[Qemu-devel] [PATCH 1/2] QEmu: support disk filenames with comma

["Crístian Viana" <vianac@linux.vnet.ibm.com>]

If there is a disk file with a comma in the name, QEmu expects a double
comma instead of a single one (e.g., the file "virtual,disk.img" needs
to be specified as "virtual,,disk.img" in QEmu's command line). This
patch fixes libvirt to work with that feature. Fix RHBZ #801036.

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index de2d4a1..685a278 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -1628,6 +1628,48 @@ qemuSafeSerialParamValue(const char *value)
     return 0;
 }
 
+static const char *
+qemuEscapeCommas(const char *name)
+{
+    const char *name_ptr = name;
+    char *escaped_name, *escaped_name_ptr;
+    size_t escaped_name_max_size = (strlen(name) * 2) + 1;
+
+    /* If there is no comma in the string, return a copy of the original one. */
+    if (!strchr(name, ',')) {
+        if (!(escaped_name = strdup(name))) {
+            virReportOOMError();
+            return NULL;
+        }
+        return escaped_name;
+    }
+
+    /* In the worst case the string will have a sequence of only commas,
+     * which will require double the space for the escaped string. */
+    if (VIR_ALLOC_N(escaped_name, escaped_name_max_size) < 0) {
+        virReportOOMError();
+        return NULL;
+    }
+
+    /* Insert a comma after each comma in the string. */
+    escaped_name_ptr = escaped_name;
+    while (*name_ptr != '\0') {
+        if (*name_ptr == ',') {
+            *escaped_name_ptr++ = ',';
+        }
+
+        *escaped_name_ptr++ = *name_ptr++;
+    }
+
+    escaped_name_ptr = '\0';
+
+    /* Reduce the string memory size to its current length. */
+    VIR_SHRINK_N(escaped_name, escaped_name_max_size,
+            strlen(escaped_name) - strlen(name));
+
+    return escaped_name;
+}
+
 static int
 qemuBuildRBDString(virConnectPtr conn,
                    virDomainDiskDefPtr disk,
@@ -1638,7 +1680,7 @@ qemuBuildRBDString(virConnectPtr conn,
     char *secret = NULL;
     size_t secret_size;
 
-    virBufferAsprintf(opt, "rbd:%s", disk->src);
+    virBufferAsprintf(opt, "rbd:%s", qemuEscapeCommas(disk->src));
     if (disk->auth.username) {
         virBufferEscape(opt, ":", ":id=%s", disk->auth.username);
         /* look up secret */
@@ -1922,9 +1964,9 @@ qemuBuildDriveStr(virConnectPtr conn ATTRIBUTE_UNUSED,
                 goto error;
             }
             if (disk->device == VIR_DOMAIN_DISK_DEVICE_FLOPPY)
-                virBufferAsprintf(&opt, "file=fat:floppy:%s,", disk->src);
+                virBufferAsprintf(&opt, "file=fat:floppy:%s,", qemuEscapeCommas(disk->src));
             else
-                virBufferAsprintf(&opt, "file=fat:%s,", disk->src);
+                virBufferAsprintf(&opt, "file=fat:%s,", qemuEscapeCommas(disk->src));
         } else if (disk->type == VIR_DOMAIN_DISK_TYPE_NETWORK) {
             switch (disk->protocol) {
             case VIR_DOMAIN_DISK_PROTOCOL_NBD:
@@ -1944,16 +1986,16 @@ qemuBuildDriveStr(virConnectPtr conn ATTRIBUTE_UNUSED,
                 break;
             case VIR_DOMAIN_DISK_PROTOCOL_SHEEPDOG:
                 if (disk->nhosts == 0)
-                    virBufferAsprintf(&opt, "file=sheepdog:%s,", disk->src);
+                    virBufferAsprintf(&opt, "file=sheepdog:%s,", qemuEscapeCommas(disk->src));
                 else
                     /* only one host is supported now */
                     virBufferAsprintf(&opt, "file=sheepdog:%s:%s:%s,",
                                       disk->hosts->name, disk->hosts->port,
-                                      disk->src);
+                                      qemuEscapeCommas(disk->src));
                 break;
             }
         } else {
-            virBufferAsprintf(&opt, "file=%s,", disk->src);
+            virBufferAsprintf(&opt, "file=%s,", qemuEscapeCommas(disk->src));
         }
     }
     if (qemuCapsGet(qemuCaps, QEMU_CAPS_DEVICE))
@@ -2134,7 +2176,6 @@ error:
     return NULL;
 }
 
-
 char *
 qemuBuildDriveDevStr(virDomainDefPtr def,
                      virDomainDiskDefPtr disk,
-- 
1.7.8.5