fs/smbfs/sock.c

   1 /*
   2  *  sock.c
   3  *
   4  *  Copyright (C) 1995, 1996 by Paal-Kr. Engstad and Volker Lendecke
   5  *  Copyright (C) 1997 by Volker Lendecke
   6  *
   7  *  Please add a note about your changes to smbfs in the ChangeLog file.
   8  */
   9
  10 #include <linux/fs.h>
  11 #include <linux/time.h>
  12 #include <linux/errno.h>
  13 #include <linux/socket.h>
  14 #include <linux/fcntl.h>
  15 #include <linux/file.h>
  16 #include <linux/in.h>
  17 #include <linux/net.h>
  18 #include <linux/mm.h>
  19 #include <linux/netdevice.h>
  20 #include <linux/smp_lock.h>
  21 #include <linux/workqueue.h>
  22 #include <net/scm.h>
  23 #include <net/tcp_states.h>
  24 #include <net/ip.h>
  25
  26 #include <linux/smb_fs.h>
  27 #include <linux/smb.h>
  28 #include <linux/smbno.h>
  29
  30 #include <asm/uaccess.h>
  31 #include <asm/ioctls.h>
  32
  33 #include "smb_debug.h"
  34 #include "proto.h"
  35 #include "request.h"
  36
  37
  38 static int
  39 _recvfrom(struct socket *socket, unsigned char *ubuf, int size, unsigned flags)
  40 {
  41         struct kvec iov = {ubuf, size};
  42         struct msghdr msg = {.msg_flags = flags};
  43         msg.msg_flags |= MSG_DONTWAIT | MSG_NOSIGNAL;
  44         return kernel_recvmsg(socket, &msg, &iov, 1, size, msg.msg_flags);
  45 }
  46
  47 /*
  48  * Return the server this socket belongs to
  49  */
  50 static struct smb_sb_info *
  51 server_from_socket(struct socket *socket)
  52 {
  53         return socket->sk->sk_user_data;
  54 }
  55
  56 /*
  57  * Called when there is data on the socket.
  58  */
  59 void
  60 smb_data_ready(struct sock *sk, int len)
  61 {
  62         struct smb_sb_info *server = server_from_socket(sk->sk_socket);
  63         void (*data_ready)(struct sock *, int) = server->data_ready;
  64
  65         data_ready(sk, len);
  66         VERBOSE("(%p, %d)\n", sk, len);
  67         smbiod_wake_up();
  68 }
  69
  70 int
  71 smb_valid_socket(struct inode * inode)
  72 {
  73         return (inode && S_ISSOCK(inode->i_mode) &&
  74                 SOCKET_I(inode)->type == SOCK_STREAM);
  75 }
  76
  77 static struct socket *
  78 server_sock(struct smb_sb_info *server)
  79 {
  80         struct file *file;
  81
  82         if (server && (file = server->sock_file))
  83         {
  84 #ifdef SMBFS_PARANOIA
  85                 if (!smb_valid_socket(file->f_path.dentry->d_inode))
  86                         PARANOIA("bad socket!\n");
  87 #endif
  88                 return SOCKET_I(file->f_path.dentry->d_inode);
  89         }
  90         return NULL;
  91 }
  92
  93 void
  94 smb_close_socket(struct smb_sb_info *server)
  95 {
  96         struct file * file = server->sock_file;
  97
  98         if (file) {
  99                 struct socket *sock = server_sock(server);
 100
 101                 VERBOSE("closing socket %p\n", sock);
 102                 sock->sk->sk_data_ready = server->data_ready;
 103                 server->sock_file = NULL;
 104                 fput(file);
 105         }
 106 }
 107
 108 static int
 109 smb_get_length(struct socket *socket, unsigned char *header)
 110 {
 111         int result;
 112
 113         result = _recvfrom(socket, header, 4, MSG_PEEK);
 114         if (result == -EAGAIN)
 115                 return -ENODATA;
 116         if (result < 0) {
 117                 PARANOIA("recv error = %d\n", -result);
 118                 return result;
 119         }
 120         if (result < 4)
 121                 return -ENODATA;
 122
 123         switch (header[0]) {
 124         case 0x00:
 125         case 0x82:
 126                 break;
 127
 128         case 0x85:
 129                 DEBUG1("Got SESSION KEEP ALIVE\n");
 130                 _recvfrom(socket, header, 4, 0);        /* read away */
 131                 return -ENODATA;
 132
 133         default:
 134                 PARANOIA("Invalid NBT packet, code=%x\n", header[0]);
 135                 return -EIO;
 136         }
 137
 138         /* The length in the RFC NB header is the raw data length */
 139         return smb_len(header);
 140 }
 141
 142 int
 143 smb_recv_available(struct smb_sb_info *server)
 144 {
 145         mm_segment_t oldfs;
 146         int avail, err;
 147         struct socket *sock = server_sock(server);
 148
 149         oldfs = get_fs();
 150         set_fs(get_ds());
 151         err = sock->ops->ioctl(sock, SIOCINQ, (unsigned long) &avail);
 152         set_fs(oldfs);
 153         return (err >= 0) ? avail : err;
 154 }
 155
 156 /*
 157  * Adjust the kvec to move on 'n' bytes (from nfs/sunrpc)
 158  */
 159 static int
 160 smb_move_iov(struct kvec **data, size_t *num, struct kvec *vec, unsigned amount)
 161 {
 162         struct kvec *iv = *data;
 163         int i;
 164         int len;
 165
 166         /*
 167          *      Eat any sent kvecs
 168          */
 169         while (iv->iov_len <= amount) {
 170                 amount -= iv->iov_len;
 171                 iv++;
 172                 (*num)--;
 173         }
 174
 175         /*
 176          *      And chew down the partial one
 177          */
 178         vec[0].iov_len = iv->iov_len-amount;
 179         vec[0].iov_base =((unsigned char *)iv->iov_base)+amount;
 180         iv++;
 181
 182         len = vec[0].iov_len;
 183
 184         /*
 185          *      And copy any others
 186          */
 187         for (i = 1; i < *num; i++) {
 188                 vec[i] = *iv++;
 189                 len += vec[i].iov_len;
 190         }
 191
 192         *data = vec;
 193         return len;
 194 }
 195
 196 /*
 197  * smb_receive_header
 198  * Only called by the smbiod thread.
 199  */
 200 int
 201 smb_receive_header(struct smb_sb_info *server)
 202 {
 203         struct socket *sock;
 204         int result = 0;
 205         unsigned char peek_buf[4];
 206
 207         result = -EIO;
 208         sock = server_sock(server);
 209         if (!sock)
 210                 goto out;
 211         if (sock->sk->sk_state != TCP_ESTABLISHED)
 212                 goto out;
 213
 214         if (!server->smb_read) {
 215                 result = smb_get_length(sock, peek_buf);
 216                 if (result < 0) {
 217                         if (result == -ENODATA)
 218                                 result = 0;
 219                         goto out;
 220                 }
 221                 server->smb_len = result + 4;
 222
 223                 if (server->smb_len < SMB_HEADER_LEN) {
 224                         PARANOIA("short packet: %d\n", result);
 225                         server->rstate = SMB_RECV_DROP;
 226                         result = -EIO;
 227                         goto out;
 228                 }
 229                 if (server->smb_len > SMB_MAX_PACKET_SIZE) {
 230                         PARANOIA("long packet: %d\n", result);
 231                         server->rstate = SMB_RECV_DROP;
 232                         result = -EIO;
 233                         goto out;
 234                 }
 235         }
 236
 237         result = _recvfrom(sock, server->header + server->smb_read,
 238                            SMB_HEADER_LEN - server->smb_read, 0);
 239         VERBOSE("_recvfrom: %d\n", result);
 240         if (result < 0) {
 241                 VERBOSE("receive error: %d\n", result);
 242                 goto out;
 243         }
 244         server->smb_read += result;
 245
 246         if (server->smb_read == SMB_HEADER_LEN)
 247                 server->rstate = SMB_RECV_HCOMPLETE;
 248 out:
 249         return result;
 250 }
 251
 252 static char drop_buffer[PAGE_SIZE];
 253
 254 /*
 255  * smb_receive_drop - read and throw away the data
 256  * Only called by the smbiod thread.
 257  *
 258  * FIXME: we are in the kernel, could we just tell the socket that we want
 259  * to drop stuff from the buffer?
 260  */
 261 int
 262 smb_receive_drop(struct smb_sb_info *server)
 263 {
 264         struct socket *sock;
 265         unsigned int flags;
 266         struct kvec iov;
 267         struct msghdr msg;
 268         int rlen = smb_len(server->header) - server->smb_read + 4;
 269         int result = -EIO;
 270
 271         if (rlen > PAGE_SIZE)
 272                 rlen = PAGE_SIZE;
 273
 274         sock = server_sock(server);
 275         if (!sock)
 276                 goto out;
 277         if (sock->sk->sk_state != TCP_ESTABLISHED)
 278                 goto out;
 279
 280         flags = MSG_DONTWAIT | MSG_NOSIGNAL;
 281         iov.iov_base = drop_buffer;
 282         iov.iov_len = PAGE_SIZE;
 283         msg.msg_flags = flags;
 284         msg.msg_name = NULL;
 285         msg.msg_namelen = 0;
 286         msg.msg_control = NULL;
 287
 288         result = kernel_recvmsg(sock, &msg, &iov, 1, rlen, flags);
 289
 290         VERBOSE("read: %d\n", result);
 291         if (result < 0) {
 292                 VERBOSE("receive error: %d\n", result);
 293                 goto out;
 294         }
 295         server->smb_read += result;
 296
 297         if (server->smb_read >= server->smb_len)
 298                 server->rstate = SMB_RECV_END;
 299
 300 out:
 301         return result;
 302 }
 303
 304 /*
 305  * smb_receive
 306  * Only called by the smbiod thread.
 307  */
 308 int
 309 smb_receive(struct smb_sb_info *server, struct smb_request *req)
 310 {
 311         struct socket *sock;
 312         unsigned int flags;
 313         struct kvec iov[4];
 314         struct kvec *p = req->rq_iov;
 315         size_t num = req->rq_iovlen;
 316         struct msghdr msg;
 317         int rlen;
 318         int result = -EIO;
 319
 320         sock = server_sock(server);
 321         if (!sock)
 322                 goto out;
 323         if (sock->sk->sk_state != TCP_ESTABLISHED)
 324                 goto out;
 325
 326         flags = MSG_DONTWAIT | MSG_NOSIGNAL;
 327         msg.msg_flags = flags;
 328         msg.msg_name = NULL;
 329         msg.msg_namelen = 0;
 330         msg.msg_control = NULL;
 331
 332         /* Dont repeat bytes and count available bufferspace */
 333         rlen = smb_move_iov(&p, &num, iov, req->rq_bytes_recvd);
 334         if (req->rq_rlen < rlen)
 335                 rlen = req->rq_rlen;
 336
 337         result = kernel_recvmsg(sock, &msg, p, num, rlen, flags);
 338
 339         VERBOSE("read: %d\n", result);
 340         if (result < 0) {
 341                 VERBOSE("receive error: %d\n", result);
 342                 goto out;
 343         }
 344         req->rq_bytes_recvd += result;
 345         server->smb_read += result;
 346
 347 out:
 348         return result;
 349 }
 350
 351 /*
 352  * Try to send a SMB request. This may return after sending only parts of the
 353  * request. SMB_REQ_TRANSMITTED will be set if a request was fully sent.
 354  *
 355  * Parts of this was taken from xprt_sendmsg from net/sunrpc/xprt.c
 356  */
 357 int
 358 smb_send_request(struct smb_request *req)
 359 {
 360         struct smb_sb_info *server = req->rq_server;
 361         struct socket *sock;
 362         struct msghdr msg = {.msg_flags = MSG_NOSIGNAL | MSG_DONTWAIT};
 363         int slen = req->rq_slen - req->rq_bytes_sent;
 364         int result = -EIO;
 365         struct kvec iov[4];
 366         struct kvec *p = req->rq_iov;
 367         size_t num = req->rq_iovlen;
 368
 369         sock = server_sock(server);
 370         if (!sock)
 371                 goto out;
 372         if (sock->sk->sk_state != TCP_ESTABLISHED)
 373                 goto out;
 374
 375         /* Dont repeat bytes */
 376         if (req->rq_bytes_sent)
 377                 smb_move_iov(&p, &num, iov, req->rq_bytes_sent);
 378
 379         result = kernel_sendmsg(sock, &msg, p, num, slen);
 380
 381         if (result >= 0) {
 382                 req->rq_bytes_sent += result;
 383                 if (req->rq_bytes_sent >= req->rq_slen)
 384                         req->rq_flags |= SMB_REQ_TRANSMITTED;
 385         }
 386 out:
 387         return result;
 388 }