Move socket handling out of fastd.c

1 files changed, 201 insertions, 0 deletions

diff --git a/src/socket.c b/src/socket.c
new file mode 100644
index 0000000..ca6f588
--- /dev/null
+++ b/src/socket.c
@@ -0,0 +1,201 @@
+/*
+  Copyright (c) 2012-2013, 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.
+*/
+
+
+#include "fastd.h"
+
+#include <fcntl.h>
+
+
+static int bind_socket(fastd_context_t *ctx, const fastd_bind_address_t *addr, bool warn) {
+	int fd = -1;
+	int af = AF_UNSPEC;
+
+	if (addr->addr.sa.sa_family != AF_INET) {
+		fd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
+		if (fd >= 0) {
+			af = AF_INET6;
+
+			int val = (addr->addr.sa.sa_family == AF_INET6);
+			if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val))) {
+				if (warn)
+					pr_warn_errno(ctx, "setsockopt");
+				goto error;
+			}
+		}
+	}
+	if (fd < 0 && addr->addr.sa.sa_family != AF_INET6) {
+		fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
+		if (fd < 0)
+			exit_errno(ctx, "unable to create socket");
+		else
+			af = AF_INET;
+	}
+
+	if (fd < 0)
+		goto error;
+
+	fastd_setfd(ctx, fd, FD_CLOEXEC, 0);
+	fastd_setfl(ctx, fd, O_NONBLOCK, 0);
+
+	int one = 1;
+	if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one))) {
+		pr_error_errno(ctx, "setsockopt: unable to set IP_PKTINFO");
+		goto error;
+	}
+
+	if (af == AF_INET6) {
+		if (setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one))) {
+			pr_error_errno(ctx, "setsockopt: unable to set IPV6_RECVPKTINFO");
+			goto error;
+		}
+	}
+
+	if (addr->bindtodev) {
+		if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, addr->bindtodev, strlen(addr->bindtodev))) {
+			if (warn)
+				pr_warn_errno(ctx, "setsockopt: unable to bind to device");
+			goto error;
+		}
+	}
+
+	if (ctx->conf->pmtu.set) {
+		int pmtu = ctx->conf->pmtu.state ? IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
+		if (setsockopt(fd, IPPROTO_IP, IP_MTU_DISCOVER, &pmtu, sizeof(pmtu))) {
+			pr_error_errno(ctx, "setsockopt: unable to set PMTU discovery");
+			goto error;
+		}
+	}
+
+	fastd_peer_address_t bind_address = addr->addr;
+
+	if (bind_address.sa.sa_family == AF_UNSPEC) {
+		memset(&bind_address, 0, sizeof(bind_address));
+		bind_address.sa.sa_family = af;
+
+		if (af == AF_INET6)
+			bind_address.in6.sin6_port = addr->addr.in.sin_port;
+		else
+			bind_address.in.sin_port = addr->addr.in.sin_port;
+	}
+
+	if (bind(fd, (struct sockaddr*)&bind_address, bind_address.sa.sa_family == AF_INET6 ? sizeof(struct sockaddr_in6) : sizeof(struct sockaddr_in))) {
+		if (warn)
+			pr_warn_errno(ctx, "bind");
+		goto error;
+	}
+
+	return fd;
+
+ error:
+	if (fd >= 0) {
+		if (close(fd))
+			pr_error_errno(ctx, "close");
+	}
+
+	if (warn) {
+		if (addr->bindtodev)
+			pr_warn(ctx, "unable to bind to %B on `%s'", &addr->addr, addr->bindtodev);
+		else
+			pr_warn(ctx, "unable to bind to %B", &addr->addr);
+	}
+
+	return -1;
+}
+
+static bool set_bound_address(fastd_context_t *ctx, fastd_socket_t *sock) {
+	fastd_peer_address_t addr = {};
+	socklen_t len = sizeof(addr);
+
+	if (getsockname(sock->fd, &addr.sa, &len) < 0) {
+		pr_error_errno(ctx, "getsockname");
+		return false;
+	}
+
+	if (len > sizeof(addr)) {
+		pr_error(ctx, "getsockname: got strange long address");
+		return false;
+	}
+
+	sock->bound_addr = calloc(1, sizeof(addr));
+	*sock->bound_addr = addr;
+
+	return true;
+}
+
+bool fastd_socket_handle_binds(fastd_context_t *ctx) {
+	unsigned i;
+
+	for (i = 0; i < ctx->n_socks; i++) {
+		if (ctx->socks[i].fd >= 0)
+			continue;
+
+		ctx->socks[i].fd = bind_socket(ctx, ctx->socks[i].addr, ctx->socks[i].fd < -1);
+
+		if (ctx->socks[i].fd >= 0) {
+			if (!set_bound_address(ctx, &ctx->socks[i])) {
+				fastd_socket_close(ctx, &ctx->socks[i]);
+				continue;
+			}
+
+			fastd_peer_address_t bound_addr = *ctx->socks[i].bound_addr;
+			if (!ctx->socks[i].addr->addr.sa.sa_family)
+				bound_addr.sa.sa_family = AF_UNSPEC;
+
+			if (ctx->socks[i].addr->bindtodev)
+				pr_info(ctx, "successfully bound to %B on `%s'", &bound_addr, ctx->socks[i].addr->bindtodev);
+			else
+				pr_info(ctx, "successfully bound to %B", &bound_addr);
+		}
+	}
+
+	if ((ctx->sock_default_v4 && ctx->sock_default_v4->fd < 0) || (ctx->sock_default_v6 && ctx->sock_default_v6->fd < 0))
+		return false;
+
+	return true;
+}
+
+fastd_socket_t* fastd_socket_open(fastd_context_t *ctx, fastd_peer_t *peer, int af) {
+	const fastd_bind_address_t any_address = { .addr.sa.sa_family = af };
+
+	int fd = bind_socket(ctx, &any_address, true);
+	if (fd < 0)
+		return NULL;
+
+	fastd_socket_t *sock = malloc(sizeof(fastd_socket_t));
+
+	sock->fd = fd;
+	sock->addr = NULL;
+	sock->bound_addr = NULL;
+	sock->peer = peer;
+
+	if (!set_bound_address(ctx, sock)) {
+		fastd_socket_close(ctx, sock);
+		free(sock);
+		return NULL;
+	}
+
+	return sock;
+}