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author | Roberto Bergantinos Corpas <rbergant@redhat.com> | 2022-07-14 15:54:21 -0400 |
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committer | Steve Dickson <steved@redhat.com> | 2022-07-16 14:16:55 -0400 |
commit | d81c89c161521c619e5863cd44714094ba14e4b9 (patch) | |
tree | 2fddecba5e4aa8674214762cd5c8c128fd18f1ac | |
parent | 63f3b9e883231ca08cf9c3cd8f5d582584412d94 (diff) | |
download | ti-rpc-d81c89c161521c619e5863cd44714094ba14e4b9.tar.gz |
rpcb_clnt.c add mechanism to try v2 protocol firstlibtirpc-1-3-3-rc3
There have been previous attempts to revert protocol tryout
algorithm from v4,v3,v2 to previous v2,v4,v3 :
https://www.spinics.net/lists/linux-nfs/msg89228.html
Apart from GETADDR/NAT issue originating that proposed change,
its possible that some legacy custom applications still use
v2 of protocol with libtirpc.
The change proposed here, introduces an environment variable
"RPCB_V2FIRST" so that, if defined, old behaviour is used.
This is more flexible and allow us to selectively pick what
application reverts to old behaviour instead of a system-wide
change.
Signed-off-by: Roberto Bergantinos Corpas <rbergant@redhat.com>
Signed-off-by: Steve Dickson <steved@redhat.com>
-rw-r--r-- | man/rpcbind.3t | 2 | ||||
-rw-r--r-- | src/rpcb_clnt.c | 30 | ||||
-rw-r--r-- | tirpc/rpc/pmap_prot.h | 2 |
3 files changed, 30 insertions, 4 deletions
diff --git a/man/rpcbind.3t b/man/rpcbind.3t index ec492cc..4cb271b 100644 --- a/man/rpcbind.3t +++ b/man/rpcbind.3t @@ -187,6 +187,8 @@ in .El .Sh AVAILABILITY These functions are part of libtirpc. +.Sh ENVIRONMENT +If RPCB_V2FIRST is defined, rpcbind protocol version tryout algorithm changes from v4,v2,v3 to v2,v4,v3. .Sh SEE ALSO .Xr rpc_clnt_calls 3 , .Xr rpc_svc_calls 3 , diff --git a/src/rpcb_clnt.c b/src/rpcb_clnt.c index 1a23cb1..06f4528 100644 --- a/src/rpcb_clnt.c +++ b/src/rpcb_clnt.c @@ -826,7 +826,8 @@ error: * The algorithm used: If the transports is TCP or UDP, it first tries * version 4 (srv4), then 3 and then fall back to version 2 (portmap). * With this algorithm, we get performance as well as a plan for - * obsoleting version 2. + * obsoleting version 2. This behaviour is reverted to old algorithm + * if RPCB_V2FIRST environment var is defined * * For all other transports, the algorithm remains as 4 and then 3. * @@ -847,6 +848,10 @@ __rpcb_findaddr_timed(program, version, nconf, host, clpp, tp) #ifdef NOTUSED static bool_t check_rpcbind = TRUE; #endif + +#ifdef PORTMAP + static bool_t portmap_first = FALSE; +#endif CLIENT *client = NULL; RPCB parms; enum clnt_stat clnt_st; @@ -903,8 +908,18 @@ __rpcb_findaddr_timed(program, version, nconf, host, clpp, tp) parms.r_addr = (char *) &nullstring[0]; } - /* First try from start_vers(4) and then version 3 (RPCBVERS) */ + /* First try from start_vers(4) and then version 3 (RPCBVERS), except + * if env. var RPCB_V2FIRST is defined */ +#ifdef PORTMAP + if (getenv(V2FIRST)) { + portmap_first = TRUE; + LIBTIRPC_DEBUG(3, ("__rpcb_findaddr_timed: trying v2-port first\n")); + goto portmap; + } +#endif + +rpcbind: CLNT_CONTROL(client, CLSET_RETRY_TIMEOUT, (char *) &rpcbrmttime); for (vers = start_vers; vers >= RPCBVERS; vers--) { /* Set the version */ @@ -952,10 +967,17 @@ __rpcb_findaddr_timed(program, version, nconf, host, clpp, tp) } #ifdef PORTMAP /* Try version 2 for TCP or UDP */ + if (portmap_first) + goto error; /* we tried all versions if reached here */ +portmap: if (strcmp(nconf->nc_protofmly, NC_INET) == 0) { address = __try_protocol_version_2(program, version, nconf, host, tp); - if (address == NULL) - goto error; + if (address == NULL) { + if (portmap_first) + goto rpcbind; + else + goto error; + } } #endif /* PORTMAP */ diff --git a/tirpc/rpc/pmap_prot.h b/tirpc/rpc/pmap_prot.h index 75354ce..7718b8b 100644 --- a/tirpc/rpc/pmap_prot.h +++ b/tirpc/rpc/pmap_prot.h @@ -84,6 +84,8 @@ #define PMAPPROC_DUMP ((u_long)4) #define PMAPPROC_CALLIT ((u_long)5) +#define V2FIRST "RPCB_V2FIRST" + struct pmap { long unsigned pm_prog; long unsigned pm_vers; |