diff options
Diffstat (limited to 'libs/libssh2/src/channel.c')
| -rw-r--r-- | libs/libssh2/src/channel.c | 2621 |
1 files changed, 2621 insertions, 0 deletions
diff --git a/libs/libssh2/src/channel.c b/libs/libssh2/src/channel.c new file mode 100644 index 0000000000..538a0ab0d9 --- /dev/null +++ b/libs/libssh2/src/channel.c @@ -0,0 +1,2621 @@ +/* Copyright (c) 2004-2007 Sara Golemon <sarag@libssh2.org> + * Copyright (c) 2005 Mikhail Gusarov <dottedmag@dottedmag.net> + * Copyright (c) 2008-2014 by Daniel Stenberg + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, + * with or without modification, are permitted provided + * that the following conditions are met: + * + * Redistributions of source code must retain the above + * copyright notice, this list of conditions and the + * following disclaimer. + * + * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * Neither the name of the copyright holder nor the names + * of any other contributors may be used to endorse or + * promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND + * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE + * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + */ + +#include "libssh2_priv.h" +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif +#include <fcntl.h> +#ifdef HAVE_INTTYPES_H +#include <inttypes.h> +#endif +#include <assert.h> + +#include "channel.h" +#include "transport.h" +#include "packet.h" +#include "session.h" + +/* + * _libssh2_channel_nextid + * + * Determine the next channel ID we can use at our end + */ +uint32_t +_libssh2_channel_nextid(LIBSSH2_SESSION * session) +{ + uint32_t id = session->next_channel; + LIBSSH2_CHANNEL *channel; + + channel = _libssh2_list_first(&session->channels); + + while (channel) { + if (channel->local.id > id) { + id = channel->local.id; + } + channel = _libssh2_list_next(&channel->node); + } + + /* This is a shortcut to avoid waiting for close packets on channels we've + * forgotten about, This *could* be a problem if we request and close 4 + * billion or so channels in too rapid succession for the remote end to + * respond, but the worst case scenario is that some data meant for + * another channel Gets picked up by the new one.... Pretty unlikely all + * told... + */ + session->next_channel = id + 1; + _libssh2_debug(session, LIBSSH2_TRACE_CONN, "Allocated new channel ID#%lu", + id); + return id; +} + +/* + * _libssh2_channel_locate + * + * Locate a channel pointer by number + */ +LIBSSH2_CHANNEL * +_libssh2_channel_locate(LIBSSH2_SESSION *session, uint32_t channel_id) +{ + LIBSSH2_CHANNEL *channel; + LIBSSH2_LISTENER *l; + + for(channel = _libssh2_list_first(&session->channels); + channel; + channel = _libssh2_list_next(&channel->node)) { + if (channel->local.id == channel_id) + return channel; + } + + /* We didn't find the channel in the session, let's then check its + listeners since each listener may have its own set of pending channels + */ + for(l = _libssh2_list_first(&session->listeners); l; + l = _libssh2_list_next(&l->node)) { + for(channel = _libssh2_list_first(&l->queue); + channel; + channel = _libssh2_list_next(&channel->node)) { + if (channel->local.id == channel_id) + return channel; + } + } + + return NULL; +} + +/* + * _libssh2_channel_open + * + * Establish a generic session channel + */ +LIBSSH2_CHANNEL * +_libssh2_channel_open(LIBSSH2_SESSION * session, const char *channel_type, + uint32_t channel_type_len, + uint32_t window_size, + uint32_t packet_size, + const unsigned char *message, + size_t message_len) +{ + static const unsigned char reply_codes[3] = { + SSH_MSG_CHANNEL_OPEN_CONFIRMATION, + SSH_MSG_CHANNEL_OPEN_FAILURE, + 0 + }; + unsigned char *s; + int rc; + + if (session->open_state == libssh2_NB_state_idle) { + session->open_channel = NULL; + session->open_packet = NULL; + session->open_data = NULL; + /* 17 = packet_type(1) + channel_type_len(4) + sender_channel(4) + + * window_size(4) + packet_size(4) */ + session->open_packet_len = channel_type_len + 17; + session->open_local_channel = _libssh2_channel_nextid(session); + + /* Zero the whole thing out */ + memset(&session->open_packet_requirev_state, 0, + sizeof(session->open_packet_requirev_state)); + + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Opening Channel - win %d pack %d", window_size, + packet_size); + session->open_channel = + LIBSSH2_CALLOC(session, sizeof(LIBSSH2_CHANNEL)); + if (!session->open_channel) { + _libssh2_error(session, LIBSSH2_ERROR_ALLOC, + "Unable to allocate space for channel data"); + return NULL; + } + session->open_channel->channel_type_len = channel_type_len; + session->open_channel->channel_type = + LIBSSH2_ALLOC(session, channel_type_len); + if (!session->open_channel->channel_type) { + _libssh2_error(session, LIBSSH2_ERROR_ALLOC, + "Failed allocating memory for channel type name"); + LIBSSH2_FREE(session, session->open_channel); + session->open_channel = NULL; + return NULL; + } + memcpy(session->open_channel->channel_type, channel_type, + channel_type_len); + + /* REMEMBER: local as in locally sourced */ + session->open_channel->local.id = session->open_local_channel; + session->open_channel->remote.window_size = window_size; + session->open_channel->remote.window_size_initial = window_size; + session->open_channel->remote.packet_size = packet_size; + session->open_channel->session = session; + + _libssh2_list_add(&session->channels, + &session->open_channel->node); + + s = session->open_packet = + LIBSSH2_ALLOC(session, session->open_packet_len); + if (!session->open_packet) { + _libssh2_error(session, LIBSSH2_ERROR_ALLOC, + "Unable to allocate temporary space for packet"); + goto channel_error; + } + *(s++) = SSH_MSG_CHANNEL_OPEN; + _libssh2_store_str(&s, channel_type, channel_type_len); + _libssh2_store_u32(&s, session->open_local_channel); + _libssh2_store_u32(&s, window_size); + _libssh2_store_u32(&s, packet_size); + + /* Do not copy the message */ + + session->open_state = libssh2_NB_state_created; + } + + if (session->open_state == libssh2_NB_state_created) { + rc = _libssh2_transport_send(session, + session->open_packet, + session->open_packet_len, + message, message_len); + if (rc == LIBSSH2_ERROR_EAGAIN) { + _libssh2_error(session, rc, + "Would block sending channel-open request"); + return NULL; + } + else if (rc) { + _libssh2_error(session, rc, + "Unable to send channel-open request"); + goto channel_error; + } + + session->open_state = libssh2_NB_state_sent; + } + + if (session->open_state == libssh2_NB_state_sent) { + rc = _libssh2_packet_requirev(session, reply_codes, + &session->open_data, + &session->open_data_len, 1, + session->open_packet + 5 + + channel_type_len, 4, + &session->open_packet_requirev_state); + if (rc == LIBSSH2_ERROR_EAGAIN) { + _libssh2_error(session, LIBSSH2_ERROR_EAGAIN, "Would block"); + return NULL; + } else if (rc) { + goto channel_error; + } + + if (session->open_data[0] == SSH_MSG_CHANNEL_OPEN_CONFIRMATION) { + session->open_channel->remote.id = + _libssh2_ntohu32(session->open_data + 5); + session->open_channel->local.window_size = + _libssh2_ntohu32(session->open_data + 9); + session->open_channel->local.window_size_initial = + _libssh2_ntohu32(session->open_data + 9); + session->open_channel->local.packet_size = + _libssh2_ntohu32(session->open_data + 13); + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Connection Established - ID: %lu/%lu win: %lu/%lu" + " pack: %lu/%lu", + session->open_channel->local.id, + session->open_channel->remote.id, + session->open_channel->local.window_size, + session->open_channel->remote.window_size, + session->open_channel->local.packet_size, + session->open_channel->remote.packet_size); + LIBSSH2_FREE(session, session->open_packet); + session->open_packet = NULL; + LIBSSH2_FREE(session, session->open_data); + session->open_data = NULL; + + session->open_state = libssh2_NB_state_idle; + return session->open_channel; + } + + if (session->open_data[0] == SSH_MSG_CHANNEL_OPEN_FAILURE) { + unsigned int reason_code = _libssh2_ntohu32(session->open_data + 5); + switch (reason_code) { + case SSH_OPEN_ADMINISTRATIVELY_PROHIBITED: + _libssh2_error(session, LIBSSH2_ERROR_CHANNEL_FAILURE, + "Channel open failure (administratively prohibited)"); + break; + case SSH_OPEN_CONNECT_FAILED: + _libssh2_error(session, LIBSSH2_ERROR_CHANNEL_FAILURE, + "Channel open failure (connect failed)"); + break; + case SSH_OPEN_UNKNOWN_CHANNELTYPE: + _libssh2_error(session, LIBSSH2_ERROR_CHANNEL_FAILURE, + "Channel open failure (unknown channel type)"); + break; + case SSH_OPEN_RESOURCE_SHORTAGE: + _libssh2_error(session, LIBSSH2_ERROR_CHANNEL_FAILURE, + "Channel open failure (resource shortage)"); + break; + default: + _libssh2_error(session, LIBSSH2_ERROR_CHANNEL_FAILURE, + "Channel open failure"); + } + } + } + + channel_error: + + if (session->open_data) { + LIBSSH2_FREE(session, session->open_data); + session->open_data = NULL; + } + if (session->open_packet) { + LIBSSH2_FREE(session, session->open_packet); + session->open_packet = NULL; + } + if (session->open_channel) { + unsigned char channel_id[4]; + LIBSSH2_FREE(session, session->open_channel->channel_type); + + _libssh2_list_remove(&session->open_channel->node); + + /* Clear out packets meant for this channel */ + _libssh2_htonu32(channel_id, session->open_channel->local.id); + while ((_libssh2_packet_ask(session, SSH_MSG_CHANNEL_DATA, + &session->open_data, + &session->open_data_len, 1, + channel_id, 4) >= 0) + || + (_libssh2_packet_ask(session, SSH_MSG_CHANNEL_EXTENDED_DATA, + &session->open_data, + &session->open_data_len, 1, + channel_id, 4) >= 0)) { + LIBSSH2_FREE(session, session->open_data); + session->open_data = NULL; + } + + LIBSSH2_FREE(session, session->open_channel); + session->open_channel = NULL; + } + + session->open_state = libssh2_NB_state_idle; + return NULL; +} + +/* + * libssh2_channel_open_ex + * + * Establish a generic session channel + */ +LIBSSH2_API LIBSSH2_CHANNEL * +libssh2_channel_open_ex(LIBSSH2_SESSION *session, const char *type, + unsigned int type_len, + unsigned int window_size, unsigned int packet_size, + const char *msg, unsigned int msg_len) +{ + LIBSSH2_CHANNEL *ptr; + + if(!session) + return NULL; + + BLOCK_ADJUST_ERRNO(ptr, session, + _libssh2_channel_open(session, type, type_len, + window_size, packet_size, + (unsigned char *)msg, + msg_len)); + return ptr; +} + +/* + * libssh2_channel_direct_tcpip_ex + * + * Tunnel TCP/IP connect through the SSH session to direct host/port + */ +static LIBSSH2_CHANNEL * +channel_direct_tcpip(LIBSSH2_SESSION * session, const char *host, + int port, const char *shost, int sport) +{ + LIBSSH2_CHANNEL *channel; + unsigned char *s; + + if (session->direct_state == libssh2_NB_state_idle) { + session->direct_host_len = strlen(host); + session->direct_shost_len = strlen(shost); + /* host_len(4) + port(4) + shost_len(4) + sport(4) */ + session->direct_message_len = + session->direct_host_len + session->direct_shost_len + 16; + + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Requesting direct-tcpip session to from %s:%d to %s:%d", + shost, sport, host, port); + + s = session->direct_message = + LIBSSH2_ALLOC(session, session->direct_message_len); + if (!session->direct_message) { + _libssh2_error(session, LIBSSH2_ERROR_ALLOC, + "Unable to allocate memory for direct-tcpip connection"); + return NULL; + } + _libssh2_store_str(&s, host, session->direct_host_len); + _libssh2_store_u32(&s, port); + _libssh2_store_str(&s, shost, session->direct_shost_len); + _libssh2_store_u32(&s, sport); + } + + channel = + _libssh2_channel_open(session, "direct-tcpip", + sizeof("direct-tcpip") - 1, + LIBSSH2_CHANNEL_WINDOW_DEFAULT, + LIBSSH2_CHANNEL_PACKET_DEFAULT, + session->direct_message, + session->direct_message_len); + + if (!channel && + libssh2_session_last_errno(session) == LIBSSH2_ERROR_EAGAIN) { + /* The error code is still set to LIBSSH2_ERROR_EAGAIN, set our state + to created to avoid re-creating the package on next invoke */ + session->direct_state = libssh2_NB_state_created; + return NULL; + } + /* by default we set (keep?) idle state... */ + session->direct_state = libssh2_NB_state_idle; + + LIBSSH2_FREE(session, session->direct_message); + session->direct_message = NULL; + + return channel; +} + +/* + * libssh2_channel_direct_tcpip_ex + * + * Tunnel TCP/IP connect through the SSH session to direct host/port + */ +LIBSSH2_API LIBSSH2_CHANNEL * +libssh2_channel_direct_tcpip_ex(LIBSSH2_SESSION *session, const char *host, + int port, const char *shost, int sport) +{ + LIBSSH2_CHANNEL *ptr; + + if(!session) + return NULL; + + BLOCK_ADJUST_ERRNO(ptr, session, + channel_direct_tcpip(session, host, port, shost, sport)); + return ptr; +} + +/* + * channel_forward_listen + * + * Bind a port on the remote host and listen for connections + */ +static LIBSSH2_LISTENER * +channel_forward_listen(LIBSSH2_SESSION * session, const char *host, + int port, int *bound_port, int queue_maxsize) +{ + unsigned char *s; + static const unsigned char reply_codes[3] = + { SSH_MSG_REQUEST_SUCCESS, SSH_MSG_REQUEST_FAILURE, 0 }; + int rc; + + if(!host) + host = "0.0.0.0"; + + if (session->fwdLstn_state == libssh2_NB_state_idle) { + session->fwdLstn_host_len = strlen(host); + /* 14 = packet_type(1) + request_len(4) + want_replay(1) + host_len(4) + + port(4) */ + session->fwdLstn_packet_len = + session->fwdLstn_host_len + (sizeof("tcpip-forward") - 1) + 14; + + /* Zero the whole thing out */ + memset(&session->fwdLstn_packet_requirev_state, 0, + sizeof(session->fwdLstn_packet_requirev_state)); + + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Requesting tcpip-forward session for %s:%d", host, + port); + + s = session->fwdLstn_packet = + LIBSSH2_ALLOC(session, session->fwdLstn_packet_len); + if (!session->fwdLstn_packet) { + _libssh2_error(session, LIBSSH2_ERROR_ALLOC, + "Unable to allocate memory for setenv packet"); + return NULL; + } + + *(s++) = SSH_MSG_GLOBAL_REQUEST; + _libssh2_store_str(&s, "tcpip-forward", sizeof("tcpip-forward") - 1); + *(s++) = 0x01; /* want_reply */ + + _libssh2_store_str(&s, host, session->fwdLstn_host_len); + _libssh2_store_u32(&s, port); + + session->fwdLstn_state = libssh2_NB_state_created; + } + + if (session->fwdLstn_state == libssh2_NB_state_created) { + rc = _libssh2_transport_send(session, + session->fwdLstn_packet, + session->fwdLstn_packet_len, + NULL, 0); + if (rc == LIBSSH2_ERROR_EAGAIN) { + _libssh2_error(session, LIBSSH2_ERROR_EAGAIN, + "Would block sending global-request packet for " + "forward listen request"); + return NULL; + } + else if (rc) { + _libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, + "Unable to send global-request packet for forward " + "listen request"); + LIBSSH2_FREE(session, session->fwdLstn_packet); + session->fwdLstn_packet = NULL; + session->fwdLstn_state = libssh2_NB_state_idle; + return NULL; + } + LIBSSH2_FREE(session, session->fwdLstn_packet); + session->fwdLstn_packet = NULL; + + session->fwdLstn_state = libssh2_NB_state_sent; + } + + if (session->fwdLstn_state == libssh2_NB_state_sent) { + unsigned char *data; + size_t data_len; + rc = _libssh2_packet_requirev(session, reply_codes, &data, &data_len, + 0, NULL, 0, + &session->fwdLstn_packet_requirev_state); + if (rc == LIBSSH2_ERROR_EAGAIN) { + _libssh2_error(session, LIBSSH2_ERROR_EAGAIN, "Would block"); + return NULL; + } else if (rc) { + _libssh2_error(session, LIBSSH2_ERROR_PROTO, "Unknown"); + session->fwdLstn_state = libssh2_NB_state_idle; + return NULL; + } + + if (data[0] == SSH_MSG_REQUEST_SUCCESS) { + LIBSSH2_LISTENER *listener; + + listener = LIBSSH2_CALLOC(session, sizeof(LIBSSH2_LISTENER)); + if (!listener) + _libssh2_error(session, LIBSSH2_ERROR_ALLOC, + "Unable to allocate memory for listener queue"); + else { + listener->host = + LIBSSH2_ALLOC(session, session->fwdLstn_host_len + 1); + if (!listener->host) { + _libssh2_error(session, LIBSSH2_ERROR_ALLOC, + "Unable to allocate memory for listener queue"); + LIBSSH2_FREE(session, listener); + listener = NULL; + } + else { + listener->session = session; + memcpy(listener->host, host, session->fwdLstn_host_len); + listener->host[session->fwdLstn_host_len] = 0; + if (data_len >= 5 && !port) { + listener->port = _libssh2_ntohu32(data + 1); + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Dynamic tcpip-forward port allocated: %d", + listener->port); + } + else + listener->port = port; + + listener->queue_size = 0; + listener->queue_maxsize = queue_maxsize; + + /* append this to the parent's list of listeners */ + _libssh2_list_add(&session->listeners, &listener->node); + + if (bound_port) { + *bound_port = listener->port; + } + } + } + + LIBSSH2_FREE(session, data); + session->fwdLstn_state = libssh2_NB_state_idle; + return listener; + } + else if (data[0] == SSH_MSG_REQUEST_FAILURE) { + LIBSSH2_FREE(session, data); + _libssh2_error(session, LIBSSH2_ERROR_REQUEST_DENIED, + "Unable to complete request for forward-listen"); + session->fwdLstn_state = libssh2_NB_state_idle; + return NULL; + } + } + + session->fwdLstn_state = libssh2_NB_state_idle; + + return NULL; +} + +/* + * libssh2_channel_forward_listen_ex + * + * Bind a port on the remote host and listen for connections + */ +LIBSSH2_API LIBSSH2_LISTENER * +libssh2_channel_forward_listen_ex(LIBSSH2_SESSION *session, const char *host, + int port, int *bound_port, int queue_maxsize) +{ + LIBSSH2_LISTENER *ptr; + + if(!session) + return NULL; + + BLOCK_ADJUST_ERRNO(ptr, session, + channel_forward_listen(session, host, port, bound_port, + queue_maxsize)); + return ptr; +} + +/* + * _libssh2_channel_forward_cancel + * + * Stop listening on a remote port and free the listener + * Toss out any pending (un-accept()ed) connections + * + * Return 0 on success, LIBSSH2_ERROR_EAGAIN if would block, -1 on error + */ +int _libssh2_channel_forward_cancel(LIBSSH2_LISTENER *listener) +{ + LIBSSH2_SESSION *session = listener->session; + LIBSSH2_CHANNEL *queued; + unsigned char *packet, *s; + size_t host_len = strlen(listener->host); + /* 14 = packet_type(1) + request_len(4) + want_replay(1) + host_len(4) + + port(4) */ + size_t packet_len = + host_len + 14 + sizeof("cancel-tcpip-forward") - 1; + int rc; + int retcode = 0; + + if (listener->chanFwdCncl_state == libssh2_NB_state_idle) { + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Cancelling tcpip-forward session for %s:%d", + listener->host, listener->port); + + s = packet = LIBSSH2_ALLOC(session, packet_len); + if (!packet) { + _libssh2_error(session, LIBSSH2_ERROR_ALLOC, + "Unable to allocate memory for setenv packet"); + return LIBSSH2_ERROR_ALLOC; + } + + *(s++) = SSH_MSG_GLOBAL_REQUEST; + _libssh2_store_str(&s, "cancel-tcpip-forward", + sizeof("cancel-tcpip-forward") - 1); + *(s++) = 0x00; /* want_reply */ + + _libssh2_store_str(&s, listener->host, host_len); + _libssh2_store_u32(&s, listener->port); + + listener->chanFwdCncl_state = libssh2_NB_state_created; + } else { + packet = listener->chanFwdCncl_data; + } + + if (listener->chanFwdCncl_state == libssh2_NB_state_created) { + rc = _libssh2_transport_send(session, packet, packet_len, NULL, 0); + if (rc == LIBSSH2_ERROR_EAGAIN) { + _libssh2_error(session, rc, + "Would block sending forward request"); + listener->chanFwdCncl_data = packet; + return rc; + } + else if (rc) { + _libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, + "Unable to send global-request packet for forward " + "listen request"); + /* set the state to something we don't check for, for the + unfortunate situation where we get an EAGAIN further down + when trying to bail out due to errors! */ + listener->chanFwdCncl_state = libssh2_NB_state_sent; + retcode = LIBSSH2_ERROR_SOCKET_SEND; + } + LIBSSH2_FREE(session, packet); + + listener->chanFwdCncl_state = libssh2_NB_state_sent; + } + + queued = _libssh2_list_first(&listener->queue); + while (queued) { + LIBSSH2_CHANNEL *next = _libssh2_list_next(&queued->node); + + rc = _libssh2_channel_free(queued); + if (rc == LIBSSH2_ERROR_EAGAIN) { + return rc; + } + queued = next; + } + LIBSSH2_FREE(session, listener->host); + + /* remove this entry from the parent's list of listeners */ + _libssh2_list_remove(&listener->node); + + LIBSSH2_FREE(session, listener); + + return retcode; +} + +/* + * libssh2_channel_forward_cancel + * + * Stop listening on a remote port and free the listener + * Toss out any pending (un-accept()ed) connections + * + * Return 0 on success, LIBSSH2_ERROR_EAGAIN if would block, -1 on error + */ +LIBSSH2_API int +libssh2_channel_forward_cancel(LIBSSH2_LISTENER *listener) +{ + int rc; + + if(!listener) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, listener->session, + _libssh2_channel_forward_cancel(listener)); + return rc; +} + +/* + * channel_forward_accept + * + * Accept a connection + */ +static LIBSSH2_CHANNEL * +channel_forward_accept(LIBSSH2_LISTENER *listener) +{ + int rc; + + do { + rc = _libssh2_transport_read(listener->session); + } while (rc > 0); + + if (_libssh2_list_first(&listener->queue)) { + LIBSSH2_CHANNEL *channel = _libssh2_list_first(&listener->queue); + + /* detach channel from listener's queue */ + _libssh2_list_remove(&channel->node); + + listener->queue_size--; + + /* add channel to session's channel list */ + _libssh2_list_add(&channel->session->channels, &channel->node); + + return channel; + } + + if (rc == LIBSSH2_ERROR_EAGAIN) { + _libssh2_error(listener->session, LIBSSH2_ERROR_EAGAIN, + "Would block waiting for packet"); + } + else + _libssh2_error(listener->session, LIBSSH2_ERROR_CHANNEL_UNKNOWN, + "Channel not found"); + return NULL; +} + +/* + * libssh2_channel_forward_accept + * + * Accept a connection + */ +LIBSSH2_API LIBSSH2_CHANNEL * +libssh2_channel_forward_accept(LIBSSH2_LISTENER *listener) +{ + LIBSSH2_CHANNEL *ptr; + + if(!listener) + return NULL; + + BLOCK_ADJUST_ERRNO(ptr, listener->session, + channel_forward_accept(listener)); + return ptr; + +} + +/* + * channel_setenv + * + * Set an environment variable prior to requesting a shell/program/subsystem + */ +static int channel_setenv(LIBSSH2_CHANNEL *channel, + const char *varname, unsigned int varname_len, + const char *value, unsigned int value_len) +{ + LIBSSH2_SESSION *session = channel->session; + unsigned char *s, *data; + static const unsigned char reply_codes[3] = + { SSH_MSG_CHANNEL_SUCCESS, SSH_MSG_CHANNEL_FAILURE, 0 }; + size_t data_len; + int rc; + + if (channel->setenv_state == libssh2_NB_state_idle) { + /* 21 = packet_type(1) + channel_id(4) + request_len(4) + + * request(3)"env" + want_reply(1) + varname_len(4) + value_len(4) */ + channel->setenv_packet_len = varname_len + value_len + 21; + + /* Zero the whole thing out */ + memset(&channel->setenv_packet_requirev_state, 0, + sizeof(channel->setenv_packet_requirev_state)); + + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Setting remote environment variable: %s=%s on " + "channel %lu/%lu", + varname, value, channel->local.id, channel->remote.id); + + s = channel->setenv_packet = + LIBSSH2_ALLOC(session, channel->setenv_packet_len); + if (!channel->setenv_packet) { + return _libssh2_error(session, LIBSSH2_ERROR_ALLOC, + "Unable to allocate memory " + "for setenv packet"); + } + + *(s++) = SSH_MSG_CHANNEL_REQUEST; + _libssh2_store_u32(&s, channel->remote.id); + _libssh2_store_str(&s, "env", sizeof("env") - 1); + *(s++) = 0x01; + _libssh2_store_str(&s, varname, varname_len); + _libssh2_store_str(&s, value, value_len); + + channel->setenv_state = libssh2_NB_state_created; + } + + if (channel->setenv_state == libssh2_NB_state_created) { + rc = _libssh2_transport_send(session, + channel->setenv_packet, + channel->setenv_packet_len, + NULL, 0); + if (rc == LIBSSH2_ERROR_EAGAIN) { + _libssh2_error(session, rc, + "Would block sending setenv request"); + return rc; + } else if (rc) { + LIBSSH2_FREE(session, channel->setenv_packet); + channel->setenv_packet = NULL; + channel->setenv_state = libssh2_NB_state_idle; + return _libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, + "Unable to send channel-request packet for " + "setenv request"); + } + LIBSSH2_FREE(session, channel->setenv_packet); + channel->setenv_packet = NULL; + + _libssh2_htonu32(channel->setenv_local_channel, channel->local.id); + + channel->setenv_state = libssh2_NB_state_sent; + } + + if (channel->setenv_state == libssh2_NB_state_sent) { + rc = _libssh2_packet_requirev(session, reply_codes, &data, &data_len, + 1, channel->setenv_local_channel, 4, + &channel-> + setenv_packet_requirev_state); + if (rc == LIBSSH2_ERROR_EAGAIN) { + return rc; + } + if (rc) { + channel->setenv_state = libssh2_NB_state_idle; + return rc; + } + + if (data[0] == SSH_MSG_CHANNEL_SUCCESS) { + LIBSSH2_FREE(session, data); + channel->setenv_state = libssh2_NB_state_idle; + return 0; + } + + LIBSSH2_FREE(session, data); + } + + channel->setenv_state = libssh2_NB_state_idle; + return _libssh2_error(session, LIBSSH2_ERROR_CHANNEL_REQUEST_DENIED, + "Unable to complete request for channel-setenv"); +} + +/* + * libssh2_channel_setenv_ex + * + * Set an environment variable prior to requesting a shell/program/subsystem + */ +LIBSSH2_API int +libssh2_channel_setenv_ex(LIBSSH2_CHANNEL *channel, + const char *varname, unsigned int varname_len, + const char *value, unsigned int value_len) +{ + int rc; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, + channel_setenv(channel, varname, varname_len, + value, value_len)); + return rc; +} + +/* + * channel_request_pty + * Duh... Request a PTY + */ +static int channel_request_pty(LIBSSH2_CHANNEL *channel, + const char *term, unsigned int term_len, + const char *modes, unsigned int modes_len, + int width, int height, + int width_px, int height_px) +{ + LIBSSH2_SESSION *session = channel->session; + unsigned char *s; + static const unsigned char reply_codes[3] = + { SSH_MSG_CHANNEL_SUCCESS, SSH_MSG_CHANNEL_FAILURE, 0 }; + int rc; + + if (channel->reqPTY_state == libssh2_NB_state_idle) { + /* 41 = packet_type(1) + channel(4) + pty_req_len(4) + "pty_req"(7) + + * want_reply(1) + term_len(4) + width(4) + height(4) + width_px(4) + + * height_px(4) + modes_len(4) */ + if(term_len + modes_len > 256) { + return _libssh2_error(session, LIBSSH2_ERROR_INVAL, + "term + mode lengths too large"); + } + + channel->reqPTY_packet_len = term_len + modes_len + 41; + + /* Zero the whole thing out */ + memset(&channel->reqPTY_packet_requirev_state, 0, + sizeof(channel->reqPTY_packet_requirev_state)); + + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Allocating tty on channel %lu/%lu", channel->local.id, + channel->remote.id); + + s = channel->reqPTY_packet; + + *(s++) = SSH_MSG_CHANNEL_REQUEST; + _libssh2_store_u32(&s, channel->remote.id); + _libssh2_store_str(&s, (char *)"pty-req", sizeof("pty-req") - 1); + + *(s++) = 0x01; + + _libssh2_store_str(&s, term, term_len); + _libssh2_store_u32(&s, width); + _libssh2_store_u32(&s, height); + _libssh2_store_u32(&s, width_px); + _libssh2_store_u32(&s, height_px); + _libssh2_store_str(&s, modes, modes_len); + + channel->reqPTY_state = libssh2_NB_state_created; + } + + if (channel->reqPTY_state == libssh2_NB_state_created) { + rc = _libssh2_transport_send(session, channel->reqPTY_packet, + channel->reqPTY_packet_len, + NULL, 0); + if (rc == LIBSSH2_ERROR_EAGAIN) { + _libssh2_error(session, rc, + "Would block sending pty request"); + return rc; + } else if (rc) { + channel->reqPTY_state = libssh2_NB_state_idle; + return _libssh2_error(session, rc, + "Unable to send pty-request packet"); + } + _libssh2_htonu32(channel->reqPTY_local_channel, channel->local.id); + + channel->reqPTY_state = libssh2_NB_state_sent; + } + + if (channel->reqPTY_state == libssh2_NB_state_sent) { + unsigned char *data; + size_t data_len; + unsigned char code; + rc = _libssh2_packet_requirev(session, reply_codes, &data, &data_len, + 1, channel->reqPTY_local_channel, 4, + &channel->reqPTY_packet_requirev_state); + if (rc == LIBSSH2_ERROR_EAGAIN) { + return rc; + } else if (rc) { + channel->reqPTY_state = libssh2_NB_state_idle; + return _libssh2_error(session, LIBSSH2_ERROR_PROTO, + "Failed to require the PTY package"); + } + + code = data[0]; + + LIBSSH2_FREE(session, data); + channel->reqPTY_state = libssh2_NB_state_idle; + + if (code == SSH_MSG_CHANNEL_SUCCESS) + return 0; + } + + return _libssh2_error(session, LIBSSH2_ERROR_CHANNEL_REQUEST_DENIED, + "Unable to complete request for channel request-pty"); +} + +/* + * libssh2_channel_request_pty_ex + * Duh... Request a PTY + */ +LIBSSH2_API int +libssh2_channel_request_pty_ex(LIBSSH2_CHANNEL *channel, const char *term, + unsigned int term_len, const char *modes, + unsigned int modes_len, int width, int height, + int width_px, int height_px) +{ + int rc; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, + channel_request_pty(channel, term, term_len, modes, + modes_len, width, height, + width_px, height_px)); + return rc; +} + +static int +channel_request_pty_size(LIBSSH2_CHANNEL * channel, int width, + int height, int width_px, int height_px) +{ + LIBSSH2_SESSION *session = channel->session; + unsigned char *s; + int rc; + int retcode = LIBSSH2_ERROR_PROTO; + + if (channel->reqPTY_state == libssh2_NB_state_idle) { + channel->reqPTY_packet_len = 39; + + /* Zero the whole thing out */ + memset(&channel->reqPTY_packet_requirev_state, 0, + sizeof(channel->reqPTY_packet_requirev_state)); + + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "changing tty size on channel %lu/%lu", + channel->local.id, + channel->remote.id); + + s = channel->reqPTY_packet; + + *(s++) = SSH_MSG_CHANNEL_REQUEST; + _libssh2_store_u32(&s, channel->remote.id); + _libssh2_store_str(&s, (char *)"window-change", + sizeof("window-change") - 1); + *(s++) = 0x00; /* Don't reply */ + _libssh2_store_u32(&s, width); + _libssh2_store_u32(&s, height); + _libssh2_store_u32(&s, width_px); + _libssh2_store_u32(&s, height_px); + + channel->reqPTY_state = libssh2_NB_state_created; + } + + if (channel->reqPTY_state == libssh2_NB_state_created) { + rc = _libssh2_transport_send(session, channel->reqPTY_packet, + channel->reqPTY_packet_len, + NULL, 0); + if (rc == LIBSSH2_ERROR_EAGAIN) { + _libssh2_error(session, rc, + "Would block sending window-change request"); + return rc; + } else if (rc) { + channel->reqPTY_state = libssh2_NB_state_idle; + return _libssh2_error(session, rc, + "Unable to send window-change packet"); + } + _libssh2_htonu32(channel->reqPTY_local_channel, channel->local.id); + retcode = LIBSSH2_ERROR_NONE; + } + + channel->reqPTY_state = libssh2_NB_state_idle; + return retcode; +} + +LIBSSH2_API int +libssh2_channel_request_pty_size_ex(LIBSSH2_CHANNEL *channel, int width, + int height, int width_px, int height_px) +{ + int rc; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, + channel_request_pty_size(channel, width, height, width_px, + height_px)); + return rc; +} + +/* Keep this an even number */ +#define LIBSSH2_X11_RANDOM_COOKIE_LEN 32 + +/* + * channel_x11_req + * Request X11 forwarding + */ +static int +channel_x11_req(LIBSSH2_CHANNEL *channel, int single_connection, + const char *auth_proto, const char *auth_cookie, + int screen_number) +{ + LIBSSH2_SESSION *session = channel->session; + unsigned char *s; + static const unsigned char reply_codes[3] = + { SSH_MSG_CHANNEL_SUCCESS, SSH_MSG_CHANNEL_FAILURE, 0 }; + size_t proto_len = + auth_proto ? strlen(auth_proto) : (sizeof("MIT-MAGIC-COOKIE-1") - 1); + size_t cookie_len = + auth_cookie ? strlen(auth_cookie) : LIBSSH2_X11_RANDOM_COOKIE_LEN; + int rc; + + if (channel->reqX11_state == libssh2_NB_state_idle) { + /* 30 = packet_type(1) + channel(4) + x11_req_len(4) + "x11-req"(7) + + * want_reply(1) + single_cnx(1) + proto_len(4) + cookie_len(4) + + * screen_num(4) */ + channel->reqX11_packet_len = proto_len + cookie_len + 30; + + /* Zero the whole thing out */ + memset(&channel->reqX11_packet_requirev_state, 0, + sizeof(channel->reqX11_packet_requirev_state)); + + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Requesting x11-req for channel %lu/%lu: single=%d " + "proto=%s cookie=%s screen=%d", + channel->local.id, channel->remote.id, + single_connection, + auth_proto ? auth_proto : "MIT-MAGIC-COOKIE-1", + auth_cookie ? auth_cookie : "<random>", screen_number); + + s = channel->reqX11_packet = + LIBSSH2_ALLOC(session, channel->reqX11_packet_len); + if (!channel->reqX11_packet) { + return _libssh2_error(session, LIBSSH2_ERROR_ALLOC, + "Unable to allocate memory for pty-request"); + } + + *(s++) = SSH_MSG_CHANNEL_REQUEST; + _libssh2_store_u32(&s, channel->remote.id); + _libssh2_store_str(&s, "x11-req", sizeof("x11-req") - 1); + + *(s++) = 0x01; /* want_reply */ + *(s++) = single_connection ? 0x01 : 0x00; + + _libssh2_store_str(&s, auth_proto?auth_proto:"MIT-MAGIC-COOKIE-1", + proto_len); + + _libssh2_store_u32(&s, cookie_len); + if (auth_cookie) { + memcpy(s, auth_cookie, cookie_len); + } else { + int i; + /* note: the extra +1 below is necessary since the sprintf() + loop will always write 3 bytes so the last one will write + the trailing zero at the LIBSSH2_X11_RANDOM_COOKIE_LEN/2 + border */ + unsigned char buffer[(LIBSSH2_X11_RANDOM_COOKIE_LEN / 2) +1]; + + _libssh2_random(buffer, LIBSSH2_X11_RANDOM_COOKIE_LEN / 2); + for(i = 0; i < (LIBSSH2_X11_RANDOM_COOKIE_LEN / 2); i++) { + sprintf((char *)&s[i*2], "%02X", buffer[i]); + } + } + s += cookie_len; + + _libssh2_store_u32(&s, screen_number); + channel->reqX11_state = libssh2_NB_state_created; + } + + if (channel->reqX11_state == libssh2_NB_state_created) { + rc = _libssh2_transport_send(session, channel->reqX11_packet, + channel->reqX11_packet_len, + NULL, 0); + if (rc == LIBSSH2_ERROR_EAGAIN) { + _libssh2_error(session, rc, + "Would block sending X11-req packet"); + return rc; + } + if (rc) { + LIBSSH2_FREE(session, channel->reqX11_packet); + channel->reqX11_packet = NULL; + channel->reqX11_state = libssh2_NB_state_idle; + return _libssh2_error(session, rc, + "Unable to send x11-req packet"); + } + LIBSSH2_FREE(session, channel->reqX11_packet); + channel->reqX11_packet = NULL; + + _libssh2_htonu32(channel->reqX11_local_channel, channel->local.id); + + channel->reqX11_state = libssh2_NB_state_sent; + } + + if (channel->reqX11_state == libssh2_NB_state_sent) { + size_t data_len; + unsigned char *data; + unsigned char code; + + rc = _libssh2_packet_requirev(session, reply_codes, &data, &data_len, + 1, channel->reqX11_local_channel, 4, + &channel->reqX11_packet_requirev_state); + if (rc == LIBSSH2_ERROR_EAGAIN) { + return rc; + } else if (rc) { + channel->reqX11_state = libssh2_NB_state_idle; + return _libssh2_error(session, rc, + "waiting for x11-req response packet"); + } + + code = data[0]; + LIBSSH2_FREE(session, data); + channel->reqX11_state = libssh2_NB_state_idle; + + if (code == SSH_MSG_CHANNEL_SUCCESS) + return 0; + } + + return _libssh2_error(session, LIBSSH2_ERROR_CHANNEL_REQUEST_DENIED, + "Unable to complete request for channel x11-req"); +} + +/* + * libssh2_channel_x11_req_ex + * Request X11 forwarding + */ +LIBSSH2_API int +libssh2_channel_x11_req_ex(LIBSSH2_CHANNEL *channel, int single_connection, + const char *auth_proto, const char *auth_cookie, + int screen_number) +{ + int rc; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, + channel_x11_req(channel, single_connection, auth_proto, + auth_cookie, screen_number)); + return rc; +} + + +/* + * _libssh2_channel_process_startup + * + * Primitive for libssh2_channel_(shell|exec|subsystem) + */ +int +_libssh2_channel_process_startup(LIBSSH2_CHANNEL *channel, + const char *request, size_t request_len, + const char *message, size_t message_len) +{ + LIBSSH2_SESSION *session = channel->session; + unsigned char *s; + static const unsigned char reply_codes[3] = + { SSH_MSG_CHANNEL_SUCCESS, SSH_MSG_CHANNEL_FAILURE, 0 }; + int rc; + + if (channel->process_state == libssh2_NB_state_end) { + return _libssh2_error(session, LIBSSH2_ERROR_BAD_USE, + "Channel can not be reused"); + } + + if (channel->process_state == libssh2_NB_state_idle) { + /* 10 = packet_type(1) + channel(4) + request_len(4) + want_reply(1) */ + channel->process_packet_len = request_len + 10; + + /* Zero the whole thing out */ + memset(&channel->process_packet_requirev_state, 0, + sizeof(channel->process_packet_requirev_state)); + + if (message) + channel->process_packet_len += + 4; + + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "starting request(%s) on channel %lu/%lu, message=%s", + request, channel->local.id, channel->remote.id, + message?message:"<null>"); + s = channel->process_packet = + LIBSSH2_ALLOC(session, channel->process_packet_len); + if (!channel->process_packet) + return _libssh2_error(session, LIBSSH2_ERROR_ALLOC, + "Unable to allocate memory " + "for channel-process request"); + + *(s++) = SSH_MSG_CHANNEL_REQUEST; + _libssh2_store_u32(&s, channel->remote.id); + _libssh2_store_str(&s, request, request_len); + *(s++) = 0x01; + + if (message) + _libssh2_store_u32(&s, message_len); + + channel->process_state = libssh2_NB_state_created; + } + + if (channel->process_state == libssh2_NB_state_created) { + rc = _libssh2_transport_send(session, + channel->process_packet, + channel->process_packet_len, + (unsigned char *)message, message_len); + if (rc == LIBSSH2_ERROR_EAGAIN) { + _libssh2_error(session, rc, + "Would block sending channel request"); + return rc; + } + else if (rc) { + LIBSSH2_FREE(session, channel->process_packet); + channel->process_packet = NULL; + channel->process_state = libssh2_NB_state_end; + return _libssh2_error(session, rc, + "Unable to send channel request"); + } + LIBSSH2_FREE(session, channel->process_packet); + channel->process_packet = NULL; + + _libssh2_htonu32(channel->process_local_channel, channel->local.id); + + channel->process_state = libssh2_NB_state_sent; + } + + if (channel->process_state == libssh2_NB_state_sent) { + unsigned char *data; + size_t data_len; + unsigned char code; + rc = _libssh2_packet_requirev(session, reply_codes, &data, &data_len, + 1, channel->process_local_channel, 4, + &channel->process_packet_requirev_state); + if (rc == LIBSSH2_ERROR_EAGAIN) { + return rc; + } else if (rc) { + channel->process_state = libssh2_NB_state_end; + return _libssh2_error(session, rc, + "Failed waiting for channel success"); + } + + code = data[0]; + LIBSSH2_FREE(session, data); + channel->process_state = libssh2_NB_state_end; + + if (code == SSH_MSG_CHANNEL_SUCCESS) + return 0; + } + + return _libssh2_error(session, LIBSSH2_ERROR_CHANNEL_REQUEST_DENIED, + "Unable to complete request for " + "channel-process-startup"); +} + +/* + * libssh2_channel_process_startup + * + * Primitive for libssh2_channel_(shell|exec|subsystem) + */ +LIBSSH2_API int +libssh2_channel_process_startup(LIBSSH2_CHANNEL *channel, + const char *req, unsigned int req_len, + const char *msg, unsigned int msg_len) +{ + int rc; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, + _libssh2_channel_process_startup(channel, req, req_len, + msg, msg_len)); + return rc; +} + + +/* + * libssh2_channel_set_blocking + * + * Set a channel's BEHAVIOR blocking on or off. The socket will remain non- + * blocking. + */ +LIBSSH2_API void +libssh2_channel_set_blocking(LIBSSH2_CHANNEL * channel, int blocking) +{ + if(channel) + (void) _libssh2_session_set_blocking(channel->session, blocking); +} + +/* + * _libssh2_channel_flush + * + * Flush data from one (or all) stream + * Returns number of bytes flushed, or negative on failure + */ +int +_libssh2_channel_flush(LIBSSH2_CHANNEL *channel, int streamid) +{ + if (channel->flush_state == libssh2_NB_state_idle) { + LIBSSH2_PACKET *packet = + _libssh2_list_first(&channel->session->packets); + channel->flush_refund_bytes = 0; + channel->flush_flush_bytes = 0; + + while (packet) { + LIBSSH2_PACKET *next = _libssh2_list_next(&packet->node); + unsigned char packet_type = packet->data[0]; + + if (((packet_type == SSH_MSG_CHANNEL_DATA) + || (packet_type == SSH_MSG_CHANNEL_EXTENDED_DATA)) + && (_libssh2_ntohu32(packet->data + 1) == channel->local.id)) { + /* It's our channel at least */ + long packet_stream_id = + (packet_type == SSH_MSG_CHANNEL_DATA) ? 0 : + _libssh2_ntohu32(packet->data + 5); + if ((streamid == LIBSSH2_CHANNEL_FLUSH_ALL) + || ((packet_type == SSH_MSG_CHANNEL_EXTENDED_DATA) + && ((streamid == LIBSSH2_CHANNEL_FLUSH_EXTENDED_DATA) + || (streamid == packet_stream_id))) + || ((packet_type == SSH_MSG_CHANNEL_DATA) + && (streamid == 0))) { + int bytes_to_flush = packet->data_len - packet->data_head; + + _libssh2_debug(channel->session, LIBSSH2_TRACE_CONN, + "Flushing %d bytes of data from stream " + "%lu on channel %lu/%lu", + bytes_to_flush, packet_stream_id, + channel->local.id, channel->remote.id); + + /* It's one of the streams we wanted to flush */ + channel->flush_refund_bytes += packet->data_len - 13; + channel->flush_flush_bytes += bytes_to_flush; + + LIBSSH2_FREE(channel->session, packet->data); + + /* remove this packet from the parent's list */ + _libssh2_list_remove(&packet->node); + LIBSSH2_FREE(channel->session, packet); + } + } + packet = next; + } + + channel->flush_state = libssh2_NB_state_created; + } + + channel->read_avail -= channel->flush_flush_bytes; + channel->remote.window_size -= channel->flush_flush_bytes; + + if (channel->flush_refund_bytes) { + int rc; + + rc = _libssh2_channel_receive_window_adjust(channel, + channel->flush_refund_bytes, + 1, NULL); + if (rc == LIBSSH2_ERROR_EAGAIN) + return rc; + } + + channel->flush_state = libssh2_NB_state_idle; + + return channel->flush_flush_bytes; +} + +/* + * libssh2_channel_flush_ex + * + * Flush data from one (or all) stream + * Returns number of bytes flushed, or negative on failure + */ +LIBSSH2_API int +libssh2_channel_flush_ex(LIBSSH2_CHANNEL *channel, int stream) +{ + int rc; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, + _libssh2_channel_flush(channel, stream)); + return rc; +} + +/* + * libssh2_channel_get_exit_status + * + * Return the channel's program exit status. Note that the actual protocol + * provides the full 32bit this function returns. We cannot abuse it to + * return error values in case of errors so we return a zero if channel is + * NULL. + */ +LIBSSH2_API int +libssh2_channel_get_exit_status(LIBSSH2_CHANNEL *channel) +{ + if(!channel) + return 0; + + return channel->exit_status; +} + +/* + * libssh2_channel_get_exit_signal + * + * Get exit signal (without leading "SIG"), error message, and language + * tag into newly allocated buffers of indicated length. Caller can + * use NULL pointers to indicate that the value should not be set. The + * *_len variables are set if they are non-NULL even if the + * corresponding string parameter is NULL. Returns LIBSSH2_ERROR_NONE + * on success, or an API error code. + */ +LIBSSH2_API int +libssh2_channel_get_exit_signal(LIBSSH2_CHANNEL *channel, + char **exitsignal, + size_t *exitsignal_len, + char **errmsg, + size_t *errmsg_len, + char **langtag, + size_t *langtag_len) +{ + size_t namelen = 0; + + if (channel) { + LIBSSH2_SESSION *session = channel->session; + + if (channel->exit_signal) { + namelen = strlen(channel->exit_signal); + if (exitsignal) { + *exitsignal = LIBSSH2_ALLOC(session, namelen + 1); + if (!*exitsignal) { + return _libssh2_error(session, LIBSSH2_ERROR_ALLOC, + "Unable to allocate memory for signal name"); + } + memcpy(*exitsignal, channel->exit_signal, namelen); + (*exitsignal)[namelen] = '\0'; + } + if (exitsignal_len) + *exitsignal_len = namelen; + } else { + if (exitsignal) + *exitsignal = NULL; + if (exitsignal_len) + *exitsignal_len = 0; + } + + /* TODO: set error message and language tag */ + + if (errmsg) + *errmsg = NULL; + + if (errmsg_len) + *errmsg_len = 0; + + if (langtag) + *langtag = NULL; + + if (langtag_len) + *langtag_len = 0; + } + + return LIBSSH2_ERROR_NONE; +} + +/* + * _libssh2_channel_receive_window_adjust + * + * Adjust the receive window for a channel by adjustment bytes. If the amount + * to be adjusted is less than LIBSSH2_CHANNEL_MINADJUST and force is 0 the + * adjustment amount will be queued for a later packet. + * + * Calls _libssh2_error() ! + */ +int +_libssh2_channel_receive_window_adjust(LIBSSH2_CHANNEL * channel, + uint32_t adjustment, + unsigned char force, + unsigned int *store) +{ + int rc; + + if(store) + *store = channel->remote.window_size; + + if (channel->adjust_state == libssh2_NB_state_idle) { + if (!force + && (adjustment + channel->adjust_queue < + LIBSSH2_CHANNEL_MINADJUST)) { + _libssh2_debug(channel->session, LIBSSH2_TRACE_CONN, + "Queueing %lu bytes for receive window adjustment " + "for channel %lu/%lu", + adjustment, channel->local.id, channel->remote.id); + channel->adjust_queue += adjustment; + return 0; + } + + if (!adjustment && !channel->adjust_queue) { + return 0; + } + + adjustment += channel->adjust_queue; + channel->adjust_queue = 0; + + /* Adjust the window based on the block we just freed */ + channel->adjust_adjust[0] = SSH_MSG_CHANNEL_WINDOW_ADJUST; + _libssh2_htonu32(&channel->adjust_adjust[1], channel->remote.id); + _libssh2_htonu32(&channel->adjust_adjust[5], adjustment); + _libssh2_debug(channel->session, LIBSSH2_TRACE_CONN, + "Adjusting window %lu bytes for data on " + "channel %lu/%lu", + adjustment, channel->local.id, channel->remote.id); + + channel->adjust_state = libssh2_NB_state_created; + } + + rc = _libssh2_transport_send(channel->session, channel->adjust_adjust, 9, + NULL, 0); + if (rc == LIBSSH2_ERROR_EAGAIN) { + _libssh2_error(channel->session, rc, + "Would block sending window adjust"); + return rc; + } + else if (rc) { + channel->adjust_queue = adjustment; + return _libssh2_error(channel->session, LIBSSH2_ERROR_SOCKET_SEND, + "Unable to send transfer-window adjustment " + "packet, deferring"); + } + else { + channel->remote.window_size += adjustment; + } + + channel->adjust_state = libssh2_NB_state_idle; + + return 0; +} + +/* + * libssh2_channel_receive_window_adjust + * + * DEPRECATED + * + * Adjust the receive window for a channel by adjustment bytes. If the amount + * to be adjusted is less than LIBSSH2_CHANNEL_MINADJUST and force is 0 the + * adjustment amount will be queued for a later packet. + * + * Returns the new size of the receive window (as understood by remote end). + * Note that it might return EAGAIN too which is highly stupid. + * + */ +LIBSSH2_API unsigned long +libssh2_channel_receive_window_adjust(LIBSSH2_CHANNEL *channel, + unsigned long adj, + unsigned char force) +{ + unsigned int window; + int rc; + + if(!channel) + return (unsigned long)LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, + _libssh2_channel_receive_window_adjust(channel, adj, + force, &window)); + + /* stupid - but this is how it was made to work before and this is just + kept for backwards compatibility */ + return rc?(unsigned long)rc:window; +} + +/* + * libssh2_channel_receive_window_adjust2 + * + * Adjust the receive window for a channel by adjustment bytes. If the amount + * to be adjusted is less than LIBSSH2_CHANNEL_MINADJUST and force is 0 the + * adjustment amount will be queued for a later packet. + * + * Stores the new size of the receive window in the data 'window' points to. + * + * Returns the "normal" error code: 0 for success, negative for failure. + */ +LIBSSH2_API int +libssh2_channel_receive_window_adjust2(LIBSSH2_CHANNEL *channel, + unsigned long adj, + unsigned char force, + unsigned int *window) +{ + int rc; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, + _libssh2_channel_receive_window_adjust(channel, adj, force, + window)); + return rc; +} + +int +_libssh2_channel_extended_data(LIBSSH2_CHANNEL *channel, int ignore_mode) +{ + if (channel->extData2_state == libssh2_NB_state_idle) { + _libssh2_debug(channel->session, LIBSSH2_TRACE_CONN, + "Setting channel %lu/%lu handle_extended_data" + " mode to %d", + channel->local.id, channel->remote.id, ignore_mode); + channel->remote.extended_data_ignore_mode = (char)ignore_mode; + + channel->extData2_state = libssh2_NB_state_created; + } + + if (channel->extData2_state == libssh2_NB_state_idle) { + if (ignore_mode == LIBSSH2_CHANNEL_EXTENDED_DATA_IGNORE) { + int rc = + _libssh2_channel_flush(channel, + LIBSSH2_CHANNEL_FLUSH_EXTENDED_DATA); + if(LIBSSH2_ERROR_EAGAIN == rc) + return rc; + } + } + + channel->extData2_state = libssh2_NB_state_idle; + return 0; +} + +/* + * libssh2_channel_handle_extended_data2() + * + */ +LIBSSH2_API int +libssh2_channel_handle_extended_data2(LIBSSH2_CHANNEL *channel, + int mode) +{ + int rc; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, _libssh2_channel_extended_data(channel, + mode)); + return rc; +} + +/* + * libssh2_channel_handle_extended_data + * + * DEPRECATED DO NOTE USE! + * + * How should extended data look to the calling app? Keep it in separate + * channels[_read() _read_stdder()]? (NORMAL) Merge the extended data to the + * standard data? [everything via _read()]? (MERGE) Ignore it entirely [toss + * out packets as they come in]? (IGNORE) + */ +LIBSSH2_API void +libssh2_channel_handle_extended_data(LIBSSH2_CHANNEL *channel, + int ignore_mode) +{ + (void)libssh2_channel_handle_extended_data2(channel, ignore_mode); +} + + + +/* + * _libssh2_channel_read + * + * Read data from a channel + * + * It is important to not return 0 until the currently read channel is + * complete. If we read stuff from the wire but it was no payload data to fill + * in the buffer with, we MUST make sure to return LIBSSH2_ERROR_EAGAIN. + * + * The receive window must be maintained (enlarged) by the user of this + * function. + */ +ssize_t _libssh2_channel_read(LIBSSH2_CHANNEL *channel, int stream_id, + char *buf, size_t buflen) +{ + LIBSSH2_SESSION *session = channel->session; + int rc; + int bytes_read = 0; + int bytes_want; + int unlink_packet; + LIBSSH2_PACKET *read_packet; + LIBSSH2_PACKET *read_next; + + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "channel_read() wants %d bytes from channel %lu/%lu " + "stream #%d", + (int) buflen, channel->local.id, channel->remote.id, + stream_id); + + /* expand the receiving window first if it has become too narrow */ + if( (channel->read_state == libssh2_NB_state_jump1) || + (channel->remote.window_size < channel->remote.window_size_initial / 4 * 3 + buflen) ) { + + uint32_t adjustment = channel->remote.window_size_initial + buflen - channel->remote.window_size; + if (adjustment < LIBSSH2_CHANNEL_MINADJUST) + adjustment = LIBSSH2_CHANNEL_MINADJUST; + + /* the actual window adjusting may not finish so we need to deal with + this special state here */ + channel->read_state = libssh2_NB_state_jump1; + rc = _libssh2_channel_receive_window_adjust(channel, adjustment, + 0, NULL); + if (rc) + return rc; + + channel->read_state = libssh2_NB_state_idle; + } + + /* Process all pending incoming packets. Tests prove that this way + produces faster transfers. */ + do { + rc = _libssh2_transport_read(session); + } while (rc > 0); + + if ((rc < 0) && (rc != LIBSSH2_ERROR_EAGAIN)) + return _libssh2_error(session, rc, "transport read"); + + read_packet = _libssh2_list_first(&session->packets); + while (read_packet && (bytes_read < (int) buflen)) { + /* previously this loop condition also checked for + !channel->remote.close but we cannot let it do this: + + We may have a series of packets to read that are still pending even + if a close has been received. Acknowledging the close too early + makes us flush buffers prematurely and loose data. + */ + + LIBSSH2_PACKET *readpkt = read_packet; + + /* In case packet gets destroyed during this iteration */ + read_next = _libssh2_list_next(&readpkt->node); + + channel->read_local_id = + _libssh2_ntohu32(readpkt->data + 1); + + /* + * Either we asked for a specific extended data stream + * (and data was available), + * or the standard stream (and data was available), + * or the standard stream with extended_data_merge + * enabled and data was available + */ + if ((stream_id + && (readpkt->data[0] == SSH_MSG_CHANNEL_EXTENDED_DATA) + && (channel->local.id == channel->read_local_id) + && (stream_id == (int) _libssh2_ntohu32(readpkt->data + 5))) + || (!stream_id && (readpkt->data[0] == SSH_MSG_CHANNEL_DATA) + && (channel->local.id == channel->read_local_id)) + || (!stream_id + && (readpkt->data[0] == SSH_MSG_CHANNEL_EXTENDED_DATA) + && (channel->local.id == channel->read_local_id) + && (channel->remote.extended_data_ignore_mode == + LIBSSH2_CHANNEL_EXTENDED_DATA_MERGE))) { + + /* figure out much more data we want to read */ + bytes_want = buflen - bytes_read; + unlink_packet = FALSE; + + if (bytes_want >= (int) (readpkt->data_len - readpkt->data_head)) { + /* we want more than this node keeps, so adjust the number and + delete this node after the copy */ + bytes_want = readpkt->data_len - readpkt->data_head; + unlink_packet = TRUE; + } + + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "channel_read() got %d of data from %lu/%lu/%d%s", + bytes_want, channel->local.id, + channel->remote.id, stream_id, + unlink_packet?" [ul]":""); + + /* copy data from this struct to the target buffer */ + memcpy(&buf[bytes_read], + &readpkt->data[readpkt->data_head], bytes_want); + + /* advance pointer and counter */ + readpkt->data_head += bytes_want; + bytes_read += bytes_want; + + /* if drained, remove from list */ + if (unlink_packet) { + /* detach readpkt from session->packets list */ + _libssh2_list_remove(&readpkt->node); + + LIBSSH2_FREE(session, readpkt->data); + LIBSSH2_FREE(session, readpkt); + } + } + + /* check the next struct in the chain */ + read_packet = read_next; + } + + if (!bytes_read) { + /* If the channel is already at EOF or even closed, we need to signal + that back. We may have gotten that info while draining the incoming + transport layer until EAGAIN so we must not be fooled by that + return code. */ + if(channel->remote.eof || channel->remote.close) + return 0; + else if(rc != LIBSSH2_ERROR_EAGAIN) + return 0; + + /* if the transport layer said EAGAIN then we say so as well */ + return _libssh2_error(session, rc, "would block"); + } + + channel->read_avail -= bytes_read; + channel->remote.window_size -= bytes_read; + + return bytes_read; +} + +/* + * libssh2_channel_read_ex + * + * Read data from a channel (blocking or non-blocking depending on set state) + * + * When this is done non-blocking, it is important to not return 0 until the + * currently read channel is complete. If we read stuff from the wire but it + * was no payload data to fill in the buffer with, we MUST make sure to return + * LIBSSH2_ERROR_EAGAIN. + * + * This function will first make sure there's a receive window enough to + * receive a full buffer's wort of contents. An application may choose to + * adjust the receive window more to increase transfer performance. + */ +LIBSSH2_API ssize_t +libssh2_channel_read_ex(LIBSSH2_CHANNEL *channel, int stream_id, char *buf, + size_t buflen) +{ + int rc; + unsigned long recv_window; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + recv_window = libssh2_channel_window_read_ex(channel, NULL, NULL); + + if(buflen > recv_window) { + BLOCK_ADJUST(rc, channel->session, + _libssh2_channel_receive_window_adjust(channel, buflen, + 1, NULL)); + } + + BLOCK_ADJUST(rc, channel->session, + _libssh2_channel_read(channel, stream_id, buf, buflen)); + return rc; +} + +/* + * _libssh2_channel_packet_data_len + * + * Return the size of the data block of the current packet, or 0 if there + * isn't a packet. + */ +size_t +_libssh2_channel_packet_data_len(LIBSSH2_CHANNEL * channel, int stream_id) +{ + LIBSSH2_SESSION *session = channel->session; + LIBSSH2_PACKET *read_packet; + uint32_t read_local_id; + + read_packet = _libssh2_list_first(&session->packets); + if (read_packet == NULL) + return 0; + + while (read_packet) { + read_local_id = _libssh2_ntohu32(read_packet->data + 1); + + /* + * Either we asked for a specific extended data stream + * (and data was available), + * or the standard stream (and data was available), + * or the standard stream with extended_data_merge + * enabled and data was available + */ + if ((stream_id + && (read_packet->data[0] == SSH_MSG_CHANNEL_EXTENDED_DATA) + && (channel->local.id == read_local_id) + && (stream_id == (int) _libssh2_ntohu32(read_packet->data + 5))) + || + (!stream_id + && (read_packet->data[0] == SSH_MSG_CHANNEL_DATA) + && (channel->local.id == read_local_id)) + || + (!stream_id + && (read_packet->data[0] == SSH_MSG_CHANNEL_EXTENDED_DATA) + && (channel->local.id == read_local_id) + && (channel->remote.extended_data_ignore_mode + == LIBSSH2_CHANNEL_EXTENDED_DATA_MERGE))) + { + return (read_packet->data_len - read_packet->data_head); + } + read_packet = _libssh2_list_next(&read_packet->node); + } + + return 0; +} + +/* + * _libssh2_channel_write + * + * Send data to a channel. Note that if this returns EAGAIN, the caller must + * call this function again with the SAME input arguments. + * + * Returns: number of bytes sent, or if it returns a negative number, that is + * the error code! + */ +ssize_t +_libssh2_channel_write(LIBSSH2_CHANNEL *channel, int stream_id, + const unsigned char *buf, size_t buflen) +{ + int rc = 0; + LIBSSH2_SESSION *session = channel->session; + ssize_t wrote = 0; /* counter for this specific this call */ + + /* In theory we could split larger buffers into several smaller packets + * but it turns out to be really hard and nasty to do while still offering + * the API/prototype. + * + * Instead we only deal with the first 32K in this call and for the parent + * function to call it again with the remainder! 32K is a conservative + * limit based on the text in RFC4253 section 6.1. + */ + if(buflen > 32700) + buflen = 32700; + + if (channel->write_state == libssh2_NB_state_idle) { + unsigned char *s = channel->write_packet; + + _libssh2_debug(channel->session, LIBSSH2_TRACE_CONN, + "Writing %d bytes on channel %lu/%lu, stream #%d", + (int) buflen, channel->local.id, channel->remote.id, + stream_id); + + if (channel->local.close) + return _libssh2_error(channel->session, + LIBSSH2_ERROR_CHANNEL_CLOSED, + "We've already closed this channel"); + else if (channel->local.eof) + return _libssh2_error(channel->session, + LIBSSH2_ERROR_CHANNEL_EOF_SENT, + "EOF has already been received, " + "data might be ignored"); + + /* drain the incoming flow first, mostly to make sure we get all + * pending window adjust packets */ + do + rc = _libssh2_transport_read(session); + while (rc > 0); + + if((rc < 0) && (rc != LIBSSH2_ERROR_EAGAIN)) { + return _libssh2_error(channel->session, rc, + "Failure while draining incoming flow"); + } + + if(channel->local.window_size <= 0) { + /* there's no room for data so we stop */ + + /* Waiting on the socket to be writable would be wrong because we + * would be back here immediately, but a readable socket might + * herald an incoming window adjustment. + */ + session->socket_block_directions = LIBSSH2_SESSION_BLOCK_INBOUND; + + return (rc==LIBSSH2_ERROR_EAGAIN?rc:0); + } + + channel->write_bufwrite = buflen; + + *(s++) = stream_id ? SSH_MSG_CHANNEL_EXTENDED_DATA : + SSH_MSG_CHANNEL_DATA; + _libssh2_store_u32(&s, channel->remote.id); + if (stream_id) + _libssh2_store_u32(&s, stream_id); + + /* Don't exceed the remote end's limits */ + /* REMEMBER local means local as the SOURCE of the data */ + if (channel->write_bufwrite > channel->local.window_size) { + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Splitting write block due to %lu byte " + "window_size on %lu/%lu/%d", + channel->local.window_size, channel->local.id, + channel->remote.id, stream_id); + channel->write_bufwrite = channel->local.window_size; + } + if (channel->write_bufwrite > channel->local.packet_size) { + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Splitting write block due to %lu byte " + "packet_size on %lu/%lu/%d", + channel->local.packet_size, channel->local.id, + channel->remote.id, stream_id); + channel->write_bufwrite = channel->local.packet_size; + } + /* store the size here only, the buffer is passed in as-is to + _libssh2_transport_send() */ + _libssh2_store_u32(&s, channel->write_bufwrite); + channel->write_packet_len = s - channel->write_packet; + + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Sending %d bytes on channel %lu/%lu, stream_id=%d", + (int) channel->write_bufwrite, channel->local.id, + channel->remote.id, stream_id); + + channel->write_state = libssh2_NB_state_created; + } + + if (channel->write_state == libssh2_NB_state_created) { + rc = _libssh2_transport_send(session, channel->write_packet, + channel->write_packet_len, + buf, channel->write_bufwrite); + if (rc == LIBSSH2_ERROR_EAGAIN) { + return _libssh2_error(session, rc, + "Unable to send channel data"); + } + else if (rc) { + channel->write_state = libssh2_NB_state_idle; + return _libssh2_error(session, rc, + "Unable to send channel data"); + } + /* Shrink local window size */ + channel->local.window_size -= channel->write_bufwrite; + + wrote += channel->write_bufwrite; + + /* Since _libssh2_transport_write() succeeded, we must return + now to allow the caller to provide the next chunk of data. + + We cannot move on to send the next piece of data that may + already have been provided in this same function call, as we + risk getting EAGAIN for that and we can't return information + both about sent data as well as EAGAIN. So, by returning short + now, the caller will call this function again with new data to + send */ + + channel->write_state = libssh2_NB_state_idle; + + return wrote; + } + + return LIBSSH2_ERROR_INVAL; /* reaching this point is really bad */ +} + +/* + * libssh2_channel_write_ex + * + * Send data to a channel + */ +LIBSSH2_API ssize_t +libssh2_channel_write_ex(LIBSSH2_CHANNEL *channel, int stream_id, + const char *buf, size_t buflen) +{ + ssize_t rc; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, + _libssh2_channel_write(channel, stream_id, + (unsigned char *)buf, buflen)); + return rc; +} + +/* + * channel_send_eof + * + * Send EOF on channel + */ +static int channel_send_eof(LIBSSH2_CHANNEL *channel) +{ + LIBSSH2_SESSION *session = channel->session; + unsigned char packet[5]; /* packet_type(1) + channelno(4) */ + int rc; + + _libssh2_debug(session, LIBSSH2_TRACE_CONN, "Sending EOF on channel %lu/%lu", + channel->local.id, channel->remote.id); + packet[0] = SSH_MSG_CHANNEL_EOF; + _libssh2_htonu32(packet + 1, channel->remote.id); + rc = _libssh2_transport_send(session, packet, 5, NULL, 0); + if (rc == LIBSSH2_ERROR_EAGAIN) { + _libssh2_error(session, rc, + "Would block sending EOF"); + return rc; + } + else if (rc) { + return _libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, + "Unable to send EOF on channel"); + } + channel->local.eof = 1; + + return 0; +} + +/* + * libssh2_channel_send_eof + * + * Send EOF on channel + */ +LIBSSH2_API int +libssh2_channel_send_eof(LIBSSH2_CHANNEL *channel) +{ + int rc; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, channel_send_eof(channel)); + return rc; +} + +/* + * libssh2_channel_eof + * + * Read channel's eof status + */ +LIBSSH2_API int +libssh2_channel_eof(LIBSSH2_CHANNEL * channel) +{ + LIBSSH2_SESSION *session; + LIBSSH2_PACKET *packet; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + session = channel->session; + packet = _libssh2_list_first(&session->packets); + + while (packet) { + if (((packet->data[0] == SSH_MSG_CHANNEL_DATA) + || (packet->data[0] == SSH_MSG_CHANNEL_EXTENDED_DATA)) + && (channel->local.id == _libssh2_ntohu32(packet->data + 1))) { + /* There's data waiting to be read yet, mask the EOF status */ + return 0; + } + packet = _libssh2_list_next(&packet->node); + } + + return channel->remote.eof; +} + +/* + * channel_wait_eof + * + * Awaiting channel EOF + */ +static int channel_wait_eof(LIBSSH2_CHANNEL *channel) +{ + LIBSSH2_SESSION *session = channel->session; + int rc; + + if (channel->wait_eof_state == libssh2_NB_state_idle) { + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Awaiting close of channel %lu/%lu", channel->local.id, + channel->remote.id); + + channel->wait_eof_state = libssh2_NB_state_created; + } + + /* + * While channel is not eof, read more packets from the network. + * Either the EOF will be set or network timeout will occur. + */ + do { + if (channel->remote.eof) { + break; + } + rc = _libssh2_transport_read(session); + if (rc == LIBSSH2_ERROR_EAGAIN) { + return rc; + } + else if (rc < 0) { + channel->wait_eof_state = libssh2_NB_state_idle; + return _libssh2_error(session, rc, + "_libssh2_transport_read() bailed out!"); + } + } while (1); + + channel->wait_eof_state = libssh2_NB_state_idle; + + return 0; +} + +/* + * libssh2_channel_wait_eof + * + * Awaiting channel EOF + */ +LIBSSH2_API int +libssh2_channel_wait_eof(LIBSSH2_CHANNEL *channel) +{ + int rc; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, channel_wait_eof(channel)); + return rc; +} + +int _libssh2_channel_close(LIBSSH2_CHANNEL * channel) +{ + LIBSSH2_SESSION *session = channel->session; + int rc = 0; + + if (channel->local.close) { + /* Already closed, act like we sent another close, + * even though we didn't... shhhhhh */ + channel->close_state = libssh2_NB_state_idle; + return 0; + } + + if (!channel->local.eof) { + if ((rc = channel_send_eof(channel))) { + if (rc == LIBSSH2_ERROR_EAGAIN) { + return rc; + } + _libssh2_error(session, rc, + "Unable to send EOF, but closing channel anyway"); + } + } + + /* ignore if we have received a remote eof or not, as it is now too + late for us to wait for it. Continue closing! */ + + if (channel->close_state == libssh2_NB_state_idle) { + _libssh2_debug(session, LIBSSH2_TRACE_CONN, "Closing channel %lu/%lu", + channel->local.id, channel->remote.id); + + channel->close_packet[0] = SSH_MSG_CHANNEL_CLOSE; + _libssh2_htonu32(channel->close_packet + 1, channel->remote.id); + + channel->close_state = libssh2_NB_state_created; + } + + if (channel->close_state == libssh2_NB_state_created) { + rc = _libssh2_transport_send(session, channel->close_packet, 5, + NULL, 0); + if (rc == LIBSSH2_ERROR_EAGAIN) { + _libssh2_error(session, rc, + "Would block sending close-channel"); + return rc; + + } else if (rc) { + _libssh2_error(session, rc, + "Unable to send close-channel request, " + "but closing anyway"); + /* skip waiting for the response and fall through to + LIBSSH2_CHANNEL_CLOSE below */ + + } else + channel->close_state = libssh2_NB_state_sent; + } + + if (channel->close_state == libssh2_NB_state_sent) { + /* We must wait for the remote SSH_MSG_CHANNEL_CLOSE message */ + + while (!channel->remote.close && !rc && + (session->socket_state != LIBSSH2_SOCKET_DISCONNECTED)) + rc = _libssh2_transport_read(session); + } + + if(rc != LIBSSH2_ERROR_EAGAIN) { + /* set the local close state first when we're perfectly confirmed to not + do any more EAGAINs */ + channel->local.close = 1; + + /* We call the callback last in this function to make it keep the local + data as long as EAGAIN is returned. */ + if (channel->close_cb) { + LIBSSH2_CHANNEL_CLOSE(session, channel); + } + + channel->close_state = libssh2_NB_state_idle; + } + + /* return 0 or an error */ + return rc>=0?0:rc; +} + +/* + * libssh2_channel_close + * + * Close a channel + */ +LIBSSH2_API int +libssh2_channel_close(LIBSSH2_CHANNEL *channel) +{ + int rc; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, _libssh2_channel_close(channel) ); + return rc; +} + +/* + * channel_wait_closed + * + * Awaiting channel close after EOF + */ +static int channel_wait_closed(LIBSSH2_CHANNEL *channel) +{ + LIBSSH2_SESSION *session = channel->session; + int rc; + + if (!libssh2_channel_eof(channel)) { + return _libssh2_error(session, LIBSSH2_ERROR_INVAL, + "libssh2_channel_wait_closed() invoked when " + "channel is not in EOF state"); + } + + if (channel->wait_closed_state == libssh2_NB_state_idle) { + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Awaiting close of channel %lu/%lu", channel->local.id, + channel->remote.id); + + channel->wait_closed_state = libssh2_NB_state_created; + } + + /* + * While channel is not closed, read more packets from the network. + * Either the channel will be closed or network timeout will occur. + */ + if (!channel->remote.close) { + do { + rc = _libssh2_transport_read(session); + if (channel->remote.close) + /* it is now closed, move on! */ + break; + } while (rc > 0); + if(rc < 0) + return rc; + } + + channel->wait_closed_state = libssh2_NB_state_idle; + + return 0; +} + +/* + * libssh2_channel_wait_closed + * + * Awaiting channel close after EOF + */ +LIBSSH2_API int +libssh2_channel_wait_closed(LIBSSH2_CHANNEL *channel) +{ + int rc; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, channel_wait_closed(channel)); + return rc; +} + +/* + * _libssh2_channel_free + * + * Make sure a channel is closed, then remove the channel from the session + * and free its resource(s) + * + * Returns 0 on success, negative on failure + */ +int _libssh2_channel_free(LIBSSH2_CHANNEL *channel) +{ + LIBSSH2_SESSION *session = channel->session; + unsigned char channel_id[4]; + unsigned char *data; + size_t data_len; + int rc; + + assert(session); + + if (channel->free_state == libssh2_NB_state_idle) { + _libssh2_debug(session, LIBSSH2_TRACE_CONN, + "Freeing channel %lu/%lu resources", channel->local.id, + channel->remote.id); + + channel->free_state = libssh2_NB_state_created; + } + + /* Allow channel freeing even when the socket has lost its connection */ + if (!channel->local.close + && (session->socket_state == LIBSSH2_SOCKET_CONNECTED)) { + rc = _libssh2_channel_close(channel); + + if(rc == LIBSSH2_ERROR_EAGAIN) + return rc; + + /* ignore all other errors as they otherwise risk blocking the channel + free from happening */ + } + + channel->free_state = libssh2_NB_state_idle; + + if (channel->exit_signal) { + LIBSSH2_FREE(session, channel->exit_signal); + } + + /* + * channel->remote.close *might* not be set yet, Well... + * We've sent the close packet, what more do you want? + * Just let packet_add ignore it when it finally arrives + */ + + /* Clear out packets meant for this channel */ + _libssh2_htonu32(channel_id, channel->local.id); + while ((_libssh2_packet_ask(session, SSH_MSG_CHANNEL_DATA, &data, + &data_len, 1, channel_id, 4) >= 0) + || + (_libssh2_packet_ask(session, SSH_MSG_CHANNEL_EXTENDED_DATA, &data, + &data_len, 1, channel_id, 4) >= 0)) { + LIBSSH2_FREE(session, data); + } + + /* free "channel_type" */ + if (channel->channel_type) { + LIBSSH2_FREE(session, channel->channel_type); + } + + /* Unlink from channel list */ + _libssh2_list_remove(&channel->node); + + /* + * Make sure all memory used in the state variables are free + */ + if (channel->setenv_packet) { + LIBSSH2_FREE(session, channel->setenv_packet); + } + if (channel->reqX11_packet) { + LIBSSH2_FREE(session, channel->reqX11_packet); + } + if (channel->process_packet) { + LIBSSH2_FREE(session, channel->process_packet); + } + + LIBSSH2_FREE(session, channel); + + return 0; +} + +/* + * libssh2_channel_free + * + * Make sure a channel is closed, then remove the channel from the session + * and free its resource(s) + * + * Returns 0 on success, negative on failure + */ +LIBSSH2_API int +libssh2_channel_free(LIBSSH2_CHANNEL *channel) +{ + int rc; + + if(!channel) + return LIBSSH2_ERROR_BAD_USE; + + BLOCK_ADJUST(rc, channel->session, _libssh2_channel_free(channel)); + return rc; +} +/* + * libssh2_channel_window_read_ex + * + * Check the status of the read window. Returns the number of bytes which the + * remote end may send without overflowing the window limit read_avail (if + * passed) will be populated with the number of bytes actually available to be + * read window_size_initial (if passed) will be populated with the + * window_size_initial as defined by the channel_open request + */ +LIBSSH2_API unsigned long +libssh2_channel_window_read_ex(LIBSSH2_CHANNEL *channel, + unsigned long *read_avail, + unsigned long *window_size_initial) +{ + if(!channel) + return 0; /* no channel, no window! */ + + if (window_size_initial) { + *window_size_initial = channel->remote.window_size_initial; + } + + if (read_avail) { + size_t bytes_queued = 0; + LIBSSH2_PACKET *packet = + _libssh2_list_first(&channel->session->packets); + + while (packet) { + unsigned char packet_type = packet->data[0]; + + if (((packet_type == SSH_MSG_CHANNEL_DATA) + || (packet_type == SSH_MSG_CHANNEL_EXTENDED_DATA)) + && (_libssh2_ntohu32(packet->data + 1) == channel->local.id)) { + bytes_queued += packet->data_len - packet->data_head; + } + + packet = _libssh2_list_next(&packet->node); + } + + *read_avail = bytes_queued; + } + + return channel->remote.window_size; +} + +/* + * libssh2_channel_window_write_ex + * + * Check the status of the write window Returns the number of bytes which may + * be safely written on the channel without blocking window_size_initial (if + * passed) will be populated with the size of the initial window as defined by + * the channel_open request + */ +LIBSSH2_API unsigned long +libssh2_channel_window_write_ex(LIBSSH2_CHANNEL *channel, + unsigned long *window_size_initial) +{ + if(!channel) + return 0; /* no channel, no window! */ + + if (window_size_initial) { + /* For locally initiated channels this is very often 0, so it's not + * *that* useful as information goes */ + *window_size_initial = channel->local.window_size_initial; + } + + return channel->local.window_size; +} |