[PATCH] supplicant: Make unix socket non-blocking.

[Ben Greear]

On 01/05/2012 10:52 AM, greearb at candelatech.com wrote:
> From: Ben Greear<greearb at candelatech.com>
>
> This keeps wpa_cli from hanging forever if the other end of the
> socket dies.

Hello Jouni:

I've been posting this patch for a while, and it has
neither gotten picked up nor commented upon.

If you get a chance, please let me know if this
patch needs more work to be accepted.  If you just
don't want the patch..let me know and
I'll quit worrying about it.

Thanks,
Ben

>
> Signed-hostap: Ben Greear<greearb at candelatech.com>
> ---
> :100644 100644 3b25f77... 8ed9dee... M	src/common/wpa_ctrl.c
> :100644 100644 306a222... 113d361... M	wpa_supplicant/ctrl_iface_unix.c
>   src/common/wpa_ctrl.c            |   23 +++++++++++++++++++++++
>   wpa_supplicant/ctrl_iface_unix.c |   15 ++++++++++++++-
>   2 files changed, 37 insertions(+), 1 deletions(-)
>
> diff --git a/src/common/wpa_ctrl.c b/src/common/wpa_ctrl.c
> index 3b25f77..8ed9dee 100644
> --- a/src/common/wpa_ctrl.c
> +++ b/src/common/wpa_ctrl.c
> @@ -295,6 +295,7 @@ int wpa_ctrl_request(struct wpa_ctrl *ctrl, const char *cmd, size_t cmd_len,
>   		     void (*msg_cb)(char *msg, size_t len))
>   {
>   	struct timeval tv;
> +	struct os_time started_at;
>   	int res;
>   	fd_set rfds;
>   	const char *_cmd;
> @@ -321,7 +322,29 @@ int wpa_ctrl_request(struct wpa_ctrl *ctrl, const char *cmd, size_t cmd_len,
>   		_cmd_len = cmd_len;
>   	}
>
> +	errno = 0;
> +	started_at.sec = 0;
> +	started_at.usec = 0;
> +retry_send:
>   	if (send(ctrl->s, _cmd, _cmd_len, 0)<  0) {
> +		if ((errno == EAGAIN) || (errno = EBUSY)
> +		    || (errno == EWOULDBLOCK)) {
> +			/* Must be non-blocking socket...try for a bit longer
> +			 * before giving up.
> +			 */
> +			if (started_at.sec == 0)
> +				os_get_time(&started_at);
> +			else {
> +				struct os_time n;
> +				os_get_time(&n);
> +				/* Try for a few seconds. */
> +				if (n.sec>  (started_at.sec + 5))
> +					goto send_err;
> +			}
> +			os_sleep(1, 0);
> +			goto retry_send;
> +		}
> +	send_err:
>   		os_free(cmd_buf);
>   		return -1;
>   	}
> diff --git a/wpa_supplicant/ctrl_iface_unix.c b/wpa_supplicant/ctrl_iface_unix.c
> index 306a222..113d361 100644
> --- a/wpa_supplicant/ctrl_iface_unix.c
> +++ b/wpa_supplicant/ctrl_iface_unix.c
> @@ -20,7 +20,8 @@
>   #ifdef ANDROID
>   #include<cutils/sockets.h>
>   #endif /* ANDROID */
> -
> +#include<unistd.h>
> +#include<fcntl.h>
>   #include "utils/common.h"
>   #include "utils/eloop.h"
>   #include "utils/list.h"
> @@ -265,6 +266,7 @@ wpa_supplicant_ctrl_iface_init(struct wpa_supplicant *wpa_s)
>   	char *buf, *dir = NULL, *gid_str = NULL;
>   	struct group *grp;
>   	char *endp;
> +	int  flags;
>
>   	priv = os_zalloc(sizeof(*priv));
>   	if (priv == NULL)
> @@ -411,6 +413,17 @@ wpa_supplicant_ctrl_iface_init(struct wpa_supplicant *wpa_s)
>   #ifdef ANDROID
>   havesock:
>   #endif /* ANDROID */
> +
> +	/* Make socket non-blocking so that we don't hang forever if
> +	 * target dies unexpectedly.
> +	 */
> +	flags = fcntl(priv->sock, F_GETFL);
> +	flags |= (O_NONBLOCK);
> +	if (fcntl(priv->sock, F_SETFL, flags)<  0) {
> +		perror("fcntl(ctrl, O_NONBLOCK)");
> +		/* Not fatal, continue on.*/
> +	}
> +
>   	eloop_register_read_sock(priv->sock, wpa_supplicant_ctrl_iface_receive,
>   				 wpa_s, priv);
>   	wpa_msg_register_cb(wpa_supplicant_ctrl_iface_msg_cb);


-- 
Ben Greear <greearb at candelatech.com>
Candela Technologies Inc  http://www.candelatech.com