int winscp_regular_request(char *request)
{
/*
* winscp uses one of two requests to terminate each command.
* we must determine which (if any) is terminating this request. fun!
*/
char *new_request=NULL;
int retval=0;
int retzero=1;
new_request=strend(request, WINSCP_EOF_REQ_ZERO);
if (NULL == new_request)
{
retzero=0;
new_request=strend(request, WINSCP_EOF_REQ_STATUS);
if (NULL == new_request)
{
new_request=strend(request, WINSCP_EOF_REQ_RETVAL);
if (NULL == new_request)
{
printf ("command wasn't terminated with %s, %s or %s\n",
WINSCP_EOF_REQ_RETVAL, WINSCP_EOF_REQ_ZERO, WINSCP_EOF_REQ_STATUS);
return(-1); /* bogus termination */
}
}
}
/*
* here is where we fool winscp clients into believing we are a real shell
*/
if ((exact_match(new_request, "echo \"$status\"")) ||
(exact_match(new_request, "echo \"$?\"")))
{
printf ("0\n");
fflush(stdout);
}
/*
* ignore unalias and unset commands
*/
else if ((NULL!=strbeg(new_request,"unset ")) ||
(NULL!=strbeg(new_request,"unalias ")))
retval=0;
else
{
retval=process_ssh_request(new_request);
if (retzero) /* ignore actual retval if winscp wants us to */
retval=0;
}
free(new_request);
return(retval);
}
eParserSymbol parse_get_symbol( char *pszString, uint32_t *new_offset )
{
uint32_t symIndex;
uint32_t offset = 0;
while ( isspace( pszString[offset] ) )
offset++;
if ( pszString[offset] == '\0' )
{
(*new_offset) = offset;
return SYM_END;
}
for ( symIndex = 0; ; symIndex++ )
{
if ( g_parseTable[symIndex].symbol == SYM_NOTFOUND )
{
(*new_offset) = offset;
return SYM_NOTFOUND;
}
if ( strbeg( pszString+offset, g_parseTable[symIndex].text ) == 0 )
{
offset += cgc_strlen( g_parseTable[symIndex].text );
(*new_offset) = offset;
return g_parseTable[symIndex].symbol;
}
}
(*new_offset) = offset;
return SYM_NOTFOUND;
}
enum irc_type
irc_get_type(char *msg)
{
unsigned int i;
for(i=0; ; i++) {
if(i>=IRC_MSG_LEN) return T_OTHER;
if(msg[i]=='\0') return T_OTHER;
if(msg[i]==' ') break;
}
i++;
if(strbeg(msg+i, "JOIN")) return T_JOIN;
if(strbeg(msg+i, "PRIVMSG")) {
if(msg[i+8]==conf.chan[0]) return T_CHAN;
return T_MSG;
}
return T_OTHER;
}
void
irc_loop(void)
{
char buf[IRC_MSG_LEN];
while(1) {
irc_read(buf);
if(strbeg(buf, "PING")) {
buf[1] = 'O';
irc_cmd(buf);
}
else
mod_handle(buf);
}
}
int winscp_transit_request(char *request)
{
char *new_request=NULL;
/*
* for scp -t and scp -f commands, winscp preceeds each
* command with a "begin-of-file" marker we need to
* provide, everything after that can be handled by
* winscp_regular_request.
*/
new_request=strbeg(request,WINSCP_BOF_REQ);
if (NULL == new_request)
{
return(-1); /* improper transit cmd */
}
printf ("%s\n",WINSCP_BOF); /* start transfer */
fflush(stdout);
return(winscp_regular_request(new_request));
}
int process_ssh_request(char *request)
{
char **av, **tmp_av, **tenv;
char *flat_request,*tmpstring, *tmprequest;
char bad_winscp3str[] = "test -x /usr/lib/sftp-server && exec /usr/lib/sftp-server test -x /usr/local/lib/sftp-server && exec /usr/local/lib/sftp-server exec sftp-server";
int retval;
int reqlen=strlen(request);
char **env = NULL;
debug(LOG_DEBUG, "processing request: \"%s\"\n", request);
tmprequest=strdup(request);
#ifdef WINSCP_COMPAT
bad_winscp3str[57]=10;
bad_winscp3str[127]=10;
if(strcmp(request,bad_winscp3str)==0)
{
/*
* switch out the command to use, winscp wont know the difference
*/
free(tmprequest);
tmprequest=strdup(PROG_SFTP_SERVER);
syslog(LOG_DEBUG, "winscp3 compat correcting to: \"[%s]\"\n", PROG_SFTP_SERVER);
}
#endif
#ifdef GFTP_COMPAT
/*
* gFTP compatibility hack
*/
if (NULL != (tmpstring=strbeg(request, "echo -n xsftp ; ")))
{
free(tmprequest);
tmprequest=strdup(tmpstring);
printf("xsftp");
fflush(stdout);
}
#endif
#ifdef RESTRICTIVE_FILENAMES
/*
* we flat out reject special chars
*/
if (!valid_chars(tmprequest))
{
debug(LOG_DEBUG, "rejected because of invalid chars (%s)", logstamp());
free(tmprequest);
return(-1);
}
#endif
#ifdef WINSCP_COMPAT
if (strbeg(tmprequest,PROG_CD))
{
char *destdir=(char *)malloc(reqlen);
if (destdir == NULL)
{
perror("malloc");
exit(EXIT_FAILURE);
}
/*
* well, now that scponly is a persistent shell
* i have to maintain a $PWD. damn.
* we're going to INSIST upon a double quote
* encapsulated new directory to change to.
*/
if ((tmprequest[(reqlen-1)]=='"') && (tmprequest[3]=='"'))
{
bzero(destdir,reqlen);
strncpy(destdir,&tmprequest[4],reqlen-5);
debug(LOG_INFO, "chdir: %s (%s)", tmprequest, logstamp());
retval=chdir(destdir);
free(destdir);
free(tmprequest);
return(retval);
}
syslog(LOG_ERR, "bogus chdir request: %s (%s)", tmprequest, logstamp());
free(tmprequest);
return(-1);
}
#endif
/*
* convert request string to an arg_vector
*/
av = build_arg_vector(tmprequest);
/*
* clean any path info from request and substitute our known pathnames
*/
av[0] = substitute_known_path(av[0]);
/*
* we only process wildcards for scp commands
*/
#ifdef ENABLE_WILDCARDS
#ifdef ENABLE_SCP2
if (exact_match(av[0],PROG_SCP))
av = expand_wildcards(av);
#endif
#endif
/*
* check for a compile time chdir configuration
*/
#ifdef ENABLE_DEFAULT_CHDIR
if (exact_match(av[0],PROG_SFTP_SERVER))
{
syslog(LOG_INFO, "changing initial directory to %s", DEFAULT_CHDIR);
chdir(DEFAULT_CHDIR);
}
#endif
flat_request = flatten_vector(av);
/*
* Use a temp arg vector since getopt will permute the command line arguments
* for anything that it does not know about. If all rsync options are well
* defined this isn't necessary.
*/
tmp_av = build_arg_vector(flat_request);
if(check_dangerous_args(tmp_av))
{
syslog(LOG_ERR, "requested command (%s) tried to use disallowed argument (%s))",
flat_request, logstamp());
exit(EXIT_FAILURE);
}
discard_vector(tmp_av);
if (valid_arg_vector(av))
{
/*
* Unison needs the HOME environment variable be set to the directory
* where the .unison directory resides.
*/
#ifdef USE_SAFE_ENVIRONMENT
safeenv[0] = NULL;
filter_allowed_env_vars();
tenv = safeenv;
if (debuglevel) {
while (NULL != *tenv) {
syslog(LOG_DEBUG, "Environment contains \"%s\"", *tenv++);
}
}
env = safeenv;
#endif
#ifdef UNISON_COMPAT
/* the HOME environment variable should have been set above, but I need to make sure
* that it's value as read from the environment is replaced with the actual value
* as it exists within the chroot, which is what the applications will expect to see.
*/
if (replace_env_entry("HOME",homedir) && (((strlen(homedir) + 6 ) > FILENAME_MAX) || !mysetenv("HOME",homedir)))
{
syslog(LOG_ERR, "could not set HOME environment variable (%s)", logstamp());
exit(EXIT_FAILURE);
}
debug(LOG_DEBUG, "set non-chrooted HOME environment variable to %s (%s)", homedir, logstamp());
#endif
syslog(LOG_INFO, "running: %s (%s)", flat_request, logstamp());
#ifdef WINSCP_COMPAT
if (winscp_mode)
{
int status=0;
if (fork() == 0)
retval=execve(av[0],av,env);
else
{
wait(&status);
fflush(stdout);
fflush(stderr);
discard_vector(av);
#ifdef USE_SAFE_ENVIRONMENT
discard_child_vectors(safeenv);
#endif
free(flat_request);
free(tmprequest);
return(WEXITSTATUS(status));
}
}
else
#endif
{
debug(LOG_DEBUG, "about to exec \"%s\" (%s)", av[0], logstamp());
retval=execve(av[0],av,env);
}
syslog(LOG_ERR, "failed: %s with error %s(%u) (%s)", flat_request, strerror(errno), errno, logstamp());
free(flat_request);
discard_vector(av);
#ifdef USE_SAFE_ENVIRONMENT
discard_child_vectors(safeenv);
#endif
#ifdef WINSCP_COMPAT
if (winscp_mode)
{
free(tmprequest);
return(-1);
}
else
#endif
exit(errno);
}
/*
* reaching this point in the code means the request isnt one of
* our accepted commands
*/
if (debuglevel)
{
if (exact_match(flat_request,tmprequest))
syslog (LOG_ERR, "denied request: %s [%s]", tmprequest, logstamp());
else
syslog (LOG_ERR, "denied request: %s (resolved to: %s) [%s]", tmprequest, flat_request, logstamp());
}
free(flat_request);
#ifdef WINSCP_COMPAT
if (winscp_mode)
{
printf ("command not permitted by scponly\n");
free(tmprequest);
return(-1);
}
else
#endif
exit(EXIT_FAILURE);
}
