bonding: Fix up parameter parsing

	A recent change to add an additional hash policy modified
bond_parse_parm, but it now does not correctly match parameters passed in
via sysfs.

	Rewrote bond_parse_parm to handle (a) parameter matches that
are substrings of one another and (b) user input with whitespace (e.g.,
sysfs input often has a trailing newline).

Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

3 files changed, 23 insertions, 12 deletions

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 3ede0a2e6860..379c5d87c804 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -4540,18 +4540,27 @@ static void bond_free_all(void)
 
 /*
  * Convert string input module parms.  Accept either the
- * number of the mode or its string name.
+ * number of the mode or its string name.  A bit complicated because
+ * some mode names are substrings of other names, and calls from sysfs
+ * may have whitespace in the name (trailing newlines, for example).
  */
-int bond_parse_parm(char *mode_arg, struct bond_parm_tbl *tbl)
+int bond_parse_parm(const char *buf, struct bond_parm_tbl *tbl)
 {
-        int i;
+        int mode = -1, i, rv;
+        char modestr[BOND_MAX_MODENAME_LEN + 1] = { 0, };
+
+        rv = sscanf(buf, "%d", &mode);
+        if (!rv) {
+                rv = sscanf(buf, "%20s", modestr);
+                if (!rv)
+                        return -1;
+        }
 
         for (i = 0; tbl[i].modename; i++) {
-                if ((isdigit(*mode_arg) &&
-                     tbl[i].mode == simple_strtol(mode_arg, NULL, 0)) ||
-                    (strcmp(mode_arg, tbl[i].modename) == 0)) {
+                if (mode == tbl[i].mode)
+                        return tbl[i].mode;
+                if (strcmp(modestr, tbl[i].modename) == 0)
                         return tbl[i].mode;
-                }
         }
 
         return -1;
diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 28a2d803e7e5..bff4f2b84ce0 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -423,7 +423,7 @@ static ssize_t bonding_store_mode(struct device *d,
                 goto out;
         }
 
-        new_value = bond_parse_parm((char *)buf, bond_mode_tbl);
+        new_value = bond_parse_parm(buf, bond_mode_tbl);
         if (new_value < 0)  {
                 printk(KERN_ERR DRV_NAME
                        ": %s: Ignoring invalid mode value %.*s.\n",
@@ -478,7 +478,7 @@ static ssize_t bonding_store_xmit_hash(struct device *d,
                 goto out;
         }
 
-        new_value = bond_parse_parm((char *)buf, xmit_hashtype_tbl);
+        new_value = bond_parse_parm(buf, xmit_hashtype_tbl);
         if (new_value < 0)  {
                 printk(KERN_ERR DRV_NAME
                        ": %s: Ignoring invalid xmit hash policy value %.*s.\n",
@@ -518,7 +518,7 @@ static ssize_t bonding_store_arp_validate(struct device *d,
         int new_value;
         struct bonding *bond = to_bond(d);
 
-        new_value = bond_parse_parm((char *)buf, arp_validate_tbl);
+        new_value = bond_parse_parm(buf, arp_validate_tbl);
         if (new_value < 0) {
                 printk(KERN_ERR DRV_NAME
                        ": %s: Ignoring invalid arp_validate value %s\n",
@@ -941,7 +941,7 @@ static ssize_t bonding_store_lacp(struct device *d,
                 goto out;
         }
 
-        new_value = bond_parse_parm((char *)buf, bond_lacp_tbl);
+        new_value = bond_parse_parm(buf, bond_lacp_tbl);
 
         if ((new_value == 1) || (new_value == 0)) {
                 bond->params.lacp_fast = new_value;
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index e1e4734e23ce..6d83be49899a 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -141,6 +141,8 @@ struct bond_parm_tbl {
         int mode;
 };
 
+#define BOND_MAX_MODENAME_LEN 20
+
 struct vlan_entry {
         struct list_head vlan_list;
         __be32 vlan_ip;
@@ -314,7 +316,7 @@ void bond_mii_monitor(struct work_struct *);
 void bond_loadbalance_arp_mon(struct work_struct *);
 void bond_activebackup_arp_mon(struct work_struct *);
 void bond_set_mode_ops(struct bonding *bond, int mode);
-int bond_parse_parm(char *mode_arg, struct bond_parm_tbl *tbl);
+int bond_parse_parm(const char *mode_arg, struct bond_parm_tbl *tbl);
 void bond_select_active_slave(struct bonding *bond);
 void bond_change_active_slave(struct bonding *bond, struct slave *new_active);
 void bond_register_arp(struct bonding *);