/* Copyright (c) 2004-2007, Sara Golemon * 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" #include #include #ifndef WIN32 #include #endif /* Needed for struct iovec on some platforms */ #ifdef HAVE_SYS_UIO_H #include #endif #include #include #ifdef HAVE_POLL # include #else # ifdef HAVE_SELECT # ifdef HAVE_SYS_SELECT_H # include # else # include # include # endif # endif #endif #include inline int libssh2_packet_queue_listener(LIBSSH2_SESSION *session, unsigned char *data, unsigned long datalen); inline int libssh2_packet_x11_open(LIBSSH2_SESSION *session, unsigned char *data, unsigned long datalen); /* {{{ libssh2_packet_queue_listener * Queue a connection request for a listener */ inline int libssh2_packet_queue_listener(LIBSSH2_SESSION *session, unsigned char *data, unsigned long datalen) { /* Look for a matching listener */ unsigned char *s = data + (sizeof("forwarded-tcpip") - 1) + 5; /* 17 = packet_type(1) + channel(4) + reason(4) + descr(4) + lang(4) */ unsigned long packet_len = 17 + (sizeof("Forward not requested") - 1); unsigned char *p, packet[17 + (sizeof("Forward not requested") - 1)]; LIBSSH2_LISTENER *l = session->listeners; char failure_code = 1; /* SSH_OPEN_ADMINISTRATIVELY_PROHIBITED */ uint32_t sender_channel, initial_window_size, packet_size; unsigned char *host, *shost; uint32_t port, sport, host_len, shost_len; (void)datalen; sender_channel = libssh2_ntohu32(s); s += 4; initial_window_size = libssh2_ntohu32(s); s += 4; packet_size = libssh2_ntohu32(s); s += 4; host_len = libssh2_ntohu32(s); s += 4; host = s; s += host_len; port = libssh2_ntohu32(s); s += 4; shost_len = libssh2_ntohu32(s); s += 4; shost = s; s += shost_len; sport = libssh2_ntohu32(s); s += 4; #ifdef LIBSSH2_DEBUG_CONNECTION _libssh2_debug(session, LIBSSH2_DBG_CONN, "Remote received connection from %s:%ld to %s:%ld", shost, sport, host, port); #endif while (l) { if ((l->port == (int)port) && (strlen(l->host) == host_len) && (memcmp(l->host, host, host_len) == 0)) { /* This is our listener */ LIBSSH2_CHANNEL *channel, *last_queued = l->queue; if (l->queue_maxsize && (l->queue_maxsize <= l->queue_size)) { /* Queue is full */ failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */ #ifdef LIBSSH2_DEBUG_CONNECTION _libssh2_debug(session, LIBSSH2_DBG_CONN, "Listener queue full, ignoring"); #endif break; } channel = LIBSSH2_ALLOC(session, sizeof(LIBSSH2_CHANNEL)); if (!channel) { libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate a channel for new connection", 0); failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */ break; } memset(channel, 0, sizeof(LIBSSH2_CHANNEL)); channel->session = session; channel->channel_type_len = sizeof("forwarded-tcpip") - 1; channel->channel_type = LIBSSH2_ALLOC(session, channel->channel_type_len + 1); if (!channel->channel_type) { libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate a channel for new connection", 0); LIBSSH2_FREE(session, channel); failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */ break; } memcpy(channel->channel_type, "forwarded-tcpip", channel->channel_type_len + 1); channel->remote.id = sender_channel; channel->remote.window_size_initial = LIBSSH2_CHANNEL_WINDOW_DEFAULT; channel->remote.window_size = LIBSSH2_CHANNEL_WINDOW_DEFAULT; channel->remote.packet_size = LIBSSH2_CHANNEL_PACKET_DEFAULT; channel->local.id = libssh2_channel_nextid(session); channel->local.window_size_initial = initial_window_size; channel->local.window_size = initial_window_size; channel->local.packet_size = packet_size; #ifdef LIBSSH2_DEBUG_CONNECTION _libssh2_debug(session, LIBSSH2_DBG_CONN, "Connection queued: channel %lu/%lu win %lu/%lu packet %lu/%lu", channel->local.id, channel->remote.id, channel->local.window_size, channel->remote.window_size, channel->local.packet_size, channel->remote.packet_size); #endif p = packet; *(p++) = SSH_MSG_CHANNEL_OPEN_CONFIRMATION; libssh2_htonu32(p, channel->remote.id); p += 4; libssh2_htonu32(p, channel->local.id); p += 4; libssh2_htonu32(p, channel->remote.window_size_initial); p += 4; libssh2_htonu32(p, channel->remote.packet_size); p += 4; if (libssh2_packet_write(session, packet, 17)) { libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send channel open confirmation", 0); return -1; } /* Link the channel into the end of the queue list */ if (!last_queued) { l->queue = channel; return 0; } while (last_queued->next) last_queued = last_queued->next; last_queued->next = channel; channel->prev = last_queued; l->queue_size++; return 0; } l = l->next; } /* We're not listening to you */ { p = packet; *(p++) = SSH_MSG_CHANNEL_OPEN_FAILURE; libssh2_htonu32(p, sender_channel); p += 4; libssh2_htonu32(p, failure_code); p += 4; libssh2_htonu32(p, sizeof("Forward not requested") - 1); p += 4; memcpy(s, "Forward not requested", sizeof("Forward not requested") - 1); p += sizeof("Forward not requested") - 1; libssh2_htonu32(p, 0); if (libssh2_packet_write(session, packet, packet_len)) { libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send open failure", 0); return -1; } return 0; } } /* }}} */ /* {{{ libssh2_packet_x11_open * Accept a forwarded X11 connection */ inline int libssh2_packet_x11_open(LIBSSH2_SESSION *session, unsigned char *data, unsigned long datalen) { int failure_code = 2; /* SSH_OPEN_CONNECT_FAILED */ unsigned char *s = data + (sizeof("x11") - 1) + 5; unsigned long packet_len = 17 + (sizeof("X11 Forward Unavailable") - 1); unsigned char *p, packet[17 + (sizeof("X11 Forward Unavailable") - 1)]; /* packet_type(1) + channel(4) + reason(4) + descr(4) + lang(4) */ LIBSSH2_CHANNEL *channel; unsigned long sender_channel, initial_window_size, packet_size; unsigned char *shost; unsigned long sport, shost_len; (void)datalen; sender_channel = libssh2_ntohu32(s); s += 4; initial_window_size = libssh2_ntohu32(s); s += 4; packet_size = libssh2_ntohu32(s); s += 4; shost_len = libssh2_ntohu32(s); s += 4; shost = s; s += shost_len; sport = libssh2_ntohu32(s); s += 4; #ifdef LIBSSH2_DEBUG_CONNECTION _libssh2_debug(session, LIBSSH2_DBG_CONN, "X11 Connection Received from %s:%ld on channel %lu", shost, sport, sender_channel); #endif if (session->x11) { channel = LIBSSH2_ALLOC(session, sizeof(LIBSSH2_CHANNEL)); if (!channel) { libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate a channel for new connection", 0); failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */ goto x11_exit; } memset(channel, 0, sizeof(LIBSSH2_CHANNEL)); channel->session = session; channel->channel_type_len = sizeof("x11") - 1; channel->channel_type = LIBSSH2_ALLOC(session, channel->channel_type_len + 1); if (!channel->channel_type) { libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate a channel for new connection", 0); LIBSSH2_FREE(session, channel); failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */ goto x11_exit; } memcpy(channel->channel_type, "x11", channel->channel_type_len + 1); channel->remote.id = sender_channel; channel->remote.window_size_initial = LIBSSH2_CHANNEL_WINDOW_DEFAULT; channel->remote.window_size = LIBSSH2_CHANNEL_WINDOW_DEFAULT; channel->remote.packet_size = LIBSSH2_CHANNEL_PACKET_DEFAULT; channel->local.id = libssh2_channel_nextid(session); channel->local.window_size_initial = initial_window_size; channel->local.window_size = initial_window_size; channel->local.packet_size = packet_size; #ifdef LIBSSH2_DEBUG_CONNECTION _libssh2_debug(session, LIBSSH2_DBG_CONN, "X11 Connection established: channel %lu/%lu win %lu/%lu packet %lu/%lu", channel->local.id, channel->remote.id, channel->local.window_size, channel->remote.window_size, channel->local.packet_size, channel->remote.packet_size); #endif p = packet; *(p++) = SSH_MSG_CHANNEL_OPEN_CONFIRMATION; libssh2_htonu32(p, channel->remote.id); p += 4; libssh2_htonu32(p, channel->local.id); p += 4; libssh2_htonu32(p, channel->remote.window_size_initial); p += 4; libssh2_htonu32(p, channel->remote.packet_size); p += 4; if (libssh2_packet_write(session, packet, 17)) { libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send channel open confirmation", 0); return -1; } /* Link the channel into the session */ if (session->channels.tail) { session->channels.tail->next = channel; channel->prev = session->channels.tail; } else { session->channels.head = channel; channel->prev = NULL; } channel->next = NULL; session->channels.tail = channel; /* * Pass control to the callback, they may turn right around and * free the channel, or actually use it */ LIBSSH2_X11_OPEN(channel, (char *)shost, sport); return 0; } else { failure_code = 4; /* SSH_OPEN_RESOURCE_SHORTAGE */ } x11_exit: p = packet; *(p++) = SSH_MSG_CHANNEL_OPEN_FAILURE; libssh2_htonu32(p, sender_channel); p += 4; libssh2_htonu32(p, failure_code); p += 4; libssh2_htonu32(p, sizeof("X11 Forward Unavailable") - 1); p += 4; memcpy(s, "X11 Forward Unavailable", sizeof("X11 Forward Unavailable") - 1); p += sizeof("X11 Forward Unavailable") - 1; libssh2_htonu32(p, 0); if (libssh2_packet_write(session, packet, packet_len)) { libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND, "Unable to send open failure", 0); return -1; } return 0; } /* }}} */ /* {{{ libssh2_packet_new * Create a new packet and attach it to the brigade */ int libssh2_packet_add(LIBSSH2_SESSION *session, unsigned char *data, size_t datalen, int macstate) { LIBSSH2_PACKET *packet; unsigned long data_head = 0; #ifdef LIBSSH2_DEBUG_TRANSPORT _libssh2_debug(session, LIBSSH2_DBG_TRANS, "Packet type %d received, length=%d", (int)data[0], (int)datalen); #endif if (macstate == LIBSSH2_MAC_INVALID) { if (session->macerror) { if (LIBSSH2_MACERROR(session, (char *)data, datalen) == 0) { /* Calling app has given the OK, Process it anyway */ macstate = LIBSSH2_MAC_CONFIRMED; } else { libssh2_error(session, LIBSSH2_ERROR_INVALID_MAC, "Invalid Message Authentication Code received", 0); if (session->ssh_msg_disconnect) { LIBSSH2_DISCONNECT(session, SSH_DISCONNECT_MAC_ERROR, "Invalid MAC received", sizeof("Invalid MAC received") - 1, "", 0); } return -1; } } else { libssh2_error(session, LIBSSH2_ERROR_INVALID_MAC, "Invalid Message Authentication Code received", 0); if (session->ssh_msg_disconnect) { LIBSSH2_DISCONNECT(session, SSH_DISCONNECT_MAC_ERROR, "Invalid MAC received", sizeof("Invalid MAC received") - 1, "", 0); } return -1; } } /* A couple exceptions to the packet adding rule: */ switch (data[0]) { case SSH_MSG_DISCONNECT: { char *message, *language; int reason, message_len, language_len; reason = libssh2_ntohu32(data + 1); message_len = libssh2_ntohu32(data + 5); message = (char *)data + 9; /* packet_type(1) + reason(4) + message_len(4) */ language_len = libssh2_ntohu32(data + 9 + message_len); /* This is where we hack on the data a little, * Use the MSB of language_len to to a terminating NULL (In all liklihood it is already) * Shift the language tag back a byte (In all likelihood it's zero length anyway * Store a NULL in the last byte of the packet to terminate the language string * With the lengths passed this isn't *REALLY* necessary, but it's "kind" */ message[message_len] = '\0'; language = (char *)data + 9 + message_len + 3; if (language_len) { memcpy(language, language + 1, language_len); } language[language_len] = '\0'; if (session->ssh_msg_disconnect) { LIBSSH2_DISCONNECT(session, reason, message, message_len, language, language_len); } #ifdef LIBSSH2_DEBUG_TRANSPORT _libssh2_debug(session, LIBSSH2_DBG_TRANS, "Disconnect(%d): %s(%s)", reason, message, language); #endif LIBSSH2_FREE(session, data); session->socket_state = LIBSSH2_SOCKET_DISCONNECTED; return -1; } break; case SSH_MSG_IGNORE: /* As with disconnect, back it up one and add a trailing NULL */ memcpy(data + 4, data + 5, datalen - 5); data[datalen] = '\0'; if (session->ssh_msg_ignore) { LIBSSH2_IGNORE(session, (char *)data + 4, datalen - 5); } LIBSSH2_FREE(session, (char *)data); return 0; break; case SSH_MSG_DEBUG: { int always_display = data[0]; char *message, *language; int message_len, language_len; message_len = libssh2_ntohu32(data + 2); message = (char *)data + 6; /* packet_type(1) + display(1) + message_len(4) */ language_len = libssh2_ntohu32(data + 6 + message_len); /* This is where we hack on the data a little, * Use the MSB of language_len to to a terminating NULL (In all liklihood it is already) * Shift the language tag back a byte (In all likelihood it's zero length anyway * Store a NULL in the last byte of the packet to terminate the language string * With the lengths passed this isn't *REALLY* necessary, but it's "kind" */ message[message_len] = '\0'; language = (char *)data + 6 + message_len + 3; if (language_len) { memcpy(language, language + 1, language_len); } language[language_len] = '\0'; if (session->ssh_msg_debug) { LIBSSH2_DEBUG(session, always_display, message, message_len, language, language_len); } #ifdef LIBSSH2_DEBUG_TRANSPORT /* _libssh2_debug will actually truncate this for us so that it's not an inordinate about of data */ _libssh2_debug(session, LIBSSH2_DBG_TRANS, "Debug Packet: %s", message); #endif LIBSSH2_FREE(session, data); return 0; } break; case SSH_MSG_CHANNEL_EXTENDED_DATA: data_head += 4; /* streamid(4) */ case SSH_MSG_CHANNEL_DATA: data_head += 9; /* packet_type(1) + channelno(4) + datalen(4) */ { LIBSSH2_CHANNEL *channel = libssh2_channel_locate(session, libssh2_ntohu32(data + 1)); if (!channel) { libssh2_error(session, LIBSSH2_ERROR_CHANNEL_UNKNOWN, "Packet received for unknown channel, ignoring", 0); LIBSSH2_FREE(session, data); return 0; } #ifdef LIBSSH2_DEBUG_CONNECTION { unsigned long stream_id = 0; if (data[0] == SSH_MSG_CHANNEL_EXTENDED_DATA) { stream_id = libssh2_ntohu32(data + 5); } _libssh2_debug(session, LIBSSH2_DBG_CONN, "%d bytes received for channel %lu/%lu stream #%lu", (int)(datalen - data_head), channel->local.id, channel->remote.id, stream_id); } #endif if ((channel->remote.extended_data_ignore_mode == LIBSSH2_CHANNEL_EXTENDED_DATA_IGNORE) && (data[0] == SSH_MSG_CHANNEL_EXTENDED_DATA)) { /* Pretend we didn't receive this */ LIBSSH2_FREE(session, data); #ifdef LIBSSH2_DEBUG_CONNECTION _libssh2_debug(session, LIBSSH2_DBG_CONN, "Ignoring extended data and refunding %d bytes", (int)(datalen - 13)); #endif /* Adjust the window based on the block we just freed */ libssh2_channel_receive_window_adjust(channel, datalen - 13, 0); return 0; } /* REMEMBER! remote means remote as source of data, NOT remote window! */ if (channel->remote.packet_size < (datalen - data_head)) { /* Spec says we MAY ignore bytes sent beyond packet_size */ libssh2_error(session, LIBSSH2_ERROR_CHANNEL_PACKET_EXCEEDED, "Packet contains more data than we offered to receive, truncating", 0); datalen = channel->remote.packet_size + data_head; } if (channel->remote.window_size <= 0) { /* Spec says we MAY ignore bytes sent beyond window_size */ libssh2_error(session, LIBSSH2_ERROR_CHANNEL_WINDOW_EXCEEDED, "The current receive window is full, data ignored", 0); LIBSSH2_FREE(session, data); return 0; } /* Reset EOF status */ channel->remote.eof = 0; if ((datalen - data_head) > channel->remote.window_size) { libssh2_error(session, LIBSSH2_ERROR_CHANNEL_WINDOW_EXCEEDED, "Remote sent more data than current window allows, truncating", 0); datalen = channel->remote.window_size + data_head; } else { /* Now that we've received it, shrink our window */ channel->remote.window_size -= datalen - data_head; } } break; case SSH_MSG_CHANNEL_EOF: { LIBSSH2_CHANNEL *channel = libssh2_channel_locate(session, libssh2_ntohu32(data + 1)); if (!channel) { /* We may have freed already, just quietly ignore this... */ LIBSSH2_FREE(session, data); return 0; } #ifdef LIBSSH2_DEBUG_CONNECTION _libssh2_debug(session, LIBSSH2_DBG_CONN, "EOF received for channel %lu/%lu", channel->local.id, channel->remote.id); #endif channel->remote.eof = 1; LIBSSH2_FREE(session, data); return 0; } break; case SSH_MSG_CHANNEL_REQUEST: { if (libssh2_ntohu32(data+5) == sizeof("exit-status") - 1 && !memcmp("exit-status", data + 9, sizeof("exit-status") - 1)) { /* we've got "exit-status" packet. Set the session value */ LIBSSH2_CHANNEL *channel = libssh2_channel_locate(session, libssh2_ntohu32(data+1)); if (channel) { channel->exit_status = libssh2_ntohu32(data + 9 + sizeof("exit-status")); #ifdef LIBSSH2_DEBUG_CONNECTION _libssh2_debug(session, LIBSSH2_DBG_CONN, "Exit status %lu received for channel %lu/%lu", channel->exit_status, channel->local.id, channel->remote.id); #endif } LIBSSH2_FREE(session, data); return 0; } } break; case SSH_MSG_CHANNEL_CLOSE: { LIBSSH2_CHANNEL *channel = libssh2_channel_locate(session, libssh2_ntohu32(data + 1)); if (!channel) { /* We may have freed already, just quietly ignore this... */ LIBSSH2_FREE(session, data); return 0; } #ifdef LIBSSH2_DEBUG_CONNECTION _libssh2_debug(session, LIBSSH2_DBG_CONN, "Close received for channel %lu/%lu", channel->local.id, channel->remote.id); #endif channel->remote.close = 1; channel->remote.eof = 1; /* TODO: Add a callback for this */ LIBSSH2_FREE(session, data); return 0; } break; case SSH_MSG_CHANNEL_OPEN: if ((datalen >= (sizeof("forwarded-tcpip") + 4)) && ((sizeof("forwarded-tcpip")-1) == libssh2_ntohu32(data + 1)) && (memcmp(data + 5, "forwarded-tcpip", sizeof("forwarded-tcpip") - 1) == 0)) { int retval = libssh2_packet_queue_listener(session, data, datalen); LIBSSH2_FREE(session, data); return retval; } if ((datalen >= (sizeof("x11") + 4)) && ((sizeof("x11")-1) == libssh2_ntohu32(data + 1)) && (memcmp(data + 5, "x11", sizeof("x11") - 1) == 0)) { int retval = libssh2_packet_x11_open(session, data, datalen); LIBSSH2_FREE(session, data); return retval; } break; case SSH_MSG_CHANNEL_WINDOW_ADJUST: { LIBSSH2_CHANNEL *channel = libssh2_channel_locate(session, libssh2_ntohu32(data + 1)); unsigned long bytestoadd = libssh2_ntohu32(data + 5); if (channel && bytestoadd) { channel->local.window_size += bytestoadd; } #ifdef LIBSSH2_DEBUG_CONNECTION _libssh2_debug(session, LIBSSH2_DBG_CONN, "Window adjust received for channel %lu/%lu, adding %lu bytes, new window_size=%lu", channel->local.id, channel->remote.id, bytestoadd, channel->local.window_size); #endif LIBSSH2_FREE(session, data); return 0; } break; } packet = LIBSSH2_ALLOC(session, sizeof(LIBSSH2_PACKET)); memset(packet, 0, sizeof(LIBSSH2_PACKET)); packet->data = data; packet->data_len = datalen; packet->data_head = data_head; packet->mac = macstate; packet->brigade = &session->packets; packet->next = NULL; if (session->packets.tail) { packet->prev = session->packets.tail; packet->prev->next = packet; session->packets.tail = packet; } else { session->packets.head = packet; session->packets.tail = packet; packet->prev = NULL; } if (data[0] == SSH_MSG_KEXINIT && !(session->state & LIBSSH2_STATE_EXCHANGING_KEYS)) { /* Remote wants new keys * Well, it's already in the brigade, * let's just call back into ourselves */ #ifdef LIBSSH2_DEBUG_TRANSPORT _libssh2_debug(session, LIBSSH2_DBG_TRANS, "Renegotiating Keys"); #endif libssh2_kex_exchange(session, 1); /* If there was a key reexchange failure, let's just hope we didn't send NEWKEYS yet, otherwise remote will drop us like a rock */ } return 0; } /* }}} */ /* {{{ libssh2_packet_ask * Scan the brigade for a matching packet type, optionally poll the socket for * a packet first */ int libssh2_packet_ask_ex(LIBSSH2_SESSION *session, unsigned char packet_type, unsigned char **data, unsigned long *data_len, unsigned long match_ofs, const unsigned char *match_buf, unsigned long match_len, int poll_socket) { LIBSSH2_PACKET *packet = session->packets.head; if (poll_socket) { libssh2pack_t rc = libssh2_packet_read(session); if ((rc < 0) && !packet) { return rc; } } #ifdef LIBSSH2_DEBUG_TRANSPORT _libssh2_debug(session, LIBSSH2_DBG_TRANS, "Looking for packet of type: %d", (int)packet_type); #endif while (packet) { if (packet->data[0] == packet_type && (packet->data_len >= (match_ofs + match_len)) && (!match_buf || (memcmp(packet->data + match_ofs, match_buf, match_len) == 0))) { *data = packet->data; *data_len = packet->data_len; if (packet->prev) { packet->prev->next = packet->next; } else { session->packets.head = packet->next; } if (packet->next) { packet->next->prev = packet->prev; } else { session->packets.tail = packet->prev; } LIBSSH2_FREE(session, packet); return 0; } packet = packet->next; } return -1; } /* }}} */ /* {{{ libssh2_packet_askv * Scan for any of a list of packet types in the brigade, optionally poll the * socket for a packet first */ int libssh2_packet_askv_ex(LIBSSH2_SESSION *session, unsigned char *packet_types, unsigned char **data, unsigned long *data_len, unsigned long match_ofs, const unsigned char *match_buf, unsigned long match_len, int poll_socket) { int i, packet_types_len = strlen((char *)packet_types); for(i = 0; i < packet_types_len; i++) { if (0 == libssh2_packet_ask_ex(session, packet_types[i], data, data_len, match_ofs, match_buf, match_len, i ? 0 : poll_socket)) { return 0; } } return -1; } /* }}} */ /* {{{ waitsocket * Returns * negative on error * >0 on incoming data * 0 on timeout * * FIXME: convert to use poll on systems that have it. */ int libssh2_waitsocket(LIBSSH2_SESSION *session, long seconds) { struct timeval timeout; int rc; fd_set fd; timeout.tv_sec = seconds; timeout.tv_usec = 0; FD_ZERO(&fd); FD_SET(session->socket_fd, &fd); rc = select(session->socket_fd+1, &fd, NULL, NULL, &timeout); return rc; } /* {{{ libssh2_packet_require * [BLOCKING] for LIBSSH2_READ_TIMEOUT seconds * Loops libssh2_packet_read() until the packet requested is available * SSH_DISCONNECT or a SOCKET_DISCONNECTED will cause a bailout * * Returns negative on error * Returns 0 when it has taken care of the requested packet. */ int libssh2_packet_require_ex(LIBSSH2_SESSION *session, unsigned char packet_type, unsigned char **data, unsigned long *data_len, unsigned long match_ofs, const unsigned char *match_buf, unsigned long match_len) { time_t start = time(NULL); if (libssh2_packet_ask_ex(session, packet_type, data, data_len, match_ofs, match_buf, match_len, 0) == 0) { /* A packet was available in the packet brigade */ return 0; } #ifdef LIBSSH2_DEBUG_TRANSPORT _libssh2_debug(session, LIBSSH2_DBG_TRANS, "Blocking until packet of type %d becomes available", (int)packet_type); #endif while (session->socket_state == LIBSSH2_SOCKET_CONNECTED) { libssh2pack_t ret = libssh2_packet_read(session); if ((ret < 0) && (ret != PACKET_EAGAIN)) { /* an error which is not just because of blocking */ return ret; } if (packet_type == ret) { /* Be lazy, let packet_ask pull it out of the brigade */ ret = libssh2_packet_ask_ex(session, packet_type, data, data_len, match_ofs, match_buf, match_len, 0); return ret; } else if (ret <= 0) { /* nothing available, wait until data arrives or we time out */ long left = LIBSSH2_READ_TIMEOUT - (time(NULL) - start); if((left <= 0) || (libssh2_waitsocket(session, left) <= 0)) { return PACKET_TIMEOUT; } } } /* Only reached if the socket died */ return -1; } /* }}} */ /* {{{ libssh2_packet_burn * Loops libssh2_packet_read() until any packet is available and promptly discards it * Used during KEX exchange to discard badly guessed KEX_INIT packets */ int libssh2_packet_burn(LIBSSH2_SESSION *session) { unsigned char *data; unsigned long data_len; unsigned char all_packets[255]; int i; for(i = 1; i < 256; i++) all_packets[i - 1] = i; if (libssh2_packet_askv_ex(session, all_packets, &data, &data_len, 0, NULL, 0, 0) == 0) { i = data[0]; /* A packet was available in the packet brigade, burn it */ LIBSSH2_FREE(session, data); return i; } #ifdef LIBSSH2_DEBUG_TRANSPORT _libssh2_debug(session, LIBSSH2_DBG_TRANS, "Blocking until packet becomes available to burn"); #endif while (session->socket_state == LIBSSH2_SOCKET_CONNECTED) { int ret = libssh2_packet_read(session); if (ret < 0) { return ret; } if (ret == 0) { /* FIXME: this might busyloop */ continue; } /* Be lazy, let packet_ask pull it out of the brigade */ if (0 == libssh2_packet_ask_ex(session, ret, &data, &data_len, 0, NULL, 0, 0)) { /* Smoke 'em if you got 'em */ LIBSSH2_FREE(session, data); return ret; } } /* Only reached if the socket died */ return -1; } /* }}} */ /* {{{ libssh2_packet_requirev * [BLOCKING] * Loops libssh2_packet_read() until one of a list of packet types requested is * available * SSH_DISCONNECT or a SOCKET_DISCONNECTED will cause a bailout * packet_types is a null terminated list of packet_type numbers */ int libssh2_packet_requirev_ex(LIBSSH2_SESSION *session, unsigned char *packet_types, unsigned char **data, unsigned long *data_len, unsigned long match_ofs, const unsigned char *match_buf, unsigned long match_len) { time_t start = time(NULL); if (libssh2_packet_askv_ex(session, packet_types, data, data_len, match_ofs, match_buf, match_len, 0) == 0) { /* One of the packets listed was available in the packet brigade */ return 0; } while (session->socket_state != LIBSSH2_SOCKET_DISCONNECTED) { int ret = libssh2_packet_read(session); if ((ret < 0) && (ret != PACKET_EAGAIN)) { return ret; } if (ret <= 0) { long left = LIBSSH2_READ_TIMEOUT - (time(NULL) - start); if((left <= 0) || (libssh2_waitsocket(session, left) <= 0 )) { return PACKET_TIMEOUT; } } if (strchr((char *)packet_types, ret)) { /* Be lazy, let packet_ask pull it out of the brigade */ return libssh2_packet_askv_ex(session, packet_types, data, data_len, match_ofs, match_buf, match_len, 0); } } /* Only reached if the socket died */ return -1; } /* }}} */