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Remove historical support for capturing IPX packets in the output path

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using raw IPX sockets.  While functional, this support is disabled
using a flag that can't be changed from userspace, and google reveals
no documentation or use of that flag anywhere.  This eliminates a
potential lock order reversal and code reentrance issue in which the
output path reentered the input path in IPX.

An alternative to removal would be to use the netisr, as a comment I
added in 2005 suggests.  While this change is fairly straight-forward,
the lack of any consumers or the easy possibility of consumers (kernel
modification and recompile required) suggests that this is simply an
unused feature.

Update README to remove this TODO, and a TODO regarding IPX/IP
encapsulation which was also removed a few years ago.

MFC after:	1 week
This commit is contained in:
Robert Watson 2009-06-21 10:10:44 +00:00
parent 4ca8a62bb3
commit 941c2e1cd1
4 changed files with 0 additions and 67 deletions
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8
sys/netipx/README
View File

@ -39,11 +39,3 @@ Modifications Copyright (c) 2004-2006 Robert N. M. Watson
but unsent data. As with TCP, it should instead grab its own
reference to the socket so that it is not released, as hold onto it
until the data transfer is complete.
(3) Raw socket capture of IPX output intercepts packets in the SPX output
routine in order to feed them back into the raw socket. This results
in recursion into the socket code in the transmit path; instead,
captured packets should be fed into a netisr that reinjects them into
raw sockets from a new (asynchronous) context.
(4) IPX over IP encapsulation needs work to make it properly MPSAFE.

50
sys/netipx/ipx_input.c
View File

@ -452,53 +452,3 @@ ipx_undo_route(struct route *ro)
RTFREE(ro->ro_rt);
}
}
/*
* XXXRW: This code should be run in its own netisr dispatch to avoid a call
* back into the socket code from the IPX output path.
*/
void
ipx_watch_output(struct mbuf *m, struct ifnet *ifp)
{
struct ipxpcb *ipxp;
struct ifaddr *ifa;
struct ipx_ifaddr *ia;
/*
* Give any raw listeners a crack at the packet
*/
IPX_LIST_LOCK();
LIST_FOREACH(ipxp, &ipxrawpcb_list, ipxp_list) {
struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
if (m0 != NULL) {
struct ipx *ipx;
M_PREPEND(m0, sizeof(*ipx), M_DONTWAIT);
if (m0 == NULL)
continue;
ipx = mtod(m0, struct ipx *);
ipx->ipx_sna.x_net = ipx_zeronet;
for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
if (ifp == ia->ia_ifp)
break;
if (ia == NULL)
ipx->ipx_sna.x_host = ipx_zerohost;
else
ipx->ipx_sna.x_host =
ia->ia_addr.sipx_addr.x_host;
if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT))
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family == AF_IPX) {
ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
break;
}
}
ipx->ipx_len = ntohl(m0->m_pkthdr.len);
IPX_LOCK(ipxp);
ipx_input(m0, ipxp);
IPX_UNLOCK(ipxp);
}
}
IPX_LIST_UNLOCK();
}

8
sys/netipx/ipx_outputfl.c
View File

@ -74,8 +74,6 @@ __FBSDID("$FreeBSD$");
#include <netipx/ipx_if.h>
#include <netipx/ipx_var.h>
static int ipx_copy_output = 0;
int
ipx_outputfl(struct mbuf *m0, struct route *ro, int flags)
{
@ -150,9 +148,6 @@ ipx_outputfl(struct mbuf *m0, struct route *ro, int flags)
if (htons(ipx->ipx_len) <= ifp->if_mtu) {
ipxstat.ipxs_localout++;
if (ipx_copy_output) {
ipx_watch_output(m0, ifp);
}
error = (*ifp->if_output)(ifp, m0,
(struct sockaddr *)dst, ro);
goto done;
@ -161,9 +156,6 @@ ipx_outputfl(struct mbuf *m0, struct route *ro, int flags)
error = EMSGSIZE;
}
bad:
if (ipx_copy_output) {
ipx_watch_output(m0, ifp);
}
m_freem(m0);
done:
if (ro == &ipxroute && (flags & IPX_ROUTETOIF) == 0 &&

1
sys/netipx/ipx_var.h
View File

@ -124,7 +124,6 @@ int ipx_output_type20(struct mbuf *);
int ipx_peeraddr(struct socket *so, struct sockaddr **nam);
void ipx_printhost(struct ipx_addr *addr);
int ipx_sockaddr(struct socket *so, struct sockaddr **nam);
void ipx_watch_output(struct mbuf *m, struct ifnet *ifp);
#endif /* _KERNEL */