X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=nfs3%2Frpc.c;h=8eeec3063d32f53bd20cc89228bc8cb9f0bc8b90;hb=c3245fe423dd5c3a68b4c1e90ba253e7fae3473e;hp=38a3c228aa5c2acdce2b21de02dbb4b923608266;hpb=2246171d841d34e6368e340a6b76b7ee9d9a1084;p=bluesky.git diff --git a/nfs3/rpc.c b/nfs3/rpc.c index 38a3c22..8eeec30 100644 --- a/nfs3/rpc.c +++ b/nfs3/rpc.c @@ -21,6 +21,16 @@ #include #include #include +#include + +#include "bluesky.h" +extern BlueSkyFS *fs; + +/* TCP port number to use for NFS protocol. (Should be 2049.) */ +#define NFS_SERVICE_PORT 2051 + +/* Maximum size of a single RPC message that we will accept (8 MB). */ +#define MAX_RPC_MSGSIZE (8 << 20) static void mount_program_3(struct svc_req *rqstp, register SVCXPRT *transp) @@ -90,10 +100,113 @@ mount_program_3(struct svc_req *rqstp, register SVCXPRT *transp) return; } +struct rpc_reply { + uint32_t xid; + uint32_t type; + uint32_t stat; + uint32_t verf_flavor; + uint32_t verf_len; + uint32_t accept_stat; +}; + +static void async_rpc_write(RPCConnection *rpc, + const char *buf, gsize len); + +struct rpc_fail_reply { + uint32_t xid; + uint32_t type; + uint32_t stat; + uint32_t verf_flavor; + uint32_t verf_len; + uint32_t accept_stat; +}; + static void -nfs_program_3(struct svc_req *rqstp, register SVCXPRT *transp) +async_rpc_send_failure(RPCRequest *req, enum accept_stat stat) { - union { + struct rpc_fail_reply header; + + fprintf(stderr, "Sending RPC failure status %d\n", stat); + + header.xid = htonl(req->xid); + header.type = htonl(1); /* REPLY */ + header.stat = htonl(MSG_ACCEPTED); + header.verf_flavor = 0; + header.verf_len = 0; + header.accept_stat = htonl(stat); + + uint32_t fragment = htonl(sizeof(header) | 0x80000000); + async_rpc_write(req->connection, (const char *)&fragment, sizeof(fragment)); + async_rpc_write(req->connection, (const char *)&header, sizeof(header)); + g_io_channel_flush(req->connection->channel, NULL); + + if (req->args != NULL) { + char buf[4]; + XDR xdr; + xdrmem_create(&xdr, buf, sizeof(buf), XDR_FREE); + if (!req->xdr_args_free(&xdr, req->args)) { + fprintf(stderr, "unable to free arguments"); + } + } + + if (req->raw_args != NULL) + g_string_free(req->raw_args, TRUE); + + g_free(req); +} + +void +async_rpc_send_reply(RPCRequest *req, void *result) +{ + static char reply_buf[MAX_RPC_MSGSIZE]; + XDR xdr_out; + xdrmem_create(&xdr_out, reply_buf, MAX_RPC_MSGSIZE, XDR_ENCODE); + if (result != NULL && !req->xdr_result(&xdr_out, result)) { + async_rpc_send_failure(req, SYSTEM_ERR); + return; + } + + struct rpc_reply header; + header.xid = htonl(req->xid); + header.type = htonl(1); /* REPLY */ + header.stat = htonl(MSG_ACCEPTED); + header.verf_flavor = 0; + header.verf_len = 0; + header.accept_stat = 0; + + gsize msg_size = xdr_out.x_ops->x_getpostn(&xdr_out); + printf("Have an RPC reply of size %zd bytes\n", msg_size); + uint32_t fragment = htonl((msg_size + sizeof(header)) | 0x80000000); + async_rpc_write(req->connection, (const char *)&fragment, sizeof(fragment)); + async_rpc_write(req->connection, (const char *)&header, sizeof(header)); + async_rpc_write(req->connection, reply_buf, msg_size); + g_io_channel_flush(req->connection->channel, NULL); + + /* Clean up. */ + if (req->args != NULL) { + char buf[4]; + XDR xdr; + xdrmem_create(&xdr, buf, sizeof(buf), XDR_FREE); + if (!req->xdr_args_free(&xdr, req->args)) { + fprintf(stderr, "unable to free arguments"); + } + } + + if (req->raw_args != NULL) + g_string_free(req->raw_args, TRUE); + + g_free(req); +} + +static void +nfs_program_3(RPCRequest *req) +{ + RPCConnection *connection = req->connection; + uint32_t xid = req->xid; + const char *msg_buf = req->raw_args->str + req->raw_args_header_bytes; + size_t msg_len = req->raw_args->len - req->raw_args_header_bytes; + + union argtype { nfs_fh3 nfsproc3_getattr_3_arg; setattr3args nfsproc3_setattr_3_arg; diropargs3 nfsproc3_lookup_3_arg; @@ -115,168 +228,427 @@ nfs_program_3(struct svc_req *rqstp, register SVCXPRT *transp) nfs_fh3 nfsproc3_fsinfo_3_arg; nfs_fh3 nfsproc3_pathconf_3_arg; commit3args nfsproc3_commit_3_arg; - } argument; + }; char *result; xdrproc_t _xdr_argument, _xdr_result; - char *(*local)(char *, struct svc_req *); + char *(*local)(char *, RPCRequest *); - switch (rqstp->rq_proc) { + switch (req->req_proc) { case NFSPROC3_NULL: _xdr_argument = (xdrproc_t) xdr_void; _xdr_result = (xdrproc_t) xdr_void; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_null_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_null_3_svc; break; case NFSPROC3_GETATTR: _xdr_argument = (xdrproc_t) xdr_nfs_fh3; _xdr_result = (xdrproc_t) xdr_getattr3res; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_getattr_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_getattr_3_svc; break; case NFSPROC3_SETATTR: _xdr_argument = (xdrproc_t) xdr_setattr3args; _xdr_result = (xdrproc_t) xdr_wccstat3; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_setattr_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_setattr_3_svc; break; case NFSPROC3_LOOKUP: _xdr_argument = (xdrproc_t) xdr_diropargs3; _xdr_result = (xdrproc_t) xdr_lookup3res; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_lookup_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_lookup_3_svc; break; case NFSPROC3_ACCESS: _xdr_argument = (xdrproc_t) xdr_access3args; _xdr_result = (xdrproc_t) xdr_access3res; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_access_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_access_3_svc; break; case NFSPROC3_READLINK: _xdr_argument = (xdrproc_t) xdr_nfs_fh3; _xdr_result = (xdrproc_t) xdr_readlink3res; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_readlink_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_readlink_3_svc; break; case NFSPROC3_READ: _xdr_argument = (xdrproc_t) xdr_read3args; _xdr_result = (xdrproc_t) xdr_read3res; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_read_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_read_3_svc; break; case NFSPROC3_WRITE: _xdr_argument = (xdrproc_t) xdr_write3args; _xdr_result = (xdrproc_t) xdr_write3res; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_write_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_write_3_svc; break; case NFSPROC3_CREATE: _xdr_argument = (xdrproc_t) xdr_create3args; _xdr_result = (xdrproc_t) xdr_diropres3; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_create_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_create_3_svc; break; case NFSPROC3_MKDIR: _xdr_argument = (xdrproc_t) xdr_mkdir3args; _xdr_result = (xdrproc_t) xdr_diropres3; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_mkdir_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_mkdir_3_svc; break; case NFSPROC3_SYMLINK: _xdr_argument = (xdrproc_t) xdr_symlink3args; _xdr_result = (xdrproc_t) xdr_diropres3; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_symlink_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_symlink_3_svc; break; case NFSPROC3_MKNOD: _xdr_argument = (xdrproc_t) xdr_mknod3args; _xdr_result = (xdrproc_t) xdr_diropres3; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_mknod_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_mknod_3_svc; break; case NFSPROC3_REMOVE: _xdr_argument = (xdrproc_t) xdr_diropargs3; _xdr_result = (xdrproc_t) xdr_wccstat3; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_remove_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_remove_3_svc; break; case NFSPROC3_RMDIR: _xdr_argument = (xdrproc_t) xdr_diropargs3; _xdr_result = (xdrproc_t) xdr_wccstat3; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_rmdir_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_rmdir_3_svc; break; case NFSPROC3_RENAME: _xdr_argument = (xdrproc_t) xdr_rename3args; _xdr_result = (xdrproc_t) xdr_rename3res; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_rename_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_rename_3_svc; break; case NFSPROC3_LINK: _xdr_argument = (xdrproc_t) xdr_link3args; _xdr_result = (xdrproc_t) xdr_link3res; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_link_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_link_3_svc; break; case NFSPROC3_READDIR: _xdr_argument = (xdrproc_t) xdr_readdir3args; _xdr_result = (xdrproc_t) xdr_readdir3res; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_readdir_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_readdir_3_svc; break; case NFSPROC3_READDIRPLUS: _xdr_argument = (xdrproc_t) xdr_readdirplus3args; _xdr_result = (xdrproc_t) xdr_readdirplus3res; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_readdirplus_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_readdirplus_3_svc; break; case NFSPROC3_FSSTAT: _xdr_argument = (xdrproc_t) xdr_nfs_fh3; _xdr_result = (xdrproc_t) xdr_fsstat3res; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_fsstat_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_fsstat_3_svc; break; case NFSPROC3_FSINFO: _xdr_argument = (xdrproc_t) xdr_nfs_fh3; _xdr_result = (xdrproc_t) xdr_fsinfo3res; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_fsinfo_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_fsinfo_3_svc; break; case NFSPROC3_PATHCONF: _xdr_argument = (xdrproc_t) xdr_nfs_fh3; _xdr_result = (xdrproc_t) xdr_pathconf3res; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_pathconf_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_pathconf_3_svc; break; case NFSPROC3_COMMIT: _xdr_argument = (xdrproc_t) xdr_commit3args; _xdr_result = (xdrproc_t) xdr_commit3res; - local = (char *(*)(char *, struct svc_req *)) nfsproc3_commit_3_svc; + local = (char *(*)(char *, RPCRequest *)) nfsproc3_commit_3_svc; break; default: - svcerr_noproc (transp); + async_rpc_send_failure(req, PROC_UNAVAIL); return; } - memset ((char *)&argument, 0, sizeof (argument)); - if (!svc_getargs (transp, (xdrproc_t) _xdr_argument, (caddr_t) &argument)) { - svcerr_decode (transp); + + /* Decode incoming message */ + req->xdr_args_free = _xdr_argument; + req->args = g_new0(union argtype, 1); + XDR xdr_in; + xdrmem_create(&xdr_in, (char *)msg_buf, msg_len, XDR_DECODE); + if (!_xdr_argument(&xdr_in, req->args)) { + async_rpc_send_failure(req, GARBAGE_ARGS); + fprintf(stderr, "RPC decode error!\n"); return; } - result = (*local)((char *)&argument, rqstp); - if (result != NULL && !svc_sendreply(transp, (xdrproc_t) _xdr_result, result)) { - svcerr_systemerr (transp); + + /* Perform the call. */ + req->xdr_result = _xdr_result; + result = (*local)((char *)req->args, req); + + /* Encode result and send reply. */ + async_rpc_send_reply(req, result); + + bluesky_flushd_invoke(fs); + + return; +} + +/* Enhanced, asynchronous-friendly RPC layer. This is a replacement for the + * built-in sunrpc parsing and dispatch that will allow for processing multiple + * requests at the same time. */ +static GMainContext *main_context; +static GMainLoop *main_loop; + +static async_rpc_init() +{ + main_context = g_main_context_new(); + main_loop = g_main_loop_new(main_context, FALSE); +} + +struct rpc_call_header { + uint32_t xid; + uint32_t mtype; + uint32_t rpcvers; + uint32_t prog; + uint32_t vers; + uint32_t proc; +}; + +struct rpc_auth { + uint32_t flavor; + uint32_t len; +}; + +/* Decode an RPC message and process it. Returns a boolean indicating whether + * the message could be processed; if false, an unrecoverable error occurred + * and the transport should be closed. */ +static gboolean async_rpc_dispatch(RPCConnection *rpc) +{ + int i; + GString *msg = rpc->msgbuf; + const char *buf = msg->str; + + if (msg->len < sizeof(struct rpc_call_header)) { + fprintf(stderr, "Short RPC message: only %zd bytes!\n", msg->len); + return FALSE; } - if (!svc_freeargs (transp, (xdrproc_t) _xdr_argument, (caddr_t) &argument)) { - fprintf (stderr, "%s", "unable to free arguments"); - exit (1); + + struct rpc_call_header *header = (struct rpc_call_header *)(msg->str); + uint32_t xid = ntohl(header->xid); + + if (ntohl(header->mtype) != 0) { + /* Not an RPC call */ + return FALSE; } - return; + + if (ntohl(header->rpcvers) != 2) { + return FALSE; + } + + RPCRequest *req = g_new0(RPCRequest, 1); + req->connection = rpc; + req->xid = xid; + + if (ntohl(header->prog) != NFS_PROGRAM) { + async_rpc_send_failure(req, PROG_UNAVAIL); + return TRUE; + } else if (ntohl(header->vers) != NFS_V3) { + /* FIXME: Should be PROG_MISMATCH */ + async_rpc_send_failure(req, PROG_UNAVAIL); + return TRUE; + } + + uint32_t proc = ntohl(header->proc); + + /* Next, skip over authentication headers. */ + buf += sizeof(struct rpc_call_header); + for (i = 0; i < 2; i++) { + struct rpc_auth *auth = (struct rpc_auth *)buf; + if (buf - msg->str + sizeof(struct rpc_auth) > msg->len) + return FALSE; + + gsize authsize = ntohl(auth->len) + sizeof(struct rpc_auth); + if (authsize > MAX_RPC_MSGSIZE) + return FALSE; + + buf += authsize; + } + + if (buf - msg->str > msg->len) + return FALSE; + + printf("Dispatching RPC procedure %d...\n", proc); + + req->raw_args = msg; + req->raw_args_header_bytes = buf - msg->str; + req->req_proc = ntohl(header->proc); + rpc->msgbuf = g_string_new(""); + + nfs_program_3(req); + + return TRUE; +} + +/* Write the given data to the RPC socket. */ +static void async_rpc_write(RPCConnection *rpc, + const char *buf, gsize len) +{ + while (len > 0) { + gsize written = 0; + switch (g_io_channel_write_chars(rpc->channel, buf, len, + &written, NULL)) { + case G_IO_STATUS_ERROR: + case G_IO_STATUS_EOF: + case G_IO_STATUS_AGAIN: + fprintf(stderr, "Error writing to socket!\n"); + return; + case G_IO_STATUS_NORMAL: + len -= written; + buf += written; + break; + } + } + + // g_io_channel_flush(rpc->channel, NULL); +} + +static gboolean async_rpc_do_read(GIOChannel *channel, + GIOCondition condition, + gpointer data) +{ + RPCConnection *rpc = (RPCConnection *)data; + + gsize bytes_to_read = 0; /* Number of bytes to attempt to read. */ + + /* If we have not yet read in the fragment header, do that first. This is + * 4 bytes that indicates the number of bytes in the message to follow + * (with the high bit set if this is the last fragment making up the + * message). */ + if (rpc->frag_len == 0) { + bytes_to_read = 4 - rpc->frag_hdr_bytes; + } else { + bytes_to_read = rpc->frag_len & 0x7fffffff; + } + + if (bytes_to_read > MAX_RPC_MSGSIZE + || rpc->msgbuf->len + bytes_to_read > MAX_RPC_MSGSIZE) + { + fprintf(stderr, "Excessive fragment size for RPC: %zd bytes\n", + bytes_to_read); + g_io_channel_shutdown(rpc->channel, TRUE, NULL); + return FALSE; + } + + gsize bytes_read = 0; + g_string_set_size(rpc->msgbuf, rpc->msgbuf->len + bytes_to_read); + char *buf = &rpc->msgbuf->str[rpc->msgbuf->len - bytes_to_read]; + switch (g_io_channel_read_chars(rpc->channel, buf, + bytes_to_read, &bytes_read, NULL)) { + case G_IO_STATUS_NORMAL: + break; + case G_IO_STATUS_AGAIN: + return TRUE; + case G_IO_STATUS_EOF: + if (bytes_read == bytes_to_read) + break; + /* else fall through */ + case G_IO_STATUS_ERROR: + fprintf(stderr, "Unexpected error or end of file on RPC stream %d!\n", + g_io_channel_unix_get_fd(rpc->channel)); + g_io_channel_shutdown(rpc->channel, TRUE, NULL); + return FALSE; + } + + g_assert(bytes_read >= 0 && bytes_read <= bytes_to_read); + + g_string_set_size(rpc->msgbuf, + rpc->msgbuf->len - (bytes_to_read - bytes_read)); + + if (rpc->frag_len == 0) { + /* Handle reading in the fragment header. If we've read the complete + * header, store the fragment size. */ + rpc->frag_hdr_bytes += bytes_read; + if (rpc->frag_hdr_bytes == 4) { + memcpy((char *)&rpc->frag_len, + &rpc->msgbuf->str[rpc->msgbuf->len - 4], 4); + rpc->frag_len = ntohl(rpc->frag_len); + g_string_set_size(rpc->msgbuf, rpc->msgbuf->len - 4); + rpc->frag_hdr_bytes = 0; + g_print("RPC fragment header: %08x\n", rpc->frag_len); + } + } else { + /* We were reading in the fragment body. */ + rpc->frag_len -= bytes_read; + + if (rpc->frag_len = 0x80000000) { + /* We have a complete message since this was the last fragment and + * there are no more bytes in it. Dispatch the message. */ + g_print("Complete RPC message: %zd bytes\n", rpc->msgbuf->len); + if (!async_rpc_dispatch(rpc)) { + fprintf(stderr, "Invalid RPC message, closing channel\n"); + g_io_channel_shutdown(rpc->channel, TRUE, NULL); + return FALSE; + } + rpc->frag_len = 0; + g_string_set_size(rpc->msgbuf, 0); + } + } + + return TRUE; +} + +static gboolean async_rpc_do_accept(GIOChannel *channel, + GIOCondition condition, + gpointer data) +{ + int fd = g_io_channel_unix_get_fd(channel); + struct sockaddr_in addr; + socklen_t addrlen = sizeof(addr); + + g_print("Received new connection on fd %d!\n", fd); + int nfd = accept(fd, (struct sockaddr *)&addr, &addrlen); + if (nfd < 0) { + fprintf(stderr, "Error accepting connection: %m\n"); + return TRUE; + } + + RPCConnection *rpc = g_new0(RPCConnection, 1); + rpc->channel = g_io_channel_unix_new(nfd); + rpc->msgbuf = g_string_new(""); + g_io_channel_set_encoding(rpc->channel, NULL, NULL); + GSource *source = g_io_create_watch(rpc->channel, G_IO_IN); + g_source_set_callback(source, (GSourceFunc)async_rpc_do_read, + rpc, NULL); + g_source_attach(source, main_context); + g_source_unref(source); + + return TRUE; +} + +static async_rpc_register_listening(int fd) +{ + GIOChannel *channel = g_io_channel_unix_new(fd); + g_io_channel_set_encoding(channel, NULL, NULL); + GSource *source = g_io_create_watch(channel, G_IO_IN); + g_source_set_callback(source, (GSourceFunc)async_rpc_do_accept, + NULL, NULL); + g_source_attach(source, main_context); + g_source_unref(source); +} + +static gpointer async_rpc_run(gpointer data) +{ + g_print("Starting NFS main loop...\n"); + g_main_loop_run(main_loop); } void register_rpc() { SVCXPRT *transp; + async_rpc_init(); + /* MOUNT protocol */ pmap_unset (MOUNT_PROGRAM, MOUNT_V3); @@ -303,23 +675,35 @@ void register_rpc() /* NFS protocol (version 3) */ pmap_unset (NFS_PROGRAM, NFS_V3); - transp = svcudp_create(RPC_ANYSOCK); - if (transp == NULL) { - fprintf (stderr, "%s", "cannot create udp service."); + int fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); + if (fd < 0) { + fprintf(stderr, "Unable to create NFS TCP socket: %m\n"); exit(1); } - if (!svc_register(transp, NFS_PROGRAM, NFS_V3, nfs_program_3, IPPROTO_UDP)) { - fprintf (stderr, "%s", "unable to register (NFS_PROGRAM, NFS_V3, udp)."); + + int n = 1; + setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *)&n, sizeof(n)); + + struct sockaddr_in addr; + addr.sin_family = AF_INET; + addr.sin_port = htons(NFS_SERVICE_PORT); + addr.sin_addr.s_addr = INADDR_ANY; + if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) { + fprintf(stderr, "Unable to bind to NFS TCP address: %m\n"); exit(1); } - transp = svctcp_create(RPC_ANYSOCK, 0, 0); - if (transp == NULL) { - fprintf (stderr, "%s", "cannot create tcp service."); + if (listen(fd, SOMAXCONN) < 0) { + fprintf(stderr, "Unable to listen on NFS TCP socket: %m\n"); exit(1); } - if (!svc_register(transp, NFS_PROGRAM, NFS_V3, nfs_program_3, IPPROTO_TCP)) { - fprintf (stderr, "%s", "unable to register (NFS_PROGRAM, NFS_V3, tcp)."); + + if (!pmap_set(NFS_PROGRAM, NFS_V3, IPPROTO_TCP, NFS_SERVICE_PORT)) { + fprintf(stderr, "Could not register NFS RPC service!\n"); exit(1); } + + async_rpc_register_listening(fd); + + g_thread_create(async_rpc_run, NULL, TRUE, NULL); }