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dhcp6relay_script.c
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dhcp6relay_script.c
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/*from $KAME: dhcp6c_script.c,v 1.11 2004/11/28 10:48:38 jinmei Exp $ */
/*
* Copyright (C) 2003 WIDE Project.
* 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.
* 3. Neither the name of the project 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 BY THE PROJECT 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 PROJECT 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.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/queue.h>
#include <sys/wait.h>
#include <sys/stat.h>
#if TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# if HAVE_SYS_TIME_H
# include <sys/time.h>
# else
# include <time.h>
# endif
#endif
#include <netinet/in.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <syslog.h>
#include <errno.h>
#include "dhcp6.h"
#include "config.h"
#include "common.h"
static char client_str[] = "client";
static char buf[BUFSIZ];
static char *iapd2str __P((int, struct dhcp6_listval *));
static char *iana2str __P((int, struct dhcp6_listval *));
int
relay6_script(scriptpath, client, dh6, len)
char *scriptpath;
struct sockaddr_in6 *client;
struct dhcp6 *dh6;
int len;
{
struct dhcp6_optinfo optinfo;
struct dhcp6opt *optend;
int i, j, iapds, ianas, envc, elen, ret = 0;
char **envp, *s, *t;
struct dhcp6_listval *v;
pid_t pid, wpid;
/* if a script is not specified, do nothing */
if (scriptpath == NULL || strlen(scriptpath) == 0)
return -1;
/* only replies are interesting */
if (dh6->dh6_msgtype != DH6_REPLY) {
if (dh6->dh6_msgtype != DH6_ADVERTISE) {
dprintf(LOG_INFO, FNAME, "forward msg#%d to client?",
dh6->dh6_msgtype);
return -1;
}
return 0;
}
/* parse options */
optend = (struct dhcp6opt *)((caddr_t) dh6 + len);
dhcp6_init_options(&optinfo);
if (dhcp6_get_options((struct dhcp6opt *)(dh6 + 1), optend,
&optinfo) < 0) {
dprintf(LOG_INFO, FNAME, "failed to parse options");
return -1;
}
/* initialize counters */
iapds = 0;
ianas = 0;
envc = 2; /* we at least include the address and the terminator */
/* count the number of variables */
for (v = TAILQ_FIRST(&optinfo.iapd_list); v; v = TAILQ_NEXT(v, link))
iapds++;
envc += iapds;
for (v = TAILQ_FIRST(&optinfo.iana_list); v; v = TAILQ_NEXT(v, link))
ianas++;
envc += ianas;
/* allocate an environments array */
if ((envp = malloc(sizeof (char *) * envc)) == NULL) {
dprintf(LOG_NOTICE, FNAME,
"failed to allocate environment buffer");
dhcp6_clear_options(&optinfo);
return -1;
}
memset(envp, 0, sizeof (char *) * envc);
/*
* Copy the parameters as environment variables
*/
i = 0;
/* address */
t = addr2str((struct sockaddr *) client);
if (t == NULL) {
dprintf(LOG_NOTICE, FNAME,
"failed to get address of client");
ret = -1;
goto clean;
}
elen = sizeof (client_str) + 1 + strlen(t) + 1;
if ((s = envp[i++] = malloc(elen)) == NULL) {
dprintf(LOG_NOTICE, FNAME,
"failed to allocate string for client");
ret = -1;
goto clean;
}
memset(s, 0, elen);
snprintf(s, elen, "%s=%s", client_str, t);
/* IAs */
j = 0;
for (v = TAILQ_FIRST(&optinfo.iapd_list); v;
v = TAILQ_NEXT(v, link)) {
if ((s = envp[i++] = iapd2str(j++, v)) == NULL) {
ret = -1;
goto clean;
}
}
j = 0;
for (v = TAILQ_FIRST(&optinfo.iana_list); v;
v = TAILQ_NEXT(v, link)) {
if ((s = envp[i++] = iana2str(j++, v)) == NULL) {
ret = -1;
goto clean;
}
}
/* launch the script */
pid = fork();
if (pid < 0) {
dprintf(LOG_ERR, FNAME, "failed to fork: %s", strerror(errno));
ret = -1;
goto clean;
} else if (pid) {
int wstatus;
do {
wpid = wait(&wstatus);
} while (wpid != pid && wpid > 0);
if (wpid < 0)
dprintf(LOG_ERR, FNAME, "wait: %s", strerror(errno));
else {
dprintf(LOG_DEBUG, FNAME,
"script \"%s\" terminated", scriptpath);
}
} else {
char *argv[2];
int fd;
argv[0] = scriptpath;
argv[1] = NULL;
if (safefile(scriptpath)) {
dprintf(LOG_ERR, FNAME,
"script \"%s\" cannot be executed safely",
scriptpath);
exit(1);
}
if (foreground == 0 &&
(fd = open("/dev/null", O_RDWR)) != -1) {
dup2(fd, STDIN_FILENO);
dup2(fd, STDOUT_FILENO);
dup2(fd, STDERR_FILENO);
if (fd > STDERR_FILENO)
close(fd);
}
execve(scriptpath, argv, envp);
dprintf(LOG_ERR, FNAME, "child: exec failed: %s",
strerror(errno));
exit(0);
}
clean:
for (i = 0; i < envc; i++)
free(envp[i]);
free(envp);
dhcp6_clear_options(&optinfo);
return ret;
}
static char *
iapd2str(num, iav)
int num;
struct dhcp6_listval *iav;
{
struct dhcp6_listval *siav;
char *s, *r, *comma;
s = buf;
memset(s, 0, BUFSIZ);
snprintf(s, BUFSIZ, "iapd_%d=", num);
comma = "";
for (siav = TAILQ_FIRST(&iav->sublist); siav;
siav = TAILQ_NEXT(siav, link)) {
switch (siav->type) {
case DHCP6_LISTVAL_PREFIX6:
snprintf(s + strlen(s), BUFSIZ - strlen(s),
"%s%s/%d", comma,
in6addr2str(&siav->val_prefix6.addr, 0),
siav->val_prefix6.plen);
comma = ",";
break;
case DHCP6_LISTVAL_STCODE:
snprintf(s + strlen(s), BUFSIZ - strlen(s),
"%s#%d", comma, siav->val_num16);
comma = ",";
break;
default:
dprintf(LOG_ERR, FNAME, "impossible subopt");
}
}
if ((r = strdup(s)) == NULL)
dprintf(LOG_ERR, FNAME, "failed to allocate iapd_%d", num);
return r;
}
static char *
iana2str(num, iav)
int num;
struct dhcp6_listval *iav;
{
struct dhcp6_listval *siav;
char *s, *r, *comma;
s = buf;
memset(s, 0, BUFSIZ);
snprintf(s, BUFSIZ, "iana_%d=", num);
comma = "";
for (siav = TAILQ_FIRST(&iav->sublist); siav;
siav = TAILQ_NEXT(siav, link)) {
switch (siav->type) {
case DHCP6_LISTVAL_STATEFULADDR6:
snprintf(s + strlen(s), BUFSIZ - strlen(s),
"%s%s", comma,
in6addr2str(&siav->val_statefuladdr6.addr, 0));
comma = ",";
break;
case DHCP6_LISTVAL_STCODE:
snprintf(s + strlen(s), BUFSIZ - strlen(s),
"%s#%d", comma, siav->val_num16);
comma = ",";
break;
default:
dprintf(LOG_ERR, FNAME, "impossible subopt");
}
}
if ((r = strdup(s)) == NULL)
dprintf(LOG_ERR, FNAME, "failed to allocate iana_%d", num);
return r;
}