1 /* -*- c-basic-offset: 8 -*- 2 rdesktop: A Remote Desktop Protocol client. 3 Protocol services - Virtual channels 4 Copyright 2003 Erik Forsberg <forsberg@cendio.se> for Cendio AB 5 Copyright (C) Matthew Chapman <matthewc.unsw.edu.au> 2003-2008 6 7 This program is free software: you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation, either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. 19 */ 20 21 #include "precomp.h" 22 23 #define MAX_CHANNELS 6 24 #define CHANNEL_CHUNK_LENGTH 1600 25 #define CHANNEL_FLAG_FIRST 0x01 26 #define CHANNEL_FLAG_LAST 0x02 27 #define CHANNEL_FLAG_SHOW_PROTOCOL 0x10 28 29 extern RDP_VERSION g_rdp_version; 30 extern RD_BOOL g_encryption; 31 32 VCHANNEL g_channels[MAX_CHANNELS]; 33 unsigned int g_num_channels; 34 35 /* FIXME: We should use the information in TAG_SRV_CHANNELS to map RDP5 36 channels to MCS channels. 37 38 The format of TAG_SRV_CHANNELS seems to be 39 40 global_channel_no (uint16le) 41 number_of_other_channels (uint16le) 42 ..followed by uint16les for the other channels. 43 */ 44 45 VCHANNEL * 46 channel_register(char *name, uint32 flags, void (*callback) (STREAM)) 47 { 48 VCHANNEL *channel; 49 50 if (g_rdp_version < RDP_V5) 51 return NULL; 52 53 if (g_num_channels >= MAX_CHANNELS) 54 { 55 error("Channel table full, increase MAX_CHANNELS\n"); 56 return NULL; 57 } 58 59 channel = &g_channels[g_num_channels]; 60 channel->mcs_id = MCS_GLOBAL_CHANNEL + 1 + g_num_channels; 61 strncpy(channel->name, name, 8); 62 channel->flags = flags; 63 channel->process = callback; 64 g_num_channels++; 65 return channel; 66 } 67 68 STREAM 69 channel_init(VCHANNEL * channel, uint32 length) 70 { 71 STREAM s; 72 73 s = sec_init(g_encryption ? SEC_ENCRYPT : 0, length + 8); 74 s_push_layer(s, channel_hdr, 8); 75 return s; 76 } 77 78 void 79 channel_send(STREAM s, VCHANNEL * channel) 80 { 81 uint32 length, flags; 82 uint32 thislength, remaining; 83 uint8 *data; 84 85 #ifdef WITH_SCARD 86 scard_lock(SCARD_LOCK_CHANNEL); 87 #endif 88 89 /* first fragment sent in-place */ 90 s_pop_layer(s, channel_hdr); 91 length = s->end - s->p - 8; 92 93 DEBUG_CHANNEL(("channel_send, length = %d\n", length)); 94 95 thislength = MIN(length, CHANNEL_CHUNK_LENGTH); 96 /* Note: In the original clipboard implementation, this number was 97 1592, not 1600. However, I don't remember the reason and 1600 seems 98 to work so.. This applies only to *this* length, not the length of 99 continuation or ending packets. */ 100 remaining = length - thislength; 101 flags = (remaining == 0) ? CHANNEL_FLAG_FIRST | CHANNEL_FLAG_LAST : CHANNEL_FLAG_FIRST; 102 if (channel->flags & CHANNEL_OPTION_SHOW_PROTOCOL) 103 flags |= CHANNEL_FLAG_SHOW_PROTOCOL; 104 105 out_uint32_le(s, length); 106 out_uint32_le(s, flags); 107 data = s->end = s->p + thislength; 108 DEBUG_CHANNEL(("Sending %d bytes with FLAG_FIRST\n", thislength)); 109 sec_send_to_channel(s, g_encryption ? SEC_ENCRYPT : 0, channel->mcs_id); 110 111 /* subsequent segments copied (otherwise would have to generate headers backwards) */ 112 while (remaining > 0) 113 { 114 thislength = MIN(remaining, CHANNEL_CHUNK_LENGTH); 115 remaining -= thislength; 116 flags = (remaining == 0) ? CHANNEL_FLAG_LAST : 0; 117 if (channel->flags & CHANNEL_OPTION_SHOW_PROTOCOL) 118 flags |= CHANNEL_FLAG_SHOW_PROTOCOL; 119 120 DEBUG_CHANNEL(("Sending %d bytes with flags %d\n", thislength, flags)); 121 122 s = sec_init(g_encryption ? SEC_ENCRYPT : 0, thislength + 8); 123 out_uint32_le(s, length); 124 out_uint32_le(s, flags); 125 out_uint8p(s, data, thislength); 126 s_mark_end(s); 127 sec_send_to_channel(s, g_encryption ? SEC_ENCRYPT : 0, channel->mcs_id); 128 129 data += thislength; 130 } 131 132 #ifdef WITH_SCARD 133 scard_unlock(SCARD_LOCK_CHANNEL); 134 #endif 135 } 136 137 void 138 channel_process(STREAM s, uint16 mcs_channel) 139 { 140 uint32 length, flags; 141 uint32 thislength; 142 VCHANNEL *channel = NULL; 143 unsigned int i; 144 STREAM in; 145 146 for (i = 0; i < g_num_channels; i++) 147 { 148 channel = &g_channels[i]; 149 if (channel->mcs_id == mcs_channel) 150 break; 151 } 152 153 if (i >= g_num_channels) 154 return; 155 156 in_uint32_le(s, length); 157 in_uint32_le(s, flags); 158 if ((flags & CHANNEL_FLAG_FIRST) && (flags & CHANNEL_FLAG_LAST)) 159 { 160 /* single fragment - pass straight up */ 161 channel->process(s); 162 } 163 else 164 { 165 /* add fragment to defragmentation buffer */ 166 in = &channel->in; 167 if (flags & CHANNEL_FLAG_FIRST) 168 { 169 if (length > in->size) 170 { 171 in->data = (uint8 *) xrealloc(in->data, length); 172 in->size = length; 173 } 174 in->p = in->data; 175 } 176 177 thislength = MIN(s->end - s->p, in->data + in->size - in->p); 178 memcpy(in->p, s->p, thislength); 179 in->p += thislength; 180 181 if (flags & CHANNEL_FLAG_LAST) 182 { 183 in->end = in->p; 184 in->p = in->data; 185 channel->process(in); 186 } 187 } 188 } 189