Add marking of DNS sockets for mark based routing

Adds an extra mark parameter to android_getaddrinfoforiface,
android_gethostbyaddrforiface and android_gethostbynameforiface that if set
will cause all packets sent by DNS requests to have that mark

Change-Id: I6f72390e4ce5bfc3cc73183f9b2fb3705a11685f
diff --git a/libc/netbsd/net/getaddrinfo.c b/libc/netbsd/net/getaddrinfo.c
index 401bc6e..0a5e436 100644
--- a/libc/netbsd/net/getaddrinfo.c
+++ b/libc/netbsd/net/getaddrinfo.c
@@ -214,7 +214,7 @@
 
 static int str2number(const char *);
 static int explore_fqdn(const struct addrinfo *, const char *,
-	const char *, struct addrinfo **, const char *iface);
+	const char *, struct addrinfo **, const char *iface, int mark);
 static int explore_null(const struct addrinfo *,
 	const char *, struct addrinfo **);
 static int explore_numeric(const struct addrinfo *, const char *,
@@ -577,12 +577,12 @@
 getaddrinfo(const char *hostname, const char *servname,
     const struct addrinfo *hints, struct addrinfo **res)
 {
-	return android_getaddrinfoforiface(hostname, servname, hints, NULL, res);
+	return android_getaddrinfoforiface(hostname, servname, hints, NULL, 0, res);
 }
 
 int
 android_getaddrinfoforiface(const char *hostname, const char *servname,
-    const struct addrinfo *hints, const char *iface, struct addrinfo **res)
+    const struct addrinfo *hints, const char *iface, int mark, struct addrinfo **res)
 {
 	struct addrinfo sentinel;
 	struct addrinfo *cur;
@@ -761,7 +761,7 @@
 			pai->ai_protocol = ex->e_protocol;
 
 		error = explore_fqdn(pai, hostname, servname,
-			&cur->ai_next, iface);
+			&cur->ai_next, iface, mark);
 
 		while (cur && cur->ai_next)
 			cur = cur->ai_next;
@@ -794,7 +794,7 @@
  */
 static int
 explore_fqdn(const struct addrinfo *pai, const char *hostname,
-    const char *servname, struct addrinfo **res, const char *iface)
+    const char *servname, struct addrinfo **res, const char *iface, int mark)
 {
 	struct addrinfo *result;
 	struct addrinfo *cur;
@@ -820,7 +820,7 @@
 		return 0;
 
 	switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo",
-			default_dns_files, hostname, pai, iface)) {
+			default_dns_files, hostname, pai, iface, mark)) {
 	case NS_TRYAGAIN:
 		error = EAI_AGAIN;
 		goto free;
@@ -1889,10 +1889,12 @@
 	struct res_target q, q2;
 	res_state res;
 	const char* iface;
+	int mark;
 
 	name = va_arg(ap, char *);
 	pai = va_arg(ap, const struct addrinfo *);
 	iface = va_arg(ap, char *);
+	mark = va_arg(ap, int);
 	//fprintf(stderr, "_dns_getaddrinfo() name = '%s'\n", name);
 
 	memset(&q, 0, sizeof(q));
@@ -1980,6 +1982,7 @@
 	 * and have a cache hit that would be wasted, so we do the rest there on miss
 	 */
 	res_setiface(res, iface);
+	res_setmark(res, mark);
 	if (res_searchN(name, &q, res) < 0) {
 		__res_put_state(res);
 		free(buf);
diff --git a/libc/netbsd/net/getnameinfo.c b/libc/netbsd/net/getnameinfo.c
index ade5240..15d2675 100644
--- a/libc/netbsd/net/getnameinfo.c
+++ b/libc/netbsd/net/getnameinfo.c
@@ -93,7 +93,7 @@
 };
 
 static int getnameinfo_inet(const struct sockaddr *, socklen_t, char *,
-    socklen_t, char *, socklen_t, int, const char*);
+    socklen_t, char *, socklen_t, int, const char*, int);
 #ifdef INET6
 static int ip6_parsenumeric(const struct sockaddr *, const char *, char *,
 				 socklen_t, int);
@@ -108,16 +108,16 @@
  */
 int getnameinfo(const struct sockaddr* sa, socklen_t salen, char* host, size_t hostlen, char* serv, size_t servlen, int flags)
 {
-	return android_getnameinfoforiface(sa, salen, host, hostlen, serv, servlen, flags, NULL);
+	return android_getnameinfoforiface(sa, salen, host, hostlen, serv, servlen, flags, NULL, 0);
 }
 
-int android_getnameinfoforiface(const struct sockaddr* sa, socklen_t salen, char* host, size_t hostlen, char* serv, size_t servlen, int flags, const char* iface)
+int android_getnameinfoforiface(const struct sockaddr* sa, socklen_t salen, char* host, size_t hostlen, char* serv, size_t servlen, int flags, const char* iface, int mark)
 {
 	switch (sa->sa_family) {
 	case AF_INET:
 	case AF_INET6:
 		return getnameinfo_inet(sa, salen, host, hostlen,
-				serv, servlen, flags, iface);
+				serv, servlen, flags, iface, mark);
 	case AF_LOCAL:
 		return getnameinfo_local(sa, salen, host, hostlen,
 		    serv, servlen, flags);
@@ -158,10 +158,10 @@
  * the address. On failure -1 is returned in which case
  * normal execution flow shall continue. */
 static int
-android_gethostbyaddr_proxy(char* nameBuf, size_t nameBufLen, const void *addr, socklen_t addrLen, int addrFamily, const char* iface)
+android_gethostbyaddr_proxy(char* nameBuf, size_t nameBufLen, const void *addr, socklen_t addrLen, int addrFamily, const char* iface, int mark)
 {
 	struct hostent *hostResult =
-			android_gethostbyaddrforiface_proxy(addr, addrLen, addrFamily, iface);
+			android_gethostbyaddrforiface_proxy(addr, addrLen, addrFamily, iface, mark);
 
 	if (hostResult == NULL) return 0;
 
@@ -179,7 +179,7 @@
 getnameinfo_inet(const struct sockaddr* sa, socklen_t salen,
        char *host, socklen_t hostlen,
        char *serv, socklen_t servlen,
-       int flags, const char* iface)
+       int flags, const char* iface, int mark)
 {
 	const struct afd *afd;
 	struct servent *sp;
@@ -321,14 +321,15 @@
 		char android_proxy_buf[MAXDNAME];
 
 		int hostnamelen = android_gethostbyaddr_proxy(android_proxy_buf,
-				MAXDNAME, addr, afd->a_addrlen, afd->a_af, iface);
+				MAXDNAME, addr, afd->a_addrlen, afd->a_af, iface, mark);
 		if (hostnamelen > 0) {
 			hp = &android_proxy_hostent;
 			hp->h_name = android_proxy_buf;
 		} else if (!hostnamelen) {
 			hp = NULL;
 		} else {
-			hp = android_gethostbyaddrforiface(addr, afd->a_addrlen, afd->a_af, iface);
+			hp = android_gethostbyaddrforiface(addr, afd->a_addrlen, afd->a_af,
+					iface, mark);
 		}
 
 		if (hp) {