X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fshared%2Fin-addr-util.c;h=d88864b5987f7387ebd99e2ea9a689d05038c478;hb=5ffa8c818120e35c89becd938d160235c069dd12;hp=b02e7516ca4d69400dc7d5dd95d3776e7eba0614;hpb=76917807eb50ccde58901e8bec7ed3d408d1cc22;p=elogind.git

diff --git a/src/shared/in-addr-util.c b/src/shared/in-addr-util.c
index b02e7516c..d88864b59 100644
--- a/src/shared/in-addr-util.c
+++ b/src/shared/in-addr-util.c
@@ -300,3 +300,39 @@ int in_addr_default_subnet_mask(const struct in_addr *addr, struct in_addr *mask
         in_addr_prefixlen_to_netmask(mask, prefixlen);
         return 0;
 }
+
+int in_addr_mask(int family, union in_addr_union *addr, unsigned char prefixlen) {
+        assert(addr);
+
+        if (family == AF_INET) {
+                struct in_addr mask;
+
+                if (!in_addr_prefixlen_to_netmask(&mask, prefixlen))
+                        return -EINVAL;
+
+                addr->in.s_addr &= mask.s_addr;
+                return 0;
+        }
+
+        if (family == AF_INET6) {
+                unsigned i;
+
+                for (i = 0; i < 16; i++) {
+                        uint8_t mask;
+
+                        if (prefixlen >= 8) {
+                                mask = 0xFF;
+                                prefixlen -= 8;
+                        } else {
+                                mask = 0xFF << (8 - prefixlen);
+                                prefixlen = 0;
+                        }
+
+                        addr->in6.s6_addr[i] &= mask;
+                }
+
+                return 0;
+        }
+
+        return -EAFNOSUPPORT;
+}