libcacard: initial commit

libcacard emulates a Common Access Card (CAC) which is a standard
for smartcards. It is used by the emulated ccid card introduced in
a following patch. Docs are available in docs/libcacard.txt

Signed-off-by: Alon Levy <alevy@redhat.com>

---

changes from v24->v25:
 * Fix out of tree builds.
 * Fix build with linux-user targets.

changes from v23->v24: (Jes Sorensen review 2)
 * Makefile.target: use obj-$(CONFIG_*) +=
 * remove unrequired includes, include qemu-common before qemu-thread
  * required adding #define NO_NSPR_10_SUPPORT (harmless)

changes from v22->v23:
 * configure fixes: (reported by Stefan Hajnoczi)
  * test a = b, not a == b (second isn't portable)
  * quote $source_path in case it contains spaces
   - this doesn't really help since there are many other places
     that need similar fixes, not introduced by this patch.

changes from v21->v22:
 * fix configure to not link libcacard if nss not found
    (reported by Stefan Hajnoczi)
 * fix vscclient linkage with simpletrace backend
    (reported by Stefan Hajnoczi)
 * card_7816.c: add missing break in ERROR_DATA_NOT_FOUND
    (reported by William van de Velde)

changes from v20->v21: (Jes Sorensen review)
 * use qemu infrastructure: qemu-thread, qemu-common (qemu_malloc
  and qemu_free), error_report
 * assert instead of ASSERT
 * cosmetic fixes
 * use strpbrk and isspace
 * add --disable-nss --enable-nss here, instead of in the final patch.
 * split vscclient, passthru and docs to following patches.

changes from v19->v20:
 * checkpatch.pl

changes from v15->v16:

Build:
 * don't erase self with distclean
 * fix make clean after make distclean
 * Makefile: make vscclient link quiet

Behavioral:
 * vcard_emul_nss: load coolkey in more situations
 * vscclient:
  * use hton,ntoh
  * send init on connect, only start vevent thread on response
  * read payload after header check, before type switch
  * remove Reconnect
  * update for vscard_common changes, empty Flush implementation

Style/Whitespace:
 * fix wrong variable usage
 * remove unused variable
 * use only C style comments
  * add copyright header
  * fix tabulation

Signed-off-by: Alon Levy <alevy@redhat.com>

libcacard: fix out of tree builds
diff --git a/libcacard/vreader.c b/libcacard/vreader.c
new file mode 100644
index 0000000..4a0125b
--- /dev/null
+++ b/libcacard/vreader.c
@@ -0,0 +1,513 @@
+/*
+ * emulate the reader
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ */
+
+#include "qemu-common.h"
+#include "qemu-thread.h"
+
+#include "vcard.h"
+#include "vcard_emul.h"
+#include "card_7816.h"
+#include "vreader.h"
+#include "vevent.h"
+
+struct VReaderStruct {
+    int    reference_count;
+    VCard *card;
+    char *name;
+    vreader_id_t id;
+    QemuMutex lock;
+    VReaderEmul  *reader_private;
+    VReaderEmulFree reader_private_free;
+};
+
+/* manage locking */
+static inline void
+vreader_lock(VReader *reader)
+{
+    qemu_mutex_lock(&reader->lock);
+}
+
+static inline void
+vreader_unlock(VReader *reader)
+{
+    qemu_mutex_unlock(&reader->lock);
+}
+
+/*
+ * vreader constructor
+ */
+VReader *
+vreader_new(const char *name, VReaderEmul *private,
+            VReaderEmulFree private_free)
+{
+    VReader *reader;
+
+    reader = (VReader *)qemu_malloc(sizeof(VReader));
+    qemu_mutex_init(&reader->lock);
+    reader->reference_count = 1;
+    reader->name = name ? strdup(name) : NULL;
+    reader->card = NULL;
+    reader->id = (vreader_id_t)-1;
+    reader->reader_private = private;
+    reader->reader_private_free = private_free;
+    return reader;
+}
+
+/* get a reference */
+VReader*
+vreader_reference(VReader *reader)
+{
+    if (reader == NULL) {
+        return NULL;
+    }
+    vreader_lock(reader);
+    reader->reference_count++;
+    vreader_unlock(reader);
+    return reader;
+}
+
+/* free a reference */
+void
+vreader_free(VReader *reader)
+{
+    if (reader == NULL) {
+        return;
+    }
+    vreader_lock(reader);
+    if (reader->reference_count-- > 1) {
+        vreader_unlock(reader);
+        return;
+    }
+    vreader_unlock(reader);
+    if (reader->card) {
+        vcard_free(reader->card);
+    }
+    if (reader->name) {
+        qemu_free(reader->name);
+    }
+    if (reader->reader_private_free) {
+        reader->reader_private_free(reader->reader_private);
+    }
+    qemu_free(reader);
+    return;
+}
+
+static VCard *
+vreader_get_card(VReader *reader)
+{
+    VCard *card;
+
+    vreader_lock(reader);
+    card = vcard_reference(reader->card);
+    vreader_unlock(reader);
+    return card;
+}
+
+VReaderStatus
+vreader_card_is_present(VReader *reader)
+{
+    VCard *card = vreader_get_card(reader);
+
+    if (card == NULL) {
+        return VREADER_NO_CARD;
+    }
+    vcard_free(card);
+    return VREADER_OK;
+}
+
+vreader_id_t
+vreader_get_id(VReader *reader)
+{
+    if (reader == NULL) {
+        return (vreader_id_t)-1;
+    }
+    return reader->id;
+}
+
+VReaderStatus
+vreader_set_id(VReader *reader, vreader_id_t id)
+{
+    if (reader == NULL) {
+        return VREADER_NO_CARD;
+    }
+    reader->id = id;
+    return VREADER_OK;
+}
+
+const char *
+vreader_get_name(VReader *reader)
+{
+    if (reader == NULL) {
+        return NULL;
+    }
+    return reader->name;
+}
+
+VReaderEmul *
+vreader_get_private(VReader *reader)
+{
+    return reader->reader_private;
+}
+
+static VReaderStatus
+vreader_reset(VReader *reader, VCardPower power, unsigned char *atr, int *len)
+{
+    VCard *card = vreader_get_card(reader);
+
+    if (card == NULL) {
+        return VREADER_NO_CARD;
+    }
+    /*
+     * clean up our state
+     */
+    vcard_reset(card, power);
+    if (atr) {
+        vcard_get_atr(card, atr, len);
+    }
+    vcard_free(card); /* free our reference */
+    return VREADER_OK;
+}
+
+VReaderStatus
+vreader_power_on(VReader *reader, unsigned char *atr, int *len)
+{
+    return vreader_reset(reader, VCARD_POWER_ON, atr, len);
+}
+
+VReaderStatus
+vreader_power_off(VReader *reader)
+{
+    return vreader_reset(reader, VCARD_POWER_OFF, NULL, 0);
+}
+
+
+VReaderStatus
+vreader_xfr_bytes(VReader *reader,
+                  unsigned char *send_buf, int send_buf_len,
+                  unsigned char *receive_buf, int *receive_buf_len)
+{
+    VCardAPDU *apdu;
+    VCardResponse *response = NULL;
+    VCardStatus card_status;
+    unsigned short status;
+    VCard *card = vreader_get_card(reader);
+
+    if (card == NULL) {
+        return VREADER_NO_CARD;
+    }
+
+    apdu = vcard_apdu_new(send_buf, send_buf_len, &status);
+    if (apdu == NULL) {
+        response = vcard_make_response(status);
+        card_status = VCARD_DONE;
+    } else {
+        card_status = vcard_process_apdu(card, apdu, &response);
+    }
+    assert(card_status == VCARD_DONE);
+    if (card_status == VCARD_DONE) {
+        int size = MIN(*receive_buf_len, response->b_total_len);
+        memcpy(receive_buf, response->b_data, size);
+        *receive_buf_len = size;
+    }
+    vcard_response_delete(response);
+    vcard_apdu_delete(apdu);
+    vcard_free(card); /* free our reference */
+    return VREADER_OK;
+}
+
+struct VReaderListStruct {
+    VReaderListEntry *head;
+    VReaderListEntry *tail;
+};
+
+struct VReaderListEntryStruct {
+    VReaderListEntry *next;
+    VReaderListEntry *prev;
+    VReader *reader;
+};
+
+
+static VReaderListEntry *
+vreader_list_entry_new(VReader *reader)
+{
+    VReaderListEntry *new_reader_list_entry;
+
+    new_reader_list_entry = (VReaderListEntry *)
+                               qemu_malloc(sizeof(VReaderListEntry));
+    new_reader_list_entry->next = NULL;
+    new_reader_list_entry->prev = NULL;
+    new_reader_list_entry->reader = vreader_reference(reader);
+    return new_reader_list_entry;
+}
+
+static void
+vreader_list_entry_delete(VReaderListEntry *entry)
+{
+    if (entry == NULL) {
+        return;
+    }
+    vreader_free(entry->reader);
+    qemu_free(entry);
+}
+
+
+static VReaderList *
+vreader_list_new(void)
+{
+    VReaderList *new_reader_list;
+
+    new_reader_list = (VReaderList *)qemu_malloc(sizeof(VReaderList));
+    new_reader_list->head = NULL;
+    new_reader_list->tail = NULL;
+    return new_reader_list;
+}
+
+void
+vreader_list_delete(VReaderList *list)
+{
+    VReaderListEntry *current_entry;
+    VReaderListEntry *next_entry = NULL;
+    for (current_entry = vreader_list_get_first(list); current_entry;
+         current_entry = next_entry) {
+        next_entry = vreader_list_get_next(current_entry);
+        vreader_list_entry_delete(current_entry);
+    }
+    list->head = NULL;
+    list->tail = NULL;
+    qemu_free(list);
+}
+
+
+VReaderListEntry *
+vreader_list_get_first(VReaderList *list)
+{
+    return list ? list->head : NULL;
+}
+
+VReaderListEntry *
+vreader_list_get_next(VReaderListEntry *current)
+{
+    return current ? current->next : NULL;
+}
+
+VReader *
+vreader_list_get_reader(VReaderListEntry *entry)
+{
+    return entry ? vreader_reference(entry->reader) : NULL;
+}
+
+static void
+vreader_queue(VReaderList *list, VReaderListEntry *entry)
+{
+    if (entry == NULL) {
+        return;
+    }
+    entry->next = NULL;
+    entry->prev = list->tail;
+    if (list->head) {
+        list->tail->next = entry;
+    } else {
+        list->head = entry;
+    }
+    list->tail = entry;
+}
+
+static void
+vreader_dequeue(VReaderList *list, VReaderListEntry *entry)
+{
+    if (entry == NULL) {
+        return;
+    }
+    if (entry->next == NULL) {
+        list->tail = entry->prev;
+    } else if (entry->prev == NULL) {
+        list->head = entry->next;
+    } else {
+        entry->prev->next = entry->next;
+        entry->next->prev = entry->prev;
+    }
+    if ((list->tail == NULL) || (list->head == NULL)) {
+        list->head = list->tail = NULL;
+    }
+    entry->next = entry->prev = NULL;
+}
+
+static VReaderList *vreader_list;
+static QemuMutex vreader_list_mutex;
+
+static void
+vreader_list_init(void)
+{
+    vreader_list = vreader_list_new();
+    qemu_mutex_init(&vreader_list_mutex);
+}
+
+static void
+vreader_list_lock(void)
+{
+    qemu_mutex_lock(&vreader_list_mutex);
+}
+
+static void
+vreader_list_unlock(void)
+{
+    qemu_mutex_unlock(&vreader_list_mutex);
+}
+
+static VReaderList *
+vreader_copy_list(VReaderList *list)
+{
+    VReaderList *new_list = NULL;
+    VReaderListEntry *current_entry = NULL;
+
+    new_list = vreader_list_new();
+    if (new_list == NULL) {
+        return NULL;
+    }
+    for (current_entry = vreader_list_get_first(list); current_entry;
+         current_entry = vreader_list_get_next(current_entry)) {
+        VReader *reader = vreader_list_get_reader(current_entry);
+        VReaderListEntry *new_entry = vreader_list_entry_new(reader);
+
+        vreader_free(reader);
+        vreader_queue(new_list, new_entry);
+    }
+    return new_list;
+}
+
+VReaderList *
+vreader_get_reader_list(void)
+{
+    VReaderList *new_reader_list;
+
+    vreader_list_lock();
+    new_reader_list = vreader_copy_list(vreader_list);
+    vreader_list_unlock();
+    return new_reader_list;
+}
+
+VReader *
+vreader_get_reader_by_id(vreader_id_t id)
+{
+    VReader *reader = NULL;
+    VReaderListEntry *current_entry = NULL;
+
+    if (id == (vreader_id_t) -1) {
+        return NULL;
+    }
+
+    vreader_list_lock();
+    for (current_entry = vreader_list_get_first(vreader_list); current_entry;
+            current_entry = vreader_list_get_next(current_entry)) {
+        VReader *creader = vreader_list_get_reader(current_entry);
+        if (creader->id == id) {
+            reader = creader;
+            break;
+        }
+        vreader_free(creader);
+    }
+    vreader_list_unlock();
+    return reader;
+}
+
+VReader *
+vreader_get_reader_by_name(const char *name)
+{
+    VReader *reader = NULL;
+    VReaderListEntry *current_entry = NULL;
+
+    vreader_list_lock();
+    for (current_entry = vreader_list_get_first(vreader_list); current_entry;
+            current_entry = vreader_list_get_next(current_entry)) {
+        VReader *creader = vreader_list_get_reader(current_entry);
+        if (strcmp(creader->name, name) == 0) {
+            reader = creader;
+            break;
+        }
+        vreader_free(creader);
+    }
+    vreader_list_unlock();
+    return reader;
+}
+
+/* called from card_emul to initialize the readers */
+VReaderStatus
+vreader_add_reader(VReader *reader)
+{
+    VReaderListEntry *reader_entry;
+
+    reader_entry = vreader_list_entry_new(reader);
+    if (reader_entry == NULL) {
+        return VREADER_OUT_OF_MEMORY;
+    }
+    vreader_list_lock();
+    vreader_queue(vreader_list, reader_entry);
+    vreader_list_unlock();
+    vevent_queue_vevent(vevent_new(VEVENT_READER_INSERT, reader, NULL));
+    return VREADER_OK;
+}
+
+
+VReaderStatus
+vreader_remove_reader(VReader *reader)
+{
+    VReaderListEntry *current_entry;
+
+    vreader_list_lock();
+    for (current_entry = vreader_list_get_first(vreader_list); current_entry;
+         current_entry = vreader_list_get_next(current_entry)) {
+        if (current_entry->reader == reader) {
+            break;
+        }
+    }
+    vreader_dequeue(vreader_list, current_entry);
+    vreader_list_unlock();
+    vreader_list_entry_delete(current_entry);
+    vevent_queue_vevent(vevent_new(VEVENT_READER_REMOVE, reader, NULL));
+    return VREADER_OK;
+}
+
+/*
+ * Generate VEVENT_CARD_INSERT or VEVENT_CARD_REMOVE based on vreader
+ * state. Separated from vreader_insert_card to allow replaying events
+ * for a given state.
+ */
+void
+vreader_queue_card_event(VReader *reader)
+{
+    vevent_queue_vevent(vevent_new(
+        reader->card ? VEVENT_CARD_INSERT : VEVENT_CARD_REMOVE, reader,
+        reader->card));
+}
+
+/*
+ * insert/remove a new card. for removal, card == NULL
+ */
+VReaderStatus
+vreader_insert_card(VReader *reader, VCard *card)
+{
+    vreader_lock(reader);
+    if (reader->card) {
+        /* decrement reference count */
+        vcard_free(reader->card);
+        reader->card = NULL;
+    }
+    reader->card = vcard_reference(card);
+    vreader_unlock(reader);
+    vreader_queue_card_event(reader);
+    return VREADER_OK;
+}
+
+/*
+ * initialize all the static reader structures
+ */
+void
+vreader_init(void)
+{
+    vreader_list_init();
+}
+