Prepare for network stack as a module

- Move cr_canseeinpcb to sys/netinet/in_prot.c in order to separate the
   INET and INET6-specific code from the rest of the prot code (It is only
   used by the network stack, so it makes sense for it to live with the
   other network stack code.)
 - Move cr_canseeinpcb prototype from sys/systm.h to netinet/in_systm.h
 - Rename cr_seeotheruids to cr_canseeotheruids and cr_seeothergids to
   cr_canseeothergids, make them non-static, and add prototypes (so they
   can be seen/called by in_prot.c functions.)
 - Remove sw_csum variable from ip6_forward in ip6_forward.c, as it is an
   unused variable.

Reviewed by:	gnn, jtl
Approved by:	sjg (mentor)
Sponsored by:	Juniper Networks, Inc.
Differential Revision:	https://reviews.freebsd.org/D2901

sys/conf/files

@@ -3750,6 +3750,7 @@ netinet/ip_id.c			optional inet
 netinet/in_mcast.c		optional inet
 netinet/in_pcb.c		optional inet | inet6
 netinet/in_pcbgroup.c		optional inet pcbgroup | inet6 pcbgroup
+netinet/in_prot.c		optional inet | inet6
 netinet/in_proto.c		optional inet | inet6
 netinet/in_rmx.c		optional inet
 netinet/in_rss.c		optional inet rss

sys/kern/kern_prot.c

@@ -76,11 +76,6 @@ FEATURE(regression,
     "Kernel support for interfaces necessary for regression testing (SECURITY RISK!)");
 #endif
 
-#if defined(INET) || defined(INET6)
-#include <netinet/in.h>
-#include <netinet/in_pcb.h>
-#endif
-
 #include <security/audit/audit.h>
 #include <security/mac/mac_framework.h>
 
@@ -1342,8 +1337,8 @@ SYSCTL_INT(_security_bsd, OID_AUTO, see_other_uids, CTLFLAG_RW,
  * References: *u1 and *u2 must not change during the call
  *             u1 may equal u2, in which case only one reference is required
  */
-static int
+int
-cr_seeotheruids(struct ucred *u1, struct ucred *u2)
+cr_canseeotheruids(struct ucred *u1, struct ucred *u2)
 {
 
 	if (!see_other_uids && u1->cr_ruid != u2->cr_ruid) {
@@ -1372,8 +1367,8 @@ SYSCTL_INT(_security_bsd, OID_AUTO, see_other_gids, CTLFLAG_RW,
  * References: *u1 and *u2 must not change during the call
  *             u1 may equal u2, in which case only one reference is required
  */
-static int
+int
-cr_seeothergids(struct ucred *u1, struct ucred *u2)
+cr_canseeothergids(struct ucred *u1, struct ucred *u2)
 {
 	int i, match;
 	
@@ -1411,9 +1406,9 @@ cr_cansee(struct ucred *u1, struct ucred *u2)
 	if ((error = mac_cred_check_visible(u1, u2)))
 		return (error);
 #endif
-	if ((error = cr_seeotheruids(u1, u2)))
+	if ((error = cr_canseeotheruids(u1, u2)))
 		return (error);
-	if ((error = cr_seeothergids(u1, u2)))
+	if ((error = cr_canseeothergids(u1, u2)))
 		return (error);
 	return (0);
 }
@@ -1472,9 +1467,9 @@ cr_cansignal(struct ucred *cred, struct proc *proc, int signum)
 	if ((error = mac_proc_check_signal(cred, proc, signum)))
 		return (error);
 #endif
-	if ((error = cr_seeotheruids(cred, proc->p_ucred)))
+	if ((error = cr_canseeotheruids(cred, proc->p_ucred)))
 		return (error);
-	if ((error = cr_seeothergids(cred, proc->p_ucred)))
+	if ((error = cr_canseeothergids(cred, proc->p_ucred)))
 		return (error);
 
 	/*
@@ -1589,9 +1584,9 @@ p_cansched(struct thread *td, struct proc *p)
 	if ((error = mac_proc_check_sched(td->td_ucred, p)))
 		return (error);
 #endif
-	if ((error = cr_seeotheruids(td->td_ucred, p->p_ucred)))
+	if ((error = cr_canseeotheruids(td->td_ucred, p->p_ucred)))
 		return (error);
-	if ((error = cr_seeothergids(td->td_ucred, p->p_ucred)))
+	if ((error = cr_canseeothergids(td->td_ucred, p->p_ucred)))
 		return (error);
 	if (td->td_ucred->cr_ruid != p->p_ucred->cr_ruid &&
 	    td->td_ucred->cr_uid != p->p_ucred->cr_ruid) {
@@ -1646,9 +1641,9 @@ p_candebug(struct thread *td, struct proc *p)
 	if ((error = mac_proc_check_debug(td->td_ucred, p)))
 		return (error);
 #endif
-	if ((error = cr_seeotheruids(td->td_ucred, p->p_ucred)))
+	if ((error = cr_canseeotheruids(td->td_ucred, p->p_ucred)))
 		return (error);
-	if ((error = cr_seeothergids(td->td_ucred, p->p_ucred)))
+	if ((error = cr_canseeothergids(td->td_ucred, p->p_ucred)))
 		return (error);
 
 	/*
@@ -1740,42 +1735,14 @@ cr_canseesocket(struct ucred *cred, struct socket *so)
 	if (error)
 		return (error);
 #endif
-	if (cr_seeotheruids(cred, so->so_cred))
+	if (cr_canseeotheruids(cred, so->so_cred))
 		return (ENOENT);
-	if (cr_seeothergids(cred, so->so_cred))
+	if (cr_canseeothergids(cred, so->so_cred))
 		return (ENOENT);
 
 	return (0);
 }
 
-#if defined(INET) || defined(INET6)
-/*-
- * Determine whether the subject represented by cred can "see" a socket.
- * Returns: 0 for permitted, ENOENT otherwise.
- */
-int
-cr_canseeinpcb(struct ucred *cred, struct inpcb *inp)
-{
-	int error;
-
-	error = prison_check(cred, inp->inp_cred);
-	if (error)
-		return (ENOENT);
-#ifdef MAC
-	INP_LOCK_ASSERT(inp);
-	error = mac_inpcb_check_visible(cred, inp);
-	if (error)
-		return (error);
-#endif
-	if (cr_seeotheruids(cred, inp->inp_cred))
-		return (ENOENT);
-	if (cr_seeothergids(cred, inp->inp_cred))
-		return (ENOENT);
-
-	return (0);
-}
-#endif
-
 /*-
  * Determine whether td can wait for the exit of p.
  * Returns: 0 for permitted, an errno value otherwise
@@ -1800,7 +1767,7 @@ p_canwait(struct thread *td, struct proc *p)
 #endif
 #if 0
 	/* XXXMAC: This could have odd effects on some shells. */
-	if ((error = cr_seeotheruids(td->td_ucred, p->p_ucred)))
+	if ((error = cr_canseeotheruids(td->td_ucred, p->p_ucred)))
 		return (error);
 #endif
 

sys/netinet/in_prot.c

@@ -0,0 +1,91 @@
+/*-
+ * Copyright (c) 1982, 1986, 1989, 1990, 1991, 1993
+ *	The Regents of the University of California.
+ * (c) UNIX System Laboratories, Inc.
+ * Copyright (c) 2000-2001 Robert N. M. Watson.
+ * All rights reserved.
+ *
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * 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.
+ * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
+ *
+ *	@(#)kern_prot.c	8.6 (Berkeley) 1/21/94
+ */
+
+/*
+ * System calls related to processes and protection
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "opt_compat.h"
+#include "opt_inet.h"
+#include "opt_inet6.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/proc.h>
+#include <sys/socket.h>
+#include <sys/jail.h>
+
+#include <netinet/in.h>
+#include <netinet/in_pcb.h>
+#include <netinet/in_systm.h>
+
+#include <security/audit/audit.h>
+#include <security/mac/mac_framework.h>
+
+/*-
+ * Determine whether the subject represented by cred can "see" a socket.
+ * Returns: 0 for permitted, ENOENT otherwise.
+ */
+int
+cr_canseeinpcb(struct ucred *cred, struct inpcb *inp)
+{
+	int error;
+
+	error = prison_check(cred, inp->inp_cred);
+	if (error)
+		return (ENOENT);
+#ifdef MAC
+	INP_LOCK_ASSERT(inp);
+	error = mac_inpcb_check_visible(cred, inp);
+	if (error)
+		return (error);
+#endif
+	if (cr_canseeotheruids(cred, inp->inp_cred))
+		return (ENOENT);
+	if (cr_canseeothergids(cred, inp->inp_cred))
+		return (ENOENT);
+
+	return (0);
+}

sys/netinet/in_systm.h

@@ -55,6 +55,11 @@ typedef u_int32_t n_long;		/* long as received from the net */
 typedef	u_int32_t n_time;		/* ms since 00:00 UTC, byte rev */
 
 #ifdef _KERNEL
+struct inpcb;
+struct ucred;
+
+int	cr_canseeinpcb(struct ucred *cred, struct inpcb *inp);
+
 uint32_t	 iptime(void);
 #endif
 

sys/netinet6/ip6_forward.c

@@ -102,9 +102,6 @@ ip6_forward(struct mbuf *m, int srcrt)
 	struct in6_addr src_in6, dst_in6, odst;
 #ifdef IPSEC
 	struct secpolicy *sp = NULL;
-#endif
-#ifdef SCTP
-	int sw_csum;
 #endif
 	struct m_tag *fwd_tag;
 	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];

sys/sys/systm.h

@@ -315,7 +315,8 @@ extern int	cpu_disable_c3_sleep;
 
 int	cr_cansee(struct ucred *u1, struct ucred *u2);
 int	cr_canseesocket(struct ucred *cred, struct socket *so);
-int	cr_canseeinpcb(struct ucred *cred, struct inpcb *inp);
+int	cr_canseeothergids(struct ucred *u1, struct ucred *u2);
+int	cr_canseeotheruids(struct ucred *u1, struct ucred *u2);
 
 char	*kern_getenv(const char *name);
 void	freeenv(char *env);