src/net/tcp/ftp.c

   1 /*
   2  * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA.
  18  */
  19
  20 #include <stdint.h>
  21 #include <stdlib.h>
  22 #include <stdio.h>
  23 #include <string.h>
  24 #include <assert.h>
  25 #include <errno.h>
  26 #include <ctype.h>
  27 #include <byteswap.h>
  28 #include <ipxe/socket.h>
  29 #include <ipxe/tcpip.h>
  30 #include <ipxe/in.h>
  31 #include <ipxe/iobuf.h>
  32 #include <ipxe/xfer.h>
  33 #include <ipxe/open.h>
  34 #include <ipxe/uri.h>
  35 #include <ipxe/features.h>
  36 #include <ipxe/ftp.h>
  37
  38 /** @file
  39  *
  40  * File transfer protocol
  41  *
  42  */
  43
  44 FEATURE ( FEATURE_PROTOCOL, "FTP", DHCP_EB_FEATURE_FTP, 1 );
  45
  46 /**
  47  * FTP states
  48  *
  49  * These @b must be sequential, i.e. a successful FTP session must
  50  * pass through each of these states in order.
  51  */
  52 enum ftp_state {
  53         FTP_CONNECT = 0,
  54         FTP_USER,
  55         FTP_PASS,
  56         FTP_TYPE,
  57         FTP_SIZE,
  58         FTP_PASV,
  59         FTP_RETR,
  60         FTP_WAIT,
  61         FTP_QUIT,
  62         FTP_DONE,
  63 };
  64
  65 /**
  66  * An FTP request
  67  *
  68  */
  69 struct ftp_request {
  70         /** Reference counter */
  71         struct refcnt refcnt;
  72         /** Data transfer interface */
  73         struct interface xfer;
  74
  75         /** URI being fetched */
  76         struct uri *uri;
  77         /** FTP control channel interface */
  78         struct interface control;
  79         /** FTP data channel interface */
  80         struct interface data;
  81
  82         /** Current state */
  83         enum ftp_state state;
  84         /** Buffer to be filled with data received via the control channel */
  85         char *recvbuf;
  86         /** Remaining size of recvbuf */
  87         size_t recvsize;
  88         /** FTP status code, as text */
  89         char status_text[5];
  90         /** Passive-mode parameters, as text */
  91         char passive_text[24]; /* "aaa,bbb,ccc,ddd,eee,fff" */
  92         /** File size, as text */
  93         char filesize[20];
  94 };
  95
  96 /**
  97  * Free FTP request
  98  *
  99  * @v refcnt            Reference counter
 100  */
 101 static void ftp_free ( struct refcnt *refcnt ) {
 102         struct ftp_request *ftp =
 103                 container_of ( refcnt, struct ftp_request, refcnt );
 104
 105         DBGC ( ftp, "FTP %p freed\n", ftp );
 106
 107         uri_put ( ftp->uri );
 108         free ( ftp );
 109 }
 110
 111 /**
 112  * Mark FTP operation as complete
 113  *
 114  * @v ftp               FTP request
 115  * @v rc                Return status code
 116  */
 117 static void ftp_done ( struct ftp_request *ftp, int rc ) {
 118
 119         DBGC ( ftp, "FTP %p completed (%s)\n", ftp, strerror ( rc ) );
 120
 121         /* Close all data transfer interfaces */
 122         intf_shutdown ( &ftp->data, rc );
 123         intf_shutdown ( &ftp->control, rc );
 124         intf_shutdown ( &ftp->xfer, rc );
 125 }
 126
 127 /*****************************************************************************
 128  *
 129  * FTP control channel
 130  *
 131  */
 132
 133 /** An FTP control channel string */
 134 struct ftp_control_string {
 135         /** Literal portion */
 136         const char *literal;
 137         /** Variable portion
 138          *
 139          * @v ftp       FTP request
 140          * @ret string  Variable portion of string
 141          */
 142         const char * ( *variable ) ( struct ftp_request *ftp );
 143 };
 144
 145 /**
 146  * Retrieve FTP pathname
 147  *
 148  * @v ftp               FTP request
 149  * @ret path            FTP pathname
 150  */
 151 static const char * ftp_uri_path ( struct ftp_request *ftp ) {
 152         return ftp->uri->path;
 153 }
 154
 155 /**
 156  * Retrieve FTP user
 157  *
 158  * @v ftp               FTP request
 159  * @ret user            FTP user
 160  */
 161 static const char * ftp_user ( struct ftp_request *ftp ) {
 162         static char *ftp_default_user = "anonymous";
 163         return ftp->uri->user ? ftp->uri->user : ftp_default_user;
 164 }
 165
 166 /**
 167  * Retrieve FTP password
 168  *
 169  * @v ftp               FTP request
 170  * @ret password        FTP password
 171  */
 172 static const char * ftp_password ( struct ftp_request *ftp ) {
 173         static char *ftp_default_password = "ipxe@ipxe.org";
 174         return ftp->uri->password ? ftp->uri->password : ftp_default_password;
 175 }
 176
 177 /** FTP control channel strings */
 178 static struct ftp_control_string ftp_strings[] = {
 179         [FTP_CONNECT]   = { NULL, NULL },
 180         [FTP_USER]      = { "USER ", ftp_user },
 181         [FTP_PASS]      = { "PASS ", ftp_password },
 182         [FTP_TYPE]      = { "TYPE I", NULL },
 183         [FTP_SIZE]      = { "SIZE ", ftp_uri_path },
 184         [FTP_PASV]      = { "PASV", NULL },
 185         [FTP_RETR]      = { "RETR ", ftp_uri_path },
 186         [FTP_WAIT]      = { NULL, NULL },
 187         [FTP_QUIT]      = { "QUIT", NULL },
 188         [FTP_DONE]      = { NULL, NULL },
 189 };
 190
 191 /**
 192  * Parse FTP byte sequence value
 193  *
 194  * @v text              Text string
 195  * @v value             Value buffer
 196  * @v len               Length of value buffer
 197  *
 198  * This parses an FTP byte sequence value (e.g. the "aaa,bbb,ccc,ddd"
 199  * form for IP addresses in PORT commands) into a byte sequence.  @c
 200  * *text will be updated to point beyond the end of the parsed byte
 201  * sequence.
 202  *
 203  * This function is safe in the presence of malformed data, though the
 204  * output is undefined.
 205  */
 206 static void ftp_parse_value ( char **text, uint8_t *value, size_t len ) {
 207         do {
 208                 *(value++) = strtoul ( *text, text, 10 );
 209                 if ( **text )
 210                         (*text)++;
 211         } while ( --len );
 212 }
 213
 214 /**
 215  * Move to next state and send the appropriate FTP control string
 216  *
 217  * @v ftp               FTP request
 218  *
 219  */
 220 static void ftp_next_state ( struct ftp_request *ftp ) {
 221         struct ftp_control_string *ftp_string;
 222         const char *literal;
 223         const char *variable;
 224
 225         /* Move to next state */
 226         if ( ftp->state < FTP_DONE )
 227                 ftp->state++;
 228
 229         /* Send control string if needed */
 230         ftp_string = &ftp_strings[ftp->state];
 231         literal = ftp_string->literal;
 232         variable = ( ftp_string->variable ?
 233                      ftp_string->variable ( ftp ) : "" );
 234         if ( literal ) {
 235                 DBGC ( ftp, "FTP %p sending %s%s\n", ftp, literal, variable );
 236                 xfer_printf ( &ftp->control, "%s%s\r\n", literal, variable );
 237         }
 238 }
 239
 240 /**
 241  * Handle an FTP control channel response
 242  *
 243  * @v ftp               FTP request
 244  *
 245  * This is called once we have received a complete response line.
 246  */
 247 static void ftp_reply ( struct ftp_request *ftp ) {
 248         char status_major = ftp->status_text[0];
 249         char separator = ftp->status_text[3];
 250
 251         DBGC ( ftp, "FTP %p received status %s\n", ftp, ftp->status_text );
 252
 253         /* Ignore malformed lines */
 254         if ( separator != ' ' )
 255                 return;
 256
 257         /* Ignore "intermediate" responses (1xx codes) */
 258         if ( status_major == '1' )
 259                 return;
 260
 261         /* If the SIZE command is not supported by the server, we go to
 262          * the next step.
 263          */
 264         if ( ( status_major == '5' ) && ( ftp->state == FTP_SIZE ) ) {
 265                 ftp_next_state ( ftp );
 266                 return;
 267         }
 268
 269         /* Anything other than success (2xx) or, in the case of a
 270          * repsonse to a "USER" command, a password prompt (3xx), is a
 271          * fatal error.
 272          */
 273         if ( ! ( ( status_major == '2' ) ||
 274                  ( ( status_major == '3' ) && ( ftp->state == FTP_USER ) ) ) ){
 275                 /* Flag protocol error and close connections */
 276                 ftp_done ( ftp, -EPROTO );
 277                 return;
 278         }
 279
 280         /* Parse file size */
 281         if ( ftp->state == FTP_SIZE ) {
 282                 size_t filesize;
 283                 char *endptr;
 284
 285                 /* Parse size */
 286                 filesize = strtoul ( ftp->filesize, &endptr, 10 );
 287                 if ( *endptr != '\0' ) {
 288                         DBGC ( ftp, "FTP %p invalid SIZE \"%s\"\n",
 289                                ftp, ftp->filesize );
 290                         ftp_done ( ftp, -EPROTO );
 291                         return;
 292                 }
 293
 294                 /* Use seek() to notify recipient of filesize */
 295                 DBGC ( ftp, "FTP %p file size is %zd bytes\n", ftp, filesize );
 296                 xfer_seek ( &ftp->xfer, filesize );
 297                 xfer_seek ( &ftp->xfer, 0 );
 298         }
 299
 300         /* Open passive connection when we get "PASV" response */
 301         if ( ftp->state == FTP_PASV ) {
 302                 char *ptr = ftp->passive_text;
 303                 union {
 304                         struct sockaddr_in sin;
 305                         struct sockaddr sa;
 306                 } sa;
 307                 int rc;
 308
 309                 sa.sin.sin_family = AF_INET;
 310                 ftp_parse_value ( &ptr, ( uint8_t * ) &sa.sin.sin_addr,
 311                                   sizeof ( sa.sin.sin_addr ) );
 312                 ftp_parse_value ( &ptr, ( uint8_t * ) &sa.sin.sin_port,
 313                                   sizeof ( sa.sin.sin_port ) );
 314                 if ( ( rc = xfer_open_socket ( &ftp->data, SOCK_STREAM,
 315                                                &sa.sa, NULL ) ) != 0 ) {
 316                         DBGC ( ftp, "FTP %p could not open data connection\n",
 317                                ftp );
 318                         ftp_done ( ftp, rc );
 319                         return;
 320                 }
 321         }
 322
 323         /* Move to next state and send control string */
 324         ftp_next_state ( ftp );
 325
 326 }
 327
 328 /**
 329  * Handle new data arriving on FTP control channel
 330  *
 331  * @v ftp               FTP request
 332  * @v iob               I/O buffer
 333  * @v meta              Data transfer metadata
 334  * @ret rc              Return status code
 335  *
 336  * Data is collected until a complete line is received, at which point
 337  * its information is passed to ftp_reply().
 338  */
 339 static int ftp_control_deliver ( struct ftp_request *ftp,
 340                                  struct io_buffer *iobuf,
 341                                  struct xfer_metadata *meta __unused ) {
 342         char *data = iobuf->data;
 343         size_t len = iob_len ( iobuf );
 344         char *recvbuf = ftp->recvbuf;
 345         size_t recvsize = ftp->recvsize;
 346         char c;
 347
 348         while ( len-- ) {
 349                 c = *(data++);
 350                 if ( ( c == '\r' ) || ( c == '\n' ) ) {
 351                         /* End of line: call ftp_reply() to handle
 352                          * completed reply.  Avoid calling ftp_reply()
 353                          * twice if we receive both \r and \n.
 354                          */
 355                         if ( recvbuf != ftp->status_text )
 356                                 ftp_reply ( ftp );
 357                         /* Start filling up the status code buffer */
 358                         recvbuf = ftp->status_text;
 359                         recvsize = sizeof ( ftp->status_text ) - 1;
 360                 } else if ( ( ftp->state == FTP_PASV ) && ( c == '(' ) ) {
 361                         /* Start filling up the passive parameter buffer */
 362                         recvbuf = ftp->passive_text;
 363                         recvsize = sizeof ( ftp->passive_text ) - 1;
 364                 } else if ( ( ftp->state == FTP_PASV ) && ( c == ')' ) ) {
 365                         /* Stop filling the passive parameter buffer */
 366                         recvsize = 0;
 367                 } else if ( ( ftp->state == FTP_SIZE ) && ( c == ' ' ) ) {
 368                         /* Start filling up the file size buffer */
 369                         recvbuf = ftp->filesize;
 370                         recvsize = sizeof ( ftp->filesize ) - 1;
 371                 } else {
 372                         /* Fill up buffer if applicable */
 373                         if ( recvsize > 0 ) {
 374                                 *(recvbuf++) = c;
 375                                 recvsize--;
 376                         }
 377                 }
 378         }
 379
 380         /* Store for next invocation */
 381         ftp->recvbuf = recvbuf;
 382         ftp->recvsize = recvsize;
 383
 384         /* Free I/O buffer */
 385         free_iob ( iobuf );
 386
 387         return 0;
 388 }
 389
 390 /** FTP control channel interface operations */
 391 static struct interface_operation ftp_control_operations[] = {
 392         INTF_OP ( xfer_deliver, struct ftp_request *, ftp_control_deliver ),
 393         INTF_OP ( intf_close, struct ftp_request *, ftp_done ),
 394 };
 395
 396 /** FTP control channel interface descriptor */
 397 static struct interface_descriptor ftp_control_desc =
 398         INTF_DESC ( struct ftp_request, control, ftp_control_operations );
 399
 400 /*****************************************************************************
 401  *
 402  * FTP data channel
 403  *
 404  */
 405
 406 /**
 407  * Handle FTP data channel being closed
 408  *
 409  * @v ftp               FTP request
 410  * @v rc                Reason for closure
 411  *
 412  * When the data channel is closed, the control channel should be left
 413  * alone; the server will send a completion message via the control
 414  * channel which we'll pick up.
 415  *
 416  * If the data channel is closed due to an error, we abort the request.
 417  */
 418 static void ftp_data_closed ( struct ftp_request *ftp, int rc ) {
 419
 420         DBGC ( ftp, "FTP %p data connection closed: %s\n",
 421                ftp, strerror ( rc ) );
 422
 423         /* If there was an error, close control channel and record status */
 424         if ( rc ) {
 425                 ftp_done ( ftp, rc );
 426         } else {
 427                 ftp_next_state ( ftp );
 428         }
 429 }
 430
 431 /** FTP data channel interface operations */
 432 static struct interface_operation ftp_data_operations[] = {
 433         INTF_OP ( intf_close, struct ftp_request *, ftp_data_closed ),
 434 };
 435
 436 /** FTP data channel interface descriptor */
 437 static struct interface_descriptor ftp_data_desc =
 438         INTF_DESC_PASSTHRU ( struct ftp_request, data, ftp_data_operations,
 439                              xfer );
 440
 441 /*****************************************************************************
 442  *
 443  * Data transfer interface
 444  *
 445  */
 446
 447 /** FTP data transfer interface operations */
 448 static struct interface_operation ftp_xfer_operations[] = {
 449         INTF_OP ( intf_close, struct ftp_request *, ftp_done ),
 450 };
 451
 452 /** FTP data transfer interface descriptor */
 453 static struct interface_descriptor ftp_xfer_desc =
 454         INTF_DESC_PASSTHRU ( struct ftp_request, xfer, ftp_xfer_operations,
 455                              data );
 456
 457 /*****************************************************************************
 458  *
 459  * URI opener
 460  *
 461  */
 462
 463 /**
 464  * Check validity of FTP control channel string
 465  *
 466  * @v string            String
 467  * @ret rc              Return status code
 468  */
 469 static int ftp_check_string ( const char *string ) {
 470         char c;
 471
 472         /* The FTP control channel is line-based.  Check for invalid
 473          * non-printable characters (e.g. newlines).
 474          */
 475         while ( ( c = *(string++) ) ) {
 476                 if ( ! isprint ( c ) )
 477                         return -EINVAL;
 478         }
 479         return 0;
 480 }
 481
 482 /**
 483  * Initiate an FTP connection
 484  *
 485  * @v xfer              Data transfer interface
 486  * @v uri               Uniform Resource Identifier
 487  * @ret rc              Return status code
 488  */
 489 static int ftp_open ( struct interface *xfer, struct uri *uri ) {
 490         struct ftp_request *ftp;
 491         struct sockaddr_tcpip server;
 492         int rc;
 493
 494         /* Sanity checks */
 495         if ( ! uri->host )
 496                 return -EINVAL;
 497         if ( ! uri->path )
 498                 return -EINVAL;
 499         if ( ( rc = ftp_check_string ( uri->path ) ) != 0 )
 500                 return rc;
 501         if ( uri->user && ( ( rc = ftp_check_string ( uri->user ) ) != 0 ) )
 502                 return rc;
 503         if ( uri->password &&
 504              ( ( rc = ftp_check_string ( uri->password ) ) != 0 ) )
 505                 return rc;
 506
 507         /* Allocate and populate structure */
 508         ftp = zalloc ( sizeof ( *ftp ) );
 509         if ( ! ftp )
 510                 return -ENOMEM;
 511         ref_init ( &ftp->refcnt, ftp_free );
 512         intf_init ( &ftp->xfer, &ftp_xfer_desc, &ftp->refcnt );
 513         intf_init ( &ftp->control, &ftp_control_desc, &ftp->refcnt );
 514         intf_init ( &ftp->data, &ftp_data_desc, &ftp->refcnt );
 515         ftp->uri = uri_get ( uri );
 516         ftp->recvbuf = ftp->status_text;
 517         ftp->recvsize = sizeof ( ftp->status_text ) - 1;
 518
 519         DBGC ( ftp, "FTP %p fetching %s\n", ftp, ftp->uri->path );
 520
 521         /* Open control connection */
 522         memset ( &server, 0, sizeof ( server ) );
 523         server.st_port = htons ( uri_port ( uri, FTP_PORT ) );
 524         if ( ( rc = xfer_open_named_socket ( &ftp->control, SOCK_STREAM,
 525                                              ( struct sockaddr * ) &server,
 526                                              uri->host, NULL ) ) != 0 )
 527                 goto err;
 528
 529         /* Attach to parent interface, mortalise self, and return */
 530         intf_plug_plug ( &ftp->xfer, xfer );
 531         ref_put ( &ftp->refcnt );
 532         return 0;
 533
 534  err:
 535         DBGC ( ftp, "FTP %p could not create request: %s\n",
 536                ftp, strerror ( rc ) );
 537         ftp_done ( ftp, rc );
 538         ref_put ( &ftp->refcnt );
 539         return rc;
 540 }
 541
 542 /** FTP URI opener */
 543 struct uri_opener ftp_uri_opener __uri_opener = {
 544         .scheme = "ftp",
 545         .open   = ftp_open,
 546 };