source: protocols/msn/invitation.c @ 1522faf

/********************************************************************\
* BitlBee -- An IRC to other IM-networks gateway                     *
*                                                                    *
* Copyright 2008 Uli Meis                                            *
* Copyright 2006 Marijn Kruisselbrink and others                     *
\********************************************************************/

/* MSN module - File transfer support             */

/*
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License with
 the Debian GNU/Linux distribution in /usr/share/common-licenses/GPL;
 if not, write to the Free Software Foundation, Inc., 51 Franklin St.,
 Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "bitlbee.h"
#include "invitation.h"
#include "msn.h"
#include "lib/ftutil.h"

#ifdef debug
#undef debug
#endif
#define debug(msg ...) log_message(LOGLVL_INFO, msg)

static void msn_ftp_free(file_transfer_t *file);
static void msn_ftpr_accept(file_transfer_t *file);
static void msn_ftp_finished(file_transfer_t *file);
static void msn_ftp_canceled(file_transfer_t *file, char *reason);
static gboolean msn_ftpr_write_request(file_transfer_t *file);

static gboolean msn_ftp_connected(gpointer data, gint fd, b_input_condition cond);
static gboolean msn_ftp_read(gpointer data, gint fd, b_input_condition cond);
gboolean msn_ftps_write(file_transfer_t *file, char *buffer, unsigned int len);

/*
 * Vararg wrapper for imcb_file_canceled().
 */
gboolean msn_ftp_abort(file_transfer_t *file, char *format, ...)
{
        va_list params;

        va_start(params, format);
        char error[128];

        if (vsnprintf(error, 128, format, params) < 0) {
                sprintf(error, "internal error parsing error string (BUG)");
        }
        va_end(params);
        imcb_file_canceled(file, error);
        return FALSE;
}

/* very useful */
#define ASSERTSOCKOP(op, msg) \
        if ((op) == -1) { \
                return msn_ftp_abort(file, msg ": %s", strerror(errno)); }

void msn_ftp_invitation_cmd(struct im_connection *ic, char *who, int cookie, char *icmd,
                            char *trailer)
{
        struct msn_message *m = g_new0(struct msn_message, 1);

        m->text = g_strdup_printf("%s"
                                  "Invitation-Command: %s\r\n"
                                  "Invitation-Cookie: %u\r\n"
                                  "%s",
                                  MSN_INVITE_HEADERS,
                                  icmd,
                                  cookie,
                                  trailer);

        m->who = g_strdup(who);

        msn_sb_write_msg(ic, m);
}

void msn_ftp_cancel_invite(struct im_connection *ic, char *who,  int cookie, char *code)
{
        char buf[64];

        g_snprintf(buf, sizeof(buf), "Cancel-Code: %s\r\n", code);
        msn_ftp_invitation_cmd(ic, who, cookie, "CANCEL", buf);
}

void msn_ftp_transfer_request(struct im_connection *ic, file_transfer_t *file, char *who)
{
        unsigned int cookie = time(NULL);   /* TODO: randomize */
        char buf[2048];

        msn_filetransfer_t *msn_file = g_new0(msn_filetransfer_t, 1);

        file->data = msn_file;
        file->free = msn_ftp_free;
        file->canceled = msn_ftp_canceled;
        file->write = msn_ftps_write;
        msn_file->md = ic->proto_data;
        msn_file->invite_cookie = cookie;
        msn_file->handle = g_strdup(who);
        msn_file->dcc = file;
        msn_file->md->filetransfers = g_slist_prepend(msn_file->md->filetransfers, msn_file->dcc);
        msn_file->fd = -1;
        msn_file->sbufpos = 3;

        g_snprintf(buf, sizeof(buf),
                   "Application-Name: File Transfer\r\n"
                   "Application-GUID: {5D3E02AB-6190-11d3-BBBB-00C04F795683}\r\n"
                   "Application-File: %s\r\n"
                   "Application-FileSize: %zd\r\n",
                   file->file_name,
                   file->file_size);

        msn_ftp_invitation_cmd(msn_file->md->ic, msn_file->handle, cookie, "INVITE", buf);

        imcb_file_recv_start(file);
}

void msn_invitation_invite(struct msn_switchboard *sb, char *handle, unsigned int cookie, char *body, int blen)
{
        char *itype = msn_findheader(body, "Application-GUID:", blen);
        char *name, *size, *invitecookie, *reject = NULL;
        user_t *u;
        size_t isize;
        file_transfer_t *file;

        if (!itype || strcmp(itype, "{5D3E02AB-6190-11d3-BBBB-00C04F795683}") != 0) {
                /* Don't know what that is - don't care */
                char *iname = msn_findheader(body, "Application-Name:", blen);
                imcb_log(sb->ic, "Received unknown MSN invitation %s (%s) from %s",
                         itype ? : "with no GUID", iname ? iname : "no application name", handle);
                g_free(iname);
                reject = "REJECT_NOT_INSTALLED";
        } else if (
                !(name = msn_findheader(body, "Application-File:", blen)) ||
                !(size = msn_findheader(body, "Application-FileSize:", blen)) ||
                !(invitecookie = msn_findheader(body, "Invitation-Cookie:", blen)) ||
                !(isize = atoll(size))) {
                imcb_log(sb->ic, "Received corrupted transfer request from %s"
                         "(name=%s, size=%s, invitecookie=%s)",
                         handle, name, size, invitecookie);
                reject = "REJECT";
        } else if (!(u = user_findhandle(sb->ic, handle))) {
                imcb_log(sb->ic, "Error in parsing transfer request, User '%s'"
                         "is not in contact list", handle);
                reject = "REJECT";
        } else if (!(file = imcb_file_send_start(sb->ic, handle, name, isize))) {
                imcb_log(sb->ic, "Error initiating transfer for request from %s for %s",
                         handle, name);
                reject = "REJECT";
        } else {
                msn_filetransfer_t *msn_file = g_new0(msn_filetransfer_t, 1);
                file->data = msn_file;
                file->accept = msn_ftpr_accept;
                file->free = msn_ftp_free;
                file->finished = msn_ftp_finished;
                file->canceled = msn_ftp_canceled;
                file->write_request = msn_ftpr_write_request;
                msn_file->md = sb->ic->proto_data;
                msn_file->invite_cookie = cookie;
                msn_file->handle = g_strdup(handle);
                msn_file->dcc = file;
                msn_file->md->filetransfers = g_slist_prepend(msn_file->md->filetransfers, msn_file->dcc);
                msn_file->fd = -1;
        }

        if (reject) {
                msn_ftp_cancel_invite(sb->ic, sb->who, cookie, reject);
        }

        g_free(name);
        g_free(size);
        g_free(invitecookie);
        g_free(itype);
}

msn_filetransfer_t* msn_find_filetransfer(struct msn_data *md, unsigned int cookie, char *handle)
{
        GSList *l;

        for (l = md->filetransfers; l; l = l->next) {
                msn_filetransfer_t *file = ((file_transfer_t *) l->data)->data;
                if (file->invite_cookie == cookie && strcmp(handle, file->handle) == 0) {
                        return file;
                }
        }
        return NULL;
}

gboolean msn_ftps_connected(gpointer data, gint fd, b_input_condition cond)
{
        file_transfer_t *file = data;
        msn_filetransfer_t *msn_file = file->data;
        struct sockaddr_storage clt_addr;
        socklen_t ssize = sizeof(clt_addr);

        debug("Connected to MSNFTP client");

        ASSERTSOCKOP(msn_file->fd = accept(fd, (struct sockaddr *) &clt_addr, &ssize), "Accepting connection");

        closesocket(fd);
        fd = msn_file->fd;
        sock_make_nonblocking(fd);

        msn_file->r_event_id = b_input_add(fd, B_EV_IO_READ, msn_ftp_read, file);

        return FALSE;
}

void msn_invitations_accept(msn_filetransfer_t *msn_file, struct msn_switchboard *sb, char *handle, unsigned int cookie,
                            char *body, int blen)
{
        file_transfer_t *file = msn_file->dcc;
        char buf[1024];
        unsigned int acookie = time(NULL);
        char host[HOST_NAME_MAX + 1];
        char port[6];
        char *errmsg;

        msn_file->auth_cookie = acookie;

        if ((msn_file->fd = ft_listen(NULL, host, port, FALSE, &errmsg)) == -1) {
                msn_ftp_abort(file, "Failed to listen locally, check your ft_listen setting in bitlbee.conf: %s",
                              errmsg);
                return;
        }

        msn_file->r_event_id = b_input_add(msn_file->fd, B_EV_IO_READ, msn_ftps_connected, file);

        g_snprintf(buf, sizeof(buf),
                   "IP-Address: %s\r\n"
                   "Port: %s\r\n"
                   "AuthCookie: %d\r\n"
                   "Launch-Application: FALSE\r\n"
                   "Request-Data: IP-Address:\r\n\r\n",
                   host,
                   port,
                   msn_file->auth_cookie);

        msn_ftp_invitation_cmd(msn_file->md->ic, handle, msn_file->invite_cookie, "ACCEPT", buf);
}

void msn_invitationr_accept(msn_filetransfer_t *msn_file, struct msn_switchboard *sb, char *handle, unsigned int cookie,
                            char *body, int blen)
{
        file_transfer_t *file = msn_file->dcc;
        char *authcookie, *ip, *port;

        if (!(authcookie = msn_findheader(body, "AuthCookie:", blen)) ||
            !(ip = msn_findheader(body, "IP-Address:", blen)) ||
            !(port = msn_findheader(body, "Port:", blen))) {
                msn_ftp_abort(file, "Received invalid accept reply");
        } else if (
                (msn_file->fd = proxy_connect(ip, atoi(port), msn_ftp_connected, file))
                < 0) {
                msn_ftp_abort(file, "Error connecting to MSN client");
        } else {
                msn_file->auth_cookie = strtoul(authcookie, NULL, 10);
        }

        g_free(authcookie);
        g_free(ip);
        g_free(port);
}

void msn_invitation_accept(struct msn_switchboard *sb, char *handle, unsigned int cookie, char *body, int blen)
{
        msn_filetransfer_t *msn_file = msn_find_filetransfer(sb->ic->proto_data, cookie, handle);
        file_transfer_t *file = msn_file ? msn_file->dcc : NULL;

        if (!msn_file) {
                imcb_log(sb->ic, "Received invitation ACCEPT message for unknown invitation (already aborted?)");
        } else if (file->sending) {
                msn_invitations_accept(msn_file, sb, handle, cookie, body, blen);
        } else {
                msn_invitationr_accept(msn_file, sb, handle, cookie, body, blen);
        }
}

void msn_invitation_cancel(struct msn_switchboard *sb, char *handle, unsigned int cookie, char *body, int blen)
{
        msn_filetransfer_t *msn_file = msn_find_filetransfer(sb->ic->proto_data, cookie, handle);

        if (!msn_file) {
                imcb_log(sb->ic, "Received invitation CANCEL message for unknown invitation (already aborted?)");
        } else {
                msn_ftp_abort(msn_file->dcc, msn_findheader(body, "Cancel-Code:", blen));
        }
}

int msn_ftp_write(file_transfer_t *file, char *format, ...)
{
        msn_filetransfer_t *msn_file = file->data;
        va_list params;
        int st;
        char *s;

        va_start(params, format);
        s = g_strdup_vprintf(format, params);
        va_end(params);

        st = write(msn_file->fd, s, strlen(s));
        if (st != strlen(s)) {
                return msn_ftp_abort(file, "Error sending data over MSNFTP connection: %s",
                                     strerror(errno));
        }

        g_free(s);
        return 1;
}

gboolean msn_ftp_connected(gpointer data, gint fd, b_input_condition cond)
{
        file_transfer_t *file = data;
        msn_filetransfer_t *msn_file = file->data;

        debug("Connected to MSNFTP server, starting authentication");
        if (!msn_ftp_write(file, "VER MSNFTP\r\n")) {
                return FALSE;
        }

        sock_make_nonblocking(msn_file->fd);
        msn_file->r_event_id = b_input_add(msn_file->fd, B_EV_IO_READ, msn_ftp_read, file);

        return FALSE;
}

gboolean msn_ftp_handle_command(file_transfer_t *file, char* line)
{
        msn_filetransfer_t *msn_file = file->data;
        char **cmd = msn_linesplit(line);
        int count = 0;

        if (cmd[0]) {
                while (cmd[++count]) {
                        ;
                }
        }

        if (count < 1) {
                return msn_ftp_abort(file, "Missing command in MSNFTP communication");
        }

        if (strcmp(cmd[0], "VER") == 0) {
                if (strcmp(cmd[1], "MSNFTP") != 0) {
                        return msn_ftp_abort(file, "Unsupported filetransfer protocol: %s", cmd[1]);
                }
                if (file->sending) {
                        msn_ftp_write(file, "VER MSNFTP\r\n");
                } else {
                        msn_ftp_write(file, "USR %s %u\r\n", msn_file->md->ic->acc->user, msn_file->auth_cookie);
                }
        } else if (strcmp(cmd[0], "FIL") == 0) {
                if (strtoul(cmd[1], NULL, 10) != file->file_size) {
                        return msn_ftp_abort(file,
                                             "FIL reply contains a different file size than the size in the invitation");
                }
                msn_ftp_write(file, "TFR\r\n");
                msn_file->status |= MSN_TRANSFER_RECEIVING;
        } else if (strcmp(cmd[0], "USR") == 0) {
                if ((strcmp(cmd[1], msn_file->handle) != 0) ||
                    (strtoul(cmd[2], NULL, 10) != msn_file->auth_cookie)) {
                        msn_ftp_abort(file, "Authentication failed. "
                                      "Expected handle: %s (got %s), cookie: %u (got %s)",
                                      msn_file->handle, cmd[1],
                                      msn_file->auth_cookie, cmd[2]);
                }
                msn_ftp_write(file, "FIL %zu\r\n", file->file_size);
        } else if (strcmp(cmd[0], "TFR") == 0) {
                file->write_request(file);
        } else if (strcmp(cmd[0], "BYE") == 0) {
                unsigned int retcode = count > 1 ? atoi(cmd[1]) : 1;

                if ((retcode == 16777989) || (retcode == 16777987)) {
                        imcb_file_finished(file);
                } else if (retcode == 2147942405) {
                        imcb_file_canceled(file, "Failure: receiver is out of disk space");
                } else if (retcode == 2164261682) {
                        imcb_file_canceled(file, "Failure: receiver cancelled the transfer");
                } else if (retcode == 2164261683) {
                        imcb_file_canceled(file, "Failure: sender has cancelled the transfer");
                } else if (retcode == 2164261694) {
                        imcb_file_canceled(file, "Failure: connection is blocked");
                } else {
                        char buf[128];

                        sprintf(buf, "Failure: unknown BYE code: %d", retcode);
                        imcb_file_canceled(file, buf);
                }
        } else if (strcmp(cmd[0], "CCL") == 0) {
                imcb_file_canceled(file, "Failure: receiver cancelled the transfer");
        } else {
                msn_ftp_abort(file, "Received invalid command %s from msn client", cmd[0]);
        }
        return TRUE;
}

gboolean msn_ftp_send(gpointer data, gint fd, b_input_condition cond)
{
        file_transfer_t *file = data;
        msn_filetransfer_t *msn_file = file->data;

        msn_file->w_event_id = 0;

        file->write_request(file);

        return FALSE;
}

/*
 * This should only be called if we can write, so just do it.
 * Add a write watch so we can write more during the next cycle (if possible).
 * This got a bit complicated because (at least) amsn expects packets of size 2045.
 */
gboolean msn_ftps_write(file_transfer_t *file, char *buffer, unsigned int len)
{
        msn_filetransfer_t *msn_file = file->data;
        int ret, overflow;

        /* what we can't send now */
        overflow = msn_file->sbufpos + len - MSNFTP_PSIZE;

        /* append what we can do the send buffer */
        memcpy(msn_file->sbuf + msn_file->sbufpos, buffer, MIN(len, MSNFTP_PSIZE - msn_file->sbufpos));
        msn_file->sbufpos += MIN(len, MSNFTP_PSIZE - msn_file->sbufpos);

        /* if we don't have enough for a full packet and there's more wait for it */
        if ((msn_file->sbufpos < MSNFTP_PSIZE) &&
            (msn_file->data_sent + msn_file->sbufpos - 3 < file->file_size)) {
                if (!msn_file->w_event_id) {
                        msn_file->w_event_id = b_input_add(msn_file->fd, B_EV_IO_WRITE, msn_ftp_send, file);
                }
                return TRUE;
        }

        /* Accumulated enough data, lets send something out */

        msn_file->sbuf[0] = 0;
        msn_file->sbuf[1] = (msn_file->sbufpos - 3) & 0xff;
        msn_file->sbuf[2] = ((msn_file->sbufpos - 3) >> 8) & 0xff;

        ASSERTSOCKOP(ret = send(msn_file->fd, msn_file->sbuf, msn_file->sbufpos, 0), "Sending");

        msn_file->data_sent += ret - 3;

        /* TODO: this should really not be fatal */
        if (ret < msn_file->sbufpos) {
                return msn_ftp_abort(file, "send() sent %d instead of %d (send buffer full!)", ret, msn_file->sbufpos);
        }

        msn_file->sbufpos = 3;

        if (overflow > 0) {
                while (overflow > (MSNFTP_PSIZE - 3)) {
                        if (!msn_ftps_write(file, buffer + len - overflow, MSNFTP_PSIZE - 3)) {
                                return FALSE;
                        }
                        overflow -= MSNFTP_PSIZE - 3;
                }
                return msn_ftps_write(file, buffer + len - overflow, overflow);
        }

        if (msn_file->data_sent == file->file_size) {
                if (msn_file->w_event_id) {
                        b_event_remove(msn_file->w_event_id);
                        msn_file->w_event_id = 0;
                }
        } else {
                /* we might already be listening if this is data from an overflow */
                if (!msn_file->w_event_id) {
                        msn_file->w_event_id = b_input_add(msn_file->fd, B_EV_IO_WRITE, msn_ftp_send, file);
                }
        }

        return TRUE;
}

/* Binary part of the file transfer protocol */
gboolean msn_ftpr_read(file_transfer_t *file)
{
        msn_filetransfer_t *msn_file = file->data;
        int st;
        unsigned char buf[3];

        if (msn_file->data_remaining) {
                msn_file->r_event_id = 0;

                ASSERTSOCKOP(st = read(msn_file->fd, file->buffer, MIN(sizeof(file->buffer),
                                                                       msn_file->data_remaining)), "Receiving");

                if (st == 0) {
                        return msn_ftp_abort(file, "Remote end closed connection");
                }

                msn_file->data_sent += st;

                msn_file->data_remaining -= st;

                file->write(file, file->buffer, st);

                if (msn_file->data_sent >= file->file_size) {
                        imcb_file_finished(file);
                }

                return FALSE;
        } else {
                ASSERTSOCKOP(st = read(msn_file->fd, buf, 1), "Receiving");
                if (st == 0) {
                        return msn_ftp_abort(file, "read returned EOF while reading data header from msn client");
                } else if (buf[0] == '\r' || buf[0] == '\n') {
                        debug("Discarding extraneous newline");
                } else if (buf[0] != 0) {
                        msn_ftp_abort(file, "Remote end canceled the transfer");
                        /* don't really care about these last 2 (should be 0,0) */
                        read(msn_file->fd, buf, 2);
                        return FALSE;
                } else {
                        unsigned int size;
                        ASSERTSOCKOP(st = read(msn_file->fd, buf, 2), "Receiving");
                        if (st < 2) {
                                return msn_ftp_abort(file,
                                                     "read returned EOF while reading data header from msn client");
                        }

                        size = buf[0] + ((unsigned int) buf[1] << 8);
                        msn_file->data_remaining = size;
                }
        }
        return TRUE;
}

/* Text mode part of the file transfer protocol */
gboolean msn_ftp_txtproto(file_transfer_t *file)
{
        msn_filetransfer_t *msn_file = file->data;
        int i = msn_file->tbufpos, st;
        char *tbuf = msn_file->tbuf;

        ASSERTSOCKOP(st = read(msn_file->fd,
                               tbuf + msn_file->tbufpos,
                               sizeof(msn_file->tbuf) - msn_file->tbufpos),
                     "Receiving");

        if (st == 0) {
                return msn_ftp_abort(file, "read returned EOF while reading text from msn client");
        }

        msn_file->tbufpos += st;

        do {
                for (; i < msn_file->tbufpos; i++) {
                        if (tbuf[i] == '\n' || tbuf[i] == '\r') {
                                tbuf[i] = '\0';
                                if (i > 0) {
                                        msn_ftp_handle_command(file, tbuf);
                                } else {
                                        while (tbuf[i] == '\n' || tbuf[i] == '\r') {
                                                i++;
                                        }
                                }
                                memmove(tbuf, tbuf + i + 1, msn_file->tbufpos - i - 1);
                                msn_file->tbufpos -= i + 1;
                                i = 0;
                                break;
                        }
                }
        } while (i < msn_file->tbufpos);

        if (msn_file->tbufpos == sizeof(msn_file->tbuf)) {
                return msn_ftp_abort(file,
                                     "Line exceeded %d bytes in text protocol",
                                     sizeof(msn_file->tbuf));
        }
        return TRUE;
}

gboolean msn_ftp_read(gpointer data, gint fd, b_input_condition cond)
{
        file_transfer_t *file = data;
        msn_filetransfer_t *msn_file = file->data;

        if (msn_file->status & MSN_TRANSFER_RECEIVING) {
                return msn_ftpr_read(file);
        } else {
                return msn_ftp_txtproto(file);
        }
}

void msn_ftp_free(file_transfer_t *file)
{
        msn_filetransfer_t *msn_file = file->data;

        if (msn_file->r_event_id) {
                b_event_remove(msn_file->r_event_id);
        }

        if (msn_file->w_event_id) {
                b_event_remove(msn_file->w_event_id);
        }

        if (msn_file->fd != -1) {
                closesocket(msn_file->fd);
        }

        msn_file->md->filetransfers = g_slist_remove(msn_file->md->filetransfers, msn_file->dcc);

        g_free(msn_file->handle);

        g_free(msn_file);
}

void msn_ftpr_accept(file_transfer_t *file)
{
        msn_filetransfer_t *msn_file = file->data;

        msn_ftp_invitation_cmd(msn_file->md->ic, msn_file->handle, msn_file->invite_cookie, "ACCEPT",
                               "Launch-Application: FALSE\r\n"
                               "Request-Data: IP-Address:\r\n");
}

void msn_ftp_finished(file_transfer_t *file)
{
        msn_ftp_write(file, "BYE 16777989\r\n");
}

void msn_ftp_canceled(file_transfer_t *file, char *reason)
{
        msn_filetransfer_t *msn_file = file->data;

        msn_ftp_cancel_invite(msn_file->md->ic, msn_file->handle,
                              msn_file->invite_cookie,
                              file->status & FT_STATUS_TRANSFERRING ?
                              "FTTIMEOUT" :
                              "FAIL");

        imcb_log(msn_file->md->ic, "File transfer aborted: %s", reason);
}

gboolean msn_ftpr_write_request(file_transfer_t *file)
{
        msn_filetransfer_t *msn_file = file->data;

        if (msn_file->r_event_id != 0) {
                msn_ftp_abort(file,
                              "BUG in MSN file transfer:"
                              "write_request called when"
                              "already watching for input");
                return FALSE;
        }

        msn_file->r_event_id =
                b_input_add(msn_file->fd, B_EV_IO_READ, msn_ftp_read, file);

        return TRUE;
}