[PATCH][pciutils] lspci: pci_id_lookup - add udev/hwdb support

[Tom Gundersen <teg@jklm.no>]

This lets you select hwdb support at compile time.

hwdb is an efficient hardware database shipped with recent versions of systemd/udev. It contains
among other sources pci.ids so querying hwdb rather than reading pci.ids directly should give
the same result.

Ideally Linux distros using systemd would like to not ship pci.ids, but use hwdb as the only source
of this information, which this patch allows.

Cc: systemd-devel@lists.freedesktop.org

---
 lib/configure    | 17 ++++++++++++++++
 lib/names-hash.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 74 insertions(+), 2 deletions(-)

diff --git a/lib/configure b/lib/configure
index 4ae20d4..674d3ea 100755
--- a/lib/configure
+++ b/lib/configure
@@ -141,6 +141,23 @@ esac
 echo >>$c '#define PCI_HAVE_PM_DUMP'
 echo " dump"
 
+echo_n "Checking for udev hwdb support... "
+if [ "$HWDB" = yes -o "$HWDB" = no ] ; then
+	echo "$HWDB (set manually)"
+else
+	if [ -f /usr/include/libudev.h -o -f /usr/local/include/libudev.h ] ; then
+		HWDB=yes
+	else
+		HWDB=no
+	fi
+	echo "$HWDB (auto-detected)"
+fi
+if [ "$HWDB" = yes ] ; then
+	echo >>$c '#define PCI_HAVE_HWDB'
+	echo >>$m 'LIBUDEV=-ludev'
+	echo >>$m 'WITH_LIBS+=$(LIBUDEV)'
+fi
+
 echo_n "Checking for zlib support... "
 if [ "$ZLIB" = yes -o "$ZLIB" = no ] ; then
 	echo "$ZLIB (set manually)"
diff --git a/lib/names-hash.c b/lib/names-hash.c
index 33f3c11..9661d03 100644
--- a/lib/names-hash.c
+++ b/lib/names-hash.c
@@ -11,6 +11,11 @@
 #include "internal.h"
 #include "names.h"
 
+#ifdef PCI_HAVE_HWDB
+#include <libudev.h>
+#include <stdio.h>
+#endif
+
 struct id_bucket {
   struct id_bucket *next;
   unsigned int full;
@@ -86,8 +91,58 @@ char
 *pci_id_lookup(struct pci_access *a, int flags, int cat, int id1, int id2, int id3, int id4)
 {
   struct id_entry *n, *best;
-  u32 id12 = id_pair(id1, id2);
-  u32 id34 = id_pair(id3, id4);
+  u32 id12, id34;
+
+#ifdef PCI_HAVE_HWDB
+  if (!(flags & PCI_LOOKUP_SKIP_LOCAL))
+    {
+      char modalias[64];
+      const char *key = NULL;
+      struct udev *udev = udev_new();
+      struct udev_hwdb *hwdb = udev_hwdb_new(udev);
+      struct udev_list_entry *entry;
+
+      switch(cat)
+        {
+        case ID_VENDOR:
+          sprintf(modalias, "pci:v%08X*", id1);
+          key = "ID_VENDOR_FROM_DATABASE";
+          break;
+        case ID_DEVICE:
+          sprintf(modalias, "pci:v%08Xd%08X*", id1, id2);
+          key = "ID_MODEL_FROM_DATABASE";
+          break;
+        case ID_SUBSYSTEM:
+          sprintf(modalias, "pci:v%08Xd%08Xsv%08Xsd%08X*", id1, id2, id3, id4);
+          key = "ID_MODEL_FROM_DATABASE";
+          break;
+        case ID_GEN_SUBSYSTEM:
+          sprintf(modalias, "pci:v*d*sv%08Xsd%08X*", id1, id2);
+          key = "ID_MODEL_FROM_DATABASE";
+          break;
+        case ID_CLASS:
+          sprintf(modalias, "pci:v*d*sv*sd*bc%02X*", id1);
+          key = "ID_PCI_CLASS_FROM_DATABASE";
+          break;
+        case ID_SUBCLASS:
+          sprintf(modalias, "pci:v*d*sv*sd*bc%02Xsc%02X*", id1, id2);
+          key = "ID_PCI_SUBCLASS_FROM_DATABASE";
+          break;
+        case ID_PROGIF:
+          sprintf(modalias, "pci:v*d*sv*sd*bc%02Xsc%02Xi%02X*", id1, id2, id3);
+          key = "ID_PCI_INTERFACE_FROM_DATABASE";
+          break;
+        }
+
+      if (key)
+          udev_list_entry_foreach(entry, udev_hwdb_get_properties_list_entry(hwdb, modalias, 0))
+              if (strcmp(udev_list_entry_get_name(entry), key) == 0)
+                return udev_list_entry_get_value(entry);
+    }
+#endif
+
+  id12 = id_pair(id1, id2);
+  id34 = id_pair(id3, id4);
 
   if (a->id_hash)
     {
-- 
1.8.3.3