/*
 * This file Copyright (C) Mnemosyne LLC
 *
 * This file is licensed by the GPL version 2. Works owned by the
 * Transmission project are granted a special exemption to clause 2 (b)
 * so that the bulk of its code can remain under the MIT license.
 * This exemption does not extend to derived works not owned by
 * the Transmission project.
 *
 * $Id$
 */

#include <assert.h>
#include <errno.h>
#include <string.h> /* memcpy */
#include <limits.h> /* INT_MAX */

#include <unistd.h>    /* close */

#ifdef HAVE_ZLIB
 #include <zlib.h>
#endif

#include <event2/buffer.h>
#include <event2/event.h>
#include <event2/http.h>
#include <event2/http_struct.h> /* TODO: eventually remove this */

#include "transmission.h"
#include "crypto.h" /* tr_cryptoRandBuf (), tr_ssha1_matches () */
#include "fdlimit.h"
#include "list.h"
#include "net.h"
#include "platform.h" /* tr_getWebClientDir () */
#include "ptrarray.h"
#include "rpcimpl.h"
#include "rpc-server.h"
#include "session.h"
#include "trevent.h"
#include "utils.h"
#include "variant.h"
#include "web.h"

/* session-id is used to make cross-site request forgery attacks difficult.
 * Don't disable this feature unless you really know what you're doing!
 * http://en.wikipedia.org/wiki/Cross-site_request_forgery
 * http://shiflett.org/articles/cross-site-request-forgeries
 * http://www.webappsec.org/lists/websecurity/archive/2008-04/msg00037.html */
#define REQUIRE_SESSION_ID

#define MY_NAME "RPC Server"
#define MY_REALM "Transmission"
#define TR_N_ELEMENTS(ary) (sizeof (ary) / sizeof (*ary))

struct tr_rpc_server
{
    bool               isEnabled;
    bool               isPasswordEnabled;
    bool               isWhitelistEnabled;
    tr_port            port;
    char *             url;
    struct in_addr     bindAddress;
    struct evhttp *    httpd;
    tr_session *       session;
    char *             username;
    char *             password;
    char *             whitelistStr;
    tr_list *          whitelist;

    char *             sessionId;
    time_t             sessionIdExpiresAt;

#ifdef HAVE_ZLIB
    bool               isStreamInitialized;
    z_stream           stream;
#endif
};

#define dbgmsg(...) \
    do { \
        if (tr_deepLoggingIsActive ()) \
            tr_deepLog (__FILE__, __LINE__, MY_NAME, __VA_ARGS__); \
    } while (0)


/***
****
***/

static char*
get_current_session_id (struct tr_rpc_server * server)
{
    const time_t now = tr_time ();

    if (!server->sessionId || (now >= server->sessionIdExpiresAt))
    {
        int i;
        const int n = 48;
        const char * pool = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
        const size_t pool_size = strlen (pool);
        unsigned char * buf = tr_new (unsigned char, n+1);

        tr_cryptoRandBuf (buf, n);
        for (i=0; i<n; ++i)
            buf[i] = pool[ buf[i] % pool_size ];
        buf[n] = '\0';

        tr_free (server->sessionId);
        server->sessionId = (char*) buf;
        server->sessionIdExpiresAt = now + (60*60); /* expire in an hour */
    }

    return server->sessionId;
}


/**
***
**/

static void
send_simple_response (struct evhttp_request * req,
                      int                     code,
                      const char *            text)
{
    const char *      code_text = tr_webGetResponseStr (code);
    struct evbuffer * body = evbuffer_new ();

    evbuffer_add_printf (body, "<h1>%d: %s</h1>", code, code_text);
    if (text)
        evbuffer_add_printf (body, "%s", text);
    evhttp_send_reply (req, code, code_text, body);

    evbuffer_free (body);
}

struct tr_mimepart
{
    char * headers;
    int headers_len;
    char * body;
    int body_len;
};

static void
tr_mimepart_free (struct tr_mimepart * p)
{
    tr_free (p->body);
    tr_free (p->headers);
    tr_free (p);
}

static void
extract_parts_from_multipart (const struct evkeyvalq * headers,
                              struct evbuffer * body,
                              tr_ptrArray * setme_parts)
{
    const char * content_type = evhttp_find_header (headers, "Content-Type");
    const char * in = (const char*) evbuffer_pullup (body, -1);
    size_t inlen = evbuffer_get_length (body);

    const char * boundary_key = "boundary=";
    const char * boundary_key_begin = content_type ? strstr (content_type, boundary_key) : NULL;
    const char * boundary_val = boundary_key_begin ? boundary_key_begin + strlen (boundary_key) : "arglebargle";
    char * boundary = tr_strdup_printf ("--%s", boundary_val);
    const size_t boundary_len = strlen (boundary);

    const char * delim = tr_memmem (in, inlen, boundary, boundary_len);
    while (delim)
    {
        size_t part_len;
        const char * part = delim + boundary_len;

        inlen -= (part - in);
        in = part;

        delim = tr_memmem (in, inlen, boundary, boundary_len);
        part_len = delim ? (size_t)(delim - part) : inlen;

        if (part_len)
        {
            const char * rnrn = tr_memmem (part, part_len, "\r\n\r\n", 4);
            if (rnrn)
            {
                struct tr_mimepart * p = tr_new (struct tr_mimepart, 1);
                p->headers_len = rnrn - part;
                p->headers = tr_strndup (part, p->headers_len);
                p->body_len = (part+part_len) - (rnrn + 4);
                p->body = tr_strndup (rnrn+4, p->body_len);
                tr_ptrArrayAppend (setme_parts, p);
            }
        }
    }

    tr_free (boundary);
}

static void
handle_upload (struct evhttp_request * req,
               struct tr_rpc_server *  server)
{
    if (req->type != EVHTTP_REQ_POST)
    {
        send_simple_response (req, 405, NULL);
    }
    else
    {
        int i;
        int n;
        bool hasSessionId = false;
        tr_ptrArray parts = TR_PTR_ARRAY_INIT;

        const char * query = strchr (req->uri, '?');
        const bool paused = query && strstr (query + 1, "paused=true");

        extract_parts_from_multipart (req->input_headers, req->input_buffer, &parts);
        n = tr_ptrArraySize (&parts);

        /* first look for the session id */
        for (i=0; i<n; ++i) {
            struct tr_mimepart * p = tr_ptrArrayNth (&parts, i);
            if (tr_memmem (p->headers, p->headers_len, TR_RPC_SESSION_ID_HEADER, strlen (TR_RPC_SESSION_ID_HEADER)))
                break;
        }
        if (i<n) {
            const struct tr_mimepart * p = tr_ptrArrayNth (&parts, i);
            const char * ours = get_current_session_id (server);
            const int ourlen = strlen (ours);
            hasSessionId = ourlen<=p->body_len && !memcmp (p->body, ours, ourlen);
        }

        if (!hasSessionId)
        {
            int code = 409;
            const char * codetext = tr_webGetResponseStr (code);
            struct evbuffer * body = evbuffer_new ();
            evbuffer_add_printf (body, "%s", "{ \"success\": false, \"msg\": \"Bad Session-Id\" }");;
            evhttp_send_reply (req, code, codetext, body);
            evbuffer_free (body);
        }
        else for (i=0; i<n; ++i)
        {
            struct tr_mimepart * p = tr_ptrArrayNth (&parts, i);
            int body_len = p->body_len;
            tr_variant top, *args;
            tr_variant test;
            bool have_source = false;
            char * body = p->body;

            if (body_len >= 2 && !memcmp (&body[body_len - 2], "\r\n", 2))
                body_len -= 2;

            tr_variantInitDict (&top, 2);
            tr_variantDictAddStr (&top, TR_KEY_method, "torrent-add");
            args = tr_variantDictAddDict (&top, TR_KEY_arguments, 2);
            tr_variantDictAddBool (args, TR_KEY_paused, paused);

            if (tr_urlIsValid (body, body_len))
            {
                tr_variantDictAddRaw (args, TR_KEY_filename, body, body_len);
                have_source = true;
            }
            else if (!tr_variantFromBenc (&test, body, body_len))
            {
                char * b64 = tr_base64_encode (body, body_len, NULL);
                tr_variantDictAddStr (args, TR_KEY_metainfo, b64);
                tr_free (b64);
                have_source = true;
            }

            if (have_source)
            {
                struct evbuffer * json = tr_variantToBuf (&top, TR_VARIANT_FMT_JSON);
                tr_rpc_request_exec_json (server->session,
                                          evbuffer_pullup (json, -1),
                                          evbuffer_get_length (json),
                                          NULL, NULL);
                evbuffer_free (json);
            }

            tr_variantFree (&top);
        }

        tr_ptrArrayDestruct (&parts, (PtrArrayForeachFunc)tr_mimepart_free);

        /* send "success" response */
        {
            int code = HTTP_OK;
            const char * codetext = tr_webGetResponseStr (code);
            struct evbuffer * body = evbuffer_new ();
            evbuffer_add_printf (body, "%s", "{ \"success\": true, \"msg\": \"Torrent Added\" }");;
            evhttp_send_reply (req, code, codetext, body);
            evbuffer_free (body);
        }
    }
}

static const char*
mimetype_guess (const char * path)
{
    unsigned int i;

    const struct
    {
        const char *    suffix;
        const char *    mime_type;
    } types[] = {
        /* these are the ones we need for serving the web client's files... */
        { "css",  "text/css"                  },
        { "gif",  "image/gif"                 },
        { "html", "text/html"                 },
        { "ico",  "image/vnd.microsoft.icon"  },
        { "js",   "application/javascript"    },
        { "png",  "image/png"                 }
    };
    const char * dot = strrchr (path, '.');

    for (i = 0; dot && i < TR_N_ELEMENTS (types); ++i)
        if (!strcmp (dot + 1, types[i].suffix))
            return types[i].mime_type;

    return "application/octet-stream";
}

static void
add_response (struct evhttp_request * req, struct tr_rpc_server * server,
              struct evbuffer * out, struct evbuffer * content)
{
#ifndef HAVE_ZLIB
    evbuffer_add_buffer (out, content);
#else
    const char * key = "Accept-Encoding";
    const char * encoding = evhttp_find_header (req->input_headers, key);
    const int do_compress = encoding && strstr (encoding, "gzip");

    if (!do_compress)
    {
        evbuffer_add_buffer (out, content);
    }
    else
    {
        int state;
        struct evbuffer_iovec iovec[1];
        void * content_ptr = evbuffer_pullup (content, -1);
        const size_t content_len = evbuffer_get_length (content);

        if (!server->isStreamInitialized)
        {
            int compressionLevel;

            server->isStreamInitialized = true;
            server->stream.zalloc = (alloc_func) Z_NULL;
            server->stream.zfree = (free_func) Z_NULL;
            server->stream.opaque = (voidpf) Z_NULL;

            /* zlib's manual says: "Add 16 to windowBits to write a simple gzip header
             * and trailer around the compressed data instead of a zlib wrapper." */
#ifdef TR_LIGHTWEIGHT
            compressionLevel = Z_DEFAULT_COMPRESSION;
#else
            compressionLevel = Z_BEST_COMPRESSION;
#endif
            deflateInit2 (&server->stream, compressionLevel, Z_DEFLATED, 15+16, 8, Z_DEFAULT_STRATEGY);
        }

        server->stream.next_in = content_ptr;
        server->stream.avail_in = content_len;

        /* allocate space for the raw data and call deflate () just once --
         * we won't use the deflated data if it's longer than the raw data,
         * so it's okay to let deflate () run out of output buffer space */
        evbuffer_reserve_space (out, content_len, iovec, 1);
        server->stream.next_out = iovec[0].iov_base;
        server->stream.avail_out = iovec[0].iov_len;
        state = deflate (&server->stream, Z_FINISH);

        if (state == Z_STREAM_END)
        {
            iovec[0].iov_len -= server->stream.avail_out;

#if 0
            fprintf (stderr, "compressed response is %.2f of original (raw==%zu bytes; compressed==%zu)\n",
                           (double)evbuffer_get_length (out)/content_len,
                             content_len, evbuffer_get_length (out));
#endif
            evhttp_add_header (req->output_headers,
                               "Content-Encoding", "gzip");
        }
        else
        {
            memcpy (iovec[0].iov_base, content_ptr, content_len);
            iovec[0].iov_len = content_len;
        }

        evbuffer_commit_space (out, iovec, 1);
        deflateReset (&server->stream);
    }
#endif
}

static void
add_time_header (struct evkeyvalq * headers, const char * key, time_t value)
{
    /* According to RFC 2616 this must follow RFC 1123's date format,
       so use gmtime instead of localtime... */
    char buf[128];
    struct tm tm = *gmtime (&value);
    strftime (buf, sizeof (buf), "%a, %d %b %Y %H:%M:%S GMT", &tm);
    evhttp_add_header (headers, key, buf);
}

static void
evbuffer_ref_cleanup_tr_free (const void * data UNUSED, size_t datalen UNUSED, void * extra)
{
    tr_free (extra);
}

static void
serve_file (struct evhttp_request * req,
            struct tr_rpc_server *  server,
            const char *            filename)
{
    if (req->type != EVHTTP_REQ_GET)
    {
        evhttp_add_header (req->output_headers, "Allow", "GET");
        send_simple_response (req, 405, NULL);
    }
    else
    {
        void * file;
        size_t file_len;
        struct evbuffer * content;
        const int error = errno;

        errno = 0;
        file_len = 0;
        file = tr_loadFile (filename, &file_len);
        content = evbuffer_new ();
        evbuffer_add_reference (content, file, file_len, evbuffer_ref_cleanup_tr_free, file);

        if (errno)
        {
            char * tmp = tr_strdup_printf ("%s (%s)", filename, tr_strerror (errno));
            send_simple_response (req, HTTP_NOTFOUND, tmp);
            tr_free (tmp);
        }
        else
        {
            struct evbuffer * out;
            const time_t now = tr_time ();

            errno = error;
            out = evbuffer_new ();
            evhttp_add_header (req->output_headers, "Content-Type", mimetype_guess (filename));
            add_time_header (req->output_headers, "Date", now);
            add_time_header (req->output_headers, "Expires", now+ (24*60*60));
            add_response (req, server, out, content);
            evhttp_send_reply (req, HTTP_OK, "OK", out);

            evbuffer_free (out);
        }

        evbuffer_free (content);
    }
}

static void
handle_web_client (struct evhttp_request * req,
                   struct tr_rpc_server *  server)
{
    const char * webClientDir = tr_getWebClientDir (server->session);

    if (!webClientDir || !*webClientDir)
    {
        send_simple_response (req, HTTP_NOTFOUND,
            "<p>Couldn't find Transmission's web interface files!</p>"
            "<p>Users: to tell Transmission where to look, "
            "set the TRANSMISSION_WEB_HOME environment "
            "variable to the folder where the web interface's "
            "index.html is located.</p>"
            "<p>Package Builders: to set a custom default at compile time, "
            "#define PACKAGE_DATA_DIR in libtransmission/platform.c "
            "or tweak tr_getClutchDir () by hand.</p>");
    }
    else
    {
        char * pch;
        char * subpath;

        subpath = tr_strdup (req->uri + strlen (server->url) + 4);
        if ((pch = strchr (subpath, '?')))
            *pch = '\0';

        if (strstr (subpath, ".."))
        {
            send_simple_response (req, HTTP_NOTFOUND, "<p>Tsk, tsk.</p>");
        }
        else
        {
            char * filename = tr_strdup_printf ("%s%s%s",
                                 webClientDir,
                                 TR_PATH_DELIMITER_STR,
                                 subpath && *subpath ? subpath : "index.html");
            serve_file (req, server, filename);
            tr_free (filename);
        }

        tr_free (subpath);
    }
}

struct rpc_response_data
{
    struct evhttp_request * req;
    struct tr_rpc_server  * server;
};

static void
rpc_response_func (tr_session      * session UNUSED,
                   struct evbuffer * response,
                   void            * user_data)
{
    struct rpc_response_data * data = user_data;
    struct evbuffer * buf = evbuffer_new ();

    add_response (data->req, data->server, buf, response);
    evhttp_add_header (data->req->output_headers,
                           "Content-Type", "application/json; charset=UTF-8");
    evhttp_send_reply (data->req, HTTP_OK, "OK", buf);

    evbuffer_free (buf);
    tr_free (data);
}


static void
handle_rpc (struct evhttp_request * req,
            struct tr_rpc_server  * server)
{
    struct rpc_response_data * data = tr_new0 (struct rpc_response_data, 1);

    data->req = req;
    data->server = server;

    if (req->type == EVHTTP_REQ_GET)
    {
        const char * q;
        if ((q = strchr (req->uri, '?')))
            tr_rpc_request_exec_uri (server->session, q+1, -1, rpc_response_func, data);
    }
    else if (req->type == EVHTTP_REQ_POST)
    {
        tr_rpc_request_exec_json (server->session,
                                  evbuffer_pullup (req->input_buffer, -1),
                                  evbuffer_get_length (req->input_buffer),
                                  rpc_response_func, data);
    }

}

static bool
isAddressAllowed (const tr_rpc_server * server,
                  const char *          address)
{
    tr_list * l;

    if (!server->isWhitelistEnabled)
        return true;

    for (l=server->whitelist; l!=NULL; l=l->next)
        if (tr_wildmat (address, l->data))
            return true;

    return false;
}

static bool
test_session_id (struct tr_rpc_server * server, struct evhttp_request * req)
{
    const char * ours = get_current_session_id (server);
    const char * theirs = evhttp_find_header (req->input_headers, TR_RPC_SESSION_ID_HEADER);
    const bool success =  theirs && !strcmp (theirs, ours);
    return success;
}

static void
handle_request (struct evhttp_request * req, void * arg)
{
    struct tr_rpc_server * server = arg;

    if (req && req->evcon)
    {
        const char * auth;
        char * user = NULL;
        char * pass = NULL;

        evhttp_add_header (req->output_headers, "Server", MY_REALM);

        auth = evhttp_find_header (req->input_headers, "Authorization");
        if (auth && !evutil_ascii_strncasecmp (auth, "basic ", 6))
        {
            int    plen;
            char * p = tr_base64_decode (auth + 6, 0, &plen);
            if (p && plen && ((pass = strchr (p, ':'))))
            {
                user = p;
                *pass++ = '\0';
            }
        }

        if (!isAddressAllowed (server, req->remote_host))
        {
            send_simple_response (req, 403,
                "<p>Unauthorized IP Address.</p>"
                "<p>Either disable the IP address whitelist or add your address to it.</p>"
                "<p>If you're editing settings.json, see the 'rpc-whitelist' and 'rpc-whitelist-enabled' entries.</p>"
                "<p>If you're still using ACLs, use a whitelist instead. See the transmission-daemon manpage for details.</p>");
        }
        else if (server->isPasswordEnabled
                 && (!pass || !user || strcmp (server->username, user)
                                     || !tr_ssha1_matches (server->password,
                                                           pass)))
        {
            evhttp_add_header (req->output_headers,
                               "WWW-Authenticate",
                               "Basic realm=\"" MY_REALM "\"");
            send_simple_response (req, 401, "Unauthorized User");
        }
        else if (strncmp (req->uri, server->url, strlen (server->url)))
        {
            char * location = tr_strdup_printf ("%sweb/", server->url);
            evhttp_add_header (req->output_headers, "Location", location);
            send_simple_response (req, HTTP_MOVEPERM, NULL);
            tr_free (location);
        }
        else if (!strncmp (req->uri + strlen (server->url), "web/", 4))
        {
            handle_web_client (req, server);
        }
        else if (!strncmp (req->uri + strlen (server->url), "upload", 6))
        {
            handle_upload (req, server);
        }
#ifdef REQUIRE_SESSION_ID
        else if (!test_session_id (server, req))
        {
            const char * sessionId = get_current_session_id (server);
            char * tmp = tr_strdup_printf (
                "<p>Your request had an invalid session-id header.</p>"
                "<p>To fix this, follow these steps:"
                "<ol><li> When reading a response, get its X-Transmission-Session-Id header and remember it"
                "<li> Add the updated header to your outgoing requests"
                "<li> When you get this 409 error message, resend your request with the updated header"
                "</ol></p>"
                "<p>This requirement has been added to help prevent "
                "<a href=\"http://en.wikipedia.org/wiki/Cross-site_request_forgery\">CSRF</a> "
                "attacks.</p>"
                "<p><code>%s: %s</code></p>",
                TR_RPC_SESSION_ID_HEADER, sessionId);
            evhttp_add_header (req->output_headers, TR_RPC_SESSION_ID_HEADER, sessionId);
            send_simple_response (req, 409, tmp);
            tr_free (tmp);
        }
#endif
        else if (!strncmp (req->uri + strlen (server->url), "rpc", 3))
        {
            handle_rpc (req, server);
        }
        else
        {
            send_simple_response (req, HTTP_NOTFOUND, req->uri);
        }

        tr_free (user);
    }
}

static void
startServer (void * vserver)
{
    tr_rpc_server * server  = vserver;
    tr_address addr;

    if (!server->httpd)
    {
        addr.type = TR_AF_INET;
        addr.addr.addr4 = server->bindAddress;
        server->httpd = evhttp_new (server->session->event_base);
        evhttp_bind_socket (server->httpd, tr_address_to_string (&addr), server->port);
        evhttp_set_gencb (server->httpd, handle_request, server);

    }
}

static void
stopServer (tr_rpc_server * server)
{
    if (server->httpd)
    {
        evhttp_free (server->httpd);
        server->httpd = NULL;
    }
}

static void
onEnabledChanged (void * vserver)
{
    tr_rpc_server * server = vserver;

    if (!server->isEnabled)
        stopServer (server);
    else
        startServer (server);
}

void
tr_rpcSetEnabled (tr_rpc_server * server,
                  bool            isEnabled)
{
    server->isEnabled = isEnabled;

    tr_runInEventThread (server->session, onEnabledChanged, server);
}

bool
tr_rpcIsEnabled (const tr_rpc_server * server)
{
    return server->isEnabled;
}

static void
restartServer (void * vserver)
{
    tr_rpc_server * server = vserver;

    if (server->isEnabled)
    {
        stopServer (server);
        startServer (server);
    }
}

void
tr_rpcSetPort (tr_rpc_server * server,
               tr_port         port)
{
    assert (server != NULL);

    if (server->port != port)
    {
        server->port = port;

        if (server->isEnabled)
            tr_runInEventThread (server->session, restartServer, server);
    }
}

tr_port
tr_rpcGetPort (const tr_rpc_server * server)
{
    return server->port;
}

void
tr_rpcSetUrl (tr_rpc_server * server, const char * url)
{
    char * tmp = server->url;
    server->url = tr_strdup (url);
    dbgmsg ("setting our URL to [%s]", server->url);
    tr_free (tmp);
}

const char*
tr_rpcGetUrl (const tr_rpc_server * server)
{
    return server->url ? server->url : "";
}

void
tr_rpcSetWhitelist (tr_rpc_server * server, const char * whitelistStr)
{
    void * tmp;
    const char * walk;

    /* keep the string */
    tmp = server->whitelistStr;
    server->whitelistStr = tr_strdup (whitelistStr);
    tr_free (tmp);

    /* clear out the old whitelist entries */
    while ((tmp = tr_list_pop_front (&server->whitelist)))
        tr_free (tmp);

    /* build the new whitelist entries */
    for (walk=whitelistStr; walk && *walk;) {
        const char * delimiters = " ,;";
        const size_t len = strcspn (walk, delimiters);
        char * token = tr_strndup (walk, len);
        tr_list_append (&server->whitelist, token);
        if (strcspn (token, "+-") < len)
            tr_ninf (MY_NAME, "Adding address to whitelist: %s (And it has a '+' or '-'!  Are you using an old ACL by mistake?)", token);
        else
            tr_ninf (MY_NAME, "Adding address to whitelist: %s", token);

        if (walk[len]=='\0')
            break;
        walk += len + 1;
    }
}

const char*
tr_rpcGetWhitelist (const tr_rpc_server * server)
{
    return server->whitelistStr ? server->whitelistStr : "";
}

void
tr_rpcSetWhitelistEnabled (tr_rpc_server  * server,
                           bool             isEnabled)
{
    server->isWhitelistEnabled = isEnabled != 0;
}

bool
tr_rpcGetWhitelistEnabled (const tr_rpc_server * server)
{
    return server->isWhitelistEnabled;
}

/****
*****  PASSWORD
****/

void
tr_rpcSetUsername (tr_rpc_server * server, const char * username)
{
    char * tmp = server->username;
    server->username = tr_strdup (username);
    dbgmsg ("setting our Username to [%s]", server->username);
    tr_free (tmp);
}

const char*
tr_rpcGetUsername (const tr_rpc_server * server)
{
    return server->username ? server->username : "";
}

void
tr_rpcSetPassword (tr_rpc_server * server,
                   const char *    password)
{
    tr_free (server->password);
    if (*password != '{')
        server->password = tr_ssha1 (password);
    else
        server->password = strdup (password);
    dbgmsg ("setting our Password to [%s]", server->password);
}

const char*
tr_rpcGetPassword (const tr_rpc_server * server)
{
    return server->password ? server->password : "" ;
}

void
tr_rpcSetPasswordEnabled (tr_rpc_server * server, bool isEnabled)
{
    server->isPasswordEnabled = isEnabled;
    dbgmsg ("setting 'password enabled' to %d", (int)isEnabled);
}

bool
tr_rpcIsPasswordEnabled (const tr_rpc_server * server)
{
    return server->isPasswordEnabled;
}

const char *
tr_rpcGetBindAddress (const tr_rpc_server * server)
{
    tr_address addr;
    addr.type = TR_AF_INET;
    addr.addr.addr4 = server->bindAddress;
    return tr_address_to_string (&addr);
}

/****
*****  LIFE CYCLE
****/

static void
closeServer (void * vserver)
{
    void * tmp;
    tr_rpc_server * s = vserver;

    stopServer (s);
    while ((tmp = tr_list_pop_front (&s->whitelist)))
        tr_free (tmp);
#ifdef HAVE_ZLIB
    if (s->isStreamInitialized)
        deflateEnd (&s->stream);
#endif
    tr_free (s->url);
    tr_free (s->sessionId);
    tr_free (s->whitelistStr);
    tr_free (s->username);
    tr_free (s->password);
    tr_free (s);
}

void
tr_rpcClose (tr_rpc_server ** ps)
{
    tr_runInEventThread ((*ps)->session, closeServer, *ps);
    *ps = NULL;
}

static void
missing_settings_key (const tr_quark q)
{
  const char * str = tr_quark_get_string (q, NULL);
  tr_nerr (MY_NAME, _("Couldn't find settings key \"%s\""), str);
} 

tr_rpc_server *
tr_rpcInit (tr_session  * session, tr_variant * settings)
{
    tr_rpc_server * s;
    bool boolVal;
    int64_t i;
    const char * str;
    tr_quark key;
    tr_address address;

    s = tr_new0 (tr_rpc_server, 1);
    s->session = session;

    key = TR_KEY_rpc_enabled;
    if (!tr_variantDictFindBool (settings, key, &boolVal))
        missing_settings_key (key);
    else
        s->isEnabled = boolVal;

    key = TR_KEY_rpc_port;
    if (!tr_variantDictFindInt (settings, key, &i))
        missing_settings_key (key);
    else
        s->port = i;

    key = TR_KEY_rpc_url;
    if (!tr_variantDictFindStr (settings, key, &str, NULL))
        missing_settings_key (key);
    else
        s->url = tr_strdup (str);

    key = TR_KEY_rpc_whitelist_enabled;
    if (!tr_variantDictFindBool (settings, key, &boolVal))
        missing_settings_key (key);
    else
        tr_rpcSetWhitelistEnabled (s, boolVal);

    key = TR_KEY_rpc_authentication_required;
    if (!tr_variantDictFindBool (settings, key, &boolVal))
        missing_settings_key (key);
    else
        tr_rpcSetPasswordEnabled (s, boolVal);

    key = TR_KEY_rpc_whitelist;
    if (!tr_variantDictFindStr (settings, key, &str, NULL) && str)
        missing_settings_key (key);
    else
        tr_rpcSetWhitelist (s, str);

    key = TR_KEY_rpc_username;
    if (!tr_variantDictFindStr (settings, key, &str, NULL))
        missing_settings_key (key);
    else
        tr_rpcSetUsername (s, str);

    key = TR_KEY_rpc_password;
    if (!tr_variantDictFindStr (settings, key, &str, NULL))
        missing_settings_key (key);
    else
        tr_rpcSetPassword (s, str);

    key = TR_KEY_rpc_bind_address;
    if (!tr_variantDictFindStr (settings, key, &str, NULL)) {
        missing_settings_key (key);
        address = tr_inaddr_any;
    } else if (!tr_address_from_string (&address, str)) {
        tr_nerr (MY_NAME, _("%s is not a valid address"), str);
        address = tr_inaddr_any;
    } else if (address.type != TR_AF_INET) {
        tr_nerr (MY_NAME, _("%s is not an IPv4 address. RPC listeners must be IPv4"), str);
        address = tr_inaddr_any;
    }
    s->bindAddress = address.addr.addr4;

    if (s->isEnabled)
    {
        tr_ninf (MY_NAME, _("Serving RPC and Web requests on port 127.0.0.1:%d%s"), (int) s->port, s->url);
        tr_runInEventThread (session, startServer, s);

        if (s->isWhitelistEnabled)
            tr_ninf (MY_NAME, "%s", _("Whitelist enabled"));

        if (s->isPasswordEnabled)
            tr_ninf (MY_NAME, "%s", _("Password required"));
    }

    return s;
}