source: vbox/trunk/src/VBox/RDP/client-1.8.3/ctrl.c@ 55121

/* -*- c-basic-offset: 8 -*-
   rdesktop: A Remote Desktop Protocol client.
   Master/Slave remote controlling
   Copyright 2013 Henrik Andersson <[email protected]> for Cendio AB

   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 3 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
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/
#include "rdesktop.h"
#include "ssl.h"

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <limits.h>
#include <unistd.h>

#define CTRL_LINEBUF_SIZE 1024
#define CTRL_RESULT_SIZE 32
#define RDESKTOP_CTRLSOCK_STORE "/.local/share/rdesktop/ctrl"

#define CTRL_HASH_FLAG_SEAMLESS  1

#define ERR_RESULT_OK 0x00
#define ERR_RESULT_NO_SUCH_COMMAND 0xffffffff

extern RD_BOOL g_seamless_rdp;
extern uint8 g_static_rdesktop_salt_16[];

static RD_BOOL _ctrl_is_slave;
static int ctrlsock;
static char ctrlsock_name[PATH_MAX];
static struct _ctrl_slave_t *_ctrl_slaves;

#define CMD_SEAMLESS_SPAWN "seamless.spawn"

typedef struct _ctrl_slave_t
{
        struct _ctrl_slave_t *prev, *next;
        int sock;
        char linebuf[CTRL_LINEBUF_SIZE];
} _ctrl_slave_t;


static void
_ctrl_slave_new(int sock)
{
        _ctrl_slave_t *it, *ns;

        /* initialize new slave list item */
        ns = (_ctrl_slave_t *) xmalloc(sizeof(_ctrl_slave_t));
        memset(ns, 0, sizeof(_ctrl_slave_t));
        ns->sock = sock;

        /* append new slave to end of list */
        it = _ctrl_slaves;

        /* find last element in list */
        while (it && it->next)
                it = it->next;

        /* if last found append new */
        if (it)
        {
                it->next = ns;
                ns->prev = it;
        }
        else
        {
                /* no elemnts in list, lets add first */
                _ctrl_slaves = ns;
        }
}

static void
_ctrl_slave_disconnect(int sock)
{
        _ctrl_slave_t *it;

        if (!_ctrl_slaves)
                return;

        it = _ctrl_slaves;

        /* find slave with sock */
        while (it->next && it->sock != sock)
                it = it->next;

        if (it->sock == sock)
        {
                /* shutdown socket */
                shutdown(sock, SHUT_RDWR);
                close(sock);

                /* remove item from list */
                if (it == _ctrl_slaves)
                {
                        if (it->next)
                                _ctrl_slaves = it->next;
                        else
                                _ctrl_slaves = NULL;
                }

                if (it->prev)
                {
                        (it->prev)->next = it->next;
                        if (it->next)
                                (it->next)->prev = it->prev;
                }
                else if (it->next)
                        (it->next)->prev = NULL;

                xfree(it);

        }
}

static void
_ctrl_command_result(_ctrl_slave_t * slave, int result)
{
        char buf[64] = { 0 };

        /* translate and send result code back to client */
        if (result == 0)
                send(slave->sock, "OK\n", 3, 0);
        else
        {
                snprintf(buf, 64, "ERROR %x\n", result);
                send(slave->sock, buf, strlen(buf), 0);
        }
}

static void
_ctrl_dispatch_command(_ctrl_slave_t * slave)
{
        char *p;
        char *cmd;
        unsigned int res;

        /* unescape linebuffer */
        cmd = utils_string_unescape(slave->linebuf);
        if (strncmp(cmd, CMD_SEAMLESS_SPAWN " ", strlen(CMD_SEAMLESS_SPAWN) + 1) == 0)
        {
                /* process seamless spawn request */
                p = strstr(cmd, "seamlessrdpshell.exe");
                if (p)
                        p += strlen("seamlessrdpshell.exe") + 1;
                else
                        p = cmd + strlen(CMD_SEAMLESS_SPAWN) + 1;

                res = ERR_RESULT_OK;

                if (seamless_send_spawn(p) == (unsigned int) -1)
                        res = 1;
        }
        else
        {
                res = ERR_RESULT_NO_SUCH_COMMAND;
        }
        xfree(cmd);

        _ctrl_command_result(slave, res);
}

static RD_BOOL
_ctrl_verify_unix_socket()
{
        int s, len;
        struct sockaddr_un saun;

        memset(&saun, 0, sizeof(struct sockaddr_un));

        if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
        {
                perror("Error creating ctrl client socket: socket()");
                exit(1);
        }

        saun.sun_family = AF_UNIX;
        strcpy(saun.sun_path, ctrlsock_name);
        len = sizeof(saun.sun_family) + strlen(saun.sun_path);

        /* test connection */
        if (connect(s, (struct sockaddr *) &saun, len) != 0)
                return False;

        shutdown(s, SHUT_RDWR);
        close(s);
        return True;
}


static void
_ctrl_create_hash(const char *user, const char *domain, const char *host, char *hash, size_t hsize)
{
        RDSSL_SHA1 sha1;
        uint8 out[20], delim;
        uint16 version;
        uint32 flags;

        /* version\0user\0domain\0host\0flags */
        flags = 0;
        delim = '\0';
        version = 0x0100;

        if (g_seamless_rdp)
                flags = CTRL_HASH_FLAG_SEAMLESS;

        rdssl_sha1_init(&sha1);
        rdssl_sha1_update(&sha1, (uint8 *) & version, sizeof(version));
        rdssl_sha1_update(&sha1, &delim, 1);

        if (user)
                rdssl_sha1_update(&sha1, (uint8 *) user, strlen(user));
        rdssl_sha1_update(&sha1, &delim, 1);

        if (domain)
                rdssl_sha1_update(&sha1, (uint8 *) domain, strlen(domain));
        rdssl_sha1_update(&sha1, &delim, 1);

        if (host)
                rdssl_sha1_update(&sha1, (uint8 *) host, strlen(host));
        rdssl_sha1_update(&sha1, &delim, 1);

        rdssl_sha1_update(&sha1, (uint8 *) & flags, sizeof(flags));
        rdssl_sha1_final(&sha1, out);

        sec_hash_to_string(hash, hsize, out, sizeof(out));
}


/** Initialize ctrl
    Ret values: <0 failure, 0 master, 1 client
 */
int
ctrl_init(const char *user, const char *domain, const char *host)
{
        struct stat st;
        struct sockaddr_un saun;
        char hash[41], path[PATH_MAX];
        char *home;

        /* check if ctrl already initialized */
        if (ctrlsock != 0 || _ctrl_is_slave)
                return 0;

        home = getenv("HOME");
        if (home == NULL)
        {
                return -1;
        }

        /* get uniq hash for ctrlsock name */
        _ctrl_create_hash(user, domain, host, hash, 41);
        snprintf(ctrlsock_name, PATH_MAX, "%s" RDESKTOP_CTRLSOCK_STORE "/%s.ctl", home, hash);
        ctrlsock_name[sizeof(ctrlsock_name) - 1] = '\0';

        /* make sure that ctrlsock store path exists */
        snprintf(path, PATH_MAX, "%s" RDESKTOP_CTRLSOCK_STORE, home);
        path[sizeof(path) - 1] = '\0';
        if (utils_mkdir_p(path, 0700) == -1)
        {
                perror(path);
                return -1;
        }

        /* check if ctrl socket already exist then this process becomes a client */
        if (stat(ctrlsock_name, &st) == 0)
        {
                /* verify that unix socket is not stale */
                if (_ctrl_verify_unix_socket() == True)
                {
                        _ctrl_is_slave = True;
                        return 1;
                }
                else
                {
                        unlink(ctrlsock_name);
                }
        }

        /* setup ctrl socket and start listening for connections */
        if ((ctrlsock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
        {
                perror("Error creating ctrl socket:");
                exit(1);
        }

        /* bind and start listening on server socket */
        memset(&saun, 0, sizeof(struct sockaddr_un));
        saun.sun_family = AF_UNIX;
        strncpy(saun.sun_path, ctrlsock_name, sizeof(saun.sun_path));
        if (bind(ctrlsock, (struct sockaddr *) &saun, sizeof(struct sockaddr_un)) < 0)
        {
                perror("Error binding ctrl socket:");
                exit(1);
        }

        if (listen(ctrlsock, 5) < 0)
        {
                perror("Error listening on socket:");
                exit(1);
        }

        /* add ctrl cleanup func to exit hooks */
        atexit(ctrl_cleanup);

        return 0;
}

void
ctrl_cleanup()
{
        if (ctrlsock)
        {
                close(ctrlsock);
                unlink(ctrlsock_name);
        }
}

RD_BOOL
ctrl_is_slave()
{
        return _ctrl_is_slave;
}


void
ctrl_add_fds(int *n, fd_set * rfds)
{
        _ctrl_slave_t *it;
        if (ctrlsock == 0)
                return;

        FD_SET(ctrlsock, rfds);
        *n = MAX(*n, ctrlsock);


        /* add connected slaves to fd set */
        it = _ctrl_slaves;
        while (it)
        {
                FD_SET(it->sock, rfds);
                *n = MAX(*n, it->sock);
                it = it->next;
        }
}

void
ctrl_check_fds(fd_set * rfds, fd_set * wfds)
{
        int ns, res, offs;
        struct sockaddr_un fsaun;
        socklen_t fromlen;
        _ctrl_slave_t *it;

        if (ctrlsock == 0)
                return;

        memset(&fsaun, 0, sizeof(struct sockaddr_un));

        /* check if we got any connections on server socket */
        if (FD_ISSET(ctrlsock, rfds))
        {
                FD_CLR(ctrlsock, rfds);
                fromlen = sizeof(fsaun);
                ns = accept(ctrlsock, (struct sockaddr *) &fsaun, &fromlen);
                if (ns < 0)
                {
                        perror("server: accept()");
                        exit(1);
                }

                _ctrl_slave_new(ns);
                return;
        }

        /* check if any of our slaves fds has data */
        it = _ctrl_slaves;
        while (it)
        {
                if (FD_ISSET(it->sock, rfds))
                {
                        offs = strlen(it->linebuf);
                        res = recv(it->sock, it->linebuf + offs, CTRL_LINEBUF_SIZE - offs, 0);
                        FD_CLR(it->sock, rfds);

                        /* linebuffer full let's disconnect slave */
                        if (it->linebuf[CTRL_LINEBUF_SIZE - 1] != '\0' &&
                            it->linebuf[CTRL_LINEBUF_SIZE - 1] != '\n')
                        {
                                _ctrl_slave_disconnect(it->sock);
                                break;
                        }

                        if (res > 0)
                        {
                                /* Check if we got full command line */
                                char *p;
                                if ((p = strchr(it->linebuf, '\n')) == NULL)
                                        continue;

                                /* iterate over string and check against escaped \n */
                                while (p)
                                {
                                        /* Check if newline is escaped */
                                        if (p > it->linebuf && *(p - 1) != '\\')
                                                break;
                                        p = strchr(p + 1, '\n');
                                }

                                /* If we havent found an nonescaped \n we need more data */
                                if (p == NULL)
                                        continue;

                                /* strip new linebuf and dispatch command */
                                *p = '\0';
                                _ctrl_dispatch_command(it);
                                memset(it->linebuf, 0, CTRL_LINEBUF_SIZE);
                        }
                        else
                        {
                                /* Peer disconnected or socket error */
                                _ctrl_slave_disconnect(it->sock);
                                break;
                        }
                }
                it = it->next;
        }
}

#if HAVE_ICONV
extern char g_codepage[16];
#endif

int
ctrl_send_command(const char *cmd, const char *arg)
{
        FILE *fp;
        struct sockaddr_un saun;
        int s, len, index, ret;
        char data[CTRL_LINEBUF_SIZE], tmp[CTRL_LINEBUF_SIZE];
        char result[CTRL_RESULT_SIZE], c, *escaped;

        escaped = NULL;

        if (!_ctrl_is_slave)
                return -1;

        if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
        {
                perror("Error creating ctrl client socket: socket()");
                exit(1);
        }

        memset(&saun, 0, sizeof(struct sockaddr_un));
        saun.sun_family = AF_UNIX;
        strcpy(saun.sun_path, ctrlsock_name);
        len = sizeof(saun.sun_family) + strlen(saun.sun_path);

        if (connect(s, (struct sockaddr *) &saun, len) < 0)
        {
                perror("Error connecting to ctrl socket: connect()");
                exit(1);
        }

        /* Bundle cmd and argument into string, convert to UTF-8 if needed */
        snprintf(data, CTRL_LINEBUF_SIZE, "%s %s", cmd, arg);
        ret = utils_locale_to_utf8(data, strlen(data), tmp, CTRL_LINEBUF_SIZE - 1);

        if (ret != 0)
                goto bail_out;

        /* escape the utf-8 string */
        escaped = utils_string_escape(tmp);
        if ((strlen(escaped) + 1) > CTRL_LINEBUF_SIZE - 1)
                goto bail_out;

        /* send escaped utf-8 command to master */
        send(s, escaped, strlen(escaped), 0);
        send(s, "\n", 1, 0);

        /* read result from master */
        fp = fdopen(s, "r");
        index = 0;
        while ((c = fgetc(fp)) != EOF && index < CTRL_RESULT_SIZE && c != '\n')
        {
                result[index] = c;
                index++;
        }
        result[index - 1] = '\0';

        if (strncmp(result, "ERROR ", 6) == 0)
        {
                if (sscanf(result, "ERROR %d", &ret) != 1)
                        ret = -1;
        }

      bail_out:
        xfree(escaped);
        shutdown(s, SHUT_RDWR);
        close(s);

        return ret;
}