| File: | src/lib/libc/rpc/pmap_prot2.c |
| Warning: | line 95, column 28 Dereference of null pointer (loaded from variable 'rp') |
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| 1 | /* $OpenBSD: pmap_prot2.c,v 1.8 2015/09/13 15:36:56 guenther Exp $ */ | |||
| 2 | ||||
| 3 | /* | |||
| 4 | * Copyright (c) 2010, Oracle America, Inc. | |||
| 5 | * | |||
| 6 | * Redistribution and use in source and binary forms, with or without | |||
| 7 | * modification, are permitted provided that the following conditions are | |||
| 8 | * met: | |||
| 9 | * | |||
| 10 | * * Redistributions of source code must retain the above copyright | |||
| 11 | * notice, this list of conditions and the following disclaimer. | |||
| 12 | * * Redistributions in binary form must reproduce the above | |||
| 13 | * copyright notice, this list of conditions and the following | |||
| 14 | * disclaimer in the documentation and/or other materials | |||
| 15 | * provided with the distribution. | |||
| 16 | * * Neither the name of the "Oracle America, Inc." nor the names of its | |||
| 17 | * contributors may be used to endorse or promote products derived | |||
| 18 | * from this software without specific prior written permission. | |||
| 19 | * | |||
| 20 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |||
| 21 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |||
| 22 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS | |||
| 23 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE | |||
| 24 | * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, | |||
| 25 | * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |||
| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE | |||
| 27 | * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |||
| 28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, | |||
| 29 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING | |||
| 30 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |||
| 31 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |||
| 32 | */ | |||
| 33 | ||||
| 34 | /* | |||
| 35 | * pmap_prot2.c | |||
| 36 | * Protocol for the local binder service, or pmap. | |||
| 37 | */ | |||
| 38 | ||||
| 39 | #include <rpc/types.h> | |||
| 40 | #include <rpc/xdr.h> | |||
| 41 | #include <rpc/pmap_prot.h> | |||
| 42 | ||||
| 43 | ||||
| 44 | /* | |||
| 45 | * What is going on with linked lists? (!) | |||
| 46 | * First recall the link list declaration from pmap_prot.h: | |||
| 47 | * | |||
| 48 | * struct pmaplist { | |||
| 49 | * struct pmap pml_map; | |||
| 50 | * struct pmaplist *pml_map; | |||
| 51 | * }; | |||
| 52 | * | |||
| 53 | * Compare that declaration with a corresponding xdr declaration that | |||
| 54 | * is (a) pointer-less, and (b) recursive: | |||
| 55 | * | |||
| 56 | * typedef union switch (bool_t) { | |||
| 57 | * | |||
| 58 | * case TRUE: struct { | |||
| 59 | * struct pmap; | |||
| 60 | * pmaplist_t foo; | |||
| 61 | * }; | |||
| 62 | * | |||
| 63 | * case FALSE: struct {}; | |||
| 64 | * } pmaplist_t; | |||
| 65 | * | |||
| 66 | * Notice that the xdr declaration has no nxt pointer while | |||
| 67 | * the C declaration has no bool_t variable. The bool_t can be | |||
| 68 | * interpreted as ``more data follows me''; if FALSE then nothing | |||
| 69 | * follows this bool_t; if TRUE then the bool_t is followed by | |||
| 70 | * an actual struct pmap, and then (recursively) by the | |||
| 71 | * xdr union, pamplist_t. | |||
| 72 | * | |||
| 73 | * This could be implemented via the xdr_union primitive, though this | |||
| 74 | * would cause a one recursive call per element in the list. Rather than do | |||
| 75 | * that we can ``unwind'' the recursion | |||
| 76 | * into a while loop and do the union arms in-place. | |||
| 77 | * | |||
| 78 | * The head of the list is what the C programmer wishes to past around | |||
| 79 | * the net, yet is the data that the pointer points to which is interesting; | |||
| 80 | * this sounds like a job for xdr_reference! | |||
| 81 | */ | |||
| 82 | bool_tint32_t | |||
| 83 | xdr_pmaplist(XDR *xdrs, struct pmaplist **rp) | |||
| 84 | { | |||
| 85 | /* | |||
| 86 | * more_elements is pre-computed in case the direction is | |||
| 87 | * XDR_ENCODE or XDR_FREE. more_elements is overwritten by | |||
| 88 | * xdr_bool when the direction is XDR_DECODE. | |||
| 89 | */ | |||
| 90 | bool_tint32_t more_elements; | |||
| 91 | int freeing = (xdrs->x_op == XDR_FREE); | |||
| ||||
| 92 | struct pmaplist **next; | |||
| 93 | ||||
| 94 | while (TRUE(1)) { | |||
| 95 | more_elements = (bool_tint32_t)(*rp != NULL0); | |||
| ||||
| 96 | if (! xdr_bool(xdrs, &more_elements)) | |||
| 97 | return (FALSE(0)); | |||
| 98 | if (! more_elements) | |||
| 99 | return (TRUE(1)); /* we are done */ | |||
| 100 | /* | |||
| 101 | * the unfortunate side effect of non-recursion is that in | |||
| 102 | * the case of freeing we must remember the next object | |||
| 103 | * before we free the current object ... | |||
| 104 | */ | |||
| 105 | if (freeing
| |||
| 106 | next = &((*rp)->pml_next); | |||
| 107 | if (! xdr_reference(xdrs, (caddr_t *)rp, | |||
| 108 | (u_int)sizeof(struct pmaplist), xdr_pmap)) | |||
| 109 | return (FALSE(0)); | |||
| 110 | rp = (freeing
| |||
| 111 | } | |||
| 112 | } | |||
| 113 | DEF_WEAK(xdr_pmaplist)__asm__(".weak " "xdr_pmaplist" " ; " "xdr_pmaplist" " = " "_libc_xdr_pmaplist" ); |