devip: more v6 improvements

ipv4local() and ipv6local() now take remote address argument,
returning the closest local address to the source. this
implements the standartized source address selection rules
instead of just returning the first local v4 or v6 address.

the source address selection was broken for esp, rudp an udp,
blindly assuming ifc->lifc->local being a valid v4 address.
use ipv6local() instead.

the v6 routing code used to lookup source address route to
decide to drop the packet instead of checking the interface
on the destination route.

factor out the route hint from Conv and put it in Routehint
structure. avoiding stack bloat in v4 routing. implement the
same trick for v6 avoiding second route lookup in ipoput6.

fix memory leak in icmpv6 router solicitation handling.

remove old unfinished handling of multiple v6 routers. should
implement source specific routes instead.

avoid duplication, use common convipvers() function.

use isv4() instead of memcmp v4prefix.

1 files changed, 15 insertions, 25 deletions

diff --git a/sys/src/9/ip/ip.h b/sys/src/9/ip/ip.h
index 7eb001ba8..84e776e4e 100644
--- a/sys/src/9/ip/ip.h
+++ b/sys/src/9/ip/ip.h
@@ -21,10 +21,10 @@ typedef struct	Proto	Proto;
 typedef struct	Arpent	Arpent;
 typedef struct	Arp Arp;
 typedef struct	Route	Route;
+typedef struct	Routehint Routehint;
 
 typedef struct	Routerparams	Routerparams;
 typedef struct 	Hostparams	Hostparams;
-typedef struct 	v6router	v6router;
 typedef struct	v6params	v6params;
 
 #pragma incomplete Arp
@@ -164,6 +164,12 @@ struct Ip4hdr
 	uchar	dst[4];		/* IP destination */
 };
 
+struct Routehint
+{
+	Route	*r;			/* last route used */
+	ulong	rgen;			/* routetable generation for *r */
+};
+
 /*
  *  one per conversation directory
  */
@@ -191,8 +197,6 @@ struct Conv
 	int	length;
 	int	state;
 
-	int	maxfragsize;		/* If set, used for fragmentation */
-
 	/* udp specific */
 	int	headers;		/* data src/dst headers in udp */
 	int	reliable;		/* true if reliable udp */
@@ -217,8 +221,7 @@ struct Conv
 
 	void*	ptcl;			/* protocol specific stuff */
 
-	Route	*r;			/* last route used */
-	ulong	rgen;			/* routetable generation for *r */
+	Routehint;
 };
 
 struct Medium
@@ -443,23 +446,10 @@ struct Fs
 	long	ndbmtime;
 };
 
-/* one per default router known to host */
-struct v6router {
-	uchar	inuse;
-	Ipifc	*ifc;
-	int	ifcid;
-	uchar	routeraddr[IPaddrlen];
-	long	ltorigin;
-	Routerparams	rp;
-};
-
 struct v6params
 {
 	Routerparams	rp;		/* v6 params, one copy per node now */
 	Hostparams	hp;
-	v6router	v6rlist[3];	/* max 3 default routers, currently */
-	int		cdrouter;	/* uses only v6rlist[cdrouter] if   */
-					/* cdrouter >= 0. */
 };
 
 
@@ -586,8 +576,8 @@ extern void	v4addroute(Fs *f, char *tag, uchar *a, uchar *mask, uchar *gate, int
 extern void	v6addroute(Fs *f, char *tag, uchar *a, uchar *mask, uchar *gate, int type);
 extern void	v4delroute(Fs *f, uchar *a, uchar *mask, int dolock);
 extern void	v6delroute(Fs *f, uchar *a, uchar *mask, int dolock);
-extern Route*	v4lookup(Fs *f, uchar *a, Conv *c);
-extern Route*	v6lookup(Fs *f, uchar *a, Conv *c);
+extern Route*	v4lookup(Fs *f, uchar *a, Routehint *h);
+extern Route*	v6lookup(Fs *f, uchar *a, Routehint *h);
 extern long	routeread(Fs *f, char*, ulong, int);
 extern long	routewrite(Fs *f, Chan*, char*, int);
 extern void	routetype(int, char*);
@@ -654,6 +644,7 @@ extern int	isv4(uchar*);
 extern void	v4tov6(uchar *v6, uchar *v4);
 extern int	v6tov4(uchar *v4, uchar *v6);
 extern int	eipfmt(Fmt*);
+extern int	convipvers(Conv *c);
 
 #define	ipmove(x, y) memmove(x, y, IPaddrlen)
 #define	ipcmp(x, y) ( (x)[IPaddrlen-1] != (y)[IPaddrlen-1] || memcmp(x, y, IPaddrlen) )
@@ -686,9 +677,8 @@ extern int	ipisbm(uchar *);
 extern int	ipismulticast(uchar *);
 extern Ipifc*	findipifc(Fs*, uchar *remote, int type);
 extern void	findlocalip(Fs*, uchar *local, uchar *remote);
-extern int	ipv4local(Ipifc *ifc, uchar *addr);
-extern int	ipv6local(Ipifc *ifc, uchar *addr);
-extern int	ipv6anylocal(Ipifc *ifc, uchar *addr);
+extern int	ipv4local(Ipifc *ifc, uchar *local, uchar *remote);
+extern int	ipv6local(Ipifc *ifc, uchar *local, uchar *remote);
 extern Iplifc*	iplocalonifc(Ipifc *ifc, uchar *ip);
 extern int	ipproxyifc(Fs *f, Ipifc *ifc, uchar *ip);
 extern int	ipismulticast(uchar *ip);
@@ -714,8 +704,8 @@ extern void	icmpttlexceeded(Fs*, uchar*, Block*);
 extern ushort	ipcsum(uchar*);
 extern void	ipiput4(Fs*, Ipifc*, Block*);
 extern void	ipiput6(Fs*, Ipifc*, Block*);
-extern int	ipoput4(Fs*, Block*, int, int, int, Conv*);
-extern int	ipoput6(Fs*, Block*, int, int, int, Conv*);
+extern int	ipoput4(Fs*, Block*, int, int, int, Routehint*);
+extern int	ipoput6(Fs*, Block*, int, int, int, Routehint*);
 extern int	ipstats(Fs*, char*, int);
 extern ushort	ptclbsum(uchar*, int);
 extern ushort	ptclcsum(Block*, int, int);