linux/net/core/sock_diag.c
Alexei Starovoitov 7ae457c1e5 net: filter: split 'struct sk_filter' into socket and bpf parts
clean up names related to socket filtering and bpf in the following way:
- everything that deals with sockets keeps 'sk_*' prefix
- everything that is pure BPF is changed to 'bpf_*' prefix

split 'struct sk_filter' into
struct sk_filter {
	atomic_t        refcnt;
	struct rcu_head rcu;
	struct bpf_prog *prog;
};
and
struct bpf_prog {
        u32                     jited:1,
                                len:31;
        struct sock_fprog_kern  *orig_prog;
        unsigned int            (*bpf_func)(const struct sk_buff *skb,
                                            const struct bpf_insn *filter);
        union {
                struct sock_filter      insns[0];
                struct bpf_insn         insnsi[0];
                struct work_struct      work;
        };
};
so that 'struct bpf_prog' can be used independent of sockets and cleans up
'unattached' bpf use cases

split SK_RUN_FILTER macro into:
    SK_RUN_FILTER to be used with 'struct sk_filter *' and
    BPF_PROG_RUN to be used with 'struct bpf_prog *'

__sk_filter_release(struct sk_filter *) gains
__bpf_prog_release(struct bpf_prog *) helper function

also perform related renames for the functions that work
with 'struct bpf_prog *', since they're on the same lines:

sk_filter_size -> bpf_prog_size
sk_filter_select_runtime -> bpf_prog_select_runtime
sk_filter_free -> bpf_prog_free
sk_unattached_filter_create -> bpf_prog_create
sk_unattached_filter_destroy -> bpf_prog_destroy
sk_store_orig_filter -> bpf_prog_store_orig_filter
sk_release_orig_filter -> bpf_release_orig_filter
__sk_migrate_filter -> bpf_migrate_filter
__sk_prepare_filter -> bpf_prepare_filter

API for attaching classic BPF to a socket stays the same:
sk_attach_filter(prog, struct sock *)/sk_detach_filter(struct sock *)
and SK_RUN_FILTER(struct sk_filter *, ctx) to execute a program
which is used by sockets, tun, af_packet

API for 'unattached' BPF programs becomes:
bpf_prog_create(struct bpf_prog **)/bpf_prog_destroy(struct bpf_prog *)
and BPF_PROG_RUN(struct bpf_prog *, ctx) to execute a program
which is used by isdn, ppp, team, seccomp, ptp, xt_bpf, cls_bpf, test_bpf

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-02 15:03:58 -07:00

232 lines
5.5 KiB
C

#include <linux/mutex.h>
#include <linux/socket.h>
#include <linux/skbuff.h>
#include <net/netlink.h>
#include <net/net_namespace.h>
#include <linux/module.h>
#include <net/sock.h>
#include <linux/inet_diag.h>
#include <linux/sock_diag.h>
static const struct sock_diag_handler *sock_diag_handlers[AF_MAX];
static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh);
static DEFINE_MUTEX(sock_diag_table_mutex);
int sock_diag_check_cookie(void *sk, __u32 *cookie)
{
if ((cookie[0] != INET_DIAG_NOCOOKIE ||
cookie[1] != INET_DIAG_NOCOOKIE) &&
((u32)(unsigned long)sk != cookie[0] ||
(u32)((((unsigned long)sk) >> 31) >> 1) != cookie[1]))
return -ESTALE;
else
return 0;
}
EXPORT_SYMBOL_GPL(sock_diag_check_cookie);
void sock_diag_save_cookie(void *sk, __u32 *cookie)
{
cookie[0] = (u32)(unsigned long)sk;
cookie[1] = (u32)(((unsigned long)sk >> 31) >> 1);
}
EXPORT_SYMBOL_GPL(sock_diag_save_cookie);
int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype)
{
u32 mem[SK_MEMINFO_VARS];
mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
return nla_put(skb, attrtype, sizeof(mem), &mem);
}
EXPORT_SYMBOL_GPL(sock_diag_put_meminfo);
int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk,
struct sk_buff *skb, int attrtype)
{
struct sock_fprog_kern *fprog;
struct sk_filter *filter;
struct nlattr *attr;
unsigned int flen;
int err = 0;
if (!may_report_filterinfo) {
nla_reserve(skb, attrtype, 0);
return 0;
}
rcu_read_lock();
filter = rcu_dereference(sk->sk_filter);
if (!filter)
goto out;
fprog = filter->prog->orig_prog;
flen = bpf_classic_proglen(fprog);
attr = nla_reserve(skb, attrtype, flen);
if (attr == NULL) {
err = -EMSGSIZE;
goto out;
}
memcpy(nla_data(attr), fprog->filter, flen);
out:
rcu_read_unlock();
return err;
}
EXPORT_SYMBOL(sock_diag_put_filterinfo);
void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
{
mutex_lock(&sock_diag_table_mutex);
inet_rcv_compat = fn;
mutex_unlock(&sock_diag_table_mutex);
}
EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);
void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
{
mutex_lock(&sock_diag_table_mutex);
inet_rcv_compat = NULL;
mutex_unlock(&sock_diag_table_mutex);
}
EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);
int sock_diag_register(const struct sock_diag_handler *hndl)
{
int err = 0;
if (hndl->family >= AF_MAX)
return -EINVAL;
mutex_lock(&sock_diag_table_mutex);
if (sock_diag_handlers[hndl->family])
err = -EBUSY;
else
sock_diag_handlers[hndl->family] = hndl;
mutex_unlock(&sock_diag_table_mutex);
return err;
}
EXPORT_SYMBOL_GPL(sock_diag_register);
void sock_diag_unregister(const struct sock_diag_handler *hnld)
{
int family = hnld->family;
if (family >= AF_MAX)
return;
mutex_lock(&sock_diag_table_mutex);
BUG_ON(sock_diag_handlers[family] != hnld);
sock_diag_handlers[family] = NULL;
mutex_unlock(&sock_diag_table_mutex);
}
EXPORT_SYMBOL_GPL(sock_diag_unregister);
static int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
int err;
struct sock_diag_req *req = nlmsg_data(nlh);
const struct sock_diag_handler *hndl;
if (nlmsg_len(nlh) < sizeof(*req))
return -EINVAL;
if (req->sdiag_family >= AF_MAX)
return -EINVAL;
if (sock_diag_handlers[req->sdiag_family] == NULL)
request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
NETLINK_SOCK_DIAG, req->sdiag_family);
mutex_lock(&sock_diag_table_mutex);
hndl = sock_diag_handlers[req->sdiag_family];
if (hndl == NULL)
err = -ENOENT;
else
err = hndl->dump(skb, nlh);
mutex_unlock(&sock_diag_table_mutex);
return err;
}
static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
int ret;
switch (nlh->nlmsg_type) {
case TCPDIAG_GETSOCK:
case DCCPDIAG_GETSOCK:
if (inet_rcv_compat == NULL)
request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
NETLINK_SOCK_DIAG, AF_INET);
mutex_lock(&sock_diag_table_mutex);
if (inet_rcv_compat != NULL)
ret = inet_rcv_compat(skb, nlh);
else
ret = -EOPNOTSUPP;
mutex_unlock(&sock_diag_table_mutex);
return ret;
case SOCK_DIAG_BY_FAMILY:
return __sock_diag_rcv_msg(skb, nlh);
default:
return -EINVAL;
}
}
static DEFINE_MUTEX(sock_diag_mutex);
static void sock_diag_rcv(struct sk_buff *skb)
{
mutex_lock(&sock_diag_mutex);
netlink_rcv_skb(skb, &sock_diag_rcv_msg);
mutex_unlock(&sock_diag_mutex);
}
static int __net_init diag_net_init(struct net *net)
{
struct netlink_kernel_cfg cfg = {
.input = sock_diag_rcv,
};
net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg);
return net->diag_nlsk == NULL ? -ENOMEM : 0;
}
static void __net_exit diag_net_exit(struct net *net)
{
netlink_kernel_release(net->diag_nlsk);
net->diag_nlsk = NULL;
}
static struct pernet_operations diag_net_ops = {
.init = diag_net_init,
.exit = diag_net_exit,
};
static int __init sock_diag_init(void)
{
return register_pernet_subsys(&diag_net_ops);
}
static void __exit sock_diag_exit(void)
{
unregister_pernet_subsys(&diag_net_ops);
}
module_init(sock_diag_init);
module_exit(sock_diag_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_SOCK_DIAG);