From b24bc54080b4bc444e60560c0db00c5867e74000 Mon Sep 17 00:00:00 2001
From: Peter Krempa <pkrempa@redhat.com>
Date: Thu, 15 Jun 2017 17:12:01 +0200
Subject: [PATCH] util: storage: Add JSON parser for new options in iSCSI
 protocol

Starting from qemu 2.9, more granular options are supported. Add parser
for the relevant bits.

With this patch libvirt is able to parse the host and target IQN of from
the JSON pseudo-protocol specification.

This corresponds to BlockdevOptionsIscsi in qemu qapi.
---
 src/util/virstoragefile.c | 63 ++++++++++++++++++++++++++++++++++++---
 tests/virstoragetest.c    | 19 ++++++++++++
 2 files changed, 78 insertions(+), 4 deletions(-)

diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
index 0bbbba650c..8e6631b459 100644
--- a/src/util/virstoragefile.c
+++ b/src/util/virstoragefile.c
@@ -2935,18 +2935,73 @@ virStorageSourceParseBackingJSONiSCSI(virStorageSourcePtr src,
                                       virJSONValuePtr json,
                                       int opaque ATTRIBUTE_UNUSED)
 {
+    const char *transport = virJSONValueObjectGetString(json, "transport");
+    const char *portal = virJSONValueObjectGetString(json, "portal");
+    const char *target = virJSONValueObjectGetString(json, "target");
     const char *uri;
+    char *port;
+    unsigned int lun = 0;
+    char *fulltarget = NULL;
+    int ret = -1;
 
     /* legacy URI based syntax passed via 'filename' option */
     if ((uri = virJSONValueObjectGetString(json, "filename")))
         return virStorageSourceParseBackingJSONUriStr(src, uri,
                                                       VIR_STORAGE_NET_PROTOCOL_ISCSI);
 
-    /* iSCSI currently supports only URI syntax passed in as filename */
-    virReportError(VIR_ERR_INVALID_ARG, "%s",
-                   _("missing iSCSI URI in JSON backing volume definition"));
+    src->type = VIR_STORAGE_TYPE_NETWORK;
+    src->protocol = VIR_STORAGE_NET_PROTOCOL_ISCSI;
 
-    return -1;
+    if (VIR_ALLOC(src->hosts) < 0)
+        goto cleanup;
+
+    src->nhosts = 1;
+
+    if (STRNEQ_NULLABLE(transport, "tcp")) {
+        virReportError(VIR_ERR_INVALID_ARG, "%s",
+                       _("only TCP transport is supported for iSCSI volumes"));
+        goto cleanup;
+    }
+
+    src->hosts->transport = VIR_STORAGE_NET_HOST_TRANS_TCP;
+
+    if (!portal) {
+        virReportError(VIR_ERR_INVALID_ARG, "%s",
+                       _("missing 'portal' address in iSCSI backing definition"));
+        goto cleanup;
+    }
+
+    if (!target) {
+        virReportError(VIR_ERR_INVALID_ARG, "%s",
+                       _("missing 'target' in iSCSI backing definition"));
+        goto cleanup;
+    }
+
+    if (VIR_STRDUP(src->hosts->name, portal) < 0)
+        goto cleanup;
+
+    if ((port = strchr(src->hosts->name, ':'))) {
+        if (VIR_STRDUP(src->hosts->port, port + 1) < 0)
+            goto cleanup;
+
+        if (strlen(src->hosts->port) == 0)
+            VIR_FREE(src->hosts->port);
+
+        *port = '\0';
+    }
+
+    ignore_value(virJSONValueObjectGetNumberUint(json, "lun", &lun));
+
+    if (virAsprintf(&fulltarget, "%s/%u", target, lun) < 0)
+        goto cleanup;
+
+    VIR_STEAL_PTR(src->path, fulltarget);
+
+    ret = 0;
+
+ cleanup:
+    VIR_FREE(fulltarget);
+    return ret;
 }
 
 
diff --git a/tests/virstoragetest.c b/tests/virstoragetest.c
index 1172082893..894f78ba9b 100644
--- a/tests/virstoragetest.c
+++ b/tests/virstoragetest.c
@@ -1502,6 +1502,25 @@ mymain(void)
                                     "\"driver\": \"file\","
                                     "\"filename\": \"/path/to/file\" } } }",
                        "<source file='/path/to/file'/>\n");
+    TEST_BACKING_PARSE("json:{\"file\":{\"driver\":\"iscsi\","
+                                       "\"transport\":\"tcp\","
+                                       "\"portal\":\"test.org\","
+                                       "\"target\":\"iqn.2016-12.com.virttest:emulated-iscsi-noauth.target\""
+                                      "}"
+                            "}",
+                       "<source protocol='iscsi' name='iqn.2016-12.com.virttest:emulated-iscsi-noauth.target/0'>\n"
+                       "  <host name='test.org'/>\n"
+                       "</source>\n");
+    TEST_BACKING_PARSE("json:{\"file\":{\"driver\":\"iscsi\","
+                                       "\"transport\":\"tcp\","
+                                       "\"portal\":\"test.org:1234\","
+                                       "\"target\":\"iqn.2016-12.com.virttest:emulated-iscsi-noauth.target\","
+                                       "\"lun\":6"
+                                      "}"
+                            "}",
+                       "<source protocol='iscsi' name='iqn.2016-12.com.virttest:emulated-iscsi-noauth.target/6'>\n"
+                       "  <host name='test.org' port='1234'/>\n"
+                       "</source>\n");
 
  cleanup:
     /* Final cleanup */