Failed to send Retry packet

[kenmcmil]

When receiving an initial packet with version 0xff000010, the quant server seems to run into some kind of problem sending a Retry packet. There are also some reports of misaligned accesses, but I don't know if these are relevant. Here is the log:

0.033   q_init quic.c:546 quant/socket 0.0.17/4ed3af4 with libev/epoll 4.22 ready
        q_init quic.c:547 submit bug reports at https://github.com/NTAP/quant/issues
0.035   q_init quic.c:567 debug build, storing fuzzer corpus data
/home/mcmillan/projects/quant/lib/deps/warpcore/lib/src/ip.h:185:13: runtime error: member access within misaligned address 0x60400000031e for type 'struct ip_hdr', which requires 4 byte alignment
0x60400000031e: note: pointer points here
 00 00 08 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00
             ^ 
/home/mcmillan/projects/quant/lib/deps/warpcore/lib/src/ip.h:186:13: runtime error: member access within misaligned address 0x60400000031e for type 'struct ip_hdr', which requires 4 byte alignment
0x60400000031e: note: pointer points here
 00 00 08 00 45 00  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00
             ^ 
/home/mcmillan/projects/quant/lib/deps/warpcore/lib/src/ip.h:187:13: runtime error: member access within misaligned address 0x60400000031e for type 'struct ip_hdr', which requires 4 byte alignment
0x60400000031e: note: pointer points here
 00 00 08 00 45 00  00 00 00 00 40 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00
             ^ 
/home/mcmillan/projects/quant/lib/deps/warpcore/lib/src/ip.h:188:11: runtime error: member access within misaligned address 0x60400000031e for type 'struct ip_hdr', which requires 4 byte alignment
0x60400000031e: note: pointer points here
 00 00 08 00 45 00  00 00 00 00 40 00 40 00  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00
             ^ 
/home/mcmillan/projects/quant/lib/deps/warpcore/lib/src/ip.h:189:15: runtime error: member access within misaligned address 0x60400000031e for type 'struct ip_hdr', which requires 4 byte alignment
0x60400000031e: note: pointer points here
 00 00 08 00 45 00  00 00 00 00 40 00 40 11  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00
             ^ 
        q_bind quic.c:393 bound serv socket on port 4443
        main server.c:240 server waiting on lo port 4443
        q_rx_ready quic.c:722 waiting for conn to get ready to rx
0.217   rx_pkts conn.c:998 cannot find conn 0:0000000000000001 for 2020-byte Retry pkt
0.217   log_pkt pkt.c:87 RX from=127.0.0.1:4987 len=2020 0xff=Retry vers=0xff000010 dcid=0000000000000001 scid=0000000000000000 odcid=0044b7d0f9d0d265574f0e342eea5e7ffb00 tok=fe613551bf34d3cbc25f41ad024613f39c480db6662590295619c6359c271e88f29abe91e816ed653411f7fb8a7a475826a3134504674da697eef2c7863e3...
        rx_pkts conn.c:1018 ignoring unexpected Retry pkt for conn 0:0000000000000001

[kenmcmil]

This was because the packet was not recognized as an initial packet, since it used the draft-16 first byte. So this is a non-issue. Closing, with apologies.

[larseggert]

Thanks for reporting anyway, and no worries!

The unaligned accesses come from me being very aggressive with sanitizer options, and the gcc version on quant.eggert.org being a bit too old to understand the function attributes to suppress false positives.