1 files changed, 300 insertions, 0 deletions
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
new file mode 100644
index 000000000..78ebcf782
--- /dev/null
+++ b/include/net/9p/client.h
@@ -0,0 +1,300 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * 9P Client Definitions
+ *
+ *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
+ */
+
+#ifndef NET_9P_CLIENT_H
+#define NET_9P_CLIENT_H
+
+#include <linux/utsname.h>
+#include <linux/idr.h>
+#include <linux/tracepoint-defs.h>
+
+/* Number of requests per row */
+#define P9_ROW_MAXTAG 255
+
+/** enum p9_proto_versions - 9P protocol versions
+ * @p9_proto_legacy: 9P Legacy mode, pre-9P2000.u
+ * @p9_proto_2000u: 9P2000.u extension
+ * @p9_proto_2000L: 9P2000.L extension
+ */
+
+enum p9_proto_versions {
+	p9_proto_legacy,
+	p9_proto_2000u,
+	p9_proto_2000L,
+};
+
+
+/**
+ * enum p9_trans_status - different states of underlying transports
+ * @Connected: transport is connected and healthy
+ * @Disconnected: transport has been disconnected
+ * @Hung: transport is connected by wedged
+ *
+ * This enumeration details the various states a transport
+ * instatiation can be in.
+ */
+
+enum p9_trans_status {
+	Connected,
+	BeginDisconnect,
+	Disconnected,
+	Hung,
+};
+
+/**
+ * enum p9_req_status_t - status of a request
+ * @REQ_STATUS_ALLOC: request has been allocated but not sent
+ * @REQ_STATUS_UNSENT: request waiting to be sent
+ * @REQ_STATUS_SENT: request sent to server
+ * @REQ_STATUS_RCVD: response received from server
+ * @REQ_STATUS_FLSHD: request has been flushed
+ * @REQ_STATUS_ERROR: request encountered an error on the client side
+ */
+
+enum p9_req_status_t {
+	REQ_STATUS_ALLOC,
+	REQ_STATUS_UNSENT,
+	REQ_STATUS_SENT,
+	REQ_STATUS_RCVD,
+	REQ_STATUS_FLSHD,
+	REQ_STATUS_ERROR,
+};
+
+/**
+ * struct p9_req_t - request slots
+ * @status: status of this request slot
+ * @t_err: transport error
+ * @wq: wait_queue for the client to block on for this request
+ * @tc: the request fcall structure
+ * @rc: the response fcall structure
+ * @req_list: link for higher level objects to chain requests
+ */
+struct p9_req_t {
+	int status;
+	int t_err;
+	refcount_t refcount;
+	wait_queue_head_t wq;
+	struct p9_fcall tc;
+	struct p9_fcall rc;
+	struct list_head req_list;
+};
+
+/**
+ * struct p9_client - per client instance state
+ * @lock: protect @fids and @reqs
+ * @msize: maximum data size negotiated by protocol
+ * @proto_version: 9P protocol version to use
+ * @trans_mod: module API instantiated with this client
+ * @status: connection state
+ * @trans: tranport instance state and API
+ * @fids: All active FID handles
+ * @reqs: All active requests.
+ * @name: node name used as client id
+ *
+ * The client structure is used to keep track of various per-client
+ * state that has been instantiated.
+ */
+struct p9_client {
+	spinlock_t lock;
+	unsigned int msize;
+	unsigned char proto_version;
+	struct p9_trans_module *trans_mod;
+	enum p9_trans_status status;
+	void *trans;
+	struct kmem_cache *fcall_cache;
+
+	union {
+		struct {
+			int rfd;
+			int wfd;
+		} fd;
+		struct {
+			u16 port;
+			bool privport;
+
+		} tcp;
+	} trans_opts;
+
+	struct idr fids;
+	struct idr reqs;
+
+	char name[__NEW_UTS_LEN + 1];
+};
+
+/**
+ * struct p9_fid - file system entity handle
+ * @clnt: back pointer to instantiating &p9_client
+ * @fid: numeric identifier for this handle
+ * @mode: current mode of this fid (enum?)
+ * @qid: the &p9_qid server identifier this handle points to
+ * @iounit: the server reported maximum transaction size for this file
+ * @uid: the numeric uid of the local user who owns this handle
+ * @rdir: readdir accounting structure (allocated on demand)
+ * @dlist: per-dentry fid tracking
+ *
+ * TODO: This needs lots of explanation.
+ */
+enum fid_source {
+	FID_FROM_OTHER,
+	FID_FROM_INODE,
+	FID_FROM_DENTRY,
+};
+
+struct p9_fid {
+	struct p9_client *clnt;
+	u32 fid;
+	refcount_t count;
+	int mode;
+	struct p9_qid qid;
+	u32 iounit;
+	kuid_t uid;
+
+	void *rdir;
+
+	struct hlist_node dlist;	/* list of all fids attached to a dentry */
+	struct hlist_node ilist;
+};
+
+/**
+ * struct p9_dirent - directory entry structure
+ * @qid: The p9 server qid for this dirent
+ * @d_off: offset to the next dirent
+ * @d_type: type of file
+ * @d_name: file name
+ */
+
+struct p9_dirent {
+	struct p9_qid qid;
+	u64 d_off;
+	unsigned char d_type;
+	char d_name[256];
+};
+
+struct iov_iter;
+
+int p9_show_client_options(struct seq_file *m, struct p9_client *clnt);
+int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb);
+int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid,
+		     const char *name);
+int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
+		       struct p9_fid *newdirfid, const char *new_name);
+struct p9_client *p9_client_create(const char *dev_name, char *options);
+void p9_client_destroy(struct p9_client *clnt);
+void p9_client_disconnect(struct p9_client *clnt);
+void p9_client_begin_disconnect(struct p9_client *clnt);
+struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
+				const char *uname, kuid_t n_uname, const char *aname);
+struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
+		const unsigned char * const *wnames, int clone);
+int p9_client_open(struct p9_fid *fid, int mode);
+int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
+							char *extension);
+int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, const char *newname);
+int p9_client_symlink(struct p9_fid *fid, const char *name, const char *symname,
+		kgid_t gid, struct p9_qid *qid);
+int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
+		kgid_t gid, struct p9_qid *qid);
+int p9_client_clunk(struct p9_fid *fid);
+int p9_client_fsync(struct p9_fid *fid, int datasync);
+int p9_client_remove(struct p9_fid *fid);
+int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags);
+int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err);
+int p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to,
+		int *err);
+int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err);
+int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
+int p9dirent_read(struct p9_client *clnt, char *buf, int len,
+		  struct p9_dirent *dirent);
+struct p9_wstat *p9_client_stat(struct p9_fid *fid);
+int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
+int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr);
+
+struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
+							u64 request_mask);
+
+int p9_client_mknod_dotl(struct p9_fid *oldfid, const char *name, int mode,
+			dev_t rdev, kgid_t gid, struct p9_qid *qid);
+int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
+				kgid_t gid, struct p9_qid *qid);
+int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
+int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
+void p9_fcall_fini(struct p9_fcall *fc);
+struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag);
+
+static inline void p9_req_get(struct p9_req_t *r)
+{
+	refcount_inc(&r->refcount);
+}
+
+static inline int p9_req_try_get(struct p9_req_t *r)
+{
+	return refcount_inc_not_zero(&r->refcount);
+}
+
+int p9_req_put(struct p9_client *c, struct p9_req_t *r);
+
+/* We cannot have the real tracepoints in header files,
+ * use a wrapper function */
+DECLARE_TRACEPOINT(9p_fid_ref);
+void do_trace_9p_fid_get(struct p9_fid *fid);
+void do_trace_9p_fid_put(struct p9_fid *fid);
+
+/* fid reference counting helpers:
+ *  - fids used for any length of time should always be referenced through
+ *    p9_fid_get(), and released with p9_fid_put()
+ *  - v9fs_fid_lookup() or similar will automatically call get for you
+ *    and also require a put
+ *  - the *_fid_add() helpers will stash the fid in the inode,
+ *    at which point it is the responsibility of evict_inode()
+ *    to call the put
+ *  - the last put will automatically send a clunk to the server
+ */
+static inline struct p9_fid *p9_fid_get(struct p9_fid *fid)
+{
+	if (tracepoint_enabled(9p_fid_ref))
+		do_trace_9p_fid_get(fid);
+
+	refcount_inc(&fid->count);
+
+	return fid;
+}
+
+static inline int p9_fid_put(struct p9_fid *fid)
+{
+	if (!fid || IS_ERR(fid))
+		return 0;
+
+	if (tracepoint_enabled(9p_fid_ref))
+		do_trace_9p_fid_put(fid);
+
+	if (!refcount_dec_and_test(&fid->count))
+		return 0;
+
+	return p9_client_clunk(fid);
+}
+
+void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status);
+
+int p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type,
+		    int16_t *tag, int rewind);
+int p9stat_read(struct p9_client *clnt, char *buf, int len,
+		struct p9_wstat *st);
+void p9stat_free(struct p9_wstat *stbuf);
+
+int p9_is_proto_dotu(struct p9_client *clnt);
+int p9_is_proto_dotl(struct p9_client *clnt);
+struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
+				   const char *attr_name, u64 *attr_size);
+int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
+			  u64 attr_size, int flags);
+int p9_client_readlink(struct p9_fid *fid, char **target);
+
+int p9_client_init(void);
+void p9_client_exit(void);
+
+#endif /* NET_9P_CLIENT_H */