1 files changed, 168 insertions, 36 deletions

diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index f624dff76852..4507f744f44e 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -47,12 +47,29 @@
 #define SCHED_TIMEOUT   10
 #define MAXPOLLWADDR    2
 
+/**
+ * struct p9_fd_opts - per-transport options
+ * @rfd: file descriptor for reading (trans=fd)
+ * @wfd: file descriptor for writing (trans=fd)
+ * @port: port to connect to (trans=tcp)
+ *
+ */
+
 struct p9_fd_opts {
         int rfd;
         int wfd;
         u16 port;
 };
 
+
+/**
+ * struct p9_trans_fd - transport state
+ * @rd: reference to file to read from
+ * @wr: reference of file to write to
+ * @conn: connection state reference
+ *
+ */
+
 struct p9_trans_fd {
         struct file *rd;
         struct file *wr;
@@ -90,10 +107,24 @@ enum {
 };
 
 struct p9_req;
-
 typedef void (*p9_conn_req_callback)(struct p9_req *req, void *a);
+
+/**
+ * struct p9_req - fd mux encoding of an rpc transaction
+ * @lock: protects req_list
+ * @tag: numeric tag for rpc transaction
+ * @tcall: request &p9_fcall structure
+ * @rcall: response &p9_fcall structure
+ * @err: error state
+ * @cb: callback for when response is received
+ * @cba: argument to pass to callback
+ * @flush: flag to indicate RPC has been flushed
+ * @req_list: list link for higher level objects to chain requests
+ *
+ */
+
 struct p9_req {
-        spinlock_t lock; /* protect request structure */
+        spinlock_t lock;
         int tag;
         struct p9_fcall *tcall;
         struct p9_fcall *rcall;
@@ -104,7 +135,39 @@ struct p9_req {
         struct list_head req_list;
 };
 
-struct p9_mux_poll_task;
+struct p9_mux_poll_task {
+        struct task_struct *task;
+        struct list_head mux_list;
+        int muxnum;
+};
+
+/**
+ * struct p9_conn - fd mux connection state information
+ * @lock: protects mux_list (?)
+ * @mux_list: list link for mux to manage multiple connections (?)
+ * @poll_task: task polling on this connection
+ * @msize: maximum size for connection (dup)
+ * @extended: 9p2000.u flag (dup)
+ * @trans: reference to transport instance for this connection
+ * @tagpool: id accounting for transactions
+ * @err: error state
+ * @equeue: event wait_q (?)
+ * @req_list: accounting for requests which have been sent
+ * @unsent_req_list: accounting for requests that haven't been sent
+ * @rcall: current response &p9_fcall structure
+ * @rpos: read position in current frame
+ * @rbuf: current read buffer
+ * @wpos: write position for current frame
+ * @wsize: amount of data to write for current frame
+ * @wbuf: current write buffer
+ * @poll_wait: array of wait_q's for various worker threads
+ * @poll_waddr: ????
+ * @pt: poll state
+ * @rq: current read work
+ * @wq: current write work
+ * @wsched: ????
+ *
+ */
 
 struct p9_conn {
         spinlock_t lock; /* protect lock structure */
@@ -132,11 +195,16 @@ struct p9_conn {
         unsigned long wsched;
 };
 
-struct p9_mux_poll_task {
-        struct task_struct *task;
-        struct list_head mux_list;
-        int muxnum;
-};
+/**
+ * struct p9_mux_rpc - fd mux rpc accounting structure
+ * @m: connection this request was issued on
+ * @err: error state
+ * @tcall: request &p9_fcall
+ * @rcall: response &p9_fcall
+ * @wqueue: wait queue that client is blocked on for this rpc
+ *
+ * Bug: isn't this information duplicated elsewhere like &p9_req
+ */
 
 struct p9_mux_rpc {
         struct p9_conn *m;
@@ -207,10 +275,12 @@ static void p9_mux_put_tag(struct p9_conn *m, u16 tag)
 
 /**
  * p9_mux_calc_poll_procs - calculates the number of polling procs
- * based on the number of mounted v9fs filesystems.
+ * @muxnum: number of mounts
  *
+ * Calculation is based on the number of mounted v9fs filesystems.
  * The current implementation returns sqrt of the number of mounts.
  */
+
 static int p9_mux_calc_poll_procs(int muxnum)
 {
         int n;
@@ -331,12 +401,11 @@ static void p9_mux_poll_stop(struct p9_conn *m)
 
 /**
  * p9_conn_create - allocate and initialize the per-session mux data
- * Creates the polling task if this is the first session.
+ * @trans: transport structure
  *
- * @trans - transport structure
- * @msize - maximum message size
- * @extended - extended flag
+ * Note: Creates the polling task if this is the first session.
  */
+
 static struct p9_conn *p9_conn_create(struct p9_trans *trans)
 {
         int i, n;
@@ -406,7 +475,10 @@ static struct p9_conn *p9_conn_create(struct p9_trans *trans)
 
 /**
  * p9_mux_destroy - cancels all pending requests and frees mux resources
+ * @m: mux to destroy
+ *
  */
+
 static void p9_conn_destroy(struct p9_conn *m)
 {
         P9_DPRINTK(P9_DEBUG_MUX, "mux %p prev %p next %p\n", m,
@@ -429,9 +501,14 @@ static void p9_conn_destroy(struct p9_conn *m)
 }
 
 /**
- * p9_pollwait - called by files poll operation to add v9fs-poll task
- *      to files wait queue
+ * p9_pollwait - add poll task to the wait queue
+ * @filp: file pointer being polled
+ * @wait_address: wait_q to block on
+ * @p: poll state
+ *
+ * called by files poll operation to add v9fs-poll task to files wait queue
  */
+
 static void
 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
 {
@@ -462,7 +539,10 @@ p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
 
 /**
  * p9_poll_mux - polls a mux and schedules read or write works if necessary
+ * @m: connection to poll
+ *
  */
+
 static void p9_poll_mux(struct p9_conn *m)
 {
         int n;
@@ -499,9 +579,14 @@ static void p9_poll_mux(struct p9_conn *m)
 }
 
 /**
- * p9_poll_proc - polls all v9fs transports for new events and queues
- *      the appropriate work to the work queue
+ * p9_poll_proc - poll worker thread
+ * @a: thread state and arguments
+ *
+ * polls all v9fs transports for new events and queues the appropriate
+ * work to the work queue
+ *
  */
+
 static int p9_poll_proc(void *a)
 {
         struct p9_conn *m, *mtmp;
@@ -527,7 +612,10 @@ static int p9_poll_proc(void *a)
 
 /**
  * p9_write_work - called when a transport can send some data
+ * @work: container for work to be done
+ *
  */
+
 static void p9_write_work(struct work_struct *work)
 {
         int n, err;
@@ -638,7 +726,10 @@ static void process_request(struct p9_conn *m, struct p9_req *req)
 
 /**
  * p9_read_work - called when there is some data to be read from a transport
+ * @work: container of work to be done
+ *
  */
+
 static void p9_read_work(struct work_struct *work)
 {
         int n, err;
@@ -793,7 +884,9 @@ error:
  * @tc: request to be sent
  * @cb: callback function to call when response is received
  * @cba: parameter to pass to the callback function
+ *
  */
+
 static struct p9_req *p9_send_request(struct p9_conn *m,
                                           struct p9_fcall *tc,
                                           p9_conn_req_callback cb, void *cba)
@@ -961,10 +1054,12 @@ p9_conn_rpc_cb(struct p9_req *req, void *a)
 /**
  * p9_fd_rpc- sends 9P request and waits until a response is available.
  *      The function can be interrupted.
- * @m: mux data
+ * @t: transport data
  * @tc: request to be sent
  * @rc: pointer where a pointer to the response is stored
+ *
  */
+
 int
 p9_fd_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
 {
@@ -1041,8 +1136,10 @@ p9_fd_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
  * @m: mux data
  * @tc: request to be sent
  * @cb: callback function to be called when response arrives
- * @cba: value to pass to the callback function
+ * @a: value to pass to the callback function
+ *
  */
+
 int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
                    p9_conn_req_callback cb, void *a)
 {
@@ -1065,7 +1162,9 @@ int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
  * p9_conn_cancel - cancel all pending requests with error
  * @m: mux data
  * @err: error code
+ *
  */
+
 void p9_conn_cancel(struct p9_conn *m, int err)
 {
         struct p9_req *req, *rtmp;
@@ -1097,35 +1196,46 @@ void p9_conn_cancel(struct p9_conn *m, int err)
 }
 
 /**
- * v9fs_parse_options - parse mount options into session structure
+ * parse_options - parse mount options into session structure
  * @options: options string passed from mount
- * @v9ses: existing v9fs session information
+ * @opts: transport-specific structure to parse options into
  *
+ * Returns 0 upon success, -ERRNO upon failure
  */
 
-static void parse_opts(char *options, struct p9_fd_opts *opts)
+static int parse_opts(char *params, struct p9_fd_opts *opts)
 {
         char *p;
         substring_t args[MAX_OPT_ARGS];
         int option;
+        char *options;
         int ret;
 
         opts->port = P9_PORT;
         opts->rfd = ~0;
         opts->wfd = ~0;
 
-        if (!options)
-                return;
+        if (!params)
+                return 0;
+
+        options = kstrdup(params, GFP_KERNEL);
+        if (!options) {
+                P9_DPRINTK(P9_DEBUG_ERROR,
+                                "failed to allocate copy of option string\n");
+                return -ENOMEM;
+        }
 
         while ((p = strsep(&options, ",")) != NULL) {
                 int token;
+                int r;
                 if (!*p)
                         continue;
                 token = match_token(p, tokens, args);
-                ret = match_int(&args[0], &option);
-                if (ret < 0) {
+                r = match_int(&args[0], &option);
+                if (r < 0) {
                         P9_DPRINTK(P9_DEBUG_ERROR,
                          "integer field, but no integer?\n");
+                        ret = r;
                         continue;
                 }
                 switch (token) {
@@ -1142,6 +1252,8 @@ static void parse_opts(char *options, struct p9_fd_opts *opts)
                         continue;
                 }
         }
+        kfree(options);
+        return 0;
 }
 
 static int p9_fd_open(struct p9_trans *trans, int rfd, int wfd)
@@ -1193,11 +1305,12 @@ static int p9_socket_open(struct p9_trans *trans, struct socket *csocket)
 
 /**
  * p9_fd_read- read from a fd
- * @v9ses: session information
+ * @trans: transport instance state
  * @v: buffer to receive data into
  * @len: size of receive buffer
  *
  */
+
 static int p9_fd_read(struct p9_trans *trans, void *v, int len)
 {
         int ret;
@@ -1220,11 +1333,12 @@ static int p9_fd_read(struct p9_trans *trans, void *v, int len)
 
 /**
  * p9_fd_write - write to a socket
- * @v9ses: session information
+ * @trans: transport instance state
  * @v: buffer to send data from
  * @len: size of send buffer
  *
  */
+
 static int p9_fd_write(struct p9_trans *trans, void *v, int len)
 {
         int ret;
@@ -1296,6 +1410,7 @@ end:
  * @trans: private socket structure
  *
  */
+
 static void p9_fd_close(struct p9_trans *trans)
 {
         struct p9_trans_fd *ts;
@@ -1318,6 +1433,23 @@ static void p9_fd_close(struct p9_trans *trans)
         kfree(ts);
 }
 
+/*
+ * stolen from NFS - maybe should be made a generic function?
+ */
+static inline int valid_ipaddr4(const char *buf)
+{
+        int rc, count, in[4];
+
+        rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
+        if (rc != 4)
+                return -EINVAL;
+        for (count = 0; count < 4; count++) {
+                if (in[count] > 255)
+                        return -EINVAL;
+        }
+        return 0;
+}
+
 static struct p9_trans *
 p9_trans_create_tcp(const char *addr, char *args, int msize, unsigned char dotu)
 {
@@ -1328,7 +1460,12 @@ p9_trans_create_tcp(const char *addr, char *args, int msize, unsigned char dotu)
         struct p9_fd_opts opts;
         struct p9_trans_fd *p;
 
-        parse_opts(args, &opts);
+        err = parse_opts(args, &opts);
+        if (err < 0)
+                return ERR_PTR(err);
+
+        if (valid_ipaddr4(addr) < 0)
+                return ERR_PTR(-EINVAL);
 
         csocket = NULL;
         trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
@@ -1508,7 +1645,7 @@ static struct p9_trans_module p9_fd_trans = {
         .create = p9_trans_create_fd,
 };
 
-static int __init p9_trans_fd_init(void)
+int p9_trans_fd_init(void)
 {
         int ret = p9_mux_global_init();
         if (ret) {
@@ -1522,9 +1659,4 @@ static int __init p9_trans_fd_init(void)
 
         return 0;
 }
-
-module_init(p9_trans_fd_init);
-
-MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
-MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
-MODULE_LICENSE("GPL");
+EXPORT_SYMBOL(p9_trans_fd_init);