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 <net/tcp.h> 35 36 #include "rds.h" 37 #include "tcp.h" 38 39 static struct kmem_cache *rds_tcp_incoming_slab; 40 41 void rds_tcp_inc_purge(struct rds_incoming *inc) 42 { 43 struct rds_tcp_incoming *tinc; 44 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); 45 rdsdebug("purging tinc %p inc %p\n", tinc, inc); 46 skb_queue_purge(&tinc->ti_skb_list); 47 } 48 49 void rds_tcp_inc_free(struct rds_incoming *inc) 50 { 51 struct rds_tcp_incoming *tinc; 52 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); 53 rds_tcp_inc_purge(inc); 54 rdsdebug("freeing tinc %p inc %p\n", tinc, inc); 55 kmem_cache_free(rds_tcp_incoming_slab, tinc); 56 } 57 58 /* 59 * this is pretty lame, but, whatever. 60 */ 61 int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iovec *first_iov, 62 size_t size) 63 { 64 struct rds_tcp_incoming *tinc; 65 struct iovec *iov, tmp; 66 struct sk_buff *skb; 67 unsigned long to_copy, skb_off; 68 int ret = 0; 69 70 if (size == 0) 71 goto out; 72 73 tinc = container_of(inc, struct rds_tcp_incoming, ti_inc); 74 iov = first_iov; 75 tmp = *iov; 76 77 skb_queue_walk(&tinc->ti_skb_list, skb) { 78 skb_off = 0; 79 while (skb_off < skb->len) { 80 while (tmp.iov_len == 0) { 81 iov++; 82 tmp = *iov; 83 } 84 85 to_copy = min(tmp.iov_len, size); 86 to_copy = min(to_copy, skb->len - skb_off); 87 88 rdsdebug("ret %d size %zu skb %p skb_off %lu " 89 "skblen %d iov_base %p iov_len %zu cpy %lu\n", 90 ret, size, skb, skb_off, skb->len, 91 tmp.iov_base, tmp.iov_len, to_copy); 92 93 /* modifies tmp as it copies */ 94 if (skb_copy_datagram_iovec(skb, skb_off, &tmp, 95 to_copy)) { 96 ret = -EFAULT; 97 goto out; 98 } 99 100 size -= to_copy; 101 ret += to_copy; 102 skb_off += to_copy; 103 if (size == 0) 104 goto out; 105 } 106 } 107 out: 108 return ret; 109 } 110 111 /* 112 * We have a series of skbs that have fragmented pieces of the congestion 113 * bitmap. They must add up to the exact size of the congestion bitmap. We 114 * use the skb helpers to copy those into the pages that make up the in-memory 115 * congestion bitmap for the remote address of this connection. We then tell 116 * the congestion core that the bitmap has been changed so that it can wake up 117 * sleepers. 118 * 119 * This is racing with sending paths which are using test_bit to see if the 120 * bitmap indicates that their recipient is congested. 121 */ 122 123 static void rds_tcp_cong_recv(struct rds_connection *conn, 124 struct rds_tcp_incoming *tinc) 125 { 126 struct sk_buff *skb; 127 unsigned int to_copy, skb_off; 128 unsigned int map_off; 129 unsigned int map_page; 130 struct rds_cong_map *map; 131 int ret; 132 133 /* catch completely corrupt packets */ 134 if (be32_to_cpu(tinc->ti_inc.i_hdr.h_len) != RDS_CONG_MAP_BYTES) 135 return; 136 137 map_page = 0; 138 map_off = 0; 139 map = conn->c_fcong; 140 141 skb_queue_walk(&tinc->ti_skb_list, skb) { 142 skb_off = 0; 143 while (skb_off < skb->len) { 144 to_copy = min_t(unsigned int, PAGE_SIZE - map_off, 145 skb->len - skb_off); 146 147 BUG_ON(map_page >= RDS_CONG_MAP_PAGES); 148 149 /* only returns 0 or -error */ 150 ret = skb_copy_bits(skb, skb_off, 151 (void *)map->m_page_addrs[map_page] + map_off, 152 to_copy); 153 BUG_ON(ret != 0); 154 155 skb_off += to_copy; 156 map_off += to_copy; 157 if (map_off == PAGE_SIZE) { 158 map_off = 0; 159 map_page++; 160 } 161 } 162 } 163 164 rds_cong_map_updated(map, ~(u64) 0); 165 } 166 167 struct rds_tcp_desc_arg { 168 struct rds_connection *conn; 169 gfp_t gfp; 170 enum km_type km; 171 }; 172 173 static int rds_tcp_data_recv(read_descriptor_t *desc, struct sk_buff *skb, 174 unsigned int offset, size_t len) 175 { 176 struct rds_tcp_desc_arg *arg = desc->arg.data; 177 struct rds_connection *conn = arg->conn; 178 struct rds_tcp_connection *tc = conn->c_transport_data; 179 struct rds_tcp_incoming *tinc = tc->t_tinc; 180 struct sk_buff *clone; 181 size_t left = len, to_copy; 182 183 rdsdebug("tcp data tc %p skb %p offset %u len %zu\n", tc, skb, offset, 184 len); 185 186 /* 187 * tcp_read_sock() interprets partial progress as an indication to stop 188 * processing. 189 */ 190 while (left) { 191 if (tinc == NULL) { 192 tinc = kmem_cache_alloc(rds_tcp_incoming_slab, 193 arg->gfp); 194 if (tinc == NULL) { 195 desc->error = -ENOMEM; 196 goto out; 197 } 198 tc->t_tinc = tinc; 199 rdsdebug("alloced tinc %p\n", tinc); 200 rds_inc_init(&tinc->ti_inc, conn, conn->c_faddr); 201 /* 202 * XXX * we might be able to use the __ variants when 203 * we've already serialized at a higher level. 204 */ 205 skb_queue_head_init(&tinc->ti_skb_list); 206 } 207 208 if (left && tc->t_tinc_hdr_rem) { 209 to_copy = min(tc->t_tinc_hdr_rem, left); 210 rdsdebug("copying %zu header from skb %p\n", to_copy, 211 skb); 212 skb_copy_bits(skb, offset, 213 (char *)&tinc->ti_inc.i_hdr + 214 sizeof(struct rds_header) - 215 tc->t_tinc_hdr_rem, 216 to_copy); 217 tc->t_tinc_hdr_rem -= to_copy; 218 left -= to_copy; 219 offset += to_copy; 220 221 if (tc->t_tinc_hdr_rem == 0) { 222 /* could be 0 for a 0 len message */ 223 tc->t_tinc_data_rem = 224 be32_to_cpu(tinc->ti_inc.i_hdr.h_len); 225 } 226 } 227 228 if (left && tc->t_tinc_data_rem) { 229 clone = skb_clone(skb, arg->gfp); 230 if (clone == NULL) { 231 desc->error = -ENOMEM; 232 goto out; 233 } 234 235 to_copy = min(tc->t_tinc_data_rem, left); 236 pskb_pull(clone, offset); 237 pskb_trim(clone, to_copy); 238 skb_queue_tail(&tinc->ti_skb_list, clone); 239 240 rdsdebug("skb %p data %p len %d off %u to_copy %zu -> " 241 "clone %p data %p len %d\n", 242 skb, skb->data, skb->len, offset, to_copy, 243 clone, clone->data, clone->len); 244 245 tc->t_tinc_data_rem -= to_copy; 246 left -= to_copy; 247 offset += to_copy; 248 } 249 250 if (tc->t_tinc_hdr_rem == 0 && tc->t_tinc_data_rem == 0) { 251 if (tinc->ti_inc.i_hdr.h_flags == RDS_FLAG_CONG_BITMAP) 252 rds_tcp_cong_recv(conn, tinc); 253 else 254 rds_recv_incoming(conn, conn->c_faddr, 255 conn->c_laddr, &tinc->ti_inc, 256 arg->gfp, arg->km); 257 258 tc->t_tinc_hdr_rem = sizeof(struct rds_header); 259 tc->t_tinc_data_rem = 0; 260 tc->t_tinc = NULL; 261 rds_inc_put(&tinc->ti_inc); 262 tinc = NULL; 263 } 264 } 265 out: 266 rdsdebug("returning len %zu left %zu skb len %d rx queue depth %d\n", 267 len, left, skb->len, 268 skb_queue_len(&tc->t_sock->sk->sk_receive_queue)); 269 return len - left; 270 } 271 272 /* the caller has to hold the sock lock */ 273 int rds_tcp_read_sock(struct rds_connection *conn, gfp_t gfp, enum km_type km) 274 { 275 struct rds_tcp_connection *tc = conn->c_transport_data; 276 struct socket *sock = tc->t_sock; 277 read_descriptor_t desc; 278 struct rds_tcp_desc_arg arg; 279 280 /* It's like glib in the kernel! */ 281 arg.conn = conn; 282 arg.gfp = gfp; 283 arg.km = km; 284 desc.arg.data = &arg; 285 desc.error = 0; 286 desc.count = 1; /* give more than one skb per call */ 287 288 tcp_read_sock(sock->sk, &desc, rds_tcp_data_recv); 289 rdsdebug("tcp_read_sock for tc %p gfp 0x%x returned %d\n", tc, gfp, 290 desc.error); 291 292 return desc.error; 293 } 294 295 /* 296 * We hold the sock lock to serialize our rds_tcp_recv->tcp_read_sock from 297 * data_ready. 298 * 299 * if we fail to allocate we're in trouble.. blindly wait some time before 300 * trying again to see if the VM can free up something for us. 301 */ 302 int rds_tcp_recv(struct rds_connection *conn) 303 { 304 struct rds_tcp_connection *tc = conn->c_transport_data; 305 struct socket *sock = tc->t_sock; 306 int ret = 0; 307 308 rdsdebug("recv worker conn %p tc %p sock %p\n", conn, tc, sock); 309 310 lock_sock(sock->sk); 311 ret = rds_tcp_read_sock(conn, GFP_KERNEL, KM_USER0); 312 release_sock(sock->sk); 313 314 return ret; 315 } 316 317 void rds_tcp_data_ready(struct sock *sk, int bytes) 318 { 319 void (*ready)(struct sock *sk, int bytes); 320 struct rds_connection *conn; 321 struct rds_tcp_connection *tc; 322 323 rdsdebug("data ready sk %p bytes %d\n", sk, bytes); 324 325 read_lock(&sk->sk_callback_lock); 326 conn = sk->sk_user_data; 327 if (conn == NULL) { /* check for teardown race */ 328 ready = sk->sk_data_ready; 329 goto out; 330 } 331 332 tc = conn->c_transport_data; 333 ready = tc->t_orig_data_ready; 334 rds_tcp_stats_inc(s_tcp_data_ready_calls); 335 336 if (rds_tcp_read_sock(conn, GFP_ATOMIC, KM_SOFTIRQ0) == -ENOMEM) 337 queue_delayed_work(rds_wq, &conn->c_recv_w, 0); 338 out: 339 read_unlock(&sk->sk_callback_lock); 340 ready(sk, bytes); 341 } 342 343 int __init rds_tcp_recv_init(void) 344 { 345 rds_tcp_incoming_slab = kmem_cache_create("rds_tcp_incoming", 346 sizeof(struct rds_tcp_incoming), 347 0, 0, NULL); 348 if (rds_tcp_incoming_slab == NULL) 349 return -ENOMEM; 350 return 0; 351 } 352 353 void rds_tcp_recv_exit(void) 354 { 355 kmem_cache_destroy(rds_tcp_incoming_slab); 356 } 357