Fixed MTP to work with TWRP

net/netlink/Kconfig

@@ -0,0 +1,19 @@
+#
+# Netlink Sockets
+#
+
+config NETLINK_MMAP
+	bool "NETLINK: mmaped IO"
+	---help---
+	  This option enables support for memory mapped netlink IO. This
+	  reduces overhead by avoiding copying data between kernel- and
+	  userspace.
+
+	  If unsure, say N.
+
+config NETLINK_DIAG
+	tristate "NETLINK: socket monitoring interface"
+	default n
+	---help---
+	  Support for NETLINK socket monitoring interface used by the ss tool.
+	  If unsure, say Y.

net/netlink/Makefile

@@ -0,0 +1,8 @@
+#
+# Makefile for the netlink driver.
+#
+
+obj-y  				:= af_netlink.o genetlink.o
+
+obj-$(CONFIG_NETLINK_DIAG)	+= netlink_diag.o
+netlink_diag-y			:= diag.o

net/netlink/af_netlink.h

@@ -0,0 +1,78 @@
+#ifndef _AF_NETLINK_H
+#define _AF_NETLINK_H
+
+#include <linux/rhashtable.h>
+#include <net/sock.h>
+
+#define NLGRPSZ(x)	(ALIGN(x, sizeof(unsigned long) * 8) / 8)
+#define NLGRPLONGS(x)	(NLGRPSZ(x)/sizeof(unsigned long))
+
+struct netlink_ring {
+	void			**pg_vec;
+	unsigned int		head;
+	unsigned int		frames_per_block;
+	unsigned int		frame_size;
+	unsigned int		frame_max;
+
+	unsigned int		pg_vec_order;
+	unsigned int		pg_vec_pages;
+	unsigned int		pg_vec_len;
+
+	atomic_t		pending;
+};
+
+struct netlink_sock {
+	/* struct sock has to be the first member of netlink_sock */
+	struct sock		sk;
+	u32			portid;
+	u32			dst_portid;
+	u32			dst_group;
+	u32			flags;
+	u32			subscriptions;
+	u32			ngroups;
+	unsigned long		*groups;
+	unsigned long		state;
+	size_t			max_recvmsg_len;
+	wait_queue_head_t	wait;
+	bool			cb_running;
+	struct netlink_callback	cb;
+	struct mutex		*cb_mutex;
+	struct mutex		cb_def_mutex;
+	void			(*netlink_rcv)(struct sk_buff *skb);
+	int			(*netlink_bind)(int group);
+	void			(*netlink_unbind)(int group);
+	struct module		*module;
+#ifdef CONFIG_NETLINK_MMAP
+	struct mutex		pg_vec_lock;
+	struct netlink_ring	rx_ring;
+	struct netlink_ring	tx_ring;
+	atomic_t		mapped;
+#endif /* CONFIG_NETLINK_MMAP */
+
+	struct rhash_head	node;
+};
+
+static inline struct netlink_sock *nlk_sk(struct sock *sk)
+{
+	return container_of(sk, struct netlink_sock, sk);
+}
+
+struct netlink_table {
+	struct rhashtable	hash;
+	struct hlist_head	mc_list;
+	struct listeners __rcu	*listeners;
+	unsigned int		flags;
+	unsigned int		groups;
+	struct mutex		*cb_mutex;
+	struct module		*module;
+	int			(*bind)(int group);
+	void			(*unbind)(int group);
+	bool			(*compare)(struct net *net, struct sock *sock);
+	int			registered;
+};
+
+extern struct netlink_table *nl_table;
+extern rwlock_t nl_table_lock;
+extern struct mutex nl_sk_hash_lock;
+
+#endif

net/netlink/diag.c

@@ -0,0 +1,235 @@
+#include <linux/module.h>
+
+#include <net/sock.h>
+#include <linux/netlink.h>
+#include <linux/sock_diag.h>
+#include <linux/netlink_diag.h>
+#include <linux/rhashtable.h>
+
+#include "af_netlink.h"
+
+#ifdef CONFIG_NETLINK_MMAP
+static int sk_diag_put_ring(struct netlink_ring *ring, int nl_type,
+			    struct sk_buff *nlskb)
+{
+	struct netlink_diag_ring ndr;
+
+	ndr.ndr_block_size = ring->pg_vec_pages << PAGE_SHIFT;
+	ndr.ndr_block_nr   = ring->pg_vec_len;
+	ndr.ndr_frame_size = ring->frame_size;
+	ndr.ndr_frame_nr   = ring->frame_max + 1;
+
+	return nla_put(nlskb, nl_type, sizeof(ndr), &ndr);
+}
+
+static int sk_diag_put_rings_cfg(struct sock *sk, struct sk_buff *nlskb)
+{
+	struct netlink_sock *nlk = nlk_sk(sk);
+	int ret;
+
+	mutex_lock(&nlk->pg_vec_lock);
+	ret = sk_diag_put_ring(&nlk->rx_ring, NETLINK_DIAG_RX_RING, nlskb);
+	if (!ret)
+		ret = sk_diag_put_ring(&nlk->tx_ring, NETLINK_DIAG_TX_RING,
+				       nlskb);
+	mutex_unlock(&nlk->pg_vec_lock);
+
+	return ret;
+}
+#else
+static int sk_diag_put_rings_cfg(struct sock *sk, struct sk_buff *nlskb)
+{
+	return 0;
+}
+#endif
+
+static int sk_diag_dump_groups(struct sock *sk, struct sk_buff *nlskb)
+{
+	struct netlink_sock *nlk = nlk_sk(sk);
+
+	if (nlk->groups == NULL)
+		return 0;
+
+	return nla_put(nlskb, NETLINK_DIAG_GROUPS, NLGRPSZ(nlk->ngroups),
+		       nlk->groups);
+}
+
+static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
+			struct netlink_diag_req *req,
+			u32 portid, u32 seq, u32 flags, int sk_ino)
+{
+	struct nlmsghdr *nlh;
+	struct netlink_diag_msg *rep;
+	struct netlink_sock *nlk = nlk_sk(sk);
+
+	nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rep),
+			flags);
+	if (!nlh)
+		return -EMSGSIZE;
+
+	rep = nlmsg_data(nlh);
+	rep->ndiag_family	= AF_NETLINK;
+	rep->ndiag_type		= sk->sk_type;
+	rep->ndiag_protocol	= sk->sk_protocol;
+	rep->ndiag_state	= sk->sk_state;
+
+	rep->ndiag_ino		= sk_ino;
+	rep->ndiag_portid	= nlk->portid;
+	rep->ndiag_dst_portid	= nlk->dst_portid;
+	rep->ndiag_dst_group	= nlk->dst_group;
+	sock_diag_save_cookie(sk, rep->ndiag_cookie);
+
+	if ((req->ndiag_show & NDIAG_SHOW_GROUPS) &&
+	    sk_diag_dump_groups(sk, skb))
+		goto out_nlmsg_trim;
+
+	if ((req->ndiag_show & NDIAG_SHOW_MEMINFO) &&
+	    sock_diag_put_meminfo(sk, skb, NETLINK_DIAG_MEMINFO))
+		goto out_nlmsg_trim;
+
+	if ((req->ndiag_show & NDIAG_SHOW_RING_CFG) &&
+	    sk_diag_put_rings_cfg(sk, skb))
+		goto out_nlmsg_trim;
+
+	return nlmsg_end(skb, nlh);
+
+out_nlmsg_trim:
+	nlmsg_cancel(skb, nlh);
+	return -EMSGSIZE;
+}
+
+static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
+				int protocol, int s_num)
+{
+	struct netlink_table *tbl = &nl_table[protocol];
+	struct rhashtable *ht = &tbl->hash;
+	const struct bucket_table *htbl = rht_dereference(ht->tbl, ht);
+	struct net *net = sock_net(skb->sk);
+	struct netlink_diag_req *req;
+	struct netlink_sock *nlsk;
+	struct sock *sk;
+	int ret = 0, num = 0, i;
+
+	req = nlmsg_data(cb->nlh);
+
+	for (i = 0; i < htbl->size; i++) {
+		rht_for_each_entry(nlsk, htbl->buckets[i], ht, node) {
+			sk = (struct sock *)nlsk;
+
+			if (!net_eq(sock_net(sk), net))
+				continue;
+			if (num < s_num) {
+				num++;
+				continue;
+			}
+
+			if (sk_diag_fill(sk, skb, req,
+					 NETLINK_CB(cb->skb).portid,
+					 cb->nlh->nlmsg_seq,
+					 NLM_F_MULTI,
+					 sock_i_ino(sk)) < 0) {
+				ret = 1;
+				goto done;
+			}
+
+			num++;
+		}
+	}
+
+	sk_for_each_bound(sk, &tbl->mc_list) {
+		if (sk_hashed(sk))
+			continue;
+		if (!net_eq(sock_net(sk), net))
+			continue;
+		if (num < s_num) {
+			num++;
+			continue;
+		}
+
+		if (sk_diag_fill(sk, skb, req,
+				 NETLINK_CB(cb->skb).portid,
+				 cb->nlh->nlmsg_seq,
+				 NLM_F_MULTI,
+				 sock_i_ino(sk)) < 0) {
+			ret = 1;
+			goto done;
+		}
+		num++;
+	}
+done:
+	cb->args[0] = num;
+	cb->args[1] = protocol;
+
+	return ret;
+}
+
+static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct netlink_diag_req *req;
+	int s_num = cb->args[0];
+
+	req = nlmsg_data(cb->nlh);
+
+	mutex_lock(&nl_sk_hash_lock);
+	read_lock(&nl_table_lock);
+
+	if (req->sdiag_protocol == NDIAG_PROTO_ALL) {
+		int i;
+
+		for (i = cb->args[1]; i < MAX_LINKS; i++) {
+			if (__netlink_diag_dump(skb, cb, i, s_num))
+				break;
+			s_num = 0;
+		}
+	} else {
+		if (req->sdiag_protocol >= MAX_LINKS) {
+			read_unlock(&nl_table_lock);
+			mutex_unlock(&nl_sk_hash_lock);
+			return -ENOENT;
+		}
+
+		__netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);
+	}
+
+	read_unlock(&nl_table_lock);
+	mutex_unlock(&nl_sk_hash_lock);
+
+	return skb->len;
+}
+
+static int netlink_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
+{
+	int hdrlen = sizeof(struct netlink_diag_req);
+	struct net *net = sock_net(skb->sk);
+
+	if (nlmsg_len(h) < hdrlen)
+		return -EINVAL;
+
+	if (h->nlmsg_flags & NLM_F_DUMP) {
+		struct netlink_dump_control c = {
+			.dump = netlink_diag_dump,
+		};
+		return netlink_dump_start(net->diag_nlsk, skb, h, &c);
+	} else
+		return -EOPNOTSUPP;
+}
+
+static const struct sock_diag_handler netlink_diag_handler = {
+	.family = AF_NETLINK,
+	.dump = netlink_diag_handler_dump,
+};
+
+static int __init netlink_diag_init(void)
+{
+	return sock_diag_register(&netlink_diag_handler);
+}
+
+static void __exit netlink_diag_exit(void)
+{
+	sock_diag_unregister(&netlink_diag_handler);
+}
+
+module_init(netlink_diag_init);
+module_exit(netlink_diag_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 16 /* AF_NETLINK */);