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Revision 1.157, Fri May 18 14:23:00 2018 UTC (5 years, 10 months ago) by schwarze
Branch: MAIN
Changes since 1.156: +3 -1 lines

In a nutshell, all mobile browsers are broken.
By default, no matter the physical screen size, they use a fixed
viewport width of about 1000px, then scale down the rendered page
to make that huge viewport fit on the physical screen.
That results in poor rendering for bad websites which assume a
large fixed-size viewport (typically requiring zooming in to be able
to actually read any text), but in atrocious rendering for good
websites that make no assumption about the screen size (unreadably
small text in the top left corner, most of the screen empty).

A standard way to disable that insane behaviour and just render
normally on the actual physical screen size does not exist.
The closest thing is the CSS3 Device Adaptation Module Level 1
https://drafts.csswg.org/css-device-adapt/
but https://caniuse.com/#feat=css-deviceadaptation tells me
that basically no browser implements it, not even on mobile.

The next closest thing is the HTML meta viewport element - even though
the problem has nothing to do with HTML and is purely a CSS issue.
Standardization is not even planned for that one:
* HTML 5.2 mentions it in passing without specifying it:
https://www.w3.org/TR/html/document-metadata.html#the-meta-element
* The Web Hypertext Application Technology Working Group
provides very incomplete information:
https://wiki.whatwg.org/wiki/MetaExtensions
* CSS3 Device Adaptation Module Level 1 already wants to deprecate it,
explaining mostly how to migrate *away* from it to some castle in
the sky that no browser implements:
https://drafts.csswg.org/css-device-adapt/#viewport-meta

While i strongly believe in sticking to well-established standards,
in the absence of standards and with atrocious behaviour being
universal, there appears to be no alternative to using whatever
works.  The meta viewport element appears to be the only way to
make real-world mobile browsers decently render any HTML page that
does not have a fixed-width layout of 1000px.  So use it, grudgingly.

Originally suggested by xcv at dr dot com.
Direction supported by espie@.

/*	$Id: cgi.c,v 1.157 2018/05/18 14:23:00 schwarze Exp $ */
/*
 * Copyright (c) 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2014, 2015, 2016, 2017 Ingo Schwarze <schwarze@usta.de>
 *
 * 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 AUTHORS DISCLAIM ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS 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.
 */
#include "config.h"

#include <sys/types.h>
#include <sys/time.h>

#include <ctype.h>
#if HAVE_ERR
#include <err.h>
#endif
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "mandoc_aux.h"
#include "mandoc.h"
#include "roff.h"
#include "mdoc.h"
#include "man.h"
#include "main.h"
#include "manconf.h"
#include "mansearch.h"
#include "cgi.h"

/*
 * A query as passed to the search function.
 */
struct	query {
	char		*manpath; /* desired manual directory */
	char		*arch; /* architecture */
	char		*sec; /* manual section */
	char		*query; /* unparsed query expression */
	int		 equal; /* match whole names, not substrings */
};

struct	req {
	struct query	  q;
	char		**p; /* array of available manpaths */
	size_t		  psz; /* number of available manpaths */
	int		  isquery; /* QUERY_STRING used, not PATH_INFO */
};

enum	focus {
	FOCUS_NONE = 0,
	FOCUS_QUERY
};

static	void		 html_print(const char *);
static	void		 html_putchar(char);
static	int		 http_decode(char *);
static	void		 parse_manpath_conf(struct req *);
static	void		 parse_path_info(struct req *req, const char *path);
static	void		 parse_query_string(struct req *, const char *);
static	void		 pg_error_badrequest(const char *);
static	void		 pg_error_internal(void);
static	void		 pg_index(const struct req *);
static	void		 pg_noresult(const struct req *, const char *);
static	void		 pg_redirect(const struct req *, const char *);
static	void		 pg_search(const struct req *);
static	void		 pg_searchres(const struct req *,
				struct manpage *, size_t);
static	void		 pg_show(struct req *, const char *);
static	void		 resp_begin_html(int, const char *, const char *);
static	void		 resp_begin_http(int, const char *);
static	void		 resp_catman(const struct req *, const char *);
static	void		 resp_copy(const char *);
static	void		 resp_end_html(void);
static	void		 resp_format(const struct req *, const char *);
static	void		 resp_searchform(const struct req *, enum focus);
static	void		 resp_show(const struct req *, const char *);
static	void		 set_query_attr(char **, char **);
static	int		 validate_filename(const char *);
static	int		 validate_manpath(const struct req *, const char *);
static	int		 validate_urifrag(const char *);

static	const char	 *scriptname = SCRIPT_NAME;

static	const int sec_prios[] = {1, 4, 5, 8, 6, 3, 7, 2, 9};
static	const char *const sec_numbers[] = {
    "0", "1", "2", "3", "3p", "4", "5", "6", "7", "8", "9"
};
static	const char *const sec_names[] = {
    "All Sections",
    "1 - General Commands",
    "2 - System Calls",
    "3 - Library Functions",
    "3p - Perl Library",
    "4 - Device Drivers",
    "5 - File Formats",
    "6 - Games",
    "7 - Miscellaneous Information",
    "8 - System Manager\'s Manual",
    "9 - Kernel Developer\'s Manual"
};
static	const int sec_MAX = sizeof(sec_names) / sizeof(char *);

static	const char *const arch_names[] = {
    "amd64",       "alpha",       "armv7",	"arm64",
    "hppa",        "i386",        "landisk",
    "loongson",    "luna88k",     "macppc",      "mips64",
    "octeon",      "sgi",         "socppc",      "sparc64",
    "amiga",       "arc",         "armish",      "arm32",
    "atari",       "aviion",      "beagle",      "cats",
    "hppa64",      "hp300",
    "ia64",        "mac68k",      "mvme68k",     "mvme88k",
    "mvmeppc",     "palm",        "pc532",       "pegasos",
    "pmax",        "powerpc",     "solbourne",   "sparc",
    "sun3",        "vax",         "wgrisc",      "x68k",
    "zaurus"
};
static	const int arch_MAX = sizeof(arch_names) / sizeof(char *);

/*
 * Print a character, escaping HTML along the way.
 * This will pass non-ASCII straight to output: be warned!
 */
static void
html_putchar(char c)
{

	switch (c) {
	case '"':
		printf("&quot;");
		break;
	case '&':
		printf("&amp;");
		break;
	case '>':
		printf("&gt;");
		break;
	case '<':
		printf("&lt;");
		break;
	default:
		putchar((unsigned char)c);
		break;
	}
}

/*
 * Call through to html_putchar().
 * Accepts NULL strings.
 */
static void
html_print(const char *p)
{

	if (NULL == p)
		return;
	while ('\0' != *p)
		html_putchar(*p++);
}

/*
 * Transfer the responsibility for the allocated string *val
 * to the query structure.
 */
static void
set_query_attr(char **attr, char **val)
{

	free(*attr);
	if (**val == '\0') {
		*attr = NULL;
		free(*val);
	} else
		*attr = *val;
	*val = NULL;
}

/*
 * Parse the QUERY_STRING for key-value pairs
 * and store the values into the query structure.
 */
static void
parse_query_string(struct req *req, const char *qs)
{
	char		*key, *val;
	size_t		 keysz, valsz;

	req->isquery	= 1;
	req->q.manpath	= NULL;
	req->q.arch	= NULL;
	req->q.sec	= NULL;
	req->q.query	= NULL;
	req->q.equal	= 1;

	key = val = NULL;
	while (*qs != '\0') {

		/* Parse one key. */

		keysz = strcspn(qs, "=;&");
		key = mandoc_strndup(qs, keysz);
		qs += keysz;
		if (*qs != '=')
			goto next;

		/* Parse one value. */

		valsz = strcspn(++qs, ";&");
		val = mandoc_strndup(qs, valsz);
		qs += valsz;

		/* Decode and catch encoding errors. */

		if ( ! (http_decode(key) && http_decode(val)))
			goto next;

		/* Handle key-value pairs. */

		if ( ! strcmp(key, "query"))
			set_query_attr(&req->q.query, &val);

		else if ( ! strcmp(key, "apropos"))
			req->q.equal = !strcmp(val, "0");

		else if ( ! strcmp(key, "manpath")) {
#ifdef COMPAT_OLDURI
			if ( ! strncmp(val, "OpenBSD ", 8)) {
				val[7] = '-';
				if ('C' == val[8])
					val[8] = 'c';
			}
#endif
			set_query_attr(&req->q.manpath, &val);
		}

		else if ( ! (strcmp(key, "sec")
#ifdef COMPAT_OLDURI
		    && strcmp(key, "sektion")
#endif
		    )) {
			if ( ! strcmp(val, "0"))
				*val = '\0';
			set_query_attr(&req->q.sec, &val);
		}

		else if ( ! strcmp(key, "arch")) {
			if ( ! strcmp(val, "default"))
				*val = '\0';
			set_query_attr(&req->q.arch, &val);
		}

		/*
		 * The key must be freed in any case.
		 * The val may have been handed over to the query
		 * structure, in which case it is now NULL.
		 */
next:
		free(key);
		key = NULL;
		free(val);
		val = NULL;

		if (*qs != '\0')
			qs++;
	}
}

/*
 * HTTP-decode a string.  The standard explanation is that this turns
 * "%4e+foo" into "n foo" in the regular way.  This is done in-place
 * over the allocated string.
 */
static int
http_decode(char *p)
{
	char             hex[3];
	char		*q;
	int              c;

	hex[2] = '\0';

	q = p;
	for ( ; '\0' != *p; p++, q++) {
		if ('%' == *p) {
			if ('\0' == (hex[0] = *(p + 1)))
				return 0;
			if ('\0' == (hex[1] = *(p + 2)))
				return 0;
			if (1 != sscanf(hex, "%x", &c))
				return 0;
			if ('\0' == c)
				return 0;

			*q = (char)c;
			p += 2;
		} else
			*q = '+' == *p ? ' ' : *p;
	}

	*q = '\0';
	return 1;
}

static void
resp_begin_http(int code, const char *msg)
{

	if (200 != code)
		printf("Status: %d %s\r\n", code, msg);

	printf("Content-Type: text/html; charset=utf-8\r\n"
	     "Cache-Control: no-cache\r\n"
	     "Pragma: no-cache\r\n"
	     "\r\n");

	fflush(stdout);
}

static void
resp_copy(const char *filename)
{
	char	 buf[4096];
	ssize_t	 sz;
	int	 fd;

	if ((fd = open(filename, O_RDONLY)) != -1) {
		fflush(stdout);
		while ((sz = read(fd, buf, sizeof(buf))) > 0)
			write(STDOUT_FILENO, buf, sz);
		close(fd);
	}
}

static void
resp_begin_html(int code, const char *msg, const char *file)
{
	char	*cp;

	resp_begin_http(code, msg);

	printf("<!DOCTYPE html>\n"
	       "<html>\n"
	       "<head>\n"
	       "  <meta charset=\"UTF-8\"/>\n"
	       "  <meta name=\"viewport\""
		      " content=\"width=device-width, initial-scale=1.0\">\n"
	       "  <link rel=\"stylesheet\" href=\"%s/mandoc.css\""
	       " type=\"text/css\" media=\"all\">\n"
	       "  <title>",
	       CSS_DIR);
	if (file != NULL) {
		if ((cp = strrchr(file, '/')) != NULL)
			file = cp + 1;
		if ((cp = strrchr(file, '.')) != NULL) {
			printf("%.*s(%s) - ", (int)(cp - file), file, cp + 1);
		} else
			printf("%s - ", file);
	}
	printf("%s</title>\n"
	       "</head>\n"
	       "<body>\n",
	       CUSTOMIZE_TITLE);

	resp_copy(MAN_DIR "/header.html");
}

static void
resp_end_html(void)
{

	resp_copy(MAN_DIR "/footer.html");

	puts("</body>\n"
	     "</html>");
}

static void
resp_searchform(const struct req *req, enum focus focus)
{
	int		 i;

	printf("<form action=\"/%s\" method=\"get\">\n"
	       "  <fieldset>\n"
	       "    <legend>Manual Page Search Parameters</legend>\n",
	       scriptname);

	/* Write query input box. */

	printf("    <input type=\"text\" name=\"query\" value=\"");
	if (req->q.query != NULL)
		html_print(req->q.query);
	printf( "\" size=\"40\"");
	if (focus == FOCUS_QUERY)
		printf(" autofocus");
	puts(">");

	/* Write submission buttons. */

	printf(	"    <button type=\"submit\" name=\"apropos\" value=\"0\">"
		"man</button>\n"
		"    <button type=\"submit\" name=\"apropos\" value=\"1\">"
		"apropos</button>\n"
		"    <br/>\n");

	/* Write section selector. */

	puts("    <select name=\"sec\">");
	for (i = 0; i < sec_MAX; i++) {
		printf("      <option value=\"%s\"", sec_numbers[i]);
		if (NULL != req->q.sec &&
		    0 == strcmp(sec_numbers[i], req->q.sec))
			printf(" selected=\"selected\"");
		printf(">%s</option>\n", sec_names[i]);
	}
	puts("    </select>");

	/* Write architecture selector. */

	printf(	"    <select name=\"arch\">\n"
		"      <option value=\"default\"");
	if (NULL == req->q.arch)
		printf(" selected=\"selected\"");
	puts(">All Architectures</option>");
	for (i = 0; i < arch_MAX; i++) {
		printf("      <option value=\"%s\"", arch_names[i]);
		if (NULL != req->q.arch &&
		    0 == strcmp(arch_names[i], req->q.arch))
			printf(" selected=\"selected\"");
		printf(">%s</option>\n", arch_names[i]);
	}
	puts("    </select>");

	/* Write manpath selector. */

	if (req->psz > 1) {
		puts("    <select name=\"manpath\">");
		for (i = 0; i < (int)req->psz; i++) {
			printf("      <option ");
			if (strcmp(req->q.manpath, req->p[i]) == 0)
				printf("selected=\"selected\" ");
			printf("value=\"");
			html_print(req->p[i]);
			printf("\">");
			html_print(req->p[i]);
			puts("</option>");
		}
		puts("    </select>");
	}

	puts("  </fieldset>\n"
	     "</form>");
}

static int
validate_urifrag(const char *frag)
{

	while ('\0' != *frag) {
		if ( ! (isalnum((unsigned char)*frag) ||
		    '-' == *frag || '.' == *frag ||
		    '/' == *frag || '_' == *frag))
			return 0;
		frag++;
	}
	return 1;
}

static int
validate_manpath(const struct req *req, const char* manpath)
{
	size_t	 i;

	for (i = 0; i < req->psz; i++)
		if ( ! strcmp(manpath, req->p[i]))
			return 1;

	return 0;
}

static int
validate_filename(const char *file)
{

	if ('.' == file[0] && '/' == file[1])
		file += 2;

	return ! (strstr(file, "../") || strstr(file, "/..") ||
	    (strncmp(file, "man", 3) && strncmp(file, "cat", 3)));
}

static void
pg_index(const struct req *req)
{

	resp_begin_html(200, NULL, NULL);
	resp_searchform(req, FOCUS_QUERY);
	printf("<p>\n"
	       "This web interface is documented in the\n"
	       "<a class=\"Xr\" href=\"/%s%sman.cgi.8\">man.cgi(8)</a>\n"
	       "manual, and the\n"
	       "<a class=\"Xr\" href=\"/%s%sapropos.1\">apropos(1)</a>\n"
	       "manual explains the query syntax.\n"
	       "</p>\n",
	       scriptname, *scriptname == '\0' ? "" : "/",
	       scriptname, *scriptname == '\0' ? "" : "/");
	resp_end_html();
}

static void
pg_noresult(const struct req *req, const char *msg)
{
	resp_begin_html(200, NULL, NULL);
	resp_searchform(req, FOCUS_QUERY);
	puts("<p>");
	puts(msg);
	puts("</p>");
	resp_end_html();
}

static void
pg_error_badrequest(const char *msg)
{

	resp_begin_html(400, "Bad Request", NULL);
	puts("<h1>Bad Request</h1>\n"
	     "<p>\n");
	puts(msg);
	printf("Try again from the\n"
	       "<a href=\"/%s\">main page</a>.\n"
	       "</p>", scriptname);
	resp_end_html();
}

static void
pg_error_internal(void)
{
	resp_begin_html(500, "Internal Server Error", NULL);
	puts("<p>Internal Server Error</p>");
	resp_end_html();
}

static void
pg_redirect(const struct req *req, const char *name)
{
	printf("Status: 303 See Other\r\n"
	    "Location: /");
	if (*scriptname != '\0')
		printf("%s/", scriptname);
	if (strcmp(req->q.manpath, req->p[0]))
		printf("%s/", req->q.manpath);
	if (req->q.arch != NULL)
		printf("%s/", req->q.arch);
	printf("%s", name);
	if (req->q.sec != NULL)
		printf(".%s", req->q.sec);
	printf("\r\nContent-Type: text/html; charset=utf-8\r\n\r\n");
}

static void
pg_searchres(const struct req *req, struct manpage *r, size_t sz)
{
	char		*arch, *archend;
	const char	*sec;
	size_t		 i, iuse;
	int		 archprio, archpriouse;
	int		 prio, priouse;

	for (i = 0; i < sz; i++) {
		if (validate_filename(r[i].file))
			continue;
		warnx("invalid filename %s in %s database",
		    r[i].file, req->q.manpath);
		pg_error_internal();
		return;
	}

	if (req->isquery && sz == 1) {
		/*
		 * If we have just one result, then jump there now
		 * without any delay.
		 */
		printf("Status: 303 See Other\r\n"
		    "Location: /");
		if (*scriptname != '\0')
			printf("%s/", scriptname);
		if (strcmp(req->q.manpath, req->p[0]))
			printf("%s/", req->q.manpath);
		printf("%s\r\n"
		    "Content-Type: text/html; charset=utf-8\r\n\r\n",
		    r[0].file);
		return;
	}

	/*
	 * In man(1) mode, show one of the pages
	 * even if more than one is found.
	 */

	iuse = 0;
	if (req->q.equal || sz == 1) {
		priouse = 20;
		archpriouse = 3;
		for (i = 0; i < sz; i++) {
			sec = r[i].file;
			sec += strcspn(sec, "123456789");
			if (sec[0] == '\0')
				continue;
			prio = sec_prios[sec[0] - '1'];
			if (sec[1] != '/')
				prio += 10;
			if (req->q.arch == NULL) {
				archprio =
				    ((arch = strchr(sec + 1, '/'))
					== NULL) ? 3 :
				    ((archend = strchr(arch + 1, '/'))
					== NULL) ? 0 :
				    strncmp(arch, "amd64/",
					archend - arch) ? 2 : 1;
				if (archprio < archpriouse) {
					archpriouse = archprio;
					priouse = prio;
					iuse = i;
					continue;
				}
				if (archprio > archpriouse)
					continue;
			}
			if (prio >= priouse)
				continue;
			priouse = prio;
			iuse = i;
		}
		resp_begin_html(200, NULL, r[iuse].file);
	} else
		resp_begin_html(200, NULL, NULL);

	resp_searchform(req,
	    req->q.equal || sz == 1 ? FOCUS_NONE : FOCUS_QUERY);

	if (sz > 1) {
		puts("<table class=\"results\">");
		for (i = 0; i < sz; i++) {
			printf("  <tr>\n"
			       "    <td>"
			       "<a class=\"Xr\" href=\"/");
			if (*scriptname != '\0')
				printf("%s/", scriptname);
			if (strcmp(req->q.manpath, req->p[0]))
				printf("%s/", req->q.manpath);
			printf("%s\">", r[i].file);
			html_print(r[i].names);
			printf("</a></td>\n"
			       "    <td><span class=\"Nd\">");
			html_print(r[i].output);
			puts("</span></td>\n"
			     "  </tr>");
		}
		puts("</table>");
	}

	if (req->q.equal || sz == 1) {
		puts("<hr>");
		resp_show(req, r[iuse].file);
	}

	resp_end_html();
}

static void
resp_catman(const struct req *req, const char *file)
{
	FILE		*f;
	char		*p;
	size_t		 sz;
	ssize_t		 len;
	int		 i;
	int		 italic, bold;

	if ((f = fopen(file, "r")) == NULL) {
		puts("<p>You specified an invalid manual file.</p>");
		return;
	}

	puts("<div class=\"catman\">\n"
	     "<pre>");

	p = NULL;
	sz = 0;

	while ((len = getline(&p, &sz, f)) != -1) {
		bold = italic = 0;
		for (i = 0; i < len - 1; i++) {
			/*
			 * This means that the catpage is out of state.
			 * Ignore it and keep going (although the
			 * catpage is bogus).
			 */

			if ('\b' == p[i] || '\n' == p[i])
				continue;

			/*
			 * Print a regular character.
			 * Close out any bold/italic scopes.
			 * If we're in back-space mode, make sure we'll
			 * have something to enter when we backspace.
			 */

			if ('\b' != p[i + 1]) {
				if (italic)
					printf("</i>");
				if (bold)
					printf("</b>");
				italic = bold = 0;
				html_putchar(p[i]);
				continue;
			} else if (i + 2 >= len)
				continue;

			/* Italic mode. */

			if ('_' == p[i]) {
				if (bold)
					printf("</b>");
				if ( ! italic)
					printf("<i>");
				bold = 0;
				italic = 1;
				i += 2;
				html_putchar(p[i]);
				continue;
			}

			/*
			 * Handle funny behaviour troff-isms.
			 * These grok'd from the original man2html.c.
			 */

			if (('+' == p[i] && 'o' == p[i + 2]) ||
					('o' == p[i] && '+' == p[i + 2]) ||
					('|' == p[i] && '=' == p[i + 2]) ||
					('=' == p[i] && '|' == p[i + 2]) ||
					('*' == p[i] && '=' == p[i + 2]) ||
					('=' == p[i] && '*' == p[i + 2]) ||
					('*' == p[i] && '|' == p[i + 2]) ||
					('|' == p[i] && '*' == p[i + 2]))  {
				if (italic)
					printf("</i>");
				if (bold)
					printf("</b>");
				italic = bold = 0;
				putchar('*');
				i += 2;
				continue;
			} else if (('|' == p[i] && '-' == p[i + 2]) ||
					('-' == p[i] && '|' == p[i + 1]) ||
					('+' == p[i] && '-' == p[i + 1]) ||
					('-' == p[i] && '+' == p[i + 1]) ||
					('+' == p[i] && '|' == p[i + 1]) ||
					('|' == p[i] && '+' == p[i + 1]))  {
				if (italic)
					printf("</i>");
				if (bold)
					printf("</b>");
				italic = bold = 0;
				putchar('+');
				i += 2;
				continue;
			}

			/* Bold mode. */

			if (italic)
				printf("</i>");
			if ( ! bold)
				printf("<b>");
			bold = 1;
			italic = 0;
			i += 2;
			html_putchar(p[i]);
		}

		/*
		 * Clean up the last character.
		 * We can get to a newline; don't print that.
		 */

		if (italic)
			printf("</i>");
		if (bold)
			printf("</b>");

		if (i == len - 1 && p[i] != '\n')
			html_putchar(p[i]);

		putchar('\n');
	}
	free(p);

	puts("</pre>\n"
	     "</div>");

	fclose(f);
}

static void
resp_format(const struct req *req, const char *file)
{
	struct manoutput conf;
	struct mparse	*mp;
	struct roff_man	*man;
	void		*vp;
	int		 fd;
	int		 usepath;

	if (-1 == (fd = open(file, O_RDONLY, 0))) {
		puts("<p>You specified an invalid manual file.</p>");
		return;
	}

	mchars_alloc();
	mp = mparse_alloc(MPARSE_SO | MPARSE_UTF8 | MPARSE_LATIN1,
	    MANDOCERR_MAX, NULL, MANDOC_OS_OTHER, req->q.manpath);
	mparse_readfd(mp, fd, file);
	close(fd);

	memset(&conf, 0, sizeof(conf));
	conf.fragment = 1;
	conf.style = mandoc_strdup(CSS_DIR "/mandoc.css");
	usepath = strcmp(req->q.manpath, req->p[0]);
	mandoc_asprintf(&conf.man, "/%s%s%s%s%%N.%%S",
	    scriptname, *scriptname == '\0' ? "" : "/",
	    usepath ? req->q.manpath : "", usepath ? "/" : "");

	mparse_result(mp, &man, NULL);
	if (man == NULL) {
		warnx("fatal mandoc error: %s/%s", req->q.manpath, file);
		pg_error_internal();
		mparse_free(mp);
		mchars_free();
		return;
	}

	vp = html_alloc(&conf);

	if (man->macroset == MACROSET_MDOC) {
		mdoc_validate(man);
		html_mdoc(vp, man);
	} else {
		man_validate(man);
		html_man(vp, man);
	}

	html_free(vp);
	mparse_free(mp);
	mchars_free();
	free(conf.man);
	free(conf.style);
}

static void
resp_show(const struct req *req, const char *file)
{

	if ('.' == file[0] && '/' == file[1])
		file += 2;

	if ('c' == *file)
		resp_catman(req, file);
	else
		resp_format(req, file);
}

static void
pg_show(struct req *req, const char *fullpath)
{
	char		*manpath;
	const char	*file;

	if ((file = strchr(fullpath, '/')) == NULL) {
		pg_error_badrequest(
		    "You did not specify a page to show.");
		return;
	}
	manpath = mandoc_strndup(fullpath, file - fullpath);
	file++;

	if ( ! validate_manpath(req, manpath)) {
		pg_error_badrequest(
		    "You specified an invalid manpath.");
		free(manpath);
		return;
	}

	/*
	 * Begin by chdir()ing into the manpath.
	 * This way we can pick up the database files, which are
	 * relative to the manpath root.
	 */

	if (chdir(manpath) == -1) {
		warn("chdir %s", manpath);
		pg_error_internal();
		free(manpath);
		return;
	}
	free(manpath);

	if ( ! validate_filename(file)) {
		pg_error_badrequest(
		    "You specified an invalid manual file.");
		return;
	}

	resp_begin_html(200, NULL, file);
	resp_searchform(req, FOCUS_NONE);
	resp_show(req, file);
	resp_end_html();
}

static void
pg_search(const struct req *req)
{
	struct mansearch	  search;
	struct manpaths		  paths;
	struct manpage		 *res;
	char			**argv;
	char			 *query, *rp, *wp;
	size_t			  ressz;
	int			  argc;

	/*
	 * Begin by chdir()ing into the root of the manpath.
	 * This way we can pick up the database files, which are
	 * relative to the manpath root.
	 */

	if (chdir(req->q.manpath) == -1) {
		warn("chdir %s", req->q.manpath);
		pg_error_internal();
		return;
	}

	search.arch = req->q.arch;
	search.sec = req->q.sec;
	search.outkey = "Nd";
	search.argmode = req->q.equal ? ARG_NAME : ARG_EXPR;
	search.firstmatch = 1;

	paths.sz = 1;
	paths.paths = mandoc_malloc(sizeof(char *));
	paths.paths[0] = mandoc_strdup(".");

	/*
	 * Break apart at spaces with backslash-escaping.
	 */

	argc = 0;
	argv = NULL;
	rp = query = mandoc_strdup(req->q.query);
	for (;;) {
		while (isspace((unsigned char)*rp))
			rp++;
		if (*rp == '\0')
			break;
		argv = mandoc_reallocarray(argv, argc + 1, sizeof(char *));
		argv[argc++] = wp = rp;
		for (;;) {
			if (isspace((unsigned char)*rp)) {
				*wp = '\0';
				rp++;
				break;
			}
			if (rp[0] == '\\' && rp[1] != '\0')
				rp++;
			if (wp != rp)
				*wp = *rp;
			if (*rp == '\0')
				break;
			wp++;
			rp++;
		}
	}

	res = NULL;
	ressz = 0;
	if (req->isquery && req->q.equal && argc == 1)
		pg_redirect(req, argv[0]);
	else if (mansearch(&search, &paths, argc, argv, &res, &ressz) == 0)
		pg_noresult(req, "You entered an invalid query.");
	else if (ressz == 0)
		pg_noresult(req, "No results found.");
	else
		pg_searchres(req, res, ressz);

	free(query);
	mansearch_free(res, ressz);
	free(paths.paths[0]);
	free(paths.paths);
}

int
main(void)
{
	struct req	 req;
	struct itimerval itimer;
	const char	*path;
	const char	*querystring;
	int		 i;

#if HAVE_PLEDGE
	/*
	 * The "rpath" pledge could be revoked after mparse_readfd()
	 * if the file desciptor to "/footer.html" would be opened
	 * up front, but it's probably not worth the complication
	 * of the code it would cause: it would require scattering
	 * pledge() calls in multiple low-level resp_*() functions.
	 */

	if (pledge("stdio rpath", NULL) == -1) {
		warn("pledge");
		pg_error_internal();
		return EXIT_FAILURE;
	}
#endif

	/* Poor man's ReDoS mitigation. */

	itimer.it_value.tv_sec = 2;
	itimer.it_value.tv_usec = 0;
	itimer.it_interval.tv_sec = 2;
	itimer.it_interval.tv_usec = 0;
	if (setitimer(ITIMER_VIRTUAL, &itimer, NULL) == -1) {
		warn("setitimer");
		pg_error_internal();
		return EXIT_FAILURE;
	}

	/*
	 * First we change directory into the MAN_DIR so that
	 * subsequent scanning for manpath directories is rooted
	 * relative to the same position.
	 */

	if (chdir(MAN_DIR) == -1) {
		warn("MAN_DIR: %s", MAN_DIR);
		pg_error_internal();
		return EXIT_FAILURE;
	}

	memset(&req, 0, sizeof(struct req));
	req.q.equal = 1;
	parse_manpath_conf(&req);

	/* Parse the path info and the query string. */

	if ((path = getenv("PATH_INFO")) == NULL)
		path = "";
	else if (*path == '/')
		path++;

	if (*path != '\0') {
		parse_path_info(&req, path);
		if (req.q.manpath == NULL || req.q.sec == NULL ||
		    *req.q.query == '\0' || access(path, F_OK) == -1)
			path = "";
	} else if ((querystring = getenv("QUERY_STRING")) != NULL)
		parse_query_string(&req, querystring);

	/* Validate parsed data and add defaults. */

	if (req.q.manpath == NULL)
		req.q.manpath = mandoc_strdup(req.p[0]);
	else if ( ! validate_manpath(&req, req.q.manpath)) {
		pg_error_badrequest(
		    "You specified an invalid manpath.");
		return EXIT_FAILURE;
	}

	if ( ! (NULL == req.q.arch || validate_urifrag(req.q.arch))) {
		pg_error_badrequest(
		    "You specified an invalid architecture.");
		return EXIT_FAILURE;
	}

	/* Dispatch to the three different pages. */

	if ('\0' != *path)
		pg_show(&req, path);
	else if (NULL != req.q.query)
		pg_search(&req);
	else
		pg_index(&req);

	free(req.q.manpath);
	free(req.q.arch);
	free(req.q.sec);
	free(req.q.query);
	for (i = 0; i < (int)req.psz; i++)
		free(req.p[i]);
	free(req.p);
	return EXIT_SUCCESS;
}

/*
 * If PATH_INFO is not a file name, translate it to a query.
 */
static void
parse_path_info(struct req *req, const char *path)
{
	char	*dir[4];
	int	 i;

	req->isquery = 0;
	req->q.equal = 1;
	req->q.manpath = mandoc_strdup(path);
	req->q.arch = NULL;

	/* Mandatory manual page name. */
	if ((req->q.query = strrchr(req->q.manpath, '/')) == NULL) {
		req->q.query = req->q.manpath;
		req->q.manpath = NULL;
	} else
		*req->q.query++ = '\0';

	/* Optional trailing section. */
	if ((req->q.sec = strrchr(req->q.query, '.')) != NULL) {
		if(isdigit((unsigned char)req->q.sec[1])) {
			*req->q.sec++ = '\0';
			req->q.sec = mandoc_strdup(req->q.sec);
		} else
			req->q.sec = NULL;
	}

	/* Handle the case of name[.section] only. */
	if (req->q.manpath == NULL)
		return;
	req->q.query = mandoc_strdup(req->q.query);

	/* Split directory components. */
	dir[i = 0] = req->q.manpath;
	while ((dir[i + 1] = strchr(dir[i], '/')) != NULL) {
		if (++i == 3) {
			pg_error_badrequest(
			    "You specified too many directory components.");
			exit(EXIT_FAILURE);
		}
		*dir[i]++ = '\0';
	}

	/* Optional manpath. */
	if ((i = validate_manpath(req, req->q.manpath)) == 0)
		req->q.manpath = NULL;
	else if (dir[1] == NULL)
		return;

	/* Optional section. */
	if (strncmp(dir[i], "man", 3) == 0) {
		free(req->q.sec);
		req->q.sec = mandoc_strdup(dir[i++] + 3);
	}
	if (dir[i] == NULL) {
		if (req->q.manpath == NULL)
			free(dir[0]);
		return;
	}
	if (dir[i + 1] != NULL) {
		pg_error_badrequest(
		    "You specified an invalid directory component.");
		exit(EXIT_FAILURE);
	}

	/* Optional architecture. */
	if (i) {
		req->q.arch = mandoc_strdup(dir[i]);
		if (req->q.manpath == NULL)
			free(dir[0]);
	} else
		req->q.arch = dir[0];
}

/*
 * Scan for indexable paths.
 */
static void
parse_manpath_conf(struct req *req)
{
	FILE	*fp;
	char	*dp;
	size_t	 dpsz;
	ssize_t	 len;

	if ((fp = fopen("manpath.conf", "r")) == NULL) {
		warn("%s/manpath.conf", MAN_DIR);
		pg_error_internal();
		exit(EXIT_FAILURE);
	}

	dp = NULL;
	dpsz = 0;

	while ((len = getline(&dp, &dpsz, fp)) != -1) {
		if (dp[len - 1] == '\n')
			dp[--len] = '\0';
		req->p = mandoc_realloc(req->p,
		    (req->psz + 1) * sizeof(char *));
		if ( ! validate_urifrag(dp)) {
			warnx("%s/manpath.conf contains "
			    "unsafe path \"%s\"", MAN_DIR, dp);
			pg_error_internal();
			exit(EXIT_FAILURE);
		}
		if (strchr(dp, '/') != NULL) {
			warnx("%s/manpath.conf contains "
			    "path with slash \"%s\"", MAN_DIR, dp);
			pg_error_internal();
			exit(EXIT_FAILURE);
		}
		req->p[req->psz++] = dp;
		dp = NULL;
		dpsz = 0;
	}
	free(dp);

	if (req->p == NULL) {
		warnx("%s/manpath.conf is empty", MAN_DIR);
		pg_error_internal();
		exit(EXIT_FAILURE);
	}
}