usbmon: Extended text API

This patch adds a new text API, codenamed '1u', which captures more URB
fields than old '1t' interface did. Also the '1u' text API is compatible
with the future "bus zero" extension.

Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 257 insertions, 40 deletions

diff --git a/drivers/usb/mon/mon_text.c b/drivers/usb/mon/mon_text.c
index 494ee3b9a226..bbf54396e5f2 100644
--- a/drivers/usb/mon/mon_text.c
+++ b/drivers/usb/mon/mon_text.c
@@ -31,9 +31,21 @@
  * to a local DoS. But we have to keep to root in order to prevent
  * password sniffing from HID devices.
  */
-#define EVENT_MAX  (2*PAGE_SIZE / sizeof(struct mon_event_text))
+#define EVENT_MAX  (4*PAGE_SIZE / sizeof(struct mon_event_text))
 
-#define PRINTF_DFL  160
+/*
+ * Potentially unlimited number; we limit it for similar allocations.
+ * The usbfs limits this to 128, but we're not quite as generous.
+ */
+#define ISODESC_MAX   5
+
+#define PRINTF_DFL  250   /* with 5 ISOs segs */
+
+struct mon_iso_desc {
+        int status;
+        unsigned int offset;
+        unsigned int length;    /* Unsigned here, signed in URB. Historic. */
+};
 
 struct mon_event_text {
         struct list_head e_link;
@@ -41,10 +53,16 @@ struct mon_event_text {
         unsigned int pipe;      /* Pipe */
         unsigned long id;       /* From pointer, most of the time */
         unsigned int tstamp;
+        int busnum;
         int length;             /* Depends on type: xfer length or act length */
         int status;
+        int interval;
+        int start_frame;
+        int error_count;
         char setup_flag;
         char data_flag;
+        int numdesc;            /* Full number */
+        struct mon_iso_desc isodesc[ISODESC_MAX];
         unsigned char setup[SETUP_MAX];
         unsigned char data[DATA_MAX];
 };
@@ -68,6 +86,28 @@ static struct dentry *mon_dir;		/* Usually /sys/kernel/debug/usbmon */
 
 static void mon_text_ctor(void *, struct kmem_cache *, unsigned long);
 
+struct mon_text_ptr {
+        int cnt, limit;
+        char *pbuf;
+};
+
+static struct mon_event_text *
+    mon_text_read_wait(struct mon_reader_text *rp, struct file *file);
+static void mon_text_read_head_t(struct mon_reader_text *rp,
+        struct mon_text_ptr *p, const struct mon_event_text *ep);
+static void mon_text_read_head_u(struct mon_reader_text *rp,
+        struct mon_text_ptr *p, const struct mon_event_text *ep);
+static void mon_text_read_statset(struct mon_reader_text *rp,
+        struct mon_text_ptr *p, const struct mon_event_text *ep);
+static void mon_text_read_intstat(struct mon_reader_text *rp,
+        struct mon_text_ptr *p, const struct mon_event_text *ep);
+static void mon_text_read_isostat(struct mon_reader_text *rp,
+        struct mon_text_ptr *p, const struct mon_event_text *ep);
+static void mon_text_read_isodesc(struct mon_reader_text *rp,
+        struct mon_text_ptr *p, const struct mon_event_text *ep);
+static void mon_text_read_data(struct mon_reader_text *rp,
+    struct mon_text_ptr *p, const struct mon_event_text *ep);
+
 /*
  * mon_text_submit
  * mon_text_complete
@@ -104,10 +144,10 @@ static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb,
                 len = DATA_MAX;
 
         if (usb_pipein(pipe)) {
-                if (ev_type == 'S')
+                if (ev_type != 'C')
                         return '<';
         } else {
-                if (ev_type == 'C')
+                if (ev_type != 'S')
                         return '>';
         }
 
@@ -146,6 +186,9 @@ static void mon_text_event(struct mon_reader_text *rp, struct urb *urb,
 {
         struct mon_event_text *ep;
         unsigned int stamp;
+        struct usb_iso_packet_descriptor *fp;
+        struct mon_iso_desc *dp;
+        int i, ndesc;
 
         stamp = mon_get_timestamp();
 
@@ -158,12 +201,36 @@ static void mon_text_event(struct mon_reader_text *rp, struct urb *urb,
         ep->type = ev_type;
         ep->pipe = urb->pipe;
         ep->id = (unsigned long) urb;
+        ep->busnum = rp->r.m_bus->u_bus->busnum;
         ep->tstamp = stamp;
         ep->length = (ev_type == 'S') ?
             urb->transfer_buffer_length : urb->actual_length;
         /* Collecting status makes debugging sense for submits, too */
         ep->status = urb->status;
 
+        if (usb_pipeint(urb->pipe)) {
+                ep->interval = urb->interval;
+        } else if (usb_pipeisoc(urb->pipe)) {
+                ep->interval = urb->interval;
+                ep->start_frame = urb->start_frame;
+                ep->error_count = urb->error_count;
+        }
+        ep->numdesc = urb->number_of_packets;
+        if (usb_pipeisoc(urb->pipe) && urb->number_of_packets > 0) {
+                if ((ndesc = urb->number_of_packets) > ISODESC_MAX)
+                        ndesc = ISODESC_MAX;
+                fp = urb->iso_frame_desc;
+                dp = ep->isodesc;
+                for (i = 0; i < ndesc; i++) {
+                        dp->status = fp->status;
+                        dp->offset = fp->offset;
+                        dp->length = (ev_type == 'S') ?
+                            fp->length : fp->actual_length;
+                        fp++;
+                        dp++;
+                }
+        }
+
         ep->setup_flag = mon_text_get_setup(ep, urb, ev_type, rp->r.m_bus);
         ep->data_flag = mon_text_get_data(ep, urb, ep->length, ev_type,
                         rp->r.m_bus);
@@ -199,6 +266,7 @@ static void mon_text_error(void *data, struct urb *urb, int error)
         ep->type = 'E';
         ep->pipe = urb->pipe;
         ep->id = (unsigned long) urb;
+        ep->busnum = 0;
         ep->tstamp = 0;
         ep->length = 0;
         ep->status = error;
@@ -300,17 +368,75 @@ err_alloc:
  *   dd if=/dbg/usbmon/0t bs=10
  * Also, we do not allow seeks and do not bother advancing the offset.
  */
-static ssize_t mon_text_read(struct file *file, char __user *buf,
+static ssize_t mon_text_read_t(struct file *file, char __user *buf,
+                                size_t nbytes, loff_t *ppos)
+{
+        struct mon_reader_text *rp = file->private_data;
+        struct mon_event_text *ep;
+        struct mon_text_ptr ptr;
+
+        if (IS_ERR(ep = mon_text_read_wait(rp, file)))
+                return PTR_ERR(ep);
+        mutex_lock(&rp->printf_lock);
+        ptr.cnt = 0;
+        ptr.pbuf = rp->printf_buf;
+        ptr.limit = rp->printf_size;
+
+        mon_text_read_head_t(rp, &ptr, ep);
+        mon_text_read_statset(rp, &ptr, ep);
+        ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt,
+            " %d", ep->length);
+        mon_text_read_data(rp, &ptr, ep);
+
+        if (copy_to_user(buf, rp->printf_buf, ptr.cnt))
+                ptr.cnt = -EFAULT;
+        mutex_unlock(&rp->printf_lock);
+        kmem_cache_free(rp->e_slab, ep);
+        return ptr.cnt;
+}
+
+static ssize_t mon_text_read_u(struct file *file, char __user *buf,
                                 size_t nbytes, loff_t *ppos)
 {
         struct mon_reader_text *rp = file->private_data;
+        struct mon_event_text *ep;
+        struct mon_text_ptr ptr;
+
+        if (IS_ERR(ep = mon_text_read_wait(rp, file)))
+                return PTR_ERR(ep);
+        mutex_lock(&rp->printf_lock);
+        ptr.cnt = 0;
+        ptr.pbuf = rp->printf_buf;
+        ptr.limit = rp->printf_size;
+
+        mon_text_read_head_u(rp, &ptr, ep);
+        if (ep->type == 'E') {
+                mon_text_read_statset(rp, &ptr, ep);
+        } else if (usb_pipeisoc(ep->pipe)) {
+                mon_text_read_isostat(rp, &ptr, ep);
+                mon_text_read_isodesc(rp, &ptr, ep);
+        } else if (usb_pipeint(ep->pipe)) {
+                mon_text_read_intstat(rp, &ptr, ep);
+        } else {
+                mon_text_read_statset(rp, &ptr, ep);
+        }
+        ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt,
+            " %d", ep->length);
+        mon_text_read_data(rp, &ptr, ep);
+
+        if (copy_to_user(buf, rp->printf_buf, ptr.cnt))
+                ptr.cnt = -EFAULT;
+        mutex_unlock(&rp->printf_lock);
+        kmem_cache_free(rp->e_slab, ep);
+        return ptr.cnt;
+}
+
+static struct mon_event_text *mon_text_read_wait(struct mon_reader_text *rp,
+    struct file *file)
+{
         struct mon_bus *mbus = rp->r.m_bus;
         DECLARE_WAITQUEUE(waita, current);
         struct mon_event_text *ep;
-        int cnt, limit;
-        char *pbuf;
-        char udir, utype;
-        int data_len, i;
 
         add_wait_queue(&rp->wait, &waita);
         set_current_state(TASK_INTERRUPTIBLE);
@@ -318,7 +444,7 @@ static ssize_t mon_text_read(struct file *file, char __user *buf,
                 if (file->f_flags & O_NONBLOCK) {
                         set_current_state(TASK_RUNNING);
                         remove_wait_queue(&rp->wait, &waita);
-                        return -EWOULDBLOCK;    /* Same as EAGAIN in Linux */
+                        return ERR_PTR(-EWOULDBLOCK);
                 }
                 /*
                  * We do not count nwaiters, because ->release is supposed
@@ -327,17 +453,19 @@ static ssize_t mon_text_read(struct file *file, char __user *buf,
                 schedule();
                 if (signal_pending(current)) {
                         remove_wait_queue(&rp->wait, &waita);
-                        return -EINTR;
+                        return ERR_PTR(-EINTR);
                 }
                 set_current_state(TASK_INTERRUPTIBLE);
         }
         set_current_state(TASK_RUNNING);
         remove_wait_queue(&rp->wait, &waita);
+        return ep;
+}
 
-        mutex_lock(&rp->printf_lock);
-        cnt = 0;
-        pbuf = rp->printf_buf;
-        limit = rp->printf_size;
+static void mon_text_read_head_t(struct mon_reader_text *rp,
+        struct mon_text_ptr *p, const struct mon_event_text *ep)
+{
+        char udir, utype;
 
         udir = usb_pipein(ep->pipe) ? 'i' : 'o';
         switch (usb_pipetype(ep->pipe)) {
@@ -346,13 +474,38 @@ static ssize_t mon_text_read(struct file *file, char __user *buf,
         case PIPE_CONTROL:      utype = 'C'; break;
         default: /* PIPE_BULK */  utype = 'B';
         }
-        cnt += snprintf(pbuf + cnt, limit - cnt,
+        p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
             "%lx %u %c %c%c:%03u:%02u",
             ep->id, ep->tstamp, ep->type,
-            utype, udir, usb_pipedevice(ep->pipe), usb_pipeendpoint(ep->pipe));
+            utype, udir,
+            usb_pipedevice(ep->pipe), usb_pipeendpoint(ep->pipe));
+}
+
+static void mon_text_read_head_u(struct mon_reader_text *rp,
+        struct mon_text_ptr *p, const struct mon_event_text *ep)
+{
+        char udir, utype;
+
+        udir = usb_pipein(ep->pipe) ? 'i' : 'o';
+        switch (usb_pipetype(ep->pipe)) {
+        case PIPE_ISOCHRONOUS:  utype = 'Z'; break;
+        case PIPE_INTERRUPT:    utype = 'I'; break;
+        case PIPE_CONTROL:      utype = 'C'; break;
+        default: /* PIPE_BULK */  utype = 'B';
+        }
+        p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
+            "%lx %u %c %c%c:%d:%03u:%u",
+            ep->id, ep->tstamp, ep->type,
+            utype, udir,
+            ep->busnum, usb_pipedevice(ep->pipe), usb_pipeendpoint(ep->pipe));
+}
+
+static void mon_text_read_statset(struct mon_reader_text *rp,
+        struct mon_text_ptr *p, const struct mon_event_text *ep)
+{
 
         if (ep->setup_flag == 0) {   /* Setup packet is present and captured */
-                cnt += snprintf(pbuf + cnt, limit - cnt,
+                p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
                     " s %02x %02x %04x %04x %04x",
                     ep->setup[0],
                     ep->setup[1],
@@ -360,40 +513,86 @@ static ssize_t mon_text_read(struct file *file, char __user *buf,
                     (ep->setup[5] << 8) | ep->setup[4],
                     (ep->setup[7] << 8) | ep->setup[6]);
         } else if (ep->setup_flag != '-') { /* Unable to capture setup packet */
-                cnt += snprintf(pbuf + cnt, limit - cnt,
+                p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
                     " %c __ __ ____ ____ ____", ep->setup_flag);
         } else {                     /* No setup for this kind of URB */
-                cnt += snprintf(pbuf + cnt, limit - cnt, " %d", ep->status);
+                p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
+                    " %d", ep->status);
+        }
+}
+
+static void mon_text_read_intstat(struct mon_reader_text *rp,
+        struct mon_text_ptr *p, const struct mon_event_text *ep)
+{
+        p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
+            " %d:%d", ep->status, ep->interval);
+}
+
+static void mon_text_read_isostat(struct mon_reader_text *rp,
+        struct mon_text_ptr *p, const struct mon_event_text *ep)
+{
+        if (ep->type == 'S') {
+                p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
+                    " %d:%d:%d", ep->status, ep->interval, ep->start_frame);
+        } else {
+                p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
+                    " %d:%d:%d:%d",
+                    ep->status, ep->interval, ep->start_frame, ep->error_count);
         }
-        cnt += snprintf(pbuf + cnt, limit - cnt, " %d", ep->length);
+}
+
+static void mon_text_read_isodesc(struct mon_reader_text *rp,
+        struct mon_text_ptr *p, const struct mon_event_text *ep)
+{
+        int ndesc;      /* Display this many */
+        int i;
+        const struct mon_iso_desc *dp;
+
+        p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
+            " %d", ep->numdesc);
+        ndesc = ep->numdesc;
+        if (ndesc > ISODESC_MAX)
+                ndesc = ISODESC_MAX;
+        if (ndesc < 0)
+                ndesc = 0;
+        dp = ep->isodesc;
+        for (i = 0; i < ndesc; i++) {
+                p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
+                    " %d:%u:%u", dp->status, dp->offset, dp->length);
+                dp++;
+        }
+}
+
+static void mon_text_read_data(struct mon_reader_text *rp,
+    struct mon_text_ptr *p, const struct mon_event_text *ep)
+{
+        int data_len, i;
 
         if ((data_len = ep->length) > 0) {
                 if (ep->data_flag == 0) {
-                        cnt += snprintf(pbuf + cnt, limit - cnt, " =");
+                        p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
+                            " =");
                         if (data_len >= DATA_MAX)
                                 data_len = DATA_MAX;
                         for (i = 0; i < data_len; i++) {
                                 if (i % 4 == 0) {
-                                        cnt += snprintf(pbuf + cnt, limit - cnt,
+                                        p->cnt += snprintf(p->pbuf + p->cnt,
+                                            p->limit - p->cnt,
                                             " ");
                                 }
-                                cnt += snprintf(pbuf + cnt, limit - cnt,
+                                p->cnt += snprintf(p->pbuf + p->cnt,
+                                    p->limit - p->cnt,
                                     "%02x", ep->data[i]);
                         }
-                        cnt += snprintf(pbuf + cnt, limit - cnt, "\n");
+                        p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
+                            "\n");
                 } else {
-                        cnt += snprintf(pbuf + cnt, limit - cnt,
+                        p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt,
                             " %c\n", ep->data_flag);
                 }
         } else {
-                cnt += snprintf(pbuf + cnt, limit - cnt, "\n");
+                p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, "\n");
         }
-
-        if (copy_to_user(buf, rp->printf_buf, cnt))
-                cnt = -EFAULT;
-        mutex_unlock(&rp->printf_lock);
-        kmem_cache_free(rp->e_slab, ep);
-        return cnt;
 }
 
 static int mon_text_release(struct inode *inode, struct file *file)
@@ -439,14 +638,19 @@ static int mon_text_release(struct inode *inode, struct file *file)
         return 0;
 }
 
-static const struct file_operations mon_fops_text = {
+static const struct file_operations mon_fops_text_t = {
         .owner =        THIS_MODULE,
         .open =         mon_text_open,
         .llseek =       no_llseek,
-        .read =         mon_text_read,
-        /* .write =     mon_text_write, */
-        /* .poll =              mon_text_poll, */
-        /* .ioctl =     mon_text_ioctl, */
+        .read =         mon_text_read_t,
+        .release =      mon_text_release,
+};
+
+static const struct file_operations mon_fops_text_u = {
+        .owner =        THIS_MODULE,
+        .open =         mon_text_open,
+        .llseek =       no_llseek,
+        .read =         mon_text_read_u,
         .release =      mon_text_release,
 };
 
@@ -460,12 +664,19 @@ int mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus)
         rc = snprintf(name, NAMESZ, "%dt", ubus->busnum);
         if (rc <= 0 || rc >= NAMESZ)
                 goto err_print_t;
-        d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text);
+        d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text_t);
         if (d == NULL)
                 goto err_create_t;
         mbus->dent_t = d;
 
-        /* XXX The stats do not belong to here (text API), but oh well... */
+        rc = snprintf(name, NAMESZ, "%du", ubus->busnum);
+        if (rc <= 0 || rc >= NAMESZ)
+                goto err_print_u;
+        d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text_u);
+        if (d == NULL)
+                goto err_create_u;
+        mbus->dent_u = d;
+
         rc = snprintf(name, NAMESZ, "%ds", ubus->busnum);
         if (rc <= 0 || rc >= NAMESZ)
                 goto err_print_s;
@@ -478,6 +689,10 @@ int mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus)
 
 err_create_s:
 err_print_s:
+        debugfs_remove(mbus->dent_u);
+        mbus->dent_u = NULL;
+err_create_u:
+err_print_u:
         debugfs_remove(mbus->dent_t);
         mbus->dent_t = NULL;
 err_create_t:
@@ -487,6 +702,7 @@ err_print_t:
 
 void mon_text_del(struct mon_bus *mbus)
 {
+        debugfs_remove(mbus->dent_u);
         debugfs_remove(mbus->dent_t);
         debugfs_remove(mbus->dent_s);
 }
diff --git a/drivers/usb/mon/usb_mon.h b/drivers/usb/mon/usb_mon.h
index efdfd8993d9e..a1e2b8e9d777 100644
--- a/drivers/usb/mon/usb_mon.h
+++ b/drivers/usb/mon/usb_mon.h
@@ -22,6 +22,7 @@ struct mon_bus {
         int text_inited;
         struct dentry *dent_s;          /* Debugging file */
         struct dentry *dent_t;          /* Text interface file */
+        struct dentry *dent_u;          /* Second text interface file */
         int uses_dma;
 
         /* Ref */