remove sfeed_tail and recently added security considerations

... both are out-of-scope for sfeed.

- sfeed_tail can be written as some simple customized awk script reading from a
  FIFO. The C version did not work well on FIFO's.
- Security considerations are mentioned in the official HTML spec and applies to
  all HTML and protocol handlers, so is out-of-scope.

5 files changed, 0 insertions, 1033 deletions

diff --git a/Makefile b/Makefile
index a53f31a..37a881c 100644
--- a/Makefile
+++ b/Makefile
@@ -14,7 +14,6 @@ BIN = \
 	sfeed_mbox\
 	sfeed_opml_import\
 	sfeed_plain\
-	sfeed_tail\
 	sfeed_twtxt\
 	sfeed_web\
 	sfeed_xmlenc
@@ -24,7 +23,6 @@ SCRIPTS = \
 
 SRC = ${BIN:=.c}
 HDR = \
-	tree.h\
 	util.h\
 	xml.h
 
diff --git a/README b/README
index 21e4c35..2467b7d 100644
--- a/README
+++ b/README
@@ -128,7 +128,6 @@ sfeed_opml_export - Generate an OPML XML file from a sfeedrc config file.
 sfeed_opml_import - Generate a sfeedrc config file from an OPML XML file.
 sfeed_mbox        - Format feed data (TSV) to mbox.
 sfeed_plain       - Format feed data (TSV) to a plain-text list.
-sfeed_tail        - Format unseen feed data (TSV) to a plain-text list.
 sfeed_twtxt       - Format feed data (TSV) to a twtxt feed.
 sfeed_update      - Update feeds and merge with old feeds in the directory
                     $HOME/.sfeed/feeds by default.
@@ -508,52 +507,6 @@ Now run:
 Now you can view feeds in mutt(1) for example.
 
 
-Security considerations
------------------------
-
-About automated remote resource loading and content execution:
-
-Some feeds will use a tracking pixel (1x1 image size) in HTML content with some
-unique ID. Some even have embedded Javascript code, iframes, CSS. Opening such
-content and loading these resources automatically may leak unwanted
-information.
-
-For example on Slashdot:
-<img src="http://feeds.feedburner.com/~r/Slashdot/slashdot/~4/someid"
-     height="1" width="1" alt=""/>
-
-If such content is opened in a typical webbrowser configuration this is
-insecure. Be aware opening a link in a page generated on the local filesystem
-or network has different privileges than one on a non-local domain.
-
-Recommendation:
-Do not handle content as HTML and avoid automated remote resource loading in
-content. Convert all content to plain-text in your formatting program.
-
-
-About handling links:
-
-Be careful about handling feed links.
-
-A malicious link could be: tel:some-phonenumber, file:// or some other protocol
-scheme which depending on the viewing program and system can have an action
-assigned.
-
-Another malicious link could be pointing to a local device, for example an
-(insecure) router: http://192.168.0.1/?reboot
-
-Recommendation:
-Filter specific by protocol and non-local domain. This can be done using a grep
-or awk filter or as a setting in your viewing program.
-
-See also:
-- RFC4287 (Atom): 8. Security Considerations:
-  https://tools.ietf.org/html/rfc4287#section-8
-- RFC2854: 7. Security Considerations:
-  https://tools.ietf.org/html/rfc2854
-- Filter examples: see the sfeed README file.
-
-
 License
 -------
 
diff --git a/sfeed_tail.1 b/sfeed_tail.1
deleted file mode 100644
index 955c423..0000000
--- a/sfeed_tail.1
+++ /dev/null
@@ -1,41 +0,0 @@
-.Dd December 14, 2018
-.Dt SFEED_TAIL 1
-.Os
-.Sh NAME
-.Nm sfeed_tail
-.Nd format unseen feed data to a plain-text list
-.Sh SYNOPSIS
-.Nm
-.Ar file...
-.Sh DESCRIPTION
-.Nm
-formats only new and unseen feed data (TSV) from
-one or more
-.Ar file
-to stdout as a plain-text list.
-The basename of the
-.Ar file
-is used as the feed name in the output.
-.Pp
-Unseen items are printed per line in a similar format to
-.Xr sfeed_plain 1 ,
-duplicate items are ignored.
-The list of unique items is determined by the fields: item id, item link and
-UNIX timestamp of the item date.
-.Pp
-.Nm
-will also only process and show items that are considered new: the item
-timestamp is not older than a day ago.
-.Sh IMPLEMENTATION NOTES
-.Nm
-checks for file modifications every 10 seconds by checking the filesize and
-modification time.
-Keep in mind that because
-.Nm
-keeps a list of items it can potentially consume much memory.
-.Sh SEE ALSO
-.Xr sfeed 1 ,
-.Xr sfeed_plain 1 ,
-.Xr tail 1
-.Sh AUTHORS
-.An Hiltjo Posthuma Aq Mt hiltjo@codemadness.org
diff --git a/sfeed_tail.c b/sfeed_tail.c
deleted file mode 100644
index d611cbc..0000000
--- a/sfeed_tail.c
+++ /dev/null
@@ -1,185 +0,0 @@
-#include <sys/stat.h>
-#include <sys/types.h>
-
-#include <ctype.h>
-#include <err.h>
-#include <locale.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-#include "tree.h"
-#include "util.h"
-
-static char *line;
-static size_t linesize;
-static int changed, firsttime = 1;
-static time_t comparetime;
-
-struct line {
-	char *id;
-	char *link;
-	char *title;
-	time_t timestamp;
-	RB_ENTRY(line) entry;
-};
-
-int
-linecmp(struct line *e1, struct line *e2)
-{
-	int r;
-
-	if ((r = strcmp(e1->id, e2->id)))
-		return r;
-	else if ((r = strcmp(e1->title, e2->title)))
-		return r;
-	return strcmp(e1->link, e2->link);
-}
-RB_HEAD(linetree, line) head = RB_INITIALIZER(&head);
-RB_GENERATE_STATIC(linetree, line, entry, linecmp)
-
-/* remove old entries from the tree that won't be shown anyway. */
-static void
-gc(void)
-{
-	struct line *l, *tmp;
-
-	RB_FOREACH_SAFE(l, linetree, &head, tmp) {
-		if (l->timestamp < comparetime) {
-			free(l->id);
-			free(l->link);
-			free(l->title);
-			RB_REMOVE(linetree, &head, l);
-			free(l);
-		}
-	}
-}
-
-static void
-printfeed(FILE *fp, const char *feedname)
-{
-	struct line *add, search;
-	char *fields[FieldLast];
-	ssize_t linelen;
-	time_t parsedtime;
-	struct tm *tm;
-
-	while ((linelen = getline(&line, &linesize, fp)) > 0) {
-		if (line[linelen - 1] == '\n')
-			line[--linelen] = '\0';
-
-		if (!parseline(line, fields))
-			break;
-		parsedtime = 0;
-		if (strtotime(fields[FieldUnixTimestamp], &parsedtime))
-			continue;
-		if (!(tm = localtime(&parsedtime)))
-			err(1, "localtime");
-
-		/* old news: skip */
-		if (parsedtime < comparetime)
-			continue;
-
-		search.id = fields[FieldId];
-		search.link = fields[FieldLink];
-		search.title = fields[FieldTitle];
-		search.timestamp = parsedtime;
-		if (RB_FIND(linetree, &head, &search))
-			continue;
-
-		changed = 1;
-
-		if (!(add = calloc(1, sizeof(*add))))
-			err(1, "calloc");
-		if (!(add->id = strdup(fields[FieldId])))
-			err(1, "strdup");
-		if (!(add->link = strdup(fields[FieldLink])))
-			err(1, "strdup");
-		if (!(add->title = strdup(fields[FieldTitle])))
-			err(1, "strdup");
-		add->timestamp = parsedtime;
-		RB_INSERT(linetree, &head, add);
-
-		if (feedname[0]) {
-			printutf8pad(stdout, feedname, 15, ' ');
-			fputs("  ", stdout);
-		}
-
-		fprintf(stdout, "%04d-%02d-%02d %02d:%02d  ",
-		        tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
-		        tm->tm_hour, tm->tm_min);
-		printutf8pad(stdout, fields[FieldTitle], 70, ' ');
-		printf(" %s\n", fields[FieldLink]);
-	}
-}
-
-int
-main(int argc, char *argv[])
-{
-	struct stat *stfiles, st;
-	char *name;
-	FILE *fp;
-	int i, slept = 0;
-
-	if (pledge("stdio rpath", NULL) == -1)
-		err(1, "pledge");
-
-	if (argc <= 1) {
-		fprintf(stderr, "usage: %s <file>...\n", argv[0]);
-		return 1;
-	}
-
-	setlocale(LC_CTYPE, "");
-
-	if (!(stfiles = calloc(argc - 1, sizeof(*stfiles))))
-		err(1, "calloc");
-
-	while (1) {
-		changed = 0;
-
-		if ((comparetime = time(NULL)) == -1)
-			err(1, "time");
-		/* 1 day is old news */
-		comparetime -= 86400;
-
-		for (i = 1; i < argc; i++) {
-			if (!(fp = fopen(argv[i], "r"))) {
-				if (firsttime)
-					err(1, "fopen: %s", argv[i]);
-				/* don't report when the file is missing after the first run */
-				continue;
-			}
-			if (fstat(fileno(fp), &st) == -1) {
-				if (firsttime)
-					err(1, "fstat: %s", argv[i]);
-				warn("fstat: %s", argv[i]);
-				fclose(fp);
-				continue;
-			}
-
-			/* did the file change? by size or modification time */
-			if (stfiles[i - 1].st_size != st.st_size ||
-			    stfiles[i - 1].st_mtime != st.st_mtime) {
-				name = ((name = strrchr(argv[i], '/'))) ? name + 1 : argv[i];
-				printfeed(fp, name);
-				if (ferror(fp))
-					warn("ferror: %s", argv[i]);
-				memcpy(&stfiles[i - 1], &st, sizeof(st));
-			}
-
-			fclose(fp);
-		}
-
-		/* "garbage collect" on a change or every 5 minutes */
-		if (changed || slept > 300) {
-			gc();
-			changed = 0;
-			slept = 0;
-		}
-		sleep(10);
-		slept += 10;
-		firsttime = 0;
-	}
-	return 0;
-}
diff --git a/tree.h b/tree.h
deleted file mode 100644
index 472e955..0000000
--- a/tree.h
+++ /dev/null
@@ -1,758 +0,0 @@
-/*	$OpenBSD: tree.h,v 1.29 2017/07/30 19:27:20 deraadt Exp $	*/
-/*
- * Copyright 2002 Niels Provos <provos@citi.umich.edu>
- * 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 ``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 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.
- */
-
-#ifndef	_SYS_TREE_H_
-#define	_SYS_TREE_H_
-
-/*
- * This file defines data structures for red-black trees.
- *
- * A red-black tree is a binary search tree with the node color as an
- * extra attribute.  It fulfills a set of conditions:
- *	- every search path from the root to a leaf consists of the
- *	  same number of black nodes,
- *	- each red node (except for the root) has a black parent,
- *	- each leaf node is black.
- *
- * Every operation on a red-black tree is bounded as O(lg n).
- * The maximum height of a red-black tree is 2lg (n+1).
- */
-
-/* Macros that define a red-black tree */
-#define RB_HEAD(name, type)						\
-struct name {								\
-	struct type *rbh_root; /* root of the tree */			\
-}
-
-#define RB_INITIALIZER(root)						\
-	{ NULL }
-
-#define RB_INIT(root) do {						\
-	(root)->rbh_root = NULL;					\
-} while (0)
-
-#define RB_BLACK	0
-#define RB_RED		1
-#define RB_ENTRY(type)							\
-struct {								\
-	struct type *rbe_left;		/* left element */		\
-	struct type *rbe_right;		/* right element */		\
-	struct type *rbe_parent;	/* parent element */		\
-	int rbe_color;			/* node color */		\
-}
-
-#define RB_LEFT(elm, field)		(elm)->field.rbe_left
-#define RB_RIGHT(elm, field)		(elm)->field.rbe_right
-#define RB_PARENT(elm, field)		(elm)->field.rbe_parent
-#define RB_COLOR(elm, field)		(elm)->field.rbe_color
-#define RB_ROOT(head)			(head)->rbh_root
-#define RB_EMPTY(head)			(RB_ROOT(head) == NULL)
-
-#define RB_SET(elm, parent, field) do {					\
-	RB_PARENT(elm, field) = parent;					\
-	RB_LEFT(elm, field) = RB_RIGHT(elm, field) = NULL;		\
-	RB_COLOR(elm, field) = RB_RED;					\
-} while (0)
-
-#define RB_SET_BLACKRED(black, red, field) do {				\
-	RB_COLOR(black, field) = RB_BLACK;				\
-	RB_COLOR(red, field) = RB_RED;					\
-} while (0)
-
-#ifndef RB_AUGMENT
-#define RB_AUGMENT(x)	do {} while (0)
-#endif
-
-#define RB_ROTATE_LEFT(head, elm, tmp, field) do {			\
-	(tmp) = RB_RIGHT(elm, field);					\
-	if ((RB_RIGHT(elm, field) = RB_LEFT(tmp, field))) {		\
-		RB_PARENT(RB_LEFT(tmp, field), field) = (elm);		\
-	}								\
-	RB_AUGMENT(elm);						\
-	if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {		\
-		if ((elm) == RB_LEFT(RB_PARENT(elm, field), field))	\
-			RB_LEFT(RB_PARENT(elm, field), field) = (tmp);	\
-		else							\
-			RB_RIGHT(RB_PARENT(elm, field), field) = (tmp);	\
-	} else								\
-		(head)->rbh_root = (tmp);				\
-	RB_LEFT(tmp, field) = (elm);					\
-	RB_PARENT(elm, field) = (tmp);					\
-	RB_AUGMENT(tmp);						\
-	if ((RB_PARENT(tmp, field)))					\
-		RB_AUGMENT(RB_PARENT(tmp, field));			\
-} while (0)
-
-#define RB_ROTATE_RIGHT(head, elm, tmp, field) do {			\
-	(tmp) = RB_LEFT(elm, field);					\
-	if ((RB_LEFT(elm, field) = RB_RIGHT(tmp, field))) {		\
-		RB_PARENT(RB_RIGHT(tmp, field), field) = (elm);		\
-	}								\
-	RB_AUGMENT(elm);						\
-	if ((RB_PARENT(tmp, field) = RB_PARENT(elm, field))) {		\
-		if ((elm) == RB_LEFT(RB_PARENT(elm, field), field))	\
-			RB_LEFT(RB_PARENT(elm, field), field) = (tmp);	\
-		else							\
-			RB_RIGHT(RB_PARENT(elm, field), field) = (tmp);	\
-	} else								\
-		(head)->rbh_root = (tmp);				\
-	RB_RIGHT(tmp, field) = (elm);					\
-	RB_PARENT(elm, field) = (tmp);					\
-	RB_AUGMENT(tmp);						\
-	if ((RB_PARENT(tmp, field)))					\
-		RB_AUGMENT(RB_PARENT(tmp, field));			\
-} while (0)
-
-/* Generates prototypes and inline functions */
-#define	RB_PROTOTYPE(name, type, field, cmp)				\
-	RB_PROTOTYPE_INTERNAL(name, type, field, cmp,)
-#define	RB_PROTOTYPE_STATIC(name, type, field, cmp)			\
-	RB_PROTOTYPE_INTERNAL(name, type, field, cmp, __attribute__((__unused__)) static)
-#define RB_PROTOTYPE_INTERNAL(name, type, field, cmp, attr)		\
-attr void name##_RB_INSERT_COLOR(struct name *, struct type *);		\
-attr void name##_RB_REMOVE_COLOR(struct name *, struct type *, struct type *);\
-attr struct type *name##_RB_REMOVE(struct name *, struct type *);	\
-attr struct type *name##_RB_INSERT(struct name *, struct type *);	\
-attr struct type *name##_RB_FIND(struct name *, struct type *);		\
-attr struct type *name##_RB_NFIND(struct name *, struct type *);	\
-attr struct type *name##_RB_NEXT(struct type *);			\
-attr struct type *name##_RB_PREV(struct type *);			\
-attr struct type *name##_RB_MINMAX(struct name *, int);			\
-									\
-
-/* Main rb operation.
- * Moves node close to the key of elm to top
- */
-#define	RB_GENERATE(name, type, field, cmp)				\
-	RB_GENERATE_INTERNAL(name, type, field, cmp,)
-#define	RB_GENERATE_STATIC(name, type, field, cmp)			\
-	RB_GENERATE_INTERNAL(name, type, field, cmp, __attribute__((__unused__)) static)
-#define RB_GENERATE_INTERNAL(name, type, field, cmp, attr)		\
-attr void								\
-name##_RB_INSERT_COLOR(struct name *head, struct type *elm)		\
-{									\
-	struct type *parent, *gparent, *tmp;				\
-	while ((parent = RB_PARENT(elm, field)) &&			\
-	    RB_COLOR(parent, field) == RB_RED) {			\
-		gparent = RB_PARENT(parent, field);			\
-		if (parent == RB_LEFT(gparent, field)) {		\
-			tmp = RB_RIGHT(gparent, field);			\
-			if (tmp && RB_COLOR(tmp, field) == RB_RED) {	\
-				RB_COLOR(tmp, field) = RB_BLACK;	\
-				RB_SET_BLACKRED(parent, gparent, field);\
-				elm = gparent;				\
-				continue;				\
-			}						\
-			if (RB_RIGHT(parent, field) == elm) {		\
-				RB_ROTATE_LEFT(head, parent, tmp, field);\
-				tmp = parent;				\
-				parent = elm;				\
-				elm = tmp;				\
-			}						\
-			RB_SET_BLACKRED(parent, gparent, field);	\
-			RB_ROTATE_RIGHT(head, gparent, tmp, field);	\
-		} else {						\
-			tmp = RB_LEFT(gparent, field);			\
-			if (tmp && RB_COLOR(tmp, field) == RB_RED) {	\
-				RB_COLOR(tmp, field) = RB_BLACK;	\
-				RB_SET_BLACKRED(parent, gparent, field);\
-				elm = gparent;				\
-				continue;				\
-			}						\
-			if (RB_LEFT(parent, field) == elm) {		\
-				RB_ROTATE_RIGHT(head, parent, tmp, field);\
-				tmp = parent;				\
-				parent = elm;				\
-				elm = tmp;				\
-			}						\
-			RB_SET_BLACKRED(parent, gparent, field);	\
-			RB_ROTATE_LEFT(head, gparent, tmp, field);	\
-		}							\
-	}								\
-	RB_COLOR(head->rbh_root, field) = RB_BLACK;			\
-}									\
-									\
-attr void								\
-name##_RB_REMOVE_COLOR(struct name *head, struct type *parent, struct type *elm) \
-{									\
-	struct type *tmp;						\
-	while ((elm == NULL || RB_COLOR(elm, field) == RB_BLACK) &&	\
-	    elm != RB_ROOT(head)) {					\
-		if (RB_LEFT(parent, field) == elm) {			\
-			tmp = RB_RIGHT(parent, field);			\
-			if (RB_COLOR(tmp, field) == RB_RED) {		\
-				RB_SET_BLACKRED(tmp, parent, field);	\
-				RB_ROTATE_LEFT(head, parent, tmp, field);\
-				tmp = RB_RIGHT(parent, field);		\
-			}						\
-			if ((RB_LEFT(tmp, field) == NULL ||		\
-			    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
-			    (RB_RIGHT(tmp, field) == NULL ||		\
-			    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
-				RB_COLOR(tmp, field) = RB_RED;		\
-				elm = parent;				\
-				parent = RB_PARENT(elm, field);		\
-			} else {					\
-				if (RB_RIGHT(tmp, field) == NULL ||	\
-				    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK) {\
-					struct type *oleft;		\
-					if ((oleft = RB_LEFT(tmp, field)))\
-						RB_COLOR(oleft, field) = RB_BLACK;\
-					RB_COLOR(tmp, field) = RB_RED;	\
-					RB_ROTATE_RIGHT(head, tmp, oleft, field);\
-					tmp = RB_RIGHT(parent, field);	\
-				}					\
-				RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
-				RB_COLOR(parent, field) = RB_BLACK;	\
-				if (RB_RIGHT(tmp, field))		\
-					RB_COLOR(RB_RIGHT(tmp, field), field) = RB_BLACK;\
-				RB_ROTATE_LEFT(head, parent, tmp, field);\
-				elm = RB_ROOT(head);			\
-				break;					\
-			}						\
-		} else {						\
-			tmp = RB_LEFT(parent, field);			\
-			if (RB_COLOR(tmp, field) == RB_RED) {		\
-				RB_SET_BLACKRED(tmp, parent, field);	\
-				RB_ROTATE_RIGHT(head, parent, tmp, field);\
-				tmp = RB_LEFT(parent, field);		\
-			}						\
-			if ((RB_LEFT(tmp, field) == NULL ||		\
-			    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) &&\
-			    (RB_RIGHT(tmp, field) == NULL ||		\
-			    RB_COLOR(RB_RIGHT(tmp, field), field) == RB_BLACK)) {\
-				RB_COLOR(tmp, field) = RB_RED;		\
-				elm = parent;				\
-				parent = RB_PARENT(elm, field);		\
-			} else {					\
-				if (RB_LEFT(tmp, field) == NULL ||	\
-				    RB_COLOR(RB_LEFT(tmp, field), field) == RB_BLACK) {\
-					struct type *oright;		\
-					if ((oright = RB_RIGHT(tmp, field)))\
-						RB_COLOR(oright, field) = RB_BLACK;\
-					RB_COLOR(tmp, field) = RB_RED;	\
-					RB_ROTATE_LEFT(head, tmp, oright, field);\
-					tmp = RB_LEFT(parent, field);	\
-				}					\
-				RB_COLOR(tmp, field) = RB_COLOR(parent, field);\
-				RB_COLOR(parent, field) = RB_BLACK;	\
-				if (RB_LEFT(tmp, field))		\
-					RB_COLOR(RB_LEFT(tmp, field), field) = RB_BLACK;\
-				RB_ROTATE_RIGHT(head, parent, tmp, field);\
-				elm = RB_ROOT(head);			\
-				break;					\
-			}						\
-		}							\
-	}								\
-	if (elm)							\
-		RB_COLOR(elm, field) = RB_BLACK;			\
-}									\
-									\
-attr struct type *							\
-name##_RB_REMOVE(struct name *head, struct type *elm)			\
-{									\
-	struct type *child, *parent, *old = elm;			\
-	int color;							\
-	if (RB_LEFT(elm, field) == NULL)				\
-		child = RB_RIGHT(elm, field);				\
-	else if (RB_RIGHT(elm, field) == NULL)				\
-		child = RB_LEFT(elm, field);				\
-	else {								\
-		struct type *left;					\
-		elm = RB_RIGHT(elm, field);				\
-		while ((left = RB_LEFT(elm, field)))			\
-			elm = left;					\
-		child = RB_RIGHT(elm, field);				\
-		parent = RB_PARENT(elm, field);				\
-		color = RB_COLOR(elm, field);				\
-		if (child)						\
-			RB_PARENT(child, field) = parent;		\
-		if (parent) {						\
-			if (RB_LEFT(parent, field) == elm)		\
-				RB_LEFT(parent, field) = child;		\
-			else						\
-				RB_RIGHT(parent, field) = child;	\
-			RB_AUGMENT(parent);				\
-		} else							\
-			RB_ROOT(head) = child;				\
-		if (RB_PARENT(elm, field) == old)			\
-			parent = elm;					\
-		(elm)->field = (old)->field;				\
-		if (RB_PARENT(old, field)) {				\
-			if (RB_LEFT(RB_PARENT(old, field), field) == old)\
-				RB_LEFT(RB_PARENT(old, field), field) = elm;\
-			else						\
-				RB_RIGHT(RB_PARENT(old, field), field) = elm;\
-			RB_AUGMENT(RB_PARENT(old, field));		\
-		} else							\
-			RB_ROOT(head) = elm;				\
-		RB_PARENT(RB_LEFT(old, field), field) = elm;		\
-		if (RB_RIGHT(old, field))				\
-			RB_PARENT(RB_RIGHT(old, field), field) = elm;	\
-		if (parent) {						\
-			left = parent;					\
-			do {						\
-				RB_AUGMENT(left);			\
-			} while ((left = RB_PARENT(left, field)));	\
-		}							\
-		goto color;						\
-	}								\
-	parent = RB_PARENT(elm, field);					\
-	color = RB_COLOR(elm, field);					\
-	if (child)							\
-		RB_PARENT(child, field) = parent;			\
-	if (parent) {							\
-		if (RB_LEFT(parent, field) == elm)			\
-			RB_LEFT(parent, field) = child;			\
-		else							\
-			RB_RIGHT(parent, field) = child;		\
-		RB_AUGMENT(parent);					\
-	} else								\
-		RB_ROOT(head) = child;					\
-color:									\
-	if (color == RB_BLACK)						\
-		name##_RB_REMOVE_COLOR(head, parent, child);		\
-	return (old);							\
-}									\
-									\
-/* Inserts a node into the RB tree */					\
-attr struct type *							\
-name##_RB_INSERT(struct name *head, struct type *elm)			\
-{									\
-	struct type *tmp;						\
-	struct type *parent = NULL;					\
-	int comp = 0;							\
-	tmp = RB_ROOT(head);						\
-	while (tmp) {							\
-		parent = tmp;						\
-		comp = (cmp)(elm, parent);				\
-		if (comp < 0)						\
-			tmp = RB_LEFT(tmp, field);			\
-		else if (comp > 0)					\
-			tmp = RB_RIGHT(tmp, field);			\
-		else							\
-			return (tmp);					\
-	}								\
-	RB_SET(elm, parent, field);					\
-	if (parent != NULL) {						\
-		if (comp < 0)						\
-			RB_LEFT(parent, field) = elm;			\
-		else							\
-			RB_RIGHT(parent, field) = elm;			\
-		RB_AUGMENT(parent);					\
-	} else								\
-		RB_ROOT(head) = elm;					\
-	name##_RB_INSERT_COLOR(head, elm);				\
-	return (NULL);							\
-}									\
-									\
-/* Finds the node with the same key as elm */				\
-attr struct type *							\
-name##_RB_FIND(struct name *head, struct type *elm)			\
-{									\
-	struct type *tmp = RB_ROOT(head);				\
-	int comp;							\
-	while (tmp) {							\
-		comp = cmp(elm, tmp);					\
-		if (comp < 0)						\
-			tmp = RB_LEFT(tmp, field);			\
-		else if (comp > 0)					\
-			tmp = RB_RIGHT(tmp, field);			\
-		else							\
-			return (tmp);					\
-	}								\
-	return (NULL);							\
-}									\
-									\
-/* Finds the first node greater than or equal to the search key */	\
-attr struct type *							\
-name##_RB_NFIND(struct name *head, struct type *elm)			\
-{									\
-	struct type *tmp = RB_ROOT(head);				\
-	struct type *res = NULL;					\
-	int comp;							\
-	while (tmp) {							\
-		comp = cmp(elm, tmp);					\
-		if (comp < 0) {						\
-			res = tmp;					\
-			tmp = RB_LEFT(tmp, field);			\
-		}							\
-		else if (comp > 0)					\
-			tmp = RB_RIGHT(tmp, field);			\
-		else							\
-			return (tmp);					\
-	}								\
-	return (res);							\
-}									\
-									\
-/* ARGSUSED */								\
-attr struct type *							\
-name##_RB_NEXT(struct type *elm)					\
-{									\
-	if (RB_RIGHT(elm, field)) {					\
-		elm = RB_RIGHT(elm, field);				\
-		while (RB_LEFT(elm, field))				\
-			elm = RB_LEFT(elm, field);			\
-	} else {							\
-		if (RB_PARENT(elm, field) &&				\
-		    (elm == RB_LEFT(RB_PARENT(elm, field), field)))	\
-			elm = RB_PARENT(elm, field);			\
-		else {							\
-			while (RB_PARENT(elm, field) &&			\
-			    (elm == RB_RIGHT(RB_PARENT(elm, field), field)))\
-				elm = RB_PARENT(elm, field);		\
-			elm = RB_PARENT(elm, field);			\
-		}							\
-	}								\
-	return (elm);							\
-}									\
-									\
-/* ARGSUSED */								\
-attr struct type *							\
-name##_RB_PREV(struct type *elm)					\
-{									\
-	if (RB_LEFT(elm, field)) {					\
-		elm = RB_LEFT(elm, field);				\
-		while (RB_RIGHT(elm, field))				\
-			elm = RB_RIGHT(elm, field);			\
-	} else {							\
-		if (RB_PARENT(elm, field) &&				\
-		    (elm == RB_RIGHT(RB_PARENT(elm, field), field)))	\
-			elm = RB_PARENT(elm, field);			\
-		else {							\
-			while (RB_PARENT(elm, field) &&			\
-			    (elm == RB_LEFT(RB_PARENT(elm, field), field)))\
-				elm = RB_PARENT(elm, field);		\
-			elm = RB_PARENT(elm, field);			\
-		}							\
-	}								\
-	return (elm);							\
-}									\
-									\
-attr struct type *							\
-name##_RB_MINMAX(struct name *head, int val)				\
-{									\
-	struct type *tmp = RB_ROOT(head);				\
-	struct type *parent = NULL;					\
-	while (tmp) {							\
-		parent = tmp;						\
-		if (val < 0)						\
-			tmp = RB_LEFT(tmp, field);			\
-		else							\
-			tmp = RB_RIGHT(tmp, field);			\
-	}								\
-	return (parent);						\
-}
-
-#define RB_NEGINF	-1
-#define RB_INF	1
-
-#define RB_INSERT(name, x, y)	name##_RB_INSERT(x, y)
-#define RB_REMOVE(name, x, y)	name##_RB_REMOVE(x, y)
-#define RB_FIND(name, x, y)	name##_RB_FIND(x, y)
-#define RB_NFIND(name, x, y)	name##_RB_NFIND(x, y)
-#define RB_NEXT(name, x, y)	name##_RB_NEXT(y)
-#define RB_PREV(name, x, y)	name##_RB_PREV(y)
-#define RB_MIN(name, x)		name##_RB_MINMAX(x, RB_NEGINF)
-#define RB_MAX(name, x)		name##_RB_MINMAX(x, RB_INF)
-
-#define RB_FOREACH(x, name, head)					\
-	for ((x) = RB_MIN(name, head);					\
-	     (x) != NULL;						\
-	     (x) = name##_RB_NEXT(x))
-
-#define RB_FOREACH_SAFE(x, name, head, y)				\
-	for ((x) = RB_MIN(name, head);					\
-	    ((x) != NULL) && ((y) = name##_RB_NEXT(x), 1);		\
-	     (x) = (y))
-
-#define RB_FOREACH_REVERSE(x, name, head)				\
-	for ((x) = RB_MAX(name, head);					\
-	     (x) != NULL;						\
-	     (x) = name##_RB_PREV(x))
-
-#define RB_FOREACH_REVERSE_SAFE(x, name, head, y)			\
-	for ((x) = RB_MAX(name, head);					\
-	    ((x) != NULL) && ((y) = name##_RB_PREV(x), 1);		\
-	     (x) = (y))
-
-
-/*
- * Copyright (c) 2016 David Gwynne <dlg@openbsd.org>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-
-struct rb_type {
-	int		(*t_compare)(const void *, const void *);
-	void		(*t_augment)(void *);
-	unsigned int	  t_offset;	/* offset of rb_entry in type */
-};
-
-struct rb_tree {
-	struct rb_entry	*rbt_root;
-};
-
-struct rb_entry {
-	struct rb_entry	 *rbt_parent;
-	struct rb_entry	 *rbt_left;
-	struct rb_entry	 *rbt_right;
-	unsigned int	  rbt_color;
-};
-
-#define RBT_HEAD(_name, _type)						\
-struct _name {								\
-	struct rb_tree rbh_root;					\
-}
-
-#define RBT_ENTRY(_type)	struct rb_entry
-
-static inline void
-_rb_init(struct rb_tree *rbt)
-{
-	rbt->rbt_root = NULL;
-}
-
-static inline int
-_rb_empty(struct rb_tree *rbt)
-{
-	return (rbt->rbt_root == NULL);
-}
-
-void	*_rb_insert(const struct rb_type *, struct rb_tree *, void *);
-void	*_rb_remove(const struct rb_type *, struct rb_tree *, void *);
-void	*_rb_find(const struct rb_type *, struct rb_tree *, const void *);
-void	*_rb_nfind(const struct rb_type *, struct rb_tree *, const void *);
-void	*_rb_root(const struct rb_type *, struct rb_tree *);
-void	*_rb_min(const struct rb_type *, struct rb_tree *);
-void	*_rb_max(const struct rb_type *, struct rb_tree *);
-void	*_rb_next(const struct rb_type *, void *);
-void	*_rb_prev(const struct rb_type *, void *);
-void	*_rb_left(const struct rb_type *, void *);
-void	*_rb_right(const struct rb_type *, void *);
-void	*_rb_parent(const struct rb_type *, void *);
-void	 _rb_set_left(const struct rb_type *, void *, void *);
-void	 _rb_set_right(const struct rb_type *, void *, void *);
-void	 _rb_set_parent(const struct rb_type *, void *, void *);
-void	 _rb_poison(const struct rb_type *, void *, unsigned long);
-int	 _rb_check(const struct rb_type *, void *, unsigned long);
-
-#define RBT_INITIALIZER(_head)	{ { NULL } }
-
-#define RBT_PROTOTYPE(_name, _type, _field, _cmp)			\
-extern const struct rb_type *const _name##_RBT_TYPE;			\
-									\
-__unused static inline void						\
-_name##_RBT_INIT(struct _name *head)					\
-{									\
-	_rb_init(&head->rbh_root);					\
-}									\
-									\
-__unused static inline struct _type *					\
-_name##_RBT_INSERT(struct _name *head, struct _type *elm)		\
-{									\
-	return _rb_insert(_name##_RBT_TYPE, &head->rbh_root, elm);	\
-}									\
-									\
-__unused static inline struct _type *					\
-_name##_RBT_REMOVE(struct _name *head, struct _type *elm)		\
-{									\
-	return _rb_remove(_name##_RBT_TYPE, &head->rbh_root, elm);	\
-}									\
-									\
-__unused static inline struct _type *					\
-_name##_RBT_FIND(struct _name *head, const struct _type *key)		\
-{									\
-	return _rb_find(_name##_RBT_TYPE, &head->rbh_root, key);	\
-}									\
-									\
-__unused static inline struct _type *					\
-_name##_RBT_NFIND(struct _name *head, const struct _type *key)		\
-{									\
-	return _rb_nfind(_name##_RBT_TYPE, &head->rbh_root, key);	\
-}									\
-									\
-__unused static inline struct _type *					\
-_name##_RBT_ROOT(struct _name *head)					\
-{									\
-	return _rb_root(_name##_RBT_TYPE, &head->rbh_root);		\
-}									\
-									\
-__unused static inline int						\
-_name##_RBT_EMPTY(struct _name *head)					\
-{									\
-	return _rb_empty(&head->rbh_root);				\
-}									\
-									\
-__unused static inline struct _type *					\
-_name##_RBT_MIN(struct _name *head)					\
-{									\
-	return _rb_min(_name##_RBT_TYPE, &head->rbh_root);		\
-}									\
-									\
-__unused static inline struct _type *					\
-_name##_RBT_MAX(struct _name *head)					\
-{									\
-	return _rb_max(_name##_RBT_TYPE, &head->rbh_root);		\
-}									\
-									\
-__unused static inline struct _type *					\
-_name##_RBT_NEXT(struct _type *elm)					\
-{									\
-	return _rb_next(_name##_RBT_TYPE, elm);				\
-}									\
-									\
-__unused static inline struct _type *					\
-_name##_RBT_PREV(struct _type *elm)					\
-{									\
-	return _rb_prev(_name##_RBT_TYPE, elm);				\
-}									\
-									\
-__unused static inline struct _type *					\
-_name##_RBT_LEFT(struct _type *elm)					\
-{									\
-	return _rb_left(_name##_RBT_TYPE, elm);				\
-}									\
-									\
-__unused static inline struct _type *					\
-_name##_RBT_RIGHT(struct _type *elm)					\
-{									\
-	return _rb_right(_name##_RBT_TYPE, elm);			\
-}									\
-									\
-__unused static inline struct _type *					\
-_name##_RBT_PARENT(struct _type *elm)					\
-{									\
-	return _rb_parent(_name##_RBT_TYPE, elm);			\
-}									\
-									\
-__unused static inline void						\
-_name##_RBT_SET_LEFT(struct _type *elm, struct _type *left)		\
-{									\
-	return _rb_set_left(_name##_RBT_TYPE, elm, left);		\
-}									\
-									\
-__unused static inline void						\
-_name##_RBT_SET_RIGHT(struct _type *elm, struct _type *right)		\
-{									\
-	return _rb_set_right(_name##_RBT_TYPE, elm, right);		\
-}									\
-									\
-__unused static inline void						\
-_name##_RBT_SET_PARENT(struct _type *elm, struct _type *parent)		\
-{									\
-	return _rb_set_parent(_name##_RBT_TYPE, elm, parent);		\
-}									\
-									\
-__unused static inline void						\
-_name##_RBT_POISON(struct _type *elm, unsigned long poison)		\
-{									\
-	return _rb_poison(_name##_RBT_TYPE, elm, poison);		\
-}									\
-									\
-__unused static inline int						\
-_name##_RBT_CHECK(struct _type *elm, unsigned long poison)		\
-{									\
-	return _rb_check(_name##_RBT_TYPE, elm, poison);		\
-}
-
-#define RBT_GENERATE_INTERNAL(_name, _type, _field, _cmp, _aug)		\
-static int								\
-_name##_RBT_COMPARE(const void *lptr, const void *rptr)			\
-{									\
-	const struct _type *l = lptr, *r = rptr;			\
-	return _cmp(l, r);						\
-}									\
-static const struct rb_type _name##_RBT_INFO = {			\
-	_name##_RBT_COMPARE,						\
-	_aug,								\
-	offsetof(struct _type, _field),					\
-};									\
-const struct rb_type *const _name##_RBT_TYPE = &_name##_RBT_INFO
-
-#define RBT_GENERATE_AUGMENT(_name, _type, _field, _cmp, _aug)		\
-static void								\
-_name##_RBT_AUGMENT(void *ptr)						\
-{									\
-	struct _type *p = ptr;						\
-	return _aug(p);							\
-}									\
-RBT_GENERATE_INTERNAL(_name, _type, _field, _cmp, _name##_RBT_AUGMENT)
-
-#define RBT_GENERATE(_name, _type, _field, _cmp)			\
-    RBT_GENERATE_INTERNAL(_name, _type, _field, _cmp, NULL)
-
-#define RBT_INIT(_name, _head)		_name##_RBT_INIT(_head)
-#define RBT_INSERT(_name, _head, _elm)	_name##_RBT_INSERT(_head, _elm)
-#define RBT_REMOVE(_name, _head, _elm)	_name##_RBT_REMOVE(_head, _elm)
-#define RBT_FIND(_name, _head, _key)	_name##_RBT_FIND(_head, _key)
-#define RBT_NFIND(_name, _head, _key)	_name##_RBT_NFIND(_head, _key)
-#define RBT_ROOT(_name, _head)		_name##_RBT_ROOT(_head)
-#define RBT_EMPTY(_name, _head)		_name##_RBT_EMPTY(_head)
-#define RBT_MIN(_name, _head)		_name##_RBT_MIN(_head)
-#define RBT_MAX(_name, _head)		_name##_RBT_MAX(_head)
-#define RBT_NEXT(_name, _elm)		_name##_RBT_NEXT(_elm)
-#define RBT_PREV(_name, _elm)		_name##_RBT_PREV(_elm)
-#define RBT_LEFT(_name, _elm)		_name##_RBT_LEFT(_elm)
-#define RBT_RIGHT(_name, _elm)		_name##_RBT_RIGHT(_elm)
-#define RBT_PARENT(_name, _elm)		_name##_RBT_PARENT(_elm)
-#define RBT_SET_LEFT(_name, _elm, _l)	_name##_RBT_SET_LEFT(_elm, _l)
-#define RBT_SET_RIGHT(_name, _elm, _r)	_name##_RBT_SET_RIGHT(_elm, _r)
-#define RBT_SET_PARENT(_name, _elm, _p)	_name##_RBT_SET_PARENT(_elm, _p)
-#define RBT_POISON(_name, _elm, _p)	_name##_RBT_POISON(_elm, _p)
-#define RBT_CHECK(_name, _elm, _p)	_name##_RBT_CHECK(_elm, _p)
-
-#define RBT_FOREACH(_e, _name, _head)					\
-	for ((_e) = RBT_MIN(_name, (_head));				\
-	     (_e) != NULL;						\
-	     (_e) = RBT_NEXT(_name, (_e)))
-
-#define RBT_FOREACH_SAFE(_e, _name, _head, _n)				\
-	for ((_e) = RBT_MIN(_name, (_head));				\
-	     (_e) != NULL && ((_n) = RBT_NEXT(_name, (_e)), 1);	\
-	     (_e) = (_n))
-
-#define RBT_FOREACH_REVERSE(_e, _name, _head)				\
-	for ((_e) = RBT_MAX(_name, (_head));				\
-	     (_e) != NULL;						\
-	     (_e) = RBT_PREV(_name, (_e)))
-
-#define RBT_FOREACH_REVERSE_SAFE(_e, _name, _head, _n)			\
-	for ((_e) = RBT_MAX(_name, (_head));				\
-	     (_e) != NULL && ((_n) = RBT_PREV(_name, (_e)), 1);	\
-	     (_e) = (_n))
-
-#endif	/* _SYS_TREE_H_ */