From b99b055ba975c1663beaf94dbfe8f5c5c7398996 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Sun, 15 Dec 2019 23:21:18 +0900
Subject: [PATCH] udev: support AlternativeName= setting in .link file
(cherry picked from commit a5053a158b43c5ddee90f4915b9fc603e0191d6d)
Related: #1850986
---
man/systemd.link.xml | 8 ++++
src/libsystemd/sd-netlink/netlink-util.c | 40 ++++++++++++++++
src/libsystemd/sd-netlink/netlink-util.h | 1 +
src/shared/conf-parser.c | 60 ++++++++++++++++++++++++
src/shared/conf-parser.h | 1 +
src/udev/net/link-config-gperf.gperf | 1 +
src/udev/net/link-config.c | 5 ++
src/udev/net/link-config.h | 1 +
8 files changed, 117 insertions(+)
diff --git a/man/systemd.link.xml b/man/systemd.link.xml
index 32657308d0..0b0d83349d 100644
--- a/man/systemd.link.xml
+++ b/man/systemd.link.xml
@@ -343,6 +343,14 @@
</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><varname>AlternativeName=</varname></term>
+ <listitem>
+ <para>The alternative interface name to use. This option can be specified multiple times.
+ If the empty string is assigned to this option, the list is reset, and all prior assignments
+ have no effect.</para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term><varname>MTUBytes=</varname></term>
<listitem>
diff --git a/src/libsystemd/sd-netlink/netlink-util.c b/src/libsystemd/sd-netlink/netlink-util.c
index 3928dfbabf..c1c306f121 100644
--- a/src/libsystemd/sd-netlink/netlink-util.c
+++ b/src/libsystemd/sd-netlink/netlink-util.c
@@ -4,6 +4,7 @@
#include "netlink-internal.h"
#include "netlink-util.h"
+#include "strv.h"
int rtnl_set_link_name(sd_netlink **rtnl, int ifindex, const char *name) {
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *message = NULL;
@@ -80,6 +81,45 @@ int rtnl_set_link_properties(sd_netlink **rtnl, int ifindex, const char *alias,
return 0;
}
+int rtnl_set_link_alternative_names(sd_netlink **rtnl, int ifindex, char * const *alternative_names) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *message = NULL;
+ int r;
+
+ assert(rtnl);
+ assert(ifindex > 0);
+
+ if (strv_isempty(alternative_names))
+ return 0;
+
+ if (!*rtnl) {
+ r = sd_netlink_open(rtnl);
+ if (r < 0)
+ return r;
+ }
+
+ r = sd_rtnl_message_new_link(*rtnl, &message, RTM_NEWLINKPROP, ifindex);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_open_container(message, IFLA_PROP_LIST);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_append_strv(message, IFLA_ALT_IFNAME, alternative_names);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_close_container(message);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_call(*rtnl, message, 0, NULL);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
int rtnl_message_new_synthetic_error(sd_netlink *rtnl, int error, uint32_t serial, sd_netlink_message **ret) {
struct nlmsgerr *err;
int r;
diff --git a/src/libsystemd/sd-netlink/netlink-util.h b/src/libsystemd/sd-netlink/netlink-util.h
index 882a616310..92de19c092 100644
--- a/src/libsystemd/sd-netlink/netlink-util.h
+++ b/src/libsystemd/sd-netlink/netlink-util.h
@@ -38,6 +38,7 @@ static inline bool rtnl_message_type_is_routing_policy_rule(uint16_t type) {
int rtnl_set_link_name(sd_netlink **rtnl, int ifindex, const char *name);
int rtnl_set_link_properties(sd_netlink **rtnl, int ifindex, const char *alias, const struct ether_addr *mac, uint32_t mtu);
+int rtnl_set_link_alternative_names(sd_netlink **rtnl, int ifindex, char * const *alternative_names);
int rtnl_log_parse_error(int r);
int rtnl_log_create_error(int r);
diff --git a/src/shared/conf-parser.c b/src/shared/conf-parser.c
index 246b7431e4..1f40f00c72 100644
--- a/src/shared/conf-parser.c
+++ b/src/shared/conf-parser.c
@@ -970,6 +970,66 @@ int config_parse_ifname(
return 0;
}
+int config_parse_ifnames(
+ 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) {
+
+ _cleanup_strv_free_ char **names = NULL;
+ char ***s = data;
+ const char *p;
+ int r;
+
+ assert(filename);
+ assert(lvalue);
+ assert(rvalue);
+ assert(data);
+
+ if (isempty(rvalue)) {
+ *s = strv_free(*s);
+ return 0;
+ }
+
+ p = rvalue;
+ for (;;) {
+ _cleanup_free_ char *word = NULL;
+
+ r = extract_first_word(&p, &word, NULL, 0);
+ if (r < 0) {
+ log_syntax(unit, LOG_ERR, filename, line, r,
+ "Failed to extract interface name, ignoring assignment: %s",
+ rvalue);
+ return 0;
+ }
+ if (r == 0)
+ break;
+
+ if (!ifname_valid_full(word, ltype)) {
+ log_syntax(unit, LOG_ERR, filename, line, 0,
+ "Interface name is not valid or too long, ignoring assignment: %s",
+ word);
+ continue;
+ }
+
+ r = strv_consume(&names, TAKE_PTR(word));
+ if (r < 0)
+ return log_oom();
+ }
+
+ r = strv_extend_strv(s, names, true);
+ if (r < 0)
+ return log_oom();
+
+ return 0;
+}
+
int config_parse_ip_port(
const char *unit,
const char *filename,
diff --git a/src/shared/conf-parser.h b/src/shared/conf-parser.h
index a0a5c89c27..375b2e5a74 100644
--- a/src/shared/conf-parser.h
+++ b/src/shared/conf-parser.h
@@ -137,6 +137,7 @@ CONFIG_PARSER_PROTOTYPE(config_parse_signal);
CONFIG_PARSER_PROTOTYPE(config_parse_personality);
CONFIG_PARSER_PROTOTYPE(config_parse_permille);
CONFIG_PARSER_PROTOTYPE(config_parse_ifname);
+CONFIG_PARSER_PROTOTYPE(config_parse_ifnames);
CONFIG_PARSER_PROTOTYPE(config_parse_ip_port);
CONFIG_PARSER_PROTOTYPE(config_parse_join_controllers);
CONFIG_PARSER_PROTOTYPE(config_parse_mtu);
diff --git a/src/udev/net/link-config-gperf.gperf b/src/udev/net/link-config-gperf.gperf
index b37836d852..913c754145 100644
--- a/src/udev/net/link-config-gperf.gperf
+++ b/src/udev/net/link-config-gperf.gperf
@@ -34,6 +34,7 @@ Link.MACAddressPolicy, config_parse_mac_policy, 0,
Link.MACAddress, config_parse_hwaddr, 0, offsetof(link_config, mac)
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.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 5113586457..d07a1a1874 100644
--- a/src/udev/net/link-config.c
+++ b/src/udev/net/link-config.c
@@ -67,6 +67,7 @@ static void link_config_free(link_config *link) {
free(link->mac);
free(link->name_policy);
free(link->name);
+ strv_free(link->alternative_names);
free(link->alias);
free(link);
@@ -468,6 +469,10 @@ 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 (r < 0)
+ return log_warning_errno(r, "Could not set AlternativeName= on %s: %m", old_name);
+
*name = new_name;
return 0;
diff --git a/src/udev/net/link-config.h b/src/udev/net/link-config.h
index 4798bb101c..93d5fdce59 100644
--- a/src/udev/net/link-config.h
+++ b/src/udev/net/link-config.h
@@ -50,6 +50,7 @@ struct link_config {
MACPolicy mac_policy;
NamePolicy *name_policy;
char *name;
+ char **alternative_names;
char *alias;
uint32_t mtu;
size_t speed;