From 953a02d11bed5f1b01e3f37a4bb17a5464d3a2ba Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 18 Mar 2019 12:01:02 +0100
Subject: [PATCH] tree-wide: port various users over to
 socket_bind_to_ifindex()

---
 src/basic/socket-label.c              |  8 +++++---
 src/libsystemd-network/dhcp-network.c |  8 ++------
 src/libsystemd-network/icmp6-util.c   | 12 ++++--------
 src/resolve/resolved-dns-stub.c       | 10 ++++++----
 4 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/src/basic/socket-label.c b/src/basic/socket-label.c
index 4ed19cd..b5e9b37 100644
--- a/src/basic/socket-label.c
+++ b/src/basic/socket-label.c
@@ -68,9 +68,11 @@ int socket_address_listen(
         }
 
         if (IN_SET(socket_address_family(a), AF_INET, AF_INET6)) {
-                if (bind_to_device)
-                        if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, bind_to_device, strlen(bind_to_device)+1) < 0)
-                                return -errno;
+                if (bind_to_device) {
+                        r = socket_bind_to_ifname(fd, bind_to_device);
+                        if (r < 0)
+                                return r;
+                }
 
                 if (reuse_port) {
                         r = setsockopt_int(fd, SOL_SOCKET, SO_REUSEPORT, true);
diff --git a/src/libsystemd-network/dhcp-network.c b/src/libsystemd-network/dhcp-network.c
index b62eed0..94c10ed 100644
--- a/src/libsystemd-network/dhcp-network.c
+++ b/src/libsystemd-network/dhcp-network.c
@@ -153,7 +153,6 @@ int dhcp_network_bind_udp_socket(int ifindex, be32_t address, uint16_t port) {
                 .in.sin_addr.s_addr = address,
         };
         _cleanup_close_ int s = -1;
-        char ifname[IF_NAMESIZE] = "";
         int r;
 
         s = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
@@ -169,12 +168,9 @@ int dhcp_network_bind_udp_socket(int ifindex, be32_t address, uint16_t port) {
                 return r;
 
         if (ifindex > 0) {
-                if (if_indextoname(ifindex, ifname) == 0)
-                        return -errno;
-
-                r = setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
+                r = socket_bind_to_ifindex(s, ifindex);
                 if (r < 0)
-                        return -errno;
+                        return r;
         }
 
         if (address == INADDR_ANY) {
diff --git a/src/libsystemd-network/icmp6-util.c b/src/libsystemd-network/icmp6-util.c
index e535b12..e1f193a 100644
--- a/src/libsystemd-network/icmp6-util.c
+++ b/src/libsystemd-network/icmp6-util.c
@@ -31,9 +31,8 @@
 
 static int icmp6_bind_router_message(const struct icmp6_filter *filter,
                                      const struct ipv6_mreq *mreq) {
-        int index = mreq->ipv6mr_interface;
+        int ifindex = mreq->ipv6mr_interface;
         _cleanup_close_ int s = -1;
-        char ifname[IF_NAMESIZE] = "";
         int r;
 
         s = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK, IPPROTO_ICMPV6);
@@ -52,7 +51,7 @@ static int icmp6_bind_router_message(const struct icmp6_filter *filter,
            IPV6_PKTINFO socket option also applies for ICMPv6 multicast.
            Empirical experiments indicates otherwise and therefore an
            IPV6_MULTICAST_IF socket option is used here instead */
-        r = setsockopt_int(s, IPPROTO_IPV6, IPV6_MULTICAST_IF, index);
+        r = setsockopt_int(s, IPPROTO_IPV6, IPV6_MULTICAST_IF, ifindex);
         if (r < 0)
                 return r;
 
@@ -76,12 +75,9 @@ static int icmp6_bind_router_message(const struct icmp6_filter *filter,
         if (r < 0)
                 return r;
 
-        if (if_indextoname(index, ifname) == 0)
-                return -errno;
-
-        r = setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
+        r = socket_bind_to_ifindex(s, ifindex);
         if (r < 0)
-                return -errno;
+                return r;
 
         return TAKE_FD(s);
 }
diff --git a/src/resolve/resolved-dns-stub.c b/src/resolve/resolved-dns-stub.c
index 2bf04db..65c8094 100644
--- a/src/resolve/resolved-dns-stub.c
+++ b/src/resolve/resolved-dns-stub.c
@@ -421,8 +421,9 @@ static int manager_dns_stub_udp_fd(Manager *m) {
                 return r;
 
         /* Make sure no traffic from outside the local host can leak to onto this socket */
-        if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, "lo", 3) < 0)
-                return -errno;
+        r = socket_bind_to_ifindex(fd, LOOPBACK_IFINDEX);
+        if (r < 0)
+                return r;
 
         if (bind(fd, &sa.sa, sizeof(sa.in)) < 0)
                 return -errno;
@@ -514,8 +515,9 @@ static int manager_dns_stub_tcp_fd(Manager *m) {
                 return r;
 
         /* Make sure no traffic from outside the local host can leak to onto this socket */
-        if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, "lo", 3) < 0)
-                return -errno;
+        r = socket_bind_to_ifindex(fd, LOOPBACK_IFINDEX);
+        if (r < 0)
+                return r;
 
         if (bind(fd, &sa.sa, sizeof(sa.in)) < 0)
                 return -errno;
-- 
2.7.4