More progress on async

This commit is contained in:
Neel Goyal 2013-08-14 17:19:06 -04:00
parent bf92cb6bb4
commit ad20c23f42
6 changed files with 296 additions and 29 deletions

View File

@ -135,10 +135,9 @@ static getdns_return_t set_os_defaults(getdns_context_t context) {
*
* call this to initialize the context that is used in other getdns calls
*/
getdns_return_t
getdns_context_create(
getdns_return_t getdns_context_create(
getdns_context_t *context,
bool set_from_os
int set_from_os
)
{
getdns_context_t result = NULL;
@ -173,6 +172,7 @@ getdns_context_create(
result->edns_do_bit = 0;
result->event_base = NULL;
result->resolver_socket = 0;
result->outbound_reqs = outbound_reqs;
result->update_callback = NULL;
@ -216,6 +216,12 @@ getdns_context_destroy(
getdns_dict_destroy(context->outbound_reqs);
/* TODO: cancel all events */
if (context->resolver_socket != 0) {
evutil_closesocket(context->resolver_socket);
}
free(context);
return;
} /* getdns_context_destroy */

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@ -41,7 +41,11 @@ struct getdns_context_t {
/* Event loop */
struct event_base* event_base;
/* outbound request dict (transaction -> req struct) */
getdns_dict *outbound_reqs;
/* socket */
evutil_socket_t resolver_socket;
} ;
#endif

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@ -696,10 +696,9 @@ getdns_service(
getdns_callback_t callbackfn
);
getdns_return_t
getdns_context_create(
getdns_return_t getdns_context_create(
getdns_context_t *context,
bool set_from_os
int set_from_os
);
void

View File

@ -28,29 +28,272 @@
* THE SOFTWARE.
*/
/**
* Much of this is based on / duplicated code from libevent evdns. Credits to
* Nick Mathewson and Niels Provos
*
* https://github.com/libevent/libevent/
*
* libevent dns is based on software by Adam Langly. Adam's original message:
*
* Async DNS Library
* Adam Langley <agl@imperialviolet.org>
* http://www.imperialviolet.org/eventdns.html
* Public Domain code
*
* This software is Public Domain. To view a copy of the public domain dedication,
* visit http://creativecommons.org/licenses/publicdomain/ or send a letter to
* Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA.
*
* I ask and expect, but do not require, that all derivative works contain an
* attribution similar to:
* Parts developed by Adam Langley <agl@imperialviolet.org>
*
* You may wish to replace the word "Parts" with something else depending on
* the amount of original code.
*
* (Derivative works does not include programs which link against, run or include
* the source verbatim in their source distributions)
*
* Version: 0.1b
*/
#include <getdns_context.h>
#include <ldns/ldns.h>
/* outbound request */
typedef struct getdns_outbound_req {
/* useful macros */
#define gd_malloc(sz) context->memory_allocator(sz)
#define gd_free(ptr) context->memory_deallocator(ptr)
/* stub or recursive */
uint16_t req_type;
/* transaction id */
getdns_transaction_t transaction_id;
/* callback */
getdns_callback_t callback;
/* user arg to pass to callback */
void* userarg;
/* list of servers this can send to */
getdns_list *upstream;
struct getdns_dns_req;
typedef struct getdns_nameserver {
evutil_socket_t socket; /* a connected UDP socket */
struct sockaddr_storage address;
ev_socklen_t addrlen;
int failed_times; /* number of times which we have given this server a chance */
int timedout; /* number of times in a row a request has timed out */
struct event event;
struct event timeout_event; /* used to keep the timeout for */
/* when we next probe this server. */
/* Valid if state == 0 */
/* Outstanding probe request for this nameserver, if any */
struct getdns_dns_req *probe_request;
char state; /* zero if we think that this server is down */
char choked; /* true if we have an EAGAIN from this server's socket */
char write_waiting; /* true if we are waiting for EV_WRITE events */
/* getdns context */
getdns_context_t context;
/* Number of currently inflight requests: used
* to track when we should add/del the event. */
int requests_inflight;
} getdns_nameserver;
} getdns_async_req;
/* network request - state for a network request and referenced
* by the the outbound_req
*/
typedef struct getdns_network_req {
ldns_pkt *pkt; /* the dns packet data */
uint16_t request_type; /* query type */
int reissue_count;
int tx_count; /* the number of times that this packet has been sent */
/* not owned */
struct nameserver *ns; /* the server which we last sent it (unused) */
getdns_dict *upstream_server;
struct event timeout_event;
getdns_transaction_t trans_id; /* the transaction id */
unsigned transmit_me :1; /* needs to be transmitted */
getdns_context_t context;
struct getdns_dns_req *owner;
} getdns_network_req;
/* outbound request - manages recursion and stub reqs */
typedef struct getdns_dns_req {
struct getdns_network_req *current_req;
getdns_context_t context;
uint16_t resolver_type;
/* callback data */
getdns_callback_t user_callback;
void *user_pointer;
int pending_cb; /* Waiting for its callback to be invoked; not
* owned by event base any more. */
/* search not supported.. yet */
} getdns_dns_req;
/* stuff to make it compile pedantically */
#define UNUSED_PARAM(x) ((void)(x))
/* TODO: flags */
static ldns_pkt *create_new_pkt(getdns_context_t context,
const char* name,
uint16_t request_type,
struct getdns_dict* extensions) {
ldns_pkt *pkt = NULL;
ldns_rr_type type = (ldns_rr_type) request_type;
ldns_pkt_query_new_frm_str(&pkt, name,
type,
LDNS_RR_CLASS_IN, 0);
if (pkt) {
/* id */
ldns_pkt_set_id(pkt, ldns_get_random());
}
return pkt;
}
static void network_req_free(getdns_context_t context,
getdns_network_req* net_req) {
if (!net_req) {
return;
}
if (net_req->pkt) {
ldns_pkt_free(net_req->pkt);
}
gd_free(net_req);
}
static getdns_network_req* network_req_new(getdns_context_t context,
const char* name,
uint16_t request_type,
struct getdns_dict* extensions,
getdns_transaction_t *transaction_id) {
getdns_network_req *net_req = NULL;
ldns_pkt *pkt = NULL;
net_req = gd_malloc(sizeof(getdns_network_req));
if (!net_req) {
return NULL;
}
net_req->ns = NULL;
net_req->pkt = NULL;
net_req->context = context;
net_req->request_type = request_type;
/* create ldns packet */
pkt = create_new_pkt(context, name, request_type, extensions);
if (!pkt) {
/* free up the req */
network_req_free(context, net_req);
return NULL;
}
net_req->pkt = pkt;
net_req->trans_id = ldns_pkt_id(pkt);
if (transaction_id) {
*transaction_id = net_req->trans_id;
}
return net_req;
}
static void dns_req_free(getdns_context_t context,
getdns_dns_req* req) {
if (!req) {
return;
}
network_req_free(context, req->current_req);
gd_free(req);
}
/* create a new dns req to be submitted */
static getdns_dns_req* dns_req_new(getdns_context_t context,
const char* name,
uint16_t request_type,
struct getdns_dict *extensions,
getdns_transaction_t *transaction_id) {
getdns_dns_req *result = NULL;
getdns_network_req *net_req = NULL;
result = gd_malloc(sizeof(getdns_dns_req));
if (result == NULL) {
return NULL;
}
result->context = context;
result->current_req = NULL;
result->pending_cb = 0;
result->resolver_type = context->resolution_type;
/* create the initial network request */
net_req = network_req_new(context, name, request_type,
extensions, transaction_id);
if (!net_req) {
dns_req_free(context, result);
result = NULL;
}
result->current_req = net_req;
net_req->owner = result;
return result;
}
static getdns_return_t dict_to_sockaddr(getdns_dict* ns, struct sockaddr_storage* output) {
struct getdns_bindata *address_type = NULL;
struct getdns_bindata *address_data = NULL;
uint16_t port = htons(53);
memset(output, 0, sizeof(struct sockaddr_storage));
output->ss_family = AF_UNSPEC;
getdns_dict_get_bindata(ns, GETDNS_STR_ADDRESS_TYPE, &address_type);
getdns_dict_get_bindata(ns, GETDNS_STR_ADDRESS_DATA, &address_data);
if (!address_type || !address_data) {
return GETDNS_RETURN_GENERIC_ERROR;
}
if (strcmp((char*) address_type->data, GETDNS_STR_IPV4)) {
/* data is an in_addr_t */
struct sockaddr_in* addr = (struct sockaddr_in*) output;
addr->sin_family = AF_INET;
addr->sin_port = port;
memcpy(&(addr->sin_addr), address_data->data, address_data->size);
} else {
/* data is a v6 addr in host order */
struct sockaddr_in6* addr = (struct sockaddr_in6*) output;
addr->sin6_family = AF_INET6;
addr->sin6_port = port;
memcpy(&(addr->sin6_addr), address_data->data, address_data->size);
}
return GETDNS_RETURN_GOOD;
}
/* submit a new request to the event loop */
static getdns_return_t submit_new_dns_req(getdns_dns_req *request) {
getdns_dict *nameserver = NULL;
getdns_context_t context = request->context;
struct sockaddr_storage sockdata;
/* get first upstream server */
getdns_list_get_dict(context->upstream_list, 0, &nameserver);
if (!nameserver) {
return GETDNS_RETURN_GENERIC_ERROR;
}
/* setup socket */
if (dict_to_sockaddr(nameserver, &sockdata) != GETDNS_RETURN_GOOD) {
return GETDNS_RETURN_GENERIC_ERROR;
}
evutil_socket_t sock = socket(sockdata.ss_family, SOCK_DGRAM, 0);
evutil_make_socket_closeonexec(sock);
evutil_make_socket_nonblocking(sock);
return GETDNS_RETURN_GOOD;
}
/*
* getdns_general
*/
@ -69,17 +312,31 @@ getdns_general(
if (transaction_id != NULL) {
*transaction_id = 0;
}
if (context->event_base == NULL ||
callback == NULL) {
if (!context || context->event_base == NULL ||
callback == NULL ||
context->resolution_type != GETDNS_CONTEXT_STUB) {
/* Can't do async without an event loop
* or callback
*
* Only supports stub right now.
*/
return GETDNS_RETURN_BAD_CONTEXT;
}
/* create a req */
getdns_dns_req *dns_req = dns_req_new(context, name, request_type,
extensions, transaction_id);
if (dns_req == NULL) {
return GETDNS_RETURN_GENERIC_ERROR;
}
dns_req->user_callback = callback;
dns_req->user_pointer = userarg;
/* submit it */
submit_new_dns_req(dns_req);
UNUSED_PARAM(name);
UNUSED_PARAM(request_type);
UNUSED_PARAM(extensions);
UNUSED_PARAM(userarg);
return GETDNS_RETURN_GOOD;
} /* getdns_general */

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@ -1,4 +1,5 @@
#include <event2/event.h>
#include <event.h>
#include <getdns_core_only.h>
/* For libevent, which we are using for these examples */

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@ -45,7 +45,7 @@ void
tst_bindatasetget(void)
{
char msg[TSTMSGBUF];
size_t index;
size_t index = 0;
getdns_return_t retval;
struct getdns_list *list = NULL;
struct getdns_bindata *new_bindata = NULL;
@ -123,7 +123,7 @@ void
tst_dictsetget(void)
{
char msg[TSTMSGBUF];
size_t index;
size_t index = 0;
uint32_t ans_int;
getdns_return_t retval;
struct getdns_list *list = NULL;
@ -199,7 +199,7 @@ void
tst_listsetget(void)
{
char msg[TSTMSGBUF];
size_t index;
size_t index = 0;
getdns_return_t retval;
uint32_t ans_int;
struct getdns_list *list = NULL;
@ -276,7 +276,7 @@ void
tst_intsetget(void)
{
char msg[TSTMSGBUF];
size_t index;
size_t index = 0;
uint32_t ans_int;
getdns_return_t retval;
struct getdns_list *list = NULL;