Add support for peers specified by hostnames

1 files changed, 123 insertions, 0 deletions

diff --git a/src/resolve.c b/src/resolve.c
new file mode 100644
index 0000000..1fbb1bf
--- /dev/null
+++ b/src/resolve.c
@@ -0,0 +1,123 @@
+/*
+  Copyright (c) 2012, Matthias Schiffer <mschiffer@universe-factory.net>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#define _GNU_SOURCE
+
+#include "fastd.h"
+#include "peer.h"
+
+#include <netdb.h>
+#include <pthread.h>
+#include <signal.h>
+
+
+typedef struct _resolv_arg {
+	fastd_context *ctx;
+	pthread_t master_thread;
+	char *hostname;
+	sa_family_t af;
+	uint16_t port;
+} resolv_arg;
+
+
+static void* fastd_resolve_peer_handshake_do(void *varg) {
+	resolv_arg *arg = varg;
+
+	struct addrinfo hints;
+	struct addrinfo *res = NULL;
+	int gai_ret;
+	bool error = false;
+
+	char portstr[6];
+	snprintf(portstr, 6, "%u", arg->port);
+
+	memset(&hints, 0, sizeof(struct addrinfo));
+	hints.ai_family = arg->af;
+	hints.ai_socktype = SOCK_DGRAM;
+	hints.ai_protocol = IPPROTO_UDP;
+	hints.ai_flags = AI_NUMERICSERV | AI_ADDRCONFIG;
+#ifdef AI_IDN
+	hints.ai_flags |= AI_IDN;
+#endif
+
+	gai_ret = getaddrinfo(arg->hostname, portstr, &hints, &res);
+
+	if (gai_ret) {
+		pr_debug(arg->ctx, "Resolving host `%s' failed: %s", arg->hostname, gai_strerror(gai_ret));
+		error = true;
+	}
+	else if (res->ai_addrlen > sizeof(fastd_peer_address)) {
+		pr_warn(arg->ctx, "Resolving host `%s': unsupported address returned", arg->hostname);
+		error = true;
+	}
+
+	fastd_resolve_return *ret = malloc(sizeof(fastd_resolve_return));
+
+	ret->ctx = arg->ctx;
+
+	ret->hostname = arg->hostname;
+	ret->af = arg->af;
+	ret->port = arg->port;
+
+	if (!error) {
+		pr_debug(arg->ctx, "Resolved host `%s' successfully", arg->hostname);
+		memcpy(&ret->addr, res->ai_addr, res->ai_addrlen);
+	}
+	else {
+		ret->addr.sa.sa_family = AF_UNSPEC;
+	}
+
+	union sigval sigval;
+	sigval.sival_ptr = ret;
+	if (pthread_sigqueue(arg->master_thread, SIGUSR1, sigval))
+		exit_errno(arg->ctx, "pthread_sigqueue");
+
+	freeaddrinfo(res);
+	free(arg);
+
+	return NULL;
+}
+
+void fastd_resolve_peer_handshake(fastd_context *ctx, fastd_peer *peer) {
+	pr_debug(ctx, "Resolving host `%s' for peer %P...", peer->config->hostname, peer);
+
+	resolv_arg *arg = malloc(sizeof(resolv_arg));
+
+	arg->ctx = ctx;
+	arg->master_thread = pthread_self();
+	arg->hostname = strdup(peer->config->hostname);
+	arg->af = peer->config->address.sa.sa_family;
+	arg->port = ntohs(peer->config->address.in.sin_port);
+
+	pthread_t thread;
+	if (pthread_create(&thread, NULL, fastd_resolve_peer_handshake_do, arg) != 0) {
+		pr_error_errno(ctx, "unable to create resolver thread");
+		free(arg->hostname);
+		free(arg);
+	}
+
+	pthread_detach(thread);
+}