capsule-wrappers.c

#include "capsule/capsule.h"
#include "capsule/capsule-private.h"
#include "capsule/capsule-malloc.h"
#include "utils/utils.h"
#include "utils/ld-libs.h"

#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <malloc.h>

static int
dso_is_exported (const char *dsopath, char **exported)
{
    for( char **ex = exported; ex && *ex; ex++ )
        if( soname_matches_path( *ex, dsopath ) )
            return 1;

    return 0;
}

static void *
_dlsym_from_capsules (const char *symbol)
{
    void *addr = NULL;

    for( size_t n = 0; n < _capsule_list->next; n++ )
    {
        capsule cap = ptr_list_nth_ptr( _capsule_list, n );

        if( !cap )
            continue;

        // TODO: If handle != cap->dl_handle, should we skip it?
        // TODO: RTLD_NEXT isn't implemented (is it implementable?)
        addr = _capsule_original_dlsym ( cap->dl_handle, symbol );

        if( addr )
        {
            Dl_info dso = { 0 };

            // only keep addr from the capsule if it's from an exported DSO:
            // or if we are unable to determine where it came from (what?)
            if( dladdr( addr, &dso ) )
            {
                if( !dso_is_exported( dso.dli_fname, cap->ns->combined_export ) )
                    addr = NULL;

                DEBUG( DEBUG_DLFUNC|DEBUG_WRAPPERS,
                       "symbol %s is from soname %s - %s",
                       symbol, dso.dli_fname, addr ? "OK" : "Ignored" );

                if( addr )
                    break;
            }
        }
    }

    return addr;
}

static int
_dlsymbol_is_encapsulated (const void *addr)
{
    Dl_info dso = { 0 };

    // no info, symbol may not even be valid: