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Finish r275196: do not dereference rtentry in if_output() routines.

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The only piece of information that is required is rt_flags subset.

In particular, if_loop() requires RTF_REJECT and RTF_BLACKHOLE flags
  to check if this particular mbuf needs to be dropped (and what
  error should be returned).
Note that if_loop() will always return EHOSTUNREACH for "reject" routes
  regardless of RTF_HOST flag existence. This is due to upcoming routing
  changes where RTF_HOST value won't be available as lookup result.

All other functions require RTF_GATEWAY flag to check if they need
  to return EHOSTUNREACH instead of EHOSTDOWN error.

There are 11 places where non-zero 'struct route' is passed to if_output().
For most of the callers (forwarding, bpf, arp) does not care about exact
  error value. In fact, the only place where this result is propagated
  is ip_output(). (ip6_output() passes NULL route to nd6_output_ifp()).

Given that, add 3 new 'struct route' flags (RT_REJECT, RT_BLACKHOLE and
  RT_IS_GW) and inline function (rt_update_ro_flags()) to copy necessary
  rte flags to ro_flags. Call this function in ip_output() after looking up/
  verifying rte.

Reviewed by:	ae
This commit is contained in:
melifaro 2016-01-09 16:34:37 +00:00
parent b67974b0be
commit e4b451498b
9 changed files with 34 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
sys/net/if_arcsubr.c
View File

@ -113,9 +113,8 @@ arc_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
error = 0;
#if defined(INET) || defined(INET6)
if (ro != NULL && ro->ro_rt != NULL &&
(ro->ro_rt->rt_flags & RTF_GATEWAY) != 0)
is_gw = 1;
if (ro != NULL)
is_gw = (ro->ro_flags & RT_HAS_GW) != 0;
#endif
switch (dst->sa_family) {

4
sys/net/if_ethersubr.c
View File

@ -202,7 +202,6 @@ ether_resolve_addr(struct ifnet *ifp, struct mbuf *m,
uint32_t *pflags)
{
struct ether_header *eh;
struct rtentry *rt;
uint32_t lleflags = 0;
int error = 0;
#if defined(INET) || defined(INET6)
@ -253,8 +252,7 @@ ether_resolve_addr(struct ifnet *ifp, struct mbuf *m,
}
if (error == EHOSTDOWN) {
rt = (ro != NULL) ? ro->ro_rt : NULL;
if (rt != NULL && (rt->rt_flags & RTF_GATEWAY) != 0)
if (ro != NULL && (ro->ro_flags & RT_HAS_GW) != 0)
error = EHOSTUNREACH;
}

5
sys/net/if_fddisubr.c
View File

@ -119,9 +119,8 @@ fddi_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
getmicrotime(&ifp->if_lastchange);
#if defined(INET) || defined(INET6)
if (ro != NULL && ro->ro_rt != NULL &&
(ro->ro_rt->rt_flags & RTF_GATEWAY) != 0)
is_gw = 1;
if (ro != NULL)
is_gw = (ro->ro_flags & RT_HAS_GW) != 0;
#endif
switch (dst->sa_family) {

9
sys/net/if_fwsubr.c
View File

@ -106,9 +106,8 @@ firewire_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
}
#if defined(INET) || defined(INET6)
if (ro != NULL && ro->ro_rt != NULL &&
(ro->ro_rt->rt_flags & RTF_GATEWAY) != 0)
is_gw = 1;
if (ro != NULL)
is_gw = (ro->ro_flags & RT_HAS_GW) != 0;
#endif
/*
* For unicast, we make a tag to store the lladdr of the
@ -145,10 +144,6 @@ firewire_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
* doesn't fit into the arp model.
*/
if (unicast) {
is_gw = 0;
if (ro != NULL && ro->ro_rt != NULL &&
(ro->ro_rt->rt_flags & RTF_GATEWAY) != 0)
is_gw = 1;
error = arpresolve(ifp, is_gw, m, dst, (u_char *) destfw, NULL);
if (error)
return (error == EWOULDBLOCK ? 0 : error);

8
sys/net/if_iso88025subr.c
View File

@ -214,12 +214,8 @@ iso88025_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
struct rtentry *rt0 = NULL;
int is_gw = 0;
if (ro != NULL) {
rt0 = ro->ro_rt;
if (rt0 != NULL && (rt0->rt_flags & RTF_GATEWAY) != 0)
is_gw = 1;
}
if (ro != NULL)
is_gw = (ro->ro_flags & RT_HAS_GW) != 0;
#ifdef MAC
error = mac_ifnet_check_transmit(ifp, m);
if (error)

8
sys/net/if_loop.c
View File

@ -202,15 +202,12 @@ looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
struct route *ro)
{
u_int32_t af;
struct rtentry *rt = NULL;
#ifdef MAC
int error;
#endif
M_ASSERTPKTHDR(m); /* check if we have the packet header */
if (ro != NULL)
rt = ro->ro_rt;
#ifdef MAC
error = mac_ifnet_check_transmit(ifp, m);
if (error) {
@ -219,10 +216,9 @@ looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
}
#endif
if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
if (ro != NULL && ro->ro_flags & (RT_REJECT|RT_BLACKHOLE)) {
m_freem(m);
return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
return (ro->ro_flags & RT_BLACKHOLE ? 0 : EHOSTUNREACH);
}
if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);

23
sys/net/route.h
View File

@ -64,9 +64,13 @@ struct route {
#define RT_CACHING_CONTEXT 0x1 /* XXX: not used anywhere */
#define RT_NORTREF 0x2 /* doesn't hold reference on ro_rt */
#define RT_L2_ME (1 << RT_L2_ME_BIT)
#define RT_MAY_LOOP (1 << RT_MAY_LOOP_BIT)
#define RT_HAS_HEADER (1 << RT_HAS_HEADER_BIT)
#define RT_L2_ME (1 << RT_L2_ME_BIT) /* 0x0004 */
#define RT_MAY_LOOP (1 << RT_MAY_LOOP_BIT) /* 0x0008 */
#define RT_HAS_HEADER (1 << RT_HAS_HEADER_BIT) /* 0x0010 */
#define RT_REJECT 0x0020 /* Destination is reject */
#define RT_BLACKHOLE 0x0040 /* Destination is blackhole */
#define RT_HAS_GW 0x0080 /* Destination has GW */
struct rt_metrics {
u_long rmx_locks; /* Kernel must leave these values alone */
@ -215,6 +219,19 @@ fib_rte_to_nh_flags(int rt_flags)
return (res);
}
/* rte<>ro_flags translation */
static inline void
rt_update_ro_flags(struct route *ro)
{
int rt_flags = ro->ro_rt->rt_flags;
ro->ro_flags &= ~ (RT_REJECT|RT_BLACKHOLE|RT_HAS_GW);
ro->ro_flags = (rt_flags & RTF_REJECT) ? RT_REJECT : 0;
ro->ro_flags |= (rt_flags & RTF_BLACKHOLE) ? RT_BLACKHOLE : 0;
ro->ro_flags |= (rt_flags & RTF_GATEWAY) ? RT_HAS_GW : 0;
}
/*
* Routing statistics.
*/

1
sys/netinet/ip_output.c
View File

@ -376,6 +376,7 @@ again:
ia = ifatoia(rte->rt_ifa);
ifp = rte->rt_ifp;
counter_u64_add(rte->rt_pksent, 1);
rt_update_ro_flags(ro);
if (rte->rt_flags & RTF_GATEWAY)
gw = (struct sockaddr_in *)rte->rt_gateway;
if (rte->rt_flags & RTF_HOST)

8
sys/ofed/drivers/infiniband/ulp/ipoib/ipoib_main.c
View File

@ -1260,16 +1260,12 @@ ipoib_output(struct ifnet *ifp, struct mbuf *m,
#if defined(INET) || defined(INET6)
struct llentry *lle = NULL;
#endif
struct rtentry *rt0 = NULL;
struct ipoib_header *eh;
int error = 0, is_gw = 0;
short type;
if (ro != NULL) {
rt0 = ro->ro_rt;
if (rt0 != NULL && (rt0->rt_flags & RTF_GATEWAY) != 0)
is_gw = 1;
}
if (ro != NULL)
is_gw = (ro->ro_flags & RT_HAS_GW) != 0;
#ifdef MAC
error = mac_ifnet_check_transmit(ifp, m);
if (error)