ccid-card-passthru, dev-smartcard-reader: add debug environment variables

Introduces a new utility function: parse_debug_env to avoid code
duplication.

This overrides whatever debug value is set on the corresponding devices
from the command line, and is meant to ease the usage with any
management stack. For libvirt you can set environment variables by
extending the dom namespace, i.e:

<domain type='kvm' id='3' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
  <qemu:commandline>
    <qemu:env name='QEMU_CCID_PASSTHRU_DEBUG' value='4'/>
    <qemu:env name='QEMU_CCID_DEBUG' value='4'/>
  </qemu:commandline>
</domain>

Signed-off-by: Alon Levy <alevy@redhat.com>
Reviewed-by: Marc-André Lureau <mlureau@redhat.com>

diff --git a/hw/usb/ccid-card-passthru.c b/hw/usb/ccid-card-passthru.c
index 16d51c92954a05858e36eee972881476369b40a3..01c7e6f20dedd79b4d2ec01ec49b64869bc0a045 100644 (file)
--- a/hw/usb/ccid-card-passthru.c
+++ b/hw/usb/ccid-card-passthru.c
@@ -350,6 +350,8 @@ static int passthru_initfn(CCIDCardState *base)
         error_report("missing chardev");
         return -1;
     }
+    card->debug = parse_debug_env("QEMU_CCID_PASSTHRU_DEBUG", D_VERBOSE,
+                                  card->debug);
     assert(sizeof(DEFAULT_ATR) <= MAX_ATR_SIZE);
     memcpy(card->atr, DEFAULT_ATR, sizeof(DEFAULT_ATR));
     card->atr_length = sizeof(DEFAULT_ATR);

diff --git a/hw/usb/dev-smartcard-reader.c b/hw/usb/dev-smartcard-reader.c
index 98f3be1f0f065754ab2797d82b50638576543f13..35f234e6ad5bf79940f3ba59bd85528938d645a9 100644 (file)
--- a/hw/usb/dev-smartcard-reader.c
+++ b/hw/usb/dev-smartcard-reader.c
@@ -1260,6 +1260,7 @@ static int ccid_initfn(USBDevice *dev)
     s->bulk_out_pos = 0;
     ccid_reset_parameters(s);
     ccid_reset(s);
+    s->debug = parse_debug_env("QEMU_CCID_DEBUG", D_VERBOSE, s->debug);
     return 0;
 }
 

diff --git a/include/qemu-common.h b/include/qemu-common.h
index 3b1873e4ef5f4b7efea2ca862ef44c69f4107e14..a39cdba27f6744da9e15bcf80856fbd259cddcc7 100644 (file)
--- a/include/qemu-common.h
+++ b/include/qemu-common.h
@@ -482,4 +482,9 @@ can_use_buffer_find_nonzero_offset(const void *buf, size_t len)
 }
 size_t buffer_find_nonzero_offset(const void *buf, size_t len);
 
+/*
+ * helper to parse debug environment variables
+ */
+int parse_debug_env(const char *name, int max, int initial);
+
 #endif

diff --git a/util/cutils.c b/util/cutils.c
index 5024253405ac99b26e84a4566c5b14982c4b4046..a1658197cf66711944ddf36ac237e27e67739400 100644 (file)
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -482,3 +482,26 @@ int uleb128_decode_small(const uint8_t *in, uint32_t *n)
         return 2;
     }
 }
+
+/*
+ * helper to parse debug environment variables
+ */
+int parse_debug_env(const char *name, int max, int initial)
+{
+    char *debug_env = getenv(name);
+    char *inv = NULL;
+    int debug;
+
+    if (!debug_env) {
+        return initial;
+    }
+    debug = strtol(debug_env, &inv, 10);
+    if (inv == debug_env) {
+        return initial;
+    }
+    if (debug < 0 || debug > max) {
+        fprintf(stderr, "warning: %s not in [0, %d]", name, max);
+        return initial;
+    }
+    return debug;
+}