Date: Tue, 9 Apr 2013 12:58:33 +0100 From: "Steven Hartland" <killing@multiplay.co.uk> To: <freebsd-net@freebsd.org> Subject: Review of patch for raw packet source address selection under jails Message-ID: <FAD0AD4FCFDF46E3A614EF333AA2FE76@multiplay.co.uk>
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Currently source address selection for raw packets under jails
uses prison_get_ip4 in the INADDR_ANY case.
This can cause an invalid source address to be used, including
using addresses which are unusable e.g. down interfaces
un-routable addresses etc.
I suspect this is a hang over from when jails where essentially
single IP.
The attached patch switches to use full resolution for raw
packets via in_pcbladdr, which fixes this problem in all of
our testing.
Is this the correct path to take?
Regards
Steve
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filename="jail-raw-srcaddr.patch"
Fix jailed raw sockets not setting the correct source address by=0A=
calling in_pcbladdr instead of prison_get_ip4=0A=
--- sys/netinet/in_pcb.h.orig 2013-04-05 16:59:33.005670964 +0000=0A=
+++ sys/netinet/in_pcb.h 2013-04-05 17:00:24.725266747 +0000=0A=
@@ -490,6 +490,8 @@=0A=
struct ucred *, int);=0A=
int in_pcbbind_setup(struct inpcb *, struct sockaddr *, in_addr_t *,=0A=
u_short *, struct ucred *);=0A=
+int in_pcbladdr(struct inpcb *, struct in_addr *, struct in_addr *,=0A=
+ struct ucred *);=0A=
int in_pcbconnect(struct inpcb *, struct sockaddr *, struct ucred *);=0A=
int in_pcbconnect_setup(struct inpcb *, struct sockaddr *, in_addr_t *,=0A=
u_short *, in_addr_t *, u_short *, struct inpcb **,=0A=
--- sys/netinet/in_pcb.c.orig 2013-04-05 16:59:28.252798648 +0000=0A=
+++ sys/netinet/in_pcb.c 2013-04-05 16:59:38.888509732 +0000=0A=
@@ -596,7 +596,7 @@=0A=
* Do proper source address selection on an unbound socket in case=0A=
* of connect. Take jails into account as well.=0A=
*/=0A=
-static int=0A=
+int=0A=
in_pcbladdr(struct inpcb *inp, struct in_addr *faddr, struct in_addr =
*laddr,=0A=
struct ucred *cred)=0A=
{=0A=
--- sys/netinet/raw_ip.c.orig 2013-04-05 16:44:24.458314711 +0000=0A=
+++ sys/netinet/raw_ip.c 2013-04-05 17:10:54.902524046 +0000=0A=
@@ -442,16 +442,16 @@=0A=
ip->ip_p =3D inp->inp_ip_p;=0A=
ip->ip_len =3D m->m_pkthdr.len;=0A=
ip->ip_src =3D inp->inp_laddr;=0A=
+ ip->ip_dst.s_addr =3D dst;=0A=
if (jailed(inp->inp_cred)) {=0A=
/*=0A=
* prison_local_ip4() would be good enough but would=0A=
* let a source of INADDR_ANY pass, which we do not=0A=
- * want to see from jails. We do not go through the=0A=
- * pain of in_pcbladdr() for raw sockets.=0A=
+ * want to see from jails.=0A=
*/=0A=
if (ip->ip_src.s_addr =3D=3D INADDR_ANY)=0A=
- error =3D prison_get_ip4(inp->inp_cred,=0A=
- &ip->ip_src);=0A=
+ error =3D in_pcbladdr(inp, &ip->ip_dst, &ip->ip_src,=0A=
+ inp->inp_cred);=0A=
else=0A=
error =3D prison_local_ip4(inp->inp_cred,=0A=
&ip->ip_src);=0A=
@@ -461,7 +461,6 @@=0A=
return (error);=0A=
}=0A=
}=0A=
- ip->ip_dst.s_addr =3D dst;=0A=
ip->ip_ttl =3D inp->inp_ip_ttl;=0A=
} else {=0A=
if (m->m_pkthdr.len > IP_MAXPACKET) {=0A=
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