net: diag: Add support to filter on device index

Add support to inet_diag facility to filter sockets based on device
index. If an interface index is in the filter only sockets bound
to that index (sk_bound_dev_if) are returned.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 25 insertions, 0 deletions

diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 25af1243649b..38c2c47fe0e8 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -44,6 +44,7 @@ struct inet_diag_entry {
         u16 dport;
         u16 family;
         u16 userlocks;
+        u32 ifindex;
 };
 
 static DEFINE_MUTEX(inet_diag_table_mutex);
@@ -571,6 +572,14 @@ static int inet_diag_bc_run(const struct nlattr *_bc,
                         yes = 0;
                         break;
                 }
+                case INET_DIAG_BC_DEV_COND: {
+                        u32 ifindex;
+
+                        ifindex = *((const u32 *)(op + 1));
+                        if (ifindex != entry->ifindex)
+                                yes = 0;
+                        break;
+                }
                 }
 
                 if (yes) {
@@ -613,6 +622,7 @@ int inet_diag_bc_sk(const struct nlattr *bc, struct sock *sk)
         entry_fill_addrs(&entry, sk);
         entry.sport = inet->inet_num;
         entry.dport = ntohs(inet->inet_dport);
+        entry.ifindex = sk->sk_bound_dev_if;
         entry.userlocks = sk_fullsock(sk) ? sk->sk_userlocks : 0;
 
         return inet_diag_bc_run(bc, &entry);
@@ -636,6 +646,17 @@ static int valid_cc(const void *bc, int len, int cc)
         return 0;
 }
 
+/* data is u32 ifindex */
+static bool valid_devcond(const struct inet_diag_bc_op *op, int len,
+                          int *min_len)
+{
+        /* Check ifindex space. */
+        *min_len += sizeof(u32);
+        if (len < *min_len)
+                return false;
+
+        return true;
+}
 /* Validate an inet_diag_hostcond. */
 static bool valid_hostcond(const struct inet_diag_bc_op *op, int len,
                            int *min_len)
@@ -700,6 +721,10 @@ static int inet_diag_bc_audit(const void *bytecode, int bytecode_len)
                         if (!valid_hostcond(bc, len, &min_len))
                                 return -EINVAL;
                         break;
+                case INET_DIAG_BC_DEV_COND:
+                        if (!valid_devcond(bc, len, &min_len))
+                                return -EINVAL;
+                        break;
                 case INET_DIAG_BC_S_GE:
                 case INET_DIAG_BC_S_LE:
                 case INET_DIAG_BC_D_GE: