From 4f47e35ee4026f24ee99a0bfa7ba5b2f24a92a02 Mon Sep 17 00:00:00 2001

From: Yu Watanabe <watanabe.yu+github@gmail.com>

Date: Mon, 16 Dec 2019 23:44:42 +0900

Subject: [PATCH] udev: introduce AlternativeNamesPolicy= setting

(cherry picked from commit ef1d2c07f9567dfea8a4e012d8779a4ded2d9ae6)

Resolves: #1850986

---

 man/systemd.link.xml                 | 11 +++++

 src/udev/net/link-config-gperf.gperf |  1 +

 src/udev/net/link-config.c           | 62 ++++++++++++++++++++++++++--

 src/udev/net/link-config.h           |  5 +++

 4 files changed, 76 insertions(+), 3 deletions(-)

diff --git a/man/systemd.link.xml b/man/systemd.link.xml

index c8ebb751ee..13dcce0879 100644

--- a/man/systemd.link.xml

+++ b/man/systemd.link.xml

@@ -343,6 +343,17 @@

           </para>

         </listitem>

       </varlistentry>

+      <varlistentry>

+        <term><varname>AlternativeNamesPolicy=</varname></term>

+        <listitem>

+          <para>A space-separated list of policies by which the interface's alternative names

+          should be set. Each of the policies may fail, and all successful policies are used. The

+          available policies are <literal>database</literal>, <literal>onboard</literal>,

+          <literal>slot</literal>, <literal>path</literal>, and <literal>mac</literal>. If the

+          kernel does not support the alternative names, then this setting will be ignored.

+          </para>

+        </listitem>

+      </varlistentry>

       <varlistentry>

         <term><varname>AlternativeName=</varname></term>

         <listitem>

diff --git a/src/udev/net/link-config-gperf.gperf b/src/udev/net/link-config-gperf.gperf

index 913c754145..df8404e7b8 100644

--- a/src/udev/net/link-config-gperf.gperf

+++ b/src/udev/net/link-config-gperf.gperf

@@ -35,6 +35,7 @@ Link.MACAddress,                 config_parse_hwaddr,        0,

 Link.NamePolicy,                 config_parse_name_policy,   0,                             offsetof(link_config, name_policy)

 Link.Name,                       config_parse_ifname,        0,                             offsetof(link_config, name)

 Link.AlternativeName,            config_parse_ifnames,       1,                             offsetof(link_config, alternative_names)

+Link.AlternativeNamesPolicy,     config_parse_alternative_names_policy, 0,                  offsetof(link_config, alternative_names_policy)

 Link.Alias,                      config_parse_ifalias,       0,                             offsetof(link_config, alias)

 Link.MTUBytes,                   config_parse_mtu,           AF_UNSPEC,                     offsetof(link_config, mtu)

 Link.BitsPerSecond,              config_parse_si_size,       0,                             offsetof(link_config, speed)

diff --git a/src/udev/net/link-config.c b/src/udev/net/link-config.c

index 8e88c8e5c4..6ceb4c698e 100644

--- a/src/udev/net/link-config.c

+++ b/src/udev/net/link-config.c

@@ -69,6 +69,7 @@ static void link_config_free(link_config *link) {

         free(link->name_policy);

         free(link->name);

         strv_free(link->alternative_names);

+        free(link->alternative_names_policy);

         free(link->alias);

         free(link);

@@ -349,6 +350,7 @@ static int get_mac(struct udev_device *device, bool want_random,

 int link_config_apply(link_config_ctx *ctx, link_config *config,

                       struct udev_device *device, const char **name) {

+        _cleanup_strv_free_ char **altnames = NULL;

         bool respect_predictable = false;

         struct ether_addr generated_mac;

         struct ether_addr *mac = NULL;

@@ -473,11 +475,52 @@ int link_config_apply(link_config_ctx *ctx, link_config *config,

         if (r < 0)

                 return log_warning_errno(r, "Could not set Alias=, MACAddress= or MTU= on %s: %m", old_name);

-        r = rtnl_set_link_alternative_names(&ctx->rtnl, ifindex, config->alternative_names);

+        if (config->alternative_names) {

+                altnames = strv_copy(config->alternative_names);

+                if (!altnames)

+                        return log_oom();

+        }

+

+        if (config->alternative_names_policy)

+                for (NamePolicy *p = config->alternative_names_policy; *p != _NAMEPOLICY_INVALID; p++) {

+                        const char *n;

+

+                        switch (*p) {

+                        case NAMEPOLICY_DATABASE:

+                                n = udev_device_get_property_value(device, "ID_NET_NAME_FROM_DATABASE");

+                                break;

+                        case NAMEPOLICY_ONBOARD:

+                                n = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");

+                                break;

+                        case NAMEPOLICY_SLOT:

+                                n = udev_device_get_property_value(device, "ID_NET_NAME_SLOT");

+                                break;

+                        case NAMEPOLICY_PATH:

+                                n = udev_device_get_property_value(device, "ID_NET_NAME_PATH");

+                                break;

+                        case NAMEPOLICY_MAC:

+                                n = udev_device_get_property_value(device, "ID_NET_NAME_MAC");

+                                break;

+                        default:

+                                assert_not_reached("invalid policy");

+                        }

+                        if (!isempty(n)) {

+                                r = strv_extend(&altnames, n);

+                                if (r < 0)

+                                        return log_oom();

+                        }

+                }

+

+        if (new_name)

+                strv_remove(altnames, new_name);

+        strv_remove(altnames, old_name);

+        strv_uniq(altnames);

+

+        r = rtnl_set_link_alternative_names(&ctx->rtnl, ifindex, altnames);

         if (r == -EOPNOTSUPP)

-                log_debug_errno(r, "Could not set AlternativeName= on %s, ignoring: %m", old_name);

+                log_debug_errno(r, "Could not set AlternativeName= or apply AlternativeNamesPolicy= on %s, ignoring: %m", old_name);

         else if (r < 0)

-                return log_warning_errno(r, "Could not set AlternativeName= on %s: %m", old_name);

+                return log_warning_errno(r, "Could not set AlternativeName= or apply AlternativeNamesPolicy= on %s: %m", old_name);

         *name = new_name;

@@ -524,3 +567,16 @@ DEFINE_STRING_TABLE_LOOKUP(name_policy, NamePolicy);

 DEFINE_CONFIG_PARSE_ENUMV(config_parse_name_policy, name_policy, NamePolicy,

                           _NAMEPOLICY_INVALID,

                           "Failed to parse interface name policy");

+

+static const char* const alternative_names_policy_table[_NAMEPOLICY_MAX] = {

+        [NAMEPOLICY_DATABASE] = "database",

+        [NAMEPOLICY_ONBOARD] = "onboard",

+        [NAMEPOLICY_SLOT] = "slot",

+        [NAMEPOLICY_PATH] = "path",

+        [NAMEPOLICY_MAC] = "mac",

+};

+

+DEFINE_STRING_TABLE_LOOKUP(alternative_names_policy, NamePolicy);

+DEFINE_CONFIG_PARSE_ENUMV(config_parse_alternative_names_policy, alternative_names_policy, NamePolicy,

+                          _NAMEPOLICY_INVALID,

+                          "Failed to parse alternative names policy");

diff --git a/src/udev/net/link-config.h b/src/udev/net/link-config.h

index 93d5fdce59..634bd2ec54 100644

--- a/src/udev/net/link-config.h

+++ b/src/udev/net/link-config.h

@@ -49,6 +49,7 @@ struct link_config {

         struct ether_addr *mac;

         MACPolicy mac_policy;

         NamePolicy *name_policy;

+        NamePolicy *alternative_names_policy;

         char *name;

         char **alternative_names;

         char *alias;

@@ -78,6 +79,9 @@ int link_get_driver(link_config_ctx *ctx, struct udev_device *device, char **ret

 const char *name_policy_to_string(NamePolicy p) _const_;

 NamePolicy name_policy_from_string(const char *p) _pure_;

+const char *alternative_names_policy_to_string(NamePolicy p) _const_;

+NamePolicy alternative_names_policy_from_string(const char *p) _pure_;

+

 const char *mac_policy_to_string(MACPolicy p) _const_;

 MACPolicy mac_policy_from_string(const char *p) _pure_;

@@ -86,3 +90,4 @@ const struct ConfigPerfItem* link_config_gperf_lookup(const char *key, GPERF_LEN

 int config_parse_mac_policy(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);

 int config_parse_name_policy(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);

+int config_parse_alternative_names_policy(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);