/* $NetBSD: xdr_rec.c,v 1.41 2024/03/22 19:45:22 andvar Exp $ */ /* * Copyright (c) 2010, Oracle America, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials * provided with the distribution. * * Neither the name of the "Oracle America, Inc." nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #if defined(LIBC_SCCS) && !defined(lint) #if 0 static char *sccsid = "@(#)xdr_rec.c 1.21 87/08/11 Copyr 1984 Sun Micro"; static char *sccsid = "@(#)xdr_rec.c 2.2 88/08/01 4.0 RPCSRC"; #else __RCSID("$NetBSD: xdr_rec.c,v 1.41 2024/03/22 19:45:22 andvar Exp $"); #endif #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 "namespace.h" #include "reentrant.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include "rpc_internal.h" #ifdef __weak_alias __weak_alias(xdrrec_create,_xdrrec_create) __weak_alias(xdrrec_endofrecord,_xdrrec_endofrecord) __weak_alias(xdrrec_eof,_xdrrec_eof) __weak_alias(xdrrec_skiprecord,_xdrrec_skiprecord) #endif static bool_t xdrrec_getlong(XDR *, long *); static bool_t xdrrec_putlong(XDR *, const long *); static bool_t xdrrec_getbytes(XDR *, char *, u_int); static bool_t xdrrec_putbytes(XDR *, const char *, u_int); static u_int xdrrec_getpos(XDR *); static bool_t xdrrec_setpos(XDR *, u_int); static int32_t *xdrrec_inline(XDR *, u_int); static void xdrrec_destroy(XDR *); static const struct xdr_ops xdrrec_ops = { xdrrec_getlong, xdrrec_putlong, xdrrec_getbytes, xdrrec_putbytes, xdrrec_getpos, xdrrec_setpos, xdrrec_inline, xdrrec_destroy, NULL, /* xdrrec_control */ }; /* * A record is composed of one or more record fragments. * A record fragment is a four-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 ((uint32_t)(1U << 31)) typedef struct rec_strm { char *tcp_handle; /* * out-goung bits */ int (*writeit)(char *, char *, int); char *out_base; /* output buffer (points to frag header) */ char *out_finger; /* next output position */ char *out_boundry; /* data cannot up to this address */ uint32_t *frag_header; /* beginning of current fragment */ bool_t frag_sent; /* true if buffer sent in middle of record */ /* * in-coming bits */ int (*readit)(char *, char *, int); u_long in_size; /* fixed size of the input buffer */ char *in_base; char *in_finger; /* location of next byte to be had */ char *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; bool_t nonblock; bool_t in_haveheader; uint32_t in_header; char *in_hdrp; int in_hdrlen; int in_reclen; int in_received; int in_maxrec; } RECSTREAM; static u_int fix_buf_size(u_int); static bool_t flush_out(RECSTREAM *, bool_t); static bool_t fill_input_buf(RECSTREAM *); static bool_t get_input_bytes(RECSTREAM *, char *, u_int); static bool_t set_input_fragment(RECSTREAM *); static bool_t skip_input_bytes(RECSTREAM *, long); static bool_t realloc_stream(RECSTREAM *, int); /* * 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( XDR *xdrs, u_int sendsize, u_int recvsize, char *tcp_handle, /* like read, but pass it a tcp_handle, not sock */ int (*readit)(char *, char *, int), /* like write, but pass it a tcp_handle, not sock */ int (*writeit)(char *, char *, int)) { RECSTREAM *rstrm = mem_alloc(sizeof(RECSTREAM)); if (rstrm == NULL) { warn("%s: out of memory", __func__); /* * This is bad. Should rework xdrrec_create to * return a handle, and in this case return NULL */ return; } rstrm->sendsize = sendsize = fix_buf_size(sendsize); rstrm->out_base = malloc(rstrm->sendsize); if (rstrm->out_base == NULL) { warn("%s: out of memory", __func__); mem_free(rstrm, sizeof(RECSTREAM)); return; } rstrm->recvsize = recvsize = fix_buf_size(recvsize); rstrm->in_base = malloc(recvsize); if (rstrm->in_base == NULL) { warn("%s: out of memory", __func__); mem_free(rstrm->out_base, sendsize); mem_free(rstrm, sizeof(RECSTREAM)); return; } /* * now the rest ... */ xdrs->x_ops = &xdrrec_ops; xdrs->x_private = rstrm; rstrm->tcp_handle = tcp_handle; rstrm->readit = readit; rstrm->writeit = writeit; rstrm->out_finger = rstrm->out_boundry = rstrm->out_base; rstrm->frag_header = (uint32_t *)(void *)rstrm->out_base; rstrm->out_finger += sizeof(uint32_t); 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; rstrm->in_haveheader = FALSE; rstrm->in_hdrlen = 0; rstrm->in_hdrp = (char *)(void *)&rstrm->in_header; rstrm->nonblock = FALSE; rstrm->in_reclen = 0; rstrm->in_received = 0; } /* * The routines defined below are the xdr ops which will go into the * xdr handle filled in by xdrrec_create. */ static bool_t xdrrec_getlong(XDR *xdrs, long *lp) { RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); int32_t *buflp = (int32_t *)(void *)(rstrm->in_finger); int32_t mylong; /* first try the inline, fast case */ if ((rstrm->fbtbc >= (long)sizeof(int32_t)) && (((uintptr_t)rstrm->in_boundry - (uintptr_t)buflp) >= sizeof(int32_t))) { *lp = (long)ntohl((uint32_t)(*buflp)); rstrm->fbtbc -= sizeof(int32_t); rstrm->in_finger += sizeof(int32_t); } else { if (! xdrrec_getbytes(xdrs, (char *)(void *)&mylong, (u_int)sizeof(int32_t))) return (FALSE); *lp = (long)ntohl((uint32_t)mylong); } return (TRUE); } static bool_t xdrrec_putlong(XDR *xdrs, const long *lp) { RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); int32_t *dest_lp = ((int32_t *)(void *)(rstrm->out_finger)); if ((rstrm->out_finger += sizeof(int32_t)) > rstrm->out_boundry) { /* * this case should almost never happen so the code is * inefficient */ rstrm->out_finger -= sizeof(int32_t); rstrm->frag_sent = TRUE; if (! flush_out(rstrm, FALSE)) return (FALSE); dest_lp = ((int32_t *)(void *)(rstrm->out_finger)); rstrm->out_finger += sizeof(int32_t); } *dest_lp = (int32_t)htonl((uint32_t)(*lp)); return (TRUE); } static bool_t /* must manage buffers, fragments, and records */ xdrrec_getbytes(XDR *xdrs, char *addr, u_int len) { RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); u_int current; while (len > 0) { current = (u_int)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(XDR *xdrs, const char *addr, u_int len) { RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); size_t current; while (len > 0) { current = (size_t)((u_long)rstrm->out_boundry - (u_long)rstrm->out_finger); current = (len < current) ? len : current; memmove(rstrm->out_finger, addr, current); rstrm->out_finger += current; addr += current; _DIAGASSERT(__type_fit(u_int, current)); len -= (u_int)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(XDR *xdrs) { RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; off_t pos; pos = lseek((int)(u_long)rstrm->tcp_handle, (off_t)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 = (off_t) -1; break; } return ((u_int) pos); } static bool_t xdrrec_setpos(XDR *xdrs, u_int pos) { RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; u_int currpos = xdrrec_getpos(xdrs); int delta = currpos - pos; char *newpos; if ((int)currpos != -1) switch (xdrs->x_op) { case XDR_ENCODE: newpos = rstrm->out_finger - delta; if ((newpos > (char *)(void *)(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; case XDR_FREE: break; } return (FALSE); } static int32_t * xdrrec_inline(XDR *xdrs, u_int len) { RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; int32_t *buf = NULL; switch (xdrs->x_op) { case XDR_ENCODE: if ((rstrm->out_finger + len) <= rstrm->out_boundry) { buf = (int32_t *)(void *)rstrm->out_finger; rstrm->out_finger += len; } break; case XDR_DECODE: if ((len <= (u_int)rstrm->fbtbc) && ((rstrm->in_finger + len) <= rstrm->in_boundry)) { buf = (int32_t *)(void *)rstrm->in_finger; rstrm->fbtbc -= len; rstrm->in_finger += len; } break; case XDR_FREE: break; } return (buf); } static void xdrrec_destroy(XDR *xdrs) { RECSTREAM *rstrm = (RECSTREAM *)xdrs->x_private; mem_free(rstrm->out_base, rstrm->sendsize); mem_free(rstrm->in_base, rstrm->recvsize); mem_free(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(XDR *xdrs) { RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); enum xprt_stat xstat; if (rstrm->nonblock) { if (__xdrrec_getrec(xdrs, &xstat, FALSE)) { rstrm->fbtbc = 0; return TRUE; } if (rstrm->in_finger == rstrm->in_boundry && xstat == XPRT_MOREREQS) { rstrm->fbtbc = 0; return TRUE; } return FALSE; } 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 function. * Returns TRUE iff there is no more input in the buffer * after consuming the rest of the current record. */ bool_t xdrrec_eof(XDR *xdrs) { 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 parameters tells whether the record should be flushed to the * (output) tcp stream. (This let's the package support batched or * pipelined procedure calls.) TRUE => immediate flush to tcp connection. */ bool_t xdrrec_endofrecord(XDR *xdrs, int sendnow) { RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); u_long len; /* fragment length */ if (sendnow || rstrm->frag_sent || ((u_long)rstrm->out_finger + sizeof(uint32_t) >= (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(uint32_t); *(rstrm->frag_header) = htonl((uint32_t)len | LAST_FRAG); rstrm->frag_header = (uint32_t *)(void *)rstrm->out_finger; rstrm->out_finger += sizeof(uint32_t); return (TRUE); } /* * Fill the stream buffer with a record for a non-blocking connection. * Return true if a record is available in the buffer, false if not. */ bool_t __xdrrec_getrec(XDR *xdrs, enum xprt_stat *statp, bool_t expectdata) { RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); ssize_t n; int fraglen; if (!rstrm->in_haveheader) { n = rstrm->readit(rstrm->tcp_handle, rstrm->in_hdrp, (int)sizeof (rstrm->in_header) - rstrm->in_hdrlen); if (n == 0) { *statp = expectdata ? XPRT_DIED : XPRT_IDLE; return FALSE; } if (n < 0) { *statp = XPRT_DIED; return FALSE; } rstrm->in_hdrp += n; _DIAGASSERT(__type_fit(int, n)); rstrm->in_hdrlen += (int)n; if (rstrm->in_hdrlen < (int)sizeof(rstrm->in_header)) { *statp = XPRT_MOREREQS; return FALSE; } rstrm->in_header = ntohl(rstrm->in_header); fraglen = (int)(rstrm->in_header & ~LAST_FRAG); if (fraglen == 0 || fraglen > rstrm->in_maxrec || (rstrm->in_reclen + fraglen) > rstrm->in_maxrec) { *statp = XPRT_DIED; return FALSE; } rstrm->in_reclen += fraglen; if ((u_int)rstrm->in_reclen > rstrm->recvsize) { if (!realloc_stream(rstrm, rstrm->in_reclen)) { *statp = XPRT_DIED; return FALSE; } } if (rstrm->in_header & LAST_FRAG) { rstrm->in_header &= ~LAST_FRAG; rstrm->last_frag = TRUE; } } n = rstrm->readit(rstrm->tcp_handle, rstrm->in_base + rstrm->in_received, (rstrm->in_reclen - rstrm->in_received)); if (n < 0) { *statp = XPRT_DIED; return FALSE; } if (n == 0) { *statp = expectdata ? XPRT_DIED : XPRT_IDLE; return FALSE; } _DIAGASSERT(__type_fit(int, n)); rstrm->in_received += (int)n; if (rstrm->in_received == rstrm->in_reclen) { rstrm->in_haveheader = FALSE; rstrm->in_hdrp = (char *)(void *)&rstrm->in_header; rstrm->in_hdrlen = 0; if (rstrm->last_frag) { rstrm->fbtbc = rstrm->in_reclen; rstrm->in_boundry = rstrm->in_base + rstrm->in_reclen; rstrm->in_finger = rstrm->in_base; rstrm->in_reclen = rstrm->in_received = 0; *statp = XPRT_MOREREQS; return TRUE; } } *statp = XPRT_MOREREQS; return FALSE; } bool_t __xdrrec_setnonblock(XDR *xdrs, int maxrec) { RECSTREAM *rstrm = (RECSTREAM *)(xdrs->x_private); rstrm->nonblock = TRUE; if (maxrec == 0) maxrec = rstrm->recvsize; rstrm->in_maxrec = maxrec; return TRUE; } /* * Internal useful routines */ static bool_t flush_out(RECSTREAM *rstrm, bool_t eor) { uint32_t eormask = (eor == TRUE) ? LAST_FRAG : 0; uint32_t len = (uint32_t)((u_long)(rstrm->out_finger) - (u_long)(rstrm->frag_header) - sizeof(uint32_t)); *(rstrm->frag_header) = htonl(len | eormask); len = (uint32_t)((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 = (uint32_t *)(void *)rstrm->out_base; rstrm->out_finger = (char *)rstrm->out_base + sizeof(uint32_t); return (TRUE); } static bool_t /* knows nothing about records! Only about input buffers */ fill_input_buf(RECSTREAM *rstrm) { char *where; uint32_t i; int len; if (rstrm->nonblock) return FALSE; where = rstrm->in_base; i = (uint32_t)((u_long)rstrm->in_boundry % BYTES_PER_XDR_UNIT); where += i; len = (uint32_t)(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(RECSTREAM *rstrm, char *addr, u_int len) { u_int current; if (rstrm->nonblock) { if (len > ((uintptr_t)rstrm->in_boundry - (uintptr_t)rstrm->in_finger)) return FALSE; memcpy(addr, rstrm->in_finger, len); rstrm->in_finger += len; return TRUE; } while (len > 0) { uintptr_t d = ((uintptr_t)rstrm->in_boundry - (uintptr_t)rstrm->in_finger); _DIAGASSERT(__type_fit(u_int, d)); current = (u_int)d; if (current == 0) { if (! fill_input_buf(rstrm)) return (FALSE); continue; } current = (len < current) ? len : current; memmove(addr, rstrm->in_finger, 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(RECSTREAM *rstrm) { uint32_t header; if (rstrm->nonblock) return FALSE; if (! get_input_bytes(rstrm, (char *)(void *)&header, (u_int)sizeof(header))) return (FALSE); header = ntohl(header); rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE; /* * Sanity check. Try not to accept wildly incorrect * record sizes. Unfortunately, the only record size * we can positively identify as being 'wildly incorrect' * is zero. Ridiculously large record sizes may look wrong, * but we don't have any way to be certain that they aren't * what the client actually intended to send us. */ if (header == 0) return(FALSE); rstrm->fbtbc = header & (~LAST_FRAG); return (TRUE); } static bool_t /* consumes input bytes; knows nothing about records! */ skip_input_bytes(RECSTREAM *rstrm, long cnt) { uint32_t current; while (cnt > 0) { current = (uint32_t)((long)rstrm->in_boundry - (long)rstrm->in_finger); if (current == 0) { if (! fill_input_buf(rstrm)) return (FALSE); continue; } current = ((uint32_t)cnt < current) ? (uint32_t)cnt : current; rstrm->in_finger += current; cnt -= current; } return (TRUE); } static u_int fix_buf_size(u_int s) { if (s < 100) s = 4000; return (RNDUP(s)); } /* * Reallocate the input buffer for a non-block stream. */ static bool_t realloc_stream(RECSTREAM *rstrm, int size) { ptrdiff_t diff; char *buf; if ((u_int)size > rstrm->recvsize) { buf = realloc(rstrm->in_base, (size_t)size); if (buf == NULL) return FALSE; diff = buf - rstrm->in_base; rstrm->in_finger += diff; rstrm->in_base = buf; rstrm->in_boundry = buf + size; rstrm->recvsize = size; rstrm->in_size = size; } return TRUE; }