dhcp6c_script.c

/*	$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 "dhcp6c.h"
#include "common.h"

static char sipserver_str[] = "new_sip_servers";
static char sipname_str[] = "new_sip_name";
static char dnsserver_str[] = "new_domain_name_servers";
static char dnsname_str[] = "new_domain_name";
static char ntpserver_str[] = "new_ntp_servers";
static char nisserver_str[] = "new_nis_servers";
static char nisname_str[] = "new_nis_name";
static char nispserver_str[] = "new_nisp_servers";
static char nispname_str[] = "new_nisp_name";
static char bcmcsserver_str[] = "new_bcmcs_servers";
static char bcmcsname_str[] = "new_bcmcs_name";
static char raw_dhcp_option_str[] = "raw_dhcp_option";

int client6_script(char *, int, struct dhcp6_optinfo *);

int
client6_script(scriptpath, state, optinfo)
	char *scriptpath;
	int state;
	struct dhcp6_optinfo *optinfo;
{
	int i, dnsservers, ntpservers, dnsnamelen, envc, elen, ret = 0;
	int sipservers, sipnamelen;
	int nisservers, nisnamelen;
	int nispservers, nispnamelen;
	int bcmcsservers, bcmcsnamelen;
	char **envp, *s;
	char reason[32];
	char prefixinfo[32];
	struct dhcp6_listval *v;
	struct dhcp6_event ev;
	struct rawoption *rawop;
	pid_t pid, wpid;
	struct dhcp6_listval *iav, *siav;

	/* if a script is not specified, do nothing */
	if (scriptpath == NULL || strlen(scriptpath) == 0)
		return -1;
	d_printf(LOG_DEBUG, FNAME, "executes %s", scriptpath);

	ev.state = state;

	/* initialize counters */
	dnsservers = 0;
	ntpservers = 0;
	dnsnamelen = 0;
	sipservers = 0;
	sipnamelen = 0;
	nisservers = 0;
	nisnamelen = 0;
	nispservers = 0;
	nispnamelen = 0;
	bcmcsservers = 0;
	bcmcsnamelen = 0;
	envc = 3;     /* we at least include the reason, prefix and the terminator */
	if (state == DHCP6S_EXIT)
		goto setenv;

	/* count the number of variables */
	for (v = TAILQ_FIRST(&optinfo->dns_list); v; v = TAILQ_NEXT(v, link))
		dnsservers++;
	envc += dnsservers ? 1 : 0;
	for (v = TAILQ_FIRST(&optinfo->dnsname_list); v;
	    v = TAILQ_NEXT(v, link)) {
		dnsnamelen += v->val_vbuf.dv_len;
	}
	envc += dnsnamelen ? 1 : 0;
	for (v = TAILQ_FIRST(&optinfo->ntp_list); v; v = TAILQ_NEXT(v, link))
		ntpservers++;
	envc += ntpservers ? 1 : 0;
	for (v = TAILQ_FIRST(&optinfo->sip_list); v; v = TAILQ_NEXT(v, link))
		sipservers++;
	envc += sipservers ? 1 : 0;
	for (v = TAILQ_FIRST(&optinfo->sipname_list); v;
	    v = TAILQ_NEXT(v, link)) {
		sipnamelen += v->val_vbuf.dv_len;
	}
	envc += sipnamelen ? 1 : 0;

	for (v = TAILQ_FIRST(&optinfo->nis_list); v; v = TAILQ_NEXT(v, link))
		nisservers++;
	envc += nisservers ? 1 : 0;
	for (v = TAILQ_FIRST(&optinfo->nisname_list); v;
	    v = TAILQ_NEXT(v, link)) {
		nisnamelen += v->val_vbuf.dv_len;
	}
	envc += nisnamelen ? 1 : 0;

	for (v = TAILQ_FIRST(&optinfo->nisp_list); v; v = TAILQ_NEXT(v, link))
		nispservers++;
	envc += nispservers ? 1 : 0;
	for (v = TAILQ_FIRST(&optinfo->nispname_list); v;
	    v = TAILQ_NEXT(v, link)) {
		nispnamelen += v->val_vbuf.dv_len;
	}
	envc += nispnamelen ? 1 : 0;

	for (v = TAILQ_FIRST(&optinfo->bcmcs_list); v; v = TAILQ_NEXT(v, link))
		bcmcsservers++;
	envc += bcmcsservers ? 1 : 0;
	for (v = TAILQ_FIRST(&optinfo->bcmcsname_list); v;
	    v = TAILQ_NEXT(v, link)) {
		bcmcsnamelen += v->val_vbuf.dv_len;
	}
	envc += bcmcsnamelen ? 1 : 0;

setenv:
	/* allocate an environments array */
	if ((envp = malloc(sizeof (char *) * envc)) == NULL) {
		d_printf(LOG_NOTICE, FNAME,
		    "failed to allocate environment buffer");
		return -1;
	}
	memset(envp, 0, sizeof (char *) * envc);

	/*
	 * Copy the parameters as environment variables
	 */
	snprintf(reason, sizeof(reason), "REASON=%s",
	    dhcp6_event_statestr(&ev));
	i = 0;
	/* reason */
	if ((envp[i++] = strdup(reason)) == NULL) {
		d_printf(LOG_NOTICE, FNAME,
		    "failed to allocate reason strings");
		ret = -1;
		goto clean;
	}
	if (state == DHCP6S_EXIT)
		goto launch;

	/* prefix delegation */
	for (iav = TAILQ_FIRST(&optinfo->iapd_list); iav; iav = TAILQ_NEXT(iav, link)) {
		for (siav = TAILQ_FIRST(&iav->sublist); siav; siav = TAILQ_NEXT(siav, link)) {
			if (siav->type == DHCP6_LISTVAL_PREFIX6) {
				snprintf(prefixinfo, sizeof(prefixinfo),
				    "PDINFO=%s/%d",
				    in6addr2str(&siav->val_prefix6.addr, 0),
				    siav->val_prefix6.plen);
				if ((envp[i++] = strdup(prefixinfo)) == NULL) {
					d_printf(LOG_NOTICE, FNAME, "failed to allocate prefixinfo strings");
					ret = -1;
					goto clean;
				}
			}
		}
	}

	/* "var=addr1 addr2 ... addrN" + null char for termination */
	if (dnsservers) {
		elen = sizeof (dnsserver_str) +
		    (INET6_ADDRSTRLEN + 1) * dnsservers + 1;
		if ((s = envp[i++] = malloc(elen)) == NULL) {
			d_printf(LOG_NOTICE, FNAME,
			    "failed to allocate strings for DNS servers");
			ret = -1;
			goto clean;
		}
		memset(s, 0, elen);
		snprintf(s, elen, "%s=", dnsserver_str);
		for (v = TAILQ_FIRST(&optinfo->dns_list); v;
		    v = TAILQ_NEXT(v, link)) {
			char *addr;

			addr = in6addr2str(&v->val_addr6, 0);
			strlcat(s, addr, elen);
			strlcat(s, " ", elen);
		}
	}
	if (ntpservers) {
		elen = sizeof (ntpserver_str) +
		    (INET6_ADDRSTRLEN + 1) * ntpservers + 1;
		if ((s = envp[i++] = malloc(elen)) == NULL) {
			d_printf(LOG_NOTICE, FNAME,
			    "failed to allocate strings for NTP servers");
			ret = -1;
			goto clean;
		}
		memset(s, 0, elen);
		snprintf(s, elen, "%s=", ntpserver_str);
		for (v = TAILQ_FIRST(&optinfo->ntp_list); v;
		    v = TAILQ_NEXT(v, link)) {
			char *addr;

			addr = in6addr2str(&v->val_addr6, 0);
			strlcat(s, addr, elen);
			strlcat(s, " ", elen);
		}
	}

	if (dnsnamelen) {
		elen = sizeof (dnsname_str) + dnsnamelen + 1;
		if ((s = envp[i++] = malloc(elen)) == NULL) {
			d_printf(LOG_NOTICE, FNAME,
			    "failed to allocate strings for DNS name");
			ret = -1;
			goto clean;
		}
		memset(s, 0, elen);
		snprintf(s, elen, "%s=", dnsname_str);
		for (v = TAILQ_FIRST(&optinfo->dnsname_list); v;
		    v = TAILQ_NEXT(v, link)) {
			strlcat(s, v->val_vbuf.dv_buf, elen);
			strlcat(s, " ", elen);
		}
	}

	if (sipservers) {
		elen = sizeof (sipserver_str) +
		    (INET6_ADDRSTRLEN + 1) * sipservers + 1;
		if ((s = envp[i++] = malloc(elen)) == NULL) {
			d_printf(LOG_NOTICE, FNAME,
			    "failed to allocate strings for SIP servers");
			ret = -1;
			goto clean;
		}
		memset(s, 0, elen);
		snprintf(s, elen, "%s=", sipserver_str);
		for (v = TAILQ_FIRST(&optinfo->sip_list); v;
		    v = TAILQ_NEXT(v, link)) {
			char *addr;

			addr = in6addr2str(&v->val_addr6, 0);
			strlcat(s, addr, elen);
			strlcat(s, " ", elen);
		}
	}
	if (sipnamelen) {
		elen = sizeof (sipname_str) + sipnamelen + 1;
		if ((s = envp[i++] = malloc(elen)) == NULL) {
			d_printf(LOG_NOTICE, FNAME,
			    "failed to allocate strings for SIP domain name");
			ret = -1;
			goto clean;
		}
		memset(s, 0, elen);
		snprintf(s, elen, "%s=", sipname_str);
		for (v = TAILQ_FIRST(&optinfo->sipname_list); v;
		    v = TAILQ_NEXT(v, link)) {
			strlcat(s, v->val_vbuf.dv_buf, elen);
			strlcat(s, " ", elen);
		}
	}

	if (nisservers) {
		elen = sizeof (nisserver_str) +
		    (INET6_ADDRSTRLEN + 1) * nisservers + 1;
		if ((s = envp[i++] = malloc(elen)) == NULL) {
			d_printf(LOG_NOTICE, FNAME,
			    "failed to allocate strings for NIS servers");
			ret = -1;
			goto clean;
		}
		memset(s, 0, elen);
		snprintf(s, elen, "%s=", nisserver_str);
		for (v = TAILQ_FIRST(&optinfo->nis_list); v;
		    v = TAILQ_NEXT(v, link)) {
			char *addr;

			addr = in6addr2str(&v->val_addr6, 0);
			strlcat(s, addr, elen);
			strlcat(s, " ", elen);
		}
	}
	if (nisnamelen) {
		elen = sizeof (nisname_str) + nisnamelen + 1;
		if ((s = envp[i++] = malloc(elen)) == NULL) {
			d_printf(LOG_NOTICE, FNAME,
			    "failed to allocate strings for NIS domain name");
			ret = -1;
			goto clean;
		}
		memset(s, 0, elen);
		snprintf(s, elen, "%s=", nisname_str);
		for (v = TAILQ_FIRST(&optinfo->nisname_list); v;
		    v = TAILQ_NEXT(v, link)) {
			strlcat(s, v->val_vbuf.dv_buf, elen);
			strlcat(s, " ", elen);
		}
	}

	if (nispservers) {
		elen = sizeof (nispserver_str) +
		    (INET6_ADDRSTRLEN + 1) * nispservers + 1;
		if ((s = envp[i++] = malloc(elen)) == NULL) {
			d_printf(LOG_NOTICE, FNAME,
			    "failed to allocate strings for NIS+ servers");
			ret = -1;
			goto clean;
		}
		memset(s, 0, elen);
		snprintf(s, elen, "%s=", nispserver_str);
		for (v = TAILQ_FIRST(&optinfo->nisp_list); v;
		    v = TAILQ_NEXT(v, link)) {
			char *addr;

			addr = in6addr2str(&v->val_addr6, 0);
			strlcat(s, addr, elen);
			strlcat(s, " ", elen);
		}
	}
	if (nispnamelen) {
		elen = sizeof (nispname_str) + nispnamelen + 1;
		if ((s = envp[i++] = malloc(elen)) == NULL) {
			d_printf(LOG_NOTICE, FNAME,
			    "failed to allocate strings for NIS+ domain name");
			ret = -1;
			goto clean;
		}
		memset(s, 0, elen);
		snprintf(s, elen, "%s=", nispname_str);
		for (v = TAILQ_FIRST(&optinfo->nispname_list); v;
		    v = TAILQ_NEXT(v, link)) {
			strlcat(s, v->val_vbuf.dv_buf, elen);
			strlcat(s, " ", elen);
		}
	}

	if (bcmcsservers) {
		elen = sizeof (bcmcsserver_str) +
		    (INET6_ADDRSTRLEN + 1) * bcmcsservers + 1;
		if ((s = envp[i++] = malloc(elen)) == NULL) {
			d_printf(LOG_NOTICE, FNAME,
			    "failed to allocate strings for BCMC servers");
			ret = -1;
			goto clean;
		}
		memset(s, 0, elen);
		snprintf(s, elen, "%s=", bcmcsserver_str);
		for (v = TAILQ_FIRST(&optinfo->bcmcs_list); v;
		    v = TAILQ_NEXT(v, link)) {
			char *addr;

			addr = in6addr2str(&v->val_addr6, 0);
			strlcat(s, addr, elen);
			strlcat(s, " ", elen);
		}
	}
	if (bcmcsnamelen) {
		elen = sizeof (bcmcsname_str) + bcmcsnamelen + 1;
		if ((s = envp[i++] = malloc(elen)) == NULL) {
			d_printf(LOG_NOTICE, FNAME,
			    "failed to allocate strings for BCMC domain name");
			ret = -1;
			goto clean;
		}
		memset(s, 0, elen);
		snprintf(s, elen, "%s=", bcmcsname_str);
		for (v = TAILQ_FIRST(&optinfo->bcmcsname_list); v;
		    v = TAILQ_NEXT(v, link)) {
			strlcat(s, v->val_vbuf.dv_buf, elen);
			strlcat(s, " ", elen);
		}
	}
	/* XXX */
	for (rawop = TAILQ_FIRST(&optinfo->rawops); rawop; rawop = TAILQ_NEXT(rawop, link)) {
		// max of 5 numbers after last underscore (seems like max DHCPv6 option could be 65535)
		elen = sizeof(raw_dhcp_option_str) + 1 /* underscore */ + 1 /* equals sign */ + 5;
		elen += rawop->datalen * 2;
		if ((s = envp[i++] = malloc(elen)) == NULL) {
			d_printf(LOG_NOTICE, FNAME,
			    "failed to allocate string for DHCPv6 option %d",
			    rawop->opnum);
			ret = -1;
			goto clean;
		}

		// make raw options available as raw_dhcp_option_xyz=hexresponse
		snprintf(s, elen, "%s_%d=", raw_dhcp_option_str, rawop->opnum);
		const char * hex = "0123456789abcdef";
		char * val = (char*)malloc(3);
		for (int o = 0; o < rawop->datalen; o++) {
			val[0] = hex[(rawop->data[o]>>4) & 0x0F];
			val[1] = hex[(rawop->data[o]   ) & 0x0F];
			val[2] = 0x00;
			strlcat(s, val, 1);
		}
		free(val);
	}
launch:
	/* launch the script */
	pid = fork();
	if (pid < 0) {
		d_printf(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)
			d_printf(LOG_ERR, FNAME, "wait: %s", strerror(errno));
		else {
			d_printf(LOG_DEBUG, FNAME,
			    "script \"%s\" terminated", scriptpath);
		}
	} else {
		char *argv[2];
		int fd;

		argv[0] = scriptpath;
		argv[1] = NULL;

		if (safefile(scriptpath)) {
			d_printf(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);

		d_printf(LOG_ERR, FNAME, "child: exec failed: %s",
		    strerror(errno));
		exit(0);
	}

  clean:
	for (i = 0; i < envc; i++)
		free(envp[i]);
	free(envp);

	return ret;
}