[src/is-mlppp]: src/sys/net MLPPP mrru negotiation.

[is <is%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a32d16a9f03f
branches:  is-mlppp
changeset: 930654:a32d16a9f03f
user:      is <is%NetBSD.org@localhost>
date:      Sat Apr 11 09:40:02 2020 +0000

description:
MLPPP mrru negotiation.

diffstat:

 sys/net/if_spppsubr.c |  45 ++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 42 insertions(+), 3 deletions(-)

diffs (94 lines):

diff -r 1575d6d69522 -r a32d16a9f03f sys/net/if_spppsubr.c
--- a/sys/net/if_spppsubr.c     Sat Apr 11 08:11:58 2020 +0000
+++ b/sys/net/if_spppsubr.c     Sat Apr 11 09:40:02 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_spppsubr.c,v 1.187.2.8 2020/04/11 08:11:58 is Exp $  */
+/*     $NetBSD: if_spppsubr.c,v 1.187.2.9 2020/04/11 09:40:02 is Exp $  */
 
 /*
  * Synchronous PPP/Cisco link level subroutines.
@@ -41,7 +41,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_spppsubr.c,v 1.187.2.8 2020/04/11 08:11:58 is Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_spppsubr.c,v 1.187.2.9 2020/04/11 09:40:02 is Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_inet.h"
@@ -2354,7 +2354,6 @@
        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_xpctd = 0;
 
@@ -2434,6 +2433,10 @@
                sp->lcp.mru = PP_MTU;
        sp->lcp.their_mru = PP_MTU;
 
+       sp->lcp.mrru = sp->pp_if.if_mtu;
+       sp->lcp.opts |= (1 << LCP_OPT_MP_MRRU);
+       sp->lcp.their_mrru = 0;
+
        /*
         * If we are authenticator, negotiate LCP_AUTH
         */
@@ -2822,6 +2825,19 @@
                        sp->lcp.opts &= ~(1 << LCP_OPT_MRU);
                        sp->lcp.mru = PP_MTU;
                        break;
+               case LCP_OPT_MP_MRRU:
+                       /*
+                        * the peer is rejecting a multilink MRRU.
+                        * give up on MP in the incoming direction.
+                        */
+                       if (debug) {
+                               addlog("%s: warning: peer rejected our MRRU of "
+                                   "%ld bytes. Defaulting to no MLPPP\n",
+                                   ifp->if_xname, sp->lcp.mrru);
+                       }
+                       sp->lcp.opts &= ~(1 << LCP_OPT_MP_MRRU);
+                       sp->lcp.mrru = 0;
+                       break;
                case LCP_OPT_AUTH_PROTO:
                        /*
                         * Peer doesn't want to authenticate himself,
@@ -2924,6 +2940,22 @@
                                sp->lcp.opts |= (1 << LCP_OPT_MRU);
                        }
                        break;
+               case LCP_OPT_MP_MRRU:
+                       /*
+                        * Peer wants to advise us to negotiate an multilink MRRU.
+                        * Agree on it if it's reasonable, or use
+                        * default otherwise.
+                        */
+                       if (len >= 4 && l == 4) {
+                               u_int mrru = p[2] * 256 + p[3];
+                               if (debug)
+                                       addlog(" %d", mrru);
+                               if (mrru < PPP_MINMRU || mru > sp->pp_if.if_mtu)
+                                       mru = sp->pp_if.if_mtu;
+                               sp->lcp.mrru = mrru;
+                               sp->lcp.opts |= (1 << LCP_OPT_MP_MRRU);
+                       }
+                       break;
                case LCP_OPT_AUTH_PROTO:
                        /*
                         * Peer doesn't like our authentication method,
@@ -3089,6 +3121,13 @@
                opt[i++] = sp->lcp.mru;
        }
 
+       if (sp->lcp.opts & (1 << LCP_OPT_MP_MRRU)) {
+               opt[i++] = LCP_OPT_MP_MRRU;
+               opt[i++] = 4;
+               opt[i++] = sp->lcp.mrru >> 8;
+               opt[i++] = sp->lcp.mrru;
+       }
+
        if (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) {
                authproto = sp->hisauth.proto;
                opt[i++] = LCP_OPT_AUTH_PROTO;