Header And Logo
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#include "postgres.h"#include <sys/stat.h>#include "dynloader.h"#include "lib/stringinfo.h"#include "miscadmin.h"#include "utils/dynamic_loader.h"#include "utils/hsearch.h"
Go to the source code of this file.
Data Structures | |
| struct | rendezvousHashEntry |
| struct | df_files |
Defines | |
| #define | SAME_INODE(A, B) ((A).st_ino == (B).inode && (A).st_dev == (B).device) |
Typedefs | |
| typedef void(* | PG_init_t )(void) |
| typedef void(* | PG_fini_t )(void) |
| typedef struct df_files | DynamicFileList |
Functions | |
| static void * | internal_load_library (const char *libname) |
| static void | incompatible_module_error (const char *libname, const Pg_magic_struct *module_magic_data) |
| static void | internal_unload_library (const char *libname) |
| static bool | file_exists (const char *name) |
| static char * | expand_dynamic_library_name (const char *name) |
| static void | check_restricted_library_name (const char *name) |
| static char * | substitute_libpath_macro (const char *name) |
| static char * | find_in_dynamic_libpath (const char *basename) |
| PGFunction | load_external_function (char *filename, char *funcname, bool signalNotFound, void **filehandle) |
| void | load_file (const char *filename, bool restricted) |
| PGFunction | lookup_external_function (void *filehandle, char *funcname) |
| void ** | find_rendezvous_variable (const char *varName) |
Variables | |
| static DynamicFileList * | file_list = NULL |
| static DynamicFileList * | file_tail = NULL |
| char * | Dynamic_library_path |
| static const Pg_magic_struct | magic_data = PG_MODULE_MAGIC_DATA |
| #define SAME_INODE | ( | A, | ||
| B | ||||
| ) | ((A).st_ino == (B).inode && (A).st_dev == (B).device) |
Definition at line 67 of file dfmgr.c.
Referenced by internal_load_library(), and internal_unload_library().
| typedef struct df_files DynamicFileList |
| static void check_restricted_library_name | ( | const char * | name | ) | [static] |
Definition at line 539 of file dfmgr.c.
References ereport, errcode(), errmsg(), ERROR, first_dir_separator(), and NULL.
Referenced by load_file().
| static char * expand_dynamic_library_name | ( | const char * | name | ) | [static] |
Definition at line 482 of file dfmgr.c.
References AssertArg, file_exists(), find_in_dynamic_libpath(), first_dir_separator(), palloc(), pfree(), pstrdup(), and substitute_libpath_macro().
Referenced by load_external_function(), and load_file().
{
bool have_slash;
char *new;
char *full;
AssertArg(name);
have_slash = (first_dir_separator(name) != NULL);
if (!have_slash)
{
full = find_in_dynamic_libpath(name);
if (full)
return full;
}
else
{
full = substitute_libpath_macro(name);
if (file_exists(full))
return full;
pfree(full);
}
new = palloc(strlen(name) + strlen(DLSUFFIX) + 1);
strcpy(new, name);
strcat(new, DLSUFFIX);
if (!have_slash)
{
full = find_in_dynamic_libpath(new);
pfree(new);
if (full)
return full;
}
else
{
full = substitute_libpath_macro(new);
pfree(new);
if (file_exists(full))
return full;
pfree(full);
}
/*
* If we can't find the file, just return the string as-is. The ensuing
* load attempt will fail and report a suitable message.
*/
return pstrdup(name);
}
| static bool file_exists | ( | const char * | name | ) | [static] |
Definition at line 450 of file dfmgr.c.
References AssertArg, ereport, errcode_for_file_access(), errmsg(), ERROR, and NULL.
Referenced by expand_dynamic_library_name(), find_in_dynamic_libpath(), isolation_start_test(), psql_start_test(), and results_differ().
| static char * find_in_dynamic_libpath | ( | const char * | basename | ) | [static] |
Definition at line 591 of file dfmgr.c.
References AssertArg, AssertState, canonicalize_path(), DEBUG3, Dynamic_library_path, elog, ereport, errcode(), errmsg(), ERROR, file_exists(), first_dir_separator(), first_path_var_separator(), is_absolute_path, NULL, palloc(), pfree(), strlcpy(), and substitute_libpath_macro().
Referenced by expand_dynamic_library_name().
{
const char *p;
size_t baselen;
AssertArg(basename != NULL);
AssertArg(first_dir_separator(basename) == NULL);
AssertState(Dynamic_library_path != NULL);
p = Dynamic_library_path;
if (strlen(p) == 0)
return NULL;
baselen = strlen(basename);
for (;;)
{
size_t len;
char *piece;
char *mangled;
char *full;
piece = first_path_var_separator(p);
if (piece == p)
ereport(ERROR,
(errcode(ERRCODE_INVALID_NAME),
errmsg("zero-length component in parameter \"dynamic_library_path\"")));
if (piece == NULL)
len = strlen(p);
else
len = piece - p;
piece = palloc(len + 1);
strlcpy(piece, p, len + 1);
mangled = substitute_libpath_macro(piece);
pfree(piece);
canonicalize_path(mangled);
/* only absolute paths */
if (!is_absolute_path(mangled))
ereport(ERROR,
(errcode(ERRCODE_INVALID_NAME),
errmsg("component in parameter \"dynamic_library_path\" is not an absolute path")));
full = palloc(strlen(mangled) + 1 + baselen + 1);
sprintf(full, "%s/%s", mangled, basename);
pfree(mangled);
elog(DEBUG3, "find_in_dynamic_libpath: trying \"%s\"", full);
if (file_exists(full))
return full;
pfree(full);
if (p[len] == '\0')
break;
else
p += len + 1;
}
return NULL;
}
| void** find_rendezvous_variable | ( | const char * | varName | ) |
Definition at line 675 of file dfmgr.c.
References HASHCTL::entrysize, hash_create(), HASH_ELEM, HASH_ENTER, hash_search(), HASHCTL::keysize, MemSet, NULL, and rendezvousHashEntry::varValue.
Referenced by _PG_init().
{
static HTAB *rendezvousHash = NULL;
rendezvousHashEntry *hentry;
bool found;
/* Create a hashtable if we haven't already done so in this process */
if (rendezvousHash == NULL)
{
HASHCTL ctl;
MemSet(&ctl, 0, sizeof(ctl));
ctl.keysize = NAMEDATALEN;
ctl.entrysize = sizeof(rendezvousHashEntry);
rendezvousHash = hash_create("Rendezvous variable hash",
16,
&ctl,
HASH_ELEM);
}
/* Find or create the hashtable entry for this varName */
hentry = (rendezvousHashEntry *) hash_search(rendezvousHash,
varName,
HASH_ENTER,
&found);
/* Initialize to NULL if first time */
if (!found)
hentry->varValue = NULL;
return &hentry->varValue;
}
| static void incompatible_module_error | ( | const char * | libname, | |
| const Pg_magic_struct * | module_magic_data | |||
| ) | [static] |
Definition at line 301 of file dfmgr.c.
References _, appendStringInfo(), appendStringInfoChar(), StringInfoData::data, ereport, errdetail(), errdetail_internal(), errmsg(), ERROR, Pg_magic_struct::float4byval, Pg_magic_struct::float8byval, Pg_magic_struct::funcmaxargs, Pg_magic_struct::indexmaxkeys, initStringInfo(), StringInfoData::len, Pg_magic_struct::namedatalen, and Pg_magic_struct::version.
Referenced by internal_load_library().
{
StringInfoData details;
/*
* If the version doesn't match, just report that, because the rest of the
* block might not even have the fields we expect.
*/
if (magic_data.version != module_magic_data->version)
ereport(ERROR,
(errmsg("incompatible library \"%s\": version mismatch",
libname),
errdetail("Server is version %d.%d, library is version %d.%d.",
magic_data.version / 100,
magic_data.version % 100,
module_magic_data->version / 100,
module_magic_data->version % 100)));
/*
* Otherwise, spell out which fields don't agree.
*
* XXX this code has to be adjusted any time the set of fields in a magic
* block change!
*/
initStringInfo(&details);
if (module_magic_data->funcmaxargs != magic_data.funcmaxargs)
{
if (details.len)
appendStringInfoChar(&details, '\n');
appendStringInfo(&details,
_("Server has FUNC_MAX_ARGS = %d, library has %d."),
magic_data.funcmaxargs,
module_magic_data->funcmaxargs);
}
if (module_magic_data->indexmaxkeys != magic_data.indexmaxkeys)
{
if (details.len)
appendStringInfoChar(&details, '\n');
appendStringInfo(&details,
_("Server has INDEX_MAX_KEYS = %d, library has %d."),
magic_data.indexmaxkeys,
module_magic_data->indexmaxkeys);
}
if (module_magic_data->namedatalen != magic_data.namedatalen)
{
if (details.len)
appendStringInfoChar(&details, '\n');
appendStringInfo(&details,
_("Server has NAMEDATALEN = %d, library has %d."),
magic_data.namedatalen,
module_magic_data->namedatalen);
}
if (module_magic_data->float4byval != magic_data.float4byval)
{
if (details.len)
appendStringInfoChar(&details, '\n');
appendStringInfo(&details,
_("Server has FLOAT4PASSBYVAL = %s, library has %s."),
magic_data.float4byval ? "true" : "false",
module_magic_data->float4byval ? "true" : "false");
}
if (module_magic_data->float8byval != magic_data.float8byval)
{
if (details.len)
appendStringInfoChar(&details, '\n');
appendStringInfo(&details,
_("Server has FLOAT8PASSBYVAL = %s, library has %s."),
magic_data.float8byval ? "true" : "false",
module_magic_data->float8byval ? "true" : "false");
}
if (details.len == 0)
appendStringInfo(&details,
_("Magic block has unexpected length or padding difference."));
ereport(ERROR,
(errmsg("incompatible library \"%s\": magic block mismatch",
libname),
errdetail_internal("%s", details.data)));
}
| static void * internal_load_library | ( | const char * | libname | ) | [static] |
Definition at line 179 of file dfmgr.c.
References df_files::device, ereport, errcode(), errcode_for_file_access(), errhint(), errmsg(), ERROR, df_files::filename, free, df_files::handle, incompatible_module_error(), df_files::inode, Pg_magic_struct::len, malloc, memcmp(), MemSet, df_files::next, NULL, pg_dlclose, pg_dlerror, pg_dlopen, pg_dlsym, PG_MAGIC_FUNCTION_NAME_STRING, and SAME_INODE.
Referenced by load_external_function(), and load_file().
{
DynamicFileList *file_scanner;
PGModuleMagicFunction magic_func;
char *load_error;
struct stat stat_buf;
PG_init_t PG_init;
/*
* Scan the list of loaded FILES to see if the file has been loaded.
*/
for (file_scanner = file_list;
file_scanner != NULL &&
strcmp(libname, file_scanner->filename) != 0;
file_scanner = file_scanner->next)
;
if (file_scanner == NULL)
{
/*
* Check for same files - different paths (ie, symlink or link)
*/
if (stat(libname, &stat_buf) == -1)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not access file \"%s\": %m",
libname)));
for (file_scanner = file_list;
file_scanner != NULL &&
!SAME_INODE(stat_buf, *file_scanner);
file_scanner = file_scanner->next)
;
}
if (file_scanner == NULL)
{
/*
* File not loaded yet.
*/
file_scanner = (DynamicFileList *)
malloc(sizeof(DynamicFileList) + strlen(libname));
if (file_scanner == NULL)
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
MemSet(file_scanner, 0, sizeof(DynamicFileList));
strcpy(file_scanner->filename, libname);
file_scanner->device = stat_buf.st_dev;
#ifndef WIN32
file_scanner->inode = stat_buf.st_ino;
#endif
file_scanner->next = NULL;
file_scanner->handle = pg_dlopen(file_scanner->filename);
if (file_scanner->handle == NULL)
{
load_error = (char *) pg_dlerror();
free((char *) file_scanner);
/* errcode_for_file_access might not be appropriate here? */
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not load library \"%s\": %s",
libname, load_error)));
}
/* Check the magic function to determine compatibility */
magic_func = (PGModuleMagicFunction)
pg_dlsym(file_scanner->handle, PG_MAGIC_FUNCTION_NAME_STRING);
if (magic_func)
{
const Pg_magic_struct *magic_data_ptr = (*magic_func) ();
if (magic_data_ptr->len != magic_data.len ||
memcmp(magic_data_ptr, &magic_data, magic_data.len) != 0)
{
/* copy data block before unlinking library */
Pg_magic_struct module_magic_data = *magic_data_ptr;
/* try to unlink library */
pg_dlclose(file_scanner->handle);
free((char *) file_scanner);
/* issue suitable complaint */
incompatible_module_error(libname, &module_magic_data);
}
}
else
{
/* try to unlink library */
pg_dlclose(file_scanner->handle);
free((char *) file_scanner);
/* complain */
ereport(ERROR,
(errmsg("incompatible library \"%s\": missing magic block",
libname),
errhint("Extension libraries are required to use the PG_MODULE_MAGIC macro.")));
}
/*
* If the library has a _PG_init() function, call it.
*/
PG_init = (PG_init_t) pg_dlsym(file_scanner->handle, "_PG_init");
if (PG_init)
(*PG_init) ();
/* OK to link it into list */
if (file_list == NULL)
file_list = file_scanner;
else
file_tail->next = file_scanner;
file_tail = file_scanner;
}
return file_scanner->handle;
}
| static void internal_unload_library | ( | const char * | libname | ) | [static] |
Definition at line 396 of file dfmgr.c.
References clear_external_function_hash(), ereport, errcode_for_file_access(), errmsg(), ERROR, df_files::filename, free, df_files::handle, df_files::next, pg_dlclose, pg_dlsym, and SAME_INODE.
Referenced by load_file().
{
#ifdef NOT_USED
DynamicFileList *file_scanner,
*prv,
*nxt;
struct stat stat_buf;
PG_fini_t PG_fini;
/*
* We need to do stat() in order to determine whether this is the same
* file as a previously loaded file; it's also handy so as to give a good
* error message if bogus file name given.
*/
if (stat(libname, &stat_buf) == -1)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not access file \"%s\": %m", libname)));
/*
* We have to zap all entries in the list that match on either filename or
* inode, else internal_load_library() will still think it's present.
*/
prv = NULL;
for (file_scanner = file_list; file_scanner != NULL; file_scanner = nxt)
{
nxt = file_scanner->next;
if (strcmp(libname, file_scanner->filename) == 0 ||
SAME_INODE(stat_buf, *file_scanner))
{
if (prv)
prv->next = nxt;
else
file_list = nxt;
/*
* If the library has a _PG_fini() function, call it.
*/
PG_fini = (PG_fini_t) pg_dlsym(file_scanner->handle, "_PG_fini");
if (PG_fini)
(*PG_fini) ();
clear_external_function_hash(file_scanner->handle);
pg_dlclose(file_scanner->handle);
free((char *) file_scanner);
/* prv does not change */
}
else
prv = file_scanner;
}
#endif /* NOT_USED */
}
| PGFunction load_external_function | ( | char * | filename, | |
| char * | funcname, | |||
| bool | signalNotFound, | |||
| void ** | filehandle | |||
| ) |
Definition at line 102 of file dfmgr.c.
References ereport, errcode(), errmsg(), ERROR, expand_dynamic_library_name(), internal_load_library(), NULL, pfree(), and pg_dlsym.
Referenced by fmgr_c_validator(), and fmgr_info_C_lang().
{
char *fullname;
void *lib_handle;
PGFunction retval;
/* Expand the possibly-abbreviated filename to an exact path name */
fullname = expand_dynamic_library_name(filename);
/* Load the shared library, unless we already did */
lib_handle = internal_load_library(fullname);
/* Return handle if caller wants it */
if (filehandle)
*filehandle = lib_handle;
/* Look up the function within the library */
retval = (PGFunction) pg_dlsym(lib_handle, funcname);
if (retval == NULL && signalNotFound)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_FUNCTION),
errmsg("could not find function \"%s\" in file \"%s\"",
funcname, fullname)));
pfree(fullname);
return retval;
}
| void load_file | ( | const char * | filename, | |
| bool | restricted | |||
| ) |
Definition at line 141 of file dfmgr.c.
References check_restricted_library_name(), expand_dynamic_library_name(), internal_load_library(), internal_unload_library(), and pfree().
Referenced by load_libraries(), standard_ProcessUtility(), and WalReceiverMain().
{
char *fullname;
/* Apply security restriction if requested */
if (restricted)
check_restricted_library_name(filename);
/* Expand the possibly-abbreviated filename to an exact path name */
fullname = expand_dynamic_library_name(filename);
/* Unload the library if currently loaded */
internal_unload_library(fullname);
/* Load the shared library */
(void) internal_load_library(fullname);
pfree(fullname);
}
| PGFunction lookup_external_function | ( | void * | filehandle, | |
| char * | funcname | |||
| ) |
Definition at line 166 of file dfmgr.c.
References pg_dlsym.
Referenced by fetch_finfo_record().
{
return (PGFunction) pg_dlsym(filehandle, funcname);
}
| static char * substitute_libpath_macro | ( | const char * | name | ) | [static] |
Definition at line 554 of file dfmgr.c.
References AssertArg, ereport, errcode(), errmsg(), ERROR, first_dir_separator(), NULL, palloc(), pkglib_path, and pstrdup().
Referenced by expand_dynamic_library_name(), and find_in_dynamic_libpath().
{
const char *sep_ptr;
char *ret;
AssertArg(name != NULL);
/* Currently, we only recognize $libdir at the start of the string */
if (name[0] != '$')
return pstrdup(name);
if ((sep_ptr = first_dir_separator(name)) == NULL)
sep_ptr = name + strlen(name);
if (strlen("$libdir") != sep_ptr - name ||
strncmp(name, "$libdir", strlen("$libdir")) != 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_NAME),
errmsg("invalid macro name in dynamic library path: %s",
name)));
ret = palloc(strlen(pkglib_path) + strlen(sep_ptr) + 1);
strcpy(ret, pkglib_path);
strcat(ret, sep_ptr);
return ret;
}
| char* Dynamic_library_path |
Definition at line 72 of file dfmgr.c.
Referenced by find_in_dynamic_libpath().
DynamicFileList* file_list = NULL [static] |
DynamicFileList* file_tail = NULL [static] |
const Pg_magic_struct magic_data = PG_MODULE_MAGIC_DATA [static] |
1.7.1