diff options
Diffstat (limited to 'net/core/sock_diag.c')
-rw-r--r-- | net/core/sock_diag.c | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c new file mode 100644 index 0000000000..b1e29e18d1 --- /dev/null +++ b/net/core/sock_diag.c @@ -0,0 +1,343 @@ +/* License: GPL */ + +#include <linux/filter.h> +#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/kernel.h> +#include <linux/tcp.h> +#include <linux/workqueue.h> +#include <linux/nospec.h> +#include <linux/cookie.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); +static struct workqueue_struct *broadcast_wq; + +DEFINE_COOKIE(sock_cookie); + +u64 __sock_gen_cookie(struct sock *sk) +{ + u64 res = atomic64_read(&sk->sk_cookie); + + if (!res) { + u64 new = gen_cookie_next(&sock_cookie); + + atomic64_cmpxchg(&sk->sk_cookie, res, new); + + /* Another thread might have changed sk_cookie before us. */ + res = atomic64_read(&sk->sk_cookie); + } + return res; +} + +int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie) +{ + u64 res; + + if (cookie[0] == INET_DIAG_NOCOOKIE && cookie[1] == INET_DIAG_NOCOOKIE) + return 0; + + res = sock_gen_cookie(sk); + if ((u32)res != cookie[0] || (u32)(res >> 32) != cookie[1]) + return -ESTALE; + + return 0; +} +EXPORT_SYMBOL_GPL(sock_diag_check_cookie); + +void sock_diag_save_cookie(struct sock *sk, __u32 *cookie) +{ + u64 res = sock_gen_cookie(sk); + + cookie[0] = (u32)res; + cookie[1] = (u32)(res >> 32); +} +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]; + + sk_get_meminfo(sk, mem); + + 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; + if (!fprog) + goto out; + + 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); + +struct broadcast_sk { + struct sock *sk; + struct work_struct work; +}; + +static size_t sock_diag_nlmsg_size(void) +{ + return NLMSG_ALIGN(sizeof(struct inet_diag_msg) + + nla_total_size(sizeof(u8)) /* INET_DIAG_PROTOCOL */ + + nla_total_size_64bit(sizeof(struct tcp_info))); /* INET_DIAG_INFO */ +} + +static void sock_diag_broadcast_destroy_work(struct work_struct *work) +{ + struct broadcast_sk *bsk = + container_of(work, struct broadcast_sk, work); + struct sock *sk = bsk->sk; + const struct sock_diag_handler *hndl; + struct sk_buff *skb; + const enum sknetlink_groups group = sock_diag_destroy_group(sk); + int err = -1; + + WARN_ON(group == SKNLGRP_NONE); + + skb = nlmsg_new(sock_diag_nlmsg_size(), GFP_KERNEL); + if (!skb) + goto out; + + mutex_lock(&sock_diag_table_mutex); + hndl = sock_diag_handlers[sk->sk_family]; + if (hndl && hndl->get_info) + err = hndl->get_info(skb, sk); + mutex_unlock(&sock_diag_table_mutex); + + if (!err) + nlmsg_multicast(sock_net(sk)->diag_nlsk, skb, 0, group, + GFP_KERNEL); + else + kfree_skb(skb); +out: + sk_destruct(sk); + kfree(bsk); +} + +void sock_diag_broadcast_destroy(struct sock *sk) +{ + /* Note, this function is often called from an interrupt context. */ + struct broadcast_sk *bsk = + kmalloc(sizeof(struct broadcast_sk), GFP_ATOMIC); + if (!bsk) + return sk_destruct(sk); + bsk->sk = sk; + INIT_WORK(&bsk->work, sock_diag_broadcast_destroy_work); + queue_work(broadcast_wq, &bsk->work); +} + +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_cmd(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; + req->sdiag_family = array_index_nospec(req->sdiag_family, AF_MAX); + + if (sock_diag_handlers[req->sdiag_family] == NULL) + sock_load_diag_module(req->sdiag_family, 0); + + mutex_lock(&sock_diag_table_mutex); + hndl = sock_diag_handlers[req->sdiag_family]; + if (hndl == NULL) + err = -ENOENT; + else if (nlh->nlmsg_type == SOCK_DIAG_BY_FAMILY) + err = hndl->dump(skb, nlh); + else if (nlh->nlmsg_type == SOCK_DESTROY && hndl->destroy) + err = hndl->destroy(skb, nlh); + else + err = -EOPNOTSUPP; + mutex_unlock(&sock_diag_table_mutex); + + return err; +} + +static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + int ret; + + switch (nlh->nlmsg_type) { + case TCPDIAG_GETSOCK: + case DCCPDIAG_GETSOCK: + if (inet_rcv_compat == NULL) + sock_load_diag_module(AF_INET, 0); + + 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: + case SOCK_DESTROY: + return __sock_diag_cmd(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 sock_diag_bind(struct net *net, int group) +{ + switch (group) { + case SKNLGRP_INET_TCP_DESTROY: + case SKNLGRP_INET_UDP_DESTROY: + if (!sock_diag_handlers[AF_INET]) + sock_load_diag_module(AF_INET, 0); + break; + case SKNLGRP_INET6_TCP_DESTROY: + case SKNLGRP_INET6_UDP_DESTROY: + if (!sock_diag_handlers[AF_INET6]) + sock_load_diag_module(AF_INET6, 0); + break; + } + return 0; +} + +int sock_diag_destroy(struct sock *sk, int err) +{ + if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + if (!sk->sk_prot->diag_destroy) + return -EOPNOTSUPP; + + return sk->sk_prot->diag_destroy(sk, err); +} +EXPORT_SYMBOL_GPL(sock_diag_destroy); + +static int __net_init diag_net_init(struct net *net) +{ + struct netlink_kernel_cfg cfg = { + .groups = SKNLGRP_MAX, + .input = sock_diag_rcv, + .bind = sock_diag_bind, + .flags = NL_CFG_F_NONROOT_RECV, + }; + + 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) +{ + broadcast_wq = alloc_workqueue("sock_diag_events", 0, 0); + BUG_ON(!broadcast_wq); + return register_pernet_subsys(&diag_net_ops); +} +device_initcall(sock_diag_init); |