svn commit: r337876 - stable/10/lib/libjail

[Jamie Gritton]

Author: jamie
Date: Wed Aug 15 21:38:44 2018
New Revision: 337876
URL: https://svnweb.freebsd.org/changeset/base/337876

Log:
  MFC r331332:
  
    If a jail parameter isn't found, try loading a related kernel module.
  
  PR:		192092

Modified:
  stable/10/lib/libjail/jail.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/lib/libjail/jail.c
==============================================================================
--- stable/10/lib/libjail/jail.c	Wed Aug 15 21:38:10 2018	(r337875)
+++ stable/10/lib/libjail/jail.c	Wed Aug 15 21:38:44 2018	(r337876)
@@ -30,6 +30,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/param.h>
 #include <sys/types.h>
 #include <sys/jail.h>
+#include <sys/linker.h>
 #include <sys/socket.h>
 #include <sys/sysctl.h>
 
@@ -57,6 +58,7 @@ __FBSDID("$FreeBSD$");
 static int jailparam_import_enum(const char **values, int nvalues,
     const char *valstr, size_t valsize, int *value);
 static int jailparam_type(struct jailparam *jp);
+static int kldload_param(const char *name);
 static char *noname(const char *name);
 static char *nononame(const char *name);
 
@@ -885,6 +887,9 @@ jailparam_type(struct jailparam *jp)
 			    "sysctl(0.3.%s): %s", name, strerror(errno));
 			return (-1);
 		}
+		if (kldload_param(name) >= 0 && sysctl(mib, 2, mib + 2, &miblen,
+		    desc.s, strlen(desc.s)) >= 0)
+			goto mib_desc;
 		/*
 		 * The parameter probably doesn't exist.  But it might be
 		 * the "no" counterpart to a boolean.
@@ -1021,6 +1026,33 @@ jailparam_type(struct jailparam *jp)
 		jp->jp_valuelen = 0;
 	}
 	return (0);
+}
+
+/*
+ * Attempt to load a kernel module matching an otherwise nonexistent parameter.
+ */
+static int
+kldload_param(const char *name)
+{
+	int kl;
+
+	if (strcmp(name, "linux") == 0 || strncmp(name, "linux.", 6) == 0)
+		kl = kldload("linux");
+	else if (strcmp(name, "sysvmsg") == 0 || strcmp(name, "sysvsem") == 0 ||
+	    strcmp(name, "sysvshm") == 0)
+		kl = kldload(name);
+	else {
+		errno = ENOENT;
+		return (-1);
+	}
+	if (kl < 0 && errno == EEXIST) {
+		/*
+		 * In the module is already loaded, then it must not contain
+		 * the parameter.
+		 */
+		errno = ENOENT;
+	}
+	return kl;
 }
 
 /*