dnsproxy: Listen on IN6ADDR_ANY not Legacy INADDR_ANY

We set the IPV6_V6ONLY sockopt so that Legacy IP connections also work.
Fall back to listening on INADDR_ANY if IPv6 family support isn't present.

diff --git a/plugins/dnsproxy.c b/plugins/dnsproxy.c
index 775974f..5ce6429 100644 (file)
--- a/plugins/dnsproxy.c
+++ b/plugins/dnsproxy.c
@@ -1293,8 +1293,14 @@ static int create_dns_listener(int protocol)
 {
        GIOChannel *channel;
        const char *ifname = "lo", *proto;
-       struct sockaddr_in sin;
-       int sk, type;
+       union {
+               struct sockaddr sa;
+               struct sockaddr_in6 sin6;
+               struct sockaddr_in sin;
+       } s;
+       socklen_t slen;
+       int sk, type, v6only = 0;
+       int family = AF_INET6;
 
        DBG("");
 
@@ -1313,7 +1319,12 @@ static int create_dns_listener(int protocol)
                return -EINVAL;
        }
 
-       sk = socket(AF_INET, type, protocol);
+       sk = socket(family, type, protocol);
+       if (sk < 0 && family == AF_INET6 && errno == EAFNOSUPPORT) {
+               connman_error("No IPv6 support; DNS proxy listening only on Legacy IP");
+               family = AF_INET;
+               sk = socket(family, type, protocol);
+       }
        if (sk < 0) {
                connman_error("Failed to create %s listener socket", proto);
                return -EIO;
@@ -1325,14 +1336,30 @@ static int create_dns_listener(int protocol)
                close(sk);
                return -EIO;
        }
+       /* Ensure it accepts Legacy IP connections too */
+       if (family == AF_INET6 &&
+           setsockopt(sk, SOL_IPV6, IPV6_V6ONLY, &v6only, sizeof(v6only)) < 0) {
+               connman_error("Failed to clear V6ONLY on %s listener socket",
+                             proto);
+               close(sk);
+               return -EIO;
+       }
 
-       memset(&sin, 0, sizeof(sin));
-       sin.sin_family = AF_INET;
-       sin.sin_port = htons(53);
-       sin.sin_addr.s_addr = inet_addr("127.0.0.1");
-       sin.sin_addr.s_addr = htonl(INADDR_ANY);
+       if (family == AF_INET) {
+               memset(&s.sin, 0, sizeof(s.sin));
+               s.sin.sin_family = AF_INET;
+               s.sin.sin_port = htons(53);
+               s.sin.sin_addr.s_addr = htonl(INADDR_ANY);
+               slen = sizeof(s.sin);
+       } else {
+               memset(&s.sin6, 0, sizeof(s.sin6));
+               s.sin6.sin6_family = AF_INET6;
+               s.sin6.sin6_port = htons(53);
+               s.sin6.sin6_addr = in6addr_any;
+               slen = sizeof(s.sin6);
+       }
 
-       if (bind(sk, (struct sockaddr *) &sin, sizeof(sin)) < 0) {
+       if (bind(sk, &s.sa, slen) < 0) {
                connman_error("Failed to bind %s listener socket", proto);
                close(sk);
                return -EIO;