[Qemu-devel] PATCH: enabling TCP keepalives on VNC connections

[Qemu-devel] PATCH: enabling TCP keepalives on VNC connections

[David S. Ahern]

[-- Attachment #1: Type: text/plain, Size: 396 bytes --]

Something is blocking this message from my gmail account; trying again
with this one.

This patch enables TCP keepalives on VNC connections for linux hosts.
After 60-seconds of idle time, probes are sent every 12 seconds with the
connection resetting after 5 failed probes (ie., connection is closed if
no response received in 60-seconds).

Signed-off-by: David Ahern <dsahern@gmail.com>


david

[-- Attachment #2: vnc-enable-keepalives.patch --]
[-- Type: text/plain, Size: 1778 bytes --]

diff --git a/vnc.c b/vnc.c
index ab1f044..7a8bbd7 100644
--- a/vnc.c
+++ b/vnc.c
@@ -32,6 +32,12 @@
 
 #define VNC_REFRESH_INTERVAL (1000 / 30)
 
+#ifdef __linux__
+#define VNC_TCP_KEEPIDLE  60
+#define VNC_TCP_KEEPINTVL 12
+#define VNC_TCP_KEEPCNT    5
+#endif
+
 #include "vnc_keysym.h"
 #include "d3des.h"
 
@@ -2015,12 +2021,41 @@ static void vnc_listen_read(void *opaque)
     VncDisplay *vs = opaque;
     struct sockaddr_in addr;
     socklen_t addrlen = sizeof(addr);
+    int val;
 
     /* Catch-up */
     vga_hw_update();
 
     int csock = accept(vs->lsock, (struct sockaddr *)&addr, &addrlen);
     if (csock != -1) {
+#ifdef __linux__
+        /* best effort to enable keep alives */
+        val = 1;
+        if (setsockopt(csock, SOL_SOCKET, SO_KEEPALIVE,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to enable keepalives\n");
+        }
+
+        /* after N-seconds of idle time, send probes every X seconds
+         * dropping the connection after Y failed probes.
+         */
+        val = VNC_TCP_KEEPIDLE;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPIDLE,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp idle interval\n");
+        }
+        val = VNC_TCP_KEEPINTVL;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPINTVL,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp probe interval\n");
+        }
+        val = VNC_TCP_KEEPCNT;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPCNT,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp missed probe count\n");
+        }
+#endif
+
         vnc_connect(vs, csock);
     }
 }

Re: [Qemu-devel] PATCH: enabling TCP keepalives on VNC connections

[Anthony Liguori]

David S. Ahern wrote:
> Something is blocking this message from my gmail account; trying again
> with this one.
>
> This patch enables TCP keepalives on VNC connections for linux hosts.
> After 60-seconds of idle time, probes are sent every 12 seconds with the
> connection resetting after 5 failed probes (ie., connection is closed if
> no response received in 60-seconds).
>
> Signed-off-by: David Ahern <dsahern@gmail.com>
>
>
> david
>   
> diff --git a/vnc.c b/vnc.c
> index ab1f044..7a8bbd7 100644
> --- a/vnc.c
> +++ b/vnc.c
> @@ -32,6 +32,12 @@
>  
>  #define VNC_REFRESH_INTERVAL (1000 / 30)
>  
> +#ifdef __linux__
> +#define VNC_TCP_KEEPIDLE  60
> +#define VNC_TCP_KEEPINTVL 12
> +#define VNC_TCP_KEEPCNT    5
> +#endif
>   

Should probe in configure and make an appropriate CONFIG_.  This is not 
necessarily a linux specific feature.

>  #include "vnc_keysym.h"
>  #include "d3des.h"
>  
> @@ -2015,12 +2021,41 @@ static void vnc_listen_read(void *opaque)
>      VncDisplay *vs = opaque;
>      struct sockaddr_in addr;
>      socklen_t addrlen = sizeof(addr);
> +    int val;
>  
>      /* Catch-up */
>      vga_hw_update();
>  
>      int csock = accept(vs->lsock, (struct sockaddr *)&addr, &addrlen);
>      if (csock != -1) {
> +#ifdef __linux__
> +        /* best effort to enable keep alives */
> +        val = 1;
> +        if (setsockopt(csock, SOL_SOCKET, SO_KEEPALIVE,
> +                       &val, sizeof(val)) < 0) {
> +            fprintf(stderr, "VNC: failed to enable keepalives\n");
> +        }
>   

If we want to enable keep alive universally, wouldn't we also want it on 
the tcp: character devices?

-- 
Regards,

Anthony Liguori

Re: [Qemu-devel] PATCH: enabling TCP keepalives on VNC connections

[David S. Ahern]

Anthony Liguori wrote:
> David S. Ahern wrote:
>> Something is blocking this message from my gmail account; trying again
>> with this one.
>>
>> This patch enables TCP keepalives on VNC connections for linux hosts.
>> After 60-seconds of idle time, probes are sent every 12 seconds with the
>> connection resetting after 5 failed probes (ie., connection is closed if
>> no response received in 60-seconds).
>>
>> Signed-off-by: David Ahern <dsahern@gmail.com>
>>
>>
>> david
>>   diff --git a/vnc.c b/vnc.c
>> index ab1f044..7a8bbd7 100644
>> --- a/vnc.c
>> +++ b/vnc.c
>> @@ -32,6 +32,12 @@
>>  
>>  #define VNC_REFRESH_INTERVAL (1000 / 30)
>>  
>> +#ifdef __linux__
>> +#define VNC_TCP_KEEPIDLE  60
>> +#define VNC_TCP_KEEPINTVL 12
>> +#define VNC_TCP_KEEPCNT    5
>> +#endif
>>   
> 
> Should probe in configure and make an appropriate CONFIG_.  This is not
> necessarily a linux specific feature.

ok. I can only test on linux and mac os x; I do not have a means for
building on windows.

> 
>>  #include "vnc_keysym.h"
>>  #include "d3des.h"
>>  
>> @@ -2015,12 +2021,41 @@ static void vnc_listen_read(void *opaque)
>>      VncDisplay *vs = opaque;
>>      struct sockaddr_in addr;
>>      socklen_t addrlen = sizeof(addr);
>> +    int val;
>>  
>>      /* Catch-up */
>>      vga_hw_update();
>>  
>>      int csock = accept(vs->lsock, (struct sockaddr *)&addr, &addrlen);
>>      if (csock != -1) {
>> +#ifdef __linux__
>> +        /* best effort to enable keep alives */
>> +        val = 1;
>> +        if (setsockopt(csock, SOL_SOCKET, SO_KEEPALIVE,
>> +                       &val, sizeof(val)) < 0) {
>> +            fprintf(stderr, "VNC: failed to enable keepalives\n");
>> +        }
>>   
> 
> If we want to enable keep alive universally, wouldn't we also want it on
> the tcp: character devices?
> 

Ok. I can make a generic library call that takes the timers as input
options. If the timer is 0 means leave at OS default. What about other
accept() callers - e.g.,gdbstub?

I'll take a look at this end of next week after my vacation around this
weekend.

david

[Qemu-devel] PATCH: enabling TCP keepalives on VNC connections

[David Ahern]

[-- Attachment #1: Type: text/plain, Size: 311 bytes --]

This patch enables TCP keepalives on VNC connections for linux hosts.
After 60-seconds of idle time, probes are sent every 12 seconds with the
connection resetting after 5 failed probes (ie., connection is closed if
no response received in 60-seconds).

Signed-off-by: David Ahern <dsahern@gmail.com>


david



[-- Attachment #2: vnc-enable-keepalives.patch --]
[-- Type: text/plain, Size: 1778 bytes --]

diff --git a/vnc.c b/vnc.c
index ab1f044..7a8bbd7 100644
--- a/vnc.c
+++ b/vnc.c
@@ -32,6 +32,12 @@
 
 #define VNC_REFRESH_INTERVAL (1000 / 30)
 
+#ifdef __linux__
+#define VNC_TCP_KEEPIDLE  60
+#define VNC_TCP_KEEPINTVL 12
+#define VNC_TCP_KEEPCNT    5
+#endif
+
 #include "vnc_keysym.h"
 #include "d3des.h"
 
@@ -2015,12 +2021,41 @@ static void vnc_listen_read(void *opaque)
     VncDisplay *vs = opaque;
     struct sockaddr_in addr;
     socklen_t addrlen = sizeof(addr);
+    int val;
 
     /* Catch-up */
     vga_hw_update();
 
     int csock = accept(vs->lsock, (struct sockaddr *)&addr, &addrlen);
     if (csock != -1) {
+#ifdef __linux__
+        /* best effort to enable keep alives */
+        val = 1;
+        if (setsockopt(csock, SOL_SOCKET, SO_KEEPALIVE,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to enable keepalives\n");
+        }
+
+        /* after N-seconds of idle time, send probes every X seconds
+         * dropping the connection after Y failed probes.
+         */
+        val = VNC_TCP_KEEPIDLE;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPIDLE,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp idle interval\n");
+        }
+        val = VNC_TCP_KEEPINTVL;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPINTVL,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp probe interval\n");
+        }
+        val = VNC_TCP_KEEPCNT;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPCNT,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp missed probe count\n");
+        }
+#endif
+
         vnc_connect(vs, csock);
     }
 }

[Qemu-devel] PATCH: enabling TCP keepalives on VNC connections

[David Ahern]

[-- Attachment #1: Type: text/plain, Size: 309 bytes --]

This patch enables TCP keepalives on VNC connections for linux hosts.
After 60-seconds of idle time, probes are sent every 12 seconds with the
connection resetting after 5 failed probes (ie., connection is closed if
no response received in 60-seconds).

Signed-off-by: David Ahern <dsahern@gmail.com>


david

[-- Attachment #2: vnc-enable-keepalives.patch --]
[-- Type: text/plain, Size: 1778 bytes --]

diff --git a/vnc.c b/vnc.c
index ab1f044..7a8bbd7 100644
--- a/vnc.c
+++ b/vnc.c
@@ -32,6 +32,12 @@
 
 #define VNC_REFRESH_INTERVAL (1000 / 30)
 
+#ifdef __linux__
+#define VNC_TCP_KEEPIDLE  60
+#define VNC_TCP_KEEPINTVL 12
+#define VNC_TCP_KEEPCNT    5
+#endif
+
 #include "vnc_keysym.h"
 #include "d3des.h"
 
@@ -2015,12 +2021,41 @@ static void vnc_listen_read(void *opaque)
     VncDisplay *vs = opaque;
     struct sockaddr_in addr;
     socklen_t addrlen = sizeof(addr);
+    int val;
 
     /* Catch-up */
     vga_hw_update();
 
     int csock = accept(vs->lsock, (struct sockaddr *)&addr, &addrlen);
     if (csock != -1) {
+#ifdef __linux__
+        /* best effort to enable keep alives */
+        val = 1;
+        if (setsockopt(csock, SOL_SOCKET, SO_KEEPALIVE,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to enable keepalives\n");
+        }
+
+        /* after N-seconds of idle time, send probes every X seconds
+         * dropping the connection after Y failed probes.
+         */
+        val = VNC_TCP_KEEPIDLE;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPIDLE,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp idle interval\n");
+        }
+        val = VNC_TCP_KEEPINTVL;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPINTVL,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp probe interval\n");
+        }
+        val = VNC_TCP_KEEPCNT;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPCNT,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp missed probe count\n");
+        }
+#endif
+
         vnc_connect(vs, csock);
     }
 }

[Qemu-devel] PATCH: enabling TCP keepalives on VNC connections

[David Ahern]

[-- Attachment #1: Type: text/plain, Size: 312 bytes --]

This patch enables TCP keepalives on VNC connections for linux hosts.
After 60-seconds of idle time, probes are sent every 12 seconds with the
connection resetting after 5 failed probes (ie., connection is closed if
no response received in 60-seconds).

Signed-off-by: David Ahern <dsahern@gmail.com>


david




[-- Attachment #2: vnc-enable-keepalives.patch --]
[-- Type: text/plain, Size: 1778 bytes --]

diff --git a/vnc.c b/vnc.c
index ab1f044..7a8bbd7 100644
--- a/vnc.c
+++ b/vnc.c
@@ -32,6 +32,12 @@
 
 #define VNC_REFRESH_INTERVAL (1000 / 30)
 
+#ifdef __linux__
+#define VNC_TCP_KEEPIDLE  60
+#define VNC_TCP_KEEPINTVL 12
+#define VNC_TCP_KEEPCNT    5
+#endif
+
 #include "vnc_keysym.h"
 #include "d3des.h"
 
@@ -2015,12 +2021,41 @@ static void vnc_listen_read(void *opaque)
     VncDisplay *vs = opaque;
     struct sockaddr_in addr;
     socklen_t addrlen = sizeof(addr);
+    int val;
 
     /* Catch-up */
     vga_hw_update();
 
     int csock = accept(vs->lsock, (struct sockaddr *)&addr, &addrlen);
     if (csock != -1) {
+#ifdef __linux__
+        /* best effort to enable keep alives */
+        val = 1;
+        if (setsockopt(csock, SOL_SOCKET, SO_KEEPALIVE,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to enable keepalives\n");
+        }
+
+        /* after N-seconds of idle time, send probes every X seconds
+         * dropping the connection after Y failed probes.
+         */
+        val = VNC_TCP_KEEPIDLE;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPIDLE,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp idle interval\n");
+        }
+        val = VNC_TCP_KEEPINTVL;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPINTVL,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp probe interval\n");
+        }
+        val = VNC_TCP_KEEPCNT;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPCNT,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp missed probe count\n");
+        }
+#endif
+
         vnc_connect(vs, csock);
     }
 }

[Qemu-devel] PATCH: enabling TCP keepalives on VNC connections

[David Ahern]

[-- Attachment #1: Type: text/plain, Size: 310 bytes --]

This patch enables TCP keepalives on VNC connections for linux hosts.
After 60-seconds of idle time, probes are sent every 12 seconds with the
connection resetting after 5 failed probes (ie., connection is closed if
no response received in 60-seconds).

Signed-off-by: David Ahern <dsahern@gmail.com>


david


[-- Attachment #2: vnc-enable-keepalives.patch --]
[-- Type: text/plain, Size: 1778 bytes --]

diff --git a/vnc.c b/vnc.c
index ab1f044..7a8bbd7 100644
--- a/vnc.c
+++ b/vnc.c
@@ -32,6 +32,12 @@
 
 #define VNC_REFRESH_INTERVAL (1000 / 30)
 
+#ifdef __linux__
+#define VNC_TCP_KEEPIDLE  60
+#define VNC_TCP_KEEPINTVL 12
+#define VNC_TCP_KEEPCNT    5
+#endif
+
 #include "vnc_keysym.h"
 #include "d3des.h"
 
@@ -2015,12 +2021,41 @@ static void vnc_listen_read(void *opaque)
     VncDisplay *vs = opaque;
     struct sockaddr_in addr;
     socklen_t addrlen = sizeof(addr);
+    int val;
 
     /* Catch-up */
     vga_hw_update();
 
     int csock = accept(vs->lsock, (struct sockaddr *)&addr, &addrlen);
     if (csock != -1) {
+#ifdef __linux__
+        /* best effort to enable keep alives */
+        val = 1;
+        if (setsockopt(csock, SOL_SOCKET, SO_KEEPALIVE,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to enable keepalives\n");
+        }
+
+        /* after N-seconds of idle time, send probes every X seconds
+         * dropping the connection after Y failed probes.
+         */
+        val = VNC_TCP_KEEPIDLE;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPIDLE,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp idle interval\n");
+        }
+        val = VNC_TCP_KEEPINTVL;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPINTVL,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp probe interval\n");
+        }
+        val = VNC_TCP_KEEPCNT;
+        if (setsockopt(csock, IPPROTO_TCP, TCP_KEEPCNT,
+                       &val, sizeof(val)) < 0) {
+            fprintf(stderr, "VNC: failed to set tcp missed probe count\n");
+        }
+#endif
+
         vnc_connect(vs, csock);
     }
 }