tmate/tmate-session.c
2016-01-02 09:45:34 -05:00

140 lines
3.6 KiB
C

#include <event2/dns.h>
#include <event2/util.h>
#include <event2/event.h>
#include <sys/socket.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "tmate.h"
#define TMATE_DNS_RETRY_TIMEOUT 10
struct tmate_session tmate_session;
static void lookup_and_connect(void);
static void on_dns_retry(__unused evutil_socket_t fd, __unused short what,
__unused void *arg)
{
lookup_and_connect();
}
static void dns_cb(int errcode, struct evutil_addrinfo *addr, void *ptr)
{
struct evutil_addrinfo *ai;
struct timeval tv;
const char *host = ptr;
if (errcode) {
tmate_status_message("%s lookup failure. Retrying in %d seconds (%s)",
host, TMATE_DNS_RETRY_TIMEOUT,
evutil_gai_strerror(errcode));
tv.tv_sec = TMATE_DNS_RETRY_TIMEOUT;
tv.tv_usec = 0;
evtimer_assign(&tmate_session.ev_dns_retry, tmate_session.ev_base,
on_dns_retry, NULL);
evtimer_add(&tmate_session.ev_dns_retry, &tv);
return;
}
tmate_status_message("Connecting to %s...", host);
for (ai = addr; ai; ai = ai->ai_next) {
char buf[128];
const char *ip = NULL;
if (ai->ai_family == AF_INET) {
struct sockaddr_in *sin = (struct sockaddr_in *)ai->ai_addr;
ip = evutil_inet_ntop(AF_INET, &sin->sin_addr, buf, 128);
} else if (ai->ai_family == AF_INET6) {
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)ai->ai_addr;
ip = evutil_inet_ntop(AF_INET6, &sin6->sin6_addr, buf, 128);
}
tmate_debug("Trying server %s", ip);
/*
* Note: We don't deal with the client list. Clients manage it
* and free client structs when necessary.
*/
(void)tmate_ssh_client_alloc(&tmate_session, ip);
}
evutil_freeaddrinfo(addr);
/*
* XXX For some reason, freeing the DNS resolver makes MacOSX flip out...
* not sure what's going on...
* evdns_base_free(tmate_session.ev_dnsbase, 0);
* tmate_session.ev_dnsbase = NULL;
*/
}
static void lookup_and_connect(void)
{
struct evutil_addrinfo hints;
const char *tmate_server_host;
if (!tmate_session.ev_dnsbase)
tmate_session.ev_dnsbase = evdns_base_new(tmate_session.ev_base, 1);
if (!tmate_session.ev_dnsbase)
tmate_fatal("Cannot initialize the DNS lookup service");
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_flags = EVUTIL_AI_ADDRCONFIG;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
tmate_server_host = options_get_string(global_options,
"tmate-server-host");
tmate_info("Looking up %s...", tmate_server_host);
(void)evdns_getaddrinfo(tmate_session.ev_dnsbase, tmate_server_host, NULL,
&hints, dns_cb, (void *)tmate_server_host);
}
static void __tmate_session_init(struct tmate_session *session,
struct event_base *base)
{
memset(session, 0, sizeof(*session));
session->ev_base = base;
/*
* Early initialization of encoder because we need to parse
* config files to get the server configs, but while we are parsing
* config files, we need to buffer bind commands and all for the
* slave.
* Decoder is setup later.
*/
tmate_encoder_init(&session->encoder, NULL, &tmate_session);
session->min_sx = -1;
session->min_sy = -1;
TAILQ_INIT(&session->clients);
}
void tmate_session_init(struct event_base *base)
{
__tmate_session_init(&tmate_session, base);
tmate_write_header();
}
void tmate_session_start(void)
{
/* We split init and start because:
* - We need to process the tmux config file during the connection as
* we are setting up the tmate identity.
* - While we are parsing the config file, we need to be able to
* serialize it, and so we need a worker encoder.
*/
lookup_and_connect();
}