> Hi Sebastian,
>
> On Jan 17, 2011, at 4:12 PM, Sebastian Proca wrote:
>
> > It's strange for me how comes that, depending on the
> specified arguments, I get two different errors:
> >
> > I case :
> >
> > # ./dtls_udp_echo 127.0.0.1
> > SSL_connect: Connection refused
> > error:00000000:lib(0):func(0):reason(0)
> > Unexpected error while writing: 5
> > error:00000000:lib(0):func(0):reason(0)
> >
> > II case :
> >
> > # ./dtls_udp_echo -p 23232 -V 127.0.0.1
> > SSL_connect: Connection refused
> > error:00000000:lib(0):func(0):reason(0)
> >
> > Connected to 127.0.0.1
> >
> ------------------------------------------------------------
> > Segmentation fault
> >
> > Wireshark shows the beginning of dtls negotiation, but
> it's clear that after these errors, it stops.
> >
> > Does someone know the correct usage of this sample?
> I'm out of ideas!
>
> You probably don't have a server running. Use:
>
> ./dtls_udp_echo
>
> without any parameters to start a server listening on all
> available addresses. You can then start a client with:
>
> ./dtls_udp_echo 127.0.0.1
>
> All of the examples listed on our website are both server
> and client. If you specify an address on the command line,
> it will use it to start a client which connects to it.
> Otherwise, without an address it will start a server and
> listen for incoming connections.
>
> Best regards
> Robin
Hi Robin,
Thank you for your help! I understand now the way that this application should
be used. Yet, I didn't manage to obtain a working dtls session.
After I start the server :
# ./dtls_udp_echo
I start the client, but I receive the error bellow:
# ./dtls_udp_echo 127.0.0.1
Unexpected error while writing: 1
error:14103138:SSL routines:DTLS1_READ_FAILED:read timeout expired, but the
started server shows no error, nothing.
I wanted to understand more of these errors so I used strace.
At the server's part I saw few lines that caught my attention:
==================================================================
# ./dtls_udp_echo
execve("./dtls_udp_echo", ["./dtls_udp_echo"], [/* 39 vars */]) = 0
brk(0) = 0x8d6b000
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
mmap2(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0xb77a6000
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY) = 3
fstat64(3, {st_mode=S_IFREG|0644, st_size=83867, ...}) = 0
mmap2(NULL, 83867, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb7791000
close(3) = 0
access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory)
...
more lines
...
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0xb778f000
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0xb778e000
set_thread_area({entry_number:-1 -> 6, base_addr:0xb778e6c0, limit:1048575,
seg_32bit:1, contents:0, read_exec_only:0, limit_in_pages:1, seg_not_present:0,
useable:1}) = 0
mprotect(0xe2c000, 4096, PROT_READ) = 0
mprotect(0x268000, 8192, PROT_READ) = 0
mprotect(0xd58000, 4096, PROT_READ) = 0
mprotect(0x112000, 4096, PROT_READ) = 0
mprotect(0x573000, 32768, PROT_READ) = 0
mprotect(0xf6a000, 4096, PROT_READ) = 0
mprotect(0x804c000, 4096, PROT_READ) = 0
mprotect(0x3c9000, 4096, PROT_READ) = 0
munmap(0xb7791000, 83867) = 0
set_tid_address(0xb778e728) = 12589
set_robust_list(0xb778e730, 0xc) = 0
futex(0xbfb1c2a0, FUTEX_WAKE_PRIVATE, 1) = 0
futex(0xbfb1c2a0, FUTEX_WAIT_BITSET_PRIVATE|FUTEX_CLOCK_REALTIME, 1, NULL,
bfb1c2b0) = -1 EAGAIN (Resource temporarily unavailable)
....
======================================================
On client's side I get these traces:
write(3,
"\26\376\377\0\0\0\0\0\0\0\0\0?\1\0\0003\0\0\0\0\0\0\0003\376\377M6\276\316\3"...,
76) = 76
recvfrom(3, 0x9f5b3c0, 18437, 0, 0xbfc40ebc, 0xbfc40eb8) = -1 EAGAIN (Resource
temporarily unavailable)
getsockopt(3, SOL_IP, 0xe /* IP_??? */, [16436], [4]) = 0
======================================================
So the message that both server and client have is "Resource temporarily
unavailable".
Did someone have the same problem? How can this be solved?
Regards,
Sebastian
