Example #1
0
/* Listen on address:port. 
 * Special cases are address of "" listening on everything,
 * and address of NULL listening on localhost only.
 * Returns the number of sockets bound on success, or -1 on failure. On
 * failure, if errstring wasn't NULL, it'll be a newly malloced error
 * string.*/
int dropbear_listen(int family, const char* address, const char* port,
		int *socks, unsigned int sockcount, char **errstring, int *maxfd) {

	struct addrinfo hints, *res = NULL, *res0 = NULL;
	int err;
	unsigned int nsock;
	struct linger linger;
	int val;
	int sock;

	TRACE(("enter dropbear_listen"))
	
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = family;
	hints.ai_socktype = SOCK_STREAM;

	/* for calling getaddrinfo:
	 address == NULL and !AI_PASSIVE: local loopback
	 address == NULL and AI_PASSIVE: all interfaces
	 address != NULL: whatever the address says */
	if (!address) {
		TRACE(("dropbear_listen: local loopback"))
	} else {
		if (address[0] == '\0') {
			TRACE(("dropbear_listen: all interfaces"))
			address = NULL;
		}
		hints.ai_flags = AI_PASSIVE;
	}
	err = getaddrinfo(address, port, &hints, &res0);

	if (err) {
		if (errstring != NULL && *errstring == NULL) {
			int len;
			len = 20 + strlen(gai_strerror(err));
			*errstring = (char*)m_malloc(len);
			snprintf(*errstring, len, "Error resolving: %s", gai_strerror(err));
		}
		if (res0) {
			freeaddrinfo(res0);
			res0 = NULL;
		}
		TRACE(("leave dropbear_listen: failed resolving"))
		return -1;
	}


	nsock = 0;
	for (res = res0; res != NULL && nsock < sockcount;
			res = res->ai_next) {

		/* Get a socket */
		socks[nsock] = socket(res->ai_family, res->ai_socktype,
				res->ai_protocol);

		sock = socks[nsock]; /* For clarity */

		if (sock < 0) {
			err = errno;
			TRACE(("socket() failed"))
			continue;
		}

		/* Various useful socket options */
		val = 1;
		/* set to reuse, quick timeout */
		setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void*) &val, sizeof(val));
		linger.l_onoff = 1;
		linger.l_linger = 5;
		setsockopt(sock, SOL_SOCKET, SO_LINGER, (void*)&linger, sizeof(linger));

#if defined(IPPROTO_IPV6) && defined(IPV6_V6ONLY)
		if (res->ai_family == AF_INET6) {
			int on = 1;
			if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, 
						&on, sizeof(on)) == -1) {
				dropbear_log(LOG_WARNING, "Couldn't set IPV6_V6ONLY");
			}
		}
#endif

		set_sock_nodelay(sock);

		if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
			err = errno;
			close(sock);
			TRACE(("bind(%s) failed", port))
			continue;
		}
Example #2
0
static void connect_try_next(struct dropbear_progress_connection *c) {
	struct addrinfo *r;
	int res = 0;
	int fastopen = 0;
#ifdef DROPBEAR_CLIENT_TCP_FAST_OPEN
	struct msghdr message;
#endif

	for (r = c->res_iter; r; r = r->ai_next)
	{
		dropbear_assert(c->sock == -1);

		c->sock = socket(r->ai_family, r->ai_socktype, r->ai_protocol);
		if (c->sock < 0) {
			continue;
		}

		ses.maxfd = MAX(ses.maxfd, c->sock);
		set_sock_nodelay(c->sock);
		setnonblocking(c->sock);

#ifdef DROPBEAR_CLIENT_TCP_FAST_OPEN
		fastopen = (c->writequeue != NULL);

		if (fastopen) {
			memset(&message, 0x0, sizeof(message));
			message.msg_name = r->ai_addr;
			message.msg_namelen = r->ai_addrlen;
			/* 6 is arbitrary, enough to hold initial packets */
			unsigned int iovlen = 6; /* Linux msg_iovlen is a size_t */
			struct iovec iov[6];
			packet_queue_to_iovec(c->writequeue, iov, &iovlen);
			message.msg_iov = iov;
			message.msg_iovlen = iovlen;
			res = sendmsg(c->sock, &message, MSG_FASTOPEN);
			/* Returns EINPROGRESS if FASTOPEN wasn't available */
			if (res < 0) {
				if (errno != EINPROGRESS) {
					m_free(c->errstring);
					c->errstring = m_strdup(strerror(errno));
					/* Not entirely sure which kind of errors are normal - 2.6.32 seems to 
					return EPIPE for any (nonblocking?) sendmsg(). just fall back */
					TRACE(("sendmsg tcp_fastopen failed, falling back. %s", strerror(errno)));
					/* No kernel MSG_FASTOPEN support. Fall back below */
					fastopen = 0;
					/* Set to NULL to avoid trying again */
					c->writequeue = NULL;
				}
			} else {
				packet_queue_consume(c->writequeue, res);
			}
		}
#endif

		/* Normal connect(), used as fallback for TCP fastopen too */
		if (!fastopen) {
			res = connect(c->sock, r->ai_addr, r->ai_addrlen);
		}

		if (res < 0 && errno != EINPROGRESS) {
			/* failure */
			m_free(c->errstring);
			c->errstring = m_strdup(strerror(errno));
			close(c->sock);
			c->sock = -1;
			continue;
		} else {
			/* new connection was successful, wait for it to complete */
			break;
		}
	}

	if (r) {
		c->res_iter = r->ai_next;
	} else {
		c->res_iter = NULL;
	}
}