 172 enum km_type km; 173}; 174 175static int rds_tcp_data_recv(read_descriptor_t *desc, struct sk_buff *skb, 176 unsigned int offset, size_t len) 177{ 178 struct rds_tcp_desc_arg *arg = desc->arg.data; 179 struct rds_connection *conn = arg->conn; 180 struct rds_tcp_connection *tc = conn->c_transport_data; 181 struct rds_tcp_incoming *tinc = tc->t_tinc; 182 struct sk_buff *clone; 183 size_t left = len, to_copy; 184 185 rdsdebug("tcp data tc %p skb %p offset %u len %zu\n", tc, skb, offset, 186 len); 187 188 /* 189 * tcp_read_sock() interprets partial progress as an indication to stop 190 * processing. 191 */ 192 while (left) { 193 if (tinc == NULL) { 194 tinc = kmem_cache_alloc(rds_tcp_incoming_slab, 195 arg->gfp); 196 if (tinc == NULL) { 197 desc->error = -ENOMEM; 198 goto out; 199 } 200 tc->t_tinc = tinc; 201 rdsdebug("alloced tinc %p\n", tinc); 202 rds_inc_init(&tinc->ti_inc, conn, conn->c_faddr); 203 skb_queue_head_init(&tinc->ti_skb_list); 204 } 205 206 if (left && tc->t_tinc_hdr_rem) { 207 to_copy = min(tc->t_tinc_hdr_rem, left); 208 rdsdebug("copying %zu header from skb %p\n", to_copy, 209 skb); 210 skb_copy_bits(skb, offset, 211 (char *)&tinc->ti_inc.i_hdr + 212 sizeof(struct rds_header) - 213 tc->t_tinc_hdr_rem, 214 to_copy); 215 tc->t_tinc_hdr_rem -= to_copy; 216 left -= to_copy; 217 offset += to_copy; 218 219 if (tc->t_tinc_hdr_rem == 0) { 220 /* could be 0 for a 0 len message */ 221 tc->t_tinc_data_rem = 222 be32_to_cpu(tinc->ti_inc.i_hdr.h_len); 223 } 224 } 225 226 if (left && tc->t_tinc_data_rem) { 227 clone = skb_clone(skb, arg->gfp); 228 if (clone == NULL) { 229 desc->error = -ENOMEM; 230 goto out; 231 } 232 233 to_copy = min(tc->t_tinc_data_rem, left); 234 pskb_pull(clone, offset); 235 pskb_trim(clone, to_copy); 236 skb_queue_tail(&tinc->ti_skb_list, clone); 237 238 rdsdebug("skb %p data %p len %d off %u to_copy %zu -> " 239 "clone %p data %p len %d\n", 240 skb, skb->data, skb->len, offset, to_copy, 241 clone, clone->data, clone->len); 242 243 tc->t_tinc_data_rem -= to_copy; 244 left -= to_copy; 245 offset += to_copy; 246 } 247 248 if (tc->t_tinc_hdr_rem == 0 && tc->t_tinc_data_rem == 0) { 249 if (tinc->ti_inc.i_hdr.h_flags == RDS_FLAG_CONG_BITMAP) 250 rds_tcp_cong_recv(conn, tinc); 251 else 252 rds_recv_incoming(conn, conn->c_faddr, 253 conn->c_laddr, &tinc->ti_inc, 254 arg->gfp, arg->km); 255 256 tc->t_tinc_hdr_rem = sizeof(struct rds_header); 257 tc->t_tinc_data_rem = 0; 258 tc->t_tinc = NULL; 259 rds_inc_put(&tinc->ti_inc); 260 tinc = NULL; 261 } 262 } 263out: 264 rdsdebug("returning len %zu left %zu skb len %d rx queue depth %d\n", 265 len, left, skb->len, 266 skb_queue_len(&tc->t_sock->sk->sk_receive_queue)); 267 return len - left; 268} 269 270/* the caller has to hold the sock lock */ 271int rds_tcp_read_sock(struct rds_connection *conn, gfp_t gfp, enum km_type km) 272{ 273 struct rds_tcp_connection *tc = conn->c_transport_data; 274 struct socket *sock = tc->t_sock; 275 read_descriptor_t desc; 276 struct rds_tcp_desc_arg arg; 277 278 /* It's like glib in the kernel! */ 279 arg.conn = conn; 280 arg.gfp = gfp; 281 arg.km = km; 282 desc.arg.data = &arg; 283 desc.error = 0; 284 desc.count = 1; /* give more than one skb per call */ 285 286 tcp_read_sock(sock->sk, &desc, rds_tcp_data_recv); 287 rdsdebug("tcp_read_sock for tc %p gfp 0x%x returned %d\n", tc, gfp, 288 desc.error); 289 290 return desc.error; 291} 292 293/* 294 * We hold the sock lock to serialize our rds_tcp_recv->tcp_read_sock from 295 * data_ready. 296 * 297 * if we fail to allocate we're in trouble.. blindly wait some time before 298 * trying again to see if the VM can free up something for us. 299 */ 300int rds_tcp_recv(struct rds_connection *conn) 301{ 302 struct rds_tcp_connection *tc = conn->c_transport_data; 303 struct socket *sock = tc->t_sock; 304 int ret = 0; 305 306 rdsdebug("recv worker conn %p tc %p sock %p\n", conn, tc, sock); 307 308 lock_sock(sock->sk); 309 ret = rds_tcp_read_sock(conn, GFP_KERNEL, KM_USER0); 310 release_sock(sock->sk); 311 312 return ret; 313} 314 315void rds_tcp_data_ready(struct sock *sk, int bytes) 316{ 317 void (*ready)(struct sock *sk, int bytes); 318 struct rds_connection *conn; 319 struct rds_tcp_connection *tc; 320 321 rdsdebug("data ready sk %p bytes %d\n", sk, bytes); 322 323 read_lock_bh(&sk->sk_callback_lock); 324 conn = sk->sk_user_data; 325 if (conn == NULL) { /* check for teardown race */ 326 ready = sk->sk_data_ready; 327 goto out; 328 } 329 330 tc = conn->c_transport_data; 331 ready = tc->t_orig_data_ready; 332 rds_tcp_stats_inc(s_tcp_data_ready_calls); 333 334 if (rds_tcp_read_sock(conn, GFP_ATOMIC, KM_SOFTIRQ0) == -ENOMEM) 335 queue_delayed_work(rds_wq, &conn->c_recv_w, 0); 336out: 337 read_unlock_bh(&sk->sk_callback_lock); 338 ready(sk, bytes); 339} 340 341int __init rds_tcp_recv_init(void) 342{ 343 rds_tcp_incoming_slab = kmem_cache_create("rds_tcp_incoming", 344 sizeof(struct rds_tcp_incoming), 345 0, 0, NULL); 346 if (rds_tcp_incoming_slab == NULL) 347 return -ENOMEM; 348 return 0; 349} 350 351void rds_tcp_recv_exit(void) 352{ 353 kmem_cache_destroy(rds_tcp_incoming_slab); 354} 355