src/mod_table.c

/*
 * Copyright (c) 2019, The Linux Foundation. All rights reserved.
 *
 * 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 Linux Foundation 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 "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER 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.
 */
#ifndef FARF_ERROR
#define FARF_ERROR 1
#endif

#include <assert.h>
#include "verify.h"
#include "HAP_farf.h"
#include "HAP_pls.h"
#include "mutex.h"
#include "mod_table.h"
#include "platform_libs.h"
#include "remote64.h"
#include "uthash.h"
#include "AEEstd.h"
#include "AEEStdErr.h"
#include "sbuf_parser.h"

#include <dlfcn.h>

#define DLOPEN  dlopen
#define DLCLOSE dlclose
#define DLSYM   dlsym
#define DLERROR dlerror

/**
 * structure for the mod table
 *
 * you need to define a rw_mutex type and its read/write lock/unlock api's
 * which are under the RW_MUTEX namespace.
 *
 * this library defines 2 functions for opening modules, open_static and
 * open_dynamic.  Both return a handle that should be closed via close.
 *
 * you can also register a const handle, an invoke function for a known handle
 * value.  since handle keys are allocated, you should pick handle values that are
 * not going to be returned by malloc (0, or odd).
 */
struct static_mod_table {
   RW_MUTEX_T mut;
   struct static_mod* staticModOverrides;
   struct static_mod* staticMods;
   struct const_mod* constMods;
   boolean bInit;
};

struct open_mod_table {
   RW_MUTEX_T mut;
   struct open_mod* openMods;
   struct static_mod_table* smt;
};

typedef int (*invoke_fn)(uint32, remote_arg*);
typedef int (*handle_invoke_fn)(remote_handle64, uint32, remote_arg*);
struct static_mod {
   invoke_fn         invoke;
   handle_invoke_fn  handle_invoke;
   UT_hash_handle    hh;
   char              uri[1];
};

struct const_mod {
   invoke_fn         invoke;
   handle_invoke_fn  handle_invoke;
   uint32            key;
   remote_handle64   h64;
   UT_hash_handle    hh;
   char              uri[1];
};

struct parsed_uri {
   const char *file;
   int filelen;
   const char *sym;
   int symlen;
   const char *ver;
   int verlen;
};

struct open_mod {
   void*             dlhandle;
   invoke_fn         invoke;
   handle_invoke_fn  handle_invoke;
   uint64            key;
   UT_hash_handle    hh;
   remote_handle64   h64;
   int               refs;
   struct parsed_uri vals;
   char              uri[1];
};

static int static_mod_table_ctor(struct static_mod_table* me) {
   if(me->bInit == 0) {
      RW_MUTEX_CTOR(me->mut);
      me->staticMods = 0;
      me->staticModOverrides = 0;
      me->bInit = 1;
   }
   return 0;
}

static void static_mod_table_dtor_imp(struct static_mod_table* me) {
   struct static_mod *sm, *stmp;
   struct const_mod *dm, *ftmp;
   if(me->bInit != 0) {
      if( me->staticMods || me->constMods || me->staticModOverrides) {
         RW_MUTEX_LOCK_WRITE(me->mut);
         HASH_ITER(hh, me->staticMods, sm, stmp) {
            if(me->staticMods) {
               HASH_DEL(me->staticMods,sm);
            }
            free(sm);
            sm = NULL;
         }
         HASH_ITER(hh, me->staticModOverrides, sm, stmp) {
            if(me->staticModOverrides) {
               HASH_DEL(me->staticModOverrides,sm);
            }
            free(sm);
            sm = NULL;
         }
         HASH_ITER(hh, me->constMods, dm, ftmp) {
            if(me->constMods) {
               HASH_DEL(me->constMods,dm);
            }
            free(dm);
            dm = NULL;
         }
         RW_MUTEX_UNLOCK_WRITE(me->mut);
      }
      RW_MUTEX_DTOR(me->mut);
      me->staticMods = 0;
      me->staticModOverrides = 0;
      me->bInit = 0;
   }
}

static int open_mod_table_ctor_imp(void* ctx, void* data) {
   struct open_mod_table* me = (struct open_mod_table*)data;
   RW_MUTEX_CTOR(me->mut);
   me->openMods = 0;
   me->smt = (struct static_mod_table*) ctx;
   return 0;
}

static int open_mod_handle_close(struct open_mod *mod, remote_handle64 h);

static void open_mod_table_dtor_imp(void* data) {
   struct open_mod_table* me = (struct open_mod_table*)data;
   struct open_mod *dm, *ftmp;
   if( me->openMods) {
      RW_MUTEX_LOCK_WRITE(me->mut);
      HASH_ITER(hh, me->openMods, dm, ftmp) {
         if(me->openMods) {
            HASH_DEL(me->openMods,dm);
         }
         if(dm->h64) {
            (void)open_mod_handle_close(dm, dm->h64);
         }
         if(dm->dlhandle) {
            DLCLOSE(dm->dlhandle);
         }
         free(dm);
      }
      RW_MUTEX_UNLOCK_WRITE(me->mut);
   }
   RW_MUTEX_DTOR(me->mut);
   me->openMods = 0;
}
static int open_mod_table_open_from_static(struct open_mod_table* me,
                                           struct static_mod** tbl,
                                           const char* uri,
                                           remote_handle* handle);

static int open_mod_table_open_static_override(struct open_mod_table* me, const char* uri, remote_handle* handle) {
   FARF(HIGH, "open_mod_table_open_static_override");
   return open_mod_table_open_from_static(me, &me->smt->staticModOverrides, uri, handle);
}


static int open_mod_table_open_static(struct open_mod_table* me, const char* uri, remote_handle* handle) {
   FARF(HIGH, "open_mod_table_open_static");
   return open_mod_table_open_from_static(me, &me->smt->staticMods, uri, handle);
}

static int static_mod_add(struct static_mod_table* me, struct static_mod** tbl, const char* uri,
                          int(*invoke)(uint32 sc, remote_arg* pra),
                          int(*handle_invoke)(remote_handle64, uint32 sc, remote_arg* pra)) {
   int nErr = AEE_SUCCESS;
   struct static_mod *sm = 0;
   int len = std_strlen(uri) + 1;
   VERIFYC(NULL != (sm = ((struct static_mod*)calloc(1, sizeof(struct static_mod) + len))), AEE_ENOMEMORY);
   std_strlcpy(sm->uri, uri, len);
   sm->invoke = invoke;
   sm->handle_invoke = handle_invoke;
   RW_MUTEX_LOCK_WRITE(me->mut);
	HASH_ADD_STR(*tbl, uri, sm);
   RW_MUTEX_UNLOCK_WRITE(me->mut);
bail:
   if(nErr != AEE_SUCCESS) {
      VERIFY_EPRINTF("Error %x: static module addition failed\n", nErr);
      if(sm) {
         free(sm);
         sm = NULL;
      }
   }
   return nErr;
}

static int static_mod_table_register_static_override(struct static_mod_table* me, const char* uri, int(*pfn)(uint32 sc, remote_arg* pra)) {
   return static_mod_add(me, &me->staticModOverrides, uri, pfn, 0);
}
static int static_mod_table_register_static_override1(struct static_mod_table* me, const char* uri, int(*pfn)(remote_handle64, uint32 sc, remote_arg* pra)) {
   return static_mod_add(me, &me->staticModOverrides, uri, 0, pfn);
}
static int static_mod_table_register_static(struct static_mod_table* me, const char* uri, int(*pfn)(uint32 sc, remote_arg* pra)) {
   return static_mod_add(me, &me->staticMods, uri, pfn, 0);
}
static int static_mod_table_register_static1(struct static_mod_table* me, const char* uri, int(*pfn)(remote_handle64,uint32 sc, remote_arg* pra)) {
   return static_mod_add(me, &me->staticMods, uri, 0, pfn);
}


static int static_mod_table_register_const_handle(struct static_mod_table* me, remote_handle local,
                                                  remote_handle64 remote, const char* uri,
                                                  int(*invoke)(uint32 sc, remote_arg* pra),
                                                  int(*handle_invoke)(remote_handle64, uint32 sc, remote_arg* pra)
                                                  ) {
   int nErr = AEE_SUCCESS;
   int len = std_strlen(uri) + 1;
   struct const_mod *dm = 0, *dmOld;
   VERIFYC(NULL != (dm = ((struct const_mod*)calloc(1, sizeof(struct open_mod) + len))), AEE_ENOMEMORY);
   dm->key = local;
   dm->invoke = invoke;
   dm->handle_invoke = handle_invoke;
   dm->h64 = remote;
   std_strlcpy(dm->uri, uri, len);

   RW_MUTEX_LOCK_WRITE(me->mut);
   HASH_FIND_INT(me->constMods, &local, dmOld);
   if(dmOld == 0) {
	   HASH_ADD_INT(me->constMods, key, dm);
   }
   RW_MUTEX_UNLOCK_WRITE(me->mut);
   nErr = dmOld != 0 ? -1 : nErr;
bail:
   if(nErr != AEE_SUCCESS) {
      VERIFY_EPRINTF("Error %x: failed to register const handle in modtable\n", nErr);
      if(dm) {
         free(dm);
         dm = NULL;
      }
   }
   return nErr;
}

static int open_mod_handle_open(struct open_mod *mod, const char* name,
                                remote_handle64 *ph) {
   int nErr = AEE_SUCCESS;
   remote_arg args[3];
   int32_t len = strlen(name) + 1;
   args[0].buf.pv = &len;
   args[0].buf.nLen = sizeof(len);
   args[1].buf.pv = (void*)name;
   args[1].buf.nLen = len;
   nErr = mod->handle_invoke(0,REMOTE_SCALARS_MAKEX(0,0,2,0,0,1),args);
   if(!nErr) {
      *ph = args[2].h64;
   }
   FARF(HIGH, "allocated %x", *ph);
   return nErr;
}

static int open_mod_handle_close(struct open_mod *mod, remote_handle64 h) {
   int nErr;
   remote_arg args[1];
   args[0].h64 = h;
   FARF(HIGH, "releasing %x", h);
   nErr = mod->handle_invoke(0,REMOTE_SCALARS_MAKEX(0,1,0,0,1,0),args);
   return nErr;
}

static int notqmark(struct sbuf *buf) {
   return sbuf_notchar(buf, '?');
}
static int notandoreq(struct sbuf *buf) {
   return sbuf_notchars(buf, "&=");
}
static int notand(struct sbuf *buf) {
   return sbuf_notchar(buf, '&');
}

static int parse_uri(const char *uri, int urilen, struct parsed_uri *out) {
// "file:///librhtest_skel.so?rhtest_skel_handle_invoke&_modver=1.0"
   int nErr = 0;
   char *name, *value;
   int nameLen, valueLen;
   struct sbuf buf;
   FARF(HIGH, "parse_uri %s %d", uri, urilen);
   memset(out, 0, sizeof(*out));
   //initialize
   sbuf_parser_init(&buf, uri, urilen);

   //parse until question mark
   VERIFYC(sbuf_string(&buf, "file://"), AEE_EINVALIDFORMAT);

   //ignore the starting /
   (void)sbuf_string(&buf, "/");

   out->file = sbuf_cur(&buf);
   VERIFY(sbuf_many1(&buf, notqmark));
   out->filelen = sbuf_cur(&buf) - out->file;
   FARF(HIGH, "file:%.*s %d", out->filelen, out->file, out->filelen);
   VERIFY(sbuf_char(&buf, '?'));
   out->sym = sbuf_cur(&buf);
   VERIFY(sbuf_many1(&buf, notand));
   out->symlen = sbuf_cur(&buf) - out->sym;
   assert(out->sym + out->symlen <= uri + urilen);
   FARF(HIGH, "sym:%.*s %d", out->symlen, out->sym, out->symlen);

   if(!sbuf_end(&buf) && sbuf_char(&buf, '&')) {
     //parse each query
     while(!sbuf_end(&buf)) {
        //record where the name starts
        name = sbuf_cur(&buf);

        //name is valid until '=' or '&'
        VERIFY(sbuf_many1(&buf, notandoreq));
        nameLen = sbuf_cur(&buf) - name;

        value = 0;
        valueLen = 0;
        //if the next char is a '=' then we also get a value
        if(sbuf_char(&buf, '=')) {
           value = sbuf_cur(&buf);

           //value is until the next query that starts with '&'
           VERIFY(sbuf_many1(&buf, notand));
           valueLen = sbuf_cur(&buf) - value;
        }
        //expect '&' or end
        sbuf_char(&buf, '&');
        if(!std_strncmp(name, "_modver", nameLen)) {
           out->ver = value;
           out->verlen = valueLen;
        }
     }
   }
bail:
   if(out->filelen) {
      FARF(HIGH, "parse_uri file: %.*s", out->filelen, out->file);
   }
   if(out->symlen) {
      FARF(HIGH, "parse_uri sym: %.*s", out->symlen, out->sym);
   }
   if(out->verlen) {
      FARF(HIGH, "parse_uri version: %.*s", out->verlen, out->ver);
   }
   FARF(HIGH, "parse_uri done: %s %d err:%x", uri, urilen, nErr);
   if(nErr != AEE_SUCCESS) {
      VERIFY_EPRINTF("Error %x: parseuri failed for uri %s, urilen %d\n", nErr, uri, urilen);
   }
   return nErr;
}

static int open_mod_table_open_dynamic(struct open_mod_table* me, const char* uri, remote_handle* handle, char* dlStr, int dlerrorLen, int* pdlErr)
{
   int nErr = AEE_SUCCESS, dlErr = 0;
   struct open_mod *dm = 0, *dmOld;
   int len = strlen(uri);
   int tmplen = len*2 + sizeof("file:///lib_skel.so?_skel_handle_invoke&_modver=1.0") + 1;
   char *tmp = 0;
   FARF(HIGH, "open_mod_table_open_dynamic");
   VERIFYC(NULL != (tmp = calloc(1, tmplen)), AEE_ENOMEMORY);
   VERIFYC(NULL != (dm = ((struct open_mod*)calloc(1, sizeof(struct open_mod) + len + 1))), AEE_ENOMEMORY);
   std_memmove(dm->uri, uri, len + 1);
   FARF(HIGH, "calling parse_uri");
   (void)parse_uri(dm->uri, len, &dm->vals);
   FARF(HIGH, "done calling parse_uri");
   FARF(HIGH, "vals %d %d %d", dm->vals.filelen, dm->vals.symlen, dm->vals.verlen);
   if(dm->vals.filelen) {
      int rv = std_snprintf(tmp, tmplen, "%.*s", dm->vals.filelen, dm->vals.file);
      VERIFYC(tmplen >= rv, AEE_EBADSIZE);
   } else {
      int rv;
      rv = std_snprintf(tmp, tmplen, "lib%s_skel.so", uri);
      VERIFYC(tmplen >= rv, AEE_EBADSIZE);
   }
   FARF(HIGH, "calling dlopen for %s", tmp);
   dm->dlhandle = DLOPEN(tmp,RTLD_NOW);
   FARF(HIGH, "got %p for dlopen %s", dm->dlhandle, tmp);
   VERIFY(!(nErr = (dlErr = dm->dlhandle == 0 ? -5 : 0)));

   if(dm->vals.symlen) {
      int rv = std_snprintf(tmp, tmplen, "%.*s", dm->vals.symlen, dm->vals.sym);
      VERIFYC(tmplen >= rv, AEE_EBADSIZE);
   } else {
      int rv = std_snprintf(tmp, tmplen, "%s_skel_invoke", uri);
      VERIFYC(tmplen >= rv, AEE_EBADSIZE);
   }

   FARF(HIGH, "calling dlsym for %s", tmp);
   if(dm->vals.verlen && 0 == std_strncmp(dm->vals.ver, "1.0", dm->vals.verlen)) {
      dm->handle_invoke = (handle_invoke_fn) DLSYM(dm->dlhandle, tmp);
   } else {
      dm->invoke = (invoke_fn) DLSYM(dm->dlhandle, tmp);
   }
   FARF(HIGH, "dlsym returned %p %p", dm->invoke, dm->handle_invoke);
   VERIFYC(!(dlErr = dm->invoke || dm->handle_invoke ? 0 : AEE_ENOSUCHSYMBOL), AEE_ENOSUCHSYMBOL);

   dm->key = (uint32)(uintptr_t)dm;
   dm->refs = 1;
   if(dm->handle_invoke) {
      VERIFY(AEE_SUCCESS == (nErr = open_mod_handle_open(dm, uri, &dm->h64)));
   }
   RW_MUTEX_LOCK_WRITE(me->mut);
      do {
         HASH_FIND_INT(me->openMods, &dm->key, dmOld);
         if(dmOld) {
            dm->key++;
         }
      } while(dmOld);
      RW_MUTEX_LOCK_WRITE(me->smt->mut);
      HASH_FIND_INT(me->smt->constMods, &dm->key, dmOld);
      RW_MUTEX_UNLOCK_WRITE(me->smt->mut);
      if(dmOld == 0) {
         HASH_ADD_INT(me->openMods, key, dm);
      }
   RW_MUTEX_UNLOCK_WRITE(me->mut);
   nErr = dmOld != 0 ? -1 : nErr;
   if(nErr == 0) {
      *handle = dm->key;
   }
bail:
   if (nErr != AEE_SUCCESS) {
      if(dlErr) {
         const char* dlerr = DLERROR();
         if(dlerr != 0){
            std_strlcpy(dlStr,dlerr,dlerrorLen);
         }
         FARF(HIGH, "dlerror:%x:%s", dlErr, dlerr == 0 ? "" : dlerr);
         nErr = 0;
      }
      if(pdlErr) {
         *pdlErr = dlErr;
      }
      if(dm && dm->h64) {
         (void)open_mod_handle_close(dm, dm->h64);
      }
      if(dm && dm->dlhandle) {
         DLCLOSE(dm->dlhandle);
      }
      if(dm) {
         free(dm);
         dm = NULL;
      }
      VERIFY_EPRINTF("Error %x: open modtable dynamic failed. dlerr %x\n", nErr, dlErr);
   }
   FARF(HIGH, "done open_mod_table_open_dynamic for %s rv %x handle: %p %x", uri, nErr, *handle, dlErr);
   if(tmp) {
      free(tmp);
      tmp = NULL;
   }
   return nErr;
}

static int open_mod_table_open_from_static(struct open_mod_table* me,
                                           struct static_mod** tbl,
                                           const char* uri,
                                           remote_handle* handle)
{
   int nErr = AEE_SUCCESS;
   struct static_mod *sm = 0;
   struct open_mod *dm = 0, *dmOld = 0;
   int len = std_strlen(uri);
   int sz = len*2 + sizeof("file:///lib_skel.so?_skel_handle_invoke&_modver=1.0") + 1;
   char *tmp = 0;
   VERIFYC(NULL != (dm = ((struct open_mod*)calloc(1, sizeof(*dm) + sz))), AEE_ENOMEMORY);
   RW_MUTEX_LOCK_READ(me->mut);
	HASH_FIND_STR(*tbl, uri, sm);
   RW_MUTEX_UNLOCK_READ(me->mut);
   std_memmove(dm->uri, uri, len);
   if(sm == 0) {
      VERIFY(AEE_SUCCESS == (nErr = parse_uri(uri, len, &dm->vals)));
      FARF(HIGH, "file %.*s %d", dm->vals.filelen, dm->vals.file, dm->vals.filelen);
      FARF(HIGH, "sym %.*s %d", dm->vals.symlen, dm->vals.sym, dm->vals.symlen);
      FARF(HIGH, "version %.*s %d", dm->vals.verlen, dm->vals.ver, dm->vals.verlen);
      if(dm->vals.verlen) {
         int rv = std_snprintf(dm->uri, sz, "file:///%.*s?%.*s&_modver=%.*s",
               dm->vals.filelen, dm->vals.file,
               dm->vals.symlen,  dm->vals.sym,
               dm->vals.verlen,  dm->vals.ver);
         VERIFYC(sz >= rv, AEE_EBADSIZE);
      } else {
         int rv = std_snprintf(dm->uri, sz, "file://%.*s?%.*s",
               dm->vals.filelen, dm->vals.file,
               dm->vals.symlen,  dm->vals.sym);
         VERIFYC(sz >= rv, AEE_EBADSIZE);
      }
      FARF(HIGH, "dm->uri:%s", dm->uri);

      RW_MUTEX_LOCK_READ(me->mut);
	   HASH_FIND_STR(*tbl, dm->uri, sm);
      RW_MUTEX_UNLOCK_READ(me->mut);
   }
   VERIFYC(0 != sm, AEE_ENOTINITIALIZED);
   assert(sm->handle_invoke || sm->invoke);
   dm->handle_invoke = sm->handle_invoke;
   dm->invoke = sm->invoke;
   dm->key = (uint32)(uintptr_t)dm;
   dm->refs = 1;
   if(dm->handle_invoke) {
      VERIFY(AEE_SUCCESS == (nErr = open_mod_handle_open(dm, uri, &dm->h64)));
   }

   RW_MUTEX_LOCK_WRITE(me->mut);
      do {
         HASH_FIND_INT(me->openMods, &dm->key, dmOld);
         if(dmOld) {
            dm->key++;
         }
      } while(dmOld);
      HASH_ADD_INT(me->openMods, key, dm);
   RW_MUTEX_UNLOCK_WRITE(me->mut);

   *handle = dm->key;
bail:
   if(tmp) {
      free(tmp);
      tmp = NULL;
   }
   if(nErr != AEE_SUCCESS) {
      VERIFY_EPRINTF("Error %x: modtable open from static failed.\n", nErr);
   }
   if(nErr && dm) {
      if(dm->h64) {
         (void)open_mod_handle_close(dm, dm->h64);
      }
      free(dm);
      dm = NULL;
   }
   return nErr;
}

static int open_mod_table_open(struct open_mod_table* me, const char* uri, remote_handle* handle, char* dlerr, int dlerrorLen, int* pdlErr)
{
   int nErr = AEE_SUCCESS, dlErr = 0;
   if(pdlErr) {
      *pdlErr = 0;
   }
   if(0 != open_mod_table_open_static_override(me, uri, handle)) {
      VERIFY(AEE_SUCCESS == (nErr = open_mod_table_open_dynamic(me, uri, handle, dlerr, dlerrorLen, &dlErr)));
      if(dlErr != 0) {
         FARF(HIGH, "dynammic open failed, trying static");
         if(0 != open_mod_table_open_static(me, uri, handle)) {
            if(pdlErr) {
               *pdlErr = dlErr;
            }
         }
      }
   }
bail:
   FARF(HIGH, "done open for %s rv %d handle: %p", uri, nErr, *handle);
   if(nErr != AEE_SUCCESS) {
      VERIFY_EPRINTF("Error %x: open modtable failed\n", nErr);
   }
   return nErr;
}

static void open_mod_close(struct open_mod_table *me, struct open_mod* dm) {
   RW_MUTEX_LOCK_WRITE(me->mut);
   dm->refs--;
   if(dm->refs <= 0) {
      HASH_DEL(me->openMods,dm);
   } else {
      dm = 0;
   }
   RW_MUTEX_UNLOCK_WRITE(me->mut);
   if(dm) {
      if(dm->h64) {
         (void)open_mod_handle_close(dm, dm->h64);
      }
      if(dm->dlhandle) {
         DLCLOSE(dm->dlhandle);
      }
      free(dm);
      dm = NULL;
   }
}
static int open_mod_table_close(struct open_mod_table* me, remote_handle64 handle, char* errStr, int errStrLen, int* pdlErr)
{
   int nErr = AEE_SUCCESS;
   struct open_mod *dm, *del = 0;;
   int dlErr = 0;
   // First ensure that the handle is valid
   RW_MUTEX_LOCK_WRITE(me->mut);
   HASH_FIND_INT(me->openMods, &handle, dm);
   if(dm) {
      dm->refs--;
      if(dm->refs <= 0) {
         del = dm;
         FARF(HIGH, "deleting %s %p", del->uri, del);
         HASH_DEL(me->openMods,dm);
      } else {
         FARF(HIGH, "leaked %s", dm->uri);
         dm = 0;
      }
   }
   RW_MUTEX_UNLOCK_WRITE(me->mut);
   if(del) {
      if(del->h64) {
         (void)open_mod_handle_close(dm, dm->h64);
      }
      if(del->dlhandle) {
         dlErr = DLCLOSE(del->dlhandle);
      }
      FARF(HIGH, "free %s %p", del->uri, del);
      free(del);
      del = NULL;
   }
   VERIFY(del);

bail:
   if(dlErr) {
      const char* error = DLERROR();
      nErr = dlErr;
      if(error != 0){
         std_strlcpy(errStr,error,errStrLen);
      }
      VERIFY_EPRINTF("Error %x: open modtable close failed. dlerr %s\n", nErr, error);
   }
   if(pdlErr) {
      *pdlErr = dlErr;
   }
   return nErr;
}

static struct open_mod* open_mod_table_get_open(struct open_mod_table* me, remote_handle handle) {
   struct open_mod* om = 0;
   RW_MUTEX_LOCK_READ(me->mut);
   HASH_FIND_INT(me->openMods, &handle, om);
   if(0 != om) {
      om->refs++;
   }
   RW_MUTEX_UNLOCK_READ(me->mut);
   return om;
}
static struct const_mod* open_mod_table_get_const(struct open_mod_table* me, remote_handle handle) {
   struct const_mod* cm = 0;
   RW_MUTEX_LOCK_READ(me->smt->mut);
   HASH_FIND_INT(me->smt->constMods, &handle, cm);
   RW_MUTEX_UNLOCK_READ(me->smt->mut);
   return cm;
}

static int open_mod_table_handle_invoke(struct open_mod_table* me, remote_handle handle, uint32 sc, remote_arg* pra) {
   int nErr = AEE_SUCCESS;
   struct open_mod* om = 0;
   struct const_mod* cm = 0;
   remote_handle64 h = 0;
   invoke_fn invoke = 0;
   handle_invoke_fn handle_invoke = 0;
   cm = open_mod_table_get_const(me, handle);
   if(cm) {
      invoke = cm->invoke;
      handle_invoke = cm->handle_invoke;
      h = cm->h64;
   } else {
      VERIFYC(0 != (om = open_mod_table_get_open(me, handle)), AEE_ENOSUCHMOD);
      invoke = om->invoke;
      handle_invoke = om->handle_invoke;
      h = om->h64;
   }
   if(invoke) {
      VERIFY(AEE_SUCCESS == (nErr = invoke(sc, pra)));
   } else {
      VERIFY(AEE_SUCCESS == (nErr = handle_invoke(h, sc, pra)));
   }
bail:
   if(om) {
      open_mod_close(me, om);
   }
   FARF(HIGH, "invoke rv %p %x %x", handle, sc, nErr);
   return nErr;
}

struct mod_table {
   struct static_mod_table smt;
   struct open_mod_table omt;
};

// mod_table object
static struct static_mod_table static_mod_table_obj;


/**
  * register a static component for invocations
  * this can be called at any time including from a static constructor
  *
  * overrides will be tried first, then dynamic modules, then regular
  * static modules.
  *
  * name, name of the interface to register
  * pfn, function pointer to the skel invoke function
  *
  * for example:
  *   __attribute__((constructor)) static void my_module_ctor(void) {
  *      mod_table_register_static("my_module", my_module_skel_invoke);
  *   }
  *
  */
int mod_table_register_static_override(const char* name, int(*pfn)(uint32 sc, remote_arg* pra)) {
   if(0 == static_mod_table_ctor(&static_mod_table_obj)) {
      return static_mod_table_register_static_override(&static_mod_table_obj, name, pfn);
   }
   return AEE_EUNKNOWN;
}

int mod_table_register_static_override1(const char* name, int(*pfn)(remote_handle64, uint32 sc, remote_arg* pra)) {
   if(0 == static_mod_table_ctor(&static_mod_table_obj)) {
      return static_mod_table_register_static_override1(&static_mod_table_obj, name, pfn);
   }
   return AEE_EUNKNOWN;
}


/**
  * register a static component for invocations
  * this can be called at any time including from a static constructor
  *
  * name, name of the interface to register
  * pfn, function pointer to the skel invoke function
  *
  * for example:
  *   __attribute__((constructor)) static void my_module_ctor(void) {
  *      mod_table_register_static("my_module", my_module_skel_invoke);
  *   }
  *
  */
int mod_table_register_static(const char* name, int(*pfn)(uint32 sc, remote_arg* pra)) {
   if(0 == static_mod_table_ctor(&static_mod_table_obj)) {
      return static_mod_table_register_static(&static_mod_table_obj, name, pfn);
   }
   return AEE_EUNKNOWN;
}

int mod_table_register_static1(const char* name, int(*pfn)(remote_handle64, uint32 sc, remote_arg* pra)) {
   if(0 == static_mod_table_ctor(&static_mod_table_obj)) {
      return static_mod_table_register_static1(&static_mod_table_obj, name, pfn);
   }
   return AEE_EUNKNOWN;
}


/**
 * Open a module and get a handle to it
 *
 * uri, name of module to open
 * handle, Output handle
 * dlerr, Error String (if an error occurs)
 * dlerrorLen, Length of error String (if an error occurs)
 * pdlErr, Error identifier
 */
int mod_table_open(const char* uri, remote_handle* handle, char* dlerr, int dlerrorLen, int* pdlErr) {
   int nErr = AEE_SUCCESS;
   struct open_mod_table* pomt = 0;
   FARF(HIGH, "mod_table_open for %s", uri);
   VERIFY(AEE_SUCCESS == (nErr = HAP_pls_add_lookup((uintptr_t)open_mod_table_ctor_imp, 0, sizeof(*pomt), open_mod_table_ctor_imp, (void*)&static_mod_table_obj, open_mod_table_dtor_imp, (void**)&pomt)));
   VERIFY(AEE_SUCCESS == (nErr = open_mod_table_open(pomt,uri,handle,dlerr,dlerrorLen,pdlErr)));
bail:
   FARF(HIGH, "mod_table_open for %s nErr: %x", uri, nErr);
   if(nErr != AEE_SUCCESS) {
      VERIFY_EPRINTF("Error %x: modtable open failed\n", nErr);
   }
   return nErr;
}
/**
 * invoke a handle in the mod table
 *
 * handle, handle to invoke
 * sc, scalars, see remote.h for documentation.
 * pra, args, see remote.h for documentation.
 */
int mod_table_invoke(remote_handle handle, uint32 sc, remote_arg* pra) {
   int nErr = AEE_SUCCESS;
   struct open_mod_table* pomt = 0;
   VERIFY(AEE_SUCCESS == (nErr = HAP_pls_add_lookup((uintptr_t)open_mod_table_ctor_imp, 0, sizeof(*pomt), open_mod_table_ctor_imp, (void*)&static_mod_table_obj, open_mod_table_dtor_imp, (void**)&pomt)));
   VERIFY(AEE_SUCCESS == (nErr = open_mod_table_handle_invoke(pomt, handle, sc, pra)));
bail:
   return nErr;
}

/**
 * Closes a handle in the mod table
 *
 * handle, handle to close
 * errStr, Error String (if an error occurs)
 * errStrLen, Length of error String (if an error occurs)
 * pdlErr, Error identifier
 */
int mod_table_close(remote_handle handle, char* errStr, int errStrLen, int* pdlErr) {
   int nErr = AEE_SUCCESS;
   struct open_mod_table* pomt = 0;
   VERIFY(AEE_SUCCESS == (nErr = HAP_pls_lookup((uintptr_t)open_mod_table_ctor_imp, 0, (void**)&pomt)));
   VERIFY(AEE_SUCCESS == (nErr = open_mod_table_close(pomt, handle, errStr,errStrLen,pdlErr)));
bail:
   if(nErr != AEE_SUCCESS) {
      VERIFY_EPRINTF("Error %x: modtable close failed\n", nErr);
   }
   return nErr;
}

/**
 * internal use only
 */
int mod_table_register_const_handle(remote_handle remote, const char* uri, int(*pfn)(uint32 sc, remote_arg* pra)) {
   if(0 == static_mod_table_ctor(&static_mod_table_obj)) {
      return static_mod_table_register_const_handle(&static_mod_table_obj, remote, 0, uri, pfn, 0);
   }
   return AEE_EUNKNOWN;
}
int mod_table_register_const_handle1(remote_handle remote, remote_handle64 local, const char* uri, int(*pfn)(remote_handle64, uint32 sc, remote_arg* pra)) {
   if(0 == static_mod_table_ctor(&static_mod_table_obj)) {
      return static_mod_table_register_const_handle(&static_mod_table_obj, remote, local, uri, 0, pfn);
   }
   return AEE_EUNKNOWN;
}

// Constructor and destructor
static int mod_table_ctor(void) {
	return static_mod_table_ctor(&static_mod_table_obj);
}
static void mod_table_dtor(void) {
	static_mod_table_dtor_imp(&static_mod_table_obj);
	return;
}

PL_DEFINE(mod_table, mod_table_ctor, mod_table_dtor);