svn commit: r349898 - head/sys/contrib/ipfilter/netinet

[Cy Schubert]

Author: cy
Date: Thu Jul 11 00:08:46 2019
New Revision: 349898
URL: https://svnweb.freebsd.org/changeset/base/349898

Log:
  ipfilter commands, in this case ipf(8), passes its operations and rules
  via an ioctl interface. Rules can be added or removed and stats and
  counters can be zeroed out. As the ipfilter interprets these
  instructions or operations they are stored in an integer called
  addrem (add/remove). 1 is add, 2 is remove, and 3 is clear stats and
  counters. Much of this is not documented. This commit documents these
  operations by replacing simple integers with a self documenting
  enum along with a few basic comments.
  
  MFC after:	1 week

Modified:
  head/sys/contrib/ipfilter/netinet/fil.c

Modified: head/sys/contrib/ipfilter/netinet/fil.c
==============================================================================
--- head/sys/contrib/ipfilter/netinet/fil.c	Wed Jul 10 22:52:26 2019	(r349897)
+++ head/sys/contrib/ipfilter/netinet/fil.c	Thu Jul 11 00:08:46 2019	(r349898)
@@ -4472,7 +4472,12 @@ frrequest(softc, unit, req, data, set, makecopy)
 	int set, makecopy;
 	caddr_t data;
 {
-	int error = 0, in, family, addrem, need_free = 0;
+	int error = 0, in, family, need_free = 0;
+	enum {	OP_UNDEF,	/* undefined */
+			OP_ADD,		/* add rule */
+			OP_REM,		/* remove rule */
+			OP_ZERO 	/* zero statistics and counters */ }
+		addrem = OP_UNDEF;
 	frentry_t frd, *fp, *f, **fprev, **ftail;
 	void *ptr, *uptr, *cptr;
 	u_int *p, *pp;
@@ -4540,11 +4545,11 @@ frrequest(softc, unit, req, data, set, makecopy)
 
 	if (req == (ioctlcmd_t)SIOCINAFR || req == (ioctlcmd_t)SIOCINIFR ||
 	    req == (ioctlcmd_t)SIOCADAFR || req == (ioctlcmd_t)SIOCADIFR)
-		addrem = 0;
+		addrem = OP_ADD;	/* Add rule */
 	else if (req == (ioctlcmd_t)SIOCRMAFR || req == (ioctlcmd_t)SIOCRMIFR)
-		addrem = 1;
+		addrem = OP_REM;		/* Remove rule */
 	else if (req == (ioctlcmd_t)SIOCZRLST)
-		addrem = 2;
+		addrem = OP_ZERO;	/* Zero statistics and counters */
 	else {
 		IPFERROR(9);
 		error = EINVAL;
@@ -4578,7 +4583,7 @@ frrequest(softc, unit, req, data, set, makecopy)
 			goto donenolock;
 		}
 
-		if (addrem == 0) {
+		if (addrem == OP_UNDEF) {
 			error = ipf_funcinit(softc, fp);
 			if (error != 0)
 				goto donenolock;
@@ -4642,7 +4647,7 @@ frrequest(softc, unit, req, data, set, makecopy)
 			 * them to be created if they don't already exit.
 			 */
 			group = FR_NAME(fp, fr_group);
-			if (addrem == 0) {
+			if (addrem == OP_UNDEF) {
 				fg = ipf_group_add(softc, group, NULL,
 						   fp->fr_flags, unit, set);
 				fp->fr_grp = fg;
@@ -4947,7 +4952,7 @@ frrequest(softc, unit, req, data, set, makecopy)
 	/*
 	 * If zero'ing statistics, copy current to caller and zero.
 	 */
-	if (addrem == 2) {
+	if (addrem == OP_ZERO) {
 		if (f == NULL) {
 			IPFERROR(27);
 			error = ESRCH;
@@ -5040,7 +5045,7 @@ frrequest(softc, unit, req, data, set, makecopy)
 	/*
 	 * Request to remove a rule.
 	 */
-	if (addrem == 1) {
+	if (addrem == OP_REM) {
 		if (f == NULL) {
 			IPFERROR(29);
 			error = ESRCH;
@@ -5106,7 +5111,7 @@ frrequest(softc, unit, req, data, set, makecopy)
 		if (fp->fr_next != NULL)
 			fp->fr_next->fr_pnext = &fp->fr_next;
 		*ftail = fp;
-		if (addrem == 0)
+		if (addrem == OP_UNDEF)
 			ipf_fixskip(ftail, fp, 1);
 
 		fp->fr_icmpgrp = NULL;