src/lib-http/http-client.c

	http-client.c revision 30d917bcd48d70af0371baf27571cc198d621a62
/* Copyright (c) 2013 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "net.h"
#include "str.h"
#include "hash.h"
#include "array.h"
#include "ioloop.h"
#include "istream.h"
#include "ostream.h"
#include "connection.h"
#include "dns-lookup.h"
#include "iostream-rawlog.h"
#include "iostream-ssl.h"
#include "http-url.h"

#include "http-client-private.h"

#define HTTP_DEFAULT_PORT 80
#define HTTPS_DEFAULT_PORT 443

/* FIXME: This implementation not yet finished. The essence works: it is
   possible to submit requests through the client. Responses are dumped to
   stdout

    Structure so far:
    Client - Acts much like a browser; it is not dedicated to a single host.
             Client can accept requests to different hosts, which can be served
             at different IPs. Redirects can be handled in the background by
             making a new connection. Connections to new hosts are created once
             needed for servicing a request.
    Requests - Semantics are similar to imapc commands. Create a request,
               optionally modify some aspects of it and finally submit it.
    Hosts - We maintain a 'cache' of hosts for which we have looked up IPs.
            Requests are first queued in the host struct on a per-port basis.
    Peers - Group connections to the same ip/port (== peer_addr).
    Connections - Actual connections to a server. Once a connection is ready to
                  handle requests, it claims a request from a host object. One
                  connection hand service multiple hosts and one host can have
                  multiple associated connections, possibly to different ips and
                  ports.

  TODO: lots of cleanup, authentication, ssl, timeouts,  rawlog etc.
 */

/*
 * Logging
 */

static inline void
http_client_debug(struct http_client *client,
    const char *format, ...) ATTR_FORMAT(2, 3);

static inline void
http_client_debug(struct http_client *client,
    const char *format, ...)
{
    va_list args;

    va_start(args, format);
    if (client->set.debug)
        i_debug("http-client: %s", t_strdup_vprintf(format, args));
    va_end(args);
}

/*
 * Client
 */

struct http_client *http_client_init(const struct http_client_settings *set)
{
    struct http_client *client;
    pool_t pool;

    pool = pool_alloconly_create("http client", 1024);
    client = p_new(pool, struct http_client, 1);
    client->pool = pool;
    if (set->dns_client_socket_path != NULL && *set->dns_client_socket_path != '\0') {
        client->set.dns_client_socket_path =
            p_strdup(pool, set->dns_client_socket_path);
    }
    if (set->rawlog_dir != NULL && *set->rawlog_dir != '\0')
        client->set.rawlog_dir = p_strdup(pool, set->rawlog_dir);
    client->set.ssl_ca_dir = p_strdup(pool, set->ssl_ca_dir);
    client->set.ssl_ca = p_strdup(pool, set->ssl_ca);
    client->set.max_idle_time_msecs = set->max_idle_time_msecs;
    client->set.max_parallel_connections =
        (set->max_parallel_connections > 0 ? set->max_parallel_connections : 1);
    client->set.max_pipelined_requests =
        (set->max_pipelined_requests > 0 ? set->max_pipelined_requests : 1);
    client->set.max_attempts = set->max_attempts;
    client->set.max_redirects = set->max_redirects;
    client->set.debug = set->debug;

    client->conn_list = http_client_connection_list_init();

    hash_table_create(&client->hosts, default_pool, 0, str_hash, strcmp);
    hash_table_create(&client->peers, default_pool, 0,
        http_client_peer_addr_hash, http_client_peer_addr_cmp);

    return client;
}

void http_client_deinit(struct http_client **_client)
{
    struct http_client *client = *_client;
    struct http_client_host *host;
    struct http_client_peer *peer;

    /* free peers */
    while (client->peers_list != NULL) {
        peer = client->peers_list;
        http_client_peer_free(&peer);
    }
    hash_table_destroy(&client->peers);

    /* free hosts */
    while (client->hosts_list != NULL) {
        host = client->hosts_list;
        http_client_host_free(&host);
    }
    hash_table_destroy(&client->hosts);

    connection_list_deinit(&client->conn_list);
    pool_unref(&client->pool);
    *_client = NULL;
}

void http_client_switch_ioloop(struct http_client *client)
{
    struct connection *_conn = client->conn_list->connections;

    /* move connections */
    /* FIXME: we wouldn't necessarily need to switch all of them
       immediately, only those that have requests now. but also connections
       that get new requests before ioloop is switched again.. */
    for (; _conn != NULL; _conn = _conn->next) {
        struct http_client_connection *conn =
            (struct http_client_connection *)_conn;

        http_client_connection_switch_ioloop(conn);
    }

    /* move dns lookups */
    if (client->set.dns_client_socket_path != '\0') {
        struct http_client_host *host;

        for (host = client->hosts_list; host != NULL; host = host->next)
            http_client_host_switch_ioloop(host);
    }
}

void http_client_wait(struct http_client *client)
{
    struct ioloop *prev_ioloop = current_ioloop;

    i_assert(client->ioloop == NULL);

    if (client->pending_requests == 0)
        return;

    client->ioloop = io_loop_create();
    http_client_switch_ioloop(client);
    /* either we're waiting for network I/O or we're getting out of a
       callback using timeout_add_short(0) */
    i_assert(io_loop_have_ios(client->ioloop) ||
         io_loop_have_immediate_timeouts(client->ioloop));

    do {
        http_client_debug(client,
            "Waiting for %d requests to finish", client->pending_requests);
        io_loop_run(client->ioloop);
    } while (client->pending_requests > 0);

    http_client_debug(client, "All requests finished");

    current_ioloop = prev_ioloop;
    http_client_switch_ioloop(client);
    current_ioloop = client->ioloop;
    io_loop_destroy(&client->ioloop);
}