[Babel-users] more nlogn crash details

[Dave Taht]

I'm presently testing the below patch again....

so I went back to the pure nlogn branch to see if I could duplicate
the one crash I had early on.

It takes a while (injecting and reinjecting 12k routes over about 20
minutes), but ultimately crashed here:

#0  0x000000000040c1d4 in start_message (buf=buf at entry=0x171e5b8,
    type=type at entry=10, len=len at entry=22) at message.c:957
#1  0x000000000040c568 in send_multihop_request (buf=0x171e5b8,
    prefix=0x1cf66b8 "\374c\311/S\266)j", plen=<optimized out>,
    src_prefix=0x1cf66c9 "", src_plen=<optimized out>, seqno=<optimized out>,
    id=0x1cf66b0 "\002%\220\377\376\302*\242\374c\311/S\266)j", hop_count=127)
    at message.c:1806
#2  0x000000000040dfd9 in send_request_resend (
    prefix=0x1cf66b8 "\374c\311/S\266)j", plen=64 '@',
    src_prefix=0x1cf66c9 "", src_plen=0 '\000', seqno=<optimized out>,
    id=0x1cf66b0 "\002%\220\377\376\302*\242\374c\311/S\266)j")
    at message.c:1904
#3  0x000000000040a7ee in flush_route (route=route at entry=0x1cf8af0)
    at route.c:300
#4  0x000000000040b02e in expire_routes () at route.c:1216
#5  0x0000000000403121 in main (argc=<optimized out>, argv=<optimized out>)
    at babeld.c:751

This box does have a ton of currently disabled interfaces on it (only
eno1 exists)

babeld -L bla
eno1 wlp2s0 wlx9cefd5ff0b2c wlxec086b113afd enxd23bf0e38d7c
enx2a1c0359e29b enx029b514afb6f enx88c255560f15 enp0s20u1u1u4
enp0s20u1u1u4 enp0s20u1u2

I also managed to crash the other box same way.

the "fix" for this (been re-testing for a while), but for all I know
I'm covering up a symtom, was:

diff --git a/message.c b/message.c
index 3ca92ff..83183fe 100644
--- a/message.c
+++ b/message.c
@@ -1901,8 +1901,10 @@ send_request_resend(const unsigned char
*prefix, unsigned char plen,
     } else {
         struct interface *ifp;
         FOR_ALL_INTERFACES(ifp)
+           if(ifp->buf.buf) {
             send_multihop_request(&ifp->buf, prefix, plen,
src_prefix, src_plen,
                                   seqno, id, 127);
+           }
     }
 }

--
2.7.4


-- 

Dave Täht
CTO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-831-205-9740