1 files changed, 85 insertions, 0 deletions
diff --git a/ip/ipprefix.c b/ip/ipprefix.c
new file mode 100644
index 0000000..c5704e5
--- /dev/null
+++ b/ip/ipprefix.c
@@ -0,0 +1,85 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C)2005 USAGI/WIDE Project
+ *
+ *
+ * based on ip.c, iproute.c
+ *
+ * Authors:
+ *	Masahide NAKAMURA @USAGI
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <netinet/icmp6.h>
+
+#include "utils.h"
+#include "ip_common.h"
+
+/* prefix flags; see kernel's net/ipv6/addrconf.c and include/net/if_inet6.h */
+#define IF_PREFIX_ONLINK	0x01
+#define IF_PREFIX_AUTOCONF	0x02
+
+int print_prefix(struct nlmsghdr *n, void *arg)
+{
+	FILE *fp = (FILE *)arg;
+	struct prefixmsg *prefix = NLMSG_DATA(n);
+	int len = n->nlmsg_len;
+	struct rtattr *tb[RTA_MAX+1];
+	int family = preferred_family;
+
+	if (n->nlmsg_type != RTM_NEWPREFIX) {
+		fprintf(stderr, "Not a prefix: %08x %08x %08x\n",
+			n->nlmsg_len, n->nlmsg_type, n->nlmsg_flags);
+		return 0;
+	}
+
+	len -= NLMSG_LENGTH(sizeof(*prefix));
+	if (len < 0) {
+		fprintf(stderr, "BUG: wrong nlmsg len %d\n", len);
+		return -1;
+	}
+
+	if (family == AF_UNSPEC)
+		family = AF_INET6;
+	if (family != AF_INET6)
+		return 0;
+
+	if (prefix->prefix_family != AF_INET6) {
+		fprintf(stderr, "incorrect protocol family: %d\n", prefix->prefix_family);
+		return 0;
+	}
+	if (prefix->prefix_type != ND_OPT_PREFIX_INFORMATION) {
+		fprintf(stderr, "wrong ND type %d\n", prefix->prefix_type);
+		return 0;
+	}
+
+	parse_rtattr(tb, RTA_MAX, RTM_RTA(prefix), len);
+
+	if (tb[PREFIX_ADDRESS]) {
+		fprintf(fp, "prefix %s/%u",
+			rt_addr_n2a_rta(family, tb[PREFIX_ADDRESS]),
+			prefix->prefix_len);
+	}
+	fprintf(fp, "dev %s ", ll_index_to_name(prefix->prefix_ifindex));
+
+	if (prefix->prefix_flags & IF_PREFIX_ONLINK)
+		fprintf(fp, "onlink ");
+	if (prefix->prefix_flags & IF_PREFIX_AUTOCONF)
+		fprintf(fp, "autoconf ");
+
+	if (tb[PREFIX_CACHEINFO]) {
+		const struct prefix_cacheinfo *pc
+			 = RTA_DATA(tb[PREFIX_CACHEINFO]);
+
+		fprintf(fp, "valid %u ", pc->valid_time);
+		fprintf(fp, "preferred %u ", pc->preferred_time);
+	}
+
+	fprintf(fp, "\n");
+	fflush(fp);
+
+	return 0;
+}