lib/vconn-stream.c

   1 /*
   2  * Copyright (c) 2008, 2009 Nicira Networks.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include <config.h>
  18 #include "vconn-stream.h"
  19 #include <assert.h>
  20 #include <errno.h>
  21 #include <poll.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26 #include "leak-checker.h"
  27 #include "ofpbuf.h"
  28 #include "openflow/openflow.h"
  29 #include "poll-loop.h"
  30 #include "socket-util.h"
  31 #include "util.h"
  32 #include "vconn-provider.h"
  33 #include "vconn.h"
  34
  35 #include "vlog.h"
  36 #define THIS_MODULE VLM_vconn_stream
  37
  38 /* Active stream socket vconn. */
  39
  40 struct stream_vconn
  41 {
  42     struct vconn vconn;
  43     int fd;
  44     void (*connect_success_cb)(struct vconn *, int);
  45     struct ofpbuf *rxbuf;
  46     struct ofpbuf *txbuf;
  47     struct poll_waiter *tx_waiter;
  48 };
  49
  50 static struct vconn_class stream_vconn_class;
  51
  52 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(10, 25);
  53
  54 static void stream_clear_txbuf(struct stream_vconn *);
  55
  56 int
  57 new_stream_vconn(const char *name, int fd, int connect_status,
  58                  uint32_t remote_ip, uint16_t remote_port,
  59                  bool reconnectable,
  60                  connect_success_cb_func *connect_success_cb,
  61                  struct vconn **vconnp)
  62 {
  63     struct stream_vconn *s;
  64
  65     s = xmalloc(sizeof *s);
  66     vconn_init(&s->vconn, &stream_vconn_class, connect_status, remote_ip,
  67                remote_port, name, reconnectable);
  68     s->fd = fd;
  69     s->txbuf = NULL;
  70     s->tx_waiter = NULL;
  71     s->rxbuf = NULL;
  72     s->connect_success_cb = connect_success_cb;
  73     *vconnp = &s->vconn;
  74     return 0;
  75 }
  76
  77 static struct stream_vconn *
  78 stream_vconn_cast(struct vconn *vconn)
  79 {
  80     vconn_assert_class(vconn, &stream_vconn_class);
  81     return CONTAINER_OF(vconn, struct stream_vconn, vconn);
  82 }
  83
  84 static void
  85 stream_close(struct vconn *vconn)
  86 {
  87     struct stream_vconn *s = stream_vconn_cast(vconn);
  88     poll_cancel(s->tx_waiter);
  89     stream_clear_txbuf(s);
  90     ofpbuf_delete(s->rxbuf);
  91     close(s->fd);
  92     free(s);
  93 }
  94
  95 static int
  96 stream_connect(struct vconn *vconn)
  97 {
  98     struct stream_vconn *s = stream_vconn_cast(vconn);
  99     int retval = check_connection_completion(s->fd);
 100     if (retval) {
 101         return retval;
 102     }
 103     if (s->connect_success_cb) {
 104         s->connect_success_cb(vconn, s->fd);
 105     }
 106     return 0;
 107 }
 108
 109 static int
 110 stream_recv(struct vconn *vconn, struct ofpbuf **bufferp)
 111 {
 112     struct stream_vconn *s = stream_vconn_cast(vconn);
 113     struct ofpbuf *rx;
 114     size_t want_bytes;
 115     ssize_t retval;
 116
 117     if (s->rxbuf == NULL) {
 118         s->rxbuf = ofpbuf_new(1564);
 119     }
 120     rx = s->rxbuf;
 121
 122 again:
 123     if (sizeof(struct ofp_header) > rx->size) {
 124         want_bytes = sizeof(struct ofp_header) - rx->size;
 125     } else {
 126         struct ofp_header *oh = rx->data;
 127         size_t length = ntohs(oh->length);
 128         if (length < sizeof(struct ofp_header)) {
 129             VLOG_ERR_RL(&rl, "received too-short ofp_header (%zu bytes)",
 130                         length);
 131             return EPROTO;
 132         }
 133         want_bytes = length - rx->size;
 134         if (!want_bytes) {
 135             *bufferp = rx;
 136             s->rxbuf = NULL;
 137             return 0;
 138         }
 139     }
 140     ofpbuf_prealloc_tailroom(rx, want_bytes);
 141
 142     retval = read(s->fd, ofpbuf_tail(rx), want_bytes);
 143     if (retval > 0) {
 144         rx->size += retval;
 145         if (retval == want_bytes) {
 146             if (rx->size > sizeof(struct ofp_header)) {
 147                 *bufferp = rx;
 148                 s->rxbuf = NULL;
 149                 return 0;
 150             } else {
 151                 goto again;
 152             }
 153         }
 154         return EAGAIN;
 155     } else if (retval == 0) {
 156         if (rx->size) {
 157             VLOG_ERR_RL(&rl, "connection dropped mid-packet");
 158             return EPROTO;
 159         } else {
 160             return EOF;
 161         }
 162     } else {
 163         return errno;
 164     }
 165 }
 166
 167 static void
 168 stream_clear_txbuf(struct stream_vconn *s)
 169 {
 170     ofpbuf_delete(s->txbuf);
 171     s->txbuf = NULL;
 172     s->tx_waiter = NULL;
 173 }
 174
 175 static void
 176 stream_do_tx(int fd UNUSED, short int revents UNUSED, void *vconn_)
 177 {
 178     struct vconn *vconn = vconn_;
 179     struct stream_vconn *s = stream_vconn_cast(vconn);
 180     ssize_t n = write(s->fd, s->txbuf->data, s->txbuf->size);
 181     if (n < 0) {
 182         if (errno != EAGAIN) {
 183             VLOG_ERR_RL(&rl, "send: %s", strerror(errno));
 184             stream_clear_txbuf(s);
 185             return;
 186         }
 187     } else if (n > 0) {
 188         ofpbuf_pull(s->txbuf, n);
 189         if (!s->txbuf->size) {
 190             stream_clear_txbuf(s);
 191             return;
 192         }
 193     }
 194     s->tx_waiter = poll_fd_callback(s->fd, POLLOUT, stream_do_tx, vconn);
 195 }
 196
 197 static int
 198 stream_send(struct vconn *vconn, struct ofpbuf *buffer)
 199 {
 200     struct stream_vconn *s = stream_vconn_cast(vconn);
 201     ssize_t retval;
 202
 203     if (s->txbuf) {
 204         return EAGAIN;
 205     }
 206
 207     retval = write(s->fd, buffer->data, buffer->size);
 208     if (retval == buffer->size) {
 209         ofpbuf_delete(buffer);
 210         return 0;
 211     } else if (retval >= 0 || errno == EAGAIN) {
 212         leak_checker_claim(buffer);
 213         s->txbuf = buffer;
 214         if (retval > 0) {
 215             ofpbuf_pull(buffer, retval);
 216         }
 217         s->tx_waiter = poll_fd_callback(s->fd, POLLOUT, stream_do_tx, vconn);
 218         return 0;
 219     } else {
 220         return errno;
 221     }
 222 }
 223
 224 static void
 225 stream_wait(struct vconn *vconn, enum vconn_wait_type wait)
 226 {
 227     struct stream_vconn *s = stream_vconn_cast(vconn);
 228     switch (wait) {
 229     case WAIT_CONNECT:
 230         poll_fd_wait(s->fd, POLLOUT);
 231         break;
 232
 233     case WAIT_SEND:
 234         if (!s->txbuf) {
 235             poll_fd_wait(s->fd, POLLOUT);
 236         } else {
 237             /* Nothing to do: need to drain txbuf first. */
 238         }
 239         break;
 240
 241     case WAIT_RECV:
 242         poll_fd_wait(s->fd, POLLIN);
 243         break;
 244
 245     default:
 246         NOT_REACHED();
 247     }
 248 }
 249
 250 static struct vconn_class stream_vconn_class = {
 251     "stream",                   /* name */
 252     NULL,                       /* open */
 253     stream_close,               /* close */
 254     stream_connect,             /* connect */
 255     stream_recv,                /* recv */
 256     stream_send,                /* send */
 257     stream_wait,                /* wait */
 258 };
 259 \f
 260 /* Passive stream socket vconn. */
 261
 262 struct pstream_pvconn
 263 {
 264     struct pvconn pvconn;
 265     int fd;
 266     int (*accept_cb)(int fd, const struct sockaddr *, size_t sa_len,
 267                      struct vconn **);
 268 };
 269
 270 static struct pvconn_class pstream_pvconn_class;
 271
 272 static struct pstream_pvconn *
 273 pstream_pvconn_cast(struct pvconn *pvconn)
 274 {
 275     pvconn_assert_class(pvconn, &pstream_pvconn_class);
 276     return CONTAINER_OF(pvconn, struct pstream_pvconn, pvconn);
 277 }
 278
 279 int
 280 new_pstream_pvconn(const char *name, int fd,
 281                   int (*accept_cb)(int fd, const struct sockaddr *,
 282                                    size_t sa_len, struct vconn **),
 283                   struct pvconn **pvconnp)
 284 {
 285     struct pstream_pvconn *ps;
 286     int retval;
 287
 288     retval = set_nonblocking(fd);
 289     if (retval) {
 290         close(fd);
 291         return retval;
 292     }
 293
 294     if (listen(fd, 10) < 0) {
 295         int error = errno;
 296         VLOG_ERR("%s: listen: %s", name, strerror(error));
 297         close(fd);
 298         return error;
 299     }
 300
 301     ps = xmalloc(sizeof *ps);
 302     pvconn_init(&ps->pvconn, &pstream_pvconn_class, name);
 303     ps->fd = fd;
 304     ps->accept_cb = accept_cb;
 305     *pvconnp = &ps->pvconn;
 306     return 0;
 307 }
 308
 309 static void
 310 pstream_close(struct pvconn *pvconn)
 311 {
 312     struct pstream_pvconn *ps = pstream_pvconn_cast(pvconn);
 313     close(ps->fd);
 314     free(ps);
 315 }
 316
 317 static int
 318 pstream_accept(struct pvconn *pvconn, struct vconn **new_vconnp)
 319 {
 320     struct pstream_pvconn *ps = pstream_pvconn_cast(pvconn);
 321     struct sockaddr_storage ss;
 322     socklen_t ss_len = sizeof ss;
 323     int new_fd;
 324     int retval;
 325
 326     new_fd = accept(ps->fd, (struct sockaddr *) &ss, &ss_len);
 327     if (new_fd < 0) {
 328         int retval = errno;
 329         if (retval != EAGAIN) {
 330             VLOG_DBG_RL(&rl, "accept: %s", strerror(retval));
 331         }
 332         return retval;
 333     }
 334
 335     retval = set_nonblocking(new_fd);
 336     if (retval) {
 337         close(new_fd);
 338         return retval;
 339     }
 340
 341     return ps->accept_cb(new_fd, (const struct sockaddr *) &ss, ss_len,
 342                          new_vconnp);
 343 }
 344
 345 static void
 346 pstream_wait(struct pvconn *pvconn)
 347 {
 348     struct pstream_pvconn *ps = pstream_pvconn_cast(pvconn);
 349     poll_fd_wait(ps->fd, POLLIN);
 350 }
 351
 352 static struct pvconn_class pstream_pvconn_class = {
 353     "pstream",
 354     NULL,
 355     pstream_close,
 356     pstream_accept,
 357     pstream_wait
 358 };