xdr_rec.c /* @(#)xdr_rec.c 2.2 88/08/01 4.0 RPCSRC */ /* * Sun RPC is a product of Sun Microsystems, Inc. and is provided for * unrestricted use provided that this legend is included on all tape * media and as a part of the software program in whole or part. Users * may copy or modify Sun RPC without charge, but are not authorized * to license or distribute it to anyone else except as part of a product or * program developed by the user. * * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. * * Sun RPC is provided with no support and without any obligation on the * part of Sun Microsystems, Inc. to assist in its use, correction, * modification or enhancement. * * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC * OR ANY PART THEREOF. * * In no event will Sun Microsystems, Inc. be liable for any lost revenue * or profits or other special, indirect and consequential damages, even if * Sun has been advised of the possibility of such damages. * * Sun Microsystems, Inc. * 2550 Garcia Avenue * Mountain View, California 94043 */ #if !defined(lint) && defined(SCCSIDS) static char sccsid[] = "@(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro"; #endif /* * xdr_rec.c, Implements TCP/IP based XDR streams with a "record marking" * layer above tcp (for rpc's use). * * Copyright (C) 1984, Sun Microsystems, Inc. * * These routines interface XDRSTREAMS to a tcp/ip connection. * There is a record marking layer between the xdr stream * and the tcp transport level. A record is composed on one or more * record fragments. A record fragment is a thirty-two bit header followed * by n bytes of data, where n is contained in the header. The header * is represented as a htonl(u_long). Thegh order bit encodes * whether or not the fragment is the last fragment of the record * (1 => fragment is last, 0 => more fragments to follow. * The other 31 bits encode the byte length of the fragment. */ #include <stdio.h> #include <rpc/types.h> #include <rpc/xdr.h> #include <netinet/in.h> #include <strings.h> #include <unistd.h> #ifdef __STDC__ #include <stdlib.h> #endif #ifndef linux extern long lseek(); #endif #if NLS #include "nl_types.h" #endif static u_int fix_buf_size(); static bool_t xdrrec_getlong(); static bool_t xdrrec_putlong(); static bool_t xdrrec_getbytes(); static bool_t xdrrec_putbytes(); static u_int xdrrec_getpos(); static bool_t xdrrec_setpos(); static long * xdrrec_inline(); static void xdrrec_destroy(); static struct xdr_ops xdrrec_ops = { xdrrec_getlong, xdrrec_putlong, xdrrec_getbytes, xdrrec_putbytes, xdrrec_getpos, xdrrec_setpos, xdrrec_inline, xdrrec_destroy }; /* * A record is composed of one or more record fragments. * A record fragment is a two-byte header followed by zero to * 2**32-1 bytes. The header is treated as a long unsigned and is * encode/decoded to the network via htonl/ntohl. The low order 31 bits * are a byte count of the fragment. The highest order bit is a boolean: * 1 => this fragment is the last fragment of the record, * 0 => this fragment is followed by more fragment(s). * * The fragment/record machinery is not general; it is constructed to * meet the needs of xdr and rpc based on tcp. */ #define LAST_FRAG ((u_long)(1 << 31)) typedef struct rec_strm { caddr_t tcp_handle; caddr_t the_buffer; /* * out-goung bits */ int (*writeit)(); caddr_t out_base; /* output buffer (points to frag header) */ caddr_t out_finger; /* next output position */ caddr_t out_boundry; /* data cannot up to this address */ u_long *frag_header; /* beginning of curren fragment */ bool_t frag_sent; /* true if buffer sent in middle of record */ /* * in-coming bits */ int (*readit)(); u_long in_size; /* fixed size of the input buffer */ caddr_t in_base; caddr_t in_finger; /* location of next byte to be had */ caddr_t in_boundry; /* can read up to this location */ long fbtbc; /* fragment bytes to be consumed */ bool_t last_frag; u_int sendsize; u_int recvsize; } RECSTREAM; /* * Internal useful routines */ static bool_t flush_out(rstrm, eor) register RECSTREAM *rstrm; bool_t eor; { register u_long eormask = (eor == TRUE) ? LAST_FRAG : 0; register u_long len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) - sizeof(u_long); *(rstrm->frag_header) = htonl(len | eormask); len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->out_base); if ((*(rstrm->writeit))(rstrm->tcp_handle, rstrm->out_base, (int)len) != (int)len) return (FALSE); rstrm->frag_header = (u_long *)rstrm->out_base; rstrm->out_finger = (caddr_t)rstrm->out_base + sizeof(u_long); return (TRUE); } static bool_t /* knows nothing about records! Only about input buffers */ fill_input_buf(rstrm) register RECSTREAM *rstrm; { register caddr_t where; u_int i; register int len; where = rstrm->in_base; i = (u_int)rstrm->in_boundry % BYTES_PER_XDR_UNIT; where += i; len = rstrm->in_size - i; if ((len = (*(rstrm->readit))(rstrm->tcp_handle, where, len)) == -1) return (FALSE); rstrm->in_finger = where; where += len; rstrm->in_boundry = where; return (TRUE); } static bool_t /* knows nothing about records! Only about input buffers */ get_input_bytes(rstrm, addr, len) register RECSTREAM *rstrm; register caddr_t addr; register int len; { register int current; while (len > 0) { current = (int)rstrm->in_boundry - (int)rstrm->in_finger; if (current == 0) { if (! fill_input_buf(rstrm)) return (FALSE); continue; } current = (len < current) ? len : current; bcopy(rstrm->in_finger, addr, current); rstrm->in_finger += current; addr += current; len -= current; } return (TRUE); } static bool_t /* next two bytes of the input stream are treated as a header */ set_input_fragment(rstrm) register RECSTREAM *rstrm; { u_long header; if (! get_input_bytes(rstrm, (caddr_t)&header, sizeof(header))) return (FALSE); header = (long)ntohl(header); rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE; rstrm->fbtbc = header & (~LAST_FRAG); return (TRUE); } static bool_t /* consumes input bytes; knows nothing about records! */ skip_input_bytes(rstrm, cnt) register RECSTREAM *rstrm; long cnt; { register int current; while (cnt > 0) { current = (int)rstrm->in_boundry - (int)rstrm->in_finger; if (current == 0) { if (! fill_input_buf(rstrm)) return (FALSE); continue; } current = (cnt < current) ? cnt : current; rstrm->in_finger += current; cnt -= current; } return (TRUE); } static u_int fix_buf_size(s) register u_int s; { if (s < 100) s = 4000; return (RNDUP(s)); } /* * Create an xdr handle for xdrrec * xdrrec_create fills in xdrs. Sendsize and recvsize are * send and recv buffer sizes (0 => use default). * tcp_handle is an opaque handle that is passed as the first parameter to * the procedures readit and writeit. Readit and writeit are read and * write respectively. They are like the system * calls expect that they take an opaque handle rather than an fd. */ void xdrrec_create(xdrs, sendsize, recvsize, tcp_handle, readit, writeit) register XDR *xdrs; register u_int sendsize; register u_int recvsize; caddr_t tcp_handle; int (*readit)(); /* like read, but pass it a tcp_handle, not sock */ int (*writeit)(); /* like write, but pass it a tcp_handle, not sock */ { register RECSTREAM *rstrm = (RECSTREAM *)mem_alloc(sizeof(RECSTREAM)); #if NLS libc_nls_init(); #endif if (rstrm == NULL) { #if NLS (void)fprintf(stderr, "xdrrec_create: %s\n", catgets(_libc_cat, RpcMiscSet, RpcMiscOutOfMemory, "out of memory")); #else (void)fprintf(stderr, "xdrrec_create: out of memory\n"); #endif /* * This is bad. Should rework xdrrec_create to * return a handle, and in this case return NULL */ return; } /* * adjust sizes and allocate buffer quad byte aligned */ rstrm->sendsize = sendsize = fix_buf_size(sendsize); rstrm->recvsize = recvsize = fix_buf_size(recvsize); rstrm->the_buffer = mem_alloc(sendsize + recvsize + BYTES_PER_XDR_UNIT); if (rstrm->the_buffer == NULL) { #if NLS (void)fprintf(stderr, "xdrrec_create: %s\n", catgets(_libc_cat, RpcMiscSet, RpcMiscOutOfMemory, "out of memory")); #else (void)fprintf(stderr, "xdrrec_create: out of memory\n"); #endif return; } for (rstrm->out_base = rstrm->the_buffer; (u_int)rstrm->out_base % BYTES_PER_XDR_UNIT != 0; rstrm->out_base++); rstrm->in_base = rstrm->out_base + sendsize; /* * now the rest ... */ xdrs->x_ops = &xdrrec_ops; xdrs->x_private = (caddr_t)rstrm; rstrm->tcp_handle = tcp_handle; rstrm->readit = readit; rstrm->writeit = writeit; rstrm->out_finger = rstrm->out_boundry = rstrm->out_base; rstrm->frag_header = (u_long *)rstrm->out_base; rstrm->out_finger += sizeof(u_long); rstrm->out_boundry += sendsize; rstrm->frag_sent = FALSE; rstrm->in_size = recvsize; rstrm->in_boundry = rstrm->in_base; rstrm->in_finger = (rstrm->in_boundry += recvsize); rstrm->fbtbc = 0; rstrm->last_frag = TRUE; } /* * The reoutines defined below are the xdr ops which will go into the * xdr handle filled in by xdrrec_create. */ static bool_t xdrrec_getlong(xdrs, lp) XDR *xdrs; long *lp; { register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); register long *buflp = (long *)(rstrm->in_finger); long mylong; /* first try the inline, fast case */ if ((rstrm->fbtbc >= sizeof(long)) && (((int)rstrm->in_boundry - (int)buflp) >= sizeof(long))) { *lp = (long)ntohl((u_long)(*buflp)); rstrm->fbtbc -= sizeof(long); rstrm->in_finger += sizeof(long); } else { if (! xdrrec_getbytes(xdrs, (caddr_t)&mylong, sizeof(long))) return (FALSE); *lp = (long)ntohl((u_long)mylong); } return (TRUE); } static bool_t xdrrec_putlong(xdrs, lp) XDR *xdrs; long *lp; { register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); register long *dest_lp = ((long *)(rstrm->out_finger)); if ((rstrm->out_finger += sizeof(long)) > rstrm->out_boundry) { /* * this case should almost never happen so the code is * inefficient */ rstrm->out_finger -= sizeof(long); rstrm->frag_sent = TRUE; if (! flush_out(rstrm, FALSE)) return (FALSE); dest_lp = ((long *)(rstrm->out_finger)); rstrm->out_finger += sizeof(long); } *dest_lp = (long)htonl((u_long)(*lp)); return (TRUE); } static bool_t /* must manage buffers, fragments, and records */ xdrrec_getbytes(xdrs, addr, len) XDR *xdrs; register caddr_t addr; register u_int len; { register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); register int current; while (len > 0) { current = rstrm->fbtbc; if (current == 0) { if (rstrm->last_frag) return (FALSE); if (! set_input_fragment(rstrm)) return (FALSE); continue; } current = (len < current) ? len : current; if (! get_input_bytes(rstrm, addr, current)) return (FALSE); addr += current; rstrm->fbtbc -= current; len -= current; } return (TRUE); } static bool_t xdrrec_putbytes(xdrs, addr, len) XDR *xdrs; register caddr_t addr; register u_int len; { register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); register int current; while (len > 0) { current = (u_int)rstrm->out_boundry - (u_int)rstrm->out_finger; current = (len < current) ? len : current; bcopy(addr, rstrm->out_finger, current); rstrm->out_finger += current; addr += current; len -= current; if (rstrm->out_finger == rstrm->out_boundry) { rstrm->frag_sent = TRUE; if (! flush_out(rstrm, FALSE)) return (FALSE); } } return (TRUE); } static u_int xdrrec_getpos(xdrs) register XDR *xdrs; { register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; register long pos; pos = lseek((int)rstrm->tcp_handle, (long) 0, 1); if (pos != -1) switch (xdrs->x_op) { case XDR_ENCODE: pos += rstrm->out_finger - rstrm->out_base; break; case XDR_DECODE: pos -= rstrm->in_boundry - rstrm->in_finger; break; default: pos = (u_int) -1; break; } return ((u_int) pos); } static bool_t xdrrec_setpos(xdrs, pos) register XDR *xdrs; u_int pos; { register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; u_int currpos = xdrrec_getpos(xdrs); int delta = currpos - pos; caddr_t newpos; if ((int)currpos != -1) switch (xdrs->x_op) { case XDR_ENCODE: newpos = rstrm->out_finger - delta; if ((newpos > (caddr_t)(rstrm->frag_header)) && (newpos < rstrm->out_boundry)) { rstrm->out_finger = newpos; return (TRUE); } break; case XDR_DECODE: newpos = rstrm->in_finger - delta; if ((delta < (int)(rstrm->fbtbc)) && (newpos <= rstrm->in_boundry) && (newpos >= rstrm->in_base)) { rstrm->in_finger = newpos; rstrm->fbtbc -= delta; return (TRUE); } break; } return (FALSE); } static long * xdrrec_inline(xdrs, len) register XDR *xdrs; int len; { register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; long * buf = NULL; switch (xdrs->x_op) { case XDR_ENCODE: if ((rstrm->out_finger + len) <= rstrm->out_boundry) { buf = (long *) rstrm->out_finger; rstrm->out_finger += len; } break; case XDR_DECODE: if ((len <= rstrm->fbtbc) && ((rstrm->in_finger + len) <= rstrm->in_boundry)) { buf = (long *) rstrm->in_finger; rstrm->fbtbc -= len; rstrm->in_finger += len; } break; } return (buf); } static void xdrrec_destroy(xdrs) register XDR *xdrs; { register RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; mem_free(rstrm->the_buffer, rstrm->sendsize + rstrm->recvsize + BYTES_PER_XDR_UNIT); mem_free((caddr_t)rstrm, sizeof(RECSTREAM)); } /* * Exported routines to manage xdr records */ /* * Before reading (deserializing from the stream, one should always call * this procedure to guarantee proper record alignment. */ bool_t xdrrec_skiprecord(xdrs) XDR *xdrs; { register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { if (! skip_input_bytes(rstrm, rstrm->fbtbc)) return (FALSE); rstrm->fbtbc = 0; if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) return (FALSE); } rstrm->last_frag = FALSE; return (TRUE); } /* * Look ahead fuction. * Returns TRUE iff there is no more input in the buffer * after consuming the rest of the current record. */ bool_t xdrrec_eof(xdrs) XDR *xdrs; { register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); while (rstrm->fbtbc > 0 || (! rstrm->last_frag)) { if (! skip_input_bytes(rstrm, rstrm->fbtbc)) return (TRUE); rstrm->fbtbc = 0; if ((! rstrm->last_frag) && (! set_input_fragment(rstrm))) return (TRUE); } if (rstrm->in_finger == rstrm->in_boundry) return (TRUE); return (FALSE); } /* * The client must tell the package when an end-of-record has occurred. * The second paraemters tells whether the record should be flushed to the * (output) tcp stream. (This let's the package support batched or * pipelined procedure calls.) TRUE => immmediate flush to tcp connection. */ bool_t xdrrec_endofrecord(xdrs, sendnow) XDR *xdrs; bool_t sendnow; { register RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); register u_long len; /* fragment length */ if (sendnow || rstrm->frag_sent || ((u_long)rstrm->out_finger + sizeof(u_long) >= (u_long)rstrm->out_boundry)) { rstrm->frag_sent = FALSE; return (flush_out(rstrm, TRUE)); } len = (u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) - sizeof(u_long); *(rstrm->frag_header) = htonl((u_long)len | LAST_FRAG); rstrm->frag_header = (u_long *)rstrm->out_finger; rstrm->out_finger += sizeof(u_long); return (TRUE); }