proxy_ftp.c

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                                                   strerror(errno), NULL)));
    }

    /* record request_time for HTTP/1.1 age calculation */
    c->req_time = time(NULL);

    ctrl = ap_bcreate(p, B_RDWR | B_SOCKET);
    ap_bpushfd(ctrl, sock, sock);
/* shouldn't we implement telnet control options here? */

#ifdef CHARSET_EBCDIC
    ap_bsetflag(ctrl, B_ASCII2EBCDIC | B_EBCDIC2ASCII, 1);
#endif                          /* CHARSET_EBCDIC */

    /* possible results: */
    /* 120 Service ready in nnn minutes. */
    /* 220 Service ready for new user. */
    /* 421 Service not available, closing control connection. */
    ap_hard_timeout("proxy ftp", r);
    i = ftp_getrc_msg(ctrl, resp, sizeof resp);
    ap_log_error(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, r->server, "FTP: returned status %d", i);
    if (i == -1 || i == 421) {
        return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                      ap_proxyerror(r, HTTP_BAD_GATEWAY,
                                       "Error reading from remote server"));
    }
#if 0
    if (i == 120) {
        /*
         * RFC2068 states: 14.38 Retry-After
         * 
         * The Retry-After response-header field can be used with a 503 (Service
         * Unavailable) response to indicate how long the service is expected
         * to be unavailable to the requesting client. The value of this
         * field can be either an HTTP-date or an integer number of seconds
         * (in decimal) after the time of the response. Retry-After  =
         * "Retry-After" ":" ( HTTP-date | delta-seconds )
         */
/**INDENT** Error@756: Unbalanced parens */
        ap_set_header("Retry-After", ap_psprintf(p, "%u", 60 * wait_mins);
        return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                          ap_proxyerror(r, HTTP_SERVICE_UNAVAILABLE, resp));
    }
#endif
    if (i != 220) {
        return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                  ap_proxyerror(r, HTTP_BAD_GATEWAY, resp));
    }

    ap_log_error(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, r->server, "FTP: connected.");

    ap_bvputs(ctrl, "USER ", user, CRLF, NULL);
    ap_bflush(ctrl);            /* capture any errors */
    ap_log_error(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, r->server, "FTP: USER %s", user);

    /* possible results; 230, 331, 332, 421, 500, 501, 530 */
    /* states: 1 - error, 2 - success; 3 - send password, 4,5 fail */
    /* 230 User logged in, proceed. */
    /* 331 User name okay, need password. */
    /* 332 Need account for login. */
    /* 421 Service not available, closing control connection. */
    /* 500 Syntax error, command unrecognized. */
    /* (This may include errors such as command line too long.) */
    /* 501 Syntax error in parameters or arguments. */
    /* 530 Not logged in. */
    i = ftp_getrc(ctrl);
    ap_log_error(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, r->server, "FTP: returned status %d", i);
    if (i == -1 || i == 421) {
        return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                      ap_proxyerror(r, HTTP_BAD_GATEWAY,
                                       "Error reading from remote server"));
    }
    if (i == 530) {
        return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                      ftp_unauthorized(r, 1));
    }
    if (i != 230 && i != 331) {
        return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                      HTTP_BAD_GATEWAY);
    }

    if (i == 331) {             /* send password */
        if (password == NULL) {
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                          ftp_unauthorized(r, 0));
        }
        ap_bvputs(ctrl, "PASS ", password, CRLF, NULL);
        ap_bflush(ctrl);
        ap_log_error(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, r->server, "FTP: PASS %s", password);
        /* possible results 202, 230, 332, 421, 500, 501, 503, 530 */
        /* 230 User logged in, proceed. */
        /* 332 Need account for login. */
        /* 421 Service not available, closing control connection. */
        /* 500 Syntax error, command unrecognized. */
        /* 501 Syntax error in parameters or arguments. */
        /* 503 Bad sequence of commands. */
        /* 530 Not logged in. */
        i = ftp_getrc(ctrl);
        ap_log_error(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, r->server, "FTP: returned status %d", i);
        if (i == -1 || i == 421) {
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                          ap_proxyerror(r, HTTP_BAD_GATEWAY,
                                       "Error reading from remote server"));
        }
        if (i == 332) {
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                          ap_proxyerror(r, HTTP_UNAUTHORIZED,
                                                 "Need account for login"));
        }
        /* @@@ questionable -- we might as well return a 403 Forbidden here */
        if (i == 530)           /* log it: passwd guessing attempt? */
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                          ftp_unauthorized(r, 1));
        if (i != 230 && i != 202)
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                          HTTP_BAD_GATEWAY);
    }

    /*
     * Special handling for leading "%2f": this enforces a "cwd /" out of the
     * $HOME directory which was the starting point after login
     */
    if (strncasecmp(path, "%2f", 3) == 0) {
        path += 3;
        while (*path == '/')    /* skip leading '/' (after root %2f) */
            ++path;
        ap_bputs("CWD /" CRLF, ctrl);
        ap_bflush(ctrl);
        ap_log_error(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, r->server, "FTP: CWD /");

        /* possible results: 250, 421, 500, 501, 502, 530, 550 */
        /* 250 Requested file action okay, completed. */
        /* 421 Service not available, closing control connection. */
        /* 500 Syntax error, command unrecognized. */
        /* 501 Syntax error in parameters or arguments. */
        /* 502 Command not implemented. */
        /* 530 Not logged in. */
        /* 550 Requested action not taken. */
        i = ftp_getrc(ctrl);
        ap_log_error(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, r->server, "FTP: returned status %d", i);
        if (i == -1 || i == 421)
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                          ap_proxyerror(r, HTTP_BAD_GATEWAY,
                                       "Error reading from remote server"));
        else if (i == 550)
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                          HTTP_NOT_FOUND);
        else if (i != 250)
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                          HTTP_BAD_GATEWAY);
    }

/* set the directory (walk directory component by component):
 * this is what we must do if we don't know the OS type of the remote
 * machine
 */
    for (; (strp = strchr(path, '/')) != NULL; path = strp + 1) {
        char *slash = strp;

        *slash = '\0';

        /* Skip multiple '/' (or trailing '/') to avoid 500 errors */
        while (strp[1] == '/')
            ++strp;
        if (strp[1] == '\0')
            break;

        len = decodeenc(path);  /* Note! This decodes a %2f -> "/" */
        if (strchr(path, '/'))  /* were there any '/' characters? */
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                          ap_proxyerror(r, HTTP_BAD_REQUEST,
                       "Use of %2F is only allowed at the base directory"));

        ap_bvputs(ctrl, "CWD ", path, CRLF, NULL);
        ap_bflush(ctrl);
        ap_log_error(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, r->server, "FTP: CWD %s", path);
        *slash = '/';

/* responses: 250, 421, 500, 501, 502, 530, 550 */
        /* 250 Requested file action okay, completed. */
        /* 421 Service not available, closing control connection. */
        /* 500 Syntax error, command unrecognized. */
        /* 501 Syntax error in parameters or arguments. */
        /* 502 Command not implemented. */
        /* 530 Not logged in. */
        /* 550 Requested action not taken. */
        i = ftp_getrc(ctrl);
        ap_log_error(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, r->server, "FTP: returned status %d", i);
        if (i == -1 || i == 421)
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                          ap_proxyerror(r, HTTP_BAD_GATEWAY,
                                       "Error reading from remote server"));
        if (i == 550)
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                          HTTP_NOT_FOUND);
        if (i == 500 || i == 501)
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                          ap_proxyerror(r, HTTP_BAD_REQUEST,
                      "Syntax error in filename (reported by ftp server)"));
        if (i != 250)
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                          HTTP_BAD_GATEWAY);
    }

    if (parms != NULL && strncmp(parms, "type=", 5) == 0
        && ap_isalpha(parms[5])) {
        /*
         * "type=d" forces a dir listing. The other types (i|a|e) are
         * directly used for the ftp TYPE command
         */
        if (!(get_dirlisting = (parms[5] == 'd')))
            xfer_type = ap_toupper(parms[5]);

        /* Check valid types, rather than ignoring invalid types silently: */
        if (strchr("AEI", xfer_type) == NULL)
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                      ap_proxyerror(r, HTTP_BAD_REQUEST, ap_pstrcat(r->pool,
                       "ftp proxy supports only types 'a', 'i', or 'e': \"",
                                           parms, "\" is invalid.", NULL)));
    }
    else {
        /* make binary transfers the default */
        xfer_type = 'I';
    }

/* try to set up PASV data connection first */
    dsock = ap_psocket_ex(p, PF_INET, SOCK_STREAM, IPPROTO_TCP, 1);
    if (dsock == -1) {
        return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                ap_proxyerror(r, HTTP_INTERNAL_SERVER_ERROR,
                                      "proxy: error creating PASV socket"));
    }

#if !defined (TPF) && !defined(BEOS)
    if (conf->recv_buffer_size) {
        if (setsockopt(dsock, SOL_SOCKET, SO_RCVBUF,
                (const char *)&conf->recv_buffer_size, sizeof(int)) == -1) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
                          "setsockopt(SO_RCVBUF): Failed to set ProxyReceiveBufferSize, using default");
        }
    }
#endif

    ap_bputs("PASV" CRLF, ctrl);
    ap_bflush(ctrl);
    ap_log_error(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, r->server, "FTP: PASV command issued");
/* possible results: 227, 421, 500, 501, 502, 530 */
    /* 227 Entering Passive Mode (h1,h2,h3,h4,p1,p2). */
    /* 421 Service not available, closing control connection. */
    /* 500 Syntax error, command unrecognized. */
    /* 501 Syntax error in parameters or arguments. */
    /* 502 Command not implemented. */
    /* 530 Not logged in. */

    i = ap_bgets(pasv, sizeof(pasv), ctrl);
    if (i == -1 || i == 421) {
        return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                ap_proxyerror(r, HTTP_INTERNAL_SERVER_ERROR,
                               "proxy: PASV: control connection is toast"));
    }
    else {
        pasv[i - 1] = '\0';
        pstr = strtok(pasv, " ");       /* separate result code */
        if (pstr != NULL) {
            presult = atoi(pstr);
            if (*(pstr + strlen(pstr) + 1) == '=')
                pstr += strlen(pstr) + 2;
            else {
                pstr = strtok(NULL, "(");       /* separate address & port
                                                 * params */
                if (pstr != NULL)
                    pstr = strtok(NULL, ")");
            }
        }
        else
            presult = atoi(pasv);

        ap_log_error(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, r->server, "FTP: returned status %d", presult);

        if (presult == 227 && pstr != NULL && (sscanf(pstr,
                 "%d,%d,%d,%d,%d,%d", &h3, &h2, &h1, &h0, &p1, &p0) == 6)) {
            /* pardon the parens, but it makes gcc happy */
            paddr = (((((h3 << 8) + h2) << 8) + h1) << 8) + h0;
            pport = (p1 << 8) + p0;
            ap_log_error(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, r->server, "FTP: contacting host %d.%d.%d.%d:%d",
                         h3, h2, h1, h0, pport);
            data_addr.sin_family = AF_INET;
            data_addr.sin_addr.s_addr = htonl(paddr);
            data_addr.sin_port = htons(pport);
            i = ap_proxy_doconnect(dsock, &data_addr, r);

            if (i == -1) {
                return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                          ap_proxyerror(r, HTTP_BAD_GATEWAY,
                                                        ap_pstrcat(r->pool,
                                    "Could not connect to remote machine: ",
                                                   strerror(errno), NULL)));
            }
            pasvmode = 1;
        }
        else {
            ap_pclosesocket(p, dsock);  /* and try the regular way */
            dsock = -1;
        }
    }

    if (!pasvmode) {            /* set up data connection */
        clen = sizeof(struct sockaddr_in);
        if (getsockname(sock, (struct sockaddr *)&server, &clen) < 0) {
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                ap_proxyerror(r, HTTP_INTERNAL_SERVER_ERROR,
                                    "proxy: error getting socket address"));
        }

        dsock = ap_psocket_ex(p, PF_INET, SOCK_STREAM, IPPROTO_TCP, 1);
        if (dsock == -1) {
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                ap_proxyerror(r, HTTP_INTERNAL_SERVER_ERROR,
                                           "proxy: error creating socket"));
        }

        if (setsockopt(dsock, SOL_SOCKET, SO_REUSEADDR, (void *)&one,
                       sizeof(one)) == -1) {
#ifndef _OSD_POSIX              /* BS2000 has this option "always on" */
            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                ap_proxyerror(r, HTTP_INTERNAL_SERVER_ERROR,
                                  "proxy: error setting reuseaddr option"));
#endif                          /* _OSD_POSIX */
        }

        if (bind(dsock, (struct sockaddr *)&server,
                 sizeof(struct sockaddr_in)) == -1) {

            return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                ap_proxyerror(r, HTTP_INTERNAL_SERVER_ERROR,
             ap_psprintf(p, "proxy: error binding to ftp data socket %s:%d",
                         inet_ntoa(server.sin_addr), server.sin_port)));
        }
        listen(dsock, 2);       /* only need a short queue */
    }

/* set request; "path" holds last path component */
    len = decodeenc(path);
    if (strchr(path, '/'))      /* were there any '/' characters? */
        return ftp_cleanup_and_return(r, ctrl, data, sock, dsock,
                                      ap_proxyerror(r, HTTP_BAD_REQUEST,
                       "Use of %2F is only allowed at the base directory"));

    /* TM - if len == 0 then it must be a directory (you can't RETR nothing) */