1 files changed, 121 insertions, 0 deletions
diff --git a/lib/libjail/jail_getid.c b/lib/libjail/jail_getid.c
new file mode 100644
index 000000000000..9cc13d84e614
--- /dev/null
+++ b/lib/libjail/jail_getid.c
@@ -0,0 +1,121 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2009 James Gritton.
+ * 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.
+ */
+
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/jail.h>
+#include <sys/uio.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "jail.h"
+
+
+/*
+ * Return the JID corresponding to a jail name.
+ */
+int
+jail_getid(const char *name)
+{
+	char *ep;
+	int jid;
+	struct iovec jiov[4];
+
+	jid = strtoul(name, &ep, 10);
+	if (*name && !*ep) {
+		/*
+		 * jid == 0 is a special case; it will not appear in the
+		 * kernel's jail list, but naturally processes will be assigned
+		 * to it because it is prison 0.  Trivially return this one
+		 * without a trip to the kernel, because it always exists but
+		 * the lookup won't succeed.
+		 */
+		if (jid == 0)
+			return jid;
+		jiov[0].iov_base = __DECONST(char *, "jid");
+		jiov[0].iov_len = sizeof("jid");
+		jiov[1].iov_base = &jid;
+		jiov[1].iov_len = sizeof(jid);
+	} else {
+		jiov[0].iov_base = __DECONST(char *, "name");
+		jiov[0].iov_len = sizeof("name");
+		jiov[1].iov_len = strlen(name) + 1;
+		jiov[1].iov_base = alloca(jiov[1].iov_len);
+		strcpy(jiov[1].iov_base, name);
+	}
+	jiov[2].iov_base = __DECONST(char *, "errmsg");
+	jiov[2].iov_len = sizeof("errmsg");
+	jiov[3].iov_base = jail_errmsg;
+	jiov[3].iov_len = JAIL_ERRMSGLEN;
+	jail_errmsg[0] = 0;
+	jid = jail_get(jiov, 4, 0);
+	if (jid < 0 && !jail_errmsg[0])
+		snprintf(jail_errmsg, JAIL_ERRMSGLEN, "jail_get: %s",
+		    strerror(errno));
+	return jid;
+}
+
+/*
+ * Return the name corresponding to a JID.
+ */
+char *
+jail_getname(int jid)
+{
+	struct iovec jiov[6];
+	char *name;
+	char namebuf[MAXHOSTNAMELEN];
+
+	jiov[0].iov_base = __DECONST(char *, "jid");
+	jiov[0].iov_len = sizeof("jid");
+	jiov[1].iov_base = &jid;
+	jiov[1].iov_len = sizeof(jid);
+	jiov[2].iov_base = __DECONST(char *, "name");
+	jiov[2].iov_len = sizeof("name");
+	jiov[3].iov_base = namebuf;
+	jiov[3].iov_len = sizeof(namebuf);
+	jiov[4].iov_base = __DECONST(char *, "errmsg");
+	jiov[4].iov_len = sizeof("errmsg");
+	jiov[5].iov_base = jail_errmsg;
+	jiov[5].iov_len = JAIL_ERRMSGLEN;
+	jail_errmsg[0] = 0;
+	jid = jail_get(jiov, 6, 0);
+	if (jid < 0) {
+		if (!jail_errmsg[0])
+			snprintf(jail_errmsg, JAIL_ERRMSGLEN, "jail_get: %s",
+			    strerror(errno));
+		return NULL;
+	} else {
+		name = strdup(namebuf);
+		if (name == NULL)
+			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
+	}
+	return name;
+}