hostnamed: prefer more precise DMI info over ACPI OSPM info

(also: add comments about the used numbers)

Fixes: #3930

1 files changed, 42 insertions, 47 deletions

diff --git a/src/hostname/hostnamed.c b/src/hostname/hostnamed.c
index fe8bb62752..080a2cd138 100644
--- a/src/hostname/hostnamed.c
+++ b/src/hostname/hostnamed.c
@@ -148,56 +148,61 @@ static bool valid_deployment(const char *deployment) {
 }
 
 static const char* fallback_chassis(void) {
-        int r;
         char *type;
         unsigned t;
-        int v;
+        int v, r;
 
         v = detect_virtualization();
-
         if (VIRTUALIZATION_IS_VM(v))
                 return "vm";
         if (VIRTUALIZATION_IS_CONTAINER(v))
                 return "container";
 
-        r = read_one_line_file("/sys/firmware/acpi/pm_profile", &type);
+        r = read_one_line_file("/sys/class/dmi/id/chassis_type", &type);
         if (r < 0)
-                goto try_dmi;
+                goto try_acpi;
 
         r = safe_atou(type, &t);
         free(type);
         if (r < 0)
-                goto try_dmi;
+                goto try_acpi;
 
-        /* We only list the really obvious cases here as the ACPI data
-         * is not really super reliable.
-         *
-         * See the ACPI 5.0 Spec Section 5.2.9.1 for details:
-         *
-         * http://www.acpi.info/DOWNLOADS/ACPIspec50.pdf
+        /* We only list the really obvious cases here. The DMI data is unreliable enough, so let's not do any
+           additional guesswork on top of that.
+
+           See the SMBIOS Specification 3.0 section 7.4.1 for details about the values listed here:
+
+           https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_3.0.0.pdf
          */
 
-        switch(t) {
+        switch (t) {
 
-        case 1:
-        case 3:
-        case 6:
+        case 0x3: /* Desktop */
+        case 0x4: /* Low Profile Desktop */
+        case 0x6: /* Mini Tower */
+        case 0x7: /* Tower */
                 return "desktop";
 
-        case 2:
+        case 0x8: /* Portable */
+        case 0x9: /* Laptop */
+        case 0xA: /* Notebook */
+        case 0xE: /* Sub Notebook */
                 return "laptop";
 
-        case 4:
-        case 5:
-        case 7:
+        case 0xB: /* Hand Held */
+                return "handset";
+
+        case 0x11: /* Main Server Chassis */
+        case 0x1C: /* Blade */
+        case 0x1D: /* Blade Enclosure */
                 return "server";
 
-        case 8:
+        case 0x1E: /* Tablet */
                 return "tablet";
         }
 
-try_dmi:
-        r = read_one_line_file("/sys/class/dmi/id/chassis_type", &type);
+try_acpi:
+        r = read_one_line_file("/sys/firmware/acpi/pm_profile", &type);
         if (r < 0)
                 return NULL;
 
@@ -206,39 +211,29 @@ try_dmi:
         if (r < 0)
                 return NULL;
 
-        /* We only list the really obvious cases here. The DMI data is
-           unreliable enough, so let's not do any additional guesswork
-           on top of that.
-
-           See the SMBIOS Specification 3.0 section 7.4.1 for
-           details about the values listed here:
-
-           https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_3.0.0.pdf
+        /* We only list the really obvious cases here as the ACPI data is not really super reliable.
+         *
+         * See the ACPI 5.0 Spec Section 5.2.9.1 for details:
+         *
+         * http://www.acpi.info/DOWNLOADS/ACPIspec50.pdf
          */
 
-        switch (t) {
+        switch(t) {
 
-        case 0x3:
-        case 0x4:
-        case 0x6:
-        case 0x7:
+        case 1: /* Desktop */
+        case 3: /* Workstation */
+        case 6: /* Appliance PC */
                 return "desktop";
 
-        case 0x8:
-        case 0x9:
-        case 0xA:
-        case 0xE:
+        case 2: /* Mobile */
                 return "laptop";
 
-        case 0xB:
-                return "handset";
-
-        case 0x11:
-        case 0x1C:
-        case 0x1D:
+        case 4: /* Enterprise Server */
+        case 5: /* SOHO Server */
+        case 7: /* Performance Server */
                 return "server";
 
-        case 0x1E:
+        case 8: /* Tablet */
                 return "tablet";
         }