+/*
+ * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
+ * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation
+ *
+ * This program 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 General Public License for more details.
+ */
+
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/utsname.h>
+#include <net/if.h>
+#include <linux/sockios.h>
+#include <arpa/inet.h>
+
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+
+#include <libubox/avl-cmp.h>
+#include <libubox/utils.h>
+#include "interface.h"
+#include "util.h"
+#include "dns.h"
+
+struct interface *cur_iface = NULL;
+
+int
+interface_send_packet(struct interface *iface, struct iovec *iov, int iov_len)
+{
+ static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in_pktinfo)) / sizeof(size_t)) + 1];
+ static struct sockaddr_in a = {
+ .sin_family = AF_INET,
+ .sin_port = htons(MCAST_PORT),
+ };
+ static struct msghdr m = {
+ .msg_name = (struct sockaddr *) &a,
+ .msg_namelen = sizeof(a),
+ .msg_control = cmsg_data,
+ .msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo)),
+ };
+ struct in_pktinfo *pkti;
+ struct cmsghdr *cmsg;
+ int fd = iface->fd.fd;
+
+ m.msg_iov = iov;
+ m.msg_iovlen = iov_len;
+
+ memset(cmsg_data, 0, sizeof(cmsg_data));
+ cmsg = CMSG_FIRSTHDR(&m);
+ cmsg->cmsg_len = m.msg_controllen;
+ cmsg->cmsg_level = IPPROTO_IP;
+ cmsg->cmsg_type = IP_PKTINFO;
+
+ pkti = (struct in_pktinfo*) CMSG_DATA(cmsg);
+ pkti->ipi_ifindex = iface->ifindex;
+
+ a.sin_addr.s_addr = inet_addr(MCAST_ADDR);
+
+ return sendmsg(fd, &m, 0);
+}
+
+static void interface_free(struct interface *iface)
+{
+ if (cur_iface == iface)
+ cur_iface = NULL;
+
+ if (iface->fd.fd >= 0) {
+ uloop_fd_delete(&iface->fd);
+ close(iface->fd.fd);
+ }
+ free(iface);
+}
+
+static void interface_start(struct interface *iface)
+{
+ cur_iface = iface;
+}
+
+static void
+iface_update_cb(struct vlist_tree *tree, struct vlist_node *node_new,
+ struct vlist_node *node_old)
+{
+ struct interface *iface;
+
+ if (node_old) {
+ iface = container_of(node_old, struct interface, node);
+ interface_free(iface);
+ }
+
+ if (node_new) {
+ iface = container_of(node_new, struct interface, node);
+ interface_start(iface);
+ }
+}
+
+int interface_socket_setup(struct interface *iface)
+{
+ struct ip_mreqn mreq;
+ uint8_t ttl = 255;
+ int yes = 1;
+ int no = 0;
+ struct sockaddr_in sa = { 0 };
+ struct in_addr in;
+ int fd = iface->fd.fd;
+
+ inet_aton(iface->ip, &in);
+
+ sa.sin_family = AF_INET;
+ sa.sin_port = htons(MCAST_PORT);
+ inet_pton(AF_INET, MCAST_ADDR, &sa.sin_addr);
+
+ memset(&mreq, 0, sizeof(mreq));
+ mreq.imr_address.s_addr = in.s_addr;
+ mreq.imr_multiaddr = sa.sin_addr;
+ mreq.imr_ifindex = iface->ifindex;
+
+ if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
+ fprintf(stderr, "ioctl failed: IP_MULTICAST_TTL\n");
+
+ if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
+ fprintf(stderr, "ioctl failed: SO_REUSEADDR\n");
+
+ /* Some network drivers have issues with dropping membership of
+ * mcast groups when the iface is down, but don't allow rejoining
+ * when it comes back up. This is an ugly workaround
+ * -- this was copied from avahi --
+ */
+ setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));
+
+ if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
+ fprintf(stderr, "failed to join multicast group: %s\n", strerror(errno));
+ close(fd);
+ fd = -1;
+ return -1;
+ }
+
+ if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0)
+ fprintf(stderr, "ioctl failed: IP_RECVTTL\n");
+
+ if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0)
+ fprintf(stderr, "ioctl failed: IP_PKTINFO\n");
+
+ if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &no, sizeof(no)) < 0)
+ fprintf(stderr, "ioctl failed: IP_MULTICAST_LOOP\n");
+
+ return 0;
+}
+
+static const char*
+get_iface_ipv4(const char *ifname)
+{
+ static char buffer[INET_ADDRSTRLEN];
+ struct ifreq ir;
+ const char *ret;
+ int sock;
+
+ sock = socket(AF_INET, SOCK_DGRAM, 0);
+ if (sock < 0)
+ return NULL;
+
+ memset(&ir, 0, sizeof(struct ifreq));
+ strncpy(ir.ifr_name, ifname, sizeof(ir.ifr_name));
+
+ if (ioctl(sock, SIOCGIFADDR, &ir) < 0)
+ return NULL;
+
+ ret = inet_ntop(AF_INET, &((struct sockaddr_in *) &ir.ifr_addr)->sin_addr, buffer, sizeof(buffer));
+ close(sock);
+
+ return ret;
+}
+
+int interface_add(const char *name)
+{
+ struct interface *iface;
+ const char *ip_str;
+ char *name_buf, *ip_buf;
+
+ ip_str = get_iface_ipv4(name);
+ if (!ip_str)
+ return -1;
+
+ iface = calloc_a(sizeof(*iface),
+ &name_buf, strlen(name) + 1,
+ &ip_buf, strlen(ip_str) + 1);
+
+ iface->name = strcpy(name_buf, name);
+ iface->ip = strcpy(ip_buf, ip_str);
+ iface->ifindex = if_nametoindex(name);
+ iface->fd.fd = -1;
+
+ if (iface->ifindex <= 0)
+ goto error;
+
+ vlist_add(&interfaces, &iface->node, name);
+ return 0;
+
+error:
+ free(iface);
+ return -1;
+}
+
+VLIST_TREE(interfaces, avl_strcmp, iface_update_cb, false, false);
projects / project / mdnsd.git / commitdiff