mctp: Implement extended addressing

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
typically 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.

Includes a fix for an uninitialised var:
Reported-by: kernel test robot <lkp@intel.com>

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jeremy Kerr 2021-10-26 09:57:28 +08:00 committed by David S. Miller
parent 971f5c4079
commit 99ce45d5e7
5 changed files with 170 additions and 39 deletions

View File

@ -365,6 +365,7 @@ struct ucred {
#define SOL_TLS 282 #define SOL_TLS 282
#define SOL_XDP 283 #define SOL_XDP 283
#define SOL_MPTCP 284 #define SOL_MPTCP 284
#define SOL_MCTP 285
/* IPX options */ /* IPX options */
#define IPX_TYPE 1 #define IPX_TYPE 1

View File

@ -11,6 +11,7 @@
#include <linux/bits.h> #include <linux/bits.h>
#include <linux/mctp.h> #include <linux/mctp.h>
#include <linux/netdevice.h>
#include <net/net_namespace.h> #include <net/net_namespace.h>
#include <net/sock.h> #include <net/sock.h>
@ -58,6 +59,9 @@ struct mctp_sock {
mctp_eid_t bind_addr; mctp_eid_t bind_addr;
__u8 bind_type; __u8 bind_type;
/* sendmsg()/recvmsg() uses struct sockaddr_mctp_ext */
bool addr_ext;
/* list of mctp_sk_key, for incoming tag lookup. updates protected /* list of mctp_sk_key, for incoming tag lookup. updates protected
* by sk->net->keys_lock * by sk->net->keys_lock
*/ */
@ -153,7 +157,10 @@ struct mctp_sk_key {
struct mctp_skb_cb { struct mctp_skb_cb {
unsigned int magic; unsigned int magic;
unsigned int net; unsigned int net;
int ifindex; /* extended/direct addressing if set */
mctp_eid_t src; mctp_eid_t src;
unsigned char halen;
unsigned char haddr[MAX_ADDR_LEN];
}; };
/* skb control-block accessors with a little extra debugging for initial /* skb control-block accessors with a little extra debugging for initial
@ -177,6 +184,7 @@ static inline struct mctp_skb_cb *mctp_cb(struct sk_buff *skb)
{ {
struct mctp_skb_cb *cb = (void *)skb->cb; struct mctp_skb_cb *cb = (void *)skb->cb;
BUILD_BUG_ON(sizeof(struct mctp_skb_cb) > sizeof(skb->cb));
WARN_ON(cb->magic != 0x4d435450); WARN_ON(cb->magic != 0x4d435450);
return (void *)(skb->cb); return (void *)(skb->cb);
} }
@ -189,8 +197,7 @@ 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, * 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 * so routes cannot be referenced over a RCU grace period. Specifically: A
* caller cannot block between mctp_route_lookup and passing the route to * caller cannot block between mctp_route_lookup and mctp_route_release()
* mctp_do_route.
*/ */
struct mctp_route { struct mctp_route {
mctp_eid_t min, max; mctp_eid_t min, max;
@ -210,8 +217,6 @@ struct mctp_route {
struct mctp_route *mctp_route_lookup(struct net *net, unsigned int dnet, struct mctp_route *mctp_route_lookup(struct net *net, unsigned int dnet,
mctp_eid_t daddr); 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, int mctp_local_output(struct sock *sk, struct mctp_route *rt,
struct sk_buff *skb, mctp_eid_t daddr, u8 req_tag); struct sk_buff *skb, mctp_eid_t daddr, u8 req_tag);

View File

@ -11,6 +11,7 @@
#include <linux/types.h> #include <linux/types.h>
#include <linux/socket.h> #include <linux/socket.h>
#include <linux/netdevice.h>
typedef __u8 mctp_eid_t; typedef __u8 mctp_eid_t;
@ -28,6 +29,14 @@ struct sockaddr_mctp {
__u8 __smctp_pad1; __u8 __smctp_pad1;
}; };
struct sockaddr_mctp_ext {
struct sockaddr_mctp smctp_base;
int smctp_ifindex;
__u8 smctp_halen;
__u8 __smctp_pad0[3];
__u8 smctp_haddr[MAX_ADDR_LEN];
};
#define MCTP_NET_ANY 0x0 #define MCTP_NET_ANY 0x0
#define MCTP_ADDR_NULL 0x00 #define MCTP_ADDR_NULL 0x00
@ -36,4 +45,6 @@ struct sockaddr_mctp {
#define MCTP_TAG_MASK 0x07 #define MCTP_TAG_MASK 0x07
#define MCTP_TAG_OWNER 0x08 #define MCTP_TAG_OWNER 0x08
#define MCTP_OPT_ADDR_EXT 1
#endif /* __UAPI_MCTP_H */ #endif /* __UAPI_MCTP_H */

View File

@ -77,6 +77,7 @@ static int mctp_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
const int hlen = MCTP_HEADER_MAXLEN + sizeof(struct mctp_hdr); const int hlen = MCTP_HEADER_MAXLEN + sizeof(struct mctp_hdr);
int rc, addrlen = msg->msg_namelen; int rc, addrlen = msg->msg_namelen;
struct sock *sk = sock->sk; struct sock *sk = sock->sk;
struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
struct mctp_skb_cb *cb; struct mctp_skb_cb *cb;
struct mctp_route *rt; struct mctp_route *rt;
struct sk_buff *skb; struct sk_buff *skb;
@ -100,11 +101,6 @@ static int mctp_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
if (addr->smctp_network == MCTP_NET_ANY) if (addr->smctp_network == MCTP_NET_ANY)
addr->smctp_network = mctp_default_net(sock_net(sk)); 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, skb = sock_alloc_send_skb(sk, hlen + 1 + len,
msg->msg_flags & MSG_DONTWAIT, &rc); msg->msg_flags & MSG_DONTWAIT, &rc);
if (!skb) if (!skb)
@ -116,19 +112,45 @@ static int mctp_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
*(u8 *)skb_put(skb, 1) = addr->smctp_type; *(u8 *)skb_put(skb, 1) = addr->smctp_type;
rc = memcpy_from_msg((void *)skb_put(skb, len), msg, len); rc = memcpy_from_msg((void *)skb_put(skb, len), msg, len);
if (rc < 0) { if (rc < 0)
kfree_skb(skb); goto err_free;
return rc;
}
/* set up cb */ /* set up cb */
cb = __mctp_cb(skb); cb = __mctp_cb(skb);
cb->net = addr->smctp_network; 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 > sizeof(cb->haddr)) {
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, rc = mctp_local_output(sk, rt, skb, addr->smctp_addr.s_addr,
addr->smctp_tag); addr->smctp_tag);
return rc ? : len; return rc ? : len;
err_free:
kfree_skb(skb);
return rc;
} }
static int mctp_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, static int mctp_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
@ -136,6 +158,7 @@ static int mctp_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
{ {
DECLARE_SOCKADDR(struct sockaddr_mctp *, addr, msg->msg_name); DECLARE_SOCKADDR(struct sockaddr_mctp *, addr, msg->msg_name);
struct sock *sk = sock->sk; struct sock *sk = sock->sk;
struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
struct sk_buff *skb; struct sk_buff *skb;
size_t msglen; size_t msglen;
u8 type; u8 type;
@ -181,6 +204,16 @@ static int mctp_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
addr->smctp_tag = hdr->flags_seq_tag & addr->smctp_tag = hdr->flags_seq_tag &
(MCTP_HDR_TAG_MASK | MCTP_HDR_FLAG_TO); (MCTP_HDR_TAG_MASK | MCTP_HDR_FLAG_TO);
msg->msg_namelen = sizeof(*addr); 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; rc = len;
@ -196,12 +229,45 @@ out_free:
static int mctp_setsockopt(struct socket *sock, int level, int optname, static int mctp_setsockopt(struct socket *sock, int level, int optname,
sockptr_t optval, unsigned int optlen) sockptr_t optval, unsigned int optlen)
{ {
struct mctp_sock *msk = container_of(sock->sk, struct mctp_sock, sk);
int val;
if (level != SOL_MCTP)
return -EINVAL; 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, static int mctp_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen) 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; return -EINVAL;
} }

View File

@ -434,6 +434,7 @@ static unsigned int mctp_route_mtu(struct mctp_route *rt)
static int mctp_route_output(struct mctp_route *route, struct sk_buff *skb) 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); struct mctp_hdr *hdr = mctp_hdr(skb);
char daddr_buf[MAX_ADDR_LEN]; char daddr_buf[MAX_ADDR_LEN];
char *daddr = NULL; char *daddr = NULL;
@ -448,9 +449,14 @@ static int mctp_route_output(struct mctp_route *route, struct sk_buff *skb)
return -EMSGSIZE; return -EMSGSIZE;
} }
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 lookup fails let the device handle daddr==NULL */
if (mctp_neigh_lookup(route->dev, hdr->dest, daddr_buf) == 0) if (mctp_neigh_lookup(route->dev, hdr->dest, daddr_buf) == 0)
daddr = daddr_buf; daddr = daddr_buf;
}
rc = dev_hard_header(skb, skb->dev, ntohs(skb->protocol), rc = dev_hard_header(skb, skb->dev, ntohs(skb->protocol),
daddr, skb->dev->dev_addr, skb->len); daddr, skb->dev->dev_addr, skb->len);
@ -649,16 +655,6 @@ static struct mctp_route *mctp_route_lookup_null(struct net *net,
return NULL; 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, static int mctp_do_fragment_route(struct mctp_route *rt, struct sk_buff *skb,
unsigned int mtu, u8 tag) unsigned int mtu, u8 tag)
{ {
@ -725,7 +721,7 @@ static int mctp_do_fragment_route(struct mctp_route *rt, struct sk_buff *skb,
/* copy message payload */ /* copy message payload */
skb_copy_bits(skb, pos, skb_transport_header(skb2), size); 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); rc = rt->output(rt, skb2);
if (rc) if (rc)
break; break;
@ -734,7 +730,6 @@ static int mctp_do_fragment_route(struct mctp_route *rt, struct sk_buff *skb,
pos += size; pos += size;
} }
mctp_route_release(rt);
consume_skb(skb); consume_skb(skb);
return rc; return rc;
} }
@ -744,15 +739,51 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
{ {
struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk); struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
struct mctp_skb_cb *cb = mctp_cb(skb); struct mctp_skb_cb *cb = mctp_cb(skb);
struct mctp_route tmp_rt;
struct net_device *dev;
struct mctp_hdr *hdr; struct mctp_hdr *hdr;
unsigned long flags; unsigned long flags;
unsigned int mtu; unsigned int mtu;
mctp_eid_t saddr; mctp_eid_t saddr;
bool ext_rt;
int rc; int rc;
u8 tag; u8 tag;
rc = -ENODEV;
if (rt) {
ext_rt = false;
dev = NULL;
if (WARN_ON(!rt->dev)) if (WARN_ON(!rt->dev))
goto out_release;
} else if (cb->ifindex) {
ext_rt = true;
rt = &tmp_rt;
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; return -EINVAL;
}
spin_lock_irqsave(&rt->dev->addrs_lock, flags); spin_lock_irqsave(&rt->dev->addrs_lock, flags);
if (rt->dev->num_addrs == 0) { if (rt->dev->num_addrs == 0) {
@ -765,18 +796,17 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
spin_unlock_irqrestore(&rt->dev->addrs_lock, flags); spin_unlock_irqrestore(&rt->dev->addrs_lock, flags);
if (rc) if (rc)
return rc; goto out_release;
if (req_tag & MCTP_HDR_FLAG_TO) { if (req_tag & MCTP_HDR_FLAG_TO) {
rc = mctp_alloc_local_tag(msk, saddr, daddr, &tag); rc = mctp_alloc_local_tag(msk, saddr, daddr, &tag);
if (rc) if (rc)
return rc; goto out_release;
tag |= MCTP_HDR_FLAG_TO; tag |= MCTP_HDR_FLAG_TO;
} else { } else {
tag = req_tag; tag = req_tag;
} }
skb->protocol = htons(ETH_P_MCTP); skb->protocol = htons(ETH_P_MCTP);
skb->priority = 0; skb->priority = 0;
skb_reset_transport_header(skb); skb_reset_transport_header(skb);
@ -796,12 +826,22 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
mtu = mctp_route_mtu(rt); mtu = mctp_route_mtu(rt);
if (skb->len + sizeof(struct mctp_hdr) <= mtu) { if (skb->len + sizeof(struct mctp_hdr) <= mtu) {
hdr->flags_seq_tag = MCTP_HDR_FLAG_SOM | MCTP_HDR_FLAG_EOM | hdr->flags_seq_tag = MCTP_HDR_FLAG_SOM |
tag; MCTP_HDR_FLAG_EOM | tag;
return mctp_do_route(rt, skb); rc = rt->output(rt, skb);
} else { } 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 */ /* route management */
@ -942,8 +982,15 @@ static int mctp_pkttype_receive(struct sk_buff *skb, struct net_device *dev,
if (mh->ver < MCTP_VER_MIN || mh->ver > MCTP_VER_MAX) if (mh->ver < MCTP_VER_MIN || mh->ver > MCTP_VER_MAX)
goto err_drop; goto err_drop;
/* MCTP drivers must populate halen/haddr */
if (dev->type == ARPHRD_MCTP) {
cb = mctp_cb(skb);
} else {
cb = __mctp_cb(skb); cb = __mctp_cb(skb);
cb->halen = 0;
}
cb->net = READ_ONCE(mdev->net); cb->net = READ_ONCE(mdev->net);
cb->ifindex = dev->ifindex;
rt = mctp_route_lookup(net, cb->net, mh->dest); rt = mctp_route_lookup(net, cb->net, mh->dest);
@ -954,7 +1001,8 @@ static int mctp_pkttype_receive(struct sk_buff *skb, struct net_device *dev,
if (!rt) if (!rt)
goto err_drop; goto err_drop;
mctp_do_route(rt, skb); rt->output(rt, skb);
mctp_route_release(rt);
return NET_RX_SUCCESS; return NET_RX_SUCCESS;