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-rw-r--r--net/netlink/af_netlink.c1454
1 files changed, 1454 insertions, 0 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
new file mode 100644
index 000000000000..1d5905c90cd4
--- /dev/null
+++ b/net/netlink/af_netlink.c
@@ -0,0 +1,1454 @@
+/*
+ * NETLINK Kernel-user communication protocol.
+ *
+ * Authors: Alan Cox <alan@redhat.com>
+ * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith
+ * added netlink_proto_exit
+ * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br>
+ * use nlk_sk, as sk->protinfo is on a diet 8)
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/major.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/stat.h>
+#include <linux/socket.h>
+#include <linux/un.h>
+#include <linux/fcntl.h>
+#include <linux/termios.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <asm/uaccess.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/smp_lock.h>
+#include <linux/notifier.h>
+#include <linux/security.h>
+#include <linux/jhash.h>
+#include <linux/jiffies.h>
+#include <linux/random.h>
+#include <linux/bitops.h>
+#include <linux/mm.h>
+#include <linux/types.h>
+#include <net/sock.h>
+#include <net/scm.h>
+
+#define Nprintk(a...)
+
+struct netlink_sock {
+ /* struct sock has to be the first member of netlink_sock */
+ struct sock sk;
+ u32 pid;
+ unsigned int groups;
+ u32 dst_pid;
+ unsigned int dst_groups;
+ unsigned long state;
+ wait_queue_head_t wait;
+ struct netlink_callback *cb;
+ spinlock_t cb_lock;
+ void (*data_ready)(struct sock *sk, int bytes);
+};
+
+static inline struct netlink_sock *nlk_sk(struct sock *sk)
+{
+ return (struct netlink_sock *)sk;
+}
+
+struct nl_pid_hash {
+ struct hlist_head *table;
+ unsigned long rehash_time;
+
+ unsigned int mask;
+ unsigned int shift;
+
+ unsigned int entries;
+ unsigned int max_shift;
+
+ u32 rnd;
+};
+
+struct netlink_table {
+ struct nl_pid_hash hash;
+ struct hlist_head mc_list;
+ unsigned int nl_nonroot;
+};
+
+static struct netlink_table *nl_table;
+
+static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
+
+static int netlink_dump(struct sock *sk);
+static void netlink_destroy_callback(struct netlink_callback *cb);
+
+static DEFINE_RWLOCK(nl_table_lock);
+static atomic_t nl_table_users = ATOMIC_INIT(0);
+
+static struct notifier_block *netlink_chain;
+
+static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
+{
+ return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
+}
+
+static void netlink_sock_destruct(struct sock *sk)
+{
+ skb_queue_purge(&sk->sk_receive_queue);
+
+ if (!sock_flag(sk, SOCK_DEAD)) {
+ printk("Freeing alive netlink socket %p\n", sk);
+ return;
+ }
+ BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
+ BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
+ BUG_TRAP(!nlk_sk(sk)->cb);
+}
+
+/* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on SMP.
+ * Look, when several writers sleep and reader wakes them up, all but one
+ * immediately hit write lock and grab all the cpus. Exclusive sleep solves
+ * this, _but_ remember, it adds useless work on UP machines.
+ */
+
+static void netlink_table_grab(void)
+{
+ write_lock_bh(&nl_table_lock);
+
+ if (atomic_read(&nl_table_users)) {
+ DECLARE_WAITQUEUE(wait, current);
+
+ add_wait_queue_exclusive(&nl_table_wait, &wait);
+ for(;;) {
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ if (atomic_read(&nl_table_users) == 0)
+ break;
+ write_unlock_bh(&nl_table_lock);
+ schedule();
+ write_lock_bh(&nl_table_lock);
+ }
+
+ __set_current_state(TASK_RUNNING);
+ remove_wait_queue(&nl_table_wait, &wait);
+ }
+}
+
+static __inline__ void netlink_table_ungrab(void)
+{
+ write_unlock_bh(&nl_table_lock);
+ wake_up(&nl_table_wait);
+}
+
+static __inline__ void
+netlink_lock_table(void)
+{
+ /* read_lock() synchronizes us to netlink_table_grab */
+
+ read_lock(&nl_table_lock);
+ atomic_inc(&nl_table_users);
+ read_unlock(&nl_table_lock);
+}
+
+static __inline__ void
+netlink_unlock_table(void)
+{
+ if (atomic_dec_and_test(&nl_table_users))
+ wake_up(&nl_table_wait);
+}
+
+static __inline__ struct sock *netlink_lookup(int protocol, u32 pid)
+{
+ struct nl_pid_hash *hash = &nl_table[protocol].hash;
+ struct hlist_head *head;
+ struct sock *sk;
+ struct hlist_node *node;
+
+ read_lock(&nl_table_lock);
+ head = nl_pid_hashfn(hash, pid);
+ sk_for_each(sk, node, head) {
+ if (nlk_sk(sk)->pid == pid) {
+ sock_hold(sk);
+ goto found;
+ }
+ }
+ sk = NULL;
+found:
+ read_unlock(&nl_table_lock);
+ return sk;
+}
+
+static inline struct hlist_head *nl_pid_hash_alloc(size_t size)
+{
+ if (size <= PAGE_SIZE)
+ return kmalloc(size, GFP_ATOMIC);
+ else
+ return (struct hlist_head *)
+ __get_free_pages(GFP_ATOMIC, get_order(size));
+}
+
+static inline void nl_pid_hash_free(struct hlist_head *table, size_t size)
+{
+ if (size <= PAGE_SIZE)
+ kfree(table);
+ else
+ free_pages((unsigned long)table, get_order(size));
+}
+
+static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow)
+{
+ unsigned int omask, mask, shift;
+ size_t osize, size;
+ struct hlist_head *otable, *table;
+ int i;
+
+ omask = mask = hash->mask;
+ osize = size = (mask + 1) * sizeof(*table);
+ shift = hash->shift;
+
+ if (grow) {
+ if (++shift > hash->max_shift)
+ return 0;
+ mask = mask * 2 + 1;
+ size *= 2;
+ }
+
+ table = nl_pid_hash_alloc(size);
+ if (!table)
+ return 0;
+
+ memset(table, 0, size);
+ otable = hash->table;
+ hash->table = table;
+ hash->mask = mask;
+ hash->shift = shift;
+ get_random_bytes(&hash->rnd, sizeof(hash->rnd));
+
+ for (i = 0; i <= omask; i++) {
+ struct sock *sk;
+ struct hlist_node *node, *tmp;
+
+ sk_for_each_safe(sk, node, tmp, &otable[i])
+ __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid));
+ }
+
+ nl_pid_hash_free(otable, osize);
+ hash->rehash_time = jiffies + 10 * 60 * HZ;
+ return 1;
+}
+
+static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len)
+{
+ int avg = hash->entries >> hash->shift;
+
+ if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1))
+ return 1;
+
+ if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
+ nl_pid_hash_rehash(hash, 0);
+ return 1;
+ }
+
+ return 0;
+}
+
+static struct proto_ops netlink_ops;
+
+static int netlink_insert(struct sock *sk, u32 pid)
+{
+ struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
+ struct hlist_head *head;
+ int err = -EADDRINUSE;
+ struct sock *osk;
+ struct hlist_node *node;
+ int len;
+
+ netlink_table_grab();
+ head = nl_pid_hashfn(hash, pid);
+ len = 0;
+ sk_for_each(osk, node, head) {
+ if (nlk_sk(osk)->pid == pid)
+ break;
+ len++;
+ }
+ if (node)
+ goto err;
+
+ err = -EBUSY;
+ if (nlk_sk(sk)->pid)
+ goto err;
+
+ err = -ENOMEM;
+ if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
+ goto err;
+
+ if (len && nl_pid_hash_dilute(hash, len))
+ head = nl_pid_hashfn(hash, pid);
+ hash->entries++;
+ nlk_sk(sk)->pid = pid;
+ sk_add_node(sk, head);
+ err = 0;
+
+err:
+ netlink_table_ungrab();
+ return err;
+}
+
+static void netlink_remove(struct sock *sk)
+{
+ netlink_table_grab();
+ nl_table[sk->sk_protocol].hash.entries--;
+ sk_del_node_init(sk);
+ if (nlk_sk(sk)->groups)
+ __sk_del_bind_node(sk);
+ netlink_table_ungrab();
+}
+
+static struct proto netlink_proto = {
+ .name = "NETLINK",
+ .owner = THIS_MODULE,
+ .obj_size = sizeof(struct netlink_sock),
+};
+
+static int netlink_create(struct socket *sock, int protocol)
+{
+ struct sock *sk;
+ struct netlink_sock *nlk;
+
+ sock->state = SS_UNCONNECTED;
+
+ if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
+ return -ESOCKTNOSUPPORT;
+
+ if (protocol<0 || protocol >= MAX_LINKS)
+ return -EPROTONOSUPPORT;
+
+ sock->ops = &netlink_ops;
+
+ sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1);
+ if (!sk)
+ return -ENOMEM;
+
+ sock_init_data(sock, sk);
+
+ nlk = nlk_sk(sk);
+
+ spin_lock_init(&nlk->cb_lock);
+ init_waitqueue_head(&nlk->wait);
+ sk->sk_destruct = netlink_sock_destruct;
+
+ sk->sk_protocol = protocol;
+ return 0;
+}
+
+static int netlink_release(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct netlink_sock *nlk;
+
+ if (!sk)
+ return 0;
+
+ netlink_remove(sk);
+ nlk = nlk_sk(sk);
+
+ spin_lock(&nlk->cb_lock);
+ if (nlk->cb) {
+ nlk->cb->done(nlk->cb);
+ netlink_destroy_callback(nlk->cb);
+ nlk->cb = NULL;
+ __sock_put(sk);
+ }
+ spin_unlock(&nlk->cb_lock);
+
+ /* OK. Socket is unlinked, and, therefore,
+ no new packets will arrive */
+
+ sock_orphan(sk);
+ sock->sk = NULL;
+ wake_up_interruptible_all(&nlk->wait);
+
+ skb_queue_purge(&sk->sk_write_queue);
+
+ if (nlk->pid && !nlk->groups) {
+ struct netlink_notify n = {
+ .protocol = sk->sk_protocol,
+ .pid = nlk->pid,
+ };
+ notifier_call_chain(&netlink_chain, NETLINK_URELEASE, &n);
+ }
+
+ sock_put(sk);
+ return 0;
+}
+
+static int netlink_autobind(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
+ struct hlist_head *head;
+ struct sock *osk;
+ struct hlist_node *node;
+ s32 pid = current->pid;
+ int err;
+ static s32 rover = -4097;
+
+retry:
+ cond_resched();
+ netlink_table_grab();
+ head = nl_pid_hashfn(hash, pid);
+ sk_for_each(osk, node, head) {
+ if (nlk_sk(osk)->pid == pid) {
+ /* Bind collision, search negative pid values. */
+ pid = rover--;
+ if (rover > -4097)
+ rover = -4097;
+ netlink_table_ungrab();
+ goto retry;
+ }
+ }
+ netlink_table_ungrab();
+
+ err = netlink_insert(sk, pid);
+ if (err == -EADDRINUSE)
+ goto retry;
+ return 0;
+}
+
+static inline int netlink_capable(struct socket *sock, unsigned int flag)
+{
+ return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) ||
+ capable(CAP_NET_ADMIN);
+}
+
+static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
+{
+ struct sock *sk = sock->sk;
+ struct netlink_sock *nlk = nlk_sk(sk);
+ struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
+ int err;
+
+ if (nladdr->nl_family != AF_NETLINK)
+ return -EINVAL;
+
+ /* Only superuser is allowed to listen multicasts */
+ if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_RECV))
+ return -EPERM;
+
+ if (nlk->pid) {
+ if (nladdr->nl_pid != nlk->pid)
+ return -EINVAL;
+ } else {
+ err = nladdr->nl_pid ?
+ netlink_insert(sk, nladdr->nl_pid) :
+ netlink_autobind(sock);
+ if (err)
+ return err;
+ }
+
+ if (!nladdr->nl_groups && !nlk->groups)
+ return 0;
+
+ netlink_table_grab();
+ if (nlk->groups && !nladdr->nl_groups)
+ __sk_del_bind_node(sk);
+ else if (!nlk->groups && nladdr->nl_groups)
+ sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
+ nlk->groups = nladdr->nl_groups;
+ netlink_table_ungrab();
+
+ return 0;
+}
+
+static int netlink_connect(struct socket *sock, struct sockaddr *addr,
+ int alen, int flags)
+{
+ int err = 0;
+ struct sock *sk = sock->sk;
+ struct netlink_sock *nlk = nlk_sk(sk);
+ struct sockaddr_nl *nladdr=(struct sockaddr_nl*)addr;
+
+ if (addr->sa_family == AF_UNSPEC) {
+ sk->sk_state = NETLINK_UNCONNECTED;
+ nlk->dst_pid = 0;
+ nlk->dst_groups = 0;
+ return 0;
+ }
+ if (addr->sa_family != AF_NETLINK)
+ return -EINVAL;
+
+ /* Only superuser is allowed to send multicasts */
+ if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND))
+ return -EPERM;
+
+ if (!nlk->pid)
+ err = netlink_autobind(sock);
+
+ if (err == 0) {
+ sk->sk_state = NETLINK_CONNECTED;
+ nlk->dst_pid = nladdr->nl_pid;
+ nlk->dst_groups = nladdr->nl_groups;
+ }
+
+ return err;
+}
+
+static int netlink_getname(struct socket *sock, struct sockaddr *addr, int *addr_len, int peer)
+{
+ struct sock *sk = sock->sk;
+ struct netlink_sock *nlk = nlk_sk(sk);
+ struct sockaddr_nl *nladdr=(struct sockaddr_nl *)addr;
+
+ nladdr->nl_family = AF_NETLINK;
+ nladdr->nl_pad = 0;
+ *addr_len = sizeof(*nladdr);
+
+ if (peer) {
+ nladdr->nl_pid = nlk->dst_pid;
+ nladdr->nl_groups = nlk->dst_groups;
+ } else {
+ nladdr->nl_pid = nlk->pid;
+ nladdr->nl_groups = nlk->groups;
+ }
+ return 0;
+}
+
+static void netlink_overrun(struct sock *sk)
+{
+ if (!test_and_set_bit(0, &nlk_sk(sk)->state)) {
+ sk->sk_err = ENOBUFS;
+ sk->sk_error_report(sk);
+ }
+}
+
+static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid)
+{
+ int protocol = ssk->sk_protocol;
+ struct sock *sock;
+ struct netlink_sock *nlk;
+
+ sock = netlink_lookup(protocol, pid);
+ if (!sock)
+ return ERR_PTR(-ECONNREFUSED);
+
+ /* Don't bother queuing skb if kernel socket has no input function */
+ nlk = nlk_sk(sock);
+ if ((nlk->pid == 0 && !nlk->data_ready) ||
+ (sock->sk_state == NETLINK_CONNECTED &&
+ nlk->dst_pid != nlk_sk(ssk)->pid)) {
+ sock_put(sock);
+ return ERR_PTR(-ECONNREFUSED);
+ }
+ return sock;
+}
+
+struct sock *netlink_getsockbyfilp(struct file *filp)
+{
+ struct inode *inode = filp->f_dentry->d_inode;
+ struct sock *sock;
+
+ if (!S_ISSOCK(inode->i_mode))
+ return ERR_PTR(-ENOTSOCK);
+
+ sock = SOCKET_I(inode)->sk;
+ if (sock->sk_family != AF_NETLINK)
+ return ERR_PTR(-EINVAL);
+
+ sock_hold(sock);
+ return sock;
+}
+
+/*
+ * Attach a skb to a netlink socket.
+ * The caller must hold a reference to the destination socket. On error, the
+ * reference is dropped. The skb is not send to the destination, just all
+ * all error checks are performed and memory in the queue is reserved.
+ * Return values:
+ * < 0: error. skb freed, reference to sock dropped.
+ * 0: continue
+ * 1: repeat lookup - reference dropped while waiting for socket memory.
+ */
+int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock, long timeo)
+{
+ struct netlink_sock *nlk;
+
+ nlk = nlk_sk(sk);
+
+ if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
+ test_bit(0, &nlk->state)) {
+ DECLARE_WAITQUEUE(wait, current);
+ if (!timeo) {
+ if (!nlk->pid)
+ netlink_overrun(sk);
+ sock_put(sk);
+ kfree_skb(skb);
+ return -EAGAIN;
+ }
+
+ __set_current_state(TASK_INTERRUPTIBLE);
+ add_wait_queue(&nlk->wait, &wait);
+
+ if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
+ test_bit(0, &nlk->state)) &&
+ !sock_flag(sk, SOCK_DEAD))
+ timeo = schedule_timeout(timeo);
+
+ __set_current_state(TASK_RUNNING);
+ remove_wait_queue(&nlk->wait, &wait);
+ sock_put(sk);
+
+ if (signal_pending(current)) {
+ kfree_skb(skb);
+ return sock_intr_errno(timeo);
+ }
+ return 1;
+ }
+ skb_set_owner_r(skb, sk);
+ return 0;
+}
+
+int netlink_sendskb(struct sock *sk, struct sk_buff *skb, int protocol)
+{
+ struct netlink_sock *nlk;
+ int len = skb->len;
+
+ nlk = nlk_sk(sk);
+
+ skb_queue_tail(&sk->sk_receive_queue, skb);
+ sk->sk_data_ready(sk, len);
+ sock_put(sk);
+ return len;
+}
+
+void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
+{
+ kfree_skb(skb);
+ sock_put(sk);
+}
+
+static inline struct sk_buff *netlink_trim(struct sk_buff *skb, int allocation)
+{
+ int delta;
+
+ skb_orphan(skb);
+
+ delta = skb->end - skb->tail;
+ if (delta * 2 < skb->truesize)
+ return skb;
+
+ if (skb_shared(skb)) {
+ struct sk_buff *nskb = skb_clone(skb, allocation);
+ if (!nskb)
+ return skb;
+ kfree_skb(skb);
+ skb = nskb;
+ }
+
+ if (!pskb_expand_head(skb, 0, -delta, allocation))
+ skb->truesize -= delta;
+
+ return skb;
+}
+
+int netlink_unicast(struct sock *ssk, struct sk_buff *skb, u32 pid, int nonblock)
+{
+ struct sock *sk;
+ int err;
+ long timeo;
+
+ skb = netlink_trim(skb, gfp_any());
+
+ timeo = sock_sndtimeo(ssk, nonblock);
+retry:
+ sk = netlink_getsockbypid(ssk, pid);
+ if (IS_ERR(sk)) {
+ kfree_skb(skb);
+ return PTR_ERR(sk);
+ }
+ err = netlink_attachskb(sk, skb, nonblock, timeo);
+ if (err == 1)
+ goto retry;
+ if (err)
+ return err;
+
+ return netlink_sendskb(sk, skb, ssk->sk_protocol);
+}
+
+static __inline__ int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
+ !test_bit(0, &nlk->state)) {
+ skb_set_owner_r(skb, sk);
+ skb_queue_tail(&sk->sk_receive_queue, skb);
+ sk->sk_data_ready(sk, skb->len);
+ return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf;
+ }
+ return -1;
+}
+
+struct netlink_broadcast_data {
+ struct sock *exclude_sk;
+ u32 pid;
+ u32 group;
+ int failure;
+ int congested;
+ int delivered;
+ int allocation;
+ struct sk_buff *skb, *skb2;
+};
+
+static inline int do_one_broadcast(struct sock *sk,
+ struct netlink_broadcast_data *p)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+ int val;
+
+ if (p->exclude_sk == sk)
+ goto out;
+
+ if (nlk->pid == p->pid || !(nlk->groups & p->group))
+ goto out;
+
+ if (p->failure) {
+ netlink_overrun(sk);
+ goto out;
+ }
+
+ sock_hold(sk);
+ if (p->skb2 == NULL) {
+ if (atomic_read(&p->skb->users) != 1) {
+ p->skb2 = skb_clone(p->skb, p->allocation);
+ } else {
+ p->skb2 = p->skb;
+ atomic_inc(&p->skb->users);
+ }
+ }
+ if (p->skb2 == NULL) {
+ netlink_overrun(sk);
+ /* Clone failed. Notify ALL listeners. */
+ p->failure = 1;
+ } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
+ netlink_overrun(sk);
+ } else {
+ p->congested |= val;
+ p->delivered = 1;
+ p->skb2 = NULL;
+ }
+ sock_put(sk);
+
+out:
+ return 0;
+}
+
+int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
+ u32 group, int allocation)
+{
+ struct netlink_broadcast_data info;
+ struct hlist_node *node;
+ struct sock *sk;
+
+ skb = netlink_trim(skb, allocation);
+
+ info.exclude_sk = ssk;
+ info.pid = pid;
+ info.group = group;
+ info.failure = 0;
+ info.congested = 0;
+ info.delivered = 0;
+ info.allocation = allocation;
+ info.skb = skb;
+ info.skb2 = NULL;
+
+ /* While we sleep in clone, do not allow to change socket list */
+
+ netlink_lock_table();
+
+ sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
+ do_one_broadcast(sk, &info);
+
+ netlink_unlock_table();
+
+ if (info.skb2)
+ kfree_skb(info.skb2);
+ kfree_skb(skb);
+
+ if (info.delivered) {
+ if (info.congested && (allocation & __GFP_WAIT))
+ yield();
+ return 0;
+ }
+ if (info.failure)
+ return -ENOBUFS;
+ return -ESRCH;
+}
+
+struct netlink_set_err_data {
+ struct sock *exclude_sk;
+ u32 pid;
+ u32 group;
+ int code;
+};
+
+static inline int do_one_set_err(struct sock *sk,
+ struct netlink_set_err_data *p)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ if (sk == p->exclude_sk)
+ goto out;
+
+ if (nlk->pid == p->pid || !(nlk->groups & p->group))
+ goto out;
+
+ sk->sk_err = p->code;
+ sk->sk_error_report(sk);
+out:
+ return 0;
+}
+
+void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)
+{
+ struct netlink_set_err_data info;
+ struct hlist_node *node;
+ struct sock *sk;
+
+ info.exclude_sk = ssk;
+ info.pid = pid;
+ info.group = group;
+ info.code = code;
+
+ read_lock(&nl_table_lock);
+
+ sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
+ do_one_set_err(sk, &info);
+
+ read_unlock(&nl_table_lock);
+}
+
+static inline void netlink_rcv_wake(struct sock *sk)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ if (!skb_queue_len(&sk->sk_receive_queue))
+ clear_bit(0, &nlk->state);
+ if (!test_bit(0, &nlk->state))
+ wake_up_interruptible(&nlk->wait);
+}
+
+static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
+ struct msghdr *msg, size_t len)
+{
+ struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
+ struct sock *sk = sock->sk;
+ struct netlink_sock *nlk = nlk_sk(sk);
+ struct sockaddr_nl *addr=msg->msg_name;
+ u32 dst_pid;
+ u32 dst_groups;
+ struct sk_buff *skb;
+ int err;
+ struct scm_cookie scm;
+
+ if (msg->msg_flags&MSG_OOB)
+ return -EOPNOTSUPP;
+
+ if (NULL == siocb->scm)
+ siocb->scm = &scm;
+ err = scm_send(sock, msg, siocb->scm);
+ if (err < 0)
+ return err;
+
+ if (msg->msg_namelen) {
+ if (addr->nl_family != AF_NETLINK)
+ return -EINVAL;
+ dst_pid = addr->nl_pid;
+ dst_groups = addr->nl_groups;
+ if (dst_groups && !netlink_capable(sock, NL_NONROOT_SEND))
+ return -EPERM;
+ } else {
+ dst_pid = nlk->dst_pid;
+ dst_groups = nlk->dst_groups;
+ }
+
+ if (!nlk->pid) {
+ err = netlink_autobind(sock);
+ if (err)
+ goto out;
+ }
+
+ err = -EMSGSIZE;
+ if (len > sk->sk_sndbuf - 32)
+ goto out;
+ err = -ENOBUFS;
+ skb = alloc_skb(len, GFP_KERNEL);
+ if (skb==NULL)
+ goto out;
+
+ NETLINK_CB(skb).pid = nlk->pid;
+ NETLINK_CB(skb).groups = nlk->groups;
+ NETLINK_CB(skb).dst_pid = dst_pid;
+ NETLINK_CB(skb).dst_groups = dst_groups;
+ memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
+
+ /* What can I do? Netlink is asynchronous, so that
+ we will have to save current capabilities to
+ check them, when this message will be delivered
+ to corresponding kernel module. --ANK (980802)
+ */
+
+ err = -EFAULT;
+ if (memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len)) {
+ kfree_skb(skb);
+ goto out;
+ }
+
+ err = security_netlink_send(sk, skb);
+ if (err) {
+ kfree_skb(skb);
+ goto out;
+ }
+
+ if (dst_groups) {
+ atomic_inc(&skb->users);
+ netlink_broadcast(sk, skb, dst_pid, dst_groups, GFP_KERNEL);
+ }
+ err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
+
+out:
+ return err;
+}
+
+static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
+ struct msghdr *msg, size_t len,
+ int flags)
+{
+ struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
+ struct scm_cookie scm;
+ struct sock *sk = sock->sk;
+ struct netlink_sock *nlk = nlk_sk(sk);
+ int noblock = flags&MSG_DONTWAIT;
+ size_t copied;
+ struct sk_buff *skb;
+ int err;
+
+ if (flags&MSG_OOB)
+ return -EOPNOTSUPP;
+
+ copied = 0;
+
+ skb = skb_recv_datagram(sk,flags,noblock,&err);
+ if (skb==NULL)
+ goto out;
+
+ msg->msg_namelen = 0;
+
+ copied = skb->len;
+ if (len < copied) {
+ msg->msg_flags |= MSG_TRUNC;
+ copied = len;
+ }
+
+ skb->h.raw = skb->data;
+ err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+
+ if (msg->msg_name) {
+ struct sockaddr_nl *addr = (struct sockaddr_nl*)msg->msg_name;
+ addr->nl_family = AF_NETLINK;
+ addr->nl_pad = 0;
+ addr->nl_pid = NETLINK_CB(skb).pid;
+ addr->nl_groups = NETLINK_CB(skb).dst_groups;
+ msg->msg_namelen = sizeof(*addr);
+ }
+
+ if (NULL == siocb->scm) {
+ memset(&scm, 0, sizeof(scm));
+ siocb->scm = &scm;
+ }
+ siocb->scm->creds = *NETLINK_CREDS(skb);
+ skb_free_datagram(sk, skb);
+
+ if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2)
+ netlink_dump(sk);
+
+ scm_recv(sock, msg, siocb->scm, flags);
+
+out:
+ netlink_rcv_wake(sk);
+ return err ? : copied;
+}
+
+static void netlink_data_ready(struct sock *sk, int len)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ if (nlk->data_ready)
+ nlk->data_ready(sk, len);
+ netlink_rcv_wake(sk);
+}
+
+/*
+ * We export these functions to other modules. They provide a
+ * complete set of kernel non-blocking support for message
+ * queueing.
+ */
+
+struct sock *
+netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len))
+{
+ struct socket *sock;
+ struct sock *sk;
+
+ if (!nl_table)
+ return NULL;
+
+ if (unit<0 || unit>=MAX_LINKS)
+ return NULL;
+
+ if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
+ return NULL;
+
+ if (netlink_create(sock, unit) < 0) {
+ sock_release(sock);
+ return NULL;
+ }
+ sk = sock->sk;
+ sk->sk_data_ready = netlink_data_ready;
+ if (input)
+ nlk_sk(sk)->data_ready = input;
+
+ if (netlink_insert(sk, 0)) {
+ sock_release(sock);
+ return NULL;
+ }
+ return sk;
+}
+
+void netlink_set_nonroot(int protocol, unsigned int flags)
+{
+ if ((unsigned int)protocol < MAX_LINKS)
+ nl_table[protocol].nl_nonroot = flags;
+}
+
+static void netlink_destroy_callback(struct netlink_callback *cb)
+{
+ if (cb->skb)
+ kfree_skb(cb->skb);
+ kfree(cb);
+}
+
+/*
+ * It looks a bit ugly.
+ * It would be better to create kernel thread.
+ */
+
+static int netlink_dump(struct sock *sk)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+ struct netlink_callback *cb;
+ struct sk_buff *skb;
+ struct nlmsghdr *nlh;
+ int len;
+
+ skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL);
+ if (!skb)
+ return -ENOBUFS;
+
+ spin_lock(&nlk->cb_lock);
+
+ cb = nlk->cb;
+ if (cb == NULL) {
+ spin_unlock(&nlk->cb_lock);
+ kfree_skb(skb);
+ return -EINVAL;
+ }
+
+ len = cb->dump(skb, cb);
+
+ if (len > 0) {
+ spin_unlock(&nlk->cb_lock);
+ skb_queue_tail(&sk->sk_receive_queue, skb);
+ sk->sk_data_ready(sk, len);
+ return 0;
+ }
+
+ nlh = __nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, NLMSG_DONE, sizeof(int));
+ nlh->nlmsg_flags |= NLM_F_MULTI;
+ memcpy(NLMSG_DATA(nlh), &len, sizeof(len));
+ skb_queue_tail(&sk->sk_receive_queue, skb);
+ sk->sk_data_ready(sk, skb->len);
+
+ cb->done(cb);
+ nlk->cb = NULL;
+ spin_unlock(&nlk->cb_lock);
+
+ netlink_destroy_callback(cb);
+ __sock_put(sk);
+ return 0;
+}
+
+int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
+ struct nlmsghdr *nlh,
+ int (*dump)(struct sk_buff *skb, struct netlink_callback*),
+ int (*done)(struct netlink_callback*))
+{
+ struct netlink_callback *cb;
+ struct sock *sk;
+ struct netlink_sock *nlk;
+
+ cb = kmalloc(sizeof(*cb), GFP_KERNEL);
+ if (cb == NULL)
+ return -ENOBUFS;
+
+ memset(cb, 0, sizeof(*cb));
+ cb->dump = dump;
+ cb->done = done;
+ cb->nlh = nlh;
+ atomic_inc(&skb->users);
+ cb->skb = skb;
+
+ sk = netlink_lookup(ssk->sk_protocol, NETLINK_CB(skb).pid);
+ if (sk == NULL) {
+ netlink_destroy_callback(cb);
+ return -ECONNREFUSED;
+ }
+ nlk = nlk_sk(sk);
+ /* A dump is in progress... */
+ spin_lock(&nlk->cb_lock);
+ if (nlk->cb) {
+ spin_unlock(&nlk->cb_lock);
+ netlink_destroy_callback(cb);
+ sock_put(sk);
+ return -EBUSY;
+ }
+ nlk->cb = cb;
+ sock_hold(sk);
+ spin_unlock(&nlk->cb_lock);
+
+ netlink_dump(sk);
+ sock_put(sk);
+ return 0;
+}
+
+void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
+{
+ struct sk_buff *skb;
+ struct nlmsghdr *rep;
+ struct nlmsgerr *errmsg;
+ int size;
+
+ if (err == 0)
+ size = NLMSG_SPACE(sizeof(struct nlmsgerr));
+ else
+ size = NLMSG_SPACE(4 + NLMSG_ALIGN(nlh->nlmsg_len));
+
+ skb = alloc_skb(size, GFP_KERNEL);
+ if (!skb) {
+ struct sock *sk;
+
+ sk = netlink_lookup(in_skb->sk->sk_protocol,
+ NETLINK_CB(in_skb).pid);
+ if (sk) {
+ sk->sk_err = ENOBUFS;
+ sk->sk_error_report(sk);
+ sock_put(sk);
+ }
+ return;
+ }
+
+ rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
+ NLMSG_ERROR, sizeof(struct nlmsgerr));
+ errmsg = NLMSG_DATA(rep);
+ errmsg->error = err;
+ memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(struct nlmsghdr));
+ netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
+}
+
+
+#ifdef CONFIG_PROC_FS
+struct nl_seq_iter {
+ int link;
+ int hash_idx;
+};
+
+static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
+{
+ struct nl_seq_iter *iter = seq->private;
+ int i, j;
+ struct sock *s;
+ struct hlist_node *node;
+ loff_t off = 0;
+
+ for (i=0; i<MAX_LINKS; i++) {
+ struct nl_pid_hash *hash = &nl_table[i].hash;
+
+ for (j = 0; j <= hash->mask; j++) {
+ sk_for_each(s, node, &hash->table[j]) {
+ if (off == pos) {
+ iter->link = i;
+ iter->hash_idx = j;
+ return s;
+ }
+ ++off;
+ }
+ }
+ }
+ return NULL;
+}
+
+static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ read_lock(&nl_table_lock);
+ return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+}
+
+static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct sock *s;
+ struct nl_seq_iter *iter;
+ int i, j;
+
+ ++*pos;
+
+ if (v == SEQ_START_TOKEN)
+ return netlink_seq_socket_idx(seq, 0);
+
+ s = sk_next(v);
+ if (s)
+ return s;
+
+ iter = seq->private;
+ i = iter->link;
+ j = iter->hash_idx + 1;
+
+ do {
+ struct nl_pid_hash *hash = &nl_table[i].hash;
+
+ for (; j <= hash->mask; j++) {
+ s = sk_head(&hash->table[j]);
+ if (s) {
+ iter->link = i;
+ iter->hash_idx = j;
+ return s;
+ }
+ }
+
+ j = 0;
+ } while (++i < MAX_LINKS);
+
+ return NULL;
+}
+
+static void netlink_seq_stop(struct seq_file *seq, void *v)
+{
+ read_unlock(&nl_table_lock);
+}
+
+
+static int netlink_seq_show(struct seq_file *seq, void *v)
+{
+ if (v == SEQ_START_TOKEN)
+ seq_puts(seq,
+ "sk Eth Pid Groups "
+ "Rmem Wmem Dump Locks\n");
+ else {
+ struct sock *s = v;
+ struct netlink_sock *nlk = nlk_sk(s);
+
+ seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n",
+ s,
+ s->sk_protocol,
+ nlk->pid,
+ nlk->groups,
+ atomic_read(&s->sk_rmem_alloc),
+ atomic_read(&s->sk_wmem_alloc),
+ nlk->cb,
+ atomic_read(&s->sk_refcnt)
+ );
+
+ }
+ return 0;
+}
+
+static struct seq_operations netlink_seq_ops = {
+ .start = netlink_seq_start,
+ .next = netlink_seq_next,
+ .stop = netlink_seq_stop,
+ .show = netlink_seq_show,
+};
+
+
+static int netlink_seq_open(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq;
+ struct nl_seq_iter *iter;
+ int err;
+
+ iter = kmalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter)
+ return -ENOMEM;
+
+ err = seq_open(file, &netlink_seq_ops);
+ if (err) {
+ kfree(iter);
+ return err;
+ }
+
+ memset(iter, 0, sizeof(*iter));
+ seq = file->private_data;
+ seq->private = iter;
+ return 0;
+}
+
+static struct file_operations netlink_seq_fops = {
+ .owner = THIS_MODULE,
+ .open = netlink_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_private,
+};
+
+#endif
+
+int netlink_register_notifier(struct notifier_block *nb)
+{
+ return notifier_chain_register(&netlink_chain, nb);
+}
+
+int netlink_unregister_notifier(struct notifier_block *nb)
+{
+ return notifier_chain_unregister(&netlink_chain, nb);
+}
+
+static struct proto_ops netlink_ops = {
+ .family = PF_NETLINK,
+ .owner = THIS_MODULE,
+ .release = netlink_release,
+ .bind = netlink_bind,
+ .connect = netlink_connect,
+ .socketpair = sock_no_socketpair,
+ .accept = sock_no_accept,
+ .getname = netlink_getname,
+ .poll = datagram_poll,
+ .ioctl = sock_no_ioctl,
+ .listen = sock_no_listen,
+ .shutdown = sock_no_shutdown,
+ .setsockopt = sock_no_setsockopt,
+ .getsockopt = sock_no_getsockopt,
+ .sendmsg = netlink_sendmsg,
+ .recvmsg = netlink_recvmsg,
+ .mmap = sock_no_mmap,
+ .sendpage = sock_no_sendpage,
+};
+
+static struct net_proto_family netlink_family_ops = {
+ .family = PF_NETLINK,
+ .create = netlink_create,
+ .owner = THIS_MODULE, /* for consistency 8) */
+};
+
+extern void netlink_skb_parms_too_large(void);
+
+static int __init netlink_proto_init(void)
+{
+ struct sk_buff *dummy_skb;
+ int i;
+ unsigned long max;
+ unsigned int order;
+ int err = proto_register(&netlink_proto, 0);
+
+ if (err != 0)
+ goto out;
+
+ if (sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb))
+ netlink_skb_parms_too_large();
+
+ nl_table = kmalloc(sizeof(*nl_table) * MAX_LINKS, GFP_KERNEL);
+ if (!nl_table) {
+enomem:
+ printk(KERN_CRIT "netlink_init: Cannot allocate nl_table\n");
+ return -ENOMEM;
+ }
+
+ memset(nl_table, 0, sizeof(*nl_table) * MAX_LINKS);
+
+ if (num_physpages >= (128 * 1024))
+ max = num_physpages >> (21 - PAGE_SHIFT);
+ else
+ max = num_physpages >> (23 - PAGE_SHIFT);
+
+ order = get_bitmask_order(max) - 1 + PAGE_SHIFT;
+ max = (1UL << order) / sizeof(struct hlist_head);
+ order = get_bitmask_order(max > UINT_MAX ? UINT_MAX : max) - 1;
+
+ for (i = 0; i < MAX_LINKS; i++) {
+ struct nl_pid_hash *hash = &nl_table[i].hash;
+
+ hash->table = nl_pid_hash_alloc(1 * sizeof(*hash->table));
+ if (!hash->table) {
+ while (i-- > 0)
+ nl_pid_hash_free(nl_table[i].hash.table,
+ 1 * sizeof(*hash->table));
+ kfree(nl_table);
+ goto enomem;
+ }
+ memset(hash->table, 0, 1 * sizeof(*hash->table));
+ hash->max_shift = order;
+ hash->shift = 0;
+ hash->mask = 0;
+ hash->rehash_time = jiffies;
+ }
+
+ sock_register(&netlink_family_ops);
+#ifdef CONFIG_PROC_FS
+ proc_net_fops_create("netlink", 0, &netlink_seq_fops);
+#endif
+ /* The netlink device handler may be needed early. */
+ rtnetlink_init();
+out:
+ return err;
+}
+
+static void __exit netlink_proto_exit(void)
+{
+ sock_unregister(PF_NETLINK);
+ proc_net_remove("netlink");
+ kfree(nl_table);
+ nl_table = NULL;
+ proto_unregister(&netlink_proto);
+}
+
+core_initcall(netlink_proto_init);
+module_exit(netlink_proto_exit);
+
+MODULE_LICENSE("GPL");
+
+MODULE_ALIAS_NETPROTO(PF_NETLINK);
+
+EXPORT_SYMBOL(netlink_ack);
+EXPORT_SYMBOL(netlink_broadcast);
+EXPORT_SYMBOL(netlink_dump_start);
+EXPORT_SYMBOL(netlink_kernel_create);
+EXPORT_SYMBOL(netlink_register_notifier);
+EXPORT_SYMBOL(netlink_set_err);
+EXPORT_SYMBOL(netlink_set_nonroot);
+EXPORT_SYMBOL(netlink_unicast);
+EXPORT_SYMBOL(netlink_unregister_notifier);
+
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-18 23:20:37 +0000