/
Prefetch.cc
2233 lines (1816 loc) · 65 KB
/
Prefetch.cc
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/** @file
A brief file description
@section license License
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 "Prefetch.h"
#include "HdrUtils.h"
#include "HttpCompat.h"
#include <records/I_RecHttp.h>
#include <ts/IpMapConf.h>
#ifdef PREFETCH
struct html_tag prefetch_allowable_html_tags[] = {
// All embedded objects (fetched by the browser without requiring a click)
// should be here
//{ "a", "href"}, /* NOT USED */
{"img", "src"},
{"body", "background"},
{"frame", "src"},
{"fig", "src"},
{"applet", "code"},
{"script", "src"},
{"embed", "src"},
{"td", "background"},
{"base", "href"}, // special handling
{"meta", "content"}, // special handling
//{ "area", "href"}, //used for testing parser
{"input", "src"},
{"link", "href"},
{NULL, NULL}};
// this attribute table is hard coded. It has to be the same size as
// the prefetch_allowable_html_tags table
struct html_tag prefetch_allowable_html_attrs[] = {
{NULL, NULL},
{NULL, NULL},
{NULL, NULL},
{NULL, NULL},
{NULL, NULL},
{NULL, NULL},
{NULL, NULL},
{NULL, NULL},
{NULL, NULL},
{NULL, NULL},
{NULL, NULL},
{"rel", "stylesheet"}, // We want to prefetch the .css files that are common; make sure this matches {"link", "href"}
{NULL, NULL}};
static const char *PREFETCH_FIELD_RECURSION;
static int PREFETCH_FIELD_LEN_RECURSION;
PrefetchProcessor prefetchProcessor;
KeepAliveConnTable *g_conn_table;
static int prefetch_udp_fd = 0;
static int32_t udp_seq_no;
TSPrefetchBlastData const UDP_BLAST_DATA = {TS_PREFETCH_UDP_BLAST};
TSPrefetchBlastData const TCP_BLAST_DATA = {TS_PREFETCH_TCP_BLAST};
#define PrefetchEstablishStaticConfigStringAlloc(_ix, _n) \
REC_EstablishStaticConfigStringAlloc(_ix, _n); \
REC_RegisterConfigUpdateFunc(_n, prefetch_config_cb, NULL)
#define PrefetchEstablishStaticConfigLongLong(_ix, _n) \
REC_EstablishStaticConfigInteger(_ix, _n); \
REC_RegisterConfigUpdateFunc(_n, prefetch_config_cb, NULL)
#define PrefetchEstablishStaticConfigFloat(_ix, _n) \
REC_EstablishStaticConfigFloat(_ix, _n); \
REC_RegisterConfigUpdateFunc(_n, prefetch_config_cb, NULL)
#define PrefetchEstablishStaticConfigByte(_ix, _n) \
REC_EstablishStaticConfigByte(_ix, _n); \
REC_RegisterConfigUpdateFunc(_n, prefetch_config_cb, NULL)
static inline uint32_t
get_udp_seq_no()
{
return ink_atomic_increment(&udp_seq_no, 1);
}
static inline void
setup_udp_header(char *header, uint32_t seq_no, uint32_t pkt_no, bool last_pkt)
{
uint32_t *hdr = (uint32_t *)header;
hdr[0] = 0;
hdr[1] = htonl(seq_no);
hdr[2] = htonl((last_pkt ? PRELOAD_UDP_LAST_PKT_FLAG : 0) | (pkt_no & PRELOAD_UDP_PKT_NUM_MASK));
}
static inline void
setup_object_header(char *header, int64_t size, bool url_promise)
{
uint32_t *hdr = (uint32_t *)header;
hdr[0] = htonl(size);
hdr[1] = 0; // we are not pinning
hdr[2] = (url_promise) ? htonl(PRELOAD_HDR_URL_PROMISE_FLAG) : 0;
}
// Raghu's info about domain extraction
inline const char *
findDomainFromHost(const char *host, int host_len, bool &no_dot)
{
const char *h_cur = host + host_len - 1;
if (host_len > 4) {
// checking for .com .edu .net .org .gov .mil .int
h_cur = host + host_len - 4;
if (*h_cur == '.') {
// convert to lower case
char c3 = *(h_cur + 1);
char c1 = (c3 >= 'A' && c3 <= 'Z') ? (c3 + 'a' - 'A') : c3;
c3 = *(h_cur + 2);
char c2 = (c3 >= 'A' && c3 <= 'Z') ? (c3 + 'a' - 'A') : c3;
c3 = *(h_cur + 3);
if (c3 >= 'A' && c3 <= 'Z')
c3 += 'a' - 'A';
// there is a high posibility that the postfix is one of the seven
if ((c1 == 'c' && c2 == 'o' && c3 == 'm') || (c1 == 'e' && c2 == 'd' && c3 == 'u') || (c1 == 'n' && c2 == 'e' && c3 == 't') ||
(c1 == 'o' && c2 == 'r' && c3 == 'g') || (c1 == 'g' && c2 == 'o' && c3 == 'v') || (c1 == 'm' && c2 == 'i' && c3 == 'l') ||
(c1 == 'i' && c2 == 'n' && c3 == 't')) {
h_cur--;
while (h_cur != host) {
if (*h_cur == '.')
break;
h_cur--;
}
if (h_cur != host) {
// found a '.'
h_cur++;
} else if (*h_cur == '.')
return NULL;
return h_cur;
}
}
}
// for non-top level domains, require the first char is not '.' and
// two '.' minimum, e.g. abc.va.us
int num_dots = 0;
while (h_cur != host) {
if (*h_cur == '.') {
num_dots++;
if (num_dots == 3) {
h_cur++;
return h_cur;
}
}
h_cur--;
}
if (num_dots < 2 || *host == '.') {
if (num_dots == 0)
no_dot = true;
return NULL;
} else
return h_cur;
}
static int
normalize_url(char *url, int *len)
{
/* returns > 0 if the url is modified */
char *p, *root, *end = url + len[0];
int modified = 0; // most of the time we don't modify the url.
enum {
NONE,
FIRST_DOT,
SECOND_DOT,
SLASH,
} state;
if (!(p = strstr(url, "://")))
return -1;
p += 3;
// get to the first slash:
root = (p = strchr(p, '/'));
if (!root)
return 0;
state = SLASH;
while (++p <= end) {
switch (p[0]) {
case '\0':
case '/':
switch (state) {
case SLASH: // "//" => "/"
if (p[0]) {
modified = 1;
p[0] = 0;
}
break;
case FIRST_DOT: // "/./" => "/"
modified = 1;
p[0] = (p[-1] = 0);
break;
case SECOND_DOT: { // "/dir/../" or "/../" => "/"
modified = 1;
p[0] = (p[-1] = (p[-2] = 0));
char *dir = p - 3;
while (dir[0] == 0 && dir > root)
dir--;
ink_assert(dir[0] == '/');
if (dir > root && dir[0] == '/') {
do {
dir[0] = 0;
} while (*--dir != '/');
}
} break;
default: /* NONE */
;
}; /* end of switch (state) */
state = SLASH;
break;
case '.':
switch (state) {
case SLASH:
state = FIRST_DOT;
break;
case FIRST_DOT:
state = SECOND_DOT;
break;
default:
state = NONE;
}
break;
default:
state = NONE;
}
}
if (modified) {
// ok, now remove all the 0s in between
p = ++root;
while (p < end) {
if (p[0]) {
*root++ = p[0];
} else
len[0]--;
p++;
}
*root = 0;
return 1;
}
return 0;
}
static PrefetchConfiguration *prefetch_config;
ClassAllocator<PrefetchUrlEntry> prefetchUrlEntryAllocator("prefetchUrlEntryAllocator");
#define IS_STATUS_REDIRECT(status) \
(prefetch_config->redirection > 0 && \
(((status) == HTTP_STATUS_MOVED_PERMANENTLY) || ((status) == HTTP_STATUS_MOVED_TEMPORARILY) || \
((status) == HTTP_STATUS_SEE_OTHER) || (((status) == HTTP_STATUS_TEMPORARY_REDIRECT))))
struct PrefetchConfigCont;
typedef int (PrefetchConfigCont::*PrefetchConfigContHandler)(int, void *);
struct PrefetchConfigCont : public Continuation {
public:
PrefetchConfigCont(ProxyMutex *m) : Continuation(m)
{
SET_HANDLER((PrefetchConfigContHandler)&PrefetchConfigCont::conf_update_handler);
}
int conf_update_handler(int event, void *edata);
};
static Ptr<ProxyMutex> prefetch_reconfig_mutex;
/** Used to free old PrefetchConfiguration data. */
struct PrefetchConfigFreerCont;
typedef int (PrefetchConfigFreerCont::*PrefetchConfigFreerContHandler)(int, void *);
struct PrefetchConfigFreerCont : public Continuation {
PrefetchConfiguration *p;
int
freeEvent(int /* event ATS_UNUSED */, Event * /* e ATS_UNUSED */)
{
Debug("Prefetch", "Deleting old Prefetch config after change");
delete p;
delete this;
return EVENT_DONE;
}
PrefetchConfigFreerCont(PrefetchConfiguration *ap) : Continuation(new_ProxyMutex()), p(ap)
{
SET_HANDLER((PrefetchConfigFreerContHandler)&PrefetchConfigFreerCont::freeEvent);
}
};
int
PrefetchConfigCont::conf_update_handler(int /* event ATS_UNUSED */, void * /* edata ATS_UNUSED */)
{
Debug("Prefetch", "Handling Prefetch config change");
PrefetchConfiguration *new_prefetch_config = new PrefetchConfiguration;
if (new_prefetch_config->readConfiguration() == 0) {
// switch the prefetch_config
eventProcessor.schedule_in(new PrefetchConfigFreerCont(prefetch_config), PREFETCH_CONFIG_UPDATE_TIMEOUT, ET_TASK);
ink_atomic_swap(&prefetch_config, new_prefetch_config);
} else {
// new config construct error, we should not use the new config
Debug("Prefetch", "New config in ERROR, keeping the old config");
eventProcessor.schedule_in(new PrefetchConfigFreerCont(new_prefetch_config), PREFETCH_CONFIG_UPDATE_TIMEOUT, ET_TASK);
}
delete this;
return EVENT_DONE;
}
static int
prefetch_config_cb(const char * /* name ATS_UNUSED */, RecDataT /* data_type ATS_UNUSED */, RecData /* data ATS_UNUSED */,
void * /* cookie ATS_UNUSED */)
{
INK_MEMORY_BARRIER;
eventProcessor.schedule_in(new PrefetchConfigCont(prefetch_reconfig_mutex), HRTIME_SECONDS(1), ET_TASK);
return 0;
}
PrefetchTransform::PrefetchTransform(HttpSM *sm, HTTPHdr *resp)
: INKVConnInternal(NULL, reinterpret_cast<TSMutex>((ProxyMutex *)sm->mutex)), m_output_buf(NULL), m_output_vio(NULL), m_sm(sm)
{
refcount_inc();
HTTPHdr *request = &sm->t_state.hdr_info.client_request;
url = request->url_get()->string_get(NULL, NULL);
html_parser.Init(url, prefetch_config->html_tags_table, prefetch_config->html_attrs_table);
SET_HANDLER(&PrefetchTransform::handle_event);
Debug("PrefetchParser", "Created: transform for %s\n", url);
memset(&hash_table[0], 0, HASH_TABLE_LENGTH * sizeof(hash_table[0]));
udp_url_list = blasterUrlListAllocator.alloc();
udp_url_list->init(UDP_BLAST_DATA, prefetch_config->url_buffer_timeout, prefetch_config->url_buffer_size);
tcp_url_list = blasterUrlListAllocator.alloc();
tcp_url_list->init(TCP_BLAST_DATA, prefetch_config->url_buffer_timeout, prefetch_config->url_buffer_size);
// extract domain
host_start = request->url_get()->host_get(&host_len);
if (!host_start || !host_len)
host_start = request->value_get(MIME_FIELD_HOST, MIME_LEN_HOST, &host_len);
no_dot_in_host = false;
if (host_start && host_len) {
domain_end = host_start + (host_len - 1);
domain_start = findDomainFromHost(host_start, host_len, no_dot_in_host);
} else
domain_start = 0;
// Check for redirection and redirect get the redirect URL before parsing the
// body of the redirect.
redirect(resp);
}
PrefetchTransform::~PrefetchTransform()
{
// inform the lists that there no more urls left.
this_ethread()->schedule_imm_local(udp_url_list);
this_ethread()->schedule_imm_local(tcp_url_list);
Debug("PrefetchParserURLs", "Unique URLs 0x%p (%s):\n", this, url);
int nurls = 0;
for (int i = 0; i < HASH_TABLE_LENGTH; i++) {
PrefetchUrlEntry *e = hash_table[i];
while (e) {
Debug("PrefetchParserURLs", "(0x%p) %d: %s\n", this, i, e->url);
nurls++;
PrefetchUrlEntry *next = e->hash_link;
e->free();
e = next;
}
}
Debug("PrefetchParserURLs", "Number of embedded objects extracted for %s: %d\n", url, nurls);
if (m_output_buf)
free_MIOBuffer(m_output_buf);
ats_free(url);
}
int
PrefetchTransform::handle_event(int event, void *edata)
{
handle_event_count(event);
if (m_closed) {
if (m_deletable) {
Debug("PrefetchParser", "PrefetchTransform free(): %" PRId64 "", m_output_vio ? m_output_vio->ndone : 0);
if (m_output_buf) {
free_MIOBuffer(m_output_buf);
m_output_buf = 0;
}
Debug("Prefetch", "Freeing after closed %p", this);
free();
}
} else {
switch (event) {
case VC_EVENT_ERROR:
m_write_vio._cont->handleEvent(VC_EVENT_ERROR, &m_write_vio);
break;
case VC_EVENT_WRITE_COMPLETE:
Debug("Prefetch", "got write_complete %p", this);
ink_assert(m_output_vio == (VIO *)edata);
ink_assert(m_write_vio.ntodo() == 0);
m_output_vc->do_io_shutdown(IO_SHUTDOWN_WRITE);
break;
case VC_EVENT_WRITE_READY:
default: {
if (!m_output_vio) {
m_output_buf = new_empty_MIOBuffer();
m_output_reader = m_output_buf->alloc_reader();
m_output_vio = m_output_vc->do_io_write(this, INT64_MAX, m_output_reader);
}
// If the write vio is null, it means it doesn't want
// to get anymore event (WRITE_READY or WRITE_COMPLETE)
// It also means we're done reading
if (m_write_vio.op == VIO::NONE) {
m_output_vio->nbytes = m_write_vio.ndone;
m_output_vio->reenable();
return 0;
}
ink_assert(m_output_vc != NULL);
MUTEX_TRY_LOCK(trylock, m_write_vio.mutex, this_ethread());
if (!trylock.is_locked()) {
retry(10);
return 0;
}
if (m_closed) {
return 0;
}
int64_t towrite = m_write_vio.ntodo();
if (towrite > 0) {
IOBufferReader *buf_reader = m_write_vio.get_reader();
int64_t avail = buf_reader->read_avail();
if (towrite > avail) {
towrite = avail;
}
if (towrite > 0) {
Debug("PrefetchParser", "handle_event() "
"writing %" PRId64 " bytes to output",
towrite);
// Debug("PrefetchParser", "Read avail before = %d\n", avail);
m_output_buf->write(buf_reader, towrite);
parse_data(buf_reader);
// buf_reader->consume (towrite);
m_write_vio.ndone += towrite;
}
}
if (m_write_vio.ntodo() > 0) {
if (towrite > 0) {
m_output_vio->reenable();
m_write_vio._cont->handleEvent(VC_EVENT_WRITE_READY, &m_write_vio);
}
} else {
m_output_vio->nbytes = m_write_vio.ndone;
m_output_vio->reenable();
m_write_vio._cont->handleEvent(VC_EVENT_WRITE_COMPLETE, &m_write_vio);
}
break;
}
}
}
return 0;
}
int
PrefetchTransform::redirect(HTTPHdr *resp)
{
HTTPHdr *req = NULL;
int response_status = 0;
char *req_url = NULL;
char *redirect_url = NULL;
/* Check for responses validity. If the response is valid, determine the status of the response.
We need to find out if there was a redirection (301, 302, 303, 307).
*/
if ((resp != NULL) && (resp->valid())) {
response_status = resp->status_get();
/* OK, so we got the response. Now if the response is a redirect we have to check if we also
got a Location: header. This indicates the new location where our object is located.
If refirect_url was not found, letz falter back to just a recursion. Since
we might find the url in the body.
*/
if (resp->presence(MIME_PRESENCE_LOCATION)) {
int redirect_url_len = 0;
const char *tmp_url = resp->value_get(MIME_FIELD_LOCATION, MIME_LEN_LOCATION, &redirect_url_len);
redirect_url = (char *)alloca(redirect_url_len + 1);
ink_strlcpy(redirect_url, tmp_url, redirect_url_len + 1);
Debug("PrefetchTransform", "redirect_url = %s\n", redirect_url);
} else {
response_status = -1;
}
} else {
response_status = -1;
}
if (IS_STATUS_REDIRECT(response_status)) {
if (redirect_url) {
req = &m_sm->t_state.hdr_info.client_request;
req_url = req->url_get()->string_get(NULL, NULL);
Debug("PrefetchTransform", "Received response status = %d\n", response_status);
Debug("PrefetchTransform", "Redirect from request = %s\n", req_url);
int location_len = strlen(redirect_url);
Debug("PrefetchTransform", "Redirect url to HTTP Hdr Location: \'%s\'\n", redirect_url);
if (strncmp(redirect_url, req_url, location_len) == 0) {
Debug("PrefetchTransform", "'%s' -> '%s' - Could be a loop. Discontinuing this path.\n", req_url, redirect_url);
ats_free(req_url);
return 0;
}
PrefetchUrlEntry *entry = hash_add(redirect_url);
if (!entry) {
Debug("PrefetchParserURLs", "Ignoring duplicate url '%s'", redirect_url);
ats_free(req_url);
return 0;
}
Debug("PrefetchTransform", "Found embedded URL: %s", redirect_url);
entry->req_ip = m_sm->t_state.client_info.addr;
PrefetchBlaster *blaster = prefetchBlasterAllocator.alloc();
blaster->init(entry, &m_sm->t_state.hdr_info.client_request, this);
ats_free(req_url);
}
}
return 0;
}
int
PrefetchTransform::parse_data(IOBufferReader *reader)
{
char *url_start = NULL, *url_end = NULL;
while (html_parser.ParseHtml(reader, &url_start, &url_end)) {
PrefetchUrlEntry *entry = hash_add(url_start);
if (!entry) {
// Debug("PrefetchParserURLs", "Duplicate URL: %s", url_start);
continue;
}
// Debug("PrefetchParserURLs", "Found embedded URL: %s", url_start);
ats_ip_copy(&entry->req_ip, &m_sm->t_state.client_info.addr);
PrefetchBlaster *blaster = prefetchBlasterAllocator.alloc();
blaster->init(entry, &m_sm->t_state.hdr_info.client_request, this);
}
return 0;
}
PrefetchUrlEntry *
PrefetchTransform::hash_add(char *s)
{
uint32_t index = 0;
int str_len = strlen(s);
if (normalize_url(s, &str_len) > 0)
Debug("PrefetchParserURLs", "Normalized URL: %s\n", s);
INK_MD5 hash;
MD5Context().hash_immediate(hash, s, str_len);
index = hash.slice32(1) % HASH_TABLE_LENGTH;
PrefetchUrlEntry **e = &hash_table[index];
for (; *e; e = &(*e)->hash_link)
if (strcmp((*e)->url, s) == 0)
return NULL;
*e = prefetchUrlEntryAllocator.alloc();
(*e)->init(ats_strdup(s), hash);
return *e;
}
#define IS_RECURSIVE_PREFETCH(req_ip) (prefetch_config->max_recursion > 0 && ats_is_ip_loopback(&req_ip))
static void
check_n_attach_prefetch_transform(HttpSM *sm, HTTPHdr *resp, bool from_cache)
{
INKVConnInternal *prefetch_trans;
ip_text_buffer client_ipb;
IpEndpoint client_ip = sm->t_state.client_info.addr;
// we depend on this to setup @a client_ipb for all subsequent Debug().
Debug("PrefetchParser", "Checking response for request from %s\n", ats_ip_ntop(&client_ip, client_ipb, sizeof(client_ipb)));
unsigned int rec_depth = 0;
HTTPHdr *request = &sm->t_state.hdr_info.client_request;
if (IS_RECURSIVE_PREFETCH(client_ip)) {
rec_depth = request->value_get_int(PREFETCH_FIELD_RECURSION, PREFETCH_FIELD_LEN_RECURSION);
rec_depth++;
Debug("PrefetchTemp", "recursion: %d", rec_depth);
if (rec_depth > prefetch_config->max_recursion) {
Debug("PrefetchParserRecursion", "Recursive parsing is not done "
"since recursion depth(%d) is greater than max allowed (%d)",
rec_depth, prefetch_config->max_recursion);
return;
}
} else if (!prefetch_config->ip_map.contains(&client_ip)) {
Debug("PrefetchParser", "client (%s) does not match any of the "
"prefetch_children mentioned in configuration\n",
client_ipb);
return;
}
if (prefetch_config->max_recursion > 0) {
request->value_set_int(PREFETCH_FIELD_RECURSION, PREFETCH_FIELD_LEN_RECURSION, rec_depth);
}
int c_type_len;
const char *c_type = resp->value_get(MIME_FIELD_CONTENT_TYPE, MIME_LEN_CONTENT_TYPE, &c_type_len);
if ((c_type == NULL) || strncmp("text/html", c_type, 9) != 0) {
Debug("PrefetchParserCT", "Content type is not text/html.. skipping\n");
return;
}
/* skip if it is encoded */
c_type = resp->value_get(MIME_FIELD_CONTENT_ENCODING, MIME_LEN_CONTENT_ENCODING, &c_type_len);
if (c_type) {
char type[64];
memcpy(type, c_type, c_type_len);
type[c_type_len] = 0;
Debug("PrefetchParserCT", "Content is encoded with %s .. skipping\n", type);
return;
}
Debug("PrefetchParserCT", "Content type is text/html\n");
if (prefetch_config->pre_parse_hook) {
TSPrefetchInfo info;
HTTPHdr *req = &sm->t_state.hdr_info.client_request;
info.request_buf = reinterpret_cast<TSMBuffer>(req);
info.request_loc = reinterpret_cast<TSMLoc>(req->m_http);
info.response_buf = reinterpret_cast<TSMBuffer>(resp);
info.response_loc = reinterpret_cast<TSMLoc>(resp->m_http);
ats_ip_copy(ats_ip_sa_cast(&info.client_ip), &client_ip);
info.embedded_url = 0;
info.present_in_cache = from_cache;
ink_zero(info.url_blast);
ink_zero(info.url_response_blast);
info.object_buf = 0;
info.object_buf_reader = 0;
info.object_buf_status = TS_PREFETCH_OBJ_BUF_NOT_NEEDED;
int ret = (prefetch_config->pre_parse_hook)(TS_PREFETCH_PRE_PARSE_HOOK, &info);
if (ret == TS_PREFETCH_DISCONTINUE)
return;
}
// now insert the parser
prefetch_trans = new PrefetchTransform(sm, resp);
if (prefetch_trans) {
Debug("PrefetchParser", "Adding Prefetch Parser 0x%p\n", prefetch_trans);
TSHttpTxnHookAdd(reinterpret_cast<TSHttpTxn>(sm), TS_HTTP_RESPONSE_TRANSFORM_HOOK, reinterpret_cast<TSCont>(prefetch_trans));
DUMP_HEADER("PrefetchParserHdrs", &sm->t_state.hdr_info.client_request, (int64_t)0,
"Request Header given for Prefetch Parser");
}
}
static int
PrefetchPlugin(TSCont /* contp ATS_UNUSED */, TSEvent event, void *edata)
{
HttpSM *sm = (HttpSM *)edata;
HTTPHdr *resp = 0;
bool from_cache = false;
switch (event) {
case TS_EVENT_HTTP_CACHE_LOOKUP_COMPLETE: {
Debug("PrefetchPlugin", "Received TS_HTTP_CACHE_LOOKUP_COMPLETE_HOOK "
"event (sm = 0x%p)\n",
sm);
int status;
TSHttpTxnCacheLookupStatusGet((TSHttpTxn)sm, &status);
if (status == TS_CACHE_LOOKUP_HIT_FRESH) {
Debug("PrefetchPlugin", "Cached object is fresh\n");
resp = sm->t_state.cache_info.object_read->response_get();
from_cache = true;
} else {
Debug("PrefetchPlugin", "Cache lookup did not succeed\n");
}
break;
}
case TS_EVENT_HTTP_READ_RESPONSE_HDR:
Debug("PrefetchPlugin", "Received TS_EVENT_HTTP_READ_RESPONSE_HDR "
"event (sm = 0x%p)\n",
sm);
resp = &sm->t_state.hdr_info.server_response;
break;
default:
Debug("PrefetchPlugin", "Error: Received unexpected event\n");
return 0;
}
if (resp && resp->valid())
check_n_attach_prefetch_transform(sm, resp, from_cache);
TSHttpTxnReenable(reinterpret_cast<TSHttpTxn>(sm), TS_EVENT_HTTP_CONTINUE);
// Debug("PrefetchPlugin", "Returning after check_n_attach_prefetch_transform()\n");
return 0;
}
void
PrefetchProcessor::start()
{
// we need to create the config and register all config callbacks
// first.
prefetch_reconfig_mutex = new_ProxyMutex();
prefetch_config = new PrefetchConfiguration;
RecRegisterConfigUpdateCb("proxy.config.prefetch.prefetch_enabled", prefetch_config_cb, NULL);
RecRegisterConfigUpdateCb("proxy.config.http.server_port", prefetch_config_cb, NULL);
RecRegisterConfigUpdateCb("proxy.config.prefetch.child_port", prefetch_config_cb, NULL);
RecRegisterConfigUpdateCb("proxy.config.prefetch.url_buffer_size", prefetch_config_cb, NULL);
RecRegisterConfigUpdateCb("proxy.config.prefetch.url_buffer_timeout", prefetch_config_cb, NULL);
RecRegisterConfigUpdateCb("proxy.config.prefetch.keepalive_timeout", prefetch_config_cb, NULL);
RecRegisterConfigUpdateCb("proxy.config.prefetch.push_cached_objects", prefetch_config_cb, NULL);
RecRegisterConfigUpdateCb("proxy.config.prefetch.max_object_size", prefetch_config_cb, NULL);
RecRegisterConfigUpdateCb("proxy.config.prefetch.max_recursion", prefetch_config_cb, NULL);
RecRegisterConfigUpdateCb("proxy.config.prefetch.redirection", prefetch_config_cb, NULL);
RecRegisterConfigUpdateCb("proxy.config.prefetch.default_url_proto", prefetch_config_cb, NULL);
RecRegisterConfigUpdateCb("proxy.config.prefetch.default_url_proto", prefetch_config_cb, NULL);
RecRegisterConfigUpdateCb("proxy.config.prefetch.config_file", prefetch_config_cb, NULL);
prefetch_config->readConfiguration();
if (prefetch_config->prefetch_enabled) {
PREFETCH_FIELD_RECURSION = "@InkPrefetch";
PREFETCH_FIELD_LEN_RECURSION = strlen(PREFETCH_FIELD_RECURSION);
// hdrtoken_wks_to_length(PREFETCH_FIELD_RECURSION);
g_conn_table = new KeepAliveConnTable;
g_conn_table->init();
udp_seq_no = this_ethread()->generator.random();
prefetch_udp_fd = socketManager.socket(PF_INET, SOCK_DGRAM, 0);
TSCont contp = TSContCreate(PrefetchPlugin, NULL);
TSHttpHookAdd(TS_HTTP_CACHE_LOOKUP_COMPLETE_HOOK, contp);
TSHttpHookAdd(TS_HTTP_READ_RESPONSE_HDR_HOOK, contp);
Note("PrefetchProcessor: Started the prefetch processor\n");
} else {
Debug("PrefetchProcessor", "Prefetch processor is not started\n");
}
}
// Blaster
ClassAllocator<BlasterUrlList> blasterUrlListAllocator("blasterUrlList");
int
BlasterUrlList::handleEvent(int event, void *data)
{
switch (event) {
case EVENT_INTERVAL:
ink_assert(list_head);
if (list_head) {
invokeUrlBlaster();
}
action = NULL;
break;
case EVENT_IMMEDIATE:
/*
PrefetchTransform informed us not to expect any more URLs
This is used so that we dont wait for timeout when the mtu has not filled
but theren't any URLs left in the page.
*/
if (list_head) {
action->cancel();
action = NULL;
invokeUrlBlaster();
}
free(); // we need to call free because PrefetchTransform does not.
break;
case PREFETCH_EVENT_SEND_URL: {
PrefetchUrlEntry *entry = ((PrefetchUrlEntry *)data)->assign();
if (list_head) {
action->cancel();
action = NULL;
if ((cur_len + entry->len) > mtu) {
invokeUrlBlaster();
}
}
entry->blaster_link = list_head; // will be reversed before sending
list_head = entry;
cur_len += entry->len;
if (cur_len >= mtu || timeout == 0) {
invokeUrlBlaster();
} else {
action = this_ethread()->schedule_in(this, HRTIME_MSECONDS(timeout));
}
break;
}
default:
ink_assert(!"not reached");
}
return EVENT_DONE;
}
ClassAllocator<PrefetchUrlBlaster> prefetchUrlBlasterAllocator("prefetchUrlBlaster");
inline void
PrefetchUrlBlaster::free()
{
if (action)
action->cancel();
// free the list;
while (url_head) {
PrefetchUrlEntry *next = url_head->blaster_link;
this_ethread()->schedule_imm(url_head->resp_blaster);
url_head->free();
url_head = next;
}
mutex.clear();
prefetchUrlBlasterAllocator.free(this);
}
void
PrefetchUrlBlaster::writeBuffer(MIOBuffer *buf)
{
// reverse the list:
PrefetchUrlEntry *entry = NULL;
// int total_len = 0;
while (url_head) {
// total_len += url_head->len;
PrefetchUrlEntry *next = url_head->blaster_link;
url_head->blaster_link = entry;
entry = url_head;
url_head = next;
}
url_head = entry;
int nurls = 0;
// write it:
while (entry) {
buf->write(entry->url, entry->len);
entry = entry->blaster_link;
nurls++;
}
Debug("PrefetchBlasterUrlList", "found %d urls in the list", nurls);
return;
}
int
PrefetchUrlBlaster::udpUrlBlaster(int event, void *data)
{
switch (event) {
case SIMPLE_EVENT_EVENTS_START: {
SET_HANDLER((EventHandler)(&PrefetchUrlBlaster::udpUrlBlaster));
MIOBuffer *buf = new_MIOBuffer();
IOBufferReader *reader = buf->alloc_reader();
int udp_hdr_len = (TS_PREFETCH_TCP_BLAST == blast.type) ? 0 : PRELOAD_UDP_HEADER_LEN;
buf->fill(udp_hdr_len + PRELOAD_HEADER_LEN);
writeBuffer(buf);
if (TS_PREFETCH_TCP_BLAST == blast.type) {
setup_object_header(reader->start(), reader->read_avail(), true);
g_conn_table->append(url_head->child_ip, buf, reader);
free();
} else {
IOBufferBlock *block = buf->get_current_block();
ink_assert(reader->read_avail() == block->read_avail());
setup_udp_header(block->start(), get_udp_seq_no(), 0, true);
setup_object_header(block->start() + PRELOAD_UDP_HEADER_LEN, block->read_avail() - PRELOAD_UDP_HEADER_LEN, true);
IpEndpoint saddr;
ats_ip_copy(&saddr, &url_head->url_multicast_ip) || ats_ip_copy(&saddr, &url_head->child_ip);
ats_ip_port_cast(&saddr.sa) = htons(prefetch_config->stuffer_port);
udpNet.sendto_re(this, NULL, prefetch_udp_fd, &saddr.sa, sizeof(saddr), block, block->read_avail());
}
break;
}
case NET_EVENT_DATAGRAM_WRITE_ERROR:
Debug("PrefetchBlaster", "Error in sending the url list on UDP (%p)", data);
case NET_EVENT_DATAGRAM_WRITE_COMPLETE:
free();
break;
}
return EVENT_DONE;
}
ClassAllocator<PrefetchBlaster> prefetchBlasterAllocator("PrefetchBlasterAllocator");
int
PrefetchBlaster::init(PrefetchUrlEntry *entry, HTTPHdr *req_hdr, PrefetchTransform *p_trans)
{
mutex = new_ProxyMutex();
// extract host and the path
// by this time, the url is sufficiently error checked..
// we will just use sscanf to parse it:
// int host_pos=-1, path_pos=-1;
int url_len = strlen(entry->url);
request = new HTTPHdr;
request->copy(req_hdr);
url_clear(request->url_get()->m_url_impl); /* BugID: INKqa11148 */
// request->url_get()->clear();
// INKqa12871
request->field_delete(MIME_FIELD_HOST, MIME_LEN_HOST);
request->field_delete(MIME_FIELD_IF_MATCH, MIME_LEN_IF_MATCH);