1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
|
PORT=$(random_port)
declare -a ARGS
if [ "$NETCAT_UNIX" = "y" ]; then
FAM="AF_UNIX"
ARGS=( -${NETCAT_DGRAM:+u}U "$TEMPDIR/$PORT.sock" )
else
FAM="AF_INET"
ARGS=( ${NETCAT_DGRAM:+-u} "127.0.0.1" "$PORT" )
fi
start_server() {
#echo nc "$@"
if [ -z "$NETCAT_DGRAM" ]; then
STRACE_LINGER="n" PIPES="y" netcat_listen "$@"
else
STRACE_LINGER="y" PIPES="y" netcat_listen "$@"
fi
if [ "${BIND_ADDRESS#"{sa_family=$FAM"[,\}]}" = "$BIND_ADDRESS" ]; then # sanity check
printf "ERROR at line %d: address \"%s\" isn't %s\\n" ${BASH_LINENO[0]} "$BIND_ADDRESS" "$FAM" >&2
exit 1
fi
}
start_client() {
local in="$TEMPDIR/client.in" out="$TEMPDIR/client.out"
mkfifo -- "$in" "$out"
if [ -z "$NETCAT_DGRAM" ]; then
$NC "$@" <"$in" >"$out" {LISTEN_IN}>&- {LISTEN_OUT}<&- & CLIENT_PID=$!
else
$NC "$@" <"$in" >"$out" {LISTEN_IN}>&- {LISTEN_OUT}<&- {STRACE_FD}<&- & CLIENT_PID=$!
fi
exec {CONNECT_IN}>"$in" {CONNECT_OUT}<"$out"
rm -f -- "$in" "$out"
}
stop_client() {
kill_and_wait $CLIENT_PID
exec {CONNECT_IN}>&- {CONNECT_OUT}<&-
}
extract_source() {
local strace_recvfrom peer="" IFS_old="$IFS"
while IFS="" read -r strace_recvfrom; do
# we don't want to use `grep -m1` here because its input is
# buffered so it consumes multiple lines from the FIFO
test "${strace_recvfrom#"recvfrom($BIND_FD,"}" = "$strace_recvfrom" || break
done <&$STRACE_FD
if [[ "$strace_recvfrom" =~ ^[A-Za-z0-9_]+\([0-9]+,[[:blank:]]*\"[^\"]*\",[[:blank:]]*[0-9]+,[[:blank:]]*[^,[:blank:]]+,[[:blank:]]*(\{sa_family=([^{},[:blank:]]+)(,[^{}]+)?\}), ]]; then
peer="${BASH_REMATCH[1]}"
fi
if [ "$FAM" = "AF_INET" ] && [[ "$peer" =~ ^\{sa_family=$FAM,[[:blank:]]*sin_port=htons\(([0-9]+)\),[[:blank:]]*sin_addr=inet_addr\(\"([^\"]+)\"\)\}$ ]]; then
SPORT=${BASH_REMATCH[1]}
SADDR="${BASH_REMATCH[2]}"
elif [ "$FAM" = "AF_UNIX" ] && [[ "$peer" =~ ^\{sa_family=$FAM,[[:blank:]]*sun_path=\"([^\"]+)\"\}$ ]]; then
SPORT=""
SADDR="${BASH_REMATCH[1]}"
else
printf "ERROR at line %d: Can't extract source port from \"%s\"\\n" ${BASH_LINENO[0]} "${peer:-"$strace_recvfrom"}" >&2
exit 1
fi
IFS="$IFS_old"
PEER_ADDR="$peer"
}
#######################################################################
# without -k
start_server "${ARGS[@]}"
start_client "${ARGS[@]}"
greet server
greet client
stop_client
if [ -z "$NETCAT_DGRAM" ]; then
# the server accepts a single connection and terminates afterwards
wait $PID
else
# for UDP and not -k, the recvfrom() is followed with a connect()
extract_source
grep -m1 -E "^connect\\($BIND_FD,[[:blank:]]*\\{sa_family=$FAM," <&$STRACE_FD >"$TEMPDIR/conn"
grep -Fq -e "$PEER_ADDR" <"$TEMPDIR/conn"
if [ "$NETCAT_UNIX" = "y" ]; then
# XXX for some reason reconnecting yields EPERM with UNIX domain datagram sockets
! strace -o"$TEMPDIR/strace.log" -Z $NC -s "$SADDR" "${ARGS[@]}" 2>/dev/null
grep -Eq '^connect\([0-9]+,\s*\{sa_family='"$FAM"',[^{}]+\},\s*[0-9]+\)\s*=\s*-1\s+EPERM\s' <"$TEMPDIR/strace.log"
else
# reconnecting from a different source is a no-op (we make sure later that "foo"
# isn't read from the server) -- the test will fail if we reconnect from the
# server address+port but that should be seldom enough
$NC "${ARGS[@]}" <<<"foo"
# make sure '-vz' reports it can't connect
if $NC -vz "${ARGS[@]}" <<<"bar" 2>/dev/null; then
printf "ERROR at line %d: Could reconnect!\\n" $LINENO >&2
exit 1
fi
# can keep talking when reusing the same source though
start_client -s "$SADDR" -p $SPORT "${ARGS[@]}"
greet server
greet client
stop_client
fi
kill_and_wait "$PID"
exec {STRACE_FD}<&-
fi
exec {LISTEN_IN}>&- {LISTEN_OUT}<&-
#######################################################################
# with -k
start_server -k "${ARGS[@]}"
if [ -z "$NETCAT_DGRAM" ]; then
start_client "${ARGS[@]}"
greet server
greet client
stop_client
start_client "${ARGS[@]}"
greet client
greet server
stop_client
start_client "${ARGS[@]}"
greet server
stop_client
start_client "${ARGS[@]}"
greet client
stop_client
else
# for UDP and not -k, the recvfrom() is not connected and while it can
# receive UDP datagrams from multiple clients it cannot write to them
for ((i=0; i<4; i++)); do
start_client "${ARGS[@]}"
greet server
stop_client
done
fi
kill_and_wait $PID
# vim: set filetype=bash :
|
