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#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 struct evdns_base *ev_dnsbase;
static struct event ev_dns_retry;
static void lookup_and_connect(void);
static void on_dns_retry(evutil_socket_t fd, short what, void *arg)
{
lookup_and_connect();
}
static void dns_cb(int errcode, struct evutil_addrinfo *addr, void *ptr)
{
struct tmate_ssh_client *client;
struct evutil_addrinfo *ai;
struct timeval tv;
if (errcode) {
tmate_status_message("%s lookup failure. Retrying in %d seconds (%s)",
TMATE_HOST, TMATE_DNS_RETRY_TIMEOUT,
evutil_gai_strerror(errcode));
tv.tv_sec = TMATE_DNS_RETRY_TIMEOUT;
tv.tv_usec = 0;
evtimer_assign(&ev_dns_retry, ev_base, on_dns_retry, NULL);
evtimer_add(&ev_dns_retry, &tv);
return;
}
tmate_status_message("Connecting to %s...", TMATE_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);
evdns_base_free(ev_dnsbase, 0);
ev_dnsbase = NULL;
}
static void lookup_and_connect(void)
{
struct evutil_addrinfo hints;
if (!ev_dnsbase)
ev_dnsbase = evdns_base_new(ev_base, 1);
if (!ev_dnsbase)
tmate_fatal("Cannot initialize the DNS lookup service");
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_flags = 0;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
tmate_info("Looking up %s...", TMATE_HOST);
(void)evdns_getaddrinfo(ev_dnsbase, TMATE_HOST, NULL,
&hints, dns_cb, NULL);
}
void tmate_session_init(void)
{
tmate_catch_sigsegv();
tmate_encoder_init(&tmate_session.encoder);
tmate_decoder_init(&tmate_session.decoder);
TAILQ_INIT(&tmate_session.clients);
tmate_session.need_passphrase = 0;
tmate_session.passphrase = NULL;
/* The header will be written as soon as the first client connects */
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();
}
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