Skip to content

Commit

Permalink
bonding: fix string comparison errors
Browse files Browse the repository at this point in the history 
When a bond contains a device where one name is the subset of another
(eth1 and eth10, for example), one cannot properly set the primary
device or the currently active device.

This was reported and based on work by Takuma Umeya.  I also verified
the problem and tested that this fix resolves it.

V2: A few did not like the the current code or my changes, so I
refactored bonding_store_primary and bonding_store_active_slave to be a
bit cleaner, dropped the use of strnicmp since we did not really need
the comparison to be case insensitive, and formatted the input string
from sysfs so a comparison to IFNAMSIZ could be used.

I also discovered an error in bonding_store_active_slave that would
modify bond->primary_slave rather than bond->curr_active_slave before
forcing the bonding driver to choose a new active slave.

V3: Actually sending the proper patch....

Signed-off-by: Andy Gospodarek <[email protected]>
Reported-by: Takuma Umeya <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
  • Loading branch information
@gospo @davem330
gospo authored and davem330 committed Jul 28, 2011
1 parent 550fd08 commit f4bb2e9
Showing 1 changed file with 71 additions and 62 deletions.
133 changes: 71 additions & 62 deletions drivers/net/bonding/bond_sysfs.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1025,6 +1025,7 @@ static ssize_t bonding_store_primary(struct device *d,
int i;
struct slave *slave;
struct bonding *bond = to_bond(d);
char ifname[IFNAMSIZ];

if (!rtnl_trylock())
return restart_syscall();
Expand All @@ -1035,32 +1036,33 @@ static ssize_t bonding_store_primary(struct device *d,
if (!USES_PRIMARY(bond->params.mode)) {
pr_info("%s: Unable to set primary slave; %s is in mode %d\n",
bond->dev->name, bond->dev->name, bond->params.mode);
} else {
bond_for_each_slave(bond, slave, i) {
if (strnicmp
(slave->dev->name, buf,
strlen(slave->dev->name)) == 0) {
pr_info("%s: Setting %s as primary slave.\n",
bond->dev->name, slave->dev->name);
bond->primary_slave = slave;
strcpy(bond->params.primary, slave->dev->name);
bond_select_active_slave(bond);
goto out;
}
}
goto out;
}

/* if we got here, then we didn't match the name of any slave */
sscanf(buf, "%16s", ifname); /* IFNAMSIZ */

if (strlen(buf) == 0 || buf[0] == '\n') {
pr_info("%s: Setting primary slave to None.\n",
bond->dev->name);
bond->primary_slave = NULL;
bond_select_active_slave(bond);
} else {
pr_info("%s: Unable to set %.*s as primary slave as it is not a slave.\n",
bond->dev->name, (int)strlen(buf) - 1, buf);
/* check to see if we are clearing primary */
if (!strlen(ifname) || buf[0] == '\n') {
pr_info("%s: Setting primary slave to None.\n",
bond->dev->name);
bond->primary_slave = NULL;
bond_select_active_slave(bond);
goto out;
}

bond_for_each_slave(bond, slave, i) {
if (strncmp(slave->dev->name, ifname, IFNAMSIZ) == 0) {
pr_info("%s: Setting %s as primary slave.\n",
bond->dev->name, slave->dev->name);
bond->primary_slave = slave;
strcpy(bond->params.primary, slave->dev->name);
bond_select_active_slave(bond);
goto out;
}
}

pr_info("%s: Unable to set %.*s as primary slave.\n",
bond->dev->name, (int)strlen(buf) - 1, buf);
out:
write_unlock_bh(&bond->curr_slave_lock);
read_unlock(&bond->lock);
Expand Down Expand Up @@ -1195,6 +1197,7 @@ static ssize_t bonding_store_active_slave(struct device *d,
struct slave *old_active = NULL;
struct slave *new_active = NULL;
struct bonding *bond = to_bond(d);
char ifname[IFNAMSIZ];

if (!rtnl_trylock())
return restart_syscall();
Expand All @@ -1203,56 +1206,62 @@ static ssize_t bonding_store_active_slave(struct device *d,
read_lock(&bond->lock);
write_lock_bh(&bond->curr_slave_lock);

if (!USES_PRIMARY(bond->params.mode))
if (!USES_PRIMARY(bond->params.mode)) {
pr_info("%s: Unable to change active slave; %s is in mode %d\n",
bond->dev->name, bond->dev->name, bond->params.mode);
else {
bond_for_each_slave(bond, slave, i) {
if (strnicmp
(slave->dev->name, buf,
strlen(slave->dev->name)) == 0) {
old_active = bond->curr_active_slave;
new_active = slave;
if (new_active == old_active) {
/* do nothing */
pr_info("%s: %s is already the current active slave.\n",
goto out;
}

sscanf(buf, "%16s", ifname); /* IFNAMSIZ */

/* check to see if we are clearing active */
if (!strlen(ifname) || buf[0] == '\n') {
pr_info("%s: Clearing current active slave.\n",
bond->dev->name);
bond->curr_active_slave = NULL;
bond_select_active_slave(bond);
goto out;
}

bond_for_each_slave(bond, slave, i) {
if (strncmp(slave->dev->name, ifname, IFNAMSIZ) == 0) {
old_active = bond->curr_active_slave;
new_active = slave;
if (new_active == old_active) {
/* do nothing */
pr_info("%s: %s is already the current"
" active slave.\n",
bond->dev->name,
slave->dev->name);
goto out;
}
else {
if ((new_active) &&
(old_active) &&
(new_active->link == BOND_LINK_UP) &&
IS_UP(new_active->dev)) {
pr_info("%s: Setting %s as active"
" slave.\n",
bond->dev->name,
slave->dev->name);
goto out;
bond_change_active_slave(bond,
new_active);
}
else {
if ((new_active) &&
(old_active) &&
(new_active->link == BOND_LINK_UP) &&
IS_UP(new_active->dev)) {
pr_info("%s: Setting %s as active slave.\n",
bond->dev->name,
slave->dev->name);
bond_change_active_slave(bond, new_active);
}
else {
pr_info("%s: Could not set %s as active slave; either %s is down or the link is down.\n",
bond->dev->name,
slave->dev->name,
slave->dev->name);
}
goto out;
pr_info("%s: Could not set %s as"
" active slave; either %s is"
" down or the link is down.\n",
bond->dev->name,
slave->dev->name,
slave->dev->name);
}
goto out;
}
}

/* if we got here, then we didn't match the name of any slave */

if (strlen(buf) == 0 || buf[0] == '\n') {
pr_info("%s: Setting active slave to None.\n",
bond->dev->name);
bond->primary_slave = NULL;
bond_select_active_slave(bond);
} else {
pr_info("%s: Unable to set %.*s as active slave as it is not a slave.\n",
bond->dev->name, (int)strlen(buf) - 1, buf);
}
}

pr_info("%s: Unable to set %.*s as active slave.\n",
bond->dev->name, (int)strlen(buf) - 1, buf);
out:
write_unlock_bh(&bond->curr_slave_lock);
read_unlock(&bond->lock);
Expand Down

0 comments on commit f4bb2e9

Please sign in to comment.