[NETLINK]: Support dynamic number of multicast groups per netlink family (f7fa9b10) · Commits · e / devices / android_kernel_fairphone_FP3

net/netlink/af_netlink.c

+51 −18

Original line number	Diff line number	Diff line
		@@ -60,21 +60,24 @@
		#include <net/scm.h>

		#define Nprintk(a...)
		#define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8)

		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;
		u32 dst_group;
		u32 flags;
		u32 subscriptions;
		u32 ngroups;
		unsigned long *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);
		struct module *module;
		u32 flags;
		};

		#define NETLINK_KERNEL_SOCKET 0x1
		@@ -101,6 +104,7 @@ struct netlink_table {
		struct nl_pid_hash hash;
		struct hlist_head mc_list;
		unsigned int nl_nonroot;
		unsigned int groups;
		struct module *module;
		int registered;
		};
		@@ -138,6 +142,7 @@ static void netlink_sock_destruct(struct sock *sk)
		BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
		BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
		BUG_TRAP(!nlk_sk(sk)->cb);
		BUG_TRAP(!nlk_sk(sk)->groups);
		}

		/* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on SMP.
		@@ -333,7 +338,7 @@ static void netlink_remove(struct sock *sk)
		netlink_table_grab();
		if (sk_del_node_init(sk))
		nl_table[sk->sk_protocol].hash.entries--;
		if (nlk_sk(sk)->groups)
		if (nlk_sk(sk)->subscriptions)
		__sk_del_bind_node(sk);
		netlink_table_ungrab();
		}
		@@ -369,6 +374,8 @@ static int __netlink_create(struct socket *sock, int protocol)
		static int netlink_create(struct socket *sock, int protocol)
		{
		struct module *module = NULL;
		struct netlink_sock *nlk;
		unsigned int groups;
		int err = 0;

		sock->state = SS_UNCONNECTED;
		@@ -392,15 +399,23 @@ static int netlink_create(struct socket *sock, int protocol)
		module = nl_table[protocol].module;
		else
		err = -EPROTONOSUPPORT;
		groups = nl_table[protocol].groups;
		netlink_unlock_table();

		if (err)
		goto out;
		if (err \|\| (err = __netlink_create(sock, protocol) < 0))
		goto out_module;

		if ((err = __netlink_create(sock, protocol) < 0))
		nlk = nlk_sk(sock->sk);

		nlk->groups = kmalloc(NLGRPSZ(groups), GFP_KERNEL);
		if (nlk->groups == NULL) {
		err = -ENOMEM;
		goto out_module;
		}
		memset(nlk->groups, 0, NLGRPSZ(groups));
		nlk->ngroups = groups;

		nlk_sk(sock->sk)->module = module;
		nlk->module = module;
		out:
		return err;

		@@ -437,7 +452,7 @@ static int netlink_release(struct socket *sock)

		skb_queue_purge(&sk->sk_write_queue);

		if (nlk->pid && !nlk->groups) {
		if (nlk->pid && !nlk->subscriptions) {
		struct netlink_notify n = {
		.protocol = sk->sk_protocol,
		.pid = nlk->pid,
		@@ -455,6 +470,9 @@ static int netlink_release(struct socket *sock)
		netlink_table_ungrab();
		}

		kfree(nlk->groups);
		nlk->groups = NULL;

		sock_put(sk);
		return 0;
		}
		@@ -503,6 +521,18 @@ static inline int netlink_capable(struct socket *sock, unsigned int flag)
		capable(CAP_NET_ADMIN);
		}

		static void
		netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
		{
		struct netlink_sock *nlk = nlk_sk(sk);

		if (nlk->subscriptions && !subscriptions)
		__sk_del_bind_node(sk);
		else if (!nlk->subscriptions && subscriptions)
		sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
		nlk->subscriptions = subscriptions;
		}

		static int netlink_bind(struct socket sock, struct sockaddr addr, int addr_len)
		{
		struct sock *sk = sock->sk;
		@@ -528,15 +558,14 @@ static int netlink_bind(struct socket sock, struct sockaddr addr, int addr_len
		return err;
		}

		if (!nladdr->nl_groups && !nlk->groups)
		if (!nladdr->nl_groups && !(u32)nlk->groups[0])
		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_update_subscriptions(sk, nlk->subscriptions +
		hweight32(nladdr->nl_groups) -
		hweight32(nlk->groups[0]));
		nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) \| nladdr->nl_groups;
		netlink_table_ungrab();

		return 0;
		@@ -590,7 +619,7 @@ static int netlink_getname(struct socket sock, struct sockaddr addr, int *addr
		nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
		} else {
		nladdr->nl_pid = nlk->pid;
		nladdr->nl_groups = nlk->groups;
		nladdr->nl_groups = nlk->groups[0];
		}
		return 0;
		}
		@@ -791,7 +820,8 @@ static inline int do_one_broadcast(struct sock *sk,
		if (p->exclude_sk == sk)
		goto out;

		if (nlk->pid == p->pid \|\| !(nlk->groups & netlink_group_mask(p->group)))
		if (nlk->pid == p->pid \|\| p->group - 1 >= nlk->ngroups \|\|
		!test_bit(p->group - 1, nlk->groups))
		goto out;

		if (p->failure) {
		@@ -887,7 +917,8 @@ static inline int do_one_set_err(struct sock *sk,
		if (sk == p->exclude_sk)
		goto out;

		if (nlk->pid == p->pid \|\| !(nlk->groups & netlink_group_mask(p->group)))
		if (nlk->pid == p->pid \|\| p->group - 1 >= nlk->ngroups \|\|
		!test_bit(p->group - 1, nlk->groups))
		goto out;

		sk->sk_err = p->code;
		@@ -1112,6 +1143,7 @@ netlink_kernel_create(int unit, void (input)(struct sock sk, int len), struct
		nlk->flags \|= NETLINK_KERNEL_SOCKET;

		netlink_table_grab();
		nl_table[unit].groups = 32;
		nl_table[unit].module = module;
		nl_table[unit].registered = 1;
		netlink_table_ungrab();
		@@ -1358,7 +1390,8 @@ static int netlink_seq_show(struct seq_file seq, void v)
		s,
		s->sk_protocol,
		nlk->pid,
		nlk->groups,
		nlk->flags & NETLINK_KERNEL_SOCKET ?
		0 : (unsigned int)nlk->groups[0],
		atomic_read(&s->sk_rmem_alloc),
		atomic_read(&s->sk_wmem_alloc),
		nlk->cb,