sd-network: add new library

This is similar to sd-login, but exposes the state of networkd rather than logind.

Include it in libsystemd-dhcp and rename it to libsystemd-network.

src/libsystemd-network/dhcp-network.c

@@ -0,0 +1,109 @@
+/***
+  This file is part of systemd.
+
+  Copyright (C) 2013 Intel Corporation. All rights reserved.
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <string.h>
+#include <linux/if_packet.h>
+#include <net/ethernet.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "socket-util.h"
+
+#include "dhcp-internal.h"
+
+int dhcp_network_bind_raw_socket(int index, union sockaddr_union *link)
+{
+        int s, one = 1;
+
+        assert(index > 0);
+        assert(link);
+
+        s = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
+                   htons(ETH_P_IP));
+        if (s < 0)
+                return -errno;
+
+        link->ll.sll_family = AF_PACKET;
+        link->ll.sll_protocol = htons(ETH_P_IP);
+        link->ll.sll_ifindex =  index;
+        link->ll.sll_halen = ETH_ALEN;
+        memset(link->ll.sll_addr, 0xff, ETH_ALEN);
+
+        if (setsockopt (s, SOL_PACKET, PACKET_AUXDATA, &one, sizeof(one)) < 0)
+                return -errno;
+
+        if (bind(s, &link->sa, sizeof(link->ll)) < 0) {
+                close_nointr_nofail(s);
+                return -errno;
+        }
+
+        return s;
+}
+
+int dhcp_network_bind_udp_socket(int index, be32_t address, uint16_t port)
+{
+        int s;
+        union sockaddr_union src = {
+                .in.sin_family = AF_INET,
+                .in.sin_port = htobe16(port),
+                .in.sin_addr.s_addr = address,
+        };
+
+        s = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
+        if (s < 0)
+                return -errno;
+
+        if (bind(s, &src.sa, sizeof(src.in)) < 0) {
+                close_nointr_nofail(s);
+                return -errno;
+        }
+
+        return s;
+}
+
+int dhcp_network_send_raw_socket(int s, const union sockaddr_union *link,
+                                 const void *packet, size_t len)
+{
+        assert(link);
+        assert(packet);
+        assert(len);
+
+        if (sendto(s, packet, len, 0, &link->sa, sizeof(link->ll)) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int dhcp_network_send_udp_socket(int s, be32_t address, uint16_t port,
+                                 const void *packet, size_t len)
+{
+        union sockaddr_union dest = {
+                .in.sin_family = AF_INET,
+                .in.sin_port = htobe16(port),
+                .in.sin_addr.s_addr = address,
+        };
+
+        if (sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in)) < 0)
+                return -errno;
+
+        return 0;
+}