The netlink route parsing functions end up setting a bunch of output variables from the rt attributes. This will get messy when the routes become more complex. So, split the rt parsing into two types: a lookup (returning route target data suitable for a route lookup, like when deleting a route) and a populate (setting fields of a struct mctp_route). In doing this, we need to separate the route allocation from mctp_route_add, so add some comments on the lifetime semantics for the latter. Signed-off-by: Jeremy Kerr --- net/mctp/route.c | 194 +++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 130 insertions(+), 64 deletions(-) diff --git a/net/mctp/route.c b/net/mctp/route.c index 1731cabcc30780226d39e6e0716346f7acb5bd7e..ab5116c12b91461011c1ec3d9954609658a40a22 100644 --- a/net/mctp/route.c +++ b/net/mctp/route.c @@ -1086,25 +1086,32 @@ static unsigned int mctp_route_netid(struct mctp_route *rt) } /* route management */ -static int mctp_route_add(struct net *net, struct mctp_dev *mdev, - mctp_eid_t daddr_start, unsigned int daddr_extent, - unsigned int mtu, unsigned char type) + +/* mctp_route_add(): Add the provided route, previously allocated via + * mctp_route_alloc(). On success, takes ownership of @rt, which includes a + * hold on rt->dev for usage in the route table. On failure a caller will want + * to mctp_route_release(). + * + * We expect that the caller has set rt->type, rt->min, rt->max, rt->dev and + * rt->mtu, and that the route holds a reference to rt->dev (via mctp_dev_hold). + * Other fields will be populated. + */ +static int mctp_route_add(struct net *net, struct mctp_route *rt) { - int (*rtfn)(struct mctp_dst *dst, struct sk_buff *skb); - struct mctp_route *rt, *ert; + struct mctp_route *ert; - if (!mctp_address_unicast(daddr_start)) + if (!mctp_address_unicast(rt->min) || !mctp_address_unicast(rt->max)) return -EINVAL; - if (daddr_extent > 0xff || daddr_start + daddr_extent >= 255) + if (!rt->dev) return -EINVAL; - switch (type) { + switch (rt->type) { case RTN_LOCAL: - rtfn = mctp_dst_input; + rt->output = mctp_dst_input; break; case RTN_UNICAST: - rtfn = mctp_dst_output; + rt->output = mctp_dst_output; break; default: return -EINVAL; @@ -1112,22 +1119,9 @@ static int mctp_route_add(struct net *net, struct mctp_dev *mdev, ASSERT_RTNL(); - rt = mctp_route_alloc(); - if (!rt) - return -ENOMEM; - - rt->min = daddr_start; - rt->max = daddr_start + daddr_extent; - rt->mtu = mtu; - rt->dev = mdev; - mctp_dev_hold(rt->dev); - rt->type = type; - rt->output = rtfn; - /* Prevent duplicate identical routes. */ list_for_each_entry(ert, &net->mctp.routes, list) { if (mctp_rt_compare_exact(rt, ert)) { - mctp_route_release(rt); return -EEXIST; } } @@ -1169,7 +1163,25 @@ static int mctp_route_remove(struct net *net, unsigned int netid, int mctp_route_add_local(struct mctp_dev *mdev, mctp_eid_t addr) { - return mctp_route_add(dev_net(mdev->dev), mdev, addr, 0, 0, RTN_LOCAL); + struct mctp_route *rt; + int rc; + + rt = mctp_route_alloc(); + if (!rt) + return -ENOMEM; + + rt->min = addr; + rt->max = addr; + rt->dev = mdev; + rt->type = RTN_LOCAL; + + mctp_dev_hold(rt->dev); + + rc = mctp_route_add(dev_net(mdev->dev), rt); + if (rc) + mctp_route_release(rt); + + return rc; } int mctp_route_remove_local(struct mctp_dev *mdev, mctp_eid_t addr) @@ -1281,13 +1293,16 @@ static const struct nla_policy rta_mctp_policy[RTA_MAX + 1] = { [RTA_OIF] = { .type = NLA_U32 }, }; -/* Common part for RTM_NEWROUTE and RTM_DELROUTE parsing. - * tb must hold RTA_MAX+1 elements. - */ -static int mctp_route_nlparse(struct net *net, struct nlmsghdr *nlh, - struct netlink_ext_ack *extack, - struct nlattr **tb, struct rtmsg **rtm, - struct mctp_dev **mdev, mctp_eid_t *daddr_start) +static const struct nla_policy rta_metrics_policy[RTAX_MAX + 1] = { + [RTAX_MTU] = { .type = NLA_U32 }, +}; + +/* base parsing; common to both _lookup and _populate variants */ +static int mctp_route_nlparse_common(struct net *net, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack, + struct nlattr **tb, struct rtmsg **rtm, + struct mctp_dev **mdev, + mctp_eid_t *daddr_start) { struct net_device *dev; unsigned int ifindex; @@ -1318,61 +1333,114 @@ static int mctp_route_nlparse(struct net *net, struct nlmsghdr *nlh, return -EINVAL; } + if ((*rtm)->rtm_type != RTN_UNICAST) { + NL_SET_ERR_MSG(extack, "rtm_type must be RTN_UNICAST"); + return -EINVAL; + } + dev = __dev_get_by_index(net, ifindex); if (!dev) { NL_SET_ERR_MSG(extack, "bad ifindex"); return -ENODEV; } + *mdev = mctp_dev_get_rtnl(dev); if (!*mdev) return -ENODEV; - if (dev->flags & IFF_LOOPBACK) { - NL_SET_ERR_MSG(extack, "no routes to loopback"); - return -EINVAL; - } - return 0; } -static const struct nla_policy rta_metrics_policy[RTAX_MAX + 1] = { - [RTAX_MTU] = { .type = NLA_U32 }, -}; - -static int mctp_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, - struct netlink_ext_ack *extack) +/* Route parsing for lookup operations; we only need the "route target" + * components (ie., network and dest-EID range). + */ +static int mctp_route_nlparse_lookup(struct net *net, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack, + unsigned char *type, unsigned int *netid, + mctp_eid_t *daddr_start, + unsigned int *daddr_extent) { - struct net *net = sock_net(skb->sk); struct nlattr *tb[RTA_MAX + 1]; - struct nlattr *tbx[RTAX_MAX + 1]; - mctp_eid_t daddr_start; struct mctp_dev *mdev; struct rtmsg *rtm; - unsigned int mtu; int rc; - rc = mctp_route_nlparse(net, nlh, extack, tb, - &rtm, &mdev, &daddr_start); - if (rc < 0) + rc = mctp_route_nlparse_common(net, nlh, extack, tb, &rtm, + &mdev, daddr_start); + if (rc) return rc; - if (rtm->rtm_type != RTN_UNICAST) { - NL_SET_ERR_MSG(extack, "rtm_type must be RTN_UNICAST"); + *netid = mdev->net; + *type = rtm->rtm_type; + *daddr_extent = rtm->rtm_dst_len; + + return 0; +} + +/* Full route parse for RTM_NEWROUTE: populate @rt */ +static int mctp_route_nlparse_populate(struct net *net, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack, + struct mctp_route *rt) +{ + struct nlattr *tbx[RTAX_MAX + 1]; + struct nlattr *tb[RTA_MAX + 1]; + unsigned int daddr_extent; + struct rtmsg *rtm; + int rc; + + rc = mctp_route_nlparse_common(net, nlh, extack, tb, &rtm, + &rt->dev, &rt->min); + if (rc) + return rc; + + daddr_extent = rtm->rtm_dst_len; + + if (daddr_extent > 0xff || daddr_extent + rt->min >= 255) { + NL_SET_ERR_MSG(extack, "invalid eid range"); return -EINVAL; } - mtu = 0; + rt->type = rtm->rtm_type; + rt->max = rt->min + daddr_extent; + rt->mtu = 0; + if (tb[RTA_METRICS]) { rc = nla_parse_nested(tbx, RTAX_MAX, tb[RTA_METRICS], rta_metrics_policy, NULL); - if (rc < 0) + if (rc < 0) { + NL_SET_ERR_MSG(extack, "incorrect RTA_METRICS format"); return rc; + } if (tbx[RTAX_MTU]) - mtu = nla_get_u32(tbx[RTAX_MTU]); + rt->mtu = nla_get_u32(tbx[RTAX_MTU]); } - rc = mctp_route_add(net, mdev, daddr_start, rtm->rtm_dst_len, mtu, - rtm->rtm_type); + return 0; +} + +static int mctp_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(skb->sk); + struct mctp_route *rt; + int rc; + + rt = mctp_route_alloc(); + if (!rt) + return -ENOMEM; + + rc = mctp_route_nlparse_populate(net, nlh, extack, rt); + if (rc < 0) + goto err_free; + + mctp_dev_hold(rt->dev); + + rc = mctp_route_add(net, rt); + if (!rc) + return 0; + +err_free: + mctp_route_release(rt); return rc; } @@ -1380,23 +1448,21 @@ static int mctp_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { struct net *net = sock_net(skb->sk); - struct nlattr *tb[RTA_MAX + 1]; + unsigned int netid, daddr_extent; mctp_eid_t daddr_start; - struct mctp_dev *mdev; - struct rtmsg *rtm; + unsigned char type; int rc; - rc = mctp_route_nlparse(net, nlh, extack, tb, - &rtm, &mdev, &daddr_start); + rc = mctp_route_nlparse_lookup(net, nlh, extack, &type, &netid, + &daddr_start, &daddr_extent); if (rc < 0) return rc; /* we only have unicast routes */ - if (rtm->rtm_type != RTN_UNICAST) + if (type != RTN_UNICAST) return -EINVAL; - rc = mctp_route_remove(net, mdev->net, daddr_start, rtm->rtm_dst_len, - RTN_UNICAST); + rc = mctp_route_remove(net, netid, daddr_start, daddr_extent, type); return rc; } -- 2.39.5