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-rw-r--r--modules/http2/h2_push.c877
1 files changed, 877 insertions, 0 deletions
diff --git a/modules/http2/h2_push.c b/modules/http2/h2_push.c
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+++ b/modules/http2/h2_push.c
@@ -0,0 +1,877 @@
+/* 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.
+ */
+
+#include <assert.h>
+#include <stdio.h>
+
+#include <apr_lib.h>
+#include <apr_strings.h>
+#include <apr_hash.h>
+#include <apr_time.h>
+
+#ifdef H2_OPENSSL
+#include <openssl/evp.h>
+#endif
+
+#include <httpd.h>
+#include <http_core.h>
+#include <http_log.h>
+#include <http_protocol.h>
+
+#include "h2_private.h"
+#include "h2_protocol.h"
+#include "h2_util.h"
+#include "h2_push.h"
+#include "h2_request.h"
+#include "h2_session.h"
+#include "h2_stream.h"
+
+/*******************************************************************************
+ * link header handling
+ ******************************************************************************/
+
+static const char *policy_str(h2_push_policy policy)
+{
+ switch (policy) {
+ case H2_PUSH_NONE:
+ return "none";
+ case H2_PUSH_FAST_LOAD:
+ return "fast-load";
+ case H2_PUSH_HEAD:
+ return "head";
+ default:
+ return "default";
+ }
+}
+
+typedef struct {
+ const h2_request *req;
+ apr_uint32_t push_policy;
+ apr_pool_t *pool;
+ apr_array_header_t *pushes;
+ const char *s;
+ size_t slen;
+ size_t i;
+
+ const char *link;
+ apr_table_t *params;
+ char b[4096];
+} link_ctx;
+
+static int attr_char(char c)
+{
+ switch (c) {
+ case '!':
+ case '#':
+ case '$':
+ case '&':
+ case '+':
+ case '-':
+ case '.':
+ case '^':
+ case '_':
+ case '`':
+ case '|':
+ case '~':
+ return 1;
+ default:
+ return apr_isalnum(c);
+ }
+}
+
+static int ptoken_char(char c)
+{
+ switch (c) {
+ case '!':
+ case '#':
+ case '$':
+ case '&':
+ case '\'':
+ case '(':
+ case ')':
+ case '*':
+ case '+':
+ case '-':
+ case '.':
+ case '/':
+ case ':':
+ case '<':
+ case '=':
+ case '>':
+ case '?':
+ case '@':
+ case '[':
+ case ']':
+ case '^':
+ case '_':
+ case '`':
+ case '{':
+ case '|':
+ case '}':
+ case '~':
+ return 1;
+ default:
+ return apr_isalnum(c);
+ }
+}
+
+static int skip_ws(link_ctx *ctx)
+{
+ char c;
+ while (ctx->i < ctx->slen
+ && (((c = ctx->s[ctx->i]) == ' ') || (c == '\t'))) {
+ ++ctx->i;
+ }
+ return (ctx->i < ctx->slen);
+}
+
+static int find_chr(link_ctx *ctx, char c, size_t *pidx)
+{
+ size_t j;
+ for (j = ctx->i; j < ctx->slen; ++j) {
+ if (ctx->s[j] == c) {
+ *pidx = j;
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static int read_chr(link_ctx *ctx, char c)
+{
+ if (ctx->i < ctx->slen && ctx->s[ctx->i] == c) {
+ ++ctx->i;
+ return 1;
+ }
+ return 0;
+}
+
+static char *mk_str(link_ctx *ctx, size_t end)
+{
+ if (ctx->i < end) {
+ return apr_pstrndup(ctx->pool, ctx->s + ctx->i, end - ctx->i);
+ }
+ return (char*)"";
+}
+
+static int read_qstring(link_ctx *ctx, const char **ps)
+{
+ if (skip_ws(ctx) && read_chr(ctx, '\"')) {
+ size_t end;
+ if (find_chr(ctx, '\"', &end)) {
+ *ps = mk_str(ctx, end);
+ ctx->i = end + 1;
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static int read_ptoken(link_ctx *ctx, const char **ps)
+{
+ if (skip_ws(ctx)) {
+ size_t i;
+ for (i = ctx->i; i < ctx->slen && ptoken_char(ctx->s[i]); ++i) {
+ /* nop */
+ }
+ if (i > ctx->i) {
+ *ps = mk_str(ctx, i);
+ ctx->i = i;
+ return 1;
+ }
+ }
+ return 0;
+}
+
+
+static int read_link(link_ctx *ctx)
+{
+ if (skip_ws(ctx) && read_chr(ctx, '<')) {
+ size_t end;
+ if (find_chr(ctx, '>', &end)) {
+ ctx->link = mk_str(ctx, end);
+ ctx->i = end + 1;
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static int read_pname(link_ctx *ctx, const char **pname)
+{
+ if (skip_ws(ctx)) {
+ size_t i;
+ for (i = ctx->i; i < ctx->slen && attr_char(ctx->s[i]); ++i) {
+ /* nop */
+ }
+ if (i > ctx->i) {
+ *pname = mk_str(ctx, i);
+ ctx->i = i;
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static int read_pvalue(link_ctx *ctx, const char **pvalue)
+{
+ if (skip_ws(ctx) && read_chr(ctx, '=')) {
+ if (read_qstring(ctx, pvalue) || read_ptoken(ctx, pvalue)) {
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static int read_param(link_ctx *ctx)
+{
+ if (skip_ws(ctx) && read_chr(ctx, ';')) {
+ const char *name, *value = "";
+ if (read_pname(ctx, &name)) {
+ read_pvalue(ctx, &value); /* value is optional */
+ apr_table_setn(ctx->params, name, value);
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static int read_sep(link_ctx *ctx)
+{
+ if (skip_ws(ctx) && read_chr(ctx, ',')) {
+ return 1;
+ }
+ return 0;
+}
+
+static void init_params(link_ctx *ctx)
+{
+ if (!ctx->params) {
+ ctx->params = apr_table_make(ctx->pool, 5);
+ }
+ else {
+ apr_table_clear(ctx->params);
+ }
+}
+
+static int same_authority(const h2_request *req, const apr_uri_t *uri)
+{
+ if (uri->scheme != NULL && strcmp(uri->scheme, req->scheme)) {
+ return 0;
+ }
+ if (uri->hostinfo != NULL && strcmp(uri->hostinfo, req->authority)) {
+ return 0;
+ }
+ return 1;
+}
+
+static int set_push_header(void *ctx, const char *key, const char *value)
+{
+ size_t klen = strlen(key);
+ if (H2_HD_MATCH_LIT("User-Agent", key, klen)
+ || H2_HD_MATCH_LIT("Accept", key, klen)
+ || H2_HD_MATCH_LIT("Accept-Encoding", key, klen)
+ || H2_HD_MATCH_LIT("Accept-Language", key, klen)
+ || H2_HD_MATCH_LIT("Cache-Control", key, klen)) {
+ apr_table_setn(ctx, key, value);
+ }
+ return 1;
+}
+
+static int has_param(link_ctx *ctx, const char *param)
+{
+ const char *p = apr_table_get(ctx->params, param);
+ return !!p;
+}
+
+static int has_relation(link_ctx *ctx, const char *rel)
+{
+ const char *s, *val = apr_table_get(ctx->params, "rel");
+ if (val) {
+ if (!strcmp(rel, val)) {
+ return 1;
+ }
+ s = ap_strstr_c(val, rel);
+ if (s && (s == val || s[-1] == ' ')) {
+ s += strlen(rel);
+ if (!*s || *s == ' ') {
+ return 1;
+ }
+ }
+ }
+ return 0;
+}
+
+static int add_push(link_ctx *ctx)
+{
+ /* so, we have read a Link header and need to decide
+ * if we transform it into a push.
+ */
+ if (has_relation(ctx, "preload") && !has_param(ctx, "nopush")) {
+ apr_uri_t uri;
+ if (apr_uri_parse(ctx->pool, ctx->link, &uri) == APR_SUCCESS) {
+ if (uri.path && same_authority(ctx->req, &uri)) {
+ char *path;
+ const char *method;
+ apr_table_t *headers;
+ h2_request *req;
+ h2_push *push;
+
+ /* We only want to generate pushes for resources in the
+ * same authority than the original request.
+ * icing: i think that is wise, otherwise we really need to
+ * check that the vhost/server is available and uses the same
+ * TLS (if any) parameters.
+ */
+ path = apr_uri_unparse(ctx->pool, &uri, APR_URI_UNP_OMITSITEPART);
+ push = apr_pcalloc(ctx->pool, sizeof(*push));
+ switch (ctx->push_policy) {
+ case H2_PUSH_HEAD:
+ method = "HEAD";
+ break;
+ default:
+ method = "GET";
+ break;
+ }
+ headers = apr_table_make(ctx->pool, 5);
+ apr_table_do(set_push_header, headers, ctx->req->headers, NULL);
+ req = h2_request_create(0, ctx->pool, method, ctx->req->scheme,
+ ctx->req->authority, path, headers);
+ /* atm, we do not push on pushes */
+ h2_request_end_headers(req, ctx->pool, 0);
+ push->req = req;
+ if (has_param(ctx, "critical")) {
+ h2_priority *prio = apr_pcalloc(ctx->pool, sizeof(*prio));
+ prio->dependency = H2_DEPENDANT_BEFORE;
+ push->priority = prio;
+ }
+ if (!ctx->pushes) {
+ ctx->pushes = apr_array_make(ctx->pool, 5, sizeof(h2_push*));
+ }
+ APR_ARRAY_PUSH(ctx->pushes, h2_push*) = push;
+ }
+ }
+ }
+ return 0;
+}
+
+static void inspect_link(link_ctx *ctx, const char *s, size_t slen)
+{
+ /* RFC 5988 <https://tools.ietf.org/html/rfc5988#section-6.2.1>
+ Link = "Link" ":" #link-value
+ link-value = "<" URI-Reference ">" *( ";" link-param )
+ link-param = ( ( "rel" "=" relation-types )
+ | ( "anchor" "=" <"> URI-Reference <"> )
+ | ( "rev" "=" relation-types )
+ | ( "hreflang" "=" Language-Tag )
+ | ( "media" "=" ( MediaDesc | ( <"> MediaDesc <"> ) ) )
+ | ( "title" "=" quoted-string )
+ | ( "title*" "=" ext-value )
+ | ( "type" "=" ( media-type | quoted-mt ) )
+ | ( link-extension ) )
+ link-extension = ( parmname [ "=" ( ptoken | quoted-string ) ] )
+ | ( ext-name-star "=" ext-value )
+ ext-name-star = parmname "*" ; reserved for RFC2231-profiled
+ ; extensions. Whitespace NOT
+ ; allowed in between.
+ ptoken = 1*ptokenchar
+ ptokenchar = "!" | "#" | "$" | "%" | "&" | "'" | "("
+ | ")" | "*" | "+" | "-" | "." | "/" | DIGIT
+ | ":" | "<" | "=" | ">" | "?" | "@" | ALPHA
+ | "[" | "]" | "^" | "_" | "`" | "{" | "|"
+ | "}" | "~"
+ media-type = type-name "/" subtype-name
+ quoted-mt = <"> media-type <">
+ relation-types = relation-type
+ | <"> relation-type *( 1*SP relation-type ) <">
+ relation-type = reg-rel-type | ext-rel-type
+ reg-rel-type = LOALPHA *( LOALPHA | DIGIT | "." | "-" )
+ ext-rel-type = URI
+
+ and from <https://tools.ietf.org/html/rfc5987>
+ parmname = 1*attr-char
+ attr-char = ALPHA / DIGIT
+ / "!" / "#" / "$" / "&" / "+" / "-" / "."
+ / "^" / "_" / "`" / "|" / "~"
+ */
+
+ ctx->s = s;
+ ctx->slen = slen;
+ ctx->i = 0;
+
+ while (read_link(ctx)) {
+ init_params(ctx);
+ while (read_param(ctx)) {
+ /* nop */
+ }
+ add_push(ctx);
+ if (!read_sep(ctx)) {
+ break;
+ }
+ }
+}
+
+static int head_iter(void *ctx, const char *key, const char *value)
+{
+ if (!ap_cstr_casecmp("link", key)) {
+ inspect_link(ctx, value, strlen(value));
+ }
+ return 1;
+}
+
+#if AP_HAS_RESPONSE_BUCKETS
+apr_array_header_t *h2_push_collect(apr_pool_t *p,
+ const struct h2_request *req,
+ apr_uint32_t push_policy,
+ const ap_bucket_response *res)
+#else
+apr_array_header_t *h2_push_collect(apr_pool_t *p,
+ const struct h2_request *req,
+ apr_uint32_t push_policy,
+ const struct h2_headers *res)
+#endif
+{
+ if (req && push_policy != H2_PUSH_NONE) {
+ /* Collect push candidates from the request/response pair.
+ *
+ * One source for pushes are "rel=preload" link headers
+ * in the response.
+ *
+ * TODO: This may be extended in the future by hooks or callbacks
+ * where other modules can provide push information directly.
+ */
+ if (res->headers) {
+ link_ctx ctx;
+
+ memset(&ctx, 0, sizeof(ctx));
+ ctx.req = req;
+ ctx.push_policy = push_policy;
+ ctx.pool = p;
+
+ apr_table_do(head_iter, &ctx, res->headers, NULL);
+ if (ctx.pushes) {
+ apr_table_setn(res->headers, "push-policy",
+ policy_str(push_policy));
+ }
+ return ctx.pushes;
+ }
+ }
+ return NULL;
+}
+
+#define GCSLOG_LEVEL APLOG_TRACE1
+
+typedef struct h2_push_diary_entry {
+ apr_uint64_t hash;
+} h2_push_diary_entry;
+
+
+#ifdef H2_OPENSSL
+static void sha256_update(EVP_MD_CTX *ctx, const char *s)
+{
+ EVP_DigestUpdate(ctx, s, strlen(s));
+}
+
+static void calc_sha256_hash(h2_push_diary *diary, apr_uint64_t *phash, h2_push *push)
+{
+ EVP_MD_CTX *md;
+ apr_uint64_t val;
+ unsigned char hash[EVP_MAX_MD_SIZE];
+ unsigned len, i;
+
+ md = EVP_MD_CTX_create();
+ ap_assert(md != NULL);
+
+ i = EVP_DigestInit_ex(md, EVP_sha256(), NULL);
+ ap_assert(i == 1);
+ sha256_update(md, push->req->scheme);
+ sha256_update(md, "://");
+ sha256_update(md, push->req->authority);
+ sha256_update(md, push->req->path);
+ EVP_DigestFinal(md, hash, &len);
+ EVP_MD_CTX_destroy(md);
+
+ val = 0;
+ for (i = 0; i != len; ++i)
+ val = val * 256 + hash[i];
+ *phash = val >> (64 - diary->mask_bits);
+}
+#endif
+
+
+static unsigned int val_apr_hash(const char *str)
+{
+ apr_ssize_t len = (apr_ssize_t)strlen(str);
+ return apr_hashfunc_default(str, &len);
+}
+
+static void calc_apr_hash(h2_push_diary *diary, apr_uint64_t *phash, h2_push *push)
+{
+ apr_uint64_t val;
+ (void)diary;
+#if APR_UINT64_MAX > UINT_MAX
+ val = ((apr_uint64_t)(val_apr_hash(push->req->scheme)) << 32);
+ val ^= ((apr_uint64_t)(val_apr_hash(push->req->authority)) << 16);
+ val ^= val_apr_hash(push->req->path);
+#else
+ val = val_apr_hash(push->req->scheme);
+ val ^= val_apr_hash(push->req->authority);
+ val ^= val_apr_hash(push->req->path);
+#endif
+ *phash = val;
+}
+
+static apr_int32_t ceil_power_of_2(apr_int32_t n)
+{
+ if (n <= 2) return 2;
+ --n;
+ n |= n >> 1;
+ n |= n >> 2;
+ n |= n >> 4;
+ n |= n >> 8;
+ n |= n >> 16;
+ return ++n;
+}
+
+static h2_push_diary *diary_create(apr_pool_t *p, h2_push_digest_type dtype,
+ int N)
+{
+ h2_push_diary *diary = NULL;
+
+ if (N > 0) {
+ diary = apr_pcalloc(p, sizeof(*diary));
+
+ diary->NMax = ceil_power_of_2(N);
+ diary->N = diary->NMax;
+ /* the mask we use in value comparison depends on where we got
+ * the values from. If we calculate them ourselves, we can use
+ * the full 64 bits.
+ * If we set the diary via a compressed golomb set, we have less
+ * relevant bits and need to use a smaller mask. */
+ diary->mask_bits = 64;
+ /* grows by doubling, start with a power of 2 */
+ diary->entries = apr_array_make(p, 16, sizeof(h2_push_diary_entry));
+
+ switch (dtype) {
+#ifdef H2_OPENSSL
+ case H2_PUSH_DIGEST_SHA256:
+ diary->dtype = H2_PUSH_DIGEST_SHA256;
+ diary->dcalc = calc_sha256_hash;
+ break;
+#endif /* ifdef H2_OPENSSL */
+ default:
+ diary->dtype = H2_PUSH_DIGEST_APR_HASH;
+ diary->dcalc = calc_apr_hash;
+ break;
+ }
+ }
+
+ return diary;
+}
+
+h2_push_diary *h2_push_diary_create(apr_pool_t *p, int N)
+{
+ return diary_create(p, H2_PUSH_DIGEST_SHA256, N);
+}
+
+static int h2_push_diary_find(h2_push_diary *diary, apr_uint64_t hash)
+{
+ if (diary) {
+ h2_push_diary_entry *e;
+ int i;
+
+ /* search from the end, where the last accessed digests are */
+ for (i = diary->entries->nelts-1; i >= 0; --i) {
+ e = &APR_ARRAY_IDX(diary->entries, i, h2_push_diary_entry);
+ if (e->hash == hash) {
+ return i;
+ }
+ }
+ }
+ return -1;
+}
+
+static void move_to_last(h2_push_diary *diary, apr_size_t idx)
+{
+ h2_push_diary_entry *entries = (h2_push_diary_entry*)diary->entries->elts;
+ h2_push_diary_entry e;
+ apr_size_t lastidx;
+
+ /* Move an existing entry to the last place */
+ if (diary->entries->nelts <= 0)
+ return;
+
+ /* move entry[idx] to the end */
+ lastidx = diary->entries->nelts - 1;
+ if (idx < lastidx) {
+ e = entries[idx];
+ memmove(entries+idx, entries+idx+1, sizeof(h2_push_diary_entry) * (lastidx - idx));
+ entries[lastidx] = e;
+ }
+}
+
+static void remove_first(h2_push_diary *diary)
+{
+ h2_push_diary_entry *entries = (h2_push_diary_entry*)diary->entries->elts;
+ int lastidx;
+
+ /* move remaining entries to index 0 */
+ lastidx = diary->entries->nelts - 1;
+ if (lastidx > 0) {
+ --diary->entries->nelts;
+ memmove(entries, entries+1, sizeof(h2_push_diary_entry) * diary->entries->nelts);
+ }
+}
+
+static void h2_push_diary_append(h2_push_diary *diary, h2_push_diary_entry *e)
+{
+ while (diary->entries->nelts >= diary->N) {
+ remove_first(diary);
+ }
+ /* append a new diary entry at the end */
+ APR_ARRAY_PUSH(diary->entries, h2_push_diary_entry) = *e;
+ /* Intentional no APLOGNO */
+ ap_log_perror(APLOG_MARK, GCSLOG_LEVEL, 0, diary->entries->pool,
+ "push_diary_append: %"APR_UINT64_T_HEX_FMT, e->hash);
+}
+
+apr_array_header_t *h2_push_diary_update(h2_session *session, apr_array_header_t *pushes)
+{
+ apr_array_header_t *npushes = pushes;
+ h2_push_diary_entry e;
+ int i, idx;
+
+ if (session->push_diary && pushes) {
+ npushes = NULL;
+
+ for (i = 0; i < pushes->nelts; ++i) {
+ h2_push *push;
+
+ push = APR_ARRAY_IDX(pushes, i, h2_push*);
+ session->push_diary->dcalc(session->push_diary, &e.hash, push);
+ idx = h2_push_diary_find(session->push_diary, e.hash);
+ if (idx >= 0) {
+ /* Intentional no APLOGNO */
+ ap_log_cerror(APLOG_MARK, GCSLOG_LEVEL, 0, session->c1,
+ "push_diary_update: already there PUSH %s", push->req->path);
+ move_to_last(session->push_diary, (apr_size_t)idx);
+ }
+ else {
+ /* Intentional no APLOGNO */
+ ap_log_cerror(APLOG_MARK, GCSLOG_LEVEL, 0, session->c1,
+ "push_diary_update: adding PUSH %s", push->req->path);
+ if (!npushes) {
+ npushes = apr_array_make(pushes->pool, 5, sizeof(h2_push_diary_entry*));
+ }
+ APR_ARRAY_PUSH(npushes, h2_push*) = push;
+ h2_push_diary_append(session->push_diary, &e);
+ }
+ }
+ }
+ return npushes;
+}
+
+#if AP_HAS_RESPONSE_BUCKETS
+apr_array_header_t *h2_push_collect_update(struct h2_stream *stream,
+ const struct h2_request *req,
+ const ap_bucket_response *res)
+#else
+apr_array_header_t *h2_push_collect_update(struct h2_stream *stream,
+ const struct h2_request *req,
+ const struct h2_headers *res)
+#endif
+{
+ apr_array_header_t *pushes;
+
+ pushes = h2_push_collect(stream->pool, req, stream->push_policy, res);
+ return h2_push_diary_update(stream->session, pushes);
+}
+
+typedef struct {
+ h2_push_diary *diary;
+ unsigned char log2p;
+ int mask_bits;
+ int delta_bits;
+ int fixed_bits;
+ apr_uint64_t fixed_mask;
+ apr_pool_t *pool;
+ unsigned char *data;
+ apr_size_t datalen;
+ apr_size_t offset;
+ unsigned int bit;
+ apr_uint64_t last;
+} gset_encoder;
+
+static int cmp_puint64(const void *p1, const void *p2)
+{
+ const apr_uint64_t *pu1 = p1, *pu2 = p2;
+ return (*pu1 > *pu2)? 1 : ((*pu1 == *pu2)? 0 : -1);
+}
+
+/* in golomb bit stream encoding, bit 0 is the 8th of the first char, or
+ * more generally:
+ * char(bit/8) & cbit_mask[(bit % 8)]
+ */
+static unsigned char cbit_mask[] = {
+ 0x80u,
+ 0x40u,
+ 0x20u,
+ 0x10u,
+ 0x08u,
+ 0x04u,
+ 0x02u,
+ 0x01u,
+};
+
+static apr_status_t gset_encode_bit(gset_encoder *encoder, int bit)
+{
+ if (++encoder->bit >= 8) {
+ if (++encoder->offset >= encoder->datalen) {
+ apr_size_t nlen = encoder->datalen*2;
+ unsigned char *ndata = apr_pcalloc(encoder->pool, nlen);
+ if (!ndata) {
+ return APR_ENOMEM;
+ }
+ memcpy(ndata, encoder->data, encoder->datalen);
+ encoder->data = ndata;
+ encoder->datalen = nlen;
+ }
+ encoder->bit = 0;
+ encoder->data[encoder->offset] = 0xffu;
+ }
+ if (!bit) {
+ encoder->data[encoder->offset] &= ~cbit_mask[encoder->bit];
+ }
+ return APR_SUCCESS;
+}
+
+static apr_status_t gset_encode_next(gset_encoder *encoder, apr_uint64_t pval)
+{
+ apr_uint64_t delta, flex_bits;
+ apr_status_t status = APR_SUCCESS;
+ int i;
+
+ delta = pval - encoder->last;
+ encoder->last = pval;
+ flex_bits = (delta >> encoder->fixed_bits);
+ /* Intentional no APLOGNO */
+ ap_log_perror(APLOG_MARK, GCSLOG_LEVEL, 0, encoder->pool,
+ "h2_push_diary_enc: val=%"APR_UINT64_T_HEX_FMT", delta=%"
+ APR_UINT64_T_HEX_FMT" flex_bits=%"APR_UINT64_T_FMT", "
+ ", fixed_bits=%d, fixed_val=%"APR_UINT64_T_HEX_FMT,
+ pval, delta, flex_bits, encoder->fixed_bits, delta&encoder->fixed_mask);
+ for (; flex_bits != 0; --flex_bits) {
+ status = gset_encode_bit(encoder, 1);
+ if (status != APR_SUCCESS) {
+ return status;
+ }
+ }
+ status = gset_encode_bit(encoder, 0);
+ if (status != APR_SUCCESS) {
+ return status;
+ }
+
+ for (i = encoder->fixed_bits-1; i >= 0; --i) {
+ status = gset_encode_bit(encoder, (delta >> i) & 1);
+ if (status != APR_SUCCESS) {
+ return status;
+ }
+ }
+ return APR_SUCCESS;
+}
+
+/**
+ * Get a cache digest as described in
+ * https://datatracker.ietf.org/doc/draft-kazuho-h2-cache-digest/
+ * from the contents of the push diary.
+ *
+ * @param diary the diary to calculdate the digest from
+ * @param p the pool to use
+ * @param pdata on successful return, the binary cache digest
+ * @param plen on successful return, the length of the binary data
+ */
+apr_status_t h2_push_diary_digest_get(h2_push_diary *diary, apr_pool_t *pool,
+ int maxP, const char *authority,
+ const char **pdata, apr_size_t *plen)
+{
+ int nelts, N;
+ unsigned char log2n, log2pmax;
+ gset_encoder encoder;
+ apr_uint64_t *hashes;
+ apr_size_t hash_count, i;
+
+ nelts = diary->entries->nelts;
+ N = ceil_power_of_2(nelts);
+ log2n = h2_log2(N);
+
+ /* Now log2p is the max number of relevant bits, so that
+ * log2p + log2n == mask_bits. We can use a lower log2p
+ * and have a shorter set encoding...
+ */
+ log2pmax = h2_log2(ceil_power_of_2(maxP));
+
+ memset(&encoder, 0, sizeof(encoder));
+ encoder.diary = diary;
+ encoder.log2p = H2MIN(diary->mask_bits - log2n, log2pmax);
+ encoder.mask_bits = log2n + encoder.log2p;
+ encoder.delta_bits = diary->mask_bits - encoder.mask_bits;
+ encoder.fixed_bits = encoder.log2p;
+ encoder.fixed_mask = 1;
+ encoder.fixed_mask = (encoder.fixed_mask << encoder.fixed_bits) - 1;
+ encoder.pool = pool;
+ encoder.datalen = 512;
+ encoder.data = apr_pcalloc(encoder.pool, encoder.datalen);
+
+ encoder.data[0] = log2n;
+ encoder.data[1] = encoder.log2p;
+ encoder.offset = 1;
+ encoder.bit = 8;
+ encoder.last = 0;
+
+ /* Intentional no APLOGNO */
+ ap_log_perror(APLOG_MARK, GCSLOG_LEVEL, 0, pool,
+ "h2_push_diary_digest_get: %d entries, N=%d, log2n=%d, "
+ "mask_bits=%d, enc.mask_bits=%d, delta_bits=%d, enc.log2p=%d, authority=%s",
+ (int)nelts, (int)N, (int)log2n, diary->mask_bits,
+ (int)encoder.mask_bits, (int)encoder.delta_bits,
+ (int)encoder.log2p, authority);
+
+ if (!authority || !diary->authority
+ || !strcmp("*", authority) || !strcmp(diary->authority, authority)) {
+ hash_count = diary->entries->nelts;
+ hashes = apr_pcalloc(encoder.pool, hash_count);
+ for (i = 0; i < hash_count; ++i) {
+ hashes[i] = ((&APR_ARRAY_IDX(diary->entries, i, h2_push_diary_entry))->hash
+ >> encoder.delta_bits);
+ }
+
+ qsort(hashes, hash_count, sizeof(apr_uint64_t), cmp_puint64);
+ for (i = 0; i < hash_count; ++i) {
+ if (!i || (hashes[i] != hashes[i-1])) {
+ gset_encode_next(&encoder, hashes[i]);
+ }
+ }
+ /* Intentional no APLOGNO */
+ ap_log_perror(APLOG_MARK, GCSLOG_LEVEL, 0, pool,
+ "h2_push_diary_digest_get: golomb compressed hashes, %d bytes",
+ (int)encoder.offset + 1);
+ }
+ *pdata = (const char *)encoder.data;
+ *plen = encoder.offset + 1;
+
+ return APR_SUCCESS;
+}
+