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apache / httpd / 19d98a5802beedc00415c8ef0ab512fee0ec98b3 / . / modules / filters / mod_proxy_html.c
blob: 62f2bee2e3ee76b4fc06f1f2d03135d3ea190707 [file] [log] [blame]
/* Copyright (c) 2003-11, WebThing Ltd
* Copyright (c) 2011-, The Apache Software Foundation
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* GO_FASTER
You can #define GO_FASTER to disable trace logging.
*/
#ifdef GO_FASTER
#define VERBOSE(x)
#define VERBOSEB(x)
#else
#define VERBOSE(x) if (verbose) x
#define VERBOSEB(x) if (verbose) {x}
#endif
/* libxml2 */
#include <libxml/HTMLparser.h>
#include "http_protocol.h"
#include "http_config.h"
#include "http_log.h"
#include "apr_strings.h"
#include "apr_hash.h"
#include "apr_strmatch.h"
#include "apr_lib.h"
#include "apr_optional.h"
#include "mod_xml2enc.h"
#include "http_request.h"
#include "ap_expr.h"
/* globals set once at startup */
static ap_rxplus_t *old_expr;
static ap_regex_t *seek_meta;
static const apr_strmatch_pattern* seek_content;
static apr_status_t (*xml2enc_charset)(request_rec*, xmlCharEncoding*, const char**) = NULL;
static apr_status_t (*xml2enc_filter)(request_rec*, const char*, unsigned int) = NULL;
module AP_MODULE_DECLARE_DATA proxy_html_module;
#define M_HTML 0x01
#define M_EVENTS 0x02
#define M_CDATA 0x04
#define M_REGEX 0x08
#define M_ATSTART 0x10
#define M_ATEND 0x20
#define M_LAST 0x40
#define M_NOTLAST 0x80
#define M_INTERPOLATE_TO 0x100
#define M_INTERPOLATE_FROM 0x200
typedef struct {
const char *val;
} tattr;
typedef struct {
unsigned int start;
unsigned int end;
} meta;
typedef struct urlmap {
struct urlmap *next;
unsigned int flags;
unsigned int regflags;
union {
const char *c;
ap_regex_t *r;
} from;
const char *to;
ap_expr_info_t *cond;
} urlmap;
typedef struct {
urlmap *map;
const char *doctype;
const char *etag;
unsigned int flags;
size_t bufsz;
apr_hash_t *links;
apr_array_header_t *events;
const char *charset_out;
int extfix;
int metafix;
int strip_comments;
int interp;
int enabled;
} proxy_html_conf;
typedef struct {
ap_filter_t *f;
proxy_html_conf *cfg;
htmlParserCtxtPtr parser;
apr_bucket_brigade *bb;
char *buf;
size_t offset;
size_t avail;
const char *encoding;
urlmap *map;
const char *etag;
} saxctxt;
#define NORM_LC 0x1
#define NORM_MSSLASH 0x2
#define NORM_RESET 0x4
static htmlSAXHandler sax;
typedef enum { ATTR_IGNORE, ATTR_URI, ATTR_EVENT } rewrite_t;
static const char *const fpi_html =
"<!DOCTYPE html PUBLIC \"-//W3C//DTD HTML 4.01//EN\">\n";
static const char *const fpi_html_legacy =
"<!DOCTYPE html PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">\n";
static const char *const fpi_xhtml =
"<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\n";
static const char *const fpi_xhtml_legacy =
"<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\n";
static const char *const fpi_html5 = "<!DOCTYPE html>\n";
static const char *const html_etag = ">";
static const char *const xhtml_etag = " />";
/*#define DEFAULT_DOCTYPE fpi_html */
static const char *const DEFAULT_DOCTYPE = "";
#define DEFAULT_ETAG html_etag
static void normalise(unsigned int flags, char *str)
{
char *p;
if (flags & NORM_LC)
for (p = str; *p; ++p)
if (isupper(*p))
*p = tolower(*p);
if (flags & NORM_MSSLASH)
for (p = ap_strchr(str, '\\'); p; p = ap_strchr(p+1, '\\'))
*p = '/';
}
#define consume_buffer(ctx,inbuf,bytes,flag) \
htmlParseChunk(ctx->parser, inbuf, bytes, flag)
#define AP_fwrite(ctx,inbuf,bytes,flush) \
ap_fwrite(ctx->f->next, ctx->bb, inbuf, bytes);
/* This is always utf-8 on entry. We can convert charset within FLUSH */
#define FLUSH AP_fwrite(ctx, (chars+begin), (i-begin), 0); begin = i+1
static void pcharacters(void *ctxt, const xmlChar *uchars, int length)
{
const char *chars = (const char*) uchars;
saxctxt *ctx = (saxctxt*) ctxt;
int i;
int begin;
for (begin=i=0; i<length; i++) {
switch (chars[i]) {
case '&' : FLUSH; ap_fputs(ctx->f->next, ctx->bb, "&amp;"); break;
case '<' : FLUSH; ap_fputs(ctx->f->next, ctx->bb, "&lt;"); break;
case '>' : FLUSH; ap_fputs(ctx->f->next, ctx->bb, "&gt;"); break;
case '"' : FLUSH; ap_fputs(ctx->f->next, ctx->bb, "&quot;"); break;
default : break;
}
}
FLUSH;
}
static void preserve(saxctxt *ctx, const size_t len)
{
char *newbuf;
if (len <= (ctx->avail - ctx->offset))
return;
else while (len > (ctx->avail - ctx->offset))
ctx->avail += ctx->cfg->bufsz;
newbuf = realloc(ctx->buf, ctx->avail);
if (newbuf != ctx->buf) {
if (ctx->buf)
apr_pool_cleanup_kill(ctx->f->r->pool, ctx->buf,
(int(*)(void*))free);
apr_pool_cleanup_register(ctx->f->r->pool, newbuf,
(int(*)(void*))free, apr_pool_cleanup_null);
ctx->buf = newbuf;
}
}
static void pappend(saxctxt *ctx, const char *buf, const size_t len)
{
preserve(ctx, len);
memcpy(ctx->buf+ctx->offset, buf, len);
ctx->offset += len;
}
static void dump_content(saxctxt *ctx)
{
urlmap *m;
char *found;
size_t s_from, s_to;
size_t match;
char c = 0;
int nmatch;
ap_regmatch_t pmatch[10];
char *subs;
size_t len, offs;
urlmap *themap = ctx->map;
#ifndef GO_FASTER
int verbose = APLOGrtrace1(ctx->f->r);
#endif
pappend(ctx, &c, 1); /* append null byte */
/* parse the text for URLs */
for (m = themap; m; m = m->next) {
if (!(m->flags & M_CDATA))
continue;
if (m->flags & M_REGEX) {
nmatch = 10;
offs = 0;
while (!ap_regexec(m->from.r, ctx->buf+offs, nmatch, pmatch, 0)) {
match = pmatch[0].rm_so;
s_from = pmatch[0].rm_eo - match;
subs = ap_pregsub(ctx->f->r->pool, m->to, ctx->buf+offs,
nmatch, pmatch);
s_to = strlen(subs);
len = strlen(ctx->buf);
offs += match;
VERBOSEB(
const char *f = apr_pstrndup(ctx->f->r->pool,
ctx->buf + offs, s_from);
ap_log_rerror(APLOG_MARK, APLOG_TRACE3, 0, ctx->f->r,
"C/RX: match at %s, substituting %s", f, subs);
)
if (s_to > s_from) {
preserve(ctx, s_to - s_from);
memmove(ctx->buf+offs+s_to, ctx->buf+offs+s_from,
len + 1 - s_from - offs);
memcpy(ctx->buf+offs, subs, s_to);
}
else {
memcpy(ctx->buf + offs, subs, s_to);
memmove(ctx->buf+offs+s_to, ctx->buf+offs+s_from,
len + 1 - s_from - offs);
}
offs += s_to;
}
}
else {
s_from = strlen(m->from.c);
s_to = strlen(m->to);
for (found = strstr(ctx->buf, m->from.c); found;
found = strstr(ctx->buf+match+s_to, m->from.c)) {
match = found - ctx->buf;
if ((m->flags & M_ATSTART) && (match != 0))
break;
len = strlen(ctx->buf);
if ((m->flags & M_ATEND) && (match < (len - s_from)))
continue;
VERBOSE(ap_log_rerror(APLOG_MARK, APLOG_TRACE3, 0, ctx->f->r,
"C: matched %s, substituting %s",
m->from.c, m->to));
if (s_to > s_from) {
preserve(ctx, s_to - s_from);
memmove(ctx->buf+match+s_to, ctx->buf+match+s_from,
len + 1 - s_from - match);
memcpy(ctx->buf+match, m->to, s_to);
}
else {
memcpy(ctx->buf+match, m->to, s_to);
memmove(ctx->buf+match+s_to, ctx->buf+match+s_from,
len + 1 - s_from - match);
}
}
}
}
AP_fwrite(ctx, ctx->buf, strlen(ctx->buf), 1);
}
static void pinternalSubset(void* ctxt, const xmlChar *name,
const xmlChar *externalID, const xmlChar *sysID)
{
saxctxt* ctx = (saxctxt*) ctxt;
if (!ctxt || !name) {
/* sanity check */
return;
}
if (ctx->cfg->doctype != DEFAULT_DOCTYPE) {
/* do nothing if overridden in config */
return;
}
ap_fputstrs(ctx->f->next, ctx->bb, "<!DOCTYPE ", (const char *)name, NULL);
if (externalID) {
if (!ap_cstr_casecmp((const char*)name, "html") &&
!ap_cstr_casecmpn((const char *)externalID, "-//W3C//DTD XHTML ", 18)) {
ctx->etag = xhtml_etag;
}
else {
ctx->etag = html_etag;
}
ap_fputstrs(ctx->f->next, ctx->bb, " PUBLIC \"", (const char *)externalID, "\"", NULL);
if (sysID)
ap_fputstrs(ctx->f->next, ctx->bb, " \"", (const char *)sysID, "\"", NULL);
}
ap_fputs(ctx->f->next, ctx->bb, ">\n");
}
static void pcdata(void *ctxt, const xmlChar *uchars, int length)
{
const char *chars = (const char*) uchars;
saxctxt *ctx = (saxctxt*) ctxt;
if (ctx->cfg->extfix) {
pappend(ctx, chars, length);
}
else {
/* not sure if this should force-flush
* (i.e. can one cdata section come in multiple calls?)
*/
AP_fwrite(ctx, chars, length, 0);
}
}
static void pcomment(void *ctxt, const xmlChar *uchars)
{
const char *chars = (const char*) uchars;
saxctxt *ctx = (saxctxt*) ctxt;
if (ctx->cfg->strip_comments)
return;
if (ctx->cfg->extfix) {
pappend(ctx, "<!--", 4);
pappend(ctx, chars, strlen(chars));
pappend(ctx, "-->", 3);
}
else {
ap_fputs(ctx->f->next, ctx->bb, "<!--");
AP_fwrite(ctx, chars, strlen(chars), 1);
ap_fputs(ctx->f->next, ctx->bb, "-->");
dump_content(ctx);
}
}
static void pendElement(void *ctxt, const xmlChar *uname)
{
saxctxt *ctx = (saxctxt*) ctxt;
const char *name = (const char*) uname;
const htmlElemDesc* desc = htmlTagLookup(uname);
if ((ctx->cfg->doctype == fpi_html) || (ctx->cfg->doctype == fpi_xhtml)) {
/* enforce html */
if (!desc || desc->depr)
return;
}
else if ((ctx->cfg->doctype == fpi_html_legacy)
|| (ctx->cfg->doctype == fpi_xhtml_legacy)) {
/* enforce html legacy */
if (!desc)
return;
}
/* TODO - implement HTML "allowed here" using the stack */
/* nah. Keeping the stack is too much overhead */
if (ctx->offset > 0) {
dump_content(ctx);
ctx->offset = 0; /* having dumped it, we can re-use the memory */
}
if (!desc || !desc->empty) {
ap_fprintf(ctx->f->next, ctx->bb, "</%s>", name);
}
}
static void pstartElement(void *ctxt, const xmlChar *uname,
const xmlChar** uattrs)
{
int required_attrs;
int num_match;
size_t offs, len;
char *subs;
rewrite_t is_uri;
const char** a;
urlmap *m;
size_t s_to, s_from, match;
char *found;
saxctxt *ctx = (saxctxt*) ctxt;
size_t nmatch;
ap_regmatch_t pmatch[10];
#ifndef GO_FASTER
int verbose = APLOGrtrace1(ctx->f->r);
#endif
apr_array_header_t *linkattrs;
int i;
const char *name = (const char*) uname;
const char** attrs = (const char**) uattrs;
const htmlElemDesc* desc = htmlTagLookup(uname);
urlmap *themap = ctx->map;
#ifdef HAVE_STACK
const void** descp;
#endif
int enforce = 0;
if ((ctx->cfg->doctype == fpi_html) || (ctx->cfg->doctype == fpi_xhtml)) {
/* enforce html */
enforce = 2;
if (!desc || desc->depr)
return;
}
else if ((ctx->cfg->doctype == fpi_html)
|| (ctx->cfg->doctype == fpi_xhtml)) {
enforce = 1;
/* enforce html legacy */
if (!desc) {
return;
}
}
if (!desc && enforce) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, ctx->f->r, APLOGNO(01416)
"Bogus HTML element %s dropped", name);
return;
}
if (desc && desc->depr && (enforce == 2)) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, ctx->f->r, APLOGNO(01417)
"Deprecated HTML element %s dropped", name);
return;
}
#ifdef HAVE_STACK
descp = apr_array_push(ctx->stack);
*descp = desc;
/* TODO - implement HTML "allowed here" */
#endif
ap_fputc(ctx->f->next, ctx->bb, '<');
ap_fputs(ctx->f->next, ctx->bb, name);
required_attrs = 0;
if ((enforce > 0) && (desc != NULL) && (desc->attrs_req != NULL))
for (a = desc->attrs_req; *a; a++)
++required_attrs;
if (attrs) {
linkattrs = apr_hash_get(ctx->cfg->links, name, APR_HASH_KEY_STRING);
for (a = attrs; *a; a += 2) {
if (desc && enforce > 0) {
switch (htmlAttrAllowed(desc, (xmlChar*)*a, 2-enforce)) {
case HTML_INVALID:
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, ctx->f->r, APLOGNO(01418)
"Bogus HTML attribute %s of %s dropped",
*a, name);
continue;
case HTML_DEPRECATED:
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, ctx->f->r, APLOGNO(01419)
"Deprecated HTML attribute %s of %s dropped",
*a, name);
continue;
case HTML_REQUIRED:
required_attrs--; /* cross off the number still needed */
/* fallthrough - required implies valid */
default:
break;
}
}
ctx->offset = 0;
if (a[1]) {
pappend(ctx, a[1], strlen(a[1])+1);
is_uri = ATTR_IGNORE;
if (linkattrs) {
tattr *attrs = (tattr*) linkattrs->elts;
for (i=0; i < linkattrs->nelts; ++i) {
if (!strcmp(*a, attrs[i].val)) {
is_uri = ATTR_URI;
break;
}
}
}
if ((is_uri == ATTR_IGNORE) && ctx->cfg->extfix
&& (ctx->cfg->events != NULL)) {
for (i=0; i < ctx->cfg->events->nelts; ++i) {
tattr *attrs = (tattr*) ctx->cfg->events->elts;
if (!strcmp(*a, attrs[i].val)) {
is_uri = ATTR_EVENT;
break;
}
}
}
switch (is_uri) {
case ATTR_URI:
num_match = 0;
for (m = themap; m; m = m->next) {
if (!(m->flags & M_HTML))
continue;
if (m->flags & M_REGEX) {
nmatch = 10;
if (!ap_regexec(m->from.r, ctx->buf, nmatch,
pmatch, 0)) {
++num_match;
offs = match = pmatch[0].rm_so;
s_from = pmatch[0].rm_eo - match;
subs = ap_pregsub(ctx->f->r->pool, m->to,
ctx->buf, nmatch, pmatch);
VERBOSE({
const char *f;
f = apr_pstrndup(ctx->f->r->pool,
ctx->buf + offs, s_from);
ap_log_rerror(APLOG_MARK, APLOG_TRACE3, 0,
ctx->f->r,
"H/RX: match at %s, substituting %s",
f, subs);
})
s_to = strlen(subs);
len = strlen(ctx->buf);
if (s_to > s_from) {
preserve(ctx, s_to - s_from);
memmove(ctx->buf+offs+s_to,
ctx->buf+offs+s_from,
len + 1 - s_from - offs);
memcpy(ctx->buf+offs, subs, s_to);
}
else {
memcpy(ctx->buf + offs, subs, s_to);
memmove(ctx->buf+offs+s_to,
ctx->buf+offs+s_from,
len + 1 - s_from - offs);
}
}
} else {
s_from = strlen(m->from.c);
if (!strncasecmp(ctx->buf, m->from.c, s_from)) {
++num_match;
s_to = strlen(m->to);
len = strlen(ctx->buf);
VERBOSE(ap_log_rerror(APLOG_MARK, APLOG_TRACE3,
0, ctx->f->r,
"H: matched %s, substituting %s",
m->from.c, m->to));
if (s_to > s_from) {
preserve(ctx, s_to - s_from);
memmove(ctx->buf+s_to, ctx->buf+s_from,
len + 1 - s_from);
memcpy(ctx->buf, m->to, s_to);
}
else { /* it fits in the existing space */
memcpy(ctx->buf, m->to, s_to);
memmove(ctx->buf+s_to, ctx->buf+s_from,
len + 1 - s_from);
}
break;
}
}
/* URIs only want one match unless overridden in the config */
if ((num_match > 0) && !(m->flags & M_NOTLAST))
break;
}
break;
case ATTR_EVENT:
for (m = themap; m; m = m->next) {
num_match = 0; /* reset here since we're working per-rule */
if (!(m->flags & M_EVENTS))
continue;
if (m->flags & M_REGEX) {
nmatch = 10;
offs = 0;
while (!ap_regexec(m->from.r, ctx->buf+offs,
nmatch, pmatch, 0)) {
match = pmatch[0].rm_so;
s_from = pmatch[0].rm_eo - match;
subs = ap_pregsub(ctx->f->r->pool, m->to, ctx->buf+offs,
nmatch, pmatch);
VERBOSE({
const char *f;
f = apr_pstrndup(ctx->f->r->pool,
ctx->buf + offs, s_from);
ap_log_rerror(APLOG_MARK, APLOG_TRACE3, 0,
ctx->f->r,
"E/RX: match at %s, substituting %s",
f, subs);
})
s_to = strlen(subs);
offs += match;
len = strlen(ctx->buf);
if (s_to > s_from) {
preserve(ctx, s_to - s_from);
memmove(ctx->buf+offs+s_to,
ctx->buf+offs+s_from,
len + 1 - s_from - offs);
memcpy(ctx->buf+offs, subs, s_to);
}
else {
memcpy(ctx->buf + offs, subs, s_to);
memmove(ctx->buf+offs+s_to,
ctx->buf+offs+s_from,
len + 1 - s_from - offs);
}
offs += s_to;
++num_match;
}
}
else {
found = strstr(ctx->buf, m->from.c);
if ((m->flags & M_ATSTART) && (found != ctx->buf))
continue;
while (found) {
s_from = strlen(m->from.c);
s_to = strlen(m->to);
match = found - ctx->buf;
if ((s_from < strlen(found))
&& (m->flags & M_ATEND)) {
found = strstr(ctx->buf+match+s_from,
m->from.c);
continue;
}
else {
found = strstr(ctx->buf+match+s_to,
m->from.c);
}
VERBOSE(ap_log_rerror(APLOG_MARK, APLOG_TRACE3,
0, ctx->f->r,
"E: matched %s, substituting %s",
m->from.c, m->to));
len = strlen(ctx->buf);
if (s_to > s_from) {
preserve(ctx, s_to - s_from);
memmove(ctx->buf+match+s_to,
ctx->buf+match+s_from,
len + 1 - s_from - match);
memcpy(ctx->buf+match, m->to, s_to);
}
else {
memcpy(ctx->buf+match, m->to, s_to);
memmove(ctx->buf+match+s_to,
ctx->buf+match+s_from,
len + 1 - s_from - match);
}
++num_match;
}
}
if (num_match && (m->flags & M_LAST))
break;
}
break;
case ATTR_IGNORE:
break;
}
}
if (!a[1])
ap_fputstrs(ctx->f->next, ctx->bb, " ", a[0], NULL);
else {
if (ctx->cfg->flags != 0)
normalise(ctx->cfg->flags, ctx->buf);
/* write the attribute, using pcharacters to html-escape
anything that needs it in the value.
*/
ap_fputstrs(ctx->f->next, ctx->bb, " ", a[0], "=\"", NULL);
pcharacters(ctx, (const xmlChar*)ctx->buf, strlen(ctx->buf));
ap_fputc(ctx->f->next, ctx->bb, '"');
}
}
}
ctx->offset = 0;
if (desc && desc->empty)
ap_fputs(ctx->f->next, ctx->bb, ctx->etag);
else
ap_fputc(ctx->f->next, ctx->bb, '>');
if ((enforce > 0) && (required_attrs > 0)) {
/* if there are more required attributes than we found then complain */
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, ctx->f->r, APLOGNO(01420)
"HTML element %s is missing %d required attributes",
name, required_attrs);
}
}
static meta *metafix(request_rec *r, const char *buf)
{
meta *ret = NULL;
size_t offs = 0;
const char *p;
const char *q;
char *header;
char *content;
ap_regmatch_t pmatch[2];
char delim;
while (!ap_regexec(seek_meta, buf+offs, 2, pmatch, 0)) {
header = NULL;
content = NULL;
p = buf+offs+pmatch[1].rm_eo;
while (!apr_isalpha(*++p));
for (q = p; apr_isalnum(*q) || (*q == '-'); ++q);
header = apr_pstrndup(r->pool, p, q-p);
if (ap_cstr_casecmpn(header, "Content-", 8)) {
/* find content=... string */
p = apr_strmatch(seek_content, buf+offs+pmatch[0].rm_so,
pmatch[0].rm_eo - pmatch[0].rm_so);
/* if it doesn't contain "content", ignore, don't crash! */
if (p != NULL) {
while (*p) {
p += 7;
while (apr_isspace(*p))
++p;
/* XXX Should we search for another content= pattern? */
if (*p != '=')
break;
while (*p && apr_isspace(*++p));
if ((*p == '\'') || (*p == '"')) {
delim = *p++;
for (q = p; *q && *q != delim; ++q);
/* No terminating delimiter found? Skip the boggus directive */
if (*q != delim)
break;
} else {
for (q = p; *q && !apr_isspace(*q) && (*q != '>'); ++q);
}
content = apr_pstrndup(r->pool, p, q-p);
break;
}
}
}
else if (!ap_cstr_casecmpn(header, "Content-Type", 12)) {
ret = apr_palloc(r->pool, sizeof(meta));
ret->start = offs+pmatch[0].rm_so;
ret->end = offs+pmatch[0].rm_eo;
}
if (header && content) {
#ifndef GO_FASTER
ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r,
"Adding header [%s: %s] from HTML META",
header, content);
#endif
apr_table_setn(r->headers_out, header, content);
}
offs += pmatch[0].rm_eo;
}
return ret;
}
static const char *interpolate_vars(request_rec *r, const char *str)
{
const char *start;
const char *end;
const char *delim;
const char *before;
const char *after;
const char *replacement;
const char *var;
for (;;) {
start = str;
if (start = ap_strstr_c(start, "${"), start == NULL)
break;
if (end = ap_strchr_c(start+2, '}'), end == NULL)
break;
delim = ap_strchr_c(start, '|');
before = apr_pstrndup(r->pool, str, start-str);
after = end+1;
if (delim) {
var = apr_pstrndup(r->pool, start+2, delim-start-2);
}
else {
var = apr_pstrndup(r->pool, start+2, end-start-2);
}
replacement = apr_table_get(r->subprocess_env, var);
if (!replacement) {
if (delim)
replacement = apr_pstrndup(r->pool, delim+1, end-delim-1);
else
replacement = "";
}
str = apr_pstrcat(r->pool, before, replacement, after, NULL);
ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
"Interpolating %s => %s", var, replacement);
}
return str;
}
static void fixup_rules(saxctxt *ctx)
{
urlmap *newp;
urlmap *p;
urlmap *prev = NULL;
request_rec *r = ctx->f->r;
for (p = ctx->cfg->map; p; p = p->next) {
if (p->cond != NULL) {
const char *err;
int ok = ap_expr_exec(r, p->cond, &err);
if (err) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01421)
"Error evaluating expr: %s", err);
}
if (ok == 0) {
continue; /* condition is unsatisfied */
}
}
newp = apr_pmemdup(r->pool, p, sizeof(urlmap));
if (newp->flags & M_INTERPOLATE_FROM) {
newp->from.c = interpolate_vars(r, newp->from.c);
if (!newp->from.c || !*newp->from.c)
continue; /* don't use empty from-pattern */
if (newp->flags & M_REGEX) {
newp->from.r = ap_pregcomp(r->pool, newp->from.c,
newp->regflags);
}
}
if (newp->flags & M_INTERPOLATE_TO) {
newp->to = interpolate_vars(r, newp->to);
}
/* evaluate p->cond; continue if unsatisfied */
/* create new urlmap with memcpy and append to map */
/* interpolate from if flagged to do so */
/* interpolate to if flagged to do so */
if (prev != NULL)
prev->next = newp;
else
ctx->map = newp;
prev = newp;
}
if (prev)
prev->next = NULL;
}
static saxctxt *check_filter_init (ap_filter_t *f)
{
saxctxt *fctx;
if (!f->ctx) {
proxy_html_conf *cfg;
const char *force;
const char *errmsg = NULL;
cfg = ap_get_module_config(f->r->per_dir_config, &proxy_html_module);
force = apr_table_get(f->r->subprocess_env, "PROXY_HTML_FORCE");
if (!force) {
if (!f->r->proxyreq) {
errmsg = "Non-proxy request; not inserting proxy-html filter";
}
else if (!f->r->content_type) {
errmsg = "No content-type; bailing out of proxy-html filter";
}
else if (ap_cstr_casecmpn(f->r->content_type, "text/html", 9) &&
ap_cstr_casecmpn(f->r->content_type,
"application/xhtml+xml", 21)) {
errmsg = "Non-HTML content; not inserting proxy-html filter";
}
}
if (!cfg->links) {
errmsg = "No links configured: nothing for proxy-html filter to do";
}
if (errmsg) {
#ifndef GO_FASTER
ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, f->r, "%s", errmsg);
#endif
ap_remove_output_filter(f);
return NULL;
}
fctx = f->ctx = apr_pcalloc(f->r->pool, sizeof(saxctxt));
fctx->f = f;
fctx->bb = apr_brigade_create(f->r->pool,
f->r->connection->bucket_alloc);
fctx->cfg = cfg;
fctx->etag = cfg->etag;
apr_table_unset(f->r->headers_out, "Content-Length");
if (cfg->interp)
fixup_rules(fctx);
else
fctx->map = cfg->map;
/* defer dealing with charset_out until after sniffing charset_in
* so we can support setting one to t'other.
*/
}
return f->ctx;
}
static apr_status_t proxy_html_filter(ap_filter_t *f, apr_bucket_brigade *bb)
{
apr_bucket* b;
meta *m = NULL;
xmlCharEncoding enc;
const char *buf = 0;
apr_size_t bytes = 0;
#ifndef USE_OLD_LIBXML2
int xmlopts = XML_PARSE_RECOVER | XML_PARSE_NONET |
XML_PARSE_NOBLANKS | XML_PARSE_NOERROR | XML_PARSE_NOWARNING;
#endif
saxctxt *ctxt = check_filter_init(f);
if (!ctxt)
return ap_pass_brigade(f->next, bb);
for (b = APR_BRIGADE_FIRST(bb);
b != APR_BRIGADE_SENTINEL(bb);
b = APR_BUCKET_NEXT(b)) {
if (APR_BUCKET_IS_METADATA(b)) {
if (APR_BUCKET_IS_EOS(b)) {
if (ctxt->parser != NULL) {
consume_buffer(ctxt, buf, 0, 1);
}
APR_BRIGADE_INSERT_TAIL(ctxt->bb,
apr_bucket_eos_create(ctxt->bb->bucket_alloc));
ap_pass_brigade(ctxt->f->next, ctxt->bb);
}
else if (APR_BUCKET_IS_FLUSH(b)) {
/* pass on flush, except at start where it would cause
* headers to be sent before doc sniffing
*/
if (ctxt->parser != NULL) {
ap_fflush(ctxt->f->next, ctxt->bb);
}
}
}
else if (apr_bucket_read(b, &buf, &bytes, APR_BLOCK_READ)
== APR_SUCCESS) {
if (ctxt->parser == NULL) {
const char *cenc;
/* For documents smaller than four bytes, there is no reason to do
* HTML rewriting. The URL schema (i.e. 'http') needs four bytes alone.
* And the HTML parser needs at least four bytes to initialise correctly.
*/
if ((bytes < 4) && APR_BUCKET_IS_EOS(APR_BUCKET_NEXT(b))) {
ap_remove_output_filter(f) ;
return ap_pass_brigade(f->next, bb) ;
}
if (!xml2enc_charset ||
(xml2enc_charset(f->r, &enc, &cenc) != APR_SUCCESS)) {
if (!xml2enc_charset)
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, f->r, APLOGNO(01422)
"No i18n support found. Install mod_xml2enc if required");
enc = XML_CHAR_ENCODING_NONE;
ap_set_content_type(f->r, "text/html;charset=utf-8");
}
else {
/* if we wanted a non-default charset_out, insert the
* xml2enc filter now that we've sniffed it
*/
if (ctxt->cfg->charset_out && xml2enc_filter) {
if (*ctxt->cfg->charset_out != '*')
cenc = ctxt->cfg->charset_out;
xml2enc_filter(f->r, cenc, ENCIO_OUTPUT);
ap_set_content_type(f->r,
apr_pstrcat(f->r->pool,
"text/html;charset=",
cenc, NULL));
}
else /* Normal case, everything worked, utf-8 output */
ap_set_content_type(f->r, "text/html;charset=utf-8");
}
ap_fputs(f->next, ctxt->bb, ctxt->cfg->doctype);
ctxt->parser = htmlCreatePushParserCtxt(&sax, ctxt, buf,
4, 0, enc);
buf += 4;
bytes -= 4;
if (ctxt->parser == NULL) {
apr_status_t rv = ap_pass_brigade(f->next, bb);
ap_remove_output_filter(f);
return rv;
}
apr_pool_cleanup_register(f->r->pool, ctxt->parser,
(int(*)(void*))htmlFreeParserCtxt,
apr_pool_cleanup_null);
#ifndef USE_OLD_LIBXML2
if (xmlopts = xmlCtxtUseOptions(ctxt->parser, xmlopts), xmlopts)
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, f->r, APLOGNO(01423)
"Unsupported parser opts %x", xmlopts);
#endif
if (ctxt->cfg->metafix)
m = metafix(f->r, buf);
if (m) {
consume_buffer(ctxt, buf, m->start, 0);
consume_buffer(ctxt, buf+m->end, bytes-m->end, 0);
}
else {
consume_buffer(ctxt, buf, bytes, 0);
}
}
else {
consume_buffer(ctxt, buf, bytes, 0);
}
}
else {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, f->r, APLOGNO(01424)
"Error in bucket read");
}
}
/*ap_fflush(ctxt->f->next, ctxt->bb); // uncomment for debug */
apr_brigade_cleanup(bb);
return APR_SUCCESS;
}
static void *proxy_html_config(apr_pool_t *pool, char *x)
{
proxy_html_conf *ret = apr_pcalloc(pool, sizeof(proxy_html_conf));
ret->doctype = DEFAULT_DOCTYPE;
ret->etag = DEFAULT_ETAG;
ret->bufsz = 8192;
/* ret->interp = 1; */
/* don't initialise links and events until they get set/used */
return ret;
}
static void *proxy_html_merge(apr_pool_t *pool, void *BASE, void *ADD)
{
proxy_html_conf *base = (proxy_html_conf *) BASE;
proxy_html_conf *add = (proxy_html_conf *) ADD;
proxy_html_conf *conf = apr_palloc(pool, sizeof(proxy_html_conf));
/* don't merge declarations - just use the most specific */
conf->links = (add->links == NULL) ? base->links : add->links;
conf->events = (add->events == NULL) ? base->events : add->events;
conf->charset_out = (add->charset_out == NULL)
? base->charset_out : add->charset_out;
if (add->map && base->map) {
urlmap *a;
conf->map = NULL;
for (a = base->map; a; a = a->next) {
urlmap *save = conf->map;
conf->map = apr_pmemdup(pool, a, sizeof(urlmap));
conf->map->next = save;
}
for (a = add->map; a; a = a->next) {
urlmap *save = conf->map;
conf->map = apr_pmemdup(pool, a, sizeof(urlmap));
conf->map->next = save;
}
}
else
conf->map = add->map ? add->map : base->map;
conf->doctype = (add->doctype == DEFAULT_DOCTYPE)
? base->doctype : add->doctype;
conf->etag = (add->etag == DEFAULT_ETAG) ? base->etag : add->etag;
conf->bufsz = add->bufsz;
if (add->flags & NORM_RESET) {
conf->flags = add->flags ^ NORM_RESET;
conf->metafix = add->metafix;
conf->extfix = add->extfix;
conf->interp = add->interp;
conf->strip_comments = add->strip_comments;
conf->enabled = add->enabled;
}
else {
conf->flags = base->flags | add->flags;
conf->metafix = base->metafix | add->metafix;
conf->extfix = base->extfix | add->extfix;
conf->interp = base->interp | add->interp;
conf->strip_comments = base->strip_comments | add->strip_comments;
conf->enabled = add->enabled | base->enabled;
}
return conf;
}
#define REGFLAG(n,s,c) ((s&&(ap_strchr_c((s),(c))!=NULL)) ? (n) : 0)
#define XREGFLAG(n,s,c) ((!s||(ap_strchr_c((s),(c))==NULL)) ? (n) : 0)
static const char *comp_urlmap(cmd_parms *cmd, urlmap *newmap,
const char *from, const char *to,
const char *flags, const char *cond)
{
const char *err = NULL;
newmap->flags
= XREGFLAG(M_HTML,flags,'h')
| XREGFLAG(M_EVENTS,flags,'e')
| XREGFLAG(M_CDATA,flags,'c')
| REGFLAG(M_ATSTART,flags,'^')
| REGFLAG(M_ATEND,flags,'$')
| REGFLAG(M_REGEX,flags,'R')
| REGFLAG(M_LAST,flags,'L')
| REGFLAG(M_NOTLAST,flags,'l')
| REGFLAG(M_INTERPOLATE_TO,flags,'V')
| REGFLAG(M_INTERPOLATE_FROM,flags,'v');
if ((newmap->flags & M_INTERPOLATE_FROM) || !(newmap->flags & M_REGEX)) {
newmap->from.c = from;
newmap->to = to;
}
else {
newmap->regflags
= REGFLAG(AP_REG_EXTENDED,flags,'x')
| REGFLAG(AP_REG_ICASE,flags,'i')
| REGFLAG(AP_REG_NOSUB,flags,'n')
| REGFLAG(AP_REG_NEWLINE,flags,'s');
newmap->from.r = ap_pregcomp(cmd->pool, from, newmap->regflags);
newmap->to = to;
}
if (cond != NULL) {
/* back-compatibility: support old-style ENV expressions
* by converting to ap_expr syntax.
*
* 1. var --> env(var)
* 2. var=val --> env(var)=val
* 3. !var --> !env(var)
* 4. !var=val --> env(var)!=val
*/
char *newcond = NULL;
if (ap_rxplus_exec(cmd->temp_pool, old_expr, cond, &newcond)) {
/* we got a substitution. Check for the case (3) above
* that the regexp gets wrong: a negation without a comparison.
*/
if ((cond[0] == '!') && !ap_strchr_c(cond, '=')) {
memmove(newcond+1, newcond, strlen(newcond)-1);
newcond[0] = '!';
}
cond = newcond;
}
newmap->cond = ap_expr_parse_cmd(cmd, cond, 0, &err, NULL);
}
else {
newmap->cond = NULL;
}
return err;
}
static const char *set_urlmap(cmd_parms *cmd, void *CFG, const char *args)
{
proxy_html_conf *cfg = (proxy_html_conf *)CFG;
urlmap *map;
apr_pool_t *pool = cmd->pool;
urlmap *newmap;
const char *usage =
"Usage: ProxyHTMLURLMap from-pattern to-pattern [flags] [cond]";
const char *from;
const char *to;
const char *flags;
const char *cond = NULL;
if (from = ap_getword_conf(cmd->pool, &args), !from)
return usage;
if (to = ap_getword_conf(cmd->pool, &args), !to)
return usage;
flags = ap_getword_conf(cmd->pool, &args);
if (flags && *flags)
cond = ap_getword_conf(cmd->pool, &args);
if (cond && !*cond)
cond = NULL;
/* the args look OK, so let's use them */
newmap = apr_palloc(pool, sizeof(urlmap));
newmap->next = NULL;
if (cfg->map) {
for (map = cfg->map; map->next; map = map->next);
map->next = newmap;
}
else
cfg->map = newmap;
return comp_urlmap(cmd, newmap, from, to, flags, cond);
}
static const char *set_doctype(cmd_parms *cmd, void *CFG,
const char *t, const char *l)
{
proxy_html_conf *cfg = (proxy_html_conf *)CFG;
if (!strcasecmp(t, "auto")) {
cfg->doctype = DEFAULT_DOCTYPE; /* activates pinternalSubset */
}
else if (!strcasecmp(t, "xhtml")) {
cfg->etag = xhtml_etag;
if (l && !strcasecmp(l, "legacy"))
cfg->doctype = fpi_xhtml_legacy;
else
cfg->doctype = fpi_xhtml;
}
else if (!strcasecmp(t, "html")) {
cfg->etag = html_etag;
if (l && !strcasecmp(l, "legacy"))
cfg->doctype = fpi_html_legacy;
else
cfg->doctype = fpi_html;
}
else if (!strcasecmp(t, "html5")) {
cfg->etag = html_etag;
cfg->doctype = fpi_html5;
}
else {
cfg->doctype = apr_pstrdup(cmd->pool, t);
if (l && ((l[0] == 'x') || (l[0] == 'X')))
cfg->etag = xhtml_etag;
else
cfg->etag = html_etag;
}
return NULL;
}
static const char *set_flags(cmd_parms *cmd, void *CFG, const char *arg)
{
proxy_html_conf *cfg = CFG;
if (arg && *arg) {
if (!strcasecmp(arg, "lowercase"))
cfg->flags |= NORM_LC;
else if (!strcasecmp(arg, "dospath"))
cfg->flags |= NORM_MSSLASH;
else if (!strcasecmp(arg, "reset"))
cfg->flags |= NORM_RESET;
}
return NULL;
}
static const char *set_events(cmd_parms *cmd, void *CFG, const char *arg)
{
tattr *attr;
proxy_html_conf *cfg = CFG;
if (cfg->events == NULL)
cfg->events = apr_array_make(cmd->pool, 20, sizeof(tattr));
attr = apr_array_push(cfg->events);
attr->val = arg;
return NULL;
}
static const char *set_links(cmd_parms *cmd, void *CFG,
const char *elt, const char *att)
{
apr_array_header_t *attrs;
tattr *attr;
proxy_html_conf *cfg = CFG;
if (cfg->links == NULL)
cfg->links = apr_hash_make(cmd->pool);
attrs = apr_hash_get(cfg->links, elt, APR_HASH_KEY_STRING);
if (!attrs) {
attrs = apr_array_make(cmd->pool, 2, sizeof(tattr*));
apr_hash_set(cfg->links, elt, APR_HASH_KEY_STRING, attrs);
}
attr = apr_array_push(attrs);
attr->val = att;
return NULL;
}
static const command_rec proxy_html_cmds[] = {
AP_INIT_ITERATE("ProxyHTMLEvents", set_events, NULL,
RSRC_CONF|ACCESS_CONF,
"Strings to be treated as scripting events"),
AP_INIT_ITERATE2("ProxyHTMLLinks", set_links, NULL,
RSRC_CONF|ACCESS_CONF, "Declare HTML Attributes"),
AP_INIT_RAW_ARGS("ProxyHTMLURLMap", set_urlmap, NULL,
RSRC_CONF|ACCESS_CONF, "Map URL From To"),
AP_INIT_TAKE12("ProxyHTMLDoctype", set_doctype, NULL,
RSRC_CONF|ACCESS_CONF, "(HTML|XHTML) [Legacy]"),
AP_INIT_ITERATE("ProxyHTMLFixups", set_flags, NULL,
RSRC_CONF|ACCESS_CONF, "Options are lowercase, dospath"),
AP_INIT_FLAG("ProxyHTMLMeta", ap_set_flag_slot,
(void*)APR_OFFSETOF(proxy_html_conf, metafix),
RSRC_CONF|ACCESS_CONF, "Fix META http-equiv elements"),
AP_INIT_FLAG("ProxyHTMLInterp", ap_set_flag_slot,
(void*)APR_OFFSETOF(proxy_html_conf, interp),
RSRC_CONF|ACCESS_CONF,
"Support interpolation and conditions in URLMaps"),
AP_INIT_FLAG("ProxyHTMLExtended", ap_set_flag_slot,
(void*)APR_OFFSETOF(proxy_html_conf, extfix),
RSRC_CONF|ACCESS_CONF, "Map URLs in Javascript and CSS"),
AP_INIT_FLAG("ProxyHTMLStripComments", ap_set_flag_slot,
(void*)APR_OFFSETOF(proxy_html_conf, strip_comments),
RSRC_CONF|ACCESS_CONF, "Strip out comments"),
AP_INIT_TAKE1("ProxyHTMLBufSize", ap_set_int_slot,
(void*)APR_OFFSETOF(proxy_html_conf, bufsz),
RSRC_CONF|ACCESS_CONF, "Buffer size"),
AP_INIT_TAKE1("ProxyHTMLCharsetOut", ap_set_string_slot,
(void*)APR_OFFSETOF(proxy_html_conf, charset_out),
RSRC_CONF|ACCESS_CONF, "Usage: ProxyHTMLCharsetOut charset"),
AP_INIT_FLAG("ProxyHTMLEnable", ap_set_flag_slot,
(void*)APR_OFFSETOF(proxy_html_conf, enabled),
RSRC_CONF|ACCESS_CONF,
"Enable proxy-html and xml2enc filters"),
{ NULL }
};
static int mod_proxy_html(apr_pool_t *p, apr_pool_t *p1, apr_pool_t *p2)
{
seek_meta = ap_pregcomp(p, "<meta[^>]*(http-equiv)[^>]*>",
AP_REG_EXTENDED|AP_REG_ICASE);
seek_content = apr_strmatch_precompile(p, "content", 0);
memset(&sax, 0, sizeof(htmlSAXHandler));
sax.startElement = pstartElement;
sax.endElement = pendElement;
sax.characters = pcharacters;
sax.comment = pcomment;
sax.cdataBlock = pcdata;
sax.internalSubset = pinternalSubset;
xml2enc_charset = APR_RETRIEVE_OPTIONAL_FN(xml2enc_charset);
xml2enc_filter = APR_RETRIEVE_OPTIONAL_FN(xml2enc_filter);
if (!xml2enc_charset) {
ap_log_perror(APLOG_MARK, APLOG_NOTICE, 0, p2, APLOGNO(01425)
"I18n support in mod_proxy_html requires mod_xml2enc. "
"Without it, non-ASCII characters in proxied pages are "
"likely to display incorrectly.");
}
/* old_expr only needs to last the life of the config phase */
old_expr = ap_rxplus_compile(p1, "s/^(!)?(\\w+)((=)(.+))?$/reqenv('$2')$1$4'$5'/");
return OK;
}
static void proxy_html_insert(request_rec *r)
{
proxy_html_conf *cfg;
cfg = ap_get_module_config(r->per_dir_config, &proxy_html_module);
if (cfg->enabled) {
if (xml2enc_filter)
xml2enc_filter(r, NULL, ENCIO_INPUT_CHECKS);
ap_add_output_filter("proxy-html", NULL, r, r->connection);
}
}
static void proxy_html_hooks(apr_pool_t *p)
{
static const char *aszSucc[] = { "mod_filter.c", NULL };
ap_register_output_filter_protocol("proxy-html", proxy_html_filter,
NULL, AP_FTYPE_RESOURCE,
AP_FILTER_PROTO_CHANGE|AP_FILTER_PROTO_CHANGE_LENGTH);
/* move this to pre_config so old_expr is available to interpret
* old-style conditions on URL maps.
*/
ap_hook_pre_config(mod_proxy_html, NULL, NULL, APR_HOOK_MIDDLE);
ap_hook_insert_filter(proxy_html_insert, NULL, aszSucc, APR_HOOK_MIDDLE);
}
AP_DECLARE_MODULE(proxy_html) = {
STANDARD20_MODULE_STUFF,
proxy_html_config,
proxy_html_merge,
NULL,
NULL,
proxy_html_cmds,
proxy_html_hooks
};