Re: [RFC] rpcbind: detect support of remote calls

[Petr Vorel <pvorel@suse.cz>]

Hi Steve,

> Hey!

> On 6/2/25 9:37 AM, Petr Vorel wrote:
> > Hi Steve,

> > Ricardo found that TI-RPC rpc_pmap_rmtcall [1] tirpc_rpcb_rmtcall [2] tests are
> > failing when they use rpcbind *without* --enable-rmtcalls (the default since
> > 2018, see 2e9c289 ("rpcbind: Disable remote calls by default") [3]).

> > TL;DR: Is there a way to detect missing support from rpcbind? Because we cannot
> > blindly expect that timeout means disabled remote calls (it could be also
> > caused by regression). Other option is just to disable these tests by default
> > (detection is preferred).
> No there is not a way, that I know of, to see if remote calls
> are or are not enabled since it is a compile time flag.

How about rpcbind to print version via new -v or -V command line option.
Then compiled options could be printed as part of the output.

Nobody needed to know rpcbind version, therefore I'm not sure if testing justify
it, but that would be an easy way to provide the info.

> I really don't know what to say... In Fedora we disabled rmtcalls
> which broke NIS and in RHEL we left it enable which drives
> SELinux (and a few customers) nuts.

Thanks for info, I fully understand the chosen solution.

Kind regards,
Petr

> There is no clear answer... IMHO.

> steved.



> > # export PATH="/opt/ltp/testcases/bin:$PATH"
> > # rpc_test.sh -s tirpc_svc_4 -c tirpc_rpcb_rmtcall
> > ...
> > tirpc_rpcb_rmtcall 10.0.0.2 536875000
> > rpc_test 1 TFAIL: tirpc_rpcb_rmtcall 10.0.0.2 536875000 failed unexpectedly

> > As the name of the test suggests they are using pmap_rmtcall() and rpcb_rmtcall().
> > A bit debug info.

> > Modified rpc_test.sh to use strace:

> > +++ b/testcases/network/rpc/rpc-tirpc/rpc_test.sh
> > @@ -87,6 +87,8 @@ do_test()
> >   		done
> >   	fi
> > +	echo "$CLIENT $(tst_ipaddr) $PROGNUMNOSVC $CLIENT_EXTRA_OPTS" # FIXME: debug
> > +	EXPECT_RHOST_PASS strace -o /tmp/a $CLIENT $(tst_ipaddr) $PROGNUMNOSVC $CLIENT_EXTRA_OPTS
> >   	EXPECT_RHOST_PASS $CLIENT $(tst_ipaddr) $PROGNUMNOSVC $CLIENT_EXTRA_OPTS
> >   }

> > I see the test timeouts (full strace output below):

> > # rpc_test.sh -s tirpc_svc_4 -c tirpc_rpcb_rmtcall
> > ...
> > sendto(5, "h=\r}\0\0\0\0\0\0\0\2\0\1\206\240\0\0\0\4\0\0\0\5\0\0\0\0\0\0\0\0"..., 60, 0, {sa_family=AF_INET, sin_port=htons(111), sin_addr=inet_addr("10.0.0.2")}, 16) = 60
> > poll([{fd=5, events=POLLIN}], 1, 1000)  = 0 (Timeout)

> > Using rpcbind 1.2.7-1.2 (from Tumbleweed), output when run with debug mode:

> > # /usr/sbin/rpcbind -w -f -d
> > rpcbind: PMAPPROC_DUMP

> > rpcbind: RPCB_UNSET request for (536875000, 1, ) :
> > rpcbind: RPCB_UNSET: succeeded
> > rpcbind: RPCB_SET request for (536875000, 1, udp, 0.0.0.0.223.168) :
> > rpcbind: RPCB_SET: succeeded
> > rpcbind: RPCB_GETADDR req for (100000, 2, tcp) from 127.0.0.1.3.98:
> > mergeaddr: contact uaddr = 127.0.0.1.0.111
> > addrmerge(caller, 0.0.0.0.0.111, 127.0.0.1.0.111, tcp
> > addrmerge: hint 127.0.0.1.0.111
> > addrmerge: returning 127.0.0.1.0.111
> > mergeaddr: uaddr = 0.0.0.0.0.111, merged uaddr = 127.0.0.1.0.111
> > rpcbind: getaddr: 127.0.0.1.0.111
> > rpcbind: PMAPPROC_DUMP

> > rpcbind: RPCB_GETADDR req for (536875000, 1, udp) from 10.0.0.1.3.105:
> > mergeaddr: contact uaddr = 10.0.0.2.0.111
> > addrmerge(caller, 0.0.0.0.223.168, 10.0.0.2.0.111, udp
> > addrmerge: hint 10.0.0.2.0.111
> > addrmerge: returning 10.0.0.2.223.168
> > mergeaddr: uaddr = 0.0.0.0.223.168, merged uaddr = 10.0.0.2.223.168
> > rpcbind: getaddr: 10.0.0.2.223.168
> > rpcbind: RPCBPROC_BCAST

> > rpcbind: rpcb_indirect callit req for (536875000, 1, 1, udp) from 10.0.0.1.3.105 :
> > rpcbind: found at uaddr 0.0.0.0.223.168

> > addrmerge(caller, 0.0.0.0.223.168, NULL, udp
> > addrmerge: hint 127.0.0.1.0.111
> > addrmerge: returning 127.0.0.1.223.168
> > addrmerge(caller, 0.0.0.0.223.168, NULL, udp
> > addrmerge: hint 10.0.0.1.3.105
> > addrmerge: returning 192.168.122.43.223.168
> > rpcbind: merged uaddr 192.168.122.43.223.168

> > rpcbind: RPCB_UNSET request for (536875000, 1, ) :
> > rpcbind: Suppression RPC_UNSET(map_unset)
> > rpcbind: rbl->rpcb_map.r_owner=superuser
> > rpcbind: owner=superuser
> > rpcbind: RPCB_UNSET: succeeded

> > Obviously, if I compile rpcbind with --enable-rmtcalls and run it, both tests work:

> > $ ./autogen.sh && ./configure --enable-debug --enable-warmstarts --enable-rmtcalls --with-rpcuser=rpc --with-nss-modules="files usrfiles"
> > $ make -j`nproc`
> > # ./rpcbind -w -d -f

> > # rpc_test.sh -s tirpc_svc_4 -c tirpc_rpcb_rmtcall
> > ...
> > rpc_test 1 TINFO: using libtirpc: yes
> > tirpc_rpcb_rmtcall 10.0.0.2 536875000
> > rpc_test 1 TPASS: tirpc_rpcb_rmtcall 10.0.0.2 536875000 passed as expected

> > # rpc_test.sh -s rpc_svc_1 -c rpc_pmap_rmtcall
> > ...
> > rpc_pmap_rmtcall 10.0.0.2 536875000
> > rpc_test 1 TPASS: rpc_pmap_rmtcall 10.0.0.2 536875000 passed as expected


> > And the rpcbind outpt contains also:

> > rpcbind: rpcbproc_callit_com:  original XID 683f1705, new XID f68e200
> > rpcbind: my_svc_run:  polled on forwarding fd 7, netid udp - calling handle_reply

> > Also, wouldn't it be worth mention --enable-rmtcalls in functions' man pages?
> > (Or have I overlooked that in man?)

> > Thanks for any hint.

> > Kind regards,
> > Petr

> > [1] https://github.com/linux-test-project/ltp/tree/master/testcases/network/rpc/rpc-tirpc/tests_pack/rpc_suite/rpc/rpc_addrmanagmt_pmap_rmtcall/rpc_pmap_rmtcall.c
> > [2] https://github.com/linux-test-project/ltp/tree/master/testcases/network/rpc/rpc-tirpc/tests_pack/rpc_suite/tirpc/tirpc_expertlevel_rpcb_rmtcall/tirpc_rpcb_rmtcall.c
> > [3] https://git.linux-nfs.org/?p=steved/rpcbind.git;a=commitdiff;h=2e9c289246c647e25649914bdb0d9400c66f486e

> > Full strace on rpcbind compiled without --enable-rmtcalls (the default, thus
> > how it's shipped to the new distros):

> > # rpc_test.sh -s tirpc_svc_4 -c tirpc_rpcb_rmtcall

> > execve("/opt/ltp/testcases/bin/tirpc_rpcb_rmtcall", ["tirpc_rpcb_rmtcall", "10.0.0.2", "536875000"], 0x7ffee8701b10 /* 228 vars */) = 0
> > ...
> > openat(AT_FDCWD, "/etc/services", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
> > openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 5
> > ...
> > openat(AT_FDCWD, "/usr/etc/services", O_RDONLY|O_CLOEXEC) = 5
> > fstat(5, {st_mode=S_IFREG|0644, st_size=868338, ...}) = 0
> > read(5, "#\n# Network services, Internet s"..., 4096) = 4096
> > read(5, "[Jon_Postel]\ndaytime            "..., 4096) = 4096
> > read(5, "gs          44/udp       # MPM F"..., 4096) = 4096
> > read(5, "emote Job Service \nnetrjs-2     "..., 4096) = 4096
> > read(5, "Jon_Postel]\nhostname           1"..., 4096) = 4096
> > close(5)                                = 0
> > socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP) = 5
> > getsockname(5, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("0.0.0.0")}, [128 => 16]) = 0
> > getsockopt(5, SOL_SOCKET, SO_TYPE, [2], [4]) = 0
> > openat(AT_FDCWD, "/etc/bindresvport.blacklist", O_RDONLY) = 6
> > fstat(6, {st_mode=S_IFREG|0644, st_size=415, ...}) = 0
> > read(6, "#\n# This file contains a list of"..., 4096) = 415
> > read(6, "", 4096)                       = 0
> > close(6)                                = 0
> > getsockname(5, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("0.0.0.0")}, [128 => 16]) = 0
> > getpid()                                = 28530
> > bind(5, {sa_family=AF_INET, sin_port=htons(722), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
> > rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], [], 8) = 0
> > rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
> > getsockname(5, {sa_family=AF_INET, sin_port=htons(722), sin_addr=inet_addr("0.0.0.0")}, [128 => 16]) = 0
> > getsockopt(5, SOL_SOCKET, SO_TYPE, [2], [4]) = 0
> > gettimeofday({tv_sec=1748867467, tv_usec=890549}, NULL) = 0
> > getpid()                                = 28530
> > setsockopt(5, SOL_IP, IP_RECVERR, [1], 4) = 0
> > ioctl(5, FIONBIO, [1])                  = 0
> > ...
> > rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], [], 8) = 0
> > sendto(5, "h0`M\0\0\0\0\0\0\0\2\0\1\206\240\0\0\0\4\0\0\0\3\0\0\0\0\0\0\0\0"..., 88, 0, {sa_family=AF_INET, sin_port=htons(111), sin_addr=inet_addr("10.0.0.2")}, 16) = 88
> > poll([{fd=5, events=POLLIN}], 1, 15000) = 1 ([{fd=5, revents=POLLIN}])
> > recvfrom(5, "h0`M\0\0\0\1\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\02010.0"..., 8800, 0, NULL, NULL) = 44
> > rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
> > rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], [], 8) = 0
> > rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
> > rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], [], 8) = 0
> > close(5)                                = 0
> > rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
> > socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP) = 5
> > getsockname(5, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("0.0.0.0")}, [128 => 16]) = 0
> > getsockopt(5, SOL_SOCKET, SO_TYPE, [2], [4]) = 0
> > getsockname(5, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("0.0.0.0")}, [128 => 16]) = 0
> > getpid()                                = 28530
> > bind(5, {sa_family=AF_INET, sin_port=htons(722), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
> > rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], [], 8) = 0
> > rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
> > getsockname(5, {sa_family=AF_INET, sin_port=htons(722), sin_addr=inet_addr("0.0.0.0")}, [128 => 16]) = 0
> > getsockopt(5, SOL_SOCKET, SO_TYPE, [2], [4]) = 0
> > gettimeofday({tv_sec=1748867467, tv_usec=892984}, NULL) = 0
> > getpid()                                = 28530
> > setsockopt(5, SOL_IP, IP_RECVERR, [1], 4) = 0
> > ioctl(5, FIONBIO, [1])                  = 0
> > ...
> > sendto(5, "h0V\302\0\0\0\0\0\0\0\2\0\1\206\240\0\0\0\4\0\0\0\5\0\0\0\0\0\0\0\0"..., 60, 0, {sa_family=AF_INET, sin_port=htons(111), sin_addr=inet_addr("10.0.0.2")}, 16) = 60
> > poll([{fd=5, events=POLLIN}], 1, 1000)  = 0 (Timeout)
> > rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
> > rt_sigprocmask(SIG_SETMASK, ~[RTMIN RT_1], [], 8) = 0
> > close(5)                                = 0
> > rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
> > fstat(1, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0
> > write(1, "1\n", 2)                      = 2
> > exit_group(1)                           = ?
> > +++ exited with 1 +++