mctp: Specify route types, require rtm_type in RTM_*ROUTE messages

This change adds a 'type' attribute to routes, which can be parsed from
a RTM_NEWROUTE message. This will help to distinguish local vs. peer
routes in a future change.

This means userspace will need to set a correct rtm_type in RTM_NEWROUTE
and RTM_DELROUTE messages; we currently only accept RTN_UNICAST.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Link: https://lore.kernel.org/r/20210810023834.2231088-1-jk@codeconstruct.com.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/net/mctp.h b/include/net/mctp.h
index 54bbe04..a824d47 100644 (file)
--- a/include/net/mctp.h
+++ b/include/net/mctp.h
@@ -173,6 +173,7 @@ struct mctp_route {
 
        struct mctp_dev         *dev;
        unsigned int            mtu;
+       unsigned char           type;
        int                     (*output)(struct mctp_route *route,
                                          struct sk_buff *skb);
 

diff --git a/net/mctp/route.c b/net/mctp/route.c
index b310137..5265525 100644 (file)
--- a/net/mctp/route.c
+++ b/net/mctp/route.c
@@ -710,8 +710,9 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
 /* route management */
 static int mctp_route_add(struct mctp_dev *mdev, mctp_eid_t daddr_start,
                          unsigned int daddr_extent, unsigned int mtu,
-                         bool is_local)
+                         unsigned char type)
 {
+       int (*rtfn)(struct mctp_route *rt, struct sk_buff *skb);
        struct net *net = dev_net(mdev->dev);
        struct mctp_route *rt, *ert;
 
@@ -721,6 +722,17 @@ static int mctp_route_add(struct mctp_dev *mdev, mctp_eid_t daddr_start,
        if (daddr_extent > 0xff || daddr_start + daddr_extent >= 255)
                return -EINVAL;
 
+       switch (type) {
+       case RTN_LOCAL:
+               rtfn = mctp_route_input;
+               break;
+       case RTN_UNICAST:
+               rtfn = mctp_route_output;
+               break;
+       default:
+               return -EINVAL;
+       }
+
        rt = mctp_route_alloc();
        if (!rt)
                return -ENOMEM;
@@ -730,7 +742,8 @@ static int mctp_route_add(struct mctp_dev *mdev, mctp_eid_t daddr_start,
        rt->mtu = mtu;
        rt->dev = mdev;
        dev_hold(rt->dev->dev);
-       rt->output = is_local ? mctp_route_input : mctp_route_output;
+       rt->type = type;
+       rt->output = rtfn;
 
        ASSERT_RTNL();
        /* Prevent duplicate identical routes. */
@@ -777,7 +790,7 @@ static int mctp_route_remove(struct mctp_dev *mdev, mctp_eid_t daddr_start,
 
 int mctp_route_add_local(struct mctp_dev *mdev, mctp_eid_t addr)
 {
-       return mctp_route_add(mdev, addr, 0, 0, true);
+       return mctp_route_add(mdev, addr, 0, 0, RTN_LOCAL);
 }
 
 int mctp_route_remove_local(struct mctp_dev *mdev, mctp_eid_t addr)
@@ -936,7 +949,11 @@ static int mctp_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
        /* TODO: parse mtu from nlparse */
        mtu = 0;
 
-       rc = mctp_route_add(mdev, daddr_start, rtm->rtm_dst_len, mtu, false);
+       if (rtm->rtm_type != RTN_UNICAST)
+               return -EINVAL;
+
+       rc = mctp_route_add(mdev, daddr_start, rtm->rtm_dst_len, mtu,
+                           rtm->rtm_type);
        return rc;
 }
 
@@ -985,7 +1002,7 @@ static int mctp_fill_rtinfo(struct sk_buff *skb, struct mctp_route *rt,
        hdr->rtm_table = RT_TABLE_DEFAULT;
        hdr->rtm_protocol = RTPROT_STATIC; /* everything is user-defined */
        hdr->rtm_scope = RT_SCOPE_LINK; /* TODO: scope in mctp_route? */
-       hdr->rtm_type = RTN_ANYCAST; /* TODO: type from route */
+       hdr->rtm_type = rt->type;
 
        if (nla_put_u8(skb, RTA_DST, rt->min))
                goto cancel;