net: ipmr: add mfc newroute/delroute netlink support
authorNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Thu, 26 Nov 2015 14:23:50 +0000 (15:23 +0100)
committerDavid S. Miller <davem@davemloft.net>
Mon, 30 Nov 2015 20:26:23 +0000 (15:26 -0500)
This patch adds support to add and remove MFC entries. It uses the
same attributes like the already present dump support in order to be
consistent. There's one new entry - RTA_PREFSRC, it's used to denote an
MFC_PROXY entry (see MRT_ADD_MFC vs MRT_ADD_MFC_PROXY).
The already existing infrastructure is used to create and delete the
entries, the netlink message gets converted internally to a struct mfcctl
which is used with ipmr_mfc_add/delete.
The other used attributes are:
RTA_IIF - used for mfcc_parent (when adding it's required to be valid)
RTA_SRC - used for mfcc_origin
RTA_DST - used for mfcc_mcastgrp
RTA_TABLE - the MRT table id
RTA_MULTIPATH - the "oifs" ttl array

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/ipmr.c

index 6c24a16299c73c3b5b2151f1047a87edf119bde3..4c10ee771648d0cd7924bf342caec41df6eb836d 100644 (file)
@@ -66,6 +66,7 @@
 #include <net/netlink.h>
 #include <net/fib_rules.h>
 #include <linux/netconf.h>
+#include <net/nexthop.h>
 
 struct ipmr_rule {
        struct fib_rule         common;
@@ -2339,6 +2340,130 @@ done:
        return skb->len;
 }
 
+static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {
+       [RTA_SRC]       = { .type = NLA_U32 },
+       [RTA_DST]       = { .type = NLA_U32 },
+       [RTA_IIF]       = { .type = NLA_U32 },
+       [RTA_TABLE]     = { .type = NLA_U32 },
+       [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
+};
+
+static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol)
+{
+       switch (rtm_protocol) {
+       case RTPROT_STATIC:
+       case RTPROT_MROUTED:
+               return true;
+       }
+       return false;
+}
+
+static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc)
+{
+       struct rtnexthop *rtnh = nla_data(nla);
+       int remaining = nla_len(nla), vifi = 0;
+
+       while (rtnh_ok(rtnh, remaining)) {
+               mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops;
+               if (++vifi == MAXVIFS)
+                       break;
+               rtnh = rtnh_next(rtnh, &remaining);
+       }
+
+       return remaining > 0 ? -EINVAL : vifi;
+}
+
+/* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */
+static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
+                           struct mfcctl *mfcc, int *mrtsock,
+                           struct mr_table **mrtret)
+{
+       struct net_device *dev = NULL;
+       u32 tblid = RT_TABLE_DEFAULT;
+       struct mr_table *mrt;
+       struct nlattr *attr;
+       struct rtmsg *rtm;
+       int ret, rem;
+
+       ret = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipmr_policy);
+       if (ret < 0)
+               goto out;
+       rtm = nlmsg_data(nlh);
+
+       ret = -EINVAL;
+       if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 ||
+           rtm->rtm_type != RTN_MULTICAST ||
+           rtm->rtm_scope != RT_SCOPE_UNIVERSE ||
+           !ipmr_rtm_validate_proto(rtm->rtm_protocol))
+               goto out;
+
+       memset(mfcc, 0, sizeof(*mfcc));
+       mfcc->mfcc_parent = -1;
+       ret = 0;
+       nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) {
+               switch (nla_type(attr)) {
+               case RTA_SRC:
+                       mfcc->mfcc_origin.s_addr = nla_get_be32(attr);
+                       break;
+               case RTA_DST:
+                       mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr);
+                       break;
+               case RTA_IIF:
+                       dev = __dev_get_by_index(net, nla_get_u32(attr));
+                       if (!dev) {
+                               ret = -ENODEV;
+                               goto out;
+                       }
+                       break;
+               case RTA_MULTIPATH:
+                       if (ipmr_nla_get_ttls(attr, mfcc) < 0) {
+                               ret = -EINVAL;
+                               goto out;
+                       }
+                       break;
+               case RTA_PREFSRC:
+                       ret = 1;
+                       break;
+               case RTA_TABLE:
+                       tblid = nla_get_u32(attr);
+                       break;
+               }
+       }
+       mrt = ipmr_get_table(net, tblid);
+       if (!mrt) {
+               ret = -ENOENT;
+               goto out;
+       }
+       *mrtret = mrt;
+       *mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0;
+       if (dev)
+               mfcc->mfcc_parent = ipmr_find_vif(mrt, dev);
+
+out:
+       return ret;
+}
+
+/* takes care of both newroute and delroute */
+static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+       struct net *net = sock_net(skb->sk);
+       int ret, mrtsock, parent;
+       struct mr_table *tbl;
+       struct mfcctl mfcc;
+
+       mrtsock = 0;
+       tbl = NULL;
+       ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl);
+       if (ret < 0)
+               return ret;
+
+       parent = ret ? mfcc.mfcc_parent : -1;
+       if (nlh->nlmsg_type == RTM_NEWROUTE)
+               return ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent);
+       else
+               return ipmr_mfc_delete(tbl, &mfcc, parent);
+}
+
 #ifdef CONFIG_PROC_FS
 /* The /proc interfaces to multicast routing :
  * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
@@ -2692,6 +2817,10 @@ int __init ip_mr_init(void)
 #endif
        rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
                      NULL, ipmr_rtm_dumproute, NULL);
+       rtnl_register(RTNL_FAMILY_IPMR, RTM_NEWROUTE,
+                     ipmr_rtm_route, NULL, NULL);
+       rtnl_register(RTNL_FAMILY_IPMR, RTM_DELROUTE,
+                     ipmr_rtm_route, NULL, NULL);
        return 0;
 
 #ifdef CONFIG_IP_PIMSM_V2