Page MenuHomeFreeBSD
Files F144611404

D51835.1775770544.diff
No OneTemporary
Actions

Size
9 KB
Referenced Files
None
Subscribers
None

D51835.1775770544.diff
View Options

diff --git a/sys/netinet/icmp6.h b/sys/netinet/icmp6.h
--- a/sys/netinet/icmp6.h
+++ b/sys/netinet/icmp6.h
@@ -713,9 +713,6 @@
void icmp6_redirect_output(struct mbuf *, struct nhop_object *);
int icmp6_ratelimit(const struct in6_addr *, const int, const int);
-struct ip6ctlparam;
-void icmp6_mtudisc_update(struct ip6ctlparam *, int);
-
/* XXX: is this the right place for these macros? */
#define icmp6_ifstat_inc(ifp, tag) \
do { \
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -3205,7 +3205,7 @@
* small, set to the min.
*/
if (mtu < IPV6_MMTU)
- mtu = IPV6_MMTU - 8; /* XXXNP: what is the adjustment for? */
+ mtu = IPV6_MMTU;
return (mtu);
}
diff --git a/sys/netinet6/icmp6.c b/sys/netinet6/icmp6.c
--- a/sys/netinet6/icmp6.c
+++ b/sys/netinet6/icmp6.c
@@ -159,6 +159,7 @@
static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
struct ifnet *, int);
static int icmp6_notify_error(struct mbuf **, int, int);
+static void icmp6_mtudisc_update(struct ip6ctlparam *ip6cp);
/*
* Kernel module interface for updating icmp6stat. The argument is an index
@@ -1115,7 +1116,7 @@
if (icmp6type == ICMP6_PACKET_TOO_BIG) {
notifymtu = ntohl(icmp6->icmp6_mtu);
ip6cp.ip6c_cmdarg = (void *)&notifymtu;
- icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/
+ icmp6_mtudisc_update(&ip6cp);
}
if (ip6_ctlprotox[nxt] != NULL)
@@ -1130,47 +1131,18 @@
return (-1);
}
-void
-icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
+static void
+icmp6_mtudisc_update(struct ip6ctlparam *ip6cp)
{
struct in6_addr *dst = &ip6cp->ip6c_finaldst->sin6_addr;
struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
- struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
+ struct mbuf *m = ip6cp->ip6c_m;
u_int mtu = ntohl(icmp6->icmp6_mtu);
struct in_conninfo inc;
uint32_t max_mtu;
-#if 0
- /*
- * RFC2460 section 5, last paragraph.
- * even though minimum link MTU for IPv6 is IPV6_MMTU,
- * we may see ICMPv6 too big with mtu < IPV6_MMTU
- * due to packet translator in the middle.
- * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
- * special handling.
- */
if (mtu < IPV6_MMTU)
return;
-#endif
-
- /*
- * we reject ICMPv6 too big with abnormally small value.
- * XXX what is the good definition of "abnormally small"?
- */
- if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
- return;
-
- if (!validated)
- return;
-
- /*
- * In case the suggested mtu is less than IPV6_MMTU, we
- * only need to remember that it was for above mentioned
- * "alwaysfrag" case.
- * Try to be as close to the spec as possible.
- */
- if (mtu < IPV6_MMTU)
- mtu = IPV6_MMTU - 8;
bzero(&inc, sizeof(inc));
inc.inc_fibnum = M_GETFIB(m);
diff --git a/sys/netinet6/ip6_output.c b/sys/netinet6/ip6_output.c
--- a/sys/netinet6/ip6_output.c
+++ b/sys/netinet6/ip6_output.c
@@ -145,11 +145,10 @@
struct ip6_frag **);
static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
-static int ip6_getpmtu(struct route_in6 *, int,
- struct ifnet *, const struct in6_addr *, u_long *, int *, u_int,
- u_int);
-static int ip6_calcmtu(struct ifnet *, const struct in6_addr *, u_long,
- u_long *, int *, u_int);
+static void ip6_getpmtu(struct route_in6 *, int,
+ struct ifnet *, const struct in6_addr *, u_long *, u_int, u_int);
+static void ip6_calcmtu(struct ifnet *, const struct in6_addr *, u_long,
+ u_long *, u_int);
static int ip6_getpmtu_ctl(u_int, const struct in6_addr *, u_long *);
static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
@@ -418,7 +417,7 @@
int vlan_pcp = -1;
struct in6_ifaddr *ia = NULL;
u_long mtu;
- int alwaysfrag, dontfrag;
+ int dontfrag;
u_int32_t optlen, plen = 0, unfragpartlen;
struct ip6_exthdrs exthdrs;
struct in6_addr src0, dst0;
@@ -939,12 +938,10 @@
*ifpp = ifp;
/* Determine path MTU. */
- if ((error = ip6_getpmtu(ro_pmtu, ro != ro_pmtu, ifp, &ip6->ip6_dst,
- &mtu, &alwaysfrag, fibnum, *nexthdrp)) != 0)
- goto bad;
- KASSERT(mtu > 0, ("%s:%d: mtu %ld, ro_pmtu %p ro %p ifp %p "
- "alwaysfrag %d fibnum %u\n", __func__, __LINE__, mtu, ro_pmtu, ro,
- ifp, alwaysfrag, fibnum));
+ ip6_getpmtu(ro_pmtu, ro != ro_pmtu, ifp, &ip6->ip6_dst, &mtu, fibnum,
+ *nexthdrp);
+ KASSERT(mtu > 0, ("%s:%d: mtu %ld, ro_pmtu %p ro %p ifp %p fibnum %u",
+ __func__, __LINE__, mtu, ro_pmtu, ro, ifp, fibnum));
/*
* The caller of this function may specify to use the minimum MTU
@@ -1121,20 +1118,13 @@
* Send the packet to the outgoing interface.
* If necessary, do IPv6 fragmentation before sending.
*
- * The logic here is rather complex:
- * 1: normal case (dontfrag == 0, alwaysfrag == 0)
+ * 1: normal case (dontfrag == 0)
* 1-a: send as is if tlen <= path mtu
* 1-b: fragment if tlen > path mtu
*
* 2: if user asks us not to fragment (dontfrag == 1)
* 2-a: send as is if tlen <= interface mtu
* 2-b: error if tlen > interface mtu
- *
- * 3: if we always need to attach fragment header (alwaysfrag == 1)
- * always fragment
- *
- * 4: if dontfrag == 1 && alwaysfrag == 1
- * error, as we cannot handle this conflicting request.
*/
sw_csum = m->m_pkthdr.csum_flags;
if (!hdrsplit) {
@@ -1157,14 +1147,9 @@
dontfrag = 1;
else
dontfrag = 0;
- if (dontfrag && alwaysfrag) { /* Case 4. */
- /* Conflicting request - can't transmit. */
- error = EMSGSIZE;
- goto bad;
- }
if (dontfrag && tlen > IN6_LINKMTU(ifp) && !tso) { /* Case 2-b. */
/*
- * Even if the DONTFRAG option is specified, we cannot send the
+ * If the DONTFRAG option is specified, we cannot send the
* packet when the data length is larger than the MTU of the
* outgoing interface.
* Notify the error by sending IPV6_PATHMTU ancillary data if
@@ -1178,7 +1163,7 @@
}
/* Transmit packet without fragmentation. */
- if (dontfrag || (!alwaysfrag && tlen <= mtu)) { /* Cases 1-a and 2-a. */
+ if (dontfrag || tlen <= mtu) { /* Cases 1-a and 2-a. */
struct in6_ifaddr *ia6;
ip6 = mtod(m, struct ip6_hdr *);
@@ -1194,7 +1179,7 @@
goto done;
}
- /* Try to fragment the packet. Cases 1-b and 3. */
+ /* Try to fragment the packet. Case 1-b. */
if (mtu < IPV6_MMTU) {
/* Path MTU cannot be less than IPV6_MMTU. */
error = EMSGSIZE;
@@ -1478,9 +1463,10 @@
NET_EPOCH_ENTER(et);
nh = fib6_lookup(fibnum, &kdst, scopeid, NHR_NONE, 0);
- if (nh != NULL)
- error = ip6_calcmtu(nh->nh_ifp, dst, nh->nh_mtu, mtup, NULL, 0);
- else
+ if (nh != NULL) {
+ ip6_calcmtu(nh->nh_ifp, dst, nh->nh_mtu, mtup, 0);
+ error = 0;
+ } else
error = EHOSTUNREACH;
NET_EPOCH_EXIT(et);
@@ -1494,13 +1480,12 @@
* inside @ro_pmtu to avoid subsequent route lookups after packet
* filter processing.
*
- * Stores mtu and always-frag value into @mtup and @alwaysfragp.
- * Returns 0 on success.
+ * Stores mtu into @mtup.
*/
-static int
+static void
ip6_getpmtu(struct route_in6 *ro_pmtu, int do_lookup,
struct ifnet *ifp, const struct in6_addr *dst, u_long *mtup,
- int *alwaysfragp, u_int fibnum, u_int proto)
+ u_int fibnum, u_int proto)
{
struct nhop_object *nh;
struct in6_addr kdst;
@@ -1544,65 +1529,41 @@
if (ro_pmtu != NULL && ro_pmtu->ro_nh != NULL)
mtu = ro_pmtu->ro_nh->nh_mtu;
- return (ip6_calcmtu(ifp, dst, mtu, mtup, alwaysfragp, proto));
+ ip6_calcmtu(ifp, dst, mtu, mtup, proto);
}
/*
* Calculate MTU based on transmit @ifp, route mtu @rt_mtu and
* hostcache data for @dst.
- * Stores mtu and always-frag value into @mtup and @alwaysfragp.
- *
- * Returns 0 on success.
+ * Stores mtu into @mtup.
*/
-static int
+static void
ip6_calcmtu(struct ifnet *ifp, const struct in6_addr *dst, u_long rt_mtu,
- u_long *mtup, int *alwaysfragp, u_int proto)
+ u_long *mtup, u_int proto)
{
u_long mtu = 0;
- int alwaysfrag = 0;
- int error = 0;
if (rt_mtu > 0) {
- u_int32_t ifmtu;
- struct in_conninfo inc;
-
- bzero(&inc, sizeof(inc));
- inc.inc_flags |= INC_ISIPV6;
- inc.inc6_faddr = *dst;
-
- ifmtu = IN6_LINKMTU(ifp);
+ /* Skip the hostcache if the protocol handles PMTU changes. */
+ if (proto != IPPROTO_TCP && proto != IPPROTO_SCTP) {
+ struct in_conninfo inc = {
+ .inc_flags = INC_ISIPV6,
+ .inc6_faddr = *dst,
+ };
- /* TCP is known to react to pmtu changes so skip hc */
- if (proto != IPPROTO_TCP)
mtu = tcp_hc_getmtu(&inc);
+ }
if (mtu)
mtu = min(mtu, rt_mtu);
else
mtu = rt_mtu;
- if (mtu == 0)
- mtu = ifmtu;
- else if (mtu < IPV6_MMTU) {
- /*
- * RFC2460 section 5, last paragraph:
- * if we record ICMPv6 too big message with
- * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
- * or smaller, with framgent header attached.
- * (fragment header is needed regardless from the
- * packet size, for translators to identify packets)
- */
- alwaysfrag = 1;
- mtu = IPV6_MMTU;
- }
- } else if (ifp) {
+ }
+
+ if (mtu == 0)
mtu = IN6_LINKMTU(ifp);
- } else
- error = EHOSTUNREACH; /* XXX */
*mtup = mtu;
- if (alwaysfragp)
- *alwaysfragp = alwaysfrag;
- return (error);
}
/*

File Metadata

Mime Type
text/plain
Expires
Thu, Apr 9, 9:35 PM (6 h, 5 m)
Storage Engine
blob
Storage Format
Raw Data
Storage Handle
28309852
Default Alt Text
D51835.1775770544.diff (9 KB)

Event Timeline