Re: MPD on localhost won't work if there's no Wifi!?
On Mon, 9 Jun 2014 10:30:09 +0400, Reco wrote:
So, mpc tries standard mpd socket and fails. Adding said socket to
mpd.conf (via bind_address) should solve the issue.
Just adding a path to the socket doesn't really solve the issue (I run
MPD as my user, so there is no access to /var/run). I tried removing
/etc/mpd.conf, but strace tells me MPD still tries to find the sockets
in /var/run, and seems to ignore a socket specified in bind_to_address
in my .mpd/mpd.conf:
bind_to_address "/home/teresaejunior/.mpd/socket"
But I got it to work by running:
MPD_HOST=~/.mpd/socket mpc
And that's interesting. mpc tries to connect to 127.0.0.1:6600 and
fails, but the error shows 'connection refused', not 'failed to resolve
hostname'. Is your mpd running?
For this I deeply regret, because I generally leave MPD running, but I
had to reboot (which I don't do often, I almost always just hibernate),
and so MPD was not running. The problem I mentioned does exist, but the
strace I have sent is wrong. Here are the proper strace logs without
setting the socket in mpd.conf: the first tries the /var/run/ sockets,
but the second doesn't, and the third works because the Wifi has been
connected:
$ strace -e trace=network mpc
socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
connect(3, {sa_family=AF_FILE, path="/var/run/mpd/socket"}, 110) = -1
ENOENT (No such file or directory)
socket(PF_NETLINK, SOCK_RAW, 0) = 3
bind(3, {sa_family=AF_NETLINK, pid=0, groups=00000000}, 12) = 0
getsockname(3, {sa_family=AF_NETLINK, pid=1050, groups=00000000}, [12]) = 0
sendto(3, "\24\0\0\0\26\0\1\3=Z\225S\0\0\0\0\0\0\0\0", 20, 0,
{sa_family=AF_NETLINK, pid=0, groups=00000000}, 12) = 20
recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000},
msg_iov(1)=[{"D\0\0\0\24\0\2\0=Z\225S\32\4\0\0\2\10\200\376\1\0\0\0\10\0\1\0\177\0\0\1"...,
4096}], msg_controllen=0, msg_flags=0}, 0) = 68
recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000},
msg_iov(1)=[{"@\0\0\0\24\0\2\0=Z\225S\32\4\0\0\n\200\200\376\1\0\0\0\24\0\1\0\0\0\0\0"...,
4096}], msg_controllen=0, msg_flags=0}, 0) = 128
recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000},
msg_iov(1)=[{"\24\0\0\0\3\0\2\0=Z\225S\32\4\0\0\0\0\0\0\1\0\0\0\24\0\1\0\0\0\0\0"...,
4096}], msg_controllen=0, msg_flags=0}, 0) = 20
socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
connect(3, {sa_family=AF_FILE, path="/var/run/nscd/socket"}, 110) = -1
ENOENT (No such file or directory)
socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
connect(3, {sa_family=AF_FILE, path="/var/run/nscd/socket"}, 110) = -1
ENOENT (No such file or directory)
error: Failed to resolve host name
$ MPD_HOST=127.0.0.1 strace -e trace=network mpc
socket(PF_NETLINK, SOCK_RAW, 0) = 3
bind(3, {sa_family=AF_NETLINK, pid=0, groups=00000000}, 12) = 0
getsockname(3, {sa_family=AF_NETLINK, pid=1089, groups=00000000}, [12]) = 0
sendto(3, "\24\0\0\0\26\0\1\3CZ\225S\0\0\0\0\0\0\0\0", 20, 0,
{sa_family=AF_NETLINK, pid=0, groups=00000000}, 12) = 20
recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000},
msg_iov(1)=[{"D\0\0\0\24\0\2\0CZ\225SA\4\0\0\2\10\200\376\1\0\0\0\10\0\1\0\177\0\0\1"...,
4096}], msg_controllen=0, msg_flags=0}, 0) = 68
recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000},
msg_iov(1)=[{"@\0\0\0\24\0\2\0CZ\225SA\4\0\0\n\200\200\376\1\0\0\0\24\0\1\0\0\0\0\0"...,
4096}], msg_controllen=0, msg_flags=0}, 0) = 128
recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000},
msg_iov(1)=[{"\24\0\0\0\3\0\2\0CZ\225SA\4\0\0\0\0\0\0\1\0\0\0\24\0\1\0\0\0\0\0"...,
4096}], msg_controllen=0, msg_flags=0}, 0) = 20
error: Failed to resolve host name
$ strace -e trace=network mpc
socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
connect(3, {sa_family=AF_FILE, path="/var/run/mpd/socket"}, 110) = -1
ENOENT (No such file or directory)
socket(PF_NETLINK, SOCK_RAW, 0) = 3
bind(3, {sa_family=AF_NETLINK, pid=0, groups=00000000}, 12) = 0
getsockname(3, {sa_family=AF_NETLINK, pid=6262, groups=00000000}, [12]) = 0
sendto(3, "\24\0\0\0\26\0\1\3\305^\225S\0\0\0\0\0\0\0\0", 20, 0,
{sa_family=AF_NETLINK, pid=0, groups=00000000}, 12) = 20
recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000},
msg_iov(1)=[{"D\0\0\0\24\0\2\0\305^\225Sv\30\0\0\2\10\200\376\1\0\0\0\10\0\1\0\177\0\0\1"...,
4096}], msg_controllen=0, msg_flags=0}, 0) = 148
recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000},
msg_iov(1)=[{"@\0\0\0\24\0\2\0\305^\225Sv\30\0\0\n\200\200\376\1\0\0\0\24\0\1\0\0\0\0\0"...,
4096}], msg_controllen=0, msg_flags=0}, 0) = 128
recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000},
msg_iov(1)=[{"\24\0\0\0\3\0\2\0\305^\225Sv\30\0\0\0\0\0\0\1\0\0\0\24\0\1\0\0\0\0\0"...,
4096}], msg_controllen=0, msg_flags=0}, 0) = 20
socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
connect(3, {sa_family=AF_FILE, path="/var/run/nscd/socket"}, 110) = -1
ENOENT (No such file or directory)
socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 3
connect(3, {sa_family=AF_FILE, path="/var/run/nscd/socket"}, 110) = -1
ENOENT (No such file or directory)
socket(PF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_TCP) = 3
connect(3, {sa_family=AF_INET, sin_port=htons(6600),
sin_addr=inet_addr("127.0.0.1")}, 16) = -1 EINPROGRESS (Operation now in
progress)
getsockopt(3, SOL_SOCKET, SO_ERROR, [0], [4]) = 0
recv(3, "OK MPD 0.18.0\n", 4096, MSG_DONTWAIT) = 14
send(3, "command_list_ok_begin\nstatus\ncur"..., 58, MSG_DONTWAIT) = 58
recv(3, "volume: 100\nrepeat: 1\nrandom: 0\n"..., 4096, MSG_DONTWAIT) = 460
volume:100% repeat: on random: off single: off consume: off
If this is not difficult, I'd like to know if there is something wrong
in my network, or if this is a bug in MPD.
Thank you again for your help!
Teresa and Junior
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