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Diffstat (limited to 'src/channel.h')
| -rw-r--r-- | src/channel.h | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/src/channel.h b/src/channel.h new file mode 100644 index 0000000..dd174aa --- /dev/null +++ b/src/channel.h @@ -0,0 +1,144 @@ +/* + * Dropbear - a SSH2 server + * + * Copyright (c) 2002,2003 Matt Johnston + * All rights reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. */ + +#ifndef DROPBEAR_CHANNEL_H_ +#define DROPBEAR_CHANNEL_H_ + +#include "includes.h" +#include "buffer.h" +#include "circbuffer.h" +#include "netio.h" + +#define SSH_OPEN_ADMINISTRATIVELY_PROHIBITED 1 +#define SSH_OPEN_CONNECT_FAILED 2 +#define SSH_OPEN_UNKNOWN_CHANNEL_TYPE 3 +#define SSH_OPEN_RESOURCE_SHORTAGE 4 + +/* Not a real type */ +#define SSH_OPEN_IN_PROGRESS 99 + +#define CHAN_EXTEND_SIZE 3 /* how many extra slots to add when we need more */ + +struct ChanType; + +struct Channel { + + unsigned int index; /* the local channel index */ + unsigned int remotechan; + unsigned int recvwindow, transwindow; + unsigned int recvdonelen; + unsigned int recvmaxpacket, transmaxpacket; + void* typedata; /* a pointer to type specific data */ + int writefd; /* read from wire, written to insecure side */ + int readfd; /* read from insecure side, written to wire */ + int errfd; /* used like writefd or readfd, depending if it's client or server. + Doesn't exactly belong here, but is cleaner here */ + int bidir_fd; /* a boolean indicating that writefd/readfd are the same + file descriptor (bidirectional), such as a network socket or PTY. + That is handled differently when closing FDs */ + circbuffer *writebuf; /* data from the wire, for local consumption. Can be + initially NULL */ + circbuffer *extrabuf; /* extended-data for the program - used like writebuf + but for stderr */ + + /* whether close/eof messages have been exchanged */ + int sent_close, recv_close; + int recv_eof, sent_eof; + /* once flushing is set, readfd will close once no more data is available + (not waiting for EOF) */ + int flushing; + + struct dropbear_progress_connection *conn_pending; + int initconn; /* used for TCP forwarding, whether the channel has been + fully initialised */ + + int await_open; /* flag indicating whether we've sent an open request + for this channel (and are awaiting a confirmation + or failure). */ + + /* Used by client chansession to handle ~ escaping, NULL ignored otherwise */ + void (*read_mangler)(const struct Channel*, const unsigned char* bytes, int *len); + + const struct ChanType* type; + + enum dropbear_prio prio; +}; + +struct ChanType { + + const char *name; + /* Sets up the channel */ + int (*inithandler)(struct Channel*); + /* Called to check whether a channel should close, separately from the FD being EOF. + Used for noticing process exiting */ + int (*check_close)(struct Channel*); + /* Handler for ssh_msg_channel_request */ + void (*reqhandler)(struct Channel*); + /* Called prior to sending ssh_msg_channel_close, used for sending exit status */ + void (*closehandler)(const struct Channel*); + /* Frees resources, called just prior to channel being removed */ + void (*cleanup)(const struct Channel*); +}; + +/* Callback for connect_remote. errstring may be NULL if result == DROPBEAR_SUCCESS */ +void channel_connect_done(int result, int sock, void* user_data, const char* errstring); + +void chaninitialise(const struct ChanType *chantypes[]); +void chancleanup(void); +void setchannelfds(fd_set *readfds, fd_set *writefds, int allow_reads); +void channelio(const fd_set *readfd, const fd_set *writefd); +struct Channel* getchannel(void); +/* Returns an arbitrary channel that is in a ready state - not +being initialised and no EOF in either direction. NULL if none. */ +struct Channel* get_any_ready_channel(void); + +void recv_msg_channel_open(void); +void recv_msg_channel_request(void); +void send_msg_channel_failure(const struct Channel *channel); +void send_msg_channel_success(const struct Channel *channel); +void recv_msg_channel_data(void); +void recv_msg_channel_extended_data(void); +void recv_msg_channel_window_adjust(void); +void recv_msg_channel_close(void); +void recv_msg_channel_eof(void); + +void common_recv_msg_channel_data(struct Channel *channel, int fd, + circbuffer * buf); + +#if DROPBEAR_CLIENT +extern const struct ChanType clichansess; +#endif + +#if DROPBEAR_LISTENERS || DROPBEAR_CLIENT +int send_msg_channel_open_init(int fd, const struct ChanType *type); +void recv_msg_channel_open_confirmation(void); +void recv_msg_channel_open_failure(void); +#endif +void start_send_channel_request(const struct Channel *channel, const char *type); + +void send_msg_request_success(void); +void send_msg_request_failure(void); + + +#endif /* DROPBEAR_CHANNEL_H_ */ |