release/src/router/dropbear/channel.h

   1 /*
   2  * Dropbear - a SSH2 server
   3  *
   4  * Copyright (c) 2002,2003 Matt Johnston
   5  * All rights reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE. */
  24
  25 #ifndef DROPBEAR_CHANNEL_H_
  26 #define DROPBEAR_CHANNEL_H_
  27
  28 #include "includes.h"
  29 #include "buffer.h"
  30 #include "circbuffer.h"
  31
  32 #define SSH_OPEN_ADMINISTRATIVELY_PROHIBITED    1
  33 #define SSH_OPEN_CONNECT_FAILED                 2
  34 #define SSH_OPEN_UNKNOWN_CHANNEL_TYPE           3
  35 #define SSH_OPEN_RESOURCE_SHORTAGE              4
  36
  37 /* Not a real type */
  38 #define SSH_OPEN_IN_PROGRESS                                    99
  39
  40 #define CHAN_EXTEND_SIZE 3 /* how many extra slots to add when we need more */
  41
  42 struct ChanType;
  43
  44 enum dropbear_channel_prio {
  45         DROPBEAR_CHANNEL_PRIO_INTERACTIVE, /* pty shell, x11 */
  46         DROPBEAR_CHANNEL_PRIO_UNKNOWABLE, /* tcp - can't know what's being forwarded */
  47         DROPBEAR_CHANNEL_PRIO_BULK, /* the rest - probably scp or something */
  48         DROPBEAR_CHANNEL_PRIO_EARLY, /* channel is still being set up */
  49 };
  50
  51 struct Channel {
  52
  53         unsigned int index; /* the local channel index */
  54         unsigned int remotechan;
  55         unsigned int recvwindow, transwindow;
  56         unsigned int recvdonelen;
  57         unsigned int recvmaxpacket, transmaxpacket;
  58         void* typedata; /* a pointer to type specific data */
  59         int writefd; /* read from wire, written to insecure side */
  60         int readfd; /* read from insecure side, written to wire */
  61         int errfd; /* used like writefd or readfd, depending if it's client or server.
  62                                   Doesn't exactly belong here, but is cleaner here */
  63         circbuffer *writebuf; /* data from the wire, for local consumption. Can be
  64                                                          initially NULL */
  65         circbuffer *extrabuf; /* extended-data for the program - used like writebuf
  66                                              but for stderr */
  67
  68         /* whether close/eof messages have been exchanged */
  69         int sent_close, recv_close;
  70         int recv_eof, sent_eof;
  71
  72         /* Set after running the ChanType-specific close hander
  73          * to ensure we don't run it twice (nor type->checkclose()). */
  74         int close_handler_done;
  75
  76         struct dropbear_progress_connection *conn_pending;
  77         int initconn; /* used for TCP forwarding, whether the channel has been
  78                                          fully initialised */
  79
  80         int await_open; /* flag indicating whether we've sent an open request
  81                                            for this channel (and are awaiting a confirmation
  82                                            or failure). */
  83
  84         int flushing;
  85
  86         /* Used by client chansession to handle ~ escaping, NULL ignored otherwise */
  87         void (*read_mangler)(struct Channel*, unsigned char* bytes, int *len);
  88
  89         const struct ChanType* type;
  90
  91         enum dropbear_channel_prio prio;
  92 };
  93
  94 struct ChanType {
  95
  96         int sepfds; /* Whether this channel has separate pipes for in/out or not */
  97         char *name;
  98         int (*inithandler)(struct Channel*);
  99         int (*check_close)(struct Channel*);
 100         void (*reqhandler)(struct Channel*);
 101         void (*closehandler)(struct Channel*);
 102 };
 103
 104 /* Callback for connect_remote */
 105 void channel_connect_done(int result, int sock, void* user_data, const char* errstring);
 106
 107 void chaninitialise(const struct ChanType *chantypes[]);
 108 void chancleanup();
 109 void setchannelfds(fd_set *readfds, fd_set *writefds, int allow_reads);
 110 void channelio(fd_set *readfd, fd_set *writefd);
 111 struct Channel* getchannel();
 112 /* Returns an arbitrary channel that is in a ready state - not
 113 being initialised and no EOF in either direction. NULL if none. */
 114 struct Channel* get_any_ready_channel();
 115
 116 void recv_msg_channel_open();
 117 void recv_msg_channel_request();
 118 void send_msg_channel_failure(struct Channel *channel);
 119 void send_msg_channel_success(struct Channel *channel);
 120 void recv_msg_channel_data();
 121 void recv_msg_channel_extended_data();
 122 void recv_msg_channel_window_adjust();
 123 void recv_msg_channel_close();
 124 void recv_msg_channel_eof();
 125
 126 void common_recv_msg_channel_data(struct Channel *channel, int fd,
 127                 circbuffer * buf);
 128
 129 #ifdef DROPBEAR_CLIENT
 130 extern const struct ChanType clichansess;
 131 #endif
 132
 133 #if defined(USING_LISTENERS) || defined(DROPBEAR_CLIENT)
 134 int send_msg_channel_open_init(int fd, const struct ChanType *type);
 135 void recv_msg_channel_open_confirmation();
 136 void recv_msg_channel_open_failure();
 137 #endif
 138 void start_send_channel_request(struct Channel *channel, char *type);
 139
 140 void send_msg_request_success();
 141 void send_msg_request_failure();
 142
 143
 144 #endif /* DROPBEAR_CHANNEL_H_ */