netsurf/content/handlers/html/css.c
2020-05-06 22:54:52 +01:00

766 lines
18 KiB
C

/*
* Copyright 2013 Vincent Sanders <vince@netsurf-browser.org>
*
* This file is part of NetSurf, http://www.netsurf-browser.org/
*
* NetSurf is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* NetSurf is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* \file
* Processing for html content css operations.
*/
#include "utils/config.h"
#define _GNU_SOURCE /* strcasestr needs this for string.h */
#include <assert.h>
#include <ctype.h>
#include <stdint.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>
#include "utils/nsoption.h"
#include "utils/corestrings.h"
#include "utils/log.h"
#include "netsurf/misc.h"
#include "netsurf/content.h"
#include "content/hlcache.h"
#include "css/css.h"
#include "desktop/gui_internal.h"
#include "html/html.h"
#include "html/private.h"
#include "html/css.h"
static nsurl *html_default_stylesheet_url;
static nsurl *html_adblock_stylesheet_url;
static nsurl *html_quirks_stylesheet_url;
static nsurl *html_user_stylesheet_url;
/**
* Convert css error to netsurf error.
*/
static nserror css_error_to_nserror(css_error error)
{
switch (error) {
case CSS_OK:
return NSERROR_OK;
case CSS_NOMEM:
return NSERROR_NOMEM;
case CSS_BADPARM:
return NSERROR_BAD_PARAMETER;
case CSS_INVALID:
return NSERROR_INVALID;
case CSS_FILENOTFOUND:
return NSERROR_NOT_FOUND;
case CSS_NEEDDATA:
return NSERROR_NEED_DATA;
case CSS_BADCHARSET:
return NSERROR_BAD_ENCODING;
case CSS_EOF:
case CSS_IMPORTS_PENDING:
case CSS_PROPERTY_NOT_SET:
default:
break;
}
return NSERROR_CSS;
}
/**
* Callback for fetchcache() for stylesheets.
*/
static nserror
html_convert_css_callback(hlcache_handle *css,
const hlcache_event *event,
void *pw)
{
html_content *parent = pw;
unsigned int i;
struct html_stylesheet *s;
/* Find sheet */
for (i = 0, s = parent->stylesheets;
i != parent->stylesheet_count;
i++, s++) {
if (s->sheet == css)
break;
}
assert(i != parent->stylesheet_count);
switch (event->type) {
case CONTENT_MSG_DONE:
NSLOG(netsurf, INFO, "done stylesheet slot %d '%s'", i,
nsurl_access(hlcache_handle_get_url(css)));
parent->base.active--;
NSLOG(netsurf, INFO, "%d fetches active", parent->base.active);
break;
case CONTENT_MSG_ERROR:
NSLOG(netsurf, INFO, "stylesheet %s failed: %s",
nsurl_access(hlcache_handle_get_url(css)),
event->data.errordata.errormsg);
hlcache_handle_release(css);
s->sheet = NULL;
parent->base.active--;
NSLOG(netsurf, INFO, "%d fetches active", parent->base.active);
break;
case CONTENT_MSG_POINTER:
/* Really don't want this to continue after the switch */
return NSERROR_OK;
default:
break;
}
if (html_can_begin_conversion(parent)) {
html_begin_conversion(parent);
}
return NSERROR_OK;
}
static nserror
html_stylesheet_from_domnode(html_content *c,
dom_node *node,
hlcache_handle **sheet)
{
hlcache_child_context child;
dom_string *style;
nsurl *url;
dom_exception exc;
nserror error;
uint32_t key;
char urlbuf[64];
child.charset = c->encoding;
child.quirks = c->base.quirks;
exc = dom_node_get_text_content(node, &style);
if ((exc != DOM_NO_ERR) || (style == NULL)) {
NSLOG(netsurf, INFO, "No text content");
return NSERROR_OK;
}
error = html_css_fetcher_add_item(style, c->base_url, &key);
if (error != NSERROR_OK) {
dom_string_unref(style);
return error;
}
dom_string_unref(style);
snprintf(urlbuf, sizeof(urlbuf), "x-ns-css:%u", key);
error = nsurl_create(urlbuf, &url);
if (error != NSERROR_OK) {
return error;
}
error = hlcache_handle_retrieve(url, 0,
content_get_url(&c->base), NULL,
html_convert_css_callback, c, &child, CONTENT_CSS,
sheet);
if (error != NSERROR_OK) {
nsurl_unref(url);
return error;
}
nsurl_unref(url);
c->base.active++;
NSLOG(netsurf, INFO, "%d fetches active", c->base.active);
return NSERROR_OK;
}
/**
* Process an inline stylesheet in the document.
*
* \param c content structure
* \param style xml node of style element
* \return true on success, false if an error occurred
*/
static struct html_stylesheet *
html_create_style_element(html_content *c, dom_node *style)
{
dom_string *val;
dom_exception exc;
struct html_stylesheet *stylesheets;
/* type='text/css', or not present (invalid but common) */
exc = dom_element_get_attribute(style, corestring_dom_type, &val);
if (exc == DOM_NO_ERR && val != NULL) {
if (!dom_string_caseless_lwc_isequal(val,
corestring_lwc_text_css)) {
dom_string_unref(val);
return NULL;
}
dom_string_unref(val);
}
/* media contains 'screen' or 'all' or not present */
exc = dom_element_get_attribute(style, corestring_dom_media, &val);
if (exc == DOM_NO_ERR && val != NULL) {
if (strcasestr(dom_string_data(val), "screen") == NULL &&
strcasestr(dom_string_data(val),
"all") == NULL) {
dom_string_unref(val);
return NULL;
}
dom_string_unref(val);
}
/* Extend array */
stylesheets = realloc(c->stylesheets,
sizeof(struct html_stylesheet) *
(c->stylesheet_count + 1));
if (stylesheets == NULL) {
content_broadcast_error(&c->base, NSERROR_NOMEM, NULL);
return false;
}
c->stylesheets = stylesheets;
c->stylesheets[c->stylesheet_count].node = dom_node_ref(style);
c->stylesheets[c->stylesheet_count].sheet = NULL;
c->stylesheets[c->stylesheet_count].modified = false;
c->stylesheets[c->stylesheet_count].unused = false;
c->stylesheet_count++;
return c->stylesheets + (c->stylesheet_count - 1);
}
static bool
html_css_process_modified_style(html_content *c, struct html_stylesheet *s)
{
hlcache_handle *sheet = NULL;
nserror error;
error = html_stylesheet_from_domnode(c, s->node, &sheet);
if (error != NSERROR_OK) {
NSLOG(netsurf, INFO, "Failed to update sheet");
content_broadcast_error(&c->base, error, NULL);
return false;
}
if (sheet != NULL) {
NSLOG(netsurf, INFO, "Updating sheet %p with %p", s->sheet,
sheet);
if (s->sheet != NULL) {
switch (content_get_status(s->sheet)) {
case CONTENT_STATUS_DONE:
break;
default:
hlcache_handle_abort(s->sheet);
c->base.active--;
NSLOG(netsurf, INFO, "%d fetches active",
c->base.active);
}
hlcache_handle_release(s->sheet);
}
s->sheet = sheet;
}
s->modified = false;
return true;
}
/**
* process a stylesheet that has been modified.
*/
static void html_css_process_modified_styles(void *pw)
{
html_content *c = pw;
struct html_stylesheet *s;
unsigned int i;
bool all_done = true;
for (i = 0, s = c->stylesheets; i != c->stylesheet_count; i++, s++) {
if (c->stylesheets[i].modified) {
all_done &= html_css_process_modified_style(c, s);
}
}
/* If we failed to process any sheet, schedule a retry */
if (all_done == false) {
guit->misc->schedule(1000, html_css_process_modified_styles, c);
}
}
/* exported function documented in html/css.h */
bool html_css_update_style(html_content *c, dom_node *style)
{
unsigned int i;
struct html_stylesheet *s;
/* Find sheet */
for (i = 0, s = c->stylesheets; i != c->stylesheet_count; i++, s++) {
if (s->node == style)
break;
}
if (i == c->stylesheet_count) {
s = html_create_style_element(c, style);
}
if (s == NULL) {
NSLOG(netsurf, INFO,
"Could not find or create inline stylesheet for %p",
style);
return false;
}
s->modified = true;
guit->misc->schedule(0, html_css_process_modified_styles, c);
return true;
}
/* exported function documented in html/css.h */
bool html_css_process_style(html_content *c, dom_node *node)
{
unsigned int i;
dom_string *val;
dom_exception exc;
struct html_stylesheet *s;
/* Find sheet */
for (i = 0, s = c->stylesheets; i != c->stylesheet_count; i++, s++) {
if (s->node == node)
break;
}
/* Should already exist */
if (i == c->stylesheet_count) {
return false;
}
exc = dom_element_get_attribute(node, corestring_dom_media, &val);
if (exc == DOM_NO_ERR && val != NULL) {
if (strcasestr(dom_string_data(val), "screen") == NULL &&
strcasestr(dom_string_data(val),
"all") == NULL) {
s->unused = true;
}
dom_string_unref(val);
}
return true;
}
/* exported function documented in html/css.h */
bool html_css_process_link(html_content *htmlc, dom_node *node)
{
dom_string *rel, *type_attr, *media, *href;
struct html_stylesheet *stylesheets;
nsurl *joined;
dom_exception exc;
nserror ns_error;
hlcache_child_context child;
/* rel=<space separated list, including 'stylesheet'> */
exc = dom_element_get_attribute(node, corestring_dom_rel, &rel);
if (exc != DOM_NO_ERR || rel == NULL)
return true;
if (strcasestr(dom_string_data(rel), "stylesheet") == 0) {
dom_string_unref(rel);
return true;
} else if (strcasestr(dom_string_data(rel), "alternate") != 0) {
/* Ignore alternate stylesheets */
dom_string_unref(rel);
return true;
}
dom_string_unref(rel);
/* type='text/css' or not present */
exc = dom_element_get_attribute(node, corestring_dom_type, &type_attr);
if (exc == DOM_NO_ERR && type_attr != NULL) {
if (!dom_string_caseless_lwc_isequal(type_attr,
corestring_lwc_text_css)) {
dom_string_unref(type_attr);
return true;
}
dom_string_unref(type_attr);
}
/* media contains 'screen' or 'all' or not present */
exc = dom_element_get_attribute(node, corestring_dom_media, &media);
if (exc == DOM_NO_ERR && media != NULL) {
if (strcasestr(dom_string_data(media), "screen") == NULL &&
strcasestr(dom_string_data(media), "all") == NULL) {
dom_string_unref(media);
return true;
}
dom_string_unref(media);
}
/* href='...' */
exc = dom_element_get_attribute(node, corestring_dom_href, &href);
if (exc != DOM_NO_ERR || href == NULL)
return true;
/* TODO: only the first preferred stylesheets (ie.
* those with a title attribute) should be loaded
* (see HTML4 14.3) */
ns_error = nsurl_join(htmlc->base_url, dom_string_data(href), &joined);
if (ns_error != NSERROR_OK) {
dom_string_unref(href);
goto no_memory;
}
dom_string_unref(href);
NSLOG(netsurf, INFO, "linked stylesheet %i '%s'",
htmlc->stylesheet_count, nsurl_access(joined));
/* extend stylesheets array to allow for new sheet */
stylesheets = realloc(htmlc->stylesheets,
sizeof(struct html_stylesheet) *
(htmlc->stylesheet_count + 1));
if (stylesheets == NULL) {
nsurl_unref(joined);
ns_error = NSERROR_NOMEM;
goto no_memory;
}
htmlc->stylesheets = stylesheets;
htmlc->stylesheets[htmlc->stylesheet_count].node = NULL;
htmlc->stylesheets[htmlc->stylesheet_count].modified = false;
htmlc->stylesheets[htmlc->stylesheet_count].unused = false;
/* start fetch */
child.charset = htmlc->encoding;
child.quirks = htmlc->base.quirks;
ns_error = hlcache_handle_retrieve(joined, 0,
content_get_url(&htmlc->base),
NULL, html_convert_css_callback,
htmlc, &child, CONTENT_CSS,
&htmlc->stylesheets[htmlc->stylesheet_count].sheet);
nsurl_unref(joined);
if (ns_error != NSERROR_OK)
goto no_memory;
htmlc->stylesheet_count++;
htmlc->base.active++;
NSLOG(netsurf, INFO, "%d fetches active", htmlc->base.active);
return true;
no_memory:
content_broadcast_error(&htmlc->base, ns_error, NULL);
return false;
}
/* exported interface documented in html/html.h */
struct html_stylesheet *html_get_stylesheets(hlcache_handle *h, unsigned int *n)
{
html_content *c = (html_content *) hlcache_handle_get_content(h);
assert(c != NULL);
assert(n != NULL);
*n = c->stylesheet_count;
return c->stylesheets;
}
/* exported function documented in html/css.h */
bool html_css_saw_insecure_stylesheets(html_content *html)
{
struct html_stylesheet *s;
unsigned int i;
for (i = 0, s = html->stylesheets; i < html->stylesheet_count;
i++, s++) {
if (s->sheet != NULL) {
if (content_saw_insecure_objects(s->sheet)) {
return true;
}
}
}
return false;
}
/* exported function documented in html/css.h */
nserror html_css_free_stylesheets(html_content *html)
{
unsigned int i;
guit->misc->schedule(-1, html_css_process_modified_styles, html);
for (i = 0; i != html->stylesheet_count; i++) {
if (html->stylesheets[i].sheet != NULL) {
hlcache_handle_release(html->stylesheets[i].sheet);
}
if (html->stylesheets[i].node != NULL) {
dom_node_unref(html->stylesheets[i].node);
}
}
free(html->stylesheets);
return NSERROR_OK;
}
/* exported function documented in html/css.h */
nserror html_css_quirks_stylesheets(html_content *c)
{
nserror ns_error = NSERROR_OK;
hlcache_child_context child;
assert(c->stylesheets != NULL);
if (c->quirks == DOM_DOCUMENT_QUIRKS_MODE_FULL) {
child.charset = c->encoding;
child.quirks = c->base.quirks;
ns_error = hlcache_handle_retrieve(html_quirks_stylesheet_url,
0, content_get_url(&c->base), NULL,
html_convert_css_callback, c, &child,
CONTENT_CSS,
&c->stylesheets[STYLESHEET_QUIRKS].sheet);
if (ns_error != NSERROR_OK) {
return ns_error;
}
c->base.active++;
NSLOG(netsurf, INFO, "%d fetches active", c->base.active);
}
return ns_error;
}
/* exported function documented in html/css.h */
nserror html_css_new_stylesheets(html_content *c)
{
nserror ns_error;
hlcache_child_context child;
if (c->stylesheets != NULL) {
return NSERROR_OK; /* already initialised */
}
/* stylesheet 0 is the base style sheet,
* stylesheet 1 is the quirks mode style sheet,
* stylesheet 2 is the adblocking stylesheet,
* stylesheet 3 is the user stylesheet */
c->stylesheets = calloc(STYLESHEET_START,
sizeof(struct html_stylesheet));
if (c->stylesheets == NULL) {
return NSERROR_NOMEM;
}
c->stylesheets[STYLESHEET_BASE].sheet = NULL;
c->stylesheets[STYLESHEET_QUIRKS].sheet = NULL;
c->stylesheets[STYLESHEET_ADBLOCK].sheet = NULL;
c->stylesheets[STYLESHEET_USER].sheet = NULL;
c->stylesheet_count = STYLESHEET_START;
child.charset = c->encoding;
child.quirks = c->base.quirks;
ns_error = hlcache_handle_retrieve(html_default_stylesheet_url, 0,
content_get_url(&c->base), NULL,
html_convert_css_callback, c, &child, CONTENT_CSS,
&c->stylesheets[STYLESHEET_BASE].sheet);
if (ns_error != NSERROR_OK) {
return ns_error;
}
c->base.active++;
NSLOG(netsurf, INFO, "%d fetches active", c->base.active);
if (nsoption_bool(block_advertisements)) {
ns_error = hlcache_handle_retrieve(html_adblock_stylesheet_url,
0, content_get_url(&c->base), NULL,
html_convert_css_callback,
c, &child, CONTENT_CSS,
&c->stylesheets[STYLESHEET_ADBLOCK].sheet);
if (ns_error != NSERROR_OK) {
return ns_error;
}
c->base.active++;
NSLOG(netsurf, INFO, "%d fetches active", c->base.active);
}
ns_error = hlcache_handle_retrieve(html_user_stylesheet_url, 0,
content_get_url(&c->base), NULL,
html_convert_css_callback, c, &child, CONTENT_CSS,
&c->stylesheets[STYLESHEET_USER].sheet);
if (ns_error != NSERROR_OK) {
return ns_error;
}
c->base.active++;
NSLOG(netsurf, INFO, "%d fetches active", c->base.active);
return ns_error;
}
/* exported function documented in html/css.h */
nserror
html_css_new_selection_context(html_content *c, css_select_ctx **ret_select_ctx)
{
uint32_t i;
css_error css_ret;
css_select_ctx *select_ctx;
/* check that the base stylesheet loaded; layout fails without it */
if (c->stylesheets[STYLESHEET_BASE].sheet == NULL) {
return NSERROR_CSS_BASE;
}
/* Create selection context */
css_ret = css_select_ctx_create(&select_ctx);
if (css_ret != CSS_OK) {
return css_error_to_nserror(css_ret);
}
/* Add sheets to it */
for (i = STYLESHEET_BASE; i != c->stylesheet_count; i++) {
const struct html_stylesheet *hsheet = &c->stylesheets[i];
css_stylesheet *sheet = NULL;
css_origin origin = CSS_ORIGIN_AUTHOR;
/* Filter out stylesheets for non-screen media. */
/* TODO: We should probably pass the sheet in anyway, and let
* libcss handle the filtering.
*/
if (hsheet->unused) {
continue;
}
if (i < STYLESHEET_USER) {
origin = CSS_ORIGIN_UA;
} else if (i < STYLESHEET_START) {
origin = CSS_ORIGIN_USER;
}
if (hsheet->sheet != NULL) {
sheet = nscss_get_stylesheet(hsheet->sheet);
}
if (sheet != NULL) {
/* TODO: Pass the sheet's full media query, instead of
* "screen".
*/
css_ret = css_select_ctx_append_sheet(select_ctx,
sheet,
origin,
"screen");
if (css_ret != CSS_OK) {
css_select_ctx_destroy(select_ctx);
return css_error_to_nserror(css_ret);
}
}
}
/* return new selection context to caller */
*ret_select_ctx = select_ctx;
return NSERROR_OK;
}
/* exported function documented in html/css.h */
nserror html_css_init(void)
{
nserror error;
error = html_css_fetcher_register();
if (error != NSERROR_OK)
return error;
error = nsurl_create("resource:default.css",
&html_default_stylesheet_url);
if (error != NSERROR_OK)
return error;
error = nsurl_create("resource:adblock.css",
&html_adblock_stylesheet_url);
if (error != NSERROR_OK)
return error;
error = nsurl_create("resource:quirks.css",
&html_quirks_stylesheet_url);
if (error != NSERROR_OK)
return error;
error = nsurl_create("resource:user.css",
&html_user_stylesheet_url);
return error;
}
/* exported function documented in html/css.h */
void html_css_fini(void)
{
if (html_user_stylesheet_url != NULL) {
nsurl_unref(html_user_stylesheet_url);
html_user_stylesheet_url = NULL;
}
if (html_quirks_stylesheet_url != NULL) {
nsurl_unref(html_quirks_stylesheet_url);
html_quirks_stylesheet_url = NULL;
}
if (html_adblock_stylesheet_url != NULL) {
nsurl_unref(html_adblock_stylesheet_url);
html_adblock_stylesheet_url = NULL;
}
if (html_default_stylesheet_url != NULL) {
nsurl_unref(html_default_stylesheet_url);
html_default_stylesheet_url = NULL;
}
}