udev: net_id: introduce predictable names for netdevsim

In order to properly and predictably name netdevsim netdevices,
introduce a separate implementation, as the netdevices reside on a
specific netdevsim bus. Note that this applies only to netdevsim devices
created using sysfs, because those expose phys_port_name attribute.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>

src/udev/net/naming-scheme.c

@@ -8,6 +8,7 @@ static const NamingScheme naming_schemes[] = {
         { "v238", NAMING_V238 },
         { "v239", NAMING_V239 },
         { "v240", NAMING_V240 },
+        { "v243", NAMING_V243 },
         /* … add more schemes here, as the logic to name devices is updated … */
 };
 

src/udev/net/naming-scheme.h

@@ -27,11 +27,13 @@ typedef enum NamingSchemeFlags {
         NAMING_INFINIBAND      = 1 << 2, /* Use "ib" prefix for infiniband, see 938d30aa98df887797c9e05074a562ddacdcdf5e */
         NAMING_ZERO_ACPI_INDEX = 1 << 3, /* Allow zero acpi_index field, see d81186ef4f6a888a70f20a1e73a812d6acb9e22f */
         NAMING_ALLOW_RERENAMES = 1 << 4, /* Allow re-renaming of devices, see #9006 */
+        NAMING_NETDEVSIM       = 1 << 5, /* Allow re-renaming of netdevsim devices */
 
         /* And now the masks that combine the features above */
         NAMING_V238 = 0,
         NAMING_V239 = NAMING_V238 | NAMING_SR_IOV_V | NAMING_NPAR_ARI,
         NAMING_V240 = NAMING_V239 | NAMING_INFINIBAND | NAMING_ZERO_ACPI_INDEX | NAMING_ALLOW_RERENAMES,
+        NAMING_V243 = NAMING_V240 | NAMING_NETDEVSIM,
 
         _NAMING_SCHEME_FLAGS_INVALID = -1,
 } NamingSchemeFlags;

src/udev/udev-builtin-net_id.c

@@ -31,6 +31,7 @@
  *                                         — USB port number chain
  *   v<slot>                               - VIO slot number (IBM PowerVM)
  *   a<vendor><model>i<instance>           — Platform bus ACPI instance id
+ *   i<addr>n<phys_port_name>	           — Netdevsim bus address and port name
  *
  * All multi-function PCI devices will carry the [f<function>] number in the
  * device name, including the function 0 device.
@@ -126,6 +127,7 @@ enum netname_type{
         NET_CCW,
         NET_VIO,
         NET_PLATFORM,
+        NET_NETDEVSIM,
 };
 
 struct netnames {
@@ -145,6 +147,7 @@ struct netnames {
         char ccw_busid[IFNAMSIZ];
         char vio_slot[IFNAMSIZ];
         char platform_path[IFNAMSIZ];
+        char netdevsim_path[IFNAMSIZ];
 };
 
 struct virtfn_info {
@@ -794,6 +797,43 @@ static int names_mac(sd_device *dev, struct netnames *names) {
         return 0;
 }
 
+static int names_netdevsim(sd_device *dev, struct netnames *names) {
+        sd_device *netdevsimdev;
+        const char *sysname;
+        unsigned addr;
+        const char *port_name = NULL;
+        int r;
+        bool ok;
+
+        if (!naming_scheme_has(NAMING_NETDEVSIM))
+                return 0;
+
+        assert(dev);
+        assert(names);
+
+        r = sd_device_get_parent_with_subsystem_devtype(dev, "netdevsim", NULL, &netdevsimdev);
+        if (r < 0)
+                return r;
+        r = sd_device_get_sysname(netdevsimdev, &sysname);
+        if (r < 0)
+                return r;
+
+        if (sscanf(sysname, "netdevsim%u", &addr) != 1)
+                return -EINVAL;
+
+        r = sd_device_get_sysattr_value(dev, "phys_port_name", &port_name);
+        if (r < 0)
+                return r;
+
+        ok = snprintf_ok(names->netdevsim_path, sizeof(names->netdevsim_path), "i%un%s", addr, port_name);
+        if (!ok)
+                return -ENOBUFS;
+
+        names->type = NET_NETDEVSIM;
+
+        return 0;
+}
+
 /* IEEE Organizationally Unique Identifier vendor string */
 static int ieee_oui(sd_device *dev, struct netnames *names, bool test) {
         char str[32];
@@ -897,6 +937,16 @@ static int builtin_net_id(sd_device *dev, int argc, char *argv[], bool test) {
                 return 0;
         }
 
+        /* get netdevsim path names */
+        if (names_netdevsim(dev, &names) >= 0 && names.type == NET_NETDEVSIM) {
+                char str[IFNAMSIZ];
+
+                if (snprintf_ok(str, sizeof str, "%s%s", prefix, names.netdevsim_path))
+                        udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
+
+                return 0;
+        }
+
         /* get PCI based path names, we compose only PCI based paths */
         if (names_pci(dev, &names) < 0)
                 return 0;