networkd: add support for IPv6 tokens

This allows the admin to set the host-specific part of IPv6 addresses, but still
receive the prefix via SLAAC.

.network file snippet:

[Network]
IPv6Token=::12

gives:

$ ip token
token ::12 dev eth0

This closes https://bugs.freedesktop.org/show_bug.cgi?id=81177.

1 files changed, 44 insertions, 1 deletions

diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
index c39ba6dfa2..9ebc2d15aa 100644
--- a/src/network/networkd-network.c
+++ b/src/network/networkd-network.c
@@ -626,7 +626,7 @@ int config_parse_llmnr(
         assert(filename);
         assert(lvalue);
         assert(rvalue);
-        assert(data);
+        assert(llmnr);
 
         /* Our enum shall be a superset of booleans, hence first try
          * to parse as boolean, and then as enum */
@@ -650,3 +650,46 @@ int config_parse_llmnr(
 
         return 0;
 }
+
+int config_parse_token(
+                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) {
+
+        union in_addr_union buffer;
+        struct in6_addr *token = data;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(token);
+
+        r = in_addr_from_string(AF_INET6, rvalue, &buffer);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, -r, "Failed to parse IPv6 token, ignoring: %s", rvalue);
+                return 0;
+        }
+
+        r = in_addr_is_null(AF_INET6, &buffer);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, -r, "IPv6 token canno t be the ANY address, ignoring: %s", rvalue);
+                return 0;
+        }
+
+        if ((buffer.in6.s6_addr32[0] | buffer.in6.s6_addr32[1]) != 0) {
+                log_syntax(unit, LOG_ERR, filename, line, EINVAL, "IPv6 token canno t be longer than 64 bits, ignoring: %s", rvalue);
+                return 0;
+        }
+
+        *token = buffer.in6;
+
+        return 0;
+}