[libvirt] [PATCH 6/7] util: Introduce virIsSameHostnameInfo

[John Ferlan]

In order to assist with existing pool source hostname validation against
an incoming pool source definition, we need a way to validate that the
resolved hostname provided for the pool doesn't match some existing
pool; otherwise, we'd have a scenario where two storage pools could be
looking at the same data.

Search through all the existing pools resolved names against the proposed
definitions resolved hostnames - if any match, we return true; otherwise,
false is returned

Signed-off-by: John Ferlan <jferlan at redhat.com>
---
 src/libvirt_private.syms |   1 +
 src/util/virutil.c       | 106 +++++++++++++++++++++++++++++++++++++++++++++++
 src/util/virutil.h       |   2 +
 3 files changed, 109 insertions(+)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 5ba9635..a5f4d7f 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2323,6 +2323,7 @@ virIndexToDiskName;
 virIsCapableFCHost;
 virIsCapableVport;
 virIsDevMapperDevice;
+virIsSameHostnameInfo;
 virIsSUID;
 virIsValidHostname;
 virManageVport;
diff --git a/src/util/virutil.c b/src/util/virutil.c
index f6cc9af..c152b8c 100644
--- a/src/util/virutil.c
+++ b/src/util/virutil.c
@@ -739,6 +739,112 @@ virIsValidHostname(const char *hostname)
 }
 
 
+/*
+ * virIsSameHostnameInfo:
+ *
+ * Take two hostname representations and compare their 'getnameinfo' results
+ * to ensure that they differ. This will be used by the network storage pool
+ * validation to ensure an incoming definition doesn't match some existing
+ * pool definition just because someone tried to change the hostname string
+ * representation.  For example, "localhost" and "127.0.0.1" would fail the
+ * plain STREQ check, but they essentially are the same host, so the incoming
+ * definition should be rejected since a pool for the host already exists.
+ *
+ * @poolhostname:  String stored as the pool's hostname
+ * @defhostname: String to be used by the def's hostname
+ *
+ * Returns true if they are the same, false if not
+ */
+bool
+virIsSameHostnameInfo(const char *poolhostname,
+                      const char *defhostname)
+{
+    int r;
+    struct addrinfo poolhints, *poolinfo = NULL, *poolcur;
+    struct addrinfo defhints, *definfo = NULL, *defcur;
+    char poolhost[NI_MAXHOST];
+    char defhost[NI_MAXHOST];
+
+    memset(&poolhints, 0, sizeof(poolhints));
+    poolhints.ai_family = AF_UNSPEC;
+    poolhints.ai_protocol = IPPROTO_TCP;
+
+    if ((r = getaddrinfo(poolhostname, NULL, &poolhints, &poolinfo)) != 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("IP address lookup for poolhostname '%s' failed: %s"),
+                       poolhostname, gai_strerror(r));
+        return false;
+    }
+
+    if (!poolinfo) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("No IP address for poolhostname '%s' found"),
+                       poolhostname);
+        return false;
+    }
+
+    memset(&defhints, 0, sizeof(defhints));
+    defhints.ai_family = AF_UNSPEC;
+    defhints.ai_protocol = IPPROTO_TCP;
+
+    if ((r = getaddrinfo(defhostname, NULL, &defhints, &definfo)) != 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("IP address lookup for defhostname '%s' failed: %s"),
+                       defhostname, gai_strerror(r));
+        goto cleanup;
+    }
+
+    if (!definfo) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("No IP address for defhostname '%s' found"),
+                       defhostname);
+        goto cleanup;
+    }
+
+    for (poolcur = poolinfo; poolcur; poolcur = poolcur->ai_next) {
+
+        if ((r = getnameinfo(poolcur->ai_addr, poolcur->ai_addrlen,
+                             poolhost, sizeof(poolhost), NULL, 0,
+                             NI_NUMERICHOST)) != 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("Formatting IP address for poolhost '%s' "
+                             "failed: %s"),
+                           poolhostname, gai_strerror(r));
+            goto cleanup;
+        }
+
+
+        for (defcur = definfo; defcur; defcur = defcur->ai_next) {
+            if ((r = getnameinfo(defcur->ai_addr, defcur->ai_addrlen,
+                                 defhost, sizeof(defhost), NULL, 0,
+                                 NI_NUMERICHOST)) != 0) {
+                virReportError(VIR_ERR_INTERNAL_ERROR,
+                               _("Formatting IP address for defhost '%s' "
+                                 "failed: %s"),
+                               defhostname, gai_strerror(r));
+                goto cleanup;
+            }
+
+            if (poolcur->ai_family != defcur->ai_family)
+                continue;
+
+            if (STREQ(poolhost, defhost)) {
+                freeaddrinfo(poolinfo);
+                freeaddrinfo(definfo);
+                return true;
+            }
+        }
+    }
+
+ cleanup:
+    if (poolinfo)
+        freeaddrinfo(poolinfo);
+    if (definfo)
+        freeaddrinfo(definfo);
+    return false;
+}
+
+
 char *
 virGetUserDirectory(void)
 {
diff --git a/src/util/virutil.h b/src/util/virutil.h
index 73ad147..5a84411 100644
--- a/src/util/virutil.h
+++ b/src/util/virutil.h
@@ -132,6 +132,8 @@ static inline int pthread_sigmask(int how,
 
 char *virGetHostname(void);
 bool virIsValidHostname(const char *hostname) ATTRIBUTE_NONNULL(1);
+bool virIsSameHostnameInfo(const char *poolhostname, const char *defhostname)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 
 char *virGetUserDirectory(void);
 char *virGetUserDirectoryByUID(uid_t uid);
-- 
2.1.0