Author: melifaro
Date: Tue Sep 15 17:16:31 2015
New Revision: 287826
URL: https://svnweb.freebsd.org/changeset/base/287826
Log:
Simplify nd6_cache_lladdr:
* Move isRouter calculation code to separate nd6_is_router() function.
* Make nd6_cache_lladdr() return void: its return value hasn't been used
since r53541 KAME import in 1999.
Sponsored by: Yandex LLC
Modified:
head/sys/netinet6/nd6.c
head/sys/netinet6/nd6.h
Modified: head/sys/netinet6/nd6.c
==============================================================================
--- head/sys/netinet6/nd6.c Tue Sep 15 16:08:25 2015 (r287825)
+++ head/sys/netinet6/nd6.c Tue Sep 15 17:16:31 2015 (r287826)
@@ -1593,17 +1593,93 @@ nd6_ioctl(u_long cmd, caddr_t data, stru
}
/*
+ * Calculates new isRouter value based on provided parameters and
+ * returns it.
+ */
+static int
+nd6_is_router(int type, int code, int is_new, int old_addr, int new_addr,
+ int ln_router)
+{
+
+ /*
+ * ICMP6 type dependent behavior.
+ *
+ * NS: clear IsRouter if new entry
+ * RS: clear IsRouter
+ * RA: set IsRouter if there's lladdr
+ * redir: clear IsRouter if new entry
+ *
+ * RA case, (1):
+ * The spec says that we must set IsRouter in the following cases:
+ * - If lladdr exist, set IsRouter. This means (1-5).
+ * - If it is old entry (!newentry), set IsRouter. This means (7).
+ * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
+ * A quetion arises for (1) case. (1) case has no lladdr in the
+ * neighbor cache, this is similar to (6).
+ * This case is rare but we figured that we MUST NOT set IsRouter.
+ *
+ * newentry olladdr lladdr llchange NS RS RA redir
+ * D R
+ * 0 n n -- (1) c ? s
+ * 0 y n -- (2) c s s
+ * 0 n y -- (3) c s s
+ * 0 y y n (4) c s s
+ * 0 y y y (5) c s s
+ * 1 -- n -- (6) c c c s
+ * 1 -- y -- (7) c c s c s
+ *
+ * (c=clear s=set)
+ */
+ switch (type & 0xff) {
+ case ND_NEIGHBOR_SOLICIT:
+ /*
+ * New entry must have is_router flag cleared.
+ */
+ if (is_new) /* (6-7) */
+ ln_router = 0;
+ break;
+ case ND_REDIRECT:
+ /*
+ * If the icmp is a redirect to a better router, always set the
+ * is_router flag. Otherwise, if the entry is newly created,
+ * clear the flag. [RFC 2461, sec 8.3]
+ */
+ if (code == ND_REDIRECT_ROUTER)
+ ln_router = 1;
+ else {
+ if (is_new) /* (6-7) */
+ ln_router = 0;
+ }
+ break;
+ case ND_ROUTER_SOLICIT:
+ /*
+ * is_router flag must always be cleared.
+ */
+ ln_router = 0;
+ break;
+ case ND_ROUTER_ADVERT:
+ /*
+ * Mark an entry with lladdr as a router.
+ */
+ if ((!is_new && (old_addr || new_addr)) || /* (2-5) */
+ (is_new && new_addr)) { /* (7) */
+ ln_router = 1;
+ }
+ break;
+ }
+
+ return (ln_router);
+}
+
+/*
* Create neighbor cache entry and cache link-layer address,
* on reception of inbound ND6 packets. (RS/RA/NS/redirect)
*
* type - ICMP6 type
* code - type dependent information
*
- * XXXXX
- * The caller of this function already acquired the ndp
- * cache table lock because the cache entry is returned.
*/
-struct llentry *
+void
nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
int lladdrlen, int type, int code)
{
@@ -1617,7 +1693,6 @@ nd6_cache_lladdr(struct ifnet *ifp, stru
uint16_t router = 0;
struct sockaddr_in6 sin6;
struct mbuf *chain = NULL;
- int static_route = 0;
IF_AFDATA_UNLOCK_ASSERT(ifp);
@@ -1626,7 +1701,7 @@ nd6_cache_lladdr(struct ifnet *ifp, stru
/* nothing must be updated for unspecified address */
if (IN6_IS_ADDR_UNSPECIFIED(from))
- return NULL;
+ return;
/*
* Validation about ifp->if_addrlen and lladdrlen must be done in
@@ -1646,7 +1721,7 @@ nd6_cache_lladdr(struct ifnet *ifp, stru
flags |= ND6_EXCLUSIVE;
ln = nd6_alloc(from, 0, ifp);
if (ln == NULL)
- return (NULL);
+ return;
IF_AFDATA_WLOCK(ifp);
LLE_WLOCK(ln);
/* Prefer any existing lle over newly-created one */
@@ -1665,8 +1740,11 @@ nd6_cache_lladdr(struct ifnet *ifp, stru
}
/* do nothing if static ndp is set */
if ((ln->la_flags & LLE_STATIC)) {
- static_route = 1;
- goto done;
+ if (flags & ND6_EXCLUSIVE)
+ LLE_WUNLOCK(ln);
+ else
+ LLE_RUNLOCK(ln);
+ return;
}
olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0;
@@ -1727,85 +1805,20 @@ nd6_cache_lladdr(struct ifnet *ifp, stru
}
}
- /*
- * ICMP6 type dependent behavior.
- *
- * NS: clear IsRouter if new entry
- * RS: clear IsRouter
- * RA: set IsRouter if there's lladdr
- * redir: clear IsRouter if new entry
- *
- * RA case, (1):
- * The spec says that we must set IsRouter in the following cases:
- * - If lladdr exist, set IsRouter. This means (1-5).
- * - If it is old entry (!newentry), set IsRouter. This means (7).
- * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
- * A quetion arises for (1) case. (1) case has no lladdr in the
- * neighbor cache, this is similar to (6).
- * This case is rare but we figured that we MUST NOT set IsRouter.
- *
- * newentry olladdr lladdr llchange NS RS RA redir
- * D R
- * 0 n n -- (1) c ? s
- * 0 y n -- (2) c s s
- * 0 n y -- (3) c s s
- * 0 y y n (4) c s s
- * 0 y y y (5) c s s
- * 1 -- n -- (6) c c c s
- * 1 -- y -- (7) c c s c s
- *
- * (c=clear s=set)
- */
- switch (type & 0xff) {
- case ND_NEIGHBOR_SOLICIT:
- /*
- * New entry must have is_router flag cleared.
- */
- if (is_newentry) /* (6-7) */
- ln->ln_router = 0;
- break;
- case ND_REDIRECT:
- /*
- * If the icmp is a redirect to a better router, always set the
- * is_router flag. Otherwise, if the entry is newly created,
- * clear the flag. [RFC 2461, sec 8.3]
- */
- if (code == ND_REDIRECT_ROUTER)
- ln->ln_router = 1;
- else {
- if (is_newentry) /* (6-7) */
- ln->ln_router = 0;
- ln->la_flags |= LLE_REDIRECT;
- }
- break;
- case ND_ROUTER_SOLICIT:
- /*
- * is_router flag must always be cleared.
- */
- ln->ln_router = 0;
- break;
- case ND_ROUTER_ADVERT:
- /*
- * Mark an entry with lladdr as a router.
- */
- if ((!is_newentry && (olladdr || lladdr)) || /* (2-5) */
- (is_newentry && lladdr)) { /* (7) */
- ln->ln_router = 1;
- }
- break;
- }
+ /* Calculates new router status */
+ router = nd6_is_router(type, code, is_newentry, olladdr,
+ lladdr != NULL ? 1 : 0, ln->ln_router);
+
+ ln->ln_router = router;
+ /* Mark non-router redirects with special flag */
+ if ((type & 0xFF) == ND_REDIRECT && code != ND_REDIRECT_ROUTER)
+ ln->la_flags |= LLE_REDIRECT;
- if (ln != NULL) {
- static_route = (ln->la_flags & LLE_STATIC);
- router = ln->ln_router;
+ if (flags & ND6_EXCLUSIVE)
+ LLE_WUNLOCK(ln);
+ else
+ LLE_RUNLOCK(ln);
- if (flags & ND6_EXCLUSIVE)
- LLE_WUNLOCK(ln);
- else
- LLE_RUNLOCK(ln);
- if (static_route)
- ln = NULL;
- }
if (chain != NULL)
nd6_flush_holdchain(ifp, ifp, chain, &sin6);
@@ -1831,18 +1844,6 @@ nd6_cache_lladdr(struct ifnet *ifp, stru
*/
defrouter_select();
}
-
- return (ln);
-done:
- if (ln != NULL) {
- if (flags & ND6_EXCLUSIVE)
- LLE_WUNLOCK(ln);
- else
- LLE_RUNLOCK(ln);
- if (static_route)
- ln = NULL;
- }
- return (ln);
}
static void
Modified: head/sys/netinet6/nd6.h
==============================================================================
--- head/sys/netinet6/nd6.h Tue Sep 15 16:08:25 2015 (r287825)
+++ head/sys/netinet6/nd6.h Tue Sep 15 17:16:31 2015 (r287826)
@@ -417,7 +417,7 @@ void nd6_nud_hint(struct rtentry *, stru
int nd6_resolve(struct ifnet *, struct rtentry *, struct mbuf *,
struct sockaddr *, u_char *);
int nd6_ioctl(u_long, caddr_t, struct ifnet *);
-struct llentry *nd6_cache_lladdr(struct ifnet *, struct in6_addr *,
+void nd6_cache_lladdr(struct ifnet *, struct in6_addr *,
char *, int, int, int);
int nd6_output(struct ifnet *, struct ifnet *, struct mbuf *,
struct sockaddr_in6 *, struct rtentry *);
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