smartcard: use SpiceCharDeviceState for managing reading from the device

This patch and the following one do not introduce tokening to the smartcard
channel. But this can be done easily later, by setting the appropriate
variables in SpiceCharDeviceState (after adding the appropriate protocol messages,
and implementing this in the client side).

3 files changed, 133 insertions, 45 deletions

diff --git a/server/reds.c b/server/reds.c
index 42fad0ce..911564b8 100644
--- a/server/reds.c
+++ b/server/reds.c
@@ -3200,7 +3200,7 @@ static int spice_server_char_device_add_interface(SpiceServer *s,
     }
 #ifdef USE_SMARTCARD
     else if (strcmp(char_device->subtype, SUBTYPE_SMARTCARD) == 0) {
-        if (smartcard_device_connect(char_device) == -1) {
+        if (!(dev_state = smartcard_device_connect(char_device))) {
             return -1;
         }
     }
@@ -3213,6 +3213,8 @@ static int spice_server_char_device_add_interface(SpiceServer *s,
         /* setting the char_device state to "started" for backward compatibily with
          * qemu releases that don't call spice api for start/stop (not implemented yet) */
         spice_char_device_start(char_device->st);
+    } else {
+        spice_error("failed to create device state for %s", char_device->subtype);
     }
     return 0;
 }
diff --git a/server/smartcard.c b/server/smartcard.c
index fcf210f9..3b326daa 100644
--- a/server/smartcard.c
+++ b/server/smartcard.c
@@ -27,12 +27,23 @@
 #include "red_channel.h"
 #include "smartcard.h"
 
+/*
+ * TODO: the code doesn't really support multiple readers.
+ * For example: smartcard_char_device_add_to_readers calls smartcard_init,
+ * which can be called only once.
+ * We should allow different readers, at least one reader per client.
+ * In addition the implementation should be changed: instead of one channel for
+ * all readers, we need to have different channles for different readers,
+ * similarly to spicevmc.
+ *
+ */
 #define SMARTCARD_MAX_READERS 10
 
 typedef struct SmartCardDeviceState {
-    SpiceCharDeviceState base;
+    SpiceCharDeviceState *chardev_st;
     uint32_t             reader_id;
     uint32_t             attached;
+    /* read_from_device buffer */
     uint8_t             *buf;
     uint32_t             buf_size;
     uint8_t             *buf_pos;
@@ -53,9 +64,16 @@ typedef struct ErrorItem {
 
 typedef struct MsgItem {
     PipeItem base;
+    uint32_t refs;
+
     VSCMsgHeader* vheader;
 } MsgItem;
 
+static MsgItem *smartcard_get_vsc_msg_item(RedChannelClient *rcc, VSCMsgHeader *vheader);
+static MsgItem *smartcard_ref_vsc_msg_item(MsgItem *item);
+static void smartcard_unref_vsc_msg_item(MsgItem *item);
+static void smartcard_channel_client_pipe_add_push(RedChannelClient *rcc, PipeItem *item);
+
 typedef struct SmartCardChannel {
     RedChannel base;
 } SmartCardChannel;
@@ -73,18 +91,16 @@ static void smartcard_char_device_attach(
 static void smartcard_char_device_detach(SpiceCharDeviceInstance *char_device);
 static void smartcard_channel_write_to_reader(VSCMsgHeader *vheader);
 
-static void smartcard_char_device_on_message_from_device(
+static MsgItem *smartcard_char_device_on_message_from_device(
     SmartCardDeviceState *state, VSCMsgHeader *header);
-static void smartcard_on_message_from_device(
-    RedChannelClient *rcc, VSCMsgHeader *vheader);
-static SmartCardDeviceState* smartcard_device_state_new(void);
+static SmartCardDeviceState *smartcard_device_state_new(SpiceCharDeviceInstance *sin);
 static void smartcard_device_state_free(SmartCardDeviceState* st);
 static void smartcard_init(void);
 
-void smartcard_char_device_wakeup(SpiceCharDeviceInstance *sin)
+SpiceCharDeviceMsgToClient *smartcard_read_msg_from_device(SpiceCharDeviceInstance *sin,
+                                                           void *opaque)
 {
-    SmartCardDeviceState* state = SPICE_CONTAINEROF(
-                            sin->st, SmartCardDeviceState, base);
+    SmartCardDeviceState *state = opaque;
     SpiceCharDeviceInterface *sif = SPICE_CONTAINEROF(sin->base.sif, SpiceCharDeviceInterface, base);
     VSCMsgHeader *vheader = (VSCMsgHeader*)state->buf;
     int n;
@@ -92,6 +108,8 @@ void smartcard_char_device_wakeup(SpiceCharDeviceInstance *sin)
     int actual_length;
 
     while ((n = sif->read(sin, state->buf_pos, state->buf_size - state->buf_used)) > 0) {
+        MsgItem *msg_to_client;
+
         state->buf_pos += n;
         state->buf_used += n;
         if (state->buf_used < sizeof(VSCMsgHeader)) {
@@ -106,19 +124,59 @@ void smartcard_char_device_wakeup(SpiceCharDeviceInstance *sin)
         if (state->buf_used - sizeof(VSCMsgHeader) < actual_length) {
             continue;
         }
-        smartcard_char_device_on_message_from_device(state, vheader);
+        msg_to_client = smartcard_char_device_on_message_from_device(state, vheader);
         remaining = state->buf_used - sizeof(VSCMsgHeader) - actual_length;
         if (remaining > 0) {
             memcpy(state->buf, state->buf_pos, remaining);
         }
         state->buf_pos = state->buf;
         state->buf_used = remaining;
+        if (msg_to_client) {
+            return msg_to_client;
+        }
     }
+    return NULL;
+}
+
+static SpiceCharDeviceMsgToClient *smartcard_ref_msg_to_client(SpiceCharDeviceMsgToClient *msg,
+                                                               void *opaque)
+{
+    return smartcard_ref_vsc_msg_item((MsgItem *)msg);
+}
+
+static void smartcard_unref_msg_to_client(SpiceCharDeviceMsgToClient *msg,
+                                          void *opaque)
+{
+    smartcard_unref_vsc_msg_item((MsgItem *)msg);
+}
+
+static void smartcard_send_msg_to_client(SpiceCharDeviceMsgToClient *msg,
+                                         RedClient *client,
+                                         void *opaque)
+{
+    SmartCardDeviceState *dev = opaque;
+
+    spice_assert(dev->rcc && dev->rcc->client == client);
+    smartcard_channel_client_pipe_add_push(dev->rcc, &((MsgItem *)msg)->base);
+
+}
+
+static void smartcard_send_tokens_to_client(RedClient *client, uint32_t tokens, void *opaque)
+{
+    spice_error("not implemented");
 }
 
-void smartcard_char_device_on_message_from_device(
-    SmartCardDeviceState *state,
-    VSCMsgHeader *vheader)
+static void smartcard_remove_client(RedClient *client, void *opaque)
+{
+    SmartCardDeviceState *dev = opaque;
+
+    spice_printerr("smartcard  state %p, client %p", dev, client);
+    spice_assert(dev->rcc && dev->rcc->client == client);
+    red_channel_client_shutdown(dev->rcc);
+}
+
+MsgItem *smartcard_char_device_on_message_from_device(SmartCardDeviceState *state,
+                                                      VSCMsgHeader *vheader)
 {
     VSCMsgHeader *sent_header;
 
@@ -128,8 +186,7 @@ void smartcard_char_device_on_message_from_device(
 
     switch (vheader->type) {
         case VSC_Init:
-            return;
-            break;
+            return NULL;
         default:
             break;
     }
@@ -142,8 +199,9 @@ void smartcard_char_device_on_message_from_device(
         /* We patch the reader_id, since the device only knows about itself, and
          * we know about the sum of readers. */
         sent_header->reader_id = state->reader_id;
-        smartcard_on_message_from_device(state->rcc, sent_header);
+        return smartcard_get_vsc_msg_item(state->rcc, sent_header);
     }
+    return NULL;
 }
 
 static void smartcard_readers_detach_all(RedChannelClient *rcc)
@@ -153,7 +211,7 @@ static void smartcard_readers_detach_all(RedChannelClient *rcc)
     // TODO - can track rcc->{sin}
 
     for (i = 0 ; i < g_smartcard_readers.num; ++i) {
-        st = SPICE_CONTAINEROF(g_smartcard_readers.sin[i]->st, SmartCardDeviceState, base);
+        st = spice_char_device_state_opaque_get(g_smartcard_readers.sin[i]->st);
         if (!rcc || st->rcc == rcc) {
             smartcard_char_device_detach(g_smartcard_readers.sin[i]);
         }
@@ -162,8 +220,7 @@ static void smartcard_readers_detach_all(RedChannelClient *rcc)
 
 static int smartcard_char_device_add_to_readers(SpiceCharDeviceInstance *char_device)
 {
-    SmartCardDeviceState* state = SPICE_CONTAINEROF(
-                            char_device->st, SmartCardDeviceState, base);
+    SmartCardDeviceState *state = spice_char_device_state_opaque_get(char_device->st);
 
     if (g_smartcard_readers.num >= SMARTCARD_MAX_READERS) {
         return -1;
@@ -186,8 +243,7 @@ static SpiceCharDeviceInstance *smartcard_readers_get_unattached(void)
     SmartCardDeviceState* state;
 
     for (i = 0; i < g_smartcard_readers.num; ++i) {
-        state = SPICE_CONTAINEROF(g_smartcard_readers.sin[i]->st,
-                                  SmartCardDeviceState, base);
+        state = spice_char_device_state_opaque_get(g_smartcard_readers.sin[i]->st);
         if (!state->attached) {
             return g_smartcard_readers.sin[i];
         }
@@ -195,12 +251,24 @@ static SpiceCharDeviceInstance *smartcard_readers_get_unattached(void)
     return NULL;
 }
 
-static SmartCardDeviceState* smartcard_device_state_new(void)
+static SmartCardDeviceState *smartcard_device_state_new(SpiceCharDeviceInstance *sin)
 {
     SmartCardDeviceState *st;
+    SpiceCharDeviceCallbacks chardev_cbs = { NULL, };
+
+    chardev_cbs.read_one_msg_from_device = smartcard_read_msg_from_device;
+    chardev_cbs.ref_msg_to_client = smartcard_ref_msg_to_client;
+    chardev_cbs.unref_msg_to_client = smartcard_unref_msg_to_client;
+    chardev_cbs.send_msg_to_client = smartcard_send_msg_to_client;
+    chardev_cbs.send_tokens_to_client = smartcard_send_tokens_to_client;
+    chardev_cbs.remove_client = smartcard_remove_client;
 
     st = spice_new0(SmartCardDeviceState, 1);
-    st->base.wakeup = smartcard_char_device_wakeup;
+    st->chardev_st = spice_char_device_state_create(sin,
+                                                    0, /* tokens interval */
+                                                    ~0, /* self tokens */
+                                                    &chardev_cbs,
+                                                    st);
     st->reader_id = VSCARD_UNDEFINED_READER_ID;
     st->attached = FALSE;
     st->buf_size = APDUBufSize + sizeof(VSCMsgHeader);
@@ -214,40 +282,46 @@ static SmartCardDeviceState* smartcard_device_state_new(void)
 static void smartcard_device_state_free(SmartCardDeviceState* st)
 {
     free(st->buf);
+    spice_char_device_state_destroy(st->chardev_st);
     free(st);
 }
 
 void smartcard_device_disconnect(SpiceCharDeviceInstance *char_device)
 {
-    SmartCardDeviceState *st = SPICE_CONTAINEROF(char_device->st,
-        SmartCardDeviceState, base);
+    SmartCardDeviceState *st = spice_char_device_state_opaque_get(char_device->st);
 
     smartcard_device_state_free(st);
 }
 
-int smartcard_device_connect(SpiceCharDeviceInstance *char_device)
+SpiceCharDeviceState *smartcard_device_connect(SpiceCharDeviceInstance *char_device)
 {
     SmartCardDeviceState *st;
 
-    st = smartcard_device_state_new();
-    char_device->st = &st->base;
+    st = smartcard_device_state_new(char_device);
     if (smartcard_char_device_add_to_readers(char_device) == -1) {
         smartcard_device_state_free(st);
-        return -1;
+        return NULL;
     }
-    return 0;
+    return st->chardev_st;
 }
 
-static void smartcard_char_device_attach(
-    SpiceCharDeviceInstance *char_device, RedChannelClient *rcc)
+static void smartcard_char_device_attach(SpiceCharDeviceInstance *char_device,
+                                         RedChannelClient *rcc)
 {
-    SmartCardDeviceState *st = SPICE_CONTAINEROF(char_device->st, SmartCardDeviceState, base);
+    SmartCardDeviceState *st = spice_char_device_state_opaque_get(char_device->st);
+
 
     if (st->attached == TRUE) {
         return;
     }
     st->attached = TRUE;
     st->rcc = rcc;
+    spice_char_device_client_add(st->chardev_st,
+                                 rcc->client,
+                                 FALSE, /* no flow control yet */
+                                 0, /* send queue size */
+                                 ~0,
+                                 ~0);
     VSCMsgHeader vheader = {.type = VSC_ReaderAdd, .reader_id=st->reader_id,
         .length=0};
     smartcard_channel_write_to_reader(&vheader);
@@ -255,11 +329,13 @@ static void smartcard_char_device_attach(
 
 static void smartcard_char_device_detach(SpiceCharDeviceInstance *char_device)
 {
-    SmartCardDeviceState *st = SPICE_CONTAINEROF(char_device->st, SmartCardDeviceState, base);
+    SmartCardDeviceState *st = spice_char_device_state_opaque_get(char_device->st);
 
     if (st->attached == FALSE) {
         return;
     }
+    spice_assert(st->rcc);
+    spice_char_device_client_remove(st->chardev_st, st->rcc->client);
     st->attached = FALSE;
     st->rcc = NULL;
     VSCMsgHeader vheader = {.type = VSC_ReaderRemove, .reader_id=st->reader_id,
@@ -335,10 +411,10 @@ static void smartcard_channel_release_pipe_item(RedChannelClient *rcc,
                                       PipeItem *item, int item_pushed)
 {
     if (item->type == PIPE_ITEM_TYPE_MSG) {
-        MsgItem *mi = (MsgItem *)item;
-        free(mi->vheader);
+        smartcard_unref_vsc_msg_item((MsgItem *)item);
+    } else {
+        free(item);
     }
-    free(item);
 }
 
 static void smartcard_channel_on_disconnect(RedChannelClient *rcc)
@@ -369,19 +445,29 @@ static void smartcard_push_error(RedChannelClient *rcc, uint32_t reader_id, VSCE
     smartcard_channel_client_pipe_add_push(rcc, &error_item->base);
 }
 
-static void smartcard_push_vscmsg(RedChannelClient *rcc, VSCMsgHeader *vheader)
+static MsgItem *smartcard_get_vsc_msg_item(RedChannelClient *rcc, VSCMsgHeader *vheader)
 {
     MsgItem *msg_item = spice_new0(MsgItem, 1);
 
     red_channel_pipe_item_init(rcc->channel, &msg_item->base,
                                PIPE_ITEM_TYPE_MSG);
+    msg_item->refs = 1;
     msg_item->vheader = vheader;
-    smartcard_channel_client_pipe_add_push(rcc, &msg_item->base);
+    return msg_item;
 }
 
-void smartcard_on_message_from_device(RedChannelClient *rcc, VSCMsgHeader* vheader)
+static MsgItem *smartcard_ref_vsc_msg_item(MsgItem *item)
 {
-    smartcard_push_vscmsg(rcc, vheader);
+    item->refs++;
+    return item;
+}
+
+static void smartcard_unref_vsc_msg_item(MsgItem *item)
+{
+    if (!--item->refs) {
+        free(item->vheader);
+        free(item);
+    }
 }
 
 static void smartcard_remove_reader(RedChannelClient *rcc, uint32_t reader_id)
@@ -395,7 +481,7 @@ static void smartcard_remove_reader(RedChannelClient *rcc, uint32_t reader_id)
         return;
     }
 
-    state = SPICE_CONTAINEROF(char_device->st, SmartCardDeviceState, base);
+    state = spice_char_device_state_opaque_get(char_device->st);
     if (state->attached == FALSE) {
         smartcard_push_error(rcc, reader_id,
             VSC_GENERAL_ERROR);
diff --git a/server/smartcard.h b/server/smartcard.h
index 7881e1fd..221c777e 100644
--- a/server/smartcard.h
+++ b/server/smartcard.h
@@ -23,10 +23,10 @@
 // Maximal length of APDU
 #define APDUBufSize 270
 
-/** connect to smartcard interface, used by smartcard channel
- * returns -1 if failed, 0 if successfull
+/*
+ * connect to smartcard interface, used by smartcard channel
  */
-int smartcard_device_connect(SpiceCharDeviceInstance *char_device);
+SpiceCharDeviceState *smartcard_device_connect(SpiceCharDeviceInstance *char_device);
 void smartcard_device_disconnect(SpiceCharDeviceInstance *char_device);
 
 #endif // __SMART_CARD_H__