@@ -58,6 +58,9 @@ struct mctp_sock {
mctp_eid_t bind_addr;
__u8 bind_type;
+ /* sendmsg()/recvmsg() uses struct sockaddr_mctp_ext */
+ bool addr_ext;
+
/* list of mctp_sk_key, for incoming tag lookup. updates protected
* by sk->net->keys_lock
*/
@@ -128,10 +131,16 @@ struct mctp_sk_key {
struct mctp_skb_cb {
unsigned int magic;
- unsigned int net;
+ int net;
+ int ifindex; /* extended/direct addressing if set */
+ unsigned char halen;
mctp_eid_t src;
+ unsigned char haddr[];
};
+#define MCTP_SKB_CB_HADDR_MAXLEN (sizeof((((struct sk_buff *)(NULL))->cb)) \
+ - offsetof(struct mctp_skb_cb, haddr))
+
/* skb control-block accessors with a little extra debugging for initial
* development.
*
@@ -165,8 +174,7 @@ static inline struct mctp_skb_cb *mctp_cb(struct sk_buff *skb)
*
* Updates to the route table are performed under rtnl; all reads under RCU,
* so routes cannot be referenced over a RCU grace period. Specifically: A
- * caller cannot block between mctp_route_lookup and passing the route to
- * mctp_do_route.
+ * caller cannot block between mctp_route_lookup and mctp_route_release()
*/
struct mctp_route {
mctp_eid_t min, max;
@@ -186,8 +194,6 @@ struct mctp_route {
struct mctp_route *mctp_route_lookup(struct net *net, unsigned int dnet,
mctp_eid_t daddr);
-int mctp_do_route(struct mctp_route *rt, struct sk_buff *skb);
-
int mctp_local_output(struct sock *sk, struct mctp_route *rt,
struct sk_buff *skb, mctp_eid_t daddr, u8 req_tag);
@@ -10,6 +10,7 @@
#define __UAPI_MCTP_H
#include <linux/types.h>
+#include <linux/netdevice.h>
typedef __u8 mctp_eid_t;
@@ -25,6 +26,13 @@ struct sockaddr_mctp {
__u8 smctp_tag;
};
+struct sockaddr_mctp_ext {
+ struct sockaddr_mctp smctp_base;
+ int smctp_ifindex;
+ unsigned char smctp_halen;
+ unsigned char smctp_haddr[MAX_ADDR_LEN];
+};
+
#define MCTP_NET_ANY 0x0
#define MCTP_ADDR_NULL 0x00
@@ -33,4 +41,9 @@ struct sockaddr_mctp {
#define MCTP_TAG_MASK 0x07
#define MCTP_TAG_OWNER 0x08
+/* setsockopt(2) level & options */
+#define SOL_MCTP 0
+
+#define MCTP_OPT_ADDR_EXT 1
+
#endif /* __UAPI_MCTP_H */
@@ -74,6 +74,7 @@ static int mctp_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
const int hlen = MCTP_HEADER_MAXLEN + sizeof(struct mctp_hdr);
int rc, addrlen = msg->msg_namelen;
struct sock *sk = sock->sk;
+ struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
struct mctp_skb_cb *cb;
struct mctp_route *rt;
struct sk_buff *skb;
@@ -97,11 +98,6 @@ static int mctp_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
if (addr->smctp_network == MCTP_NET_ANY)
addr->smctp_network = mctp_default_net(sock_net(sk));
- rt = mctp_route_lookup(sock_net(sk), addr->smctp_network,
- addr->smctp_addr.s_addr);
- if (!rt)
- return -EHOSTUNREACH;
-
skb = sock_alloc_send_skb(sk, hlen + 1 + len,
msg->msg_flags & MSG_DONTWAIT, &rc);
if (!skb)
@@ -113,19 +109,45 @@ static int mctp_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
*(u8 *)skb_put(skb, 1) = addr->smctp_type;
rc = memcpy_from_msg((void *)skb_put(skb, len), msg, len);
- if (rc < 0) {
- kfree_skb(skb);
- return rc;
- }
+ if (rc < 0)
+ goto err_free;
/* set up cb */
cb = __mctp_cb(skb);
cb->net = addr->smctp_network;
+ /* direct addressing */
+ if (msk->addr_ext && addrlen >= sizeof(struct sockaddr_mctp_ext)) {
+ DECLARE_SOCKADDR(struct sockaddr_mctp_ext *,
+ extaddr, msg->msg_name);
+
+ if (extaddr->smctp_halen > MCTP_SKB_CB_HADDR_MAXLEN) {
+ rc = -EINVAL;
+ goto err_free;
+ }
+
+ cb->ifindex = extaddr->smctp_ifindex;
+ cb->halen = extaddr->smctp_halen;
+ memcpy(cb->haddr, extaddr->smctp_haddr, cb->halen);
+
+ rt = NULL;
+ } else {
+ rt = mctp_route_lookup(sock_net(sk), addr->smctp_network,
+ addr->smctp_addr.s_addr);
+ if (!rt) {
+ rc = -EHOSTUNREACH;
+ goto err_free;
+ }
+ }
+
rc = mctp_local_output(sk, rt, skb, addr->smctp_addr.s_addr,
addr->smctp_tag);
return rc ? : len;
+
+err_free:
+ kfree_skb(skb);
+ return rc;
}
static int mctp_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
@@ -133,6 +155,7 @@ static int mctp_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
{
DECLARE_SOCKADDR(struct sockaddr_mctp *, addr, msg->msg_name);
struct sock *sk = sock->sk;
+ struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
struct sk_buff *skb;
size_t msglen;
u8 type;
@@ -178,6 +201,16 @@ static int mctp_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
addr->smctp_tag = hdr->flags_seq_tag &
(MCTP_HDR_TAG_MASK | MCTP_HDR_FLAG_TO);
msg->msg_namelen = sizeof(*addr);
+
+ if (msk->addr_ext) {
+ DECLARE_SOCKADDR(struct sockaddr_mctp_ext *, ae,
+ msg->msg_name);
+ msg->msg_namelen = sizeof(*ae);
+ ae->smctp_ifindex = cb->ifindex;
+ ae->smctp_halen = cb->halen;
+ memset(ae->smctp_haddr, 0x0, sizeof(ae->smctp_haddr));
+ memcpy(ae->smctp_haddr, cb->haddr, cb->halen);
+ }
}
rc = len;
@@ -193,12 +226,45 @@ static int mctp_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
static int mctp_setsockopt(struct socket *sock, int level, int optname,
sockptr_t optval, unsigned int optlen)
{
- return -EINVAL;
+ struct mctp_sock *msk = container_of(sock->sk, struct mctp_sock, sk);
+ int val;
+
+ if (level != SOL_MCTP)
+ return -EINVAL;
+
+ if (optname == MCTP_OPT_ADDR_EXT) {
+ if (optlen != sizeof(int))
+ return -EINVAL;
+ if (copy_from_sockptr(&val, optval, sizeof(int)))
+ return -EFAULT;
+ msk->addr_ext = val;
+ return 0;
+ }
+
+ return -ENOPROTOOPT;
}
static int mctp_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen)
{
+ struct mctp_sock *msk = container_of(sock->sk, struct mctp_sock, sk);
+ int len, val;
+
+ if (level != SOL_MCTP)
+ return -EINVAL;
+
+ if (get_user(len, optlen))
+ return -EFAULT;
+
+ if (optname == MCTP_OPT_ADDR_EXT) {
+ if (len != sizeof(int))
+ return -EINVAL;
+ val = !!msk->addr_ext;
+ if (copy_to_user(optval, &val, len))
+ return -EFAULT;
+ return 0;
+ }
+
return -EINVAL;
}
@@ -376,6 +376,7 @@ static unsigned int mctp_route_mtu(struct mctp_route *rt)
static int mctp_route_output(struct mctp_route *route, struct sk_buff *skb)
{
+ struct mctp_skb_cb *cb = mctp_cb(skb);
struct mctp_hdr *hdr = mctp_hdr(skb);
char daddr_buf[MAX_ADDR_LEN];
char *daddr = NULL;
@@ -390,9 +391,14 @@ static int mctp_route_output(struct mctp_route *route, struct sk_buff *skb)
return -EMSGSIZE;
}
- /* If lookup fails let the device handle daddr==NULL */
- if (mctp_neigh_lookup(route->dev, hdr->dest, daddr_buf) == 0)
- daddr = daddr_buf;
+ if (cb->ifindex) {
+ /* direct route; use the hwaddr we stashed in sendmsg */
+ daddr = cb->haddr;
+ } else {
+ /* If lookup fails let the device handle daddr==NULL */
+ if (mctp_neigh_lookup(route->dev, hdr->dest, daddr_buf) == 0)
+ daddr = daddr_buf;
+ }
rc = dev_hard_header(skb, skb->dev, ntohs(skb->protocol),
daddr, skb->dev->dev_addr, skb->len);
@@ -570,16 +576,6 @@ static struct mctp_route *mctp_route_lookup_null(struct net *net,
return NULL;
}
-/* sends a skb to rt and releases the route. */
-int mctp_do_route(struct mctp_route *rt, struct sk_buff *skb)
-{
- int rc;
-
- rc = rt->output(rt, skb);
- mctp_route_release(rt);
- return rc;
-}
-
static int mctp_do_fragment_route(struct mctp_route *rt, struct sk_buff *skb,
unsigned int mtu, u8 tag)
{
@@ -646,7 +642,7 @@ static int mctp_do_fragment_route(struct mctp_route *rt, struct sk_buff *skb,
/* copy message payload */
skb_copy_bits(skb, pos, skb_transport_header(skb2), size);
- /* do route, but don't drop the rt reference */
+ /* do route */
rc = rt->output(rt, skb2);
if (rc)
break;
@@ -655,7 +651,6 @@ static int mctp_do_fragment_route(struct mctp_route *rt, struct sk_buff *skb,
pos += size;
}
- mctp_route_release(rt);
consume_skb(skb);
return rc;
}
@@ -665,15 +660,50 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
{
struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
struct mctp_skb_cb *cb = mctp_cb(skb);
+ struct mctp_route tmp_rt;
+ struct net_device *dev;
struct mctp_hdr *hdr;
unsigned long flags;
unsigned int mtu;
mctp_eid_t saddr;
+ bool ext_rt;
int rc;
u8 tag;
- if (WARN_ON(!rt->dev))
+ if (rt) {
+ ext_rt = false;
+ dev = NULL;
+
+ if (WARN_ON(!rt->dev))
+ goto out_release;
+
+ } else if (cb->ifindex) {
+ ext_rt = true;
+ rt = &tmp_rt;
+
+ rc = -ENODEV;
+ rcu_read_lock();
+ dev = dev_get_by_index_rcu(sock_net(sk), cb->ifindex);
+ if (!dev) {
+ rcu_read_unlock();
+ return rc;
+ }
+
+ rt->dev = __mctp_dev_get(dev);
+ rcu_read_unlock();
+
+ if (!rt->dev)
+ goto out_release;
+
+ /* establish temporary route - we set up enough to keep
+ * mctp_route_output happy
+ */
+ rt->output = mctp_route_output;
+ rt->mtu = 0;
+
+ } else {
return -EINVAL;
+ }
spin_lock_irqsave(&rt->dev->addrs_lock, flags);
if (rt->dev->num_addrs == 0) {
@@ -686,18 +716,17 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
spin_unlock_irqrestore(&rt->dev->addrs_lock, flags);
if (rc)
- return rc;
+ goto out_release;
if (req_tag & MCTP_HDR_FLAG_TO) {
rc = mctp_alloc_local_tag(msk, saddr, daddr, &tag);
if (rc)
- return rc;
+ goto out_release;
tag |= MCTP_HDR_FLAG_TO;
} else {
tag = req_tag;
}
-
skb->protocol = htons(ETH_P_MCTP);
skb->priority = 0;
skb_reset_transport_header(skb);
@@ -717,12 +746,22 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
mtu = mctp_route_mtu(rt);
if (skb->len + sizeof(struct mctp_hdr) <= mtu) {
- hdr->flags_seq_tag = MCTP_HDR_FLAG_SOM | MCTP_HDR_FLAG_EOM |
- tag;
- return mctp_do_route(rt, skb);
+ hdr->flags_seq_tag = MCTP_HDR_FLAG_SOM |
+ MCTP_HDR_FLAG_EOM | tag;
+ rc = rt->output(rt, skb);
} else {
- return mctp_do_fragment_route(rt, skb, mtu, tag);
+ rc = mctp_do_fragment_route(rt, skb, mtu, tag);
}
+
+out_release:
+ if (!ext_rt)
+ mctp_route_release(rt);
+
+ if (dev)
+ dev_put(dev);
+
+ return rc;
+
}
/* route management */
@@ -863,8 +902,15 @@ static int mctp_pkttype_receive(struct sk_buff *skb, struct net_device *dev,
if (mh->ver < MCTP_VER_MIN || mh->ver > MCTP_VER_MAX)
goto err_drop;
- cb = __mctp_cb(skb);
+ /* MCTP drivers must populate halen/haddr */
+ if (dev->type == ARPHRD_MCTP) {
+ cb = mctp_cb(skb);
+ } else {
+ cb = __mctp_cb(skb);
+ cb->halen = 0;
+ }
cb->net = READ_ONCE(mdev->net);
+ cb->ifindex = dev->ifindex;
rt = mctp_route_lookup(net, cb->net, mh->dest);
@@ -875,7 +921,8 @@ static int mctp_pkttype_receive(struct sk_buff *skb, struct net_device *dev,
if (!rt)
goto err_drop;
- mctp_do_route(rt, skb);
+ rt->output(rt, skb);
+ mctp_route_release(rt);
return NET_RX_SUCCESS;
This change allows an extended address struct - struct sockaddr_mctp_ext - to be passed to sendmsg/recvmsg. This allows userspace to specify output ifindex and physical address information (for sendmsg) or receive the input ifindex/physaddr for incoming messages (for recvmsg). This is typicaly used by userspace for MCTP address discovery and assignment operations. The extended addressing facility is conditional on a new sockopt: MCTP_OPT_ADDR_EXT; userspace must explicitly enable addressing before the kernel will consume/populate the extended address data. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> --- RFC: this patch adds a bit of an new ABI, in that the struct sockaddr for MCTP has been extended, with extra addressing data being available for applications after setting a sockopt. Using something like IP_PKTINFO might be suitable instead, but that requires sendmsg/recvmsg, and control message setup, whereas this is a a simpler interface, and also allows extended addressing info in sendto/recvfrom too. Comments most welcome! --- include/net/mctp.h | 16 +++++-- include/uapi/linux/mctp.h | 13 ++++++ net/mctp/af_mctp.c | 86 ++++++++++++++++++++++++++++++---- net/mctp/route.c | 97 +++++++++++++++++++++++++++++---------- 4 files changed, 172 insertions(+), 40 deletions(-)