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Sniff content types where appropriate. 

We never sniff for CSS, nor for non-page artefacts (e.g. treeview icons)

svn path=/trunk/netsurf/; revision=12707
This commit is contained in:
John Mark Bell 2011-09-04 06:28:09 +00:00
parent 9ee4f6146e
commit 6807fa854d
13 changed files with 941 additions and 120 deletions
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2
Makefile.sources
View File

@ -5,7 +5,7 @@
#
S_CONTENT := content.c content_factory.c dirlist.c fetch.c hlcache.c \
llcache.c urldb.c
llcache.c mimesniff.c urldb.c
S_FETCHERS := curl.c data.c file.c about.c resource.c

43
content/content_factory.c
View File

@ -147,42 +147,43 @@ content_type content_factory_type_from_mime_type(lwc_string *mime_type)
* \param llcache Underlying source data handle
* \param fallback_charset Character set to fall back to if none specified
* \param quirks Quirkiness of containing document
* \param effective_type Effective MIME type of content
* \return Pointer to content object, or NULL on failure
*/
struct content *content_factory_create_content(llcache_handle *llcache,
const char *fallback_charset, bool quirks)
const char *fallback_charset, bool quirks,
lwc_string *effective_type)
{
struct content *c;
const char *content_type_header;
const content_handler *handler;
http_content_type *ct;
http_content_type *ct = NULL;
nserror error;
content_type_header =
llcache_handle_get_header(llcache, "Content-Type");
if (content_type_header == NULL)
content_type_header = "text/plain";
error = http_parse_content_type(content_type_header, &ct);
if (error != NSERROR_OK)
handler = content_lookup(effective_type);
if (handler == NULL)
return NULL;
handler = content_lookup(ct->media_type);
if (handler == NULL) {
http_content_type_destroy(ct);
return NULL;
}
assert(handler->create != NULL);
error = handler->create(handler, ct->media_type, ct->parameters,
llcache, fallback_charset, quirks, &c);
if (error != NSERROR_OK) {
http_content_type_destroy(ct);
return NULL;
/* Use the parameters from the declared Content-Type header */
content_type_header =
llcache_handle_get_header(llcache, "Content-Type");
if (content_type_header != NULL) {
/* We don't care if this fails */
http_parse_content_type(content_type_header, &ct);
}
http_content_type_destroy(ct);
error = handler->create(handler, effective_type,
ct != NULL ? ct->parameters : NULL,
llcache, fallback_charset, quirks,
&c);
if (ct != NULL)
http_content_type_destroy(ct);
if (error != NSERROR_OK)
return NULL;
return c;
}

3
content/content_factory.h
View File

@ -82,7 +82,8 @@ nserror content_factory_register_handler(lwc_string *mime_type,
const content_handler *handler);
struct content *content_factory_create_content(struct llcache_handle *llcache,
const char *fallback_charset, bool quirks);
const char *fallback_charset, bool quirks,
lwc_string *effective_type);
content_type content_factory_type_from_mime_type(lwc_string *mime_type);

221
content/hlcache.c
View File

@ -26,6 +26,7 @@
#include "content/content.h"
#include "content/hlcache.h"
#include "content/mimesniff.h"
#include "utils/http.h"
#include "utils/log.h"
#include "utils/messages.h"
@ -50,7 +51,7 @@ struct hlcache_retrieval_ctx {
content_type accepted_types; /**< Accepted types */
hlcache_child_context child; /**< Child context */
hlcache_child_context child; /**< Child context */
};
/** High-level cache handle */
@ -79,9 +80,12 @@ static void hlcache_clean(void *ignored);
static nserror hlcache_llcache_callback(llcache_handle *handle,
const llcache_event *event, void *pw);
static bool hlcache_type_is_acceptable(llcache_handle *llcache,
static nserror hlcache_migrate_ctx(hlcache_retrieval_ctx *ctx,
lwc_string *effective_type);
static bool hlcache_type_is_acceptable(lwc_string *mime_type,
content_type accepted_types, content_type *computed_type);
static nserror hlcache_find_content(hlcache_retrieval_ctx *ctx);
static nserror hlcache_find_content(hlcache_retrieval_ctx *ctx,
lwc_string *effective_type);
static void hlcache_content_callback(struct content *c,
content_msg msg, union content_msg_data data, void *pw);
@ -441,77 +445,55 @@ nserror hlcache_llcache_callback(llcache_handle *handle,
const llcache_event *event, void *pw)
{
hlcache_retrieval_ctx *ctx = pw;
lwc_string *effective_type = NULL;
nserror error;
assert(ctx->llcache == handle);
switch (event->type) {
case LLCACHE_EVENT_HAD_HEADERS:
{
content_type type = 0;
/* Unlink the context to prevent recursion */
RING_REMOVE(hlcache_retrieval_ctx_ring, ctx);
if (hlcache_type_is_acceptable(handle,
ctx->accepted_types, &type)) {
error = hlcache_find_content(ctx);
if (error != NSERROR_OK) {
hlcache_event hlevent;
error = mimesniff_compute_effective_type(handle, NULL, 0,
ctx->flags & HLCACHE_RETRIEVE_SNIFF_TYPE,
&effective_type);
if (error == NSERROR_OK || error == NSERROR_NOT_FOUND) {
/* If the sniffer was successful or failed to find
* a Content-Type header when sniffing was
* prohibited, we must migrate the retrieval context. */
error = hlcache_migrate_ctx(ctx, effective_type);
hlevent.type = CONTENT_MSG_ERROR;
hlevent.data.error = messages_get("MiscError");
ctx->handle->cb(ctx->handle, &hlevent,
ctx->handle->pw);
llcache_handle_abort(handle);
llcache_handle_release(handle);
free((char *) ctx->child.charset);
free(ctx);
return error;
}
} else if (type == CONTENT_NONE &&
(ctx->flags & HLCACHE_RETRIEVE_MAY_DOWNLOAD)) {
/* Unknown type, and we can download, so convert */
llcache_handle_force_stream(handle);
if (ctx->handle->cb != NULL) {
hlcache_event hlevent;
hlevent.type = CONTENT_MSG_DOWNLOAD;
hlevent.data.download = handle;
ctx->handle->cb(ctx->handle, &hlevent,
ctx->handle->pw);
}
} else {
/* Unacceptable type: abort fetch and report error */
llcache_handle_abort(handle);
llcache_handle_release(handle);
if (ctx->handle->cb != NULL) {
hlcache_event hlevent;
hlevent.type = CONTENT_MSG_ERROR;
hlevent.data.error = messages_get("BadType");
ctx->handle->cb(ctx->handle, &hlevent,
ctx->handle->pw);
}
if (effective_type != NULL)
lwc_string_unref(effective_type);
}
/* No longer require retrieval context */
free((char *) ctx->child.charset);
free(ctx);
}
/* No need to report that we need data:
* we'll get some anyway if there is any */
if (error == NSERROR_NEED_DATA)
error = NSERROR_OK;
return error;
break;
case LLCACHE_EVENT_HAD_DATA:
/* fall through */
case LLCACHE_EVENT_DONE:
/* should never happen: the handler must be changed */
assert(0 && "Unexpected llcache event");
error = mimesniff_compute_effective_type(handle,
event->data.data.buf, event->data.data.len,
ctx->flags & HLCACHE_RETRIEVE_SNIFF_TYPE,
&effective_type);
if (error != NSERROR_OK) {
assert(0 && "MIME sniff failed with data");
}
error = hlcache_migrate_ctx(ctx, effective_type);
lwc_string_unref(effective_type);
return error;
break;
case LLCACHE_EVENT_DONE:
/* DONE event before we could determine the effective MIME type.
* Treat this as an error.
*/
/* Fall through */
case LLCACHE_EVENT_ERROR:
if (ctx->handle->cb != NULL) {
hlcache_event hlevent;
@ -530,33 +512,93 @@ nserror hlcache_llcache_callback(llcache_handle *handle,
}
/**
* Determine if the type of a low-level cache object is acceptable
* Migrate a retrieval context into its final destination content
*
* \param llcache Low-level cache object to consider
* \param ctx Context to migrate
* \param effective_type The effective MIME type of the content, or NULL
* \return NSERROR_OK on success,
* NSERROR_NEED_DATA on success where data is needed,
* appropriate error otherwise
*/
nserror hlcache_migrate_ctx(hlcache_retrieval_ctx *ctx,
lwc_string *effective_type)
{
content_type type = CONTENT_NONE;
nserror error = NSERROR_OK;
/* Unlink the context to prevent recursion */
RING_REMOVE(hlcache_retrieval_ctx_ring, ctx);
if (effective_type != NULL &&
hlcache_type_is_acceptable(effective_type,
ctx->accepted_types, &type)) {
error = hlcache_find_content(ctx, effective_type);
if (error != NSERROR_OK && error != NSERROR_NEED_DATA) {
hlcache_event hlevent;
hlevent.type = CONTENT_MSG_ERROR;
hlevent.data.error = messages_get("MiscError");
ctx->handle->cb(ctx->handle, &hlevent,
ctx->handle->pw);
llcache_handle_abort(ctx->llcache);
llcache_handle_release(ctx->llcache);
}
} else if (type == CONTENT_NONE &&
(ctx->flags & HLCACHE_RETRIEVE_MAY_DOWNLOAD)) {
/* Unknown type, and we can download, so convert */
llcache_handle_force_stream(ctx->llcache);
if (ctx->handle->cb != NULL) {
hlcache_event hlevent;
hlevent.type = CONTENT_MSG_DOWNLOAD;
hlevent.data.download = ctx->llcache;
ctx->handle->cb(ctx->handle, &hlevent,
ctx->handle->pw);
}
/* Ensure caller knows we need data */
error = NSERROR_NEED_DATA;
} else {
/* Unacceptable type: abort fetch and report error */
llcache_handle_abort(ctx->llcache);
llcache_handle_release(ctx->llcache);
if (ctx->handle->cb != NULL) {
hlcache_event hlevent;
hlevent.type = CONTENT_MSG_ERROR;
hlevent.data.error = messages_get("BadType");
ctx->handle->cb(ctx->handle, &hlevent,
ctx->handle->pw);
}
}
/* No longer require retrieval context */
free((char *) ctx->child.charset);
free(ctx);
return error;
}
/**
* Determine if the specified MIME type is acceptable
*
* \param mime_type MIME type to consider
* \param accepted_types Array of acceptable types, or NULL for any
* \param computed_type Pointer to location to receive computed type of object
* \return True if the type is acceptable, false otherwise
*/
bool hlcache_type_is_acceptable(llcache_handle *llcache,
bool hlcache_type_is_acceptable(lwc_string *mime_type,
content_type accepted_types, content_type *computed_type)
{
const char *content_type_header;
http_content_type *ct;
content_type type;
nserror error;
content_type_header =
llcache_handle_get_header(llcache, "Content-Type");
if (content_type_header == NULL)
content_type_header = "text/plain";
error = http_parse_content_type(content_type_header, &ct);
if (error != NSERROR_OK)
return false;
type = content_factory_type_from_mime_type(ct->media_type);
http_content_type_destroy(ct);
type = content_factory_type_from_mime_type(mime_type);
*computed_type = type;
@ -566,18 +608,23 @@ bool hlcache_type_is_acceptable(llcache_handle *llcache,
/**
* Find a content for the high-level cache handle
*
* \param ctx High-level cache retrieval context
* \return NSERROR_OK on success, appropriate error otherwise
* \param ctx High-level cache retrieval context
* \param effective_type Effective MIME type of content
* \return NSERROR_OK on success,
* NSERROR_NEED_DATA on success where data is needed,
* appropriate error otherwise
*
* \pre handle::state == HLCACHE_HANDLE_NEW
* \pre Headers must have been received for associated low-level handle
* \post Low-level handle is either released, or associated with new content
* \post High-level handle is registered with content
*/
nserror hlcache_find_content(hlcache_retrieval_ctx *ctx)
nserror hlcache_find_content(hlcache_retrieval_ctx *ctx,
lwc_string *effective_type)
{
hlcache_entry *entry;
hlcache_event event;
nserror error = NSERROR_OK;
/* Search list of cached contents for a suitable one */
for (entry = hlcache_content_list; entry != NULL; entry = entry->next) {
@ -617,7 +664,8 @@ nserror hlcache_find_content(hlcache_retrieval_ctx *ctx)
/* Create content using llhandle */
entry->content = content_factory_create_content(ctx->llcache,
ctx->child.charset, ctx->child.quirks);
ctx->child.charset, ctx->child.quirks,
effective_type);
if (entry->content == NULL) {
free(entry);
return NSERROR_NOMEM;
@ -629,6 +677,9 @@ nserror hlcache_find_content(hlcache_retrieval_ctx *ctx)
if (hlcache_content_list != NULL)
hlcache_content_list->prev = entry;
hlcache_content_list = entry;
/* Signal to caller that we created a content */
error = NSERROR_NEED_DATA;
} else {
/* Found a suitable content: no longer need low-level handle */
llcache_handle_release(ctx->llcache);
@ -676,7 +727,7 @@ nserror hlcache_find_content(hlcache_retrieval_ctx *ctx)
}
}
return NSERROR_OK;
return error;
}
/**

4
content/hlcache.h
View File

@ -60,7 +60,9 @@ enum hlcache_retrieve_flag {
* To avoid confusion, high-level flags are allocated from bit 31 down.
*/
/** It's permitted to convert this request into a download */
HLCACHE_RETRIEVE_MAY_DOWNLOAD = (1 << 31)
HLCACHE_RETRIEVE_MAY_DOWNLOAD = (1 << 31),
/* Permit content-type sniffing */
HLCACHE_RETRIEVE_SNIFF_TYPE = (1 << 30)
};
/**

17
content/llcache.c
View File

@ -1455,6 +1455,8 @@ nserror llcache_object_notify_users(llcache_object *object)
if (handle->state == LLCACHE_FETCH_DATA &&
objstate >= LLCACHE_FETCH_DATA &&
object->source_len > handle->bytes) {
size_t orig_handle_read;
/* Construct HAD_DATA event */
event.type = LLCACHE_EVENT_HAD_DATA;
event.data.data.buf =
@ -1466,9 +1468,13 @@ nserror llcache_object_notify_users(llcache_object *object)
if (object->fetch.flags &
LLCACHE_RETRIEVE_STREAM_DATA) {
/* Streaming, so reset to zero to
* minimise amount of cached source data */
* minimise amount of cached source data.
* Additionally, we don't support replay
* when streaming. */
orig_handle_read = 0;
handle->bytes = object->source_len = 0;
} else {
orig_handle_read = handle->bytes;
handle->bytes = object->source_len;
}
@ -1482,6 +1488,15 @@ nserror llcache_object_notify_users(llcache_object *object)
if (error != NSERROR_OK)
return error;
continue;
} else if (error == NSERROR_NEED_DATA) {
/* User requested replay */
handle->bytes = orig_handle_read;
/* Continue with the next user -- we'll
* reemit the data next time round */
user->iterator_target = false;
next_user = user->next;
continue;
} else if (error != NSERROR_OK) {
user->iterator_target = false;

6
content/llcache.h
View File

@ -89,12 +89,10 @@ enum llcache_retrieve_flag {
LLCACHE_RETRIEVE_FORCE_FETCH = (1 << 0),
/** Requested URL was verified */
LLCACHE_RETRIEVE_VERIFIABLE = (1 << 1),
/** Permit content-type sniffing */
LLCACHE_RETRIEVE_SNIFF_TYPE = (1 << 2),
/**< No error pages */
LLCACHE_RETRIEVE_NO_ERROR_PAGES = (1 << 3),
LLCACHE_RETRIEVE_NO_ERROR_PAGES = (1 << 2),
/**< Stream data (implies that object is not cacheable) */
LLCACHE_RETRIEVE_STREAM_DATA = (1 << 4)
LLCACHE_RETRIEVE_STREAM_DATA = (1 << 3)
};
/** Low-level cache query types */

687
content/mimesniff.c Normal file
View File

@ -0,0 +1,687 @@
/*
* Copyright 2011 John-Mark Bell <jmb@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
* MIME type sniffer (implementation)
*/
#include<string.h>
#include "content/content_factory.h"
#include "content/llcache.h"
#include "content/mimesniff.h"
#include "utils/http.h"
#include "utils/utils.h"
static lwc_string *unknown_unknown;
static lwc_string *application_unknown;
static lwc_string *any;
static lwc_string *text_xml;
static lwc_string *application_xml;
static lwc_string *text_html;
static lwc_string *text_plain;
static lwc_string *application_octet_stream;
static lwc_string *image_gif;
static lwc_string *image_png;
static lwc_string *image_jpeg;
static lwc_string *image_bmp;
static lwc_string *image_vnd_microsoft_icon;
static lwc_string *image_webp;
static lwc_string *application_rss_xml;
static lwc_string *application_atom_xml;
static lwc_string *audio_x_wave;
static lwc_string *application_ogg;
static lwc_string *video_webm;
static lwc_string *application_x_rar_compressed;
static lwc_string *application_zip;
static lwc_string *application_x_gzip;
static lwc_string *application_postscript;
static lwc_string *application_pdf;
nserror mimesniff_init(void)
{
lwc_error lerror;
#define SINIT(v, s) \
lerror = lwc_intern_string(s, SLEN(s), &v); \
if (lerror != lwc_error_ok) \
return NSERROR_NOMEM
SINIT(unknown_unknown, "unknown/unknown");
SINIT(application_unknown, "application/unknown");
SINIT(any, "*/*");
SINIT(text_xml, "text/xml");
SINIT(application_xml, "application/xml");
SINIT(text_html, "text/html");
SINIT(text_plain, "text/plain");
SINIT(application_octet_stream, "application/octet-stream");
SINIT(image_gif, "image/gif");
SINIT(image_png, "image/png");
SINIT(image_jpeg, "image/jpeg");
SINIT(image_bmp, "image/bmp");
SINIT(image_vnd_microsoft_icon, "image/vnd.microsoft.icon");
SINIT(image_webp, "image/webp");
SINIT(application_rss_xml, "application/rss+xml");
SINIT(application_atom_xml, "application/atom+xml");
SINIT(audio_x_wave, "audio/x-wave");
SINIT(application_ogg, "application/ogg");
SINIT(video_webm, "video/webm");
SINIT(application_x_rar_compressed, "application/x-rar-compressed");
SINIT(application_zip, "application/zip");
SINIT(application_x_gzip, "application/x-gzip");
SINIT(application_postscript, "application/postscript");
SINIT(application_pdf, "application/pdf");
#undef SINIT
return NSERROR_OK;
}
void mimesniff_fini(void)
{
lwc_string_unref(application_pdf);
lwc_string_unref(application_postscript);
lwc_string_unref(application_x_gzip);
lwc_string_unref(application_zip);
lwc_string_unref(application_x_rar_compressed);
lwc_string_unref(video_webm);
lwc_string_unref(application_ogg);
lwc_string_unref(audio_x_wave);
lwc_string_unref(application_atom_xml);
lwc_string_unref(application_rss_xml);
lwc_string_unref(image_webp);
lwc_string_unref(image_vnd_microsoft_icon);
lwc_string_unref(image_bmp);
lwc_string_unref(image_jpeg);
lwc_string_unref(image_png);
lwc_string_unref(image_gif);
lwc_string_unref(application_octet_stream);
lwc_string_unref(text_plain);
lwc_string_unref(text_html);
lwc_string_unref(application_xml);
lwc_string_unref(text_xml);
lwc_string_unref(any);
lwc_string_unref(application_unknown);
lwc_string_unref(unknown_unknown);
}
static bool mimesniff__has_binary_octets(const uint8_t *data, size_t len)
{
const uint8_t *end = data + len;
while (data != end) {
const uint8_t c = *data;
/* Binary iff in C0 and not ESC, CR, FF, LF, HT */
if (c <= 0x1f && c != 0x1b && c != '\r' && c != '\f' &&
c != '\n' && c != '\t')
break;
data++;
}
return data != end;
}
struct map_s {
const uint8_t *sig;
size_t len;
bool safe;
lwc_string **type;
};
static nserror mimesniff__match_unknown_ws(const uint8_t *data, size_t len,
lwc_string **effective_type)
{
#define SIG(t, s, x) { (const uint8_t *) s, SLEN(s), x, t }
static const struct map_s ws_exact_match_types[] = {
SIG(&text_xml, "<?xml", false),
{ NULL, 0, false, NULL }
};
static const struct map_s ws_inexact_match_types[] = {
SIG(&text_html, "<!DOCTYPE HTML", false),
SIG(&text_html, "<HTML", false),
SIG(&text_html, "<HEAD", false),
SIG(&text_html, "<SCRIPT", false),
SIG(&text_html, "<IFRAME", false),
SIG(&text_html, "<H1", false),
SIG(&text_html, "<DIV", false),
SIG(&text_html, "<FONT", false),
SIG(&text_html, "<TABLE", false),
SIG(&text_html, "<A", false),
SIG(&text_html, "<STYLE", false),
SIG(&text_html, "<TITLE", false),
SIG(&text_html, "<B", false),
SIG(&text_html, "<BODY", false),
SIG(&text_html, "<BR", false),
SIG(&text_html, "<P", false),
SIG(&text_html, "<!--", false),
{ NULL, 0, false, NULL }
};
#undef SIG
const uint8_t *end = data + len;
const struct map_s *it;
/* Skip leading whitespace */
while (data != end) {
const uint8_t c = *data;
if (c != '\t' && c != '\n' && c != '\f' &&
c != '\r' && c != ' ')
break;
data++;
len--;
}
if (data == end)
return NSERROR_NOT_FOUND;
for (it = ws_exact_match_types; it->sig != NULL; it++) {
if (it->len <= len && memcmp(data, it->sig, it->len) == 0) {
*effective_type = lwc_string_ref(*it->type);
return NSERROR_OK;
}
}
for (it = ws_inexact_match_types; it->sig != NULL; it++) {
/* +1 for trailing space or > */
if (len < it->len + 1)
continue;
if (strncasecmp((const char *) data,
(const char *) it->sig, it->len) == 0 &&
(data[it->len] == ' ' ||
data[it->len] == '>')) {
*effective_type = lwc_string_ref(*it->type);
return NSERROR_OK;
}
}
return NSERROR_NOT_FOUND;
}
static nserror mimesniff__match_unknown_bom(const uint8_t *data, size_t len,
lwc_string **effective_type)
{
#define SIG(t, s, x) { (const uint8_t *) s, SLEN(s), x, t }
static const struct map_s bom_match_types[] = {
SIG(&text_plain, "\xfe\xff", false),
SIG(&text_plain, "\xff\xfe", false),
SIG(&text_plain, "\xef\xbb\xbf", false),
{ NULL, 0, false, NULL }
};
#undef SIG
const struct map_s *it;
for (it = bom_match_types; it->sig != NULL; it++) {
if (it->len <= len && memcmp(data, it->sig, it->len) == 0) {
*effective_type = lwc_string_ref(*it->type);
return NSERROR_OK;
}
}
return NSERROR_NOT_FOUND;
}
static nserror mimesniff__match_unknown_riff(const uint8_t *data, size_t len,
lwc_string **effective_type)
{
#define SIG(t, s, x) { (const uint8_t *) s, SLEN(s), x, t }
static const struct map_s riff_match_types[] = {
SIG(&image_webp, "WEBPVP", true),
SIG(&audio_x_wave, "WAVE", true),
{ NULL, 0, false, NULL }
};
#undef SIG
const struct map_s *it;
for (it = riff_match_types; it->sig != NULL; it++) {
if (it->len + SLEN("RIFF????") <= len &&
memcmp(data, "RIFF", SLEN("RIFF")) == 0 &&
memcmp(data + SLEN("RIFF????"),
it->sig, it->len) == 0) {
*effective_type = lwc_string_ref(*it->type);
return NSERROR_OK;
}
}
return NSERROR_NOT_FOUND;
}
static nserror mimesniff__match_unknown_exact(const uint8_t *data, size_t len,
bool allow_unsafe, lwc_string **effective_type)
{
#define SIG(t, s, x) { (const uint8_t *) s, SLEN(s), x, t }
static const struct map_s exact_match_types[] = {
SIG(&image_gif, "GIF87a", true),
SIG(&image_gif, "GIF89a", true),
SIG(&image_png, "\x89PNG\r\n\x1a\n", true),
SIG(&image_jpeg, "\xff\xd8\xff", true),
SIG(&image_bmp, "BM", true),
SIG(&image_vnd_microsoft_icon, "\x00\x00\x01\x00", true),
SIG(&application_ogg, "OggS\x00", true),
SIG(&video_webm, "\x1a\x45\xdf\xa3", true),
SIG(&application_x_rar_compressed, "Rar \x1a\x07\x00", true),
SIG(&application_zip, "PK\x03\x04", true),
SIG(&application_x_gzip, "\x1f\x8b\x08", true),
SIG(&application_postscript, "%!PS-Adobe-", true),
SIG(&application_pdf, "%PDF-", false),
{ NULL, 0, false, NULL }
};
#undef SIG
const struct map_s *it;
for (it = exact_match_types; it->sig != NULL; it++) {
if (it->len <= len && memcmp(data, it->sig, it->len) == 0 &&
(allow_unsafe || it->safe)) {
*effective_type = lwc_string_ref(*it->type);
return NSERROR_OK;
}
}
return NSERROR_NOT_FOUND;
}
static nserror mimesniff__match_unknown(const uint8_t *data, size_t len,
bool allow_unsafe, lwc_string **effective_type)
{
if (mimesniff__match_unknown_exact(data, len, allow_unsafe,
effective_type) == NSERROR_OK)
return NSERROR_OK;
if (mimesniff__match_unknown_riff(data, len,
effective_type) == NSERROR_OK)
return NSERROR_OK;
if (allow_unsafe == false)
return NSERROR_NOT_FOUND;
if (mimesniff__match_unknown_bom(data, len,
effective_type) == NSERROR_OK)
return NSERROR_OK;
if (mimesniff__match_unknown_ws(data, len,
effective_type) == NSERROR_OK)
return NSERROR_OK;
return NSERROR_NOT_FOUND;
}
static nserror mimesniff__compute_unknown(const uint8_t *data, size_t len,
lwc_string **effective_type)
{
if (data == NULL)
return NSERROR_NEED_DATA;
len = min(len, 512);
if (mimesniff__match_unknown(data, len, true,
effective_type) == NSERROR_OK)
return NSERROR_OK;
if (mimesniff__has_binary_octets(data, len) == false) {
/* No binary octets => text/plain */
*effective_type = lwc_string_ref(text_plain);
return NSERROR_OK;
}
*effective_type = lwc_string_ref(application_octet_stream);
return NSERROR_OK;
}
static nserror mimesniff__compute_text_or_binary(const uint8_t *data,
size_t len, lwc_string **effective_type)
{
if (data == NULL)
return NSERROR_NEED_DATA;
len = min(len, 512);
if (len >= 3 && ((data[0] == 0xfe && data[1] == 0xff) ||
(data[0] == 0xff && data[1] == 0xfe) ||
(data[0] == 0xef && data[1] == 0xbb &&
data[2] == 0xbf))) {
/* Found a BOM => text/plain */
*effective_type = lwc_string_ref(text_plain);
return NSERROR_OK;
}
if (mimesniff__has_binary_octets(data, len) == false) {
/* No binary octets => text/plain */
*effective_type = lwc_string_ref(text_plain);
return NSERROR_OK;
}
if (mimesniff__match_unknown(data, len, false,
effective_type) == NSERROR_OK)
return NSERROR_OK;
*effective_type = lwc_string_ref(application_octet_stream);
return NSERROR_OK;
}
static nserror mimesniff__compute_image(lwc_string *official_type,
const uint8_t *data, size_t len, lwc_string **effective_type)
{
#define SIG(t, s) { (const uint8_t *) s, SLEN(s), t }
static const struct it_s {
const uint8_t *sig;
size_t len;
lwc_string **type;
} image_types[] = {
SIG(&image_gif, "GIF87a"),
SIG(&image_gif, "GIF89a"),
SIG(&image_png, "\x89PNG\r\n\x1a\n"),
SIG(&image_jpeg, "\xff\xd8\xff"),
SIG(&image_bmp, "BM"),
SIG(&image_vnd_microsoft_icon, "\x00\x00\x01\x00"),
{ NULL, 0, NULL }
};
#undef SIG
const struct it_s *it;
if (data == NULL)
return NSERROR_NEED_DATA;
for (it = image_types; it->sig != NULL; it++) {
if (it->len <= len && memcmp(data, it->sig, it->len) == 0) {
lwc_string_unref(official_type);
*effective_type = lwc_string_ref(*it->type);
return NSERROR_OK;
}
}
/* WebP has a signature that doesn't fit into the above table */
if (SLEN("RIFF????WEBPVP") <= len &&
memcmp(data, "RIFF", SLEN("RIFF")) == 0 &&
memcmp(data + SLEN("RIFF????"),
"WEBPVP", SLEN("WEBPVP")) == 0 ) {
lwc_string_unref(official_type);
*effective_type = lwc_string_ref(image_webp);
return NSERROR_OK;
}
*effective_type = official_type;
return NSERROR_OK;
}
static nserror mimesniff__compute_feed_or_html(const uint8_t *data,
size_t len, lwc_string **effective_type)
{
#define RDF_NS "http://www.w3.org/1999/02/22-rdf-syntax-ns#"
#define RSS_NS "http://purl.org/rss/1.0"
enum state_e {
BEFORE_BOM,
BEFORE_MARKUP,
MARKUP_START,
COMMENT_OR_DOCTYPE,
IN_COMMENT,
IN_DOCTYPE,
IN_PI,
IN_TAG,
IN_RDF
} state = BEFORE_BOM;
bool rdf = false, rss = false;
const uint8_t *end;
if (data == NULL)
return NSERROR_NEED_DATA;
end = data + min(len, 512);
while (data < end) {
const uint8_t c = *data;
#define MATCH(s) SLEN(s) <= (size_t) (end - data) && \
memcmp(data, s, SLEN(s)) == 0
switch (state) {
case BEFORE_BOM:
if (3 <= end - data && c == 0xef && data[1] == 0xbb &&
data[2] == 0xbf) {
data += 3;
}
state = BEFORE_MARKUP;
break;
case BEFORE_MARKUP:
if (c == '\t' || c == '\n' || c == '\r' || c == ' ')
data++;
else if (c != '<')
data = end;
else {
state = MARKUP_START;
data++;
}
break;
case MARKUP_START:
if (c == '!') {
state = COMMENT_OR_DOCTYPE;
data++;
} else if (c == '?') {
state = IN_PI;
data++;
} else {
/* Reconsume input */
state = IN_TAG;
}
break;
case COMMENT_OR_DOCTYPE:
if (2 <= end - data && c == '-' && data[1] == '-') {
state = IN_COMMENT;
data += 2;
} else {
/* Reconsume input */
state = IN_DOCTYPE;
}
break;
case IN_COMMENT:
if (3 <= end - data && c == '-' && data[1] == '-' &&
data[2] == '>') {
state = BEFORE_MARKUP;
data += 3;
} else
data++;
break;
case IN_DOCTYPE:
if (c == '>')
state = BEFORE_MARKUP;
data++;
break;
case IN_PI:
if (2 <= end - data && c == '?' && data[1] == '>') {
state = BEFORE_MARKUP;
data += 2;
} else
data++;
break;
case IN_TAG:
if (MATCH("rss")) {
*effective_type =
lwc_string_ref(application_rss_xml);
return NSERROR_OK;
} else if (MATCH("feed")) {
*effective_type =
lwc_string_ref(application_atom_xml);
return NSERROR_OK;
} else if (MATCH("rdf:RDF")) {
state = IN_RDF;
data += SLEN("rdf:RDF");
} else
data = end;
break;
case IN_RDF:
if (MATCH(RSS_NS)) {
rss = true;
data += SLEN(RSS_NS);
} else if (MATCH(RDF_NS)) {
rdf = true;
data += SLEN(RDF_NS);
} else
data++;
if (rdf && rss) {
*effective_type =
lwc_string_ref(application_rss_xml);
return NSERROR_OK;
}
break;
}
#undef MATCH
}
*effective_type = lwc_string_ref(text_html);
return NSERROR_OK;
#undef RSS_NS
#undef RDF_NS
}
/* See mimesniff.h for documentation */
nserror mimesniff_compute_effective_type(llcache_handle *handle,
const uint8_t *data, size_t len, bool sniff_allowed,
lwc_string **effective_type)
{
#define S(s) { s, SLEN(s) }
static const struct tt_s {
const char *data;
size_t len;
} text_types[] = {
S("text/plain"),
S("text/plain; charset=ISO-8859-1"),
S("text/plain; charset=iso-8859-1"),
S("text/plain; charset=UTF-8"),
{ NULL, 0 }
};
#undef S
const char *content_type_header;
size_t content_type_header_len;
http_content_type *ct;
const struct tt_s *tt;
bool match;
nserror error;
content_type_header =
llcache_handle_get_header(handle, "Content-Type");
if (content_type_header == NULL) {
if (sniff_allowed == false)
return NSERROR_NOT_FOUND;
/* No official type => unknown */
return mimesniff__compute_unknown(data, len, effective_type);
}
error = http_parse_content_type(content_type_header, &ct);
if (error != NSERROR_OK) {
if (sniff_allowed == false)
return NSERROR_NOT_FOUND;
/* Unparseable => unknown */
return mimesniff__compute_unknown(data, len, effective_type);
}
if (sniff_allowed == false) {
*effective_type = lwc_string_ref(ct->media_type);
http_content_type_destroy(ct);
return NSERROR_OK;
}
content_type_header_len = strlen(content_type_header);
/* Look for text types */
for (tt = text_types; tt->data != NULL; tt++) {
if (tt->len == content_type_header_len &&
memcmp(tt->data, content_type_header,
content_type_header_len) == 0) {
http_content_type_destroy(ct);
return mimesniff__compute_text_or_binary(data, len,
effective_type);
}
}
/* unknown/unknown, application/unknown, * / * */
if ((lwc_string_caseless_isequal(ct->media_type, unknown_unknown,
&match) == lwc_error_ok && match) ||
(lwc_string_caseless_isequal(ct->media_type,
application_unknown, &match) == lwc_error_ok &&
match) ||
(lwc_string_caseless_isequal(ct->media_type, any,
&match) == lwc_error_ok && match)) {
http_content_type_destroy(ct);
return mimesniff__compute_unknown(data, len, effective_type);
}
/* +xml */
if (lwc_string_length(ct->media_type) > SLEN("+xml") &&
strncasecmp(lwc_string_data(ct->media_type) +
lwc_string_length(ct->media_type) -
SLEN("+xml"),
"+xml", SLEN("+xml")) == 0) {
/* Use official type */
*effective_type = lwc_string_ref(ct->media_type);
http_content_type_destroy(ct);
return NSERROR_OK;
}
/* text/xml, application/xml */
if ((lwc_string_caseless_isequal(ct->media_type, text_xml,
&match) == lwc_error_ok && match) ||
(lwc_string_caseless_isequal(ct->media_type,
application_xml, &match) == lwc_error_ok &&
match)) {
/* Use official type */
*effective_type = lwc_string_ref(ct->media_type);
http_content_type_destroy(ct);
return NSERROR_OK;
}
/* Image types */
if (content_factory_type_from_mime_type(ct->media_type) ==
CONTENT_IMAGE) {
lwc_string *official_type = lwc_string_ref(ct->media_type);
http_content_type_destroy(ct);
return mimesniff__compute_image(official_type,
data, len, effective_type);
}
/* text/html */
if ((lwc_string_caseless_isequal(ct->media_type, text_html,
&match) == lwc_error_ok && match)) {
http_content_type_destroy(ct);
return mimesniff__compute_feed_or_html(data, len,
effective_type);
}
/* Use official type */
*effective_type = lwc_string_ref(ct->media_type);
http_content_type_destroy(ct);
return NSERROR_OK;
}

54
content/mimesniff.h Normal file
View File

@ -0,0 +1,54 @@
/*
* Copyright 2011 John-Mark Bell <jmb@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
* MIME type sniffer (interface)
*/
#ifndef NETSURF_CONTENT_MIMESNIFF_H_
#define NETSURF_CONTENT_MIMESNIFF_H_
#include <stdbool.h>
#include <libwapcaplet/libwapcaplet.h>
#include "utils/errors.h"
struct llcache_handle;
/**
* Compute the effective MIME type for an object using the sniffing
* algorithm described in draft-abarth-mime-sniff-06.
*
* \param handle Source data handle to sniff
* \param data First data chunk, or NULL
* \param len Length of \a data, in bytes
* \param sniff_allowed Whether MIME type sniffing is allowed
* \param effective_type Location to receive computed type
* \return NSERROR_OK on success,
* NSERROR_NEED_DATA iff \a data is NULL and data is needed
* NSERROR_NOT_FOUND if sniffing is prohibited and no
* Content-Type header was found
*/
nserror mimesniff_compute_effective_type(struct llcache_handle *handle,
const uint8_t *data, size_t len, bool sniff_allowed,
lwc_string **effective_type);
nserror mimesniff_init(void);
void mimesniff_fini(void);
#endif

3
desktop/browser.c
View File

@ -727,7 +727,8 @@ void browser_window_go_post(struct browser_window *bw, const char *url,
bw->history_add = add_to_history;
error = hlcache_handle_retrieve(url2,
fetch_flags | HLCACHE_RETRIEVE_MAY_DOWNLOAD,
fetch_flags | HLCACHE_RETRIEVE_MAY_DOWNLOAD |
HLCACHE_RETRIEVE_SNIFF_TYPE,
referer,
fetch_is_post ? &post : NULL,
browser_window_callback, bw,

7
desktop/netsurf.c
View File

@ -35,6 +35,7 @@
#include "content/content_factory.h"
#include "content/fetch.h"
#include "content/hlcache.h"
#include "content/mimesniff.h"
#include "content/urldb.h"
#include "css/css.h"
#include "image/image.h"
@ -155,6 +156,10 @@ nserror netsurf_init(int *pargc,
if (error != NSERROR_OK)
return error;
error = mimesniff_init();
if (error != NSERROR_OK)
return error;
url_init();
setlocale(LC_ALL, "C");
@ -209,6 +214,8 @@ void netsurf_exit(void)
LOG(("Closing fetches"));
fetch_quit();
mimesniff_fini();
/* Clean up after content handlers */
textplain_fini();
image_fini();

10
render/html.c
View File

@ -1414,8 +1414,9 @@ bool html_fetch_object(html_content *c, const char *url, struct box *box,
object->permitted_types = permitted_types;
object->background = background;
error = hlcache_handle_retrieve(url2, 0, content__get_url(&c->base),
NULL, html_object_callback, object, &child,
error = hlcache_handle_retrieve(url2, HLCACHE_RETRIEVE_SNIFF_TYPE,
content__get_url(&c->base), NULL,
html_object_callback, object, &child,
permitted_types, &object->content);
/* No longer need normalized url */
@ -1477,8 +1478,9 @@ bool html_replace_object(struct content_html_object *object, const char *url)
return res != URL_FUNC_NOMEM;
/* initialise fetch */
error = hlcache_handle_retrieve(url2, 0, content__get_url(&c->base),
NULL, html_object_callback, object, &child,
error = hlcache_handle_retrieve(url2, HLCACHE_RETRIEVE_SNIFF_TYPE,
content__get_url(&c->base), NULL,
html_object_callback, object, &child,
object->permitted_types,
&object->content);

4
utils/errors.h
View File

@ -43,7 +43,9 @@ typedef enum {
NSERROR_MNG_ERROR, /**< An MNG error occurred */
NSERROR_BAD_ENCODING /**< The character set is unknown */
NSERROR_BAD_ENCODING, /**< The character set is unknown */
NSERROR_NEED_DATA /**< More data needed */
} nserror;
#endif