git: 81a235ecde89 - main - netinet6: factor out cached route lookups from selectroute().
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Date: Fri, 08 Jul 2022 11:20:41 UTC
The branch main has been updated by melifaro:
URL: https://cgit.FreeBSD.org/src/commit/?id=81a235ecde893a666e3cfac503068d9ea1bb013c
commit 81a235ecde893a666e3cfac503068d9ea1bb013c
Author: Alexander V. Chernikov <melifaro@FreeBSD.org>
AuthorDate: 2022-07-04 15:56:56 +0000
Commit: Alexander V. Chernikov <melifaro@FreeBSD.org>
CommitDate: 2022-07-08 08:58:55 +0000
netinet6: factor out cached route lookups from selectroute().
Currently selectroute() contains two nearly-identical versions of
the route lookup logic - one for original destination and another
for the case when IPV6_NEXTHOP option was set on the socket.
Factor out handling these route lookups in a separation function to
improve readability.
This change also fixes handling of link-local IPV6_NEXTHOPs.
Differential Revision: https://reviews.freebsd.org/D35710
MFC after: 2 weeks
---
sys/netinet6/in6_src.c | 177 ++++++++++++----------------------
tests/sys/netinet6/test_ip6_output.py | 1 -
2 files changed, 60 insertions(+), 118 deletions(-)
diff --git a/sys/netinet6/in6_src.c b/sys/netinet6/in6_src.c
index 875e0a63745c..e44a1b0873b4 100644
--- a/sys/netinet6/in6_src.c
+++ b/sys/netinet6/in6_src.c
@@ -612,8 +612,41 @@ in6_selectsrc_addr(uint32_t fibnum, const struct in6_addr *dst,
return (error);
}
+static struct nhop_object *
+cache_route(uint32_t fibnum, const struct sockaddr_in6 *dst, struct route_in6 *ro,
+ uint32_t flowid)
+{
+ /*
+ * Use a cached route if it exists and is valid, else try to allocate
+ * a new one. Note that we should check the address family of the
+ * cached destination, in case of sharing the cache with IPv4.
+ * Assumes that 'struct route_in6' is exclusively locked.
+ */
+ if (ro->ro_nh != NULL && (
+ !NH_IS_VALID(ro->ro_nh) || ro->ro_dst.sin6_family != AF_INET6 ||
+ !IN6_ARE_ADDR_EQUAL(&ro->ro_dst.sin6_addr, &dst->sin6_addr)))
+ RO_NHFREE(ro);
+
+ if (ro->ro_nh == NULL) {
+ ro->ro_dst = *dst;
+
+ const struct in6_addr *paddr;
+ struct in6_addr unscoped_addr;
+ uint32_t scopeid = 0;
+ if (IN6_IS_SCOPE_LINKLOCAL(&dst->sin6_addr)) {
+ in6_splitscope(&dst->sin6_addr, &unscoped_addr, &scopeid);
+ paddr = &unscoped_addr;
+ } else
+ paddr = &dst->sin6_addr;
+ ro->ro_nh = fib6_lookup(fibnum, paddr, scopeid, NHR_REF, flowid);
+ }
+ return (ro->ro_nh);
+}
+
/*
- * clone - meaningful only for bsdi and freebsd
+ * Finds outgoing nexthop or the outgoing interface for the
+ * @dstsock.
+ * Return 0 on success and stores the lookup result in @retnh and @retifp
*/
static int
selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
@@ -628,28 +661,12 @@ selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct in6_pktinfo *pi = NULL;
struct in6_addr *dst = &dstsock->sin6_addr;
uint32_t zoneid;
-#if 0
- char ip6buf[INET6_ADDRSTRLEN];
-
- if (dstsock->sin6_addr.s6_addr32[0] == 0 &&
- dstsock->sin6_addr.s6_addr32[1] == 0 &&
- !IN6_IS_ADDR_LOOPBACK(&dstsock->sin6_addr)) {
- printf("%s: strange destination %s\n", __func__,
- ip6_sprintf(ip6buf, &dstsock->sin6_addr));
- } else {
- printf("%s: destination = %s%%%d\n", __func__,
- ip6_sprintf(ip6buf, &dstsock->sin6_addr),
- dstsock->sin6_scope_id); /* for debug */
- }
-#endif
/* If the caller specify the outgoing interface explicitly, use it. */
if (opts && (pi = opts->ip6po_pktinfo) != NULL && pi->ipi6_ifindex) {
/* XXX boundary check is assumed to be already done. */
ifp = ifnet_byindex(pi->ipi6_ifindex);
- if (ifp != NULL &&
- (norouteok || retnh == NULL ||
- IN6_IS_ADDR_MULTICAST(dst))) {
+ if (ifp != NULL && (norouteok || IN6_IS_ADDR_MULTICAST(dst))) {
/*
* we do not have to check or get the route for
* multicast.
@@ -685,104 +702,27 @@ selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
* use it as the gateway.
*/
if (opts && opts->ip6po_nexthop) {
- struct route_in6 *ron;
-
+ struct route_in6 *ron = &opts->ip6po_nextroute;
sin6_next = satosin6(opts->ip6po_nexthop);
- if (IN6_IS_ADDR_LINKLOCAL(&sin6_next->sin6_addr)) {
- /*
- * Next hop is LLA, thus it should be neighbor.
- * Determine outgoing interface by zone index.
- */
- zoneid = ntohs(in6_getscope(&sin6_next->sin6_addr));
- if (zoneid > 0) {
- ifp = in6_getlinkifnet(zoneid);
- goto done;
- }
- }
- ron = &opts->ip6po_nextroute;
- /* Use a cached route if it exists and is valid. */
- if (ron->ro_nh != NULL && (
- !NH_IS_VALID(ron->ro_nh) ||
- ron->ro_dst.sin6_family != AF_INET6 ||
- !IN6_ARE_ADDR_EQUAL(&ron->ro_dst.sin6_addr,
- &sin6_next->sin6_addr)))
- RO_NHFREE(ron);
- if (ron->ro_nh == NULL) {
- ron->ro_dst = *sin6_next;
- /*
- * sin6_next is not link-local OR scopeid is 0,
- * no need to clear scope
- */
- ron->ro_nh = fib6_lookup(fibnum,
- &sin6_next->sin6_addr, 0, NHR_REF, flowid);
- }
+
+ nh = cache_route(fibnum, sin6_next, ron, flowid);
+
/*
* The node identified by that address must be a
* neighbor of the sending host.
*/
- if (ron->ro_nh == NULL ||
- (ron->ro_nh->nh_flags & NHF_GATEWAY) != 0)
- error = EHOSTUNREACH;
- else {
- nh = ron->ro_nh;
+ if (nh != NULL && (nh->nh_flags & NHF_GATEWAY) == 0)
ifp = nh->nh_ifp;
+ else {
+ nh = NULL; // cached nh is still stored in @opts
+ error = EHOSTUNREACH;
}
- goto done;
- }
-
- /*
- * Use a cached route if it exists and is valid, else try to allocate
- * a new one. Note that we should check the address family of the
- * cached destination, in case of sharing the cache with IPv4.
- */
- if (ro) {
- if (ro->ro_nh &&
- (!NH_IS_VALID(ro->ro_nh) ||
- ((struct sockaddr *)(&ro->ro_dst))->sa_family != AF_INET6 ||
- !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr,
- dst))) {
- RO_NHFREE(ro);
- }
- if (ro->ro_nh == (struct nhop_object *)NULL) {
- struct sockaddr_in6 *sa6;
-
- /* No route yet, so try to acquire one */
- bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
- sa6 = (struct sockaddr_in6 *)&ro->ro_dst;
- *sa6 = *dstsock;
- sa6->sin6_scope_id = 0;
-
- /*
- * Currently dst has scopeid embedded iff it is LL.
- * New routing API accepts scopeid as a separate argument.
- * Convert dst before/after doing lookup
- */
- uint32_t scopeid = 0;
- if (IN6_IS_SCOPE_LINKLOCAL(&sa6->sin6_addr)) {
- /* Unwrap in6_getscope() and in6_clearscope() */
- scopeid = ntohs(sa6->sin6_addr.s6_addr16[1]);
- sa6->sin6_addr.s6_addr16[1] = 0;
- }
-
- ro->ro_nh = fib6_lookup(fibnum,
- &sa6->sin6_addr, scopeid, NHR_REF, flowid);
-
- if (IN6_IS_SCOPE_LINKLOCAL(&sa6->sin6_addr))
- sa6->sin6_addr.s6_addr16[1] = htons(scopeid);
- }
-
- /*
- * do not care about the result if we have the nexthop
- * explicitly specified.
- */
- if (opts && opts->ip6po_nexthop)
- goto done;
-
- if (ro->ro_nh)
- ifp = ro->ro_nh->nh_ifp;
+ } else if (ro != NULL) {
+ nh = cache_route(fibnum, dstsock, ro, flowid);
+ if (nh != NULL)
+ ifp = nh->nh_ifp;
else
error = EHOSTUNREACH;
- nh = ro->ro_nh;
/*
* Check if the outgoing interface conflicts with
@@ -797,10 +737,15 @@ selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
ifp->if_index !=
opts->ip6po_pktinfo->ipi6_ifindex) {
error = EHOSTUNREACH;
- goto done;
+ ifp = NULL;
+ nh = NULL;
}
}
}
+ /*
+ * Output must be consistent: no error -> both ifp and nh != NULL,
+ * otherwise both NULL
+ */
done:
if (ifp == NULL && nh == NULL) {
@@ -813,15 +758,11 @@ selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
if (error == EHOSTUNREACH)
IP6STAT_INC(ip6s_noroute);
- if (retifp != NULL) {
- if (nh != NULL)
- *retifp = nh->nh_aifp;
- else
- *retifp = ifp;
- }
-
- if (retnh != NULL)
- *retnh = nh; /* nh may be NULL */
+ if (nh != NULL)
+ *retifp = nh->nh_aifp;
+ else
+ *retifp = ifp;
+ *retnh = nh; /* nh may be NULL */
return (error);
}
@@ -889,6 +830,8 @@ in6_selectroute(struct sockaddr_in6 *dstsock, struct ip6_pktopts *opts,
struct ip6_moptions *mopts, struct route_in6 *ro,
struct ifnet **retifp, struct nhop_object **retnh, u_int fibnum, uint32_t flowid)
{
+ MPASS(retifp != NULL);
+ MPASS(retnh != NULL);
return (selectroute(dstsock, opts, mopts, ro, retifp,
retnh, 0, fibnum, flowid));
diff --git a/tests/sys/netinet6/test_ip6_output.py b/tests/sys/netinet6/test_ip6_output.py
index a84e1f9d4d60..112423698cdf 100644
--- a/tests/sys/netinet6/test_ip6_output.py
+++ b/tests/sys/netinet6/test_ip6_output.py
@@ -257,7 +257,6 @@ class TestIP6OutputLL(BaseTestIP6Ouput):
assert rx_obj["dst_iface_alias"] == "if2"
-@pytest.mark.skip(reason="Currently fails")
class TestIP6OutputNhopLL(BaseTestIP6Ouput):
def vnet2_handler(self, vnet, obj_map, pipe):
"""Generic listener that sends first received packet with metadata