[nfs-utils PATCH v2] statd: make statd_canonical_name return the presentation address if it maps to an empty hostname

[nfs-utils PATCH v2] statd: make statd_canonical_name return the presentation address if it maps to an empty hostname

[Scott Mayhew]

Certain name resolution misconfigurations (for example, a hosts file
entry with an ip address but no hostnames) can cause get_nameinfo() to
return an empty string in buf, which will lead to this cryptic failure:

Dec  7 09:37:44 hostname rpc.statd[8024]: Failed to insert: creating
/var/lib/nfs/statd/sm/: Is a directory
Dec  7 09:37:44 hostname rpc.statd[8024]: STAT_FAIL to
hostname.example.com for SM_MON of 192.168.1.2
Dec  7 09:37:44 hostname kernel: lockd: cannot monitor 192.168.1.2

It's better in that case to just go ahead and use the presentation
address instead.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
---
 utils/statd/hostname.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/utils/statd/hostname.c b/utils/statd/hostname.c
index c61087c..8cccdb8 100644
--- a/utils/statd/hostname.c
+++ b/utils/statd/hostname.c
@@ -180,9 +180,6 @@ get_nameinfo(const struct sockaddr *sap,
  * Incoming hostnames are looked up to determine the canonical hostname,
  * and incoming presentation addresses are converted to canonical
  * hostnames.
- *
- * We won't monitor peers that don't have a reverse map.  The canonical
- * name gives us a key for our monitor list.
  */
 __attribute__((__malloc__))
 char *
@@ -207,7 +204,7 @@ statd_canonical_name(const char *hostname)
 		result = get_nameinfo(ai->ai_addr, ai->ai_addrlen,
 					buf, (socklen_t)sizeof(buf));
 		freeaddrinfo(ai);
-		if (!result)
+		if (!result || buf[0] == '\0')
 			/* OK to use presentation address,
 			 * if no reverse map exists */
 			return strdup(hostname);
-- 
2.4.3

Re: [nfs-utils PATCH v2] statd: make statd_canonical_name return the presentation address if it maps to an empty hostname

[Steve Dickson]

On 12/07/2015 01:22 PM, Scott Mayhew wrote:
> Certain name resolution misconfigurations (for example, a hosts file
> entry with an ip address but no hostnames) can cause get_nameinfo() to
> return an empty string in buf, which will lead to this cryptic failure:
> 
> Dec  7 09:37:44 hostname rpc.statd[8024]: Failed to insert: creating
> /var/lib/nfs/statd/sm/: Is a directory
> Dec  7 09:37:44 hostname rpc.statd[8024]: STAT_FAIL to
> hostname.example.com for SM_MON of 192.168.1.2
> Dec  7 09:37:44 hostname kernel: lockd: cannot monitor 192.168.1.2
> 
> It's better in that case to just go ahead and use the presentation
> address instead.
> 
> Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Committed... 

steved.

> ---
>  utils/statd/hostname.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/utils/statd/hostname.c b/utils/statd/hostname.c
> index c61087c..8cccdb8 100644
> --- a/utils/statd/hostname.c
> +++ b/utils/statd/hostname.c
> @@ -180,9 +180,6 @@ get_nameinfo(const struct sockaddr *sap,
>   * Incoming hostnames are looked up to determine the canonical hostname,
>   * and incoming presentation addresses are converted to canonical
>   * hostnames.
> - *
> - * We won't monitor peers that don't have a reverse map.  The canonical
> - * name gives us a key for our monitor list.
>   */
>  __attribute__((__malloc__))
>  char *
> @@ -207,7 +204,7 @@ statd_canonical_name(const char *hostname)
>  		result = get_nameinfo(ai->ai_addr, ai->ai_addrlen,
>  					buf, (socklen_t)sizeof(buf));
>  		freeaddrinfo(ai);
> -		if (!result)
> +		if (!result || buf[0] == '\0')
>  			/* OK to use presentation address,
>  			 * if no reverse map exists */
>  			return strdup(hostname);
>