
我在 Windows 11 上的 WSL2 中运行了一个 kali linux 实例。它配置为使用镜像网络模式(如果相关)。通常,如果一个人开始在任何给定端口(例如 5055)上监听 127.0.0.1(nc -nvlp 5055
),然后在同一台机器上使用 ncat 连接到该端口(nc 127.0.0.1 5055
),则会建立连接,您将能够键入和发送数据。每当我尝试这样做时,我都会在监听端(左)收到一个连接,并在发送端(右)“成功”地执行同样的事情。但是,当我尝试发送第一位数据时,连接断开,接收方不会收到该数据。第一张图片是使用 netcat 完成的[v1.10-48]
,第二张图片是使用 nmap 的版本。为什么会这样?几周前,这曾经工作得很好,什么都没有改变。
我尝试过的事情:
- 全新安装的 kali
- 禁用Windows防火墙
- 刷新 iptables
- 以 sudo 身份运行
- 添加
-k
标志
此外,还有更多奇怪的行为:我能够在同一端口上监听多个(在本例中为 4 个)进程,没有任何问题。执行netstat -tnupl
还显示每个单独的 PID 都在独立监听:
...但情况更奇怪。当多个 netcat 监听同一个端口时,我尝试连接到该端口,它只会转到最近启动的监听器。如果我尝试创建其他当前一个端口仍处于活动状态时,连接到该端口,它将转到在仍处于活动状态的端口之前启动的侦听器。在这种情况下,ncat 的行为是理所当然的。数据可以无问题地发送和接收,只有在 ^C 时才会关闭连接
我已经绞尽脑汁想了好几个星期,想弄清楚这个问题。如果有人遇到过这种情况或有解决方案,我将不胜感激!TIA!
编辑:这是我使用的命令:
nc -nvlp 5055
->nc localhost 5055
预期行为是保持连接建立并将数据从客户端的标准输入发送到服务器端。
编辑 2:这里有一些 strace 日志,可能会有帮助
strace nc -nvlp 5055
-> strace nc 127.0.0.1 5055
(分别)
% strace nc -nvlp 5055 24-03-14 - 18:55:16
execve("/usr/bin/nc", ["nc", "-nvlp", "5055"], 0x7fff75e4b840 /* 39 vars */) = 0
brk(NULL) = 0x5578d9b11000
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f816adda000
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=89731, ...}, AT_EMPTY_PATH) = 0
mmap(NULL, 89731, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f816adc4000
close(3) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\220x\2\0\0\0\0\0"..., 832) = 832
pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784
newfstatat(3, "", {st_mode=S_IFREG|0755, st_size=1926256, ...}, AT_EMPTY_PATH) = 0
pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784
mmap(NULL, 1974096, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f816abe2000
mmap(0x7f816ac08000, 1396736, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x26000) = 0x7f816ac08000
mmap(0x7f816ad5d000, 344064, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x17b000) = 0x7f816ad5d000
mmap(0x7f816adb1000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1cf000) = 0x7f816adb1000
mmap(0x7f816adb7000, 53072, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f816adb7000
close(3) = 0
mmap(NULL, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f816abdf000
arch_prctl(ARCH_SET_FS, 0x7f816abdf740) = 0
set_tid_address(0x7f816abdfa10) = 6959
set_robust_list(0x7f816abdfa20, 24) = 0
rseq(0x7f816abe0060, 0x20, 0, 0x53053053) = 0
mprotect(0x7f816adb1000, 16384, PROT_READ) = 0
mprotect(0x5578d9a4f000, 4096, PROT_READ) = 0
mprotect(0x7f816ae0c000, 8192, PROT_READ) = 0
prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0
munmap(0x7f816adc4000, 89731) = 0
newfstatat(AT_FDCWD, "/etc/resolv.conf", {st_mode=S_IFREG|0644, st_size=196, ...}, 0) = 0
getrandom("\xe5\xc1\x3b\x27\xa4\x6e\x80\xdd", 8, GRND_NONBLOCK) = 8
brk(NULL) = 0x5578d9b11000
brk(0x5578d9b32000) = 0x5578d9b32000
openat(AT_FDCWD, "/etc/host.conf", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=9, ...}, AT_EMPTY_PATH) = 0
read(3, "multi on\n", 4096) = 9
read(3, "", 4096) = 0
close(3) = 0
futex(0x7f816adbe42c, FUTEX_WAKE_PRIVATE, 2147483647) = 0
openat(AT_FDCWD, "/etc/resolv.conf", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=196, ...}, AT_EMPTY_PATH) = 0
read(3, "# This file was automatically ge"..., 4096) = 196
read(3, "", 4096) = 0
uname({sysname="Linux", nodename="Sovngarde-2", ...}) = 0
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=196, ...}, AT_EMPTY_PATH) = 0
close(3) = 0
rt_sigaction(SIGINT, {sa_handler=0x5578d9a4a2f0, sa_mask=[INT], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f816ac1e510}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
rt_sigaction(SIGQUIT, {sa_handler=0x5578d9a4a2f0, sa_mask=[QUIT], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f816ac1e510}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
rt_sigaction(SIGTERM, {sa_handler=0x5578d9a4a2f0, sa_mask=[TERM], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f816ac1e510}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
rt_sigaction(SIGURG, {sa_handler=SIG_IGN, sa_mask=[URG], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f816ac1e510}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
rt_sigaction(SIGPIPE, {sa_handler=SIG_IGN, sa_mask=[PIPE], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f816ac1e510}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
connect(3, {sa_family=AF_UNIX, sun_path="/var/run/nscd/socket"}, 110) = -1 ENOENT (No such file or directory)
close(3) = 0
socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
connect(3, {sa_family=AF_UNIX, sun_path="/var/run/nscd/socket"}, 110) = -1 ENOENT (No such file or directory)
close(3) = 0
newfstatat(AT_FDCWD, "/etc/nsswitch.conf", {st_mode=S_IFREG|0644, st_size=526, ...}, 0) = 0
newfstatat(AT_FDCWD, "/", {st_mode=S_IFDIR|0755, st_size=4096, ...}, 0) = 0
openat(AT_FDCWD, "/etc/nsswitch.conf", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=526, ...}, AT_EMPTY_PATH) = 0
read(3, "# /etc/nsswitch.conf\n#\n# Example"..., 4096) = 526
read(3, "", 4096) = 0
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=526, ...}, AT_EMPTY_PATH) = 0
close(3) = 0
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=89731, ...}, AT_EMPTY_PATH) = 0
mmap(NULL, 89731, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f816adc4000
close(3) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v3/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v3", 0x7fff4fa94ab0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2", 0x7fff4fa94ab0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/x86_64-linux-gnu", {st_mode=S_IFDIR|0755, st_size=122880, ...}, 0) = 0
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v3/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v3", 0x7fff4fa94ab0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2", 0x7fff4fa94ab0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu", {st_mode=S_IFDIR|0755, st_size=122880, ...}, 0) = 0
openat(AT_FDCWD, "/lib/glibc-hwcaps/x86-64-v3/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/glibc-hwcaps/x86-64-v3", 0x7fff4fa94ab0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/glibc-hwcaps/x86-64-v2/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/glibc-hwcaps/x86-64-v2", 0x7fff4fa94ab0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib", {st_mode=S_IFDIR|0755, st_size=4096, ...}, 0) = 0
openat(AT_FDCWD, "/usr/lib/glibc-hwcaps/x86-64-v3/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/glibc-hwcaps/x86-64-v3", 0x7fff4fa94ab0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/glibc-hwcaps/x86-64-v2/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/glibc-hwcaps/x86-64-v2", 0x7fff4fa94ab0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib", {st_mode=S_IFDIR|0755, st_size=4096, ...}, 0) = 0
munmap(0x7f816adc4000, 89731) = 0
openat(AT_FDCWD, "/etc/services", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=12813, ...}, AT_EMPTY_PATH) = 0
lseek(3, 0, SEEK_SET) = 0
read(3, "# Network services, Internet sty"..., 4096) = 4096
read(3, "\ntinc\t\t655/tcp\t\t\t\t# tinc control"..., 4096) = 4096
read(3, "cd\t6445/tcp\tsge_execd\t# Grid Eng"..., 4096) = 4096
read(3, "es\namidxtape\t10083/tcp\t\t\t# amand"..., 4096) = 525
read(3, "", 4096) = 0
close(3) = 0
socket(AF_INET, SOCK_STREAM, IPPROTO_TCP) = 3
setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
setsockopt(3, SOL_SOCKET, SO_REUSEPORT, [1], 4) = 0
bind(3, {sa_family=AF_INET, sin_port=htons(5055), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
listen(3, 1) = 0
getsockname(3, {sa_family=AF_INET, sin_port=htons(5055), sin_addr=inet_addr("0.0.0.0")}, [16]) = 0
write(2, "listening on [any] 5055 ...", 27listening on [any] 5055 ...) = 27
write(2, "\n", 1
) = 1
rt_sigaction(SIGALRM, {sa_handler=SIG_IGN, sa_mask=[ALRM], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f816ac1e510}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
alarm(0) = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8) = 0
accept(3, {sa_family=AF_INET, sin_port=htons(60960), sin_addr=inet_addr("127.0.0.1")}, [16]) = 4
rt_sigaction(SIGALRM, {sa_handler=SIG_IGN, sa_mask=[ALRM], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f816ac1e510}, {sa_handler=SIG_IGN, sa_mask=[ALRM], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f816ac1e510}, 8) = 0
alarm(0) = 0
close(3) = 0
getsockopt(4, SOL_IP, IP_OPTIONS, 0x5578d9b12490, [40 => 0]) = 0
getsockname(4, {sa_family=AF_INET, sin_port=htons(5055), sin_addr=inet_addr("127.0.0.1")}, [16]) = 0
write(2, "connect to [127.0.0.1] from (UNK"..., 55connect to [127.0.0.1] from (UNKNOWN) [127.0.0.1] 60960) = 55
write(2, "\n", 1
) = 1
pselect6(5, [0 4], NULL, NULL, NULL, NULL
% strace nc 127.0.0.1 5055 24-03-14 - 18:55:35
execve("/usr/bin/nc", ["nc", "127.0.0.1", "5055"], 0x7ffd5f734b00 /* 39 vars */) = 0
brk(NULL) = 0x559cd1d18000
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f19a7309000
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=89731, ...}, AT_EMPTY_PATH) = 0
mmap(NULL, 89731, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f19a72f3000
close(3) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\220x\2\0\0\0\0\0"..., 832) = 832
pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784
newfstatat(3, "", {st_mode=S_IFREG|0755, st_size=1926256, ...}, AT_EMPTY_PATH) = 0
pread64(3, "\6\0\0\0\4\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0@\0\0\0\0\0\0\0"..., 784, 64) = 784
mmap(NULL, 1974096, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f19a7111000
mmap(0x7f19a7137000, 1396736, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x26000) = 0x7f19a7137000
mmap(0x7f19a728c000, 344064, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x17b000) = 0x7f19a728c000
mmap(0x7f19a72e0000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1cf000) = 0x7f19a72e0000
mmap(0x7f19a72e6000, 53072, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f19a72e6000
close(3) = 0
mmap(NULL, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f19a710e000
arch_prctl(ARCH_SET_FS, 0x7f19a710e740) = 0
set_tid_address(0x7f19a710ea10) = 7181
set_robust_list(0x7f19a710ea20, 24) = 0
rseq(0x7f19a710f060, 0x20, 0, 0x53053053) = 0
mprotect(0x7f19a72e0000, 16384, PROT_READ) = 0
mprotect(0x559cd0dd7000, 4096, PROT_READ) = 0
mprotect(0x7f19a733b000, 8192, PROT_READ) = 0
prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0
munmap(0x7f19a72f3000, 89731) = 0
newfstatat(AT_FDCWD, "/etc/resolv.conf", {st_mode=S_IFREG|0644, st_size=196, ...}, 0) = 0
getrandom("\xc7\x34\xec\xd4\xd0\x66\xcb\x26", 8, GRND_NONBLOCK) = 8
brk(NULL) = 0x559cd1d18000
brk(0x559cd1d39000) = 0x559cd1d39000
openat(AT_FDCWD, "/etc/host.conf", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=9, ...}, AT_EMPTY_PATH) = 0
read(3, "multi on\n", 4096) = 9
read(3, "", 4096) = 0
close(3) = 0
futex(0x7f19a72ed42c, FUTEX_WAKE_PRIVATE, 2147483647) = 0
openat(AT_FDCWD, "/etc/resolv.conf", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=196, ...}, AT_EMPTY_PATH) = 0
read(3, "# This file was automatically ge"..., 4096) = 196
read(3, "", 4096) = 0
uname({sysname="Linux", nodename="Sovngarde-2", ...}) = 0
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=196, ...}, AT_EMPTY_PATH) = 0
close(3) = 0
rt_sigaction(SIGINT, {sa_handler=0x559cd0dd22f0, sa_mask=[INT], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f19a714d510}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
rt_sigaction(SIGQUIT, {sa_handler=0x559cd0dd22f0, sa_mask=[QUIT], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f19a714d510}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
rt_sigaction(SIGTERM, {sa_handler=0x559cd0dd22f0, sa_mask=[TERM], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f19a714d510}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
rt_sigaction(SIGURG, {sa_handler=SIG_IGN, sa_mask=[URG], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f19a714d510}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
rt_sigaction(SIGPIPE, {sa_handler=SIG_IGN, sa_mask=[PIPE], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f19a714d510}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
connect(3, {sa_family=AF_UNIX, sun_path="/var/run/nscd/socket"}, 110) = -1 ENOENT (No such file or directory)
close(3) = 0
socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
connect(3, {sa_family=AF_UNIX, sun_path="/var/run/nscd/socket"}, 110) = -1 ENOENT (No such file or directory)
close(3) = 0
newfstatat(AT_FDCWD, "/etc/nsswitch.conf", {st_mode=S_IFREG|0644, st_size=526, ...}, 0) = 0
newfstatat(AT_FDCWD, "/", {st_mode=S_IFDIR|0755, st_size=4096, ...}, 0) = 0
openat(AT_FDCWD, "/etc/nsswitch.conf", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=526, ...}, AT_EMPTY_PATH) = 0
read(3, "# /etc/nsswitch.conf\n#\n# Example"..., 4096) = 526
read(3, "", 4096) = 0
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=526, ...}, AT_EMPTY_PATH) = 0
close(3) = 0
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=89731, ...}, AT_EMPTY_PATH) = 0
mmap(NULL, 89731, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f19a72f3000
close(3) = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v3/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v3", 0x7ffee19a18a0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2", 0x7ffee19a18a0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/x86_64-linux-gnu", {st_mode=S_IFDIR|0755, st_size=122880, ...}, 0) = 0
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v3/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v3", 0x7ffee19a18a0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/glibc-hwcaps/x86-64-v2", 0x7ffee19a18a0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu", {st_mode=S_IFDIR|0755, st_size=122880, ...}, 0) = 0
openat(AT_FDCWD, "/lib/glibc-hwcaps/x86-64-v3/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/glibc-hwcaps/x86-64-v3", 0x7ffee19a18a0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/glibc-hwcaps/x86-64-v2/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib/glibc-hwcaps/x86-64-v2", 0x7ffee19a18a0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/lib", {st_mode=S_IFDIR|0755, st_size=4096, ...}, 0) = 0
openat(AT_FDCWD, "/usr/lib/glibc-hwcaps/x86-64-v3/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/glibc-hwcaps/x86-64-v3", 0x7ffee19a18a0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/glibc-hwcaps/x86-64-v2/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib/glibc-hwcaps/x86-64-v2", 0x7ffee19a18a0, 0) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/lib/libnss_db.so.2", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
newfstatat(AT_FDCWD, "/usr/lib", {st_mode=S_IFDIR|0755, st_size=4096, ...}, 0) = 0
munmap(0x7f19a72f3000, 89731) = 0
openat(AT_FDCWD, "/etc/services", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=12813, ...}, AT_EMPTY_PATH) = 0
lseek(3, 0, SEEK_SET) = 0
read(3, "# Network services, Internet sty"..., 4096) = 4096
read(3, "\ntinc\t\t655/tcp\t\t\t\t# tinc control"..., 4096) = 4096
read(3, "cd\t6445/tcp\tsge_execd\t# Grid Eng"..., 4096) = 4096
read(3, "es\namidxtape\t10083/tcp\t\t\t# amand"..., 4096) = 525
read(3, "", 4096) = 0
close(3) = 0
newfstatat(AT_FDCWD, "/etc/nsswitch.conf", {st_mode=S_IFREG|0644, st_size=526, ...}, 0) = 0
openat(AT_FDCWD, "/etc/services", O_RDONLY|O_CLOEXEC) = 3
newfstatat(3, "", {st_mode=S_IFREG|0644, st_size=12813, ...}, AT_EMPTY_PATH) = 0
lseek(3, 0, SEEK_SET) = 0
read(3, "# Network services, Internet sty"..., 4096) = 4096
read(3, "\ntinc\t\t655/tcp\t\t\t\t# tinc control"..., 4096) = 4096
read(3, "cd\t6445/tcp\tsge_execd\t# Grid Eng"..., 4096) = 4096
read(3, "es\namidxtape\t10083/tcp\t\t\t# amand"..., 4096) = 525
read(3, "", 4096) = 0
close(3) = 0
socket(AF_INET, SOCK_STREAM, IPPROTO_TCP) = 3
setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
setsockopt(3, SOL_SOCKET, SO_REUSEPORT, [1], 4) = 0
rt_sigaction(SIGALRM, {sa_handler=SIG_IGN, sa_mask=[ALRM], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f19a714d510}, {sa_handler=SIG_DFL, sa_mask=[], sa_flags=0}, 8) = 0
alarm(0) = 0
rt_sigprocmask(SIG_BLOCK, NULL, [], 8) = 0
connect(3, {sa_family=AF_INET, sin_port=htons(5055), sin_addr=inet_addr("127.0.0.1")}, 16) = 0
rt_sigaction(SIGALRM, {sa_handler=SIG_IGN, sa_mask=[ALRM], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f19a714d510}, {sa_handler=SIG_IGN, sa_mask=[ALRM], sa_flags=SA_RESTORER|SA_RESTART, sa_restorer=0x7f19a714d510}, 8) = 0
alarm(0) = 0
pselect6(4, [0 3], NULL, NULL, NULL, NULLabc
) = 1 (in [0])
read(0, "abc\n", 8192) = 4
write(3, "abc\n", 4) = 4
pselect6(4, [0 3], NULL, NULL, NULL, NULL) = 1 (in [3])
read(3, 0x559cd1d1b710, 8192) = -1 ECONNRESET (Connection reset by peer)
close(3) = 0
close(3) = -1 EBADF (Bad file descriptor)
exit_group(0) = ?
+++ exited with 0 +++