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* Use newly-created nd6_grab_holdchain() function to retrieve lle

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hold mbuf chain instead of calling full-blown nd6_output_lle()
  for each packet. This simplifies both callers and nd6_output_lle()
  implementation.
* Make nd6_output_lle() static and remove now-unused lle and chain
  arguments.
* Rename nd6_output_flush() -> nd6_flush_holdchain() to be consistent.
* Move all pre-send transmit hooks to newly-created nd6_output_ifp().
  Now nd6_output(), nd6_output_lle() and nd6_flush_holdchain() are using
  it to send mbufs to if_output.
* Remove SeND hook from nd6_na_input() because it was implemented
  incorrectly since the beginning (r211501):
  - it tagged initial input mbuf (m) instead of m_hold
  - tagging _all_ mbufs in holdchain seems to be wrong anyway.
This commit is contained in:
Alexander V. Chernikov 2015-01-08 18:02:05 +00:00
parent 76e1ce6f68
commit d7968c29ec
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=276844
3 changed files with 101 additions and 207 deletions
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257
sys/netinet6/nd6.c
View File

@ -134,6 +134,8 @@ static struct llentry *nd6_free(struct llentry *, int);
static void nd6_llinfo_timer(void *);
static void clear_llinfo_pqueue(struct llentry *);
static void nd6_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
static int nd6_output_lle(struct ifnet *, struct ifnet *, struct mbuf *,
struct sockaddr_in6 *);
static VNET_DEFINE(struct callout, nd6_slowtimo_ch);
#define V_nd6_slowtimo_ch VNET(nd6_slowtimo_ch)
@ -1646,42 +1648,8 @@ nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
ln->ln_state = newstate;
if (ln->ln_state == ND6_LLINFO_STALE) {
/*
* XXX: since nd6_output() below will cause
* state tansition to DELAY and reset the timer,
* we must set the timer now, although it is actually
* meaningless.
*/
nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
if (ln->la_hold) {
struct mbuf *m_hold, *m_hold_next;
/*
* reset the la_hold in advance, to explicitly
* prevent a la_hold lookup in nd6_output()
* (wouldn't happen, though...)
*/
for (m_hold = ln->la_hold, ln->la_hold = NULL;
m_hold; m_hold = m_hold_next) {
m_hold_next = m_hold->m_nextpkt;
m_hold->m_nextpkt = NULL;
/*
* we assume ifp is not a p2p here, so
* just set the 2nd argument as the
* 1st one.
*/
nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &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));
}
if (ln->la_hold != NULL)
nd6_grab_holdchain(ln, &chain, &sin6);
} else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
/* probe right away */
nd6_llinfo_settimer_locked((void *)ln, 0);
@ -1764,8 +1732,8 @@ nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
if (static_route)
ln = NULL;
}
if (chain)
nd6_output_flush(ifp, ifp, chain, &sin6);
if (chain != NULL)
nd6_flush_holdchain(ifp, ifp, chain, &sin6);
/*
* When the link-layer address of a router changes, select the
@ -1833,6 +1801,79 @@ nd6_slowtimo(void *arg)
CURVNET_RESTORE();
}
void
nd6_grab_holdchain(struct llentry *ln, struct mbuf **chain,
struct sockaddr_in6 *sin6)
{
LLE_WLOCK_ASSERT(ln);
*chain = ln->la_hold;
ln->la_hold = NULL;
memcpy(sin6, L3_ADDR_SIN6(ln), sizeof(*sin6));
if (ln->ln_state == ND6_LLINFO_STALE) {
/*
* The first time we send a packet to a
* neighbor whose entry is STALE, we have
* to change the state to DELAY and a sets
* a timer to expire in DELAY_FIRST_PROBE_TIME
* seconds to ensure do neighbor unreachability
* detection on expiration.
* (RFC 2461 7.3.3)
*/
ln->la_asked = 0;
ln->ln_state = ND6_LLINFO_DELAY;
nd6_llinfo_settimer_locked(ln, (long)V_nd6_delay * hz);
}
}
static int
nd6_output_ifp(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
struct sockaddr_in6 *dst)
{
int error;
int ip6len;
struct ip6_hdr *ip6;
struct m_tag *mtag;
#ifdef MAC
mac_netinet6_nd6_send(ifp, m);
#endif
/*
* If called from nd6_ns_output() (NS), nd6_na_output() (NA),
* icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA
* as handled by rtsol and rtadvd), mbufs will be tagged for SeND
* to be diverted to user space. When re-injected into the kernel,
* send_output() will directly dispatch them to the outgoing interface.
*/
if (send_sendso_input_hook != NULL) {
mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL);
if (mtag != NULL) {
ip6 = mtod(m, struct ip6_hdr *);
ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
/* Use the SEND socket */
error = send_sendso_input_hook(m, ifp, SND_OUT,
ip6len);
/* -1 == no app on SEND socket */
if (error == 0 || error != -1)
return (error);
}
}
m_clrprotoflags(m); /* Avoid confusing lower layers. */
IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL,
mtod(m, struct ip6_hdr *));
if ((ifp->if_flags & IFF_LOOPBACK) == 0)
origifp = ifp;
error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, NULL);
return (error);
}
/*
* IPv6 packet output - light version.
* Checks if destination LLE exists and is in proper state
@ -1844,7 +1885,6 @@ nd6_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
struct sockaddr_in6 *dst, struct rtentry *rt0)
{
struct llentry *ln = NULL;
int error = 0;
/* discard the packet if IPv6 operation is disabled on the interface */
if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
@ -1875,50 +1915,14 @@ nd6_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
/* Fall back to slow processing path */
if (ln != NULL)
LLE_RUNLOCK(ln);
return (nd6_output_lle(ifp, origifp, m, dst, rt0, NULL, NULL));
return (nd6_output_lle(ifp, origifp, m, dst));
}
sendpkt:
if (ln != NULL)
LLE_RUNLOCK(ln);
#ifdef MAC
mac_netinet6_nd6_send(ifp, m);
#endif
/*
* If called from nd6_ns_output() (NS), nd6_na_output() (NA),
* icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA
* as handled by rtsol and rtadvd), mbufs will be tagged for SeND
* to be diverted to user space. When re-injected into the kernel,
* send_output() will directly dispatch them to the outgoing interface.
*/
if (send_sendso_input_hook != NULL) {
struct m_tag *mtag;
struct ip6_hdr *ip6;
int ip6len;
mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL);
if (mtag != NULL) {
ip6 = mtod(m, struct ip6_hdr *);
ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
/* Use the SEND socket */
error = send_sendso_input_hook(m, ifp, SND_OUT,
ip6len);
/* -1 == no app on SEND socket */
if (error == 0 || error != -1)
return (error);
}
}
m_clrprotoflags(m); /* Avoid confusing lower layers. */
IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL,
mtod(m, struct ip6_hdr *));
if ((ifp->if_flags & IFF_LOOPBACK) == 0)
origifp = ifp;
error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, NULL);
return (error);
return (nd6_output_ifp(ifp, origifp, m, dst));
}
@ -1931,26 +1935,13 @@ nd6_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
* in that case packets are queued in &chain.
*
*/
int
static int
nd6_output_lle(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
struct sockaddr_in6 *dst, struct rtentry *rt0, struct llentry *lle,
struct mbuf **chain)
struct sockaddr_in6 *dst)
{
struct m_tag *mtag;
struct ip6_hdr *ip6;
int error = 0;
struct llentry *lle = NULL;
int flags = 0;
int has_lle = 0;
int ip6len;
#ifdef INVARIANTS
if (lle != NULL) {
LLE_WLOCK_ASSERT(lle);
KASSERT(chain != NULL, (" lle locked but no mbuf chain pointer passed"));
}
#endif
KASSERT(m != NULL, ("NULL mbuf, nothing to send"));
/* discard the packet if IPv6 operation is disabled on the interface */
if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
@ -1958,9 +1949,6 @@ nd6_output_lle(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
return (ENETDOWN); /* better error? */
}
if (lle != NULL)
has_lle = 1;
if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
goto sendpkt;
@ -2076,88 +2064,23 @@ nd6_output_lle(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
(long)ND_IFINFO(ifp)->retrans * hz / 1000);
LLE_WUNLOCK(lle);
nd6_ns_output(ifp, NULL, &dst->sin6_addr, lle, 0);
if (has_lle != 0)
LLE_WLOCK(lle);
} else if (has_lle == 0) {
/*
* We did the lookup (no lle arg) so we
* need to do the unlock here.
*/
} else {
/* We did the lookup so we need to do the unlock here. */
LLE_WUNLOCK(lle);
}
return (0);
sendpkt:
/*
* ln is valid and the caller did not pass in
* an llentry
*/
if (lle != NULL && has_lle == 0)
if (lle != NULL)
LLE_WUNLOCK(lle);
#ifdef MAC
mac_netinet6_nd6_send(ifp, m);
#endif
/*
* If called from nd6_ns_output() (NS), nd6_na_output() (NA),
* icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA
* as handled by rtsol and rtadvd), mbufs will be tagged for SeND
* to be diverted to user space. When re-injected into the kernel,
* send_output() will directly dispatch them to the outgoing interface.
*/
if (send_sendso_input_hook != NULL) {
mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL);
if (mtag != NULL) {
ip6 = mtod(m, struct ip6_hdr *);
ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
/* Use the SEND socket */
error = send_sendso_input_hook(m, ifp, SND_OUT,
ip6len);
/* -1 == no app on SEND socket */
if (error == 0 || error != -1)
return (error);
}
}
/*
* 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 (has_lle != 0) {
if (*chain == NULL)
*chain = m;
else {
struct mbuf *mb;
/*
* append mbuf to end of deferred chain
*/
mb = *chain;
while (mb->m_nextpkt != NULL)
mb = mb->m_nextpkt;
mb->m_nextpkt = m;
}
return (error);
}
m_clrprotoflags(m); /* Avoid confusing lower layers. */
IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL,
mtod(m, struct ip6_hdr *));
if ((ifp->if_flags & IFF_LOOPBACK) == 0)
origifp = ifp;
error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, NULL);
return (error);
return (nd6_output_ifp(ifp, origifp, m, dst));
}
int
nd6_output_flush(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *chain,
nd6_flush_holdchain(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *chain,
struct sockaddr_in6 *dst)
{
struct mbuf *m, *m_head;
@ -2173,7 +2096,7 @@ nd6_output_flush(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *chain,
while (m_head) {
m = m_head;
m_head = m_head->m_nextpkt;
error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst, NULL);
error = nd6_output_ifp(ifp, origifp, m, dst);
}
/*

9
sys/netinet6/nd6.h
View File

@ -409,11 +409,10 @@ struct llentry *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 *);
int nd6_output_lle(struct ifnet *, struct ifnet *, struct mbuf *,
struct sockaddr_in6 *, struct rtentry *, struct llentry *,
struct mbuf **);
int nd6_output_flush(struct ifnet *, struct ifnet *, struct mbuf *,
struct sockaddr_in6 *);
void nd6_grab_holdchain(struct llentry *, struct mbuf **,
struct sockaddr_in6 *);
int nd6_flush_holdchain(struct ifnet *, struct ifnet *, struct mbuf *,
struct sockaddr_in6 *);
int nd6_need_cache(struct ifnet *);
int nd6_add_ifa_lle(struct in6_ifaddr *);
void nd6_rem_ifa_lle(struct in6_ifaddr *);

42
sys/netinet6/nd6_nbr.c
View File

@ -626,7 +626,6 @@ nd6_na_input(struct mbuf *m, int off, int icmp6len)
struct llentry *ln = NULL;
union nd_opts ndopts;
struct mbuf *chain = NULL;
struct m_tag *mtag;
struct sockaddr_in6 sin6;
char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
@ -653,6 +652,7 @@ nd6_na_input(struct mbuf *m, int off, int icmp6len)
is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
memset(&sin6, 0, sizeof(sin6));
taddr6 = nd_na->nd_na_target;
if (in6_setscope(&taddr6, ifp, NULL))
@ -891,43 +891,15 @@ nd6_na_input(struct mbuf *m, int off, int icmp6len)
* rt->rt_flags &= ~RTF_REJECT;
*/
ln->la_asked = 0;
if (ln->la_hold) {
struct mbuf *m_hold, *m_hold_next;
/*
* reset the la_hold in advance, to explicitly
* prevent a la_hold lookup in nd6_output()
* (wouldn't happen, though...)
*/
for (m_hold = ln->la_hold, ln->la_hold = NULL;
m_hold; m_hold = m_hold_next) {
m_hold_next = m_hold->m_nextpkt;
m_hold->m_nextpkt = NULL;
/*
* we assume ifp is not a loopback here, so just set
* the 2nd argument as the 1st one.
*/
if (send_sendso_input_hook != NULL) {
mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
sizeof(unsigned short), M_NOWAIT);
if (mtag == NULL)
goto bad;
m_tag_prepend(m, mtag);
}
nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &chain);
}
}
if (ln->la_hold != NULL)
nd6_grab_holdchain(ln, &chain, &sin6);
freeit:
if (ln != NULL) {
if (chain)
memcpy(&sin6, L3_ADDR_SIN6(ln), sizeof(sin6));
if (ln != NULL)
LLE_WUNLOCK(ln);
if (chain)
nd6_output_flush(ifp, ifp, chain, &sin6);
}
if (chain != NULL)
nd6_flush_holdchain(ifp, ifp, chain, &sin6);
if (checklink)
pfxlist_onlink_check();