mctp: Add netlink route management

This change adds RTM_GETROUTE, RTM_NEWROUTE & RTM_DELROUTE handlers,
allowing management of the MCTP route table.

Includes changes from Jeremy Kerr <jk@codeconstruct.com.au>.

Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Matt Johnston 2021-07-29 10:20:46 +08:00 committed by David S. Miller
parent 889b7da23a
commit 06d2f4c583
2 changed files with 251 additions and 9 deletions

View File

@ -111,6 +111,8 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
struct sk_buff *skb, mctp_eid_t daddr, u8 req_tag);
/* routing <--> device interface */
unsigned int mctp_default_net(struct net *net);
int mctp_default_net_set(struct net *net, unsigned int index);
int mctp_route_add_local(struct mctp_dev *mdev, mctp_eid_t addr);
int mctp_route_remove_local(struct mctp_dev *mdev, mctp_eid_t addr);
void mctp_route_remove_dev(struct mctp_dev *mdev);

View File

@ -20,6 +20,8 @@
#include <net/mctp.h>
#include <net/mctpdevice.h>
#include <net/netlink.h>
#include <net/sock.h>
/* route output callbacks */
static int mctp_route_discard(struct mctp_route *route, struct sk_buff *skb)
@ -36,8 +38,7 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
return 0;
}
static int __always_unused mctp_route_output(struct mctp_route *route,
struct sk_buff *skb)
static int mctp_route_output(struct mctp_route *route, struct sk_buff *skb)
{
unsigned int mtu;
int rc;
@ -182,20 +183,29 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
}
/* route management */
int mctp_route_add_local(struct mctp_dev *mdev, mctp_eid_t addr)
static int mctp_route_add(struct mctp_dev *mdev, mctp_eid_t daddr_start,
unsigned int daddr_extent, unsigned int mtu,
bool is_local)
{
struct net *net = dev_net(mdev->dev);
struct mctp_route *rt, *ert;
if (!mctp_address_ok(daddr_start))
return -EINVAL;
if (daddr_extent > 0xff || daddr_start + daddr_extent >= 255)
return -EINVAL;
rt = mctp_route_alloc();
if (!rt)
return -ENOMEM;
rt->min = addr;
rt->max = addr;
rt->min = daddr_start;
rt->max = daddr_start + daddr_extent;
rt->mtu = mtu;
rt->dev = mdev;
dev_hold(rt->dev->dev);
rt->output = mctp_route_input;
rt->output = is_local ? mctp_route_input : mctp_route_output;
ASSERT_RTNL();
/* Prevent duplicate identical routes. */
@ -211,22 +221,43 @@ int mctp_route_add_local(struct mctp_dev *mdev, mctp_eid_t addr)
return 0;
}
int mctp_route_remove_local(struct mctp_dev *mdev, mctp_eid_t addr)
static int mctp_route_remove(struct mctp_dev *mdev, mctp_eid_t daddr_start,
unsigned int daddr_extent)
{
struct net *net = dev_net(mdev->dev);
struct mctp_route *rt, *tmp;
mctp_eid_t daddr_end;
bool dropped;
if (daddr_extent > 0xff || daddr_start + daddr_extent >= 255)
return -EINVAL;
daddr_end = daddr_start + daddr_extent;
dropped = false;
ASSERT_RTNL();
list_for_each_entry_safe(rt, tmp, &net->mctp.routes, list) {
if (rt->dev == mdev && rt->min == addr && rt->max == addr) {
if (rt->dev == mdev &&
rt->min == daddr_start && rt->max == daddr_end) {
list_del_rcu(&rt->list);
/* TODO: immediate RTM_DELROUTE */
mctp_route_release(rt);
dropped = true;
}
}
return 0;
return dropped ? 0 : -ENOENT;
}
int mctp_route_add_local(struct mctp_dev *mdev, mctp_eid_t addr)
{
return mctp_route_add(mdev, addr, 0, 0, true);
}
int mctp_route_remove_local(struct mctp_dev *mdev, mctp_eid_t addr)
{
return mctp_route_remove(mdev, addr, 0);
}
/* removes all entries for a given device */
@ -294,6 +325,204 @@ static struct packet_type mctp_packet_type = {
.func = mctp_pkttype_receive,
};
/* netlink interface */
static const struct nla_policy rta_mctp_policy[RTA_MAX + 1] = {
[RTA_DST] = { .type = NLA_U8 },
[RTA_METRICS] = { .type = NLA_NESTED },
[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 sk_buff *skb, 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 *net = sock_net(skb->sk);
struct net_device *dev;
unsigned int ifindex;
int rc;
rc = nlmsg_parse(nlh, sizeof(struct rtmsg), tb, RTA_MAX,
rta_mctp_policy, extack);
if (rc < 0) {
NL_SET_ERR_MSG(extack, "incorrect format");
return rc;
}
if (!tb[RTA_DST]) {
NL_SET_ERR_MSG(extack, "dst EID missing");
return -EINVAL;
}
*daddr_start = nla_get_u8(tb[RTA_DST]);
if (!tb[RTA_OIF]) {
NL_SET_ERR_MSG(extack, "ifindex missing");
return -EINVAL;
}
ifindex = nla_get_u32(tb[RTA_OIF]);
*rtm = nlmsg_data(nlh);
if ((*rtm)->rtm_family != AF_MCTP) {
NL_SET_ERR_MSG(extack, "route family must be AF_MCTP");
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 int mctp_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[RTA_MAX + 1];
mctp_eid_t daddr_start;
struct mctp_dev *mdev;
struct rtmsg *rtm;
unsigned int mtu;
int rc;
rc = mctp_route_nlparse(skb, nlh, extack, tb,
&rtm, &mdev, &daddr_start);
if (rc < 0)
return rc;
if (rtm->rtm_type != RTN_UNICAST) {
NL_SET_ERR_MSG(extack, "rtm_type must be RTN_UNICAST");
return -EINVAL;
}
/* TODO: parse mtu from nlparse */
mtu = 0;
rc = mctp_route_add(mdev, daddr_start, rtm->rtm_dst_len, mtu, false);
return rc;
}
static int mctp_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[RTA_MAX + 1];
mctp_eid_t daddr_start;
struct mctp_dev *mdev;
struct rtmsg *rtm;
int rc;
rc = mctp_route_nlparse(skb, nlh, extack, tb,
&rtm, &mdev, &daddr_start);
if (rc < 0)
return rc;
/* we only have unicast routes */
if (rtm->rtm_type != RTN_UNICAST)
return -EINVAL;
rc = mctp_route_remove(mdev, daddr_start, rtm->rtm_dst_len);
return rc;
}
static int mctp_fill_rtinfo(struct sk_buff *skb, struct mctp_route *rt,
u32 portid, u32 seq, int event, unsigned int flags)
{
struct nlmsghdr *nlh;
struct rtmsg *hdr;
void *metrics;
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*hdr), flags);
if (!nlh)
return -EMSGSIZE;
hdr = nlmsg_data(nlh);
hdr->rtm_family = AF_MCTP;
/* we use the _len fields as a number of EIDs, rather than
* a number of bits in the address
*/
hdr->rtm_dst_len = rt->max - rt->min;
hdr->rtm_src_len = 0;
hdr->rtm_tos = 0;
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 */
if (nla_put_u8(skb, RTA_DST, rt->min))
goto cancel;
metrics = nla_nest_start_noflag(skb, RTA_METRICS);
if (!metrics)
goto cancel;
if (rt->mtu) {
if (nla_put_u32(skb, RTAX_MTU, rt->mtu))
goto cancel;
}
nla_nest_end(skb, metrics);
if (rt->dev) {
if (nla_put_u32(skb, RTA_OIF, rt->dev->dev->ifindex))
goto cancel;
}
/* TODO: conditional neighbour physaddr? */
nlmsg_end(skb, nlh);
return 0;
cancel:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static int mctp_dump_rtinfo(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct mctp_route *rt;
int s_idx, idx;
/* TODO: allow filtering on route data, possibly under
* cb->strict_check
*/
/* TODO: change to struct overlay */
s_idx = cb->args[0];
idx = 0;
rcu_read_lock();
list_for_each_entry_rcu(rt, &net->mctp.routes, list) {
if (idx++ < s_idx)
continue;
if (mctp_fill_rtinfo(skb, rt,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
RTM_NEWROUTE, NLM_F_MULTI) < 0)
break;
}
rcu_read_unlock();
cb->args[0] = idx;
return skb->len;
}
/* net namespace implementation */
static int __net_init mctp_routes_net_init(struct net *net)
{
@ -319,11 +548,22 @@ static struct pernet_operations mctp_net_ops = {
int __init mctp_routes_init(void)
{
dev_add_pack(&mctp_packet_type);
rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_GETROUTE,
NULL, mctp_dump_rtinfo, 0);
rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_NEWROUTE,
mctp_newroute, NULL, 0);
rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_DELROUTE,
mctp_delroute, NULL, 0);
return register_pernet_subsys(&mctp_net_ops);
}
void __exit mctp_routes_exit(void)
{
unregister_pernet_subsys(&mctp_net_ops);
rtnl_unregister(PF_MCTP, RTM_DELROUTE);
rtnl_unregister(PF_MCTP, RTM_NEWROUTE);
rtnl_unregister(PF_MCTP, RTM_GETROUTE);
dev_remove_pack(&mctp_packet_type);
}