ermyth/src/module.C

/*
 * module.C: Module management.
 * Rights to this code are documented in doc/LICENSE.
 *
 * Copyright © 2005-2007 Atheme Project (http://www.atheme.org)
 */

static char const rcsid[] = "$Id";

#include "atheme.h"

#include <dlfcn.h>

static BlockHeap *module_heap;
list_t modules;

module_t *modtarget = NULL;

void
modules_init (void)
{
  module_heap = BlockHeapCreate (sizeof (module_t), 256);

  if (!module_heap)
    {
      slog (LG_ERROR, "modules_init(): block allocator failed.");
      exit (EXIT_FAILURE);
    }

  module_load_dir (MODDIR "/modules");
}

/*
 * module_load()
 *
 * inputs:
 *       a literal filename for a module to load.
 *
 * outputs:
 *       the respective module_t object of the module.
 *
 * side effects:
 *       a module is loaded and necessary initialization code is run.
 */
module_t *
module_load (char *filespec)
{
  node_t *n;
  module_t *m;
  v1_moduleheader_t *h;
  void *handle = NULL;
#ifdef HAVE_DLINFO
  struct link_map *map;
#endif

  if ((m = module_find (filespec)))
    {
      slog (LG_INFO, "module_load(): module %s is already loaded [at 0x%lx]", filespec, m->address);
      return NULL;
    }

  handle = linker_open_ext (filespec);

  if (!handle)
    {
      char *errp = sstrdup (dlerror ());
      slog (LG_ERROR, "module_load(): error: %s", errp);
      if (me.connected)
        snoop (_("MODLOAD:ERROR: loading module \2%s\2: %s"), filespec, errp);
      free (errp);
      return NULL;
    }

  h = (v1_moduleheader_t *) linker_getsym (handle, "_header");

  if (!h)
    return NULL;

  if (h->mod != MAPI_MAGIC)
    {
      slog (LG_DEBUG, "module_load(): %s: Attempted to load an incompatible module. Aborting.", filespec);

      if (me.connected)
        snoop (_("MODLOAD:ERROR: Module \2%s\2 is not a valid " PACKAGE_NAME " module."), filespec);

      linker_close (handle);
      return NULL;
    }

  m = static_cast<module_t *> (BlockHeapAlloc (module_heap));

  strlcpy (m->modpath, filespec, BUFSIZE);
  m->handle = handle;
  m->mflags = MODTYPE_STANDARD;
  m->header = h;

#ifdef HAVE_DLINFO
  dlinfo (handle, RTLD_DI_LINKMAP, &map);
  if (map != NULL)
    m->address = (void *) map->l_addr;
  else
    m->address = handle;
#else
  /* best we can do here without dlinfo() --nenolod */
  m->address = handle;
#endif

  /* set the module target for module dependencies */
  modtarget = m;

  if (h->modinit)
    h->modinit (m);

  /* we won't be loading symbols outside the init code */
  modtarget = NULL;

  if (m->mflags & MODTYPE_FAIL)
    {
      slog (LG_ERROR, "module_load(): module %s init failed", filespec);
      if (me.connected)
        snoop (_("MODLOAD:ERROR: Init failed while loading module \2%s\2"), filespec);
      module_unload (m);
      return NULL;
    }

  n = node_create ();
  node_add (m, n, &modules);

  slog (LG_DEBUG, "module_load(): loaded %s [at 0x%lx; MAPI version %d]", h->name, m->address, h->abi_ver);

  if (me.connected && !cold_start)
    {
      wallops (_("Module %s loaded [at 0x%lx; MAPI version %d]"), h->name, m->address, h->abi_ver);
      snoop (_("MODLOAD: \2%s\2 [at 0x%lx; MAPI version %d]"), h->name, m->address, h->abi_ver);
    }

  return m;
}

/*
 * module_load_dir()
 *
 * inputs:
 *       a directory containing modules to load.
 *
 * outputs:
 *       none
 *
 * side effects:
 *       qualifying modules are passed to module_load().
 */
void
module_load_dir (char *dirspec)
{
  DIR *module_dir = NULL;
  struct dirent *ldirent = NULL;
  char module_filename[4096];

  module_dir = opendir (dirspec);

  if (!module_dir)
    {
      slog (LG_ERROR, "module_load_dir(): %s: %s", dirspec, strerror (errno));
      return;
    }

  while ((ldirent = readdir (module_dir)) != NULL)
    {
      if (!strstr (ldirent->d_name, ".so"))
        continue;

      snprintf (module_filename, sizeof (module_filename), "%s/%s", dirspec, ldirent->d_name);
      module_load (module_filename);
    }

  closedir (module_dir);
}

/*
 * module_load_dir_match()
 *
 * inputs:
 *       a directory containing modules to load, and a pattern to match against
 *       to determine whether or not a module qualifies for loading.
 *
 * outputs:
 *       none
 *
 * side effects:
 *       qualifying modules are passed to module_load().
 */
void
module_load_dir_match (char *dirspec, char *pattern)
{
  DIR *module_dir = NULL;
  struct dirent *ldirent = NULL;
  char module_filename[4096];

  module_dir = opendir (dirspec);

  if (!module_dir)
    {
      slog (LG_ERROR, "module_load_dir(): %s: %s", dirspec, strerror (errno));
      return;
    }

  while ((ldirent = readdir (module_dir)) != NULL)
    {
      if (!strstr (ldirent->d_name, ".so") && match (pattern, ldirent->d_name))
        continue;

      snprintf (module_filename, sizeof (module_filename), "%s/%s", dirspec, ldirent->d_name);
      module_load (module_filename);
    }

  closedir (module_dir);
}

/*
 * module_unload()
 *
 * inputs:
 *       a module object to unload.
 *
 * outputs:
 *       none
 *
 * side effects:
 *       a module is unloaded and neccessary deinitalization code is run.
 */
void
module_unload (module_t *m)
{
  node_t *n, *tn;

  if (!m)
    return;

  /* unload modules which depend on us */
  LIST_FOREACH_SAFE (n, tn, m->dephost.head) module_unload ((module_t *) n->data);

  /* let modules that we depend on know that we no longer exist */
  LIST_FOREACH_SAFE (n, tn, m->deplist.head)
  {
    module_t *hm = (module_t *) n->data;
    node_t *hn = node_find (m, &hm->dephost);

    node_del (hn, &hm->dephost);
    node_free (hn);
    node_del (n, &m->deplist);
    node_free (n);
  }

  n = node_find (m, &modules);
  if (n != NULL)
    {
      slog (LG_INFO, "module_unload(): unloaded %s", m->header->name);
      if (me.connected)
        {
          wallops (_("Module %s unloaded."), m->header->name);
          snoop ("MODUNLOAD: \2%s\2", m->header->name);
        }

      if (m->header->deinit)
        m->header->deinit ();
      node_del (n, &modules);
      node_free (n);
    }
  /* else unloaded in embryonic state */
  linker_close (m->handle);
  BlockHeapFree (module_heap, m);
}

/*
 * module_locate_symbol()
 *
 * inputs:
 *       a name of a module and a symbol to look for inside it.
 *
 * outputs:
 *       the pointer to the module symbol, else NULL if not found.
 *
 * side effects:
 *       none
 */
void *
module_locate_symbol (char *modname, char *sym)
{
  module_t *m;
  void *symptr;

  if (!(m = module_find_published (modname)))
    {
      slog (LG_ERROR, "module_locate_symbol(): %s is not loaded.", modname);
      return NULL;
    }

  if (modtarget != NULL && !node_find (m, &modtarget->deplist))
    {
      slog (LG_DEBUG, "module_locate_symbol(): %s added as a dependency for %s (symbol: %s)", m->header->name, modtarget->header->name, sym);
      node_add (m, node_create (), &modtarget->deplist);
      node_add (modtarget, node_create (), &m->dephost);
    }

  symptr = linker_getsym (m->handle, sym);

  if (symptr == NULL)
    slog (LG_ERROR, "module_locate_symbol(): could not find symbol %s in module %s.", sym, modname);
  return symptr;
}

/*
 * module_find()
 *
 * inputs:
 *       a name of a module to locate the object for.
 *
 * outputs:
 *       the module object if the module is located, else NULL.
 *
 * side effects:
 *       none
 */
module_t *
module_find (char *name)
{
  node_t *n;

  LIST_FOREACH (n, modules.head)
  {
    module_t *m = static_cast<module_t *> (n->data);

    if (!strcasecmp (m->modpath, name))
      return m;
  }

  return NULL;
}

/*
 * module_find_published()
 *
 * inputs:
 *       a published (in _header) name of a module to locate the object for.
 *
 * outputs:
 *       the module object if the module is located, else NULL.
 *
 * side effects:
 *       none
 */
module_t *
module_find_published (char *name)
{
  node_t *n;

  LIST_FOREACH (n, modules.head)
  {
    module_t *m = static_cast<module_t *> (n->data);

    if (!strcasecmp (m->header->name, name))
      return m;
  }

  return NULL;
}

/* vim:cinoptions=>s,e0,n0,f0,{0,}0,^0,=s,ps,t0,c3,+s,(2s,us,)20,*30,gs,hs
 * vim:ts=8
 * vim:sw=8
 * vim:noexpandtab
 */
Revision:	1.1
Committed:	Thu Jul 19 08:24:59 2007 UTC (19 years, 2 months ago) by pippijn
Content type:	text/plain
Branch:	MAIN
Log Message:	initial import. the most important changes since Atheme are: - fixed many memory leaks - fixed many bugs - converted to C++ and use more STL containers - added a (not very enhanced yet) perl module - greatly improved XML-RPC speed - added a JSON-RPC module with code from json-cpp - added a valgrind memcheck module to operserv - added a more object oriented base64 implementation - added a specialised unit test framework - improved stability - use gettimeofday() if available - reworked adding/removing commands - MemoServ IGNORE DEL can now remove indices
#	User	Rev	Content
1	pippijn	1.1	/*
2			* module.C: Module management.
3			* Rights to this code are documented in doc/LICENSE.
4			*
5			* Copyright © 2005-2007 Atheme Project (http://www.atheme.org)
6			*/
7
8			static char const rcsid[] = "$Id";
9
10			#include "atheme.h"
11
12			#include <dlfcn.h>
13
14			static BlockHeap *module_heap;
15			list_t modules;
16
17			module_t *modtarget = NULL;
18
19			void
20			modules_init (void)
21			{
22			module_heap = BlockHeapCreate (sizeof (module_t), 256);
23
24			if (!module_heap)
25			{
26			slog (LG_ERROR, "modules_init(): block allocator failed.");
27			exit (EXIT_FAILURE);
28			}
29
30			module_load_dir (MODDIR "/modules");
31			}
32
33			/*
34			* module_load()
35			*
36			* inputs:
37			* a literal filename for a module to load.
38			*
39			* outputs:
40			* the respective module_t object of the module.
41			*
42			* side effects:
43			* a module is loaded and necessary initialization code is run.
44			*/
45			module_t *
46			module_load (char *filespec)
47			{
48			node_t *n;
49			module_t *m;
50			v1_moduleheader_t *h;
51			void *handle = NULL;
52			#ifdef HAVE_DLINFO
53			struct link_map *map;
54			#endif
55
56			if ((m = module_find (filespec)))
57			{
58			slog (LG_INFO, "module_load(): module %s is already loaded [at 0x%lx]", filespec, m->address);
59			return NULL;
60			}
61
62			handle = linker_open_ext (filespec);
63
64			if (!handle)
65			{
66			char *errp = sstrdup (dlerror ());
67			slog (LG_ERROR, "module_load(): error: %s", errp);
68			if (me.connected)
69			snoop (_("MODLOAD:ERROR: loading module \2%s\2: %s"), filespec, errp);
70			free (errp);
71			return NULL;
72			}
73
74			h = (v1_moduleheader_t *) linker_getsym (handle, "_header");
75
76			if (!h)
77			return NULL;
78
79			if (h->mod != MAPI_MAGIC)
80			{
81			slog (LG_DEBUG, "module_load(): %s: Attempted to load an incompatible module. Aborting.", filespec);
82
83			if (me.connected)
84			snoop (_("MODLOAD:ERROR: Module \2%s\2 is not a valid " PACKAGE_NAME " module."), filespec);
85
86			linker_close (handle);
87			return NULL;
88			}
89
90			m = static_cast<module_t *> (BlockHeapAlloc (module_heap));
91
92			strlcpy (m->modpath, filespec, BUFSIZE);
93			m->handle = handle;
94			m->mflags = MODTYPE_STANDARD;
95			m->header = h;
96
97			#ifdef HAVE_DLINFO
98			dlinfo (handle, RTLD_DI_LINKMAP, &map);
99			if (map != NULL)
100			m->address = (void *) map->l_addr;
101			else
102			m->address = handle;
103			#else
104			/* best we can do here without dlinfo() --nenolod */
105			m->address = handle;
106			#endif
107
108			/* set the module target for module dependencies */
109			modtarget = m;
110
111			if (h->modinit)
112			h->modinit (m);
113
114			/* we won't be loading symbols outside the init code */
115			modtarget = NULL;
116
117			if (m->mflags & MODTYPE_FAIL)
118			{
119			slog (LG_ERROR, "module_load(): module %s init failed", filespec);
120			if (me.connected)
121			snoop (_("MODLOAD:ERROR: Init failed while loading module \2%s\2"), filespec);
122			module_unload (m);
123			return NULL;
124			}
125
126			n = node_create ();
127			node_add (m, n, &modules);
128
129			slog (LG_DEBUG, "module_load(): loaded %s [at 0x%lx; MAPI version %d]", h->name, m->address, h->abi_ver);
130
131			if (me.connected && !cold_start)
132			{
133			wallops (_("Module %s loaded [at 0x%lx; MAPI version %d]"), h->name, m->address, h->abi_ver);
134			snoop (_("MODLOAD: \2%s\2 [at 0x%lx; MAPI version %d]"), h->name, m->address, h->abi_ver);
135			}
136
137			return m;
138			}
139
140			/*
141			* module_load_dir()
142			*
143			* inputs:
144			* a directory containing modules to load.
145			*
146			* outputs:
147			* none
148			*
149			* side effects:
150			* qualifying modules are passed to module_load().
151			*/
152			void
153			module_load_dir (char *dirspec)
154			{
155			DIR *module_dir = NULL;
156			struct dirent *ldirent = NULL;
157			char module_filename[4096];
158
159			module_dir = opendir (dirspec);
160
161			if (!module_dir)
162			{
163			slog (LG_ERROR, "module_load_dir(): %s: %s", dirspec, strerror (errno));
164			return;
165			}
166
167			while ((ldirent = readdir (module_dir)) != NULL)
168			{
169			if (!strstr (ldirent->d_name, ".so"))
170			continue;
171
172			snprintf (module_filename, sizeof (module_filename), "%s/%s", dirspec, ldirent->d_name);
173			module_load (module_filename);
174			}
175
176			closedir (module_dir);
177			}
178
179			/*
180			* module_load_dir_match()
181			*
182			* inputs:
183			* a directory containing modules to load, and a pattern to match against
184			* to determine whether or not a module qualifies for loading.
185			*
186			* outputs:
187			* none
188			*
189			* side effects:
190			* qualifying modules are passed to module_load().
191			*/
192			void
193			module_load_dir_match (char dirspec, char pattern)
194			{
195			DIR *module_dir = NULL;
196			struct dirent *ldirent = NULL;
197			char module_filename[4096];
198
199			module_dir = opendir (dirspec);
200
201			if (!module_dir)
202			{
203			slog (LG_ERROR, "module_load_dir(): %s: %s", dirspec, strerror (errno));
204			return;
205			}
206
207			while ((ldirent = readdir (module_dir)) != NULL)
208			{
209			if (!strstr (ldirent->d_name, ".so") && match (pattern, ldirent->d_name))
210			continue;
211
212			snprintf (module_filename, sizeof (module_filename), "%s/%s", dirspec, ldirent->d_name);
213			module_load (module_filename);
214			}
215
216			closedir (module_dir);
217			}
218
219			/*
220			* module_unload()
221			*
222			* inputs:
223			* a module object to unload.
224			*
225			* outputs:
226			* none
227			*
228			* side effects:
229			* a module is unloaded and neccessary deinitalization code is run.
230			*/
231			void
232			module_unload (module_t *m)
233			{
234			node_t n, tn;
235
236			if (!m)
237			return;
238
239			/* unload modules which depend on us */
240			LIST_FOREACH_SAFE (n, tn, m->dephost.head) module_unload ((module_t *) n->data);
241
242			/* let modules that we depend on know that we no longer exist */
243			LIST_FOREACH_SAFE (n, tn, m->deplist.head)
244			{
245			module_t hm = (module_t ) n->data;
246			node_t *hn = node_find (m, &hm->dephost);
247
248			node_del (hn, &hm->dephost);
249			node_free (hn);
250			node_del (n, &m->deplist);
251			node_free (n);
252			}
253
254			n = node_find (m, &modules);
255			if (n != NULL)
256			{
257			slog (LG_INFO, "module_unload(): unloaded %s", m->header->name);
258			if (me.connected)
259			{
260			wallops (_("Module %s unloaded."), m->header->name);
261			snoop ("MODUNLOAD: \2%s\2", m->header->name);
262			}
263
264			if (m->header->deinit)
265			m->header->deinit ();
266			node_del (n, &modules);
267			node_free (n);
268			}
269			/* else unloaded in embryonic state */
270			linker_close (m->handle);
271			BlockHeapFree (module_heap, m);
272			}
273
274			/*
275			* module_locate_symbol()
276			*
277			* inputs:
278			* a name of a module and a symbol to look for inside it.
279			*
280			* outputs:
281			* the pointer to the module symbol, else NULL if not found.
282			*
283			* side effects:
284			* none
285			*/
286			void *
287			module_locate_symbol (char modname, char sym)
288			{
289			module_t *m;
290			void *symptr;
291
292			if (!(m = module_find_published (modname)))
293			{
294			slog (LG_ERROR, "module_locate_symbol(): %s is not loaded.", modname);
295			return NULL;
296			}
297
298			if (modtarget != NULL && !node_find (m, &modtarget->deplist))
299			{
300			slog (LG_DEBUG, "module_locate_symbol(): %s added as a dependency for %s (symbol: %s)", m->header->name, modtarget->header->name, sym);
301			node_add (m, node_create (), &modtarget->deplist);
302			node_add (modtarget, node_create (), &m->dephost);
303			}
304
305			symptr = linker_getsym (m->handle, sym);
306
307			if (symptr == NULL)
308			slog (LG_ERROR, "module_locate_symbol(): could not find symbol %s in module %s.", sym, modname);
309			return symptr;
310			}
311
312			/*
313			* module_find()
314			*
315			* inputs:
316			* a name of a module to locate the object for.
317			*
318			* outputs:
319			* the module object if the module is located, else NULL.
320			*
321			* side effects:
322			* none
323			*/
324			module_t *
325			module_find (char *name)
326			{
327			node_t *n;
328
329			LIST_FOREACH (n, modules.head)
330			{
331			module_t m = static_cast<module_t > (n->data);
332
333			if (!strcasecmp (m->modpath, name))
334			return m;
335			}
336
337			return NULL;
338			}
339
340			/*
341			* module_find_published()
342			*
343			* inputs:
344			* a published (in _header) name of a module to locate the object for.
345			*
346			* outputs:
347			* the module object if the module is located, else NULL.
348			*
349			* side effects:
350			* none
351			*/
352			module_t *
353			module_find_published (char *name)
354			{
355			node_t *n;
356
357			LIST_FOREACH (n, modules.head)
358			{
359			module_t m = static_cast<module_t > (n->data);
360
361			if (!strcasecmp (m->header->name, name))
362			return m;
363			}
364
365			return NULL;
366			}
367
368			/* vim:cinoptions=>s,e0,n0,f0,{0,}0,^0,=s,ps,t0,c3,+s,(2s,us,)20,*30,gs,hs
369			* vim:ts=8
370			* vim:sw=8
371			* vim:noexpandtab
372			*/