supported script execution for dhcp6relay (contributed by Bruno STEVANT)

1 files changed, 304 insertions, 0 deletions

diff --git a/dhcp6relay_script.c b/dhcp6relay_script.c
new file mode 100644
index 0000000..82f5eab
--- /dev/null
+++ b/dhcp6relay_script.c
@@ -0,0 +1,304 @@
+/*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;
+}