Security/libsecurity_cdsa_utilities/lib/cssmlist.h

   1 /*
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   8  * Version 2.0 (the 'License'). You may not use this file except in
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  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
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  23
  24
  25 //
  26 // cssmlist - CSSM_LIST operational utilities
  27 //
  28 #ifndef _H_CSSMLIST
  29 #define _H_CSSMLIST
  30
  31 #include <security_utilities/utilities.h>
  32 #include <security_cdsa_utilities/cssmalloc.h>
  33 #include <security_cdsa_utilities/cssmwalkers.h>
  34
  35
  36 namespace Security {
  37
  38 class CssmList;
  39 class TypedList;
  40
  41
  42 //
  43 // A POD Wrapper for CSSM_LIST_ELEMENTs.
  44 // List elements are pseudo-polymorphic, so we provide ways to get and
  45 // set their three personalities. It's up to the caller to get this right;
  46 // you mustn't (for example) call the data() method on a list element that
  47 // is not of (element) type CSSM_LIST_ELEMENT_DATUM. To violate this rule
  48 // will get you an assertion (not exception).
  49 //
  50 class ListElement : public PodWrapper<ListElement, CSSM_LIST_ELEMENT> {
  51 public:
  52         // type control
  53         CSSM_LIST_ELEMENT_TYPE type() const { return ElementType; }
  54         bool is(CSSM_LIST_ELEMENT_TYPE t) const { return type() == t; }
  55
  56     // list element chaining
  57         ListElement * &next() { return ListElement::overlayVar(NextElement); }
  58         ListElement *next() const { return ListElement::overlay(NextElement); }
  59         ListElement *last();
  60
  61     // CssmData personality
  62         explicit ListElement(const CssmData &data);
  63         explicit ListElement(Allocator &alloc, const CssmData &data);
  64         explicit ListElement(Allocator &alloc, const std::string &stringData);
  65
  66         CssmData &data();
  67         string toString() const { return data().toString(); }
  68         const CssmData &data() const;
  69         ListElement &operator = (const CssmData &data);
  70         operator CssmData &() { return data(); }
  71         operator std::string () const { return toString(); }
  72         bool operator == (const CssmData &other) const  { return data() == other; }
  73         bool operator != (const CssmData &other) const  { return data() != other; }
  74
  75     template <class T>
  76     void extract(T &destination, CSSM_RETURN error = CSSM_ERRCODE_INVALID_DATA)
  77     { data().extract(destination, error); }
  78
  79     // CssmList (sublist) personality
  80         explicit ListElement(const CssmList &list);
  81         CssmList &list();
  82         const CssmList &list() const;
  83         TypedList &typedList();
  84         const TypedList &typedList() const;
  85         ListElement &operator = (const CssmList &list);
  86         operator CssmList &() { return list(); }
  87     operator TypedList &();
  88
  89     // WORDID (number) personality
  90         explicit ListElement(CSSM_WORDID_TYPE word);
  91         CSSM_WORDID_TYPE word() const;
  92         ListElement &operator = (CSSM_WORDID_TYPE word);
  93     operator CSSM_WORDID_TYPE () const { return word(); }
  94
  95 public:
  96         void *operator new (size_t size, Allocator &alloc)
  97         { return alloc.malloc(size); }
  98
  99         void clear(Allocator &alloc);           // free my contents
 100 };
 101
 102 } // end namespace Security
 103
 104 // specialize destroy() to call clear() for cleanup
 105 inline void destroy(ListElement *elem, Allocator &alloc)
 106 {
 107         elem->clear(alloc);
 108         alloc.free(elem);
 109 }
 110
 111 namespace Security {
 112
 113
 114 //
 115 // A POD Wrapper for CSSM_LIST.
 116 // CssmList does no memory allocations. Retrieval functions return pointers or
 117 // references into existing content, and modifiers modify in-place without any
 118 // attempt to release previous dynamic content. May the Leaking God be with You.
 119 //
 120 class CssmList : public PodWrapper<CssmList, CSSM_LIST> {
 121 public:
 122         CssmList() { ListType = CSSM_LIST_TYPE_UNKNOWN; Head = Tail = NULL; }
 123         CssmList(const CssmList &list)  { *(CssmList *)this = list; }
 124
 125 public:
 126         CSSM_LIST_TYPE kind() const { return ListType; }        // type() reserved for TypedList
 127
 128         ListElement &operator [] (unsigned ix) const;
 129         unsigned int length() const;
 130         ListElement * &first() { return ListElement::overlayVar(Head); }
 131         ListElement *first() const { return ListElement::overlay(Head); }
 132         ListElement *last() const { return ListElement::overlay(Tail); }
 133         bool empty() const { return first() == NULL; }
 134
 135         CssmList &append(ListElement *elem);
 136         CssmList &insert(ListElement *elem, ListElement *before);
 137         CssmList &remove(ListElement *elem);
 138         CssmList &operator += (ListElement *elem) { return append(elem); }
 139         CssmList &operator -= (ListElement *elem) { return remove(elem); }
 140
 141     // logically remove the first element (skip it)
 142     void snip();
 143
 144 public:
 145         void clear(Allocator &alloc);           // free my contents
 146 };
 147
 148 } // end namespace Security
 149
 150 inline void destroy(CssmList *list, Allocator &alloc)
 151 {
 152         list->clear(alloc);
 153         alloc.free(list);
 154 }
 155
 156 namespace Security
 157 {
 158
 159 //
 160 // Enhanced overlay for CssmLists whose first element is known to be a wordid.
 161 //
 162 class TypedList : public CssmList {
 163 public:
 164     explicit TypedList(const CSSM_LIST &list) { *(CSSM_LIST *)this = list; }
 165         TypedList(Allocator &alloc, CSSM_WORDID_TYPE type);
 166         TypedList(Allocator &alloc, CSSM_WORDID_TYPE type, ListElement *elem1);
 167         TypedList(Allocator &alloc, CSSM_WORDID_TYPE type, ListElement *elem1,
 168                 ListElement *elem2);
 169         TypedList(Allocator &alloc, CSSM_WORDID_TYPE type, ListElement *elem1,
 170                 ListElement *elem2, ListElement *elem3);
 171         TypedList(Allocator &alloc, CSSM_WORDID_TYPE type, ListElement *elem1,
 172                 ListElement *elem2, ListElement *elem3, ListElement *elem4);
 173
 174         bool isProper() const;  // format check (does not throw)
 175         void checkProper(CSSM_RETURN error = CSSM_ERRCODE_INVALID_SAMPLE_VALUE) const;
 176         static TypedList &overlay(CSSM_LIST &list)
 177         { return static_cast<TypedList &>(list); }
 178         static const TypedList &overlay(const CSSM_LIST &list)
 179         { return static_cast<const TypedList &>(list); }
 180
 181         CSSM_WORDID_TYPE type() const
 182         { assert(isProper()); return first()->word(); }
 183 };
 184
 185 inline ListElement::operator TypedList &()
 186 { return TypedList::overlay(operator CssmList &()); }
 187
 188
 189 //
 190 // Data walkers to parse list elements and lists.
 191 // @@@ Walking lists by recursing over next() is stack intensive. Do this in CssmList walker by loop?
 192 //
 193 namespace DataWalkers {
 194
 195 // ListElement
 196 template <class Action>
 197 ListElement *walk(Action &operate, ListElement * &elem)
 198 {
 199         operate(elem);
 200         switch (elem->type()) {
 201         case CSSM_LIST_ELEMENT_DATUM:
 202                 walk(operate, elem->data());
 203                 break;
 204         case CSSM_LIST_ELEMENT_SUBLIST:
 205                 walk(operate, elem->list());
 206                 break;
 207         case CSSM_LIST_ELEMENT_WORDID:
 208                 break;
 209         default:
 210                 secdebug("walkers", "invalid list element type (%ux)", (unsigned)elem->type());
 211                 break;
 212         }
 213         if (elem->next())
 214                 walk(operate, elem->next());
 215         return elem;
 216 }
 217
 218 template <class Action>
 219 ListElement *walk(Action &operate, CSSM_LIST_ELEMENT * &elem)
 220 { return walk(operate, ListElement::overlayVar(elem)); }
 221
 222 // CssmList
 223 template <class Action>
 224 void enumerate(Action &operate, CssmList &list)
 225 {
 226         if (!list.empty()) {
 227                 walk(operate, list.first());
 228                 if (operate.needsRelinking)
 229                         list.Tail = list.first()->last();       // re-establish "tail" link
 230         }
 231 }
 232
 233 template <class Action>
 234 CssmList *walk(Action &operate, CssmList * &list)
 235 {
 236         operate(list);
 237         enumerate(operate, *list);
 238         return list;
 239 }
 240
 241 template <class Action>
 242 void walk(Action &operate, CssmList &list)
 243 {
 244         operate(list);
 245         enumerate(operate, list);
 246 }
 247
 248 template <class Action>
 249 void walk(Action &operate, CSSM_LIST &list)
 250 { walk(operate, CssmList::overlay(list)); }
 251
 252 template <class Action>
 253 CSSM_LIST *walk(Action &operate, CSSM_LIST * &list)
 254 { return walk(operate, CssmList::overlayVar(list)); }
 255
 256 template <class Action>
 257 TypedList *walk(Action &operate, TypedList * &list)
 258 { return static_cast<TypedList *>(walk(operate, reinterpret_cast<CssmList * &>(list))); }
 259
 260 template <class Action>
 261 void walk(Action &operate, TypedList &list)
 262 { walk(operate, static_cast<CssmList &>(list)); }
 263
 264
 265 }       // end namespace DataWalkers
 266 }       // end namespace Security
 267
 268
 269 #endif //_H_CSSMLIST