From b22a9a5c4b0a3907cf00b04a12b84a5366d1fc8d Mon Sep 17 00:00:00 2001
From: Alon Levy <alevy@redhat.com>
Date: Mon, 4 Mar 2013 18:41:28 +0200
Subject: [PATCH] ccid-card-passthru, dev-smartcard-reader: add debug
 environment variables
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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>
(cherry picked from commit b16352acf3105000e14f194b556e159d5d06cff9)

Conflicts:
	include/qemu-common.h
---
 hw/ccid-card-passthru.c       |  2 ++
 hw/usb/dev-smartcard-reader.c |  1 +
 include/qemu-common.h         |  5 +++++
 util/cutils.c                 | 23 +++++++++++++++++++++++
 4 files changed, 31 insertions(+)

diff --git a/hw/ccid-card-passthru.c b/hw/ccid-card-passthru.c
index 7fecd10..4026ccd 100644
--- a/hw/ccid-card-passthru.c
+++ b/hw/ccid-card-passthru.c
@@ -353,6 +353,8 @@ 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 75f813c..09c2403 100644
--- 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 80016ad..77d0980 100644
--- a/include/qemu-common.h
+++ b/include/qemu-common.h
@@ -430,4 +430,9 @@ int64_t pow2floor(int64_t value);
 int uleb128_encode_small(uint8_t *out, uint32_t n);
 int uleb128_decode_small(const uint8_t *in, uint32_t *n);
 
+/*
+ * 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 1439da4..32e1f5b 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -422,3 +422,26 @@ 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;
+}