[patch 5/12] s390: cmm guest sender id.

From: Martin Schwidefsky <[EMAIL PROTECTED]>

An arbitrary guest must not be allowed to trigger cmm actions.
Only one specific guest namely the one that serves as the
resource monitor may send cmm messages. Add a parameter that
allows to specify the guest that may send messages. z/VMs
resource manager has the name 'VMRMSVM' which is the default.

Signed-off-by: Martin Schwidefsky <[EMAIL PROTECTED]>

diffstat:
 arch/s390/mm/cmm.c          |    9 ++++++++-
 drivers/s390/net/smsgiucv.c |   19 ++++++++++++++-----
 drivers/s390/net/smsgiucv.h |    4 ++--
 3 files changed, 24 insertions(+), 8 deletions(-)

diff -urpN linux-2.6/arch/s390/mm/cmm.c linux-2.6-patched/arch/s390/mm/cmm.c
--- linux-2.6/arch/s390/mm/cmm.c        2005-03-02 08:38:13.000000000 +0100
+++ linux-2.6-patched/arch/s390/mm/cmm.c        2005-04-22 15:45:02.000000000 
+0200
@@ -20,6 +20,11 @@
 #include <asm/pgalloc.h>
 #include <asm/uaccess.h>
 
+static char *sender = "VMRMSVM";
+module_param(sender, charp, 0);
+MODULE_PARM_DESC(sender,
+                "Guest name that may send SMSG messages (default VMRMSVM)");
+
 #include "../../../drivers/s390/net/smsgiucv.h"
 
 #define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
@@ -367,10 +372,12 @@ static struct ctl_table cmm_dir_table[] 
 #ifdef CONFIG_CMM_IUCV
 #define SMSG_PREFIX "CMM"
 static void
-cmm_smsg_target(char *msg)
+cmm_smsg_target(char *from, char *msg)
 {
        long pages, seconds;
 
+       if (strlen(sender) > 0 && strcmp(from, sender) != 0)
+               return;
        if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
                return;
        if (strncmp(msg, "SHRINK", 6) == 0) {
diff -urpN linux-2.6/drivers/s390/net/smsgiucv.c 
linux-2.6-patched/drivers/s390/net/smsgiucv.c
--- linux-2.6/drivers/s390/net/smsgiucv.c       2005-03-02 08:37:49.000000000 
+0100
+++ linux-2.6-patched/drivers/s390/net/smsgiucv.c       2005-04-22 
15:45:02.000000000 +0200
@@ -32,7 +32,7 @@ struct smsg_callback {
        struct list_head list;
        char *prefix;
        int len;
-       void (*callback)(char *str);
+       void (*callback)(char *from, char *str);
 };
 
 MODULE_AUTHOR
@@ -55,8 +55,9 @@ smsg_message_pending(iucv_MessagePending
 {
        struct smsg_callback *cb;
        unsigned char *msg;
+       unsigned char sender[9];
        unsigned short len;
-       int rc;
+       int rc, i;
 
        len = eib->ln1msg2.ipbfln1f;
        msg = kmalloc(len + 1, GFP_ATOMIC|GFP_DMA);
@@ -69,10 +70,18 @@ smsg_message_pending(iucv_MessagePending
        if (rc == 0) {
                msg[len] = 0;
                EBCASC(msg, len);
+               memcpy(sender, msg, 8);
+               sender[8] = 0;
+               /* Remove trailing whitespace from the sender name. */
+               for (i = 7; i >= 0; i--) {
+                       if (sender[i] != ' ' && sender[i] != '\t')
+                               break;
+                       sender[i] = 0;
+               }
                spin_lock(&smsg_list_lock);
                list_for_each_entry(cb, &smsg_list, list)
                        if (strncmp(msg + 8, cb->prefix, cb->len) == 0) {
-                               cb->callback(msg + 8);
+                               cb->callback(sender, msg + 8);
                                break;
                        }
                spin_unlock(&smsg_list_lock);
@@ -91,7 +100,7 @@ static struct device_driver smsg_driver 
 };
 
 int
-smsg_register_callback(char *prefix, void (*callback)(char *str))
+smsg_register_callback(char *prefix, void (*callback)(char *from, char *str))
 {
        struct smsg_callback *cb;
 
@@ -108,7 +117,7 @@ smsg_register_callback(char *prefix, voi
 }
 
 void
-smsg_unregister_callback(char *prefix, void (*callback)(char *str))
+smsg_unregister_callback(char *prefix, void (*callback)(char *from, char *str))
 {
        struct smsg_callback *cb, *tmp;
 
diff -urpN linux-2.6/drivers/s390/net/smsgiucv.h 
linux-2.6-patched/drivers/s390/net/smsgiucv.h
--- linux-2.6/drivers/s390/net/smsgiucv.h       2005-03-02 08:37:49.000000000 
+0100
+++ linux-2.6-patched/drivers/s390/net/smsgiucv.h       2005-04-22 
15:45:02.000000000 +0200
@@ -5,6 +5,6 @@
  * Author(s): Martin Schwidefsky ([EMAIL PROTECTED])
  */
 
-int  smsg_register_callback(char *, void (*)(char *));
-void smsg_unregister_callback(char *, void (*)(char *));
+int  smsg_register_callback(char *, void (*)(char *, char *));
+void smsg_unregister_callback(char *, void (*)(char *, char *));
 
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to