2013-01-10 14:34:04

by Hemmo Nieminen

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Subject: [nfs-utils PATCH] Binding a privileged port in rpc.statd.

Hi,

It seems that rpc.statd will fail to bind to a (free) port, if
the first port it receives is listed in /etc/services. The
bindresvport will keep on returning the same port if we close
the socket too early.

The attached patch should fix this.

--
Hemmo


Attachments:
(No filename) (259.00 B)
0001-Fix-socket-binding-loop.patch (1.47 kB)
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2013-01-16 21:15:48

by Steve Dickson

[permalink] [raw]
Subject: Re: [nfs-utils PATCH] Binding a privileged port in rpc.statd.



On 10/01/13 09:27, Hemmo Nieminen wrote:
> Hi,
>
> It seems that rpc.statd will fail to bind to a (free) port, if
> the first port it receives is listed in /etc/services. The
> bindresvport will keep on returning the same port if we close
> the socket too early.
>
> The attached patch should fix this.
>
Committed....

steved.

2013-01-10 15:25:40

by J. Bruce Fields

[permalink] [raw]
Subject: Re: [nfs-utils PATCH] Binding a privileged port in rpc.statd.

On Thu, Jan 10, 2013 at 04:27:10PM +0200, Hemmo Nieminen wrote:
> Hi,
>
> It seems that rpc.statd will fail to bind to a (free) port, if
> the first port it receives is listed in /etc/services. The
> bindresvport will keep on returning the same port if we close
> the socket too early.
>
> The attached patch should fix this.

Looks right to me.--b.

>
> --
> Hemmo

> >From abdaa0c27d66c71c9500b983fc4366cb3e514fff Mon Sep 17 00:00:00 2001
> From: Hemmo Nieminen <[email protected]>
> Date: Thu, 3 Jan 2013 10:00:17 +0200
> Subject: [PATCH] Fix socket binding loop.
>
> Instead of closing the sockets before requesting a new one, keep them
> open until a suitable one is found. Otherwise bindresvport will return
> the same port over and over again.
> ---
> utils/statd/rmtcall.c | 19 +++++++++++++------
> 1 file changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/utils/statd/rmtcall.c b/utils/statd/rmtcall.c
> index 4ecb03c..fd576d9 100644
> --- a/utils/statd/rmtcall.c
> +++ b/utils/statd/rmtcall.c
> @@ -68,21 +68,19 @@ statd_get_socket(void)
> {
> struct sockaddr_in sin;
> struct servent *se;
> - int loopcnt = 100;
> + const int loopcnt = 100;
> + int i, tmp_sockets[loopcnt];
>
> if (sockfd >= 0)
> return sockfd;
>
> - while (loopcnt-- > 0) {
> -
> - if (sockfd >= 0) close(sockfd);
> + for (i = 0; i < loopcnt; ++i) {
>
> if ((sockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
> xlog(L_ERROR, "%s: Can't create socket: %m", __func__);
> - return -1;
> + break;
> }
>
> -
> memset(&sin, 0, sizeof(sin));
> sin.sin_family = AF_INET;
> sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
> @@ -96,7 +94,16 @@ statd_get_socket(void)
> if (se == NULL)
> break;
> /* rather not use that port, try again */
> +
> + tmp_sockets[i] = sockfd;
> }
> +
> + while (--i >= 0)
> + close(tmp_sockets[i]);
> +
> + if (sockfd < 0)
> + return -1;
> +
> FD_SET(sockfd, &SVC_FDSET);
> return sockfd;
> }
> --
> 1.8.1
>