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[src/is-mlppp]: src/sys/net first part of defragmentation code. No dropping/s...
details: https://anonhg.NetBSD.org/src/rev/44432312f09e
branches: is-mlppp
changeset: 930625:44432312f09e
user: is <is%NetBSD.org@localhost>
date: Fri Apr 10 17:28:37 2020 +0000
description:
first part of defragmentation code. No dropping/sequence error statistics
yet, and no MRRU negotiation so not active.
diffstat:
sys/net/if_spppsubr.c | 135 +++++++++++++++++++++++++++++++++++++++++++++++++-
sys/net/if_spppvar.h | 4 +-
2 files changed, 136 insertions(+), 3 deletions(-)
diffs (195 lines):
diff -r 282fdb5de4d5 -r 44432312f09e sys/net/if_spppsubr.c
--- a/sys/net/if_spppsubr.c Tue Apr 07 19:26:44 2020 +0000
+++ b/sys/net/if_spppsubr.c Fri Apr 10 17:28:37 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: if_spppsubr.c,v 1.187.2.3 2020/04/07 19:26:44 is Exp $ */
+/* $NetBSD: if_spppsubr.c,v 1.187.2.4 2020/04/10 17:28:37 is Exp $ */
/*
* Synchronous PPP/Cisco link level subroutines.
@@ -41,7 +41,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_spppsubr.c,v 1.187.2.3 2020/04/07 19:26:44 is Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_spppsubr.c,v 1.187.2.4 2020/04/10 17:28:37 is Exp $");
#if defined(_KERNEL_OPT)
#include "opt_inet.h"
@@ -336,6 +336,9 @@
static void sppp_lcp_check_and_close(struct sppp *sp);
static int sppp_ncp_check(struct sppp *sp);
+static struct mbuf *sppp_ml_defrag(struct sppp *sp, struct mbuf *m,
+ u_int16_t *protocolp);
+
static void sppp_ipcp_init(struct sppp *sp);
static void sppp_ipcp_up(struct sppp *sp);
static void sppp_ipcp_down(struct sppp *sp);
@@ -517,6 +520,123 @@
}
}
+
+/*
+ * Defragment an MP packet.
+ *
+ * Returns NULL or an assembled packet or the original,
+ * and adjusts the passed protocol to the inner one.
+ *
+ * Called with and returns a packet without PPP header,
+ * but with MP fragment header.
+ *
+ * Called and returns with lock held.
+ */
+static struct mbuf *
+sppp_ml_defrag(struct sppp *sp, struct mbuf *m, u_int16_t *protocolp)
+{
+ u_int8_t *p;
+ u_int8_t flags;
+ u_int32_t seqid;
+ u_int16_t protocol;
+ u_int16_t *m_protop;
+ int newflen;
+
+ if (*protocolp != PPP_MP)
+ return m; /* not ours */
+
+ if (sp->lcp.mrru == 0)
+ return m; /*
+ * ours, but we're not ready.
+ * sppp_input will arrange for rejection.
+ */
+
+ if (m->m_len < 4) {
+ m = m_pullup(m, 4);
+ if (m == NULL) {
+ if_statadd2(ifp, if_ierrors, 1, if_iqdrops, 1);
+ return NULL;
+ }
+ }
+ p = mtod(m, u_int8_t *);
+ flags = *p;
+ seqid = (p[1]<<16) + (p[2]<<8) + p[3];
+
+ m_adj(m, 4);
+
+ /* We're manipulating the defragmentation state below: */
+ SPPP_UPGRADE(sp);
+
+ if (flags & 0x80) {
+ /* Beginning fragment. */
+ sp->lcp.ml_seq_expected=seqid+1; /* next expected */
+
+ /* TODO: if prefix, count dropped? */
+
+ m_freem(sp->lcp.ml_prefix);
+ sp->lcp.ml_prefix = m;
+
+ } else if (seqid == sp->lcp.ml_seq_expected) {
+ sp->lcp.ml_seq_expected=seqid+1; /* next expected */
+ if (sp->lcp.ml_prefix == 0) {
+ /* didn't see B frame. */
+ /* TODO: count as dropped. */
+ m_freem(m);
+ return NULL;
+ }
+ /*
+ * m_cat might free the first mbuf (with pkthdr)
+ * in 2nd chain; therefore:
+ */
+ newflen = m->m_pkthdr.len;
+ m_cat(sp->lcp.ml_prefix, m);
+ lcp.ml_prefix->m_pkthdr.len += newflen;
+
+ } else {
+ /*
+ * sequence error.
+ *
+ * For now, only drop this fragment, and don't touch state-
+ * might be from the long past or future, and we could still
+ * finish our current prefix.
+ *
+ * TODO: count as dropped.
+ */
+ m_freem(sp->lcp.ml_prefix);
+ return NULL;
+ }
+ /* Successfully got the Beginning or appended a non-B packet.*/
+ if (flags & 0x40) {
+ /* B/next was E packet. Unwrap gift and deliver. */
+ m = sp->lcp.ml_prefix;
+ sp->lcp.ml_prefix = NULL;
+
+ if (m->m_len < 2) {
+ m = m_pullup(m,2)
+ if (m == NULL) {
+ * TODO: count as dropped.
+ return NULL;
+ }
+ }
+ /* RFC 1990 2.: don't assume no protocol field compression */
+ p = mtod(m, u_int8_t);
+ protocol = *p;
+
+ if (protocol & 1) {
+ m_adj(m, 1);
+ } else {
+ protocol = (protocol << 8) + p[1];
+ m_adj(m, 2);
+ }
+ *protocolp = protocol;
+
+ return m;
+ }
+
+ return NULL;
+}
+
+
/*
* Exported functions, comprising our interface to the lower layer.
*/
@@ -627,6 +747,12 @@
protocol = ntohs(h->protocol);
}
+ m = sppp_ml_defrag(sp, m, &protocol);
+ if (m == 0) {
+ SPPP_UNLOCK(sp);
+ return;
+ }
+
switch (protocol) {
default:
if (sp->state[IDX_LCP] == STATE_OPENED) {
@@ -2222,6 +2348,11 @@
/* Initialize activity timestamp: opening a connection is an activity */
sp->pp_last_receive = sp->pp_last_activity = time_uptime;
+ /* Initialize mlppp state */
+ sp->lcp.mrru = sp->lcp.their_mrru = 0;
+ sp->lcp.ml_prefix = NULL;
+ sp->lcp.ml_seq_expected = 0;
+
/*
* If this interface is passive or dial-on-demand, and we are
* still in Initial state, it means we've got an incoming
diff -r 282fdb5de4d5 -r 44432312f09e sys/net/if_spppvar.h
--- a/sys/net/if_spppvar.h Tue Apr 07 19:26:44 2020 +0000
+++ b/sys/net/if_spppvar.h Fri Apr 10 17:28:37 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: if_spppvar.h,v 1.22.12.2 2020/04/07 18:47:43 is Exp $ */
+/* $NetBSD: if_spppvar.h,v 1.22.12.3 2020/04/10 17:28:37 is Exp $ */
#ifndef _NET_IF_SPPPVAR_H_
#define _NET_IF_SPPPVAR_H_
@@ -48,6 +48,8 @@
/* multilink variables */
u_long mrru; /* our max received reconstructed unit */
u_long their_mrru; /* their max received reconstructed unit */
+ u_long ml_seq_xpctd; /* next seqid we expect to receive */
+ struct mbuf *ml_prefix; /* reassembled packet so far */
};
#define IDX_IPCP 1 /* idx into state table */
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