[Qemu-devel] [PATCH] Fix off-by-one bug limiting VNC passwords to 7 chars

[Qemu-devel] [PATCH] Fix off-by-one bug limiting VNC passwords to 7 chars

[Chris Webb]

Fix off-by-one bug limiting VNC passwords to 7 characters instead of 8

monitor_readline expects buf_size to include the terminating \0, but
do_change_vnc in monitor.c calls it as though it doesn't. The other site
where monitor_readline reads a password (in vl.c) passes the buffer length
correctly.

Signed-off-by: Chris Webb <chris@arachsys.com>
---
 monitor.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/monitor.c b/monitor.c
index 22360fc..6ae5729 100644
--- a/monitor.c
+++ b/monitor.c
@@ -433,7 +433,7 @@ static void do_change_vnc(const char *target)
     if (strcmp(target, "passwd") == 0 ||
 	strcmp(target, "password") == 0) {
 	char password[9];
-	monitor_readline("Password: ", 1, password, sizeof(password)-1);
+	monitor_readline("Password: ", 1, password, sizeof(password));
 	password[sizeof(password)-1] = '\0';
 	if (vnc_display_password(NULL, password) < 0)
 	    term_printf("could not set VNC server password\n");

Re: [Qemu-devel] [PATCH] Fix off-by-one bug limiting VNC passwords to 7 chars

[Thiemo Seufer]

Chris Webb wrote:
> Fix off-by-one bug limiting VNC passwords to 7 characters instead of 8
> 
> monitor_readline expects buf_size to include the terminating \0, but
> do_change_vnc in monitor.c calls it as though it doesn't. The other site
> where monitor_readline reads a password (in vl.c) passes the buffer length
> correctly.
> 
> Signed-off-by: Chris Webb <chris@arachsys.com>
> ---
>  monitor.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/monitor.c b/monitor.c
> index 22360fc..6ae5729 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -433,7 +433,7 @@ static void do_change_vnc(const char *target)
>      if (strcmp(target, "passwd") == 0 ||
>  	strcmp(target, "password") == 0) {
>  	char password[9];
> -	monitor_readline("Password: ", 1, password, sizeof(password)-1);
> +	monitor_readline("Password: ", 1, password, sizeof(password));
>  	password[sizeof(password)-1] = '\0';

The next line can go as well, the string is already NULL terminated.


Thiemo

Re: [Qemu-devel] [PATCH] Fix off-by-one bug limiting VNC passwords to 7 chars

[Chris Webb]

Thiemo Seufer <ths@networkno.de> writes:

> Chris Webb wrote:
[...]
> > -	monitor_readline("Password: ", 1, password, sizeof(password)-1);
> > +	monitor_readline("Password: ", 1, password, sizeof(password));
> >  	password[sizeof(password)-1] = '\0';
> 
> The next line can go as well, the string is already NULL terminated.

You're quite right. I'll update the two patches to reflect this change.

Cheers,

Chris.

[Qemu-devel] [PATCH v2] Fix off-by-one bug limiting VNC passwords to 7 chars

[Chris Webb]

Fix off-by-one bug limiting VNC passwords to 7 characters instead of 8

monitor_readline expects buf_size to include the terminating \0, but
do_change_vnc in monitor.c calls it as though it doesn't. The other site
where monitor_readline reads a password (in vl.c) passes the buffer length
correctly.

Signed-off-by: Chris Webb <chris@arachsys.com>
---
 monitor.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/monitor.c b/monitor.c
index 22360fc..a252838 100644
--- a/monitor.c
+++ b/monitor.c
@@ -433,8 +433,7 @@ static void do_change_vnc(const char *target)
     if (strcmp(target, "passwd") == 0 ||
 	strcmp(target, "password") == 0) {
 	char password[9];
-	monitor_readline("Password: ", 1, password, sizeof(password)-1);
-	password[sizeof(password)-1] = '\0';
+	monitor_readline("Password: ", 1, password, sizeof(password));
 	if (vnc_display_password(NULL, password) < 0)
 	    term_printf("could not set VNC server password\n");
     } else {

[Qemu-devel] [PATCH v2] Accept password as an argument to 'change vnc password'

[Chris Webb]

Accept password as an argument to 'change vnc password' monitor command

This allows easier use of the change vnc password monitor command from
management scripts, without having to implement expect(1)-like behaviour.

Signed-off-by: Chris Webb <chris@arachsys.com>
---
 monitor.c     |   14 +++++++++-----
 qemu-doc.texi |    8 ++++----
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/monitor.c b/monitor.c
index a252838..f6a2783 100644
--- a/monitor.c
+++ b/monitor.c
@@ -428,12 +428,16 @@ static void do_change_block(const char *device, const char *filename, const char
     qemu_key_check(bs, filename);
 }
 
-static void do_change_vnc(const char *target)
+static void do_change_vnc(const char *target, const char *arg)
 {
     if (strcmp(target, "passwd") == 0 ||
 	strcmp(target, "password") == 0) {
 	char password[9];
-	monitor_readline("Password: ", 1, password, sizeof(password));
+	if (arg) {
+	    strncpy(password, arg, sizeof(password));
+	    password[sizeof(password) - 1] = '\0';
+	} else
+	    monitor_readline("Password: ", 1, password, sizeof(password));
 	if (vnc_display_password(NULL, password) < 0)
 	    term_printf("could not set VNC server password\n");
     } else {
@@ -442,12 +446,12 @@ static void do_change_vnc(const char *target)
     }
 }
 
-static void do_change(const char *device, const char *target, const char *fmt)
+static void do_change(const char *device, const char *target, const char *arg)
 {
     if (strcmp(device, "vnc") == 0) {
-	do_change_vnc(target);
+	do_change_vnc(target, arg);
     } else {
-	do_change_block(device, target, fmt);
+	do_change_block(device, target, arg);
     }
 }
 
diff --git a/qemu-doc.texi b/qemu-doc.texi
index 1735d92..ca3b181 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -1233,11 +1233,11 @@ and @var{options} are described at @ref{sec_invocation}. eg
 (qemu) change vnc localhost:1
 @end example
 
-@item change vnc password
+@item change vnc password [@var{password}]
 
-Change the password associated with the VNC server. The monitor will prompt for
-the new password to be entered. VNC passwords are only significant upto 8 letters.
-eg.
+Change the password associated with the VNC server. If the new password is not
+supplied, the monitor will prompt for it to be entered. VNC passwords are only
+significant up to 8 letters. eg
 
 @example
 (qemu) change vnc password

[Qemu-devel] [RESEND] [PATCH v2] Fix off-by-one bug limiting VNC passwords to 7 chars

[Chris Webb]

Fix off-by-one bug limiting VNC passwords to 7 characters instead of 8

monitor_readline expects buf_size to include the terminating \0, but
do_change_vnc in monitor.c calls it as though it doesn't. The other site
where monitor_readline reads a password (in vl.c) passes the buffer length
correctly.

Signed-off-by: Chris Webb <chris@arachsys.com>
---
 monitor.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/monitor.c b/monitor.c
index 22360fc..a252838 100644
--- a/monitor.c
+++ b/monitor.c
@@ -433,8 +433,7 @@ static void do_change_vnc(const char *target)
     if (strcmp(target, "passwd") == 0 ||
 	strcmp(target, "password") == 0) {
 	char password[9];
-	monitor_readline("Password: ", 1, password, sizeof(password)-1);
-	password[sizeof(password)-1] = '\0';
+	monitor_readline("Password: ", 1, password, sizeof(password));
 	if (vnc_display_password(NULL, password) < 0)
 	    term_printf("could not set VNC server password\n");
     } else {

[Qemu-devel] [RESEND] [PATCH v2] Accept password as an argument to 'change vnc password'

[Chris Webb]

Accept password as an argument to 'change vnc password' monitor command

This allows easier use of the change vnc password monitor command from
management scripts, without having to implement expect(1)-like behaviour.

Signed-off-by: Chris Webb <chris@arachsys.com>
---
 monitor.c     |   14 +++++++++-----
 qemu-doc.texi |    8 ++++----
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/monitor.c b/monitor.c
index a252838..f6a2783 100644
--- a/monitor.c
+++ b/monitor.c
@@ -428,12 +428,16 @@ static void do_change_block(const char *device, const char *filename, const char
     qemu_key_check(bs, filename);
 }
 
-static void do_change_vnc(const char *target)
+static void do_change_vnc(const char *target, const char *arg)
 {
     if (strcmp(target, "passwd") == 0 ||
 	strcmp(target, "password") == 0) {
 	char password[9];
-	monitor_readline("Password: ", 1, password, sizeof(password));
+	if (arg) {
+	    strncpy(password, arg, sizeof(password));
+	    password[sizeof(password) - 1] = '\0';
+	} else
+	    monitor_readline("Password: ", 1, password, sizeof(password));
 	if (vnc_display_password(NULL, password) < 0)
 	    term_printf("could not set VNC server password\n");
     } else {
@@ -442,12 +446,12 @@ static void do_change_vnc(const char *target)
     }
 }
 
-static void do_change(const char *device, const char *target, const char *fmt)
+static void do_change(const char *device, const char *target, const char *arg)
 {
     if (strcmp(device, "vnc") == 0) {
-	do_change_vnc(target);
+	do_change_vnc(target, arg);
     } else {
-	do_change_block(device, target, fmt);
+	do_change_block(device, target, arg);
     }
 }
 
diff --git a/qemu-doc.texi b/qemu-doc.texi
index 1735d92..ca3b181 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -1233,11 +1233,11 @@ and @var{options} are described at @ref{sec_invocation}. eg
 (qemu) change vnc localhost:1
 @end example
 
-@item change vnc password
+@item change vnc password [@var{password}]
 
-Change the password associated with the VNC server. The monitor will prompt for
-the new password to be entered. VNC passwords are only significant upto 8 letters.
-eg.
+Change the password associated with the VNC server. If the new password is not
+supplied, the monitor will prompt for it to be entered. VNC passwords are only
+significant up to 8 letters. eg
 
 @example
 (qemu) change vnc password

[Qemu-devel] Re: [RESEND] [PATCH v2] Accept password as an argument to 'change vnc password'

[Anthony Liguori]

Chris Webb wrote:
> Accept password as an argument to 'change vnc password' monitor command
>
> This allows easier use of the change vnc password monitor command from
> management scripts, without having to implement expect(1)-like behaviour.
>
> Signed-off-by: Chris Webb <chris@arachsys.com>
>   

Applied.  Thanks.

Regards,

Anthony Liguori

> ---
>  monitor.c     |   14 +++++++++-----
>  qemu-doc.texi |    8 ++++----
>  2 files changed, 13 insertions(+), 9 deletions(-)
>
> diff --git a/monitor.c b/monitor.c
> index a252838..f6a2783 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -428,12 +428,16 @@ static void do_change_block(const char *device, const char *filename, const char
>      qemu_key_check(bs, filename);
>  }
>  
> -static void do_change_vnc(const char *target)
> +static void do_change_vnc(const char *target, const char *arg)
>  {
>      if (strcmp(target, "passwd") == 0 ||
>  	strcmp(target, "password") == 0) {
>  	char password[9];
> -	monitor_readline("Password: ", 1, password, sizeof(password));
> +	if (arg) {
> +	    strncpy(password, arg, sizeof(password));
> +	    password[sizeof(password) - 1] = '\0';
> +	} else
> +	    monitor_readline("Password: ", 1, password, sizeof(password));
>  	if (vnc_display_password(NULL, password) < 0)
>  	    term_printf("could not set VNC server password\n");
>      } else {
> @@ -442,12 +446,12 @@ static void do_change_vnc(const char *target)
>      }
>  }
>  
> -static void do_change(const char *device, const char *target, const char *fmt)
> +static void do_change(const char *device, const char *target, const char *arg)
>  {
>      if (strcmp(device, "vnc") == 0) {
> -	do_change_vnc(target);
> +	do_change_vnc(target, arg);
>      } else {
> -	do_change_block(device, target, fmt);
> +	do_change_block(device, target, arg);
>      }
>  }
>  
> diff --git a/qemu-doc.texi b/qemu-doc.texi
> index 1735d92..ca3b181 100644
> --- a/qemu-doc.texi
> +++ b/qemu-doc.texi
> @@ -1233,11 +1233,11 @@ and @var{options} are described at @ref{sec_invocation}. eg
>  (qemu) change vnc localhost:1
>  @end example
>  
> -@item change vnc password
> +@item change vnc password [@var{password}]
>  
> -Change the password associated with the VNC server. The monitor will prompt for
> -the new password to be entered. VNC passwords are only significant upto 8 letters.
> -eg.
> +Change the password associated with the VNC server. If the new password is not
> +supplied, the monitor will prompt for it to be entered. VNC passwords are only
> +significant up to 8 letters. eg
>  
>  @example
>  (qemu) change vnc password
>
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>   

[Qemu-devel] Re: [RESEND] [PATCH v2] Fix off-by-one bug limiting VNC passwords to 7 chars

[Anthony Liguori]

Applied.  Thanks.

Regards,

Anthony Liguori

Chris Webb wrote:
> Fix off-by-one bug limiting VNC passwords to 7 characters instead of 8
>
> monitor_readline expects buf_size to include the terminating \0, but
> do_change_vnc in monitor.c calls it as though it doesn't. The other site
> where monitor_readline reads a password (in vl.c) passes the buffer length
> correctly.
>
> Signed-off-by: Chris Webb <chris@arachsys.com>
> ---
>  monitor.c |    3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/monitor.c b/monitor.c
> index 22360fc..a252838 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -433,8 +433,7 @@ static void do_change_vnc(const char *target)
>      if (strcmp(target, "passwd") == 0 ||
>  	strcmp(target, "password") == 0) {
>  	char password[9];
> -	monitor_readline("Password: ", 1, password, sizeof(password)-1);
> -	password[sizeof(password)-1] = '\0';
> +	monitor_readline("Password: ", 1, password, sizeof(password));
>  	if (vnc_display_password(NULL, password) < 0)
>  	    term_printf("could not set VNC server password\n");
>      } else {
>
> --
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