Re: [patch] fix statd -n

[Peter Staubach <staubach@redhat.com>]

J. Bruce Fields wrote:
> On Thu, Apr 17, 2008 at 12:38:43PM -0400, Janne Karhunen wrote:
>   
>> Apparently lockd does not expect statd to be used with -n
>> switch: statd is expected to bind loopback, always. Attached
>> patches show one (IPv4 specific) way of fixing it. Comments?
>>     
>
> Maybe statd really should always bind to the loopback interface?  Is
> there any reason not to?
>
>   

I think that statd needs to be reachable from clients
and/or servers when the state changes on the other end.

This "-n" option really assumes that the system is single-homed
though, doesn't it?  Binding to one particular interface will
make it so that statd will not be reachable via any of the other
interfaces on the system.

Perhaps statd should always bind to the loopback interface
if it doesn't bind to INADDR_ANY?

    Thanx...

       ps

> From a quick look at the current nfs-utils code: it looks like the -n
> option only affects the operation of the sm-notify program that's called
> on boot to notify peer statd's?  I'm a little confused.  (What version
> of nfs-utils are you working from?)
>
> --b.
>
>   
>> -- 
>> // Janne
>>     
>
>   
>> --- rmtcall.c.org	2008-04-14 10:53:30.000000000 -0400
>> +++ rmtcall.c	2008-04-14 13:01:27.000000000 -0400
>> @@ -37,6 +37,7 @@
>>  #include <netdb.h>
>>  #include <string.h>
>>  #include <unistd.h>
>> +#include <errno.h>
>>  #ifdef HAVE_IFADDRS_H
>>  #include <ifaddrs.h>
>>  #endif /* HAVE_IFADDRS_H */
>> @@ -54,6 +55,34 @@
>>  
>>  static unsigned long	xid = 0;	/* RPC XID counter */
>>  static int		sockfd = -1;	/* notify socket */
>> +static int              ifset = 0;
>> +
>> +/*
>> + * Notify lockd of non-standard binding 
>> + */
>> +inline void
>> +nlm_nsm_set(unsigned int addr)
>> +{
>> +        ssize_t sz = 0;
>> +        char buf[20];
>> +        int fd;
>> +
>> +        if ( ifset )
>> +                return ;
>> +
>> +        sprintf (buf,"%u",addr);
>> +
>> +        fd = open ("/proc/sys/fs/nfs/nlm_nsm_interface", O_RDWR);
>> +        if (fd > 0) {
>> +                sz = write (fd,buf,strlen((char*)buf));
>> +                if ( sz == -1 )
>> +                        note(N_CRIT, "statd: write: %s\n", strerror(errno));
>> +                close (fd);
>> +        } else
>> +                note(N_CRIT, "statd: -n was specified with with no kernel support?\n");
>> +
>> +        ifset = 1;
>> +}
>>  
>>  /*
>>   * Initialize callback socket
>> @@ -85,6 +114,7 @@ statd_get_socket(int port)
>>  		struct hostent *hp = gethostbyname(MY_NAME);
>>  		if (hp)
>>  			sin.sin_addr = *(struct in_addr *) hp->h_addr;
>> +		nlm_nsm_set ((unsigned int)sin.sin_addr.s_addr);
>>  	}
>>  	if (port != 0) {
>>  		sin.sin_port = htons(port);
>>     
>
>   
>> diff -Naurp lockd.org/svc4proc.c lockd/svc4proc.c
>> --- lockd.org/svc4proc.c	2008-04-14 10:58:29.000000000 -0400
>> +++ lockd/svc4proc.c	2008-04-14 12:19:04.000000000 -0400
>> @@ -21,6 +21,8 @@
>>  
>>  #define NLMDBG_FACILITY		NLMDBG_CLIENT
>>  
>> +extern unsigned int nlm_nsm_interface;
>> +
>>  /*
>>   * Obtain client and file from arguments
>>   */
>> @@ -430,8 +432,9 @@ nlm4svc_proc_sm_notify(struct svc_rqst *
>>  	memcpy(&saddr, svc_addr_in(rqstp), sizeof(saddr));
>>  
>>  	dprintk("lockd: SM_NOTIFY     called\n");
>> -	if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
>> -	 || ntohs(saddr.sin_port) >= 1024) {
>> +	if (((saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK))
>> +	 && (nlm_nsm_interface && (saddr.sin_addr.s_addr != htonl(nlm_nsm_interface))))
>> +	 || (ntohs(saddr.sin_port) >= 1024)) {
>>  		char buf[RPC_MAX_ADDRBUFLEN];
>>  		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
>>  				svc_print_addr(rqstp, buf, sizeof(buf)));
>> diff -Naurp lockd.org/svc.c lockd/svc.c
>> --- lockd.org/svc.c	2008-04-14 10:58:29.000000000 -0400
>> +++ lockd/svc.c	2008-04-14 12:19:04.000000000 -0400
>> @@ -64,6 +64,7 @@ static unsigned long		nlm_grace_period;
>>  static unsigned long		nlm_timeout = LOCKD_DFLT_TIMEO;
>>  static int			nlm_udpport, nlm_tcpport;
>>  int				nsm_use_hostnames = 0;
>> +unsigned int			nlm_nsm_interface = 0;
>>  
>>  /*
>>   * Constants needed for the sysctl interface.
>> @@ -425,6 +426,14 @@ static ctl_table nlm_sysctls[] = {
>>  		.mode		= 0644,
>>  		.proc_handler	= &proc_dointvec,
>>  	},
>> +        {
>> +                .ctl_name       = CTL_UNNUMBERED,
>> +                .procname       = "nlm_nsm_interface",
>> +                .data           = &nlm_nsm_interface,
>> +                .maxlen         = sizeof(int),
>> +                .mode           = 0644,
>> +                .proc_handler   = &proc_dointvec,
>> +        },
>>  	{ .ctl_name = 0 }
>>  };
>>  
>> diff -Naurp lockd.org/svcproc.c lockd/svcproc.c
>> --- lockd.org/svcproc.c	2008-04-14 10:58:29.000000000 -0400
>> +++ lockd/svcproc.c	2008-04-14 12:19:04.000000000 -0400
>> @@ -21,6 +21,8 @@
>>  
>>  #define NLMDBG_FACILITY		NLMDBG_CLIENT
>>  
>> +extern unsigned int nlm_nsm_interface;
>> +
>>  #ifdef CONFIG_LOCKD_V4
>>  static __be32
>>  cast_to_nlm(__be32 status, u32 vers)
>> @@ -462,8 +464,9 @@ nlmsvc_proc_sm_notify(struct svc_rqst *r
>>  	memcpy(&saddr, svc_addr_in(rqstp), sizeof(saddr));
>>  
>>  	dprintk("lockd: SM_NOTIFY     called\n");
>> -	if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
>> -	 || ntohs(saddr.sin_port) >= 1024) {
>> +	if (((saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK))
>> +	 && (nlm_nsm_interface && (saddr.sin_addr.s_addr != htonl(nlm_nsm_interface))))
>> +	 || (ntohs(saddr.sin_port) >= 1024)) {
>>  		char buf[RPC_MAX_ADDRBUFLEN];
>>  		printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
>>  				svc_print_addr(rqstp, buf, sizeof(buf)));
>>     
>
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