diff options
author | kmacy <kmacy@FreeBSD.org> | 2008-12-16 23:06:36 +0000 |
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committer | kmacy <kmacy@FreeBSD.org> | 2008-12-16 23:06:36 +0000 |
commit | 447f3863c6c6567480d2cfde0634e3ad5b851f3a (patch) | |
tree | 8c34ebae20ed6389535b54b1051b2b8c6625b2df /sys/netinet6 | |
parent | af3a8d21c87b424ba0e43fbcdc2e9229d5be3a89 (diff) | |
download | FreeBSD-src-447f3863c6c6567480d2cfde0634e3ad5b851f3a.zip FreeBSD-src-447f3863c6c6567480d2cfde0634e3ad5b851f3a.tar.gz |
- Simplify handling of the deferring of mbuf transmit until after lle lock drop
- add a couple of comments to clarify intent
Diffstat (limited to 'sys/netinet6')
-rw-r--r-- | sys/netinet6/nd6.c | 40 |
1 files changed, 28 insertions, 12 deletions
diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c index 71d50d0..8f268f3 100644 --- a/sys/netinet6/nd6.c +++ b/sys/netinet6/nd6.c @@ -1407,7 +1407,7 @@ nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr, int newstate = 0; uint16_t router = 0; struct sockaddr_in6 sin6; - struct mbuf *tail = NULL, *chain = NULL; + struct mbuf *chain = NULL; int static_route = 0; IF_AFDATA_UNLOCK_ASSERT(ifp); @@ -1526,11 +1526,14 @@ nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr, * just set the 2nd argument as the * 1st one. */ - nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &tail); - if ((tail != NULL) && chain == (NULL)) - chain = tail; + nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &chain); } - if (chain) + /* + * If we have mbufs in the chain we need to do + * deferred transmit. Copy the address from the + * llentry before dropping the lock down below. + */ + if (chain != NULL) memcpy(&sin6, L3_ADDR_SIN6(ln), sizeof(sin6)); } } else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { @@ -1706,7 +1709,7 @@ nd6_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m0, int nd6_output_lle(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m0, struct sockaddr_in6 *dst, struct rtentry *rt0, struct llentry *lle, - struct mbuf **tail) + struct mbuf **chain) { INIT_VNET_INET6(curvnet); struct mbuf *m = m0; @@ -1720,7 +1723,7 @@ nd6_output_lle(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m0, LLE_WLOCK_ASSERT(lle); - KASSERT(tail != NULL, (" lle locked but no tail pointer passed")); + KASSERT(chain != NULL, (" lle locked but no mbuf chain pointer passed")); } #endif if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr)) @@ -1888,12 +1891,25 @@ nd6_output_lle(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m0, #ifdef MAC mac_netinet6_nd6_send(ifp, m); #endif + /* + * We were passed in a pointer to an lle with the lock held + * this means that we can't call if_output as we will + * recurse on the lle lock - so what we do is we create + * a list of mbufs to send and transmit them in the caller + * after the lock is dropped + */ if (lle != NULL) { - if (*tail == NULL) - *tail = m; - else { - (*tail)->m_nextpkt = m; - *tail = m; + if (*chain == NULL) + *chain = m; + else { + struct mbuf *m = *chain; + + /* + * append mbuf to end of deferred chain + */ + while (m->m_nextpkt != NULL) + m = m->m_nextpkt; + m->m_nextpkt = m; } return (error); } |