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

7 files changed, 72 insertions, 35 deletions

diff --git a/libc/include/netdb.h b/libc/include/netdb.h
index 3ea512c75..62a7a3cc8 100644
--- a/libc/include/netdb.h
+++ b/libc/include/netdb.h
@@ -207,13 +207,13 @@ void endprotoent(void);
 void endservent(void);
 void freehostent(struct hostent *);
 struct hostent	*gethostbyaddr(const void *, socklen_t, int);
-struct hostent	*android_gethostbyaddrforiface(const void *, socklen_t, int, const char*);
+struct hostent	*android_gethostbyaddrforiface(const void *, socklen_t, int, const char*, int);
 int gethostbyaddr_r(const void *, int, int, struct hostent *, char *, size_t, struct hostent **, int *);
 struct hostent	*gethostbyname(const char *);
 int gethostbyname_r(const char *, struct hostent *, char *, size_t, struct hostent **, int *);
 struct hostent	*gethostbyname2(const char *, int);
 int gethostbyname2_r(const char *, int, struct hostent *, char *, size_t, struct hostent **, int *);
-struct hostent	*android_gethostbynameforiface(const char *, int, const char *);
+struct hostent	*android_gethostbynameforiface(const char *, int, const char *, int);
 struct hostent	*gethostent(void);
 int gethostent_r(struct hostent *, char *, size_t, struct hostent **, int *);
 struct hostent	*getipnodebyaddr(const void *, size_t, int, int *);
@@ -241,9 +241,9 @@ void sethostent(int);
 void setnetent(int);
 void setprotoent(int);
 int getaddrinfo(const char *, const char *, const struct addrinfo *, struct addrinfo **);
-int android_getaddrinfoforiface(const char *, const char *, const struct addrinfo *, const char *, struct addrinfo **);
+int android_getaddrinfoforiface(const char *, const char *, const struct addrinfo *, const char *, int, struct addrinfo **);
 int getnameinfo(const struct sockaddr *, socklen_t, char *, size_t, char *, size_t, int);
-int android_getnameinfoforiface(const struct sockaddr *, socklen_t, char *, size_t, char *, size_t, int, const char *);
+int android_getnameinfoforiface(const struct sockaddr *, socklen_t, char *, size_t, char *, size_t, int, const char *, int);
 void freeaddrinfo(struct addrinfo *);
 const char	*gai_strerror(int);
 void setnetgrent(const char *);
diff --git a/libc/netbsd/gethnamaddr.c b/libc/netbsd/gethnamaddr.c
index ee5052e4c..5b2f98750 100644
--- a/libc/netbsd/gethnamaddr.c
+++ b/libc/netbsd/gethnamaddr.c
@@ -126,7 +126,7 @@ static struct hostent *_gethtbyname2(const char *, int);
 static int _dns_gethtbyaddr(void *, void *, va_list);
 static int _dns_gethtbyname(void *, void *, va_list);
 
-static struct hostent *gethostbyname_internal(const char *, int, res_state, const char *);
+static struct hostent *gethostbyname_internal(const char *, int, res_state, const char *, int);
 
 static const ns_src default_dns_files[] = {
 	{ NSSRC_FILES, 	NS_SUCCESS },
@@ -497,13 +497,13 @@ gethostbyname(const char *name)
 
 	/* try IPv6 first - if that fails do IPv4 */
 	if (res->options & RES_USE_INET6) {
-		hp = gethostbyname_internal(name, AF_INET6, res, NULL);
+		hp = gethostbyname_internal(name, AF_INET6, res, NULL, 0);
 		if (hp) {
 			__res_put_state(res);
 			return hp;
 		}
 	}
-	hp = gethostbyname_internal(name, AF_INET, res, NULL);
+	hp = gethostbyname_internal(name, AF_INET, res, NULL, 0);
 	__res_put_state(res);
 	return hp;
 }
@@ -511,18 +511,18 @@ gethostbyname(const char *name)
 struct hostent *
 gethostbyname2(const char *name, int af)
 {
-	return android_gethostbynameforiface(name, af, NULL);
+	return android_gethostbynameforiface(name, af, NULL, 0);
 }
 
 struct hostent *
-android_gethostbynameforiface(const char *name, int af, const char *iface)
+android_gethostbynameforiface(const char *name, int af, const char *iface, int mark)
 {
 	struct hostent *hp;
 	res_state res = __res_get_state();
 
 	if (res == NULL)
 		return NULL;
-	hp = gethostbyname_internal(name, af, res, iface);
+	hp = gethostbyname_internal(name, af, res, iface, mark);
 	__res_put_state(res);
 	return hp;
 }
@@ -741,7 +741,7 @@ gethostbyname_internal_real(const char *name, int af, res_state res)
 
 // very similar in proxy-ness to android_getaddrinfo_proxy
 static struct hostent *
-gethostbyname_internal(const char *name, int af, res_state res, const char *iface)
+gethostbyname_internal(const char *name, int af, res_state res, const char *iface, int mark)
 {
 	const char *cache_mode = getenv("ANDROID_DNS_MODE");
 	FILE* proxy = NULL;
@@ -749,6 +749,7 @@ gethostbyname_internal(const char *name, int af, res_state res, const char *ifac
 
 	if (cache_mode != NULL && strcmp(cache_mode, "local") == 0) {
 		res_setiface(res, iface);
+		res_setmark(res, mark);
 		return gethostbyname_internal_real(name, af, res);
 	}
 
@@ -780,7 +781,7 @@ exit:
 
 struct hostent *
 android_gethostbyaddrforiface_proxy(const void *addr,
-    socklen_t len, int af, const char* iface)
+    socklen_t len, int af, const char* iface, int mark)
 {
 	struct hostent *result = NULL;
 	FILE* proxy = android_open_proxy();
@@ -810,7 +811,7 @@ exit:
 
 struct hostent *
 android_gethostbyaddrforiface_real(const void *addr,
-    socklen_t len, int af, const char* iface)
+    socklen_t len, int af, const char* iface, int mark)
 {
 	const u_char *uaddr = (const u_char *)addr;
 	socklen_t size;
@@ -858,28 +859,28 @@ android_gethostbyaddrforiface_real(const void *addr,
 	hp = NULL;
 	h_errno = NETDB_INTERNAL;
 	if (nsdispatch(&hp, dtab, NSDB_HOSTS, "gethostbyaddr",
-	    default_dns_files, uaddr, len, af, iface) != NS_SUCCESS)
+		default_dns_files, uaddr, len, af, iface, mark) != NS_SUCCESS)
 		return NULL;
 	h_errno = NETDB_SUCCESS;
 	return hp;
 }
 
 struct hostent *
-android_gethostbyaddrforiface(const void *addr, socklen_t len, int af, const char* iface)
+android_gethostbyaddrforiface(const void *addr, socklen_t len, int af, const char* iface, int mark)
 {
 	const char *cache_mode = getenv("ANDROID_DNS_MODE");
 
 	if (cache_mode == NULL || strcmp(cache_mode, "local") != 0) {
-		return android_gethostbyaddrforiface_proxy(addr, len, af, iface);
+		return android_gethostbyaddrforiface_proxy(addr, len, af, iface, mark);
 	} else {
-		return android_gethostbyaddrforiface_real(addr,len, af,iface);
+		return android_gethostbyaddrforiface_real(addr,len, af, iface, mark);
 	}
 }
 
 struct hostent *
 gethostbyaddr(const void *addr, socklen_t len, int af)
 {
-	return android_gethostbyaddrforiface(addr, len, af, NULL);
+	return android_gethostbyaddrforiface(addr, len, af, NULL, 0);
 }
 
 
@@ -1315,6 +1316,7 @@ _dns_gethtbyaddr(void *rv, void	*cb_data, va_list ap)
 	int len, af, advance;
 	res_state res;
 	const char* iface;
+	int mark;
 	res_static rs = __res_get_static();
 
 	assert(rv != NULL);
@@ -1323,6 +1325,7 @@ _dns_gethtbyaddr(void *rv, void	*cb_data, va_list ap)
 	len = va_arg(ap, int);
 	af = va_arg(ap, int);
 	iface = va_arg(ap, char *);
+	mark = va_arg(ap, int);
 
 	switch (af) {
 	case AF_INET:
@@ -1365,6 +1368,7 @@ _dns_gethtbyaddr(void *rv, void	*cb_data, va_list ap)
 		return NS_NOTFOUND;
 	}
 	res_setiface(res, iface);
+	res_setmark(res, mark);
 	n = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf, sizeof(buf->buf));
 	if (n < 0) {
 		free(buf);
diff --git a/libc/netbsd/net/getaddrinfo.c b/libc/netbsd/net/getaddrinfo.c
index 401bc6efc..0a5e436ba 100644
--- a/libc/netbsd/net/getaddrinfo.c
+++ b/libc/netbsd/net/getaddrinfo.c
@@ -214,7 +214,7 @@ struct res_target {
 
 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 @@ int
 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 @@ android_getaddrinfoforiface(const char *hostname, const char *servname,
 			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 @@ android_getaddrinfoforiface(const char *hostname, const char *servname,
  */
 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 @@ explore_fqdn(const struct addrinfo *pai, const char *hostname,
 		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 @@ _dns_getaddrinfo(void *rv, void	*cb_data, va_list ap)
 	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 @@ _dns_getaddrinfo(void *rv, void	*cb_data, va_list ap)
 	 * 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 ade5240bd..15d267570 100644
--- a/libc/netbsd/net/getnameinfo.c
+++ b/libc/netbsd/net/getnameinfo.c
@@ -93,7 +93,7 @@ struct sockinet {
 };
 
 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 @@ static int getnameinfo_local(const struct sockaddr *, socklen_t, char *,
  */
 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 @@ getnameinfo_local(const struct sockaddr *sa, socklen_t salen,
  * 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 @@ static int
 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 @@ getnameinfo_inet(const struct sockaddr* sa, socklen_t salen,
 		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) {
diff --git a/libc/netbsd/resolv/res_init.c b/libc/netbsd/resolv/res_init.c
index ff6529944..ceb412b85 100644
--- a/libc/netbsd/resolv/res_init.c
+++ b/libc/netbsd/resolv/res_init.c
@@ -806,4 +806,11 @@ void res_setiface(res_state statp, const char* iface)
 		}
 	}
 }
+
+void res_setmark(res_state statp, int mark)
+{
+	if (statp != NULL) {
+		statp->_mark = mark;
+	}
+}
 #endif /* ANDROID_CHANGES */
diff --git a/libc/netbsd/resolv/res_send.c b/libc/netbsd/resolv/res_send.c
index 0bb5b6b0c..f65b01584 100644
--- a/libc/netbsd/resolv/res_send.c
+++ b/libc/netbsd/resolv/res_send.c
@@ -762,10 +762,13 @@ send_vc(res_state statp,
 	if (statp->_vcsock >= 0 && (statp->_flags & RES_F_VC) != 0) {
 		struct sockaddr_storage peer;
 		socklen_t size = sizeof peer;
-
+		int old_mark;
+		int mark_size = sizeof(old_mark);
 		if (getpeername(statp->_vcsock,
 				(struct sockaddr *)(void *)&peer, &size) < 0 ||
-		    !sock_eq((struct sockaddr *)(void *)&peer, nsap)) {
+		    !sock_eq((struct sockaddr *)(void *)&peer, nsap) ||
+			getsockopt(statp->_vcsock, SOL_SOCKET, SO_MARK, &old_mark, &mark_size) < 0 ||
+			old_mark != statp->_mark) {
 			res_nclose(statp);
 			statp->_flags &= ~RES_F_VC;
 		}
@@ -795,6 +798,14 @@ send_vc(res_state statp,
 				return (-1);
 			}
 		}
+		if (statp->_mark != 0) {
+			if (setsockopt(statp->_vcsock, SOL_SOCKET,
+				        SO_MARK, &statp->_mark, sizeof(statp->_mark)) < 0) {
+				*terrno = errno;
+				Perror(statp, stderr, "setsockopt", errno);
+				return -1;
+			}
+		}
 		errno = 0;
 		if (random_bind(statp->_vcsock,nsap->sa_family) < 0) {
 			*terrno = errno;
@@ -1070,6 +1081,14 @@ send_dg(res_state statp,
 				return (-1);
 			}
 		}
+
+		if (statp->_mark != 0) {
+			if (setsockopt(EXT(statp).nssocks[ns], SOL_SOCKET,
+					SO_MARK, &(statp->_mark), sizeof(statp->_mark)) < 0) {
+				res_nclose(statp);
+				return -1;
+			}
+		}
 #ifndef CANNOT_CONNECT_DGRAM
 		/*
 		 * On a 4.3BSD+ machine (client and server,
@@ -1097,6 +1116,7 @@ send_dg(res_state statp,
 #endif /* !CANNOT_CONNECT_DGRAM */
 		Dprint(statp->options & RES_DEBUG,
 		       (stdout, ";; new DG socket\n"))
+
 	}
 	s = EXT(statp).nssocks[ns];
 #ifndef CANNOT_CONNECT_DGRAM
diff --git a/libc/private/resolv_private.h b/libc/private/resolv_private.h
index 0e799ca2f..61db8c8c0 100644
--- a/libc/private/resolv_private.h
+++ b/libc/private/resolv_private.h
@@ -175,6 +175,7 @@ struct __res_state {
 	res_send_qhook qhook;		/* query hook */
 	res_send_rhook rhook;		/* response hook */
 	int	res_h_errno;		/* last one set for this context */
+	int _mark;          /* If non-0 SET_MARK to _mark on all request sockets */
 	int	_vcsock;		/* PRIVATE: for res_send VC i/o */
 	u_int	_flags;			/* PRIVATE: see below */
 	u_int	_pad;			/* make _u 64 bit aligned */
@@ -496,6 +497,7 @@ int		res_getservers(res_state,
 				    union res_sockaddr_union *, int);
 
 void res_setiface();
+void res_setmark();
 u_int  res_randomid(void);
 
 __END_DECLS