ceph/src/osd/ClassHandler.cc

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #include "include/types.h"
   5 #include "ClassHandler.h"
   6 #include "common/errno.h"
   7 #include "common/ceph_context.h"
   8
   9 #include <dlfcn.h>
  10
  11 #include <map>
  12
  13 #if defined(__FreeBSD__)
  14 #include <sys/param.h>
  15 #endif
  16
  17 #include "common/config.h"
  18 #include "common/debug.h"
  19
  20 #define dout_subsys ceph_subsys_osd
  21 #undef dout_prefix
  22 #define dout_prefix *_dout
  23
  24
  25 #define CLS_PREFIX "libcls_"
  26 #define CLS_SUFFIX ".so"
  27
  28
  29 void ClassHandler::add_embedded_class(const string& cname)
  30 {
  31   assert(mutex.is_locked());
  32   ClassData *cls = _get_class(cname, false);
  33   assert(cls->status == ClassData::CLASS_UNKNOWN);
  34   cls->status = ClassData::CLASS_INITIALIZING;
  35 }
  36
  37 int ClassHandler::open_class(const string& cname, ClassData **pcls)
  38 {
  39   Mutex::Locker lock(mutex);
  40   ClassData *cls = _get_class(cname, true);
  41   if (!cls)
  42     return -EPERM;
  43   if (cls->status != ClassData::CLASS_OPEN) {
  44     int r = _load_class(cls);
  45     if (r)
  46       return r;
  47   }
  48   *pcls = cls;
  49   return 0;
  50 }
  51
  52 int ClassHandler::open_all_classes()
  53 {
  54   ldout(cct, 10) << __func__ << dendl;
  55   DIR *dir = ::opendir(cct->_conf->osd_class_dir.c_str());
  56   if (!dir)
  57     return -errno;
  58
  59   struct dirent *pde = nullptr;
  60   int r = 0;
  61   while ((pde = ::readdir(dir))) {
  62     if (pde->d_name[0] == '.')
  63       continue;
  64     if (strlen(pde->d_name) > sizeof(CLS_PREFIX) - 1 + sizeof(CLS_SUFFIX) - 1 &&
  65         strncmp(pde->d_name, CLS_PREFIX, sizeof(CLS_PREFIX) - 1) == 0 &&
  66         strcmp(pde->d_name + strlen(pde->d_name) - (sizeof(CLS_SUFFIX) - 1), CLS_SUFFIX) == 0) {
  67       char cname[PATH_MAX + 1];
  68       strncpy(cname, pde->d_name + sizeof(CLS_PREFIX) - 1, sizeof(cname) -1);
  69       cname[strlen(cname) - (sizeof(CLS_SUFFIX) - 1)] = '\0';
  70       ldout(cct, 10) << __func__ << " found " << cname << dendl;
  71       ClassData *cls;
  72       // skip classes that aren't in 'osd class load list'
  73       r = open_class(cname, &cls);
  74       if (r < 0 && r != -EPERM)
  75         goto out;
  76     }
  77   }
  78  out:
  79   closedir(dir);
  80   return r;
  81 }
  82
  83 void ClassHandler::shutdown()
  84 {
  85   for (auto& cls : classes) {
  86     if (cls.second.handle) {
  87       dlclose(cls.second.handle);
  88     }
  89   }
  90   classes.clear();
  91 }
  92
  93 /*
  94  * Check if @cname is in the whitespace delimited list @list, or the @list
  95  * contains the wildcard "*".
  96  *
  97  * This is expensive but doesn't consume memory for an index, and is performed
  98  * only once when a class is loaded.
  99  */
 100 bool ClassHandler::in_class_list(const std::string& cname,
 101     const std::string& list)
 102 {
 103   std::istringstream ss(list);
 104   std::istream_iterator<std::string> begin{ss};
 105   std::istream_iterator<std::string> end{};
 106
 107   const std::vector<std::string> targets{cname, "*"};
 108
 109   auto it = std::find_first_of(begin, end,
 110       targets.begin(), targets.end());
 111
 112   return it != end;
 113 }
 114
 115 ClassHandler::ClassData *ClassHandler::_get_class(const string& cname,
 116     bool check_allowed)
 117 {
 118   ClassData *cls;
 119   map<string, ClassData>::iterator iter = classes.find(cname);
 120
 121   if (iter != classes.end()) {
 122     cls = &iter->second;
 123   } else {
 124     if (check_allowed && !in_class_list(cname, cct->_conf->osd_class_load_list)) {
 125       ldout(cct, 0) << "_get_class not permitted to load " << cname << dendl;
 126       return NULL;
 127     }
 128     cls = &classes[cname];
 129     ldout(cct, 10) << "_get_class adding new class name " << cname << " " << cls << dendl;
 130     cls->name = cname;
 131     cls->handler = this;
 132     cls->whitelisted = in_class_list(cname, cct->_conf->osd_class_default_list);
 133   }
 134   return cls;
 135 }
 136
 137 int ClassHandler::_load_class(ClassData *cls)
 138 {
 139   // already open
 140   if (cls->status == ClassData::CLASS_OPEN)
 141     return 0;
 142
 143   if (cls->status == ClassData::CLASS_UNKNOWN ||
 144       cls->status == ClassData::CLASS_MISSING) {
 145     char fname[PATH_MAX];
 146     snprintf(fname, sizeof(fname), "%s/" CLS_PREFIX "%s" CLS_SUFFIX,
 147              cct->_conf->osd_class_dir.c_str(),
 148              cls->name.c_str());
 149     ldout(cct, 10) << "_load_class " << cls->name << " from " << fname << dendl;
 150
 151     cls->handle = dlopen(fname, RTLD_NOW);
 152     if (!cls->handle) {
 153       struct stat st;
 154       int r = ::stat(fname, &st);
 155       if (r < 0) {
 156         r = -errno;
 157         ldout(cct, 0) << __func__ << " could not stat class " << fname
 158                       << ": " << cpp_strerror(r) << dendl;
 159       } else {
 160         ldout(cct, 0) << "_load_class could not open class " << fname
 161                       << " (dlopen failed): " << dlerror() << dendl;
 162         r = -EIO;
 163       }
 164       cls->status = ClassData::CLASS_MISSING;
 165       return r;
 166     }
 167
 168     cls_deps_t *(*cls_deps)();
 169     cls_deps = (cls_deps_t *(*)())dlsym(cls->handle, "class_deps");
 170     if (cls_deps) {
 171       cls_deps_t *deps = cls_deps();
 172       while (deps) {
 173         if (!deps->name)
 174           break;
 175         ClassData *cls_dep = _get_class(deps->name, false);
 176         cls->dependencies.insert(cls_dep);
 177         if (cls_dep->status != ClassData::CLASS_OPEN)
 178           cls->missing_dependencies.insert(cls_dep);
 179         deps++;
 180       }
 181     }
 182   }
 183
 184   // resolve dependencies
 185   set<ClassData*>::iterator p = cls->missing_dependencies.begin();
 186   while (p != cls->missing_dependencies.end()) {
 187     ClassData *dc = *p;
 188     int r = _load_class(dc);
 189     if (r < 0) {
 190       cls->status = ClassData::CLASS_MISSING_DEPS;
 191       return r;
 192     }
 193
 194     ldout(cct, 10) << "_load_class " << cls->name << " satisfied dependency " << dc->name << dendl;
 195     cls->missing_dependencies.erase(p++);
 196   }
 197
 198   // initialize
 199   void (*cls_init)() = (void (*)())dlsym(cls->handle, "__cls_init");
 200   if (cls_init) {
 201     cls->status = ClassData::CLASS_INITIALIZING;
 202     cls_init();
 203   }
 204
 205   ldout(cct, 10) << "_load_class " << cls->name << " success" << dendl;
 206   cls->status = ClassData::CLASS_OPEN;
 207   return 0;
 208 }
 209
 210
 211
 212 ClassHandler::ClassData *ClassHandler::register_class(const char *cname)
 213 {
 214   assert(mutex.is_locked());
 215
 216   ClassData *cls = _get_class(cname, false);
 217   ldout(cct, 10) << "register_class " << cname << " status " << cls->status << dendl;
 218
 219   if (cls->status != ClassData::CLASS_INITIALIZING) {
 220     ldout(cct, 0) << "class " << cname << " isn't loaded; is the class registering under the wrong name?" << dendl;
 221     return NULL;
 222   }
 223   return cls;
 224 }
 225
 226 void ClassHandler::unregister_class(ClassHandler::ClassData *cls)
 227 {
 228   /* FIXME: do we really need this one? */
 229 }
 230
 231 ClassHandler::ClassMethod *ClassHandler::ClassData::register_method(const char *mname,
 232                                                                     int flags,
 233                                                                     cls_method_call_t func)
 234 {
 235   /* no need for locking, called under the class_init mutex */
 236   if (!flags) {
 237     lderr(handler->cct) << "register_method " << name << "." << mname
 238                         << " flags " << flags << " " << (void*)func
 239                         << " FAILED -- flags must be non-zero" << dendl;
 240     return NULL;
 241   }
 242   ldout(handler->cct, 10) << "register_method " << name << "." << mname << " flags " << flags << " " << (void*)func << dendl;
 243   ClassMethod& method = methods_map[mname];
 244   method.func = func;
 245   method.name = mname;
 246   method.flags = flags;
 247   method.cls = this;
 248   return &method;
 249 }
 250
 251 ClassHandler::ClassMethod *ClassHandler::ClassData::register_cxx_method(const char *mname,
 252                                                                         int flags,
 253                                                                         cls_method_cxx_call_t func)
 254 {
 255   /* no need for locking, called under the class_init mutex */
 256   ldout(handler->cct, 10) << "register_cxx_method " << name << "." << mname << " flags " << flags << " " << (void*)func << dendl;
 257   ClassMethod& method = methods_map[mname];
 258   method.cxx_func = func;
 259   method.name = mname;
 260   method.flags = flags;
 261   method.cls = this;
 262   return &method;
 263 }
 264
 265 ClassHandler::ClassFilter *ClassHandler::ClassData::register_cxx_filter(
 266     const std::string &filter_name,
 267     cls_cxx_filter_factory_t fn)
 268 {
 269   ClassFilter &filter = filters_map[filter_name];
 270   filter.fn = fn;
 271   filter.name = filter_name;
 272   filter.cls = this;
 273   return &filter;
 274 }
 275
 276 ClassHandler::ClassMethod *ClassHandler::ClassData::_get_method(const char *mname)
 277 {
 278   map<string, ClassHandler::ClassMethod>::iterator iter = methods_map.find(mname);
 279   if (iter == methods_map.end())
 280     return NULL;
 281   return &(iter->second);
 282 }
 283
 284 int ClassHandler::ClassData::get_method_flags(const char *mname)
 285 {
 286   Mutex::Locker l(handler->mutex);
 287   ClassMethod *method = _get_method(mname);
 288   if (!method)
 289     return -ENOENT;
 290   return method->flags;
 291 }
 292
 293 void ClassHandler::ClassData::unregister_method(ClassHandler::ClassMethod *method)
 294 {
 295   /* no need for locking, called under the class_init mutex */
 296    map<string, ClassMethod>::iterator iter = methods_map.find(method->name);
 297    if (iter == methods_map.end())
 298      return;
 299    methods_map.erase(iter);
 300 }
 301
 302 void ClassHandler::ClassMethod::unregister()
 303 {
 304   cls->unregister_method(this);
 305 }
 306
 307 void ClassHandler::ClassData::unregister_filter(ClassHandler::ClassFilter *filter)
 308 {
 309   /* no need for locking, called under the class_init mutex */
 310    map<string, ClassFilter>::iterator iter = filters_map.find(filter->name);
 311    if (iter == filters_map.end())
 312      return;
 313    filters_map.erase(iter);
 314 }
 315
 316 void ClassHandler::ClassFilter::unregister()
 317 {
 318   cls->unregister_filter(this);
 319 }
 320
 321 int ClassHandler::ClassMethod::exec(cls_method_context_t ctx, bufferlist& indata, bufferlist& outdata)
 322 {
 323   int ret;
 324   if (cxx_func) {
 325     // C++ call version
 326     ret = cxx_func(ctx, &indata, &outdata);
 327   } else {
 328     // C version
 329     char *out = NULL;
 330     int olen = 0;
 331     ret = func(ctx, indata.c_str(), indata.length(), &out, &olen);
 332     if (out) {
 333       // assume *out was allocated via cls_alloc (which calls malloc!)
 334       buffer::ptr bp = buffer::claim_malloc(olen, out);
 335       outdata.push_back(bp);
 336     }
 337   }
 338   return ret;
 339 }
 340