[NETLINK]: Make use of NLA_STRING/NLA_NUL_STRING attribute validation

Converts existing NLA_STRING attributes to use the new
validation features, saving a couple of temporary buffers.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/fib_rules.c

@@ -161,9 +161,6 @@ int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 	if (err < 0)
 		goto errout;
 
-	if (tb[FRA_IFNAME] && nla_len(tb[FRA_IFNAME]) > IFNAMSIZ)
-		goto errout;
-
 	rule = kzalloc(ops->rule_size, GFP_KERNEL);
 	if (rule == NULL) {
 		err = -ENOMEM;
@@ -177,10 +174,7 @@ int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 		struct net_device *dev;
 
 		rule->ifindex = -1;
-		if (nla_strlcpy(rule->ifname, tb[FRA_IFNAME],
-				IFNAMSIZ) >= IFNAMSIZ)
-			goto errout_free;
-
+		nla_strlcpy(rule->ifname, tb[FRA_IFNAME], IFNAMSIZ);
 		dev = __dev_get_by_name(rule->ifname);
 		if (dev)
 			rule->ifindex = dev->ifindex;

net/core/rtnetlink.c

@@ -371,8 +371,8 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 }
 
 static struct nla_policy ifla_policy[IFLA_MAX+1] __read_mostly = {
-	[IFLA_IFNAME]		= { .type = NLA_STRING },
-	[IFLA_MAP]		= { .minlen = sizeof(struct rtnl_link_ifmap) },
+	[IFLA_IFNAME]		= { .type = NLA_STRING, .len = IFNAMSIZ-1 },
+	[IFLA_MAP]		= { .len = sizeof(struct rtnl_link_ifmap) },
 	[IFLA_MTU]		= { .type = NLA_U32 },
 	[IFLA_TXQLEN]		= { .type = NLA_U32 },
 	[IFLA_WEIGHT]		= { .type = NLA_U32 },
@@ -392,9 +392,8 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 	if (err < 0)
 		goto errout;
 
-	if (tb[IFLA_IFNAME] &&
-	    nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ) >= IFNAMSIZ)
-		return -EINVAL;
+	if (tb[IFLA_IFNAME])
+		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
 
 	err = -EINVAL;
 	ifm = nlmsg_data(nlh);

net/decnet/dn_rules.c

@@ -112,7 +112,7 @@ errout:
 }
 
 static struct nla_policy dn_fib_rule_policy[FRA_MAX+1] __read_mostly = {
-	[FRA_IFNAME]	= { .type = NLA_STRING },
+	[FRA_IFNAME]	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
 	[FRA_PRIORITY]	= { .type = NLA_U32 },
 	[FRA_SRC]	= { .type = NLA_U16 },
 	[FRA_DST]	= { .type = NLA_U16 },

net/ipv4/devinet.c

@@ -85,7 +85,7 @@ static struct nla_policy ifa_ipv4_policy[IFA_MAX+1] __read_mostly = {
 	[IFA_ADDRESS]   	= { .type = NLA_U32 },
 	[IFA_BROADCAST] 	= { .type = NLA_U32 },
 	[IFA_ANYCAST]   	= { .type = NLA_U32 },
-	[IFA_LABEL]     	= { .type = NLA_STRING },
+	[IFA_LABEL]     	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
 };
 
 static void rtmsg_ifa(int event, struct in_ifaddr *, struct nlmsghdr *, u32);

net/ipv4/fib_frontend.c

@@ -462,7 +462,7 @@ struct nla_policy rtm_ipv4_policy[RTA_MAX+1] __read_mostly = {
 	[RTA_PRIORITY]		= { .type = NLA_U32 },
 	[RTA_PREFSRC]		= { .type = NLA_U32 },
 	[RTA_METRICS]		= { .type = NLA_NESTED },
-	[RTA_MULTIPATH]		= { .minlen = sizeof(struct rtnexthop) },
+	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
 	[RTA_PROTOINFO]		= { .type = NLA_U32 },
 	[RTA_FLOW]		= { .type = NLA_U32 },
 	[RTA_MP_ALGO]		= { .type = NLA_U32 },

net/ipv4/fib_rules.c

@@ -179,7 +179,7 @@ static struct fib_table *fib_empty_table(void)
 }
 
 static struct nla_policy fib4_rule_policy[FRA_MAX+1] __read_mostly = {
-	[FRA_IFNAME]	= { .type = NLA_STRING },
+	[FRA_IFNAME]	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
 	[FRA_PRIORITY]	= { .type = NLA_U32 },
 	[FRA_SRC]	= { .type = NLA_U32 },
 	[FRA_DST]	= { .type = NLA_U32 },

net/ipv6/fib6_rules.c

@@ -137,10 +137,10 @@ static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
 }
 
 static struct nla_policy fib6_rule_policy[FRA_MAX+1] __read_mostly = {
-	[FRA_IFNAME]	= { .type = NLA_STRING },
+	[FRA_IFNAME]	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
 	[FRA_PRIORITY]	= { .type = NLA_U32 },
-	[FRA_SRC]	= { .minlen = sizeof(struct in6_addr) },
-	[FRA_DST]	= { .minlen = sizeof(struct in6_addr) },
+	[FRA_SRC]	= { .len = sizeof(struct in6_addr) },
+	[FRA_DST]	= { .len = sizeof(struct in6_addr) },
 	[FRA_FWMARK]	= { .type = NLA_U32 },
 	[FRA_FWMASK]	= { .type = NLA_U32 },
 	[FRA_TABLE]	= { .type = NLA_U32 },

net/ipv6/route.c

@@ -1865,7 +1865,7 @@ void rt6_mtu_change(struct net_device *dev, unsigned mtu)
 }
 
 static struct nla_policy rtm_ipv6_policy[RTA_MAX+1] __read_mostly = {
-	[RTA_GATEWAY]           = { .minlen = sizeof(struct in6_addr) },
+	[RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
 	[RTA_OIF]               = { .type = NLA_U32 },
 	[RTA_IIF]		= { .type = NLA_U32 },
 	[RTA_PRIORITY]          = { .type = NLA_U32 },

net/netlink/genetlink.c

@@ -455,7 +455,8 @@ static struct sk_buff *ctrl_build_msg(struct genl_family *family, u32 pid,
 
 static struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] __read_mostly = {
 	[CTRL_ATTR_FAMILY_ID]	= { .type = NLA_U16 },
-	[CTRL_ATTR_FAMILY_NAME]	= { .type = NLA_STRING },
+	[CTRL_ATTR_FAMILY_NAME]	= { .type = NLA_NUL_STRING,
+				    .len = GENL_NAMSIZ - 1 },
 };
 
 static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
@@ -470,12 +471,9 @@ static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
-		char name[GENL_NAMSIZ];
-
-		if (nla_strlcpy(name, info->attrs[CTRL_ATTR_FAMILY_NAME],
-				GENL_NAMSIZ) >= GENL_NAMSIZ)
-			goto errout;
+		char *name;
 
+		name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
 		res = genl_family_find_byname(name);
 	}