Subject: Re: [PATCH net-next 2/6] bonding: add helper function bond_get_targets_ip(targets, ip)

From: Nikolay Aleksandrov <[email-masked]>
Date: Wed, 19 Jun 2013 23:32:57 +0200

On 19/06/13 19:34, Veaceslav Falico wrote:
> Add function bond_get_targets_ip(targets, ip) which searches through
> targets array of ips (arp_targets) and returns the position of first
> match. If ip == 0, returns the first free slot. On failure to find the
> ip or free slot, return -1.
> 
> Use it to verify if the arp we've received is valid and in sysfs.
> 
> Signed-off-by: Veaceslav Falico <[email-masked]>
> ---
>  drivers/net/bonding/bond_main.c  |   17 ++++-------
>  drivers/net/bonding/bond_sysfs.c |   56 +++++++++++++++----------------------
>  drivers/net/bonding/bonding.h    |   16 +++++++++++
>  3 files changed, 45 insertions(+), 44 deletions(-)
> 
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 3d8b5ba..09a79eb 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -2599,22 +2599,17 @@ static void bond_arp_send_all(struct bonding *bond, struct slave *slave)
>  
>  static void bond_validate_arp(struct bonding *bond, struct slave *slave, __be32 sip, __be32 tip)
>  {
> -	int i;
> -	__be32 *targets = bond->params.arp_targets;
> -
>  	if (!bond_has_this_ip(bond, tip)) {
>  		pr_debug("bva: tip %pI4 not found\n", &tip);
>  		return;
>  	}
>  
> -	for (i = 0; (i < BOND_MAX_ARP_TARGETS) && targets[i]; i++) {
> -		pr_debug("bva: sip %pI4 tip %pI4 t[%d] %pI4 bhti(tip)\n",
> -			 &sip, &tip, i, &targets[i]);
> -		if (sip == targets[i]) {
> -			slave->last_arp_rx = jiffies;
> -			return;
> -		}
> +	if (bond_get_targets_ip(bond->params.arp_targets, sip) == -1) {
> +		pr_debug("bva: sip %pI4 not found in targets\n", &sip);
> +		return;
>  	}
Here you should probably check if sip != 0 (0.0.0.0) because ARP probes
with such src address are common to check if there's an address conflict
for example.
> +
small nitpick: I don't think this newline is really necessary.
> +	slave->last_arp_rx = jiffies;
>  }
>  
>  static int bond_arp_rcv(const struct sk_buff *skb, struct bonding *bond,
> @@ -4831,7 +4826,7 @@ static int __net_init bond_net_init(struct net *net)
>  
>  	bond_create_proc_dir(bn);
>  	bond_create_sysfs(bn);
> -	
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
> index f8bee4c..e680151 100644
> --- a/drivers/net/bonding/bond_sysfs.c
> +++ b/drivers/net/bonding/bond_sysfs.c
> @@ -591,7 +591,7 @@ static ssize_t bonding_store_arp_targets(struct device *d,
>  					 const char *buf, size_t count)
>  {
>  	__be32 newtarget;
> -	int i = 0, done = 0, ret = count;
> +	int i = 0, ret = -EINVAL;
>  	struct bonding *bond = to_bond(d);
>  	__be32 *targets;
>  
> @@ -602,57 +602,46 @@ static ssize_t bonding_store_arp_targets(struct device *d,
>  		if ((newtarget == 0) || (newtarget == htonl(INADDR_BROADCAST))) {
>  			pr_err("%s: invalid ARP target %pI4 specified for addition\n",
>  			       bond->dev->name, &newtarget);
> -			ret = -EINVAL;
>  			goto out;
>  		}
> -		/* look for an empty slot to put the target in, and check for dupes */
> -		for (i = 0; (i < BOND_MAX_ARP_TARGETS) && !done; i++) {
> -			if (targets[i] == newtarget) { /* duplicate */
> -				pr_err("%s: ARP target %pI4 is already present\n",
> -				       bond->dev->name, &newtarget);
> -				ret = -EINVAL;
> -				goto out;
> -			}
> -			if (targets[i] == 0) {
> -				pr_info("%s: adding ARP target %pI4.\n",
> -					bond->dev->name, &newtarget);
> -				done = 1;
> -				targets[i] = newtarget;
> -			}
> +
> +		if (bond_get_targets_ip(targets, newtarget) != -1) { /* dup */
> +			pr_err("%s: ARP target %pI4 is already present\n",
> +			       bond->dev->name, &newtarget);
> +			goto out;
>  		}
> -		if (!done) {
> +
> +		i = bond_get_targets_ip(targets, 0); /* first free slot */
> +		if (i == -1) {
>  			pr_err("%s: ARP target table is full!\n",
>  			       bond->dev->name);
> -			ret = -EINVAL;
>  			goto out;
>  		}
>  
> +		pr_info("%s: adding ARP target %pI4.\n", bond->dev->name,
> +			 &newtarget);
> +		targets[i] = newtarget;
> +
Extra new line here.
>  	} else if (buf[0] == '-')	{
>  		if ((newtarget == 0) || (newtarget == htonl(INADDR_BROADCAST))) {
>  			pr_err("%s: invalid ARP target %pI4 specified for removal\n",
>  			       bond->dev->name, &newtarget);
> -			ret = -EINVAL;
>  			goto out;
>  		}
>  
> -		for (i = 0; (i < BOND_MAX_ARP_TARGETS) && !done; i++) {
> -			if (targets[i] == newtarget) {
> -				int j;
> -				pr_info("%s: removing ARP target %pI4.\n",
> -					bond->dev->name, &newtarget);
> -				for (j = i; (j < (BOND_MAX_ARP_TARGETS-1)) && targets[j+1]; j++)
> -					targets[j] = targets[j+1];
> -
> -				targets[j] = 0;
> -				done = 1;
> -			}
> -		}
> -		if (!done) {
> +		i = bond_get_targets_ip(targets, newtarget);
> +		if (i == -1) {
>  			pr_info("%s: unable to remove nonexistent ARP target %pI4.\n",
>  				bond->dev->name, &newtarget);
> -			ret = -EINVAL;
>  			goto out;
>  		}
> +
> +		pr_info("%s: removing ARP target %pI4.\n", bond->dev->name,
> +			&newtarget);
> +		for (; (i < BOND_MAX_ARP_TARGETS-1) && targets[i+1]; i++)
> +			targets[i] = targets[i+1];
> +		targets[i] = 0;
> +
Another extra new line.
>  	} else {
>  		pr_err("no command found in arp_ip_targets file for bond %s. Use +<addr> or -<addr>.\n",
>  		       bond->dev->name);
> @@ -660,6 +649,7 @@ static ssize_t bonding_store_arp_targets(struct device *d,
>  		goto out;
>  	}
>  
> +	ret = count;
>  out:
>  	return ret;
>  }
> diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
> index b38609b..7feab6c 100644
> --- a/drivers/net/bonding/bonding.h
> +++ b/drivers/net/bonding/bonding.h
> @@ -464,6 +464,22 @@ static inline struct slave *bond_slave_has_mac(struct bonding *bond,
>  	return NULL;
>  }
>  
> +/* Check if the ip is present in arp ip list, or first free slot if ip == 0
> + * Returns -1 if not found, index if found
> + */
> +static inline int bond_get_targets_ip(__be32 *targets, __be32 ip)
> +{
> +	int i;
> +
> +	for (i = 0; i < BOND_MAX_ARP_TARGETS; i++)
> +		if (targets[i] == ip)
> +			return i;
> +		else if (targets[i] == 0)
> +			break;
> +
> +	return -1;
> +}
> +
>  /* exported from bond_main.c */
>  extern int bond_net_id;
>  extern const struct bond_parm_tbl bond_lacp_tbl[];