net: diag: slightly refactor the inet_diag_bc_audit error checks.

This simplifies the code a bit and also allows inet_diag_bc_audit
to send to userspace an error that isn't EINVAL.

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 38c2c47fe0e89ada9358f0bad11ffb195679f912..a89b68c6a9348d75df56d76e499cf3510ce4a7fb 100644 (file)
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -706,10 +706,16 @@ static bool valid_port_comparison(const struct inet_diag_bc_op *op,
        return true;
 }
 
-static int inet_diag_bc_audit(const void *bytecode, int bytecode_len)
+static int inet_diag_bc_audit(const struct nlattr *attr)
 {
-       const void *bc = bytecode;
-       int  len = bytecode_len;
+       const void *bytecode, *bc;
+       int bytecode_len, len;
+
+       if (!attr || nla_len(attr) < sizeof(struct inet_diag_bc_op))
+               return -EINVAL;
+
+       bytecode = bc = nla_data(attr);
+       len = bytecode_len = nla_len(attr);
 
        while (len > 0) {
                int min_len = sizeof(struct inet_diag_bc_op);
@@ -1020,13 +1026,13 @@ static int inet_diag_rcv_msg_compat(struct sk_buff *skb, struct nlmsghdr *nlh)
        if (nlh->nlmsg_flags & NLM_F_DUMP) {
                if (nlmsg_attrlen(nlh, hdrlen)) {
                        struct nlattr *attr;
+                       int err;
 
                        attr = nlmsg_find_attr(nlh, hdrlen,
                                               INET_DIAG_REQ_BYTECODE);
-                       if (!attr ||
-                           nla_len(attr) < sizeof(struct inet_diag_bc_op) ||
-                           inet_diag_bc_audit(nla_data(attr), nla_len(attr)))
-                               return -EINVAL;
+                       err = inet_diag_bc_audit(attr);
+                       if (err)
+                               return err;
                }
                {
                        struct netlink_dump_control c = {
@@ -1051,13 +1057,13 @@ static int inet_diag_handler_cmd(struct sk_buff *skb, struct nlmsghdr *h)
            h->nlmsg_flags & NLM_F_DUMP) {
                if (nlmsg_attrlen(h, hdrlen)) {
                        struct nlattr *attr;
+                       int err;
 
                        attr = nlmsg_find_attr(h, hdrlen,
                                               INET_DIAG_REQ_BYTECODE);
-                       if (!attr ||
-                           nla_len(attr) < sizeof(struct inet_diag_bc_op) ||
-                           inet_diag_bc_audit(nla_data(attr), nla_len(attr)))
-                               return -EINVAL;
+                       err = inet_diag_bc_audit(attr);
+                       if (err)
+                               return err;
                }
                {
                        struct netlink_dump_control c = {