Port new net_id capabilities from systemd-udev-197

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>

3 files changed, 440 insertions, 11 deletions

diff --git a/src/libudev/libudev-private.h b/src/libudev/libudev-private.h
index 5b7f0021e9..1b86384703 100644
--- a/src/libudev/libudev-private.h
+++ b/src/libudev/libudev-private.h
@@ -165,6 +165,7 @@ int util_log_priority(const char *priority);
 size_t util_path_encode(const char *src, char *dest, size_t size);
 void util_remove_trailing_chars(char *path, char c);
 size_t util_strpcpy(char **dest, size_t size, const char *src);
+size_t util_strpcpyf(char **dest, size_t size, const char *src, ...) __attribute__((format(printf, 3, 4)));
 size_t util_strpcpyl(char **dest, size_t size, const char *src, ...) __attribute__((sentinel));
 size_t util_strscpy(char *dest, size_t size, const char *src);
 size_t util_strscpyl(char *dest, size_t size, const char *src, ...) __attribute__((sentinel));
diff --git a/src/libudev/libudev-util.c b/src/libudev/libudev-util.c
index d3bbd05927..0ca86c815d 100644
--- a/src/libudev/libudev-util.c
+++ b/src/libudev/libudev-util.c
@@ -334,6 +334,25 @@ size_t util_strpcpy(char **dest, size_t size, const char *src)
         return size;
 }
 
+size_t util_strpcpyf(char **dest, size_t size, const char *src, ...)
+{
+        va_list va;
+        int i;
+
+        va_start(va, src);
+        i = vsnprintf(*dest, size, src, va);
+        if (i < (int)size) {
+                *dest += i;
+                size -= i;
+        } else {
+                *dest += size;
+                size = 0;
+        }
+        va_end(va);
+        *dest[0] = '\0';
+        return size;
+}
+
 /* concatenates list of strings, moves dest forward */
 size_t util_strpcpyl(char **dest, size_t size, const char *src, ...)
 {
diff --git a/src/udev/udev-builtin-net_id.c b/src/udev/udev-builtin-net_id.c
index eff4552778..7c9564f4cd 100644
--- a/src/udev/udev-builtin-net_id.c
+++ b/src/udev/udev-builtin-net_id.c
@@ -17,34 +17,443 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+/*
+ * Predictable network interface device names based on:
+ *  - firmware/bios-provided index numbers for on-board devices
+ *  - firmware-provided pci-express hotplug slot index number
+ *  - physical/geographical location of the hardware
+ *  - the interface's MAC address
+ *
+ * Two character prefixes based on the type of interface:
+ *   en -- ethernet
+ *   wl -- wlan
+ *   ww -- wwan
+ *
+ * Type of names:
+ *   o<index>                              -- on-board device index number
+ *   s<slot>[f<function>][d<dev_id>]       -- hotplug slot index number
+ *   x<MAC>                                -- MAC address
+ *   p<bus>s<slot>[f<function>][d<dev_id>] -- PCI geographical location
+ *   p<bus>s<slot>[f<function>][u<port>][..][c<config>][i<interface>]
+ *                                         -- USB port number chain
+ *
+ * All multi-function PCI devices will carry the [f<function>] number in the
+ * device name, including the function 0 device.
+ *
+ * For USB devices the full chain of port numbers of hubs is composed. If the
+ * name gets longer than the maximum number of 15 characters, the name is not
+ * exported.
+ * The usual USB configuration == 1 and interface == 0 values are suppressed.
+ *
+ * PCI ethernet card with firmware index "1":
+ *   ID_NET_NAME_ONBOARD=eno1
+ *   ID_NET_NAME_ONBOARD_LABEL=Ethernet Port 1
+ *
+ * PCI ethernet card in hotplug slot with firmware index number:
+ *   /sys/devices/pci0000:00/0000:00:1c.3/0000:05:00.0/net/ens1
+ *   ID_NET_NAME_MAC=enx000000000466
+ *   ID_NET_NAME_PATH=enp5s0
+ *   ID_NET_NAME_SLOT=ens1
+ *
+ * PCI ethernet multi-function card with 2 ports:
+ *   /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.0/net/enp2s0f0
+ *   ID_NET_NAME_MAC=enx78e7d1ea46da
+ *   ID_NET_NAME_PATH=enp2s0f0
+ *   /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.1/net/enp2s0f1
+ *   ID_NET_NAME_MAC=enx78e7d1ea46dc
+ *   ID_NET_NAME_PATH=enp2s0f1
+ *
+ * PCI wlan card:
+ *   /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlp3s0
+ *   ID_NET_NAME_MAC=wlx0024d7e31130
+ *   ID_NET_NAME_PATH=wlp3s0
+ *
+ * USB built-in 3G modem:
+ *   /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4:1.6/net/wwp0s29u1u4i6
+ *   ID_NET_NAME_MAC=wwx028037ec0200
+ *   ID_NET_NAME_PATH=wwp0s29u1u4i6
+ *
+ * USB Android phone:
+ *   /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/net/enp0s29u1u2
+ *   ID_NET_NAME_MAC=enxd626b3450fb5
+ *   ID_NET_NAME_PATH=enp0s29u1u2
+ */
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
 #include <unistd.h>
 #include <string.h>
 #include <errno.h>
+#include <net/if.h>
+#include <linux/pci_regs.h>
 
 #include "udev.h"
 
-/* IEEE Organizationally Unique Identifier */
-static int lookup_OUI(struct udev_device *dev, bool test) {
-        const char *addr;
-        unsigned int a1, a2, a3;
-        char oui[16];
+enum netname_type{
+        NET_UNDEF,
+        NET_PCI,
+        NET_USB,
+};
+
+struct netnames {
+        enum netname_type type;
+
+        uint8_t mac[6];
+        bool mac_valid;
+
+        struct udev_device *pcidev;
+        char pci_slot[IFNAMSIZ];
+        char pci_path[IFNAMSIZ];
+        char pci_onboard[IFNAMSIZ];
+        const char *pci_onboard_label;
+
+        struct udev_device *usbdev;
+        char usb_ports[IFNAMSIZ];
+};
+
+/* retrieve on-board index number and label from firmware */
+static int dev_pci_onboard(struct udev_device *dev, struct netnames *names) {
+        const char *index;
+        int idx;
+
+        /* ACPI _DSM  -- device specific method for naming a PCI or PCI Express device */
+        index = udev_device_get_sysattr_value(names->pcidev, "acpi_index");
+        /* SMBIOS type 41 -- Onboard Devices Extended Information */
+        if (!index)
+                index = udev_device_get_sysattr_value(names->pcidev, "index");
+        if (!index)
+                return -ENOENT;
+        idx = strtoul(index, NULL, 0);
+        if (idx <= 0)
+                return -EINVAL;
+        snprintf(names->pci_onboard, sizeof(names->pci_onboard), "o%d", idx);
+
+        names->pci_onboard_label = udev_device_get_sysattr_value(names->pcidev, "label");
+        return 0;
+}
+
+/* read the 256 bytes PCI configuration space to check the multi-function bit */
+static bool is_pci_multifunction(struct udev_device *dev) {
+        char filename[256];
+        FILE *f = NULL;
+        char config[64];
+        bool multi = false;
+
+        snprintf(filename, sizeof(filename), "%s/config", udev_device_get_syspath(dev));
+        f = fopen(filename, "re");
+        if (!f)
+                goto out;
+        if (fread(&config, sizeof(config), 1, f) != 1)
+                goto out;
+
+        /* bit 0-6 header type, bit 7 multi/single function device */
+        if ((config[PCI_HEADER_TYPE] & 0x80) != 0)
+                multi = true;
+out:
+        if(f)
+                fclose(f);
+        return multi;
+}
+
+static int dev_pci_slot(struct udev_device *dev, struct netnames *names) {
+        struct udev *udev = udev_device_get_udev(names->pcidev);
+        unsigned int bus;
+        unsigned int slot;
+        unsigned int func;
+        unsigned int dev_id = 0;
+        size_t l;
+        char *s;
+        const char *attr;
+        struct udev_device *pci = NULL;
+        char slots[256];
+        DIR *dir;
+        struct dirent *dent;
+        char str[256];
+        int hotplug_slot = 0;
+        int err = 0;
 
-        addr = udev_device_get_sysattr_value(dev, "address");
-        if (!addr)
+        if (sscanf(udev_device_get_sysname(names->pcidev), "0000:%x:%x.%d", &bus, &slot, &func) != 3)
                 return -ENOENT;
 
-        if (sscanf(addr, "%x:%x:%x:", &a1, &a2, &a3) != 3)
+        /* kernel provided multi-device index */
+        attr = udev_device_get_sysattr_value(dev, "dev_id");
+        if (attr)
+                dev_id = strtol(attr, NULL, 16);
+
+        /* compose a name based on the raw kernel's PCI bus, slot numbers */
+        s = names->pci_path;
+        l = util_strpcpyf(&s, sizeof(names->pci_path), "p%ds%d", bus, slot);
+        if (func > 0 || is_pci_multifunction(names->pcidev))
+                l = util_strpcpyf(&s, l, "f%d", func);
+        if (dev_id > 0)
+                l = util_strpcpyf(&s, l, "d%d", dev_id);
+        if (l == 0)
+                names->pci_path[0] = '\0';
+
+        /* ACPI _SUN  -- slot user number */
+        pci = udev_device_new_from_subsystem_sysname(udev, "subsystem", "pci");
+        if (!pci) {
+                err = -ENOENT;
+                goto out;
+        }
+        snprintf(slots, sizeof(slots), "%s/slots", udev_device_get_syspath(pci));
+        dir = opendir(slots);
+        if (!dir) {
+                err = -errno;
+                goto out;
+        }
+
+        for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
+                int i;
+                char *rest;
+                char *address;
+
+                if (dent->d_name[0] == '.')
+                        continue;
+                i = strtol(dent->d_name, &rest, 10);
+                if (rest[0] != '\0')
+                        continue;
+                if (i < 1)
+                        continue;
+                snprintf(str, sizeof(str), "%s/%s/address", slots, dent->d_name);
+                if (read_one_line_file(str, &address) >= 0) {
+                        /* match slot address with device by stripping the function */
+                        if (strncmp(address, udev_device_get_sysname(names->pcidev), strlen(address)) == 0)
+                                hotplug_slot = i;
+                        free(address);
+                }
+
+                if (hotplug_slot > 0)
+                        break;
+        }
+        closedir(dir);
+
+        if (hotplug_slot > 0) {
+                s = names->pci_slot;
+                l = util_strpcpyf(&s, sizeof(names->pci_slot), "s%d", hotplug_slot);
+                if (func > 0 || is_pci_multifunction(names->pcidev))
+                        l = util_strpcpyf(&s, l, "f%d", func);
+                if (dev_id > 0)
+                        l = util_strpcpyf(&s, l, "d%d", dev_id);
+                if (l == 0)
+                        names->pci_path[0] = '\0';
+        }
+out:
+        udev_device_unref(pci);
+        return err;
+}
+
+static int names_pci(struct udev_device *dev, struct netnames *names) {
+        struct udev_device *parent;
+
+        parent = udev_device_get_parent(dev);
+        if (!parent)
+                return -ENOENT;
+        /* check if our direct parent is a PCI device with no other bus in-between */
+        if (streq("pci", udev_device_get_subsystem(parent))) {
+                names->type = NET_PCI;
+                names->pcidev = parent;
+        } else {
+                names->pcidev = udev_device_get_parent_with_subsystem_devtype(dev, "pci", NULL);
+                if (!names->pcidev)
+                        return -ENOENT;
+        }
+        dev_pci_onboard(dev, names);
+        dev_pci_slot(dev, names);
+        return 0;
+}
+
+static int names_usb(struct udev_device *dev, struct netnames *names) {
+        char name[256];
+        char *ports;
+        char *config;
+        char *interf;
+        size_t l;
+        char *s;
+
+        names->usbdev = udev_device_get_parent_with_subsystem_devtype(dev, "usb", "usb_interface");
+        if (!names->usbdev)
+                return -ENOENT;
+
+        /* get USB port number chain, configuration, interface */
+        util_strscpy(name, sizeof(name), udev_device_get_sysname(names->usbdev));
+        s = strchr(name, '-');
+        if (!s)
+                return -EINVAL;
+        ports = s+1;
+
+        s = strchr(ports, ':');
+        if (!s)
                 return -EINVAL;
+        s[0] = '\0';
+        config = s+1;
 
-        snprintf(oui, sizeof(oui), "OUI:%X%X%X", a1, a2, a3);
-        return udev_builtin_hwdb_lookup(dev, oui, test);
+        s = strchr(config, '.');
+        if (!s)
+                return -EINVAL;
+        s[0] = '\0';
+        interf = s+1;
+
+        /* prefix every port number in the chain with "u"*/
+        s = ports;
+        while ((s = strchr(s, '.')))
+                s[0] = 'u';
+        s = names->usb_ports;
+        l = util_strpcpyl(&s, sizeof(names->usb_ports), "u", ports, NULL);
+
+        /* append USB config number, suppress the common config == 1 */
+        if (!streq(config, "1"))
+                l = util_strpcpyl(&s, sizeof(names->usb_ports), "c", config, NULL);
+
+        /* append USB interface number, suppress the interface == 0 */
+        if (!streq(interf, "0"))
+                l = util_strpcpyl(&s, sizeof(names->usb_ports), "i", interf, NULL);
+        if (l == 0)
+                return -ENAMETOOLONG;
+
+        names->type = NET_USB;
+        return 0;
+}
+
+static int names_mac(struct udev_device *dev, struct netnames *names) {
+        const char *s;
+        unsigned int i;
+        unsigned int a1, a2, a3, a4, a5, a6;
+
+        /* check for NET_ADDR_PERM, skip random MAC addresses */
+        s = udev_device_get_sysattr_value(dev, "addr_assign_type");
+        if (!s)
+                return EXIT_FAILURE;
+        i = strtoul(s, NULL, 0);
+        if (i != 0)
+                return 0;
+
+        s = udev_device_get_sysattr_value(dev, "address");
+        if (!s)
+                return -ENOENT;
+        if (sscanf(s, "%x:%x:%x:%x:%x:%x", &a1, &a2, &a3, &a4, &a5, &a6) != 6)
+                return -EINVAL;
+
+        /* skip empty MAC addresses */
+        if (a1 + a2 + a3 + a4 + a5 + a6 == 0)
+                return -EINVAL;
+
+        names->mac[0] = a1;
+        names->mac[1] = a2;
+        names->mac[2] = a3;
+        names->mac[3] = a4;
+        names->mac[4] = a5;
+        names->mac[5] = a6;
+        names->mac_valid = true;
+        return 0;
+}
+
+/* IEEE Organizationally Unique Identifier vendor string */
+static int ieee_oui(struct udev_device *dev, struct netnames *names, bool test) {
+        char str[32];
+
+        if (!names->mac_valid)
+                return -ENOENT;
+        /* skip commonly misused 00:00:00 (Xerox) prefix */
+        if (memcmp(names->mac, "\0\0\0", 3) == 0)
+                return -EINVAL;
+        snprintf(str, sizeof(str), "OUI:%02X%02X%02X%02X%02X%02X",
+                 names->mac[0], names->mac[1], names->mac[2],
+                 names->mac[3], names->mac[4], names->mac[5]);
+        udev_builtin_hwdb_lookup(dev, str, test);
+        return 0;
 }
 
 static int builtin_net_id(struct udev_device *dev, int argc, char *argv[], bool test) {
-        lookup_OUI(dev, test);
+        const char *s;
+        const char *p;
+        unsigned int i;
+        const char *devtype;
+        const char *prefix = "en";
+        struct netnames names;
+        int err;
+
+        /* handle only ARPHRD_ETHER devices */
+        s = udev_device_get_sysattr_value(dev, "type");
+        if (!s)
+                return EXIT_FAILURE;
+        i = strtoul(s, NULL, 0);
+        if (i != 1)
+                return 0;
+
+        /* skip stacked devices, like VLANs, ... */
+        s = udev_device_get_sysattr_value(dev, "ifindex");
+        if (!s)
+                return EXIT_FAILURE;
+        p = udev_device_get_sysattr_value(dev, "iflink");
+        if (!p)
+                return EXIT_FAILURE;
+        if (strcmp(s, p) != 0)
+                return 0;
+
+        devtype = udev_device_get_devtype(dev);
+        if (devtype) {
+                if (streq("wlan", devtype))
+                        prefix = "wl";
+                else if (streq("wwan", devtype))
+                        prefix = "ww";
+        }
+
+        zero(names);
+        err = names_mac(dev, &names);
+        if (err >= 0 && names.mac_valid) {
+                char str[IFNAMSIZ];
+
+                snprintf(str, sizeof(str), "%sx%02x%02x%02x%02x%02x%02x", prefix,
+                         names.mac[0], names.mac[1], names.mac[2],
+                         names.mac[3], names.mac[4], names.mac[5]);
+                udev_builtin_add_property(dev, test, "ID_NET_NAME_MAC", str);
+
+                ieee_oui(dev, &names, test);
+        }
+
+        /* get PCI based path names, we compose only PCI based paths */
+        err = names_pci(dev, &names);
+        if (err < 0)
+                goto out;
+
+        /* plain PCI device */
+        if (names.type == NET_PCI) {
+                char str[IFNAMSIZ];
+
+                if (names.pci_onboard[0])
+                        if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard) < (int)sizeof(str))
+                                udev_builtin_add_property(dev, test, "ID_NET_NAME_ONBOARD", str);
+
+                if (names.pci_onboard_label)
+                        if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard_label) < (int)sizeof(str))
+                                udev_builtin_add_property(dev, test, "ID_NET_LABEL_ONBOARD", str);
+
+                if (names.pci_path[0])
+                        if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_path) < (int)sizeof(str))
+                                udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
+
+                if (names.pci_slot[0])
+                        if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_slot) < (int)sizeof(str))
+                                udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
+                goto out;
+        }
+
+        /* USB device */
+        err = names_usb(dev, &names);
+        if (err >= 0 && names.type == NET_USB) {
+                char str[IFNAMSIZ];
+
+                if (names.pci_path[0])
+                        if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_path, names.usb_ports) < (int)sizeof(str))
+                                udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
+
+                if (names.pci_slot[0])
+                        if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_slot, names.usb_ports) < (int)sizeof(str))
+                                udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
+        }
+out:
         return EXIT_SUCCESS;
 }