2015-12-07 18:22:23

by Scott Mayhew

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

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 <[email protected]>
---
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

2015-12-12 12:13:45

by Steve Dickson

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

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 <[email protected]>
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);
>