*
* $Id: cache_vrt.c 2067 2007-09-30 20:57:30Z phk $
*
- * Runtime support for compiled VCL programs
+ * Runtime support for compiled VCL programs ESI processing.
+ *
+ * The basic ESI 1.0 is a very simple specification:
+ * http://www.w3.org/TR/esi-lang
+ * But it seems that Oracle and Akamai has embrodiered it to be almost a new
+ * layer of scripting language in HTTP transmission chains.
+ *
+ * It is not obvious how much help the "advanced" features of ESI really
+ * are to users, so our aim is to pick the fruit starting with the lowest
+ * hanging, esi:include
*/
#include <stdio.h>
#include "vcl.h"
#include "cache.h"
+/*--------------------------------------------------------------------
+ * Add one piece to the output, either verbatim or include
+ */
+
+static void
+add_piece(txt t, int kind)
+{
+
+ printf("K%d \"%.*s\"\n", kind, t.e - t.b, t.b);
+}
+
+/*--------------------------------------------------------------------
+ * Zoom over a piece of object and dike out all releveant esi: pieces.
+ * The entire txt may not be processed because an interesting part
+ * could possibly span into the next chunk of storage.
+ * Return value: number of bytes processed.
+ */
+
+static int
+vxml(txt t)
+{
+ char *p, *q, *r;
+ txt o;
+ int celem; /* closing element */
+ int remflg; /* inside <esi:remove> </esi:remove> */
+ int incmt; /* inside <!--esi ... --> comment */
+ int i;
+
+ o.b = t.b;
+ remflg = 0;
+ incmt = 0;
+ for (p = t.b; p < t.e; ) {
+ if (incmt && *p == '-') {
+ /*
+ * We are inside an <!--esi comment and need to zap
+ * the end comment marker --> when we see it.
+ */
+ if (p + 2 >= t.e) {
+ /* XXX: need to return pending incmt */
+ return (p - t.b);
+ }
+ if (!memcmp(p, "-->", 3)) {
+ incmt = 0;
+ o.e = p;
+ add_piece(o, 0);
+ p += 3;
+ o.b = p;
+ } else
+ p++;
+ continue;
+ }
+
+ if (*p != '<') {
+ /* nothing happens until next element or comment */
+ p++;
+ continue;
+ }
+
+ i = t.e - p;
+
+ if (i < 2)
+ return (p - t.b);
+
+ if (remflg == 0 && !memcmp(p, "<!--esi", i > 7 ? 7 : i)) {
+ /*
+ * ESI comment. <!--esi...-->
+ * at least 10 char, but we only test on the
+ * first seven because the tail is handled
+ * by the incmt flag.
+ */
+ if (i < 7)
+ return (p - t.b);
+
+ o.e = p;
+ add_piece(o, 0);
+
+ p += 7;
+ o.b = p;
+ incmt = 1;
+ continue;
+ }
+
+ if (!memcmp(p, "<!--", i > 4 ? 4 : i)) {
+ /*
+ * plain comment <!--...--> at least 7 char
+ */
+ if (i < 7)
+ return (p - t.b);
+ for (q = p + 4; ; q++) {
+ if (q + 2 >= t.e)
+ return (p - t.b);
+ if (!memcmp(q, "-->", 3))
+ break;
+ }
+ p = q + 3;
+ continue;
+ }
+
+ if (!memcmp(p, "<![CDATA[", i > 9 ? 9 : i)) {
+ /*
+ * cdata <![CDATA[...]]> at least 12 char
+ */
+ if (i < 12)
+ return (p - t.b);
+ for (q = p + 9; ; q++) {
+ if (q + 2 >= t.e)
+ return (p - t.b);
+ if (!memcmp(q, "]]>", 3))
+ break;
+ }
+ p = q + 3;
+ continue;
+ }
+
+ if (p[1] == '!') {
+ /* Ignore unrecognized <! sequence */
+ p += 2;
+ continue;
+ }
+
+ /* Find end of this element */
+ for (q = p + 1; q < t.e && *q != '>'; q++)
+ continue;
+ if (*q != '>')
+ return (p - t.b);
+
+ /* Opening/empty or closing element ? */
+ if (p[1] == '/') {
+ celem = 1;
+ r = p + 2;
+ if (q[-1] == '/') {
+ /* XML violation, ignore this ? */
+ }
+ } else {
+ celem = 0;
+ r = p + 1;
+ }
+
+ if (r + 9 < q && !memcmp(r, "esi:remove", 10)) {
+
+ if (celem != remflg) {
+ /* ESI 1.0 violation, ignore this element */
+ if (!remflg) {
+ o.e = p;
+ add_piece(o, 0);
+ }
+ } else if (!celem && q[-1] == '/') {
+ /* empty element */
+ o.e = p;
+ add_piece(o, 0);
+ } else if (!celem) {
+ /* open element */
+ o.e = p;
+ add_piece(o, 0);
+ remflg = !celem;
+ } else {
+ /* close element */
+ remflg = !celem;
+ }
+ p = q + 1;
+ o.b = p;
+ continue;
+ }
+
+ if (remflg && r + 3 < q && !memcmp(r, "esi:", 4)) {
+ /* ESI 1.0 violation, no nesting in esi:remove */
+ p = q + 1;
+ continue;
+ }
+
+ if (r + 10 < q && !memcmp(r, "esi:include", 11)) {
+
+ o.e = p;
+ add_piece(o, 0);
+
+ if (celem == 0) {
+ o.b = r + 11;
+ o.e = q;
+ add_piece(o, 1);
+ if (q[-1] != '/') {
+ /* ESI 1.0 violation */
+ }
+ } else {
+ /* ESI 1.0 violation */
+ }
+ p = q + 1;
+ o.b = p;
+ continue;
+ }
+
+ if (r + 3 < q && !memcmp(r, "esi:", 4)) {
+ /*
+ * Unimplemented ESI element, ignore
+ */
+ o.e = p;
+ add_piece(o, 0);
+ p = q + 1;
+ o.b = p;
+ continue;
+ }
+
+ /* Not an element we care about */
+ p = q + 1;
+ }
+ o.e = p;
+ add_piece(o, 0);
+ return (p - t.b);
+}
+
/*--------------------------------------------------------------------*/
void
VRT_ESI(struct sess *sp)
{
+ struct storage *st;
+ txt t;
+ int i;
CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
- INCOMPL();
+ CHECK_OBJ_NOTNULL(sp->obj, OBJECT_MAGIC);
+ VTAILQ_FOREACH(st, &sp->obj->store, list) {
+ t.b = (void*)st->ptr;
+ t.e = t.b + st->len;
+ i = vxml(t);
+ printf("VXML(%p+%d) = %d", st->ptr, st->len, i);
+ if (i < st->len)
+ printf(" \"%.*s\"", st->len - i, st->ptr + i);
+ printf("\n");
+ }
}
+
+/*--------------------------------------------------------------------*/
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