freebsd-skq/usr.sbin/ppp/loadalias.c
1998-04-25 09:16:23 +00:00

171 lines
4.5 KiB
C

/*-
* Copyright (c) 1997 Brian Somers <brian@Awfulhak.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR 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.
*
* $Id: loadalias.c,v 1.14 1998/01/19 22:59:57 brian Exp $
*/
#include <sys/param.h>
#include <netinet/in.h>
#include <dirent.h>
#include <dlfcn.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
#include "command.h"
#include "mbuf.h"
#include "log.h"
#include "systems.h"
#include "id.h"
#include "loadalias.h"
#include "defs.h"
#include "vars.h"
#define _PATH_ALIAS_PREFIX "/usr/lib/libalias.so.2."
#define off(item) ((int)&(((struct aliasHandlers *)0)->item))
#define entry(a) { off(a), "_" #a }
#ifndef RTLD_NOW
#define RTLD_NOW 1 /* really RTLD_LAZY */
#endif
static struct {
int offset;
const char *name;
} map[] = {
entry(PacketAliasGetFragment),
entry(PacketAliasInit),
entry(PacketAliasIn),
entry(PacketAliasOut),
entry(PacketAliasRedirectAddr),
entry(PacketAliasRedirectPort),
entry(PacketAliasSaveFragment),
entry(PacketAliasSetAddress),
entry(PacketAliasSetMode),
entry(PacketAliasFragmentIn),
{ 0, 0 }
};
static void *dl;
int
loadAliasHandlers(struct aliasHandlers * h)
{
const char *path;
const char *env;
int i;
path = _PATH_ALIAS_PREFIX;
env = getenv("_PATH_ALIAS_PREFIX");
if (env) {
if (ID0realuid() == 0)
path = env;
else
LogPrintf(LogALERT, "Ignoring environment _PATH_ALIAS_PREFIX"
" value (%s)\n", env);
}
dl = dlopen(path, RTLD_NOW);
if (dl == (void *) 0) {
/* Look for _PATH_ALIAS_PREFIX with any number appended */
int plen;
plen = strlen(path);
if (plen && plen < MAXPATHLEN - 1 && path[plen-1] == '.') {
DIR *d;
char p[MAXPATHLEN], *fix;
char *file, *dir;
strcpy(p, path);
if ((file = strrchr(p, '/')) != NULL) {
fix = file;
*file++ = '\0';
dir = p;
} else {
fix = NULL;
file = p;
dir = ".";
}
if ((d = opendir(dir))) {
struct dirent *entry;
int flen;
char *end;
long maxver, ver;
if (fix)
*fix = '/';
maxver = -1;
flen = strlen(file);
while ((entry = readdir(d)))
if (entry->d_namlen > flen && !strncmp(entry->d_name, file, flen)) {
ver = strtol(entry->d_name + flen, &end, 10);
strcpy(p + plen, entry->d_name + flen);
if (ver >= 0 && *end == '\0' && ver > maxver &&
access(p, R_OK) == 0)
maxver = ver;
}
closedir(d);
if (maxver > -1) {
sprintf(p + plen, "%ld", maxver);
dl = dlopen(p, RTLD_NOW);
}
}
}
if (dl == (void *) 0) {
LogPrintf(LogWARN, "_PATH_ALIAS_PREFIX (%s*): Invalid lib: %s\n",
path, dlerror());
return -1;
}
}
for (i = 0; map[i].name; i++) {
*(void **) ((char *) h + map[i].offset) = dlsym(dl, map[i].name);
if (*(void **) ((char *) h + map[i].offset) == (void *) 0) {
LogPrintf(LogWARN, "_PATH_ALIAS (%s*): %s: %s\n", path,
map[i].name, dlerror());
(void) dlclose(dl);
dl = (void *) 0;
return -1;
}
}
VarPacketAliasInit();
return 0;
}
void
unloadAliasHandlers()
{
if (dl) {
dlclose(dl);
dl = (void *) 0;
}
}